diff options
| -rw-r--r-- | net/l2tp/Kconfig | 25 | ||||
| -rw-r--r-- | net/l2tp/l2tp_core.c | 532 | ||||
| -rw-r--r-- | net/l2tp/l2tp_core.h | 54 | ||||
| -rw-r--r-- | net/l2tp/l2tp_ppp.c | 21 |
4 files changed, 484 insertions, 148 deletions
diff --git a/net/l2tp/Kconfig b/net/l2tp/Kconfig index ec88c5c..d60758d 100644 --- a/net/l2tp/Kconfig +++ b/net/l2tp/Kconfig @@ -19,6 +19,10 @@ menuconfig L2TP connections. L2TP is also used as a VPN protocol, popular with home workers to connect to their offices. + L2TPv3 allows other protocols as well as PPP to be carried + over L2TP tunnels. L2TPv3 is defined in RFC 3931 + <http://www.ietf.org/rfc/rfc3931.txt>. + 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 @@ -26,3 +30,24 @@ menuconfig L2TP If you don't need L2TP, say N. To compile all L2TP code as modules, choose M here. + +config L2TP_V3 + bool "L2TPv3 support (EXPERIMENTAL)" + depends on EXPERIMENTAL && L2TP + help + Layer Two Tunneling Protocol Version 3 + + From RFC 3931 <http://www.ietf.org/rfc/rfc3931.txt>. + + The Layer Two Tunneling Protocol (L2TP) provides a dynamic + mechanism for tunneling Layer 2 (L2) "circuits" across a + packet-oriented data network (e.g., over IP). L2TP, as + originally defined in RFC 2661, is a standard method for + tunneling Point-to-Point Protocol (PPP) [RFC1661] sessions. + L2TP has since been adopted for tunneling a number of other + L2 protocols, including ATM, Frame Relay, HDLC and even raw + ethernet frames. + + If you are connecting to L2TPv3 equipment, or you want to + tunnel raw ethernet frames using L2TP, say Y here. If + unsure, say N. diff --git a/net/l2tp/l2tp_core.c b/net/l2tp/l2tp_core.c index 4b6da36..0eee1a6 100644 --- a/net/l2tp/l2tp_core.c +++ b/net/l2tp/l2tp_core.c @@ -65,6 +65,7 @@ #define L2TP_HDR_VER_MASK 0x000F #define L2TP_HDR_VER_2 0x0002 +#define L2TP_HDR_VER_3 0x0003 /* L2TPv3 default L2-specific sublayer */ #define L2TP_SLFLAG_S 0x40000000 @@ -85,7 +86,7 @@ /* Private data stored for received packets in the skb. */ struct l2tp_skb_cb { - u16 ns; + u32 ns; u16 has_seq; u16 length; unsigned long expires; @@ -101,6 +102,8 @@ static unsigned int l2tp_net_id; struct l2tp_net { struct list_head l2tp_tunnel_list; rwlock_t l2tp_tunnel_list_lock; + struct hlist_head l2tp_session_hlist[L2TP_HASH_SIZE_2]; + rwlock_t l2tp_session_hlist_lock; }; static inline struct l2tp_net *l2tp_pernet(struct net *net) @@ -110,6 +113,40 @@ static inline struct l2tp_net *l2tp_pernet(struct net *net) return net_generic(net, l2tp_net_id); } +/* Session hash global list for L2TPv3. + * The session_id SHOULD be random according to RFC3931, but several + * L2TP implementations 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_2(struct l2tp_net *pn, u32 session_id) +{ + return &pn->l2tp_session_hlist[hash_32(session_id, L2TP_HASH_BITS_2)]; + +} + +/* Lookup a session by id in the global session list + */ +static struct l2tp_session *l2tp_session_find_2(struct net *net, u32 session_id) +{ + struct l2tp_net *pn = l2tp_pernet(net); + struct hlist_head *session_list = + l2tp_session_id_hash_2(pn, session_id); + struct l2tp_session *session; + struct hlist_node *walk; + + read_lock_bh(&pn->l2tp_session_hlist_lock); + hlist_for_each_entry(session, walk, session_list, global_hlist) { + if (session->session_id == session_id) { + read_unlock_bh(&pn->l2tp_session_hlist_lock); + return session; + } + } + read_unlock_bh(&pn->l2tp_session_hlist_lock); + + return NULL; +} + /* Session hash list. * The session_id SHOULD be random according to RFC2661, but several * L2TP implementations (Cisco and Microsoft) use incrementing @@ -124,13 +161,20 @@ l2tp_session_id_hash(struct l2tp_tunnel *tunnel, u32 session_id) /* Lookup a session by id */ -struct l2tp_session *l2tp_session_find(struct l2tp_tunnel *tunnel, u32 session_id) +struct l2tp_session *l2tp_session_find(struct net *net, struct l2tp_tunnel *tunnel, u32 session_id) { - struct hlist_head *session_list = - l2tp_session_id_hash(tunnel, session_id); + struct hlist_head *session_list; struct l2tp_session *session; struct hlist_node *walk; + /* In L2TPv3, session_ids are unique over all tunnels and we + * sometimes need to look them up before we know the + * tunnel. + */ + if (tunnel == NULL) + return l2tp_session_find_2(net, session_id); + + session_list = l2tp_session_id_hash(tunnel, session_id); read_lock_bh(&tunnel->hlist_lock); hlist_for_each_entry(session, walk, session_list, hlist) { if (session->session_id == session_id) { @@ -218,7 +262,7 @@ static void l2tp_recv_queue_skb(struct l2tp_session *session, struct sk_buff *sk { struct sk_buff *skbp; struct sk_buff *tmp; - u16 ns = L2TP_SKB_CB(skb)->ns; + u32 ns = L2TP_SKB_CB(skb)->ns; spin_lock_bh(&session->reorder_q.lock); skb_queue_walk_safe(&session->reorder_q, skbp, tmp) { @@ -259,6 +303,11 @@ static void l2tp_recv_dequeue_skb(struct l2tp_session *session, struct sk_buff * if (L2TP_SKB_CB(skb)->has_seq) { /* Bump our Nr */ session->nr++; + if (tunnel->version == L2TP_HDR_VER_2) + session->nr &= 0xffff; + else + session->nr &= 0xffffff; + PRINTK(session->debug, L2TP_MSG_SEQ, KERN_DEBUG, "%s: updated nr to %hu\n", session->name, session->nr); } @@ -291,8 +340,8 @@ static void l2tp_recv_dequeue(struct l2tp_session *session) 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", + "%s: oos pkt %u len %d discarded (too old), " + "waiting for %u, 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)); @@ -306,8 +355,8 @@ static void l2tp_recv_dequeue(struct l2tp_session *session) 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", + "%s: holding oos pkt %u len %d, " + "waiting for %u, 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)); @@ -352,100 +401,73 @@ static inline int l2tp_verify_udp_checksum(struct sock *sk, 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. +/* Do receive processing of L2TP data frames. We handle both L2TPv2 + * and L2TPv3 data frames here. + * + * L2TPv2 Data Message Header + * + * 0 1 2 3 + * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * |T|L|x|x|S|x|O|P|x|x|x|x| Ver | Length (opt) | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | Tunnel ID | Session ID | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | Ns (opt) | Nr (opt) | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | Offset Size (opt) | Offset pad... (opt) + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * + * Data frames are marked by T=0. All other fields are the same as + * those in L2TP control frames. + * + * L2TPv3 Data Message Header + * + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | L2TP Session Header | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | L2-Specific Sublayer | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | Tunnel Payload ... + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * + * L2TPv3 Session Header Over IP + * + * 0 1 2 3 + * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | Session ID | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | Cookie (optional, maximum 64 bits)... + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * + * L2TPv3 L2-Specific Sublayer Format + * + * 0 1 2 3 + * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * |x|S|x|x|x|x|x|x| Sequence Number | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * + * Cookie value, sublayer format and offset (pad) are negotiated with + * the peer when the session is set up. Unlike L2TPv2, we do not need + * to parse the packet header to determine if optional fields are + * present. + * + * Caller must already have parsed the frame and determined that it is + * a data (not control) frame before coming here. Fields up to the + * session-id have already been parsed and ptr points to the data + * after the session-id. */ -int l2tp_udp_recv_core(struct l2tp_tunnel *tunnel, struct sk_buff *skb, - int (*payload_hook)(struct sk_buff *skb)) +void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb, + unsigned char *ptr, unsigned char *optr, u16 hdrflags, + int length, 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; + struct l2tp_tunnel *tunnel = session->tunnel; 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; - } + u32 ns, nr; /* The ref count is increased since we now hold a pointer to * the session. Take care to decrement the refcnt when exiting @@ -455,6 +477,18 @@ int l2tp_udp_recv_core(struct l2tp_tunnel *tunnel, struct sk_buff *skb, if (session->ref) (*session->ref)(session); + /* Parse and check optional cookie */ + if (session->peer_cookie_len > 0) { + if (memcmp(ptr, &session->peer_cookie[0], session->peer_cookie_len)) { + PRINTK(tunnel->debug, L2TP_MSG_DATA, KERN_INFO, + "%s: cookie mismatch (%u/%u). Discarding.\n", + tunnel->name, tunnel->tunnel_id, session->session_id); + session->stats.rx_cookie_discards++; + goto discard; + } + ptr += session->peer_cookie_len; + } + /* Handle the optional sequence numbers. Sequence numbers are * in different places for L2TPv2 and L2TPv3. * @@ -464,21 +498,40 @@ int l2tp_udp_recv_core(struct l2tp_tunnel *tunnel, struct sk_buff *skb, */ 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; + if (tunnel->version == L2TP_HDR_VER_2) { + if (hdrflags & L2TP_HDRFLAG_S) { + ns = 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; + /* 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); + PRINTK(session->debug, L2TP_MSG_SEQ, KERN_DEBUG, + "%s: recv data ns=%u, nr=%u, session nr=%u\n", + session->name, ns, nr, session->nr); + } + } else if (session->l2specific_type == L2TP_L2SPECTYPE_DEFAULT) { + u32 l2h = ntohl(*(__be32 *) ptr); + + if (l2h & 0x40000000) { + ns = l2h & 0x00ffffff; + + /* 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=%u, session nr=%u\n", + session->name, ns, session->nr); + } } + /* Advance past L2-specific header, if present */ + ptr += session->l2specific_len; + 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, @@ -489,6 +542,7 @@ int l2tp_udp_recv_core(struct l2tp_tunnel *tunnel, struct sk_buff *skb, "%s: requested to enable seq numbers by LNS\n", session->name); session->send_seq = -1; + l2tp_session_set_header_len(session, tunnel->version); } } else { /* No sequence numbers. @@ -512,6 +566,7 @@ int l2tp_udp_recv_core(struct l2tp_tunnel *tunnel, struct sk_buff *skb, "%s: requested to disable seq numbers by LNS\n", session->name); session->send_seq = 0; + l2tp_session_set_header_len(session, tunnel->version); } else if (session->send_seq) { PRINTK(session->debug, L2TP_MSG_SEQ, KERN_WARNING, "%s: recv data has no seq numbers when required. " @@ -521,11 +576,19 @@ int l2tp_udp_recv_core(struct l2tp_tunnel *tunnel, struct sk_buff *skb, } } - /* If offset bit set, skip it. */ - if (hdrflags & L2TP_HDRFLAG_O) { - offset = ntohs(*(__be16 *)ptr); - ptr += 2 + offset; - } + /* Session data offset is handled differently for L2TPv2 and + * L2TPv3. For L2TPv2, there is an optional 16-bit value in + * the header. For L2TPv3, the offset is negotiated using AVPs + * in the session setup control protocol. + */ + if (tunnel->version == L2TP_HDR_VER_2) { + /* If offset bit set, skip it. */ + if (hdrflags & L2TP_HDRFLAG_O) { + offset = ntohs(*(__be16 *)ptr); + ptr += 2 + offset; + } + } else + ptr += session->offset; offset = ptr - optr; if (!pskb_may_pull(skb, offset)) @@ -564,8 +627,8 @@ int l2tp_udp_recv_core(struct l2tp_tunnel *tunnel, struct sk_buff *skb, 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", + "%s: oos pkt %u len %d discarded, " + "waiting for %u, 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)); @@ -586,7 +649,7 @@ int l2tp_udp_recv_core(struct l2tp_tunnel *tunnel, struct sk_buff *skb, l2tp_session_dec_refcount(session); - return 0; + return; discard: session->stats.rx_errors++; @@ -596,6 +659,111 @@ discard: (*session->deref)(session); l2tp_session_dec_refcount(session); +} +EXPORT_SYMBOL(l2tp_recv_common); + +/* 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 offset; + u16 version; + int length; + + 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 (tunnel->version == L2TP_HDR_VER_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; + } else { + ptr += 2; /* skip reserved bits */ + tunnel_id = tunnel->tunnel_id; + session_id = ntohl(*(__be32 *) ptr); + ptr += 4; + } + + /* Find the session context */ + session = l2tp_session_find(tunnel->l2tp_net, 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 (%u/%u). Passing up.\n", + tunnel->name, tunnel_id, session_id); + goto error; + } + + l2tp_recv_common(session, skb, ptr, optr, hdrflags, length, payload_hook); return 0; @@ -651,11 +819,11 @@ EXPORT_SYMBOL_GPL(l2tp_udp_encap_recv); /* 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) +static int l2tp_build_l2tpv2_header(struct l2tp_session *session, void *buf) { + struct l2tp_tunnel *tunnel = session->tunnel; __be16 *bufp = buf; + __be16 *optr = buf; u16 flags = L2TP_HDR_VER_2; u32 tunnel_id = tunnel->peer_tunnel_id; u32 session_id = session->peer_session_id; @@ -671,19 +839,51 @@ static void l2tp_build_l2tpv2_header(struct l2tp_tunnel *tunnel, *bufp++ = htons(session->ns); *bufp++ = 0; session->ns++; + session->ns &= 0xffff; PRINTK(session->debug, L2TP_MSG_SEQ, KERN_DEBUG, - "%s: updated ns to %hu\n", session->name, session->ns); + "%s: updated ns to %u\n", session->name, session->ns); } + + return bufp - optr; } -void l2tp_build_l2tp_header(struct l2tp_session *session, void *buf) +static int l2tp_build_l2tpv3_header(struct l2tp_session *session, void *buf) { - struct l2tp_tunnel *tunnel = session->tunnel; + char *bufp = buf; + char *optr = bufp; + u16 flags = L2TP_HDR_VER_3; + + /* Setup L2TP header. */ + *((__be16 *) bufp) = htons(flags); + bufp += 2; + *((__be16 *) bufp) = 0; + bufp += 2; + *((__be32 *) bufp) = htonl(session->peer_session_id); + bufp += 4; + if (session->cookie_len) { + memcpy(bufp, &session->cookie[0], session->cookie_len); + bufp += session->cookie_len; + } + if (session->l2specific_len) { + if (session->l2specific_type == L2TP_L2SPECTYPE_DEFAULT) { + u32 l2h = 0; + if (session->send_seq) { + l2h = 0x40000000 | session->ns; + session->ns++; + session->ns &= 0xffffff; + PRINTK(session->debug, L2TP_MSG_SEQ, KERN_DEBUG, + "%s: updated ns to %u\n", session->name, session->ns); + } + + *((__be32 *) bufp) = htonl(l2h); + } + bufp += session->l2specific_len; + } + if (session->offset) + bufp += session->offset; - BUG_ON(tunnel->version != L2TP_HDR_VER_2); - l2tp_build_l2tpv2_header(tunnel, session, buf); + return bufp - optr; } -EXPORT_SYMBOL_GPL(l2tp_build_l2tp_header); int l2tp_xmit_core(struct l2tp_session *session, struct sk_buff *skb, size_t data_len) { @@ -694,7 +894,7 @@ int l2tp_xmit_core(struct l2tp_session *session, struct sk_buff *skb, size_t dat /* Debug */ if (session->send_seq) PRINTK(session->debug, L2TP_MSG_DATA, KERN_DEBUG, - "%s: send %Zd bytes, ns=%hu\n", session->name, + "%s: send %Zd bytes, ns=%u\n", session->name, data_len, session->ns - 1); else PRINTK(session->debug, L2TP_MSG_DATA, KERN_DEBUG, @@ -780,7 +980,7 @@ int l2tp_xmit_skb(struct l2tp_session *session, struct sk_buff *skb, int hdr_len skb->truesize += new_headroom - old_headroom; /* Setup L2TP header */ - l2tp_build_l2tp_header(session, __skb_push(skb, hdr_len)); + session->build_header(session, __skb_push(skb, hdr_len)); udp_len = sizeof(struct udphdr) + hdr_len + data_len; /* Setup UDP header */ @@ -791,7 +991,6 @@ int l2tp_xmit_skb(struct l2tp_session *session, struct sk_buff *skb, int hdr_len 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)); @@ -911,6 +1110,14 @@ again: write_unlock_bh(&tunnel->hlist_lock); + if (tunnel->version != L2TP_HDR_VER_2) { + struct l2tp_net *pn = l2tp_pernet(tunnel->l2tp_net); + + write_lock_bh(&pn->l2tp_session_hlist_lock); + hlist_del_init(&session->global_hlist); + write_unlock_bh(&pn->l2tp_session_hlist_lock); + } + if (session->session_close != NULL) (*session->session_close)(session); @@ -997,9 +1204,6 @@ int l2tp_tunnel_create(struct net *net, int fd, int version, u32 tunnel_id, u32 goto err; } - if (version != L2TP_HDR_VER_2) - goto err; - tunnel = kzalloc(sizeof(struct l2tp_tunnel), GFP_KERNEL); if (tunnel == NULL) { err = -ENOMEM; @@ -1077,6 +1281,15 @@ void l2tp_session_free(struct l2tp_session *session) hlist_del_init(&session->hlist); write_unlock_bh(&tunnel->hlist_lock); + /* Unlink from the global hash if not L2TPv2 */ + if (tunnel->version != L2TP_HDR_VER_2) { + struct l2tp_net *pn = l2tp_pernet(tunnel->l2tp_net); + + write_lock_bh(&pn->l2tp_session_hlist_lock); + hlist_del_init(&session->global_hlist); + write_unlock_bh(&pn->l2tp_session_hlist_lock); + } + if (session->session_id != 0) atomic_dec(&l2tp_session_count); @@ -1095,6 +1308,22 @@ void l2tp_session_free(struct l2tp_session *session) } EXPORT_SYMBOL_GPL(l2tp_session_free); +/* We come here whenever a session's send_seq, cookie_len or + * l2specific_len parameters are set. + */ +void l2tp_session_set_header_len(struct l2tp_session *session, int version) +{ + if (version == L2TP_HDR_VER_2) { + session->hdr_len = 6; + if (session->send_seq) + session->hdr_len += 4; + } else { + session->hdr_len = 8 + session->cookie_len + session->l2specific_len + session->offset; + } + +} +EXPORT_SYMBOL_GPL(l2tp_session_set_header_len); + 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; @@ -1106,6 +1335,7 @@ struct l2tp_session *l2tp_session_create(int priv_size, struct l2tp_tunnel *tunn session->session_id = session_id; session->peer_session_id = peer_session_id; + session->nr = 1; sprintf(&session->name[0], "sess %u/%u", tunnel->tunnel_id, session->session_id); @@ -1113,20 +1343,36 @@ struct l2tp_session *l2tp_session_create(int priv_size, struct l2tp_tunnel *tunn skb_queue_head_init(&session->reorder_q); INIT_HLIST_NODE(&session->hlist); + INIT_HLIST_NODE(&session->global_hlist); /* Inherit debug options from tunnel */ session->debug = tunnel->debug; if (cfg) { + session->pwtype = cfg->pw_type; 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; + session->reorder_timeout = cfg->reorder_timeout; + session->offset = cfg->offset; + session->l2specific_type = cfg->l2specific_type; + session->l2specific_len = cfg->l2specific_len; + session->cookie_len = cfg->cookie_len; + memcpy(&session->cookie[0], &cfg->cookie[0], cfg->cookie_len); + session->peer_cookie_len = cfg->peer_cookie_len; + memcpy(&session->peer_cookie[0], &cfg->peer_cookie[0], cfg->peer_cookie_len); } + if (tunnel->version == L2TP_HDR_VER_2) + session->build_header = l2tp_build_l2tpv2_header; + else + session->build_header = l2tp_build_l2tpv3_header; + + l2tp_session_set_header_len(session, tunnel->version); + /* Bump the reference count. The session context is deleted * only when this drops to zero. */ @@ -1142,6 +1388,16 @@ struct l2tp_session *l2tp_session_create(int priv_size, struct l2tp_tunnel *tunn l2tp_session_id_hash(tunnel, session_id)); write_unlock_bh(&tunnel->hlist_lock); + /* And to the global session list if L2TPv3 */ + if (tunnel->version != L2TP_HDR_VER_2) { + struct l2tp_net *pn = l2tp_pernet(tunnel->l2tp_net); + + write_lock_bh(&pn->l2tp_session_hlist_lock); + hlist_add_head(&session->global_hlist, + l2tp_session_id_hash_2(pn, session_id)); + write_unlock_bh(&pn->l2tp_session_hlist_lock); + } + /* Ignore management session in session count value */ if (session->session_id != 0) atomic_inc(&l2tp_session_count); @@ -1159,6 +1415,7 @@ static __net_init int l2tp_init_net(struct net *net) { struct l2tp_net *pn; int err; + int hash; pn = kzalloc(sizeof(*pn), GFP_KERNEL); if (!pn) @@ -1167,6 +1424,11 @@ static __net_init int l2tp_init_net(struct net *net) INIT_LIST_HEAD(&pn->l2tp_tunnel_list); rwlock_init(&pn->l2tp_tunnel_list_lock); + for (hash = 0; hash < L2TP_HASH_SIZE_2; hash++) + INIT_HLIST_HEAD(&pn->l2tp_session_hlist[hash]); + + rwlock_init(&pn->l2tp_session_hlist_lock); + err = net_assign_generic(net, l2tp_net_id, pn); if (err) goto out; diff --git a/net/l2tp/l2tp_core.h b/net/l2tp/l2tp_core.h index 2efe1a3..5c53eb2 100644 --- a/net/l2tp/l2tp_core.h +++ b/net/l2tp/l2tp_core.h @@ -15,9 +15,14 @@ #define L2TP_TUNNEL_MAGIC 0x42114DDA #define L2TP_SESSION_MAGIC 0x0C04EB7D +/* Per tunnel, session hash table size */ #define L2TP_HASH_BITS 4 #define L2TP_HASH_SIZE (1 << L2TP_HASH_BITS) +/* System-wide, session hash table size */ +#define L2TP_HASH_BITS_2 8 +#define L2TP_HASH_SIZE_2 (1 << L2TP_HASH_BITS_2) + /* Debug message categories for the DEBUG socket option */ enum { L2TP_MSG_DEBUG = (1 << 0), /* verbose debug (if @@ -28,6 +33,21 @@ enum { L2TP_MSG_DATA = (1 << 3), /* data packets */ }; +enum l2tp_pwtype { + L2TP_PWTYPE_NONE = 0x0000, + L2TP_PWTYPE_ETH_VLAN = 0x0004, + L2TP_PWTYPE_ETH = 0x0005, + L2TP_PWTYPE_PPP = 0x0007, + L2TP_PWTYPE_PPP_AC = 0x0008, + L2TP_PWTYPE_IP = 0x000b, + __L2TP_PWTYPE_MAX +}; + +enum l2tp_l2spec_type { + L2TP_L2SPECTYPE_NONE, + L2TP_L2SPECTYPE_DEFAULT, +}; + struct sk_buff; struct l2tp_stats { @@ -39,6 +59,7 @@ struct l2tp_stats { u64 rx_seq_discards; u64 rx_oos_packets; u64 rx_errors; + u64 rx_cookie_discards; }; struct l2tp_tunnel; @@ -47,6 +68,7 @@ struct l2tp_tunnel; * packets and transmit outgoing ones. */ struct l2tp_session_cfg { + enum l2tp_pwtype pw_type; unsigned data_seq:2; /* data sequencing level * 0 => none, 1 => IP only, * 2 => all @@ -60,12 +82,17 @@ struct l2tp_session_cfg { * control of LNS. */ int debug; /* bitmask of debug message * categories */ - int offset; /* offset to payload */ + u16 offset; /* offset to payload */ + u16 l2specific_len; /* Layer 2 specific length */ + u16 l2specific_type; /* Layer 2 specific type */ + u8 cookie[8]; /* optional cookie */ + int cookie_len; /* 0, 4 or 8 bytes */ + u8 peer_cookie[8]; /* peer's cookie */ + int peer_cookie_len; /* 0, 4 or 8 bytes */ int reorder_timeout; /* configured reorder timeout * (in jiffies) */ int mtu; int mru; - int hdr_len; }; struct l2tp_session { @@ -76,8 +103,17 @@ struct l2tp_session { * context */ u32 session_id; u32 peer_session_id; - u16 nr; /* session NR state (receive) */ - u16 ns; /* session NR state (send) */ + u8 cookie[8]; + int cookie_len; + u8 peer_cookie[8]; + int peer_cookie_len; + u16 offset; /* offset from end of L2TP header + to beginning of data */ + u16 l2specific_len; + u16 l2specific_type; + u16 hdr_len; + u32 nr; /* session NR state (receive) */ + u32 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; @@ -100,9 +136,11 @@ struct l2tp_session { * (in jiffies) */ int mtu; int mru; - int hdr_len; + enum l2tp_pwtype pwtype; struct l2tp_stats stats; + struct hlist_node global_hlist; /* Global hash list node */ + int (*build_header)(struct l2tp_session *session, void *buf); 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); @@ -132,7 +170,6 @@ struct l2tp_tunnel { 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 */ @@ -178,7 +215,7 @@ out: return tunnel; } -extern struct l2tp_session *l2tp_session_find(struct l2tp_tunnel *tunnel, u32 session_id); +extern struct l2tp_session *l2tp_session_find(struct net *net, 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); @@ -187,14 +224,15 @@ extern int l2tp_tunnel_create(struct net *net, int fd, int version, u32 tunnel_i 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 void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb, unsigned char *ptr, unsigned char *optr, u16 hdrflags, int length, int (*payload_hook)(struct sk_buff *skb)); 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); +extern void l2tp_session_set_header_len(struct l2tp_session *session, int version); /* Tunnel reference counts. Incremented per session that is added to * the tunnel. diff --git a/net/l2tp/l2tp_ppp.c b/net/l2tp/l2tp_ppp.c index 3ad290d..bee5b14 100644 --- a/net/l2tp/l2tp_ppp.c +++ b/net/l2tp/l2tp_ppp.c @@ -670,7 +670,7 @@ static int pppol2tp_connect(struct socket *sock, struct sockaddr *uservaddr, /* Check that this session doesn't already exist */ error = -EEXIST; - session = l2tp_session_find(tunnel, sp->pppol2tp.s_session); + session = l2tp_session_find(sock_net(sk), tunnel, sp->pppol2tp.s_session); if (session != NULL) goto end; @@ -678,7 +678,6 @@ static int pppol2tp_connect(struct socket *sock, struct sockaddr *uservaddr, * 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. */ @@ -999,7 +998,7 @@ static int pppol2tp_tunnel_ioctl(struct l2tp_tunnel *tunnel, if (stats.session_id != 0) { /* resend to session ioctl handler */ struct l2tp_session *session = - l2tp_session_find(tunnel, stats.session_id); + l2tp_session_find(sock_net(sk), tunnel, stats.session_id); if (session != NULL) err = pppol2tp_session_ioctl(session, cmd, arg); else @@ -1375,6 +1374,8 @@ end: /***************************************************************************** * /proc filesystem for debug + * Since the original pppol2tp driver provided /proc/net/pppol2tp for + * L2TPv2, we dump only L2TPv2 tunnels and sessions here. *****************************************************************************/ static unsigned int pppol2tp_net_id; @@ -1391,14 +1392,24 @@ struct pppol2tp_seq_data { 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++; + for (;;) { + pd->tunnel = l2tp_tunnel_find_nth(net, pd->tunnel_idx); + pd->tunnel_idx++; + + if (pd->tunnel == NULL) + break; + + /* Ignore L2TPv3 tunnels */ + if (pd->tunnel->version < 3) + break; + } } 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); |
