1 /* $NetBSD: nd6_rtr.c,v 1.149 2020/06/12 11:04:45 roy Exp $ */ 2 /* $KAME: nd6_rtr.c,v 1.95 2001/02/07 08:09:47 itojun Exp $ */ 3 4 /* 5 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the project nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33 #include <sys/cdefs.h> 34 __KERNEL_RCSID(0, "$NetBSD: nd6_rtr.c,v 1.149 2020/06/12 11:04:45 roy Exp $"); 35 36 #ifdef _KERNEL_OPT 37 #include "opt_net_mpsafe.h" 38 #endif 39 40 #include <sys/mbuf.h> 41 #include <sys/syslog.h> 42 43 #include <net/if.h> 44 45 #include <netinet/in.h> 46 #include <netinet6/in6_var.h> 47 #include <netinet/ip6.h> 48 #include <netinet6/nd6.h> 49 #include <netinet/icmp6.h> 50 #include <netinet6/icmp6_private.h> 51 52 /* 53 * Cache the source link layer address of Router Advertisement 54 * and Solicition messages. 55 */ 56 void 57 nd6_rtr_cache(struct mbuf *m, int off, int icmp6len, int icmp6_type) 58 { 59 struct ifnet *ifp; 60 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 61 struct nd_router_solicit *nd_rs; 62 struct nd_router_advert *nd_ra; 63 struct in6_addr saddr6 = ip6->ip6_src; 64 char *lladdr = NULL; 65 int lladdrlen = 0; 66 union nd_opts ndopts; 67 struct psref psref; 68 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 69 70 ifp = m_get_rcvif_psref(m, &psref); 71 if (ifp == NULL) 72 goto freeit; 73 74 /* Sanity checks */ 75 if (ip6->ip6_hlim != 255) { 76 nd6log(LOG_ERR, "invalid hlim (%d) from %s to %s on %s\n", 77 ip6->ip6_hlim, IN6_PRINT(ip6bufs, &ip6->ip6_src), 78 IN6_PRINT(ip6bufd, &ip6->ip6_dst), if_name(ifp)); 79 goto bad; 80 } 81 82 switch (icmp6_type) { 83 case ND_ROUTER_SOLICIT: 84 /* 85 * Don't update the neighbor cache, if src = ::. 86 * This indicates that the src has no IP address assigned yet. 87 */ 88 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) 89 goto freeit; 90 91 IP6_EXTHDR_GET(nd_rs, struct nd_router_solicit *, m, off, 92 icmp6len); 93 if (nd_rs == NULL) { 94 ICMP6_STATINC(ICMP6_STAT_TOOSHORT); 95 m_put_rcvif_psref(ifp, &psref); 96 return; 97 } 98 99 icmp6len -= sizeof(*nd_rs); 100 nd6_option_init(nd_rs + 1, icmp6len, &ndopts); 101 break; 102 case ND_ROUTER_ADVERT: 103 if (!IN6_IS_ADDR_LINKLOCAL(&saddr6)) { 104 nd6log(LOG_ERR, "src %s is not link-local\n", 105 IN6_PRINT(ip6bufs, &saddr6)); 106 goto bad; 107 } 108 109 IP6_EXTHDR_GET(nd_ra, struct nd_router_advert *, m, off, 110 icmp6len); 111 if (nd_ra == NULL) { 112 ICMP6_STATINC(ICMP6_STAT_TOOSHORT); 113 m_put_rcvif_psref(ifp, &psref); 114 return; 115 } 116 117 icmp6len -= sizeof(*nd_ra); 118 nd6_option_init(nd_ra + 1, icmp6len, &ndopts); 119 break; 120 } 121 122 if (nd6_options(&ndopts) < 0) { 123 nd6log(LOG_INFO, "invalid ND option, ignored\n"); 124 /* nd6_options have incremented stats */ 125 goto freeit; 126 } 127 128 if (ndopts.nd_opts_src_lladdr) { 129 lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1); 130 lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3; 131 } 132 133 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 134 nd6log(LOG_INFO, "lladdrlen mismatch for %s " 135 "(if %d, %s packet %d)\n", 136 IN6_PRINT(ip6bufs, &saddr6), 137 ifp->if_addrlen, 138 icmp6_type == ND_ROUTER_SOLICIT ? "RS" : "RA", 139 lladdrlen - 2); 140 goto bad; 141 } 142 143 nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen, icmp6_type, 0); 144 145 freeit: 146 m_put_rcvif_psref(ifp, &psref); 147 m_freem(m); 148 return; 149 150 bad: 151 ICMP6_STATINC(icmp6_type == ND_ROUTER_SOLICIT ? 152 ICMP6_STAT_BADRS : ICMP6_STAT_BADRA); 153 m_put_rcvif_psref(ifp, &psref); 154 m_freem(m); 155 } 156