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authorTom Gundersen <teg@jklm.no>2014-02-27 01:24:05 +0100
committerTom Gundersen <teg@jklm.no>2014-02-28 01:01:13 +0100
commitfe8db0c5ee3365a2fc80ee7ebffa238f9a0a2ae2 (patch)
tree51d408aaec8fa6acd19c51839cd50618c9a00321 /src/libsystemd-network/sd-dhcp-client.c
parentc594cccee264cfd98f183ae6ec289b11e70f2d6c (diff)
sd-network: add new library
This is similar to sd-login, but exposes the state of networkd rather than logind. Include it in libsystemd-dhcp and rename it to libsystemd-network.
Diffstat (limited to 'src/libsystemd-network/sd-dhcp-client.c')
-rw-r--r--src/libsystemd-network/sd-dhcp-client.c1051
1 files changed, 1051 insertions, 0 deletions
diff --git a/src/libsystemd-network/sd-dhcp-client.c b/src/libsystemd-network/sd-dhcp-client.c
new file mode 100644
index 0000000000..1f676ccb65
--- /dev/null
+++ b/src/libsystemd-network/sd-dhcp-client.c
@@ -0,0 +1,1051 @@
+/***
+ 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 <http://www.gnu.org/licenses/>.
+***/
+
+#include <stdlib.h>
+#include <errno.h>
+#include <string.h>
+#include <stdio.h>
+#include <net/ethernet.h>
+#include <sys/param.h>
+#include <sys/ioctl.h>
+
+#include "util.h"
+#include "list.h"
+
+#include "dhcp-protocol.h"
+#include "dhcp-internal.h"
+#include "dhcp-lease-internal.h"
+#include "sd-dhcp-client.h"
+
+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;
+ uint16_t secs;
+ 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;
+ sd_dhcp_lease *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_raw(sd_event_source *s, int fd,
+ uint32_t revents, void *userdata);
+static int client_receive_message_udp(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_lease(sd_dhcp_client *client, sd_dhcp_lease **ret) {
+ assert_return(client, -EINVAL);
+ assert_return(ret, -EINVAL);
+
+ if (client->state != DHCP_STATE_BOUND &&
+ client->state != DHCP_STATE_RENEWING &&
+ client->state != DHCP_STATE_REBINDING)
+ return -EADDRNOTAVAIL;
+
+ *ret = sd_dhcp_lease_ref(client->lease);
+
+ return 0;
+}
+
+static int client_notify(sd_dhcp_client *client, int event) {
+ if (client->cb)
+ client->cb(client, event, client->userdata);
+
+ return 0;
+}
+
+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);
+
+ client->start_time = 0;
+ client->secs = 0;
+ client->state = DHCP_STATE_INIT;
+
+ if (client->lease)
+ client->lease = sd_dhcp_lease_unref(client->lease);
+
+ log_dhcp_client(client, "STOPPED");
+
+ return 0;
+}
+
+static int client_message_init(sd_dhcp_client *client, DHCPMessage *message,
+ uint8_t type, uint16_t secs, uint8_t **opt,
+ size_t *optlen) {
+ int r;
+
+ assert(secs);
+
+ r = dhcp_message_init(message, BOOTREQUEST, client->xid, type, opt,
+ optlen);
+ if (r < 0)
+ return r;
+
+ /* 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);
+
+ memcpy(&message->chaddr, &client->mac_addr, ETH_ALEN);
+
+ if (client->state == DHCP_STATE_RENEWING ||
+ client->state == DHCP_STATE_REBINDING)
+ message->ciaddr = client->lease->address;
+
+ /* Some DHCP servers will refuse to issue an DHCP lease if the Client
+ Identifier option is not set */
+ r = dhcp_option_append(opt, optlen, DHCP_OPTION_CLIENT_IDENTIFIER,
+ ETH_ALEN, &client->mac_addr);
+ if (r < 0)
+ return r;
+
+ if (type == DHCP_DISCOVER || type == DHCP_REQUEST) {
+ be16_t max_size;
+
+ r = dhcp_option_append(opt, optlen,
+ DHCP_OPTION_PARAMETER_REQUEST_LIST,
+ client->req_opts_size,
+ client->req_opts);
+ if (r < 0)
+ return r;
+
+ /* 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_MIN_OPTIONS_SIZE);
+ r = dhcp_option_append(opt, optlen,
+ DHCP_OPTION_MAXIMUM_MESSAGE_SIZE,
+ 2, &max_size);
+ if (r < 0)
+ return r;
+ }
+
+ return 0;
+}
+
+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_MIN_OPTIONS_SIZE;
+ len = sizeof(DHCPPacket) + optlen;
+
+ discover = malloc0(len);
+
+ if (!discover)
+ return -ENOMEM;
+
+ err = client_message_init(client, &discover->dhcp, DHCP_DISCOVER,
+ 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;
+
+ dhcp_packet_append_ip_headers(discover, len);
+
+ err = dhcp_network_send_raw_socket(client->fd, &client->link,
+ discover, len);
+
+ log_dhcp_client(client, "DISCOVER");
+
+ 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_MIN_OPTIONS_SIZE;
+ len = sizeof(DHCPPacket) + optlen;
+
+ request = malloc0(len);
+ if (!request)
+ return -ENOMEM;
+
+ err = client_message_init(client, &request->dhcp, DHCP_REQUEST, 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,
+ DHCP_PORT_SERVER,
+ &request->dhcp,
+ len - DHCP_IP_UDP_SIZE);
+ } else {
+ dhcp_packet_append_ip_headers(request, len);
+
+ err = dhcp_network_send_raw_socket(client->fd, &client->link,
+ request, len);
+ }
+
+ log_dhcp_client(client, "REQUEST");
+
+ return err;
+}
+
+static uint16_t client_update_secs(sd_dhcp_client *client, usec_t time_now)
+{
+ client->secs = ((time_now - client->start_time) / USEC_PER_SEC) ? : 1;
+
+ return client->secs;
+}
+
+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;
+ 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);
+
+ client->timeout_resend = sd_event_source_unref(client->timeout_resend);
+
+ r = sd_event_add_monotonic(client->event,
+ &client->timeout_resend,
+ next_timeout,
+ 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;
+
+ switch (client->state) {
+ case DHCP_STATE_INIT:
+
+ client_update_secs(client, usec);
+
+ r = client_send_discover(client, 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:
+ client_update_secs(client, usec);
+
+ r = client_send_discover(client, 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, 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,
+ sd_event_io_handler_t io_callback,
+ usec_t usec) {
+ int r;
+
+ assert(client);
+ assert(client->event);
+
+ r = sd_event_add_io(client->event, &client->receive_message,
+ client->fd, EPOLLIN, io_callback,
+ client);
+ if (r < 0)
+ goto error;
+
+ r = sd_event_source_set_priority(client->receive_message,
+ client->event_priority);
+ if (r < 0)
+ goto error;
+
+ client->timeout_resend = sd_event_source_unref(client->timeout_resend);
+
+ r = sd_event_add_monotonic(client->event,
+ &client->timeout_resend,
+ usec, 0,
+ client_timeout_resend, client);
+ 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;
+
+ log_dhcp_client(client, "EXPIRED");
+
+ 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;
+
+ log_dhcp_client(client, "TIMEOUT T2");
+
+ return client_initialize_events(client, client_receive_message_raw,
+ 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,
+ DHCP_PORT_CLIENT);
+ if (r < 0) {
+ client_stop(client, r);
+ return 0;
+ }
+
+ client->fd = r;
+
+ log_dhcp_client(client, "TIMEOUT T1");
+
+ return client_initialize_events(client, client_receive_message_udp, usec);
+}
+
+static int client_handle_offer(sd_dhcp_client *client, DHCPMessage *offer,
+ size_t len) {
+ _cleanup_dhcp_lease_unref_ sd_dhcp_lease *lease = NULL;
+ int r;
+
+ r = dhcp_lease_new(&lease);
+ if (r < 0)
+ return r;
+
+ r = dhcp_option_parse(offer, len, dhcp_lease_parse_options, lease);
+ if (r != DHCP_OFFER)
+ return -ENOMSG;
+
+ lease->address = offer->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;
+
+ log_dhcp_client(client, "OFFER");
+
+ return 0;
+}
+
+static int client_handle_ack(sd_dhcp_client *client, DHCPMessage *ack,
+ size_t len) {
+ _cleanup_dhcp_lease_unref_ sd_dhcp_lease *lease = NULL;
+ int r;
+
+ r = dhcp_lease_new(&lease);
+ if (r < 0)
+ return r;
+
+ r = dhcp_option_parse(ack, len, dhcp_lease_parse_options, lease);
+ if (r == DHCP_NAK) {
+ log_dhcp_client(client, "NAK");
+ return DHCP_EVENT_NO_LEASE;
+ }
+
+ if (r != DHCP_ACK)
+ return -ENOMSG;
+
+ lease->address = ack->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;
+ }
+
+ client->lease = sd_dhcp_lease_unref(client->lease);
+ }
+
+ client->lease = lease;
+ lease = NULL;
+
+ log_dhcp_client(client, "ACK");
+
+ 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,
+ &client->timeout_t1,
+ next_timeout,
+ 10 * USEC_PER_MSEC,
+ client_timeout_t1, client);
+ 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,
+ &client->timeout_t2,
+ next_timeout,
+ 10 * USEC_PER_MSEC,
+ client_timeout_t2, client);
+ 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,
+ &client->timeout_expire, next_timeout,
+ 10 * USEC_PER_MSEC,
+ client_timeout_expire, client);
+ 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_handle_message(sd_dhcp_client *client, DHCPMessage *message,
+ int len, usec_t time_now) {
+ int r = 0, notify_event = 0;
+
+ assert(client);
+ assert(client->event);
+ assert(message);
+
+ if (len < DHCP_MESSAGE_SIZE) {
+ log_dhcp_client(client, "message too small (%d bytes): "
+ "ignoring", len);
+ return 0;
+ }
+
+ if (message->op != BOOTREPLY) {
+ log_dhcp_client(client, "not a BOOTREPLY message: ignoring");
+ return 0;
+ }
+
+ if (be32toh(message->xid) != client->xid) {
+ log_dhcp_client(client, "received xid (%u) does not match "
+ "expected (%u): ignoring",
+ be32toh(message->xid), client->xid);
+ return 0;
+ }
+
+ if (memcmp(&message->chaddr[0], &client->mac_addr.ether_addr_octet,
+ ETHER_ADDR_LEN)) {
+ log_dhcp_client(client, "received chaddr does not match "
+ "expected: ignoring");
+ return 0;
+ }
+
+ switch (client->state) {
+ case DHCP_STATE_SELECTING:
+
+ r = client_handle_offer(client, message, len);
+ if (r >= 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,
+ &client->timeout_resend,
+ time_now, 0,
+ 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;
+ }
+
+ break;
+
+ case DHCP_STATE_REQUESTING:
+ case DHCP_STATE_RENEWING:
+ case DHCP_STATE_REBINDING:
+
+ r = client_handle_ack(client, message, 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;
+}
+
+static int client_receive_message_udp(sd_event_source *s, int fd,
+ uint32_t revents, void *userdata) {
+ sd_dhcp_client *client = userdata;
+ _cleanup_free_ DHCPMessage *message = NULL;
+ int buflen = 0, len, r;
+ usec_t time_now;
+
+ assert(s);
+ assert(client);
+ assert(client->event);
+
+ r = ioctl(fd, FIONREAD, &buflen);
+ if (r < 0 || buflen <= 0)
+ buflen = sizeof(DHCPMessage) + DHCP_MIN_OPTIONS_SIZE;
+
+ message = malloc0(buflen);
+ if (!message)
+ return -ENOMEM;
+
+ len = read(fd, message, buflen);
+ if (len < 0)
+ return 0;
+
+ r = sd_event_get_now_monotonic(client->event, &time_now);
+ if (r < 0)
+ return client_stop(client, r);
+
+ return client_handle_message(client, message, len,
+ time_now);
+}
+
+static int client_receive_message_raw(sd_event_source *s, int fd,
+ uint32_t revents, void *userdata) {
+ sd_dhcp_client *client = userdata;
+ _cleanup_free_ DHCPPacket *packet = NULL;
+ usec_t time_now;
+ uint8_t cmsgbuf[CMSG_LEN(sizeof(struct tpacket_auxdata))];
+ struct iovec iov = {};
+ struct msghdr msg = {
+ .msg_iov = &iov,
+ .msg_iovlen = 1,
+ .msg_control = cmsgbuf,
+ .msg_controllen = sizeof(cmsgbuf),
+ };
+ struct cmsghdr *cmsg;
+ bool checksum = true;
+ int buflen = 0, len, r;
+
+ assert(s);
+ assert(client);
+ assert(client->event);
+
+ r = ioctl(fd, FIONREAD, &buflen);
+ if (r < 0 || buflen <= 0)
+ buflen = sizeof(DHCPPacket) + DHCP_MIN_OPTIONS_SIZE;
+
+ packet = malloc0(buflen);
+ if (!packet)
+ return -ENOMEM;
+
+ iov.iov_base = packet;
+ iov.iov_len = buflen;
+
+ len = recvmsg(fd, &msg, 0);
+ if (len < 0) {
+ log_dhcp_client(client, "could not receive message from raw "
+ "socket: %s", strerror(errno));
+ return 0;
+ }
+
+ for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
+ if (cmsg->cmsg_level == SOL_PACKET && cmsg->cmsg_type == PACKET_AUXDATA) {
+ struct tpacket_auxdata *aux = (void *)CMSG_DATA(cmsg);
+
+ checksum = !(aux->tp_status & TP_STATUS_CSUMNOTREADY);
+ break;
+ }
+ }
+
+ r = dhcp_packet_verify_headers(packet, len, checksum);
+ if (r < 0)
+ return 0;
+
+ len -= DHCP_IP_UDP_SIZE;
+
+ r = sd_event_get_now_monotonic(client->event, &time_now);
+ if (r < 0)
+ return client_stop(client, r);
+
+ return client_handle_message(client, &packet->dhcp, len, time_now);
+}
+
+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);
+ client->secs = 0;
+
+ log_dhcp_client(client, "STARTED");
+
+ return client_initialize_events(client, client_receive_message_raw,
+ 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;
+}