/***
This file is part of systemd.
Copyright (C) 2014-2015 Intel Corporation. All rights reserved.
systemd is free software; you can redistribute it and/or modify it
under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.
systemd is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/
#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 "fd-util.h"
#include "in-addr-util.h"
#include "network-internal.h"
#include "random-util.h"
#include "string-table.h"
#include "util.h"
#define MAX_MAC_ADDR_LEN INFINIBAND_ALEN
struct sd_dhcp6_client {
unsigned n_ref;
enum DHCP6State state;
sd_event *event;
int event_priority;
int index;
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;
be32_t transaction_id;
usec_t transaction_start;
struct sd_dhcp6_lease *lease;
int fd;
bool information_request;
be16_t *req_opts;
size_t req_opts_allocated;
size_t req_opts_len;
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_cb_t cb;
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_cb_t cb, void *userdata) {
assert_return(client, -EINVAL);
client->cb = cb;
client->userdata = userdata;
return 0;
}
int sd_dhcp6_client_set_index(sd_dhcp6_client *client, int interface_index) {
assert_return(client, -EINVAL);
assert_return(interface_index >= -1, -EINVAL);
assert_return(IN_SET(client->state, DHCP6_STATE_STOPPED), -EBUSY);
client->index = interface_index;
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);
}
int sd_dhcp6_client_set_duid(
sd_dhcp6_client *client,
uint16_t type,
uint8_t *duid, size_t duid_len) {
assert_return(client, -EINVAL);
assert_return(duid, -EINVAL);
assert_return(duid_len > 0 && duid_len <= MAX_DUID_LEN, -EINVAL);
assert_return(IN_SET(client->state, DHCP6_STATE_STOPPED), -EBUSY);
switch (type) {
case DHCP6_DUID_LLT:
if (duid_len <= sizeof(client->duid.llt))
return -EINVAL;
break;
case DHCP6_DUID_EN:
if (duid_len != sizeof(client->duid.en))
return -EINVAL;
break;
case DHCP6_DUID_LL:
if (duid_len <= sizeof(client->duid.ll))
return -EINVAL;
break;
case DHCP6_DUID_UUID:
if (duid_len != sizeof(client->duid.uuid))
return -EINVAL;
break;
default:
/* accept unknown type in order to be forward compatible */
break;
}
client->duid.type = htobe16(type);
memcpy(&client->duid.raw.data, duid, duid_len);
client->duid_len = duid_len + sizeof(client->duid.type);
return 0;
}
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:
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_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) {
if (client->cb)
client->cb(client, event, client->userdata);
}
static void client_set_lease(sd_dhcp6_client *client, sd_dhcp6_lease *lease) {
if (client->lease) {
dhcp6_lease_clear_timers(&client->lease->ia);
sd_dhcp6_lease_unref(client->lease);
}
client->lease = lease;
}
static int client_reset(sd_dhcp6_client *client) {
assert_return(client, -EINVAL);
client_set_lease(client, NULL);
client->receive_message =
sd_event_source_unref(client->receive_message);
client->fd = safe_close(client->fd);
client->transaction_id = 0;
client->transaction_start = 0;
client->ia_na.timeout_t1 =
sd_event_source_unref(client->ia_na.timeout_t1);
client->ia_na.timeout_t2 =
sd_event_source_unref(client->ia_na.timeout_t2);
client->retransmit_time = 0;
client->retransmit_count = 0;
client->timeout_resend = sd_event_source_unref(client->timeout_resend);
client->timeout_resend_expire =
sd_event_source_unref(client->timeout_resend_expire);
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;
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;
r = dhcp6_option_append_ia(&opt, &optlen, &client->ia_na);
if (r < 0)
return 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;
r = dhcp6_option_append_ia(&opt, &optlen, &client->lease->ia);
if (r < 0)
return r;
break;
case DHCP6_STATE_REBIND:
message->type = DHCP6_REBIND;
r = dhcp6_option_append_ia(&opt, &optlen, &client->lease->ia);
if (r < 0)
return 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_return(s, -EINVAL);
assert_return(client, -EINVAL);
assert_return(client->lease, -EINVAL);
client->lease->ia.timeout_t2 =
sd_event_source_unref(client->lease->ia.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_return(s, -EINVAL);
assert_return(client, -EINVAL);
assert_return(client->lease, -EINVAL);
client->lease->ia.timeout_t1 =
sd_event_source_unref(client->lease->ia.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);
client->timeout_resend = sd_event_source_unref(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 (!client->timeout_resend_expire) {
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 = sd_event_add_time(client->event, &client->timeout_resend,
clock_boottime_or_monotonic(),
time_now + client->retransmit_time,
10 * USEC_PER_MSEC, client_timeout_resend,
client);
if (r < 0)
goto error;
r = sd_event_source_set_priority(client->timeout_resend,
client->event_priority);
if (r < 0)
goto error;
r = sd_event_source_set_description(client->timeout_resend, "dhcp6-resend-timer");
if (r < 0)
goto error;
if (max_retransmit_duration && !client->timeout_resend_expire) {
log_dhcp6_client(client, "Max retransmission duration %"PRIu64" secs",
max_retransmit_duration / USEC_PER_SEC);
r = sd_event_add_time(client->event,
&client->timeout_resend_expire,
clock_boottime_or_monotonic(),
time_now + max_retransmit_duration,
USEC_PER_SEC,
client_timeout_resend_expire, client);
if (r < 0)
goto error;
r = sd_event_source_set_priority(client->timeout_resend_expire,
client->event_priority);
if (r < 0)
goto error;
r = sd_event_source_set_description(client->timeout_resend_expire, "dhcp6-resend-expire-timer");
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;
assert(client);
if (client->ia_na.id)
return 0;
r = dhcp_identifier_set_iaid(client->index, client->mac_addr, client->mac_addr_len, &client->ia_na.id);
if (r < 0)
return r;
return 0;
}
static int client_parse_message(sd_dhcp6_client *client,
DHCP6Message *message, size_t len,
sd_dhcp6_lease *lease) {
int r;
uint8_t *optval, *option, *id = NULL;
uint16_t optcode, status;
size_t optlen, id_len;
bool clientid = false;
be32_t iaid_lease;
option = (uint8_t *)message + sizeof(DHCP6Message);
len -= sizeof(DHCP6Message);
while ((r = dhcp6_option_parse(&option, &len, &optcode, &optlen,
&optval)) >= 0) {
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, &id, &id_len);
if (r >= 0 && id) {
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);
if (r < 0)
return r;
break;
case SD_DHCP6_OPTION_STATUS_CODE:
if (optlen < 2)
return -EINVAL;
status = optval[0] << 8 | optval[1];
if (status) {
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(&optval, &optlen, optcode,
&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.id != iaid_lease) {
log_dhcp6_client(client, "%s has wrong IAID",
dhcp6_message_type_to_string(message->type));
return -EINVAL;
}
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;
}
}
if (r == -ENOMSG)
r = 0;
if (r < 0 || !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, &id, &id_len);
if (r < 0)
log_dhcp6_client(client, "%s has no server id",
dhcp6_message_type_to_string(message->type));
}
return r;
}
static int client_receive_reply(sd_dhcp6_client *client, DHCP6Message *reply, size_t len) {
int r;
_cleanup_(sd_dhcp6_lease_unrefp) sd_dhcp6_lease *lease = NULL;
bool rapid_commit;
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;
}
client_set_lease(client, lease);
lease = NULL;
return DHCP6_STATE_BOUND;
}
static int client_receive_advertise(sd_dhcp6_client *client, DHCP6Message *advertise, size_t len) {
int r;
_cleanup_(sd_dhcp6_lease_unrefp) sd_dhcp6_lease *lease = NULL;
uint8_t pref_advertise = 0, pref_lease = 0;
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) {
client_set_lease(client, lease);
lease = NULL;
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;
int r, buflen, len;
assert(s);
assert(client);
assert(client->event);
r = ioctl(fd, FIONREAD, &buflen);
if (r < 0)
return -errno;
else if (buflen < 0)
/* This really should not happen */
return -EIO;
message = malloc(buflen);
if (!message)
return -ENOMEM;
len = read(fd, message, buflen);
if (len < 0) {
if (errno == EAGAIN || errno == EINTR)
return 0;
log_dhcp6_client(client, "Could not receive message from UDP socket: %m");
return -errno;
} else if ((size_t)len < sizeof(DHCP6Message))
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;
}
/* fall through 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;
}
if (r >= 0) {
log_dhcp6_client(client, "Recv %s",
dhcp6_message_type_to_string(message->type));
}
return 0;
}
static int client_start(sd_dhcp6_client *client, enum DHCP6State state) {
int r;
usec_t timeout, time_now;
char time_string[FORMAT_TIMESPAN_MAX];
assert_return(client, -EINVAL);
assert_return(client->event, -EINVAL);
assert_return(client->index > 0, -EINVAL);
assert_return(client->state != state, -EINVAL);
client->timeout_resend_expire =
sd_event_source_unref(client->timeout_resend_expire);
client->timeout_resend = sd_event_source_unref(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;
switch (state) {
case DHCP6_STATE_STOPPED:
if (client->state == DHCP6_STATE_INFORMATION_REQUEST) {
client->state = DHCP6_STATE_STOPPED;
return 0;
}
/* fall through */
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:
if (client->lease->ia.lifetime_t1 == 0xffffffff ||
client->lease->ia.lifetime_t2 == 0xffffffff) {
log_dhcp6_client(client, "infinite T1 0x%08x or T2 0x%08x",
be32toh(client->lease->ia.lifetime_t1),
be32toh(client->lease->ia.lifetime_t2));
return 0;
}
timeout = client_timeout_compute_random(be32toh(client->lease->ia.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 = sd_event_add_time(client->event,
&client->lease->ia.timeout_t1,
clock_boottime_or_monotonic(), time_now + timeout,
10 * USEC_PER_SEC, client_timeout_t1,
client);
if (r < 0)
return r;
r = sd_event_source_set_priority(client->lease->ia.timeout_t1,
client->event_priority);
if (r < 0)
return r;
r = sd_event_source_set_description(client->lease->ia.timeout_t1, "dhcp6-t1-timeout");
if (r < 0)
return r;
timeout = client_timeout_compute_random(be32toh(client->lease->ia.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 = sd_event_add_time(client->event,
&client->lease->ia.timeout_t2,
clock_boottime_or_monotonic(), time_now + timeout,
10 * USEC_PER_SEC, client_timeout_t2,
client);
if (r < 0)
return r;
r = sd_event_source_set_priority(client->lease->ia.timeout_t2,
client->event_priority);
if (r < 0)
return r;
r = sd_event_source_set_description(client->lease->ia.timeout_t2, "dhcp6-t2-timeout");
if (r < 0)
return r;
client->state = state;
return 0;
}
client->transaction_id = random_u32() & htobe32(0x00ffffff);
client->transaction_start = time_now;
r = sd_event_add_time(client->event, &client->timeout_resend,
clock_boottime_or_monotonic(), 0, 0, client_timeout_resend,
client);
if (r < 0)
return r;
r = sd_event_source_set_priority(client->timeout_resend,
client->event_priority);
if (r < 0)
return r;
r = sd_event_source_set_description(client->timeout_resend, "dhcp6-resend-timeout");
if (r < 0)
return r;
return 0;
}
int sd_dhcp6_client_stop(sd_dhcp6_client *client) {
assert_return(client, -EINVAL);
client_stop(client, SD_DHCP6_CLIENT_EVENT_STOP);
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) {
int r = 0;
enum DHCP6State state = DHCP6_STATE_SOLICITATION;
assert_return(client, -EINVAL);
assert_return(client->event, -EINVAL);
assert_return(client->index > 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;
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;
r = dhcp6_network_bind_udp_socket(client->index, &client->local_address);
if (r < 0)
return r;
client->fd = r;
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;
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);
error:
client_reset(client);
return r;
}
int sd_dhcp6_client_attach_event(sd_dhcp6_client *client, sd_event *event, int 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) {
if (!client)
return NULL;
return client->event;
}
sd_dhcp6_client *sd_dhcp6_client_ref(sd_dhcp6_client *client) {
if (!client)
return NULL;
assert(client->n_ref >= 1);
client->n_ref++;
return client;
}
sd_dhcp6_client *sd_dhcp6_client_unref(sd_dhcp6_client *client) {
if (!client)
return NULL;
assert(client->n_ref >= 1);
client->n_ref--;
if (client->n_ref > 0)
return NULL;
client_reset(client);
sd_dhcp6_client_detach_event(client);
free(client->req_opts);
free(client);
return NULL;
}
int sd_dhcp6_client_new(sd_dhcp6_client **ret) {
_cleanup_(sd_dhcp6_client_unrefp) sd_dhcp6_client *client = NULL;
size_t t;
assert_return(ret, -EINVAL);
client = new0(sd_dhcp6_client, 1);
if (!client)
return -ENOMEM;
client->n_ref = 1;
client->ia_na.type = SD_DHCP6_OPTION_IA_NA;
client->index = -1;
client->fd = -1;
client->req_opts_len = ELEMENTSOF(default_req_opts);
client->req_opts = new0(be16_t, client->req_opts_len);
if (!client->req_opts)
return -ENOMEM;
for (t = 0; t < client->req_opts_len; t++)
client->req_opts[t] = htobe16(default_req_opts[t]);
*ret = client;
client = NULL;
return 0;
}