diff options
Diffstat (limited to 'src/libsystemd-network/sd-dhcp6-client.c')
| -rw-r--r-- | src/libsystemd-network/sd-dhcp6-client.c | 1516 |
1 files changed, 1516 insertions, 0 deletions
diff --git a/src/libsystemd-network/sd-dhcp6-client.c b/src/libsystemd-network/sd-dhcp6-client.c new file mode 100644 index 0000000..593ffd1 --- /dev/null +++ b/src/libsystemd-network/sd-dhcp6-client.c @@ -0,0 +1,1516 @@ +/* SPDX-License-Identifier: LGPL-2.1+ */ +/*** + Copyright © 2014-2015 Intel Corporation. All rights reserved. +***/ + +#include <errno.h> +#include <string.h> +#include <sys/ioctl.h> +#include <linux/if_infiniband.h> + +#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; +} |