diff options
Diffstat (limited to 'net/ipv6/ip6_tunnel.c')
| -rw-r--r-- | net/ipv6/ip6_tunnel.c | 1163 |
1 files changed, 1163 insertions, 0 deletions
diff --git a/net/ipv6/ip6_tunnel.c b/net/ipv6/ip6_tunnel.c new file mode 100644 index 0000000..3b1c9fa --- /dev/null +++ b/net/ipv6/ip6_tunnel.c @@ -0,0 +1,1163 @@ +/* + * IPv6 over IPv6 tunnel device + * Linux INET6 implementation + * + * Authors: + * Ville Nuorvala <vnuorval@tcs.hut.fi> + * + * $Id$ + * + * Based on: + * linux/net/ipv6/sit.c + * + * RFC 2473 + * + * 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. + * + */ + +#include <linux/config.h> +#include <linux/module.h> +#include <linux/errno.h> +#include <linux/types.h> +#include <linux/sockios.h> +#include <linux/if.h> +#include <linux/in.h> +#include <linux/ip.h> +#include <linux/if_tunnel.h> +#include <linux/net.h> +#include <linux/in6.h> +#include <linux/netdevice.h> +#include <linux/if_arp.h> +#include <linux/icmpv6.h> +#include <linux/init.h> +#include <linux/route.h> +#include <linux/rtnetlink.h> +#include <linux/netfilter_ipv6.h> + +#include <asm/uaccess.h> +#include <asm/atomic.h> + +#include <net/ip.h> +#include <net/ipv6.h> +#include <net/protocol.h> +#include <net/ip6_route.h> +#include <net/addrconf.h> +#include <net/ip6_tunnel.h> +#include <net/xfrm.h> +#include <net/dsfield.h> +#include <net/inet_ecn.h> + +MODULE_AUTHOR("Ville Nuorvala"); +MODULE_DESCRIPTION("IPv6-in-IPv6 tunnel"); +MODULE_LICENSE("GPL"); + +#define IPV6_TLV_TEL_DST_SIZE 8 + +#ifdef IP6_TNL_DEBUG +#define IP6_TNL_TRACE(x...) printk(KERN_DEBUG "%s:" x "\n", __FUNCTION__) +#else +#define IP6_TNL_TRACE(x...) do {;} while(0) +#endif + +#define IPV6_TCLASS_MASK (IPV6_FLOWINFO_MASK & ~IPV6_FLOWLABEL_MASK) + +#define HASH_SIZE 32 + +#define HASH(addr) (((addr)->s6_addr32[0] ^ (addr)->s6_addr32[1] ^ \ + (addr)->s6_addr32[2] ^ (addr)->s6_addr32[3]) & \ + (HASH_SIZE - 1)) + +static int ip6ip6_fb_tnl_dev_init(struct net_device *dev); +static int ip6ip6_tnl_dev_init(struct net_device *dev); +static void ip6ip6_tnl_dev_setup(struct net_device *dev); + +/* the IPv6 tunnel fallback device */ +static struct net_device *ip6ip6_fb_tnl_dev; + + +/* lists for storing tunnels in use */ +static struct ip6_tnl *tnls_r_l[HASH_SIZE]; +static struct ip6_tnl *tnls_wc[1]; +static struct ip6_tnl **tnls[2] = { tnls_wc, tnls_r_l }; + +/* lock for the tunnel lists */ +static DEFINE_RWLOCK(ip6ip6_lock); + +static inline struct dst_entry *ip6_tnl_dst_check(struct ip6_tnl *t) +{ + struct dst_entry *dst = t->dst_cache; + + if (dst && dst->obsolete && + dst->ops->check(dst, t->dst_cookie) == NULL) { + t->dst_cache = NULL; + dst_release(dst); + return NULL; + } + + return dst; +} + +static inline void ip6_tnl_dst_reset(struct ip6_tnl *t) +{ + dst_release(t->dst_cache); + t->dst_cache = NULL; +} + +static inline void ip6_tnl_dst_store(struct ip6_tnl *t, struct dst_entry *dst) +{ + struct rt6_info *rt = (struct rt6_info *) dst; + t->dst_cookie = rt->rt6i_node ? rt->rt6i_node->fn_sernum : 0; + dst_release(t->dst_cache); + t->dst_cache = dst; +} + +/** + * ip6ip6_tnl_lookup - fetch tunnel matching the end-point addresses + * @remote: the address of the tunnel exit-point + * @local: the address of the tunnel entry-point + * + * Return: + * tunnel matching given end-points if found, + * else fallback tunnel if its device is up, + * else %NULL + **/ + +static struct ip6_tnl * +ip6ip6_tnl_lookup(struct in6_addr *remote, struct in6_addr *local) +{ + unsigned h0 = HASH(remote); + unsigned h1 = HASH(local); + struct ip6_tnl *t; + + for (t = tnls_r_l[h0 ^ h1]; t; t = t->next) { + if (ipv6_addr_equal(local, &t->parms.laddr) && + ipv6_addr_equal(remote, &t->parms.raddr) && + (t->dev->flags & IFF_UP)) + return t; + } + if ((t = tnls_wc[0]) != NULL && (t->dev->flags & IFF_UP)) + return t; + + return NULL; +} + +/** + * ip6ip6_bucket - get head of list matching given tunnel parameters + * @p: parameters containing tunnel end-points + * + * Description: + * ip6ip6_bucket() returns the head of the list matching the + * &struct in6_addr entries laddr and raddr in @p. + * + * Return: head of IPv6 tunnel list + **/ + +static struct ip6_tnl ** +ip6ip6_bucket(struct ip6_tnl_parm *p) +{ + struct in6_addr *remote = &p->raddr; + struct in6_addr *local = &p->laddr; + unsigned h = 0; + int prio = 0; + + if (!ipv6_addr_any(remote) || !ipv6_addr_any(local)) { + prio = 1; + h = HASH(remote) ^ HASH(local); + } + return &tnls[prio][h]; +} + +/** + * ip6ip6_tnl_link - add tunnel to hash table + * @t: tunnel to be added + **/ + +static void +ip6ip6_tnl_link(struct ip6_tnl *t) +{ + struct ip6_tnl **tp = ip6ip6_bucket(&t->parms); + + t->next = *tp; + write_lock_bh(&ip6ip6_lock); + *tp = t; + write_unlock_bh(&ip6ip6_lock); +} + +/** + * ip6ip6_tnl_unlink - remove tunnel from hash table + * @t: tunnel to be removed + **/ + +static void +ip6ip6_tnl_unlink(struct ip6_tnl *t) +{ + struct ip6_tnl **tp; + + for (tp = ip6ip6_bucket(&t->parms); *tp; tp = &(*tp)->next) { + if (t == *tp) { + write_lock_bh(&ip6ip6_lock); + *tp = t->next; + write_unlock_bh(&ip6ip6_lock); + break; + } + } +} + +/** + * ip6_tnl_create() - create a new tunnel + * @p: tunnel parameters + * @pt: pointer to new tunnel + * + * Description: + * Create tunnel matching given parameters. + * + * Return: + * 0 on success + **/ + +static int +ip6_tnl_create(struct ip6_tnl_parm *p, struct ip6_tnl **pt) +{ + struct net_device *dev; + struct ip6_tnl *t; + char name[IFNAMSIZ]; + int err; + + if (p->name[0]) { + strlcpy(name, p->name, IFNAMSIZ); + } else { + int i; + for (i = 1; i < IP6_TNL_MAX; i++) { + sprintf(name, "ip6tnl%d", i); + if (__dev_get_by_name(name) == NULL) + break; + } + if (i == IP6_TNL_MAX) + return -ENOBUFS; + } + dev = alloc_netdev(sizeof (*t), name, ip6ip6_tnl_dev_setup); + if (dev == NULL) + return -ENOMEM; + + t = dev->priv; + dev->init = ip6ip6_tnl_dev_init; + t->parms = *p; + + if ((err = register_netdevice(dev)) < 0) { + free_netdev(dev); + return err; + } + dev_hold(dev); + + ip6ip6_tnl_link(t); + *pt = t; + return 0; +} + +/** + * ip6ip6_tnl_locate - find or create tunnel matching given parameters + * @p: tunnel parameters + * @create: != 0 if allowed to create new tunnel if no match found + * + * Description: + * ip6ip6_tnl_locate() first tries to locate an existing tunnel + * based on @parms. If this is unsuccessful, but @create is set a new + * tunnel device is created and registered for use. + * + * Return: + * 0 if tunnel located or created, + * -EINVAL if parameters incorrect, + * -ENODEV if no matching tunnel available + **/ + +static int +ip6ip6_tnl_locate(struct ip6_tnl_parm *p, struct ip6_tnl **pt, int create) +{ + struct in6_addr *remote = &p->raddr; + struct in6_addr *local = &p->laddr; + struct ip6_tnl *t; + + if (p->proto != IPPROTO_IPV6) + return -EINVAL; + + for (t = *ip6ip6_bucket(p); t; t = t->next) { + if (ipv6_addr_equal(local, &t->parms.laddr) && + ipv6_addr_equal(remote, &t->parms.raddr)) { + *pt = t; + return (create ? -EEXIST : 0); + } + } + if (!create) + return -ENODEV; + + return ip6_tnl_create(p, pt); +} + +/** + * ip6ip6_tnl_dev_uninit - tunnel device uninitializer + * @dev: the device to be destroyed + * + * Description: + * ip6ip6_tnl_dev_uninit() removes tunnel from its list + **/ + +static void +ip6ip6_tnl_dev_uninit(struct net_device *dev) +{ + struct ip6_tnl *t = dev->priv; + + if (dev == ip6ip6_fb_tnl_dev) { + write_lock_bh(&ip6ip6_lock); + tnls_wc[0] = NULL; + write_unlock_bh(&ip6ip6_lock); + } else { + ip6ip6_tnl_unlink(t); + } + ip6_tnl_dst_reset(t); + dev_put(dev); +} + +/** + * parse_tvl_tnl_enc_lim - handle encapsulation limit option + * @skb: received socket buffer + * + * Return: + * 0 if none was found, + * else index to encapsulation limit + **/ + +static __u16 +parse_tlv_tnl_enc_lim(struct sk_buff *skb, __u8 * raw) +{ + struct ipv6hdr *ipv6h = (struct ipv6hdr *) raw; + __u8 nexthdr = ipv6h->nexthdr; + __u16 off = sizeof (*ipv6h); + + while (ipv6_ext_hdr(nexthdr) && nexthdr != NEXTHDR_NONE) { + __u16 optlen = 0; + struct ipv6_opt_hdr *hdr; + if (raw + off + sizeof (*hdr) > skb->data && + !pskb_may_pull(skb, raw - skb->data + off + sizeof (*hdr))) + break; + + hdr = (struct ipv6_opt_hdr *) (raw + off); + if (nexthdr == NEXTHDR_FRAGMENT) { + struct frag_hdr *frag_hdr = (struct frag_hdr *) hdr; + if (frag_hdr->frag_off) + break; + optlen = 8; + } else if (nexthdr == NEXTHDR_AUTH) { + optlen = (hdr->hdrlen + 2) << 2; + } else { + optlen = ipv6_optlen(hdr); + } + if (nexthdr == NEXTHDR_DEST) { + __u16 i = off + 2; + while (1) { + struct ipv6_tlv_tnl_enc_lim *tel; + + /* No more room for encapsulation limit */ + if (i + sizeof (*tel) > off + optlen) + break; + + tel = (struct ipv6_tlv_tnl_enc_lim *) &raw[i]; + /* return index of option if found and valid */ + if (tel->type == IPV6_TLV_TNL_ENCAP_LIMIT && + tel->length == 1) + return i; + /* else jump to next option */ + if (tel->type) + i += tel->length + 2; + else + i++; + } + } + nexthdr = hdr->nexthdr; + off += optlen; + } + return 0; +} + +/** + * ip6ip6_err - tunnel error handler + * + * Description: + * ip6ip6_err() should handle errors in the tunnel according + * to the specifications in RFC 2473. + **/ + +static void +ip6ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, + int type, int code, int offset, __u32 info) +{ + struct ipv6hdr *ipv6h = (struct ipv6hdr *) skb->data; + struct ip6_tnl *t; + int rel_msg = 0; + int rel_type = ICMPV6_DEST_UNREACH; + int rel_code = ICMPV6_ADDR_UNREACH; + __u32 rel_info = 0; + __u16 len; + + /* If the packet doesn't contain the original IPv6 header we are + in trouble since we might need the source address for further + processing of the error. */ + + read_lock(&ip6ip6_lock); + if ((t = ip6ip6_tnl_lookup(&ipv6h->daddr, &ipv6h->saddr)) == NULL) + goto out; + + switch (type) { + __u32 teli; + struct ipv6_tlv_tnl_enc_lim *tel; + __u32 mtu; + case ICMPV6_DEST_UNREACH: + if (net_ratelimit()) + printk(KERN_WARNING + "%s: Path to destination invalid " + "or inactive!\n", t->parms.name); + rel_msg = 1; + break; + case ICMPV6_TIME_EXCEED: + if (code == ICMPV6_EXC_HOPLIMIT) { + if (net_ratelimit()) + printk(KERN_WARNING + "%s: Too small hop limit or " + "routing loop in tunnel!\n", + t->parms.name); + rel_msg = 1; + } + break; + case ICMPV6_PARAMPROB: + /* ignore if parameter problem not caused by a tunnel + encapsulation limit sub-option */ + if (code != ICMPV6_HDR_FIELD) { + break; + } + teli = parse_tlv_tnl_enc_lim(skb, skb->data); + + if (teli && teli == ntohl(info) - 2) { + tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->data[teli]; + if (tel->encap_limit == 0) { + if (net_ratelimit()) + printk(KERN_WARNING + "%s: Too small encapsulation " + "limit or routing loop in " + "tunnel!\n", t->parms.name); + rel_msg = 1; + } + } + break; + case ICMPV6_PKT_TOOBIG: + mtu = ntohl(info) - offset; + if (mtu < IPV6_MIN_MTU) + mtu = IPV6_MIN_MTU; + t->dev->mtu = mtu; + + if ((len = sizeof (*ipv6h) + ipv6h->payload_len) > mtu) { + rel_type = ICMPV6_PKT_TOOBIG; + rel_code = 0; + rel_info = mtu; + rel_msg = 1; + } + break; + } + if (rel_msg && pskb_may_pull(skb, offset + sizeof (*ipv6h))) { + struct rt6_info *rt; + struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC); + if (!skb2) + goto out; + + dst_release(skb2->dst); + skb2->dst = NULL; + skb_pull(skb2, offset); + skb2->nh.raw = skb2->data; + + /* Try to guess incoming interface */ + rt = rt6_lookup(&skb2->nh.ipv6h->saddr, NULL, 0, 0); + + if (rt && rt->rt6i_dev) + skb2->dev = rt->rt6i_dev; + + icmpv6_send(skb2, rel_type, rel_code, rel_info, skb2->dev); + + if (rt) + dst_release(&rt->u.dst); + + kfree_skb(skb2); + } +out: + read_unlock(&ip6ip6_lock); +} + +static inline void ip6ip6_ecn_decapsulate(struct ipv6hdr *outer_iph, + struct sk_buff *skb) +{ + struct ipv6hdr *inner_iph = skb->nh.ipv6h; + + if (INET_ECN_is_ce(ipv6_get_dsfield(outer_iph))) + IP6_ECN_set_ce(inner_iph); +} + +/** + * ip6ip6_rcv - decapsulate IPv6 packet and retransmit it locally + * @skb: received socket buffer + * + * Return: 0 + **/ + +static int +ip6ip6_rcv(struct sk_buff **pskb, unsigned int *nhoffp) +{ + struct sk_buff *skb = *pskb; + struct ipv6hdr *ipv6h; + struct ip6_tnl *t; + + if (!pskb_may_pull(skb, sizeof (*ipv6h))) + goto discard; + + ipv6h = skb->nh.ipv6h; + + read_lock(&ip6ip6_lock); + + if ((t = ip6ip6_tnl_lookup(&ipv6h->saddr, &ipv6h->daddr)) != NULL) { + if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) { + kfree_skb(skb); + return 0; + } + + if (!(t->parms.flags & IP6_TNL_F_CAP_RCV)) { + t->stat.rx_dropped++; + read_unlock(&ip6ip6_lock); + goto discard; + } + secpath_reset(skb); + skb->mac.raw = skb->nh.raw; + skb->nh.raw = skb->data; + skb->protocol = htons(ETH_P_IPV6); + skb->pkt_type = PACKET_HOST; + memset(skb->cb, 0, sizeof(struct inet6_skb_parm)); + skb->dev = t->dev; + dst_release(skb->dst); + skb->dst = NULL; + if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY) + ipv6_copy_dscp(ipv6h, skb->nh.ipv6h); + ip6ip6_ecn_decapsulate(ipv6h, skb); + t->stat.rx_packets++; + t->stat.rx_bytes += skb->len; + netif_rx(skb); + read_unlock(&ip6ip6_lock); + return 0; + } + read_unlock(&ip6ip6_lock); + icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_ADDR_UNREACH, 0, skb->dev); +discard: + return 1; +} + +static inline struct ipv6_txoptions *create_tel(__u8 encap_limit) +{ + struct ipv6_tlv_tnl_enc_lim *tel; + struct ipv6_txoptions *opt; + __u8 *raw; + + int opt_len = sizeof(*opt) + 8; + + if (!(opt = kmalloc(opt_len, GFP_ATOMIC))) { + return NULL; + } + memset(opt, 0, opt_len); + opt->tot_len = opt_len; + opt->dst0opt = (struct ipv6_opt_hdr *) (opt + 1); + opt->opt_nflen = 8; + + tel = (struct ipv6_tlv_tnl_enc_lim *) (opt->dst0opt + 1); + tel->type = IPV6_TLV_TNL_ENCAP_LIMIT; + tel->length = 1; + tel->encap_limit = encap_limit; + + raw = (__u8 *) opt->dst0opt; + raw[5] = IPV6_TLV_PADN; + raw[6] = 1; + + return opt; +} + +/** + * ip6ip6_tnl_addr_conflict - compare packet addresses to tunnel's own + * @t: the outgoing tunnel device + * @hdr: IPv6 header from the incoming packet + * + * Description: + * Avoid trivial tunneling loop by checking that tunnel exit-point + * doesn't match source of incoming packet. + * + * Return: + * 1 if conflict, + * 0 else + **/ + +static inline int +ip6ip6_tnl_addr_conflict(struct ip6_tnl *t, struct ipv6hdr *hdr) +{ + return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr); +} + +/** + * ip6ip6_tnl_xmit - encapsulate packet and send + * @skb: the outgoing socket buffer + * @dev: the outgoing tunnel device + * + * Description: + * Build new header and do some sanity checks on the packet before sending + * it. + * + * Return: + * 0 + **/ + +static int +ip6ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev) +{ + struct ip6_tnl *t = (struct ip6_tnl *) dev->priv; + struct net_device_stats *stats = &t->stat; + struct ipv6hdr *ipv6h = skb->nh.ipv6h; + struct ipv6_txoptions *opt = NULL; + int encap_limit = -1; + __u16 offset; + struct flowi fl; + struct dst_entry *dst; + struct net_device *tdev; + int mtu; + int max_headroom = sizeof(struct ipv6hdr); + u8 proto; + int err; + int pkt_len; + int dsfield; + + if (t->recursion++) { + stats->collisions++; + goto tx_err; + } + if (skb->protocol != htons(ETH_P_IPV6) || + !(t->parms.flags & IP6_TNL_F_CAP_XMIT) || + ip6ip6_tnl_addr_conflict(t, ipv6h)) { + goto tx_err; + } + if ((offset = parse_tlv_tnl_enc_lim(skb, skb->nh.raw)) > 0) { + struct ipv6_tlv_tnl_enc_lim *tel; + tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->nh.raw[offset]; + if (tel->encap_limit == 0) { + icmpv6_send(skb, ICMPV6_PARAMPROB, + ICMPV6_HDR_FIELD, offset + 2, skb->dev); + goto tx_err; + } + encap_limit = tel->encap_limit - 1; + } else if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT)) { + encap_limit = t->parms.encap_limit; + } + memcpy(&fl, &t->fl, sizeof (fl)); + proto = fl.proto; + + dsfield = ipv6_get_dsfield(ipv6h); + if ((t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)) + fl.fl6_flowlabel |= (*(__u32 *) ipv6h & IPV6_TCLASS_MASK); + if ((t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL)) + fl.fl6_flowlabel |= (*(__u32 *) ipv6h & IPV6_FLOWLABEL_MASK); + + if (encap_limit >= 0 && (opt = create_tel(encap_limit)) == NULL) + goto tx_err; + + if ((dst = ip6_tnl_dst_check(t)) != NULL) + dst_hold(dst); + else + dst = ip6_route_output(NULL, &fl); + + if (dst->error || xfrm_lookup(&dst, &fl, NULL, 0) < 0) + goto tx_err_link_failure; + + tdev = dst->dev; + + if (tdev == dev) { + stats->collisions++; + if (net_ratelimit()) + printk(KERN_WARNING + "%s: Local routing loop detected!\n", + t->parms.name); + goto tx_err_dst_release; + } + mtu = dst_mtu(dst) - sizeof (*ipv6h); + if (opt) { + max_headroom += 8; + mtu -= 8; + } + if (mtu < IPV6_MIN_MTU) + mtu = IPV6_MIN_MTU; + if (skb->dst && mtu < dst_mtu(skb->dst)) { + struct rt6_info *rt = (struct rt6_info *) skb->dst; + rt->rt6i_flags |= RTF_MODIFIED; + rt->u.dst.metrics[RTAX_MTU-1] = mtu; + } + if (skb->len > mtu) { + icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, dev); + goto tx_err_dst_release; + } + + /* + * Okay, now see if we can stuff it in the buffer as-is. + */ + max_headroom += LL_RESERVED_SPACE(tdev); + + if (skb_headroom(skb) < max_headroom || + skb_cloned(skb) || skb_shared(skb)) { + struct sk_buff *new_skb; + + if (!(new_skb = skb_realloc_headroom(skb, max_headroom))) + goto tx_err_dst_release; + + if (skb->sk) + skb_set_owner_w(new_skb, skb->sk); + kfree_skb(skb); + skb = new_skb; + } + dst_release(skb->dst); + skb->dst = dst_clone(dst); + + skb->h.raw = skb->nh.raw; + + if (opt) + ipv6_push_nfrag_opts(skb, opt, &proto, NULL); + + skb->nh.raw = skb_push(skb, sizeof(struct ipv6hdr)); + ipv6h = skb->nh.ipv6h; + *(u32*)ipv6h = fl.fl6_flowlabel | htonl(0x60000000); + dsfield = INET_ECN_encapsulate(0, dsfield); + ipv6_change_dsfield(ipv6h, ~INET_ECN_MASK, dsfield); + ipv6h->payload_len = htons(skb->len - sizeof(struct ipv6hdr)); + ipv6h->hop_limit = t->parms.hop_limit; + ipv6h->nexthdr = proto; + ipv6_addr_copy(&ipv6h->saddr, &fl.fl6_src); + ipv6_addr_copy(&ipv6h->daddr, &fl.fl6_dst); + nf_reset(skb); + pkt_len = skb->len; + err = NF_HOOK(PF_INET6, NF_IP6_LOCAL_OUT, skb, NULL, + skb->dst->dev, dst_output); + + if (err == NET_XMIT_SUCCESS || err == NET_XMIT_CN) { + stats->tx_bytes += pkt_len; + stats->tx_packets++; + } else { + stats->tx_errors++; + stats->tx_aborted_errors++; + } + ip6_tnl_dst_store(t, dst); + + if (opt) + kfree(opt); + + t->recursion--; + return 0; +tx_err_link_failure: + stats->tx_carrier_errors++; + dst_link_failure(skb); +tx_err_dst_release: + dst_release(dst); + if (opt) + kfree(opt); +tx_err: + stats->tx_errors++; + stats->tx_dropped++; + kfree_skb(skb); + t->recursion--; + return 0; +} + +static void ip6_tnl_set_cap(struct ip6_tnl *t) +{ + struct ip6_tnl_parm *p = &t->parms; + struct in6_addr *laddr = &p->laddr; + struct in6_addr *raddr = &p->raddr; + int ltype = ipv6_addr_type(laddr); + int rtype = ipv6_addr_type(raddr); + + p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV); + + if (ltype != IPV6_ADDR_ANY && rtype != IPV6_ADDR_ANY && + ((ltype|rtype) & + (IPV6_ADDR_UNICAST| + IPV6_ADDR_LOOPBACK|IPV6_ADDR_LINKLOCAL| + IPV6_ADDR_MAPPED|IPV6_ADDR_RESERVED)) == IPV6_ADDR_UNICAST) { + struct net_device *ldev = NULL; + int l_ok = 1; + int r_ok = 1; + + if (p->link) + ldev = dev_get_by_index(p->link); + + if (ltype&IPV6_ADDR_UNICAST && !ipv6_chk_addr(laddr, ldev, 0)) + l_ok = 0; + + if (rtype&IPV6_ADDR_UNICAST && ipv6_chk_addr(raddr, NULL, 0)) + r_ok = 0; + + if (l_ok && r_ok) { + if (ltype&IPV6_ADDR_UNICAST) + p->flags |= IP6_TNL_F_CAP_XMIT; + if (rtype&IPV6_ADDR_UNICAST) + p->flags |= IP6_TNL_F_CAP_RCV; + } + if (ldev) + dev_put(ldev); + } +} + +static void ip6ip6_tnl_link_config(struct ip6_tnl *t) +{ + struct net_device *dev = t->dev; + struct ip6_tnl_parm *p = &t->parms; + struct flowi *fl = &t->fl; + + memcpy(&dev->dev_addr, &p->laddr, sizeof(struct in6_addr)); + memcpy(&dev->broadcast, &p->raddr, sizeof(struct in6_addr)); + + /* Set up flowi template */ + ipv6_addr_copy(&fl->fl6_src, &p->laddr); + ipv6_addr_copy(&fl->fl6_dst, &p->raddr); + fl->oif = p->link; + fl->fl6_flowlabel = 0; + + if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS)) + fl->fl6_flowlabel |= IPV6_TCLASS_MASK & p->flowinfo; + if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL)) + fl->fl6_flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo; + + ip6_tnl_set_cap(t); + + if (p->flags&IP6_TNL_F_CAP_XMIT && p->flags&IP6_TNL_F_CAP_RCV) + dev->flags |= IFF_POINTOPOINT; + else + dev->flags &= ~IFF_POINTOPOINT; + + dev->iflink = p->link; + + if (p->flags & IP6_TNL_F_CAP_XMIT) { + struct rt6_info *rt = rt6_lookup(&p->raddr, &p->laddr, + p->link, 0); + + if (rt == NULL) + return; + + if (rt->rt6i_dev) { + dev->hard_header_len = rt->rt6i_dev->hard_header_len + + sizeof (struct ipv6hdr); + + dev->mtu = rt->rt6i_dev->mtu - sizeof (struct ipv6hdr); + + if (dev->mtu < IPV6_MIN_MTU) + dev->mtu = IPV6_MIN_MTU; + } + dst_release(&rt->u.dst); + } +} + +/** + * ip6ip6_tnl_change - update the tunnel parameters + * @t: tunnel to be changed + * @p: tunnel configuration parameters + * @active: != 0 if tunnel is ready for use + * + * Description: + * ip6ip6_tnl_change() updates the tunnel parameters + **/ + +static int +ip6ip6_tnl_change(struct ip6_tnl *t, struct ip6_tnl_parm *p) +{ + ipv6_addr_copy(&t->parms.laddr, &p->laddr); + ipv6_addr_copy(&t->parms.raddr, &p->raddr); + t->parms.flags = p->flags; + t->parms.hop_limit = p->hop_limit; + t->parms.encap_limit = p->encap_limit; + t->parms.flowinfo = p->flowinfo; + ip6ip6_tnl_link_config(t); + return 0; +} + +/** + * ip6ip6_tnl_ioctl - configure ipv6 tunnels from userspace + * @dev: virtual device associated with tunnel + * @ifr: parameters passed from userspace + * @cmd: command to be performed + * + * Description: + * ip6ip6_tnl_ioctl() is used for managing IPv6 tunnels + * from userspace. + * + * The possible commands are the following: + * %SIOCGETTUNNEL: get tunnel parameters for device + * %SIOCADDTUNNEL: add tunnel matching given tunnel parameters + * %SIOCCHGTUNNEL: change tunnel parameters to those given + * %SIOCDELTUNNEL: delete tunnel + * + * The fallback device "ip6tnl0", created during module + * initialization, can be used for creating other tunnel devices. + * + * Return: + * 0 on success, + * %-EFAULT if unable to copy data to or from userspace, + * %-EPERM if current process hasn't %CAP_NET_ADMIN set + * %-EINVAL if passed tunnel parameters are invalid, + * %-EEXIST if changing a tunnel's parameters would cause a conflict + * %-ENODEV if attempting to change or delete a nonexisting device + **/ + +static int +ip6ip6_tnl_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd) +{ + int err = 0; + int create; + struct ip6_tnl_parm p; + struct ip6_tnl *t = NULL; + + switch (cmd) { + case SIOCGETTUNNEL: + if (dev == ip6ip6_fb_tnl_dev) { + if (copy_from_user(&p, + ifr->ifr_ifru.ifru_data, + sizeof (p))) { + err = -EFAULT; + break; + } + if ((err = ip6ip6_tnl_locate(&p, &t, 0)) == -ENODEV) + t = (struct ip6_tnl *) dev->priv; + else if (err) + break; + } else + t = (struct ip6_tnl *) dev->priv; + + memcpy(&p, &t->parms, sizeof (p)); + if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof (p))) { + err = -EFAULT; + } + break; + case SIOCADDTUNNEL: + case SIOCCHGTUNNEL: + err = -EPERM; + create = (cmd == SIOCADDTUNNEL); + if (!capable(CAP_NET_ADMIN)) + break; + if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof (p))) { + err = -EFAULT; + break; + } + if (!create && dev != ip6ip6_fb_tnl_dev) { + t = (struct ip6_tnl *) dev->priv; + } + if (!t && (err = ip6ip6_tnl_locate(&p, &t, create))) { + break; + } + if (cmd == SIOCCHGTUNNEL) { + if (t->dev != dev) { + err = -EEXIST; + break; + } + ip6ip6_tnl_unlink(t); + err = ip6ip6_tnl_change(t, &p); + ip6ip6_tnl_link(t); + netdev_state_change(dev); + } + if (copy_to_user(ifr->ifr_ifru.ifru_data, + &t->parms, sizeof (p))) { + err = -EFAULT; + } else { + err = 0; + } + break; + case SIOCDELTUNNEL: + err = -EPERM; + if (!capable(CAP_NET_ADMIN)) + break; + + if (dev == ip6ip6_fb_tnl_dev) { + if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, + sizeof (p))) { + err = -EFAULT; + break; + } + err = ip6ip6_tnl_locate(&p, &t, 0); + if (err) + break; + if (t == ip6ip6_fb_tnl_dev->priv) { + err = -EPERM; + break; + } + } else { + t = (struct ip6_tnl *) dev->priv; + } + err = unregister_netdevice(t->dev); + break; + default: + err = -EINVAL; + } + return err; +} + +/** + * ip6ip6_tnl_get_stats - return the stats for tunnel device + * @dev: virtual device associated with tunnel + * + * Return: stats for device + **/ + +static struct net_device_stats * +ip6ip6_tnl_get_stats(struct net_device *dev) +{ + return &(((struct ip6_tnl *) dev->priv)->stat); +} + +/** + * ip6ip6_tnl_change_mtu - change mtu manually for tunnel device + * @dev: virtual device associated with tunnel + * @new_mtu: the new mtu + * + * Return: + * 0 on success, + * %-EINVAL if mtu too small + **/ + +static int +ip6ip6_tnl_change_mtu(struct net_device *dev, int new_mtu) +{ + if (new_mtu < IPV6_MIN_MTU) { + return -EINVAL; + } + dev->mtu = new_mtu; + return 0; +} + +/** + * ip6ip6_tnl_dev_setup - setup virtual tunnel device + * @dev: virtual device associated with tunnel + * + * Description: + * Initialize function pointers and device parameters + **/ + +static void ip6ip6_tnl_dev_setup(struct net_device *dev) +{ + SET_MODULE_OWNER(dev); + dev->uninit = ip6ip6_tnl_dev_uninit; + dev->destructor = free_netdev; + dev->hard_start_xmit = ip6ip6_tnl_xmit; + dev->get_stats = ip6ip6_tnl_get_stats; + dev->do_ioctl = ip6ip6_tnl_ioctl; + dev->change_mtu = ip6ip6_tnl_change_mtu; + + dev->type = ARPHRD_TUNNEL6; + dev->hard_header_len = LL_MAX_HEADER + sizeof (struct ipv6hdr); + dev->mtu = ETH_DATA_LEN - sizeof (struct ipv6hdr); + dev->flags |= IFF_NOARP; + dev->addr_len = sizeof(struct in6_addr); +} + + +/** + * ip6ip6_tnl_dev_init_gen - general initializer for all tunnel devices + * @dev: virtual device associated with tunnel + **/ + +static inline void +ip6ip6_tnl_dev_init_gen(struct net_device *dev) +{ + struct ip6_tnl *t = (struct ip6_tnl *) dev->priv; + t->fl.proto = IPPROTO_IPV6; + t->dev = dev; + strcpy(t->parms.name, dev->name); +} + +/** + * ip6ip6_tnl_dev_init - initializer for all non fallback tunnel devices + * @dev: virtual device associated with tunnel + **/ + +static int +ip6ip6_tnl_dev_init(struct net_device *dev) +{ + struct ip6_tnl *t = (struct ip6_tnl *) dev->priv; + ip6ip6_tnl_dev_init_gen(dev); + ip6ip6_tnl_link_config(t); + return 0; +} + +/** + * ip6ip6_fb_tnl_dev_init - initializer for fallback tunnel device + * @dev: fallback device + * + * Return: 0 + **/ + +static int +ip6ip6_fb_tnl_dev_init(struct net_device *dev) +{ + struct ip6_tnl *t = dev->priv; + ip6ip6_tnl_dev_init_gen(dev); + dev_hold(dev); + tnls_wc[0] = t; + return 0; +} + +static struct xfrm6_tunnel ip6ip6_handler = { + .handler = ip6ip6_rcv, + .err_handler = ip6ip6_err, +}; + +/** + * ip6_tunnel_init - register protocol and reserve needed resources + * + * Return: 0 on success + **/ + +static int __init ip6_tunnel_init(void) +{ + int err; + + if (xfrm6_tunnel_register(&ip6ip6_handler) < 0) { + printk(KERN_ERR "ip6ip6 init: can't register tunnel\n"); + return -EAGAIN; + } + ip6ip6_fb_tnl_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6tnl0", + ip6ip6_tnl_dev_setup); + + if (!ip6ip6_fb_tnl_dev) { + err = -ENOMEM; + goto fail; + } + ip6ip6_fb_tnl_dev->init = ip6ip6_fb_tnl_dev_init; + + if ((err = register_netdev(ip6ip6_fb_tnl_dev))) { + free_netdev(ip6ip6_fb_tnl_dev); + goto fail; + } + return 0; +fail: + xfrm6_tunnel_deregister(&ip6ip6_handler); + return err; +} + +/** + * ip6_tunnel_cleanup - free resources and unregister protocol + **/ + +static void __exit ip6_tunnel_cleanup(void) +{ + if (xfrm6_tunnel_deregister(&ip6ip6_handler) < 0) + printk(KERN_INFO "ip6ip6 close: can't deregister tunnel\n"); + + unregister_netdev(ip6ip6_fb_tnl_dev); +} + +module_init(ip6_tunnel_init); +module_exit(ip6_tunnel_cleanup); |
