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 #include <stdio.h>
  27 #include <errno.h>
  28 #include <unistd.h>
  29 #include <stdlib.h>
  30 #include <string.h>
  31 #include <sys/ioctl.h>
  32 #include <arpa/inet.h>
  33
  34 #include <netpacket/packet.h>
  35 #include <net/ethernet.h>
  36
  37 #include <linux/if.h>
  38 #include <linux/filter.h>
  39
  40 #include <glib.h>
  41
  42 #include "gdhcp.h"
  43 #include "common.h"
  44
  45 #define DISCOVER_TIMEOUT 3
  46 #define DISCOVER_RETRIES 10
  47
  48 #define REQUEST_TIMEOUT 3
  49 #define REQUEST_RETRIES 5
  50
  51 typedef enum _listen_mode {
  52         L_NONE,
  53         L2,
  54         L3,
  55 } ListenMode;
  56
  57 typedef enum _dhcp_client_state {
  58         INIT_SELECTING,
  59         REQUESTING,
  60         BOUND,
  61         RENEWING,
  62         REBINDING,
  63         RELEASED,
  64 } ClientState;
  65
  66 struct _GDHCPClient {
  67         gint ref_count;
  68         GDHCPType type;
  69         ClientState state;
  70         int ifindex;
  71         char *interface;
  72         uint8_t mac_address[6];
  73         uint32_t xid;
  74         uint32_t server_ip;
  75         uint32_t requested_ip;
  76         char *assigned_ip;
  77         uint32_t lease_seconds;
  78         ListenMode listen_mode;
  79         int listener_sockfd;
  80         uint8_t retry_times;
  81         uint8_t ack_retry_times;
  82         guint timeout;
  83         guint listener_watch;
  84         GIOChannel *listener_channel;
  85         GList *require_list;
  86         GList *request_list;
  87         GHashTable *code_value_hash;
  88         GHashTable *send_value_hash;
  89         GDHCPClientEventFunc lease_available_cb;
  90         gpointer lease_available_data;
  91         GDHCPClientEventFunc no_lease_cb;
  92         gpointer no_lease_data;
  93         GDHCPClientEventFunc lease_lost_cb;
  94         gpointer lease_lost_data;
  95         GDHCPClientEventFunc address_conflict_cb;
  96         gpointer address_conflict_data;
  97         GDHCPDebugFunc debug_func;
  98         gpointer debug_data;
  99 };
 100
 101 static inline void debug(GDHCPClient *client, const char *format, ...)
 102 {
 103         char str[256];
 104         va_list ap;
 105
 106         if (client->debug_func == NULL)
 107                 return;
 108
 109         va_start(ap, format);
 110
 111         if (vsnprintf(str, sizeof(str), format, ap) > 0)
 112                 client->debug_func(str, client->debug_data);
 113
 114         va_end(ap);
 115 }
 116
 117 /* Initialize the packet with the proper defaults */
 118 static void init_packet(GDHCPClient *dhcp_client,
 119                 struct dhcp_packet *packet, char type)
 120 {
 121         dhcp_init_header(packet, type);
 122
 123         memcpy(packet->chaddr, dhcp_client->mac_address, 6);
 124 }
 125
 126 static void add_request_options(GDHCPClient *dhcp_client,
 127                                 struct dhcp_packet *packet)
 128 {
 129         int len = 0;
 130         GList *list;
 131         uint8_t code;
 132         int end = dhcp_end_option(packet->options);
 133
 134         for (list = dhcp_client->request_list; list; list = list->next) {
 135                 code = (uint8_t) GPOINTER_TO_INT(list->data);
 136
 137                 packet->options[end + OPT_DATA + len] = code;
 138                 len++;
 139         }
 140
 141         if (len) {
 142                 packet->options[end + OPT_CODE] = DHCP_PARAM_REQ;
 143                 packet->options[end + OPT_LEN] = len;
 144                 packet->options[end + OPT_DATA + len] = DHCP_END;
 145         }
 146 }
 147
 148 static void add_binary_option(gpointer key, gpointer value, gpointer user_data)
 149 {
 150         uint8_t *option = value;
 151         struct dhcp_packet *packet = user_data;
 152
 153         dhcp_add_binary_option(packet, option);
 154 }
 155
 156 static void add_send_options(GDHCPClient *dhcp_client,
 157                                 struct dhcp_packet *packet)
 158 {
 159         g_hash_table_foreach(dhcp_client->send_value_hash,
 160                                 add_binary_option, packet);
 161 }
 162
 163 static int send_discover(GDHCPClient *dhcp_client, uint32_t requested)
 164 {
 165         struct dhcp_packet packet;
 166
 167         debug(dhcp_client, "sending DHCP discover request");
 168
 169         init_packet(dhcp_client, &packet, DHCPDISCOVER);
 170
 171         packet.xid = dhcp_client->xid;
 172
 173         if (requested)
 174                 dhcp_add_simple_option(&packet, DHCP_REQUESTED_IP, requested);
 175
 176         /* Explicitly saying that we want RFC-compliant packets helps
 177          * some buggy DHCP servers to NOT send bigger packets */
 178         dhcp_add_simple_option(&packet, DHCP_MAX_SIZE, htons(576));
 179
 180         add_request_options(dhcp_client, &packet);
 181
 182         add_send_options(dhcp_client, &packet);
 183
 184         return dhcp_send_raw_packet(&packet, INADDR_ANY, CLIENT_PORT,
 185                                         INADDR_BROADCAST, SERVER_PORT,
 186                                         MAC_BCAST_ADDR, dhcp_client->ifindex);
 187 }
 188
 189 static int send_select(GDHCPClient *dhcp_client)
 190 {
 191         struct dhcp_packet packet;
 192         struct in_addr addr;
 193
 194         debug(dhcp_client, "sending DHCP select request");
 195
 196         init_packet(dhcp_client, &packet, DHCPREQUEST);
 197
 198         packet.xid = dhcp_client->xid;
 199
 200         dhcp_add_simple_option(&packet, DHCP_REQUESTED_IP,
 201                                         dhcp_client->requested_ip);
 202         dhcp_add_simple_option(&packet, DHCP_SERVER_ID, dhcp_client->server_ip);
 203
 204         add_request_options(dhcp_client, &packet);
 205
 206         add_send_options(dhcp_client, &packet);
 207
 208         addr.s_addr = dhcp_client->requested_ip;
 209
 210         return dhcp_send_raw_packet(&packet, INADDR_ANY, CLIENT_PORT,
 211                                         INADDR_BROADCAST, SERVER_PORT,
 212                                         MAC_BCAST_ADDR, dhcp_client->ifindex);
 213 }
 214
 215 static int send_renew(GDHCPClient *dhcp_client)
 216 {
 217         struct dhcp_packet packet;
 218
 219         debug(dhcp_client, "sending DHCP renew request");
 220
 221         init_packet(dhcp_client , &packet, DHCPREQUEST);
 222         packet.xid = dhcp_client->xid;
 223         packet.ciaddr = dhcp_client->requested_ip;
 224
 225         add_request_options(dhcp_client, &packet);
 226
 227         add_send_options(dhcp_client, &packet);
 228
 229         return dhcp_send_kernel_packet(&packet,
 230                 dhcp_client->requested_ip, CLIENT_PORT,
 231                 dhcp_client->server_ip, SERVER_PORT);
 232 }
 233
 234 static int send_rebound(GDHCPClient *dhcp_client)
 235 {
 236         struct dhcp_packet packet;
 237
 238         debug(dhcp_client, "sending DHCP rebound request");
 239
 240         init_packet(dhcp_client , &packet, DHCPREQUEST);
 241         packet.xid = dhcp_client->xid;
 242         packet.ciaddr = dhcp_client->requested_ip;
 243
 244         add_request_options(dhcp_client, &packet);
 245
 246         add_send_options(dhcp_client, &packet);
 247
 248         return dhcp_send_raw_packet(&packet, INADDR_ANY, CLIENT_PORT,
 249                                         INADDR_BROADCAST, SERVER_PORT,
 250                                         MAC_BCAST_ADDR, dhcp_client->ifindex);
 251 }
 252
 253 static int send_release(GDHCPClient *dhcp_client,
 254                         uint32_t server, uint32_t ciaddr)
 255 {
 256         struct dhcp_packet packet;
 257
 258         debug(dhcp_client, "sending DHCP release request");
 259
 260         init_packet(dhcp_client, &packet, DHCPRELEASE);
 261         packet.xid = rand();
 262         packet.ciaddr = ciaddr;
 263
 264         dhcp_add_simple_option(&packet, DHCP_SERVER_ID, server);
 265
 266         return dhcp_send_kernel_packet(&packet, ciaddr, CLIENT_PORT,
 267                                                 server, SERVER_PORT);
 268 }
 269
 270
 271
 272 static void get_interface_mac_address(int index, uint8_t *mac_address)
 273 {
 274         struct ifreq ifr;
 275         int sk, err;
 276
 277         sk = socket(PF_INET, SOCK_DGRAM, 0);
 278         if (sk < 0) {
 279                 perror("Open socket error");
 280                 return;
 281         }
 282
 283         memset(&ifr, 0, sizeof(ifr));
 284         ifr.ifr_ifindex = index;
 285
 286         err = ioctl(sk, SIOCGIFNAME, &ifr);
 287         if (err < 0) {
 288                 perror("Get interface name error");
 289                 goto done;
 290         }
 291
 292         err = ioctl(sk, SIOCGIFHWADDR, &ifr);
 293         if (err < 0) {
 294                 perror("Get mac address error");
 295                 goto done;
 296         }
 297
 298         memcpy(mac_address, ifr.ifr_hwaddr.sa_data, 6);
 299
 300 done:
 301         close(sk);
 302 }
 303
 304 static void remove_value(gpointer data, gpointer user_data)
 305 {
 306         char *value = data;
 307         g_free(value);
 308 }
 309
 310 static void remove_option_value(gpointer data)
 311 {
 312         GList *option_value = data;
 313
 314         g_list_foreach(option_value, remove_value, NULL);
 315 }
 316
 317 GDHCPClient *g_dhcp_client_new(GDHCPType type,
 318                         int ifindex, GDHCPClientError *error)
 319 {
 320         GDHCPClient *dhcp_client;
 321
 322         if (ifindex < 0) {
 323                 *error = G_DHCP_CLIENT_ERROR_INVALID_INDEX;
 324                 return NULL;
 325         }
 326
 327         dhcp_client = g_try_new0(GDHCPClient, 1);
 328         if (dhcp_client == NULL) {
 329                 *error = G_DHCP_CLIENT_ERROR_NOMEM;
 330                 return NULL;
 331         }
 332
 333         dhcp_client->interface = get_interface_name(ifindex);
 334         if (dhcp_client->interface == NULL) {
 335                 *error = G_DHCP_CLIENT_ERROR_INTERFACE_UNAVAILABLE;
 336                 goto error;
 337         }
 338
 339         if (interface_is_up(ifindex) == FALSE) {
 340                 *error = G_DHCP_CLIENT_ERROR_INTERFACE_DOWN;
 341                 goto error;
 342         }
 343
 344         get_interface_mac_address(ifindex, dhcp_client->mac_address);
 345
 346         dhcp_client->listener_sockfd = -1;
 347         dhcp_client->listener_channel = NULL;
 348         dhcp_client->listen_mode = L_NONE;
 349         dhcp_client->ref_count = 1;
 350         dhcp_client->type = type;
 351         dhcp_client->ifindex = ifindex;
 352         dhcp_client->lease_available_cb = NULL;
 353         dhcp_client->no_lease_cb = NULL;
 354         dhcp_client->lease_lost_cb = NULL;
 355         dhcp_client->address_conflict_cb = NULL;
 356         dhcp_client->listener_watch = 0;
 357         dhcp_client->retry_times = 0;
 358         dhcp_client->ack_retry_times = 0;
 359         dhcp_client->code_value_hash = g_hash_table_new_full(g_direct_hash,
 360                                 g_direct_equal, NULL, remove_option_value);
 361         dhcp_client->send_value_hash = g_hash_table_new_full(g_direct_hash,
 362                                 g_direct_equal, NULL, g_free);
 363         dhcp_client->request_list = NULL;
 364         dhcp_client->require_list = NULL;
 365
 366         *error = G_DHCP_CLIENT_ERROR_NONE;
 367
 368         return dhcp_client;
 369
 370 error:
 371         g_free(dhcp_client->interface);
 372         g_free(dhcp_client);
 373         return NULL;
 374 }
 375
 376 #define SERVER_AND_CLIENT_PORTS  ((67 << 16) + 68)
 377
 378 static int dhcp_l2_socket(int ifindex)
 379 {
 380         int fd;
 381         struct sockaddr_ll sock;
 382
 383         /*
 384          * Comment:
 385          *
 386          *      I've selected not to see LL header, so BPF doesn't see it, too.
 387          *      The filter may also pass non-IP and non-ARP packets, but we do
 388          *      a more complete check when receiving the message in userspace.
 389          *
 390          * and filter shamelessly stolen from:
 391          *
 392          *      http://www.flamewarmaster.de/software/dhcpclient/
 393          *
 394          * There are a few other interesting ideas on that page (look under
 395          * "Motivation").  Use of netlink events is most interesting.  Think
 396          * of various network servers listening for events and reconfiguring.
 397          * That would obsolete sending HUP signals and/or make use of restarts.
 398          *
 399          * Copyright: 2006, 2007 Stefan Rompf <sux@loplof.de>.
 400          * License: GPL v2.
 401          *
 402          * TODO: make conditional?
 403          */
 404         static const struct sock_filter filter_instr[] = {
 405                 /* check for udp */
 406                 BPF_STMT(BPF_LD|BPF_B|BPF_ABS, 9),
 407                 /* L5, L1, is UDP? */
 408                 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, IPPROTO_UDP, 2, 0),
 409                 /* ugly check for arp on ethernet-like and IPv4 */
 410                 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 2), /* L1: */
 411                 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, 0x08000604, 3, 4),/* L3, L4 */
 412                 /* skip IP header */
 413                 BPF_STMT(BPF_LDX|BPF_B|BPF_MSH, 0), /* L5: */
 414                 /* check udp source and destination ports */
 415                 BPF_STMT(BPF_LD|BPF_W|BPF_IND, 0),
 416                 /* L3, L4 */
 417                 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, SERVER_AND_CLIENT_PORTS, 0, 1),
 418                 /* returns */
 419                 BPF_STMT(BPF_RET|BPF_K, 0x0fffffff), /* L3: pass */
 420                 BPF_STMT(BPF_RET|BPF_K, 0), /* L4: reject */
 421         };
 422
 423         static const struct sock_fprog filter_prog = {
 424                 .len = sizeof(filter_instr) / sizeof(filter_instr[0]),
 425                 /* casting const away: */
 426                 .filter = (struct sock_filter *) filter_instr,
 427         };
 428
 429         fd = socket(PF_PACKET, SOCK_DGRAM, htons(ETH_P_IP));
 430         if (fd < 0)
 431                 return fd;
 432
 433         if (SERVER_PORT == 67 && CLIENT_PORT == 68)
 434                 /* Use only if standard ports are in use */
 435                 setsockopt(fd, SOL_SOCKET, SO_ATTACH_FILTER, &filter_prog,
 436                                                         sizeof(filter_prog));
 437
 438         sock.sll_family = AF_PACKET;
 439         sock.sll_protocol = htons(ETH_P_IP);
 440         sock.sll_ifindex = ifindex;
 441
 442         if (bind(fd, (struct sockaddr *) &sock, sizeof(sock)) != 0) {
 443                 close(fd);
 444                 return -errno;
 445         }
 446
 447         return fd;
 448 }
 449
 450 static gboolean sanity_check(struct ip_udp_dhcp_packet *packet, int bytes)
 451 {
 452         if (packet->ip.protocol != IPPROTO_UDP)
 453                 return FALSE;
 454
 455         if (packet->ip.version != IPVERSION)
 456                 return FALSE;
 457
 458         if (packet->ip.ihl != sizeof(packet->ip) >> 2)
 459                 return FALSE;
 460
 461         if (packet->udp.dest != htons(CLIENT_PORT))
 462                 return FALSE;
 463
 464         if (ntohs(packet->udp.len) != (uint16_t)(bytes - sizeof(packet->ip)))
 465                 return FALSE;
 466
 467         return TRUE;
 468 }
 469
 470 static int dhcp_recv_l2_packet(struct dhcp_packet *dhcp_pkt, int fd)
 471 {
 472         int bytes;
 473         struct ip_udp_dhcp_packet packet;
 474         uint16_t check;
 475
 476         memset(&packet, 0, sizeof(packet));
 477
 478         bytes = read(fd, &packet, sizeof(packet));
 479         if (bytes < 0)
 480                 return -1;
 481
 482         if (bytes < (int) (sizeof(packet.ip) + sizeof(packet.udp)))
 483                 return -1;
 484
 485         if (bytes < ntohs(packet.ip.tot_len))
 486                 /* packet is bigger than sizeof(packet), we did partial read */
 487                 return -1;
 488
 489         /* ignore any extra garbage bytes */
 490         bytes = ntohs(packet.ip.tot_len);
 491
 492         if (sanity_check(&packet, bytes) == FALSE)
 493                 return -1;
 494
 495         check = packet.ip.check;
 496         packet.ip.check = 0;
 497         if (check != dhcp_checksum(&packet.ip, sizeof(packet.ip)))
 498                 return -1;
 499
 500         /* verify UDP checksum. IP header has to be modified for this */
 501         memset(&packet.ip, 0, offsetof(struct iphdr, protocol));
 502         /* ip.xx fields which are not memset: protocol, check, saddr, daddr */
 503         packet.ip.tot_len = packet.udp.len; /* yes, this is needed */
 504         check = packet.udp.check;
 505         packet.udp.check = 0;
 506         if (check && check != dhcp_checksum(&packet, bytes))
 507                 return -1;
 508
 509         memcpy(dhcp_pkt, &packet.data, bytes - (sizeof(packet.ip) +
 510                                                         sizeof(packet.udp)));
 511
 512         if (dhcp_pkt->cookie != htonl(DHCP_MAGIC))
 513                 return -1;
 514
 515         return bytes - (sizeof(packet.ip) + sizeof(packet.udp));
 516 }
 517
 518 static gboolean check_package_owner(GDHCPClient *dhcp_client,
 519                                         struct dhcp_packet *packet)
 520 {
 521         if (packet->xid != dhcp_client->xid)
 522                 return FALSE;
 523
 524         if (packet->hlen != 6)
 525                 return FALSE;
 526
 527         if (memcmp(packet->chaddr, dhcp_client->mac_address, 6))
 528                 return FALSE;
 529
 530         return TRUE;
 531 }
 532
 533 static void start_request(GDHCPClient *dhcp_client);
 534
 535 static gboolean request_timeout(gpointer user_data)
 536 {
 537         GDHCPClient *dhcp_client = user_data;
 538
 539         debug(dhcp_client, "request timeout (retries %d)",
 540                                         dhcp_client->retry_times);
 541
 542         dhcp_client->retry_times++;
 543
 544         start_request(dhcp_client);
 545
 546         return FALSE;
 547 }
 548
 549 static gboolean listener_event(GIOChannel *channel, GIOCondition condition,
 550                                                         gpointer user_data);
 551
 552 static int switch_listening_mode(GDHCPClient *dhcp_client,
 553                                         ListenMode listen_mode)
 554 {
 555         GIOChannel *listener_channel;
 556         int listener_sockfd;
 557
 558         debug(dhcp_client, "switch listening mode (%d ==> %d)",
 559                                 dhcp_client->listen_mode, listen_mode);
 560
 561         if (dhcp_client->listen_mode == listen_mode)
 562                 return 0;
 563
 564         if (dhcp_client->listen_mode != L_NONE) {
 565                 g_source_remove(dhcp_client->listener_watch);
 566                 dhcp_client->listener_channel = NULL;
 567                 dhcp_client->listen_mode = L_NONE;
 568                 dhcp_client->listener_sockfd = -1;
 569                 dhcp_client->listener_watch = 0;
 570         }
 571
 572         if (listen_mode == L_NONE)
 573                 return 0;
 574
 575         if (listen_mode == L2)
 576                 listener_sockfd = dhcp_l2_socket(dhcp_client->ifindex);
 577         else if (listen_mode == L3)
 578                 listener_sockfd = dhcp_l3_socket(CLIENT_PORT,
 579                                                 dhcp_client->interface);
 580         else
 581                 return -EIO;
 582
 583         if (listener_sockfd < 0)
 584                 return -EIO;
 585
 586         listener_channel = g_io_channel_unix_new(listener_sockfd);
 587         if (listener_channel == NULL) {
 588                 /* Failed to create listener channel */
 589                 close(listener_sockfd);
 590                 return -EIO;
 591         }
 592
 593         dhcp_client->listen_mode = listen_mode;
 594         dhcp_client->listener_sockfd = listener_sockfd;
 595         dhcp_client->listener_channel = listener_channel;
 596
 597         g_io_channel_set_close_on_unref(listener_channel, TRUE);
 598         dhcp_client->listener_watch =
 599                         g_io_add_watch_full(listener_channel,
 600                                                 G_PRIORITY_HIGH, G_IO_IN,
 601                                                 listener_event, dhcp_client,
 602                                                                 NULL);
 603         g_io_channel_unref(dhcp_client->listener_channel);
 604
 605         return 0;
 606 }
 607
 608 static void start_request(GDHCPClient *dhcp_client)
 609 {
 610         debug(dhcp_client, "start request (retries %d)",
 611                                         dhcp_client->retry_times);
 612
 613         if (dhcp_client->retry_times == REQUEST_RETRIES) {
 614                 dhcp_client->state = INIT_SELECTING;
 615
 616                 if (dhcp_client->no_lease_cb != NULL)
 617                         dhcp_client->no_lease_cb(dhcp_client,
 618                                         dhcp_client->no_lease_data);
 619
 620                 return;
 621         }
 622
 623         if (dhcp_client->retry_times == 0) {
 624                 dhcp_client->state = REQUESTING;
 625                 switch_listening_mode(dhcp_client, L2);
 626         }
 627
 628         send_select(dhcp_client);
 629
 630         dhcp_client->timeout = g_timeout_add_seconds_full(G_PRIORITY_HIGH,
 631                                                         REQUEST_TIMEOUT,
 632                                                         request_timeout,
 633                                                         dhcp_client,
 634                                                         NULL);
 635 }
 636
 637 static uint32_t get_lease(struct dhcp_packet *packet)
 638 {
 639         uint8_t *option_u8;
 640         uint32_t lease_seconds;
 641
 642         option_u8 = dhcp_get_option(packet, DHCP_LEASE_TIME);
 643         if (option_u8 == NULL)
 644                 return 3600;
 645
 646         lease_seconds = dhcp_get_unaligned((uint32_t *) option_u8);
 647         lease_seconds = ntohl(lease_seconds);
 648         /* paranoia: must not be prone to overflows */
 649         lease_seconds &= 0x0fffffff;
 650         if (lease_seconds < 10)
 651                 lease_seconds = 10;
 652
 653         return lease_seconds;
 654 }
 655
 656 static void restart_dhcp(GDHCPClient *dhcp_client, int retry_times)
 657 {
 658         debug(dhcp_client, "restart DHCP (retries %d)", retry_times);
 659
 660         if (dhcp_client->timeout > 0) {
 661                 g_source_remove(dhcp_client->timeout);
 662                 dhcp_client->timeout = 0;
 663         }
 664
 665         dhcp_client->retry_times = retry_times;
 666         dhcp_client->requested_ip = 0;
 667         switch_listening_mode(dhcp_client, L2);
 668
 669         g_dhcp_client_start(dhcp_client);
 670 }
 671
 672 static gboolean start_rebound_timeout(gpointer user_data)
 673 {
 674         GDHCPClient *dhcp_client = user_data;
 675
 676         debug(dhcp_client, "start rebound timeout");
 677
 678         switch_listening_mode(dhcp_client, L2);
 679
 680         dhcp_client->lease_seconds >>= 1;
 681
 682         /* We need to have enough time to receive ACK package*/
 683         if (dhcp_client->lease_seconds <= 6) {
 684
 685                 /* ip need to be cleared */
 686                 if (dhcp_client->lease_lost_cb != NULL)
 687                         dhcp_client->lease_lost_cb(dhcp_client,
 688                                         dhcp_client->lease_lost_data);
 689
 690                 restart_dhcp(dhcp_client, 0);
 691         } else {
 692                 send_rebound(dhcp_client);
 693
 694                 dhcp_client->timeout =
 695                                 g_timeout_add_seconds_full(G_PRIORITY_HIGH,
 696                                                 dhcp_client->lease_seconds >> 1,
 697                                                         start_rebound_timeout,
 698                                                                 dhcp_client,
 699                                                                 NULL);
 700         }
 701
 702         return FALSE;
 703 }
 704
 705 static void start_rebound(GDHCPClient *dhcp_client)
 706 {
 707         debug(dhcp_client, "start rebound");
 708
 709         dhcp_client->state = REBINDING;
 710
 711         dhcp_client->timeout = g_timeout_add_seconds_full(G_PRIORITY_HIGH,
 712                                                 dhcp_client->lease_seconds >> 1,
 713                                                         start_rebound_timeout,
 714                                                                 dhcp_client,
 715                                                                 NULL);
 716 }
 717
 718 static gboolean start_renew_timeout(gpointer user_data)
 719 {
 720         GDHCPClient *dhcp_client = user_data;
 721
 722         debug(dhcp_client, "start renew timeout");
 723
 724         dhcp_client->state = RENEWING;
 725
 726         dhcp_client->lease_seconds >>= 1;
 727
 728         switch_listening_mode(dhcp_client, L3);
 729         if (dhcp_client->lease_seconds <= 60)
 730                 start_rebound(dhcp_client);
 731         else {
 732                 send_renew(dhcp_client);
 733
 734                 dhcp_client->timeout =
 735                                 g_timeout_add_seconds_full(G_PRIORITY_HIGH,
 736                                                 dhcp_client->lease_seconds >> 1,
 737                                                         start_renew_timeout,
 738                                                                 dhcp_client,
 739                                                                 NULL);
 740         }
 741
 742         return FALSE;
 743 }
 744
 745 static void start_bound(GDHCPClient *dhcp_client)
 746 {
 747         debug(dhcp_client, "start bound");
 748
 749         dhcp_client->state = BOUND;
 750
 751         dhcp_client->timeout = g_timeout_add_seconds_full(G_PRIORITY_HIGH,
 752                                         dhcp_client->lease_seconds >> 1,
 753                                         start_renew_timeout, dhcp_client,
 754                                                         NULL);
 755 }
 756
 757 static gboolean restart_dhcp_timeout(gpointer user_data)
 758 {
 759         GDHCPClient *dhcp_client = user_data;
 760
 761         debug(dhcp_client, "restart DHCP timeout");
 762
 763         dhcp_client->ack_retry_times++;
 764
 765         restart_dhcp(dhcp_client, dhcp_client->ack_retry_times);
 766
 767         return FALSE;
 768 }
 769
 770 static char *get_ip(uint32_t ip)
 771 {
 772         struct in_addr addr;
 773
 774         addr.s_addr = ip;
 775
 776         return g_strdup(inet_ntoa(addr));
 777 }
 778
 779 /* get a rough idea of how long an option will be */
 780 static const uint8_t len_of_option_as_string[] = {
 781         [OPTION_IP] = sizeof("255.255.255.255 "),
 782         [OPTION_STRING] = 1,
 783         [OPTION_U8] = sizeof("255 "),
 784         [OPTION_U16] = sizeof("65535 "),
 785         [OPTION_U32] = sizeof("4294967295 "),
 786 };
 787
 788 static int sprint_nip(char *dest, const char *pre, const uint8_t *ip)
 789 {
 790         return sprintf(dest, "%s%u.%u.%u.%u", pre, ip[0], ip[1], ip[2], ip[3]);
 791 }
 792
 793 /* Create "opt_value1 option_value2 ..." string */
 794 static char *malloc_option_value_string(uint8_t *option, GDHCPOptionType type)
 795 {
 796         unsigned upper_length;
 797         int len, optlen;
 798         char *dest, *ret;
 799
 800         len = option[OPT_LEN - OPT_DATA];
 801         type &= OPTION_TYPE_MASK;
 802         optlen = dhcp_option_lengths[type];
 803         if (optlen == 0)
 804                 return NULL;
 805         upper_length = len_of_option_as_string[type] *
 806                         ((unsigned)len / (unsigned)optlen);
 807         dest = ret = malloc(upper_length + 1);
 808         if (ret == NULL)
 809                 return NULL;
 810
 811         while (len >= optlen) {
 812                 switch (type) {
 813                 case OPTION_IP:
 814                         dest += sprint_nip(dest, "", option);
 815                         break;
 816                 case OPTION_U16: {
 817                         uint16_t val_u16 = dhcp_get_unaligned(
 818                                                 (uint16_t *) option);
 819                         dest += sprintf(dest, "%u", ntohs(val_u16));
 820                         break;
 821                 }
 822                 case OPTION_U32: {
 823                         uint32_t val_u32 = dhcp_get_unaligned(
 824                                                 (uint32_t *) option);
 825                         dest += sprintf(dest, type == OPTION_U32 ? "%lu" :
 826                                         "%ld", (unsigned long) ntohl(val_u32));
 827                         break;
 828                 }
 829                 case OPTION_STRING:
 830                         memcpy(dest, option, len);
 831                         dest[len] = '\0';
 832                         return ret;
 833                 default:
 834                         break;
 835                 }
 836                 option += optlen;
 837                 len -= optlen;
 838                 if (len <= 0)
 839                         break;
 840                 *dest++ = ' ';
 841                 *dest = '\0';
 842         }
 843
 844         return ret;
 845 }
 846
 847 static GList *get_option_value_list(char *value)
 848 {
 849         char *pos = value;
 850         GList *list = NULL;
 851
 852         if (pos == NULL)
 853                 return NULL;
 854
 855         while ((pos = strchr(pos, ' ')) != NULL) {
 856                 *pos = '\0';
 857
 858                 list = g_list_append(list, g_strdup(value));
 859
 860                 value = ++pos;
 861         }
 862
 863         list = g_list_append(list, g_strdup(value));
 864
 865         return list;
 866 }
 867
 868 static void get_request(GDHCPClient *dhcp_client, struct dhcp_packet *packet)
 869 {
 870         GDHCPOptionType type;
 871         GList *list, *value_list;
 872         char *option_value;
 873         uint8_t *option;
 874         uint8_t code;
 875
 876         for (list = dhcp_client->request_list; list; list = list->next) {
 877                 code = (uint8_t) GPOINTER_TO_INT(list->data);
 878
 879                 option = dhcp_get_option(packet, code);
 880                 if (option == NULL) {
 881                         g_hash_table_remove(dhcp_client->code_value_hash,
 882                                                 GINT_TO_POINTER((int) code));
 883                         continue;
 884                 }
 885
 886                 type =  dhcp_get_code_type(code);
 887
 888                 option_value = malloc_option_value_string(option, type);
 889                 if (option_value == NULL)
 890                         g_hash_table_remove(dhcp_client->code_value_hash,
 891                                                 GINT_TO_POINTER((int) code));
 892
 893                 value_list = get_option_value_list(option_value);
 894
 895                 g_free(option_value);
 896
 897                 if (value_list == NULL)
 898                         g_hash_table_remove(dhcp_client->code_value_hash,
 899                                                 GINT_TO_POINTER((int) code));
 900                 else
 901                         g_hash_table_insert(dhcp_client->code_value_hash,
 902                                 GINT_TO_POINTER((int) code), value_list);
 903         }
 904 }
 905
 906 static gboolean listener_event(GIOChannel *channel, GIOCondition condition,
 907                                                         gpointer user_data)
 908 {
 909         GDHCPClient *dhcp_client = user_data;
 910         struct dhcp_packet packet;
 911         uint8_t *message_type, *option_u8;
 912         int re;
 913
 914         if (condition & (G_IO_NVAL | G_IO_ERR | G_IO_HUP)) {
 915                 dhcp_client->listener_watch = 0;
 916                 return FALSE;
 917         }
 918
 919         if (dhcp_client->listen_mode == L_NONE)
 920                 return FALSE;
 921
 922         if (dhcp_client->listen_mode == L2)
 923                 re = dhcp_recv_l2_packet(&packet, dhcp_client->listener_sockfd);
 924         else if (dhcp_client->listen_mode == L3)
 925                 re = dhcp_recv_l3_packet(&packet, dhcp_client->listener_sockfd);
 926         else
 927                 re = -EIO;
 928
 929         if (re < 0)
 930                 return TRUE;
 931
 932         if (check_package_owner(dhcp_client, &packet) == FALSE)
 933                 return TRUE;
 934
 935         message_type = dhcp_get_option(&packet, DHCP_MESSAGE_TYPE);
 936         if (message_type == NULL)
 937                 /* No message type option, ignore pakcage */
 938                 return TRUE;
 939
 940         debug(dhcp_client, "received DHCP packet (current state %d)",
 941                                                         dhcp_client->state);
 942
 943         switch (dhcp_client->state) {
 944         case INIT_SELECTING:
 945                 if (*message_type != DHCPOFFER)
 946                         return TRUE;
 947
 948                 g_source_remove(dhcp_client->timeout);
 949                 dhcp_client->timeout = 0;
 950                 dhcp_client->retry_times = 0;
 951
 952                 option_u8 = dhcp_get_option(&packet, DHCP_SERVER_ID);
 953                 dhcp_client->server_ip =
 954                                 dhcp_get_unaligned((uint32_t *) option_u8);
 955                 dhcp_client->requested_ip = packet.yiaddr;
 956
 957                 dhcp_client->state = REQUESTING;
 958
 959                 start_request(dhcp_client);
 960
 961                 return TRUE;
 962         case REQUESTING:
 963         case RENEWING:
 964         case REBINDING:
 965                 if (*message_type == DHCPACK) {
 966                         dhcp_client->retry_times = 0;
 967
 968                         if (dhcp_client->timeout > 0)
 969                                 g_source_remove(dhcp_client->timeout);
 970                         dhcp_client->timeout = 0;
 971
 972                         dhcp_client->lease_seconds = get_lease(&packet);
 973
 974                         get_request(dhcp_client, &packet);
 975
 976                         switch_listening_mode(dhcp_client, L_NONE);
 977
 978                         g_free(dhcp_client->assigned_ip);
 979                         dhcp_client->assigned_ip = get_ip(packet.yiaddr);
 980
 981                         /* Address should be set up here */
 982                         if (dhcp_client->lease_available_cb != NULL)
 983                                 dhcp_client->lease_available_cb(dhcp_client,
 984                                         dhcp_client->lease_available_data);
 985
 986                         start_bound(dhcp_client);
 987                 } else if (*message_type == DHCPNAK) {
 988                         dhcp_client->retry_times = 0;
 989
 990                         if (dhcp_client->timeout > 0)
 991                                 g_source_remove(dhcp_client->timeout);
 992
 993                         dhcp_client->timeout = g_timeout_add_seconds_full(
 994                                                         G_PRIORITY_HIGH, 3,
 995                                                         restart_dhcp_timeout,
 996                                                         dhcp_client,
 997                                                         NULL);
 998                 }
 999
1000                 break;
1001         default:
1002                 break;
1003         }
1004
1005         debug(dhcp_client, "processed DHCP packet (new state %d)",
1006                                                         dhcp_client->state);
1007
1008         return TRUE;
1009 }
1010
1011 static gboolean discover_timeout(gpointer user_data)
1012 {
1013         GDHCPClient *dhcp_client = user_data;
1014
1015         dhcp_client->retry_times++;
1016
1017         g_dhcp_client_start(dhcp_client);
1018
1019         return FALSE;
1020 }
1021
1022 int g_dhcp_client_start(GDHCPClient *dhcp_client)
1023 {
1024         int re;
1025
1026         if (dhcp_client->retry_times == DISCOVER_RETRIES) {
1027                 if (dhcp_client->no_lease_cb != NULL)
1028                         dhcp_client->no_lease_cb(dhcp_client,
1029                                         dhcp_client->no_lease_data);
1030
1031                 return 0;
1032         }
1033
1034         if (dhcp_client->retry_times == 0) {
1035                 g_free(dhcp_client->assigned_ip);
1036                 dhcp_client->assigned_ip = NULL;
1037
1038                 dhcp_client->state = INIT_SELECTING;
1039                 re = switch_listening_mode(dhcp_client, L2);
1040                 if (re != 0)
1041                         return re;
1042
1043                 dhcp_client->xid = rand();
1044         }
1045
1046         send_discover(dhcp_client, 0);
1047
1048         dhcp_client->timeout = g_timeout_add_seconds_full(G_PRIORITY_HIGH,
1049                                                         DISCOVER_TIMEOUT,
1050                                                         discover_timeout,
1051                                                         dhcp_client,
1052                                                         NULL);
1053         return 0;
1054 }
1055
1056 void g_dhcp_client_stop(GDHCPClient *dhcp_client)
1057 {
1058         switch_listening_mode(dhcp_client, L_NONE);
1059
1060         if (dhcp_client->state == BOUND ||
1061                         dhcp_client->state == RENEWING ||
1062                                 dhcp_client->state == REBINDING)
1063                 send_release(dhcp_client, dhcp_client->server_ip,
1064                                         dhcp_client->requested_ip);
1065
1066         if (dhcp_client->timeout > 0) {
1067                 g_source_remove(dhcp_client->timeout);
1068                 dhcp_client->timeout = 0;
1069         }
1070
1071         if (dhcp_client->listener_watch > 0) {
1072                 g_source_remove(dhcp_client->listener_watch);
1073                 dhcp_client->listener_watch = 0;
1074         }
1075
1076         dhcp_client->listener_channel = NULL;
1077
1078         dhcp_client->retry_times = 0;
1079         dhcp_client->ack_retry_times = 0;
1080
1081         dhcp_client->requested_ip = 0;
1082         dhcp_client->state = RELEASED;
1083         dhcp_client->lease_seconds = 0;
1084 }
1085
1086 GList *g_dhcp_client_get_option(GDHCPClient *dhcp_client,
1087                                         unsigned char option_code)
1088 {
1089         return g_hash_table_lookup(dhcp_client->code_value_hash,
1090                                         GINT_TO_POINTER((int) option_code));
1091 }
1092
1093 void g_dhcp_client_register_event(GDHCPClient *dhcp_client,
1094                                         GDHCPClientEvent event,
1095                                         GDHCPClientEventFunc func,
1096                                                         gpointer data)
1097 {
1098         switch (event) {
1099         case G_DHCP_CLIENT_EVENT_LEASE_AVAILABLE:
1100                 dhcp_client->lease_available_cb = func;
1101                 dhcp_client->lease_available_data = data;
1102                 return;
1103         case G_DHCP_CLIENT_EVENT_NO_LEASE:
1104                 dhcp_client->no_lease_cb = func;
1105                 dhcp_client->no_lease_data = data;
1106                 return;
1107         case G_DHCP_CLIENT_EVENT_LEASE_LOST:
1108                 dhcp_client->lease_lost_cb = func;
1109                 dhcp_client->lease_lost_data = data;
1110                 return;
1111         case G_DHCP_CLIENT_EVENT_ADDRESS_CONFLICT:
1112                 dhcp_client->address_conflict_cb = func;
1113                 dhcp_client->address_conflict_data = data;
1114                 return;
1115         }
1116 }
1117
1118 int g_dhcp_client_get_index(GDHCPClient *dhcp_client)
1119 {
1120         return dhcp_client->ifindex;
1121 }
1122
1123 char *g_dhcp_client_get_address(GDHCPClient *dhcp_client)
1124 {
1125         return g_strdup(dhcp_client->assigned_ip);
1126 }
1127
1128 GDHCPClientError g_dhcp_client_set_request(GDHCPClient *dhcp_client,
1129                                                 unsigned char option_code)
1130 {
1131         if (g_list_find(dhcp_client->request_list,
1132                         GINT_TO_POINTER((int) option_code)) == NULL)
1133                 dhcp_client->request_list = g_list_prepend(
1134                                         dhcp_client->request_list,
1135                                         (GINT_TO_POINTER((int) option_code)));
1136
1137         return G_DHCP_CLIENT_ERROR_NONE;
1138 }
1139
1140 static uint8_t *alloc_dhcp_option(int code, const char *str, int extra)
1141 {
1142         uint8_t *storage;
1143         int len = strnlen(str, 255);
1144
1145         storage = malloc(len + extra + OPT_DATA);
1146         storage[OPT_CODE] = code;
1147         storage[OPT_LEN] = len + extra;
1148         memcpy(storage + extra + OPT_DATA, str, len);
1149
1150         return storage;
1151 }
1152
1153 /* Now only support send hostname */
1154 GDHCPClientError g_dhcp_client_set_send(GDHCPClient *dhcp_client,
1155                 unsigned char option_code, const char *option_value)
1156 {
1157         uint8_t *binary_option;
1158
1159         if (option_code == G_DHCP_HOST_NAME && option_value != NULL) {
1160                 binary_option = alloc_dhcp_option(option_code,
1161                                                         option_value, 0);
1162
1163                 g_hash_table_insert(dhcp_client->send_value_hash,
1164                         GINT_TO_POINTER((int) option_code), binary_option);
1165         }
1166
1167         return G_DHCP_CLIENT_ERROR_NONE;
1168 }
1169
1170 GDHCPClient *g_dhcp_client_ref(GDHCPClient *dhcp_client)
1171 {
1172         if (dhcp_client == NULL)
1173                 return NULL;
1174
1175         g_atomic_int_inc(&dhcp_client->ref_count);
1176
1177         return dhcp_client;
1178 }
1179
1180 void g_dhcp_client_unref(GDHCPClient *dhcp_client)
1181 {
1182         if (dhcp_client == NULL)
1183                 return;
1184
1185         if (g_atomic_int_dec_and_test(&dhcp_client->ref_count) == FALSE)
1186                 return;
1187
1188         g_dhcp_client_stop(dhcp_client);
1189
1190         g_free(dhcp_client->interface);
1191         g_free(dhcp_client->assigned_ip);
1192
1193         g_list_free(dhcp_client->request_list);
1194         g_list_free(dhcp_client->require_list);
1195
1196         g_hash_table_destroy(dhcp_client->code_value_hash);
1197         g_hash_table_destroy(dhcp_client->send_value_hash);
1198
1199         g_free(dhcp_client);
1200 }
1201
1202 void g_dhcp_client_set_debug(GDHCPClient *dhcp_client,
1203                                 GDHCPDebugFunc func, gpointer user_data)
1204 {
1205         if (dhcp_client == NULL)
1206                 return;
1207
1208         dhcp_client->debug_func = func;
1209         dhcp_client->debug_data = user_data;
1210 }