X-Git-Url: https://git.decadent.org.uk/gitweb/?p=odhcp6c.git;a=blobdiff_plain;f=src%2Fra.c;h=09d5c1d9ce5985dd6300c4dca3d53ff3c0d60849;hp=ceded54ab9340c90be76b19b3802c0bad576bfa9;hb=ec864c44e9959a5d65cc564182f4e960e47c6e9e;hpb=b4d90de3204d4b7b813f0e1bc0019b8607a29c9f diff --git a/src/ra.c b/src/ra.c index ceded54..09d5c1d 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 @@ -24,6 +24,7 @@ #include #include #include +#include #include #include @@ -53,6 +54,15 @@ static char if_name[IF_NAMESIZE] = {0}; static volatile int rs_attempt = 0; static struct in6_addr lladdr = IN6ADDR_ANY_INIT; +struct { + struct icmp6_hdr hdr; + struct icmpv6_opt lladdr; +} rs = { + .hdr = {ND_ROUTER_SOLICIT, 0, 0, {{0}}}, + .lladdr = {ND_OPT_SOURCE_LINKADDR, 1, {0}}, +}; + + static void ra_send_rs(int signal __attribute__((unused))); int ra_init(const char *ifname, const struct in6_addr *ifid) @@ -90,6 +100,7 @@ int ra_init(const char *ifname, const struct in6_addr *ifid) .ifi = {.ifi_index = if_index} }; send(rtnl, &req, sizeof(req), 0); + ra_link_up(); // Filter ICMPv6 package types struct icmp6_filter filt; @@ -130,9 +141,16 @@ 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}}}; 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)); + const struct icmpv6_opt llnull = {ND_OPT_SOURCE_LINKADDR, 1, {0}}; + size_t len; + + if ((rs_attempt % 2 == 0) && memcmp(&rs.lladdr, &llnull, sizeof(llnull))) + len = sizeof(rs); + else + len = sizeof(struct icmp6_hdr); + + sendto(sock, &rs, len, MSG_DONTWAIT, (struct sockaddr*)&dest, sizeof(dest)); if (++rs_attempt <= 3) alarm(4); @@ -142,19 +160,21 @@ static void ra_send_rs(int signal __attribute__((unused))) static int16_t pref_to_priority(uint8_t flags) { flags = (flags >> 3) & 0x03; - return (flags == 0x0) ? 1024 : (flags == 0x1) ? 512 : - (flags == 0x3) ? 2048 : -1; + return (flags == 0x0) ? 512 : (flags == 0x1) ? 384 : + (flags == 0x3) ? 640 : -1; } -static void update_proc(const char *sect, const char *opt, uint32_t value) +static int update_proc(const char *sect, const char *opt, uint32_t value) { char buf[64]; snprintf(buf, sizeof(buf), "/proc/sys/net/ipv6/%s/%s/%s", sect, if_name, opt); int fd = open(buf, O_WRONLY); - write(fd, buf, snprintf(buf, sizeof(buf), "%u", value)); + int ret = write(fd, buf, snprintf(buf, sizeof(buf), "%u", value)); close(fd); + + return ret; } @@ -177,6 +197,14 @@ bool ra_link_up(void) resp.msg.ifi_index != if_index) continue; + ssize_t alen = NLMSG_PAYLOAD(&resp.hdr, sizeof(resp.msg)); + for (struct rtattr *rta = (struct rtattr*)(resp.pad); + RTA_OK(rta, alen); rta = RTA_NEXT(rta, alen)) { + if (rta->rta_type == IFLA_ADDRESS && + RTA_PAYLOAD(rta) >= sizeof(rs.lladdr.data)) + memcpy(rs.lladdr.data, RTA_DATA(rta), sizeof(rs.lladdr.data)); + } + bool hascarrier = resp.msg.ifi_flags & IFF_LOWER_UP; if (!firstcall && nocarrier != !hascarrier) ret = true; @@ -227,34 +255,41 @@ bool ra_process(void) bool changed = false; 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)) { - // 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); - break; - } - } - fclose(fp); - } + struct sockaddr_in6 addr = {AF_INET6, 0, 0, ALL_IPV6_ROUTERS, if_index}; + socklen_t alen = sizeof(addr); + int sock = socket(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6); + + if (!connect(sock, (struct sockaddr*)&addr, sizeof(addr)) && + !getsockname(sock, (struct sockaddr*)&addr, &alen)) + lladdr = addr.sin6_addr; + + close(sock); } while (true) { struct sockaddr_in6 from; struct iovec iov = {buf, sizeof(buf)}; - struct msghdr msg = {&from, sizeof(from), &iov, 1, - cmsg_buf, sizeof(cmsg_buf), 0}; + struct msghdr msg = { + .msg_name = (void *) &from, + .msg_namelen = sizeof(from), + .msg_iov = &iov, + .msg_iovlen = 1, + .msg_control = cmsg_buf, + .msg_controllen = sizeof(cmsg_buf), + .msg_flags = 0 + }; ssize_t len = recvmsg(sock, &msg, MSG_DONTWAIT); if (len <= 0) break; + if (IN6_IS_ADDR_UNSPECIFIED(&lladdr)) + continue; + int hlim = 0; for (struct cmsghdr *ch = CMSG_FIRSTHDR(&msg); ch != NULL; ch = CMSG_NXTHDR(&msg, ch)) @@ -286,18 +321,20 @@ bool ra_process(void) entry.priority = pref_to_priority(0); entry.valid = router_valid; entry.preferred = entry.valid; - changed |= odhcp6c_update_entry(STATE_RA_ROUTE, &entry); + changed |= odhcp6c_update_entry(STATE_RA_ROUTE, &entry, 0, true); // Parse hoplimit if (adv->nd_ra_curhoplimit) 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 @@ -322,7 +359,7 @@ bool ra_process(void) continue; if (entry.priority > 0) - changed |= odhcp6c_update_entry(STATE_RA_ROUTE, &entry); + changed |= odhcp6c_update_entry(STATE_RA_ROUTE, &entry, 0, true); } else if (opt->type == ND_OPT_PREFIX_INFORMATION && opt->len == 4) { struct nd_opt_prefix_info *pinfo = (struct nd_opt_prefix_info*)opt; entry.router = any; @@ -339,7 +376,7 @@ bool ra_process(void) continue; if (pinfo->nd_opt_pi_flags_reserved & ND_OPT_PI_FLAG_ONLINK) - changed |= odhcp6c_update_entry_safe(STATE_RA_ROUTE, &entry, 7200); + changed |= odhcp6c_update_entry(STATE_RA_ROUTE, &entry, 7200, true); if (!(pinfo->nd_opt_pi_flags_reserved & ND_OPT_PI_FLAG_AUTO) || pinfo->nd_opt_pi_prefix_len != 64) @@ -348,7 +385,7 @@ bool ra_process(void) entry.target.s6_addr32[2] = lladdr.s6_addr32[2]; entry.target.s6_addr32[3] = lladdr.s6_addr32[3]; - changed |= odhcp6c_update_entry_safe(STATE_RA_PREFIX, &entry, 7200); + changed |= odhcp6c_update_entry(STATE_RA_PREFIX, &entry, 7200, true); } else if (opt->type == ND_OPT_RECURSIVE_DNS && opt->len > 2) { entry.router = from.sin6_addr; entry.priority = 0; @@ -360,7 +397,7 @@ bool ra_process(void) for (ssize_t i = 0; i < (opt->len - 1) / 2; ++i) { memcpy(&entry.target, &opt->data[6 + i * sizeof(entry.target)], sizeof(entry.target)); - changed |= odhcp6c_update_entry(STATE_RA_DNS, &entry); + changed |= odhcp6c_update_entry(STATE_RA_DNS, &entry, 0, true); } } }