blob: 68b41dfb6cd777a9b6278358103d230a3f95eb88 [file] [log] [blame] [raw]
/* 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 == -ENETDOWN) {
/* the link is down. Don't return an error or the I/O event
source will be disconnected and we won't be able to receive
packets again when the link comes back. */
return 0;
}
if (buflen < 0)
return buflen;
message = malloc(buflen);
if (!message)
return -ENOMEM;
len = recv(fd, message, buflen, 0);
if (len < 0) {
/* see comment above for why we shouldn't error out on ENETDOWN. */
if (IN_SET(errno, EAGAIN, EINTR, ENETDOWN))
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;
}