/* * Neighbour Discovery for IPv6 * Linux INET6 implementation * * Authors: * Pedro Roque * Mike Shaver * * 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. */ /* * Changes: * * Lars Fenneberg : fixed MTU setting on receipt * of an RA. * * Janos Farkas : kmalloc failure checks * Alexey Kuznetsov : state machine reworked * and moved to net/core. * Pekka Savola : RFC2461 validation * YOSHIFUJI Hideaki @USAGI : Verify ND options properly */ /* Set to 3 to get tracing... */ #define ND_DEBUG 1 #define ND_PRINTK(x...) printk(KERN_DEBUG x) #define ND_NOPRINTK(x...) do { ; } while(0) #define ND_PRINTK0 ND_PRINTK #define ND_PRINTK1 ND_NOPRINTK #define ND_PRINTK2 ND_NOPRINTK #if ND_DEBUG >= 1 #undef ND_PRINTK1 #define ND_PRINTK1 ND_PRINTK #endif #if ND_DEBUG >= 2 #undef ND_PRINTK2 #define ND_PRINTK2 ND_PRINTK #endif #include #include #include #include #include #include #include #include #include #include #include #ifdef CONFIG_SYSCTL #include #endif #include #include #include #include #include #include #include #include #include #include #include #include #include #include static struct socket *ndisc_socket; static u32 ndisc_hash(const void *pkey, const struct net_device *dev); static int ndisc_constructor(struct neighbour *neigh); static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb); static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb); static int pndisc_constructor(struct pneigh_entry *n); static void pndisc_destructor(struct pneigh_entry *n); static void pndisc_redo(struct sk_buff *skb); static struct neigh_ops ndisc_generic_ops = { AF_INET6, NULL, ndisc_solicit, ndisc_error_report, neigh_resolve_output, neigh_connected_output, dev_queue_xmit, dev_queue_xmit }; static struct neigh_ops ndisc_hh_ops = { AF_INET6, NULL, ndisc_solicit, ndisc_error_report, neigh_resolve_output, neigh_resolve_output, dev_queue_xmit, dev_queue_xmit }; static struct neigh_ops ndisc_direct_ops = { AF_INET6, NULL, NULL, NULL, dev_queue_xmit, dev_queue_xmit, dev_queue_xmit, dev_queue_xmit }; struct neigh_table nd_tbl = { NULL, AF_INET6, sizeof(struct neighbour) + sizeof(struct in6_addr), sizeof(struct in6_addr), ndisc_hash, ndisc_constructor, pndisc_constructor, pndisc_destructor, pndisc_redo, "ndisc_cache", { NULL, NULL, &nd_tbl, 0, NULL, NULL, 30*HZ, 1*HZ, 60*HZ, 30*HZ, 5*HZ, 3, 3, 0, 3, 1*HZ, (8*HZ)/10, 64, 0 }, 30*HZ, 128, 512, 1024, }; #define NDISC_OPT_SPACE(len) (((len)+2+7)&~7) static u8 *ndisc_fill_option(u8 *opt, int type, void *data, int data_len) { int space = NDISC_OPT_SPACE(data_len); opt[0] = type; opt[1] = space>>3; memcpy(opt+2, data, data_len); data_len += 2; opt += data_len; if ((space -= data_len) > 0) memset(opt, 0, space); return opt + space; } struct nd_opt_hdr *ndisc_next_option(struct nd_opt_hdr *cur, struct nd_opt_hdr *end) { int type; if (!cur || !end || cur >= end) return NULL; type = cur->nd_opt_type; do { cur = ((void *)cur) + (cur->nd_opt_len << 3); } while(cur < end && cur->nd_opt_type != type); return (cur <= end && cur->nd_opt_type == type ? cur : NULL); } struct ndisc_options *ndisc_parse_options(u8 *opt, int opt_len, struct ndisc_options *ndopts) { struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)opt; if (!nd_opt || opt_len < 0 || !ndopts) return NULL; memset(ndopts, 0, sizeof(*ndopts)); while (opt_len) { int l; if (opt_len < sizeof(struct nd_opt_hdr)) return NULL; l = nd_opt->nd_opt_len << 3; if (opt_len < l || l == 0) return NULL; switch (nd_opt->nd_opt_type) { case ND_OPT_SOURCE_LL_ADDR: case ND_OPT_TARGET_LL_ADDR: case ND_OPT_MTU: case ND_OPT_REDIRECT_HDR: if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) { ND_PRINTK2((KERN_WARNING "ndisc_parse_options(): duplicated ND6 option found: type=%d\n", nd_opt->nd_opt_type)); } else { ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt; } break; case ND_OPT_PREFIX_INFO: ndopts->nd_opts_pi_end = nd_opt; if (ndopts->nd_opt_array[nd_opt->nd_opt_type] == 0) ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt; break; default: /* * Unknown options must be silently ignored, * to accomodate future extension to the protocol. */ ND_PRINTK2(KERN_WARNING "ndisc_parse_options(): ignored unsupported option; type=%d, len=%d\n", nd_opt->nd_opt_type, nd_opt->nd_opt_len); } opt_len -= l; nd_opt = ((void *)nd_opt) + l; } return ndopts; } int ndisc_mc_map(struct in6_addr *addr, char *buf, struct net_device *dev, int dir) { switch (dev->type) { case ARPHRD_ETHER: case ARPHRD_IEEE802: /* Not sure. Check it later. --ANK */ case ARPHRD_FDDI: ipv6_eth_mc_map(addr, buf); return 0; case ARPHRD_IEEE802_TR: ipv6_tr_mc_map(addr,buf); return 0; case ARPHRD_ARCNET: ipv6_arcnet_mc_map(addr, buf); return 0; default: if (dir) { memcpy(buf, dev->broadcast, dev->addr_len); return 0; } } return -EINVAL; } static u32 ndisc_hash(const void *pkey, const struct net_device *dev) { const u32 *p32 = pkey; u32 addr_hash, i; addr_hash = 0; for (i = 0; i < (sizeof(struct in6_addr) / sizeof(u32)); i++) addr_hash ^= *p32++; return jhash_2words(addr_hash, dev->ifindex, nd_tbl.hash_rnd); } static int ndisc_constructor(struct neighbour *neigh) { struct in6_addr *addr = (struct in6_addr*)&neigh->primary_key; struct net_device *dev = neigh->dev; struct inet6_dev *in6_dev = in6_dev_get(dev); int addr_type; if (in6_dev == NULL) return -EINVAL; addr_type = ipv6_addr_type(addr); if (in6_dev->nd_parms) neigh->parms = in6_dev->nd_parms; if (addr_type&IPV6_ADDR_MULTICAST) neigh->type = RTN_MULTICAST; else neigh->type = RTN_UNICAST; if (dev->hard_header == NULL) { neigh->nud_state = NUD_NOARP; neigh->ops = &ndisc_direct_ops; neigh->output = neigh->ops->queue_xmit; } else { if (addr_type&IPV6_ADDR_MULTICAST) { neigh->nud_state = NUD_NOARP; ndisc_mc_map(addr, neigh->ha, dev, 1); } else if (dev->flags&(IFF_NOARP|IFF_LOOPBACK)) { neigh->nud_state = NUD_NOARP; memcpy(neigh->ha, dev->dev_addr, dev->addr_len); if (dev->flags&IFF_LOOPBACK) neigh->type = RTN_LOCAL; } else if (dev->flags&IFF_POINTOPOINT) { neigh->nud_state = NUD_NOARP; memcpy(neigh->ha, dev->broadcast, dev->addr_len); } if (dev->hard_header_cache) neigh->ops = &ndisc_hh_ops; else neigh->ops = &ndisc_generic_ops; if (neigh->nud_state&NUD_VALID) neigh->output = neigh->ops->connected_output; else neigh->output = neigh->ops->output; } in6_dev_put(in6_dev); return 0; } static int pndisc_constructor(struct pneigh_entry *n) { struct in6_addr *addr = (struct in6_addr*)&n->key; struct in6_addr maddr; struct net_device *dev = n->dev; if (dev == NULL || __in6_dev_get(dev) == NULL) return -EINVAL; addrconf_addr_solict_mult(addr, &maddr); ipv6_dev_mc_inc(dev, &maddr); return 0; } static void pndisc_destructor(struct pneigh_entry *n) { struct in6_addr *addr = (struct in6_addr*)&n->key; struct in6_addr maddr; struct net_device *dev = n->dev; if (dev == NULL || __in6_dev_get(dev) == NULL) return; addrconf_addr_solict_mult(addr, &maddr); ipv6_dev_mc_dec(dev, &maddr); } static int ndisc_build_ll_hdr(struct sk_buff *skb, struct net_device *dev, struct in6_addr *daddr, struct neighbour *neigh, int len) { unsigned char ha[MAX_ADDR_LEN]; unsigned char *h_dest = NULL; skb_reserve(skb, (dev->hard_header_len + 15) & ~15); if (dev->hard_header) { if (ipv6_addr_type(daddr) & IPV6_ADDR_MULTICAST) { ndisc_mc_map(daddr, ha, dev, 1); h_dest = ha; } else if (neigh) { read_lock_bh(&neigh->lock); if (neigh->nud_state&NUD_VALID) { memcpy(ha, neigh->ha, dev->addr_len); h_dest = ha; } read_unlock_bh(&neigh->lock); } else { neigh = neigh_lookup(&nd_tbl, daddr, dev); if (neigh) { read_lock_bh(&neigh->lock); if (neigh->nud_state&NUD_VALID) { memcpy(ha, neigh->ha, dev->addr_len); h_dest = ha; } read_unlock_bh(&neigh->lock); neigh_release(neigh); } } if (dev->hard_header(skb, dev, ETH_P_IPV6, h_dest, NULL, len) < 0) return 0; } return 1; } /* * Send a Neighbour Advertisement */ void ndisc_send_na(struct net_device *dev, struct neighbour *neigh, struct in6_addr *daddr, struct in6_addr *solicited_addr, int router, int solicited, int override, int inc_opt) { static struct in6_addr tmpaddr; struct inet6_ifaddr *ifp; struct sock *sk = ndisc_socket->sk; struct in6_addr *src_addr; struct nd_msg *msg; int len; struct sk_buff *skb; int err; len = sizeof(struct icmp6hdr) + sizeof(struct in6_addr); if (inc_opt) { if (dev->addr_len) len += NDISC_OPT_SPACE(dev->addr_len); else inc_opt = 0; } skb = sock_alloc_send_skb(sk, MAX_HEADER + len + dev->hard_header_len + 15, 1, &err); if (skb == NULL) { ND_PRINTK1("send_na: alloc skb failed\n"); return; } /* for anycast or proxy, solicited_addr != src_addr */ ifp = ipv6_get_ifaddr(solicited_addr, dev); if (ifp) { src_addr = solicited_addr; in6_ifa_put(ifp); } else { if (ipv6_dev_get_saddr(dev, daddr, &tmpaddr, 0)) return; src_addr = &tmpaddr; } if (ndisc_build_ll_hdr(skb, dev, daddr, neigh, len) == 0) { kfree_skb(skb); return; } ip6_nd_hdr(sk, skb, dev, src_addr, daddr, IPPROTO_ICMPV6, len); msg = (struct nd_msg *) skb_put(skb, len); msg->icmph.icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT; msg->icmph.icmp6_code = 0; msg->icmph.icmp6_cksum = 0; msg->icmph.icmp6_unused = 0; msg->icmph.icmp6_router = router; msg->icmph.icmp6_solicited = solicited; msg->icmph.icmp6_override = !!override; /* Set the target address. */ ipv6_addr_copy(&msg->target, solicited_addr); if (inc_opt) ndisc_fill_option(msg->opt, ND_OPT_TARGET_LL_ADDR, dev->dev_addr, dev->addr_len); /* checksum */ msg->icmph.icmp6_cksum = csum_ipv6_magic(src_addr, daddr, len, IPPROTO_ICMPV6, csum_partial((__u8 *) msg, len, 0)); dev_queue_xmit(skb); ICMP6_INC_STATS(Icmp6OutNeighborAdvertisements); ICMP6_INC_STATS(Icmp6OutMsgs); } void ndisc_send_ns(struct net_device *dev, struct neighbour *neigh, struct in6_addr *solicit, struct in6_addr *daddr, struct in6_addr *saddr) { struct sock *sk = ndisc_socket->sk; struct sk_buff *skb; struct nd_msg *msg; struct in6_addr addr_buf; int len; int err; int send_llinfo; if (saddr == NULL) { if (ipv6_get_lladdr(dev, &addr_buf)) return; saddr = &addr_buf; } len = sizeof(struct icmp6hdr) + sizeof(struct in6_addr); send_llinfo = dev->addr_len && ipv6_addr_type(saddr) != IPV6_ADDR_ANY; if (send_llinfo) len += NDISC_OPT_SPACE(dev->addr_len); skb = sock_alloc_send_skb(sk, MAX_HEADER + len + dev->hard_header_len + 15, 1, &err); if (skb == NULL) { ND_PRINTK1("send_ns: alloc skb failed\n"); return; } if (ndisc_build_ll_hdr(skb, dev, daddr, neigh, len) == 0) { kfree_skb(skb); return; } ip6_nd_hdr(sk, skb, dev, saddr, daddr, IPPROTO_ICMPV6, len); msg = (struct nd_msg *)skb_put(skb, len); msg->icmph.icmp6_type = NDISC_NEIGHBOUR_SOLICITATION; msg->icmph.icmp6_code = 0; msg->icmph.icmp6_cksum = 0; msg->icmph.icmp6_unused = 0; /* Set the target address. */ ipv6_addr_copy(&msg->target, solicit); if (send_llinfo) ndisc_fill_option(msg->opt, ND_OPT_SOURCE_LL_ADDR, dev->dev_addr, dev->addr_len); /* checksum */ msg->icmph.icmp6_cksum = csum_ipv6_magic(&skb->nh.ipv6h->saddr, daddr, len, IPPROTO_ICMPV6, csum_partial((__u8 *) msg, len, 0)); /* send it! */ dev_queue_xmit(skb); ICMP6_INC_STATS(Icmp6OutNeighborSolicits); ICMP6_INC_STATS(Icmp6OutMsgs); } void ndisc_send_rs(struct net_device *dev, struct in6_addr *saddr, struct in6_addr *daddr) { struct sock *sk = ndisc_socket->sk; struct sk_buff *skb; struct icmp6hdr *hdr; __u8 * opt; int len; int err; len = sizeof(struct icmp6hdr); if (dev->addr_len) len += NDISC_OPT_SPACE(dev->addr_len); skb = sock_alloc_send_skb(sk, MAX_HEADER + len + dev->hard_header_len + 15, 1, &err); if (skb == NULL) { ND_PRINTK1("send_ns: alloc skb failed\n"); return; } if (ndisc_build_ll_hdr(skb, dev, daddr, NULL, len) == 0) { kfree_skb(skb); return; } ip6_nd_hdr(sk, skb, dev, saddr, daddr, IPPROTO_ICMPV6, len); hdr = (struct icmp6hdr *) skb_put(skb, len); hdr->icmp6_type = NDISC_ROUTER_SOLICITATION; hdr->icmp6_code = 0; hdr->icmp6_cksum = 0; hdr->icmp6_unused = 0; opt = (u8*) (hdr + 1); if (dev->addr_len) ndisc_fill_option(opt, ND_OPT_SOURCE_LL_ADDR, dev->dev_addr, dev->addr_len); /* checksum */ hdr->icmp6_cksum = csum_ipv6_magic(&skb->nh.ipv6h->saddr, daddr, len, IPPROTO_ICMPV6, csum_partial((__u8 *) hdr, len, 0)); /* send it! */ dev_queue_xmit(skb); ICMP6_INC_STATS(Icmp6OutRouterSolicits); ICMP6_INC_STATS(Icmp6OutMsgs); } static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb) { /* * "The sender MUST return an ICMP * destination unreachable" */ dst_link_failure(skb); kfree_skb(skb); } /* Called with locked neigh: either read or both */ static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb) { struct in6_addr *saddr = NULL; struct in6_addr mcaddr; struct net_device *dev = neigh->dev; struct in6_addr *target = (struct in6_addr *)&neigh->primary_key; int probes = atomic_read(&neigh->probes); if (skb && ipv6_chk_addr(&skb->nh.ipv6h->saddr, dev)) saddr = &skb->nh.ipv6h->saddr; if ((probes -= neigh->parms->ucast_probes) < 0) { if (!(neigh->nud_state&NUD_VALID)) ND_PRINTK1("trying to ucast probe in NUD_INVALID\n"); ndisc_send_ns(dev, neigh, target, target, saddr); } else if ((probes -= neigh->parms->app_probes) < 0) { #ifdef CONFIG_ARPD neigh_app_ns(neigh); #endif } else { addrconf_addr_solict_mult(target, &mcaddr); ndisc_send_ns(dev, NULL, target, &mcaddr, saddr); } } void ndisc_recv_ns(struct sk_buff *skb) { struct nd_msg *msg = (struct nd_msg *)skb->h.raw; struct in6_addr *saddr = &skb->nh.ipv6h->saddr; struct in6_addr *daddr = &skb->nh.ipv6h->daddr; u8 *lladdr = NULL; int lladdrlen = 0; u32 ndoptlen = skb->tail - msg->opt; struct ndisc_options ndopts; struct net_device *dev = skb->dev; struct inet6_ifaddr *ifp; struct neighbour *neigh; if (skb->len < sizeof(struct nd_msg)) { if (net_ratelimit()) printk(KERN_WARNING "ICMP NS: packet too short\n"); return; } if (ipv6_addr_type(&msg->target)&IPV6_ADDR_MULTICAST) { if (net_ratelimit()) printk(KERN_WARNING "ICMP NS: target address is multicast\n"); return; } if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts)) { if (net_ratelimit()) printk(KERN_WARNING "ICMP NS: invalid ND option, ignored.\n"); return; } if (ndopts.nd_opts_src_lladdr) { lladdr = (u8*)(ndopts.nd_opts_src_lladdr + 1); lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3; if (lladdrlen != NDISC_OPT_SPACE(dev->addr_len)) { if (net_ratelimit()) printk(KERN_WARNING "ICMP NS: bad lladdr length.\n"); return; } } /* XXX: RFC2461 7.1.1: * If the IP source address is the unspecified address, there * MUST NOT be source link-layer address option in the message. * * NOTE! Linux kernel < 2.4.4 broke this rule. */ /* XXX: RFC2461 7.1.1: * If the IP source address is the unspecified address, the IP * destination address MUST be a solicited-node multicast address. */ if ((ifp = ipv6_get_ifaddr(&msg->target, dev)) != NULL) { int addr_type = ipv6_addr_type(saddr); if (ifp->flags & IFA_F_TENTATIVE) { /* Address is tentative. If the source is unspecified address, it is someone does DAD, otherwise we ignore solicitations until DAD timer expires. */ if (addr_type == IPV6_ADDR_ANY) { if (dev->type == ARPHRD_IEEE802_TR) { unsigned char *sadr = skb->mac.raw ; if (((sadr[8] &0x7f) != (dev->dev_addr[0] & 0x7f)) || (sadr[9] != dev->dev_addr[1]) || (sadr[10] != dev->dev_addr[2]) || (sadr[11] != dev->dev_addr[3]) || (sadr[12] != dev->dev_addr[4]) || (sadr[13] != dev->dev_addr[5])) { addrconf_dad_failure(ifp) ; } } else { addrconf_dad_failure(ifp); } } else in6_ifa_put(ifp); return; } if (addr_type == IPV6_ADDR_ANY) { struct in6_addr maddr; ipv6_addr_all_nodes(&maddr); ndisc_send_na(dev, NULL, &maddr, &ifp->addr, ifp->idev->cnf.forwarding, 0, ipv6_addr_type(&ifp->addr)&IPV6_ADDR_ANYCAST ? 0 : 1, 1); in6_ifa_put(ifp); return; } if (addr_type & IPV6_ADDR_UNICAST) { int inc = ipv6_addr_type(daddr)&IPV6_ADDR_MULTICAST; if (inc) NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_mcast); else NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_ucast); /* * update / create cache entry * for the source adddress */ neigh = neigh_event_ns(&nd_tbl, lladdr, saddr, dev); if (neigh || !dev->hard_header) { ndisc_send_na(dev, neigh, saddr, &ifp->addr, ifp->idev->cnf.forwarding, 1, ipv6_addr_type(&ifp->addr)&IPV6_ADDR_ANYCAST ? 0 : 1, 1); if (neigh) neigh_release(neigh); } } in6_ifa_put(ifp); } else if (ipv6_chk_acast_addr(dev, &msg->target)) { struct inet6_dev *idev = in6_dev_get(dev); int addr_type = ipv6_addr_type(saddr); /* anycast */ if (!idev) { /* XXX: count this drop? */ return; } if (addr_type == IPV6_ADDR_ANY) { struct in6_addr maddr; ipv6_addr_all_nodes(&maddr); ndisc_send_na(dev, NULL, &maddr, &msg->target, idev->cnf.forwarding, 0, 0, 1); in6_dev_put(idev); return; } if (addr_type & IPV6_ADDR_UNICAST) { int inc = ipv6_addr_type(daddr)&IPV6_ADDR_MULTICAST; if (inc) NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_mcast); else NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_ucast); /* * update / create cache entry * for the source adddress */ neigh = neigh_event_ns(&nd_tbl, lladdr, saddr, skb->dev); if (neigh || !dev->hard_header) { ndisc_send_na(dev, neigh, saddr, &msg->target, idev->cnf.forwarding, 1, 0, inc); if (neigh) neigh_release(neigh); } } in6_dev_put(idev); } else { struct inet6_dev *in6_dev = in6_dev_get(dev); int addr_type = ipv6_addr_type(saddr); if (in6_dev && in6_dev->cnf.forwarding && (addr_type & IPV6_ADDR_UNICAST) && pneigh_lookup(&nd_tbl, &msg->target, dev, 0)) { int inc = ipv6_addr_type(daddr)&IPV6_ADDR_MULTICAST; if (skb->stamp.tv_sec == 0 || skb->pkt_type == PACKET_HOST || inc == 0 || in6_dev->nd_parms->proxy_delay == 0) { if (inc) NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_mcast); else NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_ucast); neigh = neigh_event_ns(&nd_tbl, lladdr, saddr, dev); if (neigh) { ndisc_send_na(dev, neigh, saddr, &msg->target, 0, 1, 0, 1); neigh_release(neigh); } } else { struct sk_buff *n = skb_clone(skb, GFP_ATOMIC); if (n) pneigh_enqueue(&nd_tbl, in6_dev->nd_parms, n); in6_dev_put(in6_dev); return; } } if (in6_dev) in6_dev_put(in6_dev); } return; } void ndisc_recv_na(struct sk_buff *skb) { struct nd_msg *msg = (struct nd_msg *)skb->h.raw; struct in6_addr *saddr = &skb->nh.ipv6h->saddr; struct in6_addr *daddr = &skb->nh.ipv6h->daddr; u8 *lladdr = NULL; int lladdrlen = 0; u32 ndoptlen = skb->tail - msg->opt; struct ndisc_options ndopts; struct net_device *dev = skb->dev; struct inet6_ifaddr *ifp; struct neighbour *neigh; if (skb->len < sizeof(struct nd_msg)) { if (net_ratelimit()) printk(KERN_WARNING "ICMP NA: packet too short\n"); return; } if (ipv6_addr_type(&msg->target)&IPV6_ADDR_MULTICAST) { if (net_ratelimit()) printk(KERN_WARNING "NDISC NA: target address is multicast\n"); return; } if ((ipv6_addr_type(daddr)&IPV6_ADDR_MULTICAST) && msg->icmph.icmp6_solicited) { ND_PRINTK0("NDISC: solicited NA is multicasted\n"); return; } if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts)) { if (net_ratelimit()) printk(KERN_WARNING "ICMP NS: invalid ND option, ignored.\n"); return; } if (ndopts.nd_opts_tgt_lladdr) { lladdr = (u8*)(ndopts.nd_opts_tgt_lladdr + 1); lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3; if (lladdrlen != NDISC_OPT_SPACE(dev->addr_len)) { if (net_ratelimit()) printk(KERN_WARNING "NDISC NA: invalid lladdr length.\n"); return; } } if ((ifp = ipv6_get_ifaddr(&msg->target, dev))) { if (ifp->flags & IFA_F_TENTATIVE) { addrconf_dad_failure(ifp); return; } /* What should we make now? The advertisement is invalid, but ndisc specs say nothing about it. It could be misconfiguration, or an smart proxy agent tries to help us :-) */ ND_PRINTK0("%s: someone advertises our address!\n", ifp->idev->dev->name); in6_ifa_put(ifp); return; } neigh = neigh_lookup(&nd_tbl, &msg->target, dev); if (neigh) { if (neigh->flags & NTF_ROUTER) { if (msg->icmph.icmp6_router == 0) { /* * Change: router to host */ struct rt6_info *rt; rt = rt6_get_dflt_router(saddr, dev); if (rt) { /* It is safe only because we aer in BH */ dst_release(&rt->u.dst); ip6_del_rt(rt, NULL, NULL); } } } else { if (msg->icmph.icmp6_router) neigh->flags |= NTF_ROUTER; } neigh_update(neigh, lladdr, msg->icmph.icmp6_solicited ? NUD_REACHABLE : NUD_STALE, msg->icmph.icmp6_override, 1); neigh_release(neigh); } } static void ndisc_router_discovery(struct sk_buff *skb) { struct ra_msg *ra_msg = (struct ra_msg *) skb->h.raw; struct neighbour *neigh; struct inet6_dev *in6_dev; struct rt6_info *rt; int lifetime; struct ndisc_options ndopts; int optlen; __u8 * opt = (__u8 *)(ra_msg + 1); optlen = (skb->tail - skb->h.raw) - sizeof(struct ra_msg); if (!(ipv6_addr_type(&skb->nh.ipv6h->saddr) & IPV6_ADDR_LINKLOCAL)) { if (net_ratelimit()) printk(KERN_WARNING "ICMP RA: source address is not linklocal\n"); return; } if (optlen < 0) { if (net_ratelimit()) printk(KERN_WARNING "ICMP RA: packet too short\n"); return; } /* * set the RA_RECV flag in the interface */ in6_dev = in6_dev_get(skb->dev); if (in6_dev == NULL) { ND_PRINTK1("RA: can't find in6 device\n"); return; } if (in6_dev->cnf.forwarding || !in6_dev->cnf.accept_ra) { in6_dev_put(in6_dev); return; } if (!ndisc_parse_options(opt, optlen, &ndopts)) { in6_dev_put(in6_dev); if (net_ratelimit()) ND_PRINTK2(KERN_WARNING "ICMP6 RA: invalid ND option, ignored.\n"); return; } if (in6_dev->if_flags & IF_RS_SENT) { /* * flag that an RA was received after an RS was sent * out on this interface. */ in6_dev->if_flags |= IF_RA_RCVD; } /* * Remember the managed/otherconf flags from most recently * received RA message (RFC 2462) -- yoshfuji */ in6_dev->if_flags = (in6_dev->if_flags & ~(IF_RA_MANAGED | IF_RA_OTHERCONF)) | (ra_msg->icmph.icmp6_addrconf_managed ? IF_RA_MANAGED : 0) | (ra_msg->icmph.icmp6_addrconf_other ? IF_RA_OTHERCONF : 0); lifetime = ntohs(ra_msg->icmph.icmp6_rt_lifetime); rt = rt6_get_dflt_router(&skb->nh.ipv6h->saddr, skb->dev); if (rt && lifetime == 0) { ip6_del_rt(rt, NULL, NULL); rt = NULL; } if (rt == NULL && lifetime) { ND_PRINTK2("ndisc_rdisc: adding default router\n"); rt = rt6_add_dflt_router(&skb->nh.ipv6h->saddr, skb->dev); if (rt == NULL) { ND_PRINTK1("route_add failed\n"); in6_dev_put(in6_dev); return; } neigh = rt->rt6i_nexthop; if (neigh == NULL) { ND_PRINTK1("nd: add default router: null neighbour\n"); dst_release(&rt->u.dst); in6_dev_put(in6_dev); return; } neigh->flags |= NTF_ROUTER; /* * If we where using an "all destinations on link" route * delete it */ rt6_purge_dflt_routers(RTF_ALLONLINK); } if (rt) rt->rt6i_expires = jiffies + (HZ * lifetime); if (ra_msg->icmph.icmp6_hop_limit) in6_dev->cnf.hop_limit = ra_msg->icmph.icmp6_hop_limit; /* * Update Reachable Time and Retrans Timer */ if (in6_dev->nd_parms) { unsigned long rtime = ntohl(ra_msg->retrans_timer); if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/HZ) { rtime = (rtime*HZ)/1000; if (rtime < HZ/10) rtime = HZ/10; in6_dev->nd_parms->retrans_time = rtime; } rtime = ntohl(ra_msg->reachable_time); if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/(3*HZ)) { rtime = (rtime*HZ)/1000; if (rtime < HZ/10) rtime = HZ/10; if (rtime != in6_dev->nd_parms->base_reachable_time) { in6_dev->nd_parms->base_reachable_time = rtime; in6_dev->nd_parms->gc_staletime = 3 * rtime; in6_dev->nd_parms->reachable_time = neigh_rand_reach_time(rtime); } } } /* * Process options. */ if (rt && (neigh = rt->rt6i_nexthop) != NULL) { u8 *lladdr = NULL; int lladdrlen; if (ndopts.nd_opts_src_lladdr) { lladdr = (u8*)((ndopts.nd_opts_src_lladdr)+1); lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3; if (lladdrlen != NDISC_OPT_SPACE(skb->dev->addr_len)) { if (net_ratelimit()) ND_PRINTK2(KERN_WARNING "ICMP6 RA: Invalid lladdr length.\n"); goto out; } } neigh_update(neigh, lladdr, NUD_STALE, 1, 1); } if (ndopts.nd_opts_pi) { struct nd_opt_hdr *p; for (p = ndopts.nd_opts_pi; p; p = ndisc_next_option(p, ndopts.nd_opts_pi_end)) { addrconf_prefix_rcv(skb->dev, (u8*)p, (p->nd_opt_len) << 3); } } if (ndopts.nd_opts_mtu) { u32 mtu; memcpy(&mtu, ((u8*)(ndopts.nd_opts_mtu+1))+2, sizeof(mtu)); mtu = ntohl(mtu); if (mtu < IPV6_MIN_MTU || mtu > skb->dev->mtu) { if (net_ratelimit()) { ND_PRINTK0("NDISC: router announcement with mtu = %d\n", mtu); } } if (in6_dev->cnf.mtu6 != mtu) { in6_dev->cnf.mtu6 = mtu; if (rt) rt->u.dst.pmtu = mtu; rt6_mtu_change(skb->dev, mtu); } } if (ndopts.nd_opts_tgt_lladdr || ndopts.nd_opts_rh) { if (net_ratelimit()) ND_PRINTK0(KERN_WARNING "ICMP6 RA: got illegal option with RA"); } out: if (rt) dst_release(&rt->u.dst); in6_dev_put(in6_dev); } static void ndisc_redirect_rcv(struct sk_buff *skb) { struct inet6_dev *in6_dev; struct icmp6hdr *icmph; struct in6_addr *dest; struct in6_addr *target; /* new first hop to destination */ struct neighbour *neigh; int on_link = 0; struct ndisc_options ndopts; int optlen; u8 *lladdr = NULL; int lladdrlen; if (!(ipv6_addr_type(&skb->nh.ipv6h->saddr) & IPV6_ADDR_LINKLOCAL)) { if (net_ratelimit()) printk(KERN_WARNING "ICMP redirect: source address is not linklocal\n"); return; } optlen = skb->tail - skb->h.raw; optlen -= sizeof(struct icmp6hdr) + 2 * sizeof(struct in6_addr); if (optlen < 0) { if (net_ratelimit()) printk(KERN_WARNING "ICMP redirect: packet too small\n"); return; } icmph = (struct icmp6hdr *) skb->h.raw; target = (struct in6_addr *) (icmph + 1); dest = target + 1; if (ipv6_addr_type(dest) & IPV6_ADDR_MULTICAST) { if (net_ratelimit()) printk(KERN_WARNING "ICMP redirect for multicast addr\n"); return; } if (ipv6_addr_cmp(dest, target) == 0) { on_link = 1; } else if (!(ipv6_addr_type(target) & IPV6_ADDR_LINKLOCAL)) { if (net_ratelimit()) printk(KERN_WARNING "ICMP redirect: target address is not linklocal\n"); return; } in6_dev = in6_dev_get(skb->dev); if (!in6_dev) return; if (in6_dev->cnf.forwarding || !in6_dev->cnf.accept_redirects) { in6_dev_put(in6_dev); return; } /* XXX: RFC2461 8.1: * The IP source address of the Redirect MUST be the same as the current * first-hop router for the specified ICMP Destination Address. */ if (!ndisc_parse_options((u8*)(dest + 1), optlen, &ndopts)) { if (net_ratelimit()) ND_PRINTK2(KERN_WARNING "ICMP6 Redirect: invalid ND options, rejected.\n"); in6_dev_put(in6_dev); return; } if (ndopts.nd_opts_tgt_lladdr) { lladdr = (u8*)(ndopts.nd_opts_tgt_lladdr + 1); lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3; if (lladdrlen != NDISC_OPT_SPACE(skb->dev->addr_len)) { if (net_ratelimit()) ND_PRINTK2(KERN_WARNING "ICMP6 Redirect: invalid lladdr length.\n"); in6_dev_put(in6_dev); return; } } /* passed validation tests */ /* We install redirect only if nexthop state is valid. */ neigh = __neigh_lookup(&nd_tbl, target, skb->dev, 1); if (neigh) { neigh_update(neigh, lladdr, NUD_STALE, 1, 1); if (neigh->nud_state&NUD_VALID) rt6_redirect(dest, &skb->nh.ipv6h->saddr, neigh, on_link); else __neigh_event_send(neigh, NULL); neigh_release(neigh); } in6_dev_put(in6_dev); } void ndisc_send_redirect(struct sk_buff *skb, struct neighbour *neigh, struct in6_addr *target) { struct sock *sk = ndisc_socket->sk; int len = sizeof(struct icmp6hdr) + 2 * sizeof(struct in6_addr); struct sk_buff *buff; struct icmp6hdr *icmph; struct in6_addr saddr_buf; struct in6_addr *addrp; struct net_device *dev; struct rt6_info *rt; u8 *opt; int rd_len; int err; int hlen; dev = skb->dev; rt = rt6_lookup(&skb->nh.ipv6h->saddr, NULL, dev->ifindex, 1); if (rt == NULL) return; if (rt->rt6i_flags & RTF_GATEWAY) { ND_PRINTK1("ndisc_send_redirect: not a neighbour\n"); dst_release(&rt->u.dst); return; } if (!xrlim_allow(&rt->u.dst, 1*HZ)) { dst_release(&rt->u.dst); return; } dst_release(&rt->u.dst); if (dev->addr_len) { if (neigh->nud_state&NUD_VALID) { len += NDISC_OPT_SPACE(dev->addr_len); } else { /* If nexthop is not valid, do not redirect! We will make it later, when will be sure, that it is alive. */ return; } } rd_len = min_t(unsigned int, IPV6_MIN_MTU-sizeof(struct ipv6hdr)-len, skb->len + 8); rd_len &= ~0x7; len += rd_len; if (ipv6_get_lladdr(dev, &saddr_buf)) { ND_PRINTK1("redirect: no link_local addr for dev\n"); return; } buff = sock_alloc_send_skb(sk, MAX_HEADER + len + dev->hard_header_len + 15, 1, &err); if (buff == NULL) { ND_PRINTK1("ndisc_send_redirect: alloc_skb failed\n"); return; } hlen = 0; if (ndisc_build_ll_hdr(buff, dev, &skb->nh.ipv6h->saddr, NULL, len) == 0) { kfree_skb(buff); return; } ip6_nd_hdr(sk, buff, dev, &saddr_buf, &skb->nh.ipv6h->saddr, IPPROTO_ICMPV6, len); icmph = (struct icmp6hdr *) skb_put(buff, len); memset(icmph, 0, sizeof(struct icmp6hdr)); icmph->icmp6_type = NDISC_REDIRECT; /* * copy target and destination addresses */ addrp = (struct in6_addr *)(icmph + 1); ipv6_addr_copy(addrp, target); addrp++; ipv6_addr_copy(addrp, &skb->nh.ipv6h->daddr); opt = (u8*) (addrp + 1); /* * include target_address option */ if (dev->addr_len) opt = ndisc_fill_option(opt, ND_OPT_TARGET_LL_ADDR, neigh->ha, dev->addr_len); /* * build redirect option and copy skb over to the new packet. */ memset(opt, 0, 8); *(opt++) = ND_OPT_REDIRECT_HDR; *(opt++) = (rd_len >> 3); opt += 6; memcpy(opt, skb->nh.ipv6h, rd_len - 8); icmph->icmp6_cksum = csum_ipv6_magic(&saddr_buf, &skb->nh.ipv6h->saddr, len, IPPROTO_ICMPV6, csum_partial((u8 *) icmph, len, 0)); dev_queue_xmit(buff); ICMP6_INC_STATS(Icmp6OutRedirects); ICMP6_INC_STATS(Icmp6OutMsgs); } static void pndisc_redo(struct sk_buff *skb) { ndisc_rcv(skb); kfree_skb(skb); } int ndisc_rcv(struct sk_buff *skb) { struct nd_msg *msg = (struct nd_msg *) skb->h.raw; __skb_push(skb, skb->data-skb->h.raw); if (skb->nh.ipv6h->hop_limit != 255) { if (net_ratelimit()) printk(KERN_WARNING "ICMP NDISC: fake message with non-255 Hop Limit received: %d\n", skb->nh.ipv6h->hop_limit); return 0; } if (msg->icmph.icmp6_code != 0) { if (net_ratelimit()) printk(KERN_WARNING "ICMP NDISC: code is not zero\n"); return 0; } switch (msg->icmph.icmp6_type) { case NDISC_NEIGHBOUR_SOLICITATION: ndisc_recv_ns(skb); break; case NDISC_NEIGHBOUR_ADVERTISEMENT: ndisc_recv_na(skb); break; case NDISC_ROUTER_ADVERTISEMENT: ndisc_router_discovery(skb); break; case NDISC_REDIRECT: ndisc_redirect_rcv(skb); break; }; return 0; } static int ndisc_netdev_event(struct notifier_block *this, unsigned long event, void *ptr) { struct net_device *dev = ptr; switch (event) { case NETDEV_CHANGEADDR: neigh_changeaddr(&nd_tbl, dev); fib6_run_gc(0); break; default: break; } return NOTIFY_DONE; } struct notifier_block ndisc_netdev_notifier = { .notifier_call = ndisc_netdev_event, }; int __init ndisc_init(struct net_proto_family *ops) { struct sock *sk; int err; ndisc_socket = sock_alloc(); if (ndisc_socket == NULL) { printk(KERN_ERR "Failed to create the NDISC control socket.\n"); return -1; } ndisc_socket->inode->i_uid = 0; ndisc_socket->inode->i_gid = 0; ndisc_socket->type = SOCK_RAW; if((err = ops->create(ndisc_socket, IPPROTO_ICMPV6)) < 0) { printk(KERN_DEBUG "Failed to initialize the NDISC control socket (err %d).\n", err); sock_release(ndisc_socket); ndisc_socket = NULL; /* For safety. */ return err; } sk = ndisc_socket->sk; sk->allocation = GFP_ATOMIC; sk->net_pinfo.af_inet6.hop_limit = 255; /* Do not loopback ndisc messages */ sk->net_pinfo.af_inet6.mc_loop = 0; sk->prot->unhash(sk); /* * Initialize the neighbour table */ neigh_table_init(&nd_tbl); #ifdef CONFIG_SYSCTL neigh_sysctl_register(NULL, &nd_tbl.parms, NET_IPV6, NET_IPV6_NEIGH, "ipv6"); #endif register_netdevice_notifier(&ndisc_netdev_notifier); return 0; } void ndisc_cleanup(void) { neigh_table_clear(&nd_tbl); sock_release(ndisc_socket); ndisc_socket = NULL; /* For safety. */ }