X-Git-Url: https://git.decadent.org.uk/gitweb/?a=blobdiff_plain;f=src%2Fdhcpv6.c;h=75bc50e84e89f641f0b6f450650f86c60f1b83b3;hb=26c5d8724355b29694af684ee29b47e52129a33c;hp=9b03227e0482352476ba497f7f4fabb4bc90033c;hpb=7ea97a433c3ce62dab3d99f6dbe72a6cb319cd44;p=odhcp6c.git diff --git a/src/dhcpv6.c b/src/dhcpv6.c index 9b03227..75bc50e 100644 --- a/src/dhcpv6.c +++ b/src/dhcpv6.c @@ -26,6 +26,7 @@ #include #include #include +#include #include #include @@ -58,6 +59,8 @@ static void dhcpv6_handle_ia_status_code(const enum dhcpv6_msg orig, 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; @@ -95,6 +98,8 @@ static int64_t t1 = 0, t2 = 0, t3 = 0; static int request_prefix = -1; 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]; @@ -142,6 +147,7 @@ int init_dhcpv6(const char *ifname, int request_pd, int sol_timeout) sizeof(ifr.ifr_name)); if (ioctl(sock, SIOCGIFHWADDR, &ifr) < 0) continue; + memcpy(&duid[8], ifr.ifr_hwaddr.sa_data, ETHER_ADDR_LEN); } @@ -156,6 +162,7 @@ int init_dhcpv6(const char *ifname, int request_pd, int sol_timeout) htons(DHCPV6_OPT_SIP_SERVER_A), htons(DHCPV6_OPT_DNS_SERVERS), htons(DHCPV6_OPT_DNS_DOMAIN), + htons(DHCPV6_OPT_UNICAST), htons(DHCPV6_OPT_NTP_SERVER), htons(DHCPV6_OPT_AFTR_NAME), htons(DHCPV6_OPT_PD_EXCLUDE), @@ -165,31 +172,21 @@ int init_dhcpv6(const char *ifname, int request_pd, int sol_timeout) }; odhcp6c_add_state(STATE_ORO, oro, sizeof(oro)); - do { - // Configure IPv6-options - int val = 1; - if (setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY, &val, sizeof(val)) < 0) - break; - if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(val)) < 0) - break; - if (setsockopt(sock, IPPROTO_IPV6, IPV6_RECVPKTINFO, &val, sizeof(val)) < 0) - break; - - val = 0; - if (setsockopt(sock, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &val, sizeof(val)) < 0) - break; - if (setsockopt(sock, SOL_SOCKET, SO_BINDTODEVICE, ifname, strlen(ifname)) < 0) - break; - - 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) - break; - - return 0; - } while (0); + // Configure IPv6-options + int val = 1; + setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY, &val, sizeof(val)); + setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(val)); + setsockopt(sock, IPPROTO_IPV6, IPV6_RECVPKTINFO, &val, sizeof(val)); + val = 0; + setsockopt(sock, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &val, sizeof(val)); + setsockopt(sock, SOL_SOCKET, SO_BINDTODEVICE, ifname, strlen(ifname)); + + 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) + return -1; - return -1; + return 0; } @@ -371,7 +368,29 @@ static void dhcpv6_send(enum dhcpv6_msg type, uint8_t trid[3], uint32_t ecs) 0, ALL_DHCPV6_RELAYS, ifindex}; struct msghdr msg = {&srv, sizeof(srv), iov, cnt, NULL, 0, 0}; - sendmsg(sock, &msg, 0); + 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 DHCPV6 message to %s (%s)", + inet_ntop(AF_INET6, (const void *)&srv.sin6_addr, + in6_str, sizeof(in6_str)), strerror(errno)); + } } @@ -452,7 +471,7 @@ int dhcpv6_request(enum dhcpv6_msg type) } // Receive rounds - for (; len < 0 && round_start < round_end; + for (; len < 0 && (round_start < round_end); round_start = odhcp6c_get_milli_time()) { uint8_t buf[1536], cmsg_buf[CMSG_SPACE(sizeof(struct in6_pktinfo))]; struct iovec iov = {buf, sizeof(buf)}; @@ -550,7 +569,11 @@ static bool dhcpv6_response_is_valid(const void *buf, ssize_t 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) { + if ((odata + olen) > end) { + options_valid = false; + break; + } + else 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) { @@ -653,7 +676,8 @@ static int dhcpv6_handle_advert(enum dhcpv6_msg orig, const int rc, { uint16_t olen, otype; uint8_t *odata, pref = 0; - struct dhcpv6_server_cand cand = {false, false, 0, 0, {0}, NULL, NULL, 0, 0}; + struct dhcpv6_server_cand cand = {false, false, 0, 0, {0}, + IN6ADDR_ANY_INIT, NULL, NULL, 0, 0}; bool have_na = false; int have_pd = 0; @@ -691,6 +715,8 @@ static int dhcpv6_handle_advert(enum dhcpv6_msg orig, const int rc, } 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)) { + cand.server_addr = *(struct in6_addr *)odata; } else if (otype == DHCPV6_OPT_RECONF_ACCEPT) { cand.wants_reconfigure = true; } else if (otype == DHCPV6_OPT_IA_PD && request_prefix) { @@ -731,7 +757,7 @@ static int dhcpv6_handle_advert(enum dhcpv6_msg orig, const int rc, 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); - odhcp6c_add_state(STATE_SERVER_CAND, &cand, sizeof(cand)); + dhcpv6_add_server_cand(&cand); } return (rc > 1 || (pref == 255 && cand.preference > 0)) ? 1 : -1; @@ -740,49 +766,7 @@ static int dhcpv6_handle_advert(enum dhcpv6_msg orig, const int rc, static int dhcpv6_commit_advert(void) { - size_t cand_len; - struct dhcpv6_server_cand *c = NULL, *cand = - odhcp6c_get_state(STATE_SERVER_CAND, &cand_len); - - bool retry = false; - for (size_t i = 0; i < cand_len / sizeof(*c); ++i) { - if (cand[i].has_noaddravail) - retry = true; // We want to try again - - if (!c || c->preference < cand[i].preference) - c = &cand[i]; - } - - if (retry && na_mode == IA_MODE_TRY) { - // We give it a second try without the IA_NA - na_mode = IA_MODE_NONE; - return dhcpv6_request(DHCPV6_MSG_SOLICIT); - } - - if (c) { - uint16_t hdr[2] = {htons(DHCPV6_OPT_SERVERID), - htons(c->duid_len)}; - odhcp6c_add_state(STATE_SERVER_ID, hdr, sizeof(hdr)); - odhcp6c_add_state(STATE_SERVER_ID, c->duid, c->duid_len); - accept_reconfig = c->wants_reconfigure; - if (c->ia_na_len) - odhcp6c_add_state(STATE_IA_NA, c->ia_na, c->ia_na_len); - if (c->ia_pd_len) - odhcp6c_add_state(STATE_IA_PD, c->ia_pd, c->ia_pd_len); - } - - for (size_t i = 0; i < cand_len / sizeof(*c); ++i) { - free(cand[i].ia_na); - free(cand[i].ia_pd); - } - odhcp6c_clear_state(STATE_SERVER_CAND); - - if (!c) - return -1; - else if ((request_prefix && c->ia_pd_len) || (na_mode != IA_MODE_NONE && c->ia_na_len)) - return DHCPV6_STATEFUL; - else - return DHCPV6_STATELESS; + return dhcpv6_promote_server_cand(); } @@ -884,6 +868,8 @@ static int dhcpv6_handle_reply(enum dhcpv6_msg orig, _unused const int rc, continue; dhcpv6_parse_ia(ia_hdr, odata + olen + sizeof(*ia_hdr)); + } else if (otype == DHCPV6_OPT_UNICAST && olen == sizeof(server_addr)) { + 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; @@ -950,13 +936,23 @@ static int dhcpv6_handle_reply(enum dhcpv6_msg orig, _unused const int rc, ret = -1; break; + case DHCPV6_MSG_REQUEST: + // All server candidates can be cleared if not yet bound + if (!odhcp6c_is_bound()) + dhcpv6_clear_all_server_cand(); + default : break; } } } - else if (ret > 0) + else if (ret > 0) { + // All server candidates can be cleared if not yet bound + if (!odhcp6c_is_bound()) + dhcpv6_clear_all_server_cand(); + t1 = refresh; + } return ret; } @@ -1163,7 +1159,18 @@ static void dhcpv6_handle_status_code(const enum dhcpv6_msg orig, break; case DHCPV6_UseMulticast: - // TODO handle multicast status code + 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: @@ -1220,3 +1227,86 @@ static void dhcpv6_handle_ia_status_code(const enum dhcpv6_msg orig, break; } } + +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; + } + + odhcp6c_insert_state(STATE_SERVER_CAND, i * sizeof(*c), cand, sizeof(*cand)); +} + +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) { + if (c[i].ia_na) + free(c[i].ia_na); + if (c[i].ia_pd) + 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; + 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 (request_prefix) + ret = DHCPV6_STATEFUL; + } + + odhcp6c_remove_state(STATE_SERVER_CAND, 0, sizeof(*cand)); + + return ret; +}