/** * Copyright (C) 2012-2014 Steven Barth * Copyright (C) 2017-2018 Hans Dedecker * * 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 * the Free Software Foundation. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "odhcp6c.h" #ifdef USE_LIBUBOX #include #else #include "md5.h" #endif #define ALL_DHCPV6_RELAYS {{{0xff, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,\ 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x02}}} #define DHCPV6_CLIENT_PORT 546 #define DHCPV6_SERVER_PORT 547 #define DHCPV6_DUID_LLADDR 3 #define DHCPV6_REQ_DELAY 1 #define DHCPV6_SOL_MAX_RT_MIN 60 #define DHCPV6_SOL_MAX_RT_MAX 86400 #define DHCPV6_INF_MAX_RT_MIN 60 #define DHCPV6_INF_MAX_RT_MAX 86400 static bool dhcpv6_response_is_valid(const void *buf, ssize_t len, const uint8_t transaction[3], enum dhcpv6_msg type, const struct in6_addr *daddr); static unsigned int dhcpv6_parse_ia(void *opt, void *end); static unsigned int dhcpv6_calc_refresh_timers(void); static void dhcpv6_handle_status_code(_unused const enum dhcpv6_msg orig, const uint16_t code, const void *status_msg, const int len, int *ret); static void dhcpv6_handle_ia_status_code(const enum dhcpv6_msg orig, const struct dhcpv6_ia_hdr *ia_hdr, const uint16_t code, const void *status_msg, const int len, bool handled_status_codes[_DHCPV6_Status_Max], int *ret); static void dhcpv6_add_server_cand(const struct dhcpv6_server_cand *cand); static void dhcpv6_clear_all_server_cand(void); static reply_handler dhcpv6_handle_reply; static reply_handler dhcpv6_handle_advert; static reply_handler dhcpv6_handle_rebind_reply; static reply_handler dhcpv6_handle_reconfigure; static int dhcpv6_commit_advert(void); // RFC 3315 - 5.5 Timeout and Delay values static struct dhcpv6_retx dhcpv6_retx[_DHCPV6_MSG_MAX] = { [DHCPV6_MSG_UNKNOWN] = {false, 1, 120, 0, "", dhcpv6_handle_reconfigure, NULL}, [DHCPV6_MSG_SOLICIT] = {true, 1, DHCPV6_SOL_MAX_RT, 0, "SOLICIT", dhcpv6_handle_advert, dhcpv6_commit_advert}, [DHCPV6_MSG_REQUEST] = {true, 1, DHCPV6_REQ_MAX_RT, 10, "REQUEST", dhcpv6_handle_reply, NULL}, [DHCPV6_MSG_RENEW] = {false, 10, DHCPV6_REN_MAX_RT, 0, "RENEW", dhcpv6_handle_reply, NULL}, [DHCPV6_MSG_REBIND] = {false, 10, DHCPV6_REB_MAX_RT, 0, "REBIND", dhcpv6_handle_rebind_reply, NULL}, [DHCPV6_MSG_RELEASE] = {false, 1, 0, 5, "RELEASE", NULL, NULL}, [DHCPV6_MSG_DECLINE] = {false, 1, 0, 5, "DECLINE", NULL, NULL}, [DHCPV6_MSG_INFO_REQ] = {true, 1, DHCPV6_INF_MAX_RT, 0, "INFOREQ", dhcpv6_handle_reply, NULL}, }; // Sockets static int sock = -1; static int ifindex = -1; static int64_t t1 = 0, t2 = 0, t3 = 0; // IA states static enum odhcp6c_ia_mode na_mode = IA_MODE_NONE, pd_mode = IA_MODE_NONE; static bool accept_reconfig = false; // Server unicast address static struct in6_addr server_addr = IN6ADDR_ANY_INIT; // Reconfigure key static uint8_t reconf_key[16]; // client options static unsigned int client_options = 0; static uint32_t ntohl_unaligned(const uint8_t *data) { uint32_t buf; memcpy(&buf, data, sizeof(buf)); return ntohl(buf); } static char *dhcpv6_msg_to_str(enum dhcpv6_msg msg) { switch (msg) { case DHCPV6_MSG_SOLICIT: return "SOLICIT"; case DHCPV6_MSG_ADVERT: return "ADVERTISE"; case DHCPV6_MSG_REQUEST: return "REQUEST"; case DHCPV6_MSG_RENEW: return "RENEW"; case DHCPV6_MSG_REBIND: return "REBIND"; case DHCPV6_MSG_REPLY: return "REPLY"; case DHCPV6_MSG_RELEASE: return "RELEASE"; case DHCPV6_MSG_DECLINE: return "DECLINE"; case DHCPV6_MSG_RECONF: return "RECONFIGURE"; case DHCPV6_MSG_INFO_REQ: return "INFORMATION REQUEST"; default: break; } return "UNKNOWN"; } static char *dhcpv6_status_code_to_str(uint16_t code) { switch (code) { case DHCPV6_Success: return "Success"; case DHCPV6_UnspecFail: return "Unspecified Failure"; case DHCPV6_NoAddrsAvail: return "No Address Available"; case DHCPV6_NoBinding: return "No Binding"; case DHCPV6_NotOnLink: return "Not On Link"; case DHCPV6_UseMulticast: return "Use Multicast"; case DHCPV6_NoPrefixAvail: return "No Prefix Available"; default: break; } return "Unknown"; } int init_dhcpv6(const char *ifname, unsigned int options, int sol_timeout) { client_options = options; dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = sol_timeout; sock = socket(AF_INET6, SOCK_DGRAM | SOCK_CLOEXEC, IPPROTO_UDP); if (sock < 0) goto failure; // Detect interface struct ifreq ifr; memset(&ifr, 0, sizeof(ifr)); strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name) - 1); if (ioctl(sock, SIOCGIFINDEX, &ifr) < 0) goto failure; ifindex = ifr.ifr_ifindex; // Create client DUID size_t client_id_len; odhcp6c_get_state(STATE_CLIENT_ID, &client_id_len); if (client_id_len == 0) { uint8_t duid[14] = {0, DHCPV6_OPT_CLIENTID, 0, 10, 0, DHCPV6_DUID_LLADDR, 0, 1}; if (ioctl(sock, SIOCGIFHWADDR, &ifr) >= 0) memcpy(&duid[8], ifr.ifr_hwaddr.sa_data, ETHER_ADDR_LEN); uint8_t zero[ETHER_ADDR_LEN] = {0, 0, 0, 0, 0, 0}; struct ifreq ifs[100], *ifp, *ifend; struct ifconf ifc; ifc.ifc_req = ifs; ifc.ifc_len = sizeof(ifs); if (!memcmp(&duid[8], zero, ETHER_ADDR_LEN) && ioctl(sock, SIOCGIFCONF, &ifc) >= 0) { // If our interface doesn't have an address... ifend = ifs + (ifc.ifc_len / sizeof(struct ifreq)); for (ifp = ifc.ifc_req; ifp < ifend && !memcmp(&duid[8], zero, ETHER_ADDR_LEN); ifp++) { memcpy(ifr.ifr_name, ifp->ifr_name, sizeof(ifr.ifr_name)); if (ioctl(sock, SIOCGIFHWADDR, &ifr) < 0) continue; memcpy(&duid[8], ifr.ifr_hwaddr.sa_data, ETHER_ADDR_LEN); } } odhcp6c_add_state(STATE_CLIENT_ID, duid, sizeof(duid)); } // Create ORO if (!(client_options & DHCPV6_STRICT_OPTIONS)) { uint16_t oro[] = { htons(DHCPV6_OPT_SIP_SERVER_D), htons(DHCPV6_OPT_SIP_SERVER_A), htons(DHCPV6_OPT_DNS_SERVERS), htons(DHCPV6_OPT_DNS_DOMAIN), htons(DHCPV6_OPT_SNTP_SERVERS), htons(DHCPV6_OPT_NTP_SERVER), htons(DHCPV6_OPT_AFTR_NAME), htons(DHCPV6_OPT_PD_EXCLUDE), #ifdef EXT_CER_ID htons(DHCPV6_OPT_CER_ID), #endif htons(DHCPV6_OPT_S46_CONT_MAPE), htons(DHCPV6_OPT_S46_CONT_MAPT), htons(DHCPV6_OPT_S46_CONT_LW), }; odhcp6c_add_state(STATE_ORO, oro, sizeof(oro)); } // Required oro uint16_t req_oro[] = { htons(DHCPV6_OPT_INF_MAX_RT), htons(DHCPV6_OPT_SOL_MAX_RT), htons(DHCPV6_OPT_INFO_REFRESH), }; odhcp6c_add_state(STATE_ORO, req_oro, sizeof(req_oro)); // Configure IPv6-options int val = 1; if (setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY, &val, sizeof(val)) < 0) goto failure; if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(val)) < 0) goto failure; if (setsockopt(sock, IPPROTO_IPV6, IPV6_RECVPKTINFO, &val, sizeof(val)) < 0) goto failure; if (setsockopt(sock, SOL_SOCKET, SO_BINDTODEVICE, ifname, strlen(ifname)) < 0) goto failure; struct sockaddr_in6 client_addr = { .sin6_family = AF_INET6, .sin6_port = htons(DHCPV6_CLIENT_PORT), .sin6_flowinfo = 0 }; if (bind(sock, (struct sockaddr*)&client_addr, sizeof(client_addr)) < 0) goto failure; return 0; failure: if (sock >= 0) close(sock); return -1; } enum { IOV_HDR=0, IOV_ORO, IOV_CL_ID, IOV_SRV_ID, IOV_OPTS, IOV_RECONF_ACCEPT, IOV_FQDN, IOV_HDR_IA_NA, IOV_IA_NA, IOV_IA_PD, IOV_TOTAL }; int dhcpv6_set_ia_mode(enum odhcp6c_ia_mode na, enum odhcp6c_ia_mode pd) { int mode = DHCPV6_UNKNOWN; na_mode = na; pd_mode = pd; if (na_mode == IA_MODE_NONE && pd_mode == IA_MODE_NONE) mode = DHCPV6_STATELESS; else if (na_mode == IA_MODE_FORCE || pd_mode == IA_MODE_FORCE) mode = DHCPV6_STATEFUL; return mode; } static void dhcpv6_send(enum dhcpv6_msg type, uint8_t trid[3], uint32_t ecs) { // Build FQDN char fqdn_buf[256]; gethostname(fqdn_buf, sizeof(fqdn_buf)); struct { uint16_t type; uint16_t len; uint8_t flags; uint8_t data[256]; } fqdn; size_t fqdn_len = 5 + dn_comp(fqdn_buf, fqdn.data, sizeof(fqdn.data), NULL, NULL); fqdn.type = htons(DHCPV6_OPT_FQDN); fqdn.len = htons(fqdn_len - 4); fqdn.flags = 0; // Build Client ID size_t cl_id_len; void *cl_id = odhcp6c_get_state(STATE_CLIENT_ID, &cl_id_len); // Get Server ID size_t srv_id_len; void *srv_id = odhcp6c_get_state(STATE_SERVER_ID, &srv_id_len); // Build IA_PDs size_t ia_pd_entries = 0, ia_pd_len = 0; uint8_t *ia_pd; if (type == DHCPV6_MSG_SOLICIT) { odhcp6c_clear_state(STATE_IA_PD); size_t n_prefixes; struct odhcp6c_request_prefix *request_prefixes = odhcp6c_get_state(STATE_IA_PD_INIT, &n_prefixes); n_prefixes /= sizeof(struct odhcp6c_request_prefix); ia_pd = alloca(n_prefixes * (sizeof(struct dhcpv6_ia_hdr) + sizeof(struct dhcpv6_ia_prefix))); for (size_t i = 0; i < n_prefixes; i++) { struct dhcpv6_ia_hdr hdr_ia_pd = { htons(DHCPV6_OPT_IA_PD), htons(sizeof(hdr_ia_pd) - 4 + sizeof(struct dhcpv6_ia_prefix) * !!request_prefixes[i].length), request_prefixes[i].iaid, 0, 0 }; struct dhcpv6_ia_prefix pref = { .type = htons(DHCPV6_OPT_IA_PREFIX), .len = htons(sizeof(pref) - 4), .prefix = request_prefixes[i].length }; memcpy(ia_pd + ia_pd_len, &hdr_ia_pd, sizeof(hdr_ia_pd)); ia_pd_len += sizeof(hdr_ia_pd); if (request_prefixes[i].length) { memcpy(ia_pd + ia_pd_len, &pref, sizeof(pref)); ia_pd_len += sizeof(pref); } } } else { struct odhcp6c_entry *e = odhcp6c_get_state(STATE_IA_PD, &ia_pd_entries); ia_pd_entries /= sizeof(*e); // we're too lazy to count our distinct IAIDs, // so just allocate maximally needed space ia_pd = alloca(ia_pd_entries * (sizeof(struct dhcpv6_ia_prefix) + 10 + sizeof(struct dhcpv6_ia_hdr))); for (size_t i = 0; i < ia_pd_entries; ++i) { uint32_t iaid = e[i].iaid; // check if this is an unprocessed IAID and skip if not. int new_iaid = 1; for (int j = i-1; j >= 0; j--) { if (e[j].iaid == iaid) { new_iaid = 0; break; } } if (!new_iaid) continue; // construct header struct dhcpv6_ia_hdr hdr_ia_pd = { htons(DHCPV6_OPT_IA_PD), htons(sizeof(hdr_ia_pd) - 4), iaid, 0, 0 }; memcpy(ia_pd + ia_pd_len, &hdr_ia_pd, sizeof(hdr_ia_pd)); struct dhcpv6_ia_hdr *hdr = (struct dhcpv6_ia_hdr *) (ia_pd + ia_pd_len); ia_pd_len += sizeof(hdr_ia_pd); for (size_t j = i; j < ia_pd_entries; j++) { if (e[j].iaid != iaid) continue; uint8_t ex_len = 0; if (e[j].priority > 0) ex_len = ((e[j].priority - e[j].length - 1) / 8) + 6; struct dhcpv6_ia_prefix p = { .type = htons(DHCPV6_OPT_IA_PREFIX), .len = htons(sizeof(p) - 4U + ex_len), .prefix = e[j].length, .addr = e[j].target }; if (type == DHCPV6_MSG_REQUEST) { p.preferred = htonl(e[j].preferred); p.valid = htonl(e[j].valid); } memcpy(ia_pd + ia_pd_len, &p, sizeof(p)); ia_pd_len += sizeof(p); if (ex_len) { ia_pd[ia_pd_len++] = 0; ia_pd[ia_pd_len++] = DHCPV6_OPT_PD_EXCLUDE; ia_pd[ia_pd_len++] = 0; ia_pd[ia_pd_len++] = ex_len - 4; ia_pd[ia_pd_len++] = e[j].priority; uint32_t excl = ntohl(e[j].router.s6_addr32[1]); excl >>= (64 - e[j].priority); excl <<= 8 - ((e[j].priority - e[j].length) % 8); for (size_t i = ex_len - 5; i > 0; --i, excl >>= 8) ia_pd[ia_pd_len + i] = excl & 0xff; ia_pd_len += ex_len - 5; } hdr->len = htons(ntohs(hdr->len) + ntohs(p.len) + 4U); } } } // Build IA_NAs size_t ia_na_entries, ia_na_len = 0; void *ia_na = NULL; struct odhcp6c_entry *e = odhcp6c_get_state(STATE_IA_NA, &ia_na_entries); ia_na_entries /= sizeof(*e); struct dhcpv6_ia_hdr hdr_ia_na = { htons(DHCPV6_OPT_IA_NA), htons(sizeof(hdr_ia_na) - 4), htonl(1), 0, 0 }; struct dhcpv6_ia_addr pa[ia_na_entries]; for (size_t i = 0; i < ia_na_entries; ++i) { pa[i].type = htons(DHCPV6_OPT_IA_ADDR); pa[i].len = htons(sizeof(pa[i]) - 4U); pa[i].addr = e[i].target; if (type == DHCPV6_MSG_REQUEST) { pa[i].preferred = htonl(e[i].preferred); pa[i].valid = htonl(e[i].valid); } else { pa[i].preferred = 0; pa[i].valid = 0; } } ia_na = pa; ia_na_len = sizeof(pa); hdr_ia_na.len = htons(ntohs(hdr_ia_na.len) + ia_na_len); // Reconfigure Accept struct { uint16_t type; uint16_t length; } reconf_accept = {htons(DHCPV6_OPT_RECONF_ACCEPT), 0}; // Option list size_t opts_len; void *opts = odhcp6c_get_state(STATE_OPTS, &opts_len); // Option Request List size_t oro_entries, oro_len = 0; uint16_t *oro, *s_oro = odhcp6c_get_state(STATE_ORO, &oro_entries); oro_entries /= sizeof(*s_oro); oro = alloca(oro_entries * sizeof(*oro)); for (size_t i = 0; i < oro_entries; i++) { struct odhcp6c_opt *opt = odhcp6c_find_opt(htons(s_oro[i])); if (opt) { if (!(opt->flags & OPT_ORO)) continue; if ((opt->flags & OPT_ORO_SOLICIT) && type != DHCPV6_MSG_SOLICIT) continue; if ((opt->flags & OPT_ORO_STATELESS) && type != DHCPV6_MSG_INFO_REQ) continue; if ((opt->flags & OPT_ORO_STATEFUL) && type == DHCPV6_MSG_INFO_REQ) continue; } oro[oro_len++] = s_oro[i]; } oro_len *= sizeof(*oro); // Prepare Header struct { uint8_t type; uint8_t trid[3]; uint16_t elapsed_type; uint16_t elapsed_len; uint16_t elapsed_value; uint16_t oro_type; uint16_t oro_len; } hdr = { type, {trid[0], trid[1], trid[2]}, htons(DHCPV6_OPT_ELAPSED), htons(2), htons((ecs > 0xffff) ? 0xffff : ecs), htons(DHCPV6_OPT_ORO), htons(oro_len), }; struct iovec iov[IOV_TOTAL] = { [IOV_HDR] = {&hdr, sizeof(hdr)}, [IOV_ORO] = {oro, oro_len}, [IOV_CL_ID] = {cl_id, cl_id_len}, [IOV_SRV_ID] = {srv_id, srv_id_len}, [IOV_OPTS] = { opts, opts_len }, [IOV_RECONF_ACCEPT] = {&reconf_accept, sizeof(reconf_accept)}, [IOV_FQDN] = {&fqdn, fqdn_len}, [IOV_HDR_IA_NA] = {&hdr_ia_na, sizeof(hdr_ia_na)}, [IOV_IA_NA] = {ia_na, ia_na_len}, [IOV_IA_PD] = {ia_pd, ia_pd_len}, }; size_t cnt = IOV_TOTAL; if (type == DHCPV6_MSG_INFO_REQ) cnt = IOV_HDR_IA_NA; // Disable IAs if not used if (type != DHCPV6_MSG_SOLICIT && ia_na_len == 0) iov[IOV_HDR_IA_NA].iov_len = 0; if (na_mode == IA_MODE_NONE) iov[IOV_HDR_IA_NA].iov_len = 0; if ((type != DHCPV6_MSG_SOLICIT && type != DHCPV6_MSG_REQUEST) || !(client_options & DHCPV6_ACCEPT_RECONFIGURE)) iov[IOV_RECONF_ACCEPT].iov_len = 0; if (!(client_options & DHCPV6_CLIENT_FQDN)) iov[IOV_FQDN].iov_len = 0; struct sockaddr_in6 srv = {AF_INET6, htons(DHCPV6_SERVER_PORT), 0, ALL_DHCPV6_RELAYS, ifindex}; struct msghdr msg = {.msg_name = &srv, .msg_namelen = sizeof(srv), .msg_iov = iov, .msg_iovlen = cnt}; switch (type) { case DHCPV6_MSG_REQUEST: case DHCPV6_MSG_RENEW: case DHCPV6_MSG_RELEASE: case DHCPV6_MSG_DECLINE: if (!IN6_IS_ADDR_UNSPECIFIED(&server_addr) && odhcp6c_addr_in_scope(&server_addr)) { srv.sin6_addr = server_addr; if (!IN6_IS_ADDR_LINKLOCAL(&server_addr)) srv.sin6_scope_id = 0; } break; default: break; } if (sendmsg(sock, &msg, 0) < 0) { char in6_str[INET6_ADDRSTRLEN]; syslog(LOG_ERR, "Failed to send %s message to %s (%s)", dhcpv6_msg_to_str(type), inet_ntop(AF_INET6, (const void *)&srv.sin6_addr, in6_str, sizeof(in6_str)), strerror(errno)); } } static int64_t dhcpv6_rand_delay(int64_t time) { int random; odhcp6c_random(&random, sizeof(random)); return (time * ((int64_t)random % 1000LL)) / 10000LL; } int dhcpv6_request(enum dhcpv6_msg type) { uint8_t rc = 0; uint64_t timeout = UINT32_MAX; struct dhcpv6_retx *retx = &dhcpv6_retx[type]; if (retx->delay) { struct timespec ts = {0, 0}; ts.tv_nsec = (dhcpv6_rand_delay((10000 * DHCPV6_REQ_DELAY) / 2) + (1000 * DHCPV6_REQ_DELAY) / 2) * 1000000; while (nanosleep(&ts, &ts) < 0 && errno == EINTR); } if (type == DHCPV6_MSG_UNKNOWN) timeout = t1; else if (type == DHCPV6_MSG_RENEW) timeout = (t2 > t1) ? t2 - t1 : ((t1 == UINT32_MAX) ? UINT32_MAX : 0); else if (type == DHCPV6_MSG_REBIND) timeout = (t3 > t2) ? t3 - t2 : ((t2 == UINT32_MAX) ? UINT32_MAX : 0); if (timeout == 0) return -1; syslog(LOG_NOTICE, "Starting %s transaction (timeout %"PRIu64"s, max rc %d)", retx->name, timeout, retx->max_rc); uint64_t start = odhcp6c_get_milli_time(), round_start = start, elapsed; // Generate transaction ID uint8_t trid[3] = {0, 0, 0}; if (type != DHCPV6_MSG_UNKNOWN) odhcp6c_random(trid, sizeof(trid)); ssize_t len = -1; int64_t rto = 0; do { if (rto == 0) { int64_t delay = dhcpv6_rand_delay(retx->init_timeo * 1000); // First RT MUST be strictly greater than IRT for solicit messages (RFC3313 17.1.2) while (type == DHCPV6_MSG_SOLICIT && delay <= 0) delay = dhcpv6_rand_delay(retx->init_timeo * 1000); rto = (retx->init_timeo * 1000 + delay); } else rto = (2 * rto + dhcpv6_rand_delay(rto)); if (retx->max_timeo && (rto >= retx->max_timeo * 1000)) rto = retx->max_timeo * 1000 + dhcpv6_rand_delay(retx->max_timeo * 1000); // Calculate end for this round and elapsed time uint64_t round_end = round_start + rto; elapsed = round_start - start; // Don't wait too long if timeout differs from infinite if ((timeout != UINT32_MAX) && (round_end - start > timeout * 1000)) round_end = timeout * 1000 + start; // Built and send package switch (type) { case DHCPV6_MSG_UNKNOWN: break; default: syslog(LOG_NOTICE, "Send %s message (elapsed %"PRIu64"ms, rc %d)", retx->name, elapsed, rc); // Fall through case DHCPV6_MSG_SOLICIT: case DHCPV6_MSG_INFO_REQ: dhcpv6_send(type, trid, elapsed / 10); rc++; } // Receive rounds for (; len < 0 && (round_start < round_end); round_start = odhcp6c_get_milli_time()) { uint8_t buf[1536]; union { struct cmsghdr hdr; uint8_t buf[CMSG_SPACE(sizeof(struct in6_pktinfo))]; } cmsg_buf; struct iovec iov = {buf, sizeof(buf)}; struct sockaddr_in6 addr; struct msghdr msg = {.msg_name = &addr, .msg_namelen = sizeof(addr), .msg_iov = &iov, .msg_iovlen = 1, .msg_control = cmsg_buf.buf, .msg_controllen = sizeof(cmsg_buf)}; struct in6_pktinfo *pktinfo = NULL; const struct dhcpv6_header *hdr = (const struct dhcpv6_header *)buf; // Check for pending signal if (odhcp6c_signal_process()) return -1; // Set timeout for receiving uint64_t t = round_end - round_start; struct timeval tv = {t / 1000, (t % 1000) * 1000}; if (setsockopt(sock, SOL_SOCKET, SO_RCVTIMEO, &tv, sizeof(tv)) < 0) syslog(LOG_ERR, "setsockopt SO_RCVTIMEO failed (%s)", strerror(errno)); // Receive cycle len = recvmsg(sock, &msg, 0); if (len < 0) continue; for (struct cmsghdr *ch = CMSG_FIRSTHDR(&msg); ch != NULL; ch = CMSG_NXTHDR(&msg, ch)) { if (ch->cmsg_level == SOL_IPV6 && ch->cmsg_type == IPV6_PKTINFO) { pktinfo = (struct in6_pktinfo *)CMSG_DATA(ch); break; } } if (pktinfo == NULL) { len = -1; continue; } if (!dhcpv6_response_is_valid(buf, len, trid, type, &pktinfo->ipi6_addr)) { len = -1; continue; } uint8_t *opt = &buf[4]; uint8_t *opt_end = opt + len - 4; round_start = odhcp6c_get_milli_time(); elapsed = round_start - start; syslog(LOG_NOTICE, "Got a valid %s after %"PRIu64"ms", dhcpv6_msg_to_str(hdr->msg_type), elapsed); if (retx->handler_reply) len = retx->handler_reply(type, rc, opt, opt_end, &addr); if (len > 0 && round_end - round_start > 1000) round_end = 1000 + round_start; } // Allow if (retx->handler_finish) len = retx->handler_finish(); } while (len < 0 && ((timeout == UINT32_MAX) || (elapsed / 1000 < timeout)) && (!retx->max_rc || rc < retx->max_rc)); return len; } // Message validation checks according to RFC3315 chapter 15 static bool dhcpv6_response_is_valid(const void *buf, ssize_t len, const uint8_t transaction[3], enum dhcpv6_msg type, const struct in6_addr *daddr) { const struct dhcpv6_header *rep = buf; if (len < (ssize_t)sizeof(*rep) || memcmp(rep->tr_id, transaction, sizeof(rep->tr_id))) return false; // Invalid reply if (type == DHCPV6_MSG_SOLICIT) { if (rep->msg_type != DHCPV6_MSG_ADVERT && rep->msg_type != DHCPV6_MSG_REPLY) return false; } else if (type == DHCPV6_MSG_UNKNOWN) { if (!accept_reconfig || rep->msg_type != DHCPV6_MSG_RECONF) return false; } else if (rep->msg_type != DHCPV6_MSG_REPLY) return false; uint8_t *end = ((uint8_t*)buf) + len, *odata = NULL, rcmsg = DHCPV6_MSG_UNKNOWN; uint16_t otype, olen = UINT16_MAX; bool clientid_ok = false, serverid_ok = false, rcauth_ok = false, ia_present = false, options_valid = true; size_t client_id_len, server_id_len; void *client_id = odhcp6c_get_state(STATE_CLIENT_ID, &client_id_len); void *server_id = odhcp6c_get_state(STATE_SERVER_ID, &server_id_len); dhcpv6_for_each_option(&rep[1], end, otype, olen, odata) { if (otype == DHCPV6_OPT_CLIENTID) { clientid_ok = (olen + 4U == client_id_len) && !memcmp( &odata[-4], client_id, client_id_len); } else if (otype == DHCPV6_OPT_SERVERID) { if (server_id_len) serverid_ok = (olen + 4U == server_id_len) && !memcmp( &odata[-4], server_id, server_id_len); else serverid_ok = true; } else if (otype == DHCPV6_OPT_AUTH && olen == -4 + sizeof(struct dhcpv6_auth_reconfigure)) { struct dhcpv6_auth_reconfigure *r = (void*)&odata[-4]; if (r->protocol != 3 || r->algorithm != 1 || r->reconf_type != 2) continue; md5_ctx_t md5; uint8_t serverhash[16], secretbytes[64]; uint32_t hash[4]; memcpy(serverhash, r->key, sizeof(serverhash)); memset(r->key, 0, sizeof(r->key)); memset(secretbytes, 0, sizeof(secretbytes)); memcpy(secretbytes, reconf_key, sizeof(reconf_key)); for (size_t i = 0; i < sizeof(secretbytes); ++i) secretbytes[i] ^= 0x36; md5_begin(&md5); md5_hash(secretbytes, sizeof(secretbytes), &md5); md5_hash(buf, len, &md5); md5_end(hash, &md5); for (size_t i = 0; i < sizeof(secretbytes); ++i) { secretbytes[i] ^= 0x36; secretbytes[i] ^= 0x5c; } md5_begin(&md5); md5_hash(secretbytes, sizeof(secretbytes), &md5); md5_hash(hash, 16, &md5); md5_end(hash, &md5); rcauth_ok = !memcmp(hash, serverhash, sizeof(hash)); } else if (otype == DHCPV6_OPT_RECONF_MESSAGE && olen == 1) { rcmsg = odata[0]; } else if ((otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA)) { ia_present = true; if (olen < -4 + sizeof(struct dhcpv6_ia_hdr)) options_valid = false; } else if ((otype == DHCPV6_OPT_IA_ADDR) || (otype == DHCPV6_OPT_IA_PREFIX) || (otype == DHCPV6_OPT_PD_EXCLUDE)) // Options are not allowed on global level options_valid = false; } if (!options_valid || ((odata + olen) > end)) return false; if (type == DHCPV6_MSG_INFO_REQ && ia_present) return false; if (rep->msg_type == DHCPV6_MSG_RECONF) { if ((rcmsg != DHCPV6_MSG_RENEW && rcmsg != DHCPV6_MSG_REBIND && rcmsg != DHCPV6_MSG_INFO_REQ) || (rcmsg == DHCPV6_MSG_INFO_REQ && ia_present) || !rcauth_ok || IN6_IS_ADDR_MULTICAST(daddr)) return false; } return clientid_ok && serverid_ok; } int dhcpv6_poll_reconfigure(void) { int ret = dhcpv6_request(DHCPV6_MSG_UNKNOWN); switch (ret) { /* * Only RENEW/REBIND/INFORMATION REQUEST * message transmission can be requested * by a RECONFIGURE */ case DHCPV6_MSG_RENEW: case DHCPV6_MSG_REBIND: case DHCPV6_MSG_INFO_REQ: ret = dhcpv6_request(ret); break; default: break; } return ret; } static int dhcpv6_handle_reconfigure(enum dhcpv6_msg orig, const int rc, const void *opt, const void *end, _unused const struct sockaddr_in6 *from) { uint16_t otype, olen; uint8_t *odata; enum dhcpv6_msg msg = DHCPV6_MSG_UNKNOWN; dhcpv6_for_each_option(opt, end, otype, olen, odata) { if (otype == DHCPV6_OPT_RECONF_MESSAGE && olen == 1) { switch (odata[0]) { case DHCPV6_MSG_REBIND: if (t2 != UINT32_MAX) t2 = 0; // Fall through case DHCPV6_MSG_RENEW: if (t1 != UINT32_MAX) t1 = 0; // Fall through case DHCPV6_MSG_INFO_REQ: msg = odata[0]; syslog(LOG_NOTICE, "Need to respond with %s in reply to %s", dhcpv6_msg_to_str(msg), dhcpv6_msg_to_str(DHCPV6_MSG_RECONF)); break; default: break; } } } if (msg != DHCPV6_MSG_UNKNOWN) dhcpv6_handle_reply(orig, rc, NULL, NULL, NULL); return (msg == DHCPV6_MSG_UNKNOWN? -1: (int)msg); } // Collect all advertised servers static int dhcpv6_handle_advert(enum dhcpv6_msg orig, const int rc, const void *opt, const void *end, _unused const struct sockaddr_in6 *from) { uint16_t olen, otype; uint8_t *odata, pref = 0; struct dhcpv6_server_cand cand = {false, false, 0, 0, {0}, IN6ADDR_ANY_INIT, DHCPV6_SOL_MAX_RT, DHCPV6_INF_MAX_RT, NULL, NULL, 0, 0}; bool have_na = false; int have_pd = 0; dhcpv6_for_each_option(opt, end, otype, olen, odata) { if (orig == DHCPV6_MSG_SOLICIT && ((otype == DHCPV6_OPT_IA_PD && pd_mode != IA_MODE_NONE) || (otype == DHCPV6_OPT_IA_NA && na_mode != IA_MODE_NONE)) && olen > -4 + sizeof(struct dhcpv6_ia_hdr)) { struct dhcpv6_ia_hdr *ia_hdr = (void*)(&odata[-4]); dhcpv6_parse_ia(ia_hdr, odata + olen + sizeof(*ia_hdr)); } if (otype == DHCPV6_OPT_SERVERID && olen <= 130) { memcpy(cand.duid, odata, olen); cand.duid_len = olen; } else if (otype == DHCPV6_OPT_PREF && olen >= 1 && cand.preference >= 0) { cand.preference = pref = odata[0]; } else if (otype == DHCPV6_OPT_UNICAST && olen == sizeof(cand.server_addr)) { if (!(client_options & DHCPV6_IGNORE_OPT_UNICAST)) cand.server_addr = *(struct in6_addr *)odata; } else if (otype == DHCPV6_OPT_RECONF_ACCEPT) { cand.wants_reconfigure = true; } else if (otype == DHCPV6_OPT_SOL_MAX_RT && olen == 4) { uint32_t sol_max_rt = ntohl_unaligned(odata); if (sol_max_rt >= DHCPV6_SOL_MAX_RT_MIN && sol_max_rt <= DHCPV6_SOL_MAX_RT_MAX) cand.sol_max_rt = sol_max_rt; } else if (otype == DHCPV6_OPT_INF_MAX_RT && olen == 4) { uint32_t inf_max_rt = ntohl_unaligned(odata); if (inf_max_rt >= DHCPV6_INF_MAX_RT_MIN && inf_max_rt <= DHCPV6_INF_MAX_RT_MAX) cand.inf_max_rt = inf_max_rt; } else if (otype == DHCPV6_OPT_IA_PD && olen >= -4 + sizeof(struct dhcpv6_ia_hdr)) { struct dhcpv6_ia_hdr *h = (struct dhcpv6_ia_hdr*)&odata[-4]; uint8_t *oend = odata + olen, *d; dhcpv6_for_each_option(&h[1], oend, otype, olen, d) { if (otype == DHCPV6_OPT_IA_PREFIX && olen >= -4 + sizeof(struct dhcpv6_ia_prefix)) { struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&d[-4]; have_pd = p->prefix; } } } else if (otype == DHCPV6_OPT_IA_NA && olen >= -4 + sizeof(struct dhcpv6_ia_hdr)) { struct dhcpv6_ia_hdr *h = (struct dhcpv6_ia_hdr*)&odata[-4]; uint8_t *oend = odata + olen, *d; dhcpv6_for_each_option(&h[1], oend, otype, olen, d) { if (otype == DHCPV6_OPT_IA_ADDR && olen >= -4 + sizeof(struct dhcpv6_ia_addr)) have_na = true; } } } if ((!have_na && na_mode == IA_MODE_FORCE) || (!have_pd && pd_mode == IA_MODE_FORCE)) { /* * RFC7083 states to process the SOL_MAX_RT and * INF_MAX_RT options even if the DHCPv6 server * did not propose any IA_NA and/or IA_PD */ dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = cand.sol_max_rt; dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = cand.inf_max_rt; return -1; } if (na_mode != IA_MODE_NONE && !have_na) { cand.has_noaddravail = true; cand.preference -= 1000; } if (pd_mode != IA_MODE_NONE) { if (have_pd) cand.preference += 2000 + (128 - have_pd); else cand.preference -= 2000; } if (cand.duid_len > 0) { cand.ia_na = odhcp6c_move_state(STATE_IA_NA, &cand.ia_na_len); cand.ia_pd = odhcp6c_move_state(STATE_IA_PD, &cand.ia_pd_len); dhcpv6_add_server_cand(&cand); } return (rc > 1 || (pref == 255 && cand.preference > 0)) ? 1 : -1; } static int dhcpv6_commit_advert(void) { return dhcpv6_promote_server_cand(); } static int dhcpv6_handle_rebind_reply(enum dhcpv6_msg orig, const int rc, const void *opt, const void *end, const struct sockaddr_in6 *from) { dhcpv6_handle_advert(orig, rc, opt, end, from); if (dhcpv6_commit_advert() < 0) return -1; return dhcpv6_handle_reply(orig, rc, opt, end, from); } static int dhcpv6_handle_reply(enum dhcpv6_msg orig, _unused const int rc, const void *opt, const void *end, const struct sockaddr_in6 *from) { uint8_t *odata; uint16_t otype, olen; uint32_t refresh = 86400; int ret = 1; unsigned int state_IAs; unsigned int updated_IAs = 0; bool handled_status_codes[_DHCPV6_Status_Max] = { false, }; odhcp6c_expire(); if (orig == DHCPV6_MSG_UNKNOWN) { static time_t last_update = 0; time_t now = odhcp6c_get_milli_time() / 1000; uint32_t elapsed = (last_update > 0) ? now - last_update : 0; last_update = now; if (t1 != UINT32_MAX) t1 -= elapsed; if (t2 != UINT32_MAX) t2 -= elapsed; if (t3 != UINT32_MAX) t3 -= elapsed; if (t1 < 0) t1 = 0; if (t2 < 0) t2 = 0; if (t3 < 0) t3 = 0; } if (orig == DHCPV6_MSG_REQUEST && !odhcp6c_is_bound()) { // Delete NA and PD we have in the state from the Advert odhcp6c_clear_state(STATE_IA_NA); odhcp6c_clear_state(STATE_IA_PD); } if (opt) { odhcp6c_clear_state(STATE_DNS); odhcp6c_clear_state(STATE_SEARCH); odhcp6c_clear_state(STATE_SNTP_IP); odhcp6c_clear_state(STATE_NTP_IP); odhcp6c_clear_state(STATE_NTP_FQDN); odhcp6c_clear_state(STATE_SIP_IP); odhcp6c_clear_state(STATE_SIP_FQDN); odhcp6c_clear_state(STATE_AFTR_NAME); odhcp6c_clear_state(STATE_CER); odhcp6c_clear_state(STATE_S46_MAPT); odhcp6c_clear_state(STATE_S46_MAPE); odhcp6c_clear_state(STATE_S46_LW); odhcp6c_clear_state(STATE_PASSTHRU); odhcp6c_clear_state(STATE_CUSTOM_OPTS); // Parse and find all matching IAs dhcpv6_for_each_option(opt, end, otype, olen, odata) { struct odhcp6c_opt *dopt = odhcp6c_find_opt(otype); if ((otype == DHCPV6_OPT_IA_PD || otype == DHCPV6_OPT_IA_NA) && olen > -4 + sizeof(struct dhcpv6_ia_hdr)) { struct dhcpv6_ia_hdr *ia_hdr = (void*)(&odata[-4]); if ((na_mode == IA_MODE_NONE && otype == DHCPV6_OPT_IA_NA) || (pd_mode == IA_MODE_NONE && otype == DHCPV6_OPT_IA_PD)) continue; // Test ID if (ia_hdr->iaid != htonl(1) && otype == DHCPV6_OPT_IA_NA) continue; uint16_t code = DHCPV6_Success; uint16_t stype, slen; uint8_t *sdata; // Get and handle status code dhcpv6_for_each_option(&ia_hdr[1], odata + olen, stype, slen, sdata) { if (stype == DHCPV6_OPT_STATUS && slen >= 2) { uint8_t *mdata = (slen > 2) ? &sdata[2] : NULL; uint16_t mlen = (slen > 2) ? slen - 2 : 0; code = ((int)sdata[0]) << 8 | ((int)sdata[1]); if (code == DHCPV6_Success) continue; dhcpv6_handle_ia_status_code(orig, ia_hdr, code, mdata, mlen, handled_status_codes, &ret); if (ret > 0) return ret; break; } } if (code != DHCPV6_Success) continue; updated_IAs += dhcpv6_parse_ia(ia_hdr, odata + olen); } else if (otype == DHCPV6_OPT_UNICAST && olen == sizeof(server_addr)) { if (!(client_options & DHCPV6_IGNORE_OPT_UNICAST)) server_addr = *(struct in6_addr *)odata; } else if (otype == DHCPV6_OPT_STATUS && olen >= 2) { uint8_t *mdata = (olen > 2) ? &odata[2] : NULL; uint16_t mlen = (olen > 2) ? olen - 2 : 0; uint16_t code = ((int)odata[0]) << 8 | ((int)odata[1]); dhcpv6_handle_status_code(orig, code, mdata, mlen, &ret); } else if (otype == DHCPV6_OPT_DNS_SERVERS) { if (olen % 16 == 0) odhcp6c_add_state(STATE_DNS, odata, olen); } else if (otype == DHCPV6_OPT_DNS_DOMAIN) odhcp6c_add_state(STATE_SEARCH, odata, olen); else if (otype == DHCPV6_OPT_SNTP_SERVERS) { if (olen % 16 == 0) odhcp6c_add_state(STATE_SNTP_IP, odata, olen); } else if (otype == DHCPV6_OPT_NTP_SERVER) { uint16_t stype, slen; uint8_t *sdata; // Test status and bail if error dhcpv6_for_each_option(odata, odata + olen, stype, slen, sdata) { if (slen == 16 && (stype == NTP_MC_ADDR || stype == NTP_SRV_ADDR)) odhcp6c_add_state(STATE_NTP_IP, sdata, slen); else if (slen > 0 && stype == NTP_SRV_FQDN) odhcp6c_add_state(STATE_NTP_FQDN, sdata, slen); } } else if (otype == DHCPV6_OPT_SIP_SERVER_A) { if (olen == 16) odhcp6c_add_state(STATE_SIP_IP, odata, olen); } else if (otype == DHCPV6_OPT_SIP_SERVER_D) odhcp6c_add_state(STATE_SIP_FQDN, odata, olen); else if (otype == DHCPV6_OPT_INFO_REFRESH && olen >= 4) { refresh = ntohl_unaligned(odata); } else if (otype == DHCPV6_OPT_AUTH) { if (olen == -4 + sizeof(struct dhcpv6_auth_reconfigure)) { struct dhcpv6_auth_reconfigure *r = (void*)&odata[-4]; if (r->protocol == 3 && r->algorithm == 1 && r->reconf_type == 1) memcpy(reconf_key, r->key, sizeof(r->key)); } } else if (otype == DHCPV6_OPT_AFTR_NAME && olen > 3) { size_t cur_len; odhcp6c_get_state(STATE_AFTR_NAME, &cur_len); if (cur_len == 0) odhcp6c_add_state(STATE_AFTR_NAME, odata, olen); } else if (otype == DHCPV6_OPT_SOL_MAX_RT && olen == 4) { uint32_t sol_max_rt = ntohl_unaligned(odata); if (sol_max_rt >= DHCPV6_SOL_MAX_RT_MIN && sol_max_rt <= DHCPV6_SOL_MAX_RT_MAX) dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = sol_max_rt; } else if (otype == DHCPV6_OPT_INF_MAX_RT && olen == 4) { uint32_t inf_max_rt = ntohl_unaligned(odata); if (inf_max_rt >= DHCPV6_INF_MAX_RT_MIN && inf_max_rt <= DHCPV6_INF_MAX_RT_MAX) dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = inf_max_rt; #ifdef EXT_CER_ID } else if (otype == DHCPV6_OPT_CER_ID && olen == -4 + sizeof(struct dhcpv6_cer_id)) { struct dhcpv6_cer_id *cer_id = (void*)&odata[-4]; struct in6_addr any = IN6ADDR_ANY_INIT; if (memcmp(&cer_id->addr, &any, sizeof(any))) odhcp6c_add_state(STATE_CER, &cer_id->addr, sizeof(any)); #endif } else if (otype == DHCPV6_OPT_S46_CONT_MAPT) { odhcp6c_add_state(STATE_S46_MAPT, odata, olen); } else if (otype == DHCPV6_OPT_S46_CONT_MAPE) { size_t mape_len; odhcp6c_get_state(STATE_S46_MAPE, &mape_len); if (mape_len == 0) odhcp6c_add_state(STATE_S46_MAPE, odata, olen); } else if (otype == DHCPV6_OPT_S46_CONT_LW) { odhcp6c_add_state(STATE_S46_LW, odata, olen); } else odhcp6c_add_state(STATE_CUSTOM_OPTS, &odata[-4], olen + 4); if (!dopt || !(dopt->flags & OPT_NO_PASSTHRU)) odhcp6c_add_state(STATE_PASSTHRU, &odata[-4], olen + 4); } } // Bail out if fatal status code was received if (ret <= 0) return ret; switch (orig) { case DHCPV6_MSG_REQUEST: case DHCPV6_MSG_REBIND: case DHCPV6_MSG_RENEW: state_IAs = dhcpv6_calc_refresh_timers(); // In case there're no state IA entries // keep sending request/renew/rebind messages if (state_IAs == 0) { ret = 0; break; } if (orig == DHCPV6_MSG_REQUEST) { // All server candidates can be cleared if not yet bound if (!odhcp6c_is_bound()) dhcpv6_clear_all_server_cand(); odhcp6c_clear_state(STATE_SERVER_ADDR); odhcp6c_add_state(STATE_SERVER_ADDR, &from->sin6_addr, 16); } else if (orig == DHCPV6_MSG_RENEW) { // Send further renews if T1 is not set and if // there're IAs which were not in the Reply message if (!t1 && state_IAs != updated_IAs) { if (updated_IAs) // Publish updates script_call("updated", 0, false); /* * RFC8415 states following in §18.2.10.1 : * Sends a Renew/Rebind if any of the IAs are not in the Reply * message, but as this likely indicates that the server that * responded does not support that IA type, sending immediately is * unlikely to produce a different result. Therefore, the client * MUST rate-limit its transmissions (see Section 14.1) and MAY just * wait for the normal retransmission time (as if the Reply message * had not been received). The client continues to use other * bindings for which the server did return information */ ret = -1; } } else if (orig == DHCPV6_MSG_REBIND) { odhcp6c_clear_state(STATE_SERVER_ADDR); odhcp6c_add_state(STATE_SERVER_ADDR, &from->sin6_addr, 16); // Send further rebinds if T1 and T2 is not set and if // there're IAs which were not in the Reply message if (!t1 && !t2 && state_IAs != updated_IAs) { if (updated_IAs) // Publish updates script_call("updated", 0, false); /* * RFC8415 states following in §18.2.10.1 : * Sends a Renew/Rebind if any of the IAs are not in the Reply * message, but as this likely indicates that the server that * responded does not support that IA type, sending immediately is * unlikely to produce a different result. Therefore, the client * MUST rate-limit its transmissions (see Section 14.1) and MAY just * wait for the normal retransmission time (as if the Reply message * had not been received). The client continues to use other * bindings for which the server did return information */ ret = -1; } } break; case DHCPV6_MSG_INFO_REQ: // All server candidates can be cleared if not yet bound if (!odhcp6c_is_bound()) dhcpv6_clear_all_server_cand(); t1 = refresh; break; default: break; } return ret; } static unsigned int dhcpv6_parse_ia(void *opt, void *end) { struct dhcpv6_ia_hdr *ia_hdr = (struct dhcpv6_ia_hdr *)opt; unsigned int updated_IAs = 0; uint32_t t1, t2; uint16_t otype, olen; uint8_t *odata; char buf[INET6_ADDRSTRLEN]; t1 = ntohl(ia_hdr->t1); t2 = ntohl(ia_hdr->t2); if (t1 > t2) return 0; syslog(LOG_INFO, "%s %04x T1 %d T2 %d", ntohs(ia_hdr->type) == DHCPV6_OPT_IA_PD ? "IA_PD" : "IA_NA", ntohl(ia_hdr->iaid), t1, t2); // Update address IA dhcpv6_for_each_option(&ia_hdr[1], end, otype, olen, odata) { struct odhcp6c_entry entry = {IN6ADDR_ANY_INIT, 0, 0, IN6ADDR_ANY_INIT, 0, 0, 0, 0, 0, 0}; entry.iaid = ia_hdr->iaid; if (otype == DHCPV6_OPT_IA_PREFIX) { struct dhcpv6_ia_prefix *prefix = (void*)&odata[-4]; if (olen + 4U < sizeof(*prefix)) continue; entry.valid = ntohl(prefix->valid); entry.preferred = ntohl(prefix->preferred); if (entry.preferred > entry.valid) continue; entry.t1 = (t1 ? t1 : (entry.preferred != UINT32_MAX ? 0.5 * entry.preferred : UINT32_MAX)); entry.t2 = (t2 ? t2 : (entry.preferred != UINT32_MAX ? 0.8 * entry.preferred : UINT32_MAX)); if (entry.t1 > entry.t2) entry.t1 = entry.t2; entry.length = prefix->prefix; entry.target = prefix->addr; uint16_t stype, slen; uint8_t *sdata; // Parse PD-exclude bool ok = true; dhcpv6_for_each_option(odata + sizeof(*prefix) - 4U, odata + olen, stype, slen, sdata) { if (stype != DHCPV6_OPT_PD_EXCLUDE || slen < 2) continue; uint8_t elen = sdata[0]; if (elen > 64) elen = 64; if (entry.length < 32 || elen <= entry.length) { ok = false; continue; } uint8_t bytes = ((elen - entry.length - 1) / 8) + 1; if (slen <= bytes) { ok = false; continue; } uint32_t exclude = 0; do { exclude = exclude << 8 | sdata[bytes]; } while (--bytes); exclude >>= 8 - ((elen - entry.length) % 8); exclude <<= 64 - elen; // Abusing router & priority fields for exclusion entry.router = entry.target; entry.router.s6_addr32[1] |= htonl(exclude); entry.priority = elen; } if (ok) { if (odhcp6c_update_entry(STATE_IA_PD, &entry, 0, 0)) updated_IAs++; syslog(LOG_INFO, "%s/%d preferred %d valid %d", inet_ntop(AF_INET6, &entry.target, buf, sizeof(buf)), entry.length, entry.preferred , entry.valid); } entry.priority = 0; memset(&entry.router, 0, sizeof(entry.router)); } else if (otype == DHCPV6_OPT_IA_ADDR) { struct dhcpv6_ia_addr *addr = (void*)&odata[-4]; if (olen + 4U < sizeof(*addr)) continue; entry.preferred = ntohl(addr->preferred); entry.valid = ntohl(addr->valid); if (entry.preferred > entry.valid) continue; entry.t1 = (t1 ? t1 : (entry.preferred != UINT32_MAX ? 0.5 * entry.preferred : UINT32_MAX)); entry.t2 = (t2 ? t2 : (entry.preferred != UINT32_MAX ? 0.8 * entry.preferred : UINT32_MAX)); if (entry.t1 > entry.t2) entry.t1 = entry.t2; entry.length = 128; entry.target = addr->addr; if (odhcp6c_update_entry(STATE_IA_NA, &entry, 0, 0)) updated_IAs++; syslog(LOG_INFO, "%s preferred %d valid %d", inet_ntop(AF_INET6, &entry.target, buf, sizeof(buf)), entry.preferred , entry.valid); } } return updated_IAs; } static unsigned int dhcpv6_calc_refresh_timers(void) { struct odhcp6c_entry *e; size_t ia_na_entries, ia_pd_entries, i; int64_t l_t1 = UINT32_MAX, l_t2 = UINT32_MAX, l_t3 = 0; e = odhcp6c_get_state(STATE_IA_NA, &ia_na_entries); ia_na_entries /= sizeof(*e); for (i = 0; i < ia_na_entries; i++) { if (e[i].t1 < l_t1) l_t1 = e[i].t1; if (e[i].t2 < l_t2) l_t2 = e[i].t2; if (e[i].valid > l_t3) l_t3 = e[i].valid; } e = odhcp6c_get_state(STATE_IA_PD, &ia_pd_entries); ia_pd_entries /= sizeof(*e); for (i = 0; i < ia_pd_entries; i++) { if (e[i].t1 < l_t1) l_t1 = e[i].t1; if (e[i].t2 < l_t2) l_t2 = e[i].t2; if (e[i].valid > l_t3) l_t3 = e[i].valid; } if (ia_pd_entries || ia_na_entries) { t1 = l_t1; t2 = l_t2; t3 = l_t3; syslog(LOG_INFO, "T1 %"PRId64"s, T2 %"PRId64"s, T3 %"PRId64"s", t1, t2, t3); } return (unsigned int)(ia_pd_entries + ia_na_entries); } static void dhcpv6_log_status_code(const uint16_t code, const char *scope, const void *status_msg, int len) { const char *src = status_msg; char buf[len + 3]; char *dst = buf; if (len) { *dst++ = '('; while (len--) { *dst = isprint((unsigned char)*src) ? *src : '?'; src++; dst++; } *dst++ = ')'; } *dst = 0; syslog(LOG_WARNING, "Server returned %s status '%s %s'", scope, dhcpv6_status_code_to_str(code), buf); } static void dhcpv6_handle_status_code(const enum dhcpv6_msg orig, const uint16_t code, const void *status_msg, const int len, int *ret) { dhcpv6_log_status_code(code, "message", status_msg, len); switch (code) { case DHCPV6_UnspecFail: // Generic failure *ret = 0; break; case DHCPV6_UseMulticast: switch(orig) { case DHCPV6_MSG_REQUEST: case DHCPV6_MSG_RENEW: case DHCPV6_MSG_RELEASE: case DHCPV6_MSG_DECLINE: // Message needs to be retransmitted according to RFC3315 chapter 18.1.8 server_addr = in6addr_any; *ret = 0; break; default: break; } break; case DHCPV6_NoAddrsAvail: case DHCPV6_NoPrefixAvail: if (orig == DHCPV6_MSG_REQUEST) *ret = 0; // Failure break; default: break; } } static void dhcpv6_handle_ia_status_code(const enum dhcpv6_msg orig, const struct dhcpv6_ia_hdr *ia_hdr, const uint16_t code, const void *status_msg, const int len, bool handled_status_codes[_DHCPV6_Status_Max], int *ret) { dhcpv6_log_status_code(code, ia_hdr->type == DHCPV6_OPT_IA_NA ? "IA_NA" : "IA_PD", status_msg, len); switch (code) { case DHCPV6_NoBinding: switch (orig) { case DHCPV6_MSG_RENEW: case DHCPV6_MSG_REBIND: if ((*ret > 0) && !handled_status_codes[code]) *ret = dhcpv6_request(DHCPV6_MSG_REQUEST); break; default: break; } break; default: *ret = 0; break; } } // Note this always takes ownership of cand->ia_na and cand->ia_pd static void dhcpv6_add_server_cand(const struct dhcpv6_server_cand *cand) { size_t cand_len, i; struct dhcpv6_server_cand *c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len); // Remove identical duid server candidate for (i = 0; i < cand_len / sizeof(*c); ++i) { if (cand->duid_len == c[i].duid_len && !memcmp(cand->duid, c[i].duid, cand->duid_len)) { free(c[i].ia_na); free(c[i].ia_pd); odhcp6c_remove_state(STATE_SERVER_CAND, i * sizeof(*c), sizeof(*c)); break; } } for (i = 0, c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len); i < cand_len / sizeof(*c); ++i) { if (c[i].preference < cand->preference) break; } if (odhcp6c_insert_state(STATE_SERVER_CAND, i * sizeof(*c), cand, sizeof(*cand))) { free(cand->ia_na); free(cand->ia_pd); } } static void dhcpv6_clear_all_server_cand(void) { size_t cand_len, i; struct dhcpv6_server_cand *c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len); // Server candidates need deep delete for IA_NA/IA_PD for (i = 0; i < cand_len / sizeof(*c); ++i) { free(c[i].ia_na); free(c[i].ia_pd); } odhcp6c_clear_state(STATE_SERVER_CAND); } int dhcpv6_promote_server_cand(void) { size_t cand_len; struct dhcpv6_server_cand *cand = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len); uint16_t hdr[2]; int ret = DHCPV6_STATELESS; // Clear lingering candidate state info odhcp6c_clear_state(STATE_SERVER_ID); odhcp6c_clear_state(STATE_IA_NA); odhcp6c_clear_state(STATE_IA_PD); if (!cand_len) return -1; if (cand->has_noaddravail && na_mode == IA_MODE_TRY) { na_mode = IA_MODE_NONE; dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = cand->sol_max_rt; dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = cand->inf_max_rt; return dhcpv6_request(DHCPV6_MSG_SOLICIT); } hdr[0] = htons(DHCPV6_OPT_SERVERID); hdr[1] = htons(cand->duid_len); odhcp6c_add_state(STATE_SERVER_ID, hdr, sizeof(hdr)); odhcp6c_add_state(STATE_SERVER_ID, cand->duid, cand->duid_len); accept_reconfig = cand->wants_reconfigure; if (cand->ia_na_len) { odhcp6c_add_state(STATE_IA_NA, cand->ia_na, cand->ia_na_len); free(cand->ia_na); if (na_mode != IA_MODE_NONE) ret = DHCPV6_STATEFUL; } if (cand->ia_pd_len) { odhcp6c_add_state(STATE_IA_PD, cand->ia_pd, cand->ia_pd_len); free(cand->ia_pd); if (pd_mode != IA_MODE_NONE) ret = DHCPV6_STATEFUL; } dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = cand->sol_max_rt; dhcpv6_retx[DHCPV6_MSG_INFO_REQ].max_timeo = cand->inf_max_rt; odhcp6c_remove_state(STATE_SERVER_CAND, 0, sizeof(*cand)); return ret; }