ndisc.c
上传用户:jlfgdled
上传日期:2013-04-10
资源大小:33168k
文件大小:32k
- /*
- * 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:
- *
- * Lars Fenneberg : fixed MTU setting on receipt
- * of an RA.
- *
- * Janos Farkas : kmalloc failure checks
- * Alexey Kuznetsov : state machine reworked
- * and moved to net/core.
- * Pekka Savola : RFC2461 validation
- * YOSHIFUJI Hideaki @USAGI : Verify ND options properly
- */
- /* Set to 3 to get tracing... */
- #define ND_DEBUG 1
- #define ND_PRINTK(x...) printk(KERN_DEBUG x)
- #define ND_NOPRINTK(x...) do { ; } while(0)
- #define ND_PRINTK0 ND_PRINTK
- #define ND_PRINTK1 ND_NOPRINTK
- #define ND_PRINTK2 ND_NOPRINTK
- #if ND_DEBUG >= 1
- #undef ND_PRINTK1
- #define ND_PRINTK1 ND_PRINTK
- #endif
- #if ND_DEBUG >= 2
- #undef ND_PRINTK2
- #define ND_PRINTK2 ND_PRINTK
- #endif
- #define __NO_VERSION__
- #include <linux/module.h>
- #include <linux/config.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>
- #ifdef CONFIG_SYSCTL
- #include <linux/sysctl.h>
- #endif
- #include <linux/if_arp.h>
- #include <linux/ipv6.h>
- #include <linux/icmpv6.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/checksum.h>
- #include <linux/proc_fs.h>
- static struct socket *ndisc_socket;
- static u32 ndisc_hash(const void *pkey, const struct net_device *dev);
- static int ndisc_constructor(struct neighbour *neigh);
- static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb);
- static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb);
- static int pndisc_constructor(struct pneigh_entry *n);
- static void pndisc_destructor(struct pneigh_entry *n);
- static void pndisc_redo(struct sk_buff *skb);
- static struct neigh_ops ndisc_generic_ops =
- {
- AF_INET6,
- NULL,
- ndisc_solicit,
- ndisc_error_report,
- neigh_resolve_output,
- neigh_connected_output,
- dev_queue_xmit,
- dev_queue_xmit
- };
- static struct neigh_ops ndisc_hh_ops =
- {
- AF_INET6,
- NULL,
- ndisc_solicit,
- ndisc_error_report,
- neigh_resolve_output,
- neigh_resolve_output,
- dev_queue_xmit,
- dev_queue_xmit
- };
- static struct neigh_ops ndisc_direct_ops =
- {
- AF_INET6,
- NULL,
- NULL,
- NULL,
- dev_queue_xmit,
- dev_queue_xmit,
- dev_queue_xmit,
- dev_queue_xmit
- };
- struct neigh_table nd_tbl =
- {
- NULL,
- AF_INET6,
- sizeof(struct neighbour) + sizeof(struct in6_addr),
- sizeof(struct in6_addr),
- ndisc_hash,
- ndisc_constructor,
- pndisc_constructor,
- pndisc_destructor,
- pndisc_redo,
- "ndisc_cache",
- { NULL, NULL, &nd_tbl, 0, NULL, NULL,
- 30*HZ, 1*HZ, 60*HZ, 30*HZ, 5*HZ, 3, 3, 0, 3, 1*HZ, (8*HZ)/10, 64, 0 },
- 30*HZ, 128, 512, 1024,
- };
- #define NDISC_OPT_SPACE(len) (((len)+2+7)&~7)
- static u8 *ndisc_fill_option(u8 *opt, int type, void *data, int data_len)
- {
- int space = NDISC_OPT_SPACE(data_len);
- opt[0] = type;
- opt[1] = space>>3;
- memcpy(opt+2, data, data_len);
- data_len += 2;
- opt += data_len;
- if ((space -= data_len) > 0)
- memset(opt, 0, space);
- return opt + space;
- }
- struct nd_opt_hdr *ndisc_next_option(struct nd_opt_hdr *cur,
- struct nd_opt_hdr *end)
- {
- int type;
- if (!cur || !end || cur >= end)
- return NULL;
- type = cur->nd_opt_type;
- do {
- cur = ((void *)cur) + (cur->nd_opt_len << 3);
- } while(cur < end && cur->nd_opt_type != type);
- return (cur <= end && cur->nd_opt_type == type ? cur : NULL);
- }
- struct ndisc_options *ndisc_parse_options(u8 *opt, int opt_len,
- struct ndisc_options *ndopts)
- {
- struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)opt;
- if (!nd_opt || opt_len < 0 || !ndopts)
- return NULL;
- memset(ndopts, 0, sizeof(*ndopts));
- while (opt_len) {
- int l;
- if (opt_len < sizeof(struct nd_opt_hdr))
- return NULL;
- l = nd_opt->nd_opt_len << 3;
- if (opt_len < l || l == 0)
- return NULL;
- switch (nd_opt->nd_opt_type) {
- case ND_OPT_SOURCE_LL_ADDR:
- case ND_OPT_TARGET_LL_ADDR:
- case ND_OPT_MTU:
- case ND_OPT_REDIRECT_HDR:
- if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) {
- ND_PRINTK2((KERN_WARNING
- "ndisc_parse_options(): duplicated ND6 option found: type=%dn",
- nd_opt->nd_opt_type));
- } else {
- ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
- }
- break;
- case ND_OPT_PREFIX_INFO:
- ndopts->nd_opts_pi_end = nd_opt;
- if (ndopts->nd_opt_array[nd_opt->nd_opt_type] == 0)
- ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt;
- break;
- default:
- /*
- * Unknown options must be silently ignored,
- * to accomodate future extension to the protocol.
- */
- ND_PRINTK2(KERN_WARNING
- "ndisc_parse_options(): ignored unsupported option; type=%d, len=%dn",
- nd_opt->nd_opt_type, nd_opt->nd_opt_len);
- }
- opt_len -= l;
- nd_opt = ((void *)nd_opt) + l;
- }
- return ndopts;
- }
- int ndisc_mc_map(struct in6_addr *addr, char *buf, struct net_device *dev, int dir)
- {
- switch (dev->type) {
- case ARPHRD_ETHER:
- case ARPHRD_IEEE802: /* Not sure. Check it later. --ANK */
- case ARPHRD_FDDI:
- ipv6_eth_mc_map(addr, buf);
- return 0;
- case ARPHRD_IEEE802_TR:
- ipv6_tr_mc_map(addr,buf);
- return 0;
- default:
- if (dir) {
- memcpy(buf, dev->broadcast, dev->addr_len);
- return 0;
- }
- }
- return -EINVAL;
- }
- static u32 ndisc_hash(const void *pkey, const struct net_device *dev)
- {
- u32 hash_val;
- hash_val = *(u32*)(pkey + sizeof(struct in6_addr) - 4);
- hash_val ^= (hash_val>>16);
- hash_val ^= hash_val>>8;
- hash_val ^= hash_val>>3;
- hash_val = (hash_val^dev->ifindex)&NEIGH_HASHMASK;
- return hash_val;
- }
- static int ndisc_constructor(struct neighbour *neigh)
- {
- struct in6_addr *addr = (struct in6_addr*)&neigh->primary_key;
- struct net_device *dev = neigh->dev;
- struct inet6_dev *in6_dev = in6_dev_get(dev);
- int addr_type;
- if (in6_dev == NULL)
- return -EINVAL;
- addr_type = ipv6_addr_type(addr);
- if (in6_dev->nd_parms)
- neigh->parms = in6_dev->nd_parms;
- if (addr_type&IPV6_ADDR_MULTICAST)
- neigh->type = RTN_MULTICAST;
- else
- neigh->type = RTN_UNICAST;
- if (dev->hard_header == NULL) {
- neigh->nud_state = NUD_NOARP;
- neigh->ops = &ndisc_direct_ops;
- neigh->output = neigh->ops->queue_xmit;
- } else {
- if (addr_type&IPV6_ADDR_MULTICAST) {
- neigh->nud_state = NUD_NOARP;
- ndisc_mc_map(addr, neigh->ha, dev, 1);
- } else if (dev->flags&(IFF_NOARP|IFF_LOOPBACK)) {
- neigh->nud_state = NUD_NOARP;
- memcpy(neigh->ha, dev->dev_addr, dev->addr_len);
- if (dev->flags&IFF_LOOPBACK)
- neigh->type = RTN_LOCAL;
- } else if (dev->flags&IFF_POINTOPOINT) {
- neigh->nud_state = NUD_NOARP;
- memcpy(neigh->ha, dev->broadcast, dev->addr_len);
- }
- if (dev->hard_header_cache)
- neigh->ops = &ndisc_hh_ops;
- else
- neigh->ops = &ndisc_generic_ops;
- if (neigh->nud_state&NUD_VALID)
- neigh->output = neigh->ops->connected_output;
- else
- neigh->output = neigh->ops->output;
- }
- in6_dev_put(in6_dev);
- return 0;
- }
- static int pndisc_constructor(struct pneigh_entry *n)
- {
- struct in6_addr *addr = (struct in6_addr*)&n->key;
- struct in6_addr maddr;
- struct net_device *dev = n->dev;
- if (dev == NULL || __in6_dev_get(dev) == NULL)
- return -EINVAL;
- addrconf_addr_solict_mult(addr, &maddr);
- ipv6_dev_mc_inc(dev, &maddr);
- return 0;
- }
- static void pndisc_destructor(struct pneigh_entry *n)
- {
- struct in6_addr *addr = (struct in6_addr*)&n->key;
- struct in6_addr maddr;
- struct net_device *dev = n->dev;
- if (dev == NULL || __in6_dev_get(dev) == NULL)
- return;
- addrconf_addr_solict_mult(addr, &maddr);
- ipv6_dev_mc_dec(dev, &maddr);
- }
- static int
- ndisc_build_ll_hdr(struct sk_buff *skb, struct net_device *dev,
- struct in6_addr *daddr, struct neighbour *neigh, int len)
- {
- unsigned char ha[MAX_ADDR_LEN];
- unsigned char *h_dest = NULL;
- skb_reserve(skb, (dev->hard_header_len + 15) & ~15);
- if (dev->hard_header) {
- if (ipv6_addr_type(daddr) & IPV6_ADDR_MULTICAST) {
- ndisc_mc_map(daddr, ha, dev, 1);
- h_dest = ha;
- } else if (neigh) {
- read_lock_bh(&neigh->lock);
- if (neigh->nud_state&NUD_VALID) {
- memcpy(ha, neigh->ha, dev->addr_len);
- h_dest = ha;
- }
- read_unlock_bh(&neigh->lock);
- } else {
- neigh = neigh_lookup(&nd_tbl, daddr, dev);
- if (neigh) {
- read_lock_bh(&neigh->lock);
- if (neigh->nud_state&NUD_VALID) {
- memcpy(ha, neigh->ha, dev->addr_len);
- h_dest = ha;
- }
- read_unlock_bh(&neigh->lock);
- neigh_release(neigh);
- }
- }
- if (dev->hard_header(skb, dev, ETH_P_IPV6, h_dest, NULL, len) < 0)
- return 0;
- }
- return 1;
- }
- /*
- * Send a Neighbour Advertisement
- */
- void ndisc_send_na(struct net_device *dev, struct neighbour *neigh,
- struct in6_addr *daddr, struct in6_addr *solicited_addr,
- int router, int solicited, int override, int inc_opt)
- {
- 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, &err);
- if (skb == NULL) {
- ND_PRINTK1("send_na: alloc skb failedn");
- 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(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);
- ICMP6_INC_STATS(Icmp6OutNeighborAdvertisements);
- ICMP6_INC_STATS(Icmp6OutMsgs);
- }
- void ndisc_send_ns(struct net_device *dev, struct neighbour *neigh,
- struct in6_addr *solicit,
- struct in6_addr *daddr, struct in6_addr *saddr)
- {
- struct sock *sk = ndisc_socket->sk;
- struct sk_buff *skb;
- struct nd_msg *msg;
- struct in6_addr addr_buf;
- int len;
- int err;
- int send_llinfo;
- if (saddr == NULL) {
- if (ipv6_get_lladdr(dev, &addr_buf))
- return;
- saddr = &addr_buf;
- }
- len = sizeof(struct icmp6hdr) + sizeof(struct in6_addr);
- send_llinfo = dev->addr_len && ipv6_addr_type(saddr) != IPV6_ADDR_ANY;
- if (send_llinfo)
- len += NDISC_OPT_SPACE(dev->addr_len);
- skb = sock_alloc_send_skb(sk, MAX_HEADER + len + dev->hard_header_len + 15,
- 0, &err);
- if (skb == NULL) {
- ND_PRINTK1("send_ns: alloc skb failedn");
- return;
- }
- if (ndisc_build_ll_hdr(skb, dev, daddr, neigh, len) == 0) {
- kfree_skb(skb);
- return;
- }
- ip6_nd_hdr(sk, skb, dev, saddr, daddr, IPPROTO_ICMPV6, len);
- msg = (struct nd_msg *)skb_put(skb, len);
- msg->icmph.icmp6_type = NDISC_NEIGHBOUR_SOLICITATION;
- msg->icmph.icmp6_code = 0;
- msg->icmph.icmp6_cksum = 0;
- msg->icmph.icmp6_unused = 0;
- /* Set the target address. */
- ipv6_addr_copy(&msg->target, solicit);
- if (send_llinfo)
- ndisc_fill_option(msg->opt, ND_OPT_SOURCE_LL_ADDR, dev->dev_addr, dev->addr_len);
- /* checksum */
- msg->icmph.icmp6_cksum = csum_ipv6_magic(&skb->nh.ipv6h->saddr,
- daddr, len,
- IPPROTO_ICMPV6,
- csum_partial((__u8 *) msg,
- len, 0));
- /* send it! */
- dev_queue_xmit(skb);
- ICMP6_INC_STATS(Icmp6OutNeighborSolicits);
- ICMP6_INC_STATS(Icmp6OutMsgs);
- }
- void ndisc_send_rs(struct net_device *dev, struct in6_addr *saddr,
- struct in6_addr *daddr)
- {
- struct sock *sk = ndisc_socket->sk;
- struct sk_buff *skb;
- struct icmp6hdr *hdr;
- __u8 * opt;
- int len;
- int err;
- len = sizeof(struct icmp6hdr);
- if (dev->addr_len)
- len += NDISC_OPT_SPACE(dev->addr_len);
- skb = sock_alloc_send_skb(sk, MAX_HEADER + len + dev->hard_header_len + 15,
- 0, &err);
- if (skb == NULL) {
- ND_PRINTK1("send_ns: alloc skb failedn");
- return;
- }
- if (ndisc_build_ll_hdr(skb, dev, daddr, NULL, len) == 0) {
- kfree_skb(skb);
- return;
- }
- ip6_nd_hdr(sk, skb, dev, saddr, daddr, IPPROTO_ICMPV6, len);
- hdr = (struct icmp6hdr *) skb_put(skb, len);
- hdr->icmp6_type = NDISC_ROUTER_SOLICITATION;
- hdr->icmp6_code = 0;
- hdr->icmp6_cksum = 0;
- hdr->icmp6_unused = 0;
- opt = (u8*) (hdr + 1);
- if (dev->addr_len)
- ndisc_fill_option(opt, ND_OPT_SOURCE_LL_ADDR, dev->dev_addr, dev->addr_len);
- /* checksum */
- hdr->icmp6_cksum = csum_ipv6_magic(&skb->nh.ipv6h->saddr, daddr, len,
- IPPROTO_ICMPV6,
- csum_partial((__u8 *) hdr, len, 0));
- /* send it! */
- dev_queue_xmit(skb);
- ICMP6_INC_STATS(Icmp6OutRouterSolicits);
- ICMP6_INC_STATS(Icmp6OutMsgs);
- }
-
- static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb)
- {
- /*
- * "The sender MUST return an ICMP
- * destination unreachable"
- */
- dst_link_failure(skb);
- kfree_skb(skb);
- }
- /* Called with locked neigh: either read or both */
- static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb)
- {
- struct in6_addr *saddr = NULL;
- struct in6_addr mcaddr;
- struct net_device *dev = neigh->dev;
- struct in6_addr *target = (struct in6_addr *)&neigh->primary_key;
- int probes = atomic_read(&neigh->probes);
- if (skb && ipv6_chk_addr(&skb->nh.ipv6h->saddr, dev))
- saddr = &skb->nh.ipv6h->saddr;
- if ((probes -= neigh->parms->ucast_probes) < 0) {
- if (!(neigh->nud_state&NUD_VALID))
- ND_PRINTK1("trying to ucast probe in NUD_INVALIDn");
- 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 void ndisc_router_discovery(struct sk_buff *skb)
- {
- struct ra_msg *ra_msg = (struct ra_msg *) skb->h.raw;
- struct neighbour *neigh;
- struct inet6_dev *in6_dev;
- struct rt6_info *rt;
- int lifetime;
- struct ndisc_options ndopts;
- int optlen;
- __u8 * opt = (__u8 *)(ra_msg + 1);
- optlen = (skb->tail - skb->h.raw) - sizeof(struct ra_msg);
- if (!(ipv6_addr_type(&skb->nh.ipv6h->saddr) & IPV6_ADDR_LINKLOCAL)) {
- if (net_ratelimit())
- printk(KERN_WARNING "ICMP RA: source address is not linklocaln");
- return;
- }
- if (optlen < 0) {
- if (net_ratelimit())
- printk(KERN_WARNING "ICMP RA: packet too shortn");
- return;
- }
- /*
- * set the RA_RECV flag in the interface
- */
- in6_dev = in6_dev_get(skb->dev);
- if (in6_dev == NULL) {
- ND_PRINTK1("RA: can't find in6 devicen");
- return;
- }
- if (in6_dev->cnf.forwarding || !in6_dev->cnf.accept_ra) {
- in6_dev_put(in6_dev);
- return;
- }
- if (!ndisc_parse_options(opt, optlen, &ndopts)) {
- if (net_ratelimit())
- ND_PRINTK2(KERN_WARNING
- "ICMP6 RA: invalid ND option, ignored.n");
- return;
- }
- if (in6_dev->if_flags & IF_RS_SENT) {
- /*
- * flag that an RA was received after an RS was sent
- * out on this interface.
- */
- in6_dev->if_flags |= IF_RA_RCVD;
- }
- 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);
- rt = NULL;
- }
- if (rt == NULL && lifetime) {
- ND_PRINTK2("ndisc_rdisc: adding default routern");
- rt = rt6_add_dflt_router(&skb->nh.ipv6h->saddr, skb->dev);
- if (rt == NULL) {
- ND_PRINTK1("route_add failedn");
- in6_dev_put(in6_dev);
- return;
- }
- neigh = rt->rt6i_nexthop;
- if (neigh == NULL) {
- ND_PRINTK1("nd: add default router: null neighbourn");
- dst_release(&rt->u.dst);
- in6_dev_put(in6_dev);
- return;
- }
- neigh->flags |= NTF_ROUTER;
- /*
- * If we where using an "all destinations on link" route
- * delete it
- */
- rt6_purge_dflt_routers(RTF_ALLONLINK);
- }
- if (rt)
- rt->rt6i_expires = jiffies + (HZ * lifetime);
- if (ra_msg->icmph.icmp6_hop_limit)
- in6_dev->cnf.hop_limit = ra_msg->icmph.icmp6_hop_limit;
- /*
- * Update Reachable Time and Retrans Timer
- */
- if (in6_dev->nd_parms) {
- __u32 rtime = ntohl(ra_msg->retrans_timer);
- if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/HZ) {
- rtime = (rtime*HZ)/1000;
- if (rtime < HZ/10)
- rtime = HZ/10;
- in6_dev->nd_parms->retrans_time = rtime;
- }
- rtime = ntohl(ra_msg->reachable_time);
- if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/(3*HZ)) {
- rtime = (rtime*HZ)/1000;
- if (rtime < HZ/10)
- rtime = HZ/10;
- if (rtime != in6_dev->nd_parms->base_reachable_time) {
- in6_dev->nd_parms->base_reachable_time = rtime;
- in6_dev->nd_parms->gc_staletime = 3 * rtime;
- in6_dev->nd_parms->reachable_time = neigh_rand_reach_time(rtime);
- }
- }
- }
- /*
- * Process options.
- */
- if (rt && (neigh = rt->rt6i_nexthop) != NULL) {
- u8 *lladdr = NULL;
- int lladdrlen;
- if (ndopts.nd_opts_src_lladdr) {
- lladdr = (u8*)((ndopts.nd_opts_src_lladdr)+1);
- lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3;
- if (lladdrlen != NDISC_OPT_SPACE(skb->dev->addr_len)) {
- if (net_ratelimit())
- ND_PRINTK2(KERN_WARNING
- "ICMP6 RA: Invalid lladdr length.n");
- goto out;
- }
- }
- neigh_update(neigh, lladdr, NUD_STALE, 1, 1);
- }
- if (ndopts.nd_opts_pi) {
- struct nd_opt_hdr *p;
- for (p = ndopts.nd_opts_pi;
- p;
- p = ndisc_next_option(p, ndopts.nd_opts_pi_end)) {
- addrconf_prefix_rcv(skb->dev, (u8*)p, (p->nd_opt_len) << 3);
- }
- }
- if (ndopts.nd_opts_mtu) {
- u32 mtu;
- memcpy(&mtu, ((u8*)(ndopts.nd_opts_mtu+1))+2, sizeof(mtu));
- mtu = ntohl(mtu);
- if (mtu < IPV6_MIN_MTU || mtu > skb->dev->mtu) {
- if (net_ratelimit()) {
- ND_PRINTK0("NDISC: router announcement with mtu = %dn",
- mtu);
- }
- }
- if (in6_dev->cnf.mtu6 != mtu) {
- in6_dev->cnf.mtu6 = mtu;
- if (rt)
- rt->u.dst.pmtu = mtu;
- rt6_mtu_change(skb->dev, mtu);
- }
- }
-
- if (ndopts.nd_opts_tgt_lladdr || ndopts.nd_opts_rh) {
- if (net_ratelimit())
- ND_PRINTK0(KERN_WARNING
- "ICMP6 RA: got illegal option with RA");
- }
- out:
- if (rt)
- dst_release(&rt->u.dst);
- in6_dev_put(in6_dev);
- }
- static void ndisc_redirect_rcv(struct sk_buff *skb)
- {
- struct inet6_dev *in6_dev;
- struct icmp6hdr *icmph;
- struct in6_addr *dest;
- struct in6_addr *target; /* new first hop to destination */
- struct neighbour *neigh;
- int on_link = 0;
- struct ndisc_options ndopts;
- int optlen;
- u8 *lladdr = NULL;
- int lladdrlen;
- if (!(ipv6_addr_type(&skb->nh.ipv6h->saddr) & IPV6_ADDR_LINKLOCAL)) {
- if (net_ratelimit())
- printk(KERN_WARNING "ICMP redirect: source address is not linklocaln");
- return;
- }
- optlen = skb->tail - skb->h.raw;
- optlen -= sizeof(struct icmp6hdr) + 2 * sizeof(struct in6_addr);
- if (optlen < 0) {
- if (net_ratelimit())
- printk(KERN_WARNING "ICMP redirect: packet too smalln");
- return;
- }
- icmph = (struct icmp6hdr *) skb->h.raw;
- target = (struct in6_addr *) (icmph + 1);
- dest = target + 1;
- if (ipv6_addr_type(dest) & IPV6_ADDR_MULTICAST) {
- if (net_ratelimit())
- printk(KERN_WARNING "ICMP redirect for multicast addrn");
- return;
- }
- if (ipv6_addr_cmp(dest, target) == 0) {
- on_link = 1;
- } else if (!(ipv6_addr_type(target) & IPV6_ADDR_LINKLOCAL)) {
- if (net_ratelimit())
- printk(KERN_WARNING "ICMP redirect: target address is not linklocaln");
- return;
- }
- in6_dev = in6_dev_get(skb->dev);
- if (!in6_dev)
- return;
- if (in6_dev->cnf.forwarding || !in6_dev->cnf.accept_redirects) {
- in6_dev_put(in6_dev);
- return;
- }
- /* XXX: RFC2461 8.1:
- * The IP source address of the Redirect MUST be the same as the current
- * first-hop router for the specified ICMP Destination Address.
- */
-
- if (!ndisc_parse_options((u8*)(dest + 1), optlen, &ndopts)) {
- if (net_ratelimit())
- ND_PRINTK2(KERN_WARNING
- "ICMP6 Redirect: invalid ND options, rejected.n");
- in6_dev_put(in6_dev);
- return;
- }
- if (ndopts.nd_opts_tgt_lladdr) {
- lladdr = (u8*)(ndopts.nd_opts_tgt_lladdr + 1);
- lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3;
- if (lladdrlen != NDISC_OPT_SPACE(skb->dev->addr_len)) {
- if (net_ratelimit())
- ND_PRINTK2(KERN_WARNING
- "ICMP6 Redirect: invalid lladdr length.n");
- in6_dev_put(in6_dev);
- return;
- }
- }
- /* passed validation tests */
- /*
- We install redirect only if nexthop state is valid.
- */
- neigh = __neigh_lookup(&nd_tbl, target, skb->dev, 1);
- if (neigh) {
- neigh_update(neigh, lladdr, NUD_STALE, 1, 1);
- if (neigh->nud_state&NUD_VALID)
- rt6_redirect(dest, &skb->nh.ipv6h->saddr, neigh, on_link);
- else
- __neigh_event_send(neigh, NULL);
- neigh_release(neigh);
- }
- in6_dev_put(in6_dev);
- }
- void ndisc_send_redirect(struct sk_buff *skb, struct neighbour *neigh,
- struct in6_addr *target)
- {
- struct sock *sk = ndisc_socket->sk;
- int len = sizeof(struct icmp6hdr) + 2 * sizeof(struct in6_addr);
- struct sk_buff *buff;
- struct icmp6hdr *icmph;
- struct in6_addr saddr_buf;
- struct in6_addr *addrp;
- struct net_device *dev;
- struct rt6_info *rt;
- u8 *opt;
- int rd_len;
- int err;
- int hlen;
- dev = skb->dev;
- rt = rt6_lookup(&skb->nh.ipv6h->saddr, NULL, dev->ifindex, 1);
- if (rt == NULL)
- return;
- if (rt->rt6i_flags & RTF_GATEWAY) {
- ND_PRINTK1("ndisc_send_redirect: not a neighbourn");
- dst_release(&rt->u.dst);
- return;
- }
- if (!xrlim_allow(&rt->u.dst, 1*HZ)) {
- dst_release(&rt->u.dst);
- return;
- }
- dst_release(&rt->u.dst);
- if (dev->addr_len) {
- if (neigh->nud_state&NUD_VALID) {
- len += NDISC_OPT_SPACE(dev->addr_len);
- } else {
- /* If nexthop is not valid, do not redirect!
- We will make it later, when will be sure,
- that it is alive.
- */
- return;
- }
- }
- rd_len = min_t(unsigned int,
- IPV6_MIN_MTU-sizeof(struct ipv6hdr)-len, skb->len + 8);
- rd_len &= ~0x7;
- len += rd_len;
- if (ipv6_get_lladdr(dev, &saddr_buf)) {
- ND_PRINTK1("redirect: no link_local addr for devn");
- return;
- }
- buff = sock_alloc_send_skb(sk, MAX_HEADER + len + dev->hard_header_len + 15,
- 0, &err);
- if (buff == NULL) {
- ND_PRINTK1("ndisc_send_redirect: alloc_skb failedn");
- return;
- }
- hlen = 0;
- if (ndisc_build_ll_hdr(buff, dev, &skb->nh.ipv6h->saddr, NULL, len) == 0) {
- kfree_skb(buff);
- return;
- }
- ip6_nd_hdr(sk, buff, dev, &saddr_buf, &skb->nh.ipv6h->saddr,
- IPPROTO_ICMPV6, len);
- icmph = (struct icmp6hdr *) skb_put(buff, len);
- memset(icmph, 0, sizeof(struct icmp6hdr));
- icmph->icmp6_type = NDISC_REDIRECT;
- /*
- * copy target and destination addresses
- */
- addrp = (struct in6_addr *)(icmph + 1);
- ipv6_addr_copy(addrp, target);
- addrp++;
- ipv6_addr_copy(addrp, &skb->nh.ipv6h->daddr);
- opt = (u8*) (addrp + 1);
- /*
- * include target_address option
- */
- if (dev->addr_len)
- opt = ndisc_fill_option(opt, ND_OPT_TARGET_LL_ADDR, neigh->ha, dev->addr_len);
- /*
- * build redirect option and copy skb over to the new packet.
- */
- memset(opt, 0, 8);
- *(opt++) = ND_OPT_REDIRECT_HDR;
- *(opt++) = (rd_len >> 3);
- opt += 6;
- memcpy(opt, skb->nh.ipv6h, rd_len - 8);
- icmph->icmp6_cksum = csum_ipv6_magic(&saddr_buf, &skb->nh.ipv6h->saddr,
- len, IPPROTO_ICMPV6,
- csum_partial((u8 *) icmph, len, 0));
- dev_queue_xmit(buff);
- ICMP6_INC_STATS(Icmp6OutRedirects);
- ICMP6_INC_STATS(Icmp6OutMsgs);
- }
- static void pndisc_redo(struct sk_buff *skb)
- {
- ndisc_rcv(skb);
- kfree_skb(skb);
- }
- int ndisc_rcv(struct sk_buff *skb)
- {
- struct net_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;
- __skb_push(skb, skb->data-skb->h.raw);
- if (skb->nh.ipv6h->hop_limit != 255) {
- if (net_ratelimit())
- printk(KERN_WARNING
- "ICMP NDISC: fake message with non-255 Hop Limit received: %dn",
- skb->nh.ipv6h->hop_limit);
- return 0;
- }
- if (msg->icmph.icmp6_code != 0) {
- if (net_ratelimit())
- printk(KERN_WARNING "ICMP NDISC: code is not zeron");
- return 0;
- }
- switch (msg->icmph.icmp6_type) {
- case NDISC_NEIGHBOUR_SOLICITATION:
- {
- struct nd_msg *msg = (struct nd_msg *)skb->h.raw;
- u8 *lladdr = NULL;
- int lladdrlen = 0;
- u32 ndoptlen = skb->tail - msg->opt;
- struct ndisc_options ndopts;
- if (skb->len < sizeof(struct nd_msg)) {
- if (net_ratelimit())
- printk(KERN_WARNING "ICMP NS: packet too shortn");
- return 0;
- }
- if (ipv6_addr_type(&msg->target)&IPV6_ADDR_MULTICAST) {
- if (net_ratelimit())
- printk(KERN_WARNING "ICMP NS: target address is multicastn");
- return 0;
- }
- if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts)) {
- if (net_ratelimit())
- printk(KERN_WARNING "ICMP NS: invalid ND option, ignored.n");
- return 0;
- }
- if (ndopts.nd_opts_src_lladdr) {
- lladdr = (u8*)(ndopts.nd_opts_src_lladdr + 1);
- lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3;
- if (lladdrlen != NDISC_OPT_SPACE(skb->dev->addr_len)) {
- if (net_ratelimit())
- printk(KERN_WARNING "ICMP NS: bad lladdr length.n");
- return 0;
- }
- }
- /* XXX: RFC2461 7.1.1:
- * If the IP source address is the unspecified address, there
- * MUST NOT be source link-layer address option in the message.
- *
- * NOTE! Linux kernel < 2.4.4 broke this rule.
- */
-
- /* XXX: RFC2461 7.1.1:
- * If the IP source address is the unspecified address, the IP
- * destination address MUST be a solicited-node multicast address.
- */
- if ((ifp = ipv6_get_ifaddr(&msg->target, dev)) != NULL) {
- int addr_type = ipv6_addr_type(saddr);
- if (ifp->flags & IFA_F_TENTATIVE) {
- /* Address is tentative. If the source
- is unspecified address, it is someone
- does DAD, otherwise we ignore solicitations
- until DAD timer expires.
- */
- if (addr_type == IPV6_ADDR_ANY) {
- if (dev->type == ARPHRD_IEEE802_TR) {
- unsigned char *sadr = skb->mac.raw ;
- if (((sadr[8] &0x7f) != (dev->dev_addr[0] & 0x7f)) ||
- (sadr[9] != dev->dev_addr[1]) ||
- (sadr[10] != dev->dev_addr[2]) ||
- (sadr[11] != dev->dev_addr[3]) ||
- (sadr[12] != dev->dev_addr[4]) ||
- (sadr[13] != dev->dev_addr[5]))
- {
- addrconf_dad_failure(ifp) ;
- }
- } else {
- addrconf_dad_failure(ifp);
- }
- } else
- in6_ifa_put(ifp);
- return 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,
- ipv6_addr_type(&ifp->addr)&IPV6_ADDR_ANYCAST ? 0 : 1,
- 1);
- in6_ifa_put(ifp);
- 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 = neigh_event_ns(&nd_tbl, lladdr, saddr, skb->dev);
- if (neigh || !dev->hard_header) {
- ndisc_send_na(dev, neigh, saddr, &ifp->addr,
- ifp->idev->cnf.forwarding, 1,
- ipv6_addr_type(&ifp->addr)&IPV6_ADDR_ANYCAST ? 0 : 1,
- 1);
- if (neigh)
- neigh_release(neigh);
- }
- }
- in6_ifa_put(ifp);
- } else {
- struct inet6_dev *in6_dev = in6_dev_get(dev);
- int addr_type = ipv6_addr_type(saddr);
- if (in6_dev && in6_dev->cnf.forwarding &&
- (addr_type & IPV6_ADDR_UNICAST) &&
- pneigh_lookup(&nd_tbl, &msg->target, dev, 0)) {
- int inc = ipv6_addr_type(daddr)&IPV6_ADDR_MULTICAST;
- if (skb->stamp.tv_sec == 0 ||
- skb->pkt_type == PACKET_HOST ||
- inc == 0 ||
- in6_dev->nd_parms->proxy_delay == 0) {
- if (inc)
- nd_tbl.stats.rcv_probes_mcast++;
- else
- nd_tbl.stats.rcv_probes_ucast++;
-
- neigh = neigh_event_ns(&nd_tbl, lladdr, saddr, skb->dev);
- if (neigh) {
- ndisc_send_na(dev, neigh, saddr, &msg->target,
- 0, 1, 0, 1);
- neigh_release(neigh);
- }
- } else {
- struct sk_buff *n = skb_clone(skb, GFP_ATOMIC);
- if (n)
- pneigh_enqueue(&nd_tbl, in6_dev->nd_parms, n);
- in6_dev_put(in6_dev);
- return 0;
- }
- }
- if (in6_dev)
- in6_dev_put(in6_dev);
-
- }
- return 0;
- }
- case NDISC_NEIGHBOUR_ADVERTISEMENT:
- {
- struct nd_msg *msg = (struct nd_msg *)skb->h.raw;
- u8 *lladdr = NULL;
- int lladdrlen = 0;
- u32 ndoptlen = skb->tail - msg->opt;
- struct ndisc_options ndopts;
- if (skb->len < sizeof(struct nd_msg)) {
- if (net_ratelimit())
- printk(KERN_WARNING "ICMP NA: packet too shortn");
- return 0;
- }
- if (ipv6_addr_type(&msg->target)&IPV6_ADDR_MULTICAST) {
- if (net_ratelimit())
- printk(KERN_WARNING "NDISC NA: target address is multicastn");
- return 0;
- }
- if ((ipv6_addr_type(daddr)&IPV6_ADDR_MULTICAST) &&
- msg->icmph.icmp6_solicited) {
- ND_PRINTK0("NDISC: solicited NA is multicastedn");
- return 0;
- }
-
- if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts)) {
- if (net_ratelimit())
- printk(KERN_WARNING "ICMP NS: invalid ND option, ignored.n");
- return 0;
- }
- if (ndopts.nd_opts_tgt_lladdr) {
- lladdr = (u8*)(ndopts.nd_opts_tgt_lladdr + 1);
- lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3;
- if (lladdrlen != NDISC_OPT_SPACE(skb->dev->addr_len)) {
- if (net_ratelimit())
- printk(KERN_WARNING "NDISC NA: invalid lladdr length.n");
- return 0;
- }
- }
- if ((ifp = ipv6_get_ifaddr(&msg->target, dev))) {
- if (ifp->flags & IFA_F_TENTATIVE) {
- 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 advertises our address!n",
- ifp->idev->dev->name);
- in6_ifa_put(ifp);
- return 0;
- }
- neigh = neigh_lookup(&nd_tbl, &msg->target, skb->dev);
- if (neigh) {
- if (neigh->flags & NTF_ROUTER) {
- if (msg->icmph.icmp6_router == 0) {
- /*
- * Change: router to host
- */
- struct rt6_info *rt;
- rt = rt6_get_dflt_router(saddr, skb->dev);
- if (rt) {
- ip6_del_rt(rt);
- }
- }
- } else {
- if (msg->icmph.icmp6_router)
- neigh->flags |= NTF_ROUTER;
- }
- neigh_update(neigh, lladdr,
- msg->icmph.icmp6_solicited ? NUD_REACHABLE : NUD_STALE,
- msg->icmph.icmp6_override, 1);
- neigh_release(neigh);
- }
- break;
- }
- case NDISC_ROUTER_ADVERTISEMENT:
- ndisc_router_discovery(skb);
- break;
- case NDISC_REDIRECT:
- ndisc_redirect_rcv(skb);
- break;
- };
- return 0;
- }
- int __init ndisc_init(struct net_proto_family *ops)
- {
- struct sock *sk;
- int err;
- ndisc_socket = sock_alloc();
- if (ndisc_socket == NULL) {
- printk(KERN_ERR
- "Failed to create the NDISC control socket.n");
- return -1;
- }
- ndisc_socket->inode->i_uid = 0;
- ndisc_socket->inode->i_gid = 0;
- ndisc_socket->type = SOCK_RAW;
- if((err = ops->create(ndisc_socket, IPPROTO_ICMPV6)) < 0) {
- printk(KERN_DEBUG
- "Failed to initialize the NDISC control socket (err %d).n",
- err);
- sock_release(ndisc_socket);
- ndisc_socket = NULL; /* For safety. */
- return err;
- }
- sk = ndisc_socket->sk;
- sk->allocation = GFP_ATOMIC;
- sk->net_pinfo.af_inet6.hop_limit = 255;
- /* Do not loopback ndisc messages */
- sk->net_pinfo.af_inet6.mc_loop = 0;
- sk->prot->unhash(sk);
- /*
- * Initialize the neighbour table
- */
-
- neigh_table_init(&nd_tbl);
- #ifdef CONFIG_SYSCTL
- neigh_sysctl_register(NULL, &nd_tbl.parms, NET_IPV6, NET_IPV6_NEIGH, "ipv6");
- #endif
- return 0;
- }
- void ndisc_cleanup(void)
- {
- neigh_table_clear(&nd_tbl);
- sock_release(ndisc_socket);
- ndisc_socket = NULL; /* For safety. */
- }