/* SPDX-License-Identifier: LGPL-2.1-or-later */ /*** Copyright © 2014-2015 Intel Corporation. All rights reserved. ***/ #include #include #include #include #include "sd-dhcp6-client.h" #include "alloc-util.h" #include "device-util.h" #include "dhcp-identifier.h" #include "dhcp6-internal.h" #include "dhcp6-lease-internal.h" #include "dns-domain.h" #include "event-util.h" #include "fd-util.h" #include "hexdecoct.h" #include "hostname-util.h" #include "in-addr-util.h" #include "io-util.h" #include "random-util.h" #include "socket-util.h" #include "sort-util.h" #include "strv.h" #include "web-util.h" #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_transaction(sd_dhcp6_client *client, 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(!sd_dhcp6_client_is_running(client), -EBUSY); assert_return(ifindex > 0, -EINVAL); client->ifindex = ifindex; return 0; } int sd_dhcp6_client_set_ifname(sd_dhcp6_client *client, const char *ifname) { assert_return(client, -EINVAL); assert_return(ifname, -EINVAL); if (!ifname_valid_full(ifname, IFNAME_VALID_ALTERNATIVE)) return -EINVAL; return free_and_strdup(&client->ifname, ifname); } int sd_dhcp6_client_get_ifname(sd_dhcp6_client *client, const char **ret) { int r; assert_return(client, -EINVAL); r = get_ifname(client->ifindex, &client->ifname); if (r < 0) return r; if (ret) *ret = client->ifname; 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(!sd_dhcp6_client_is_running(client), -EBUSY); assert_return(local_address, -EINVAL); assert_return(in6_addr_is_link_local(local_address) > 0, -EINVAL); 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 <= sizeof(client->hw_addr.bytes), -EINVAL); /* Unlike the other setters, it is OK to set a new MAC address while the client is running, * as the MAC address is used only when setting DUID or IAID. */ 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 { client->arp_type = ARPHRD_NONE; client->hw_addr.length = 0; return 0; } client->arp_type = arp_type; hw_addr_set(&client->hw_addr, addr, addr_len); return 0; } int sd_dhcp6_client_set_prefix_delegation_hint( sd_dhcp6_client *client, uint8_t prefixlen, const struct in6_addr *pd_prefix) { _cleanup_free_ DHCP6Address *prefix = NULL; assert_return(client, -EINVAL); assert_return(!sd_dhcp6_client_is_running(client), -EBUSY); if (!pd_prefix) { /* clear previous assignments. */ dhcp6_ia_clear_addresses(&client->ia_pd); return 0; } assert_return(prefixlen > 0 && prefixlen <= 128, -EINVAL); prefix = new(DHCP6Address, 1); if (!prefix) return -ENOMEM; *prefix = (DHCP6Address) { .iapdprefix.address = *pd_prefix, .iapdprefix.prefixlen = prefixlen, }; LIST_PREPEND(addresses, client->ia_pd.addresses, TAKE_PTR(prefix)); return 1; } int sd_dhcp6_client_add_vendor_option(sd_dhcp6_client *client, sd_dhcp6_option *v) { int r; assert_return(client, -EINVAL); assert_return(!sd_dhcp6_client_is_running(client), -EBUSY); if (!v) { /* Clear the previous assignments. */ ordered_set_clear(client->vendor_options); return 0; } r = ordered_set_ensure_put(&client->vendor_options, &dhcp6_option_hash_ops, v); if (r < 0) return r; sd_dhcp6_option_ref(v); return 1; } static int client_ensure_duid(sd_dhcp6_client *client) { assert(client); if (client->duid_len != 0) return 0; return dhcp_identifier_set_duid_en(client->test_mode, &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, DUIDType duid_type, const void *duid, size_t duid_len, usec_t llt_time) { int r; assert_return(client, -EINVAL); assert_return(!sd_dhcp6_client_is_running(client), -EBUSY); assert_return(duid_len == 0 || duid, -EINVAL); if (duid) { 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 log_dhcp6_client_errno(client, r, "Failed to validate length of DUID: %m"); log_dhcp6_client(client, "Using DUID of type %i of incorrect length, proceeding.", 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 { r = dhcp_identifier_set_duid(duid_type, &client->hw_addr, client->arp_type, llt_time, client->test_mode, &client->duid, &client->duid_len); if (r == -EOPNOTSUPP) return log_dhcp6_client_errno(client, r, "Failed to set %s. MAC address is not set or " "interface type is not supported.", duid_type_to_string(duid_type)); if (r < 0) return log_dhcp6_client_errno(client, r, "Failed to set %s: %m", duid_type_to_string(duid_type)); } 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_duid_as_string( sd_dhcp6_client *client, char **duid) { _cleanup_free_ char *p = NULL, *s = NULL, *t = NULL; const char *v; int r; assert_return(client, -EINVAL); assert_return(client->duid_len > 0, -ENODATA); assert_return(duid, -EINVAL); v = duid_type_to_string(be16toh(client->duid.type)); if (v) { s = strdup(v); if (!s) return -ENOMEM; } else { r = asprintf(&s, "%0x", client->duid.type); if (r < 0) return -ENOMEM; } t = hexmem(&client->duid.raw.data, client->duid_len); if (!t) return -ENOMEM; p = strjoin(s, ":", t); if (!p) return -ENOMEM; *duid = TAKE_PTR(p); return 0; } int sd_dhcp6_client_set_iaid(sd_dhcp6_client *client, uint32_t iaid) { assert_return(client, -EINVAL); assert_return(!sd_dhcp6_client_is_running(client), -EBUSY); client->ia_na.header.id = htobe32(iaid); client->ia_pd.header.id = htobe32(iaid); client->iaid_set = true; 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->dev, &client->hw_addr, /* legacy_unstable_byteorder = */ true, &iaid); if (r < 0) return r; client->ia_na.header.id = iaid; client->ia_pd.header.id = iaid; client->iaid_set = true; return 0; } int sd_dhcp6_client_get_iaid(sd_dhcp6_client *client, uint32_t *iaid) { assert_return(client, -EINVAL); assert_return(iaid, -EINVAL); if (!client->iaid_set) return -ENODATA; *iaid = be32toh(client->ia_na.header.id); return 0; } void dhcp6_client_set_test_mode(sd_dhcp6_client *client, bool test_mode) { assert(client); client->test_mode = test_mode; } int sd_dhcp6_client_set_fqdn( sd_dhcp6_client *client, const char *fqdn) { assert_return(client, -EINVAL); assert_return(!sd_dhcp6_client_is_running(client), -EBUSY); /* Make sure FQDN qualifies as DNS and as Linux hostname */ if (fqdn && !(hostname_is_valid(fqdn, 0) && 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(!sd_dhcp6_client_is_running(client), -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; } static int be16_compare_func(const be16_t *a, const be16_t *b) { return CMP(be16toh(*a), be16toh(*b)); } int sd_dhcp6_client_set_request_option(sd_dhcp6_client *client, uint16_t option) { be16_t opt; assert_return(client, -EINVAL); assert_return(!sd_dhcp6_client_is_running(client), -EBUSY); if (!dhcp6_option_can_request(option)) return -EINVAL; opt = htobe16(option); if (typesafe_bsearch(&opt, client->req_opts, client->n_req_opts, be16_compare_func)) return -EEXIST; if (!GREEDY_REALLOC(client->req_opts, client->n_req_opts + 1)) return -ENOMEM; client->req_opts[client->n_req_opts++] = opt; /* Sort immediately to make the above binary search will work for the next time. */ typesafe_qsort(client->req_opts, client->n_req_opts, be16_compare_func); return 0; } int sd_dhcp6_client_set_request_mud_url(sd_dhcp6_client *client, const char *mudurl) { assert_return(client, -EINVAL); assert_return(!sd_dhcp6_client_is_running(client), -EBUSY); assert_return(mudurl, -EINVAL); assert_return(strlen(mudurl) <= UINT8_MAX, -EINVAL); assert_return(http_url_is_valid(mudurl), -EINVAL); return free_and_strdup(&client->mudurl, mudurl); } int sd_dhcp6_client_set_request_user_class(sd_dhcp6_client *client, char * const *user_class) { char **s; assert_return(client, -EINVAL); assert_return(!sd_dhcp6_client_is_running(client), -EBUSY); assert_return(!strv_isempty(user_class), -EINVAL); STRV_FOREACH(p, user_class) { size_t len = strlen(*p); if (len > UINT16_MAX || len == 0) return -EINVAL; } s = strv_copy(user_class); if (!s) return -ENOMEM; return strv_free_and_replace(client->user_class, s); } int sd_dhcp6_client_set_request_vendor_class(sd_dhcp6_client *client, char * const *vendor_class) { char **s; assert_return(client, -EINVAL); assert_return(!sd_dhcp6_client_is_running(client), -EBUSY); assert_return(!strv_isempty(vendor_class), -EINVAL); STRV_FOREACH(p, vendor_class) { size_t len = strlen(*p); if (len > UINT16_MAX || len == 0) return -EINVAL; } s = strv_copy(vendor_class); if (!s) return -ENOMEM; return strv_free_and_replace(client->vendor_class, s); } 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_ia, DHCP6_REQUEST_IA_PD); return 0; } int sd_dhcp6_client_set_prefix_delegation(sd_dhcp6_client *client, int delegation) { assert_return(client, -EINVAL); assert_return(!sd_dhcp6_client_is_running(client), -EBUSY); SET_FLAG(client->request_ia, 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_ia, DHCP6_REQUEST_IA_NA); return 0; } int sd_dhcp6_client_set_address_request(sd_dhcp6_client *client, int request) { assert_return(client, -EINVAL); assert_return(!sd_dhcp6_client_is_running(client), -EBUSY); SET_FLAG(client->request_ia, DHCP6_REQUEST_IA_NA, request); return 0; } int dhcp6_client_set_transaction_id(sd_dhcp6_client *client, uint32_t transaction_id) { assert(client); assert(client->test_mode); /* This is for tests or fuzzers. */ client->transaction_id = transaction_id & htobe32(0x00ffffff); return 0; } int sd_dhcp6_client_set_rapid_commit(sd_dhcp6_client *client, int enable) { assert_return(client, -EINVAL); assert_return(!sd_dhcp6_client_is_running(client), -EBUSY); client->rapid_commit = enable; 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; } int sd_dhcp6_client_add_option(sd_dhcp6_client *client, sd_dhcp6_option *v) { int r; assert_return(client, -EINVAL); assert_return(v, -EINVAL); r = ordered_hashmap_ensure_put(&client->extra_options, &dhcp6_option_hash_ops, UINT_TO_PTR(v->option), v); if (r < 0) return r; sd_dhcp6_option_ref(v); return 0; } static void client_set_state(sd_dhcp6_client *client, DHCP6State state) { assert(client); if (client->state == state) return; log_dhcp6_client(client, "State changed: %s -> %s", dhcp6_state_to_string(client->state), dhcp6_state_to_string(state)); client->state = state; } static void client_notify(sd_dhcp6_client *client, int event) { assert(client); if (client->callback) client->callback(client, event, client->userdata); } static void client_cleanup(sd_dhcp6_client *client) { assert(client); client->lease = sd_dhcp6_lease_unref(client->lease); /* Reset IRT here. Otherwise, we cannot restart the client in the information requesting mode, * even though the lease is freed below. */ client->information_request_time_usec = 0; client->information_refresh_time_usec = 0; (void) event_source_disable(client->receive_message); (void) event_source_disable(client->timeout_resend); (void) event_source_disable(client->timeout_expire); (void) event_source_disable(client->timeout_t1); (void) event_source_disable(client->timeout_t2); client_set_state(client, DHCP6_STATE_STOPPED); } static void client_stop(sd_dhcp6_client *client, int error) { DHCP6_CLIENT_DONT_DESTROY(client); assert(client); client_notify(client, error); client_cleanup(client); } static int client_append_common_options_in_managed_mode( sd_dhcp6_client *client, uint8_t **buf, size_t *offset, const DHCP6IA *ia_na, const DHCP6IA *ia_pd) { int r; assert(client); assert(IN_SET(client->state, DHCP6_STATE_SOLICITATION, DHCP6_STATE_REQUEST, DHCP6_STATE_RENEW, DHCP6_STATE_REBIND)); assert(buf); assert(*buf); assert(offset); if (FLAGS_SET(client->request_ia, DHCP6_REQUEST_IA_NA) && ia_na) { r = dhcp6_option_append_ia(buf, offset, ia_na); if (r < 0) return r; } if (FLAGS_SET(client->request_ia, DHCP6_REQUEST_IA_PD) && ia_pd) { r = dhcp6_option_append_ia(buf, offset, ia_pd); if (r < 0) return r; } r = dhcp6_option_append_fqdn(buf, offset, client->fqdn); if (r < 0) return r; r = dhcp6_option_append_user_class(buf, offset, client->user_class); if (r < 0) return r; r = dhcp6_option_append_vendor_class(buf, offset, client->vendor_class); if (r < 0) return r; r = dhcp6_option_append_vendor_option(buf, offset, client->vendor_options); if (r < 0) return r; return 0; } static DHCP6MessageType client_message_type_from_state(sd_dhcp6_client *client) { assert(client); switch (client->state) { case DHCP6_STATE_INFORMATION_REQUEST: return DHCP6_MESSAGE_INFORMATION_REQUEST; case DHCP6_STATE_SOLICITATION: return DHCP6_MESSAGE_SOLICIT; case DHCP6_STATE_REQUEST: return DHCP6_MESSAGE_REQUEST; case DHCP6_STATE_RENEW: return DHCP6_MESSAGE_RENEW; case DHCP6_STATE_REBIND: return DHCP6_MESSAGE_REBIND; default: assert_not_reached(); } } static int client_append_oro(sd_dhcp6_client *client, uint8_t **buf, size_t *offset) { _cleanup_free_ be16_t *p = NULL; be16_t *req_opts; size_t n; assert(client); assert(buf); assert(*buf); assert(offset); switch (client->state) { case DHCP6_STATE_INFORMATION_REQUEST: n = client->n_req_opts; p = new(be16_t, n + 2); if (!p) return -ENOMEM; memcpy_safe(p, client->req_opts, n * sizeof(be16_t)); p[n++] = htobe16(SD_DHCP6_OPTION_INFORMATION_REFRESH_TIME); /* RFC 8415 section 21.23 */ p[n++] = htobe16(SD_DHCP6_OPTION_INF_MAX_RT); /* RFC 8415 section 21.25 */ typesafe_qsort(p, n, be16_compare_func); req_opts = p; break; case DHCP6_STATE_SOLICITATION: n = client->n_req_opts; p = new(be16_t, n + 1); if (!p) return -ENOMEM; memcpy_safe(p, client->req_opts, n * sizeof(be16_t)); p[n++] = htobe16(SD_DHCP6_OPTION_SOL_MAX_RT); /* RFC 8415 section 21.24 */ typesafe_qsort(p, n, be16_compare_func); req_opts = p; break; default: n = client->n_req_opts; req_opts = client->req_opts; } if (n == 0) return 0; return dhcp6_option_append(buf, offset, SD_DHCP6_OPTION_ORO, n * sizeof(be16_t), req_opts); } int dhcp6_client_send_message(sd_dhcp6_client *client) { _cleanup_free_ uint8_t *buf = NULL; struct in6_addr all_servers = IN6ADDR_ALL_DHCP6_RELAY_AGENTS_AND_SERVERS_INIT; struct sd_dhcp6_option *j; usec_t elapsed_usec, time_now; be16_t elapsed_time; DHCP6Message *message; size_t offset; int r; assert(client); assert(client->event); r = sd_event_now(client->event, CLOCK_BOOTTIME, &time_now); if (r < 0) return r; if (!GREEDY_REALLOC0(buf, offsetof(DHCP6Message, options))) return -ENOMEM; message = (DHCP6Message*) buf; message->transaction_id = client->transaction_id; message->type = client_message_type_from_state(client); offset = offsetof(DHCP6Message, options); switch (client->state) { case DHCP6_STATE_INFORMATION_REQUEST: break; case DHCP6_STATE_SOLICITATION: if (client->rapid_commit) { r = dhcp6_option_append(&buf, &offset, SD_DHCP6_OPTION_RAPID_COMMIT, 0, NULL); if (r < 0) return r; } r = client_append_common_options_in_managed_mode(client, &buf, &offset, &client->ia_na, &client->ia_pd); if (r < 0) return r; break; case DHCP6_STATE_REQUEST: case DHCP6_STATE_RENEW: r = dhcp6_option_append(&buf, &offset, SD_DHCP6_OPTION_SERVERID, client->lease->serverid_len, client->lease->serverid); if (r < 0) return r; _fallthrough_; case DHCP6_STATE_REBIND: assert(client->lease); r = client_append_common_options_in_managed_mode(client, &buf, &offset, client->lease->ia_na, client->lease->ia_pd); if (r < 0) return r; break; case DHCP6_STATE_STOPPED: case DHCP6_STATE_BOUND: default: assert_not_reached(); } if (client->mudurl) { r = dhcp6_option_append(&buf, &offset, SD_DHCP6_OPTION_MUD_URL_V6, strlen(client->mudurl), client->mudurl); if (r < 0) return r; } r = client_append_oro(client, &buf, &offset); if (r < 0) return r; assert(client->duid_len > 0); r = dhcp6_option_append(&buf, &offset, SD_DHCP6_OPTION_CLIENTID, client->duid_len, &client->duid); if (r < 0) return r; ORDERED_HASHMAP_FOREACH(j, client->extra_options) { r = dhcp6_option_append(&buf, &offset, j->option, j->length, j->data); if (r < 0) return r; } /* RFC 8415 Section 21.9. * A client MUST include an Elapsed Time option in messages to indicate how long the client has * been trying to complete a DHCP message exchange. */ elapsed_usec = MIN(usec_sub_unsigned(time_now, client->transaction_start) / USEC_PER_MSEC / 10, (usec_t) UINT16_MAX); elapsed_time = htobe16(elapsed_usec); r = dhcp6_option_append(&buf, &offset, 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, buf, offset); if (r < 0) return r; log_dhcp6_client(client, "Sent %s", dhcp6_message_type_to_string(client_message_type_from_state(client))); return 0; } static usec_t client_timeout_compute_random(usec_t val) { return usec_sub_unsigned(val, random_u64_range(val / 10)); } static int client_timeout_resend(sd_event_source *s, uint64_t usec, void *userdata) { sd_dhcp6_client *client = ASSERT_PTR(userdata); usec_t init_retransmit_time, max_retransmit_time; int r; assert(client->event); 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 > 0 && client->lease) { (void) client_start_transaction(client, DHCP6_STATE_REQUEST); return 0; } init_retransmit_time = DHCP6_SOL_TIMEOUT; max_retransmit_time = DHCP6_SOL_MAX_RT; break; case DHCP6_STATE_REQUEST: if (client->retransmit_count >= DHCP6_REQ_MAX_RC) { client_stop(client, SD_DHCP6_CLIENT_EVENT_RETRANS_MAX); return 0; } init_retransmit_time = DHCP6_REQ_TIMEOUT; max_retransmit_time = DHCP6_REQ_MAX_RT; 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; /* Also, instead of setting MRD, the expire timer is already set in client_enter_bound_state(). */ break; case DHCP6_STATE_STOPPED: case DHCP6_STATE_BOUND: default: assert_not_reached(); } r = dhcp6_client_send_message(client); if (r >= 0) client->retransmit_count++; if (client->retransmit_time == 0) { 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 (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(client->retransmit_time, USEC_PER_SEC)); r = event_reset_time_relative(client->event, &client->timeout_resend, CLOCK_BOOTTIME, client->retransmit_time, 10 * USEC_PER_MSEC, client_timeout_resend, client, client->event_priority, "dhcp6-resend-timer", true); if (r < 0) client_stop(client, r); return 0; } static int client_start_transaction(sd_dhcp6_client *client, DHCP6State state) { int r; assert(client); assert(client->event); switch (state) { case DHCP6_STATE_INFORMATION_REQUEST: case DHCP6_STATE_SOLICITATION: assert(client->state == DHCP6_STATE_STOPPED); break; case DHCP6_STATE_REQUEST: assert(client->state == DHCP6_STATE_SOLICITATION); break; case DHCP6_STATE_RENEW: assert(client->state == DHCP6_STATE_BOUND); break; case DHCP6_STATE_REBIND: assert(IN_SET(client->state, DHCP6_STATE_BOUND, DHCP6_STATE_RENEW)); break; case DHCP6_STATE_STOPPED: case DHCP6_STATE_BOUND: default: assert_not_reached(); } client_set_state(client, state); client->retransmit_time = 0; client->retransmit_count = 0; client->transaction_id = random_u32() & htobe32(0x00ffffff); r = sd_event_now(client->event, CLOCK_BOOTTIME, &client->transaction_start); if (r < 0) goto error; r = event_reset_time(client->event, &client->timeout_resend, CLOCK_BOOTTIME, 0, 0, client_timeout_resend, client, client->event_priority, "dhcp6-resend-timeout", true); if (r < 0) goto error; r = sd_event_source_set_enabled(client->receive_message, SD_EVENT_ON); if (r < 0) goto error; return 0; error: client_stop(client, r); return r; } static int client_timeout_expire(sd_event_source *s, uint64_t usec, void *userdata) { sd_dhcp6_client *client = ASSERT_PTR(userdata); DHCP6_CLIENT_DONT_DESTROY(client); DHCP6State state; (void) event_source_disable(client->timeout_expire); (void) event_source_disable(client->timeout_t2); (void) event_source_disable(client->timeout_t1); 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) (void) client_start_transaction(client, DHCP6_STATE_SOLICITATION); return 0; } static int client_timeout_t2(sd_event_source *s, uint64_t usec, void *userdata) { sd_dhcp6_client *client = ASSERT_PTR(userdata); (void) event_source_disable(client->timeout_t2); (void) event_source_disable(client->timeout_t1); log_dhcp6_client(client, "Timeout T2"); (void) client_start_transaction(client, DHCP6_STATE_REBIND); return 0; } static int client_timeout_t1(sd_event_source *s, uint64_t usec, void *userdata) { sd_dhcp6_client *client = ASSERT_PTR(userdata); (void) event_source_disable(client->timeout_t1); log_dhcp6_client(client, "Timeout T1"); (void) client_start_transaction(client, DHCP6_STATE_RENEW); return 0; } static int client_enter_bound_state(sd_dhcp6_client *client) { usec_t lifetime_t1, lifetime_t2, lifetime_valid; int r; assert(client); assert(client->lease); assert(IN_SET(client->state, DHCP6_STATE_SOLICITATION, DHCP6_STATE_REQUEST, DHCP6_STATE_RENEW, DHCP6_STATE_REBIND)); (void) event_source_disable(client->receive_message); (void) event_source_disable(client->timeout_resend); r = dhcp6_lease_get_lifetime(client->lease, &lifetime_t1, &lifetime_t2, &lifetime_valid); if (r < 0) goto error; lifetime_t2 = client_timeout_compute_random(lifetime_t2); lifetime_t1 = client_timeout_compute_random(MIN(lifetime_t1, lifetime_t2)); if (lifetime_t1 == USEC_INFINITY) { log_dhcp6_client(client, "Infinite T1"); event_source_disable(client->timeout_t1); } else { log_dhcp6_client(client, "T1 expires in %s", FORMAT_TIMESPAN(lifetime_t1, USEC_PER_SEC)); r = event_reset_time_relative(client->event, &client->timeout_t1, CLOCK_BOOTTIME, lifetime_t1, 10 * USEC_PER_SEC, client_timeout_t1, client, client->event_priority, "dhcp6-t1-timeout", true); if (r < 0) goto error; } if (lifetime_t2 == USEC_INFINITY) { log_dhcp6_client(client, "Infinite T2"); event_source_disable(client->timeout_t2); } else { log_dhcp6_client(client, "T2 expires in %s", FORMAT_TIMESPAN(lifetime_t2, USEC_PER_SEC)); r = event_reset_time_relative(client->event, &client->timeout_t2, CLOCK_BOOTTIME, lifetime_t2, 10 * USEC_PER_SEC, client_timeout_t2, client, client->event_priority, "dhcp6-t2-timeout", true); if (r < 0) goto error; } if (lifetime_valid == USEC_INFINITY) { log_dhcp6_client(client, "Infinite valid lifetime"); event_source_disable(client->timeout_expire); } else { log_dhcp6_client(client, "Valid lifetime expires in %s", FORMAT_TIMESPAN(lifetime_valid, USEC_PER_SEC)); r = event_reset_time_relative(client->event, &client->timeout_expire, CLOCK_BOOTTIME, lifetime_valid, USEC_PER_SEC, client_timeout_expire, client, client->event_priority, "dhcp6-lease-expire", true); if (r < 0) goto error; } client_set_state(client, DHCP6_STATE_BOUND); client_notify(client, SD_DHCP6_CLIENT_EVENT_IP_ACQUIRE); return 0; error: client_stop(client, r); return r; } static int log_invalid_message_type(sd_dhcp6_client *client, const DHCP6Message *message) { const char *type_str; assert(client); assert(message); type_str = dhcp6_message_type_to_string(message->type); if (type_str) return log_dhcp6_client_errno(client, SYNTHETIC_ERRNO(EINVAL), "Received unexpected %s message, ignoring.", type_str); else return log_dhcp6_client_errno(client, SYNTHETIC_ERRNO(EINVAL), "Received unsupported message type %u, ignoring.", message->type); } static int client_process_information( sd_dhcp6_client *client, DHCP6Message *message, size_t len, const triple_timestamp *timestamp, const struct in6_addr *server_address) { _cleanup_(sd_dhcp6_lease_unrefp) sd_dhcp6_lease *lease = NULL; int r; assert(client); assert(message); if (message->type != DHCP6_MESSAGE_REPLY) return log_invalid_message_type(client, message); r = dhcp6_lease_new_from_message(client, message, len, timestamp, server_address, &lease); if (r < 0) return log_dhcp6_client_errno(client, r, "Failed to process received reply message, ignoring: %m"); log_dhcp6_client(client, "Processed %s message", dhcp6_message_type_to_string(message->type)); sd_dhcp6_lease_unref(client->lease); client->lease = TAKE_PTR(lease); /* Do not call client_stop() here, as it frees the acquired lease. */ (void) event_source_disable(client->receive_message); (void) event_source_disable(client->timeout_resend); client_set_state(client, DHCP6_STATE_STOPPED); client_notify(client, SD_DHCP6_CLIENT_EVENT_INFORMATION_REQUEST); return 0; } static int client_process_reply( sd_dhcp6_client *client, DHCP6Message *message, size_t len, const triple_timestamp *timestamp, const struct in6_addr *server_address) { _cleanup_(sd_dhcp6_lease_unrefp) sd_dhcp6_lease *lease = NULL; int r; assert(client); assert(message); if (message->type != DHCP6_MESSAGE_REPLY) return log_invalid_message_type(client, message); r = dhcp6_lease_new_from_message(client, message, len, timestamp, server_address, &lease); if (r == -EADDRNOTAVAIL) { /* If NoBinding status code is received, we cannot request the address anymore. * Let's restart transaction from the beginning. */ if (client->state == DHCP6_STATE_REQUEST) /* The lease is not acquired yet, hence it is not necessary to notify the restart. */ client_cleanup(client); else /* We need to notify the previous lease was expired. */ client_stop(client, SD_DHCP6_CLIENT_EVENT_RESEND_EXPIRE); return client_start_transaction(client, DHCP6_STATE_SOLICITATION); } if (r < 0) return log_dhcp6_client_errno(client, r, "Failed to process received reply message, ignoring: %m"); log_dhcp6_client(client, "Processed %s message", dhcp6_message_type_to_string(message->type)); sd_dhcp6_lease_unref(client->lease); client->lease = TAKE_PTR(lease); return client_enter_bound_state(client); } static int client_process_advertise_or_rapid_commit_reply( sd_dhcp6_client *client, DHCP6Message *message, size_t len, const triple_timestamp *timestamp, const struct in6_addr *server_address) { _cleanup_(sd_dhcp6_lease_unrefp) sd_dhcp6_lease *lease = NULL; uint8_t pref_advertise, pref_lease = 0; int r; assert(client); assert(message); if (!IN_SET(message->type, DHCP6_MESSAGE_ADVERTISE, DHCP6_MESSAGE_REPLY)) return log_invalid_message_type(client, message); r = dhcp6_lease_new_from_message(client, message, len, timestamp, server_address, &lease); if (r < 0) return log_dhcp6_client_errno(client, r, "Failed to process received %s message, ignoring: %m", dhcp6_message_type_to_string(message->type)); if (message->type == DHCP6_MESSAGE_REPLY) { bool rapid_commit; if (!client->rapid_commit) return log_dhcp6_client_errno(client, SYNTHETIC_ERRNO(EINVAL), "Received unexpected reply message, even we sent a solicit message without the rapid commit option, ignoring."); r = dhcp6_lease_get_rapid_commit(lease, &rapid_commit); if (r < 0) return r; if (!rapid_commit) return log_dhcp6_client_errno(client, SYNTHETIC_ERRNO(EINVAL), "Received reply message without rapid commit flag, ignoring."); log_dhcp6_client(client, "Processed %s message", dhcp6_message_type_to_string(message->type)); sd_dhcp6_lease_unref(client->lease); client->lease = TAKE_PTR(lease); return client_enter_bound_state(client); } r = dhcp6_lease_get_preference(lease, &pref_advertise); if (r < 0) return r; if (client->lease) { r = dhcp6_lease_get_preference(client->lease, &pref_lease); if (r < 0) return r; } log_dhcp6_client(client, "Processed %s message", dhcp6_message_type_to_string(message->type)); if (!client->lease || pref_advertise > pref_lease) { /* If this is the first advertise message or has higher preference, then save the lease. */ sd_dhcp6_lease_unref(client->lease); client->lease = TAKE_PTR(lease); } if (pref_advertise == 255 || client->retransmit_count > 1) (void) client_start_transaction(client, DHCP6_STATE_REQUEST); return 0; } static int client_receive_message( sd_event_source *s, int fd, uint32_t revents, void *userdata) { sd_dhcp6_client *client = ASSERT_PTR(userdata); DHCP6_CLIENT_DONT_DESTROY(client); /* This needs to be initialized with zero. See #20741. */ CMSG_BUFFER_TYPE(CMSG_SPACE_TIMEVAL) control = {}; struct iovec iov; union sockaddr_union sa = {}; struct msghdr msg = { .msg_name = &sa.sa, .msg_namelen = sizeof(sa), .msg_iov = &iov, .msg_iovlen = 1, .msg_control = &control, .msg_controllen = sizeof(control), }; struct cmsghdr *cmsg; triple_timestamp t = {}; _cleanup_free_ DHCP6Message *message = NULL; struct in6_addr *server_address = NULL; ssize_t buflen, len; buflen = next_datagram_size_fd(fd); if (buflen < 0) { if (ERRNO_IS_TRANSIENT(buflen) || ERRNO_IS_DISCONNECT(buflen)) return 0; log_dhcp6_client_errno(client, buflen, "Failed to determine datagram size to read, ignoring: %m"); return 0; } message = malloc(buflen); if (!message) return -ENOMEM; iov = IOVEC_MAKE(message, buflen); len = recvmsg_safe(fd, &msg, MSG_DONTWAIT); if (len < 0) { if (ERRNO_IS_TRANSIENT(len) || ERRNO_IS_DISCONNECT(len)) return 0; log_dhcp6_client_errno(client, len, "Could not receive message from UDP socket, ignoring: %m"); return 0; } if ((size_t) len < sizeof(DHCP6Message)) { log_dhcp6_client(client, "Too small to be DHCP6 message: ignoring"); return 0; } /* msg_namelen == 0 happens when running the test-suite over a socketpair */ if (msg.msg_namelen > 0) { if (msg.msg_namelen != sizeof(struct sockaddr_in6) || sa.in6.sin6_family != AF_INET6) { log_dhcp6_client(client, "Received message from invalid source, ignoring."); return 0; } server_address = &sa.in6.sin6_addr; } CMSG_FOREACH(cmsg, &msg) { if (cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SO_TIMESTAMP && cmsg->cmsg_len == CMSG_LEN(sizeof(struct timeval))) triple_timestamp_from_realtime(&t, timeval_load(CMSG_TYPED_DATA(cmsg, struct timeval))); } if (client->transaction_id != (message->transaction_id & htobe32(0x00ffffff))) return 0; switch (client->state) { case DHCP6_STATE_INFORMATION_REQUEST: if (client_process_information(client, message, len, &t, server_address) < 0) return 0; break; case DHCP6_STATE_SOLICITATION: if (client_process_advertise_or_rapid_commit_reply(client, message, len, &t, server_address) < 0) return 0; break; case DHCP6_STATE_REQUEST: case DHCP6_STATE_RENEW: case DHCP6_STATE_REBIND: if (client_process_reply(client, message, len, &t, server_address) < 0) return 0; break; case DHCP6_STATE_BOUND: case DHCP6_STATE_STOPPED: default: assert_not_reached(); } return 0; } int sd_dhcp6_client_stop(sd_dhcp6_client *client) { if (!client) return 0; client_stop(client, SD_DHCP6_CLIENT_EVENT_STOP); client->receive_message = sd_event_source_unref(client->receive_message); 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) { DHCP6State state = DHCP6_STATE_SOLICITATION; int r; assert_return(client, -EINVAL); assert_return(client->event, -EINVAL); assert_return(client->ifindex > 0, -EINVAL); assert_return(in6_addr_is_link_local(&client->local_address) > 0, -EINVAL); assert_return(!sd_dhcp6_client_is_running(client), -EBUSY); assert_return(client->information_request || client->request_ia != 0, -EINVAL); /* Even if the client is in the STOPPED state, the lease acquired in the previous information * request may be stored. */ client->lease = sd_dhcp6_lease_unref(client->lease); 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) return log_dhcp6_client_errno(client, r, "Failed to bind to UDP socket at address %s: %m", IN6_ADDR_TO_STRING(&client->local_address)); client->fd = r; } if (!client->receive_message) { _cleanup_(sd_event_source_disable_unrefp) sd_event_source *s = NULL; r = sd_event_add_io(client->event, &s, client->fd, EPOLLIN, client_receive_message, client); if (r < 0) return r; r = sd_event_source_set_priority(s, client->event_priority); if (r < 0) return r; r = sd_event_source_set_description(s, "dhcp6-receive-message"); if (r < 0) return r; client->receive_message = TAKE_PTR(s); } if (client->information_request) { usec_t t = now(CLOCK_MONOTONIC); if (t < usec_add(client->information_request_time_usec, client->information_refresh_time_usec)) return 0; client->information_request_time_usec = t; state = DHCP6_STATE_INFORMATION_REQUEST; } log_dhcp6_client(client, "Starting in %s mode", client->information_request ? "Information request" : "Solicit"); return client_start_transaction(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); assert_return(!sd_dhcp6_client_is_running(client), -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); assert_return(!sd_dhcp6_client_is_running(client), -EBUSY); 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; } int sd_dhcp6_client_attach_device(sd_dhcp6_client *client, sd_device *dev) { assert_return(client, -EINVAL); return device_unref_and_replace(client->dev, dev); } static sd_dhcp6_client *dhcp6_client_free(sd_dhcp6_client *client) { if (!client) return NULL; sd_dhcp6_lease_unref(client->lease); sd_event_source_disable_unref(client->receive_message); sd_event_source_disable_unref(client->timeout_resend); sd_event_source_disable_unref(client->timeout_expire); sd_event_source_disable_unref(client->timeout_t1); sd_event_source_disable_unref(client->timeout_t2); sd_event_unref(client->event); client->fd = safe_close(client->fd); sd_device_unref(client->dev); free(client->req_opts); free(client->fqdn); free(client->mudurl); dhcp6_ia_clear_addresses(&client->ia_pd); ordered_hashmap_free(client->extra_options); ordered_set_free(client->vendor_options); strv_free(client->user_class); strv_free(client->vendor_class); free(client->ifname); 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; assert_return(ret, -EINVAL); 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_ia = DHCP6_REQUEST_IA_NA | DHCP6_REQUEST_IA_PD, .fd = -EBADF, .rapid_commit = true, }; *ret = TAKE_PTR(client); return 0; }