diff options
Diffstat (limited to 'sys/netinet6/nd6_nbr.c')
| -rw-r--r-- | sys/netinet6/nd6_nbr.c | 1123 |
1 files changed, 1123 insertions, 0 deletions
diff --git a/sys/netinet6/nd6_nbr.c b/sys/netinet6/nd6_nbr.c new file mode 100644 index 0000000..2836d48 --- /dev/null +++ b/sys/netinet6/nd6_nbr.c @@ -0,0 +1,1123 @@ +/* + * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the name of the project nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + * $FreeBSD$ + */ + +#include "opt_inet.h" +#include "opt_ipsec.h" + +#include <sys/param.h> +#include <sys/systm.h> +#include <sys/malloc.h> +#include <sys/mbuf.h> +#include <sys/socket.h> +#include <sys/sockio.h> +#include <sys/time.h> +#include <sys/kernel.h> +#include <sys/errno.h> +#include <sys/syslog.h> +#include <sys/queue.h> + +#include <net/if.h> +#include <net/if_types.h> +#include <net/if_dl.h> +#include <net/route.h> + +#include <netinet/in.h> +#include <netinet/in_var.h> +#include <netinet6/in6_var.h> +#include <netinet6/ip6.h> +#include <netinet6/ip6_var.h> +#include <netinet6/nd6.h> +#include <netinet6/icmp6.h> + +#include <net/net_osdep.h> + +#define SDL(s) ((struct sockaddr_dl *)s) + +struct dadq; +static struct dadq *nd6_dad_find __P((struct ifaddr *)); +static void nd6_dad_timer __P((struct ifaddr *)); +static void nd6_dad_ns_input __P((struct ifaddr *)); +static void nd6_dad_na_input __P((struct ifaddr *)); + +/* ignore NS in DAD - specwise incorrect, */ +int dad_ignore_ns = 0; + +/* + * Input an Neighbor Solicitation Message. + * + * Based on RFC 2461 + * Based on RFC 2462 (duplicated address detection) + * + * XXX proxy advertisement + */ +void +nd6_ns_input(m, off, icmp6len) + struct mbuf *m; + int off, icmp6len; +{ + struct ifnet *ifp = m->m_pkthdr.rcvif; + struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); + struct nd_neighbor_solicit *nd_ns + = (struct nd_neighbor_solicit *)((caddr_t)ip6 + off); + struct in6_addr saddr6 = ip6->ip6_src; + struct in6_addr daddr6 = ip6->ip6_dst; + struct in6_addr taddr6 = nd_ns->nd_ns_target; + struct in6_addr myaddr6; + char *lladdr = NULL; + struct ifaddr *ifa; + int lladdrlen = 0; + int anycast = 0, proxy = 0, tentative = 0; + int tlladdr; + union nd_opts ndopts; + + if (ip6->ip6_hlim != 255) { + log(LOG_ERR, + "nd6_ns_input: invalid hlim %d\n", ip6->ip6_hlim); + return; + } + + if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) { + /* dst has to be solicited node multicast address. */ + if (daddr6.s6_addr16[0] == IPV6_ADDR_INT16_MLL + /*don't check ifindex portion*/ + && daddr6.s6_addr32[1] == 0 + && daddr6.s6_addr32[2] == IPV6_ADDR_INT32_ONE + && daddr6.s6_addr8[12] == 0xff) { + ; /*good*/ + } else { + log(LOG_INFO, "nd6_ns_input: bad DAD packet " + "(wrong ip6 dst)\n"); + goto bad; + } + } + + if (IN6_IS_ADDR_MULTICAST(&taddr6)) { + log(LOG_INFO, "nd6_ns_input: bad NS target (multicast)\n"); + goto bad; + } + + if (IN6_IS_SCOPE_LINKLOCAL(&taddr6)) + taddr6.s6_addr16[1] = htons(ifp->if_index); + + icmp6len -= sizeof(*nd_ns); + nd6_option_init(nd_ns + 1, icmp6len, &ndopts); + if (nd6_options(&ndopts) < 0) { + log(LOG_INFO, "nd6_ns_input: invalid ND option, ignored\n"); + goto bad; + } + + if (ndopts.nd_opts_src_lladdr) { + lladdr = (char *)(ndopts.nd_opts_src_lladdr +1); + lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3; + } + + if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) && lladdr) { + log(LOG_INFO, "nd6_ns_input: bad DAD packet " + "(link-layer address option)\n"); + goto bad; + } + + /* + * Attaching target link-layer address to the NA? + * (RFC 2461 7.2.4) + * + * NS IP dst is unicast/anycast MUST NOT add + * NS IP dst is solicited-node multicast MUST add + * + * In implementation, we add target link-layer address by default. + * We do not add one in MUST NOT cases. + */ + if (!IN6_IS_ADDR_MULTICAST(&daddr6)) + tlladdr = 0; + else + tlladdr = 1; + + /* + * Target address (taddr6) must be either: + * (1) Valid unicast/anycast address for my receiving interface, + * (2) Unicast address for which I'm offering proxy service, or + * (3) "tentative" address on which DAD is being performed. + */ + /* (1) and (3) check. */ + ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6); + + /* (2) check. */ + if (!ifa && nd6_proxyall) { + struct rtentry *rt; + struct sockaddr_in6 tsin6; + + bzero(&tsin6, sizeof tsin6); + tsin6.sin6_len = sizeof(struct sockaddr_in6); + tsin6.sin6_family = AF_INET6; + tsin6.sin6_addr = taddr6; + + rt = rtalloc1((struct sockaddr *)&tsin6, 0, 0); + if (rt && rt->rt_ifp != ifp) { + /* + * search link local addr for ifp, and use it for + * proxy NA. + */ + ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(ifp); + if (ifa) + proxy = 1; + } + rtfree(rt); + } + if (!ifa) { + /* + * We've got a NS packet, and we don't have that adddress + * assigned for us. We MUST silently ignore it. + * See RFC2461 7.2.3. + */ + return; + } + myaddr6 = *IFA_IN6(ifa); + anycast = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_ANYCAST; + tentative = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE; + if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DUPLICATED) + return; + + if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { + log(LOG_INFO, + "nd6_ns_input: lladdrlen mismatch for %s " + "(if %d, NS packet %d)\n", + ip6_sprintf(&taddr6), ifp->if_addrlen, lladdrlen - 2); + } + + if (IN6_ARE_ADDR_EQUAL(&myaddr6, &saddr6)) { + log(LOG_INFO, + "nd6_ns_input: duplicate IP6 address %s\n", + ip6_sprintf(&saddr6)); + return; + } + + /* + * We have neighbor solicitation packet, with target address equals to + * one of my tentative address. + * + * src addr how to process? + * --- --- + * multicast of course, invalid (rejected in ip6_input) + * unicast somebody is doing address resolution -> ignore + * unspec dup address detection + * + * The processing is defined in RFC 2462. + */ + if (tentative) { + /* + * If source address is unspecified address, it is for + * duplicated address detection. + * + * If not, the packet is for addess resolution; + * silently ignore it. + */ + if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) + nd6_dad_ns_input(ifa); + + return; + } + + /* + * If the source address is unspecified address, entries must not + * be created or updated. + * It looks that sender is performing DAD. Output NA toward + * all-node multicast address, to tell the sender that I'm using + * the address. + * S bit ("solicited") must be zero. + */ + if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) { + saddr6 = in6addr_linklocal_allnodes; + saddr6.s6_addr16[1] = htons(ifp->if_index); + nd6_na_output(ifp, &saddr6, &taddr6, + ((anycast || proxy || !tlladdr) + ? 0 : ND_NA_FLAG_OVERRIDE) + | (ip6_forwarding ? ND_NA_FLAG_ROUTER : 0), + tlladdr); + return; + } + + nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen, ND_NEIGHBOR_SOLICIT, 0); + + nd6_na_output(ifp, &saddr6, &taddr6, + ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) + | (ip6_forwarding ? ND_NA_FLAG_ROUTER : 0) + | ND_NA_FLAG_SOLICITED, + tlladdr); + return; + + bad: + log(LOG_ERR, "nd6_ns_input: src=%s\n", ip6_sprintf(&saddr6)); + log(LOG_ERR, "nd6_ns_input: dst=%s\n", ip6_sprintf(&daddr6)); + log(LOG_ERR, "nd6_ns_input: tgt=%s\n", ip6_sprintf(&taddr6)); + return; +} + +/* + * Output an Neighbor Solicitation Message. Caller specifies: + * - ICMP6 header source IP6 address + * - ND6 header target IP6 address + * - ND6 header source datalink address + * + * Based on RFC 2461 + * Based on RFC 2462 (duplicated address detection) + */ +void +nd6_ns_output(ifp, daddr6, taddr6, ln, dad) + struct ifnet *ifp; + struct in6_addr *daddr6, *taddr6; + struct llinfo_nd6 *ln; /* for source address determination */ + int dad; /* duplicated address detection */ +{ + struct mbuf *m; + struct ip6_hdr *ip6; + struct nd_neighbor_solicit *nd_ns; + struct in6_ifaddr *ia = NULL; + struct ip6_moptions im6o; + int icmp6len; + caddr_t mac; + struct ifnet *outif = NULL; + + if (IN6_IS_ADDR_MULTICAST(taddr6)) + return; + + if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL) + return; + + if (daddr6 == NULL || IN6_IS_ADDR_MULTICAST(daddr6)) { + m->m_flags |= M_MCAST; + im6o.im6o_multicast_ifp = ifp; + im6o.im6o_multicast_hlim = 255; + im6o.im6o_multicast_loop = 0; + } + + icmp6len = sizeof(*nd_ns); + m->m_pkthdr.len = m->m_len = sizeof(*ip6) + icmp6len; + MH_ALIGN(m, m->m_len + 16); /* 1+1+6 is enought. but just in case */ + + /* fill neighbor solicitation packet */ + ip6 = mtod(m, struct ip6_hdr *); + ip6->ip6_flow = 0; + ip6->ip6_vfc = IPV6_VERSION; + /* ip6->ip6_plen will be set later */ + ip6->ip6_nxt = IPPROTO_ICMPV6; + ip6->ip6_hlim = 255; + if (daddr6) + ip6->ip6_dst = *daddr6; + else { + ip6->ip6_dst.s6_addr16[0] = IPV6_ADDR_INT16_MLL; + ip6->ip6_dst.s6_addr16[1] = htons(ifp->if_index); + ip6->ip6_dst.s6_addr32[1] = 0; + ip6->ip6_dst.s6_addr32[2] = IPV6_ADDR_INT32_ONE; + ip6->ip6_dst.s6_addr32[3] = taddr6->s6_addr32[3]; + ip6->ip6_dst.s6_addr8[12] = 0xff; + } + if (!dad) { + /* spec-wise correct, scope match */ + /* + * RFC2461 7.2.2: + * "If the source address of the packet prompting the + * solicitation is the same as one of the addresses assigned + * to the outgoing interface, that address SHOULD be placed + * in the IP Source Address of the outgoing solicitation. + * Otherwise, any one of the addresses assigned to the + * interface should be used." + * + * We use the source address for the prompting packet + * (saddr6), if: + * - saddr6 is given from the caller (by giving "ln"), and + * - saddr6 belongs to the outgoing interface. + * Otherwise, we perform a scope-wise match. + */ + struct ip6_hdr *hip6; /*hold ip6*/ + struct in6_addr *saddr6; + + if (ln && ln->ln_hold) { + hip6 = mtod(ln->ln_hold, struct ip6_hdr *); + /* XXX pullup? */ + if (sizeof(*hip6) < ln->ln_hold->m_len) + saddr6 = &hip6->ip6_src; + else + saddr6 = NULL; + } else + saddr6 = NULL; + if (saddr6 && in6ifa_ifpwithaddr(ifp, saddr6)) + bcopy(saddr6, &ip6->ip6_src, sizeof(*saddr6)); + else { + ia = in6_ifawithifp(ifp, &ip6->ip6_dst); + if (ia == NULL) { + m_freem(m); /*XXX*/ + return; + } + ip6->ip6_src = ia->ia_addr.sin6_addr; + } + } else { + /* + * Source address for DAD packet must always be IPv6 + * unspecified address. (0::0) + */ + bzero(&ip6->ip6_src, sizeof(ip6->ip6_src)); + } + nd_ns = (struct nd_neighbor_solicit *)(ip6 + 1); + nd_ns->nd_ns_type = ND_NEIGHBOR_SOLICIT; + nd_ns->nd_ns_code = 0; + nd_ns->nd_ns_reserved = 0; + nd_ns->nd_ns_target = *taddr6; + + if (IN6_IS_SCOPE_LINKLOCAL(&nd_ns->nd_ns_target)) + nd_ns->nd_ns_target.s6_addr16[1] = 0; + + /* + * Add source link-layer address option. + * + * spec implementation + * --- --- + * DAD packet MUST NOT do not add the option + * there's no link layer address: + * impossible do not add the option + * there's link layer address: + * Multicast NS MUST add one add the option + * Unicast NS SHOULD add one add the option + */ + if (!dad && (mac = nd6_ifptomac(ifp))) { + int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen; + struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1); + /* 8 byte alignments... */ + optlen = (optlen + 7) & ~7; + + m->m_pkthdr.len += optlen; + m->m_len += optlen; + icmp6len += optlen; + bzero((caddr_t)nd_opt, optlen); + nd_opt->nd_opt_type = ND_OPT_SOURCE_LINKADDR; + nd_opt->nd_opt_len = optlen >> 3; + bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen); + } + + ip6->ip6_plen = htons((u_short)icmp6len); + nd_ns->nd_ns_cksum = 0; + nd_ns->nd_ns_cksum + = in6_cksum(m, IPPROTO_ICMPV6, sizeof(*ip6), icmp6len); + +#ifdef IPSEC + m->m_pkthdr.rcvif = NULL; +#endif /*IPSEC*/ + ip6_output(m, NULL, NULL, dad ? IPV6_DADOUTPUT : 0, &im6o, &outif); + if (outif) { + icmp6_ifstat_inc(outif, ifs6_out_msg); + icmp6_ifstat_inc(outif, ifs6_out_neighborsolicit); + } + icmp6stat.icp6s_outhist[ND_NEIGHBOR_SOLICIT]++; +} + +/* + * Neighbor advertisement input handling. + * + * Based on RFC 2461 + * Based on RFC 2462 (duplicated address detection) + */ +void +nd6_na_input(m, off, icmp6len) + struct mbuf *m; + int off, icmp6len; +{ + struct ifnet *ifp = m->m_pkthdr.rcvif; + struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); + struct nd_neighbor_advert *nd_na + = (struct nd_neighbor_advert *)((caddr_t)ip6 + off); + struct in6_addr daddr6 = ip6->ip6_dst; + struct in6_addr taddr6 = nd_na->nd_na_target; + int flags = nd_na->nd_na_flags_reserved; + int is_router = ((flags & ND_NA_FLAG_ROUTER) != 0); + int is_solicited = ((flags & ND_NA_FLAG_SOLICITED) != 0); + int is_override = ((flags & ND_NA_FLAG_OVERRIDE) != 0); + char *lladdr = NULL; + int lladdrlen = 0; + struct ifaddr *ifa; + struct llinfo_nd6 *ln; + struct rtentry *rt; + struct sockaddr_dl *sdl; + union nd_opts ndopts; + + if (ip6->ip6_hlim != 255) { + log(LOG_ERR, + "nd6_na_input: invalid hlim %d\n", ip6->ip6_hlim); + return; + } + + if (IN6_IS_SCOPE_LINKLOCAL(&taddr6)) + taddr6.s6_addr16[1] = htons(ifp->if_index); + + if (IN6_IS_ADDR_MULTICAST(&taddr6)) { + log(LOG_ERR, + "nd6_na_input: invalid target address %s\n", + ip6_sprintf(&taddr6)); + return; + } + if (IN6_IS_ADDR_MULTICAST(&daddr6)) + if (is_solicited) { + log(LOG_ERR, + "nd6_na_input: a solicited adv is multicasted\n"); + return; + } + + icmp6len -= sizeof(*nd_na); + nd6_option_init(nd_na + 1, icmp6len, &ndopts); + if (nd6_options(&ndopts) < 0) { + log(LOG_INFO, "nd6_na_input: invalid ND option, ignored\n"); + return; + } + + if (ndopts.nd_opts_tgt_lladdr) { + lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1); + lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3; + } + + ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6); + + /* + * Target address matches one of my interface address. + * + * If my address is tentative, this means that there's somebody + * already using the same address as mine. This indicates DAD failure. + * This is defined in RFC 2462. + * + * Otherwise, process as defined in RFC 2461. + */ + if (ifa + && (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE)) { + nd6_dad_na_input(ifa); + return; + } + + /* Just for safety, maybe unnecessery. */ + if (ifa) { + log(LOG_ERR, + "nd6_na_input: duplicate IP6 address %s\n", + ip6_sprintf(&taddr6)); + return; + } + + if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { + log(LOG_INFO, + "nd6_na_input: lladdrlen mismatch for %s " + "(if %d, NA packet %d)\n", + ip6_sprintf(&taddr6), ifp->if_addrlen, lladdrlen - 2); + } + + /* + * If no neighbor cache entry is found, NA SHOULD silently be discarded. + */ + rt = nd6_lookup(&taddr6, 0, ifp); + if ((rt == NULL) || + ((ln = (struct llinfo_nd6 *)rt->rt_llinfo) == NULL) || + ((sdl = SDL(rt->rt_gateway)) == NULL)) + return; + + if (ln->ln_state == ND6_LLINFO_INCOMPLETE) { + /* + * If the link-layer has address, and no lladdr option came, + * discard the packet. + */ + if (ifp->if_addrlen && !lladdr) + return; + + /* + * Record link-layer address, and update the state. + */ + sdl->sdl_alen = ifp->if_addrlen; + bcopy(lladdr, LLADDR(sdl), ifp->if_addrlen); + if (is_solicited) { + ln->ln_state = ND6_LLINFO_REACHABLE; + if (ln->ln_expire) + ln->ln_expire = time_second + + nd_ifinfo[rt->rt_ifp->if_index].reachable; + } else + ln->ln_state = ND6_LLINFO_STALE; + ln->ln_router = is_router; + } else { + int llchange; + + /* + * Check if the link-layer address has changed or not. + */ + if (!lladdr) + llchange = 0; + else { + if (sdl->sdl_alen) { + if (bcmp(lladdr, LLADDR(sdl), ifp->if_addrlen)) + llchange = 1; + else + llchange = 0; + } else + llchange = 1; + } + + /* + * This is VERY complex. Look at it with care. + * + * override solicit lladdr llchange action + * (L: record lladdr) + * + * 0 0 n -- (2c) + * 0 0 y n (2b) L + * 0 0 y y (1) REACHABLE->STALE + * 0 1 n -- (2c) *->REACHABLE + * 0 1 y n (2b) L *->REACHABLE + * 0 1 y y (1) REACHABLE->STALE + * 1 0 n -- (2a) + * 1 0 y n (2a) L + * 1 0 y y (2a) L *->STALE + * 1 1 n -- (2a) *->REACHABLE + * 1 1 y n (2a) L *->REACHABLE + * 1 1 y y (2a) L *->REACHABLE + */ + if (!is_override && (lladdr && llchange)) { /* (1) */ + /* + * If state is REACHABLE, make it STALE. + * no other updates should be done. + */ + if (ln->ln_state == ND6_LLINFO_REACHABLE) + ln->ln_state = ND6_LLINFO_STALE; + return; + } else if (is_override /* (2a) */ + || (!is_override && (lladdr && !llchange)) /* (2b) */ + || !lladdr) { /* (2c) */ + /* + * Update link-local address, if any. + */ + if (lladdr) { + sdl->sdl_alen = ifp->if_addrlen; + bcopy(lladdr, LLADDR(sdl), ifp->if_addrlen); + } + + /* + * If solicited, make the state REACHABLE. + * If not solicited and the link-layer address was + * changed, make it STALE. + */ + if (is_solicited) { + ln->ln_state = ND6_LLINFO_REACHABLE; + if (ln->ln_expire) { + ln->ln_expire = time_second + + nd_ifinfo[ifp->if_index].reachable; + } + } else { + if (lladdr && llchange) + ln->ln_state = ND6_LLINFO_STALE; + } + } + + if (ln->ln_router && !is_router) { + /* + * The peer dropped the router flag. + * Remove the sender from the Default Router List and + * update the Destination Cache entries. + */ + struct nd_defrouter *dr; + struct in6_addr *in6; + int s; + + in6 = &((struct sockaddr_in6 *)rt_key(rt))->sin6_addr; + s = splnet(); + dr = defrouter_lookup(in6, rt->rt_ifp); + if (dr) + defrtrlist_del(dr); + else if (!ip6_forwarding && ip6_accept_rtadv) { + /* + * Even if the neighbor is not in the default + * router list, the neighbor may be used + * as a next hop for some destinations + * (e.g. redirect case). So we must + * call rt6_flush explicitly. + */ + rt6_flush(&ip6->ip6_src, rt->rt_ifp); + } + splx(s); + } + ln->ln_router = is_router; + } + rt->rt_flags &= ~RTF_REJECT; + ln->ln_asked = 0; + if (ln->ln_hold) { + nd6_output(ifp, ln->ln_hold, + (struct sockaddr_in6 *)rt_key(rt), rt); + ln->ln_hold = 0; + } +} + +/* + * Neighbor advertisement output handling. + * + * Based on RFC 2461 + * + * XXX NA delay for anycast address is not implemented yet + * (RFC 2461 7.2.7) + * XXX proxy advertisement? + */ +void +nd6_na_output(ifp, daddr6, taddr6, flags, tlladdr) + struct ifnet *ifp; + struct in6_addr *daddr6, *taddr6; + u_long flags; + int tlladdr; /* 1 if include target link-layer address */ +{ + struct mbuf *m; + struct ip6_hdr *ip6; + struct nd_neighbor_advert *nd_na; + struct in6_ifaddr *ia = NULL; + struct ip6_moptions im6o; + int icmp6len; + caddr_t mac; + struct ifnet *outif; + + if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL) + return; + + if (IN6_IS_ADDR_MULTICAST(daddr6)) { + m->m_flags |= M_MCAST; + im6o.im6o_multicast_ifp = ifp; + im6o.im6o_multicast_hlim = 255; + im6o.im6o_multicast_loop = 0; + } + + icmp6len = sizeof(*nd_na); + m->m_pkthdr.len = m->m_len = sizeof(struct ip6_hdr) + icmp6len; + MH_ALIGN(m, m->m_len + 16); /* 1+1+6 is enough. but just in case */ + + /* fill neighbor advertisement packet */ + ip6 = mtod(m, struct ip6_hdr *); + ip6->ip6_flow = 0; + ip6->ip6_vfc = IPV6_VERSION; + ip6->ip6_nxt = IPPROTO_ICMPV6; + ip6->ip6_hlim = 255; + if (IN6_IS_ADDR_UNSPECIFIED(daddr6)) { + /* reply to DAD */ + ip6->ip6_dst.s6_addr16[0] = IPV6_ADDR_INT16_MLL; + ip6->ip6_dst.s6_addr16[1] = htons(ifp->if_index); + ip6->ip6_dst.s6_addr32[1] = 0; + ip6->ip6_dst.s6_addr32[2] = 0; + ip6->ip6_dst.s6_addr32[3] = IPV6_ADDR_INT32_ONE; + flags &= ~ND_NA_FLAG_SOLICITED; + } else + ip6->ip6_dst = *daddr6; + + /* + * Select a source whose scope is the same as that of the dest. + */ + ia = in6_ifawithifp(ifp, &ip6->ip6_dst); + if (ia == NULL) { + m_freem(m); + return; + } + ip6->ip6_src = ia->ia_addr.sin6_addr; + nd_na = (struct nd_neighbor_advert *)(ip6 + 1); + nd_na->nd_na_type = ND_NEIGHBOR_ADVERT; + nd_na->nd_na_code = 0; + nd_na->nd_na_target = *taddr6; + if (IN6_IS_SCOPE_LINKLOCAL(&nd_na->nd_na_target)) + nd_na->nd_na_target.s6_addr16[1] = 0; + + /* + * "tlladdr" indicates NS's condition for adding tlladdr or not. + * see nd6_ns_input() for details. + * Basically, if NS packet is sent to unicast/anycast addr, + * target lladdr option SHOULD NOT be included. + */ + if (tlladdr && (mac = nd6_ifptomac(ifp))) { + int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen; + struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_na + 1); + + /* roundup to 8 bytes alignment! */ + optlen = (optlen + 7) & ~7; + + m->m_pkthdr.len += optlen; + m->m_len += optlen; + icmp6len += optlen; + bzero((caddr_t)nd_opt, optlen); + nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR; + nd_opt->nd_opt_len = optlen >> 3; + bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen); + } else + flags &= ~ND_NA_FLAG_OVERRIDE; + + ip6->ip6_plen = htons((u_short)icmp6len); + nd_na->nd_na_flags_reserved = flags; + nd_na->nd_na_cksum = 0; + nd_na->nd_na_cksum = + in6_cksum(m, IPPROTO_ICMPV6, sizeof(struct ip6_hdr), icmp6len); + +#ifdef IPSEC + m->m_pkthdr.rcvif = NULL; +#endif /*IPSEC*/ + ip6_output(m, NULL, NULL, 0, &im6o, &outif); + if (outif) { + icmp6_ifstat_inc(outif, ifs6_out_msg); + icmp6_ifstat_inc(outif, ifs6_out_neighboradvert); + } + icmp6stat.icp6s_outhist[ND_NEIGHBOR_ADVERT]++; +} + +caddr_t +nd6_ifptomac(ifp) + struct ifnet *ifp; +{ + switch (ifp->if_type) { + case IFT_ARCNET: + case IFT_ETHER: + case IFT_FDDI: + return ((caddr_t)(ifp + 1)); + break; + default: + return NULL; + } +} + +TAILQ_HEAD(dadq_head, dadq); +struct dadq { + TAILQ_ENTRY(dadq) dad_list; + struct ifaddr *dad_ifa; + int dad_count; /* max NS to send */ + int dad_ns_ocount; /* NS sent so far */ + int dad_ns_icount; + int dad_na_icount; + struct callout_handle dad_timer; +}; + +static struct dadq_head dadq; + +static struct dadq * +nd6_dad_find(ifa) + struct ifaddr *ifa; +{ + struct dadq *dp; + + for (dp = dadq.tqh_first; dp; dp = dp->dad_list.tqe_next) { + if (dp->dad_ifa == ifa) + return dp; + } + return NULL; +} + +/* + * Start Duplicated Address Detection (DAD) for specified interface address. + */ +void +nd6_dad_start(ifa, tick) + struct ifaddr *ifa; + int *tick; /* minimum delay ticks for IFF_UP event */ +{ + struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; + struct dadq *dp; + static int dad_init = 0; + + if (!dad_init) { + TAILQ_INIT(&dadq); + dad_init++; + } + + /* + * If we don't need DAD, don't do it. + * There are several cases: + * - DAD is disabled (ip6_dad_count == 0) + * - the interface address is anycast + */ + if (!(ia->ia6_flags & IN6_IFF_TENTATIVE)) { + printf("nd6_dad_start: called with non-tentative address " + "%s(%s)\n", + ip6_sprintf(&ia->ia_addr.sin6_addr), + ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); + return; + } + if (ia->ia6_flags & IN6_IFF_ANYCAST) { + ia->ia6_flags &= ~IN6_IFF_TENTATIVE; + return; + } + if (!ip6_dad_count) { + ia->ia6_flags &= ~IN6_IFF_TENTATIVE; + return; + } + if (!ifa->ifa_ifp) + panic("nd6_dad_start: ifa->ifa_ifp == NULL"); + if (!(ifa->ifa_ifp->if_flags & IFF_UP)) + return; + if (nd6_dad_find(ifa) != NULL) { + /* DAD already in progress */ + return; + } + + dp = malloc(sizeof(*dp), M_IP6NDP, M_NOWAIT); + if (dp == NULL) { + printf("nd6_dad_start: memory allocation failed for " + "%s(%s)\n", + ip6_sprintf(&ia->ia_addr.sin6_addr), + ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); + return; + } + bzero(dp, sizeof(*dp)); + TAILQ_INSERT_TAIL(&dadq, (struct dadq *)dp, dad_list); + + /* XXXJRT This is probably a purely debugging message. */ + printf("%s: starting DAD for %s\n", if_name(ifa->ifa_ifp), + ip6_sprintf(&ia->ia_addr.sin6_addr)); + + /* + * Send NS packet for DAD, ip6_dad_count times. + * Note that we must delay the first transmission, if this is the + * first packet to be sent from the interface after interface + * (re)initialization. + */ + dp->dad_ifa = ifa; + ifa->ifa_refcnt++; /*just for safety*/ + dp->dad_count = ip6_dad_count; + dp->dad_ns_icount = dp->dad_na_icount = 0; + dp->dad_ns_ocount = 0; + if (!tick) { + dp->dad_ns_ocount++; + nd6_ns_output(ifa->ifa_ifp, NULL, &ia->ia_addr.sin6_addr, + NULL, 1); + dp->dad_timer = + timeout((void (*) __P((void *)))nd6_dad_timer, (void *)ifa, + nd_ifinfo[ifa->ifa_ifp->if_index].retrans * hz / 1000); + } else { + int ntick; + + if (*tick == 0) + ntick = random() % (MAX_RTR_SOLICITATION_DELAY * hz); + else + ntick = *tick + random() % (hz / 2); + *tick = ntick; + dp->dad_timer = + timeout((void (*) __P((void *)))nd6_dad_timer, (void *)ifa, + ntick); + } +} + +static void +nd6_dad_timer(ifa) + struct ifaddr *ifa; +{ + int s; + struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; + struct dadq *dp; + + s = splnet(); /*XXX*/ + + /* Sanity check */ + if (ia == NULL) { + printf("nd6_dad_timer: called with null parameter\n"); + goto done; + } + dp = nd6_dad_find(ifa); + if (dp == NULL) { + printf("nd6_dad_timer: DAD structure not found\n"); + goto done; + } + if (ia->ia6_flags & IN6_IFF_DUPLICATED) { + printf("nd6_dad_timer: called with duplicated address " + "%s(%s)\n", + ip6_sprintf(&ia->ia_addr.sin6_addr), + ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); + goto done; + } + if ((ia->ia6_flags & IN6_IFF_TENTATIVE) == 0) { + printf("nd6_dad_timer: called with non-tentative address " + "%s(%s)\n", + ip6_sprintf(&ia->ia_addr.sin6_addr), + ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); + goto done; + } + + /* Need more checks? */ + if (dp->dad_ns_ocount < dp->dad_count) { + /* + * We have more NS to go. Send NS packet for DAD. + */ + dp->dad_ns_ocount++; + nd6_ns_output(ifa->ifa_ifp, NULL, &ia->ia_addr.sin6_addr, + NULL, 1); + dp->dad_timer = + timeout((void (*) __P((void *)))nd6_dad_timer, (void *)ifa, + nd_ifinfo[ifa->ifa_ifp->if_index].retrans * hz / 1000); + } else { + /* + * We have transmitted sufficient number of DAD packets. + * See what we've got. + */ + int duplicate; + + duplicate = 0; + + if (dp->dad_na_icount) { + /* + * the check is in nd6_dad_na_input(), + * but just in case + */ + duplicate++; + } + + if (dp->dad_ns_icount) { + /* We've seen NS, means DAD has failed. */ + duplicate++; + } + + if (duplicate) { + /* (*dp) will be freed in nd6_dad_duplicated() */ + dp = NULL; + nd6_dad_duplicated(ifa); + } else { + /* + * We are done with DAD. No NA came, no NS came. + * duplicated address found. + */ + ia->ia6_flags &= ~IN6_IFF_TENTATIVE; + + /* XXXJRT This is probably a purely debugging message */ + printf("%s: DAD complete for %s - no duplicates " + "found\n", if_name(ifa->ifa_ifp), + ip6_sprintf(&ia->ia_addr.sin6_addr)); + + TAILQ_REMOVE(&dadq, (struct dadq *)dp, dad_list); + free(dp, M_IP6NDP); + dp = NULL; + ifa->ifa_refcnt--; + } + } + +done: + splx(s); +} + +void +nd6_dad_duplicated(ifa) + struct ifaddr *ifa; +{ + struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; + struct dadq *dp; + + dp = nd6_dad_find(ifa); + if (dp == NULL) { + printf("nd6_dad_duplicated: DAD structure not found\n"); + return; + } + + log(LOG_ERR, "%s: DAD detected duplicate IPv6 address %s: %d NS, " + "%d NA\n", if_name(ifa->ifa_ifp), + ip6_sprintf(&ia->ia_addr.sin6_addr), + dp->dad_ns_icount, dp->dad_na_icount); + + ia->ia6_flags &= ~IN6_IFF_TENTATIVE; + ia->ia6_flags |= IN6_IFF_DUPLICATED; + + /* We are done with DAD, with duplicated address found. (failure) */ + untimeout((void (*) __P((void *)))nd6_dad_timer, (void *)ifa + , dp->dad_timer); + + printf("%s: DAD complete for %s - duplicate found\n", + if_name(ifa->ifa_ifp), ip6_sprintf(&ia->ia_addr.sin6_addr)); + printf("%s: manual intervention required\n", if_name(ifa->ifa_ifp)); + + TAILQ_REMOVE(&dadq, (struct dadq *)dp, dad_list); + free(dp, M_IP6NDP); + dp = NULL; + ifa->ifa_refcnt--; +} + +void +nd6_dad_ns_input(ifa) + struct ifaddr *ifa; +{ + struct in6_ifaddr *ia; + struct ifnet *ifp; + struct in6_addr *taddr6; + struct dadq *dp; + int duplicate; + + if (!ifa) + panic("ifa == NULL in nd6_dad_ns_input"); + + ia = (struct in6_ifaddr *)ifa; + ifp = ifa->ifa_ifp; + taddr6 = &ia->ia_addr.sin6_addr; + duplicate = 0; + dp = nd6_dad_find(ifa); + + /* + * If it is from myself, ignore this. + */ + if (ifp && (ifp->if_flags & IFF_LOOPBACK)) + return; + + /* Quickhack - completely ignore DAD NS packets */ + if (dad_ignore_ns) { + log(LOG_INFO, "nd6_dad_ns_input: ignoring DAD NS packet for " + "address %s(%s)\n", ip6_sprintf(taddr6), + if_name(ifa->ifa_ifp)); + return; + } + + /* + * if I'm yet to start DAD, someone else started using this address + * first. I have a duplicate and you win. + */ + if (!dp || dp->dad_ns_ocount == 0) + duplicate++; + + /* XXX more checks for loopback situation - see nd6_dad_timer too */ + + if (duplicate) { + dp = NULL; /* will be freed in nd6_dad_duplicated() */ + nd6_dad_duplicated(ifa); + } else { + /* + * not sure if I got a duplicate. + * increment ns count and see what happens. + */ + if (dp) + dp->dad_ns_icount++; + } +} + +void +nd6_dad_na_input(ifa) + struct ifaddr *ifa; +{ + struct dadq *dp; + + if (!ifa) + panic("ifa == NULL in nd6_dad_na_input"); + + dp = nd6_dad_find(ifa); + if (dp) + dp->dad_na_icount++; + + /* remove the address. */ + nd6_dad_duplicated(ifa); +} |
