/* * 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. */ /* 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 #define __NO_VERSION__ #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 static struct socket *ndisc_socket; 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_constructor, pndisc_constructor, pndisc_destructor, pndisc_redo, { 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; } int ndisc_mc_map(struct in6_addr *addr, char *buf, struct 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; default: if (dir) { memcpy(buf, dev->broadcast, dev->addr_len); return 0; } } return -EINVAL; } static int ndisc_constructor(struct neighbour *neigh) { struct in6_addr *addr = (struct in6_addr*)&neigh->primary_key; struct device *dev = neigh->dev; struct inet6_dev *in6_dev = ipv6_get_idev(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; } return 0; } static int pndisc_constructor(struct pneigh_entry *n) { struct in6_addr *addr = (struct in6_addr*)&n->key; struct in6_addr maddr; struct device *dev = n->dev; if (dev == NULL || ipv6_get_idev(dev) == NULL) return -EINVAL; #ifndef CONFIG_IPV6_NO_PB addrconf_addr_solict_mult_old(addr, &maddr); ipv6_dev_mc_inc(dev, &maddr); #endif #ifdef CONFIG_IPV6_EUI64 addrconf_addr_solict_mult_new(addr, &maddr); ipv6_dev_mc_inc(dev, &maddr); #endif return 0; } static void pndisc_destructor(struct pneigh_entry *n) { struct in6_addr *addr = (struct in6_addr*)&n->key; struct in6_addr maddr; struct device *dev = n->dev; if (dev == NULL || ipv6_get_idev(dev) == NULL) return; #ifndef CONFIG_IPV6_NO_PB addrconf_addr_solict_mult_old(addr, &maddr); ipv6_dev_mc_dec(dev, &maddr); #endif #ifdef CONFIG_IPV6_EUI64 addrconf_addr_solict_mult_new(addr, &maddr); ipv6_dev_mc_dec(dev, &maddr); #endif } static int ndisc_build_ll_hdr(struct sk_buff *skb, struct 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) { h_dest = neigh->ha; } else { neigh = neigh_lookup(&nd_tbl, daddr, dev); if (neigh) { if (neigh->nud_state&NUD_VALID) { memcpy(ha, neigh->ha, dev->addr_len); h_dest = ha; } 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 device *dev, struct neighbour *neigh, struct in6_addr *daddr, struct in6_addr *solicited_addr, int router, int solicited, int override, int inc_opt) { struct sock *sk = ndisc_socket->sk; 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, 0, 0, &err); if (skb == NULL) { ND_PRINTK1("send_na: 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, solicited_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((void*)&msg->opt, ND_OPT_TARGET_LL_ADDR, dev->dev_addr, dev->addr_len); /* checksum */ msg->icmph.icmp6_cksum = csum_ipv6_magic(solicited_addr, daddr, len, IPPROTO_ICMPV6, csum_partial((__u8 *) msg, len, 0)); dev_queue_xmit(skb); icmpv6_statistics.Icmp6OutNeighborAdvertisements++; icmpv6_statistics.Icmp6OutMsgs++; } void ndisc_send_ns(struct 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; int len; int err; len = sizeof(struct icmp6hdr) + sizeof(struct in6_addr); 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, 0, 0, &err); if (skb == NULL) { ND_PRINTK1("send_ns: alloc skb failed\n"); return; } if (saddr == NULL) { struct inet6_ifaddr *ifa; /* use link local address */ ifa = ipv6_get_lladdr(dev); if (ifa) saddr = &ifa->addr; } 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 (dev->addr_len) ndisc_fill_option((void*)&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); icmpv6_statistics.Icmp6OutNeighborSolicits++; icmpv6_statistics.Icmp6OutMsgs++; } void ndisc_send_rs(struct 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, 0, 0, &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); icmpv6_statistics.Icmp6OutRouterSolicits++; icmpv6_statistics.Icmp6OutMsgs++; } static u8 * ndisc_find_option(u8 *opt, int opt_len, int len, int option) { while (opt_len <= len) { int l = opt[1]<<3; if (opt[0] == option && l >= opt_len) return opt + 2; if (l == 0) { if (net_ratelimit()) printk(KERN_WARNING "ndisc: option has 0 len\n"); return NULL; } opt += l; len -= l; } return NULL; } 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); } static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb) { struct in6_addr *saddr = NULL; struct in6_addr mcaddr; struct device *dev = neigh->dev; struct in6_addr *target = (struct in6_addr *)&neigh->primary_key; int probes = neigh->probes; if (skb && ipv6_chk_addr(&skb->nh.ipv6h->saddr, dev, 0)) 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 { #ifdef CONFIG_IPV6_EUI64 addrconf_addr_solict_mult_new(target, &mcaddr); ndisc_send_ns(dev, NULL, target, &mcaddr, saddr); #endif #ifndef CONFIG_IPV6_NO_PB addrconf_addr_solict_mult_old(target, &mcaddr); ndisc_send_ns(dev, NULL, target, &mcaddr, saddr); #endif } } static void ndisc_update(struct neighbour *neigh, u8* opt, int len, int type) { opt = ndisc_find_option(opt, neigh->dev->addr_len+2, len, type); neigh_update(neigh, opt, NUD_STALE, 1, 1); } 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; int optlen; __u8 * opt = (__u8 *)(ra_msg + 1); optlen = (skb->tail - skb->h.raw) - sizeof(struct ra_msg); if (skb->nh.ipv6h->hop_limit != 255) { printk(KERN_INFO "NDISC: fake router advertisement received\n"); return; } /* * set the RA_RECV flag in the interface */ in6_dev = ipv6_get_idev(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) 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; } 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); dst_release(&rt->u.dst); 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"); return; } neigh = rt->rt6i_nexthop; if (neigh == NULL) { ND_PRINTK1("nd: add default router: null neighbour\n"); dst_release(&rt->u.dst); 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) { if (ra_msg->retrans_timer) in6_dev->nd_parms->retrans_time = (ntohl(ra_msg->retrans_timer)*HZ)/1000; if (ra_msg->reachable_time) { __u32 rtime = (ntohl(ra_msg->reachable_time)*HZ)/1000; 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. */ while (optlen > 0) { int len = (opt[1] << 3); if (len == 0) { ND_PRINTK0("RA: opt has 0 len\n"); break; } switch(*opt) { case ND_OPT_SOURCE_LL_ADDR: if (rt == NULL) break; if ((neigh = rt->rt6i_nexthop) != NULL && skb->dev->addr_len + 2 >= len) neigh_update(neigh, opt+2, NUD_STALE, 1, 1); break; case ND_OPT_PREFIX_INFO: addrconf_prefix_rcv(skb->dev, opt, len); break; case ND_OPT_MTU: { int mtu; mtu = htonl(*(__u32 *)(opt+4)); if (mtu < IPV6_MIN_MTU || mtu > skb->dev->mtu) { ND_PRINTK0("NDISC: router " "announcement with mtu = %d\n", mtu); break; } if (in6_dev->cnf.mtu6 != mtu) { in6_dev->cnf.mtu6 = mtu; if (rt) rt->u.dst.pmtu = mtu; rt6_mtu_change(skb->dev, mtu); } } break; case ND_OPT_TARGET_LL_ADDR: case ND_OPT_REDIRECT_HDR: ND_PRINTK0("got illegal option with RA"); break; default: ND_PRINTK0("unknown option in RA\n"); }; optlen -= len; opt += len; } if (rt) dst_release(&rt->u.dst); } 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; int optlen; if (skb->nh.ipv6h->hop_limit != 255) { printk(KERN_WARNING "NDISC: fake ICMP redirect received\n"); return; } if (!(ipv6_addr_type(&skb->nh.ipv6h->saddr) & IPV6_ADDR_LINKLOCAL)) { 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) { 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) { 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)) { printk(KERN_WARNING "ICMP redirect: target address is not linklocal\n"); return; } in6_dev = ipv6_get_idev(skb->dev); if (!in6_dev || in6_dev->cnf.forwarding || !in6_dev->cnf.accept_redirects) return; /* passed validation tests */ /* We install redirect only if nexthop state is valid. */ neigh = __neigh_lookup(&nd_tbl, target, skb->dev, 1); if (neigh) { ndisc_update(neigh, (u8*)(dest + 1), optlen, ND_OPT_TARGET_LL_ADDR); 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); } } 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 inet6_ifaddr *ifp; struct icmp6hdr *icmph; struct in6_addr *addrp; struct 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(IPV6_MIN_MTU-sizeof(struct ipv6hdr)-len, skb->len + 8); rd_len &= ~0x7; len += rd_len; ifp = ipv6_get_lladdr(dev); if (ifp == NULL) { 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, 0, 0, &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, &ifp->addr, &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(&ifp->addr, &skb->nh.ipv6h->saddr, len, IPPROTO_ICMPV6, csum_partial((u8 *) icmph, len, 0)); dev_queue_xmit(buff); icmpv6_statistics.Icmp6OutRedirects++; icmpv6_statistics.Icmp6OutMsgs++; } static __inline__ struct neighbour * ndisc_recv_ns(struct in6_addr *saddr, struct sk_buff *skb) { u8 *opt; opt = skb->h.raw; opt += sizeof(struct icmp6hdr) + sizeof(struct in6_addr); opt = ndisc_find_option(opt, skb->dev->addr_len+2, skb->tail - opt, ND_OPT_SOURCE_LL_ADDR); return neigh_event_ns(&nd_tbl, opt, saddr, skb->dev); } static __inline__ int ndisc_recv_na(struct neighbour *neigh, struct sk_buff *skb) { struct nd_msg *msg = (struct nd_msg *) skb->h.raw; u8 *opt; opt = skb->h.raw; opt += sizeof(struct icmp6hdr) + sizeof(struct in6_addr); opt = ndisc_find_option(opt, skb->dev->addr_len+2, skb->tail - opt, ND_OPT_TARGET_LL_ADDR); return neigh_update(neigh, opt, msg->icmph.icmp6_solicited ? NUD_REACHABLE : NUD_STALE, msg->icmph.icmp6_override, 1); } static void pndisc_redo(struct sk_buff *skb) { ndisc_rcv(skb, skb->len); kfree_skb(skb); } int ndisc_rcv(struct sk_buff *skb, unsigned long len) { struct device *dev = skb->dev; struct in6_addr *saddr = &skb->nh.ipv6h->saddr; struct in6_addr *daddr = &skb->nh.ipv6h->daddr; struct nd_msg *msg = (struct nd_msg *) skb->h.raw; struct neighbour *neigh; struct inet6_ifaddr *ifp; switch (msg->icmph.icmp6_type) { case NDISC_NEIGHBOUR_SOLICITATION: if ((ifp = ipv6_chk_addr(&msg->target, dev, 1)) != NULL) { int addr_type = ipv6_addr_type(saddr); if (ifp->flags & ADDR_INVALID) return 0; if (ifp->flags & DAD_INCOMPLETE) { /* 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) addrconf_dad_failure(ifp); return 0; } 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, 1, 1); return 0; } if (addr_type & IPV6_ADDR_UNICAST) { int inc = ipv6_addr_type(daddr)&IPV6_ADDR_MULTICAST; if (inc) nd_tbl.stats.rcv_probes_mcast++; else nd_tbl.stats.rcv_probes_ucast++; /* * update / create cache entry * for the source adddress */ neigh = ndisc_recv_ns(saddr, skb); if (neigh) { ndisc_send_na(dev, neigh, saddr, &ifp->addr, ifp->idev->cnf.forwarding, 1, inc, inc); neigh_release(neigh); } } } else { struct inet6_dev *in6_dev = ipv6_get_idev(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) nd_tbl.stats.rcv_probes_mcast++; else nd_tbl.stats.rcv_probes_ucast++; neigh = ndisc_recv_ns(saddr, skb); if (neigh) { ndisc_send_na(dev, neigh, saddr, &msg->target, 0, 1, 0, inc); neigh_release(neigh); } } else { /* Hack. It will be freed upon exit from ndisc_rcv */ atomic_inc(&skb->users); pneigh_enqueue(&nd_tbl, in6_dev->nd_parms, skb); return 0; } } } return 0; case NDISC_NEIGHBOUR_ADVERTISEMENT: if ((ipv6_addr_type(saddr)&IPV6_ADDR_MULTICAST) && msg->icmph.icmp6_solicited) { ND_PRINTK0("NDISC: solicited NA is multicasted\n"); return 0; } /* BUG! Target can be link-local on ANOTHER interface. Fixed. */ if ((ifp = ipv6_chk_addr(&msg->target, dev, 1))) { if (ifp->flags & ADDR_INVALID) return 0; if (ifp->flags & DAD_INCOMPLETE) { addrconf_dad_failure(ifp); return 0; } /* 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 avertise our address!\n", ifp->idev->dev->name); return 0; } neigh = __neigh_lookup(&nd_tbl, &msg->target, skb->dev, 0); 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, skb->dev); if (rt) { /* It is safe only because we aer in BH */ dst_release(&rt->u.dst); ip6_del_rt(rt); } } } else { if (msg->icmph.icmp6_router) neigh->flags |= NTF_ROUTER; } ndisc_recv_na(neigh, skb); neigh_release(neigh); } break; case NDISC_ROUTER_ADVERTISEMENT: ndisc_router_discovery(skb); break; case NDISC_REDIRECT: ndisc_redirect_rcv(skb); break; }; return 0; } #ifdef CONFIG_PROC_FS #ifndef CONFIG_RTNETLINK int ndisc_get_info(char *buffer, char **start, off_t offset, int length, int dummy) { int len=0; off_t pos=0; int size; unsigned long now = jiffies; int i; neigh_table_lock(&nd_tbl); for (i = 0; i <= NEIGH_HASHMASK; i++) { struct neighbour *neigh; for (neigh = nd_tbl.hash_buckets[i]; neigh; neigh = neigh->next) { int j; size = 0; for (j=0; j<16; j++) { sprintf(buffer+len+size, "%02x", neigh->primary_key[j]); size += 2; } size += sprintf(buffer+len+size, " %02x %02x %02x %02x %08lx %08lx %08x %04x %04x %04x %8s ", i, 128, neigh->type, neigh->nud_state, now - neigh->used, now - neigh->confirmed, neigh->parms->reachable_time, neigh->parms->gc_staletime, atomic_read(&neigh->refcnt), neigh->flags | (!neigh->hh ? 0 : (neigh->hh->hh_output==dev_queue_xmit ? 4 : 2)), neigh->dev->name); if ((neigh->nud_state&NUD_VALID) && neigh->dev->addr_len) { for (j=0; j < neigh->dev->addr_len; j++) { sprintf(buffer+len+size, "%02x", neigh->ha[j]); size += 2; } } else { size += sprintf(buffer+len+size, "000000000000"); } size += sprintf(buffer+len+size, "\n"); len += size; pos += size; if (pos <= offset) len=0; if (pos >= offset+length) goto done; } } done: neigh_table_unlock(&nd_tbl); *start = buffer+len-(pos-offset); /* Start of wanted data */ len = pos-offset; /* Start slop */ if (len>length) len = length; /* Ending slop */ if (len<0) len = 0; return len; } struct proc_dir_entry ndisc_proc_entry = { PROC_NET_NDISC, 5, "ndisc", S_IFREG | S_IRUGO, 1, 0, 0, 0, NULL, &ndisc_get_info }; #endif #endif /* CONFIG_PROC_FS */ __initfunc(int 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; } #ifndef _HURD_ ndisc_socket->inode->i_uid = 0; ndisc_socket->inode->i_gid = 0; #endif ndisc_socket->type = SOCK_RAW; if((err = ops->create(ndisc_socket, IPPROTO_ICMPV6)) < 0) { printk(KERN_DEBUG "Failed to initializee 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->num = 256; /* * Initialize the neighbour table */ neigh_table_init(&nd_tbl); #ifdef CONFIG_PROC_FS #ifndef CONFIG_RTNETLINK proc_net_register(&ndisc_proc_entry); #endif #endif #ifdef CONFIG_SYSCTL neigh_sysctl_register(NULL, &nd_tbl.parms, NET_IPV6, NET_IPV6_NEIGH, "ipv6"); #endif return 0; } void ndisc_cleanup(void) { #ifdef CONFIG_PROC_FS #ifndef CONFIG_RTNETLINK proc_net_unregister(ndisc_proc_entry.low_ino); #endif #endif neigh_table_clear(&nd_tbl); sock_release(ndisc_socket); ndisc_socket = NULL; /* For safety. */ }