/* * IPv6 tunneling device * Linux INET6 implementation * * Authors: * Ville Nuorvala * Yasuyuki Kozakai * * Based on: * linux/net/ipv6/sit.c and linux/net/ipv4/ipip.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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include MODULE_AUTHOR("Ville Nuorvala"); MODULE_DESCRIPTION("IPv6 tunneling device"); 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", __func__) #else #define IP6_TNL_TRACE(x...) do {;} while(0) #endif #define IPV6_TCLASS_MASK (IPV6_FLOWINFO_MASK & ~IPV6_FLOWLABEL_MASK) #define IPV6_TCLASS_SHIFT 20 #define HASH_SIZE 32 #define HASH(addr) ((__force u32)((addr)->s6_addr32[0] ^ (addr)->s6_addr32[1] ^ \ (addr)->s6_addr32[2] ^ (addr)->s6_addr32[3]) & \ (HASH_SIZE - 1)) static int ip6_fb_tnl_dev_init(struct net_device *dev); static int ip6_tnl_dev_init(struct net_device *dev); static void ip6_tnl_dev_setup(struct net_device *dev); static int ip6_tnl_net_id; struct ip6_tnl_net { /* the IPv6 tunnel fallback device */ struct net_device *fb_tnl_dev; /* lists for storing tunnels in use */ struct ip6_tnl *tnls_r_l[HASH_SIZE]; struct ip6_tnl *tnls_wc[1]; struct ip6_tnl **tnls[2]; }; /* lock for the tunnel lists */ static DEFINE_RWLOCK(ip6_tnl_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; } /** * ip6_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 * ip6_tnl_lookup(struct net *net, struct in6_addr *remote, struct in6_addr *local) { unsigned h0 = HASH(remote); unsigned h1 = HASH(local); struct ip6_tnl *t; struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); for (t = ip6n->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 = ip6n->tnls_wc[0]) != NULL && (t->dev->flags & IFF_UP)) return t; return NULL; } /** * ip6_tnl_bucket - get head of list matching given tunnel parameters * @p: parameters containing tunnel end-points * * Description: * ip6_tnl_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 ** ip6_tnl_bucket(struct ip6_tnl_net *ip6n, 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 &ip6n->tnls[prio][h]; } /** * ip6_tnl_link - add tunnel to hash table * @t: tunnel to be added **/ static void ip6_tnl_link(struct ip6_tnl_net *ip6n, struct ip6_tnl *t) { struct ip6_tnl **tp = ip6_tnl_bucket(ip6n, &t->parms); t->next = *tp; write_lock_bh(&ip6_tnl_lock); *tp = t; write_unlock_bh(&ip6_tnl_lock); } /** * ip6_tnl_unlink - remove tunnel from hash table * @t: tunnel to be removed **/ static void ip6_tnl_unlink(struct ip6_tnl_net *ip6n, struct ip6_tnl *t) { struct ip6_tnl **tp; for (tp = ip6_tnl_bucket(ip6n, &t->parms); *tp; tp = &(*tp)->next) { if (t == *tp) { write_lock_bh(&ip6_tnl_lock); *tp = t->next; write_unlock_bh(&ip6_tnl_lock); break; } } } /** * ip6_tnl_create() - create a new tunnel * @p: tunnel parameters * @pt: pointer to new tunnel * * Description: * Create tunnel matching given parameters. * * Return: * created tunnel or NULL **/ static struct ip6_tnl *ip6_tnl_create(struct net *net, struct ip6_tnl_parm *p) { struct net_device *dev; struct ip6_tnl *t; char name[IFNAMSIZ]; int err; struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); if (p->name[0]) strlcpy(name, p->name, IFNAMSIZ); else sprintf(name, "ip6tnl%%d"); dev = alloc_netdev(sizeof (*t), name, ip6_tnl_dev_setup); if (dev == NULL) goto failed; dev_net_set(dev, net); if (strchr(name, '%')) { if (dev_alloc_name(dev, name) < 0) goto failed_free; } t = netdev_priv(dev); dev->init = ip6_tnl_dev_init; t->parms = *p; if ((err = register_netdevice(dev)) < 0) goto failed_free; dev_hold(dev); ip6_tnl_link(ip6n, t); return t; failed_free: free_netdev(dev); failed: return NULL; } /** * ip6_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: * ip6_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: * matching tunnel or NULL **/ static struct ip6_tnl *ip6_tnl_locate(struct net *net, struct ip6_tnl_parm *p, int create) { struct in6_addr *remote = &p->raddr; struct in6_addr *local = &p->laddr; struct ip6_tnl *t; struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); for (t = *ip6_tnl_bucket(ip6n, p); t; t = t->next) { if (ipv6_addr_equal(local, &t->parms.laddr) && ipv6_addr_equal(remote, &t->parms.raddr)) return t; } if (!create) return NULL; return ip6_tnl_create(net, p); } /** * ip6_tnl_dev_uninit - tunnel device uninitializer * @dev: the device to be destroyed * * Description: * ip6_tnl_dev_uninit() removes tunnel from its list **/ static void ip6_tnl_dev_uninit(struct net_device *dev) { struct ip6_tnl *t = netdev_priv(dev); struct net *net = dev_net(dev); struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); if (dev == ip6n->fb_tnl_dev) { write_lock_bh(&ip6_tnl_lock); ip6n->tnls_wc[0] = NULL; write_unlock_bh(&ip6_tnl_lock); } else { ip6_tnl_unlink(ip6n, 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; } /** * ip6_tnl_err - tunnel error handler * * Description: * ip6_tnl_err() should handle errors in the tunnel according * to the specifications in RFC 2473. **/ static int ip6_tnl_err(struct sk_buff *skb, __u8 ipproto, struct inet6_skb_parm *opt, int *type, int *code, int *msg, __u32 *info, int offset) { 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; int err = -ENOENT; /* 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(&ip6_tnl_lock); if ((t = ip6_tnl_lookup(dev_net(skb->dev), &ipv6h->daddr, &ipv6h->saddr)) == NULL) goto out; if (t->parms.proto != ipproto && t->parms.proto != 0) goto out; err = 0; 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: teli = 0; if ((*code) == ICMPV6_HDR_FIELD) teli = parse_tlv_tnl_enc_lim(skb, skb->data); if (teli && teli == *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; } } else if (net_ratelimit()) { printk(KERN_WARNING "%s: Recipient unable to parse tunneled " "packet!\n ", t->parms.name); } break; case ICMPV6_PKT_TOOBIG: mtu = *info - offset; if (mtu < IPV6_MIN_MTU) mtu = IPV6_MIN_MTU; t->dev->mtu = mtu; if ((len = sizeof (*ipv6h) + ntohs(ipv6h->payload_len)) > mtu) { rel_type = ICMPV6_PKT_TOOBIG; rel_code = 0; rel_info = mtu; rel_msg = 1; } break; } *type = rel_type; *code = rel_code; *info = rel_info; *msg = rel_msg; out: read_unlock(&ip6_tnl_lock); return err; } static int ip4ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, int type, int code, int offset, __be32 info) { int rel_msg = 0; int rel_type = type; int rel_code = code; __u32 rel_info = ntohl(info); int err; struct sk_buff *skb2; struct iphdr *eiph; struct flowi fl; struct rtable *rt; err = ip6_tnl_err(skb, IPPROTO_IPIP, opt, &rel_type, &rel_code, &rel_msg, &rel_info, offset); if (err < 0) return err; if (rel_msg == 0) return 0; switch (rel_type) { case ICMPV6_DEST_UNREACH: if (rel_code != ICMPV6_ADDR_UNREACH) return 0; rel_type = ICMP_DEST_UNREACH; rel_code = ICMP_HOST_UNREACH; break; case ICMPV6_PKT_TOOBIG: if (rel_code != 0) return 0; rel_type = ICMP_DEST_UNREACH; rel_code = ICMP_FRAG_NEEDED; break; default: return 0; } if (!pskb_may_pull(skb, offset + sizeof(struct iphdr))) return 0; skb2 = skb_clone(skb, GFP_ATOMIC); if (!skb2) return 0; dst_release(skb2->dst); skb2->dst = NULL; skb_pull(skb2, offset); skb_reset_network_header(skb2); eiph = ip_hdr(skb2); /* Try to guess incoming interface */ memset(&fl, 0, sizeof(fl)); fl.fl4_dst = eiph->saddr; fl.fl4_tos = RT_TOS(eiph->tos); fl.proto = IPPROTO_IPIP; if (ip_route_output_key(dev_net(skb->dev), &rt, &fl)) goto out; skb2->dev = rt->u.dst.dev; /* route "incoming" packet */ if (rt->rt_flags & RTCF_LOCAL) { ip_rt_put(rt); rt = NULL; fl.fl4_dst = eiph->daddr; fl.fl4_src = eiph->saddr; fl.fl4_tos = eiph->tos; if (ip_route_output_key(dev_net(skb->dev), &rt, &fl) || rt->u.dst.dev->type != ARPHRD_TUNNEL) { ip_rt_put(rt); goto out; } skb2->dst = (struct dst_entry *)rt; } else { ip_rt_put(rt); if (ip_route_input(skb2, eiph->daddr, eiph->saddr, eiph->tos, skb2->dev) || skb2->dst->dev->type != ARPHRD_TUNNEL) goto out; } /* change mtu on this route */ if (rel_type == ICMP_DEST_UNREACH && rel_code == ICMP_FRAG_NEEDED) { if (rel_info > dst_mtu(skb2->dst)) goto out; skb2->dst->ops->update_pmtu(skb2->dst, rel_info); } icmp_send(skb2, rel_type, rel_code, htonl(rel_info)); out: kfree_skb(skb2); return 0; } static int ip6ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, int type, int code, int offset, __be32 info) { int rel_msg = 0; int rel_type = type; int rel_code = code; __u32 rel_info = ntohl(info); int err; err = ip6_tnl_err(skb, IPPROTO_IPV6, opt, &rel_type, &rel_code, &rel_msg, &rel_info, offset); if (err < 0) return err; if (rel_msg && pskb_may_pull(skb, offset + sizeof(struct ipv6hdr))) { struct rt6_info *rt; struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC); if (!skb2) return 0; dst_release(skb2->dst); skb2->dst = NULL; skb_pull(skb2, offset); skb_reset_network_header(skb2); /* Try to guess incoming interface */ rt = rt6_lookup(dev_net(skb->dev), &ipv6_hdr(skb2)->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); } return 0; } static void ip4ip6_dscp_ecn_decapsulate(struct ip6_tnl *t, struct ipv6hdr *ipv6h, struct sk_buff *skb) { __u8 dsfield = ipv6_get_dsfield(ipv6h) & ~INET_ECN_MASK; if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY) ipv4_change_dsfield(ip_hdr(skb), INET_ECN_MASK, dsfield); if (INET_ECN_is_ce(dsfield)) IP_ECN_set_ce(ip_hdr(skb)); } static void ip6ip6_dscp_ecn_decapsulate(struct ip6_tnl *t, struct ipv6hdr *ipv6h, struct sk_buff *skb) { if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY) ipv6_copy_dscp(ipv6_get_dsfield(ipv6h), ipv6_hdr(skb)); if (INET_ECN_is_ce(ipv6_get_dsfield(ipv6h))) IP6_ECN_set_ce(ipv6_hdr(skb)); } static inline int ip6_tnl_rcv_ctl(struct ip6_tnl *t) { struct ip6_tnl_parm *p = &t->parms; int ret = 0; struct net *net = dev_net(t->dev); if (p->flags & IP6_TNL_F_CAP_RCV) { struct net_device *ldev = NULL; if (p->link) ldev = dev_get_by_index(net, p->link); if ((ipv6_addr_is_multicast(&p->laddr) || likely(ipv6_chk_addr(net, &p->laddr, ldev, 0))) && likely(!ipv6_chk_addr(net, &p->raddr, NULL, 0))) ret = 1; if (ldev) dev_put(ldev); } return ret; } /** * ip6_tnl_rcv - decapsulate IPv6 packet and retransmit it locally * @skb: received socket buffer * @protocol: ethernet protocol ID * @dscp_ecn_decapsulate: the function to decapsulate DSCP code and ECN * * Return: 0 **/ static int ip6_tnl_rcv(struct sk_buff *skb, __u16 protocol, __u8 ipproto, void (*dscp_ecn_decapsulate)(struct ip6_tnl *t, struct ipv6hdr *ipv6h, struct sk_buff *skb)) { struct ip6_tnl *t; struct ipv6hdr *ipv6h = ipv6_hdr(skb); read_lock(&ip6_tnl_lock); if ((t = ip6_tnl_lookup(dev_net(skb->dev), &ipv6h->saddr, &ipv6h->daddr)) != NULL) { if (t->parms.proto != ipproto && t->parms.proto != 0) { read_unlock(&ip6_tnl_lock); goto discard; } if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) { read_unlock(&ip6_tnl_lock); goto discard; } if (!ip6_tnl_rcv_ctl(t)) { t->dev->stats.rx_dropped++; read_unlock(&ip6_tnl_lock); goto discard; } secpath_reset(skb); skb->mac_header = skb->network_header; skb_reset_network_header(skb); skb->protocol = htons(protocol); 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; nf_reset(skb); dscp_ecn_decapsulate(t, ipv6h, skb); t->dev->stats.rx_packets++; t->dev->stats.rx_bytes += skb->len; netif_rx(skb); read_unlock(&ip6_tnl_lock); return 0; } read_unlock(&ip6_tnl_lock); return 1; discard: kfree_skb(skb); return 0; } static int ip4ip6_rcv(struct sk_buff *skb) { return ip6_tnl_rcv(skb, ETH_P_IP, IPPROTO_IPIP, ip4ip6_dscp_ecn_decapsulate); } static int ip6ip6_rcv(struct sk_buff *skb) { return ip6_tnl_rcv(skb, ETH_P_IPV6, IPPROTO_IPV6, ip6ip6_dscp_ecn_decapsulate); } struct ipv6_tel_txoption { struct ipv6_txoptions ops; __u8 dst_opt[8]; }; static void init_tel_txopt(struct ipv6_tel_txoption *opt, __u8 encap_limit) { memset(opt, 0, sizeof(struct ipv6_tel_txoption)); opt->dst_opt[2] = IPV6_TLV_TNL_ENCAP_LIMIT; opt->dst_opt[3] = 1; opt->dst_opt[4] = encap_limit; opt->dst_opt[5] = IPV6_TLV_PADN; opt->dst_opt[6] = 1; opt->ops.dst0opt = (struct ipv6_opt_hdr *) opt->dst_opt; opt->ops.opt_nflen = 8; } /** * ip6_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 ip6_tnl_addr_conflict(struct ip6_tnl *t, struct ipv6hdr *hdr) { return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr); } static inline int ip6_tnl_xmit_ctl(struct ip6_tnl *t) { struct ip6_tnl_parm *p = &t->parms; int ret = 0; struct net *net = dev_net(t->dev); if (p->flags & IP6_TNL_F_CAP_XMIT) { struct net_device *ldev = NULL; if (p->link) ldev = dev_get_by_index(net, p->link); if (unlikely(!ipv6_chk_addr(net, &p->laddr, ldev, 0))) printk(KERN_WARNING "%s xmit: Local address not yet configured!\n", p->name); else if (!ipv6_addr_is_multicast(&p->raddr) && unlikely(ipv6_chk_addr(net, &p->raddr, NULL, 0))) printk(KERN_WARNING "%s xmit: Routing loop! " "Remote address found on this node!\n", p->name); else ret = 1; if (ldev) dev_put(ldev); } return ret; } /** * ip6_tnl_xmit2 - encapsulate packet and send * @skb: the outgoing socket buffer * @dev: the outgoing tunnel device * @dsfield: dscp code for outer header * @fl: flow of tunneled packet * @encap_limit: encapsulation limit * @pmtu: Path MTU is stored if packet is too big * * Description: * Build new header and do some sanity checks on the packet before sending * it. * * Return: * 0 on success * -1 fail * %-EMSGSIZE message too big. return mtu in this case. **/ static int ip6_tnl_xmit2(struct sk_buff *skb, struct net_device *dev, __u8 dsfield, struct flowi *fl, int encap_limit, __u32 *pmtu) { struct ip6_tnl *t = netdev_priv(dev); struct net_device_stats *stats = &t->dev->stats; struct ipv6hdr *ipv6h = ipv6_hdr(skb); struct iphdr *iph = ip_hdr(skb); struct ipv6_tel_txoption opt; struct dst_entry *dst; struct net_device *tdev; int mtu; unsigned int max_headroom = sizeof(struct ipv6hdr); u8 proto; int err = -1; int pkt_len; if ((dst = ip6_tnl_dst_check(t)) != NULL) dst_hold(dst); else { dst = ip6_route_output(dev_net(dev), 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 (encap_limit >= 0) { max_headroom += 8; mtu -= 8; } if (mtu < IPV6_MIN_MTU) mtu = IPV6_MIN_MTU; if (skb->dst) skb->dst->ops->update_pmtu(skb->dst, mtu); if (skb->len > mtu && (iph->frag_off & htons(IP_DF))) { *pmtu = mtu; err = -EMSGSIZE; 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_shared(skb) || (skb_cloned(skb) && !skb_clone_writable(skb, 0))) { 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->transport_header = skb->network_header; proto = fl->proto; if (encap_limit >= 0) { init_tel_txopt(&opt, encap_limit); ipv6_push_nfrag_opts(skb, &opt.ops, &proto, NULL); } skb_push(skb, sizeof(struct ipv6hdr)); skb_reset_network_header(skb); ipv6h = ipv6_hdr(skb); *(__be32*)ipv6h = fl->fl6_flowlabel | htonl(0x60000000); dsfield = INET_ECN_encapsulate(0, dsfield); ipv6_change_dsfield(ipv6h, ~INET_ECN_MASK, dsfield); 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; skb->local_df =1; err = ip6_local_out(skb); if (net_xmit_eval(err) == 0) { stats->tx_bytes += pkt_len; stats->tx_packets++; } else { stats->tx_errors++; stats->tx_aborted_errors++; } ip6_tnl_dst_store(t, dst); return 0; tx_err_link_failure: stats->tx_carrier_errors++; dst_link_failure(skb); tx_err_dst_release: dst_release(dst); return err; } static inline int ip4ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev) { struct ip6_tnl *t = netdev_priv(dev); struct iphdr *iph = ip_hdr(skb); int encap_limit = -1; struct flowi fl; __u8 dsfield; __u32 mtu; int err; if ((t->parms.proto != IPPROTO_IPIP && t->parms.proto != 0) || !ip6_tnl_xmit_ctl(t)) return -1; if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT)) encap_limit = t->parms.encap_limit; memcpy(&fl, &t->fl, sizeof (fl)); fl.proto = IPPROTO_IPIP; dsfield = ipv4_get_dsfield(iph); if ((t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)) fl.fl6_flowlabel |= htonl((__u32)iph->tos << IPV6_TCLASS_SHIFT) & IPV6_TCLASS_MASK; err = ip6_tnl_xmit2(skb, dev, dsfield, &fl, encap_limit, &mtu); if (err != 0) { /* XXX: send ICMP error even if DF is not set. */ if (err == -EMSGSIZE) icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu)); return -1; } return 0; } static inline int ip6ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev) { struct ip6_tnl *t = netdev_priv(dev); struct ipv6hdr *ipv6h = ipv6_hdr(skb); int encap_limit = -1; __u16 offset; struct flowi fl; __u8 dsfield; __u32 mtu; int err; if ((t->parms.proto != IPPROTO_IPV6 && t->parms.proto != 0) || !ip6_tnl_xmit_ctl(t) || ip6_tnl_addr_conflict(t, ipv6h)) return -1; offset = parse_tlv_tnl_enc_lim(skb, skb_network_header(skb)); if (offset > 0) { struct ipv6_tlv_tnl_enc_lim *tel; tel = (struct ipv6_tlv_tnl_enc_lim *)&skb_network_header(skb)[offset]; if (tel->encap_limit == 0) { icmpv6_send(skb, ICMPV6_PARAMPROB, ICMPV6_HDR_FIELD, offset + 2, skb->dev); return -1; } 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)); fl.proto = IPPROTO_IPV6; dsfield = ipv6_get_dsfield(ipv6h); if ((t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)) fl.fl6_flowlabel |= (*(__be32 *) ipv6h & IPV6_TCLASS_MASK); if ((t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL)) fl.fl6_flowlabel |= (*(__be32 *) ipv6h & IPV6_FLOWLABEL_MASK); err = ip6_tnl_xmit2(skb, dev, dsfield, &fl, encap_limit, &mtu); if (err != 0) { if (err == -EMSGSIZE) icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, dev); return -1; } return 0; } static int ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev) { struct ip6_tnl *t = netdev_priv(dev); struct net_device_stats *stats = &t->dev->stats; int ret; if (t->recursion++) { stats->collisions++; goto tx_err; } switch (skb->protocol) { case htons(ETH_P_IP): ret = ip4ip6_tnl_xmit(skb, dev); break; case htons(ETH_P_IPV6): ret = ip6ip6_tnl_xmit(skb, dev); break; default: goto tx_err; } if (ret < 0) goto tx_err; t->recursion--; return 0; 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; int ltype = ipv6_addr_type(&p->laddr); int rtype = ipv6_addr_type(&p->raddr); p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV); if (ltype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) && rtype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) && !((ltype|rtype) & IPV6_ADDR_LOOPBACK) && (!((ltype|rtype) & IPV6_ADDR_LINKLOCAL) || p->link)) { if (ltype&IPV6_ADDR_UNICAST) p->flags |= IP6_TNL_F_CAP_XMIT; if (rtype&IPV6_ADDR_UNICAST) p->flags |= IP6_TNL_F_CAP_RCV; } } static void ip6_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) { int strict = (ipv6_addr_type(&p->raddr) & (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL)); struct rt6_info *rt = rt6_lookup(dev_net(dev), &p->raddr, &p->laddr, p->link, strict); 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); } } /** * ip6_tnl_change - update the tunnel parameters * @t: tunnel to be changed * @p: tunnel configuration parameters * @active: != 0 if tunnel is ready for use * * Description: * ip6_tnl_change() updates the tunnel parameters **/ static int ip6_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; t->parms.link = p->link; t->parms.proto = p->proto; ip6_tnl_dst_reset(t); ip6_tnl_link_config(t); return 0; } /** * ip6_tnl_ioctl - configure ipv6 tunnels from userspace * @dev: virtual device associated with tunnel * @ifr: parameters passed from userspace * @cmd: command to be performed * * Description: * ip6_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 ip6_tnl_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd) { int err = 0; struct ip6_tnl_parm p; struct ip6_tnl *t = NULL; struct net *net = dev_net(dev); struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); switch (cmd) { case SIOCGETTUNNEL: if (dev == ip6n->fb_tnl_dev) { if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof (p))) { err = -EFAULT; break; } t = ip6_tnl_locate(net, &p, 0); } if (t == NULL) t = netdev_priv(dev); 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; if (!capable(CAP_NET_ADMIN)) break; err = -EFAULT; if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof (p))) break; err = -EINVAL; if (p.proto != IPPROTO_IPV6 && p.proto != IPPROTO_IPIP && p.proto != 0) break; t = ip6_tnl_locate(net, &p, cmd == SIOCADDTUNNEL); if (dev != ip6n->fb_tnl_dev && cmd == SIOCCHGTUNNEL) { if (t != NULL) { if (t->dev != dev) { err = -EEXIST; break; } } else t = netdev_priv(dev); ip6_tnl_unlink(ip6n, t); err = ip6_tnl_change(t, &p); ip6_tnl_link(ip6n, t); netdev_state_change(dev); } if (t) { err = 0; if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof (p))) err = -EFAULT; } else err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT); break; case SIOCDELTUNNEL: err = -EPERM; if (!capable(CAP_NET_ADMIN)) break; if (dev == ip6n->fb_tnl_dev) { err = -EFAULT; if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof (p))) break; err = -ENOENT; if ((t = ip6_tnl_locate(net, &p, 0)) == NULL) break; err = -EPERM; if (t->dev == ip6n->fb_tnl_dev) break; dev = t->dev; } err = 0; unregister_netdevice(dev); break; default: err = -EINVAL; } return err; } /** * ip6_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 ip6_tnl_change_mtu(struct net_device *dev, int new_mtu) { if (new_mtu < IPV6_MIN_MTU) { return -EINVAL; } dev->mtu = new_mtu; return 0; } /** * ip6_tnl_dev_setup - setup virtual tunnel device * @dev: virtual device associated with tunnel * * Description: * Initialize function pointers and device parameters **/ static void ip6_tnl_dev_setup(struct net_device *dev) { dev->uninit = ip6_tnl_dev_uninit; dev->destructor = free_netdev; dev->hard_start_xmit = ip6_tnl_xmit; dev->do_ioctl = ip6_tnl_ioctl; dev->change_mtu = ip6_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); dev->features |= NETIF_F_NETNS_LOCAL | NETIF_F_DF_RFC2473; } /** * ip6_tnl_dev_init_gen - general initializer for all tunnel devices * @dev: virtual device associated with tunnel **/ static inline void ip6_tnl_dev_init_gen(struct net_device *dev) { struct ip6_tnl *t = netdev_priv(dev); t->dev = dev; strcpy(t->parms.name, dev->name); } /** * ip6_tnl_dev_init - initializer for all non fallback tunnel devices * @dev: virtual device associated with tunnel **/ static int ip6_tnl_dev_init(struct net_device *dev) { struct ip6_tnl *t = netdev_priv(dev); ip6_tnl_dev_init_gen(dev); ip6_tnl_link_config(t); return 0; } /** * ip6_fb_tnl_dev_init - initializer for fallback tunnel device * @dev: fallback device * * Return: 0 **/ static int ip6_fb_tnl_dev_init(struct net_device *dev) { struct ip6_tnl *t = netdev_priv(dev); struct net *net = dev_net(dev); struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); ip6_tnl_dev_init_gen(dev); t->parms.proto = IPPROTO_IPV6; dev_hold(dev); ip6n->tnls_wc[0] = t; return 0; } static struct xfrm6_tunnel ip4ip6_handler = { .handler = ip4ip6_rcv, .err_handler = ip4ip6_err, .priority = 1, }; static struct xfrm6_tunnel ip6ip6_handler = { .handler = ip6ip6_rcv, .err_handler = ip6ip6_err, .priority = 1, }; static void ip6_tnl_destroy_tunnels(struct ip6_tnl_net *ip6n) { int h; struct ip6_tnl *t; for (h = 0; h < HASH_SIZE; h++) { while ((t = ip6n->tnls_r_l[h]) != NULL) unregister_netdevice(t->dev); } t = ip6n->tnls_wc[0]; unregister_netdevice(t->dev); } static int ip6_tnl_init_net(struct net *net) { int err; struct ip6_tnl_net *ip6n; err = -ENOMEM; ip6n = kzalloc(sizeof(struct ip6_tnl_net), GFP_KERNEL); if (ip6n == NULL) goto err_alloc; err = net_assign_generic(net, ip6_tnl_net_id, ip6n); if (err < 0) goto err_assign; ip6n->tnls[0] = ip6n->tnls_wc; ip6n->tnls[1] = ip6n->tnls_r_l; err = -ENOMEM; ip6n->fb_tnl_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6tnl0", ip6_tnl_dev_setup); if (!ip6n->fb_tnl_dev) goto err_alloc_dev; ip6n->fb_tnl_dev->init = ip6_fb_tnl_dev_init; dev_net_set(ip6n->fb_tnl_dev, net); err = register_netdev(ip6n->fb_tnl_dev); if (err < 0) goto err_register; return 0; err_register: free_netdev(ip6n->fb_tnl_dev); err_alloc_dev: /* nothing */ err_assign: kfree(ip6n); err_alloc: return err; } static void ip6_tnl_exit_net(struct net *net) { struct ip6_tnl_net *ip6n; ip6n = net_generic(net, ip6_tnl_net_id); rtnl_lock(); ip6_tnl_destroy_tunnels(ip6n); rtnl_unlock(); kfree(ip6n); } static struct pernet_operations ip6_tnl_net_ops = { .init = ip6_tnl_init_net, .exit = ip6_tnl_exit_net, }; /** * 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(&ip4ip6_handler, AF_INET)) { printk(KERN_ERR "ip6_tunnel init: can't register ip4ip6\n"); err = -EAGAIN; goto out; } if (xfrm6_tunnel_register(&ip6ip6_handler, AF_INET6)) { printk(KERN_ERR "ip6_tunnel init: can't register ip6ip6\n"); err = -EAGAIN; goto unreg_ip4ip6; } err = register_pernet_gen_device(&ip6_tnl_net_id, &ip6_tnl_net_ops); if (err < 0) goto err_pernet; return 0; err_pernet: xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6); unreg_ip4ip6: xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET); out: return err; } /** * ip6_tunnel_cleanup - free resources and unregister protocol **/ static void __exit ip6_tunnel_cleanup(void) { if (xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET)) printk(KERN_INFO "ip6_tunnel close: can't deregister ip4ip6\n"); if (xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6)) printk(KERN_INFO "ip6_tunnel close: can't deregister ip6ip6\n"); unregister_pernet_gen_device(ip6_tnl_net_id, &ip6_tnl_net_ops); } module_init(ip6_tunnel_init); module_exit(ip6_tunnel_cleanup);