X-Git-Url: https://git.decadent.org.uk/gitweb/?p=odhcp6c.git;a=blobdiff_plain;f=src%2Fra.c;h=b700c9a8270a10aba5a162f10d0c4c061e785e27;hp=bc5b225e87b0596bf1e4cde73738bf1ba48053ae;hb=b9c8be24207e4197c9b529c157d7ea04f3f4bdb8;hpb=456288f9af45cf094be4ca8160ff186867dec8ff diff --git a/src/ra.c b/src/ra.c index bc5b225..b700c9a 100644 --- a/src/ra.c +++ b/src/ra.c @@ -1,5 +1,5 @@ /** - * Copyright (C) 2012-2013 Steven Barth + * Copyright (C) 2012-2014 Steven Barth * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License v2 as published by @@ -13,6 +13,7 @@ */ #include +#include #include #include #include @@ -24,6 +25,8 @@ #include #include #include +#include +#include #include #include @@ -130,9 +133,26 @@ int ra_init(const char *ifname, const struct in6_addr *ifid) static void ra_send_rs(int signal __attribute__((unused))) { - const struct icmp6_hdr rs = {ND_ROUTER_SOLICIT, 0, 0, {{0}}}; + struct { + struct icmp6_hdr hdr; + struct icmpv6_opt lladdr; + } rs = { + .hdr = {ND_ROUTER_SOLICIT, 0, 0, {{0}}}, + .lladdr = {ND_OPT_SOURCE_LINKADDR, 1, {0}}, + }; const struct sockaddr_in6 dest = {AF_INET6, 0, 0, ALL_IPV6_ROUTERS, if_index}; - sendto(sock, &rs, sizeof(rs), MSG_DONTWAIT, (struct sockaddr*)&dest, sizeof(dest)); + size_t len = sizeof(rs); + + struct ifreq ifr; + memset(&ifr, 0, sizeof(ifr)); + strncpy(ifr.ifr_name, if_name, sizeof(ifr.ifr_name)); + if (!ioctl(sock, SIOCGIFHWADDR, &ifr) + && memcmp(rs.lladdr.data, ifr.ifr_hwaddr.sa_data, 6)) + memcpy(rs.lladdr.data, ifr.ifr_hwaddr.sa_data, 6); + else + len = sizeof(struct icmp6_hdr); + + sendto(sock, &rs, len, MSG_DONTWAIT, (struct sockaddr*)&dest, sizeof(dest)); if (++rs_attempt <= 3) alarm(4); @@ -195,72 +215,66 @@ bool ra_link_up(void) return ret; } -static int ra_icmpv6_valid(struct sockaddr_in6 *source, int hlim, uint8_t *data, size_t len) +static bool ra_icmpv6_valid(struct sockaddr_in6 *source, int hlim, uint8_t *data, size_t len) { - struct icmp6_hdr *hdr = (struct icmp6_hdr *)data; - struct icmpv6_opt *opt; - size_t optlen; - - if (hlim != 255) - return 0; - - if (len < sizeof(*hdr)) - return 0; + struct icmp6_hdr *hdr = (struct icmp6_hdr*)data; + struct icmpv6_opt *opt, *end = (struct icmpv6_opt*)&data[len]; - if (hdr->icmp6_code) - return 0; + if (hlim != 255 || len < sizeof(*hdr) || hdr->icmp6_code) + return false; switch (hdr->icmp6_type) { case ND_ROUTER_ADVERT: if (!IN6_IS_ADDR_LINKLOCAL(&source->sin6_addr)) - return 0; + return false; - opt = (struct icmpv6_opt *)((struct nd_router_advert *)data + 1); - optlen = len - sizeof(struct nd_router_advert); + opt = (struct icmpv6_opt*)((struct nd_router_advert*)data + 1); break; default: - return 0; + return false; } - while (optlen > 0) { - size_t l = opt->len << 3; - - if (optlen < sizeof(*opt)) - return 0; - - if (l > optlen || l == 0) - return 0; - - opt = (struct icmpv6_opt *)(((uint8_t *)opt) + l); - - optlen -= l; - } + icmpv6_for_each_option(opt, opt, end) + ; - return 1; + return opt == end; } bool ra_process(void) { bool found = false; bool changed = false; + bool has_lladdr = !IN6_IS_ADDR_UNSPECIFIED(&lladdr); uint8_t buf[1500], cmsg_buf[128]; struct nd_router_advert *adv = (struct nd_router_advert*)buf; - struct odhcp6c_entry entry = {IN6ADDR_ANY_INIT, 0, 0, IN6ADDR_ANY_INIT, 0, 0, 0, 0, 0}; + struct odhcp6c_entry entry = {IN6ADDR_ANY_INIT, 0, 0, IN6ADDR_ANY_INIT, 0, 0, 0, 0, 0, 0}; const struct in6_addr any = IN6ADDR_ANY_INIT; - if (IN6_IS_ADDR_UNSPECIFIED(&lladdr)) { + if (!has_lladdr) { // Autodetect interface-id if not specified - FILE *fp = fopen("/proc/net/if_inet6", "r"); - if (fp) { - char addrbuf[33], ifbuf[16]; - while (fscanf(fp, "%32s %*x %*x %*x %*x %15s", addrbuf, ifbuf) == 2) { - if (!strcmp(ifbuf, if_name)) { - script_unhexlify((uint8_t*)&lladdr, sizeof(lladdr), addrbuf); + struct ifaddrs *ifaddr, *ifa; + + if (getifaddrs(&ifaddr) == 0) { + for (ifa = ifaddr; ifa != NULL; ifa = ifa->ifa_next) { + struct sockaddr_in6 *addr; + + if (ifa->ifa_addr == NULL || ifa->ifa_addr->sa_family != AF_INET6) + continue; + + addr = (struct sockaddr_in6*)ifa->ifa_addr; + + if (!IN6_IS_ADDR_LINKLOCAL(&addr->sin6_addr)) + continue; + + if (!strcmp(ifa->ifa_name, if_name)) { + lladdr = addr->sin6_addr; + has_lladdr = true; break; } } - fclose(fp); + + freeifaddrs(ifaddr); } } @@ -274,6 +288,9 @@ bool ra_process(void) if (len <= 0) break; + if (!has_lladdr) + continue; + int hlim = 0; for (struct cmsghdr *ch = CMSG_FIRSTHDR(&msg); ch != NULL; ch = CMSG_NXTHDR(&msg, ch)) @@ -312,28 +329,30 @@ bool ra_process(void) update_proc("conf", "hop_limit", adv->nd_ra_curhoplimit); // Parse ND parameters - if (ntohl(adv->nd_ra_reachable) <= 3600000) - update_proc("neigh", "base_reachable_time_ms", ntohl(adv->nd_ra_reachable)); + uint32_t reachable = ntohl(adv->nd_ra_reachable); + if (reachable > 0 && reachable <= 3600000) + update_proc("neigh", "base_reachable_time_ms", reachable); - if (ntohl(adv->nd_ra_retransmit) <= 60000) - update_proc("neigh", "retrans_time_ms", ntohl(adv->nd_ra_retransmit)); + uint32_t retransmit = ntohl(adv->nd_ra_retransmit); + if (retransmit > 0 && retransmit <= 60000) + update_proc("neigh", "retrans_time_ms", retransmit); // Evaluate options struct icmpv6_opt *opt; icmpv6_for_each_option(opt, &adv[1], &buf[len]) { if (opt->type == ND_OPT_MTU) { - struct nd_opt_mtu *mtu = (struct nd_opt_mtu *)opt; - if (ntohl(mtu->nd_opt_mtu_mtu) >= 1280 && ntohl(mtu->nd_opt_mtu_mtu) <= 65535) - update_proc("conf", "mtu", ntohl(mtu->nd_opt_mtu_mtu)); + uint32_t *mtu = (uint32_t*)&opt->data[2]; + if (ntohl(*mtu) >= 1280 && ntohl(*mtu) <= 65535) + update_proc("conf", "mtu", ntohl(*mtu)); } else if (opt->type == ND_OPT_ROUTE_INFORMATION && opt->len <= 3) { - struct nd_opt_route_info *rinfo = (struct nd_opt_route_info *)opt; entry.router = from.sin6_addr; entry.target = any; - entry.priority = pref_to_priority(rinfo->nd_opt_ri_prf); - entry.length = rinfo->nd_opt_ri_prefix_len; - entry.valid = ntohl(rinfo->nd_opt_ri_route_lifetime); - memcpy(&entry.target, &rinfo->nd_opt_ri_prefix[0], (rinfo->nd_opt_ri_len - 1) * 8); + entry.priority = pref_to_priority(opt->data[1]); + entry.length = opt->data[0]; + uint32_t *valid = (uint32_t*)&opt->data[2]; + entry.valid = ntohl(*valid); + memcpy(&entry.target, &opt->data[6], (opt->len - 1) * 8); if (entry.length > 128 || IN6_IS_ADDR_LINKLOCAL(&entry.target) || IN6_IS_ADDR_LOOPBACK(&entry.target) @@ -343,7 +362,7 @@ bool ra_process(void) if (entry.priority > 0) changed |= odhcp6c_update_entry(STATE_RA_ROUTE, &entry); } else if (opt->type == ND_OPT_PREFIX_INFORMATION && opt->len == 4) { - struct nd_opt_prefix_info *pinfo = (struct nd_opt_prefix_info *)opt; + struct nd_opt_prefix_info *pinfo = (struct nd_opt_prefix_info*)opt; entry.router = any; entry.target = pinfo->nd_opt_pi_prefix; entry.priority = 256; @@ -369,15 +388,15 @@ bool ra_process(void) changed |= odhcp6c_update_entry_safe(STATE_RA_PREFIX, &entry, 7200); } else if (opt->type == ND_OPT_RECURSIVE_DNS && opt->len > 2) { - struct nd_opt_recursive_dns *rdns = (struct nd_opt_recursive_dns *)opt; entry.router = from.sin6_addr; entry.priority = 0; entry.length = 128; - entry.valid = ntohl(rdns->lifetime); + uint32_t *valid = (uint32_t*)&opt->data[2]; + entry.valid = ntohl(*valid); entry.preferred = 0; for (ssize_t i = 0; i < (opt->len - 1) / 2; ++i) { - memcpy(&entry.target, &rdns->servers[i], + memcpy(&entry.target, &opt->data[6 + i * sizeof(entry.target)], sizeof(entry.target)); changed |= odhcp6c_update_entry(STATE_RA_DNS, &entry); }