X-Git-Url: https://git.decadent.org.uk/gitweb/?p=odhcp6c.git;a=blobdiff_plain;f=src%2Fra.c;h=64cc8d85ac7ab961382ac80f7aaf6c4557fa4030;hp=9a579851524786704875d675100d8fded72ef6b7;hb=1234ab04386fd63eafb19ecf245b730d6461e869;hpb=74ef11cad687fd165457f212cfe15bc5ad7a2cd1 diff --git a/src/ra.c b/src/ra.c index 9a57985..64cc8d8 100644 --- a/src/ra.c +++ b/src/ra.c @@ -29,13 +29,26 @@ #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, rtnl_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 +57,40 @@ 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); @@ -60,48 +102,24 @@ 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 val = 255; setsockopt(sock, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &val, sizeof(val)); + // Receive multicast hops + val = 1; + setsockopt(sock, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &val, sizeof(val)); + // Bind to one device 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); - 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); - } - } - - // Open rtnetlink socket - rtnl_sock = socket(AF_NETLINK, SOCK_RAW | SOCK_CLOEXEC, NETLINK_ROUTE); - struct sockaddr_nl rtnl_kernel = { .nl_family = AF_NETLINK }; - if (connect(rtnl_sock, (struct sockaddr*)&rtnl_kernel, sizeof(rtnl_kernel))) - return -1; - uint32_t group = RTNLGRP_IPV6_IFADDR; - setsockopt(rtnl_sock, SOL_NETLINK, NETLINK_ADD_MEMBERSHIP, &group, sizeof(group)); - - // Add async-mode - fcntl(rtnl_sock, F_SETOWN, ourpid); - fcntl(rtnl_sock, F_SETFL, fcntl(rtnl_sock, F_GETFL) | O_ASYNC); - // Send RS signal(SIGALRM, ra_send_rs); ra_send_rs(SIGALRM); @@ -140,80 +158,89 @@ static void update_proc(const char *sect, const char *opt, uint32_t value) } -static bool ra_deduplicate(const struct in6_addr *any, uint8_t length) +bool ra_link_up(void) { - struct odhcp6c_entry entry = {IN6ADDR_ANY_INIT, length, 0, *any, 0, 0, 0}; - struct odhcp6c_entry *x = odhcp6c_find_entry(STATE_RA_PREFIX, &entry); - if (x && IN6_ARE_ADDR_EQUAL(&x->target, any)) { - odhcp6c_random(&x->target.s6_addr32[2], 2 * sizeof(uint32_t)); - } else if (odhcp6c_find_entry(STATE_IA_NA, &entry)) { - dhcpv6_request(DHCPV6_MSG_DECLINE); - raise(SIGUSR2); - } - - return !!x; -} + 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; -bool ra_rtnl_process(void) -{ - bool found = false; - uint32_t elapsed = odhcp6c_elapsed(); - uint8_t buf[8192]; - while (true) { - ssize_t len = recv(rtnl_sock, buf, sizeof(buf), MSG_DONTWAIT); - if (len < 0) - break; + nocarrier = !hascarrier; + firstcall = false; + } while (read > 0); - if (elapsed > 10) - continue; + if (ret) { + syslog(LOG_NOTICE, "carrier => %i event on %s", (int)!nocarrier, if_name); - for (struct nlmsghdr *nh = (struct nlmsghdr*)buf; NLMSG_OK(nh, (size_t)len); - nh = NLMSG_NEXT(nh, len)) { - struct ifaddrmsg *ifa = NLMSG_DATA(nh); - struct in6_addr *addr = NULL; - if (NLMSG_PAYLOAD(nh, 0) < sizeof(*ifa) || ifa->ifa_index != if_index || - (nh->nlmsg_type == RTM_NEWADDR && !(ifa->ifa_flags & IFA_F_DADFAILED)) || - (nh->nlmsg_type == RTM_DELADDR && !(ifa->ifa_flags & IFA_F_TENTATIVE)) || - (nh->nlmsg_type != RTM_NEWADDR && nh->nlmsg_type != RTM_DELADDR)) - continue; - - ssize_t alen = NLMSG_PAYLOAD(nh, sizeof(*ifa)); - for (struct rtattr *rta = (struct rtattr*)&ifa[1]; RTA_OK(rta, alen); - rta = RTA_NEXT(rta, alen)) - if (rta->rta_type == IFA_ADDRESS && RTA_PAYLOAD(rta) >= sizeof(*addr)) - addr = RTA_DATA(rta); - - if (addr) { - char ipbuf[INET6_ADDRSTRLEN]; - inet_ntop(AF_INET6, addr, ipbuf, sizeof(ipbuf)); - syslog(LOG_WARNING, "duplicate address detected: %s (code: %u:%x)", - ipbuf, (unsigned)nh->nlmsg_type, (unsigned)ifa->ifa_flags); - found |= ra_deduplicate(addr, ifa->ifa_prefixlen); - } - } + rs_attempt = 0; + ra_send_rs(SIGALRM); } - return found; -} + return ret; +} bool ra_process(void) { bool found = false; - uint8_t buf[1500]; + 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}; + struct odhcp6c_entry entry = {IN6ADDR_ANY_INIT, 0, 0, IN6ADDR_ANY_INIT, 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); + } + } + while (true) { struct sockaddr_in6 from; - socklen_t from_len = sizeof(from); - ssize_t len = recvfrom(sock, buf, sizeof(buf), MSG_DONTWAIT, &from, &from_len); + struct iovec iov = {buf, sizeof(buf)}; + struct msghdr msg = {&from, sizeof(from), &iov, 1, + cmsg_buf, sizeof(cmsg_buf), 0}; + + ssize_t len = recvmsg(sock, &msg, MSG_DONTWAIT); if (len < 0) break; else if (len < (ssize_t)sizeof(*adv)) continue; + int hlim = 0; + for (struct cmsghdr *ch = CMSG_FIRSTHDR(&msg); ch != NULL; + ch = CMSG_NXTHDR(&msg, ch)) + if (ch->cmsg_level == IPPROTO_IPV6 && + ch->cmsg_type == IPV6_HOPLIMIT) + memcpy(&hlim, CMSG_DATA(ch), sizeof(hlim)); + + if (hlim != 255) + continue; + // Stop sending solicits if (rs_attempt > 0) { alarm(0); @@ -235,7 +262,7 @@ 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 ND parameters if (ntohl(adv->nd_ra_reachable) <= 3600000) @@ -267,7 +294,7 @@ 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; @@ -284,7 +311,7 @@ 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) @@ -293,7 +320,7 @@ 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; @@ -305,7 +332,7 @@ 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); } } } @@ -321,5 +348,5 @@ bool ra_process(void) if (found) odhcp6c_expire(); - return found; + return found && changed; }