X-Git-Url: https://git.decadent.org.uk/gitweb/?p=odhcp6c.git;a=blobdiff_plain;f=src%2Fra.c;h=570ff6fef28c7e5950c989d79b365a6844835982;hp=83f17584cbe93f9a4587a0e095432fa295b91de1;hb=b146f9adc80cc2c2cdf2b04bfeec4c861a2a0e23;hpb=0a3874a2dc344c7b40592951a726bfdd81283487 diff --git a/src/ra.c b/src/ra.c index 83f1758..570ff6f 100644 --- a/src/ra.c +++ b/src/ra.c @@ -13,6 +13,7 @@ */ #include +#include #include #include #include @@ -24,18 +25,32 @@ #include #include #include +#include #include #include #include +#ifndef SOL_NETLINK +#define SOL_NETLINK 270 +#endif + +#ifndef NETLINK_ADD_MEMBERSHIP +#define NETLINK_ADD_MEMBERSHIP 1 +#endif + +#ifndef IFF_LOWER_UP +#define IFF_LOWER_UP 0x10000 +#endif #include "odhcp6c.h" #include "ra.h" -static int sock = -1; -static unsigned if_index = 0; +static bool nocarrier = false; + +static int sock = -1, rtnl = -1; +static int if_index = 0; static char if_name[IF_NAMESIZE] = {0}; static volatile int rs_attempt = 0; static struct in6_addr lladdr = IN6ADDR_ANY_INIT; @@ -44,11 +59,40 @@ static void ra_send_rs(int signal __attribute__((unused))); int ra_init(const char *ifname, const struct in6_addr *ifid) { + const pid_t ourpid = getpid(); sock = socket(AF_INET6, SOCK_RAW | SOCK_CLOEXEC, IPPROTO_ICMPV6); + if (sock < 0) + return -1; + if_index = if_nametoindex(ifname); + if (!if_index) + return -1; + strncpy(if_name, ifname, sizeof(if_name) - 1); lladdr = *ifid; + rtnl = socket(AF_NETLINK, SOCK_DGRAM | SOCK_CLOEXEC, NETLINK_ROUTE); + if (rtnl < 0) + return -1; + + struct sockaddr_nl rtnl_kernel = { .nl_family = AF_NETLINK }; + if (connect(rtnl, (const struct sockaddr*)&rtnl_kernel, sizeof(rtnl_kernel)) < 0) + return -1; + + int val = RTNLGRP_LINK; + setsockopt(rtnl, SOL_NETLINK, NETLINK_ADD_MEMBERSHIP, &val, sizeof(val)); + fcntl(rtnl, F_SETOWN, ourpid); + fcntl(rtnl, F_SETFL, fcntl(sock, F_GETFL) | O_ASYNC); + + struct { + struct nlmsghdr hdr; + struct ifinfomsg ifi; + } req = { + .hdr = {sizeof(req), RTM_GETLINK, NLM_F_REQUEST, 1, 0}, + .ifi = {.ifi_index = if_index} + }; + send(rtnl, &req, sizeof(req), 0); + // Filter ICMPv6 package types struct icmp6_filter filt; ICMP6_FILTER_SETBLOCKALL(&filt); @@ -60,7 +104,7 @@ int ra_init(const char *ifname, const struct in6_addr *ifid) setsockopt(sock, IPPROTO_IPV6, IPV6_ADD_MEMBERSHIP, &an, sizeof(an)); // Let the kernel compute our checksums - int val = 2; + val = 2; setsockopt(sock, IPPROTO_RAW, IPV6_CHECKSUM, &val, sizeof(val)); // This is required by RFC 4861 @@ -75,7 +119,6 @@ int ra_init(const char *ifname, const struct in6_addr *ifid) setsockopt(sock, SOL_SOCKET, SO_BINDTODEVICE, ifname, strlen(ifname)); // Add async-mode - const pid_t ourpid = getpid(); fcntl(sock, F_SETOWN, ourpid); fcntl(sock, F_SETFL, fcntl(sock, F_GETFL) | O_ASYNC); @@ -117,26 +160,103 @@ static void update_proc(const char *sect, const char *opt, uint32_t value) } +bool ra_link_up(void) +{ + static bool firstcall = true; + struct { + struct nlmsghdr hdr; + struct ifinfomsg msg; + uint8_t pad[4000]; + } resp; + + bool ret = false; + ssize_t read; + + do { + read = recv(rtnl, &resp, sizeof(resp), MSG_DONTWAIT); + if (read < 0 || !NLMSG_OK(&resp.hdr, (size_t)read) || + resp.hdr.nlmsg_type != RTM_NEWLINK || + resp.msg.ifi_index != if_index) + continue; + + bool hascarrier = resp.msg.ifi_flags & IFF_LOWER_UP; + if (!firstcall && nocarrier != !hascarrier) + ret = true; + + nocarrier = !hascarrier; + firstcall = false; + } while (read > 0); + + if (ret) { + syslog(LOG_NOTICE, "carrier => %i event on %s", (int)!nocarrier, if_name); + + rs_attempt = 0; + ra_send_rs(SIGALRM); + } + + return ret; +} + +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, *end = (struct icmpv6_opt*)&data[len]; + + 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 false; + + opt = (struct icmpv6_opt*)((struct nd_router_advert*)data + 1); + break; + + default: + return false; + } + + icmpv6_for_each_option(opt, opt, end) + ; + + 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}; + 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); } } @@ -147,9 +267,10 @@ bool ra_process(void) cmsg_buf, sizeof(cmsg_buf), 0}; ssize_t len = recvmsg(sock, &msg, MSG_DONTWAIT); - if (len < 0) + if (len <= 0) break; - else if (len < (ssize_t)sizeof(*adv)) + + if (!has_lladdr) continue; int hlim = 0; @@ -159,7 +280,7 @@ bool ra_process(void) ch->cmsg_type == IPV6_HOPLIMIT) memcpy(&hlim, CMSG_DATA(ch), sizeof(hlim)); - if (hlim != 255) + if (!ra_icmpv6_valid(&from, hlim, buf, len)) continue; // Stop sending solicits @@ -183,7 +304,11 @@ bool ra_process(void) entry.priority = pref_to_priority(0); entry.valid = router_valid; entry.preferred = entry.valid; - odhcp6c_update_entry(STATE_RA_ROUTE, &entry); + changed |= odhcp6c_update_entry(STATE_RA_ROUTE, &entry); + + // 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) @@ -215,7 +340,7 @@ bool ra_process(void) continue; if (entry.priority > 0) - odhcp6c_update_entry(STATE_RA_ROUTE, &entry); + 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; entry.router = any; @@ -232,7 +357,7 @@ bool ra_process(void) continue; if (pinfo->nd_opt_pi_flags_reserved & ND_OPT_PI_FLAG_ONLINK) - odhcp6c_update_entry_safe(STATE_RA_ROUTE, &entry, 7200); + changed |= odhcp6c_update_entry_safe(STATE_RA_ROUTE, &entry, 7200); if (!(pinfo->nd_opt_pi_flags_reserved & ND_OPT_PI_FLAG_AUTO) || pinfo->nd_opt_pi_prefix_len != 64) @@ -241,7 +366,7 @@ bool ra_process(void) entry.target.s6_addr32[2] = lladdr.s6_addr32[2]; entry.target.s6_addr32[3] = lladdr.s6_addr32[3]; - odhcp6c_update_entry_safe(STATE_RA_PREFIX, &entry, 7200); + changed |= odhcp6c_update_entry_safe(STATE_RA_PREFIX, &entry, 7200); } else if (opt->type == ND_OPT_RECURSIVE_DNS && opt->len > 2) { entry.router = from.sin6_addr; entry.priority = 0; @@ -253,7 +378,7 @@ 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)); - odhcp6c_update_entry(STATE_RA_DNS, &entry); + changed |= odhcp6c_update_entry(STATE_RA_DNS, &entry); } } } @@ -269,5 +394,5 @@ bool ra_process(void) if (found) odhcp6c_expire(); - return found; + return found && changed; }