gdhcp/client.c

   1 /*
   2  *
   3  *  DHCP client library with GLib integration
   4  *
   5  *  Copyright (C) 2009-2010  Intel Corporation. All rights reserved.
   6  *
   7  *  This program is free software; you can redistribute it and/or modify
   8  *  it under the terms of the GNU General Public License version 2 as
   9  *  published by the Free Software Foundation.
  10  *
  11  *  This program is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *  GNU General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU General Public License
  17  *  along with this program; if not, write to the Free Software
  18  *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  19  *
  20  */
  21
  22 #ifdef HAVE_CONFIG_H
  23 #include <config.h>
  24 #endif
  25
  26 #define _GNU_SOURCE
  27 #include <stdio.h>
  28 #include <errno.h>
  29 #include <unistd.h>
  30 #include <stdlib.h>
  31 #include <string.h>
  32 #include <sys/ioctl.h>
  33 #include <arpa/inet.h>
  34
  35 #include <netpacket/packet.h>
  36 #include <netinet/if_ether.h>
  37 #include <net/ethernet.h>
  38
  39 #include <linux/if.h>
  40 #include <linux/filter.h>
  41
  42 #include <glib.h>
  43
  44 #include "gdhcp.h"
  45 #include "common.h"
  46 #include "ipv4ll.h"
  47
  48 #define DISCOVER_TIMEOUT 3
  49 #define DISCOVER_RETRIES 10
  50
  51 #define REQUEST_TIMEOUT 3
  52 #define REQUEST_RETRIES 5
  53
  54 typedef enum _listen_mode {
  55         L_NONE,
  56         L2,
  57         L3,
  58         L_ARP,
  59 } ListenMode;
  60
  61 typedef enum _dhcp_client_state {
  62         INIT_SELECTING,
  63         REQUESTING,
  64         BOUND,
  65         RENEWING,
  66         REBINDING,
  67         RELEASED,
  68         IPV4LL_PROBE,
  69         IPV4LL_ANNOUNCE,
  70         IPV4LL_MONITOR,
  71         IPV4LL_DEFEND,
  72 } ClientState;
  73
  74 struct _GDHCPClient {
  75         int ref_count;
  76         GDHCPType type;
  77         ClientState state;
  78         int ifindex;
  79         char *interface;
  80         uint8_t mac_address[6];
  81         uint32_t xid;
  82         uint32_t server_ip;
  83         uint32_t requested_ip;
  84         char *assigned_ip;
  85         uint32_t lease_seconds;
  86         ListenMode listen_mode;
  87         int listener_sockfd;
  88         uint8_t retry_times;
  89         uint8_t ack_retry_times;
  90         uint8_t conflicts;
  91         guint timeout;
  92         guint listener_watch;
  93         GIOChannel *listener_channel;
  94         GList *require_list;
  95         GList *request_list;
  96         GHashTable *code_value_hash;
  97         GHashTable *send_value_hash;
  98         GDHCPClientEventFunc lease_available_cb;
  99         gpointer lease_available_data;
 100         GDHCPClientEventFunc ipv4ll_available_cb;
 101         gpointer ipv4ll_available_data;
 102         GDHCPClientEventFunc no_lease_cb;
 103         gpointer no_lease_data;
 104         GDHCPClientEventFunc lease_lost_cb;
 105         gpointer lease_lost_data;
 106         GDHCPClientEventFunc ipv4ll_lost_cb;
 107         gpointer ipv4ll_lost_data;
 108         GDHCPClientEventFunc address_conflict_cb;
 109         gpointer address_conflict_data;
 110         GDHCPDebugFunc debug_func;
 111         gpointer debug_data;
 112         char *last_address;
 113 };
 114
 115 static inline void debug(GDHCPClient *client, const char *format, ...)
 116 {
 117         char str[256];
 118         va_list ap;
 119
 120         if (client->debug_func == NULL)
 121                 return;
 122
 123         va_start(ap, format);
 124
 125         if (vsnprintf(str, sizeof(str), format, ap) > 0)
 126                 client->debug_func(str, client->debug_data);
 127
 128         va_end(ap);
 129 }
 130
 131 /* Initialize the packet with the proper defaults */
 132 static void init_packet(GDHCPClient *dhcp_client,
 133                 struct dhcp_packet *packet, char type)
 134 {
 135         dhcp_init_header(packet, type);
 136
 137         memcpy(packet->chaddr, dhcp_client->mac_address, 6);
 138 }
 139
 140 static void add_request_options(GDHCPClient *dhcp_client,
 141                                 struct dhcp_packet *packet)
 142 {
 143         int len = 0;
 144         GList *list;
 145         uint8_t code;
 146         int end = dhcp_end_option(packet->options);
 147
 148         for (list = dhcp_client->request_list; list; list = list->next) {
 149                 code = (uint8_t) GPOINTER_TO_INT(list->data);
 150
 151                 packet->options[end + OPT_DATA + len] = code;
 152                 len++;
 153         }
 154
 155         if (len) {
 156                 packet->options[end + OPT_CODE] = DHCP_PARAM_REQ;
 157                 packet->options[end + OPT_LEN] = len;
 158                 packet->options[end + OPT_DATA + len] = DHCP_END;
 159         }
 160 }
 161
 162 static void add_binary_option(gpointer key, gpointer value, gpointer user_data)
 163 {
 164         uint8_t *option = value;
 165         struct dhcp_packet *packet = user_data;
 166
 167         dhcp_add_binary_option(packet, option);
 168 }
 169
 170 static void add_send_options(GDHCPClient *dhcp_client,
 171                                 struct dhcp_packet *packet)
 172 {
 173         g_hash_table_foreach(dhcp_client->send_value_hash,
 174                                 add_binary_option, packet);
 175 }
 176
 177 static int send_discover(GDHCPClient *dhcp_client, uint32_t requested)
 178 {
 179         struct dhcp_packet packet;
 180
 181         debug(dhcp_client, "sending DHCP discover request");
 182
 183         init_packet(dhcp_client, &packet, DHCPDISCOVER);
 184
 185         packet.xid = dhcp_client->xid;
 186
 187         if (requested)
 188                 dhcp_add_simple_option(&packet, DHCP_REQUESTED_IP, requested);
 189
 190         /* Explicitly saying that we want RFC-compliant packets helps
 191          * some buggy DHCP servers to NOT send bigger packets */
 192         dhcp_add_simple_option(&packet, DHCP_MAX_SIZE, htons(576));
 193
 194         add_request_options(dhcp_client, &packet);
 195
 196         add_send_options(dhcp_client, &packet);
 197
 198         return dhcp_send_raw_packet(&packet, INADDR_ANY, CLIENT_PORT,
 199                                         INADDR_BROADCAST, SERVER_PORT,
 200                                         MAC_BCAST_ADDR, dhcp_client->ifindex);
 201 }
 202
 203 static int send_select(GDHCPClient *dhcp_client)
 204 {
 205         struct dhcp_packet packet;
 206
 207         debug(dhcp_client, "sending DHCP select request");
 208
 209         init_packet(dhcp_client, &packet, DHCPREQUEST);
 210
 211         packet.xid = dhcp_client->xid;
 212
 213         dhcp_add_simple_option(&packet, DHCP_REQUESTED_IP,
 214                                         dhcp_client->requested_ip);
 215         dhcp_add_simple_option(&packet, DHCP_SERVER_ID, dhcp_client->server_ip);
 216
 217         add_request_options(dhcp_client, &packet);
 218
 219         add_send_options(dhcp_client, &packet);
 220
 221         return dhcp_send_raw_packet(&packet, INADDR_ANY, CLIENT_PORT,
 222                                         INADDR_BROADCAST, SERVER_PORT,
 223                                         MAC_BCAST_ADDR, dhcp_client->ifindex);
 224 }
 225
 226 static int send_renew(GDHCPClient *dhcp_client)
 227 {
 228         struct dhcp_packet packet;
 229
 230         debug(dhcp_client, "sending DHCP renew request");
 231
 232         init_packet(dhcp_client , &packet, DHCPREQUEST);
 233         packet.xid = dhcp_client->xid;
 234         packet.ciaddr = dhcp_client->requested_ip;
 235
 236         add_request_options(dhcp_client, &packet);
 237
 238         add_send_options(dhcp_client, &packet);
 239
 240         return dhcp_send_kernel_packet(&packet,
 241                 dhcp_client->requested_ip, CLIENT_PORT,
 242                 dhcp_client->server_ip, SERVER_PORT);
 243 }
 244
 245 static int send_rebound(GDHCPClient *dhcp_client)
 246 {
 247         struct dhcp_packet packet;
 248
 249         debug(dhcp_client, "sending DHCP rebound request");
 250
 251         init_packet(dhcp_client , &packet, DHCPREQUEST);
 252         packet.xid = dhcp_client->xid;
 253         packet.ciaddr = dhcp_client->requested_ip;
 254
 255         add_request_options(dhcp_client, &packet);
 256
 257         add_send_options(dhcp_client, &packet);
 258
 259         return dhcp_send_raw_packet(&packet, INADDR_ANY, CLIENT_PORT,
 260                                         INADDR_BROADCAST, SERVER_PORT,
 261                                         MAC_BCAST_ADDR, dhcp_client->ifindex);
 262 }
 263
 264 static int send_release(GDHCPClient *dhcp_client,
 265                         uint32_t server, uint32_t ciaddr)
 266 {
 267         struct dhcp_packet packet;
 268
 269         debug(dhcp_client, "sending DHCP release request");
 270
 271         init_packet(dhcp_client, &packet, DHCPRELEASE);
 272         packet.xid = rand();
 273         packet.ciaddr = ciaddr;
 274
 275         dhcp_add_simple_option(&packet, DHCP_SERVER_ID, server);
 276
 277         return dhcp_send_kernel_packet(&packet, ciaddr, CLIENT_PORT,
 278                                                 server, SERVER_PORT);
 279 }
 280
 281 static gboolean ipv4ll_probe_timeout(gpointer dhcp_data);
 282 static int switch_listening_mode(GDHCPClient *dhcp_client,
 283                                         ListenMode listen_mode);
 284
 285 static gboolean send_probe_packet(gpointer dhcp_data)
 286 {
 287         GDHCPClient *dhcp_client;
 288         guint timeout;
 289
 290         dhcp_client = dhcp_data;
 291         /* if requested_ip is not valid, pick a new address*/
 292         if (dhcp_client->requested_ip == 0) {
 293                 debug(dhcp_client, "pick a new random address");
 294                 dhcp_client->requested_ip = ipv4ll_random_ip(0);
 295         }
 296
 297         debug(dhcp_client, "sending IPV4LL probe request");
 298
 299         if (dhcp_client->retry_times == 1) {
 300                 dhcp_client->state = IPV4LL_PROBE;
 301                 switch_listening_mode(dhcp_client, L_ARP);
 302         }
 303         ipv4ll_send_arp_packet(dhcp_client->mac_address, 0,
 304                         dhcp_client->requested_ip, dhcp_client->ifindex);
 305
 306         if (dhcp_client->retry_times < PROBE_NUM) {
 307                 /*add a random timeout in range of PROBE_MIN to PROBE_MAX*/
 308                 timeout = ipv4ll_random_delay_ms(PROBE_MAX-PROBE_MIN);
 309                 timeout += PROBE_MIN*1000;
 310         } else
 311                 timeout = (ANNOUNCE_WAIT * 1000);
 312
 313         dhcp_client->timeout = g_timeout_add_full(G_PRIORITY_HIGH,
 314                                                  timeout,
 315                                                  ipv4ll_probe_timeout,
 316                                                  dhcp_client,
 317                                                  NULL);
 318         return FALSE;
 319 }
 320
 321 static gboolean ipv4ll_announce_timeout(gpointer dhcp_data);
 322 static gboolean ipv4ll_defend_timeout(gpointer dhcp_data);
 323
 324 static gboolean send_announce_packet(gpointer dhcp_data)
 325 {
 326         GDHCPClient *dhcp_client;
 327
 328         dhcp_client = dhcp_data;
 329
 330         debug(dhcp_client, "sending IPV4LL announce request");
 331
 332         ipv4ll_send_arp_packet(dhcp_client->mac_address,
 333                                 dhcp_client->requested_ip,
 334                                 dhcp_client->requested_ip,
 335                                 dhcp_client->ifindex);
 336
 337         if (dhcp_client->timeout > 0)
 338                 g_source_remove(dhcp_client->timeout);
 339         dhcp_client->timeout = 0;
 340
 341         if (dhcp_client->state == IPV4LL_DEFEND) {
 342                 dhcp_client->timeout =
 343                         g_timeout_add_seconds_full(G_PRIORITY_HIGH,
 344                                                 DEFEND_INTERVAL,
 345                                                 ipv4ll_defend_timeout,
 346                                                 dhcp_client,
 347                                                 NULL);
 348                 return TRUE;
 349         } else
 350                 dhcp_client->timeout =
 351                         g_timeout_add_seconds_full(G_PRIORITY_HIGH,
 352                                                 ANNOUNCE_INTERVAL,
 353                                                 ipv4ll_announce_timeout,
 354                                                 dhcp_client,
 355                                                 NULL);
 356         return TRUE;
 357 }
 358
 359 static void get_interface_mac_address(int index, uint8_t *mac_address)
 360 {
 361         struct ifreq ifr;
 362         int sk, err;
 363
 364         sk = socket(PF_INET, SOCK_DGRAM | SOCK_CLOEXEC, 0);
 365         if (sk < 0) {
 366                 perror("Open socket error");
 367                 return;
 368         }
 369
 370         memset(&ifr, 0, sizeof(ifr));
 371         ifr.ifr_ifindex = index;
 372
 373         err = ioctl(sk, SIOCGIFNAME, &ifr);
 374         if (err < 0) {
 375                 perror("Get interface name error");
 376                 goto done;
 377         }
 378
 379         err = ioctl(sk, SIOCGIFHWADDR, &ifr);
 380         if (err < 0) {
 381                 perror("Get mac address error");
 382                 goto done;
 383         }
 384
 385         memcpy(mac_address, ifr.ifr_hwaddr.sa_data, 6);
 386
 387 done:
 388         close(sk);
 389 }
 390
 391 static void remove_value(gpointer data, gpointer user_data)
 392 {
 393         char *value = data;
 394         g_free(value);
 395 }
 396
 397 static void remove_option_value(gpointer data)
 398 {
 399         GList *option_value = data;
 400
 401         g_list_foreach(option_value, remove_value, NULL);
 402 }
 403
 404 GDHCPClient *g_dhcp_client_new(GDHCPType type,
 405                         int ifindex, GDHCPClientError *error)
 406 {
 407         GDHCPClient *dhcp_client;
 408
 409         if (ifindex < 0) {
 410                 *error = G_DHCP_CLIENT_ERROR_INVALID_INDEX;
 411                 return NULL;
 412         }
 413
 414         dhcp_client = g_try_new0(GDHCPClient, 1);
 415         if (dhcp_client == NULL) {
 416                 *error = G_DHCP_CLIENT_ERROR_NOMEM;
 417                 return NULL;
 418         }
 419
 420         dhcp_client->interface = get_interface_name(ifindex);
 421         if (dhcp_client->interface == NULL) {
 422                 *error = G_DHCP_CLIENT_ERROR_INTERFACE_UNAVAILABLE;
 423                 goto error;
 424         }
 425
 426         if (interface_is_up(ifindex) == FALSE) {
 427                 *error = G_DHCP_CLIENT_ERROR_INTERFACE_DOWN;
 428                 goto error;
 429         }
 430
 431         get_interface_mac_address(ifindex, dhcp_client->mac_address);
 432
 433         dhcp_client->listener_sockfd = -1;
 434         dhcp_client->listener_channel = NULL;
 435         dhcp_client->listen_mode = L_NONE;
 436         dhcp_client->ref_count = 1;
 437         dhcp_client->type = type;
 438         dhcp_client->ifindex = ifindex;
 439         dhcp_client->lease_available_cb = NULL;
 440         dhcp_client->ipv4ll_available_cb = NULL;
 441         dhcp_client->no_lease_cb = NULL;
 442         dhcp_client->lease_lost_cb = NULL;
 443         dhcp_client->ipv4ll_lost_cb = NULL;
 444         dhcp_client->address_conflict_cb = NULL;
 445         dhcp_client->listener_watch = 0;
 446         dhcp_client->retry_times = 0;
 447         dhcp_client->ack_retry_times = 0;
 448         dhcp_client->code_value_hash = g_hash_table_new_full(g_direct_hash,
 449                                 g_direct_equal, NULL, remove_option_value);
 450         dhcp_client->send_value_hash = g_hash_table_new_full(g_direct_hash,
 451                                 g_direct_equal, NULL, g_free);
 452         dhcp_client->request_list = NULL;
 453         dhcp_client->require_list = NULL;
 454
 455         *error = G_DHCP_CLIENT_ERROR_NONE;
 456
 457         return dhcp_client;
 458
 459 error:
 460         g_free(dhcp_client->interface);
 461         g_free(dhcp_client);
 462         return NULL;
 463 }
 464
 465 #define SERVER_AND_CLIENT_PORTS  ((67 << 16) + 68)
 466
 467 static int dhcp_l2_socket(int ifindex)
 468 {
 469         int fd;
 470         struct sockaddr_ll sock;
 471
 472         /*
 473          * Comment:
 474          *
 475          *      I've selected not to see LL header, so BPF doesn't see it, too.
 476          *      The filter may also pass non-IP and non-ARP packets, but we do
 477          *      a more complete check when receiving the message in userspace.
 478          *
 479          * and filter shamelessly stolen from:
 480          *
 481          *      http://www.flamewarmaster.de/software/dhcpclient/
 482          *
 483          * There are a few other interesting ideas on that page (look under
 484          * "Motivation").  Use of netlink events is most interesting.  Think
 485          * of various network servers listening for events and reconfiguring.
 486          * That would obsolete sending HUP signals and/or make use of restarts.
 487          *
 488          * Copyright: 2006, 2007 Stefan Rompf <sux@loplof.de>.
 489          * License: GPL v2.
 490          *
 491          * TODO: make conditional?
 492          */
 493         static const struct sock_filter filter_instr[] = {
 494                 /* check for udp */
 495                 BPF_STMT(BPF_LD|BPF_B|BPF_ABS, 9),
 496                 /* L5, L1, is UDP? */
 497                 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, IPPROTO_UDP, 2, 0),
 498                 /* ugly check for arp on ethernet-like and IPv4 */
 499                 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 2), /* L1: */
 500                 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, 0x08000604, 3, 4),/* L3, L4 */
 501                 /* skip IP header */
 502                 BPF_STMT(BPF_LDX|BPF_B|BPF_MSH, 0), /* L5: */
 503                 /* check udp source and destination ports */
 504                 BPF_STMT(BPF_LD|BPF_W|BPF_IND, 0),
 505                 /* L3, L4 */
 506                 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, SERVER_AND_CLIENT_PORTS, 0, 1),
 507                 /* returns */
 508                 BPF_STMT(BPF_RET|BPF_K, 0x0fffffff), /* L3: pass */
 509                 BPF_STMT(BPF_RET|BPF_K, 0), /* L4: reject */
 510         };
 511
 512         static const struct sock_fprog filter_prog = {
 513                 .len = sizeof(filter_instr) / sizeof(filter_instr[0]),
 514                 /* casting const away: */
 515                 .filter = (struct sock_filter *) filter_instr,
 516         };
 517
 518         fd = socket(PF_PACKET, SOCK_DGRAM | SOCK_CLOEXEC, htons(ETH_P_IP));
 519         if (fd < 0)
 520                 return fd;
 521
 522         if (SERVER_PORT == 67 && CLIENT_PORT == 68)
 523                 /* Use only if standard ports are in use */
 524                 setsockopt(fd, SOL_SOCKET, SO_ATTACH_FILTER, &filter_prog,
 525                                                         sizeof(filter_prog));
 526
 527         memset(&sock, 0, sizeof(sock));
 528         sock.sll_family = AF_PACKET;
 529         sock.sll_protocol = htons(ETH_P_IP);
 530         sock.sll_ifindex = ifindex;
 531
 532         if (bind(fd, (struct sockaddr *) &sock, sizeof(sock)) != 0) {
 533                 close(fd);
 534                 return -errno;
 535         }
 536
 537         return fd;
 538 }
 539
 540 static gboolean sanity_check(struct ip_udp_dhcp_packet *packet, int bytes)
 541 {
 542         if (packet->ip.protocol != IPPROTO_UDP)
 543                 return FALSE;
 544
 545         if (packet->ip.version != IPVERSION)
 546                 return FALSE;
 547
 548         if (packet->ip.ihl != sizeof(packet->ip) >> 2)
 549                 return FALSE;
 550
 551         if (packet->udp.dest != htons(CLIENT_PORT))
 552                 return FALSE;
 553
 554         if (ntohs(packet->udp.len) != (uint16_t)(bytes - sizeof(packet->ip)))
 555                 return FALSE;
 556
 557         return TRUE;
 558 }
 559
 560 static int dhcp_recv_l2_packet(struct dhcp_packet *dhcp_pkt, int fd)
 561 {
 562         int bytes;
 563         struct ip_udp_dhcp_packet packet;
 564         uint16_t check;
 565
 566         memset(&packet, 0, sizeof(packet));
 567
 568         bytes = read(fd, &packet, sizeof(packet));
 569         if (bytes < 0)
 570                 return -1;
 571
 572         if (bytes < (int) (sizeof(packet.ip) + sizeof(packet.udp)))
 573                 return -1;
 574
 575         if (bytes < ntohs(packet.ip.tot_len))
 576                 /* packet is bigger than sizeof(packet), we did partial read */
 577                 return -1;
 578
 579         /* ignore any extra garbage bytes */
 580         bytes = ntohs(packet.ip.tot_len);
 581
 582         if (sanity_check(&packet, bytes) == FALSE)
 583                 return -1;
 584
 585         check = packet.ip.check;
 586         packet.ip.check = 0;
 587         if (check != dhcp_checksum(&packet.ip, sizeof(packet.ip)))
 588                 return -1;
 589
 590         /* verify UDP checksum. IP header has to be modified for this */
 591         memset(&packet.ip, 0, offsetof(struct iphdr, protocol));
 592         /* ip.xx fields which are not memset: protocol, check, saddr, daddr */
 593         packet.ip.tot_len = packet.udp.len; /* yes, this is needed */
 594         check = packet.udp.check;
 595         packet.udp.check = 0;
 596         if (check && check != dhcp_checksum(&packet, bytes))
 597                 return -1;
 598
 599         memcpy(dhcp_pkt, &packet.data, bytes - (sizeof(packet.ip) +
 600                                                         sizeof(packet.udp)));
 601
 602         if (dhcp_pkt->cookie != htonl(DHCP_MAGIC))
 603                 return -1;
 604
 605         return bytes - (sizeof(packet.ip) + sizeof(packet.udp));
 606 }
 607
 608 static void ipv4ll_start(GDHCPClient *dhcp_client)
 609 {
 610         guint timeout;
 611         int seed;
 612
 613         if (dhcp_client->timeout > 0) {
 614                 g_source_remove(dhcp_client->timeout);
 615                 dhcp_client->timeout = 0;
 616         }
 617
 618         switch_listening_mode(dhcp_client, L_NONE);
 619         dhcp_client->type = G_DHCP_IPV4LL;
 620         dhcp_client->retry_times = 0;
 621         dhcp_client->requested_ip = 0;
 622
 623         /*try to start with a based mac address ip*/
 624         seed = (dhcp_client->mac_address[4] << 8 | dhcp_client->mac_address[4]);
 625         dhcp_client->requested_ip = ipv4ll_random_ip(seed);
 626
 627         /*first wait a random delay to avoid storm of arp request on boot*/
 628         timeout = ipv4ll_random_delay_ms(PROBE_WAIT);
 629
 630         dhcp_client->retry_times++;
 631         dhcp_client->timeout = g_timeout_add_full(G_PRIORITY_HIGH,
 632                                                 timeout,
 633                                                 send_probe_packet,
 634                                                 dhcp_client,
 635                                                 NULL);
 636 }
 637
 638 static void ipv4ll_stop(GDHCPClient *dhcp_client)
 639 {
 640
 641         switch_listening_mode(dhcp_client, L_NONE);
 642
 643         if (dhcp_client->timeout > 0)
 644                 g_source_remove(dhcp_client->timeout);
 645
 646         if (dhcp_client->listener_watch > 0) {
 647                 g_source_remove(dhcp_client->listener_watch);
 648                 dhcp_client->listener_watch = 0;
 649         }
 650
 651         dhcp_client->state = IPV4LL_PROBE;
 652         dhcp_client->retry_times = 0;
 653         dhcp_client->requested_ip = 0;
 654
 655         g_free(dhcp_client->assigned_ip);
 656         dhcp_client->assigned_ip = NULL;
 657 }
 658
 659 static int ipv4ll_recv_arp_packet(GDHCPClient *dhcp_client)
 660 {
 661         int bytes;
 662         struct ether_arp arp;
 663         uint32_t ip_requested;
 664         int source_conflict;
 665         int target_conflict;
 666
 667         memset(&arp, 0, sizeof(arp));
 668         bytes = 0;
 669         bytes = read(dhcp_client->listener_sockfd, &arp, sizeof(arp));
 670         if (bytes < 0)
 671                 return bytes;
 672
 673         if (arp.arp_op != htons(ARPOP_REPLY) &&
 674                         arp.arp_op != htons(ARPOP_REQUEST))
 675                 return -EINVAL;
 676
 677         ip_requested = ntohl(dhcp_client->requested_ip);
 678         source_conflict = !memcmp(arp.arp_spa, &ip_requested,
 679                                                 sizeof(ip_requested));
 680
 681         target_conflict = !memcmp(arp.arp_tpa, &ip_requested,
 682                                 sizeof(ip_requested));
 683
 684         if (!source_conflict && !target_conflict)
 685                 return 0;
 686
 687         dhcp_client->conflicts++;
 688
 689         debug(dhcp_client, "IPV4LL conflict detected");
 690
 691         if (dhcp_client->state == IPV4LL_MONITOR) {
 692                 if (!source_conflict)
 693                         return 0;
 694                 dhcp_client->state = IPV4LL_DEFEND;
 695                 debug(dhcp_client, "DEFEND mode conflicts : %d",
 696                         dhcp_client->conflicts);
 697                 /*Try to defend with a single announce*/
 698                 send_announce_packet(dhcp_client);
 699                 return 0;
 700         }
 701
 702         if (dhcp_client->state == IPV4LL_DEFEND) {
 703                 if (!source_conflict)
 704                         return 0;
 705                 else if (dhcp_client->ipv4ll_lost_cb != NULL)
 706                         dhcp_client->ipv4ll_lost_cb(dhcp_client,
 707                                                 dhcp_client->ipv4ll_lost_data);
 708         }
 709
 710         ipv4ll_stop(dhcp_client);
 711
 712         if (dhcp_client->conflicts < MAX_CONFLICTS) {
 713                 /*restart whole state machine*/
 714                 dhcp_client->retry_times++;
 715                 dhcp_client->timeout =
 716                         g_timeout_add_full(G_PRIORITY_HIGH,
 717                                         ipv4ll_random_delay_ms(PROBE_WAIT),
 718                                         send_probe_packet,
 719                                         dhcp_client,
 720                                         NULL);
 721         }
 722         /* Here we got a lot of conflicts, RFC3927 states that we have
 723          * to wait RATE_LIMIT_INTERVAL before retrying,
 724          * but we just report failure.
 725          */
 726         else if (dhcp_client->no_lease_cb != NULL)
 727                         dhcp_client->no_lease_cb(dhcp_client,
 728                                                 dhcp_client->no_lease_data);
 729
 730         return 0;
 731 }
 732
 733 static gboolean check_package_owner(GDHCPClient *dhcp_client,
 734                                         struct dhcp_packet *packet)
 735 {
 736         if (packet->xid != dhcp_client->xid)
 737                 return FALSE;
 738
 739         if (packet->hlen != 6)
 740                 return FALSE;
 741
 742         if (memcmp(packet->chaddr, dhcp_client->mac_address, 6))
 743                 return FALSE;
 744
 745         return TRUE;
 746 }
 747
 748 static void start_request(GDHCPClient *dhcp_client);
 749
 750 static gboolean request_timeout(gpointer user_data)
 751 {
 752         GDHCPClient *dhcp_client = user_data;
 753
 754         debug(dhcp_client, "request timeout (retries %d)",
 755                                         dhcp_client->retry_times);
 756
 757         dhcp_client->retry_times++;
 758
 759         start_request(dhcp_client);
 760
 761         return FALSE;
 762 }
 763
 764 static gboolean listener_event(GIOChannel *channel, GIOCondition condition,
 765                                                         gpointer user_data);
 766
 767 static int switch_listening_mode(GDHCPClient *dhcp_client,
 768                                         ListenMode listen_mode)
 769 {
 770         GIOChannel *listener_channel;
 771         int listener_sockfd;
 772
 773         debug(dhcp_client, "switch listening mode (%d ==> %d)",
 774                                 dhcp_client->listen_mode, listen_mode);
 775
 776         if (dhcp_client->listen_mode == listen_mode)
 777                 return 0;
 778
 779         if (dhcp_client->listen_mode != L_NONE) {
 780                 g_source_remove(dhcp_client->listener_watch);
 781                 dhcp_client->listener_channel = NULL;
 782                 dhcp_client->listen_mode = L_NONE;
 783                 dhcp_client->listener_sockfd = -1;
 784                 dhcp_client->listener_watch = 0;
 785         }
 786
 787         if (listen_mode == L_NONE)
 788                 return 0;
 789
 790         if (listen_mode == L2)
 791                 listener_sockfd = dhcp_l2_socket(dhcp_client->ifindex);
 792         else if (listen_mode == L3)
 793                 listener_sockfd = dhcp_l3_socket(CLIENT_PORT,
 794                                                 dhcp_client->interface);
 795         else if (listen_mode == L_ARP)
 796                 listener_sockfd = ipv4ll_arp_socket(dhcp_client->ifindex);
 797         else
 798                 return -EIO;
 799
 800         if (listener_sockfd < 0)
 801                 return -EIO;
 802
 803         listener_channel = g_io_channel_unix_new(listener_sockfd);
 804         if (listener_channel == NULL) {
 805                 /* Failed to create listener channel */
 806                 close(listener_sockfd);
 807                 return -EIO;
 808         }
 809
 810         dhcp_client->listen_mode = listen_mode;
 811         dhcp_client->listener_sockfd = listener_sockfd;
 812         dhcp_client->listener_channel = listener_channel;
 813
 814         g_io_channel_set_close_on_unref(listener_channel, TRUE);
 815         dhcp_client->listener_watch =
 816                         g_io_add_watch_full(listener_channel, G_PRIORITY_HIGH,
 817                                 G_IO_IN | G_IO_NVAL | G_IO_ERR | G_IO_HUP,
 818                                                 listener_event, dhcp_client,
 819                                                                 NULL);
 820         g_io_channel_unref(dhcp_client->listener_channel);
 821
 822         return 0;
 823 }
 824
 825 static void start_request(GDHCPClient *dhcp_client)
 826 {
 827         debug(dhcp_client, "start request (retries %d)",
 828                                         dhcp_client->retry_times);
 829
 830         if (dhcp_client->retry_times == REQUEST_RETRIES) {
 831                 dhcp_client->state = INIT_SELECTING;
 832                 ipv4ll_start(dhcp_client);
 833
 834                 return;
 835         }
 836
 837         if (dhcp_client->retry_times == 0) {
 838                 dhcp_client->state = REQUESTING;
 839                 switch_listening_mode(dhcp_client, L2);
 840         }
 841
 842         send_select(dhcp_client);
 843
 844         dhcp_client->timeout = g_timeout_add_seconds_full(G_PRIORITY_HIGH,
 845                                                         REQUEST_TIMEOUT,
 846                                                         request_timeout,
 847                                                         dhcp_client,
 848                                                         NULL);
 849 }
 850
 851 static uint32_t get_lease(struct dhcp_packet *packet)
 852 {
 853         uint8_t *option_u8;
 854         uint32_t lease_seconds;
 855
 856         option_u8 = dhcp_get_option(packet, DHCP_LEASE_TIME);
 857         if (option_u8 == NULL)
 858                 return 3600;
 859
 860         lease_seconds = dhcp_get_unaligned((uint32_t *) option_u8);
 861         lease_seconds = ntohl(lease_seconds);
 862         /* paranoia: must not be prone to overflows */
 863         lease_seconds &= 0x0fffffff;
 864         if (lease_seconds < 10)
 865                 lease_seconds = 10;
 866
 867         return lease_seconds;
 868 }
 869
 870 static void restart_dhcp(GDHCPClient *dhcp_client, int retry_times)
 871 {
 872         debug(dhcp_client, "restart DHCP (retries %d)", retry_times);
 873
 874         if (dhcp_client->timeout > 0) {
 875                 g_source_remove(dhcp_client->timeout);
 876                 dhcp_client->timeout = 0;
 877         }
 878
 879         dhcp_client->retry_times = retry_times;
 880         dhcp_client->requested_ip = 0;
 881         switch_listening_mode(dhcp_client, L2);
 882
 883         g_dhcp_client_start(dhcp_client, dhcp_client->last_address);
 884 }
 885
 886 static gboolean start_rebound_timeout(gpointer user_data)
 887 {
 888         GDHCPClient *dhcp_client = user_data;
 889
 890         debug(dhcp_client, "start rebound timeout");
 891
 892         switch_listening_mode(dhcp_client, L2);
 893
 894         dhcp_client->lease_seconds >>= 1;
 895
 896         /* We need to have enough time to receive ACK package*/
 897         if (dhcp_client->lease_seconds <= 6) {
 898
 899                 /* ip need to be cleared */
 900                 if (dhcp_client->lease_lost_cb != NULL)
 901                         dhcp_client->lease_lost_cb(dhcp_client,
 902                                         dhcp_client->lease_lost_data);
 903
 904                 restart_dhcp(dhcp_client, 0);
 905         } else {
 906                 send_rebound(dhcp_client);
 907
 908                 dhcp_client->timeout =
 909                                 g_timeout_add_seconds_full(G_PRIORITY_HIGH,
 910                                                 dhcp_client->lease_seconds >> 1,
 911                                                         start_rebound_timeout,
 912                                                                 dhcp_client,
 913                                                                 NULL);
 914         }
 915
 916         return FALSE;
 917 }
 918
 919 static void start_rebound(GDHCPClient *dhcp_client)
 920 {
 921         debug(dhcp_client, "start rebound");
 922
 923         dhcp_client->state = REBINDING;
 924
 925         dhcp_client->timeout = g_timeout_add_seconds_full(G_PRIORITY_HIGH,
 926                                                 dhcp_client->lease_seconds >> 1,
 927                                                         start_rebound_timeout,
 928                                                                 dhcp_client,
 929                                                                 NULL);
 930 }
 931
 932 static gboolean start_renew_timeout(gpointer user_data)
 933 {
 934         GDHCPClient *dhcp_client = user_data;
 935
 936         debug(dhcp_client, "start renew timeout");
 937
 938         dhcp_client->state = RENEWING;
 939
 940         dhcp_client->lease_seconds >>= 1;
 941
 942         switch_listening_mode(dhcp_client, L3);
 943         if (dhcp_client->lease_seconds <= 60)
 944                 start_rebound(dhcp_client);
 945         else {
 946                 send_renew(dhcp_client);
 947
 948                 if (dhcp_client->timeout > 0)
 949                         g_source_remove(dhcp_client->timeout);
 950
 951                 dhcp_client->timeout =
 952                                 g_timeout_add_seconds_full(G_PRIORITY_HIGH,
 953                                                 dhcp_client->lease_seconds >> 1,
 954                                                         start_renew_timeout,
 955                                                                 dhcp_client,
 956                                                                 NULL);
 957         }
 958
 959         return FALSE;
 960 }
 961
 962 static void start_bound(GDHCPClient *dhcp_client)
 963 {
 964         debug(dhcp_client, "start bound");
 965
 966         dhcp_client->state = BOUND;
 967
 968         if (dhcp_client->timeout > 0)
 969                 g_source_remove(dhcp_client->timeout);
 970
 971         dhcp_client->timeout = g_timeout_add_seconds_full(G_PRIORITY_HIGH,
 972                                         dhcp_client->lease_seconds >> 1,
 973                                         start_renew_timeout, dhcp_client,
 974                                                         NULL);
 975 }
 976
 977 static gboolean restart_dhcp_timeout(gpointer user_data)
 978 {
 979         GDHCPClient *dhcp_client = user_data;
 980
 981         debug(dhcp_client, "restart DHCP timeout");
 982
 983         dhcp_client->ack_retry_times++;
 984
 985         restart_dhcp(dhcp_client, dhcp_client->ack_retry_times);
 986
 987         return FALSE;
 988 }
 989
 990 static char *get_ip(uint32_t ip)
 991 {
 992         struct in_addr addr;
 993
 994         addr.s_addr = ip;
 995
 996         return g_strdup(inet_ntoa(addr));
 997 }
 998
 999 /* get a rough idea of how long an option will be */
1000 static const uint8_t len_of_option_as_string[] = {
1001         [OPTION_IP] = sizeof("255.255.255.255 "),
1002         [OPTION_STRING] = 1,
1003         [OPTION_U8] = sizeof("255 "),
1004         [OPTION_U16] = sizeof("65535 "),
1005         [OPTION_U32] = sizeof("4294967295 "),
1006 };
1007
1008 static int sprint_nip(char *dest, const char *pre, const uint8_t *ip)
1009 {
1010         return sprintf(dest, "%s%u.%u.%u.%u", pre, ip[0], ip[1], ip[2], ip[3]);
1011 }
1012
1013 /* Create "opt_value1 option_value2 ..." string */
1014 static char *malloc_option_value_string(uint8_t *option, GDHCPOptionType type)
1015 {
1016         unsigned upper_length;
1017         int len, optlen;
1018         char *dest, *ret;
1019
1020         len = option[OPT_LEN - OPT_DATA];
1021         type &= OPTION_TYPE_MASK;
1022         optlen = dhcp_option_lengths[type];
1023         if (optlen == 0)
1024                 return NULL;
1025         upper_length = len_of_option_as_string[type] *
1026                         ((unsigned)len / (unsigned)optlen);
1027         dest = ret = malloc(upper_length + 1);
1028         if (ret == NULL)
1029                 return NULL;
1030
1031         while (len >= optlen) {
1032                 switch (type) {
1033                 case OPTION_IP:
1034                         dest += sprint_nip(dest, "", option);
1035                         break;
1036                 case OPTION_U16: {
1037                         uint16_t val_u16 = dhcp_get_unaligned(
1038                                                 (uint16_t *) option);
1039                         dest += sprintf(dest, "%u", ntohs(val_u16));
1040                         break;
1041                 }
1042                 case OPTION_U32: {
1043                         uint32_t val_u32 = dhcp_get_unaligned(
1044                                                 (uint32_t *) option);
1045                         dest += sprintf(dest, type == OPTION_U32 ? "%lu" :
1046                                         "%ld", (unsigned long) ntohl(val_u32));
1047                         break;
1048                 }
1049                 case OPTION_STRING:
1050                         memcpy(dest, option, len);
1051                         dest[len] = '\0';
1052                         return ret;
1053                 default:
1054                         break;
1055                 }
1056                 option += optlen;
1057                 len -= optlen;
1058                 if (len <= 0)
1059                         break;
1060                 *dest++ = ' ';
1061                 *dest = '\0';
1062         }
1063
1064         return ret;
1065 }
1066
1067 static GList *get_option_value_list(char *value, GDHCPOptionType type)
1068 {
1069         char *pos = value;
1070         GList *list = NULL;
1071
1072         if (pos == NULL)
1073                 return NULL;
1074
1075         if (type == OPTION_STRING)
1076                 return g_list_append(list, g_strdup(value));
1077
1078         while ((pos = strchr(pos, ' ')) != NULL) {
1079                 *pos = '\0';
1080
1081                 list = g_list_append(list, g_strdup(value));
1082
1083                 value = ++pos;
1084         }
1085
1086         list = g_list_append(list, g_strdup(value));
1087
1088         return list;
1089 }
1090
1091 static void get_request(GDHCPClient *dhcp_client, struct dhcp_packet *packet)
1092 {
1093         GDHCPOptionType type;
1094         GList *list, *value_list;
1095         char *option_value;
1096         uint8_t *option;
1097         uint8_t code;
1098
1099         for (list = dhcp_client->request_list; list; list = list->next) {
1100                 code = (uint8_t) GPOINTER_TO_INT(list->data);
1101
1102                 option = dhcp_get_option(packet, code);
1103                 if (option == NULL) {
1104                         g_hash_table_remove(dhcp_client->code_value_hash,
1105                                                 GINT_TO_POINTER((int) code));
1106                         continue;
1107                 }
1108
1109                 type =  dhcp_get_code_type(code);
1110
1111                 option_value = malloc_option_value_string(option, type);
1112                 if (option_value == NULL)
1113                         g_hash_table_remove(dhcp_client->code_value_hash,
1114                                                 GINT_TO_POINTER((int) code));
1115
1116                 value_list = get_option_value_list(option_value, type);
1117
1118                 g_free(option_value);
1119
1120                 if (value_list == NULL)
1121                         g_hash_table_remove(dhcp_client->code_value_hash,
1122                                                 GINT_TO_POINTER((int) code));
1123                 else
1124                         g_hash_table_insert(dhcp_client->code_value_hash,
1125                                 GINT_TO_POINTER((int) code), value_list);
1126         }
1127 }
1128
1129 static gboolean listener_event(GIOChannel *channel, GIOCondition condition,
1130                                                         gpointer user_data)
1131 {
1132         GDHCPClient *dhcp_client = user_data;
1133         struct dhcp_packet packet;
1134         uint8_t *message_type, *option_u8;
1135         int re;
1136
1137         if (condition & (G_IO_NVAL | G_IO_ERR | G_IO_HUP)) {
1138                 dhcp_client->listener_watch = 0;
1139                 return FALSE;
1140         }
1141
1142         if (dhcp_client->listen_mode == L_NONE)
1143                 return FALSE;
1144
1145         if (dhcp_client->listen_mode == L2)
1146                 re = dhcp_recv_l2_packet(&packet, dhcp_client->listener_sockfd);
1147         else if (dhcp_client->listen_mode == L3)
1148                 re = dhcp_recv_l3_packet(&packet, dhcp_client->listener_sockfd);
1149         else if (dhcp_client->listen_mode == L_ARP) {
1150                 re = ipv4ll_recv_arp_packet(dhcp_client);
1151                 return TRUE;
1152         }
1153         else
1154                 re = -EIO;
1155
1156         if (re < 0)
1157                 return TRUE;
1158
1159         if (check_package_owner(dhcp_client, &packet) == FALSE)
1160                 return TRUE;
1161
1162         message_type = dhcp_get_option(&packet, DHCP_MESSAGE_TYPE);
1163         if (message_type == NULL)
1164                 /* No message type option, ignore package */
1165                 return TRUE;
1166
1167         debug(dhcp_client, "received DHCP packet (current state %d)",
1168                                                         dhcp_client->state);
1169
1170         switch (dhcp_client->state) {
1171         case INIT_SELECTING:
1172                 if (*message_type != DHCPOFFER)
1173                         return TRUE;
1174
1175                 g_source_remove(dhcp_client->timeout);
1176                 dhcp_client->timeout = 0;
1177                 dhcp_client->retry_times = 0;
1178
1179                 option_u8 = dhcp_get_option(&packet, DHCP_SERVER_ID);
1180                 dhcp_client->server_ip =
1181                                 dhcp_get_unaligned((uint32_t *) option_u8);
1182                 dhcp_client->requested_ip = packet.yiaddr;
1183
1184                 dhcp_client->state = REQUESTING;
1185
1186                 start_request(dhcp_client);
1187
1188                 return TRUE;
1189         case REQUESTING:
1190         case RENEWING:
1191         case REBINDING:
1192                 if (*message_type == DHCPACK) {
1193                         dhcp_client->retry_times = 0;
1194
1195                         if (dhcp_client->timeout > 0)
1196                                 g_source_remove(dhcp_client->timeout);
1197                         dhcp_client->timeout = 0;
1198
1199                         dhcp_client->lease_seconds = get_lease(&packet);
1200
1201                         get_request(dhcp_client, &packet);
1202
1203                         switch_listening_mode(dhcp_client, L_NONE);
1204
1205                         g_free(dhcp_client->assigned_ip);
1206                         dhcp_client->assigned_ip = get_ip(packet.yiaddr);
1207
1208                         /* Address should be set up here */
1209                         if (dhcp_client->lease_available_cb != NULL)
1210                                 dhcp_client->lease_available_cb(dhcp_client,
1211                                         dhcp_client->lease_available_data);
1212
1213                         start_bound(dhcp_client);
1214                 } else if (*message_type == DHCPNAK) {
1215                         dhcp_client->retry_times = 0;
1216
1217                         if (dhcp_client->timeout > 0)
1218                                 g_source_remove(dhcp_client->timeout);
1219
1220                         dhcp_client->timeout = g_timeout_add_seconds_full(
1221                                                         G_PRIORITY_HIGH, 3,
1222                                                         restart_dhcp_timeout,
1223                                                         dhcp_client,
1224                                                         NULL);
1225                 }
1226
1227                 break;
1228         default:
1229                 break;
1230         }
1231
1232         debug(dhcp_client, "processed DHCP packet (new state %d)",
1233                                                         dhcp_client->state);
1234
1235         return TRUE;
1236 }
1237
1238 static gboolean discover_timeout(gpointer user_data)
1239 {
1240         GDHCPClient *dhcp_client = user_data;
1241
1242         dhcp_client->retry_times++;
1243
1244         /*
1245          * We do not send the REQUESTED IP option if we are retrying because
1246          * if the server is non-authoritative it will ignore the request if the
1247          * option is present.
1248          */
1249         g_dhcp_client_start(dhcp_client, NULL);
1250
1251         return FALSE;
1252 }
1253
1254 static gboolean ipv4ll_defend_timeout(gpointer dhcp_data)
1255 {
1256         GDHCPClient *dhcp_client = dhcp_data;
1257
1258         debug(dhcp_client, "back to MONITOR mode");
1259
1260         dhcp_client->conflicts = 0;
1261         dhcp_client->state = IPV4LL_MONITOR;
1262
1263         return FALSE;
1264 }
1265
1266 static gboolean ipv4ll_announce_timeout(gpointer dhcp_data)
1267 {
1268         GDHCPClient *dhcp_client = dhcp_data;
1269         uint32_t ip;
1270
1271         debug(dhcp_client, "request timeout (retries %d)",
1272                dhcp_client->retry_times);
1273
1274         if (dhcp_client->retry_times != ANNOUNCE_NUM){
1275                 dhcp_client->retry_times++;
1276                 send_announce_packet(dhcp_client);
1277                 return FALSE;
1278         }
1279
1280         ip = htonl(dhcp_client->requested_ip);
1281         debug(dhcp_client, "switching to monitor mode");
1282         dhcp_client->state = IPV4LL_MONITOR;
1283         dhcp_client->assigned_ip = get_ip(ip);
1284
1285         if (dhcp_client->ipv4ll_available_cb != NULL)
1286                 dhcp_client->ipv4ll_available_cb(dhcp_client,
1287                                         dhcp_client->ipv4ll_available_data);
1288         dhcp_client->conflicts = 0;
1289
1290         return FALSE;
1291 }
1292
1293 static gboolean ipv4ll_probe_timeout(gpointer dhcp_data)
1294 {
1295
1296         GDHCPClient *dhcp_client = dhcp_data;
1297
1298         debug(dhcp_client, "IPV4LL probe timeout (retries %d)",
1299                dhcp_client->retry_times);
1300
1301         if (dhcp_client->retry_times == PROBE_NUM) {
1302                 dhcp_client->state = IPV4LL_ANNOUNCE;
1303                 dhcp_client->retry_times = 0;
1304
1305                 dhcp_client->retry_times++;
1306                 send_announce_packet(dhcp_client);
1307                 return FALSE;
1308         }
1309         dhcp_client->retry_times++;
1310         send_probe_packet(dhcp_client);
1311
1312         return FALSE;
1313 }
1314
1315 int g_dhcp_client_start(GDHCPClient *dhcp_client, const char *last_address)
1316 {
1317         int re;
1318         uint32_t addr;
1319
1320         if (dhcp_client->retry_times == DISCOVER_RETRIES) {
1321                 ipv4ll_start(dhcp_client);
1322                 return 0;
1323         }
1324
1325         if (dhcp_client->retry_times == 0) {
1326                 g_free(dhcp_client->assigned_ip);
1327                 dhcp_client->assigned_ip = NULL;
1328
1329                 dhcp_client->state = INIT_SELECTING;
1330                 re = switch_listening_mode(dhcp_client, L2);
1331                 if (re != 0)
1332                         return re;
1333
1334                 dhcp_client->xid = rand();
1335         }
1336
1337         if (last_address == NULL) {
1338                 addr = 0;
1339         } else {
1340                 addr = inet_addr(last_address);
1341                 if (addr == 0xFFFFFFFF) {
1342                         addr = 0;
1343                 } else {
1344                         g_free(dhcp_client->last_address);
1345                         dhcp_client->last_address = g_strdup(last_address);
1346                 }
1347         }
1348         send_discover(dhcp_client, addr);
1349
1350         dhcp_client->timeout = g_timeout_add_seconds_full(G_PRIORITY_HIGH,
1351                                                         DISCOVER_TIMEOUT,
1352                                                         discover_timeout,
1353                                                         dhcp_client,
1354                                                         NULL);
1355         return 0;
1356 }
1357
1358 void g_dhcp_client_stop(GDHCPClient *dhcp_client)
1359 {
1360         switch_listening_mode(dhcp_client, L_NONE);
1361
1362         if (dhcp_client->state == BOUND ||
1363                         dhcp_client->state == RENEWING ||
1364                                 dhcp_client->state == REBINDING)
1365                 send_release(dhcp_client, dhcp_client->server_ip,
1366                                         dhcp_client->requested_ip);
1367
1368         if (dhcp_client->timeout > 0) {
1369                 g_source_remove(dhcp_client->timeout);
1370                 dhcp_client->timeout = 0;
1371         }
1372
1373         if (dhcp_client->listener_watch > 0) {
1374                 g_source_remove(dhcp_client->listener_watch);
1375                 dhcp_client->listener_watch = 0;
1376         }
1377
1378         dhcp_client->listener_channel = NULL;
1379
1380         dhcp_client->retry_times = 0;
1381         dhcp_client->ack_retry_times = 0;
1382
1383         dhcp_client->requested_ip = 0;
1384         dhcp_client->state = RELEASED;
1385         dhcp_client->lease_seconds = 0;
1386 }
1387
1388 GList *g_dhcp_client_get_option(GDHCPClient *dhcp_client,
1389                                         unsigned char option_code)
1390 {
1391         return g_hash_table_lookup(dhcp_client->code_value_hash,
1392                                         GINT_TO_POINTER((int) option_code));
1393 }
1394
1395 void g_dhcp_client_register_event(GDHCPClient *dhcp_client,
1396                                         GDHCPClientEvent event,
1397                                         GDHCPClientEventFunc func,
1398                                                         gpointer data)
1399 {
1400         switch (event) {
1401         case G_DHCP_CLIENT_EVENT_LEASE_AVAILABLE:
1402                 dhcp_client->lease_available_cb = func;
1403                 dhcp_client->lease_available_data = data;
1404                 return;
1405         case G_DHCP_CLIENT_EVENT_IPV4LL_AVAILABLE:
1406                 dhcp_client->ipv4ll_available_cb = func;
1407                 dhcp_client->ipv4ll_available_data = data;
1408                 return;
1409         case G_DHCP_CLIENT_EVENT_NO_LEASE:
1410                 dhcp_client->no_lease_cb = func;
1411                 dhcp_client->no_lease_data = data;
1412                 return;
1413         case G_DHCP_CLIENT_EVENT_LEASE_LOST:
1414                 dhcp_client->lease_lost_cb = func;
1415                 dhcp_client->lease_lost_data = data;
1416                 return;
1417         case G_DHCP_CLIENT_EVENT_IPV4LL_LOST:
1418                 dhcp_client->ipv4ll_lost_cb = func;
1419                 dhcp_client->ipv4ll_lost_data = data;
1420                 return;
1421         case G_DHCP_CLIENT_EVENT_ADDRESS_CONFLICT:
1422                 dhcp_client->address_conflict_cb = func;
1423                 dhcp_client->address_conflict_data = data;
1424                 return;
1425         }
1426 }
1427
1428 int g_dhcp_client_get_index(GDHCPClient *dhcp_client)
1429 {
1430         return dhcp_client->ifindex;
1431 }
1432
1433 char *g_dhcp_client_get_address(GDHCPClient *dhcp_client)
1434 {
1435         return g_strdup(dhcp_client->assigned_ip);
1436 }
1437
1438 char *g_dhcp_client_get_netmask(GDHCPClient *dhcp_client)
1439 {
1440         GList *option = NULL;
1441
1442         switch (dhcp_client->state) {
1443         case IPV4LL_DEFEND:
1444         case IPV4LL_MONITOR:
1445                 return g_strdup("255.255.0.0");
1446         case BOUND:
1447         case RENEWING:
1448         case REBINDING:
1449                 option = g_dhcp_client_get_option(dhcp_client, G_DHCP_SUBNET);
1450                 if (option != NULL)
1451                         return g_strdup(option->data);
1452         case INIT_SELECTING:
1453         case REQUESTING:
1454         case RELEASED:
1455         case IPV4LL_PROBE:
1456         case IPV4LL_ANNOUNCE:
1457                 break;
1458         }
1459         return NULL;
1460 }
1461
1462 GDHCPClientError g_dhcp_client_set_request(GDHCPClient *dhcp_client,
1463                                                 unsigned char option_code)
1464 {
1465         if (g_list_find(dhcp_client->request_list,
1466                         GINT_TO_POINTER((int) option_code)) == NULL)
1467                 dhcp_client->request_list = g_list_prepend(
1468                                         dhcp_client->request_list,
1469                                         (GINT_TO_POINTER((int) option_code)));
1470
1471         return G_DHCP_CLIENT_ERROR_NONE;
1472 }
1473
1474 static uint8_t *alloc_dhcp_option(int code, const char *str, int extra)
1475 {
1476         uint8_t *storage;
1477         int len = strnlen(str, 255);
1478
1479         storage = malloc(len + extra + OPT_DATA);
1480         storage[OPT_CODE] = code;
1481         storage[OPT_LEN] = len + extra;
1482         memcpy(storage + extra + OPT_DATA, str, len);
1483
1484         return storage;
1485 }
1486
1487 /* Now only support send hostname */
1488 GDHCPClientError g_dhcp_client_set_send(GDHCPClient *dhcp_client,
1489                 unsigned char option_code, const char *option_value)
1490 {
1491         uint8_t *binary_option;
1492
1493         if (option_code == G_DHCP_HOST_NAME && option_value != NULL) {
1494                 binary_option = alloc_dhcp_option(option_code,
1495                                                         option_value, 0);
1496
1497                 g_hash_table_insert(dhcp_client->send_value_hash,
1498                         GINT_TO_POINTER((int) option_code), binary_option);
1499         }
1500
1501         return G_DHCP_CLIENT_ERROR_NONE;
1502 }
1503
1504 GDHCPClient *g_dhcp_client_ref(GDHCPClient *dhcp_client)
1505 {
1506         if (dhcp_client == NULL)
1507                 return NULL;
1508
1509         __sync_fetch_and_add(&dhcp_client->ref_count, 1);
1510
1511         return dhcp_client;
1512 }
1513
1514 void g_dhcp_client_unref(GDHCPClient *dhcp_client)
1515 {
1516         if (dhcp_client == NULL)
1517                 return;
1518
1519         if (__sync_fetch_and_sub(&dhcp_client->ref_count, 1) != 1)
1520                 return;
1521
1522         g_dhcp_client_stop(dhcp_client);
1523
1524         g_free(dhcp_client->interface);
1525         g_free(dhcp_client->assigned_ip);
1526         g_free(dhcp_client->last_address);
1527
1528         g_list_free(dhcp_client->request_list);
1529         g_list_free(dhcp_client->require_list);
1530
1531         g_hash_table_destroy(dhcp_client->code_value_hash);
1532         g_hash_table_destroy(dhcp_client->send_value_hash);
1533
1534         g_free(dhcp_client);
1535 }
1536
1537 void g_dhcp_client_set_debug(GDHCPClient *dhcp_client,
1538                                 GDHCPDebugFunc func, gpointer user_data)
1539 {
1540         if (dhcp_client == NULL)
1541                 return;
1542
1543         dhcp_client->debug_func = func;
1544         dhcp_client->debug_data = user_data;
1545 }