/* * 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: * * Pierre Ynard : export userland ND options * through netlink (RDNSS support) * 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(fmt, args...) do { if (net_ratelimit()) { printk(fmt, ## args); } } while(0) #define ND_NOPRINTK(x...) do { ; } while(0) #define ND_PRINTK0 ND_PRINTK #define ND_PRINTK1 ND_NOPRINTK #define ND_PRINTK2 ND_NOPRINTK #define ND_PRINTK3 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 #if ND_DEBUG >= 3 #undef ND_PRINTK3 #define ND_PRINTK3 ND_PRINTK #endif #include #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 #include #include #include #include #include #include #include static u32 ndisc_hash(const void *pkey, const struct net_device *dev, __u32 rnd); 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 const struct neigh_ops ndisc_generic_ops = { .family = AF_INET6, .solicit = ndisc_solicit, .error_report = ndisc_error_report, .output = neigh_resolve_output, .connected_output = neigh_connected_output, }; static const struct neigh_ops ndisc_hh_ops = { .family = AF_INET6, .solicit = ndisc_solicit, .error_report = ndisc_error_report, .output = neigh_resolve_output, .connected_output = neigh_resolve_output, }; static const struct neigh_ops ndisc_direct_ops = { .family = AF_INET6, .output = neigh_direct_output, .connected_output = neigh_direct_output, }; struct neigh_table nd_tbl = { .family = AF_INET6, .key_len = sizeof(struct in6_addr), .hash = ndisc_hash, .constructor = ndisc_constructor, .pconstructor = pndisc_constructor, .pdestructor = pndisc_destructor, .proxy_redo = pndisc_redo, .id = "ndisc_cache", .parms = { .tbl = &nd_tbl, .base_reachable_time = ND_REACHABLE_TIME, .retrans_time = ND_RETRANS_TIMER, .gc_staletime = 60 * HZ, .reachable_time = ND_REACHABLE_TIME, .delay_probe_time = 5 * HZ, .queue_len_bytes = 64*1024, .ucast_probes = 3, .mcast_probes = 3, .anycast_delay = 1 * HZ, .proxy_delay = (8 * HZ) / 10, .proxy_qlen = 64, }, .gc_interval = 30 * HZ, .gc_thresh1 = 128, .gc_thresh2 = 512, .gc_thresh3 = 1024, }; /* ND options */ struct ndisc_options { struct nd_opt_hdr *nd_opt_array[__ND_OPT_ARRAY_MAX]; #ifdef CONFIG_IPV6_ROUTE_INFO struct nd_opt_hdr *nd_opts_ri; struct nd_opt_hdr *nd_opts_ri_end; #endif struct nd_opt_hdr *nd_useropts; struct nd_opt_hdr *nd_useropts_end; }; #define nd_opts_src_lladdr nd_opt_array[ND_OPT_SOURCE_LL_ADDR] #define nd_opts_tgt_lladdr nd_opt_array[ND_OPT_TARGET_LL_ADDR] #define nd_opts_pi nd_opt_array[ND_OPT_PREFIX_INFO] #define nd_opts_pi_end nd_opt_array[__ND_OPT_PREFIX_INFO_END] #define nd_opts_rh nd_opt_array[ND_OPT_REDIRECT_HDR] #define nd_opts_mtu nd_opt_array[ND_OPT_MTU] #define NDISC_OPT_SPACE(len) (((len)+2+7)&~7) /* * Return the padding between the option length and the start of the * link addr. Currently only IP-over-InfiniBand needs this, although * if RFC 3831 IPv6-over-Fibre Channel is ever implemented it may * also need a pad of 2. */ static int ndisc_addr_option_pad(unsigned short type) { switch (type) { case ARPHRD_INFINIBAND: return 2; default: return 0; } } static inline int ndisc_opt_addr_space(struct net_device *dev) { return NDISC_OPT_SPACE(dev->addr_len + ndisc_addr_option_pad(dev->type)); } static u8 *ndisc_fill_addr_option(u8 *opt, int type, void *data, int data_len, unsigned short addr_type) { int space = NDISC_OPT_SPACE(data_len); int pad = ndisc_addr_option_pad(addr_type); opt[0] = type; opt[1] = space>>3; memset(opt + 2, 0, pad); opt += pad; space -= pad; memcpy(opt+2, data, data_len); data_len += 2; opt += data_len; if ((space -= data_len) > 0) memset(opt, 0, space); return opt + space; } static 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; } static inline int ndisc_is_useropt(struct nd_opt_hdr *opt) { return opt->nd_opt_type == ND_OPT_RDNSS; } static struct nd_opt_hdr *ndisc_next_useropt(struct nd_opt_hdr *cur, struct nd_opt_hdr *end) { if (!cur || !end || cur >= end) return NULL; do { cur = ((void *)cur) + (cur->nd_opt_len << 3); } while(cur < end && !ndisc_is_useropt(cur)); return cur <= end && ndisc_is_useropt(cur) ? cur : NULL; } static 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 "%s(): duplicated ND6 option found: type=%d\n", __func__, 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]) ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt; break; #ifdef CONFIG_IPV6_ROUTE_INFO case ND_OPT_ROUTE_INFO: ndopts->nd_opts_ri_end = nd_opt; if (!ndopts->nd_opts_ri) ndopts->nd_opts_ri = nd_opt; break; #endif default: if (ndisc_is_useropt(nd_opt)) { ndopts->nd_useropts_end = nd_opt; if (!ndopts->nd_useropts) ndopts->nd_useropts = nd_opt; } else { /* * Unknown options must be silently ignored, * to accommodate future extension to the * protocol. */ ND_PRINTK2(KERN_NOTICE "%s(): ignored unsupported option; type=%d, len=%d\n", __func__, nd_opt->nd_opt_type, nd_opt->nd_opt_len); } } opt_len -= l; nd_opt = ((void *)nd_opt) + l; } return ndopts; } static inline u8 *ndisc_opt_addr_data(struct nd_opt_hdr *p, struct net_device *dev) { u8 *lladdr = (u8 *)(p + 1); int lladdrlen = p->nd_opt_len << 3; int prepad = ndisc_addr_option_pad(dev->type); if (lladdrlen != NDISC_OPT_SPACE(dev->addr_len + prepad)) return NULL; return lladdr + prepad; } int ndisc_mc_map(const 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; case ARPHRD_INFINIBAND: ipv6_ib_mc_map(addr, dev->broadcast, buf); return 0; case ARPHRD_IPGRE: return ipv6_ipgre_mc_map(addr, dev->broadcast, buf); default: if (dir) { memcpy(buf, dev->broadcast, dev->addr_len); return 0; } } return -EINVAL; } EXPORT_SYMBOL(ndisc_mc_map); static u32 ndisc_hash(const void *pkey, const struct net_device *dev, __u32 hash_rnd) { 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, 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; struct neigh_parms *parms; int is_multicast = ipv6_addr_is_multicast(addr); in6_dev = in6_dev_get(dev); if (in6_dev == NULL) { return -EINVAL; } parms = in6_dev->nd_parms; __neigh_parms_put(neigh->parms); neigh->parms = neigh_parms_clone(parms); neigh->type = is_multicast ? RTN_MULTICAST : RTN_UNICAST; if (!dev->header_ops) { neigh->nud_state = NUD_NOARP; neigh->ops = &ndisc_direct_ops; neigh->output = neigh_direct_output; } else { if (is_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->header_ops->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); } struct sk_buff *ndisc_build_skb(struct net_device *dev, const struct in6_addr *daddr, const struct in6_addr *saddr, struct icmp6hdr *icmp6h, const struct in6_addr *target, int llinfo) { struct net *net = dev_net(dev); struct sock *sk = net->ipv6.ndisc_sk; struct sk_buff *skb; struct icmp6hdr *hdr; int hlen = LL_RESERVED_SPACE(dev); int tlen = dev->needed_tailroom; int len; int err; u8 *opt; if (!dev->addr_len) llinfo = 0; len = sizeof(struct icmp6hdr) + (target ? sizeof(*target) : 0); if (llinfo) len += ndisc_opt_addr_space(dev); skb = sock_alloc_send_skb(sk, (MAX_HEADER + sizeof(struct ipv6hdr) + len + hlen + tlen), 1, &err); if (!skb) { ND_PRINTK0(KERN_ERR "ICMPv6 ND: %s() failed to allocate an skb, err=%d.\n", __func__, err); return NULL; } skb_reserve(skb, hlen); ip6_nd_hdr(sk, skb, dev, saddr, daddr, IPPROTO_ICMPV6, len); skb->transport_header = skb->tail; skb_put(skb, len); hdr = (struct icmp6hdr *)skb_transport_header(skb); memcpy(hdr, icmp6h, sizeof(*hdr)); opt = skb_transport_header(skb) + sizeof(struct icmp6hdr); if (target) { *(struct in6_addr *)opt = *target; opt += sizeof(*target); } if (llinfo) ndisc_fill_addr_option(opt, llinfo, dev->dev_addr, dev->addr_len, dev->type); hdr->icmp6_cksum = csum_ipv6_magic(saddr, daddr, len, IPPROTO_ICMPV6, csum_partial(hdr, len, 0)); return skb; } EXPORT_SYMBOL(ndisc_build_skb); void ndisc_send_skb(struct sk_buff *skb, struct net_device *dev, struct neighbour *neigh, const struct in6_addr *daddr, const struct in6_addr *saddr, struct icmp6hdr *icmp6h) { struct flowi6 fl6; struct dst_entry *dst; struct net *net = dev_net(dev); struct sock *sk = net->ipv6.ndisc_sk; struct inet6_dev *idev; int err; u8 type; type = icmp6h->icmp6_type; icmpv6_flow_init(sk, &fl6, type, saddr, daddr, dev->ifindex); dst = icmp6_dst_alloc(dev, neigh, daddr); if (!dst) { kfree_skb(skb); return; } dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), NULL, 0); if (IS_ERR(dst)) { kfree_skb(skb); return; } skb_dst_set(skb, dst); rcu_read_lock(); idev = __in6_dev_get(dst->dev); IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_OUT, skb->len); err = NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT, skb, NULL, dst->dev, dst_output); if (!err) { ICMP6MSGOUT_INC_STATS(net, idev, type); ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS); } rcu_read_unlock(); } EXPORT_SYMBOL(ndisc_send_skb); /* * Send a Neighbour Discover packet */ static void __ndisc_send(struct net_device *dev, struct neighbour *neigh, const struct in6_addr *daddr, const struct in6_addr *saddr, struct icmp6hdr *icmp6h, const struct in6_addr *target, int llinfo) { struct sk_buff *skb; skb = ndisc_build_skb(dev, daddr, saddr, icmp6h, target, llinfo); if (!skb) return; ndisc_send_skb(skb, dev, neigh, daddr, saddr, icmp6h); } static void ndisc_send_na(struct net_device *dev, struct neighbour *neigh, const struct in6_addr *daddr, const struct in6_addr *solicited_addr, int router, int solicited, int override, int inc_opt) { struct in6_addr tmpaddr; struct inet6_ifaddr *ifp; const struct in6_addr *src_addr; struct icmp6hdr icmp6h = { .icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT, }; /* for anycast or proxy, solicited_addr != src_addr */ ifp = ipv6_get_ifaddr(dev_net(dev), solicited_addr, dev, 1); if (ifp) { src_addr = solicited_addr; if (ifp->flags & IFA_F_OPTIMISTIC) override = 0; inc_opt |= ifp->idev->cnf.force_tllao; in6_ifa_put(ifp); } else { if (ipv6_dev_get_saddr(dev_net(dev), dev, daddr, inet6_sk(dev_net(dev)->ipv6.ndisc_sk)->srcprefs, &tmpaddr)) return; src_addr = &tmpaddr; } icmp6h.icmp6_router = router; icmp6h.icmp6_solicited = solicited; icmp6h.icmp6_override = override; __ndisc_send(dev, neigh, daddr, src_addr, &icmp6h, solicited_addr, inc_opt ? ND_OPT_TARGET_LL_ADDR : 0); } static void ndisc_send_unsol_na(struct net_device *dev) { struct inet6_dev *idev; struct inet6_ifaddr *ifa; struct in6_addr mcaddr; idev = in6_dev_get(dev); if (!idev) return; read_lock_bh(&idev->lock); list_for_each_entry(ifa, &idev->addr_list, if_list) { addrconf_addr_solict_mult(&ifa->addr, &mcaddr); ndisc_send_na(dev, NULL, &mcaddr, &ifa->addr, /*router=*/ !!idev->cnf.forwarding, /*solicited=*/ false, /*override=*/ true, /*inc_opt=*/ true); } read_unlock_bh(&idev->lock); in6_dev_put(idev); } void ndisc_send_ns(struct net_device *dev, struct neighbour *neigh, const struct in6_addr *solicit, const struct in6_addr *daddr, const struct in6_addr *saddr) { struct in6_addr addr_buf; struct icmp6hdr icmp6h = { .icmp6_type = NDISC_NEIGHBOUR_SOLICITATION, }; if (saddr == NULL) { if (ipv6_get_lladdr(dev, &addr_buf, (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC))) return; saddr = &addr_buf; } __ndisc_send(dev, neigh, daddr, saddr, &icmp6h, solicit, !ipv6_addr_any(saddr) ? ND_OPT_SOURCE_LL_ADDR : 0); } void ndisc_send_rs(struct net_device *dev, const struct in6_addr *saddr, const struct in6_addr *daddr) { struct icmp6hdr icmp6h = { .icmp6_type = NDISC_ROUTER_SOLICITATION, }; int send_sllao = dev->addr_len; #ifdef CONFIG_IPV6_OPTIMISTIC_DAD /* * According to section 2.2 of RFC 4429, we must not * send router solicitations with a sllao from * optimistic addresses, but we may send the solicitation * if we don't include the sllao. So here we check * if our address is optimistic, and if so, we * suppress the inclusion of the sllao. */ if (send_sllao) { struct inet6_ifaddr *ifp = ipv6_get_ifaddr(dev_net(dev), saddr, dev, 1); if (ifp) { if (ifp->flags & IFA_F_OPTIMISTIC) { send_sllao = 0; } in6_ifa_put(ifp); } else { send_sllao = 0; } } #endif __ndisc_send(dev, NULL, daddr, saddr, &icmp6h, NULL, send_sllao ? ND_OPT_SOURCE_LL_ADDR : 0); } 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(dev_net(dev), &ipv6_hdr(skb)->saddr, dev, 1)) saddr = &ipv6_hdr(skb)->saddr; if ((probes -= neigh->parms->ucast_probes) < 0) { if (!(neigh->nud_state & NUD_VALID)) { ND_PRINTK1(KERN_DEBUG "%s(): trying to ucast probe in NUD_INVALID: %pI6\n", __func__, target); } 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); } } static int pndisc_is_router(const void *pkey, struct net_device *dev) { struct pneigh_entry *n; int ret = -1; read_lock_bh(&nd_tbl.lock); n = __pneigh_lookup(&nd_tbl, dev_net(dev), pkey, dev); if (n) ret = !!(n->flags & NTF_ROUTER); read_unlock_bh(&nd_tbl.lock); return ret; } static void ndisc_recv_ns(struct sk_buff *skb) { struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb); const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr; const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr; u8 *lladdr = NULL; u32 ndoptlen = skb->tail - (skb->transport_header + offsetof(struct nd_msg, opt)); struct ndisc_options ndopts; struct net_device *dev = skb->dev; struct inet6_ifaddr *ifp; struct inet6_dev *idev = NULL; struct neighbour *neigh; int dad = ipv6_addr_any(saddr); int inc; int is_router = -1; if (ipv6_addr_is_multicast(&msg->target)) { ND_PRINTK2(KERN_WARNING "ICMPv6 NS: multicast target address"); return; } /* * RFC2461 7.1.1: * DAD has to be destined for solicited node multicast address. */ if (dad && !(daddr->s6_addr32[0] == htonl(0xff020000) && daddr->s6_addr32[1] == htonl(0x00000000) && daddr->s6_addr32[2] == htonl(0x00000001) && daddr->s6_addr [12] == 0xff )) { ND_PRINTK2(KERN_WARNING "ICMPv6 NS: bad DAD packet (wrong destination)\n"); return; } if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts)) { ND_PRINTK2(KERN_WARNING "ICMPv6 NS: invalid ND options\n"); return; } if (ndopts.nd_opts_src_lladdr) { lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, dev); if (!lladdr) { ND_PRINTK2(KERN_WARNING "ICMPv6 NS: invalid link-layer address length\n"); return; } /* 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. */ if (dad) { ND_PRINTK2(KERN_WARNING "ICMPv6 NS: bad DAD packet (link-layer address option)\n"); return; } } inc = ipv6_addr_is_multicast(daddr); ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1); if (ifp) { if (ifp->flags & (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)) { if (dad) { if (dev->type == ARPHRD_IEEE802_TR) { const unsigned char *sadr; sadr = skb_mac_header(skb); if (((sadr[8] ^ dev->dev_addr[0]) & 0x7f) == 0 && 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]) { /* looped-back to us */ goto out; } } /* * We are colliding with another node * who is doing DAD * so fail our DAD process */ addrconf_dad_failure(ifp); return; } else { /* * This is not a dad solicitation. * If we are an optimistic node, * we should respond. * Otherwise, we should ignore it. */ if (!(ifp->flags & IFA_F_OPTIMISTIC)) goto out; } } idev = ifp->idev; } else { struct net *net = dev_net(dev); idev = in6_dev_get(dev); if (!idev) { /* XXX: count this drop? */ return; } if (ipv6_chk_acast_addr(net, dev, &msg->target) || (idev->cnf.forwarding && (net->ipv6.devconf_all->proxy_ndp || idev->cnf.proxy_ndp) && (is_router = pndisc_is_router(&msg->target, dev)) >= 0)) { if (!(NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED) && skb->pkt_type != PACKET_HOST && inc != 0 && idev->nd_parms->proxy_delay != 0) { /* * for anycast or proxy, * sender should delay its response * by a random time between 0 and * MAX_ANYCAST_DELAY_TIME seconds. * (RFC2461) -- yoshfuji */ struct sk_buff *n = skb_clone(skb, GFP_ATOMIC); if (n) pneigh_enqueue(&nd_tbl, idev->nd_parms, n); goto out; } } else goto out; } if (is_router < 0) is_router = !!idev->cnf.forwarding; if (dad) { ndisc_send_na(dev, NULL, &in6addr_linklocal_allnodes, &msg->target, is_router, 0, (ifp != NULL), 1); goto out; } 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 address */ neigh = __neigh_lookup(&nd_tbl, saddr, dev, !inc || lladdr || !dev->addr_len); if (neigh) neigh_update(neigh, lladdr, NUD_STALE, NEIGH_UPDATE_F_WEAK_OVERRIDE| NEIGH_UPDATE_F_OVERRIDE); if (neigh || !dev->header_ops) { ndisc_send_na(dev, neigh, saddr, &msg->target, is_router, 1, (ifp != NULL && inc), inc); if (neigh) neigh_release(neigh); } out: if (ifp) in6_ifa_put(ifp); else in6_dev_put(idev); } static void ndisc_recv_na(struct sk_buff *skb) { struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb); const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr; const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr; u8 *lladdr = NULL; u32 ndoptlen = skb->tail - (skb->transport_header + offsetof(struct nd_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)) { ND_PRINTK2(KERN_WARNING "ICMPv6 NA: packet too short\n"); return; } if (ipv6_addr_is_multicast(&msg->target)) { ND_PRINTK2(KERN_WARNING "ICMPv6 NA: target address is multicast.\n"); return; } if (ipv6_addr_is_multicast(daddr) && msg->icmph.icmp6_solicited) { ND_PRINTK2(KERN_WARNING "ICMPv6 NA: solicited NA is multicasted.\n"); return; } if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts)) { ND_PRINTK2(KERN_WARNING "ICMPv6 NS: invalid ND option\n"); return; } if (ndopts.nd_opts_tgt_lladdr) { lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr, dev); if (!lladdr) { ND_PRINTK2(KERN_WARNING "ICMPv6 NA: invalid link-layer address length\n"); return; } } ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1); if (ifp) { if (skb->pkt_type != PACKET_LOOPBACK && (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 :-) We should not print the error if NA has been received from loopback - it is just our own unsolicited advertisement. */ if (skb->pkt_type != PACKET_LOOPBACK) ND_PRINTK1(KERN_WARNING "ICMPv6 NA: someone advertises our address %pI6 on %s!\n", &ifp->addr, ifp->idev->dev->name); in6_ifa_put(ifp); return; } neigh = neigh_lookup(&nd_tbl, &msg->target, dev); if (neigh) { u8 old_flags = neigh->flags; struct net *net = dev_net(dev); if (neigh->nud_state & NUD_FAILED) goto out; /* * Don't update the neighbor cache entry on a proxy NA from * ourselves because either the proxied node is off link or it * has already sent a NA to us. */ if (lladdr && !memcmp(lladdr, dev->dev_addr, dev->addr_len) && net->ipv6.devconf_all->forwarding && net->ipv6.devconf_all->proxy_ndp && pneigh_lookup(&nd_tbl, net, &msg->target, dev, 0)) { /* XXX: idev->cnf.prixy_ndp */ goto out; } neigh_update(neigh, lladdr, msg->icmph.icmp6_solicited ? NUD_REACHABLE : NUD_STALE, NEIGH_UPDATE_F_WEAK_OVERRIDE| (msg->icmph.icmp6_override ? NEIGH_UPDATE_F_OVERRIDE : 0)| NEIGH_UPDATE_F_OVERRIDE_ISROUTER| (msg->icmph.icmp6_router ? NEIGH_UPDATE_F_ISROUTER : 0)); if ((old_flags & ~neigh->flags) & NTF_ROUTER) { /* * Change: router to host */ struct rt6_info *rt; rt = rt6_get_dflt_router(saddr, dev); if (rt) ip6_del_rt(rt); } out: neigh_release(neigh); } } static void ndisc_recv_rs(struct sk_buff *skb) { struct rs_msg *rs_msg = (struct rs_msg *)skb_transport_header(skb); unsigned long ndoptlen = skb->len - sizeof(*rs_msg); struct neighbour *neigh; struct inet6_dev *idev; const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr; struct ndisc_options ndopts; u8 *lladdr = NULL; if (skb->len < sizeof(*rs_msg)) return; idev = __in6_dev_get(skb->dev); if (!idev) { if (net_ratelimit()) ND_PRINTK1("ICMP6 RS: can't find in6 device\n"); return; } /* Don't accept RS if we're not in router mode */ if (!idev->cnf.forwarding) goto out; /* * Don't update NCE if src = ::; * this implies that the source node has no ip address assigned yet. */ if (ipv6_addr_any(saddr)) goto out; /* Parse ND options */ if (!ndisc_parse_options(rs_msg->opt, ndoptlen, &ndopts)) { if (net_ratelimit()) ND_PRINTK2("ICMP6 NS: invalid ND option, ignored\n"); goto out; } if (ndopts.nd_opts_src_lladdr) { lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, skb->dev); if (!lladdr) goto out; } neigh = __neigh_lookup(&nd_tbl, saddr, skb->dev, 1); if (neigh) { neigh_update(neigh, lladdr, NUD_STALE, NEIGH_UPDATE_F_WEAK_OVERRIDE| NEIGH_UPDATE_F_OVERRIDE| NEIGH_UPDATE_F_OVERRIDE_ISROUTER); neigh_release(neigh); } out: return; } static void ndisc_ra_useropt(struct sk_buff *ra, struct nd_opt_hdr *opt) { struct icmp6hdr *icmp6h = (struct icmp6hdr *)skb_transport_header(ra); struct sk_buff *skb; struct nlmsghdr *nlh; struct nduseroptmsg *ndmsg; struct net *net = dev_net(ra->dev); int err; int base_size = NLMSG_ALIGN(sizeof(struct nduseroptmsg) + (opt->nd_opt_len << 3)); size_t msg_size = base_size + nla_total_size(sizeof(struct in6_addr)); skb = nlmsg_new(msg_size, GFP_ATOMIC); if (skb == NULL) { err = -ENOBUFS; goto errout; } nlh = nlmsg_put(skb, 0, 0, RTM_NEWNDUSEROPT, base_size, 0); if (nlh == NULL) { goto nla_put_failure; } ndmsg = nlmsg_data(nlh); ndmsg->nduseropt_family = AF_INET6; ndmsg->nduseropt_ifindex = ra->dev->ifindex; ndmsg->nduseropt_icmp_type = icmp6h->icmp6_type; ndmsg->nduseropt_icmp_code = icmp6h->icmp6_code; ndmsg->nduseropt_opts_len = opt->nd_opt_len << 3; memcpy(ndmsg + 1, opt, opt->nd_opt_len << 3); NLA_PUT(skb, NDUSEROPT_SRCADDR, sizeof(struct in6_addr), &ipv6_hdr(ra)->saddr); nlmsg_end(skb, nlh); rtnl_notify(skb, net, 0, RTNLGRP_ND_USEROPT, NULL, GFP_ATOMIC); return; nla_put_failure: nlmsg_free(skb); err = -EMSGSIZE; errout: rtnl_set_sk_err(net, RTNLGRP_ND_USEROPT, err); } static inline int accept_ra(struct inet6_dev *in6_dev) { /* * If forwarding is enabled, RA are not accepted unless the special * hybrid mode (accept_ra=2) is enabled. */ if (in6_dev->cnf.forwarding && in6_dev->cnf.accept_ra < 2) return 0; return in6_dev->cnf.accept_ra; } static void ndisc_router_discovery(struct sk_buff *skb) { struct ra_msg *ra_msg = (struct ra_msg *)skb_transport_header(skb); struct neighbour *neigh = NULL; struct inet6_dev *in6_dev; struct rt6_info *rt = NULL; int lifetime; struct ndisc_options ndopts; int optlen; unsigned int pref = 0; __u8 * opt = (__u8 *)(ra_msg + 1); optlen = (skb->tail - skb->transport_header) - sizeof(struct ra_msg); if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) { ND_PRINTK2(KERN_WARNING "ICMPv6 RA: source address is not link-local.\n"); return; } if (optlen < 0) { ND_PRINTK2(KERN_WARNING "ICMPv6 RA: packet too short\n"); return; } #ifdef CONFIG_IPV6_NDISC_NODETYPE if (skb->ndisc_nodetype == NDISC_NODETYPE_HOST) { ND_PRINTK2(KERN_WARNING "ICMPv6 RA: from host or unauthorized router\n"); return; } #endif /* * set the RA_RECV flag in the interface */ in6_dev = __in6_dev_get(skb->dev); if (in6_dev == NULL) { ND_PRINTK0(KERN_ERR "ICMPv6 RA: can't find inet6 device for %s.\n", skb->dev->name); return; } if (!ndisc_parse_options(opt, optlen, &ndopts)) { ND_PRINTK2(KERN_WARNING "ICMP6 RA: invalid ND options\n"); return; } if (!accept_ra(in6_dev)) goto skip_linkparms; #ifdef CONFIG_IPV6_NDISC_NODETYPE /* skip link-specific parameters from interior routers */ if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) goto skip_linkparms; #endif 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); if (!in6_dev->cnf.accept_ra_defrtr) goto skip_defrtr; if (ipv6_chk_addr(dev_net(in6_dev->dev), &ipv6_hdr(skb)->saddr, NULL, 0)) goto skip_defrtr; lifetime = ntohs(ra_msg->icmph.icmp6_rt_lifetime); #ifdef CONFIG_IPV6_ROUTER_PREF pref = ra_msg->icmph.icmp6_router_pref; /* 10b is handled as if it were 00b (medium) */ if (pref == ICMPV6_ROUTER_PREF_INVALID || !in6_dev->cnf.accept_ra_rtr_pref) pref = ICMPV6_ROUTER_PREF_MEDIUM; #endif rt = rt6_get_dflt_router(&ipv6_hdr(skb)->saddr, skb->dev); if (rt) neigh = dst_get_neighbour_noref(&rt->dst); if (rt && lifetime == 0) { neigh_clone(neigh); ip6_del_rt(rt); rt = NULL; } if (rt == NULL && lifetime) { ND_PRINTK3(KERN_DEBUG "ICMPv6 RA: adding default router.\n"); rt = rt6_add_dflt_router(&ipv6_hdr(skb)->saddr, skb->dev, pref); if (rt == NULL) { ND_PRINTK0(KERN_ERR "ICMPv6 RA: %s() failed to add default route.\n", __func__); return; } neigh = dst_get_neighbour_noref(&rt->dst); if (neigh == NULL) { ND_PRINTK0(KERN_ERR "ICMPv6 RA: %s() got default router without neighbour.\n", __func__); dst_release(&rt->dst); return; } neigh->flags |= NTF_ROUTER; } else if (rt) { rt->rt6i_flags = (rt->rt6i_flags & ~RTF_PREF_MASK) | RTF_PREF(pref); } 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; if (rt) dst_metric_set(&rt->dst, RTAX_HOPLIMIT, ra_msg->icmph.icmp6_hop_limit); } skip_defrtr: /* * 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; in6_dev->tstamp = jiffies; inet6_ifinfo_notify(RTM_NEWLINK, in6_dev); } 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); in6_dev->tstamp = jiffies; inet6_ifinfo_notify(RTM_NEWLINK, in6_dev); } } } skip_linkparms: /* * Process options. */ if (!neigh) neigh = __neigh_lookup(&nd_tbl, &ipv6_hdr(skb)->saddr, skb->dev, 1); if (neigh) { u8 *lladdr = NULL; if (ndopts.nd_opts_src_lladdr) { lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, skb->dev); if (!lladdr) { ND_PRINTK2(KERN_WARNING "ICMPv6 RA: invalid link-layer address length\n"); goto out; } } neigh_update(neigh, lladdr, NUD_STALE, NEIGH_UPDATE_F_WEAK_OVERRIDE| NEIGH_UPDATE_F_OVERRIDE| NEIGH_UPDATE_F_OVERRIDE_ISROUTER| NEIGH_UPDATE_F_ISROUTER); } if (!accept_ra(in6_dev)) goto out; #ifdef CONFIG_IPV6_ROUTE_INFO if (ipv6_chk_addr(dev_net(in6_dev->dev), &ipv6_hdr(skb)->saddr, NULL, 0)) goto skip_routeinfo; if (in6_dev->cnf.accept_ra_rtr_pref && ndopts.nd_opts_ri) { struct nd_opt_hdr *p; for (p = ndopts.nd_opts_ri; p; p = ndisc_next_option(p, ndopts.nd_opts_ri_end)) { struct route_info *ri = (struct route_info *)p; #ifdef CONFIG_IPV6_NDISC_NODETYPE if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT && ri->prefix_len == 0) continue; #endif if (ri->prefix_len > in6_dev->cnf.accept_ra_rt_info_max_plen) continue; rt6_route_rcv(skb->dev, (u8*)p, (p->nd_opt_len) << 3, &ipv6_hdr(skb)->saddr); } } skip_routeinfo: #endif #ifdef CONFIG_IPV6_NDISC_NODETYPE /* skip link-specific ndopts from interior routers */ if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) goto out; #endif if (in6_dev->cnf.accept_ra_pinfo && 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) { __be32 n; u32 mtu; memcpy(&n, ((u8*)(ndopts.nd_opts_mtu+1))+2, sizeof(mtu)); mtu = ntohl(n); if (mtu < IPV6_MIN_MTU || mtu > skb->dev->mtu) { ND_PRINTK2(KERN_WARNING "ICMPv6 RA: invalid mtu: %d\n", mtu); } else if (in6_dev->cnf.mtu6 != mtu) { in6_dev->cnf.mtu6 = mtu; if (rt) dst_metric_set(&rt->dst, RTAX_MTU, mtu); rt6_mtu_change(skb->dev, mtu); } } if (ndopts.nd_useropts) { struct nd_opt_hdr *p; for (p = ndopts.nd_useropts; p; p = ndisc_next_useropt(p, ndopts.nd_useropts_end)) { ndisc_ra_useropt(skb, p); } } if (ndopts.nd_opts_tgt_lladdr || ndopts.nd_opts_rh) { ND_PRINTK2(KERN_WARNING "ICMPv6 RA: invalid RA options"); } out: if (rt) dst_release(&rt->dst); else if (neigh) neigh_release(neigh); } static void ndisc_redirect_rcv(struct sk_buff *skb) { struct inet6_dev *in6_dev; struct icmp6hdr *icmph; const struct in6_addr *dest; const 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; #ifdef CONFIG_IPV6_NDISC_NODETYPE switch (skb->ndisc_nodetype) { case NDISC_NODETYPE_HOST: case NDISC_NODETYPE_NODEFAULT: ND_PRINTK2(KERN_WARNING "ICMPv6 Redirect: from host or unauthorized router\n"); return; } #endif if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) { ND_PRINTK2(KERN_WARNING "ICMPv6 Redirect: source address is not link-local.\n"); return; } optlen = skb->tail - skb->transport_header; optlen -= sizeof(struct icmp6hdr) + 2 * sizeof(struct in6_addr); if (optlen < 0) { ND_PRINTK2(KERN_WARNING "ICMPv6 Redirect: packet too short\n"); return; } icmph = icmp6_hdr(skb); target = (const struct in6_addr *) (icmph + 1); dest = target + 1; if (ipv6_addr_is_multicast(dest)) { ND_PRINTK2(KERN_WARNING "ICMPv6 Redirect: destination address is multicast.\n"); return; } if (ipv6_addr_equal(dest, target)) { on_link = 1; } else if (ipv6_addr_type(target) != (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) { ND_PRINTK2(KERN_WARNING "ICMPv6 Redirect: target address is not link-local unicast.\n"); return; } in6_dev = __in6_dev_get(skb->dev); if (!in6_dev) return; if (in6_dev->cnf.forwarding || !in6_dev->cnf.accept_redirects) return; /* 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)) { ND_PRINTK2(KERN_WARNING "ICMPv6 Redirect: invalid ND options\n"); return; } if (ndopts.nd_opts_tgt_lladdr) { lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr, skb->dev); if (!lladdr) { ND_PRINTK2(KERN_WARNING "ICMPv6 Redirect: invalid link-layer address length\n"); return; } } neigh = __neigh_lookup(&nd_tbl, target, skb->dev, 1); if (neigh) { rt6_redirect(dest, &ipv6_hdr(skb)->daddr, &ipv6_hdr(skb)->saddr, neigh, lladdr, on_link); neigh_release(neigh); } } void ndisc_send_redirect(struct sk_buff *skb, struct neighbour *neigh, const struct in6_addr *target) { struct net_device *dev = skb->dev; struct net *net = dev_net(dev); struct sock *sk = net->ipv6.ndisc_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 rt6_info *rt; struct dst_entry *dst; struct inet6_dev *idev; struct flowi6 fl6; u8 *opt; int hlen, tlen; int rd_len; int err; u8 ha_buf[MAX_ADDR_LEN], *ha = NULL; if (ipv6_get_lladdr(dev, &saddr_buf, IFA_F_TENTATIVE)) { ND_PRINTK2(KERN_WARNING "ICMPv6 Redirect: no link-local address on %s\n", dev->name); return; } if (!ipv6_addr_equal(&ipv6_hdr(skb)->daddr, target) && ipv6_addr_type(target) != (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) { ND_PRINTK2(KERN_WARNING "ICMPv6 Redirect: target address is not link-local unicast.\n"); return; } icmpv6_flow_init(sk, &fl6, NDISC_REDIRECT, &saddr_buf, &ipv6_hdr(skb)->saddr, dev->ifindex); dst = ip6_route_output(net, NULL, &fl6); if (dst == NULL) return; dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), NULL, 0); if (IS_ERR(dst)) return; rt = (struct rt6_info *) dst; if (rt->rt6i_flags & RTF_GATEWAY) { ND_PRINTK2(KERN_WARNING "ICMPv6 Redirect: destination is not a neighbour.\n"); goto release; } if (!rt->rt6i_peer) rt6_bind_peer(rt, 1); if (!inet_peer_xrlim_allow(rt->rt6i_peer, 1*HZ)) goto release; if (dev->addr_len) { read_lock_bh(&neigh->lock); if (neigh->nud_state & NUD_VALID) { memcpy(ha_buf, neigh->ha, dev->addr_len); read_unlock_bh(&neigh->lock); ha = ha_buf; len += ndisc_opt_addr_space(dev); } else read_unlock_bh(&neigh->lock); } rd_len = min_t(unsigned int, IPV6_MIN_MTU-sizeof(struct ipv6hdr)-len, skb->len + 8); rd_len &= ~0x7; len += rd_len; hlen = LL_RESERVED_SPACE(dev); tlen = dev->needed_tailroom; buff = sock_alloc_send_skb(sk, (MAX_HEADER + sizeof(struct ipv6hdr) + len + hlen + tlen), 1, &err); if (buff == NULL) { ND_PRINTK0(KERN_ERR "ICMPv6 Redirect: %s() failed to allocate an skb, err=%d.\n", __func__, err); goto release; } skb_reserve(buff, hlen); ip6_nd_hdr(sk, buff, dev, &saddr_buf, &ipv6_hdr(skb)->saddr, IPPROTO_ICMPV6, len); skb_set_transport_header(buff, skb_tail_pointer(buff) - buff->data); skb_put(buff, len); icmph = icmp6_hdr(buff); memset(icmph, 0, sizeof(struct icmp6hdr)); icmph->icmp6_type = NDISC_REDIRECT; /* * copy target and destination addresses */ addrp = (struct in6_addr *)(icmph + 1); *addrp = *target; addrp++; *addrp = ipv6_hdr(skb)->daddr; opt = (u8*) (addrp + 1); /* * include target_address option */ if (ha) opt = ndisc_fill_addr_option(opt, ND_OPT_TARGET_LL_ADDR, ha, dev->addr_len, dev->type); /* * 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, ipv6_hdr(skb), rd_len - 8); icmph->icmp6_cksum = csum_ipv6_magic(&saddr_buf, &ipv6_hdr(skb)->saddr, len, IPPROTO_ICMPV6, csum_partial(icmph, len, 0)); skb_dst_set(buff, dst); rcu_read_lock(); idev = __in6_dev_get(dst->dev); IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_OUT, skb->len); err = NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT, buff, NULL, dst->dev, dst_output); if (!err) { ICMP6MSGOUT_INC_STATS(net, idev, NDISC_REDIRECT); ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS); } rcu_read_unlock(); return; release: dst_release(dst); } static void pndisc_redo(struct sk_buff *skb) { ndisc_recv_ns(skb); kfree_skb(skb); } int ndisc_rcv(struct sk_buff *skb) { struct nd_msg *msg; if (!pskb_may_pull(skb, skb->len)) return 0; msg = (struct nd_msg *)skb_transport_header(skb); __skb_push(skb, skb->data - skb_transport_header(skb)); if (ipv6_hdr(skb)->hop_limit != 255) { ND_PRINTK2(KERN_WARNING "ICMPv6 NDISC: invalid hop-limit: %d\n", ipv6_hdr(skb)->hop_limit); return 0; } if (msg->icmph.icmp6_code != 0) { ND_PRINTK2(KERN_WARNING "ICMPv6 NDISC: invalid ICMPv6 code: %d\n", msg->icmph.icmp6_code); return 0; } memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb)); 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_SOLICITATION: ndisc_recv_rs(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; struct net *net = dev_net(dev); switch (event) { case NETDEV_CHANGEADDR: neigh_changeaddr(&nd_tbl, dev); fib6_run_gc(~0UL, net); break; case NETDEV_DOWN: neigh_ifdown(&nd_tbl, dev); fib6_run_gc(~0UL, net); break; case NETDEV_NOTIFY_PEERS: ndisc_send_unsol_na(dev); break; default: break; } return NOTIFY_DONE; } static struct notifier_block ndisc_netdev_notifier = { .notifier_call = ndisc_netdev_event, }; #ifdef CONFIG_SYSCTL static void ndisc_warn_deprecated_sysctl(struct ctl_table *ctl, const char *func, const char *dev_name) { static char warncomm[TASK_COMM_LEN]; static int warned; if (strcmp(warncomm, current->comm) && warned < 5) { strcpy(warncomm, current->comm); printk(KERN_WARNING "process `%s' is using deprecated sysctl (%s) " "net.ipv6.neigh.%s.%s; " "Use net.ipv6.neigh.%s.%s_ms " "instead.\n", warncomm, func, dev_name, ctl->procname, dev_name, ctl->procname); warned++; } } int ndisc_ifinfo_sysctl_change(struct ctl_table *ctl, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { struct net_device *dev = ctl->extra1; struct inet6_dev *idev; int ret; if ((strcmp(ctl->procname, "retrans_time") == 0) || (strcmp(ctl->procname, "base_reachable_time") == 0)) ndisc_warn_deprecated_sysctl(ctl, "syscall", dev ? dev->name : "default"); if (strcmp(ctl->procname, "retrans_time") == 0) ret = proc_dointvec(ctl, write, buffer, lenp, ppos); else if (strcmp(ctl->procname, "base_reachable_time") == 0) ret = proc_dointvec_jiffies(ctl, write, buffer, lenp, ppos); else if ((strcmp(ctl->procname, "retrans_time_ms") == 0) || (strcmp(ctl->procname, "base_reachable_time_ms") == 0)) ret = proc_dointvec_ms_jiffies(ctl, write, buffer, lenp, ppos); else ret = -1; if (write && ret == 0 && dev && (idev = in6_dev_get(dev)) != NULL) { if (ctl->data == &idev->nd_parms->base_reachable_time) idev->nd_parms->reachable_time = neigh_rand_reach_time(idev->nd_parms->base_reachable_time); idev->tstamp = jiffies; inet6_ifinfo_notify(RTM_NEWLINK, idev); in6_dev_put(idev); } return ret; } #endif static int __net_init ndisc_net_init(struct net *net) { struct ipv6_pinfo *np; struct sock *sk; int err; err = inet_ctl_sock_create(&sk, PF_INET6, SOCK_RAW, IPPROTO_ICMPV6, net); if (err < 0) { ND_PRINTK0(KERN_ERR "ICMPv6 NDISC: Failed to initialize the control socket (err %d).\n", err); return err; } net->ipv6.ndisc_sk = sk; np = inet6_sk(sk); np->hop_limit = 255; /* Do not loopback ndisc messages */ np->mc_loop = 0; return 0; } static void __net_exit ndisc_net_exit(struct net *net) { inet_ctl_sock_destroy(net->ipv6.ndisc_sk); } static struct pernet_operations ndisc_net_ops = { .init = ndisc_net_init, .exit = ndisc_net_exit, }; int __init ndisc_init(void) { int err; err = register_pernet_subsys(&ndisc_net_ops); if (err) return err; /* * Initialize the neighbour table */ neigh_table_init(&nd_tbl); #ifdef CONFIG_SYSCTL err = neigh_sysctl_register(NULL, &nd_tbl.parms, "ipv6", &ndisc_ifinfo_sysctl_change); if (err) goto out_unregister_pernet; #endif err = register_netdevice_notifier(&ndisc_netdev_notifier); if (err) goto out_unregister_sysctl; out: return err; out_unregister_sysctl: #ifdef CONFIG_SYSCTL neigh_sysctl_unregister(&nd_tbl.parms); out_unregister_pernet: #endif unregister_pernet_subsys(&ndisc_net_ops); goto out; } void ndisc_cleanup(void) { unregister_netdevice_notifier(&ndisc_netdev_notifier); #ifdef CONFIG_SYSCTL neigh_sysctl_unregister(&nd_tbl.parms); #endif neigh_table_clear(&nd_tbl); unregister_pernet_subsys(&ndisc_net_ops); }