/* SPDX-License-Identifier: LGPL-2.1+ */ /*** Copyright © 2014-2015 Intel Corporation. All rights reserved. ***/ #include #include #include #include #include "sd-dhcp6-client.h" #include "alloc-util.h" #include "dhcp-identifier.h" #include "dhcp6-internal.h" #include "dhcp6-lease-internal.h" #include "dhcp6-protocol.h" #include "dns-domain.h" #include "event-util.h" #include "fd-util.h" #include "hostname-util.h" #include "in-addr-util.h" #include "network-internal.h" #include "random-util.h" #include "socket-util.h" #include "string-table.h" #include "util.h" #define MAX_MAC_ADDR_LEN INFINIBAND_ALEN /* what to request from the server, addresses (IA_NA) and/or prefixes (IA_PD) */ enum { DHCP6_REQUEST_IA_NA = 1, DHCP6_REQUEST_IA_TA = 2, /* currently not used */ DHCP6_REQUEST_IA_PD = 4, }; struct sd_dhcp6_client { unsigned n_ref; enum DHCP6State state; sd_event *event; int event_priority; int ifindex; struct in6_addr local_address; uint8_t mac_addr[MAX_MAC_ADDR_LEN]; size_t mac_addr_len; uint16_t arp_type; DHCP6IA ia_na; DHCP6IA ia_pd; sd_event_source *timeout_t1; sd_event_source *timeout_t2; unsigned request; be32_t transaction_id; usec_t transaction_start; struct sd_dhcp6_lease *lease; int fd; bool information_request; bool iaid_set; be16_t *req_opts; size_t req_opts_allocated; size_t req_opts_len; char *fqdn; sd_event_source *receive_message; usec_t retransmit_time; uint8_t retransmit_count; sd_event_source *timeout_resend; sd_event_source *timeout_resend_expire; sd_dhcp6_client_callback_t callback; void *userdata; struct duid duid; size_t duid_len; }; static const uint16_t default_req_opts[] = { SD_DHCP6_OPTION_DNS_SERVERS, SD_DHCP6_OPTION_DOMAIN_LIST, SD_DHCP6_OPTION_NTP_SERVER, SD_DHCP6_OPTION_SNTP_SERVERS, }; const char * dhcp6_message_type_table[_DHCP6_MESSAGE_MAX] = { [DHCP6_SOLICIT] = "SOLICIT", [DHCP6_ADVERTISE] = "ADVERTISE", [DHCP6_REQUEST] = "REQUEST", [DHCP6_CONFIRM] = "CONFIRM", [DHCP6_RENEW] = "RENEW", [DHCP6_REBIND] = "REBIND", [DHCP6_REPLY] = "REPLY", [DHCP6_RELEASE] = "RELEASE", [DHCP6_DECLINE] = "DECLINE", [DHCP6_RECONFIGURE] = "RECONFIGURE", [DHCP6_INFORMATION_REQUEST] = "INFORMATION-REQUEST", [DHCP6_RELAY_FORW] = "RELAY-FORW", [DHCP6_RELAY_REPL] = "RELAY-REPL", }; DEFINE_STRING_TABLE_LOOKUP(dhcp6_message_type, int); const char * dhcp6_message_status_table[_DHCP6_STATUS_MAX] = { [DHCP6_STATUS_SUCCESS] = "Success", [DHCP6_STATUS_UNSPEC_FAIL] = "Unspecified failure", [DHCP6_STATUS_NO_ADDRS_AVAIL] = "No addresses available", [DHCP6_STATUS_NO_BINDING] = "Binding unavailable", [DHCP6_STATUS_NOT_ON_LINK] = "Not on link", [DHCP6_STATUS_USE_MULTICAST] = "Use multicast", }; DEFINE_STRING_TABLE_LOOKUP(dhcp6_message_status, int); #define DHCP6_CLIENT_DONT_DESTROY(client) \ _cleanup_(sd_dhcp6_client_unrefp) _unused_ sd_dhcp6_client *_dont_destroy_##client = sd_dhcp6_client_ref(client) static int client_start(sd_dhcp6_client *client, enum DHCP6State state); int sd_dhcp6_client_set_callback( sd_dhcp6_client *client, sd_dhcp6_client_callback_t cb, void *userdata) { assert_return(client, -EINVAL); client->callback = cb; client->userdata = userdata; return 0; } int sd_dhcp6_client_set_ifindex(sd_dhcp6_client *client, int ifindex) { assert_return(client, -EINVAL); assert_return(ifindex >= -1, -EINVAL); assert_return(IN_SET(client->state, DHCP6_STATE_STOPPED), -EBUSY); client->ifindex = ifindex; return 0; } int sd_dhcp6_client_set_local_address( sd_dhcp6_client *client, const struct in6_addr *local_address) { assert_return(client, -EINVAL); assert_return(local_address, -EINVAL); assert_return(in_addr_is_link_local(AF_INET6, (const union in_addr_union *) local_address) > 0, -EINVAL); assert_return(IN_SET(client->state, DHCP6_STATE_STOPPED), -EBUSY); client->local_address = *local_address; return 0; } int sd_dhcp6_client_set_mac( sd_dhcp6_client *client, const uint8_t *addr, size_t addr_len, uint16_t arp_type) { assert_return(client, -EINVAL); assert_return(addr, -EINVAL); assert_return(addr_len > 0 && addr_len <= MAX_MAC_ADDR_LEN, -EINVAL); assert_return(arp_type > 0, -EINVAL); assert_return(IN_SET(client->state, DHCP6_STATE_STOPPED), -EBUSY); if (arp_type == ARPHRD_ETHER) assert_return(addr_len == ETH_ALEN, -EINVAL); else if (arp_type == ARPHRD_INFINIBAND) assert_return(addr_len == INFINIBAND_ALEN, -EINVAL); else return -EINVAL; if (client->mac_addr_len == addr_len && memcmp(&client->mac_addr, addr, addr_len) == 0) return 0; memcpy(&client->mac_addr, addr, addr_len); client->mac_addr_len = addr_len; client->arp_type = arp_type; return 0; } static int client_ensure_duid(sd_dhcp6_client *client) { if (client->duid_len != 0) return 0; return dhcp_identifier_set_duid_en(&client->duid, &client->duid_len); } /** * Sets DUID. If duid is non-null, the DUID is set to duid_type + duid * without further modification. Otherwise, if duid_type is supported, DUID * is set based on that type. Otherwise, an error is returned. */ static int dhcp6_client_set_duid_internal( sd_dhcp6_client *client, uint16_t duid_type, const void *duid, size_t duid_len, usec_t llt_time) { int r; assert_return(client, -EINVAL); assert_return(duid_len == 0 || duid != NULL, -EINVAL); assert_return(IN_SET(client->state, DHCP6_STATE_STOPPED), -EBUSY); if (duid != NULL) { r = dhcp_validate_duid_len(duid_type, duid_len, true); if (r < 0) { r = dhcp_validate_duid_len(duid_type, duid_len, false); if (r < 0) return r; log_dhcp6_client(client, "Setting DUID of type %u with unexpected content", duid_type); } client->duid.type = htobe16(duid_type); memcpy(&client->duid.raw.data, duid, duid_len); client->duid_len = sizeof(client->duid.type) + duid_len; } else switch (duid_type) { case DUID_TYPE_LLT: if (client->mac_addr_len == 0) return -EOPNOTSUPP; r = dhcp_identifier_set_duid_llt(&client->duid, llt_time, client->mac_addr, client->mac_addr_len, client->arp_type, &client->duid_len); if (r < 0) return r; break; case DUID_TYPE_EN: r = dhcp_identifier_set_duid_en(&client->duid, &client->duid_len); if (r < 0) return r; break; case DUID_TYPE_LL: if (client->mac_addr_len == 0) return -EOPNOTSUPP; r = dhcp_identifier_set_duid_ll(&client->duid, client->mac_addr, client->mac_addr_len, client->arp_type, &client->duid_len); if (r < 0) return r; break; case DUID_TYPE_UUID: r = dhcp_identifier_set_duid_uuid(&client->duid, &client->duid_len); if (r < 0) return r; break; default: return -EINVAL; } return 0; } int sd_dhcp6_client_set_duid( sd_dhcp6_client *client, uint16_t duid_type, const void *duid, size_t duid_len) { return dhcp6_client_set_duid_internal(client, duid_type, duid, duid_len, 0); } int sd_dhcp6_client_set_duid_llt( sd_dhcp6_client *client, usec_t llt_time) { return dhcp6_client_set_duid_internal(client, DUID_TYPE_LLT, NULL, 0, llt_time); } int sd_dhcp6_client_set_iaid(sd_dhcp6_client *client, uint32_t iaid) { assert_return(client, -EINVAL); assert_return(IN_SET(client->state, DHCP6_STATE_STOPPED), -EBUSY); client->ia_na.ia_na.id = htobe32(iaid); client->ia_pd.ia_pd.id = htobe32(iaid); client->iaid_set = true; return 0; } int sd_dhcp6_client_set_fqdn( sd_dhcp6_client *client, const char *fqdn) { assert_return(client, -EINVAL); /* Make sure FQDN qualifies as DNS and as Linux hostname */ if (fqdn && !(hostname_is_valid(fqdn, false) && dns_name_is_valid(fqdn) > 0)) return -EINVAL; return free_and_strdup(&client->fqdn, fqdn); } int sd_dhcp6_client_set_information_request(sd_dhcp6_client *client, int enabled) { assert_return(client, -EINVAL); assert_return(IN_SET(client->state, DHCP6_STATE_STOPPED), -EBUSY); client->information_request = enabled; return 0; } int sd_dhcp6_client_get_information_request(sd_dhcp6_client *client, int *enabled) { assert_return(client, -EINVAL); assert_return(enabled, -EINVAL); *enabled = client->information_request; return 0; } int sd_dhcp6_client_set_request_option(sd_dhcp6_client *client, uint16_t option) { size_t t; assert_return(client, -EINVAL); assert_return(client->state == DHCP6_STATE_STOPPED, -EBUSY); switch(option) { case SD_DHCP6_OPTION_DNS_SERVERS: case SD_DHCP6_OPTION_DOMAIN_LIST: case SD_DHCP6_OPTION_SNTP_SERVERS: case SD_DHCP6_OPTION_NTP_SERVER: case SD_DHCP6_OPTION_RAPID_COMMIT: break; default: return -EINVAL; } for (t = 0; t < client->req_opts_len; t++) if (client->req_opts[t] == htobe16(option)) return -EEXIST; if (!GREEDY_REALLOC(client->req_opts, client->req_opts_allocated, client->req_opts_len + 1)) return -ENOMEM; client->req_opts[client->req_opts_len++] = htobe16(option); return 0; } int sd_dhcp6_client_get_prefix_delegation(sd_dhcp6_client *client, int *delegation) { assert_return(client, -EINVAL); assert_return(delegation, -EINVAL); *delegation = FLAGS_SET(client->request, DHCP6_REQUEST_IA_PD); return 0; } int sd_dhcp6_client_set_prefix_delegation(sd_dhcp6_client *client, int delegation) { assert_return(client, -EINVAL); SET_FLAG(client->request, DHCP6_REQUEST_IA_PD, delegation); return 0; } int sd_dhcp6_client_get_address_request(sd_dhcp6_client *client, int *request) { assert_return(client, -EINVAL); assert_return(request, -EINVAL); *request = FLAGS_SET(client->request, DHCP6_REQUEST_IA_NA); return 0; } int sd_dhcp6_client_set_address_request(sd_dhcp6_client *client, int request) { assert_return(client, -EINVAL); SET_FLAG(client->request, DHCP6_REQUEST_IA_NA, request); return 0; } int sd_dhcp6_client_set_transaction_id(sd_dhcp6_client *client, uint32_t transaction_id) { assert_return(client, -EINVAL); client->transaction_id = transaction_id; return 0; } int sd_dhcp6_client_get_lease(sd_dhcp6_client *client, sd_dhcp6_lease **ret) { assert_return(client, -EINVAL); if (!client->lease) return -ENOMSG; if (ret) *ret = client->lease; return 0; } static void client_notify(sd_dhcp6_client *client, int event) { assert(client); if (client->callback) client->callback(client, event, client->userdata); } static int client_reset(sd_dhcp6_client *client) { assert(client); client->lease = sd_dhcp6_lease_unref(client->lease); client->receive_message = sd_event_source_unref(client->receive_message); client->transaction_id = 0; client->transaction_start = 0; client->retransmit_time = 0; client->retransmit_count = 0; (void) event_source_disable(client->timeout_resend); (void) event_source_disable(client->timeout_resend_expire); (void) event_source_disable(client->timeout_t1); (void) event_source_disable(client->timeout_t2); client->state = DHCP6_STATE_STOPPED; return 0; } static void client_stop(sd_dhcp6_client *client, int error) { DHCP6_CLIENT_DONT_DESTROY(client); assert(client); client_notify(client, error); client_reset(client); } static int client_send_message(sd_dhcp6_client *client, usec_t time_now) { _cleanup_free_ DHCP6Message *message = NULL; struct in6_addr all_servers = IN6ADDR_ALL_DHCP6_RELAY_AGENTS_AND_SERVERS_INIT; size_t len, optlen = 512; uint8_t *opt; int r; usec_t elapsed_usec; be16_t elapsed_time; assert(client); len = sizeof(DHCP6Message) + optlen; message = malloc0(len); if (!message) return -ENOMEM; opt = (uint8_t *)(message + 1); message->transaction_id = client->transaction_id; switch(client->state) { case DHCP6_STATE_INFORMATION_REQUEST: message->type = DHCP6_INFORMATION_REQUEST; break; case DHCP6_STATE_SOLICITATION: message->type = DHCP6_SOLICIT; r = dhcp6_option_append(&opt, &optlen, SD_DHCP6_OPTION_RAPID_COMMIT, 0, NULL); if (r < 0) return r; if (FLAGS_SET(client->request, DHCP6_REQUEST_IA_NA)) { r = dhcp6_option_append_ia(&opt, &optlen, &client->ia_na); if (r < 0) return r; } if (client->fqdn) { r = dhcp6_option_append_fqdn(&opt, &optlen, client->fqdn); if (r < 0) return r; } if (FLAGS_SET(client->request, DHCP6_REQUEST_IA_PD)) { r = dhcp6_option_append_pd(opt, optlen, &client->ia_pd); if (r < 0) return r; opt += r; optlen -= r; } break; case DHCP6_STATE_REQUEST: case DHCP6_STATE_RENEW: if (client->state == DHCP6_STATE_REQUEST) message->type = DHCP6_REQUEST; else message->type = DHCP6_RENEW; r = dhcp6_option_append(&opt, &optlen, SD_DHCP6_OPTION_SERVERID, client->lease->serverid_len, client->lease->serverid); if (r < 0) return r; if (FLAGS_SET(client->request, DHCP6_REQUEST_IA_NA)) { r = dhcp6_option_append_ia(&opt, &optlen, &client->lease->ia); if (r < 0) return r; } if (client->fqdn) { r = dhcp6_option_append_fqdn(&opt, &optlen, client->fqdn); if (r < 0) return r; } if (FLAGS_SET(client->request, DHCP6_REQUEST_IA_PD)) { r = dhcp6_option_append_pd(opt, optlen, &client->lease->pd); if (r < 0) return r; opt += r; optlen -= r; } break; case DHCP6_STATE_REBIND: message->type = DHCP6_REBIND; if (FLAGS_SET(client->request, DHCP6_REQUEST_IA_NA)) { r = dhcp6_option_append_ia(&opt, &optlen, &client->lease->ia); if (r < 0) return r; } if (client->fqdn) { r = dhcp6_option_append_fqdn(&opt, &optlen, client->fqdn); if (r < 0) return r; } if (FLAGS_SET(client->request, DHCP6_REQUEST_IA_PD)) { r = dhcp6_option_append_pd(opt, optlen, &client->lease->pd); if (r < 0) return r; opt += r; optlen -= r; } break; case DHCP6_STATE_STOPPED: case DHCP6_STATE_BOUND: return -EINVAL; } r = dhcp6_option_append(&opt, &optlen, SD_DHCP6_OPTION_ORO, client->req_opts_len * sizeof(be16_t), client->req_opts); if (r < 0) return r; assert(client->duid_len); r = dhcp6_option_append(&opt, &optlen, SD_DHCP6_OPTION_CLIENTID, client->duid_len, &client->duid); if (r < 0) return r; elapsed_usec = time_now - client->transaction_start; if (elapsed_usec < 0xffff * USEC_PER_MSEC * 10) elapsed_time = htobe16(elapsed_usec / USEC_PER_MSEC / 10); else elapsed_time = 0xffff; r = dhcp6_option_append(&opt, &optlen, SD_DHCP6_OPTION_ELAPSED_TIME, sizeof(elapsed_time), &elapsed_time); if (r < 0) return r; r = dhcp6_network_send_udp_socket(client->fd, &all_servers, message, len - optlen); if (r < 0) return r; log_dhcp6_client(client, "Sent %s", dhcp6_message_type_to_string(message->type)); return 0; } static int client_timeout_t2(sd_event_source *s, uint64_t usec, void *userdata) { sd_dhcp6_client *client = userdata; assert(s); assert(client); assert(client->lease); (void) event_source_disable(client->timeout_t2); log_dhcp6_client(client, "Timeout T2"); client_start(client, DHCP6_STATE_REBIND); return 0; } static int client_timeout_t1(sd_event_source *s, uint64_t usec, void *userdata) { sd_dhcp6_client *client = userdata; assert(s); assert(client); assert(client->lease); (void) event_source_disable(client->timeout_t1); log_dhcp6_client(client, "Timeout T1"); client_start(client, DHCP6_STATE_RENEW); return 0; } static int client_timeout_resend_expire(sd_event_source *s, uint64_t usec, void *userdata) { sd_dhcp6_client *client = userdata; DHCP6_CLIENT_DONT_DESTROY(client); enum DHCP6State state; assert(s); assert(client); assert(client->event); state = client->state; client_stop(client, SD_DHCP6_CLIENT_EVENT_RESEND_EXPIRE); /* RFC 3315, section 18.1.4., says that "...the client may choose to use a Solicit message to locate a new DHCP server..." */ if (state == DHCP6_STATE_REBIND) client_start(client, DHCP6_STATE_SOLICITATION); return 0; } static usec_t client_timeout_compute_random(usec_t val) { return val - val / 10 + (random_u32() % (2 * USEC_PER_SEC)) * val / 10 / USEC_PER_SEC; } static int client_timeout_resend(sd_event_source *s, uint64_t usec, void *userdata) { int r = 0; sd_dhcp6_client *client = userdata; usec_t time_now, init_retransmit_time = 0, max_retransmit_time = 0; usec_t max_retransmit_duration = 0; uint8_t max_retransmit_count = 0; char time_string[FORMAT_TIMESPAN_MAX]; uint32_t expire = 0; assert(s); assert(client); assert(client->event); (void) event_source_disable(client->timeout_resend); switch (client->state) { case DHCP6_STATE_INFORMATION_REQUEST: init_retransmit_time = DHCP6_INF_TIMEOUT; max_retransmit_time = DHCP6_INF_MAX_RT; break; case DHCP6_STATE_SOLICITATION: if (client->retransmit_count && client->lease) { client_start(client, DHCP6_STATE_REQUEST); return 0; } init_retransmit_time = DHCP6_SOL_TIMEOUT; max_retransmit_time = DHCP6_SOL_MAX_RT; break; case DHCP6_STATE_REQUEST: init_retransmit_time = DHCP6_REQ_TIMEOUT; max_retransmit_time = DHCP6_REQ_MAX_RT; max_retransmit_count = DHCP6_REQ_MAX_RC; break; case DHCP6_STATE_RENEW: init_retransmit_time = DHCP6_REN_TIMEOUT; max_retransmit_time = DHCP6_REN_MAX_RT; /* RFC 3315, section 18.1.3. says max retransmit duration will be the remaining time until T2. Instead of setting MRD, wait for T2 to trigger with the same end result */ break; case DHCP6_STATE_REBIND: init_retransmit_time = DHCP6_REB_TIMEOUT; max_retransmit_time = DHCP6_REB_MAX_RT; if (event_source_is_enabled(client->timeout_resend_expire) <= 0) { r = dhcp6_lease_ia_rebind_expire(&client->lease->ia, &expire); if (r < 0) { client_stop(client, r); return 0; } max_retransmit_duration = expire * USEC_PER_SEC; } break; case DHCP6_STATE_STOPPED: case DHCP6_STATE_BOUND: return 0; } if (max_retransmit_count && client->retransmit_count >= max_retransmit_count) { client_stop(client, SD_DHCP6_CLIENT_EVENT_RETRANS_MAX); return 0; } r = sd_event_now(client->event, clock_boottime_or_monotonic(), &time_now); if (r < 0) goto error; r = client_send_message(client, time_now); if (r >= 0) client->retransmit_count++; if (!client->retransmit_time) { client->retransmit_time = client_timeout_compute_random(init_retransmit_time); if (client->state == DHCP6_STATE_SOLICITATION) client->retransmit_time += init_retransmit_time / 10; } else { if (max_retransmit_time && client->retransmit_time > max_retransmit_time / 2) client->retransmit_time = client_timeout_compute_random(max_retransmit_time); else client->retransmit_time += client_timeout_compute_random(client->retransmit_time); } log_dhcp6_client(client, "Next retransmission in %s", format_timespan(time_string, FORMAT_TIMESPAN_MAX, client->retransmit_time, USEC_PER_SEC)); r = event_reset_time(client->event, &client->timeout_resend, clock_boottime_or_monotonic(), time_now + client->retransmit_time, 10 * USEC_PER_MSEC, client_timeout_resend, client, client->event_priority, "dhcp6-resend-timer", true); if (r < 0) goto error; if (max_retransmit_duration && event_source_is_enabled(client->timeout_resend_expire) <= 0) { log_dhcp6_client(client, "Max retransmission duration %"PRIu64" secs", max_retransmit_duration / USEC_PER_SEC); r = event_reset_time(client->event, &client->timeout_resend_expire, clock_boottime_or_monotonic(), time_now + max_retransmit_duration, USEC_PER_SEC, client_timeout_resend_expire, client, client->event_priority, "dhcp6-resend-expire-timer", true); if (r < 0) goto error; } error: if (r < 0) client_stop(client, r); return 0; } static int client_ensure_iaid(sd_dhcp6_client *client) { int r; uint32_t iaid; assert(client); if (client->iaid_set) return 0; r = dhcp_identifier_set_iaid(client->ifindex, client->mac_addr, client->mac_addr_len, true, &iaid); if (r < 0) return r; client->ia_na.ia_na.id = iaid; client->ia_pd.ia_pd.id = iaid; client->iaid_set = true; return 0; } static int client_parse_message( sd_dhcp6_client *client, DHCP6Message *message, size_t len, sd_dhcp6_lease *lease) { uint32_t lt_t1 = ~0, lt_t2 = ~0; bool clientid = false; size_t pos = 0; int r; assert(client); assert(message); assert(len >= sizeof(DHCP6Message)); assert(lease); len -= sizeof(DHCP6Message); while (pos < len) { DHCP6Option *option = (DHCP6Option *) &message->options[pos]; uint16_t optcode, optlen; be32_t iaid_lease; uint8_t *optval; int status; if (len < pos + offsetof(DHCP6Option, data)) return -ENOBUFS; optcode = be16toh(option->code); optlen = be16toh(option->len); optval = option->data; if (len < pos + offsetof(DHCP6Option, data) + optlen) return -ENOBUFS; switch (optcode) { case SD_DHCP6_OPTION_CLIENTID: if (clientid) { log_dhcp6_client(client, "%s contains multiple clientids", dhcp6_message_type_to_string(message->type)); return -EINVAL; } if (optlen != client->duid_len || memcmp(&client->duid, optval, optlen) != 0) { log_dhcp6_client(client, "%s DUID does not match", dhcp6_message_type_to_string(message->type)); return -EINVAL; } clientid = true; break; case SD_DHCP6_OPTION_SERVERID: r = dhcp6_lease_get_serverid(lease, NULL, NULL); if (r >= 0) { log_dhcp6_client(client, "%s contains multiple serverids", dhcp6_message_type_to_string(message->type)); return -EINVAL; } r = dhcp6_lease_set_serverid(lease, optval, optlen); if (r < 0) return r; break; case SD_DHCP6_OPTION_PREFERENCE: if (optlen != 1) return -EINVAL; r = dhcp6_lease_set_preference(lease, optval[0]); if (r < 0) return r; break; case SD_DHCP6_OPTION_STATUS_CODE: status = dhcp6_option_parse_status(option, optlen + sizeof(DHCP6Option)); if (status < 0) return status; if (status > 0) { log_dhcp6_client(client, "%s Status %s", dhcp6_message_type_to_string(message->type), dhcp6_message_status_to_string(status)); return -EINVAL; } break; case SD_DHCP6_OPTION_IA_NA: if (client->state == DHCP6_STATE_INFORMATION_REQUEST) { log_dhcp6_client(client, "Information request ignoring IA NA option"); break; } r = dhcp6_option_parse_ia(option, &lease->ia); if (r < 0 && r != -ENOMSG) return r; r = dhcp6_lease_get_iaid(lease, &iaid_lease); if (r < 0) return r; if (client->ia_na.ia_na.id != iaid_lease) { log_dhcp6_client(client, "%s has wrong IAID for IA NA", dhcp6_message_type_to_string(message->type)); return -EINVAL; } if (lease->ia.addresses) { lt_t1 = MIN(lt_t1, be32toh(lease->ia.ia_na.lifetime_t1)); lt_t2 = MIN(lt_t2, be32toh(lease->ia.ia_na.lifetime_t1)); } break; case SD_DHCP6_OPTION_IA_PD: if (client->state == DHCP6_STATE_INFORMATION_REQUEST) { log_dhcp6_client(client, "Information request ignoring IA PD option"); break; } r = dhcp6_option_parse_ia(option, &lease->pd); if (r < 0 && r != -ENOMSG) return r; r = dhcp6_lease_get_pd_iaid(lease, &iaid_lease); if (r < 0) return r; if (client->ia_pd.ia_pd.id != iaid_lease) { log_dhcp6_client(client, "%s has wrong IAID for IA PD", dhcp6_message_type_to_string(message->type)); return -EINVAL; } if (lease->pd.addresses) { lt_t1 = MIN(lt_t1, be32toh(lease->pd.ia_pd.lifetime_t1)); lt_t2 = MIN(lt_t2, be32toh(lease->pd.ia_pd.lifetime_t2)); } break; case SD_DHCP6_OPTION_RAPID_COMMIT: r = dhcp6_lease_set_rapid_commit(lease); if (r < 0) return r; break; case SD_DHCP6_OPTION_DNS_SERVERS: r = dhcp6_lease_set_dns(lease, optval, optlen); if (r < 0) return r; break; case SD_DHCP6_OPTION_DOMAIN_LIST: r = dhcp6_lease_set_domains(lease, optval, optlen); if (r < 0) return r; break; case SD_DHCP6_OPTION_NTP_SERVER: r = dhcp6_lease_set_ntp(lease, optval, optlen); if (r < 0) return r; break; case SD_DHCP6_OPTION_SNTP_SERVERS: r = dhcp6_lease_set_sntp(lease, optval, optlen); if (r < 0) return r; break; } pos += offsetof(DHCP6Option, data) + optlen; } if (!clientid) { log_dhcp6_client(client, "%s has incomplete options", dhcp6_message_type_to_string(message->type)); return -EINVAL; } if (client->state != DHCP6_STATE_INFORMATION_REQUEST) { r = dhcp6_lease_get_serverid(lease, NULL, NULL); if (r < 0) { log_dhcp6_client(client, "%s has no server id", dhcp6_message_type_to_string(message->type)); return -EINVAL; } } else { if (lease->ia.addresses) { lease->ia.ia_na.lifetime_t1 = htobe32(lt_t1); lease->ia.ia_na.lifetime_t2 = htobe32(lt_t2); } if (lease->pd.addresses) { lease->pd.ia_pd.lifetime_t1 = htobe32(lt_t1); lease->pd.ia_pd.lifetime_t2 = htobe32(lt_t2); } } return 0; } static int client_receive_reply(sd_dhcp6_client *client, DHCP6Message *reply, size_t len) { _cleanup_(sd_dhcp6_lease_unrefp) sd_dhcp6_lease *lease = NULL; bool rapid_commit; int r; assert(client); assert(reply); if (reply->type != DHCP6_REPLY) return 0; r = dhcp6_lease_new(&lease); if (r < 0) return -ENOMEM; r = client_parse_message(client, reply, len, lease); if (r < 0) return r; if (client->state == DHCP6_STATE_SOLICITATION) { r = dhcp6_lease_get_rapid_commit(lease, &rapid_commit); if (r < 0) return r; if (!rapid_commit) return 0; } sd_dhcp6_lease_unref(client->lease); client->lease = TAKE_PTR(lease); return DHCP6_STATE_BOUND; } static int client_receive_advertise(sd_dhcp6_client *client, DHCP6Message *advertise, size_t len) { _cleanup_(sd_dhcp6_lease_unrefp) sd_dhcp6_lease *lease = NULL; uint8_t pref_advertise = 0, pref_lease = 0; int r; if (advertise->type != DHCP6_ADVERTISE) return 0; r = dhcp6_lease_new(&lease); if (r < 0) return r; r = client_parse_message(client, advertise, len, lease); if (r < 0) return r; r = dhcp6_lease_get_preference(lease, &pref_advertise); if (r < 0) return r; r = dhcp6_lease_get_preference(client->lease, &pref_lease); if (r < 0 || pref_advertise > pref_lease) { sd_dhcp6_lease_unref(client->lease); client->lease = TAKE_PTR(lease); r = 0; } if (pref_advertise == 255 || client->retransmit_count > 1) r = DHCP6_STATE_REQUEST; return r; } static int client_receive_message( sd_event_source *s, int fd, uint32_t revents, void *userdata) { sd_dhcp6_client *client = userdata; DHCP6_CLIENT_DONT_DESTROY(client); _cleanup_free_ DHCP6Message *message = NULL; ssize_t buflen, len; int r = 0; assert(s); assert(client); assert(client->event); buflen = next_datagram_size_fd(fd); if (buflen < 0) return buflen; message = malloc(buflen); if (!message) return -ENOMEM; len = recv(fd, message, buflen, 0); if (len < 0) { if (IN_SET(errno, EAGAIN, EINTR)) return 0; return log_dhcp6_client_errno(client, errno, "Could not receive message from UDP socket: %m"); } if ((size_t) len < sizeof(DHCP6Message)) { log_dhcp6_client(client, "Too small to be DHCP6 message: ignoring"); return 0; } switch(message->type) { case DHCP6_SOLICIT: case DHCP6_REQUEST: case DHCP6_CONFIRM: case DHCP6_RENEW: case DHCP6_REBIND: case DHCP6_RELEASE: case DHCP6_DECLINE: case DHCP6_INFORMATION_REQUEST: case DHCP6_RELAY_FORW: case DHCP6_RELAY_REPL: return 0; case DHCP6_ADVERTISE: case DHCP6_REPLY: case DHCP6_RECONFIGURE: break; default: log_dhcp6_client(client, "Unknown message type %d", message->type); return 0; } if (client->transaction_id != (message->transaction_id & htobe32(0x00ffffff))) return 0; switch (client->state) { case DHCP6_STATE_INFORMATION_REQUEST: r = client_receive_reply(client, message, len); if (r < 0) return 0; client_notify(client, SD_DHCP6_CLIENT_EVENT_INFORMATION_REQUEST); client_start(client, DHCP6_STATE_STOPPED); break; case DHCP6_STATE_SOLICITATION: r = client_receive_advertise(client, message, len); if (r == DHCP6_STATE_REQUEST) { client_start(client, r); break; } _fallthrough_; /* for Soliciation Rapid Commit option check */ case DHCP6_STATE_REQUEST: case DHCP6_STATE_RENEW: case DHCP6_STATE_REBIND: r = client_receive_reply(client, message, len); if (r < 0) return 0; if (r == DHCP6_STATE_BOUND) { r = client_start(client, DHCP6_STATE_BOUND); if (r < 0) { client_stop(client, r); return 0; } client_notify(client, SD_DHCP6_CLIENT_EVENT_IP_ACQUIRE); } break; case DHCP6_STATE_BOUND: break; case DHCP6_STATE_STOPPED: return 0; } log_dhcp6_client(client, "Recv %s", dhcp6_message_type_to_string(message->type)); return 0; } static int client_get_lifetime(sd_dhcp6_client *client, uint32_t *lifetime_t1, uint32_t *lifetime_t2) { assert_return(client, -EINVAL); assert_return(client->lease, -EINVAL); if (FLAGS_SET(client->request, DHCP6_REQUEST_IA_NA) && client->lease->ia.addresses) { *lifetime_t1 = be32toh(client->lease->ia.ia_na.lifetime_t1); *lifetime_t2 = be32toh(client->lease->ia.ia_na.lifetime_t2); return 0; } if (FLAGS_SET(client->request, DHCP6_REQUEST_IA_PD) && client->lease->pd.addresses) { *lifetime_t1 = be32toh(client->lease->pd.ia_pd.lifetime_t1); *lifetime_t2 = be32toh(client->lease->pd.ia_pd.lifetime_t2); return 0; } return -ENOMSG; } static int client_start(sd_dhcp6_client *client, enum DHCP6State state) { int r; usec_t timeout, time_now; char time_string[FORMAT_TIMESPAN_MAX]; uint32_t lifetime_t1, lifetime_t2; assert_return(client, -EINVAL); assert_return(client->event, -EINVAL); assert_return(client->ifindex > 0, -EINVAL); assert_return(client->state != state, -EINVAL); (void) event_source_disable(client->timeout_resend_expire); (void) event_source_disable(client->timeout_resend); client->retransmit_time = 0; client->retransmit_count = 0; r = sd_event_now(client->event, clock_boottime_or_monotonic(), &time_now); if (r < 0) return r; if (!client->receive_message) { r = sd_event_add_io(client->event, &client->receive_message, client->fd, EPOLLIN, client_receive_message, client); if (r < 0) goto error; r = sd_event_source_set_priority(client->receive_message, client->event_priority); if (r < 0) goto error; r = sd_event_source_set_description(client->receive_message, "dhcp6-receive-message"); if (r < 0) goto error; } switch (state) { case DHCP6_STATE_STOPPED: if (client->state == DHCP6_STATE_INFORMATION_REQUEST) { client->state = DHCP6_STATE_STOPPED; return 0; } _fallthrough_; case DHCP6_STATE_SOLICITATION: client->state = DHCP6_STATE_SOLICITATION; break; case DHCP6_STATE_INFORMATION_REQUEST: case DHCP6_STATE_REQUEST: case DHCP6_STATE_RENEW: case DHCP6_STATE_REBIND: client->state = state; break; case DHCP6_STATE_BOUND: r = client_get_lifetime(client, &lifetime_t1, &lifetime_t2); if (r < 0) goto error; if (lifetime_t1 == 0xffffffff || lifetime_t2 == 0xffffffff) { log_dhcp6_client(client, "Infinite T1 0x%08x or T2 0x%08x", lifetime_t1, lifetime_t2); return 0; } timeout = client_timeout_compute_random(lifetime_t1 * USEC_PER_SEC); log_dhcp6_client(client, "T1 expires in %s", format_timespan(time_string, FORMAT_TIMESPAN_MAX, timeout, USEC_PER_SEC)); r = event_reset_time(client->event, &client->timeout_t1, clock_boottime_or_monotonic(), time_now + timeout, 10 * USEC_PER_SEC, client_timeout_t1, client, client->event_priority, "dhcp6-t1-timeout", true); if (r < 0) goto error; timeout = client_timeout_compute_random(lifetime_t2 * USEC_PER_SEC); log_dhcp6_client(client, "T2 expires in %s", format_timespan(time_string, FORMAT_TIMESPAN_MAX, timeout, USEC_PER_SEC)); r = event_reset_time(client->event, &client->timeout_t2, clock_boottime_or_monotonic(), time_now + timeout, 10 * USEC_PER_SEC, client_timeout_t2, client, client->event_priority, "dhcp6-t2-timeout", true); if (r < 0) goto error; client->state = state; return 0; } client->transaction_id = random_u32() & htobe32(0x00ffffff); client->transaction_start = time_now; r = event_reset_time(client->event, &client->timeout_resend, clock_boottime_or_monotonic(), 0, 0, client_timeout_resend, client, client->event_priority, "dhcp6-resend-timeout", true); if (r < 0) goto error; return 0; error: client_reset(client); return r; } int sd_dhcp6_client_stop(sd_dhcp6_client *client) { assert_return(client, -EINVAL); client_stop(client, SD_DHCP6_CLIENT_EVENT_STOP); client->fd = safe_close(client->fd); return 0; } int sd_dhcp6_client_is_running(sd_dhcp6_client *client) { assert_return(client, -EINVAL); return client->state != DHCP6_STATE_STOPPED; } int sd_dhcp6_client_start(sd_dhcp6_client *client) { enum DHCP6State state = DHCP6_STATE_SOLICITATION; int r = 0; assert_return(client, -EINVAL); assert_return(client->event, -EINVAL); assert_return(client->ifindex > 0, -EINVAL); assert_return(in_addr_is_link_local(AF_INET6, (const union in_addr_union *) &client->local_address) > 0, -EINVAL); if (!IN_SET(client->state, DHCP6_STATE_STOPPED)) return -EBUSY; if (!client->information_request && !client->request) return -EINVAL; r = client_reset(client); if (r < 0) return r; r = client_ensure_iaid(client); if (r < 0) return r; r = client_ensure_duid(client); if (r < 0) return r; if (client->fd < 0) { r = dhcp6_network_bind_udp_socket(client->ifindex, &client->local_address); if (r < 0) { _cleanup_free_ char *p = NULL; (void) in_addr_to_string(AF_INET6, (const union in_addr_union*) &client->local_address, &p); return log_dhcp6_client_errno(client, r, "Failed to bind to UDP socket at address %s: %m", strna(p)); } client->fd = r; } if (client->information_request) state = DHCP6_STATE_INFORMATION_REQUEST; log_dhcp6_client(client, "Started in %s mode", client->information_request? "Information request": "Managed"); return client_start(client, state); } int sd_dhcp6_client_attach_event(sd_dhcp6_client *client, sd_event *event, int64_t priority) { int r; assert_return(client, -EINVAL); assert_return(!client->event, -EBUSY); if (event) client->event = sd_event_ref(event); else { r = sd_event_default(&client->event); if (r < 0) return 0; } client->event_priority = priority; return 0; } int sd_dhcp6_client_detach_event(sd_dhcp6_client *client) { assert_return(client, -EINVAL); client->event = sd_event_unref(client->event); return 0; } sd_event *sd_dhcp6_client_get_event(sd_dhcp6_client *client) { assert_return(client, NULL); return client->event; } static sd_dhcp6_client *dhcp6_client_free(sd_dhcp6_client *client) { assert(client); client->timeout_resend = sd_event_source_unref(client->timeout_resend); client->timeout_resend_expire = sd_event_source_unref(client->timeout_resend_expire); client->timeout_t1 = sd_event_source_unref(client->timeout_t1); client->timeout_t2 = sd_event_source_unref(client->timeout_t2); client_reset(client); client->fd = safe_close(client->fd); sd_dhcp6_client_detach_event(client); free(client->req_opts); free(client->fqdn); return mfree(client); } DEFINE_TRIVIAL_REF_UNREF_FUNC(sd_dhcp6_client, sd_dhcp6_client, dhcp6_client_free); int sd_dhcp6_client_new(sd_dhcp6_client **ret) { _cleanup_(sd_dhcp6_client_unrefp) sd_dhcp6_client *client = NULL; _cleanup_free_ be16_t *req_opts = NULL; size_t t; assert_return(ret, -EINVAL); req_opts = new(be16_t, ELEMENTSOF(default_req_opts)); if (!req_opts) return -ENOMEM; for (t = 0; t < ELEMENTSOF(default_req_opts); t++) req_opts[t] = htobe16(default_req_opts[t]); client = new(sd_dhcp6_client, 1); if (!client) return -ENOMEM; *client = (sd_dhcp6_client) { .n_ref = 1, .ia_na.type = SD_DHCP6_OPTION_IA_NA, .ia_pd.type = SD_DHCP6_OPTION_IA_PD, .ifindex = -1, .request = DHCP6_REQUEST_IA_NA, .fd = -1, .req_opts_len = ELEMENTSOF(default_req_opts), .req_opts = TAKE_PTR(req_opts), }; *ret = TAKE_PTR(client); return 0; }