/***
This file is part of systemd.
Copyright (C) 2013 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 .
***/
#include
#include
#include
#include
#include
#include
#include "util.h"
#include "list.h"
#include "dhcp-protocol.h"
#include "dhcp-internal.h"
#include "sd-dhcp-client.h"
#define DHCP_CLIENT_MIN_OPTIONS_SIZE 312
#define client_state_machine_check(s, r) \
do { \
if (s != DHCP_STATE_BOUND && \
s != DHCP_STATE_RENEWING && \
s != DHCP_STATE_REBINDING) { \
return (r); \
} \
} while (false)
struct DHCPLease {
uint32_t t1;
uint32_t t2;
uint32_t lifetime;
be32_t address;
be32_t server_address;
be32_t subnet_mask;
be32_t router;
struct in_addr *dns;
size_t dns_size;
uint16_t mtu;
char *domainname;
char *hostname;
};
typedef struct DHCPLease DHCPLease;
struct sd_dhcp_client {
DHCPState state;
sd_event *event;
int event_priority;
sd_event_source *timeout_resend;
int index;
int fd;
union sockaddr_union link;
sd_event_source *receive_message;
uint8_t *req_opts;
size_t req_opts_allocated;
size_t req_opts_size;
be32_t last_addr;
struct ether_addr mac_addr;
uint32_t xid;
usec_t start_time;
unsigned int attempt;
usec_t request_sent;
sd_event_source *timeout_t1;
sd_event_source *timeout_t2;
sd_event_source *timeout_expire;
sd_dhcp_client_cb_t cb;
void *userdata;
DHCPLease *lease;
};
static const uint8_t default_req_opts[] = {
DHCP_OPTION_SUBNET_MASK,
DHCP_OPTION_ROUTER,
DHCP_OPTION_HOST_NAME,
DHCP_OPTION_DOMAIN_NAME,
DHCP_OPTION_DOMAIN_NAME_SERVER,
DHCP_OPTION_NTP_SERVER,
};
static int client_receive_message(sd_event_source *s, int fd,
uint32_t revents, void *userdata);
int sd_dhcp_client_set_callback(sd_dhcp_client *client, sd_dhcp_client_cb_t cb,
void *userdata) {
assert_return(client, -EINVAL);
client->cb = cb;
client->userdata = userdata;
return 0;
}
int sd_dhcp_client_set_request_option(sd_dhcp_client *client, uint8_t option) {
size_t i;
assert_return(client, -EINVAL);
assert_return (client->state == DHCP_STATE_INIT, -EBUSY);
switch(option) {
case DHCP_OPTION_PAD:
case DHCP_OPTION_OVERLOAD:
case DHCP_OPTION_MESSAGE_TYPE:
case DHCP_OPTION_PARAMETER_REQUEST_LIST:
case DHCP_OPTION_END:
return -EINVAL;
default:
break;
}
for (i = 0; i < client->req_opts_size; i++)
if (client->req_opts[i] == option)
return -EEXIST;
if (!GREEDY_REALLOC(client->req_opts, client->req_opts_allocated,
client->req_opts_size + 1))
return -ENOMEM;
client->req_opts[client->req_opts_size++] = option;
return 0;
}
int sd_dhcp_client_set_request_address(sd_dhcp_client *client,
const struct in_addr *last_addr) {
assert_return(client, -EINVAL);
assert_return(client->state == DHCP_STATE_INIT, -EBUSY);
if (last_addr)
client->last_addr = last_addr->s_addr;
else
client->last_addr = INADDR_ANY;
return 0;
}
int sd_dhcp_client_set_index(sd_dhcp_client *client, int interface_index) {
assert_return(client, -EINVAL);
assert_return(client->state == DHCP_STATE_INIT, -EBUSY);
assert_return(interface_index >= -1, -EINVAL);
client->index = interface_index;
return 0;
}
int sd_dhcp_client_set_mac(sd_dhcp_client *client,
const struct ether_addr *addr) {
assert_return(client, -EINVAL);
assert_return(client->state == DHCP_STATE_INIT, -EBUSY);
memcpy(&client->mac_addr, addr, ETH_ALEN);
return 0;
}
int sd_dhcp_client_get_address(sd_dhcp_client *client, struct in_addr *addr) {
assert_return(client, -EINVAL);
assert_return(addr, -EINVAL);
client_state_machine_check (client->state, -EADDRNOTAVAIL);
addr->s_addr = client->lease->address;
return 0;
}
int sd_dhcp_client_get_mtu(sd_dhcp_client *client, uint16_t *mtu) {
assert_return(client, -EINVAL);
assert_return(mtu, -EINVAL);
client_state_machine_check (client->state, -EADDRNOTAVAIL);
if (client->lease->mtu)
*mtu = client->lease->mtu;
else
return -ENOENT;
return 0;
}
int sd_dhcp_client_get_dns(sd_dhcp_client *client, struct in_addr **addr, size_t *addr_size) {
assert_return(client, -EINVAL);
assert_return(addr, -EINVAL);
assert_return(addr_size, -EINVAL);
client_state_machine_check (client->state, -EADDRNOTAVAIL);
if (client->lease->dns_size) {
*addr_size = client->lease->dns_size;
*addr = client->lease->dns;
} else
return -ENOENT;
return 0;
}
int sd_dhcp_client_get_domainname(sd_dhcp_client *client, const char **domainname) {
assert_return(client, -EINVAL);
assert_return(domainname, -EINVAL);
client_state_machine_check (client->state, -EADDRNOTAVAIL);
if (client->lease->domainname)
*domainname = client->lease->domainname;
else
return -ENOENT;
return 0;
}
int sd_dhcp_client_get_hostname(sd_dhcp_client *client, const char **hostname) {
assert_return(client, -EINVAL);
assert_return(hostname, -EINVAL);
client_state_machine_check (client->state, -EADDRNOTAVAIL);
if (client->lease->hostname)
*hostname = client->lease->hostname;
else
return -ENOENT;
return 0;
}
int sd_dhcp_client_get_router(sd_dhcp_client *client, struct in_addr *addr) {
assert_return(client, -EINVAL);
assert_return(addr, -EINVAL);
client_state_machine_check (client->state, -EADDRNOTAVAIL);
addr->s_addr = client->lease->router;
return 0;
}
int sd_dhcp_client_get_netmask(sd_dhcp_client *client, struct in_addr *addr) {
assert_return(client, -EINVAL);
assert_return(addr, -EINVAL);
client_state_machine_check (client->state, -EADDRNOTAVAIL);
addr->s_addr = client->lease->subnet_mask;
return 0;
}
static int client_notify(sd_dhcp_client *client, int event) {
if (client->cb)
client->cb(client, event, client->userdata);
return 0;
}
static void lease_free(DHCPLease *lease) {
if (!lease)
return;
free(lease->hostname);
free(lease->domainname);
free(lease->dns);
free(lease);
}
DEFINE_TRIVIAL_CLEANUP_FUNC(DHCPLease*, lease_free);
#define _cleanup_lease_free_ _cleanup_(lease_freep)
static int client_stop(sd_dhcp_client *client, int error) {
assert_return(client, -EINVAL);
client->receive_message =
sd_event_source_unref(client->receive_message);
if (client->fd >= 0)
close(client->fd);
client->fd = -1;
client->timeout_resend = sd_event_source_unref(client->timeout_resend);
client->timeout_t1 = sd_event_source_unref(client->timeout_t1);
client->timeout_t2 = sd_event_source_unref(client->timeout_t2);
client->timeout_expire = sd_event_source_unref(client->timeout_expire);
client->attempt = 1;
client_notify(client, error);
switch (client->state) {
case DHCP_STATE_INIT:
case DHCP_STATE_SELECTING:
case DHCP_STATE_REQUESTING:
case DHCP_STATE_BOUND:
client->start_time = 0;
client->state = DHCP_STATE_INIT;
break;
case DHCP_STATE_INIT_REBOOT:
case DHCP_STATE_REBOOTING:
case DHCP_STATE_RENEWING:
case DHCP_STATE_REBINDING:
break;
}
if (client->lease) {
lease_free(client->lease);
client->lease = NULL;
}
return 0;
}
static int client_packet_init(sd_dhcp_client *client, uint8_t type,
DHCPMessage *message, uint16_t secs,
uint8_t **opt, size_t *optlen) {
int err;
be16_t max_size;
*opt = (uint8_t *)(message + 1);
if (*optlen < 4)
return -ENOBUFS;
*optlen -= 4;
message->op = BOOTREQUEST;
message->htype = 1;
message->hlen = ETHER_ADDR_LEN;
message->xid = htobe32(client->xid);
/* Although 'secs' field is a SHOULD in RFC 2131, certain DHCP servers
refuse to issue an DHCP lease if 'secs' is set to zero */
message->secs = htobe16(secs);
if (client->state == DHCP_STATE_RENEWING ||
client->state == DHCP_STATE_REBINDING)
message->ciaddr = client->lease->address;
memcpy(&message->chaddr, &client->mac_addr, ETH_ALEN);
(*opt)[0] = 0x63;
(*opt)[1] = 0x82;
(*opt)[2] = 0x53;
(*opt)[3] = 0x63;
*opt += 4;
err = dhcp_option_append(opt, optlen, DHCP_OPTION_MESSAGE_TYPE, 1,
&type);
if (err < 0)
return err;
/* Some DHCP servers will refuse to issue an DHCP lease if the Cliient
Identifier option is not set */
err = dhcp_option_append(opt, optlen, DHCP_OPTION_CLIENT_IDENTIFIER,
ETH_ALEN, &client->mac_addr);
if (err < 0)
return err;
if (type == DHCP_DISCOVER || type == DHCP_REQUEST) {
err = dhcp_option_append(opt, optlen,
DHCP_OPTION_PARAMETER_REQUEST_LIST,
client->req_opts_size,
client->req_opts);
if (err < 0)
return err;
/* Some DHCP servers will send bigger DHCP packets than the
defined default size unless the Maximum Messge Size option
is explicitely set */
max_size = htobe16(DHCP_IP_UDP_SIZE + DHCP_MESSAGE_SIZE +
DHCP_CLIENT_MIN_OPTIONS_SIZE);
err = dhcp_option_append(opt, optlen,
DHCP_OPTION_MAXIMUM_MESSAGE_SIZE,
2, &max_size);
if (err < 0)
return err;
}
return 0;
}
static uint16_t client_checksum(void *buf, int len) {
uint32_t sum;
uint16_t *check;
int i;
uint8_t *odd;
sum = 0;
check = buf;
for (i = 0; i < len / 2 ; i++)
sum += check[i];
if (len & 0x01) {
odd = buf;
sum += odd[len - 1];
}
while (sum >> 16)
sum = (sum & 0xffff) + (sum >> 16);
return ~sum;
}
static void client_append_ip_headers(DHCPPacket *packet, uint16_t len) {
packet->ip.version = IPVERSION;
packet->ip.ihl = DHCP_IP_SIZE / 4;
packet->ip.tot_len = htobe16(len);
packet->ip.protocol = IPPROTO_UDP;
packet->ip.saddr = INADDR_ANY;
packet->ip.daddr = INADDR_BROADCAST;
packet->udp.source = htobe16(DHCP_PORT_CLIENT);
packet->udp.dest = htobe16(DHCP_PORT_SERVER);
packet->udp.len = htobe16(len - DHCP_IP_SIZE);
packet->ip.check = packet->udp.len;
packet->udp.check = client_checksum(&packet->ip.ttl, len - 8);
packet->ip.ttl = IPDEFTTL;
packet->ip.check = 0;
packet->ip.check = client_checksum(&packet->ip, DHCP_IP_SIZE);
}
static int client_send_discover(sd_dhcp_client *client, uint16_t secs) {
int err = 0;
_cleanup_free_ DHCPPacket *discover;
size_t optlen, len;
uint8_t *opt;
optlen = DHCP_CLIENT_MIN_OPTIONS_SIZE;
len = sizeof(DHCPPacket) + optlen;
discover = malloc0(len);
if (!discover)
return -ENOMEM;
err = client_packet_init(client, DHCP_DISCOVER, &discover->dhcp,
secs, &opt, &optlen);
if (err < 0)
return err;
if (client->last_addr != INADDR_ANY) {
err = dhcp_option_append(&opt, &optlen,
DHCP_OPTION_REQUESTED_IP_ADDRESS,
4, &client->last_addr);
if (err < 0)
return err;
}
err = dhcp_option_append(&opt, &optlen, DHCP_OPTION_END, 0, NULL);
if (err < 0)
return err;
client_append_ip_headers(discover, len);
err = dhcp_network_send_raw_socket(client->fd, &client->link,
discover, len);
return err;
}
static int client_send_request(sd_dhcp_client *client, uint16_t secs) {
_cleanup_free_ DHCPPacket *request;
size_t optlen, len;
int err;
uint8_t *opt;
optlen = DHCP_CLIENT_MIN_OPTIONS_SIZE;
len = DHCP_MESSAGE_SIZE + optlen;
request = malloc0(len);
if (!request)
return -ENOMEM;
err = client_packet_init(client, DHCP_REQUEST, &request->dhcp, secs,
&opt, &optlen);
if (err < 0)
return err;
if (client->state == DHCP_STATE_REQUESTING) {
err = dhcp_option_append(&opt, &optlen,
DHCP_OPTION_REQUESTED_IP_ADDRESS,
4, &client->lease->address);
if (err < 0)
return err;
err = dhcp_option_append(&opt, &optlen,
DHCP_OPTION_SERVER_IDENTIFIER,
4, &client->lease->server_address);
if (err < 0)
return err;
}
err = dhcp_option_append(&opt, &optlen, DHCP_OPTION_END, 0, NULL);
if (err < 0)
return err;
if (client->state == DHCP_STATE_RENEWING) {
err = dhcp_network_send_udp_socket(client->fd,
client->lease->server_address,
&request->dhcp,
len - DHCP_IP_UDP_SIZE);
} else {
client_append_ip_headers(request, len);
err = dhcp_network_send_raw_socket(client->fd, &client->link,
request, len);
}
return err;
}
static int client_timeout_resend(sd_event_source *s, uint64_t usec,
void *userdata) {
sd_dhcp_client *client = userdata;
usec_t next_timeout = 0;
uint32_t time_left;
uint16_t secs;
int r = 0;
assert(s);
assert(client);
assert(client->event);
switch (client->state) {
case DHCP_STATE_RENEWING:
time_left = (client->lease->t2 - client->lease->t1)/2;
if (time_left < 60)
time_left = 60;
next_timeout = usec + time_left * USEC_PER_SEC;
break;
case DHCP_STATE_REBINDING:
time_left = (client->lease->lifetime - client->lease->t2)/2;
if (time_left < 60)
time_left = 60;
next_timeout = usec + time_left * USEC_PER_SEC;
break;
case DHCP_STATE_INIT:
case DHCP_STATE_INIT_REBOOT:
case DHCP_STATE_REBOOTING:
case DHCP_STATE_SELECTING:
case DHCP_STATE_REQUESTING:
case DHCP_STATE_BOUND:
if (client->attempt < 64)
client->attempt *= 2;
next_timeout = usec + (client->attempt - 1) * USEC_PER_SEC;
break;
}
next_timeout += (random_u32() & 0x1fffff);
r = sd_event_add_monotonic(client->event, next_timeout,
10 * USEC_PER_MSEC,
client_timeout_resend, client,
&client->timeout_resend);
if (r < 0)
goto error;
r = sd_event_source_set_priority(client->timeout_resend, client->event_priority);
if (r < 0)
goto error;
secs = (usec - client->start_time) / USEC_PER_SEC;
switch (client->state) {
case DHCP_STATE_INIT:
r = client_send_discover(client, secs);
if (r >= 0) {
client->state = DHCP_STATE_SELECTING;
client->attempt = 1;
} else {
if (client->attempt >= 64)
goto error;
}
break;
case DHCP_STATE_SELECTING:
r = client_send_discover(client, secs);
if (r < 0 && client->attempt >= 64)
goto error;
break;
case DHCP_STATE_REQUESTING:
case DHCP_STATE_RENEWING:
case DHCP_STATE_REBINDING:
r = client_send_request(client, secs);
if (r < 0 && client->attempt >= 64)
goto error;
client->request_sent = usec;
break;
case DHCP_STATE_INIT_REBOOT:
case DHCP_STATE_REBOOTING:
case DHCP_STATE_BOUND:
break;
}
return 0;
error:
client_stop(client, r);
/* Errors were dealt with when stopping the client, don't spill
errors into the event loop handler */
return 0;
}
static int client_initialize_events(sd_dhcp_client *client, usec_t usec) {
int r;
assert(client);
assert(client->event);
r = sd_event_add_io(client->event, client->fd, EPOLLIN,
client_receive_message, client,
&client->receive_message);
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_add_monotonic(client->event, usec, 0,
client_timeout_resend, client,
&client->timeout_resend);
if (r < 0)
goto error;
r = sd_event_source_set_priority(client->timeout_resend, client->event_priority);
error:
if (r < 0)
client_stop(client, r);
return 0;
}
static int client_timeout_expire(sd_event_source *s, uint64_t usec,
void *userdata) {
sd_dhcp_client *client = userdata;
client_stop(client, DHCP_EVENT_EXPIRED);
return 0;
}
static int client_timeout_t2(sd_event_source *s, uint64_t usec, void *userdata) {
sd_dhcp_client *client = userdata;
int r;
if (client->fd >= 0) {
client->receive_message =
sd_event_source_unref(client->receive_message);
close(client->fd);
client->fd = -1;
}
client->state = DHCP_STATE_REBINDING;
client->attempt = 1;
r = dhcp_network_bind_raw_socket(client->index, &client->link);
if (r < 0) {
client_stop(client, r);
return 0;
}
client->fd = r;
return client_initialize_events(client, usec);
}
static int client_timeout_t1(sd_event_source *s, uint64_t usec, void *userdata) {
sd_dhcp_client *client = userdata;
int r;
client->state = DHCP_STATE_RENEWING;
client->attempt = 1;
r = dhcp_network_bind_udp_socket(client->index,
client->lease->address);
if (r < 0) {
client_stop(client, r);
return 0;
}
client->fd = r;
return client_initialize_events(client, usec);
}
static int client_parse_offer(uint8_t code, uint8_t len, const uint8_t *option,
void *user_data) {
DHCPLease *lease = user_data;
be32_t val;
switch(code) {
case DHCP_OPTION_IP_ADDRESS_LEASE_TIME:
if (len == 4) {
memcpy(&val, option, 4);
lease->lifetime = be32toh(val);
}
break;
case DHCP_OPTION_SERVER_IDENTIFIER:
if (len >= 4)
memcpy(&lease->server_address, option, 4);
break;
case DHCP_OPTION_SUBNET_MASK:
if (len >= 4)
memcpy(&lease->subnet_mask, option, 4);
break;
case DHCP_OPTION_ROUTER:
if (len >= 4)
memcpy(&lease->router, option, 4);
break;
case DHCP_OPTION_DOMAIN_NAME_SERVER:
if (len && !(len % 4)) {
unsigned i;
lease->dns_size = len / 4;
free(lease->dns);
lease->dns = new0(struct in_addr, lease->dns_size);
if (!lease->dns)
return -ENOMEM;
for (i = 0; i < lease->dns_size; i++) {
memcpy(&lease->dns[i].s_addr, option + 4 * i, 4);
}
}
break;
case DHCP_OPTION_INTERFACE_MTU:
if (len >= 2) {
be16_t mtu;
memcpy(&mtu, option, 2);
lease->mtu = be16toh(mtu);
if (lease->mtu < 68)
lease->mtu = 0;
}
break;
case DHCP_OPTION_DOMAIN_NAME:
if (len >= 1) {
free(lease->domainname);
lease->domainname = strndup((const char *)option, len);
}
break;
case DHCP_OPTION_HOST_NAME:
if (len >= 1) {
free(lease->hostname);
lease->hostname = strndup((const char *)option, len);
}
break;
case DHCP_OPTION_RENEWAL_T1_TIME:
if (len == 4) {
memcpy(&val, option, 4);
lease->t1 = be32toh(val);
}
break;
case DHCP_OPTION_REBINDING_T2_TIME:
if (len == 4) {
memcpy(&val, option, 4);
lease->t2 = be32toh(val);
}
break;
}
return 0;
}
static int client_verify_headers(sd_dhcp_client *client, DHCPPacket *message,
size_t len) {
size_t hdrlen;
if (len < (DHCP_IP_UDP_SIZE + DHCP_MESSAGE_SIZE))
return -EINVAL;
hdrlen = message->ip.ihl * 4;
if (hdrlen < 20 || hdrlen > len || client_checksum(&message->ip,
hdrlen))
return -EINVAL;
message->ip.check = message->udp.len;
message->ip.ttl = 0;
if (hdrlen + be16toh(message->udp.len) > len ||
client_checksum(&message->ip.ttl, be16toh(message->udp.len) + 12))
return -EINVAL;
if (be16toh(message->udp.source) != DHCP_PORT_SERVER ||
be16toh(message->udp.dest) != DHCP_PORT_CLIENT)
return -EINVAL;
if (message->dhcp.op != BOOTREPLY)
return -EINVAL;
if (be32toh(message->dhcp.xid) != client->xid)
return -EINVAL;
if (memcmp(&message->dhcp.chaddr[0], &client->mac_addr.ether_addr_octet,
ETHER_ADDR_LEN))
return -EINVAL;
return 0;
}
static int client_receive_offer(sd_dhcp_client *client, DHCPPacket *offer,
size_t len) {
_cleanup_lease_free_ DHCPLease *lease = NULL;
int r;
r = client_verify_headers(client, offer, len);
if (r < 0)
return r;
lease = new0(DHCPLease, 1);
if (!lease)
return -ENOMEM;
len = len - DHCP_IP_UDP_SIZE;
r = dhcp_option_parse(&offer->dhcp, len, client_parse_offer,
lease);
if (r != DHCP_OFFER)
return -ENOMSG;
lease->address = offer->dhcp.yiaddr;
if (lease->address == INADDR_ANY ||
lease->server_address == INADDR_ANY ||
lease->subnet_mask == INADDR_ANY ||
lease->lifetime == 0)
return -ENOMSG;
client->lease = lease;
lease = NULL;
return 0;
}
static int client_receive_ack(sd_dhcp_client *client, const uint8_t *buf,
size_t len) {
DHCPPacket *ack;
DHCPMessage *dhcp;
_cleanup_lease_free_ DHCPLease *lease = NULL;
int r;
if (client->state == DHCP_STATE_RENEWING) {
dhcp = (DHCPMessage *)buf;
} else {
ack = (DHCPPacket *)buf;
r = client_verify_headers(client, ack, len);
if (r < 0)
return r;
dhcp = &ack->dhcp;
len -= DHCP_IP_UDP_SIZE;
}
lease = new0(DHCPLease, 1);
if (!lease)
return -ENOMEM;
r = dhcp_option_parse(dhcp, len, client_parse_offer, lease);
if (r == DHCP_NAK)
return DHCP_EVENT_NO_LEASE;
if (r != DHCP_ACK)
return -ENOMSG;
lease->address = dhcp->yiaddr;
if (lease->address == INADDR_ANY ||
lease->server_address == INADDR_ANY ||
lease->subnet_mask == INADDR_ANY || lease->lifetime == 0)
return -ENOMSG;
r = DHCP_EVENT_IP_ACQUIRE;
if (client->lease) {
if (client->lease->address != lease->address ||
client->lease->subnet_mask != lease->subnet_mask ||
client->lease->router != lease->router) {
r = DHCP_EVENT_IP_CHANGE;
}
lease_free(client->lease);
}
client->lease = lease;
lease = NULL;
return r;
}
static uint64_t client_compute_timeout(uint64_t request_sent,
uint32_t lifetime) {
return request_sent + (lifetime - 3) * USEC_PER_SEC +
+ (random_u32() & 0x1fffff);
}
static int client_set_lease_timeouts(sd_dhcp_client *client, uint64_t usec) {
uint64_t next_timeout;
int r;
assert(client);
assert(client->event);
if (client->lease->lifetime < 10)
return -EINVAL;
client->timeout_t1 = sd_event_source_unref(client->timeout_t1);
client->timeout_t2 = sd_event_source_unref(client->timeout_t2);
client->timeout_expire = sd_event_source_unref(client->timeout_expire);
if (!client->lease->t1)
client->lease->t1 = client->lease->lifetime / 2;
next_timeout = client_compute_timeout(client->request_sent,
client->lease->t1);
if (next_timeout < usec)
return -EINVAL;
r = sd_event_add_monotonic(client->event, next_timeout,
10 * USEC_PER_MSEC,
client_timeout_t1, client,
&client->timeout_t1);
if (r < 0)
return r;
r = sd_event_source_set_priority(client->timeout_t1, client->event_priority);
if (r < 0)
return r;
if (!client->lease->t2)
client->lease->t2 = client->lease->lifetime * 7 / 8;
if (client->lease->t2 < client->lease->t1)
return -EINVAL;
if (client->lease->lifetime < client->lease->t2)
return -EINVAL;
next_timeout = client_compute_timeout(client->request_sent,
client->lease->t2);
if (next_timeout < usec)
return -EINVAL;
r = sd_event_add_monotonic(client->event, next_timeout,
10 * USEC_PER_MSEC,
client_timeout_t2, client,
&client->timeout_t2);
if (r < 0)
return r;
r = sd_event_source_set_priority(client->timeout_t2, client->event_priority);
if (r < 0)
return r;
next_timeout = client_compute_timeout(client->request_sent,
client->lease->lifetime);
if (next_timeout < usec)
return -EINVAL;
r = sd_event_add_monotonic(client->event, next_timeout,
10 * USEC_PER_MSEC,
client_timeout_expire, client,
&client->timeout_expire);
if (r < 0)
return r;
r = sd_event_source_set_priority(client->timeout_expire, client->event_priority);
if (r < 0)
return r;
return 0;
}
static int client_receive_message(sd_event_source *s, int fd,
uint32_t revents, void *userdata) {
sd_dhcp_client *client = userdata;
uint8_t buf[sizeof(DHCPPacket) + DHCP_CLIENT_MIN_OPTIONS_SIZE];
int buflen = sizeof(buf);
int len, r = 0, notify_event = 0;
DHCPPacket *message;
usec_t time_now;
assert(s);
assert(client);
assert(client->event);
len = read(fd, &buf, buflen);
if (len < 0)
return 0;
r = sd_event_get_now_monotonic(client->event, &time_now);
if (r < 0)
goto error;
switch (client->state) {
case DHCP_STATE_SELECTING:
message = (DHCPPacket *)&buf;
if (client_receive_offer(client, message, len) >= 0) {
client->timeout_resend =
sd_event_source_unref(client->timeout_resend);
client->state = DHCP_STATE_REQUESTING;
client->attempt = 1;
r = sd_event_add_monotonic(client->event, time_now, 0,
client_timeout_resend,
client,
&client->timeout_resend);
if (r < 0)
goto error;
r = sd_event_source_set_priority(client->timeout_resend, client->event_priority);
if (r < 0)
goto error;
}
break;
case DHCP_STATE_REQUESTING:
case DHCP_STATE_RENEWING:
case DHCP_STATE_REBINDING:
r = client_receive_ack(client, buf, len);
if (r == DHCP_EVENT_NO_LEASE)
goto error;
if (r >= 0) {
client->timeout_resend =
sd_event_source_unref(client->timeout_resend);
if (client->state == DHCP_STATE_REQUESTING)
notify_event = DHCP_EVENT_IP_ACQUIRE;
else if (r != DHCP_EVENT_IP_ACQUIRE)
notify_event = r;
client->state = DHCP_STATE_BOUND;
client->attempt = 1;
client->last_addr = client->lease->address;
r = client_set_lease_timeouts(client, time_now);
if (r < 0)
goto error;
if (notify_event)
client_notify(client, notify_event);
client->receive_message =
sd_event_source_unref(client->receive_message);
close(client->fd);
client->fd = -1;
}
r = 0;
break;
case DHCP_STATE_INIT:
case DHCP_STATE_INIT_REBOOT:
case DHCP_STATE_REBOOTING:
case DHCP_STATE_BOUND:
break;
}
error:
if (r < 0 || r == DHCP_EVENT_NO_LEASE)
return client_stop(client, r);
return 0;
}
int sd_dhcp_client_start(sd_dhcp_client *client) {
int r;
assert_return(client, -EINVAL);
assert_return(client->event, -EINVAL);
assert_return(client->index > 0, -EINVAL);
assert_return(client->state == DHCP_STATE_INIT ||
client->state == DHCP_STATE_INIT_REBOOT, -EBUSY);
client->xid = random_u32();
r = dhcp_network_bind_raw_socket(client->index, &client->link);
if (r < 0) {
client_stop(client, r);
return r;
}
client->fd = r;
client->start_time = now(CLOCK_MONOTONIC);
return client_initialize_events(client, client->start_time);
}
int sd_dhcp_client_stop(sd_dhcp_client *client) {
return client_stop(client, DHCP_EVENT_STOP);
}
int sd_dhcp_client_attach_event(sd_dhcp_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_dhcp_client_detach_event(sd_dhcp_client *client) {
assert_return(client, -EINVAL);
client->event = sd_event_unref(client->event);
return 0;
}
sd_event *sd_dhcp_client_get_event(sd_dhcp_client *client) {
if (!client)
return NULL;
return client->event;
}
void sd_dhcp_client_free(sd_dhcp_client *client) {
if (!client)
return;
sd_dhcp_client_stop(client);
sd_dhcp_client_detach_event(client);
free(client->req_opts);
free(client);
}
DEFINE_TRIVIAL_CLEANUP_FUNC(sd_dhcp_client*, sd_dhcp_client_free);
#define _cleanup_dhcp_client_free_ _cleanup_(sd_dhcp_client_freep)
int sd_dhcp_client_new(sd_dhcp_client **ret) {
_cleanup_dhcp_client_free_ sd_dhcp_client *client = NULL;
assert_return(ret, -EINVAL);
client = new0(sd_dhcp_client, 1);
if (!client)
return -ENOMEM;
client->state = DHCP_STATE_INIT;
client->index = -1;
client->fd = -1;
client->attempt = 1;
client->req_opts_size = ELEMENTSOF(default_req_opts);
client->req_opts = memdup(default_req_opts, client->req_opts_size);
if (!client->req_opts)
return -ENOMEM;
*ret = client;
client = NULL;
return 0;
}