| /* |
| * Neighbour Discovery for IPv6 |
| * Linux INET6 implementation |
| * |
| * Authors: |
| * Pedro Roque <roque@di.fc.ul.pt> |
| * Mike Shaver <shaver@ingenia.com> |
| * |
| * 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: |
| * |
| * Alexey I. Froloff : RFC6106 (DNSSL) support |
| * 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 |
| */ |
| |
| #define pr_fmt(fmt) "ICMPv6: " fmt |
| |
| #include <linux/module.h> |
| #include <linux/errno.h> |
| #include <linux/types.h> |
| #include <linux/socket.h> |
| #include <linux/sockios.h> |
| #include <linux/sched.h> |
| #include <linux/net.h> |
| #include <linux/in6.h> |
| #include <linux/route.h> |
| #include <linux/init.h> |
| #include <linux/rcupdate.h> |
| #include <linux/slab.h> |
| #ifdef CONFIG_SYSCTL |
| #include <linux/sysctl.h> |
| #endif |
| |
| #include <linux/if_addr.h> |
| #include <linux/if_arp.h> |
| #include <linux/ipv6.h> |
| #include <linux/icmpv6.h> |
| #include <linux/jhash.h> |
| |
| #include <net/sock.h> |
| #include <net/snmp.h> |
| |
| #include <net/ipv6.h> |
| #include <net/protocol.h> |
| #include <net/ndisc.h> |
| #include <net/ip6_route.h> |
| #include <net/addrconf.h> |
| #include <net/icmp.h> |
| |
| #include <net/netlink.h> |
| #include <linux/rtnetlink.h> |
| |
| #include <net/flow.h> |
| #include <net/ip6_checksum.h> |
| #include <net/inet_common.h> |
| #include <linux/proc_fs.h> |
| |
| #include <linux/netfilter.h> |
| #include <linux/netfilter_ipv6.h> |
| |
| /* Set to 3 to get tracing... */ |
| #define ND_DEBUG 1 |
| |
| #define ND_PRINTK(val, level, fmt, ...) \ |
| do { \ |
| if (val <= ND_DEBUG) \ |
| net_##level##_ratelimited(fmt, ##__VA_ARGS__); \ |
| } while (0) |
| |
| static u32 ndisc_hash(const void *pkey, |
| const struct net_device *dev, |
| __u32 *hash_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, |
| }; |
| |
| static void ndisc_fill_addr_option(struct sk_buff *skb, int type, void *data) |
| { |
| int pad = ndisc_addr_option_pad(skb->dev->type); |
| int data_len = skb->dev->addr_len; |
| int space = ndisc_opt_addr_space(skb->dev); |
| u8 *opt = skb_put(skb, space); |
| |
| 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); |
| } |
| |
| 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 || |
| opt->nd_opt_type == ND_OPT_DNSSL; |
| } |
| |
| 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; |
| } |
| |
| 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_PRINTK(2, warn, |
| "%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_PRINTK(2, 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; |
| } |
| |
| 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_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) |
| { |
| return ndisc_hashfn(pkey, dev, 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; |
| bool 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); |
| } |
| |
| static struct sk_buff *ndisc_alloc_skb(struct net_device *dev, |
| int len) |
| { |
| int hlen = LL_RESERVED_SPACE(dev); |
| int tlen = dev->needed_tailroom; |
| struct sock *sk = dev_net(dev)->ipv6.ndisc_sk; |
| struct sk_buff *skb; |
| int err; |
| |
| skb = sock_alloc_send_skb(sk, |
| hlen + sizeof(struct ipv6hdr) + len + tlen, |
| 1, &err); |
| if (!skb) { |
| ND_PRINTK(0, err, "ndisc: %s failed to allocate an skb, err=%d\n", |
| __func__, err); |
| return NULL; |
| } |
| |
| skb->protocol = htons(ETH_P_IPV6); |
| skb->dev = dev; |
| |
| skb_reserve(skb, hlen + sizeof(struct ipv6hdr)); |
| skb_reset_transport_header(skb); |
| |
| return skb; |
| } |
| |
| static void ip6_nd_hdr(struct sk_buff *skb, |
| const struct in6_addr *saddr, |
| const struct in6_addr *daddr, |
| int hop_limit, int len) |
| { |
| struct ipv6hdr *hdr; |
| |
| skb_push(skb, sizeof(*hdr)); |
| skb_reset_network_header(skb); |
| hdr = ipv6_hdr(skb); |
| |
| ip6_flow_hdr(hdr, 0, 0); |
| |
| hdr->payload_len = htons(len); |
| hdr->nexthdr = IPPROTO_ICMPV6; |
| hdr->hop_limit = hop_limit; |
| |
| hdr->saddr = *saddr; |
| hdr->daddr = *daddr; |
| } |
| |
| static void ndisc_send_skb(struct sk_buff *skb, |
| const struct in6_addr *daddr, |
| const struct in6_addr *saddr) |
| { |
| struct dst_entry *dst = skb_dst(skb); |
| struct net *net = dev_net(skb->dev); |
| struct sock *sk = net->ipv6.ndisc_sk; |
| struct inet6_dev *idev; |
| int err; |
| struct icmp6hdr *icmp6h = icmp6_hdr(skb); |
| u8 type; |
| |
| type = icmp6h->icmp6_type; |
| |
| if (!dst) { |
| struct sock *sk = net->ipv6.ndisc_sk; |
| struct flowi6 fl6; |
| |
| icmpv6_flow_init(sk, &fl6, type, saddr, daddr, skb->dev->ifindex); |
| dst = icmp6_dst_alloc(skb->dev, &fl6); |
| if (IS_ERR(dst)) { |
| kfree_skb(skb); |
| return; |
| } |
| |
| skb_dst_set(skb, dst); |
| } |
| |
| icmp6h->icmp6_cksum = csum_ipv6_magic(saddr, daddr, skb->len, |
| IPPROTO_ICMPV6, |
| csum_partial(icmp6h, |
| skb->len, 0)); |
| |
| ip6_nd_hdr(skb, saddr, daddr, inet6_sk(sk)->hop_limit, skb->len); |
| |
| 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(); |
| } |
| |
| static void ndisc_send_na(struct net_device *dev, struct neighbour *neigh, |
| const struct in6_addr *daddr, |
| const struct in6_addr *solicited_addr, |
| bool router, bool solicited, bool override, bool inc_opt) |
| { |
| struct sk_buff *skb; |
| struct in6_addr tmpaddr; |
| struct inet6_ifaddr *ifp; |
| const struct in6_addr *src_addr; |
| struct nd_msg *msg; |
| int optlen = 0; |
| |
| /* 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 = false; |
| 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; |
| } |
| |
| if (!dev->addr_len) |
| inc_opt = 0; |
| if (inc_opt) |
| optlen += ndisc_opt_addr_space(dev); |
| |
| skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen); |
| if (!skb) |
| return; |
| |
| msg = (struct nd_msg *)skb_put(skb, sizeof(*msg)); |
| *msg = (struct nd_msg) { |
| .icmph = { |
| .icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT, |
| .icmp6_router = router, |
| .icmp6_solicited = solicited, |
| .icmp6_override = override, |
| }, |
| .target = *solicited_addr, |
| }; |
| |
| if (inc_opt) |
| ndisc_fill_addr_option(skb, ND_OPT_TARGET_LL_ADDR, |
| dev->dev_addr); |
| |
| |
| ndisc_send_skb(skb, daddr, src_addr); |
| } |
| |
| static void ndisc_send_unsol_na(struct net_device *dev) |
| { |
| struct inet6_dev *idev; |
| struct inet6_ifaddr *ifa; |
| |
| idev = in6_dev_get(dev); |
| if (!idev) |
| return; |
| |
| read_lock_bh(&idev->lock); |
| list_for_each_entry(ifa, &idev->addr_list, if_list) { |
| ndisc_send_na(dev, NULL, &in6addr_linklocal_allnodes, &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 sk_buff *skb; |
| struct in6_addr addr_buf; |
| int inc_opt = dev->addr_len; |
| int optlen = 0; |
| struct nd_msg *msg; |
| |
| if (saddr == NULL) { |
| if (ipv6_get_lladdr(dev, &addr_buf, |
| (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC))) |
| return; |
| saddr = &addr_buf; |
| } |
| |
| if (ipv6_addr_any(saddr)) |
| inc_opt = false; |
| if (inc_opt) |
| optlen += ndisc_opt_addr_space(dev); |
| |
| skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen); |
| if (!skb) |
| return; |
| |
| msg = (struct nd_msg *)skb_put(skb, sizeof(*msg)); |
| *msg = (struct nd_msg) { |
| .icmph = { |
| .icmp6_type = NDISC_NEIGHBOUR_SOLICITATION, |
| }, |
| .target = *solicit, |
| }; |
| |
| if (inc_opt) |
| ndisc_fill_addr_option(skb, ND_OPT_SOURCE_LL_ADDR, |
| dev->dev_addr); |
| |
| ndisc_send_skb(skb, daddr, saddr); |
| } |
| |
| void ndisc_send_rs(struct net_device *dev, const struct in6_addr *saddr, |
| const struct in6_addr *daddr) |
| { |
| struct sk_buff *skb; |
| struct rs_msg *msg; |
| int send_sllao = dev->addr_len; |
| int optlen = 0; |
| |
| #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 |
| if (send_sllao) |
| optlen += ndisc_opt_addr_space(dev); |
| |
| skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen); |
| if (!skb) |
| return; |
| |
| msg = (struct rs_msg *)skb_put(skb, sizeof(*msg)); |
| *msg = (struct rs_msg) { |
| .icmph = { |
| .icmp6_type = NDISC_ROUTER_SOLICITATION, |
| }, |
| }; |
| |
| if (send_sllao) |
| ndisc_fill_addr_option(skb, ND_OPT_SOURCE_LL_ADDR, |
| dev->dev_addr); |
| |
| ndisc_send_skb(skb, daddr, saddr); |
| } |
| |
| |
| 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_PRINTK(1, dbg, |
| "%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_pointer(skb) - (skb_transport_header(skb) + |
| 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); |
| bool inc; |
| int is_router = -1; |
| |
| if (skb->len < sizeof(struct nd_msg)) { |
| ND_PRINTK(2, warn, "NS: packet too short\n"); |
| return; |
| } |
| |
| if (ipv6_addr_is_multicast(&msg->target)) { |
| ND_PRINTK(2, warn, "NS: multicast target address\n"); |
| return; |
| } |
| |
| /* |
| * RFC2461 7.1.1: |
| * DAD has to be destined for solicited node multicast address. |
| */ |
| if (dad && !ipv6_addr_is_solict_mult(daddr)) { |
| ND_PRINTK(2, warn, "NS: bad DAD packet (wrong destination)\n"); |
| return; |
| } |
| |
| if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts)) { |
| ND_PRINTK(2, warn, "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_PRINTK(2, warn, |
| "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_PRINTK(2, warn, |
| "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) { |
| /* |
| * 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 && |
| 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, false, (ifp != NULL), true); |
| 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, |
| true, (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_pointer(skb) - (skb_transport_header(skb) + |
| 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_PRINTK(2, warn, "NA: packet too short\n"); |
| return; |
| } |
| |
| if (ipv6_addr_is_multicast(&msg->target)) { |
| ND_PRINTK(2, warn, "NA: target address is multicast\n"); |
| return; |
| } |
| |
| if (ipv6_addr_is_multicast(daddr) && |
| msg->icmph.icmp6_solicited) { |
| ND_PRINTK(2, warn, "NA: solicited NA is multicasted\n"); |
| return; |
| } |
| |
| if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts)) { |
| ND_PRINTK(2, warn, "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_PRINTK(2, warn, |
| "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_PRINTK(1, warn, |
| "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.proxy_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) { |
| ND_PRINTK(1, err, "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)) { |
| ND_PRINTK(2, notice, "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); |
| |
| if (nla_put(skb, NDUSEROPT_SRCADDR, sizeof(struct in6_addr), |
| &ipv6_hdr(ra)->saddr)) |
| goto nla_put_failure; |
| 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 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_pointer(skb) - skb_transport_header(skb)) - |
| sizeof(struct ra_msg); |
| |
| if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) { |
| ND_PRINTK(2, warn, "RA: source address is not link-local\n"); |
| return; |
| } |
| if (optlen < 0) { |
| ND_PRINTK(2, warn, "RA: packet too short\n"); |
| return; |
| } |
| |
| #ifdef CONFIG_IPV6_NDISC_NODETYPE |
| if (skb->ndisc_nodetype == NDISC_NODETYPE_HOST) { |
| ND_PRINTK(2, warn, "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_PRINTK(0, err, "RA: can't find inet6 device for %s\n", |
| skb->dev->name); |
| return; |
| } |
| |
| if (!ndisc_parse_options(opt, optlen, &ndopts)) { |
| ND_PRINTK(2, warn, "RA: invalid ND options\n"); |
| return; |
| } |
| |
| if (!ipv6_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_neigh_lookup(&rt->dst, &ipv6_hdr(skb)->saddr); |
| if (!neigh) { |
| ND_PRINTK(0, err, |
| "RA: %s got default router without neighbour\n", |
| __func__); |
| ip6_rt_put(rt); |
| return; |
| } |
| } |
| if (rt && lifetime == 0) { |
| ip6_del_rt(rt); |
| rt = NULL; |
| } |
| |
| if (rt == NULL && lifetime) { |
| ND_PRINTK(3, dbg, "RA: adding default router\n"); |
| |
| rt = rt6_add_dflt_router(&ipv6_hdr(skb)->saddr, skb->dev, pref); |
| if (rt == NULL) { |
| ND_PRINTK(0, err, |
| "RA: %s failed to add default route\n", |
| __func__); |
| return; |
| } |
| |
| neigh = dst_neigh_lookup(&rt->dst, &ipv6_hdr(skb)->saddr); |
| if (neigh == NULL) { |
| ND_PRINTK(0, err, |
| "RA: %s got default router without neighbour\n", |
| __func__); |
| ip6_rt_put(rt); |
| return; |
| } |
| neigh->flags |= NTF_ROUTER; |
| } else if (rt) { |
| rt->rt6i_flags = (rt->rt6i_flags & ~RTF_PREF_MASK) | RTF_PREF(pref); |
| } |
| |
| if (rt) |
| rt6_set_expires(rt, 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_PRINTK(2, warn, |
| "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 (!ipv6_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, |
| ndopts.nd_opts_src_lladdr != NULL); |
| } |
| } |
| |
| 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_PRINTK(2, warn, "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_PRINTK(2, warn, "RA: invalid RA options\n"); |
| } |
| out: |
| ip6_rt_put(rt); |
| if (neigh) |
| neigh_release(neigh); |
| } |
| |
| static void ndisc_redirect_rcv(struct sk_buff *skb) |
| { |
| u8 *hdr; |
| struct ndisc_options ndopts; |
| struct rd_msg *msg = (struct rd_msg *)skb_transport_header(skb); |
| u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) + |
| offsetof(struct rd_msg, opt)); |
| |
| #ifdef CONFIG_IPV6_NDISC_NODETYPE |
| switch (skb->ndisc_nodetype) { |
| case NDISC_NODETYPE_HOST: |
| case NDISC_NODETYPE_NODEFAULT: |
| ND_PRINTK(2, warn, |
| "Redirect: from host or unauthorized router\n"); |
| return; |
| } |
| #endif |
| |
| if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) { |
| ND_PRINTK(2, warn, |
| "Redirect: source address is not link-local\n"); |
| return; |
| } |
| |
| if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts)) |
| return; |
| |
| if (!ndopts.nd_opts_rh) { |
| ip6_redirect_no_header(skb, dev_net(skb->dev), 0, 0); |
| return; |
| } |
| |
| hdr = (u8 *)ndopts.nd_opts_rh; |
| hdr += 8; |
| if (!pskb_pull(skb, hdr - skb_transport_header(skb))) |
| return; |
| |
| icmpv6_notify(skb, NDISC_REDIRECT, 0, 0); |
| } |
| |
| static void ndisc_fill_redirect_hdr_option(struct sk_buff *skb, |
| struct sk_buff *orig_skb, |
| int rd_len) |
| { |
| u8 *opt = skb_put(skb, rd_len); |
| |
| memset(opt, 0, 8); |
| *(opt++) = ND_OPT_REDIRECT_HDR; |
| *(opt++) = (rd_len >> 3); |
| opt += 6; |
| |
| memcpy(opt, ipv6_hdr(orig_skb), rd_len - 8); |
| } |
| |
| void ndisc_send_redirect(struct sk_buff *skb, 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 optlen = 0; |
| struct inet_peer *peer; |
| struct sk_buff *buff; |
| struct rd_msg *msg; |
| struct in6_addr saddr_buf; |
| struct rt6_info *rt; |
| struct dst_entry *dst; |
| struct flowi6 fl6; |
| int rd_len; |
| u8 ha_buf[MAX_ADDR_LEN], *ha = NULL; |
| bool ret; |
| |
| if (ipv6_get_lladdr(dev, &saddr_buf, IFA_F_TENTATIVE)) { |
| ND_PRINTK(2, warn, "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_PRINTK(2, warn, |
| "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->error) { |
| dst_release(dst); |
| 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_PRINTK(2, warn, |
| "Redirect: destination is not a neighbour\n"); |
| goto release; |
| } |
| peer = inet_getpeer_v6(net->ipv6.peers, &rt->rt6i_dst.addr, 1); |
| ret = inet_peer_xrlim_allow(peer, 1*HZ); |
| if (peer) |
| inet_putpeer(peer); |
| if (!ret) |
| goto release; |
| |
| if (dev->addr_len) { |
| struct neighbour *neigh = dst_neigh_lookup(skb_dst(skb), target); |
| if (!neigh) { |
| ND_PRINTK(2, warn, |
| "Redirect: no neigh for target address\n"); |
| goto release; |
| } |
| |
| 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; |
| optlen += ndisc_opt_addr_space(dev); |
| } else |
| read_unlock_bh(&neigh->lock); |
| |
| neigh_release(neigh); |
| } |
| |
| rd_len = min_t(unsigned int, |
| IPV6_MIN_MTU - sizeof(struct ipv6hdr) - sizeof(*msg) - optlen, |
| skb->len + 8); |
| rd_len &= ~0x7; |
| optlen += rd_len; |
| |
| buff = ndisc_alloc_skb(dev, sizeof(*msg) + optlen); |
| if (!buff) |
| goto release; |
| |
| msg = (struct rd_msg *)skb_put(buff, sizeof(*msg)); |
| *msg = (struct rd_msg) { |
| .icmph = { |
| .icmp6_type = NDISC_REDIRECT, |
| }, |
| .target = *target, |
| .dest = ipv6_hdr(skb)->daddr, |
| }; |
| |
| /* |
| * include target_address option |
| */ |
| |
| if (ha) |
| ndisc_fill_addr_option(buff, ND_OPT_TARGET_LL_ADDR, ha); |
| |
| /* |
| * build redirect option and copy skb over to the new packet. |
| */ |
| |
| if (rd_len) |
| ndisc_fill_redirect_hdr_option(buff, skb, rd_len); |
| |
| skb_dst_set(buff, dst); |
| ndisc_send_skb(buff, &ipv6_hdr(skb)->saddr, &saddr_buf); |
| return; |
| |
| release: |
| dst_release(dst); |
| } |
| |
| static void pndisc_redo(struct sk_buff *skb) |
| { |
| ndisc_recv_ns(skb); |
| kfree_skb(skb); |
| } |
| |
| static bool ndisc_suppress_frag_ndisc(struct sk_buff *skb) |
| { |
| struct inet6_dev *idev = __in6_dev_get(skb->dev); |
| |
| if (!idev) |
| return true; |
| if (IP6CB(skb)->flags & IP6SKB_FRAGMENTED && |
| idev->cnf.suppress_frag_ndisc) { |
| net_warn_ratelimited("Received fragmented ndisc packet. Carefully consider disabling suppress_frag_ndisc.\n"); |
| return true; |
| } |
| return false; |
| } |
| |
| int ndisc_rcv(struct sk_buff *skb) |
| { |
| struct nd_msg *msg; |
| |
| if (ndisc_suppress_frag_ndisc(skb)) |
| return 0; |
| |
| if (skb_linearize(skb)) |
| 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_PRINTK(2, warn, "NDISC: invalid hop-limit: %d\n", |
| ipv6_hdr(skb)->hop_limit); |
| return 0; |
| } |
| |
| if (msg->icmph.icmp6_code != 0) { |
| ND_PRINTK(2, warn, "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 = netdev_notifier_info_to_dev(ptr); |
| struct net *net = dev_net(dev); |
| struct inet6_dev *idev; |
| |
| switch (event) { |
| case NETDEV_CHANGEADDR: |
| neigh_changeaddr(&nd_tbl, dev); |
| fib6_run_gc(0, net, false); |
| idev = in6_dev_get(dev); |
| if (!idev) |
| break; |
| if (idev->cnf.ndisc_notify) |
| ndisc_send_unsol_na(dev); |
| in6_dev_put(idev); |
| break; |
| case NETDEV_DOWN: |
| neigh_ifdown(&nd_tbl, dev); |
| fib6_run_gc(0, net, false); |
| 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); |
| pr_warn("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_PRINTK(0, err, |
| "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); |
| } |