diff options
| -rw-r--r-- | drivers/net/Kconfig | 7 | ||||
| -rw-r--r-- | include/linux/if_pppol2tp.h | 2 | ||||
| -rw-r--r-- | net/Kconfig | 1 | ||||
| -rw-r--r-- | net/Makefile | 2 | ||||
| -rw-r--r-- | net/l2tp/Kconfig | 28 | ||||
| -rw-r--r-- | net/l2tp/Makefile | 5 | ||||
| -rw-r--r-- | net/l2tp/l2tp_core.c | 1227 | ||||
| -rw-r--r-- | net/l2tp/l2tp_core.h | 254 | ||||
| -rw-r--r-- | net/l2tp/l2tp_ppp.c | 1658 | ||||
| -rw-r--r-- | net/l2tp/pppol2tp.c | 2680 |
10 files changed, 3175 insertions, 2689 deletions
diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig index 2cffcb8..a55bff2 100644 --- a/drivers/net/Kconfig +++ b/drivers/net/Kconfig @@ -3158,17 +3158,12 @@ config PPPOATM config PPPOL2TP tristate "PPP over L2TP (EXPERIMENTAL)" - depends on EXPERIMENTAL && PPP && INET + depends on EXPERIMENTAL && L2TP && PPP help Support for PPP-over-L2TP socket family. L2TP is a protocol used by ISPs and enterprises to tunnel PPP traffic over UDP tunnels. L2TP is replacing PPTP for VPN uses. - This kernel component handles only L2TP data packets: a - userland daemon handles L2TP the control protocol (tunnel - and session setup). One such daemon is OpenL2TP - (http://openl2tp.sourceforge.net/). - config SLIP tristate "SLIP (serial line) support" ---help--- diff --git a/include/linux/if_pppol2tp.h b/include/linux/if_pppol2tp.h index c58baea..1a1fb6e 100644 --- a/include/linux/if_pppol2tp.h +++ b/include/linux/if_pppol2tp.h @@ -2,7 +2,7 @@ * Linux PPP over L2TP (PPPoL2TP) Socket Implementation (RFC 2661) * * This file supplies definitions required by the PPP over L2TP driver - * (pppol2tp.c). All version information wrt this file is located in pppol2tp.c + * (l2tp_ppp.c). All version information wrt this file is located in l2tp_ppp.c * * License: * This program is free software; you can redistribute it and/or diff --git a/net/Kconfig b/net/Kconfig index e10d55c..0d68b40 100644 --- a/net/Kconfig +++ b/net/Kconfig @@ -186,6 +186,7 @@ source "net/sctp/Kconfig" source "net/rds/Kconfig" source "net/tipc/Kconfig" source "net/atm/Kconfig" +source "net/l2tp/Kconfig" source "net/802/Kconfig" source "net/bridge/Kconfig" source "net/dsa/Kconfig" diff --git a/net/Makefile b/net/Makefile index 13ca77e..cb7bdc1 100644 --- a/net/Makefile +++ b/net/Makefile @@ -40,7 +40,7 @@ obj-$(CONFIG_BT) += bluetooth/ obj-$(CONFIG_SUNRPC) += sunrpc/ obj-$(CONFIG_AF_RXRPC) += rxrpc/ obj-$(CONFIG_ATM) += atm/ -obj-$(CONFIG_PPPOL2TP) += l2tp/ +obj-$(CONFIG_L2TP) += l2tp/ obj-$(CONFIG_DECNET) += decnet/ obj-$(CONFIG_ECONET) += econet/ obj-$(CONFIG_PHONET) += phonet/ diff --git a/net/l2tp/Kconfig b/net/l2tp/Kconfig new file mode 100644 index 0000000..ec88c5c --- /dev/null +++ b/net/l2tp/Kconfig @@ -0,0 +1,28 @@ +# +# Layer Two Tunneling Protocol (L2TP) +# + +menuconfig L2TP + tristate "Layer Two Tunneling Protocol (L2TP)" + depends on INET + ---help--- + Layer Two Tunneling Protocol + + From RFC 2661 <http://www.ietf.org/rfc/rfc2661.txt>. + + L2TP facilitates the tunneling of packets across an + intervening network in a way that is as transparent as + possible to both end-users and applications. + + L2TP is often used to tunnel PPP traffic over IP + tunnels. One IP tunnel may carry thousands of individual PPP + connections. L2TP is also used as a VPN protocol, popular + with home workers to connect to their offices. + + The kernel component handles only L2TP data packets: a + userland daemon handles L2TP the control protocol (tunnel + and session setup). One such daemon is OpenL2TP + (http://openl2tp.org/). + + If you don't need L2TP, say N. To compile all L2TP code as + modules, choose M here. diff --git a/net/l2tp/Makefile b/net/l2tp/Makefile index 9af41e8..c91f208 100644 --- a/net/l2tp/Makefile +++ b/net/l2tp/Makefile @@ -2,4 +2,7 @@ # Makefile for the L2TP. # -obj-$(CONFIG_PPPOL2TP) += pppol2tp.o +obj-$(CONFIG_L2TP) += l2tp_core.o + +# Build l2tp as modules if L2TP is M +obj-$(subst y,$(CONFIG_L2TP),$(CONFIG_PPPOL2TP)) += l2tp_ppp.o diff --git a/net/l2tp/l2tp_core.c b/net/l2tp/l2tp_core.c new file mode 100644 index 0000000..4b6da36 --- /dev/null +++ b/net/l2tp/l2tp_core.c @@ -0,0 +1,1227 @@ +/* + * L2TP core. + * + * Copyright (c) 2008,2009,2010 Katalix Systems Ltd + * + * This file contains some code of the original L2TPv2 pppol2tp + * driver, which has the following copyright: + * + * Authors: Martijn van Oosterhout <kleptog@svana.org> + * James Chapman (jchapman@katalix.com) + * Contributors: + * Michal Ostrowski <mostrows@speakeasy.net> + * Arnaldo Carvalho de Melo <acme@xconectiva.com.br> + * David S. Miller (davem@redhat.com) + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include <linux/module.h> +#include <linux/string.h> +#include <linux/list.h> +#include <linux/uaccess.h> + +#include <linux/kernel.h> +#include <linux/spinlock.h> +#include <linux/kthread.h> +#include <linux/sched.h> +#include <linux/slab.h> +#include <linux/errno.h> +#include <linux/jiffies.h> + +#include <linux/netdevice.h> +#include <linux/net.h> +#include <linux/inetdevice.h> +#include <linux/skbuff.h> +#include <linux/init.h> +#include <linux/ip.h> +#include <linux/udp.h> +#include <linux/hash.h> +#include <linux/sort.h> +#include <linux/file.h> +#include <linux/nsproxy.h> +#include <net/net_namespace.h> +#include <net/netns/generic.h> +#include <net/dst.h> +#include <net/ip.h> +#include <net/udp.h> +#include <net/xfrm.h> + +#include <asm/byteorder.h> +#include <asm/atomic.h> + +#include "l2tp_core.h" + +#define L2TP_DRV_VERSION "V2.0" + +/* L2TP header constants */ +#define L2TP_HDRFLAG_T 0x8000 +#define L2TP_HDRFLAG_L 0x4000 +#define L2TP_HDRFLAG_S 0x0800 +#define L2TP_HDRFLAG_O 0x0200 +#define L2TP_HDRFLAG_P 0x0100 + +#define L2TP_HDR_VER_MASK 0x000F +#define L2TP_HDR_VER_2 0x0002 + +/* L2TPv3 default L2-specific sublayer */ +#define L2TP_SLFLAG_S 0x40000000 +#define L2TP_SL_SEQ_MASK 0x00ffffff + +#define L2TP_HDR_SIZE_SEQ 10 +#define L2TP_HDR_SIZE_NOSEQ 6 + +/* Default trace flags */ +#define L2TP_DEFAULT_DEBUG_FLAGS 0 + +#define PRINTK(_mask, _type, _lvl, _fmt, args...) \ + do { \ + if ((_mask) & (_type)) \ + printk(_lvl "L2TP: " _fmt, ##args); \ + } while (0) + +/* Private data stored for received packets in the skb. + */ +struct l2tp_skb_cb { + u16 ns; + u16 has_seq; + u16 length; + unsigned long expires; +}; + +#define L2TP_SKB_CB(skb) ((struct l2tp_skb_cb *) &skb->cb[sizeof(struct inet_skb_parm)]) + +static atomic_t l2tp_tunnel_count; +static atomic_t l2tp_session_count; + +/* per-net private data for this module */ +static unsigned int l2tp_net_id; +struct l2tp_net { + struct list_head l2tp_tunnel_list; + rwlock_t l2tp_tunnel_list_lock; +}; + +static inline struct l2tp_net *l2tp_pernet(struct net *net) +{ + BUG_ON(!net); + + return net_generic(net, l2tp_net_id); +} + +/* Session hash list. + * The session_id SHOULD be random according to RFC2661, but several + * L2TP implementations (Cisco and Microsoft) use incrementing + * session_ids. So we do a real hash on the session_id, rather than a + * simple bitmask. + */ +static inline struct hlist_head * +l2tp_session_id_hash(struct l2tp_tunnel *tunnel, u32 session_id) +{ + return &tunnel->session_hlist[hash_32(session_id, L2TP_HASH_BITS)]; +} + +/* Lookup a session by id + */ +struct l2tp_session *l2tp_session_find(struct l2tp_tunnel *tunnel, u32 session_id) +{ + struct hlist_head *session_list = + l2tp_session_id_hash(tunnel, session_id); + struct l2tp_session *session; + struct hlist_node *walk; + + read_lock_bh(&tunnel->hlist_lock); + hlist_for_each_entry(session, walk, session_list, hlist) { + if (session->session_id == session_id) { + read_unlock_bh(&tunnel->hlist_lock); + return session; + } + } + read_unlock_bh(&tunnel->hlist_lock); + + return NULL; +} +EXPORT_SYMBOL_GPL(l2tp_session_find); + +struct l2tp_session *l2tp_session_find_nth(struct l2tp_tunnel *tunnel, int nth) +{ + int hash; + struct hlist_node *walk; + struct l2tp_session *session; + int count = 0; + + read_lock_bh(&tunnel->hlist_lock); + for (hash = 0; hash < L2TP_HASH_SIZE; hash++) { + hlist_for_each_entry(session, walk, &tunnel->session_hlist[hash], hlist) { + if (++count > nth) { + read_unlock_bh(&tunnel->hlist_lock); + return session; + } + } + } + + read_unlock_bh(&tunnel->hlist_lock); + + return NULL; +} +EXPORT_SYMBOL_GPL(l2tp_session_find_nth); + +/* Lookup a tunnel by id + */ +struct l2tp_tunnel *l2tp_tunnel_find(struct net *net, u32 tunnel_id) +{ + struct l2tp_tunnel *tunnel; + struct l2tp_net *pn = l2tp_pernet(net); + + read_lock_bh(&pn->l2tp_tunnel_list_lock); + list_for_each_entry(tunnel, &pn->l2tp_tunnel_list, list) { + if (tunnel->tunnel_id == tunnel_id) { + read_unlock_bh(&pn->l2tp_tunnel_list_lock); + return tunnel; + } + } + read_unlock_bh(&pn->l2tp_tunnel_list_lock); + + return NULL; +} +EXPORT_SYMBOL_GPL(l2tp_tunnel_find); + +struct l2tp_tunnel *l2tp_tunnel_find_nth(struct net *net, int nth) +{ + struct l2tp_net *pn = l2tp_pernet(net); + struct l2tp_tunnel *tunnel; + int count = 0; + + read_lock_bh(&pn->l2tp_tunnel_list_lock); + list_for_each_entry(tunnel, &pn->l2tp_tunnel_list, list) { + if (++count > nth) { + read_unlock_bh(&pn->l2tp_tunnel_list_lock); + return tunnel; + } + } + + read_unlock_bh(&pn->l2tp_tunnel_list_lock); + + return NULL; +} +EXPORT_SYMBOL_GPL(l2tp_tunnel_find_nth); + +/***************************************************************************** + * Receive data handling + *****************************************************************************/ + +/* Queue a skb in order. We come here only if the skb has an L2TP sequence + * number. + */ +static void l2tp_recv_queue_skb(struct l2tp_session *session, struct sk_buff *skb) +{ + struct sk_buff *skbp; + struct sk_buff *tmp; + u16 ns = L2TP_SKB_CB(skb)->ns; + + spin_lock_bh(&session->reorder_q.lock); + skb_queue_walk_safe(&session->reorder_q, skbp, tmp) { + if (L2TP_SKB_CB(skbp)->ns > ns) { + __skb_queue_before(&session->reorder_q, skbp, skb); + PRINTK(session->debug, L2TP_MSG_SEQ, KERN_DEBUG, + "%s: pkt %hu, inserted before %hu, reorder_q len=%d\n", + session->name, ns, L2TP_SKB_CB(skbp)->ns, + skb_queue_len(&session->reorder_q)); + session->stats.rx_oos_packets++; + goto out; + } + } + + __skb_queue_tail(&session->reorder_q, skb); + +out: + spin_unlock_bh(&session->reorder_q.lock); +} + +/* Dequeue a single skb. + */ +static void l2tp_recv_dequeue_skb(struct l2tp_session *session, struct sk_buff *skb) +{ + struct l2tp_tunnel *tunnel = session->tunnel; + int length = L2TP_SKB_CB(skb)->length; + + /* We're about to requeue the skb, so return resources + * to its current owner (a socket receive buffer). + */ + skb_orphan(skb); + + tunnel->stats.rx_packets++; + tunnel->stats.rx_bytes += length; + session->stats.rx_packets++; + session->stats.rx_bytes += length; + + if (L2TP_SKB_CB(skb)->has_seq) { + /* Bump our Nr */ + session->nr++; + PRINTK(session->debug, L2TP_MSG_SEQ, KERN_DEBUG, + "%s: updated nr to %hu\n", session->name, session->nr); + } + + /* call private receive handler */ + if (session->recv_skb != NULL) + (*session->recv_skb)(session, skb, L2TP_SKB_CB(skb)->length); + else + kfree_skb(skb); + + if (session->deref) + (*session->deref)(session); +} + +/* Dequeue skbs from the session's reorder_q, subject to packet order. + * Skbs that have been in the queue for too long are simply discarded. + */ +static void l2tp_recv_dequeue(struct l2tp_session *session) +{ + struct sk_buff *skb; + struct sk_buff *tmp; + + /* If the pkt at the head of the queue has the nr that we + * expect to send up next, dequeue it and any other + * in-sequence packets behind it. + */ + spin_lock_bh(&session->reorder_q.lock); + skb_queue_walk_safe(&session->reorder_q, skb, tmp) { + if (time_after(jiffies, L2TP_SKB_CB(skb)->expires)) { + session->stats.rx_seq_discards++; + session->stats.rx_errors++; + PRINTK(session->debug, L2TP_MSG_SEQ, KERN_DEBUG, + "%s: oos pkt %hu len %d discarded (too old), " + "waiting for %hu, reorder_q_len=%d\n", + session->name, L2TP_SKB_CB(skb)->ns, + L2TP_SKB_CB(skb)->length, session->nr, + skb_queue_len(&session->reorder_q)); + __skb_unlink(skb, &session->reorder_q); + kfree_skb(skb); + if (session->deref) + (*session->deref)(session); + continue; + } + + if (L2TP_SKB_CB(skb)->has_seq) { + if (L2TP_SKB_CB(skb)->ns != session->nr) { + PRINTK(session->debug, L2TP_MSG_SEQ, KERN_DEBUG, + "%s: holding oos pkt %hu len %d, " + "waiting for %hu, reorder_q_len=%d\n", + session->name, L2TP_SKB_CB(skb)->ns, + L2TP_SKB_CB(skb)->length, session->nr, + skb_queue_len(&session->reorder_q)); + goto out; + } + } + __skb_unlink(skb, &session->reorder_q); + + /* Process the skb. We release the queue lock while we + * do so to let other contexts process the queue. + */ + spin_unlock_bh(&session->reorder_q.lock); + l2tp_recv_dequeue_skb(session, skb); + spin_lock_bh(&session->reorder_q.lock); + } + +out: + spin_unlock_bh(&session->reorder_q.lock); +} + +static inline int l2tp_verify_udp_checksum(struct sock *sk, + struct sk_buff *skb) +{ + struct udphdr *uh = udp_hdr(skb); + u16 ulen = ntohs(uh->len); + struct inet_sock *inet; + __wsum psum; + + if (sk->sk_no_check || skb_csum_unnecessary(skb) || !uh->check) + return 0; + + inet = inet_sk(sk); + psum = csum_tcpudp_nofold(inet->inet_saddr, inet->inet_daddr, ulen, + IPPROTO_UDP, 0); + + if ((skb->ip_summed == CHECKSUM_COMPLETE) && + !csum_fold(csum_add(psum, skb->csum))) + return 0; + + skb->csum = psum; + + return __skb_checksum_complete(skb); +} + +/* Internal UDP receive frame. Do the real work of receiving an L2TP data frame + * here. The skb is not on a list when we get here. + * Returns 0 if the packet was a data packet and was successfully passed on. + * Returns 1 if the packet was not a good data packet and could not be + * forwarded. All such packets are passed up to userspace to deal with. + */ +int l2tp_udp_recv_core(struct l2tp_tunnel *tunnel, struct sk_buff *skb, + int (*payload_hook)(struct sk_buff *skb)) +{ + struct l2tp_session *session = NULL; + unsigned char *ptr, *optr; + u16 hdrflags; + u32 tunnel_id, session_id; + int length; + int offset; + u16 version; + u16 ns, nr; + + if (tunnel->sock && l2tp_verify_udp_checksum(tunnel->sock, skb)) + goto discard_bad_csum; + + /* UDP always verifies the packet length. */ + __skb_pull(skb, sizeof(struct udphdr)); + + /* Short packet? */ + if (!pskb_may_pull(skb, L2TP_HDR_SIZE_SEQ)) { + PRINTK(tunnel->debug, L2TP_MSG_DATA, KERN_INFO, + "%s: recv short packet (len=%d)\n", tunnel->name, skb->len); + goto error; + } + + /* Point to L2TP header */ + optr = ptr = skb->data; + + /* Trace packet contents, if enabled */ + if (tunnel->debug & L2TP_MSG_DATA) { + length = min(32u, skb->len); + if (!pskb_may_pull(skb, length)) + goto error; + + printk(KERN_DEBUG "%s: recv: ", tunnel->name); + + offset = 0; + do { + printk(" %02X", ptr[offset]); + } while (++offset < length); + + printk("\n"); + } + + /* Get L2TP header flags */ + hdrflags = ntohs(*(__be16 *)ptr); + + /* Check protocol version */ + version = hdrflags & L2TP_HDR_VER_MASK; + if (version != tunnel->version) { + PRINTK(tunnel->debug, L2TP_MSG_DATA, KERN_INFO, + "%s: recv protocol version mismatch: got %d expected %d\n", + tunnel->name, version, tunnel->version); + goto error; + } + + /* Get length of L2TP packet */ + length = skb->len; + + /* If type is control packet, it is handled by userspace. */ + if (hdrflags & L2TP_HDRFLAG_T) { + PRINTK(tunnel->debug, L2TP_MSG_DATA, KERN_DEBUG, + "%s: recv control packet, len=%d\n", tunnel->name, length); + goto error; + } + + /* Skip flags */ + ptr += 2; + + /* If length is present, skip it */ + if (hdrflags & L2TP_HDRFLAG_L) + ptr += 2; + + /* Extract tunnel and session ID */ + tunnel_id = ntohs(*(__be16 *) ptr); + ptr += 2; + session_id = ntohs(*(__be16 *) ptr); + ptr += 2; + + /* Find the session context */ + session = l2tp_session_find(tunnel, session_id); + if (!session) { + /* Not found? Pass to userspace to deal with */ + PRINTK(tunnel->debug, L2TP_MSG_DATA, KERN_INFO, + "%s: no session found (%hu/%hu). Passing up.\n", + tunnel->name, tunnel_id, session_id); + goto error; + } + + /* The ref count is increased since we now hold a pointer to + * the session. Take care to decrement the refcnt when exiting + * this function from now on... + */ + l2tp_session_inc_refcount(session); + if (session->ref) + (*session->ref)(session); + + /* Handle the optional sequence numbers. Sequence numbers are + * in different places for L2TPv2 and L2TPv3. + * + * If we are the LAC, enable/disable sequence numbers under + * the control of the LNS. If no sequence numbers present but + * we were expecting them, discard frame. + */ + ns = nr = 0; + L2TP_SKB_CB(skb)->has_seq = 0; + if (hdrflags & L2TP_HDRFLAG_S) { + ns = (u16) ntohs(*(__be16 *) ptr); + ptr += 2; + nr = ntohs(*(__be16 *) ptr); + ptr += 2; + + /* Store L2TP info in the skb */ + L2TP_SKB_CB(skb)->ns = ns; + L2TP_SKB_CB(skb)->has_seq = 1; + + PRINTK(session->debug, L2TP_MSG_SEQ, KERN_DEBUG, + "%s: recv data ns=%hu, nr=%hu, session nr=%hu\n", + session->name, ns, nr, session->nr); + } + + if (L2TP_SKB_CB(skb)->has_seq) { + /* Received a packet with sequence numbers. If we're the LNS, + * check if we sre sending sequence numbers and if not, + * configure it so. + */ + if ((!session->lns_mode) && (!session->send_seq)) { + PRINTK(session->debug, L2TP_MSG_SEQ, KERN_INFO, + "%s: requested to enable seq numbers by LNS\n", + session->name); + session->send_seq = -1; + } + } else { + /* No sequence numbers. + * If user has configured mandatory sequence numbers, discard. + */ + if (session->recv_seq) { + PRINTK(session->debug, L2TP_MSG_SEQ, KERN_WARNING, + "%s: recv data has no seq numbers when required. " + "Discarding\n", session->name); + session->stats.rx_seq_discards++; + goto discard; + } + + /* If we're the LAC and we're sending sequence numbers, the + * LNS has requested that we no longer send sequence numbers. + * If we're the LNS and we're sending sequence numbers, the + * LAC is broken. Discard the frame. + */ + if ((!session->lns_mode) && (session->send_seq)) { + PRINTK(session->debug, L2TP_MSG_SEQ, KERN_INFO, + "%s: requested to disable seq numbers by LNS\n", + session->name); + session->send_seq = 0; + } else if (session->send_seq) { + PRINTK(session->debug, L2TP_MSG_SEQ, KERN_WARNING, + "%s: recv data has no seq numbers when required. " + "Discarding\n", session->name); + session->stats.rx_seq_discards++; + goto discard; + } + } + + /* If offset bit set, skip it. */ + if (hdrflags & L2TP_HDRFLAG_O) { + offset = ntohs(*(__be16 *)ptr); + ptr += 2 + offset; + } + + offset = ptr - optr; + if (!pskb_may_pull(skb, offset)) + goto discard; + + __skb_pull(skb, offset); + + /* If caller wants to process the payload before we queue the + * packet, do so now. + */ + if (payload_hook) + if ((*payload_hook)(skb)) + goto discard; + + /* Prepare skb for adding to the session's reorder_q. Hold + * packets for max reorder_timeout or 1 second if not + * reordering. + */ + L2TP_SKB_CB(skb)->length = length; + L2TP_SKB_CB(skb)->expires = jiffies + + (session->reorder_timeout ? session->reorder_timeout : HZ); + + /* Add packet to the session's receive queue. Reordering is done here, if + * enabled. Saved L2TP protocol info is stored in skb->sb[]. + */ + if (L2TP_SKB_CB(skb)->has_seq) { + if (session->reorder_timeout != 0) { + /* Packet reordering enabled. Add skb to session's + * reorder queue, in order of ns. + */ + l2tp_recv_queue_skb(session, skb); + } else { + /* Packet reordering disabled. Discard out-of-sequence + * packets + */ + if (L2TP_SKB_CB(skb)->ns != session->nr) { + session->stats.rx_seq_discards++; + PRINTK(session->debug, L2TP_MSG_SEQ, KERN_DEBUG, + "%s: oos pkt %hu len %d discarded, " + "waiting for %hu, reorder_q_len=%d\n", + session->name, L2TP_SKB_CB(skb)->ns, + L2TP_SKB_CB(skb)->length, session->nr, + skb_queue_len(&session->reorder_q)); + goto discard; + } + skb_queue_tail(&session->reorder_q, skb); + } + } else { + /* No sequence numbers. Add the skb to the tail of the + * reorder queue. This ensures that it will be + * delivered after all previous sequenced skbs. + */ + skb_queue_tail(&session->reorder_q, skb); + } + + /* Try to dequeue as many skbs from reorder_q as we can. */ + l2tp_recv_dequeue(session); + + l2tp_session_dec_refcount(session); + + return 0; + +discard: + session->stats.rx_errors++; + kfree_skb(skb); + + if (session->deref) + (*session->deref)(session); + + l2tp_session_dec_refcount(session); + + return 0; + +discard_bad_csum: + LIMIT_NETDEBUG("%s: UDP: bad checksum\n", tunnel->name); + UDP_INC_STATS_USER(tunnel->l2tp_net, UDP_MIB_INERRORS, 0); + tunnel->stats.rx_errors++; + kfree_skb(skb); + + return 0; + +error: + /* Put UDP header back */ + __skb_push(skb, sizeof(struct udphdr)); + + return 1; +} +EXPORT_SYMBOL_GPL(l2tp_udp_recv_core); + +/* UDP encapsulation receive handler. See net/ipv4/udp.c. + * Return codes: + * 0 : success. + * <0: error + * >0: skb should be passed up to userspace as UDP. + */ +int l2tp_udp_encap_recv(struct sock *sk, struct sk_buff *skb) +{ + struct l2tp_tunnel *tunnel; + + tunnel = l2tp_sock_to_tunnel(sk); + if (tunnel == NULL) + goto pass_up; + + PRINTK(tunnel->debug, L2TP_MSG_DATA, KERN_DEBUG, + "%s: received %d bytes\n", tunnel->name, skb->len); + + if (l2tp_udp_recv_core(tunnel, skb, tunnel->recv_payload_hook)) + goto pass_up_put; + + sock_put(sk); + return 0; + +pass_up_put: + sock_put(sk); +pass_up: + return 1; +} +EXPORT_SYMBOL_GPL(l2tp_udp_encap_recv); + +/************************************************************************ + * Transmit handling + ***********************************************************************/ + +/* Build an L2TP header for the session into the buffer provided. + */ +static void l2tp_build_l2tpv2_header(struct l2tp_tunnel *tunnel, + struct l2tp_session *session, + void *buf) +{ + __be16 *bufp = buf; + u16 flags = L2TP_HDR_VER_2; + u32 tunnel_id = tunnel->peer_tunnel_id; + u32 session_id = session->peer_session_id; + + if (session->send_seq) + flags |= L2TP_HDRFLAG_S; + + /* Setup L2TP header. */ + *bufp++ = htons(flags); + *bufp++ = htons(tunnel_id); + *bufp++ = htons(session_id); + if (session->send_seq) { + *bufp++ = htons(session->ns); + *bufp++ = 0; + session->ns++; + PRINTK(session->debug, L2TP_MSG_SEQ, KERN_DEBUG, + "%s: updated ns to %hu\n", session->name, session->ns); + } +} + +void l2tp_build_l2tp_header(struct l2tp_session *session, void *buf) +{ + struct l2tp_tunnel *tunnel = session->tunnel; + + BUG_ON(tunnel->version != L2TP_HDR_VER_2); + l2tp_build_l2tpv2_header(tunnel, session, buf); +} +EXPORT_SYMBOL_GPL(l2tp_build_l2tp_header); + +int l2tp_xmit_core(struct l2tp_session *session, struct sk_buff *skb, size_t data_len) +{ + struct l2tp_tunnel *tunnel = session->tunnel; + unsigned int len = skb->len; + int error; + + /* Debug */ + if (session->send_seq) + PRINTK(session->debug, L2TP_MSG_DATA, KERN_DEBUG, + "%s: send %Zd bytes, ns=%hu\n", session->name, + data_len, session->ns - 1); + else + PRINTK(session->debug, L2TP_MSG_DATA, KERN_DEBUG, + "%s: send %Zd bytes\n", session->name, data_len); + + if (session->debug & L2TP_MSG_DATA) { + int i; + unsigned char *datap = skb->data + sizeof(struct udphdr); + + printk(KERN_DEBUG "%s: xmit:", session->name); + for (i = 0; i < (len - sizeof(struct udphdr)); i++) { + printk(" %02X", *datap++); + if (i == 31) { + printk(" ..."); + break; + } + } + printk("\n"); + } + + /* Queue the packet to IP for output */ + error = ip_queue_xmit(skb, 1); + + /* Update stats */ + if (error >= 0) { + tunnel->stats.tx_packets++; + tunnel->stats.tx_bytes += len; + session->stats.tx_packets++; + session->stats.tx_bytes += len; + } else { + tunnel->stats.tx_errors++; + session->stats.tx_errors++; + } + + return 0; +} +EXPORT_SYMBOL_GPL(l2tp_xmit_core); + +/* Automatically called when the skb is freed. + */ +static void l2tp_sock_wfree(struct sk_buff *skb) +{ + sock_put(skb->sk); +} + +/* For data skbs that we transmit, we associate with the tunnel socket + * but don't do accounting. + */ +static inline void l2tp_skb_set_owner_w(struct sk_buff *skb, struct sock *sk) +{ + sock_hold(sk); + skb->sk = sk; + skb->destructor = l2tp_sock_wfree; +} + +/* If caller requires the skb to have a ppp header, the header must be + * inserted in the skb data before calling this function. + */ +int l2tp_xmit_skb(struct l2tp_session *session, struct sk_buff *skb, int hdr_len) +{ + int data_len = skb->len; + struct sock *sk = session->tunnel->sock; + struct udphdr *uh; + unsigned int udp_len; + struct inet_sock *inet; + __wsum csum; + int old_headroom; + int new_headroom; + int headroom; + + /* Check that there's enough headroom in the skb to insert IP, + * UDP and L2TP headers. If not enough, expand it to + * make room. Adjust truesize. + */ + headroom = NET_SKB_PAD + sizeof(struct iphdr) + + sizeof(struct udphdr) + hdr_len; + old_headroom = skb_headroom(skb); + if (skb_cow_head(skb, headroom)) + goto abort; + + new_headroom = skb_headroom(skb); + skb_orphan(skb); + skb->truesize += new_headroom - old_headroom; + + /* Setup L2TP header */ + l2tp_build_l2tp_header(session, __skb_push(skb, hdr_len)); + udp_len = sizeof(struct udphdr) + hdr_len + data_len; + + /* Setup UDP header */ + inet = inet_sk(sk); + __skb_push(skb, sizeof(*uh)); + skb_reset_transport_header(skb); + uh = udp_hdr(skb); + uh->source = inet->inet_sport; + uh->dest = inet->inet_dport; + uh->len = htons(udp_len); + + uh->check = 0; + + memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); + IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED | + IPSKB_REROUTED); + nf_reset(skb); + + /* Get routing info from the tunnel socket */ + skb_dst_drop(skb); + skb_dst_set(skb, dst_clone(__sk_dst_get(sk))); + l2tp_skb_set_owner_w(skb, sk); + + /* Calculate UDP checksum if configured to do so */ + if (sk->sk_no_check == UDP_CSUM_NOXMIT) + skb->ip_summed = CHECKSUM_NONE; + else if ((skb_dst(skb) && skb_dst(skb)->dev) && + (!(skb_dst(skb)->dev->features & NETIF_F_V4_CSUM))) { + skb->ip_summed = CHECKSUM_COMPLETE; + csum = skb_checksum(skb, 0, udp_len, 0); + uh->check = csum_tcpudp_magic(inet->inet_saddr, + inet->inet_daddr, + udp_len, IPPROTO_UDP, csum); + if (uh->check == 0) + uh->check = CSUM_MANGLED_0; + } else { + skb->ip_summed = CHECKSUM_PARTIAL; + skb->csum_start = skb_transport_header(skb) - skb->head; + skb->csum_offset = offsetof(struct udphdr, check); + uh->check = ~csum_tcpudp_magic(inet->inet_saddr, + inet->inet_daddr, + udp_len, IPPROTO_UDP, 0); + } + + l2tp_xmit_core(session, skb, data_len); + +abort: + return 0; +} +EXPORT_SYMBOL_GPL(l2tp_xmit_skb); + +/***************************************************************************** + * Tinnel and session create/destroy. + *****************************************************************************/ + +/* Tunnel socket destruct hook. + * The tunnel context is deleted only when all session sockets have been + * closed. + */ +void l2tp_tunnel_destruct(struct sock *sk) +{ + struct l2tp_tunnel *tunnel; + + tunnel = sk->sk_user_data; + if (tunnel == NULL) + goto end; + + PRINTK(tunnel->debug, L2TP_MSG_CONTROL, KERN_INFO, + "%s: closing...\n", tunnel->name); + + /* Close all sessions */ + l2tp_tunnel_closeall(tunnel); + + /* No longer an encapsulation socket. See net/ipv4/udp.c */ + (udp_sk(sk))->encap_type = 0; + (udp_sk(sk))->encap_rcv = NULL; + + /* Remove hooks into tunnel socket */ + tunnel->sock = NULL; + sk->sk_destruct = tunnel->old_sk_destruct; + sk->sk_user_data = NULL; + + /* Call the original destructor */ + if (sk->sk_destruct) + (*sk->sk_destruct)(sk); + + /* We're finished with the socket */ + l2tp_tunnel_dec_refcount(tunnel); + +end: + return; +} +EXPORT_SYMBOL(l2tp_tunnel_destruct); + +/* When the tunnel is closed, all the attached sessions need to go too. + */ +void l2tp_tunnel_closeall(struct l2tp_tunnel *tunnel) +{ + int hash; + struct hlist_node *walk; + struct hlist_node *tmp; + struct l2tp_session *session; + + BUG_ON(tunnel == NULL); + + PRINTK(tunnel->debug, L2TP_MSG_CONTROL, KERN_INFO, + "%s: closing all sessions...\n", tunnel->name); + + write_lock_bh(&tunnel->hlist_lock); + for (hash = 0; hash < L2TP_HASH_SIZE; hash++) { +again: + hlist_for_each_safe(walk, tmp, &tunnel->session_hlist[hash]) { + session = hlist_entry(walk, struct l2tp_session, hlist); + + PRINTK(session->debug, L2TP_MSG_CONTROL, KERN_INFO, + "%s: closing session\n", session->name); + + hlist_del_init(&session->hlist); + + /* Since we should hold the sock lock while + * doing any unbinding, we need to release the + * lock we're holding before taking that lock. + * Hold a reference to the sock so it doesn't + * disappear as we're jumping between locks. + */ + if (session->ref != NULL) + (*session->ref)(session); + + write_unlock_bh(&tunnel->hlist_lock); + + if (session->session_close != NULL) + (*session->session_close)(session); + + if (session->deref != NULL) + (*session->deref)(session); + + write_lock_bh(&tunnel->hlist_lock); + + /* Now restart from the beginning of this hash + * chain. We always remove a session from the + * list so we are guaranteed to make forward + * progress. + */ + goto again; + } + } + write_unlock_bh(&tunnel->hlist_lock); +} +EXPORT_SYMBOL_GPL(l2tp_tunnel_closeall); + +/* Really kill the tunnel. + * Come here only when all sessions have been cleared from the tunnel. + */ +void l2tp_tunnel_free(struct l2tp_tunnel *tunnel) +{ + struct l2tp_net *pn = l2tp_pernet(tunnel->l2tp_net); + + BUG_ON(atomic_read(&tunnel->ref_count) != 0); + BUG_ON(tunnel->sock != NULL); + + PRINTK(tunnel->debug, L2TP_MSG_CONTROL, KERN_INFO, + "%s: free...\n", tunnel->name); + + /* Remove from tunnel list */ + write_lock_bh(&pn->l2tp_tunnel_list_lock); + list_del_init(&tunnel->list); + write_unlock_bh(&pn->l2tp_tunnel_list_lock); + + atomic_dec(&l2tp_tunnel_count); + kfree(tunnel); +} +EXPORT_SYMBOL_GPL(l2tp_tunnel_free); + +int l2tp_tunnel_create(struct net *net, int fd, int version, u32 tunnel_id, u32 peer_tunnel_id, struct l2tp_tunnel_cfg *cfg, struct l2tp_tunnel **tunnelp) +{ + struct l2tp_tunnel *tunnel = NULL; + int err; + struct socket *sock = NULL; + struct sock *sk = NULL; + struct l2tp_net *pn; + + /* Get the tunnel socket from the fd, which was opened by + * the userspace L2TP daemon. + */ + err = -EBADF; + sock = sockfd_lookup(fd, &err); + if (!sock) { + printk(KERN_ERR "tunl %hu: sockfd_lookup(fd=%d) returned %d\n", + tunnel_id, fd, err); + goto err; + } + + sk = sock->sk; + + /* Quick sanity checks */ + err = -EPROTONOSUPPORT; + if (sk->sk_protocol != IPPROTO_UDP) { + printk(KERN_ERR "tunl %hu: fd %d wrong protocol, got %d, expected %d\n", + tunnel_id, fd, sk->sk_protocol, IPPROTO_UDP); + goto err; + } + err = -EAFNOSUPPORT; + if (sock->ops->family != AF_INET) { + printk(KERN_ERR "tunl %hu: fd %d wrong family, got %d, expected %d\n", + tunnel_id, fd, sock->ops->family, AF_INET); + goto err; + } + + /* Check if this socket has already been prepped */ + tunnel = (struct l2tp_tunnel *)sk->sk_user_data; + if (tunnel != NULL) { + /* This socket has already been prepped */ + err = -EBUSY; + goto err; + } + + if (version != L2TP_HDR_VER_2) + goto err; + + tunnel = kzalloc(sizeof(struct l2tp_tunnel), GFP_KERNEL); + if (tunnel == NULL) { + err = -ENOMEM; + goto err; + } + + tunnel->version = version; + tunnel->tunnel_id = tunnel_id; + tunnel->peer_tunnel_id = peer_tunnel_id; + tunnel->debug = L2TP_DEFAULT_DEBUG_FLAGS; + + tunnel->magic = L2TP_TUNNEL_MAGIC; + sprintf(&tunnel->name[0], "tunl %u", tunnel_id); + rwlock_init(&tunnel->hlist_lock); + + /* The net we belong to */ + tunnel->l2tp_net = net; + pn = l2tp_pernet(net); + + if (cfg) + tunnel->debug = cfg->debug; + + /* Mark socket as an encapsulation socket. See net/ipv4/udp.c */ + udp_sk(sk)->encap_type = UDP_ENCAP_L2TPINUDP; + udp_sk(sk)->encap_rcv = l2tp_udp_encap_recv; + + sk->sk_user_data = tunnel; + + /* Hook on the tunnel socket destructor so that we can cleanup + * if the tunnel socket goes away. + */ + tunnel->old_sk_destruct = sk->sk_destruct; + sk->sk_destruct = &l2tp_tunnel_destruct; + tunnel->sock = sk; + sk->sk_allocation = GFP_ATOMIC; + + /* Add tunnel to our list */ + INIT_LIST_HEAD(&tunnel->list); + write_lock_bh(&pn->l2tp_tunnel_list_lock); + list_add(&tunnel->list, &pn->l2tp_tunnel_list); + write_unlock_bh(&pn->l2tp_tunnel_list_lock); + atomic_inc(&l2tp_tunnel_count); + + /* Bump the reference count. The tunnel context is deleted + * only when this drops to zero. + */ + l2tp_tunnel_inc_refcount(tunnel); + + err = 0; +err: + if (tunnelp) + *tunnelp = tunnel; + + if (sock) + sockfd_put(sock); + + return err; +} +EXPORT_SYMBOL_GPL(l2tp_tunnel_create); + +/* Really kill the session. + */ +void l2tp_session_free(struct l2tp_session *session) +{ + struct l2tp_tunnel *tunnel; + + BUG_ON(atomic_read(&session->ref_count) != 0); + + tunnel = session->tunnel; + if (tunnel != NULL) { + BUG_ON(tunnel->magic != L2TP_TUNNEL_MAGIC); + + /* Delete the session from the hash */ + write_lock_bh(&tunnel->hlist_lock); + hlist_del_init(&session->hlist); + write_unlock_bh(&tunnel->hlist_lock); + + if (session->session_id != 0) + atomic_dec(&l2tp_session_count); + + sock_put(tunnel->sock); + + /* This will delete the tunnel context if this + * is the last session on the tunnel. + */ + session->tunnel = NULL; + l2tp_tunnel_dec_refcount(tunnel); + } + + kfree(session); + + return; +} +EXPORT_SYMBOL_GPL(l2tp_session_free); + +struct l2tp_session *l2tp_session_create(int priv_size, struct l2tp_tunnel *tunnel, u32 session_id, u32 peer_session_id, struct l2tp_session_cfg *cfg) +{ + struct l2tp_session *session; + + session = kzalloc(sizeof(struct l2tp_session) + priv_size, GFP_KERNEL); + if (session != NULL) { + session->magic = L2TP_SESSION_MAGIC; + session->tunnel = tunnel; + + session->session_id = session_id; + session->peer_session_id = peer_session_id; + + sprintf(&session->name[0], "sess %u/%u", + tunnel->tunnel_id, session->session_id); + + skb_queue_head_init(&session->reorder_q); + + INIT_HLIST_NODE(&session->hlist); + + /* Inherit debug options from tunnel */ + session->debug = tunnel->debug; + + if (cfg) { + session->debug = cfg->debug; + session->hdr_len = cfg->hdr_len; + session->mtu = cfg->mtu; + session->mru = cfg->mru; + session->send_seq = cfg->send_seq; + session->recv_seq = cfg->recv_seq; + session->lns_mode = cfg->lns_mode; + } + + /* Bump the reference count. The session context is deleted + * only when this drops to zero. + */ + l2tp_session_inc_refcount(session); + l2tp_tunnel_inc_refcount(tunnel); + + /* Ensure tunnel socket isn't deleted */ + sock_hold(tunnel->sock); + + /* Add session to the tunnel's hash list */ + write_lock_bh(&tunnel->hlist_lock); + hlist_add_head(&session->hlist, + l2tp_session_id_hash(tunnel, session_id)); + write_unlock_bh(&tunnel->hlist_lock); + + /* Ignore management session in session count value */ + if (session->session_id != 0) + atomic_inc(&l2tp_session_count); + } + + return session; +} +EXPORT_SYMBOL_GPL(l2tp_session_create); + +/***************************************************************************** + * Init and cleanup + *****************************************************************************/ + +static __net_init int l2tp_init_net(struct net *net) +{ + struct l2tp_net *pn; + int err; + + pn = kzalloc(sizeof(*pn), GFP_KERNEL); + if (!pn) + return -ENOMEM; + + INIT_LIST_HEAD(&pn->l2tp_tunnel_list); + rwlock_init(&pn->l2tp_tunnel_list_lock); + + err = net_assign_generic(net, l2tp_net_id, pn); + if (err) + goto out; + + return 0; + +out: + kfree(pn); + return err; +} + +static __net_exit void l2tp_exit_net(struct net *net) +{ + struct l2tp_net *pn; + + pn = net_generic(net, l2tp_net_id); + /* + * if someone has cached our net then + * further net_generic call will return NULL + */ + net_assign_generic(net, l2tp_net_id, NULL); + kfree(pn); +} + +static struct pernet_operations l2tp_net_ops = { + .init = l2tp_init_net, + .exit = l2tp_exit_net, + .id = &l2tp_net_id, + .size = sizeof(struct l2tp_net), +}; + +static int __init l2tp_init(void) +{ + int rc = 0; + + rc = register_pernet_device(&l2tp_net_ops); + if (rc) + goto out; + + printk(KERN_INFO "L2TP core driver, %s\n", L2TP_DRV_VERSION); + +out: + return rc; +} + +static void __exit l2tp_exit(void) +{ + unregister_pernet_device(&l2tp_net_ops); +} + +module_init(l2tp_init); +module_exit(l2tp_exit); + +MODULE_AUTHOR("James Chapman <jchapman@katalix.com>"); +MODULE_DESCRIPTION("L2TP core"); +MODULE_LICENSE("GPL"); +MODULE_VERSION(L2TP_DRV_VERSION); + diff --git a/net/l2tp/l2tp_core.h b/net/l2tp/l2tp_core.h new file mode 100644 index 0000000..2efe1a3 --- /dev/null +++ b/net/l2tp/l2tp_core.h @@ -0,0 +1,254 @@ +/* + * L2TP internal definitions. + * + * Copyright (c) 2008,2009 Katalix Systems Ltd + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#ifndef _L2TP_CORE_H_ +#define _L2TP_CORE_H_ + +/* Just some random numbers */ +#define L2TP_TUNNEL_MAGIC 0x42114DDA +#define L2TP_SESSION_MAGIC 0x0C04EB7D + +#define L2TP_HASH_BITS 4 +#define L2TP_HASH_SIZE (1 << L2TP_HASH_BITS) + +/* Debug message categories for the DEBUG socket option */ +enum { + L2TP_MSG_DEBUG = (1 << 0), /* verbose debug (if + * compiled in) */ + L2TP_MSG_CONTROL = (1 << 1), /* userspace - kernel + * interface */ + L2TP_MSG_SEQ = (1 << 2), /* sequence numbers */ + L2TP_MSG_DATA = (1 << 3), /* data packets */ +}; + +struct sk_buff; + +struct l2tp_stats { + u64 tx_packets; + u64 tx_bytes; + u64 tx_errors; + u64 rx_packets; + u64 rx_bytes; + u64 rx_seq_discards; + u64 rx_oos_packets; + u64 rx_errors; +}; + +struct l2tp_tunnel; + +/* Describes a session. Contains information to determine incoming + * packets and transmit outgoing ones. + */ +struct l2tp_session_cfg { + unsigned data_seq:2; /* data sequencing level + * 0 => none, 1 => IP only, + * 2 => all + */ + unsigned recv_seq:1; /* expect receive packets with + * sequence numbers? */ + unsigned send_seq:1; /* send packets with sequence + * numbers? */ + unsigned lns_mode:1; /* behave as LNS? LAC enables + * sequence numbers under + * control of LNS. */ + int debug; /* bitmask of debug message + * categories */ + int offset; /* offset to payload */ + int reorder_timeout; /* configured reorder timeout + * (in jiffies) */ + int mtu; + int mru; + int hdr_len; +}; + +struct l2tp_session { + int magic; /* should be + * L2TP_SESSION_MAGIC */ + + struct l2tp_tunnel *tunnel; /* back pointer to tunnel + * context */ + u32 session_id; + u32 peer_session_id; + u16 nr; /* session NR state (receive) */ + u16 ns; /* session NR state (send) */ + struct sk_buff_head reorder_q; /* receive reorder queue */ + struct hlist_node hlist; /* Hash list node */ + atomic_t ref_count; + + char name[32]; /* for logging */ + unsigned data_seq:2; /* data sequencing level + * 0 => none, 1 => IP only, + * 2 => all + */ + unsigned recv_seq:1; /* expect receive packets with + * sequence numbers? */ + unsigned send_seq:1; /* send packets with sequence + * numbers? */ + unsigned lns_mode:1; /* behave as LNS? LAC enables + * sequence numbers under + * control of LNS. */ + int debug; /* bitmask of debug message + * categories */ + int reorder_timeout; /* configured reorder timeout + * (in jiffies) */ + int mtu; + int mru; + int hdr_len; + struct l2tp_stats stats; + + void (*recv_skb)(struct l2tp_session *session, struct sk_buff *skb, int data_len); + void (*session_close)(struct l2tp_session *session); + void (*ref)(struct l2tp_session *session); + void (*deref)(struct l2tp_session *session); + + uint8_t priv[0]; /* private data */ +}; + +/* Describes the tunnel. It contains info to track all the associated + * sessions so incoming packets can be sorted out + */ +struct l2tp_tunnel_cfg { + int debug; /* bitmask of debug message + * categories */ +}; + +struct l2tp_tunnel { + int magic; /* Should be L2TP_TUNNEL_MAGIC */ + rwlock_t hlist_lock; /* protect session_hlist */ + struct hlist_head session_hlist[L2TP_HASH_SIZE]; + /* hashed list of sessions, + * hashed by id */ + u32 tunnel_id; + u32 peer_tunnel_id; + int version; /* 2=>L2TPv2, 3=>L2TPv3 */ + + char name[20]; /* for logging */ + int debug; /* bitmask of debug message + * categories */ + int hdr_len; + struct l2tp_stats stats; + + struct list_head list; /* Keep a list of all tunnels */ + struct net *l2tp_net; /* the net we belong to */ + + atomic_t ref_count; + + int (*recv_payload_hook)(struct sk_buff *skb); + void (*old_sk_destruct)(struct sock *); + struct sock *sock; /* Parent socket */ + int fd; + + uint8_t priv[0]; /* private data */ +}; + +static inline void *l2tp_tunnel_priv(struct l2tp_tunnel *tunnel) +{ + return &tunnel->priv[0]; +} + +static inline void *l2tp_session_priv(struct l2tp_session *session) +{ + return &session->priv[0]; +} + +static inline struct l2tp_tunnel *l2tp_sock_to_tunnel(struct sock *sk) +{ + struct l2tp_tunnel *tunnel; + + if (sk == NULL) + return NULL; + + sock_hold(sk); + tunnel = (struct l2tp_tunnel *)(sk->sk_user_data); + if (tunnel == NULL) { + sock_put(sk); + goto out; + } + + BUG_ON(tunnel->magic != L2TP_TUNNEL_MAGIC); + +out: + return tunnel; +} + +extern struct l2tp_session *l2tp_session_find(struct l2tp_tunnel *tunnel, u32 session_id); +extern struct l2tp_session *l2tp_session_find_nth(struct l2tp_tunnel *tunnel, int nth); +extern struct l2tp_tunnel *l2tp_tunnel_find(struct net *net, u32 tunnel_id); +extern struct l2tp_tunnel *l2tp_tunnel_find_nth(struct net *net, int nth); + +extern int l2tp_tunnel_create(struct net *net, int fd, int version, u32 tunnel_id, u32 peer_tunnel_id, struct l2tp_tunnel_cfg *cfg, struct l2tp_tunnel **tunnelp); +extern struct l2tp_session *l2tp_session_create(int priv_size, struct l2tp_tunnel *tunnel, u32 session_id, u32 peer_session_id, struct l2tp_session_cfg *cfg); +extern void l2tp_tunnel_free(struct l2tp_tunnel *tunnel); +extern void l2tp_session_free(struct l2tp_session *session); +extern int l2tp_udp_recv_core(struct l2tp_tunnel *tunnel, struct sk_buff *skb, int (*payload_hook)(struct sk_buff *skb)); +extern int l2tp_udp_encap_recv(struct sock *sk, struct sk_buff *skb); + +extern void l2tp_build_l2tp_header(struct l2tp_session *session, void *buf); +extern int l2tp_xmit_core(struct l2tp_session *session, struct sk_buff *skb, size_t data_len); +extern int l2tp_xmit_skb(struct l2tp_session *session, struct sk_buff *skb, int hdr_len); +extern void l2tp_tunnel_destruct(struct sock *sk); +extern void l2tp_tunnel_closeall(struct l2tp_tunnel *tunnel); + +/* Tunnel reference counts. Incremented per session that is added to + * the tunnel. + */ +static inline void l2tp_tunnel_inc_refcount_1(struct l2tp_tunnel *tunnel) +{ + atomic_inc(&tunnel->ref_count); +} + +static inline void l2tp_tunnel_dec_refcount_1(struct l2tp_tunnel *tunnel) +{ + if (atomic_dec_and_test(&tunnel->ref_count)) + l2tp_tunnel_free(tunnel); +} +#ifdef L2TP_REFCNT_DEBUG +#define l2tp_tunnel_inc_refcount(_t) do { \ + printk(KERN_DEBUG "l2tp_tunnel_inc_refcount: %s:%d %s: cnt=%d\n", __func__, __LINE__, (_t)->name, atomic_read(&_t->ref_count)); \ + l2tp_tunnel_inc_refcount_1(_t); \ + } while (0) +#define l2tp_tunnel_dec_refcount(_t) do { \ + printk(KERN_DEBUG "l2tp_tunnel_dec_refcount: %s:%d %s: cnt=%d\n", __func__, __LINE__, (_t)->name, atomic_read(&_t->ref_count)); \ + l2tp_tunnel_dec_refcount_1(_t); \ + } while (0) +#else +#define l2tp_tunnel_inc_refcount(t) l2tp_tunnel_inc_refcount_1(t) +#define l2tp_tunnel_dec_refcount(t) l2tp_tunnel_dec_refcount_1(t) +#endif + +/* Session reference counts. Incremented when code obtains a reference + * to a session. + */ +static inline void l2tp_session_inc_refcount_1(struct l2tp_session *session) +{ + atomic_inc(&session->ref_count); +} + +static inline void l2tp_session_dec_refcount_1(struct l2tp_session *session) +{ + if (atomic_dec_and_test(&session->ref_count)) + l2tp_session_free(session); +} + +#ifdef L2TP_REFCNT_DEBUG +#define l2tp_session_inc_refcount(_s) do { \ + printk(KERN_DEBUG "l2tp_session_inc_refcount: %s:%d %s: cnt=%d\n", __func__, __LINE__, (_s)->name, atomic_read(&_s->ref_count)); \ + l2tp_session_inc_refcount_1(_s); \ + } while (0) +#define l2tp_session_dec_refcount(_s) do { \ + printk(KERN_DEBUG "l2tp_session_dec_refcount: %s:%d %s: cnt=%d\n", __func__, __LINE__, (_s)->name, atomic_read(&_s->ref_count)); \ + l2tp_session_dec_refcount_1(_s); \ + } while (0) +#else +#define l2tp_session_inc_refcount(s) l2tp_session_inc_refcount_1(s) +#define l2tp_session_dec_refcount(s) l2tp_session_dec_refcount_1(s) +#endif + +#endif /* _L2TP_CORE_H_ */ diff --git a/net/l2tp/l2tp_ppp.c b/net/l2tp/l2tp_ppp.c new file mode 100644 index 0000000..baac072 --- /dev/null +++ b/net/l2tp/l2tp_ppp.c @@ -0,0 +1,1658 @@ +/***************************************************************************** + * Linux PPP over L2TP (PPPoX/PPPoL2TP) Sockets + * + * PPPoX --- Generic PPP encapsulation socket family + * PPPoL2TP --- PPP over L2TP (RFC 2661) + * + * Version: 2.0.0 + * + * Authors: James Chapman (jchapman@katalix.com) + * + * Based on original work by Martijn van Oosterhout <kleptog@svana.org> + * + * License: + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + * + */ + +/* This driver handles only L2TP data frames; control frames are handled by a + * userspace application. + * + * To send data in an L2TP session, userspace opens a PPPoL2TP socket and + * attaches it to a bound UDP socket with local tunnel_id / session_id and + * peer tunnel_id / session_id set. Data can then be sent or received using + * regular socket sendmsg() / recvmsg() calls. Kernel parameters of the socket + * can be read or modified using ioctl() or [gs]etsockopt() calls. + * + * When a PPPoL2TP socket is connected with local and peer session_id values + * zero, the socket is treated as a special tunnel management socket. + * + * Here's example userspace code to create a socket for sending/receiving data + * over an L2TP session:- + * + * struct sockaddr_pppol2tp sax; + * int fd; + * int session_fd; + * + * fd = socket(AF_PPPOX, SOCK_DGRAM, PX_PROTO_OL2TP); + * + * sax.sa_family = AF_PPPOX; + * sax.sa_protocol = PX_PROTO_OL2TP; + * sax.pppol2tp.fd = tunnel_fd; // bound UDP socket + * sax.pppol2tp.addr.sin_addr.s_addr = addr->sin_addr.s_addr; + * sax.pppol2tp.addr.sin_port = addr->sin_port; + * sax.pppol2tp.addr.sin_family = AF_INET; + * sax.pppol2tp.s_tunnel = tunnel_id; + * sax.pppol2tp.s_session = session_id; + * sax.pppol2tp.d_tunnel = peer_tunnel_id; + * sax.pppol2tp.d_session = peer_session_id; + * + * session_fd = connect(fd, (struct sockaddr *)&sax, sizeof(sax)); + * + * A pppd plugin that allows PPP traffic to be carried over L2TP using + * this driver is available from the OpenL2TP project at + * http://openl2tp.sourceforge.net. + */ + +#include <linux/module.h> +#include <linux/string.h> +#include <linux/list.h> +#include <linux/uaccess.h> + +#include <linux/kernel.h> +#include <linux/spinlock.h> +#include <linux/kthread.h> +#include <linux/sched.h> +#include <linux/slab.h> +#include <linux/errno.h> +#include <linux/jiffies.h> + +#include <linux/netdevice.h> +#include <linux/net.h> +#include <linux/inetdevice.h> +#include <linux/skbuff.h> +#include <linux/init.h> +#include <linux/ip.h> +#include <linux/udp.h> +#include <linux/if_pppox.h> +#include <linux/if_pppol2tp.h> +#include <net/sock.h> +#include <linux/ppp_channel.h> +#include <linux/ppp_defs.h> +#include <linux/if_ppp.h> +#include <linux/file.h> +#include <linux/hash.h> +#include <linux/sort.h> +#include <linux/proc_fs.h> +#include <linux/nsproxy.h> +#include <net/net_namespace.h> +#include <net/netns/generic.h> +#include <net/dst.h> +#include <net/ip.h> +#include <net/udp.h> +#include <net/xfrm.h> + +#include <asm/byteorder.h> +#include <asm/atomic.h> + +#include "l2tp_core.h" + +#define PPPOL2TP_DRV_VERSION "V2.0" + +/* Space for UDP, L2TP and PPP headers */ +#define PPPOL2TP_HEADER_OVERHEAD 40 + +#define PRINTK(_mask, _type, _lvl, _fmt, args...) \ + do { \ + if ((_mask) & (_type)) \ + printk(_lvl "PPPOL2TP: " _fmt, ##args); \ + } while (0) + +/* Number of bytes to build transmit L2TP headers. + * Unfortunately the size is different depending on whether sequence numbers + * are enabled. + */ +#define PPPOL2TP_L2TP_HDR_SIZE_SEQ 10 +#define PPPOL2TP_L2TP_HDR_SIZE_NOSEQ 6 + +/* Private data of each session. This data lives at the end of struct + * l2tp_session, referenced via session->priv[]. + */ +struct pppol2tp_session { + int owner; /* pid that opened the socket */ + + struct sock *sock; /* Pointer to the session + * PPPoX socket */ + struct sock *tunnel_sock; /* Pointer to the tunnel UDP + * socket */ + int flags; /* accessed by PPPIOCGFLAGS. + * Unused. */ +}; + +static int pppol2tp_xmit(struct ppp_channel *chan, struct sk_buff *skb); + +static struct ppp_channel_ops pppol2tp_chan_ops = { pppol2tp_xmit , NULL }; +static const struct proto_ops pppol2tp_ops; + +/* Helpers to obtain tunnel/session contexts from sockets. + */ +static inline struct l2tp_session *pppol2tp_sock_to_session(struct sock *sk) +{ + struct l2tp_session *session; + + if (sk == NULL) + return NULL; + + sock_hold(sk); + session = (struct l2tp_session *)(sk->sk_user_data); + if (session == NULL) { + sock_put(sk); + goto out; + } + + BUG_ON(session->magic != L2TP_SESSION_MAGIC); + +out: + return session; +} + +/***************************************************************************** + * Receive data handling + *****************************************************************************/ + +static int pppol2tp_recv_payload_hook(struct sk_buff *skb) +{ + /* Skip PPP header, if present. In testing, Microsoft L2TP clients + * don't send the PPP header (PPP header compression enabled), but + * other clients can include the header. So we cope with both cases + * here. The PPP header is always FF03 when using L2TP. + * + * Note that skb->data[] isn't dereferenced from a u16 ptr here since + * the field may be unaligned. + */ + if (!pskb_may_pull(skb, 2)) + return 1; + + if ((skb->data[0] == 0xff) && (skb->data[1] == 0x03)) + skb_pull(skb, 2); + + return 0; +} + +/* Receive message. This is the recvmsg for the PPPoL2TP socket. + */ +static int pppol2tp_recvmsg(struct kiocb *iocb, struct socket *sock, + struct msghdr *msg, size_t len, + int flags) +{ + int err; + struct sk_buff *skb; + struct sock *sk = sock->sk; + + err = -EIO; + if (sk->sk_state & PPPOX_BOUND) + goto end; + + msg->msg_namelen = 0; + + err = 0; + skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT, + flags & MSG_DONTWAIT, &err); + if (!skb) + goto end; + + if (len > skb->len) + len = skb->len; + else if (len < skb->len) + msg->msg_flags |= MSG_TRUNC; + + err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, len); + if (likely(err == 0)) + err = len; + + kfree_skb(skb); +end: + return err; +} + +static void pppol2tp_recv(struct l2tp_session *session, struct sk_buff *skb, int data_len) +{ + struct pppol2tp_session *ps = l2tp_session_priv(session); + struct sock *sk = NULL; + + /* If the socket is bound, send it in to PPP's input queue. Otherwise + * queue it on the session socket. + */ + sk = ps->sock; + if (sk == NULL) + goto no_sock; + + if (sk->sk_state & PPPOX_BOUND) { + struct pppox_sock *po; + PRINTK(session->debug, PPPOL2TP_MSG_DATA, KERN_DEBUG, + "%s: recv %d byte data frame, passing to ppp\n", + session->name, data_len); + + /* We need to forget all info related to the L2TP packet + * gathered in the skb as we are going to reuse the same + * skb for the inner packet. + * Namely we need to: + * - reset xfrm (IPSec) information as it applies to + * the outer L2TP packet and not to the inner one + * - release the dst to force a route lookup on the inner + * IP packet since skb->dst currently points to the dst + * of the UDP tunnel + * - reset netfilter information as it doesn't apply + * to the inner packet either + */ + secpath_reset(skb); + skb_dst_drop(skb); + nf_reset(skb); + + po = pppox_sk(sk); + ppp_input(&po->chan, skb); + } else { + PRINTK(session->debug, PPPOL2TP_MSG_DATA, KERN_INFO, + "%s: socket not bound\n", session->name); + + /* Not bound. Nothing we can do, so discard. */ + session->stats.rx_errors++; + kfree_skb(skb); + } + + return; + +no_sock: + PRINTK(session->debug, PPPOL2TP_MSG_DATA, KERN_INFO, + "%s: no socket\n", session->name); + kfree_skb(skb); +} + +static void pppol2tp_session_sock_hold(struct l2tp_session *session) +{ + struct pppol2tp_session *ps = l2tp_session_priv(session); + + if (ps->sock) + sock_hold(ps->sock); +} + +static void pppol2tp_session_sock_put(struct l2tp_session *session) +{ + struct pppol2tp_session *ps = l2tp_session_priv(session); + + if (ps->sock) + sock_put(ps->sock); +} + +/************************************************************************ + * Transmit handling + ***********************************************************************/ + +/* Tell how big L2TP headers are for a particular session. This + * depends on whether sequence numbers are being used. + */ +static inline int pppol2tp_l2tp_header_len(struct l2tp_session *session) +{ + if (session->send_seq) + return PPPOL2TP_L2TP_HDR_SIZE_SEQ; + + return PPPOL2TP_L2TP_HDR_SIZE_NOSEQ; +} + +/* This is the sendmsg for the PPPoL2TP pppol2tp_session socket. We come here + * when a user application does a sendmsg() on the session socket. L2TP and + * PPP headers must be inserted into the user's data. + */ +static int pppol2tp_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *m, + size_t total_len) +{ + static const unsigned char ppph[2] = { 0xff, 0x03 }; + struct sock *sk = sock->sk; + struct sk_buff *skb; + int error; + struct l2tp_session *session; + struct l2tp_tunnel *tunnel; + struct pppol2tp_session *ps; + + error = -ENOTCONN; + if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED)) + goto error; + + /* Get session and tunnel contexts */ + error = -EBADF; + session = pppol2tp_sock_to_session(sk); + if (session == NULL) + goto error; + + ps = l2tp_session_priv(session); + tunnel = l2tp_sock_to_tunnel(ps->tunnel_sock); + if (tunnel == NULL) + goto error_put_sess; + + /* Allocate a socket buffer */ + error = -ENOMEM; + skb = sock_wmalloc(sk, NET_SKB_PAD + sizeof(struct iphdr) + + sizeof(struct udphdr) + session->hdr_len + + sizeof(ppph) + total_len, + 0, GFP_KERNEL); + if (!skb) + goto error_put_sess_tun; + + /* Reserve space for headers. */ + skb_reserve(skb, NET_SKB_PAD); + skb_reset_network_header(skb); + skb_reserve(skb, sizeof(struct iphdr)); + skb_reset_transport_header(skb); + skb_reserve(skb, sizeof(struct udphdr)); + + /* Add PPP header */ + skb->data[0] = ppph[0]; + skb->data[1] = ppph[1]; + skb_put(skb, 2); + + /* Copy user data into skb */ + error = memcpy_fromiovec(skb->data, m->msg_iov, total_len); + if (error < 0) { + kfree_skb(skb); + goto error_put_sess_tun; + } + skb_put(skb, total_len); + + l2tp_xmit_skb(session, skb, session->hdr_len); + + sock_put(ps->tunnel_sock); + + return error; + +error_put_sess_tun: + sock_put(ps->tunnel_sock); +error_put_sess: + sock_put(sk); +error: + return error; +} + +/* Transmit function called by generic PPP driver. Sends PPP frame + * over PPPoL2TP socket. + * + * This is almost the same as pppol2tp_sendmsg(), but rather than + * being called with a msghdr from userspace, it is called with a skb + * from the kernel. + * + * The supplied skb from ppp doesn't have enough headroom for the + * insertion of L2TP, UDP and IP headers so we need to allocate more + * headroom in the skb. This will create a cloned skb. But we must be + * careful in the error case because the caller will expect to free + * the skb it supplied, not our cloned skb. So we take care to always + * leave the original skb unfreed if we return an error. + */ +static int pppol2tp_xmit(struct ppp_channel *chan, struct sk_buff *skb) +{ + static const u8 ppph[2] = { 0xff, 0x03 }; + struct sock *sk = (struct sock *) chan->private; + struct sock *sk_tun; + int hdr_len; + struct l2tp_session *session; + struct l2tp_tunnel *tunnel; + struct pppol2tp_session *ps; + int old_headroom; + int new_headroom; + + if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED)) + goto abort; + + /* Get session and tunnel contexts from the socket */ + session = pppol2tp_sock_to_session(sk); + if (session == NULL) + goto abort; + + ps = l2tp_session_priv(session); + sk_tun = ps->tunnel_sock; + if (sk_tun == NULL) + goto abort_put_sess; + tunnel = l2tp_sock_to_tunnel(sk_tun); + if (tunnel == NULL) + goto abort_put_sess; + + /* What header length is configured for this session? */ + hdr_len = pppol2tp_l2tp_header_len(session); + + old_headroom = skb_headroom(skb); + if (skb_cow_head(skb, sizeof(ppph))) + goto abort_put_sess_tun; + + new_headroom = skb_headroom(skb); + skb->truesize += new_headroom - old_headroom; + + /* Setup PPP header */ + __skb_push(skb, sizeof(ppph)); + skb->data[0] = ppph[0]; + skb->data[1] = ppph[1]; + + l2tp_xmit_skb(session, skb, hdr_len); + + sock_put(sk_tun); + sock_put(sk); + return 1; + +abort_put_sess_tun: + sock_put(sk_tun); +abort_put_sess: + sock_put(sk); +abort: + /* Free the original skb */ + kfree_skb(skb); + return 1; +} + +/***************************************************************************** + * Session (and tunnel control) socket create/destroy. + *****************************************************************************/ + +/* Called by l2tp_core when a session socket is being closed. + */ +static void pppol2tp_session_close(struct l2tp_session *session) +{ + struct pppol2tp_session *ps = l2tp_session_priv(session); + struct sock *sk = ps->sock; + struct sk_buff *skb; + + BUG_ON(session->magic != L2TP_SESSION_MAGIC); + + if (session->session_id == 0) + goto out; + + if (sk != NULL) { + lock_sock(sk); + + if (sk->sk_state & (PPPOX_CONNECTED | PPPOX_BOUND)) { + pppox_unbind_sock(sk); + sk->sk_state = PPPOX_DEAD; + sk->sk_state_change(sk); + } + + /* Purge any queued data */ + skb_queue_purge(&sk->sk_receive_queue); + skb_queue_purge(&sk->sk_write_queue); + while ((skb = skb_dequeue(&session->reorder_q))) { + kfree_skb(skb); + sock_put(sk); + } + + release_sock(sk); + } + +out: + return; +} + +/* Really kill the session socket. (Called from sock_put() if + * refcnt == 0.) + */ +static void pppol2tp_session_destruct(struct sock *sk) +{ + struct l2tp_session *session; + + if (sk->sk_user_data != NULL) { + session = sk->sk_user_data; + if (session == NULL) + goto out; + + sk->sk_user_data = NULL; + BUG_ON(session->magic != L2TP_SESSION_MAGIC); + l2tp_session_dec_refcount(session); + } + +out: + return; +} + +/* Called when the PPPoX socket (session) is closed. + */ +static int pppol2tp_release(struct socket *sock) +{ + struct sock *sk = sock->sk; + struct l2tp_session *session; + int error; + + if (!sk) + return 0; + + error = -EBADF; + lock_sock(sk); + if (sock_flag(sk, SOCK_DEAD) != 0) + goto error; + + pppox_unbind_sock(sk); + + /* Signal the death of the socket. */ + sk->sk_state = PPPOX_DEAD; + sock_orphan(sk); + sock->sk = NULL; + + session = pppol2tp_sock_to_session(sk); + + /* Purge any queued data */ + skb_queue_purge(&sk->sk_receive_queue); + skb_queue_purge(&sk->sk_write_queue); + if (session != NULL) { + struct sk_buff *skb; + while ((skb = skb_dequeue(&session->reorder_q))) { + kfree_skb(skb); + sock_put(sk); + } + sock_put(sk); + } + + release_sock(sk); + + /* This will delete the session context via + * pppol2tp_session_destruct() if the socket's refcnt drops to + * zero. + */ + sock_put(sk); + + return 0; + +error: + release_sock(sk); + return error; +} + +static struct proto pppol2tp_sk_proto = { + .name = "PPPOL2TP", + .owner = THIS_MODULE, + .obj_size = sizeof(struct pppox_sock), +}; + +static int pppol2tp_backlog_recv(struct sock *sk, struct sk_buff *skb) +{ + int rc; + + rc = l2tp_udp_encap_recv(sk, skb); + if (rc) + kfree_skb(skb); + + return NET_RX_SUCCESS; +} + +/* socket() handler. Initialize a new struct sock. + */ +static int pppol2tp_create(struct net *net, struct socket *sock) +{ + int error = -ENOMEM; + struct sock *sk; + + sk = sk_alloc(net, PF_PPPOX, GFP_KERNEL, &pppol2tp_sk_proto); + if (!sk) + goto out; + + sock_init_data(sock, sk); + + sock->state = SS_UNCONNECTED; + sock->ops = &pppol2tp_ops; + + sk->sk_backlog_rcv = pppol2tp_backlog_recv; + sk->sk_protocol = PX_PROTO_OL2TP; + sk->sk_family = PF_PPPOX; + sk->sk_state = PPPOX_NONE; + sk->sk_type = SOCK_STREAM; + sk->sk_destruct = pppol2tp_session_destruct; + + error = 0; + +out: + return error; +} + +/* connect() handler. Attach a PPPoX socket to a tunnel UDP socket + */ +static int pppol2tp_connect(struct socket *sock, struct sockaddr *uservaddr, + int sockaddr_len, int flags) +{ + struct sock *sk = sock->sk; + struct sockaddr_pppol2tp *sp = (struct sockaddr_pppol2tp *) uservaddr; + struct pppox_sock *po = pppox_sk(sk); + struct l2tp_session *session = NULL; + struct l2tp_tunnel *tunnel; + struct pppol2tp_session *ps; + struct dst_entry *dst; + struct l2tp_session_cfg cfg = { 0, }; + int error = 0; + + lock_sock(sk); + + error = -EINVAL; + if (sp->sa_protocol != PX_PROTO_OL2TP) + goto end; + + /* Check for already bound sockets */ + error = -EBUSY; + if (sk->sk_state & PPPOX_CONNECTED) + goto end; + + /* We don't supporting rebinding anyway */ + error = -EALREADY; + if (sk->sk_user_data) + goto end; /* socket is already attached */ + + /* Don't bind if s_tunnel is 0 */ + error = -EINVAL; + if (sp->pppol2tp.s_tunnel == 0) + goto end; + + /* Special case: create tunnel context if s_session and + * d_session is 0. Otherwise look up tunnel using supplied + * tunnel id. + */ + if ((sp->pppol2tp.s_session == 0) && (sp->pppol2tp.d_session == 0)) { + error = l2tp_tunnel_create(sock_net(sk), sp->pppol2tp.fd, 2, sp->pppol2tp.s_tunnel, sp->pppol2tp.d_tunnel, NULL, &tunnel); + if (error < 0) + goto end; + } else { + tunnel = l2tp_tunnel_find(sock_net(sk), sp->pppol2tp.s_tunnel); + + /* Error if we can't find the tunnel */ + error = -ENOENT; + if (tunnel == NULL) + goto end; + + /* Error if socket is not prepped */ + if (tunnel->sock == NULL) + goto end; + } + + if (tunnel->recv_payload_hook == NULL) + tunnel->recv_payload_hook = pppol2tp_recv_payload_hook; + + /* Check that this session doesn't already exist */ + error = -EEXIST; + session = l2tp_session_find(tunnel, sp->pppol2tp.s_session); + if (session != NULL) + goto end; + + /* Default MTU must allow space for UDP/L2TP/PPP + * headers. + */ + cfg.mtu = cfg.mru = 1500 - PPPOL2TP_HEADER_OVERHEAD; + cfg.hdr_len = PPPOL2TP_L2TP_HDR_SIZE_NOSEQ; + cfg.debug = tunnel->debug; + + /* Allocate and initialize a new session context. */ + session = l2tp_session_create(sizeof(struct pppol2tp_session), + tunnel, sp->pppol2tp.s_session, + sp->pppol2tp.d_session, &cfg); + if (session == NULL) { + error = -ENOMEM; + goto end; + } + + ps = l2tp_session_priv(session); + ps->owner = current->pid; + ps->sock = sk; + ps->tunnel_sock = tunnel->sock; + + session->recv_skb = pppol2tp_recv; + session->session_close = pppol2tp_session_close; + + /* We need to know each time a skb is dropped from the reorder + * queue. + */ + session->ref = pppol2tp_session_sock_hold; + session->deref = pppol2tp_session_sock_put; + + /* If PMTU discovery was enabled, use the MTU that was discovered */ + dst = sk_dst_get(sk); + if (dst != NULL) { + u32 pmtu = dst_mtu(__sk_dst_get(sk)); + if (pmtu != 0) + session->mtu = session->mru = pmtu - + PPPOL2TP_HEADER_OVERHEAD; + dst_release(dst); + } + + /* Special case: if source & dest session_id == 0x0000, this + * socket is being created to manage the tunnel. Just set up + * the internal context for use by ioctl() and sockopt() + * handlers. + */ + if ((session->session_id == 0) && + (session->peer_session_id == 0)) { + error = 0; + goto out_no_ppp; + } + + /* The only header we need to worry about is the L2TP + * header. This size is different depending on whether + * sequence numbers are enabled for the data channel. + */ + po->chan.hdrlen = PPPOL2TP_L2TP_HDR_SIZE_NOSEQ; + + po->chan.private = sk; + po->chan.ops = &pppol2tp_chan_ops; + po->chan.mtu = session->mtu; + + error = ppp_register_net_channel(sock_net(sk), &po->chan); + if (error) + goto end; + +out_no_ppp: + /* This is how we get the session context from the socket. */ + sk->sk_user_data = session; + sk->sk_state = PPPOX_CONNECTED; + PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO, + "%s: created\n", session->name); + +end: + release_sock(sk); + + return error; +} + +/* getname() support. + */ +static int pppol2tp_getname(struct socket *sock, struct sockaddr *uaddr, + int *usockaddr_len, int peer) +{ + int len = sizeof(struct sockaddr_pppol2tp); + struct sockaddr_pppol2tp sp; + int error = 0; + struct l2tp_session *session; + struct l2tp_tunnel *tunnel; + struct sock *sk = sock->sk; + struct inet_sock *inet; + struct pppol2tp_session *pls; + + error = -ENOTCONN; + if (sk == NULL) + goto end; + if (sk->sk_state != PPPOX_CONNECTED) + goto end; + + error = -EBADF; + session = pppol2tp_sock_to_session(sk); + if (session == NULL) + goto end; + + pls = l2tp_session_priv(session); + tunnel = l2tp_sock_to_tunnel(pls->tunnel_sock); + if (tunnel == NULL) { + error = -EBADF; + goto end_put_sess; + } + + memset(&sp, 0, len); + sp.sa_family = AF_PPPOX; + sp.sa_protocol = PX_PROTO_OL2TP; + sp.pppol2tp.fd = tunnel->fd; + sp.pppol2tp.pid = pls->owner; + sp.pppol2tp.s_tunnel = tunnel->tunnel_id; + sp.pppol2tp.d_tunnel = tunnel->peer_tunnel_id; + sp.pppol2tp.s_session = session->session_id; + sp.pppol2tp.d_session = session->peer_session_id; + inet = inet_sk(sk); + sp.pppol2tp.addr.sin_family = AF_INET; + sp.pppol2tp.addr.sin_port = inet->inet_dport; + sp.pppol2tp.addr.sin_addr.s_addr = inet->inet_daddr; + + memcpy(uaddr, &sp, len); + + *usockaddr_len = len; + + sock_put(pls->tunnel_sock); +end_put_sess: + sock_put(sk); + error = 0; + +end: + return error; +} + +/**************************************************************************** + * ioctl() handlers. + * + * The PPPoX socket is created for L2TP sessions: tunnels have their own UDP + * sockets. However, in order to control kernel tunnel features, we allow + * userspace to create a special "tunnel" PPPoX socket which is used for + * control only. Tunnel PPPoX sockets have session_id == 0 and simply allow + * the user application to issue L2TP setsockopt(), getsockopt() and ioctl() + * calls. + ****************************************************************************/ + +static void pppol2tp_copy_stats(struct pppol2tp_ioc_stats *dest, + struct l2tp_stats *stats) +{ + dest->tx_packets = stats->tx_packets; + dest->tx_bytes = stats->tx_bytes; + dest->tx_errors = stats->tx_errors; + dest->rx_packets = stats->rx_packets; + dest->rx_bytes = stats->rx_bytes; + dest->rx_seq_discards = stats->rx_seq_discards; + dest->rx_oos_packets = stats->rx_oos_packets; + dest->rx_errors = stats->rx_errors; +} + +/* Session ioctl helper. + */ +static int pppol2tp_session_ioctl(struct l2tp_session *session, + unsigned int cmd, unsigned long arg) +{ + struct ifreq ifr; + int err = 0; + struct sock *sk; + int val = (int) arg; + struct pppol2tp_session *ps = l2tp_session_priv(session); + struct l2tp_tunnel *tunnel = session->tunnel; + struct pppol2tp_ioc_stats stats; + + PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_DEBUG, + "%s: pppol2tp_session_ioctl(cmd=%#x, arg=%#lx)\n", + session->name, cmd, arg); + + sk = ps->sock; + sock_hold(sk); + + switch (cmd) { + case SIOCGIFMTU: + err = -ENXIO; + if (!(sk->sk_state & PPPOX_CONNECTED)) + break; + + err = -EFAULT; + if (copy_from_user(&ifr, (void __user *) arg, sizeof(struct ifreq))) + break; + ifr.ifr_mtu = session->mtu; + if (copy_to_user((void __user *) arg, &ifr, sizeof(struct ifreq))) + break; + + PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO, + "%s: get mtu=%d\n", session->name, session->mtu); + err = 0; + break; + + case SIOCSIFMTU: + err = -ENXIO; + if (!(sk->sk_state & PPPOX_CONNECTED)) + break; + + err = -EFAULT; + if (copy_from_user(&ifr, (void __user *) arg, sizeof(struct ifreq))) + break; + + session->mtu = ifr.ifr_mtu; + + PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO, + "%s: set mtu=%d\n", session->name, session->mtu); + err = 0; + break; + + case PPPIOCGMRU: + err = -ENXIO; + if (!(sk->sk_state & PPPOX_CONNECTED)) + break; + + err = -EFAULT; + if (put_user(session->mru, (int __user *) arg)) + break; + + PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO, + "%s: get mru=%d\n", session->name, session->mru); + err = 0; + break; + + case PPPIOCSMRU: + err = -ENXIO; + if (!(sk->sk_state & PPPOX_CONNECTED)) + break; + + err = -EFAULT; + if (get_user(val, (int __user *) arg)) + break; + + session->mru = val; + PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO, + "%s: set mru=%d\n", session->name, session->mru); + err = 0; + break; + + case PPPIOCGFLAGS: + err = -EFAULT; + if (put_user(ps->flags, (int __user *) arg)) + break; + + PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO, + "%s: get flags=%d\n", session->name, ps->flags); + err = 0; + break; + + case PPPIOCSFLAGS: + err = -EFAULT; + if (get_user(val, (int __user *) arg)) + break; + ps->flags = val; + PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO, + "%s: set flags=%d\n", session->name, ps->flags); + err = 0; + break; + + case PPPIOCGL2TPSTATS: + err = -ENXIO; + if (!(sk->sk_state & PPPOX_CONNECTED)) + break; + + memset(&stats, 0, sizeof(stats)); + stats.tunnel_id = tunnel->tunnel_id; + stats.session_id = session->session_id; + pppol2tp_copy_stats(&stats, &session->stats); + if (copy_to_user((void __user *) arg, &stats, + sizeof(stats))) + break; + PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO, + "%s: get L2TP stats\n", session->name); + err = 0; + break; + + default: + err = -ENOSYS; + break; + } + + sock_put(sk); + + return err; +} + +/* Tunnel ioctl helper. + * + * Note the special handling for PPPIOCGL2TPSTATS below. If the ioctl data + * specifies a session_id, the session ioctl handler is called. This allows an + * application to retrieve session stats via a tunnel socket. + */ +static int pppol2tp_tunnel_ioctl(struct l2tp_tunnel *tunnel, + unsigned int cmd, unsigned long arg) +{ + int err = 0; + struct sock *sk; + struct pppol2tp_ioc_stats stats; + + PRINTK(tunnel->debug, PPPOL2TP_MSG_CONTROL, KERN_DEBUG, + "%s: pppol2tp_tunnel_ioctl(cmd=%#x, arg=%#lx)\n", + tunnel->name, cmd, arg); + + sk = tunnel->sock; + sock_hold(sk); + + switch (cmd) { + case PPPIOCGL2TPSTATS: + err = -ENXIO; + if (!(sk->sk_state & PPPOX_CONNECTED)) + break; + + if (copy_from_user(&stats, (void __user *) arg, + sizeof(stats))) { + err = -EFAULT; + break; + } + if (stats.session_id != 0) { + /* resend to session ioctl handler */ + struct l2tp_session *session = + l2tp_session_find(tunnel, stats.session_id); + if (session != NULL) + err = pppol2tp_session_ioctl(session, cmd, arg); + else + err = -EBADR; + break; + } +#ifdef CONFIG_XFRM + stats.using_ipsec = (sk->sk_policy[0] || sk->sk_policy[1]) ? 1 : 0; +#endif + pppol2tp_copy_stats(&stats, &tunnel->stats); + if (copy_to_user((void __user *) arg, &stats, sizeof(stats))) { + err = -EFAULT; + break; + } + PRINTK(tunnel->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO, + "%s: get L2TP stats\n", tunnel->name); + err = 0; + break; + + default: + err = -ENOSYS; + break; + } + + sock_put(sk); + + return err; +} + +/* Main ioctl() handler. + * Dispatch to tunnel or session helpers depending on the socket. + */ +static int pppol2tp_ioctl(struct socket *sock, unsigned int cmd, + unsigned long arg) +{ + struct sock *sk = sock->sk; + struct l2tp_session *session; + struct l2tp_tunnel *tunnel; + struct pppol2tp_session *ps; + int err; + + if (!sk) + return 0; + + err = -EBADF; + if (sock_flag(sk, SOCK_DEAD) != 0) + goto end; + + err = -ENOTCONN; + if ((sk->sk_user_data == NULL) || + (!(sk->sk_state & (PPPOX_CONNECTED | PPPOX_BOUND)))) + goto end; + + /* Get session context from the socket */ + err = -EBADF; + session = pppol2tp_sock_to_session(sk); + if (session == NULL) + goto end; + + /* Special case: if session's session_id is zero, treat ioctl as a + * tunnel ioctl + */ + ps = l2tp_session_priv(session); + if ((session->session_id == 0) && + (session->peer_session_id == 0)) { + err = -EBADF; + tunnel = l2tp_sock_to_tunnel(ps->tunnel_sock); + if (tunnel == NULL) + goto end_put_sess; + + err = pppol2tp_tunnel_ioctl(tunnel, cmd, arg); + sock_put(ps->tunnel_sock); + goto end_put_sess; + } + + err = pppol2tp_session_ioctl(session, cmd, arg); + +end_put_sess: + sock_put(sk); +end: + return err; +} + +/***************************************************************************** + * setsockopt() / getsockopt() support. + * + * The PPPoX socket is created for L2TP sessions: tunnels have their own UDP + * sockets. In order to control kernel tunnel features, we allow userspace to + * create a special "tunnel" PPPoX socket which is used for control only. + * Tunnel PPPoX sockets have session_id == 0 and simply allow the user + * application to issue L2TP setsockopt(), getsockopt() and ioctl() calls. + *****************************************************************************/ + +/* Tunnel setsockopt() helper. + */ +static int pppol2tp_tunnel_setsockopt(struct sock *sk, + struct l2tp_tunnel *tunnel, + int optname, int val) +{ + int err = 0; + + switch (optname) { + case PPPOL2TP_SO_DEBUG: + tunnel->debug = val; + PRINTK(tunnel->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO, + "%s: set debug=%x\n", tunnel->name, tunnel->debug); + break; + + default: + err = -ENOPROTOOPT; + break; + } + + return err; +} + +/* Session setsockopt helper. + */ +static int pppol2tp_session_setsockopt(struct sock *sk, + struct l2tp_session *session, + int optname, int val) +{ + int err = 0; + struct pppol2tp_session *ps = l2tp_session_priv(session); + + switch (optname) { + case PPPOL2TP_SO_RECVSEQ: + if ((val != 0) && (val != 1)) { + err = -EINVAL; + break; + } + session->recv_seq = val ? -1 : 0; + PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO, + "%s: set recv_seq=%d\n", session->name, session->recv_seq); + break; + + case PPPOL2TP_SO_SENDSEQ: + if ((val != 0) && (val != 1)) { + err = -EINVAL; + break; + } + session->send_seq = val ? -1 : 0; + { + struct sock *ssk = ps->sock; + struct pppox_sock *po = pppox_sk(ssk); + po->chan.hdrlen = val ? PPPOL2TP_L2TP_HDR_SIZE_SEQ : + PPPOL2TP_L2TP_HDR_SIZE_NOSEQ; + } + PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO, + "%s: set send_seq=%d\n", session->name, session->send_seq); + break; + + case PPPOL2TP_SO_LNSMODE: + if ((val != 0) && (val != 1)) { + err = -EINVAL; + break; + } + session->lns_mode = val ? -1 : 0; + PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO, + "%s: set lns_mode=%d\n", session->name, session->lns_mode); + break; + + case PPPOL2TP_SO_DEBUG: + session->debug = val; + PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO, + "%s: set debug=%x\n", session->name, session->debug); + break; + + case PPPOL2TP_SO_REORDERTO: + session->reorder_timeout = msecs_to_jiffies(val); + PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO, + "%s: set reorder_timeout=%d\n", session->name, session->reorder_timeout); + break; + + default: + err = -ENOPROTOOPT; + break; + } + + return err; +} + +/* Main setsockopt() entry point. + * Does API checks, then calls either the tunnel or session setsockopt + * handler, according to whether the PPPoL2TP socket is a for a regular + * session or the special tunnel type. + */ +static int pppol2tp_setsockopt(struct socket *sock, int level, int optname, + char __user *optval, unsigned int optlen) +{ + struct sock *sk = sock->sk; + struct l2tp_session *session; + struct l2tp_tunnel *tunnel; + struct pppol2tp_session *ps; + int val; + int err; + + if (level != SOL_PPPOL2TP) + return udp_prot.setsockopt(sk, level, optname, optval, optlen); + + if (optlen < sizeof(int)) + return -EINVAL; + + if (get_user(val, (int __user *)optval)) + return -EFAULT; + + err = -ENOTCONN; + if (sk->sk_user_data == NULL) + goto end; + + /* Get session context from the socket */ + err = -EBADF; + session = pppol2tp_sock_to_session(sk); + if (session == NULL) + goto end; + + /* Special case: if session_id == 0x0000, treat as operation on tunnel + */ + ps = l2tp_session_priv(session); + if ((session->session_id == 0) && + (session->peer_session_id == 0)) { + err = -EBADF; + tunnel = l2tp_sock_to_tunnel(ps->tunnel_sock); + if (tunnel == NULL) + goto end_put_sess; + + err = pppol2tp_tunnel_setsockopt(sk, tunnel, optname, val); + sock_put(ps->tunnel_sock); + } else + err = pppol2tp_session_setsockopt(sk, session, optname, val); + + err = 0; + +end_put_sess: + sock_put(sk); +end: + return err; +} + +/* Tunnel getsockopt helper. Called with sock locked. + */ +static int pppol2tp_tunnel_getsockopt(struct sock *sk, + struct l2tp_tunnel *tunnel, + int optname, int *val) +{ + int err = 0; + + switch (optname) { + case PPPOL2TP_SO_DEBUG: + *val = tunnel->debug; + PRINTK(tunnel->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO, + "%s: get debug=%x\n", tunnel->name, tunnel->debug); + break; + + default: + err = -ENOPROTOOPT; + break; + } + + return err; +} + +/* Session getsockopt helper. Called with sock locked. + */ +static int pppol2tp_session_getsockopt(struct sock *sk, + struct l2tp_session *session, + int optname, int *val) +{ + int err = 0; + + switch (optname) { + case PPPOL2TP_SO_RECVSEQ: + *val = session->recv_seq; + PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO, + "%s: get recv_seq=%d\n", session->name, *val); + break; + + case PPPOL2TP_SO_SENDSEQ: + *val = session->send_seq; + PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO, + "%s: get send_seq=%d\n", session->name, *val); + break; + + case PPPOL2TP_SO_LNSMODE: + *val = session->lns_mode; + PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO, + "%s: get lns_mode=%d\n", session->name, *val); + break; + + case PPPOL2TP_SO_DEBUG: + *val = session->debug; + PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO, + "%s: get debug=%d\n", session->name, *val); + break; + + case PPPOL2TP_SO_REORDERTO: + *val = (int) jiffies_to_msecs(session->reorder_timeout); + PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO, + "%s: get reorder_timeout=%d\n", session->name, *val); + break; + + default: + err = -ENOPROTOOPT; + } + + return err; +} + +/* Main getsockopt() entry point. + * Does API checks, then calls either the tunnel or session getsockopt + * handler, according to whether the PPPoX socket is a for a regular session + * or the special tunnel type. + */ +static int pppol2tp_getsockopt(struct socket *sock, int level, + int optname, char __user *optval, int __user *optlen) +{ + struct sock *sk = sock->sk; + struct l2tp_session *session; + struct l2tp_tunnel *tunnel; + int val, len; + int err; + struct pppol2tp_session *ps; + + if (level != SOL_PPPOL2TP) + return udp_prot.getsockopt(sk, level, optname, optval, optlen); + + if (get_user(len, (int __user *) optlen)) + return -EFAULT; + + len = min_t(unsigned int, len, sizeof(int)); + + if (len < 0) + return -EINVAL; + + err = -ENOTCONN; + if (sk->sk_user_data == NULL) + goto end; + + /* Get the session context */ + err = -EBADF; + session = pppol2tp_sock_to_session(sk); + if (session == NULL) + goto end; + + /* Special case: if session_id == 0x0000, treat as operation on tunnel */ + ps = l2tp_session_priv(session); + if ((session->session_id == 0) && + (session->peer_session_id == 0)) { + err = -EBADF; + tunnel = l2tp_sock_to_tunnel(ps->tunnel_sock); + if (tunnel == NULL) + goto end_put_sess; + + err = pppol2tp_tunnel_getsockopt(sk, tunnel, optname, &val); + sock_put(ps->tunnel_sock); + } else + err = pppol2tp_session_getsockopt(sk, session, optname, &val); + + err = -EFAULT; + if (put_user(len, (int __user *) optlen)) + goto end_put_sess; + + if (copy_to_user((void __user *) optval, &val, len)) + goto end_put_sess; + + err = 0; + +end_put_sess: + sock_put(sk); +end: + return err; +} + +/***************************************************************************** + * /proc filesystem for debug + *****************************************************************************/ + +static unsigned int pppol2tp_net_id; + +#ifdef CONFIG_PROC_FS + +struct pppol2tp_seq_data { + struct seq_net_private p; + int tunnel_idx; /* current tunnel */ + int session_idx; /* index of session within current tunnel */ + struct l2tp_tunnel *tunnel; + struct l2tp_session *session; /* NULL means get next tunnel */ +}; + +static void pppol2tp_next_tunnel(struct net *net, struct pppol2tp_seq_data *pd) +{ + pd->tunnel = l2tp_tunnel_find_nth(net, pd->tunnel_idx); + pd->tunnel_idx++; +} + +static void pppol2tp_next_session(struct net *net, struct pppol2tp_seq_data *pd) +{ + pd->session = l2tp_session_find_nth(pd->tunnel, pd->session_idx); + pd->session_idx++; + if (pd->session == NULL) { + pd->session_idx = 0; + pppol2tp_next_tunnel(net, pd); + } +} + +static void *pppol2tp_seq_start(struct seq_file *m, loff_t *offs) +{ + struct pppol2tp_seq_data *pd = SEQ_START_TOKEN; + loff_t pos = *offs; + struct net *net; + + if (!pos) + goto out; + + BUG_ON(m->private == NULL); + pd = m->private; + net = seq_file_net(m); + + if (pd->tunnel == NULL) + pppol2tp_next_tunnel(net, pd); + else + pppol2tp_next_session(net, pd); + + /* NULL tunnel and session indicates end of list */ + if ((pd->tunnel == NULL) && (pd->session == NULL)) + pd = NULL; + +out: + return pd; +} + +static void *pppol2tp_seq_next(struct seq_file *m, void *v, loff_t *pos) +{ + (*pos)++; + return NULL; +} + +static void pppol2tp_seq_stop(struct seq_file *p, void *v) +{ + /* nothing to do */ +} + +static void pppol2tp_seq_tunnel_show(struct seq_file *m, void *v) +{ + struct l2tp_tunnel *tunnel = v; + + seq_printf(m, "\nTUNNEL '%s', %c %d\n", + tunnel->name, + (tunnel == tunnel->sock->sk_user_data) ? 'Y' : 'N', + atomic_read(&tunnel->ref_count) - 1); + seq_printf(m, " %08x %llu/%llu/%llu %llu/%llu/%llu\n", + tunnel->debug, + (unsigned long long)tunnel->stats.tx_packets, + (unsigned long long)tunnel->stats.tx_bytes, + (unsigned long long)tunnel->stats.tx_errors, + (unsigned long long)tunnel->stats.rx_packets, + (unsigned long long)tunnel->stats.rx_bytes, + (unsigned long long)tunnel->stats.rx_errors); +} + +static void pppol2tp_seq_session_show(struct seq_file *m, void *v) +{ + struct l2tp_session *session = v; + struct l2tp_tunnel *tunnel = session->tunnel; + struct pppol2tp_session *ps = l2tp_session_priv(session); + u32 ip = 0; + u16 port = 0; + + if (tunnel->sock) { + struct inet_sock *inet = inet_sk(tunnel->sock); + ip = ntohl(inet->inet_saddr); + port = ntohs(inet->inet_sport); + } + + seq_printf(m, " SESSION '%s' %08X/%d %04X/%04X -> " + "%04X/%04X %d %c\n", + session->name, ip, port, + tunnel->tunnel_id, + session->session_id, + tunnel->peer_tunnel_id, + session->peer_session_id, + ps->sock->sk_state, + (session == ps->sock->sk_user_data) ? + 'Y' : 'N'); + seq_printf(m, " %d/%d/%c/%c/%s %08x %u\n", + session->mtu, session->mru, + session->recv_seq ? 'R' : '-', + session->send_seq ? 'S' : '-', + session->lns_mode ? "LNS" : "LAC", + session->debug, + jiffies_to_msecs(session->reorder_timeout)); + seq_printf(m, " %hu/%hu %llu/%llu/%llu %llu/%llu/%llu\n", + session->nr, session->ns, + (unsigned long long)session->stats.tx_packets, + (unsigned long long)session->stats.tx_bytes, + (unsigned long long)session->stats.tx_errors, + (unsigned long long)session->stats.rx_packets, + (unsigned long long)session->stats.rx_bytes, + (unsigned long long)session->stats.rx_errors); +} + +static int pppol2tp_seq_show(struct seq_file *m, void *v) +{ + struct pppol2tp_seq_data *pd = v; + + /* display header on line 1 */ + if (v == SEQ_START_TOKEN) { + seq_puts(m, "PPPoL2TP driver info, " PPPOL2TP_DRV_VERSION "\n"); + seq_puts(m, "TUNNEL name, user-data-ok session-count\n"); + seq_puts(m, " debug tx-pkts/bytes/errs rx-pkts/bytes/errs\n"); + seq_puts(m, " SESSION name, addr/port src-tid/sid " + "dest-tid/sid state user-data-ok\n"); + seq_puts(m, " mtu/mru/rcvseq/sendseq/lns debug reorderto\n"); + seq_puts(m, " nr/ns tx-pkts/bytes/errs rx-pkts/bytes/errs\n"); + goto out; + } + + /* Show the tunnel or session context. + */ + if (pd->session == NULL) + pppol2tp_seq_tunnel_show(m, pd->tunnel); + else + pppol2tp_seq_session_show(m, pd->session); + +out: + return 0; +} + +static const struct seq_operations pppol2tp_seq_ops = { + .start = pppol2tp_seq_start, + .next = pppol2tp_seq_next, + .stop = pppol2tp_seq_stop, + .show = pppol2tp_seq_show, +}; + +/* Called when our /proc file is opened. We allocate data for use when + * iterating our tunnel / session contexts and store it in the private + * data of the seq_file. + */ +static int pppol2tp_proc_open(struct inode *inode, struct file *file) +{ + return seq_open_net(inode, file, &pppol2tp_seq_ops, + sizeof(struct pppol2tp_seq_data)); +} + +static const struct file_operations pppol2tp_proc_fops = { + .owner = THIS_MODULE, + .open = pppol2tp_proc_open, + .read = seq_read, + .llseek = seq_lseek, + .release = seq_release_net, +}; + +#endif /* CONFIG_PROC_FS */ + +/***************************************************************************** + * Network namespace + *****************************************************************************/ + +static __net_init int pppol2tp_init_net(struct net *net) +{ + struct proc_dir_entry *pde; + int err = 0; + + pde = proc_net_fops_create(net, "pppol2tp", S_IRUGO, &pppol2tp_proc_fops); + if (!pde) { + err = -ENOMEM; + goto out; + } + +out: + return err; +} + +static __net_exit void pppol2tp_exit_net(struct net *net) +{ + proc_net_remove(net, "pppol2tp"); +} + +static struct pernet_operations pppol2tp_net_ops = { + .init = pppol2tp_init_net, + .exit = pppol2tp_exit_net, + .id = &pppol2tp_net_id, +}; + +/***************************************************************************** + * Init and cleanup + *****************************************************************************/ + +static const struct proto_ops pppol2tp_ops = { + .family = AF_PPPOX, + .owner = THIS_MODULE, + .release = pppol2tp_release, + .bind = sock_no_bind, + .connect = pppol2tp_connect, + .socketpair = sock_no_socketpair, + .accept = sock_no_accept, + .getname = pppol2tp_getname, + .poll = datagram_poll, + .listen = sock_no_listen, + .shutdown = sock_no_shutdown, + .setsockopt = pppol2tp_setsockopt, + .getsockopt = pppol2tp_getsockopt, + .sendmsg = pppol2tp_sendmsg, + .recvmsg = pppol2tp_recvmsg, + .mmap = sock_no_mmap, + .ioctl = pppox_ioctl, +}; + +static struct pppox_proto pppol2tp_proto = { + .create = pppol2tp_create, + .ioctl = pppol2tp_ioctl +}; + +static int __init pppol2tp_init(void) +{ + int err; + + err = register_pernet_device(&pppol2tp_net_ops); + if (err) + goto out; + + err = proto_register(&pppol2tp_sk_proto, 0); + if (err) + goto out_unregister_pppol2tp_pernet; + + err = register_pppox_proto(PX_PROTO_OL2TP, &pppol2tp_proto); + if (err) + goto out_unregister_pppol2tp_proto; + + printk(KERN_INFO "PPPoL2TP kernel driver, %s\n", + PPPOL2TP_DRV_VERSION); + +out: + return err; +out_unregister_pppol2tp_proto: + proto_unregister(&pppol2tp_sk_proto); +out_unregister_pppol2tp_pernet: + unregister_pernet_device(&pppol2tp_net_ops); + goto out; +} + +static void __exit pppol2tp_exit(void) +{ + unregister_pppox_proto(PX_PROTO_OL2TP); + proto_unregister(&pppol2tp_sk_proto); + unregister_pernet_device(&pppol2tp_net_ops); +} + +module_init(pppol2tp_init); +module_exit(pppol2tp_exit); + +MODULE_AUTHOR("James Chapman <jchapman@katalix.com>"); +MODULE_DESCRIPTION("PPP over L2TP over UDP"); +MODULE_LICENSE("GPL"); +MODULE_VERSION(PPPOL2TP_DRV_VERSION); diff --git a/net/l2tp/pppol2tp.c b/net/l2tp/pppol2tp.c deleted file mode 100644 index 449a982..0000000 --- a/net/l2tp/pppol2tp.c +++ /dev/null @@ -1,2680 +0,0 @@ -/***************************************************************************** - * Linux PPP over L2TP (PPPoX/PPPoL2TP) Sockets - * - * PPPoX --- Generic PPP encapsulation socket family - * PPPoL2TP --- PPP over L2TP (RFC 2661) - * - * Version: 1.0.0 - * - * Authors: Martijn van Oosterhout <kleptog@svana.org> - * James Chapman (jchapman@katalix.com) - * Contributors: - * Michal Ostrowski <mostrows@speakeasy.net> - * Arnaldo Carvalho de Melo <acme@xconectiva.com.br> - * David S. Miller (davem@redhat.com) - * - * License: - * This program is free software; you can redistribute it and/or - * modify it under the terms of the GNU General Public License - * as published by the Free Software Foundation; either version - * 2 of the License, or (at your option) any later version. - * - */ - -/* This driver handles only L2TP data frames; control frames are handled by a - * userspace application. - * - * To send data in an L2TP session, userspace opens a PPPoL2TP socket and - * attaches it to a bound UDP socket with local tunnel_id / session_id and - * peer tunnel_id / session_id set. Data can then be sent or received using - * regular socket sendmsg() / recvmsg() calls. Kernel parameters of the socket - * can be read or modified using ioctl() or [gs]etsockopt() calls. - * - * When a PPPoL2TP socket is connected with local and peer session_id values - * zero, the socket is treated as a special tunnel management socket. - * - * Here's example userspace code to create a socket for sending/receiving data - * over an L2TP session:- - * - * struct sockaddr_pppol2tp sax; - * int fd; - * int session_fd; - * - * fd = socket(AF_PPPOX, SOCK_DGRAM, PX_PROTO_OL2TP); - * - * sax.sa_family = AF_PPPOX; - * sax.sa_protocol = PX_PROTO_OL2TP; - * sax.pppol2tp.fd = tunnel_fd; // bound UDP socket - * sax.pppol2tp.addr.sin_addr.s_addr = addr->sin_addr.s_addr; - * sax.pppol2tp.addr.sin_port = addr->sin_port; - * sax.pppol2tp.addr.sin_family = AF_INET; - * sax.pppol2tp.s_tunnel = tunnel_id; - * sax.pppol2tp.s_session = session_id; - * sax.pppol2tp.d_tunnel = peer_tunnel_id; - * sax.pppol2tp.d_session = peer_session_id; - * - * session_fd = connect(fd, (struct sockaddr *)&sax, sizeof(sax)); - * - * A pppd plugin that allows PPP traffic to be carried over L2TP using - * this driver is available from the OpenL2TP project at - * http://openl2tp.sourceforge.net. - */ - -#include <linux/module.h> -#include <linux/string.h> -#include <linux/list.h> -#include <asm/uaccess.h> - -#include <linux/kernel.h> -#include <linux/spinlock.h> -#include <linux/kthread.h> -#include <linux/sched.h> -#include <linux/slab.h> -#include <linux/errno.h> -#include <linux/jiffies.h> - -#include <linux/netdevice.h> -#include <linux/net.h> -#include <linux/inetdevice.h> -#include <linux/skbuff.h> -#include <linux/init.h> -#include <linux/ip.h> -#include <linux/udp.h> -#include <linux/if_pppox.h> -#include <linux/if_pppol2tp.h> -#include <net/sock.h> -#include <linux/ppp_channel.h> -#include <linux/ppp_defs.h> -#include <linux/if_ppp.h> -#include <linux/file.h> -#include <linux/hash.h> -#include <linux/sort.h> -#include <linux/proc_fs.h> -#include <linux/nsproxy.h> -#include <net/net_namespace.h> -#include <net/netns/generic.h> -#include <net/dst.h> -#include <net/ip.h> -#include <net/udp.h> -#include <net/xfrm.h> - -#include <asm/byteorder.h> -#include <asm/atomic.h> - - -#define PPPOL2TP_DRV_VERSION "V1.0" - -/* L2TP header constants */ -#define L2TP_HDRFLAG_T 0x8000 -#define L2TP_HDRFLAG_L 0x4000 -#define L2TP_HDRFLAG_S 0x0800 -#define L2TP_HDRFLAG_O 0x0200 -#define L2TP_HDRFLAG_P 0x0100 - -#define L2TP_HDR_VER_MASK 0x000F -#define L2TP_HDR_VER 0x0002 - -/* Space for UDP, L2TP and PPP headers */ -#define PPPOL2TP_HEADER_OVERHEAD 40 - -/* Just some random numbers */ -#define L2TP_TUNNEL_MAGIC 0x42114DDA -#define L2TP_SESSION_MAGIC 0x0C04EB7D - -#define PPPOL2TP_HASH_BITS 4 -#define PPPOL2TP_HASH_SIZE (1 << PPPOL2TP_HASH_BITS) - -/* Default trace flags */ -#define PPPOL2TP_DEFAULT_DEBUG_FLAGS 0 - -#define PRINTK(_mask, _type, _lvl, _fmt, args...) \ - do { \ - if ((_mask) & (_type)) \ - printk(_lvl "PPPOL2TP: " _fmt, ##args); \ - } while(0) - -/* Number of bytes to build transmit L2TP headers. - * Unfortunately the size is different depending on whether sequence numbers - * are enabled. - */ -#define PPPOL2TP_L2TP_HDR_SIZE_SEQ 10 -#define PPPOL2TP_L2TP_HDR_SIZE_NOSEQ 6 - -struct pppol2tp_tunnel; - -/* Describes a session. It is the sk_user_data field in the PPPoL2TP - * socket. Contains information to determine incoming packets and transmit - * outgoing ones. - */ -struct pppol2tp_session -{ - int magic; /* should be - * L2TP_SESSION_MAGIC */ - int owner; /* pid that opened the socket */ - - struct sock *sock; /* Pointer to the session - * PPPoX socket */ - struct sock *tunnel_sock; /* Pointer to the tunnel UDP - * socket */ - - struct pppol2tp_addr tunnel_addr; /* Description of tunnel */ - - struct pppol2tp_tunnel *tunnel; /* back pointer to tunnel - * context */ - - char name[20]; /* "sess xxxxx/yyyyy", where - * x=tunnel_id, y=session_id */ - int mtu; - int mru; - int flags; /* accessed by PPPIOCGFLAGS. - * Unused. */ - unsigned recv_seq:1; /* expect receive packets with - * sequence numbers? */ - unsigned send_seq:1; /* send packets with sequence - * numbers? */ - unsigned lns_mode:1; /* behave as LNS? LAC enables - * sequence numbers under - * control of LNS. */ - int debug; /* bitmask of debug message - * categories */ - int reorder_timeout; /* configured reorder timeout - * (in jiffies) */ - u16 nr; /* session NR state (receive) */ - u16 ns; /* session NR state (send) */ - struct sk_buff_head reorder_q; /* receive reorder queue */ - struct pppol2tp_ioc_stats stats; - struct hlist_node hlist; /* Hash list node */ -}; - -/* The sk_user_data field of the tunnel's UDP socket. It contains info to track - * all the associated sessions so incoming packets can be sorted out - */ -struct pppol2tp_tunnel -{ - int magic; /* Should be L2TP_TUNNEL_MAGIC */ - rwlock_t hlist_lock; /* protect session_hlist */ - struct hlist_head session_hlist[PPPOL2TP_HASH_SIZE]; - /* hashed list of sessions, - * hashed by id */ - int debug; /* bitmask of debug message - * categories */ - char name[12]; /* "tunl xxxxx" */ - struct pppol2tp_ioc_stats stats; - - void (*old_sk_destruct)(struct sock *); - - struct sock *sock; /* Parent socket */ - struct list_head list; /* Keep a list of all open - * prepared sockets */ - struct net *pppol2tp_net; /* the net we belong to */ - - atomic_t ref_count; -}; - -/* Private data stored for received packets in the skb. - */ -struct pppol2tp_skb_cb { - u16 ns; - u16 nr; - u16 has_seq; - u16 length; - unsigned long expires; -}; - -#define PPPOL2TP_SKB_CB(skb) ((struct pppol2tp_skb_cb *) &skb->cb[sizeof(struct inet_skb_parm)]) - -static int pppol2tp_xmit(struct ppp_channel *chan, struct sk_buff *skb); -static void pppol2tp_tunnel_free(struct pppol2tp_tunnel *tunnel); - -static atomic_t pppol2tp_tunnel_count; -static atomic_t pppol2tp_session_count; -static struct ppp_channel_ops pppol2tp_chan_ops = { pppol2tp_xmit , NULL }; -static const struct proto_ops pppol2tp_ops; - -/* per-net private data for this module */ -static int pppol2tp_net_id __read_mostly; -struct pppol2tp_net { - struct list_head pppol2tp_tunnel_list; - rwlock_t pppol2tp_tunnel_list_lock; -}; - -static inline struct pppol2tp_net *pppol2tp_pernet(struct net *net) -{ - BUG_ON(!net); - - return net_generic(net, pppol2tp_net_id); -} - -/* Helpers to obtain tunnel/session contexts from sockets. - */ -static inline struct pppol2tp_session *pppol2tp_sock_to_session(struct sock *sk) -{ - struct pppol2tp_session *session; - - if (sk == NULL) - return NULL; - - sock_hold(sk); - session = (struct pppol2tp_session *)(sk->sk_user_data); - if (session == NULL) { - sock_put(sk); - goto out; - } - - BUG_ON(session->magic != L2TP_SESSION_MAGIC); -out: - return session; -} - -static inline struct pppol2tp_tunnel *pppol2tp_sock_to_tunnel(struct sock *sk) -{ - struct pppol2tp_tunnel *tunnel; - - if (sk == NULL) - return NULL; - - sock_hold(sk); - tunnel = (struct pppol2tp_tunnel *)(sk->sk_user_data); - if (tunnel == NULL) { - sock_put(sk); - goto out; - } - - BUG_ON(tunnel->magic != L2TP_TUNNEL_MAGIC); -out: - return tunnel; -} - -/* Tunnel reference counts. Incremented per session that is added to - * the tunnel. - */ -static inline void pppol2tp_tunnel_inc_refcount(struct pppol2tp_tunnel *tunnel) -{ - atomic_inc(&tunnel->ref_count); -} - -static inline void pppol2tp_tunnel_dec_refcount(struct pppol2tp_tunnel *tunnel) -{ - if (atomic_dec_and_test(&tunnel->ref_count)) - pppol2tp_tunnel_free(tunnel); -} - -/* Session hash list. - * The session_id SHOULD be random according to RFC2661, but several - * L2TP implementations (Cisco and Microsoft) use incrementing - * session_ids. So we do a real hash on the session_id, rather than a - * simple bitmask. - */ -static inline struct hlist_head * -pppol2tp_session_id_hash(struct pppol2tp_tunnel *tunnel, u16 session_id) -{ - unsigned long hash_val = (unsigned long) session_id; - return &tunnel->session_hlist[hash_long(hash_val, PPPOL2TP_HASH_BITS)]; -} - -/* Lookup a session by id - */ -static struct pppol2tp_session * -pppol2tp_session_find(struct pppol2tp_tunnel *tunnel, u16 session_id) -{ - struct hlist_head *session_list = - pppol2tp_session_id_hash(tunnel, session_id); - struct pppol2tp_session *session; - struct hlist_node *walk; - - read_lock_bh(&tunnel->hlist_lock); - hlist_for_each_entry(session, walk, session_list, hlist) { - if (session->tunnel_addr.s_session == session_id) { - read_unlock_bh(&tunnel->hlist_lock); - return session; - } - } - read_unlock_bh(&tunnel->hlist_lock); - - return NULL; -} - -/* Lookup a tunnel by id - */ -static struct pppol2tp_tunnel *pppol2tp_tunnel_find(struct net *net, u16 tunnel_id) -{ - struct pppol2tp_tunnel *tunnel; - struct pppol2tp_net *pn = pppol2tp_pernet(net); - - read_lock_bh(&pn->pppol2tp_tunnel_list_lock); - list_for_each_entry(tunnel, &pn->pppol2tp_tunnel_list, list) { - if (tunnel->stats.tunnel_id == tunnel_id) { - read_unlock_bh(&pn->pppol2tp_tunnel_list_lock); - return tunnel; - } - } - read_unlock_bh(&pn->pppol2tp_tunnel_list_lock); - - return NULL; -} - -/***************************************************************************** - * Receive data handling - *****************************************************************************/ - -/* Queue a skb in order. We come here only if the skb has an L2TP sequence - * number. - */ -static void pppol2tp_recv_queue_skb(struct pppol2tp_session *session, struct sk_buff *skb) -{ - struct sk_buff *skbp; - struct sk_buff *tmp; - u16 ns = PPPOL2TP_SKB_CB(skb)->ns; - - spin_lock_bh(&session->reorder_q.lock); - skb_queue_walk_safe(&session->reorder_q, skbp, tmp) { - if (PPPOL2TP_SKB_CB(skbp)->ns > ns) { - __skb_queue_before(&session->reorder_q, skbp, skb); - PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_DEBUG, - "%s: pkt %hu, inserted before %hu, reorder_q len=%d\n", - session->name, ns, PPPOL2TP_SKB_CB(skbp)->ns, - skb_queue_len(&session->reorder_q)); - session->stats.rx_oos_packets++; - goto out; - } - } - - __skb_queue_tail(&session->reorder_q, skb); - -out: - spin_unlock_bh(&session->reorder_q.lock); -} - -/* Dequeue a single skb. - */ -static void pppol2tp_recv_dequeue_skb(struct pppol2tp_session *session, struct sk_buff *skb) -{ - struct pppol2tp_tunnel *tunnel = session->tunnel; - int length = PPPOL2TP_SKB_CB(skb)->length; - struct sock *session_sock = NULL; - - /* We're about to requeue the skb, so return resources - * to its current owner (a socket receive buffer). - */ - skb_orphan(skb); - - tunnel->stats.rx_packets++; - tunnel->stats.rx_bytes += length; - session->stats.rx_packets++; - session->stats.rx_bytes += length; - - if (PPPOL2TP_SKB_CB(skb)->has_seq) { - /* Bump our Nr */ - session->nr++; - PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_DEBUG, - "%s: updated nr to %hu\n", session->name, session->nr); - } - - /* If the socket is bound, send it in to PPP's input queue. Otherwise - * queue it on the session socket. - */ - session_sock = session->sock; - if (session_sock->sk_state & PPPOX_BOUND) { - struct pppox_sock *po; - PRINTK(session->debug, PPPOL2TP_MSG_DATA, KERN_DEBUG, - "%s: recv %d byte data frame, passing to ppp\n", - session->name, length); - - /* We need to forget all info related to the L2TP packet - * gathered in the skb as we are going to reuse the same - * skb for the inner packet. - * Namely we need to: - * - reset xfrm (IPSec) information as it applies to - * the outer L2TP packet and not to the inner one - * - release the dst to force a route lookup on the inner - * IP packet since skb->dst currently points to the dst - * of the UDP tunnel - * - reset netfilter information as it doesn't apply - * to the inner packet either - */ - secpath_reset(skb); - skb_dst_drop(skb); - nf_reset(skb); - - po = pppox_sk(session_sock); - ppp_input(&po->chan, skb); - } else { - PRINTK(session->debug, PPPOL2TP_MSG_DATA, KERN_INFO, - "%s: socket not bound\n", session->name); - - /* Not bound. Nothing we can do, so discard. */ - session->stats.rx_errors++; - kfree_skb(skb); - } - - sock_put(session->sock); -} - -/* Dequeue skbs from the session's reorder_q, subject to packet order. - * Skbs that have been in the queue for too long are simply discarded. - */ -static void pppol2tp_recv_dequeue(struct pppol2tp_session *session) -{ - struct sk_buff *skb; - struct sk_buff *tmp; - - /* If the pkt at the head of the queue has the nr that we - * expect to send up next, dequeue it and any other - * in-sequence packets behind it. - */ - spin_lock_bh(&session->reorder_q.lock); - skb_queue_walk_safe(&session->reorder_q, skb, tmp) { - if (time_after(jiffies, PPPOL2TP_SKB_CB(skb)->expires)) { - session->stats.rx_seq_discards++; - session->stats.rx_errors++; - PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_DEBUG, - "%s: oos pkt %hu len %d discarded (too old), " - "waiting for %hu, reorder_q_len=%d\n", - session->name, PPPOL2TP_SKB_CB(skb)->ns, - PPPOL2TP_SKB_CB(skb)->length, session->nr, - skb_queue_len(&session->reorder_q)); - __skb_unlink(skb, &session->reorder_q); - kfree_skb(skb); - sock_put(session->sock); - continue; - } - - if (PPPOL2TP_SKB_CB(skb)->has_seq) { - if (PPPOL2TP_SKB_CB(skb)->ns != session->nr) { - PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_DEBUG, - "%s: holding oos pkt %hu len %d, " - "waiting for %hu, reorder_q_len=%d\n", - session->name, PPPOL2TP_SKB_CB(skb)->ns, - PPPOL2TP_SKB_CB(skb)->length, session->nr, - skb_queue_len(&session->reorder_q)); - goto out; - } - } - __skb_unlink(skb, &session->reorder_q); - - /* Process the skb. We release the queue lock while we - * do so to let other contexts process the queue. - */ - spin_unlock_bh(&session->reorder_q.lock); - pppol2tp_recv_dequeue_skb(session, skb); - spin_lock_bh(&session->reorder_q.lock); - } - -out: - spin_unlock_bh(&session->reorder_q.lock); -} - -static inline int pppol2tp_verify_udp_checksum(struct sock *sk, - struct sk_buff *skb) -{ - struct udphdr *uh = udp_hdr(skb); - u16 ulen = ntohs(uh->len); - struct inet_sock *inet; - __wsum psum; - - if (sk->sk_no_check || skb_csum_unnecessary(skb) || !uh->check) - return 0; - - inet = inet_sk(sk); - psum = csum_tcpudp_nofold(inet->inet_saddr, inet->inet_daddr, ulen, - IPPROTO_UDP, 0); - - if ((skb->ip_summed == CHECKSUM_COMPLETE) && - !csum_fold(csum_add(psum, skb->csum))) - return 0; - - skb->csum = psum; - - return __skb_checksum_complete(skb); -} - -/* Internal receive frame. Do the real work of receiving an L2TP data frame - * here. The skb is not on a list when we get here. - * Returns 0 if the packet was a data packet and was successfully passed on. - * Returns 1 if the packet was not a good data packet and could not be - * forwarded. All such packets are passed up to userspace to deal with. - */ -static int pppol2tp_recv_core(struct sock *sock, struct sk_buff *skb) -{ - struct pppol2tp_session *session = NULL; - struct pppol2tp_tunnel *tunnel; - unsigned char *ptr, *optr; - u16 hdrflags; - u16 tunnel_id, session_id; - int length; - int offset; - - tunnel = pppol2tp_sock_to_tunnel(sock); - if (tunnel == NULL) - goto no_tunnel; - - if (tunnel->sock && pppol2tp_verify_udp_checksum(tunnel->sock, skb)) - goto discard_bad_csum; - - /* UDP always verifies the packet length. */ - __skb_pull(skb, sizeof(struct udphdr)); - - /* Short packet? */ - if (!pskb_may_pull(skb, 12)) { - PRINTK(tunnel->debug, PPPOL2TP_MSG_DATA, KERN_INFO, - "%s: recv short packet (len=%d)\n", tunnel->name, skb->len); - goto error; - } - - /* Point to L2TP header */ - optr = ptr = skb->data; - - /* Get L2TP header flags */ - hdrflags = ntohs(*(__be16*)ptr); - - /* Trace packet contents, if enabled */ - if (tunnel->debug & PPPOL2TP_MSG_DATA) { - length = min(16u, skb->len); - if (!pskb_may_pull(skb, length)) - goto error; - - printk(KERN_DEBUG "%s: recv: ", tunnel->name); - - offset = 0; - do { - printk(" %02X", ptr[offset]); - } while (++offset < length); - - printk("\n"); - } - - /* Get length of L2TP packet */ - length = skb->len; - - /* If type is control packet, it is handled by userspace. */ - if (hdrflags & L2TP_HDRFLAG_T) { - PRINTK(tunnel->debug, PPPOL2TP_MSG_DATA, KERN_DEBUG, - "%s: recv control packet, len=%d\n", tunnel->name, length); - goto error; - } - - /* Skip flags */ - ptr += 2; - - /* If length is present, skip it */ - if (hdrflags & L2TP_HDRFLAG_L) - ptr += 2; - - /* Extract tunnel and session ID */ - tunnel_id = ntohs(*(__be16 *) ptr); - ptr += 2; - session_id = ntohs(*(__be16 *) ptr); - ptr += 2; - - /* Find the session context */ - session = pppol2tp_session_find(tunnel, session_id); - if (!session) { - /* Not found? Pass to userspace to deal with */ - PRINTK(tunnel->debug, PPPOL2TP_MSG_DATA, KERN_INFO, - "%s: no socket found (%hu/%hu). Passing up.\n", - tunnel->name, tunnel_id, session_id); - goto error; - } - sock_hold(session->sock); - - /* The ref count on the socket was increased by the above call since - * we now hold a pointer to the session. Take care to do sock_put() - * when exiting this function from now on... - */ - - /* Handle the optional sequence numbers. If we are the LAC, - * enable/disable sequence numbers under the control of the LNS. If - * no sequence numbers present but we were expecting them, discard - * frame. - */ - if (hdrflags & L2TP_HDRFLAG_S) { - u16 ns, nr; - ns = ntohs(*(__be16 *) ptr); - ptr += 2; - nr = ntohs(*(__be16 *) ptr); - ptr += 2; - - /* Received a packet with sequence numbers. If we're the LNS, - * check if we sre sending sequence numbers and if not, - * configure it so. - */ - if ((!session->lns_mode) && (!session->send_seq)) { - PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_INFO, - "%s: requested to enable seq numbers by LNS\n", - session->name); - session->send_seq = -1; - } - - /* Store L2TP info in the skb */ - PPPOL2TP_SKB_CB(skb)->ns = ns; - PPPOL2TP_SKB_CB(skb)->nr = nr; - PPPOL2TP_SKB_CB(skb)->has_seq = 1; - - PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_DEBUG, - "%s: recv data ns=%hu, nr=%hu, session nr=%hu\n", - session->name, ns, nr, session->nr); - } else { - /* No sequence numbers. - * If user has configured mandatory sequence numbers, discard. - */ - if (session->recv_seq) { - PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_WARNING, - "%s: recv data has no seq numbers when required. " - "Discarding\n", session->name); - session->stats.rx_seq_discards++; - goto discard; - } - - /* If we're the LAC and we're sending sequence numbers, the - * LNS has requested that we no longer send sequence numbers. - * If we're the LNS and we're sending sequence numbers, the - * LAC is broken. Discard the frame. - */ - if ((!session->lns_mode) && (session->send_seq)) { - PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_INFO, - "%s: requested to disable seq numbers by LNS\n", - session->name); - session->send_seq = 0; - } else if (session->send_seq) { - PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_WARNING, - "%s: recv data has no seq numbers when required. " - "Discarding\n", session->name); - session->stats.rx_seq_discards++; - goto discard; - } - - /* Store L2TP info in the skb */ - PPPOL2TP_SKB_CB(skb)->has_seq = 0; - } - - /* If offset bit set, skip it. */ - if (hdrflags & L2TP_HDRFLAG_O) { - offset = ntohs(*(__be16 *)ptr); - ptr += 2 + offset; - } - - offset = ptr - optr; - if (!pskb_may_pull(skb, offset)) - goto discard; - - __skb_pull(skb, offset); - - /* Skip PPP header, if present. In testing, Microsoft L2TP clients - * don't send the PPP header (PPP header compression enabled), but - * other clients can include the header. So we cope with both cases - * here. The PPP header is always FF03 when using L2TP. - * - * Note that skb->data[] isn't dereferenced from a u16 ptr here since - * the field may be unaligned. - */ - if (!pskb_may_pull(skb, 2)) - goto discard; - - if ((skb->data[0] == 0xff) && (skb->data[1] == 0x03)) - skb_pull(skb, 2); - - /* Prepare skb for adding to the session's reorder_q. Hold - * packets for max reorder_timeout or 1 second if not - * reordering. - */ - PPPOL2TP_SKB_CB(skb)->length = length; - PPPOL2TP_SKB_CB(skb)->expires = jiffies + - (session->reorder_timeout ? session->reorder_timeout : HZ); - - /* Add packet to the session's receive queue. Reordering is done here, if - * enabled. Saved L2TP protocol info is stored in skb->sb[]. - */ - if (PPPOL2TP_SKB_CB(skb)->has_seq) { - if (session->reorder_timeout != 0) { - /* Packet reordering enabled. Add skb to session's - * reorder queue, in order of ns. - */ - pppol2tp_recv_queue_skb(session, skb); - } else { - /* Packet reordering disabled. Discard out-of-sequence - * packets - */ - if (PPPOL2TP_SKB_CB(skb)->ns != session->nr) { - session->stats.rx_seq_discards++; - PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_DEBUG, - "%s: oos pkt %hu len %d discarded, " - "waiting for %hu, reorder_q_len=%d\n", - session->name, PPPOL2TP_SKB_CB(skb)->ns, - PPPOL2TP_SKB_CB(skb)->length, session->nr, - skb_queue_len(&session->reorder_q)); - goto discard; - } - skb_queue_tail(&session->reorder_q, skb); - } - } else { - /* No sequence numbers. Add the skb to the tail of the - * reorder queue. This ensures that it will be - * delivered after all previous sequenced skbs. - */ - skb_queue_tail(&session->reorder_q, skb); - } - - /* Try to dequeue as many skbs from reorder_q as we can. */ - pppol2tp_recv_dequeue(session); - sock_put(sock); - - return 0; - -discard: - session->stats.rx_errors++; - kfree_skb(skb); - sock_put(session->sock); - sock_put(sock); - - return 0; - -discard_bad_csum: - LIMIT_NETDEBUG("%s: UDP: bad checksum\n", tunnel->name); - UDP_INC_STATS_USER(&init_net, UDP_MIB_INERRORS, 0); - tunnel->stats.rx_errors++; - kfree_skb(skb); - sock_put(sock); - - return 0; - -error: - /* Put UDP header back */ - __skb_push(skb, sizeof(struct udphdr)); - sock_put(sock); - -no_tunnel: - return 1; -} - -/* UDP encapsulation receive handler. See net/ipv4/udp.c. - * Return codes: - * 0 : success. - * <0: error - * >0: skb should be passed up to userspace as UDP. - */ -static int pppol2tp_udp_encap_recv(struct sock *sk, struct sk_buff *skb) -{ - struct pppol2tp_tunnel *tunnel; - - tunnel = pppol2tp_sock_to_tunnel(sk); - if (tunnel == NULL) - goto pass_up; - - PRINTK(tunnel->debug, PPPOL2TP_MSG_DATA, KERN_DEBUG, - "%s: received %d bytes\n", tunnel->name, skb->len); - - if (pppol2tp_recv_core(sk, skb)) - goto pass_up_put; - - sock_put(sk); - return 0; - -pass_up_put: - sock_put(sk); -pass_up: - return 1; -} - -/* Receive message. This is the recvmsg for the PPPoL2TP socket. - */ -static int pppol2tp_recvmsg(struct kiocb *iocb, struct socket *sock, - struct msghdr *msg, size_t len, - int flags) -{ - int err; - struct sk_buff *skb; - struct sock *sk = sock->sk; - - err = -EIO; - if (sk->sk_state & PPPOX_BOUND) - goto end; - - msg->msg_namelen = 0; - - err = 0; - skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT, - flags & MSG_DONTWAIT, &err); - if (!skb) - goto end; - - if (len > skb->len) - len = skb->len; - else if (len < skb->len) - msg->msg_flags |= MSG_TRUNC; - - err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, len); - if (likely(err == 0)) - err = len; - - kfree_skb(skb); -end: - return err; -} - -/************************************************************************ - * Transmit handling - ***********************************************************************/ - -/* Tell how big L2TP headers are for a particular session. This - * depends on whether sequence numbers are being used. - */ -static inline int pppol2tp_l2tp_header_len(struct pppol2tp_session *session) -{ - if (session->send_seq) - return PPPOL2TP_L2TP_HDR_SIZE_SEQ; - - return PPPOL2TP_L2TP_HDR_SIZE_NOSEQ; -} - -/* Build an L2TP header for the session into the buffer provided. - */ -static void pppol2tp_build_l2tp_header(struct pppol2tp_session *session, - void *buf) -{ - __be16 *bufp = buf; - u16 flags = L2TP_HDR_VER; - - if (session->send_seq) - flags |= L2TP_HDRFLAG_S; - - /* Setup L2TP header. - * FIXME: Can this ever be unaligned? Is direct dereferencing of - * 16-bit header fields safe here for all architectures? - */ - *bufp++ = htons(flags); - *bufp++ = htons(session->tunnel_addr.d_tunnel); - *bufp++ = htons(session->tunnel_addr.d_session); - if (session->send_seq) { - *bufp++ = htons(session->ns); - *bufp++ = 0; - session->ns++; - PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_DEBUG, - "%s: updated ns to %hu\n", session->name, session->ns); - } -} - -/* This is the sendmsg for the PPPoL2TP pppol2tp_session socket. We come here - * when a user application does a sendmsg() on the session socket. L2TP and - * PPP headers must be inserted into the user's data. - */ -static int pppol2tp_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *m, - size_t total_len) -{ - static const unsigned char ppph[2] = { 0xff, 0x03 }; - struct sock *sk = sock->sk; - struct inet_sock *inet; - __wsum csum; - struct sk_buff *skb; - int error; - int hdr_len; - struct pppol2tp_session *session; - struct pppol2tp_tunnel *tunnel; - struct udphdr *uh; - unsigned int len; - struct sock *sk_tun; - u16 udp_len; - - error = -ENOTCONN; - if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED)) - goto error; - - /* Get session and tunnel contexts */ - error = -EBADF; - session = pppol2tp_sock_to_session(sk); - if (session == NULL) - goto error; - - sk_tun = session->tunnel_sock; - tunnel = pppol2tp_sock_to_tunnel(sk_tun); - if (tunnel == NULL) - goto error_put_sess; - - /* What header length is configured for this session? */ - hdr_len = pppol2tp_l2tp_header_len(session); - - /* Allocate a socket buffer */ - error = -ENOMEM; - skb = sock_wmalloc(sk, NET_SKB_PAD + sizeof(struct iphdr) + - sizeof(struct udphdr) + hdr_len + - sizeof(ppph) + total_len, - 0, GFP_KERNEL); - if (!skb) - goto error_put_sess_tun; - - /* Reserve space for headers. */ - skb_reserve(skb, NET_SKB_PAD); - skb_reset_network_header(skb); - skb_reserve(skb, sizeof(struct iphdr)); - skb_reset_transport_header(skb); - - /* Build UDP header */ - inet = inet_sk(sk_tun); - udp_len = hdr_len + sizeof(ppph) + total_len; - uh = (struct udphdr *) skb->data; - uh->source = inet->inet_sport; - uh->dest = inet->inet_dport; - uh->len = htons(udp_len); - uh->check = 0; - skb_put(skb, sizeof(struct udphdr)); - - /* Build L2TP header */ - pppol2tp_build_l2tp_header(session, skb->data); - skb_put(skb, hdr_len); - - /* Add PPP header */ - skb->data[0] = ppph[0]; - skb->data[1] = ppph[1]; - skb_put(skb, 2); - - /* Copy user data into skb */ - error = memcpy_fromiovec(skb->data, m->msg_iov, total_len); - if (error < 0) { - kfree_skb(skb); - goto error_put_sess_tun; - } - skb_put(skb, total_len); - - /* Calculate UDP checksum if configured to do so */ - if (sk_tun->sk_no_check == UDP_CSUM_NOXMIT) - skb->ip_summed = CHECKSUM_NONE; - else if (!(skb_dst(skb)->dev->features & NETIF_F_V4_CSUM)) { - skb->ip_summed = CHECKSUM_COMPLETE; - csum = skb_checksum(skb, 0, udp_len, 0); - uh->check = csum_tcpudp_magic(inet->inet_saddr, - inet->inet_daddr, - udp_len, IPPROTO_UDP, csum); - if (uh->check == 0) - uh->check = CSUM_MANGLED_0; - } else { - skb->ip_summed = CHECKSUM_PARTIAL; - skb->csum_start = skb_transport_header(skb) - skb->head; - skb->csum_offset = offsetof(struct udphdr, check); - uh->check = ~csum_tcpudp_magic(inet->inet_saddr, - inet->inet_daddr, - udp_len, IPPROTO_UDP, 0); - } - - /* Debug */ - if (session->send_seq) - PRINTK(session->debug, PPPOL2TP_MSG_DATA, KERN_DEBUG, - "%s: send %Zd bytes, ns=%hu\n", session->name, - total_len, session->ns - 1); - else - PRINTK(session->debug, PPPOL2TP_MSG_DATA, KERN_DEBUG, - "%s: send %Zd bytes\n", session->name, total_len); - - if (session->debug & PPPOL2TP_MSG_DATA) { - int i; - unsigned char *datap = skb->data; - - printk(KERN_DEBUG "%s: xmit:", session->name); - for (i = 0; i < total_len; i++) { - printk(" %02X", *datap++); - if (i == 15) { - printk(" ..."); - break; - } - } - printk("\n"); - } - - /* Queue the packet to IP for output */ - len = skb->len; - error = ip_queue_xmit(skb, 1); - - /* Update stats */ - if (error >= 0) { - tunnel->stats.tx_packets++; - tunnel->stats.tx_bytes += len; - session->stats.tx_packets++; - session->stats.tx_bytes += len; - } else { - tunnel->stats.tx_errors++; - session->stats.tx_errors++; - } - - return error; - -error_put_sess_tun: - sock_put(session->tunnel_sock); -error_put_sess: - sock_put(sk); -error: - return error; -} - -/* Automatically called when the skb is freed. - */ -static void pppol2tp_sock_wfree(struct sk_buff *skb) -{ - sock_put(skb->sk); -} - -/* For data skbs that we transmit, we associate with the tunnel socket - * but don't do accounting. - */ -static inline void pppol2tp_skb_set_owner_w(struct sk_buff *skb, struct sock *sk) -{ - sock_hold(sk); - skb->sk = sk; - skb->destructor = pppol2tp_sock_wfree; -} - -/* Transmit function called by generic PPP driver. Sends PPP frame - * over PPPoL2TP socket. - * - * This is almost the same as pppol2tp_sendmsg(), but rather than - * being called with a msghdr from userspace, it is called with a skb - * from the kernel. - * - * The supplied skb from ppp doesn't have enough headroom for the - * insertion of L2TP, UDP and IP headers so we need to allocate more - * headroom in the skb. This will create a cloned skb. But we must be - * careful in the error case because the caller will expect to free - * the skb it supplied, not our cloned skb. So we take care to always - * leave the original skb unfreed if we return an error. - */ -static int pppol2tp_xmit(struct ppp_channel *chan, struct sk_buff *skb) -{ - static const u8 ppph[2] = { 0xff, 0x03 }; - struct sock *sk = (struct sock *) chan->private; - struct sock *sk_tun; - int hdr_len; - u16 udp_len; - struct pppol2tp_session *session; - struct pppol2tp_tunnel *tunnel; - int rc; - int headroom; - int data_len = skb->len; - struct inet_sock *inet; - __wsum csum; - struct udphdr *uh; - unsigned int len; - int old_headroom; - int new_headroom; - - if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED)) - goto abort; - - /* Get session and tunnel contexts from the socket */ - session = pppol2tp_sock_to_session(sk); - if (session == NULL) - goto abort; - - sk_tun = session->tunnel_sock; - if (sk_tun == NULL) - goto abort_put_sess; - tunnel = pppol2tp_sock_to_tunnel(sk_tun); - if (tunnel == NULL) - goto abort_put_sess; - - /* What header length is configured for this session? */ - hdr_len = pppol2tp_l2tp_header_len(session); - - /* Check that there's enough headroom in the skb to insert IP, - * UDP and L2TP and PPP headers. If not enough, expand it to - * make room. Adjust truesize. - */ - headroom = NET_SKB_PAD + sizeof(struct iphdr) + - sizeof(struct udphdr) + hdr_len + sizeof(ppph); - old_headroom = skb_headroom(skb); - if (skb_cow_head(skb, headroom)) - goto abort_put_sess_tun; - - new_headroom = skb_headroom(skb); - skb_orphan(skb); - skb->truesize += new_headroom - old_headroom; - - /* Setup PPP header */ - __skb_push(skb, sizeof(ppph)); - skb->data[0] = ppph[0]; - skb->data[1] = ppph[1]; - - /* Setup L2TP header */ - pppol2tp_build_l2tp_header(session, __skb_push(skb, hdr_len)); - - udp_len = sizeof(struct udphdr) + hdr_len + sizeof(ppph) + data_len; - - /* Setup UDP header */ - inet = inet_sk(sk_tun); - __skb_push(skb, sizeof(*uh)); - skb_reset_transport_header(skb); - uh = udp_hdr(skb); - uh->source = inet->inet_sport; - uh->dest = inet->inet_dport; - uh->len = htons(udp_len); - uh->check = 0; - - /* Debug */ - if (session->send_seq) - PRINTK(session->debug, PPPOL2TP_MSG_DATA, KERN_DEBUG, - "%s: send %d bytes, ns=%hu\n", session->name, - data_len, session->ns - 1); - else - PRINTK(session->debug, PPPOL2TP_MSG_DATA, KERN_DEBUG, - "%s: send %d bytes\n", session->name, data_len); - - if (session->debug & PPPOL2TP_MSG_DATA) { - int i; - unsigned char *datap = skb->data; - - printk(KERN_DEBUG "%s: xmit:", session->name); - for (i = 0; i < data_len; i++) { - printk(" %02X", *datap++); - if (i == 31) { - printk(" ..."); - break; - } - } - printk("\n"); - } - - memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); - IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED | - IPSKB_REROUTED); - nf_reset(skb); - - /* Get routing info from the tunnel socket */ - skb_dst_drop(skb); - skb_dst_set(skb, dst_clone(__sk_dst_get(sk_tun))); - pppol2tp_skb_set_owner_w(skb, sk_tun); - - /* Calculate UDP checksum if configured to do so */ - if (sk_tun->sk_no_check == UDP_CSUM_NOXMIT) - skb->ip_summed = CHECKSUM_NONE; - else if ((skb_dst(skb) && skb_dst(skb)->dev) && - (!(skb_dst(skb)->dev->features & NETIF_F_V4_CSUM))) { - skb->ip_summed = CHECKSUM_COMPLETE; - csum = skb_checksum(skb, 0, udp_len, 0); - uh->check = csum_tcpudp_magic(inet->inet_saddr, - inet->inet_daddr, - udp_len, IPPROTO_UDP, csum); - if (uh->check == 0) - uh->check = CSUM_MANGLED_0; - } else { - skb->ip_summed = CHECKSUM_PARTIAL; - skb->csum_start = skb_transport_header(skb) - skb->head; - skb->csum_offset = offsetof(struct udphdr, check); - uh->check = ~csum_tcpudp_magic(inet->inet_saddr, - inet->inet_daddr, - udp_len, IPPROTO_UDP, 0); - } - - /* Queue the packet to IP for output */ - len = skb->len; - rc = ip_queue_xmit(skb, 1); - - /* Update stats */ - if (rc >= 0) { - tunnel->stats.tx_packets++; - tunnel->stats.tx_bytes += len; - session->stats.tx_packets++; - session->stats.tx_bytes += len; - } else { - tunnel->stats.tx_errors++; - session->stats.tx_errors++; - } - - sock_put(sk_tun); - sock_put(sk); - return 1; - -abort_put_sess_tun: - sock_put(sk_tun); -abort_put_sess: - sock_put(sk); -abort: - /* Free the original skb */ - kfree_skb(skb); - return 1; -} - -/***************************************************************************** - * Session (and tunnel control) socket create/destroy. - *****************************************************************************/ - -/* When the tunnel UDP socket is closed, all the attached sockets need to go - * too. - */ -static void pppol2tp_tunnel_closeall(struct pppol2tp_tunnel *tunnel) -{ - int hash; - struct hlist_node *walk; - struct hlist_node *tmp; - struct pppol2tp_session *session; - struct sock *sk; - - BUG_ON(tunnel == NULL); - - PRINTK(tunnel->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO, - "%s: closing all sessions...\n", tunnel->name); - - write_lock_bh(&tunnel->hlist_lock); - for (hash = 0; hash < PPPOL2TP_HASH_SIZE; hash++) { -again: - hlist_for_each_safe(walk, tmp, &tunnel->session_hlist[hash]) { - struct sk_buff *skb; - - session = hlist_entry(walk, struct pppol2tp_session, hlist); - - sk = session->sock; - - PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO, - "%s: closing session\n", session->name); - - hlist_del_init(&session->hlist); - - /* Since we should hold the sock lock while - * doing any unbinding, we need to release the - * lock we're holding before taking that lock. - * Hold a reference to the sock so it doesn't - * disappear as we're jumping between locks. - */ - sock_hold(sk); - write_unlock_bh(&tunnel->hlist_lock); - lock_sock(sk); - - if (sk->sk_state & (PPPOX_CONNECTED | PPPOX_BOUND)) { - pppox_unbind_sock(sk); - sk->sk_state = PPPOX_DEAD; - sk->sk_state_change(sk); - } - - /* Purge any queued data */ - skb_queue_purge(&sk->sk_receive_queue); - skb_queue_purge(&sk->sk_write_queue); - while ((skb = skb_dequeue(&session->reorder_q))) { - kfree_skb(skb); - sock_put(sk); - } - - release_sock(sk); - sock_put(sk); - - /* Now restart from the beginning of this hash - * chain. We always remove a session from the - * list so we are guaranteed to make forward - * progress. - */ - write_lock_bh(&tunnel->hlist_lock); - goto again; - } - } - write_unlock_bh(&tunnel->hlist_lock); -} - -/* Really kill the tunnel. - * Come here only when all sessions have been cleared from the tunnel. - */ -static void pppol2tp_tunnel_free(struct pppol2tp_tunnel *tunnel) -{ - struct pppol2tp_net *pn = pppol2tp_pernet(tunnel->pppol2tp_net); - - /* Remove from socket list */ - write_lock_bh(&pn->pppol2tp_tunnel_list_lock); - list_del_init(&tunnel->list); - write_unlock_bh(&pn->pppol2tp_tunnel_list_lock); - - atomic_dec(&pppol2tp_tunnel_count); - kfree(tunnel); -} - -/* Tunnel UDP socket destruct hook. - * The tunnel context is deleted only when all session sockets have been - * closed. - */ -static void pppol2tp_tunnel_destruct(struct sock *sk) -{ - struct pppol2tp_tunnel *tunnel; - - tunnel = sk->sk_user_data; - if (tunnel == NULL) - goto end; - - PRINTK(tunnel->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO, - "%s: closing...\n", tunnel->name); - - /* Close all sessions */ - pppol2tp_tunnel_closeall(tunnel); - - /* No longer an encapsulation socket. See net/ipv4/udp.c */ - (udp_sk(sk))->encap_type = 0; - (udp_sk(sk))->encap_rcv = NULL; - - /* Remove hooks into tunnel socket */ - tunnel->sock = NULL; - sk->sk_destruct = tunnel->old_sk_destruct; - sk->sk_user_data = NULL; - - /* Call original (UDP) socket descructor */ - if (sk->sk_destruct != NULL) - (*sk->sk_destruct)(sk); - - pppol2tp_tunnel_dec_refcount(tunnel); - -end: - return; -} - -/* Really kill the session socket. (Called from sock_put() if - * refcnt == 0.) - */ -static void pppol2tp_session_destruct(struct sock *sk) -{ - struct pppol2tp_session *session = NULL; - - if (sk->sk_user_data != NULL) { - struct pppol2tp_tunnel *tunnel; - - session = sk->sk_user_data; - if (session == NULL) - goto out; - - BUG_ON(session->magic != L2TP_SESSION_MAGIC); - - /* Don't use pppol2tp_sock_to_tunnel() here to - * get the tunnel context because the tunnel - * socket might have already been closed (its - * sk->sk_user_data will be NULL) so use the - * session's private tunnel ptr instead. - */ - tunnel = session->tunnel; - if (tunnel != NULL) { - BUG_ON(tunnel->magic != L2TP_TUNNEL_MAGIC); - - /* If session_id is zero, this is a null - * session context, which was created for a - * socket that is being used only to manage - * tunnels. - */ - if (session->tunnel_addr.s_session != 0) { - /* Delete the session socket from the - * hash - */ - write_lock_bh(&tunnel->hlist_lock); - hlist_del_init(&session->hlist); - write_unlock_bh(&tunnel->hlist_lock); - - atomic_dec(&pppol2tp_session_count); - } - - /* This will delete the tunnel context if this - * is the last session on the tunnel. - */ - session->tunnel = NULL; - session->tunnel_sock = NULL; - pppol2tp_tunnel_dec_refcount(tunnel); - } - } - - kfree(session); -out: - return; -} - -/* Called when the PPPoX socket (session) is closed. - */ -static int pppol2tp_release(struct socket *sock) -{ - struct sock *sk = sock->sk; - struct pppol2tp_session *session; - int error; - - if (!sk) - return 0; - - error = -EBADF; - lock_sock(sk); - if (sock_flag(sk, SOCK_DEAD) != 0) - goto error; - - pppox_unbind_sock(sk); - - /* Signal the death of the socket. */ - sk->sk_state = PPPOX_DEAD; - sock_orphan(sk); - sock->sk = NULL; - - session = pppol2tp_sock_to_session(sk); - - /* Purge any queued data */ - skb_queue_purge(&sk->sk_receive_queue); - skb_queue_purge(&sk->sk_write_queue); - if (session != NULL) { - struct sk_buff *skb; - while ((skb = skb_dequeue(&session->reorder_q))) { - kfree_skb(skb); - sock_put(sk); - } - sock_put(sk); - } - - release_sock(sk); - - /* This will delete the session context via - * pppol2tp_session_destruct() if the socket's refcnt drops to - * zero. - */ - sock_put(sk); - - return 0; - -error: - release_sock(sk); - return error; -} - -/* Internal function to prepare a tunnel (UDP) socket to have PPPoX - * sockets attached to it. - */ -static struct sock *pppol2tp_prepare_tunnel_socket(struct net *net, - int fd, u16 tunnel_id, int *error) -{ - int err; - struct socket *sock = NULL; - struct sock *sk; - struct pppol2tp_tunnel *tunnel; - struct pppol2tp_net *pn; - struct sock *ret = NULL; - - /* Get the tunnel UDP socket from the fd, which was opened by - * the userspace L2TP daemon. - */ - err = -EBADF; - sock = sockfd_lookup(fd, &err); - if (!sock) { - PRINTK(-1, PPPOL2TP_MSG_CONTROL, KERN_ERR, - "tunl %hu: sockfd_lookup(fd=%d) returned %d\n", - tunnel_id, fd, err); - goto err; - } - - sk = sock->sk; - - /* Quick sanity checks */ - err = -EPROTONOSUPPORT; - if (sk->sk_protocol != IPPROTO_UDP) { - PRINTK(-1, PPPOL2TP_MSG_CONTROL, KERN_ERR, - "tunl %hu: fd %d wrong protocol, got %d, expected %d\n", - tunnel_id, fd, sk->sk_protocol, IPPROTO_UDP); - goto err; - } - err = -EAFNOSUPPORT; - if (sock->ops->family != AF_INET) { - PRINTK(-1, PPPOL2TP_MSG_CONTROL, KERN_ERR, - "tunl %hu: fd %d wrong family, got %d, expected %d\n", - tunnel_id, fd, sock->ops->family, AF_INET); - goto err; - } - - err = -ENOTCONN; - - /* Check if this socket has already been prepped */ - tunnel = (struct pppol2tp_tunnel *)sk->sk_user_data; - if (tunnel != NULL) { - /* User-data field already set */ - err = -EBUSY; - BUG_ON(tunnel->magic != L2TP_TUNNEL_MAGIC); - - /* This socket has already been prepped */ - ret = tunnel->sock; - goto out; - } - - /* This socket is available and needs prepping. Create a new tunnel - * context and init it. - */ - sk->sk_user_data = tunnel = kzalloc(sizeof(struct pppol2tp_tunnel), GFP_KERNEL); - if (sk->sk_user_data == NULL) { - err = -ENOMEM; - goto err; - } - - tunnel->magic = L2TP_TUNNEL_MAGIC; - sprintf(&tunnel->name[0], "tunl %hu", tunnel_id); - - tunnel->stats.tunnel_id = tunnel_id; - tunnel->debug = PPPOL2TP_DEFAULT_DEBUG_FLAGS; - - /* Hook on the tunnel socket destructor so that we can cleanup - * if the tunnel socket goes away. - */ - tunnel->old_sk_destruct = sk->sk_destruct; - sk->sk_destruct = pppol2tp_tunnel_destruct; - - tunnel->sock = sk; - sk->sk_allocation = GFP_ATOMIC; - - /* Misc init */ - rwlock_init(&tunnel->hlist_lock); - - /* The net we belong to */ - tunnel->pppol2tp_net = net; - pn = pppol2tp_pernet(net); - - /* Add tunnel to our list */ - INIT_LIST_HEAD(&tunnel->list); - write_lock_bh(&pn->pppol2tp_tunnel_list_lock); - list_add(&tunnel->list, &pn->pppol2tp_tunnel_list); - write_unlock_bh(&pn->pppol2tp_tunnel_list_lock); - atomic_inc(&pppol2tp_tunnel_count); - - /* Bump the reference count. The tunnel context is deleted - * only when this drops to zero. - */ - pppol2tp_tunnel_inc_refcount(tunnel); - - /* Mark socket as an encapsulation socket. See net/ipv4/udp.c */ - (udp_sk(sk))->encap_type = UDP_ENCAP_L2TPINUDP; - (udp_sk(sk))->encap_rcv = pppol2tp_udp_encap_recv; - - ret = tunnel->sock; - - *error = 0; -out: - if (sock) - sockfd_put(sock); - - return ret; - -err: - *error = err; - goto out; -} - -static struct proto pppol2tp_sk_proto = { - .name = "PPPOL2TP", - .owner = THIS_MODULE, - .obj_size = sizeof(struct pppox_sock), -}; - -/* socket() handler. Initialize a new struct sock. - */ -static int pppol2tp_create(struct net *net, struct socket *sock) -{ - int error = -ENOMEM; - struct sock *sk; - - sk = sk_alloc(net, PF_PPPOX, GFP_KERNEL, &pppol2tp_sk_proto); - if (!sk) - goto out; - - sock_init_data(sock, sk); - - sock->state = SS_UNCONNECTED; - sock->ops = &pppol2tp_ops; - - sk->sk_backlog_rcv = pppol2tp_recv_core; - sk->sk_protocol = PX_PROTO_OL2TP; - sk->sk_family = PF_PPPOX; - sk->sk_state = PPPOX_NONE; - sk->sk_type = SOCK_STREAM; - sk->sk_destruct = pppol2tp_session_destruct; - - error = 0; - -out: - return error; -} - -/* connect() handler. Attach a PPPoX socket to a tunnel UDP socket - */ -static int pppol2tp_connect(struct socket *sock, struct sockaddr *uservaddr, - int sockaddr_len, int flags) -{ - struct sock *sk = sock->sk; - struct sockaddr_pppol2tp *sp = (struct sockaddr_pppol2tp *) uservaddr; - struct pppox_sock *po = pppox_sk(sk); - struct sock *tunnel_sock = NULL; - struct pppol2tp_session *session = NULL; - struct pppol2tp_tunnel *tunnel; - struct dst_entry *dst; - int error = 0; - - lock_sock(sk); - - error = -EINVAL; - if (sp->sa_protocol != PX_PROTO_OL2TP) - goto end; - - /* Check for already bound sockets */ - error = -EBUSY; - if (sk->sk_state & PPPOX_CONNECTED) - goto end; - - /* We don't supporting rebinding anyway */ - error = -EALREADY; - if (sk->sk_user_data) - goto end; /* socket is already attached */ - - /* Don't bind if s_tunnel is 0 */ - error = -EINVAL; - if (sp->pppol2tp.s_tunnel == 0) - goto end; - - /* Special case: prepare tunnel socket if s_session and - * d_session is 0. Otherwise look up tunnel using supplied - * tunnel id. - */ - if ((sp->pppol2tp.s_session == 0) && (sp->pppol2tp.d_session == 0)) { - tunnel_sock = pppol2tp_prepare_tunnel_socket(sock_net(sk), - sp->pppol2tp.fd, - sp->pppol2tp.s_tunnel, - &error); - if (tunnel_sock == NULL) - goto end; - - sock_hold(tunnel_sock); - tunnel = tunnel_sock->sk_user_data; - } else { - tunnel = pppol2tp_tunnel_find(sock_net(sk), sp->pppol2tp.s_tunnel); - - /* Error if we can't find the tunnel */ - error = -ENOENT; - if (tunnel == NULL) - goto end; - - tunnel_sock = tunnel->sock; - } - - /* Check that this session doesn't already exist */ - error = -EEXIST; - session = pppol2tp_session_find(tunnel, sp->pppol2tp.s_session); - if (session != NULL) - goto end; - - /* Allocate and initialize a new session context. */ - session = kzalloc(sizeof(struct pppol2tp_session), GFP_KERNEL); - if (session == NULL) { - error = -ENOMEM; - goto end; - } - - skb_queue_head_init(&session->reorder_q); - - session->magic = L2TP_SESSION_MAGIC; - session->owner = current->pid; - session->sock = sk; - session->tunnel = tunnel; - session->tunnel_sock = tunnel_sock; - session->tunnel_addr = sp->pppol2tp; - sprintf(&session->name[0], "sess %hu/%hu", - session->tunnel_addr.s_tunnel, - session->tunnel_addr.s_session); - - session->stats.tunnel_id = session->tunnel_addr.s_tunnel; - session->stats.session_id = session->tunnel_addr.s_session; - - INIT_HLIST_NODE(&session->hlist); - - /* Inherit debug options from tunnel */ - session->debug = tunnel->debug; - - /* Default MTU must allow space for UDP/L2TP/PPP - * headers. - */ - session->mtu = session->mru = 1500 - PPPOL2TP_HEADER_OVERHEAD; - - /* If PMTU discovery was enabled, use the MTU that was discovered */ - dst = sk_dst_get(sk); - if (dst != NULL) { - u32 pmtu = dst_mtu(__sk_dst_get(sk)); - if (pmtu != 0) - session->mtu = session->mru = pmtu - - PPPOL2TP_HEADER_OVERHEAD; - dst_release(dst); - } - - /* Special case: if source & dest session_id == 0x0000, this socket is - * being created to manage the tunnel. Don't add the session to the - * session hash list, just set up the internal context for use by - * ioctl() and sockopt() handlers. - */ - if ((session->tunnel_addr.s_session == 0) && - (session->tunnel_addr.d_session == 0)) { - error = 0; - sk->sk_user_data = session; - goto out_no_ppp; - } - - /* Get tunnel context from the tunnel socket */ - tunnel = pppol2tp_sock_to_tunnel(tunnel_sock); - if (tunnel == NULL) { - error = -EBADF; - goto end; - } - - /* Right now, because we don't have a way to push the incoming skb's - * straight through the UDP layer, the only header we need to worry - * about is the L2TP header. This size is different depending on - * whether sequence numbers are enabled for the data channel. - */ - po->chan.hdrlen = PPPOL2TP_L2TP_HDR_SIZE_NOSEQ; - - po->chan.private = sk; - po->chan.ops = &pppol2tp_chan_ops; - po->chan.mtu = session->mtu; - - error = ppp_register_net_channel(sock_net(sk), &po->chan); - if (error) - goto end_put_tun; - - /* This is how we get the session context from the socket. */ - sk->sk_user_data = session; - - /* Add session to the tunnel's hash list */ - write_lock_bh(&tunnel->hlist_lock); - hlist_add_head(&session->hlist, - pppol2tp_session_id_hash(tunnel, - session->tunnel_addr.s_session)); - write_unlock_bh(&tunnel->hlist_lock); - - atomic_inc(&pppol2tp_session_count); - -out_no_ppp: - pppol2tp_tunnel_inc_refcount(tunnel); - sk->sk_state = PPPOX_CONNECTED; - PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO, - "%s: created\n", session->name); - -end_put_tun: - sock_put(tunnel_sock); -end: - release_sock(sk); - - if (error != 0) { - if (session) - PRINTK(session->debug, - PPPOL2TP_MSG_CONTROL, KERN_WARNING, - "%s: connect failed: %d\n", - session->name, error); - else - PRINTK(-1, PPPOL2TP_MSG_CONTROL, KERN_WARNING, - "connect failed: %d\n", error); - } - - return error; -} - -/* getname() support. - */ -static int pppol2tp_getname(struct socket *sock, struct sockaddr *uaddr, - int *usockaddr_len, int peer) -{ - int len = sizeof(struct sockaddr_pppol2tp); - struct sockaddr_pppol2tp sp; - int error = 0; - struct pppol2tp_session *session; - - error = -ENOTCONN; - if (sock->sk->sk_state != PPPOX_CONNECTED) - goto end; - - session = pppol2tp_sock_to_session(sock->sk); - if (session == NULL) { - error = -EBADF; - goto end; - } - - sp.sa_family = AF_PPPOX; - sp.sa_protocol = PX_PROTO_OL2TP; - memcpy(&sp.pppol2tp, &session->tunnel_addr, - sizeof(struct pppol2tp_addr)); - - memcpy(uaddr, &sp, len); - - *usockaddr_len = len; - - error = 0; - sock_put(sock->sk); - -end: - return error; -} - -/**************************************************************************** - * ioctl() handlers. - * - * The PPPoX socket is created for L2TP sessions: tunnels have their own UDP - * sockets. However, in order to control kernel tunnel features, we allow - * userspace to create a special "tunnel" PPPoX socket which is used for - * control only. Tunnel PPPoX sockets have session_id == 0 and simply allow - * the user application to issue L2TP setsockopt(), getsockopt() and ioctl() - * calls. - ****************************************************************************/ - -/* Session ioctl helper. - */ -static int pppol2tp_session_ioctl(struct pppol2tp_session *session, - unsigned int cmd, unsigned long arg) -{ - struct ifreq ifr; - int err = 0; - struct sock *sk = session->sock; - int val = (int) arg; - - PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_DEBUG, - "%s: pppol2tp_session_ioctl(cmd=%#x, arg=%#lx)\n", - session->name, cmd, arg); - - sock_hold(sk); - - switch (cmd) { - case SIOCGIFMTU: - err = -ENXIO; - if (!(sk->sk_state & PPPOX_CONNECTED)) - break; - - err = -EFAULT; - if (copy_from_user(&ifr, (void __user *) arg, sizeof(struct ifreq))) - break; - ifr.ifr_mtu = session->mtu; - if (copy_to_user((void __user *) arg, &ifr, sizeof(struct ifreq))) - break; - - PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO, - "%s: get mtu=%d\n", session->name, session->mtu); - err = 0; - break; - - case SIOCSIFMTU: - err = -ENXIO; - if (!(sk->sk_state & PPPOX_CONNECTED)) - break; - - err = -EFAULT; - if (copy_from_user(&ifr, (void __user *) arg, sizeof(struct ifreq))) - break; - - session->mtu = ifr.ifr_mtu; - - PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO, - "%s: set mtu=%d\n", session->name, session->mtu); - err = 0; - break; - - case PPPIOCGMRU: - err = -ENXIO; - if (!(sk->sk_state & PPPOX_CONNECTED)) - break; - - err = -EFAULT; - if (put_user(session->mru, (int __user *) arg)) - break; - - PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO, - "%s: get mru=%d\n", session->name, session->mru); - err = 0; - break; - - case PPPIOCSMRU: - err = -ENXIO; - if (!(sk->sk_state & PPPOX_CONNECTED)) - break; - - err = -EFAULT; - if (get_user(val,(int __user *) arg)) - break; - - session->mru = val; - PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO, - "%s: set mru=%d\n", session->name, session->mru); - err = 0; - break; - - case PPPIOCGFLAGS: - err = -EFAULT; - if (put_user(session->flags, (int __user *) arg)) - break; - - PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO, - "%s: get flags=%d\n", session->name, session->flags); - err = 0; - break; - - case PPPIOCSFLAGS: - err = -EFAULT; - if (get_user(val, (int __user *) arg)) - break; - session->flags = val; - PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO, - "%s: set flags=%d\n", session->name, session->flags); - err = 0; - break; - - case PPPIOCGL2TPSTATS: - err = -ENXIO; - if (!(sk->sk_state & PPPOX_CONNECTED)) - break; - - if (copy_to_user((void __user *) arg, &session->stats, - sizeof(session->stats))) - break; - PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO, - "%s: get L2TP stats\n", session->name); - err = 0; - break; - - default: - err = -ENOSYS; - break; - } - - sock_put(sk); - - return err; -} - -/* Tunnel ioctl helper. - * - * Note the special handling for PPPIOCGL2TPSTATS below. If the ioctl data - * specifies a session_id, the session ioctl handler is called. This allows an - * application to retrieve session stats via a tunnel socket. - */ -static int pppol2tp_tunnel_ioctl(struct pppol2tp_tunnel *tunnel, - unsigned int cmd, unsigned long arg) -{ - int err = 0; - struct sock *sk = tunnel->sock; - struct pppol2tp_ioc_stats stats_req; - - PRINTK(tunnel->debug, PPPOL2TP_MSG_CONTROL, KERN_DEBUG, - "%s: pppol2tp_tunnel_ioctl(cmd=%#x, arg=%#lx)\n", tunnel->name, - cmd, arg); - - sock_hold(sk); - - switch (cmd) { - case PPPIOCGL2TPSTATS: - err = -ENXIO; - if (!(sk->sk_state & PPPOX_CONNECTED)) - break; - - if (copy_from_user(&stats_req, (void __user *) arg, - sizeof(stats_req))) { - err = -EFAULT; - break; - } - if (stats_req.session_id != 0) { - /* resend to session ioctl handler */ - struct pppol2tp_session *session = - pppol2tp_session_find(tunnel, stats_req.session_id); - if (session != NULL) - err = pppol2tp_session_ioctl(session, cmd, arg); - else - err = -EBADR; - break; - } -#ifdef CONFIG_XFRM - tunnel->stats.using_ipsec = (sk->sk_policy[0] || sk->sk_policy[1]) ? 1 : 0; -#endif - if (copy_to_user((void __user *) arg, &tunnel->stats, - sizeof(tunnel->stats))) { - err = -EFAULT; - break; - } - PRINTK(tunnel->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO, - "%s: get L2TP stats\n", tunnel->name); - err = 0; - break; - - default: - err = -ENOSYS; - break; - } - - sock_put(sk); - - return err; -} - -/* Main ioctl() handler. - * Dispatch to tunnel or session helpers depending on the socket. - */ -static int pppol2tp_ioctl(struct socket *sock, unsigned int cmd, - unsigned long arg) -{ - struct sock *sk = sock->sk; - struct pppol2tp_session *session; - struct pppol2tp_tunnel *tunnel; - int err; - - if (!sk) - return 0; - - err = -EBADF; - if (sock_flag(sk, SOCK_DEAD) != 0) - goto end; - - err = -ENOTCONN; - if ((sk->sk_user_data == NULL) || - (!(sk->sk_state & (PPPOX_CONNECTED | PPPOX_BOUND)))) - goto end; - - /* Get session context from the socket */ - err = -EBADF; - session = pppol2tp_sock_to_session(sk); - if (session == NULL) - goto end; - - /* Special case: if session's session_id is zero, treat ioctl as a - * tunnel ioctl - */ - if ((session->tunnel_addr.s_session == 0) && - (session->tunnel_addr.d_session == 0)) { - err = -EBADF; - tunnel = pppol2tp_sock_to_tunnel(session->tunnel_sock); - if (tunnel == NULL) - goto end_put_sess; - - err = pppol2tp_tunnel_ioctl(tunnel, cmd, arg); - sock_put(session->tunnel_sock); - goto end_put_sess; - } - - err = pppol2tp_session_ioctl(session, cmd, arg); - -end_put_sess: - sock_put(sk); -end: - return err; -} - -/***************************************************************************** - * setsockopt() / getsockopt() support. - * - * The PPPoX socket is created for L2TP sessions: tunnels have their own UDP - * sockets. In order to control kernel tunnel features, we allow userspace to - * create a special "tunnel" PPPoX socket which is used for control only. - * Tunnel PPPoX sockets have session_id == 0 and simply allow the user - * application to issue L2TP setsockopt(), getsockopt() and ioctl() calls. - *****************************************************************************/ - -/* Tunnel setsockopt() helper. - */ -static int pppol2tp_tunnel_setsockopt(struct sock *sk, - struct pppol2tp_tunnel *tunnel, - int optname, int val) -{ - int err = 0; - - switch (optname) { - case PPPOL2TP_SO_DEBUG: - tunnel->debug = val; - PRINTK(tunnel->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO, - "%s: set debug=%x\n", tunnel->name, tunnel->debug); - break; - - default: - err = -ENOPROTOOPT; - break; - } - - return err; -} - -/* Session setsockopt helper. - */ -static int pppol2tp_session_setsockopt(struct sock *sk, - struct pppol2tp_session *session, - int optname, int val) -{ - int err = 0; - - switch (optname) { - case PPPOL2TP_SO_RECVSEQ: - if ((val != 0) && (val != 1)) { - err = -EINVAL; - break; - } - session->recv_seq = val ? -1 : 0; - PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO, - "%s: set recv_seq=%d\n", session->name, - session->recv_seq); - break; - - case PPPOL2TP_SO_SENDSEQ: - if ((val != 0) && (val != 1)) { - err = -EINVAL; - break; - } - session->send_seq = val ? -1 : 0; - { - struct sock *ssk = session->sock; - struct pppox_sock *po = pppox_sk(ssk); - po->chan.hdrlen = val ? PPPOL2TP_L2TP_HDR_SIZE_SEQ : - PPPOL2TP_L2TP_HDR_SIZE_NOSEQ; - } - PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO, - "%s: set send_seq=%d\n", session->name, session->send_seq); - break; - - case PPPOL2TP_SO_LNSMODE: - if ((val != 0) && (val != 1)) { - err = -EINVAL; - break; - } - session->lns_mode = val ? -1 : 0; - PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO, - "%s: set lns_mode=%d\n", session->name, - session->lns_mode); - break; - - case PPPOL2TP_SO_DEBUG: - session->debug = val; - PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO, - "%s: set debug=%x\n", session->name, session->debug); - break; - - case PPPOL2TP_SO_REORDERTO: - session->reorder_timeout = msecs_to_jiffies(val); - PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO, - "%s: set reorder_timeout=%d\n", session->name, - session->reorder_timeout); - break; - - default: - err = -ENOPROTOOPT; - break; - } - - return err; -} - -/* Main setsockopt() entry point. - * Does API checks, then calls either the tunnel or session setsockopt - * handler, according to whether the PPPoL2TP socket is a for a regular - * session or the special tunnel type. - */ -static int pppol2tp_setsockopt(struct socket *sock, int level, int optname, - char __user *optval, unsigned int optlen) -{ - struct sock *sk = sock->sk; - struct pppol2tp_session *session = sk->sk_user_data; - struct pppol2tp_tunnel *tunnel; - int val; - int err; - - if (level != SOL_PPPOL2TP) - return udp_prot.setsockopt(sk, level, optname, optval, optlen); - - if (optlen < sizeof(int)) - return -EINVAL; - - if (get_user(val, (int __user *)optval)) - return -EFAULT; - - err = -ENOTCONN; - if (sk->sk_user_data == NULL) - goto end; - - /* Get session context from the socket */ - err = -EBADF; - session = pppol2tp_sock_to_session(sk); - if (session == NULL) - goto end; - - /* Special case: if session_id == 0x0000, treat as operation on tunnel - */ - if ((session->tunnel_addr.s_session == 0) && - (session->tunnel_addr.d_session == 0)) { - err = -EBADF; - tunnel = pppol2tp_sock_to_tunnel(session->tunnel_sock); - if (tunnel == NULL) - goto end_put_sess; - - err = pppol2tp_tunnel_setsockopt(sk, tunnel, optname, val); - sock_put(session->tunnel_sock); - } else - err = pppol2tp_session_setsockopt(sk, session, optname, val); - - err = 0; - -end_put_sess: - sock_put(sk); -end: - return err; -} - -/* Tunnel getsockopt helper. Called with sock locked. - */ -static int pppol2tp_tunnel_getsockopt(struct sock *sk, - struct pppol2tp_tunnel *tunnel, - int optname, int *val) -{ - int err = 0; - - switch (optname) { - case PPPOL2TP_SO_DEBUG: - *val = tunnel->debug; - PRINTK(tunnel->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO, - "%s: get debug=%x\n", tunnel->name, tunnel->debug); - break; - - default: - err = -ENOPROTOOPT; - break; - } - - return err; -} - -/* Session getsockopt helper. Called with sock locked. - */ -static int pppol2tp_session_getsockopt(struct sock *sk, - struct pppol2tp_session *session, - int optname, int *val) -{ - int err = 0; - - switch (optname) { - case PPPOL2TP_SO_RECVSEQ: - *val = session->recv_seq; - PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO, - "%s: get recv_seq=%d\n", session->name, *val); - break; - - case PPPOL2TP_SO_SENDSEQ: - *val = session->send_seq; - PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO, - "%s: get send_seq=%d\n", session->name, *val); - break; - - case PPPOL2TP_SO_LNSMODE: - *val = session->lns_mode; - PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO, - "%s: get lns_mode=%d\n", session->name, *val); - break; - - case PPPOL2TP_SO_DEBUG: - *val = session->debug; - PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO, - "%s: get debug=%d\n", session->name, *val); - break; - - case PPPOL2TP_SO_REORDERTO: - *val = (int) jiffies_to_msecs(session->reorder_timeout); - PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO, - "%s: get reorder_timeout=%d\n", session->name, *val); - break; - - default: - err = -ENOPROTOOPT; - } - - return err; -} - -/* Main getsockopt() entry point. - * Does API checks, then calls either the tunnel or session getsockopt - * handler, according to whether the PPPoX socket is a for a regular session - * or the special tunnel type. - */ -static int pppol2tp_getsockopt(struct socket *sock, int level, - int optname, char __user *optval, int __user *optlen) -{ - struct sock *sk = sock->sk; - struct pppol2tp_session *session = sk->sk_user_data; - struct pppol2tp_tunnel *tunnel; - int val, len; - int err; - - if (level != SOL_PPPOL2TP) - return udp_prot.getsockopt(sk, level, optname, optval, optlen); - - if (get_user(len, (int __user *) optlen)) - return -EFAULT; - - len = min_t(unsigned int, len, sizeof(int)); - - if (len < 0) - return -EINVAL; - - err = -ENOTCONN; - if (sk->sk_user_data == NULL) - goto end; - - /* Get the session context */ - err = -EBADF; - session = pppol2tp_sock_to_session(sk); - if (session == NULL) - goto end; - - /* Special case: if session_id == 0x0000, treat as operation on tunnel */ - if ((session->tunnel_addr.s_session == 0) && - (session->tunnel_addr.d_session == 0)) { - err = -EBADF; - tunnel = pppol2tp_sock_to_tunnel(session->tunnel_sock); - if (tunnel == NULL) - goto end_put_sess; - - err = pppol2tp_tunnel_getsockopt(sk, tunnel, optname, &val); - sock_put(session->tunnel_sock); - } else - err = pppol2tp_session_getsockopt(sk, session, optname, &val); - - err = -EFAULT; - if (put_user(len, (int __user *) optlen)) - goto end_put_sess; - - if (copy_to_user((void __user *) optval, &val, len)) - goto end_put_sess; - - err = 0; - -end_put_sess: - sock_put(sk); -end: - return err; -} - -/***************************************************************************** - * /proc filesystem for debug - *****************************************************************************/ - -#ifdef CONFIG_PROC_FS - -#include <linux/seq_file.h> - -struct pppol2tp_seq_data { - struct seq_net_private p; - struct pppol2tp_tunnel *tunnel; /* current tunnel */ - struct pppol2tp_session *session; /* NULL means get first session in tunnel */ -}; - -static struct pppol2tp_session *next_session(struct pppol2tp_tunnel *tunnel, struct pppol2tp_session *curr) -{ - struct pppol2tp_session *session = NULL; - struct hlist_node *walk; - int found = 0; - int next = 0; - int i; - - read_lock_bh(&tunnel->hlist_lock); - for (i = 0; i < PPPOL2TP_HASH_SIZE; i++) { - hlist_for_each_entry(session, walk, &tunnel->session_hlist[i], hlist) { - if (curr == NULL) { - found = 1; - goto out; - } - if (session == curr) { - next = 1; - continue; - } - if (next) { - found = 1; - goto out; - } - } - } -out: - read_unlock_bh(&tunnel->hlist_lock); - if (!found) - session = NULL; - - return session; -} - -static struct pppol2tp_tunnel *next_tunnel(struct pppol2tp_net *pn, - struct pppol2tp_tunnel *curr) -{ - struct pppol2tp_tunnel *tunnel = NULL; - - read_lock_bh(&pn->pppol2tp_tunnel_list_lock); - if (list_is_last(&curr->list, &pn->pppol2tp_tunnel_list)) { - goto out; - } - tunnel = list_entry(curr->list.next, struct pppol2tp_tunnel, list); -out: - read_unlock_bh(&pn->pppol2tp_tunnel_list_lock); - - return tunnel; -} - -static void *pppol2tp_seq_start(struct seq_file *m, loff_t *offs) -{ - struct pppol2tp_seq_data *pd = SEQ_START_TOKEN; - struct pppol2tp_net *pn; - loff_t pos = *offs; - - if (!pos) - goto out; - - BUG_ON(m->private == NULL); - pd = m->private; - pn = pppol2tp_pernet(seq_file_net(m)); - - if (pd->tunnel == NULL) { - if (!list_empty(&pn->pppol2tp_tunnel_list)) - pd->tunnel = list_entry(pn->pppol2tp_tunnel_list.next, struct pppol2tp_tunnel, list); - } else { - pd->session = next_session(pd->tunnel, pd->session); - if (pd->session == NULL) { - pd->tunnel = next_tunnel(pn, pd->tunnel); - } - } - - /* NULL tunnel and session indicates end of list */ - if ((pd->tunnel == NULL) && (pd->session == NULL)) - pd = NULL; - -out: - return pd; -} - -static void *pppol2tp_seq_next(struct seq_file *m, void *v, loff_t *pos) -{ - (*pos)++; - return NULL; -} - -static void pppol2tp_seq_stop(struct seq_file *p, void *v) -{ - /* nothing to do */ -} - -static void pppol2tp_seq_tunnel_show(struct seq_file *m, void *v) -{ - struct pppol2tp_tunnel *tunnel = v; - - seq_printf(m, "\nTUNNEL '%s', %c %d\n", - tunnel->name, - (tunnel == tunnel->sock->sk_user_data) ? 'Y':'N', - atomic_read(&tunnel->ref_count) - 1); - seq_printf(m, " %08x %llu/%llu/%llu %llu/%llu/%llu\n", - tunnel->debug, - (unsigned long long)tunnel->stats.tx_packets, - (unsigned long long)tunnel->stats.tx_bytes, - (unsigned long long)tunnel->stats.tx_errors, - (unsigned long long)tunnel->stats.rx_packets, - (unsigned long long)tunnel->stats.rx_bytes, - (unsigned long long)tunnel->stats.rx_errors); -} - -static void pppol2tp_seq_session_show(struct seq_file *m, void *v) -{ - struct pppol2tp_session *session = v; - - seq_printf(m, " SESSION '%s' %08X/%d %04X/%04X -> " - "%04X/%04X %d %c\n", - session->name, - ntohl(session->tunnel_addr.addr.sin_addr.s_addr), - ntohs(session->tunnel_addr.addr.sin_port), - session->tunnel_addr.s_tunnel, - session->tunnel_addr.s_session, - session->tunnel_addr.d_tunnel, - session->tunnel_addr.d_session, - session->sock->sk_state, - (session == session->sock->sk_user_data) ? - 'Y' : 'N'); - seq_printf(m, " %d/%d/%c/%c/%s %08x %u\n", - session->mtu, session->mru, - session->recv_seq ? 'R' : '-', - session->send_seq ? 'S' : '-', - session->lns_mode ? "LNS" : "LAC", - session->debug, - jiffies_to_msecs(session->reorder_timeout)); - seq_printf(m, " %hu/%hu %llu/%llu/%llu %llu/%llu/%llu\n", - session->nr, session->ns, - (unsigned long long)session->stats.tx_packets, - (unsigned long long)session->stats.tx_bytes, - (unsigned long long)session->stats.tx_errors, - (unsigned long long)session->stats.rx_packets, - (unsigned long long)session->stats.rx_bytes, - (unsigned long long)session->stats.rx_errors); -} - -static int pppol2tp_seq_show(struct seq_file *m, void *v) -{ - struct pppol2tp_seq_data *pd = v; - - /* display header on line 1 */ - if (v == SEQ_START_TOKEN) { - seq_puts(m, "PPPoL2TP driver info, " PPPOL2TP_DRV_VERSION "\n"); - seq_puts(m, "TUNNEL name, user-data-ok session-count\n"); - seq_puts(m, " debug tx-pkts/bytes/errs rx-pkts/bytes/errs\n"); - seq_puts(m, " SESSION name, addr/port src-tid/sid " - "dest-tid/sid state user-data-ok\n"); - seq_puts(m, " mtu/mru/rcvseq/sendseq/lns debug reorderto\n"); - seq_puts(m, " nr/ns tx-pkts/bytes/errs rx-pkts/bytes/errs\n"); - goto out; - } - - /* Show the tunnel or session context. - */ - if (pd->session == NULL) - pppol2tp_seq_tunnel_show(m, pd->tunnel); - else - pppol2tp_seq_session_show(m, pd->session); - -out: - return 0; -} - -static const struct seq_operations pppol2tp_seq_ops = { - .start = pppol2tp_seq_start, - .next = pppol2tp_seq_next, - .stop = pppol2tp_seq_stop, - .show = pppol2tp_seq_show, -}; - -/* Called when our /proc file is opened. We allocate data for use when - * iterating our tunnel / session contexts and store it in the private - * data of the seq_file. - */ -static int pppol2tp_proc_open(struct inode *inode, struct file *file) -{ - return seq_open_net(inode, file, &pppol2tp_seq_ops, - sizeof(struct pppol2tp_seq_data)); -} - -static const struct file_operations pppol2tp_proc_fops = { - .owner = THIS_MODULE, - .open = pppol2tp_proc_open, - .read = seq_read, - .llseek = seq_lseek, - .release = seq_release_net, -}; - -#endif /* CONFIG_PROC_FS */ - -/***************************************************************************** - * Init and cleanup - *****************************************************************************/ - -static const struct proto_ops pppol2tp_ops = { - .family = AF_PPPOX, - .owner = THIS_MODULE, - .release = pppol2tp_release, - .bind = sock_no_bind, - .connect = pppol2tp_connect, - .socketpair = sock_no_socketpair, - .accept = sock_no_accept, - .getname = pppol2tp_getname, - .poll = datagram_poll, - .listen = sock_no_listen, - .shutdown = sock_no_shutdown, - .setsockopt = pppol2tp_setsockopt, - .getsockopt = pppol2tp_getsockopt, - .sendmsg = pppol2tp_sendmsg, - .recvmsg = pppol2tp_recvmsg, - .mmap = sock_no_mmap, - .ioctl = pppox_ioctl, -}; - -static struct pppox_proto pppol2tp_proto = { - .create = pppol2tp_create, - .ioctl = pppol2tp_ioctl -}; - -static __net_init int pppol2tp_init_net(struct net *net) -{ - struct pppol2tp_net *pn = pppol2tp_pernet(net); - struct proc_dir_entry *pde; - - INIT_LIST_HEAD(&pn->pppol2tp_tunnel_list); - rwlock_init(&pn->pppol2tp_tunnel_list_lock); - - pde = proc_net_fops_create(net, "pppol2tp", S_IRUGO, &pppol2tp_proc_fops); -#ifdef CONFIG_PROC_FS - if (!pde) - return -ENOMEM; -#endif - - return 0; -} - -static __net_exit void pppol2tp_exit_net(struct net *net) -{ - proc_net_remove(net, "pppol2tp"); -} - -static struct pernet_operations pppol2tp_net_ops = { - .init = pppol2tp_init_net, - .exit = pppol2tp_exit_net, - .id = &pppol2tp_net_id, - .size = sizeof(struct pppol2tp_net), -}; - -static int __init pppol2tp_init(void) -{ - int err; - - err = proto_register(&pppol2tp_sk_proto, 0); - if (err) - goto out; - err = register_pppox_proto(PX_PROTO_OL2TP, &pppol2tp_proto); - if (err) - goto out_unregister_pppol2tp_proto; - - err = register_pernet_device(&pppol2tp_net_ops); - if (err) - goto out_unregister_pppox_proto; - - printk(KERN_INFO "PPPoL2TP kernel driver, %s\n", - PPPOL2TP_DRV_VERSION); - -out: - return err; -out_unregister_pppox_proto: - unregister_pppox_proto(PX_PROTO_OL2TP); -out_unregister_pppol2tp_proto: - proto_unregister(&pppol2tp_sk_proto); - goto out; -} - -static void __exit pppol2tp_exit(void) -{ - unregister_pppox_proto(PX_PROTO_OL2TP); - unregister_pernet_device(&pppol2tp_net_ops); - proto_unregister(&pppol2tp_sk_proto); -} - -module_init(pppol2tp_init); -module_exit(pppol2tp_exit); - -MODULE_AUTHOR("Martijn van Oosterhout <kleptog@svana.org>, " - "James Chapman <jchapman@katalix.com>"); -MODULE_DESCRIPTION("PPP over L2TP over UDP"); -MODULE_LICENSE("GPL"); -MODULE_VERSION(PPPOL2TP_DRV_VERSION); |
