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 #include <net/if_arp.h>
  37
  38 #include <linux/if.h>
  39 #include <linux/filter.h>
  40
  41 #include <glib.h>
  42
  43 #include "gdhcp.h"
  44 #include "common.h"
  45
  46 #define DISCOVER_TIMEOUT 3
  47 #define DISCOVER_RETRIES 3
  48
  49 #define REQUEST_TIMEOUT 3
  50 #define REQUEST_RETRIES 3
  51
  52 typedef enum _listen_mode {
  53         L_NONE,
  54         L2,
  55         L3,
  56 } ListenMode;
  57
  58 typedef enum _dhcp_client_state {
  59         INIT_SELECTING,
  60         REQUESTING,
  61         BOUND,
  62         RENEWING,
  63         REBINDING,
  64         RELEASED,
  65 } ClientState;
  66
  67 struct _GDHCPClient {
  68         gint ref_count;
  69         GDHCPType type;
  70         ClientState state;
  71         int ifindex;
  72         char *interface;
  73         uint8_t mac_address[6];
  74         uint32_t xid;
  75         uint32_t server_ip;
  76         uint32_t requested_ip;
  77         char *assigned_ip;
  78         uint32_t lease_seconds;
  79         ListenMode listen_mode;
  80         int listener_sockfd;
  81         uint8_t retry_times;
  82         uint8_t ack_retry_times;
  83         guint timeout;
  84         guint listener_watch;
  85         GIOChannel *listener_channel;
  86         GList *require_list;
  87         GList *request_list;
  88         GHashTable *code_value_hash;
  89         GHashTable *send_value_hash;
  90         GDHCPClientEventFunc lease_available_cb;
  91         gpointer lease_available_data;
  92         GDHCPClientEventFunc no_lease_cb;
  93         gpointer no_lease_data;
  94         GDHCPClientEventFunc lease_lost_cb;
  95         gpointer lease_lost_data;
  96         GDHCPClientEventFunc address_conflict_cb;
  97         gpointer address_conflict_data;
  98         GDHCPDebugFunc debug_func;
  99         gpointer debug_data;
 100 };
 101
 102 static inline void debug(GDHCPClient *client, const char *format, ...)
 103 {
 104         char str[256];
 105         va_list ap;
 106
 107         if (client->debug_func == NULL)
 108                 return;
 109
 110         va_start(ap, format);
 111
 112         if (vsnprintf(str, sizeof(str), format, ap) > 0)
 113                 client->debug_func(str, client->debug_data);
 114
 115         va_end(ap);
 116 }
 117
 118 /* Initialize the packet with the proper defaults */
 119 static void init_packet(GDHCPClient *dhcp_client,
 120                 struct dhcp_packet *packet, char type)
 121 {
 122         dhcp_init_header(packet, type);
 123
 124         memcpy(packet->chaddr, dhcp_client->mac_address, 6);
 125 }
 126
 127 static void add_request_options(GDHCPClient *dhcp_client,
 128                                 struct dhcp_packet *packet)
 129 {
 130         int len = 0;
 131         GList *list;
 132         uint8_t code;
 133         int end = dhcp_end_option(packet->options);
 134
 135         for (list = dhcp_client->request_list; list; list = list->next) {
 136                 code = (uint8_t) GPOINTER_TO_INT(list->data);
 137
 138                 packet->options[end + OPT_DATA + len] = code;
 139                 len++;
 140         }
 141
 142         if (len) {
 143                 packet->options[end + OPT_CODE] = DHCP_PARAM_REQ;
 144                 packet->options[end + OPT_LEN] = len;
 145                 packet->options[end + OPT_DATA + len] = DHCP_END;
 146         }
 147 }
 148
 149 static void add_binary_option(gpointer key, gpointer value, gpointer user_data)
 150 {
 151         uint8_t *option = value;
 152         struct dhcp_packet *packet = user_data;
 153
 154         dhcp_add_binary_option(packet, option);
 155 }
 156
 157 static void add_send_options(GDHCPClient *dhcp_client,
 158                                 struct dhcp_packet *packet)
 159 {
 160         g_hash_table_foreach(dhcp_client->send_value_hash,
 161                                 add_binary_option, packet);
 162 }
 163
 164 static int send_discover(GDHCPClient *dhcp_client, uint32_t requested)
 165 {
 166         struct dhcp_packet packet;
 167
 168         debug(dhcp_client, "sending DHCP discover request");
 169
 170         init_packet(dhcp_client, &packet, DHCPDISCOVER);
 171
 172         packet.xid = dhcp_client->xid;
 173
 174         if (requested)
 175                 dhcp_add_simple_option(&packet, DHCP_REQUESTED_IP, requested);
 176
 177         /* Explicitly saying that we want RFC-compliant packets helps
 178          * some buggy DHCP servers to NOT send bigger packets */
 179         dhcp_add_simple_option(&packet, DHCP_MAX_SIZE, htons(576));
 180
 181         add_request_options(dhcp_client, &packet);
 182
 183         add_send_options(dhcp_client, &packet);
 184
 185         return dhcp_send_raw_packet(&packet, INADDR_ANY, CLIENT_PORT,
 186                                         INADDR_BROADCAST, SERVER_PORT,
 187                                         MAC_BCAST_ADDR, dhcp_client->ifindex);
 188 }
 189
 190 static int send_select(GDHCPClient *dhcp_client)
 191 {
 192         struct dhcp_packet packet;
 193         struct in_addr addr;
 194
 195         debug(dhcp_client, "sending DHCP select request");
 196
 197         init_packet(dhcp_client, &packet, DHCPREQUEST);
 198
 199         packet.xid = dhcp_client->xid;
 200
 201         dhcp_add_simple_option(&packet, DHCP_REQUESTED_IP,
 202                                         dhcp_client->requested_ip);
 203         dhcp_add_simple_option(&packet, DHCP_SERVER_ID, dhcp_client->server_ip);
 204
 205         add_request_options(dhcp_client, &packet);
 206
 207         add_send_options(dhcp_client, &packet);
 208
 209         addr.s_addr = dhcp_client->requested_ip;
 210
 211         return dhcp_send_raw_packet(&packet, INADDR_ANY, CLIENT_PORT,
 212                                         INADDR_BROADCAST, SERVER_PORT,
 213                                         MAC_BCAST_ADDR, dhcp_client->ifindex);
 214 }
 215
 216 static int send_renew(GDHCPClient *dhcp_client)
 217 {
 218         struct dhcp_packet packet;
 219
 220         debug(dhcp_client, "sending DHCP renew request");
 221
 222         init_packet(dhcp_client , &packet, DHCPREQUEST);
 223         packet.xid = dhcp_client->xid;
 224         packet.ciaddr = dhcp_client->requested_ip;
 225
 226         add_request_options(dhcp_client, &packet);
 227
 228         add_send_options(dhcp_client, &packet);
 229
 230         return dhcp_send_kernel_packet(&packet,
 231                 dhcp_client->requested_ip, CLIENT_PORT,
 232                 dhcp_client->server_ip, SERVER_PORT);
 233 }
 234
 235 static int send_rebound(GDHCPClient *dhcp_client)
 236 {
 237         struct dhcp_packet packet;
 238
 239         debug(dhcp_client, "sending DHCP rebound request");
 240
 241         init_packet(dhcp_client , &packet, DHCPREQUEST);
 242         packet.xid = dhcp_client->xid;
 243         packet.ciaddr = dhcp_client->requested_ip;
 244
 245         add_request_options(dhcp_client, &packet);
 246
 247         add_send_options(dhcp_client, &packet);
 248
 249         return dhcp_send_raw_packet(&packet, INADDR_ANY, CLIENT_PORT,
 250                                         INADDR_BROADCAST, SERVER_PORT,
 251                                         MAC_BCAST_ADDR, dhcp_client->ifindex);
 252 }
 253
 254 static int send_release(GDHCPClient *dhcp_client,
 255                         uint32_t server, uint32_t ciaddr)
 256 {
 257         struct dhcp_packet packet;
 258
 259         debug(dhcp_client, "sending DHCP release request");
 260
 261         init_packet(dhcp_client, &packet, DHCPRELEASE);
 262         packet.xid = rand();
 263         packet.ciaddr = ciaddr;
 264
 265         dhcp_add_simple_option(&packet, DHCP_SERVER_ID, server);
 266
 267         return dhcp_send_kernel_packet(&packet, ciaddr, CLIENT_PORT,
 268                                                 server, SERVER_PORT);
 269 }
 270
 271 static gboolean interface_is_up(int index)
 272 {
 273         int sk, err;
 274         struct ifreq ifr;
 275         gboolean ret = FALSE;
 276
 277         sk = socket(PF_INET, SOCK_DGRAM, 0);
 278         if (sk < 0) {
 279                 perror("Open socket error");
 280                 return FALSE;
 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, SIOCGIFFLAGS, &ifr);
 293         if (err < 0) {
 294                 perror("Get interface flags error");
 295                 goto done;
 296         }
 297
 298         if (ifr.ifr_flags & IFF_UP)
 299                 ret = TRUE;
 300
 301 done:
 302         close(sk);
 303
 304         return ret;
 305 }
 306
 307 static char *get_interface_name(int index)
 308 {
 309         struct ifreq ifr;
 310         int sk, err;
 311
 312         if (index < 0)
 313                 return NULL;
 314
 315         sk = socket(PF_INET, SOCK_DGRAM, 0);
 316         if (sk < 0) {
 317                 perror("Open socket error");
 318                 return NULL;
 319         }
 320
 321         memset(&ifr, 0, sizeof(ifr));
 322         ifr.ifr_ifindex = index;
 323
 324         err = ioctl(sk, SIOCGIFNAME, &ifr);
 325         if (err < 0) {
 326                 perror("Get interface name error");
 327                 close(sk);
 328                 return NULL;
 329         }
 330
 331         close(sk);
 332
 333         return g_strdup(ifr.ifr_name);
 334 }
 335
 336 static void get_interface_mac_address(int index, uint8_t *mac_address)
 337 {
 338         struct ifreq ifr;
 339         int sk, err;
 340
 341         sk = socket(PF_INET, SOCK_DGRAM, 0);
 342         if (sk < 0) {
 343                 perror("Open socket error");
 344                 return;
 345         }
 346
 347         memset(&ifr, 0, sizeof(ifr));
 348         ifr.ifr_ifindex = index;
 349
 350         err = ioctl(sk, SIOCGIFNAME, &ifr);
 351         if (err < 0) {
 352                 perror("Get interface name error");
 353                 goto done;
 354         }
 355
 356         err = ioctl(sk, SIOCGIFHWADDR, &ifr);
 357         if (err < 0) {
 358                 perror("Get mac address error");
 359                 goto done;
 360         }
 361
 362         memcpy(mac_address, ifr.ifr_hwaddr.sa_data, 6);
 363
 364 done:
 365         close(sk);
 366 }
 367
 368 static void remove_value(gpointer data, gpointer user_data)
 369 {
 370         char *value = data;
 371         g_free(value);
 372 }
 373
 374 static void remove_option_value(gpointer data)
 375 {
 376         GList *option_value = data;
 377
 378         g_list_foreach(option_value, remove_value, NULL);
 379 }
 380
 381 GDHCPClient *g_dhcp_client_new(GDHCPType type,
 382                         int ifindex, GDHCPClientError *error)
 383 {
 384         GDHCPClient *dhcp_client;
 385
 386         if (ifindex < 0) {
 387                 *error = G_DHCP_CLIENT_ERROR_INVALID_INDEX;
 388                 return NULL;
 389         }
 390
 391         dhcp_client = g_try_new0(GDHCPClient, 1);
 392         if (dhcp_client == NULL) {
 393                 *error = G_DHCP_CLIENT_ERROR_NOMEM;
 394                 return NULL;
 395         }
 396
 397         dhcp_client->interface = get_interface_name(ifindex);
 398         if (dhcp_client->interface == NULL) {
 399                 *error = G_DHCP_CLIENT_ERROR_INTERFACE_UNAVAILABLE;
 400                 goto error;
 401         }
 402
 403         if (interface_is_up(ifindex) == FALSE) {
 404                 *error = G_DHCP_CLIENT_ERROR_INTERFACE_DOWN;
 405                 goto error;
 406         }
 407
 408         get_interface_mac_address(ifindex, dhcp_client->mac_address);
 409
 410         dhcp_client->listener_sockfd = -1;
 411         dhcp_client->listener_channel = NULL;
 412         dhcp_client->listen_mode = L_NONE;
 413         dhcp_client->ref_count = 1;
 414         dhcp_client->type = type;
 415         dhcp_client->ifindex = ifindex;
 416         dhcp_client->lease_available_cb = NULL;
 417         dhcp_client->no_lease_cb = NULL;
 418         dhcp_client->lease_lost_cb = NULL;
 419         dhcp_client->address_conflict_cb = NULL;
 420         dhcp_client->listener_watch = 0;
 421         dhcp_client->retry_times = 0;
 422         dhcp_client->ack_retry_times = 0;
 423         dhcp_client->code_value_hash = g_hash_table_new_full(g_direct_hash,
 424                                 g_direct_equal, NULL, remove_option_value);
 425         dhcp_client->send_value_hash = g_hash_table_new_full(g_direct_hash,
 426                                 g_direct_equal, NULL, g_free);
 427         dhcp_client->request_list = NULL;
 428         dhcp_client->require_list = NULL;
 429
 430         *error = G_DHCP_CLIENT_ERROR_NONE;
 431
 432         return dhcp_client;
 433
 434 error:
 435         g_free(dhcp_client->interface);
 436         g_free(dhcp_client);
 437         return NULL;
 438 }
 439
 440 #define SERVER_AND_CLIENT_PORTS  ((67 << 16) + 68)
 441
 442 static int dhcp_l2_socket(int ifindex)
 443 {
 444         int fd;
 445         struct sockaddr_ll sock;
 446
 447         /*
 448          * Comment:
 449          *
 450          *      I've selected not to see LL header, so BPF doesn't see it, too.
 451          *      The filter may also pass non-IP and non-ARP packets, but we do
 452          *      a more complete check when receiving the message in userspace.
 453          *
 454          * and filter shamelessly stolen from:
 455          *
 456          *      http://www.flamewarmaster.de/software/dhcpclient/
 457          *
 458          * There are a few other interesting ideas on that page (look under
 459          * "Motivation").  Use of netlink events is most interesting.  Think
 460          * of various network servers listening for events and reconfiguring.
 461          * That would obsolete sending HUP signals and/or make use of restarts.
 462          *
 463          * Copyright: 2006, 2007 Stefan Rompf <sux@loplof.de>.
 464          * License: GPL v2.
 465          *
 466          * TODO: make conditional?
 467          */
 468         static const struct sock_filter filter_instr[] = {
 469                 /* check for udp */
 470                 BPF_STMT(BPF_LD|BPF_B|BPF_ABS, 9),
 471                 /* L5, L1, is UDP? */
 472                 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, IPPROTO_UDP, 2, 0),
 473                 /* ugly check for arp on ethernet-like and IPv4 */
 474                 BPF_STMT(BPF_LD|BPF_W|BPF_ABS, 2), /* L1: */
 475                 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, 0x08000604, 3, 4),/* L3, L4 */
 476                 /* skip IP header */
 477                 BPF_STMT(BPF_LDX|BPF_B|BPF_MSH, 0), /* L5: */
 478                 /* check udp source and destination ports */
 479                 BPF_STMT(BPF_LD|BPF_W|BPF_IND, 0),
 480                 /* L3, L4 */
 481                 BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, SERVER_AND_CLIENT_PORTS, 0, 1),
 482                 /* returns */
 483                 BPF_STMT(BPF_RET|BPF_K, 0x0fffffff), /* L3: pass */
 484                 BPF_STMT(BPF_RET|BPF_K, 0), /* L4: reject */
 485         };
 486
 487         static const struct sock_fprog filter_prog = {
 488                 .len = sizeof(filter_instr) / sizeof(filter_instr[0]),
 489                 /* casting const away: */
 490                 .filter = (struct sock_filter *) filter_instr,
 491         };
 492
 493         fd = socket(PF_PACKET, SOCK_DGRAM, htons(ETH_P_IP));
 494         if (fd < 0)
 495                 return fd;
 496
 497         if (SERVER_PORT == 67 && CLIENT_PORT == 68)
 498                 /* Use only if standard ports are in use */
 499                 setsockopt(fd, SOL_SOCKET, SO_ATTACH_FILTER, &filter_prog,
 500                                                         sizeof(filter_prog));
 501
 502         sock.sll_family = AF_PACKET;
 503         sock.sll_protocol = htons(ETH_P_IP);
 504         sock.sll_ifindex = ifindex;
 505
 506         if (bind(fd, (struct sockaddr *) &sock, sizeof(sock)) != 0) {
 507                 close(fd);
 508                 return -errno;
 509         }
 510
 511         return fd;
 512 }
 513
 514 static gboolean sanity_check(struct ip_udp_dhcp_packet *packet, int bytes)
 515 {
 516         if (packet->ip.protocol != IPPROTO_UDP)
 517                 return FALSE;
 518
 519         if (packet->ip.version != IPVERSION)
 520                 return FALSE;
 521
 522         if (packet->ip.ihl != sizeof(packet->ip) >> 2)
 523                 return FALSE;
 524
 525         if (packet->udp.dest != htons(CLIENT_PORT))
 526                 return FALSE;
 527
 528         if (ntohs(packet->udp.len) != (uint16_t)(bytes - sizeof(packet->ip)))
 529                 return FALSE;
 530
 531         return TRUE;
 532 }
 533
 534 static int dhcp_recv_l2_packet(struct dhcp_packet *dhcp_pkt, int fd)
 535 {
 536         int bytes;
 537         struct ip_udp_dhcp_packet packet;
 538         uint16_t check;
 539
 540         memset(&packet, 0, sizeof(packet));
 541
 542         bytes = read(fd, &packet, sizeof(packet));
 543         if (bytes < 0)
 544                 return -1;
 545
 546         if (bytes < (int) (sizeof(packet.ip) + sizeof(packet.udp)))
 547                 return -1;
 548
 549         if (bytes < ntohs(packet.ip.tot_len))
 550                 /* packet is bigger than sizeof(packet), we did partial read */
 551                 return -1;
 552
 553         /* ignore any extra garbage bytes */
 554         bytes = ntohs(packet.ip.tot_len);
 555
 556         if (sanity_check(&packet, bytes) == FALSE)
 557                 return -1;
 558
 559         check = packet.ip.check;
 560         packet.ip.check = 0;
 561         if (check != dhcp_checksum(&packet.ip, sizeof(packet.ip)))
 562                 return -1;
 563
 564         /* verify UDP checksum. IP header has to be modified for this */
 565         memset(&packet.ip, 0, offsetof(struct iphdr, protocol));
 566         /* ip.xx fields which are not memset: protocol, check, saddr, daddr */
 567         packet.ip.tot_len = packet.udp.len; /* yes, this is needed */
 568         check = packet.udp.check;
 569         packet.udp.check = 0;
 570         if (check && check != dhcp_checksum(&packet, bytes))
 571                 return -1;
 572
 573         memcpy(dhcp_pkt, &packet.data, bytes - (sizeof(packet.ip) +
 574                                                         sizeof(packet.udp)));
 575
 576         if (dhcp_pkt->cookie != htonl(DHCP_MAGIC))
 577                 return -1;
 578
 579         return bytes - (sizeof(packet.ip) + sizeof(packet.udp));
 580 }
 581
 582 static gboolean check_package_owner(GDHCPClient *dhcp_client,
 583                                         struct dhcp_packet *packet)
 584 {
 585         if (packet->xid != dhcp_client->xid)
 586                 return FALSE;
 587
 588         if (packet->hlen != 6)
 589                 return FALSE;
 590
 591         if (memcmp(packet->chaddr, dhcp_client->mac_address, 6))
 592                 return FALSE;
 593
 594         return TRUE;
 595 }
 596
 597 static void start_request(GDHCPClient *dhcp_client);
 598
 599 static gboolean request_timeout(gpointer user_data)
 600 {
 601         GDHCPClient *dhcp_client = user_data;
 602
 603         dhcp_client->retry_times++;
 604
 605         start_request(dhcp_client);
 606
 607         return FALSE;
 608 }
 609
 610 static gboolean listener_event(GIOChannel *channel, GIOCondition condition,
 611                                                         gpointer user_data);
 612
 613 static int switch_listening_mode(GDHCPClient *dhcp_client,
 614                                         ListenMode listen_mode)
 615 {
 616         GIOChannel *listener_channel;
 617         int listener_sockfd;
 618
 619         if (dhcp_client->listen_mode == listen_mode)
 620                 return 0;
 621
 622         if (dhcp_client->listen_mode != L_NONE) {
 623                 g_source_remove(dhcp_client->listener_watch);
 624                 dhcp_client->listener_channel = NULL;
 625                 dhcp_client->listen_mode = L_NONE;
 626                 dhcp_client->listener_sockfd = -1;
 627                 dhcp_client->listener_watch = 0;
 628         }
 629
 630         if (listen_mode == L_NONE)
 631                 return 0;
 632
 633         if (listen_mode == L2)
 634                 listener_sockfd = dhcp_l2_socket(dhcp_client->ifindex);
 635         else if (listen_mode == L3)
 636                 listener_sockfd = dhcp_l3_socket(CLIENT_PORT,
 637                                                 dhcp_client->interface);
 638         else
 639                 return -EIO;
 640
 641         if (listener_sockfd < 0)
 642                 return -EIO;
 643
 644         listener_channel = g_io_channel_unix_new(listener_sockfd);
 645         if (listener_channel == NULL) {
 646                 /* Failed to create listener channel */
 647                 close(listener_sockfd);
 648                 return -EIO;
 649         }
 650
 651         dhcp_client->listen_mode = listen_mode;
 652         dhcp_client->listener_sockfd = listener_sockfd;
 653         dhcp_client->listener_channel = listener_channel;
 654
 655         g_io_channel_set_close_on_unref(listener_channel, TRUE);
 656         dhcp_client->listener_watch =
 657                         g_io_add_watch_full(listener_channel,
 658                                                 G_PRIORITY_HIGH, G_IO_IN,
 659                                                 listener_event, dhcp_client,
 660                                                                 NULL);
 661         g_io_channel_unref(dhcp_client->listener_channel);
 662
 663         return 0;
 664 }
 665
 666 static void start_request(GDHCPClient *dhcp_client)
 667 {
 668         if (dhcp_client->retry_times == REQUEST_RETRIES) {
 669                 dhcp_client->state = INIT_SELECTING;
 670
 671                 if (dhcp_client->no_lease_cb != NULL)
 672                         dhcp_client->no_lease_cb(dhcp_client,
 673                                         dhcp_client->no_lease_data);
 674
 675                 return;
 676         }
 677
 678         if (dhcp_client->retry_times == 0) {
 679                 dhcp_client->state = REQUESTING;
 680                 switch_listening_mode(dhcp_client, L2);
 681         }
 682
 683         send_select(dhcp_client);
 684
 685         dhcp_client->timeout = g_timeout_add_seconds_full(G_PRIORITY_HIGH,
 686                                                         REQUEST_TIMEOUT,
 687                                                         request_timeout,
 688                                                         dhcp_client,
 689                                                         NULL);
 690 }
 691
 692 static uint32_t get_lease(struct dhcp_packet *packet)
 693 {
 694         uint8_t *option_u8;
 695         uint32_t lease_seconds;
 696
 697         option_u8 = dhcp_get_option(packet, DHCP_LEASE_TIME);
 698         if (option_u8 == NULL)
 699                 return 3600;
 700
 701         lease_seconds = dhcp_get_unaligned((uint32_t *) option_u8);
 702         lease_seconds = ntohl(lease_seconds);
 703         /* paranoia: must not be prone to overflows */
 704         lease_seconds &= 0x0fffffff;
 705         if (lease_seconds < 10)
 706                 lease_seconds = 10;
 707
 708         return lease_seconds;
 709 }
 710
 711 static void restart_dhcp(GDHCPClient *dhcp_client, int retry_times)
 712 {
 713         if (dhcp_client->timeout > 0) {
 714                 g_source_remove(dhcp_client->timeout);
 715                 dhcp_client->timeout = 0;
 716         }
 717
 718         dhcp_client->retry_times = retry_times;
 719         dhcp_client->requested_ip = 0;
 720         switch_listening_mode(dhcp_client, L2);
 721
 722         g_dhcp_client_start(dhcp_client);
 723 }
 724
 725 static gboolean start_rebound_timeout(gpointer user_data)
 726 {
 727         GDHCPClient *dhcp_client = user_data;
 728
 729         switch_listening_mode(dhcp_client, L2);
 730
 731         dhcp_client->lease_seconds >>= 1;
 732
 733         /* We need to have enough time to receive ACK package*/
 734         if (dhcp_client->lease_seconds <= 6) {
 735
 736                 /* ip need to be cleared */
 737                 if (dhcp_client->lease_lost_cb != NULL)
 738                         dhcp_client->lease_lost_cb(dhcp_client,
 739                                         dhcp_client->lease_lost_data);
 740
 741                 restart_dhcp(dhcp_client, 0);
 742         } else {
 743                 send_rebound(dhcp_client);
 744
 745                 dhcp_client->timeout =
 746                                 g_timeout_add_seconds_full(G_PRIORITY_HIGH,
 747                                                 dhcp_client->lease_seconds >> 1,
 748                                                         start_rebound_timeout,
 749                                                                 dhcp_client,
 750                                                                 NULL);
 751         }
 752
 753         return FALSE;
 754 }
 755
 756 static void start_rebound(GDHCPClient *dhcp_client)
 757 {
 758         dhcp_client->state = REBINDING;
 759
 760         dhcp_client->timeout = g_timeout_add_seconds_full(G_PRIORITY_HIGH,
 761                                                 dhcp_client->lease_seconds >> 1,
 762                                                         start_rebound_timeout,
 763                                                                 dhcp_client,
 764                                                                 NULL);
 765 }
 766
 767 static gboolean start_renew_timeout(gpointer user_data)
 768 {
 769         GDHCPClient *dhcp_client = user_data;
 770
 771         dhcp_client->state = RENEWING;
 772
 773         dhcp_client->lease_seconds >>= 1;
 774
 775         switch_listening_mode(dhcp_client, L3);
 776         if (dhcp_client->lease_seconds <= 60)
 777                 start_rebound(dhcp_client);
 778         else {
 779                 send_renew(dhcp_client);
 780
 781                 dhcp_client->timeout =
 782                                 g_timeout_add_seconds_full(G_PRIORITY_HIGH,
 783                                                 dhcp_client->lease_seconds >> 1,
 784                                                         start_renew_timeout,
 785                                                                 dhcp_client,
 786                                                                 NULL);
 787         }
 788
 789         return FALSE;
 790 }
 791
 792 static void start_bound(GDHCPClient *dhcp_client)
 793 {
 794         dhcp_client->state = BOUND;
 795
 796         dhcp_client->timeout = g_timeout_add_seconds_full(G_PRIORITY_HIGH,
 797                                         dhcp_client->lease_seconds >> 1,
 798                                         start_renew_timeout, dhcp_client,
 799                                                         NULL);
 800 }
 801
 802 static gboolean restart_dhcp_timeout(gpointer user_data)
 803 {
 804         GDHCPClient *dhcp_client = user_data;
 805
 806         dhcp_client->ack_retry_times++;
 807
 808         restart_dhcp(dhcp_client, dhcp_client->ack_retry_times);
 809
 810         return FALSE;
 811 }
 812
 813 static char *get_ip(uint32_t ip)
 814 {
 815         struct in_addr addr;
 816
 817         addr.s_addr = ip;
 818
 819         return g_strdup(inet_ntoa(addr));
 820 }
 821
 822 /* get a rough idea of how long an option will be */
 823 static const uint8_t len_of_option_as_string[] = {
 824         [OPTION_IP] = sizeof("255.255.255.255 "),
 825         [OPTION_STRING] = 1,
 826         [OPTION_U8] = sizeof("255 "),
 827         [OPTION_U16] = sizeof("65535 "),
 828         [OPTION_U32] = sizeof("4294967295 "),
 829 };
 830
 831 static int sprint_nip(char *dest, const char *pre, const uint8_t *ip)
 832 {
 833         return sprintf(dest, "%s%u.%u.%u.%u", pre, ip[0], ip[1], ip[2], ip[3]);
 834 }
 835
 836 /* Create "opt_value1 option_value2 ..." string */
 837 static char *malloc_option_value_string(uint8_t *option, GDHCPOptionType type)
 838 {
 839         unsigned upper_length;
 840         int len, optlen;
 841         char *dest, *ret;
 842
 843         len = option[OPT_LEN - OPT_DATA];
 844         type &= OPTION_TYPE_MASK;
 845         optlen = dhcp_option_lengths[type];
 846         if (optlen == 0)
 847                 return NULL;
 848         upper_length = len_of_option_as_string[type] *
 849                         ((unsigned)len / (unsigned)optlen);
 850         dest = ret = malloc(upper_length + 1);
 851         if (ret == NULL)
 852                 return NULL;
 853
 854         while (len >= optlen) {
 855                 switch (type) {
 856                 case OPTION_IP:
 857                         dest += sprint_nip(dest, "", option);
 858                         break;
 859                 case OPTION_U16: {
 860                         uint16_t val_u16 = dhcp_get_unaligned(
 861                                                 (uint16_t *) option);
 862                         dest += sprintf(dest, "%u", ntohs(val_u16));
 863                         break;
 864                 }
 865                 case OPTION_U32: {
 866                         uint32_t val_u32 = dhcp_get_unaligned(
 867                                                 (uint32_t *) option);
 868                         dest += sprintf(dest, type == OPTION_U32 ? "%lu" :
 869                                         "%ld", (unsigned long) ntohl(val_u32));
 870                         break;
 871                 }
 872                 case OPTION_STRING:
 873                         memcpy(dest, option, len);
 874                         dest[len] = '\0';
 875                         return ret;
 876                 default:
 877                         break;
 878                 }
 879                 option += optlen;
 880                 len -= optlen;
 881                 if (len <= 0)
 882                         break;
 883                 *dest++ = ' ';
 884                 *dest = '\0';
 885         }
 886
 887         return ret;
 888 }
 889
 890 static GList *get_option_value_list(char *value)
 891 {
 892         char *pos = value;
 893         GList *list = NULL;
 894
 895         while ((pos = strchr(pos, ' ')) != NULL) {
 896                 *pos = '\0';
 897
 898                 list =  g_list_append(list, g_strdup(value));
 899
 900                 value = ++pos;
 901         }
 902
 903         list =  g_list_append(list, g_strdup(value));
 904
 905         return list;
 906 }
 907
 908 static void get_request(GDHCPClient *dhcp_client, struct dhcp_packet *packet)
 909 {
 910         GDHCPOptionType type;
 911         GList *list, *value_list;
 912         char *option_value;
 913         uint8_t *option;
 914         uint8_t code;
 915
 916         for (list = dhcp_client->request_list; list; list = list->next) {
 917                 code = (uint8_t) GPOINTER_TO_INT(list->data);
 918
 919                 option = dhcp_get_option(packet, code);
 920                 if (option == NULL) {
 921                         g_hash_table_remove(dhcp_client->code_value_hash,
 922                                                 GINT_TO_POINTER((int) code));
 923                         continue;
 924                 }
 925
 926                 type =  dhcp_get_code_type(code);
 927
 928                 option_value = malloc_option_value_string(option, type);
 929                 if (option_value == NULL)
 930                         g_hash_table_remove(dhcp_client->code_value_hash,
 931                                                 GINT_TO_POINTER((int) code));
 932
 933                 value_list = get_option_value_list(option_value);
 934
 935                 g_free(option_value);
 936
 937                 if (value_list == NULL)
 938                         g_hash_table_remove(dhcp_client->code_value_hash,
 939                                                 GINT_TO_POINTER((int) code));
 940                 else
 941                         g_hash_table_insert(dhcp_client->code_value_hash,
 942                                 GINT_TO_POINTER((int) code), value_list);
 943         }
 944 }
 945
 946 static gboolean listener_event(GIOChannel *channel, GIOCondition condition,
 947                                                         gpointer user_data)
 948 {
 949         GDHCPClient *dhcp_client = user_data;
 950         struct dhcp_packet packet;
 951         uint8_t *message_type, *option_u8;
 952         int re;
 953
 954         if (condition & (G_IO_NVAL | G_IO_ERR | G_IO_HUP)) {
 955                 dhcp_client->listener_watch = 0;
 956                 return FALSE;
 957         }
 958
 959         if (dhcp_client->listen_mode == L_NONE)
 960                 return FALSE;
 961
 962         if (dhcp_client->listen_mode == L2)
 963                 re = dhcp_recv_l2_packet(&packet, dhcp_client->listener_sockfd);
 964         else if (dhcp_client->listen_mode == L3)
 965                 re = dhcp_recv_l3_packet(&packet, dhcp_client->listener_sockfd);
 966         else
 967                 re = -EIO;
 968
 969         if (re < 0)
 970                 return TRUE;
 971
 972         if (check_package_owner(dhcp_client, &packet) == FALSE)
 973                 return TRUE;
 974
 975         message_type = dhcp_get_option(&packet, DHCP_MESSAGE_TYPE);
 976         if (message_type == NULL)
 977                 /* No message type option, ignore pakcage */
 978                 return TRUE;
 979
 980         switch (dhcp_client->state) {
 981         case INIT_SELECTING:
 982                 if (*message_type != DHCPOFFER)
 983                         return TRUE;
 984
 985                 g_source_remove(dhcp_client->timeout);
 986                 dhcp_client->timeout = 0;
 987                 dhcp_client->retry_times = 0;
 988
 989                 option_u8 = dhcp_get_option(&packet, DHCP_SERVER_ID);
 990                 dhcp_client->server_ip =
 991                                 dhcp_get_unaligned((uint32_t *) option_u8);
 992                 dhcp_client->requested_ip = packet.yiaddr;
 993
 994                 dhcp_client->state = REQUESTING;
 995
 996                 start_request(dhcp_client);
 997
 998                 return TRUE;
 999         case REQUESTING:
1000         case RENEWING:
1001         case REBINDING:
1002                 if (*message_type == DHCPACK) {
1003                         dhcp_client->retry_times = 0;
1004
1005                         if (dhcp_client->timeout > 0)
1006                                 g_source_remove(dhcp_client->timeout);
1007                         dhcp_client->timeout = 0;
1008
1009                         dhcp_client->lease_seconds = get_lease(&packet);
1010
1011                         get_request(dhcp_client, &packet);
1012
1013                         switch_listening_mode(dhcp_client, L_NONE);
1014
1015                         g_free(dhcp_client->assigned_ip);
1016                         dhcp_client->assigned_ip = get_ip(packet.yiaddr);
1017
1018                         /* Address should be set up here */
1019                         if (dhcp_client->lease_available_cb != NULL)
1020                                 dhcp_client->lease_available_cb(dhcp_client,
1021                                         dhcp_client->lease_available_data);
1022
1023                         start_bound(dhcp_client);
1024                 } else if (*message_type == DHCPNAK) {
1025                         dhcp_client->retry_times = 0;
1026
1027                         if (dhcp_client->timeout > 0)
1028                                 g_source_remove(dhcp_client->timeout);
1029
1030                         dhcp_client->timeout = g_timeout_add_seconds_full(
1031                                                         G_PRIORITY_HIGH, 3,
1032                                                         restart_dhcp_timeout,
1033                                                         dhcp_client,
1034                                                         NULL);
1035                 }
1036
1037                 break;
1038         default:
1039                 break;
1040         }
1041
1042         return TRUE;
1043 }
1044
1045 static gboolean discover_timeout(gpointer user_data)
1046 {
1047         GDHCPClient *dhcp_client = user_data;
1048
1049         dhcp_client->retry_times++;
1050
1051         g_dhcp_client_start(dhcp_client);
1052
1053         return FALSE;
1054 }
1055
1056 int g_dhcp_client_start(GDHCPClient *dhcp_client)
1057 {
1058         int re;
1059
1060         if (dhcp_client->retry_times == DISCOVER_RETRIES) {
1061                 if (dhcp_client->no_lease_cb != NULL)
1062                         dhcp_client->no_lease_cb(dhcp_client,
1063                                         dhcp_client->no_lease_data);
1064
1065                 return 0;
1066         }
1067
1068         if (dhcp_client->retry_times == 0) {
1069                 g_free(dhcp_client->assigned_ip);
1070                 dhcp_client->assigned_ip = NULL;
1071
1072                 dhcp_client->state = INIT_SELECTING;
1073                 re = switch_listening_mode(dhcp_client, L2);
1074                 if (re != 0)
1075                         return re;
1076
1077                 dhcp_client->xid = rand();
1078         }
1079
1080         send_discover(dhcp_client, 0);
1081
1082         dhcp_client->timeout = g_timeout_add_seconds_full(G_PRIORITY_HIGH,
1083                                                         DISCOVER_TIMEOUT,
1084                                                         discover_timeout,
1085                                                         dhcp_client,
1086                                                         NULL);
1087         return 0;
1088 }
1089
1090 void g_dhcp_client_stop(GDHCPClient *dhcp_client)
1091 {
1092         switch_listening_mode(dhcp_client, L_NONE);
1093
1094         if (dhcp_client->state == BOUND ||
1095                         dhcp_client->state == RENEWING ||
1096                                 dhcp_client->state == REBINDING)
1097                 send_release(dhcp_client, dhcp_client->server_ip,
1098                                         dhcp_client->requested_ip);
1099
1100         if (dhcp_client->timeout > 0) {
1101                 g_source_remove(dhcp_client->timeout);
1102                 dhcp_client->timeout = 0;
1103         }
1104
1105         if (dhcp_client->listener_watch > 0) {
1106                 g_source_remove(dhcp_client->listener_watch);
1107                 dhcp_client->listener_watch = 0;
1108         }
1109
1110         dhcp_client->listener_channel = NULL;
1111
1112         dhcp_client->retry_times = 0;
1113         dhcp_client->ack_retry_times = 0;
1114
1115         dhcp_client->requested_ip = 0;
1116         dhcp_client->state = RELEASED;
1117         dhcp_client->lease_seconds = 0;
1118 }
1119
1120 GList *g_dhcp_client_get_option(GDHCPClient *dhcp_client,
1121                                         unsigned char option_code)
1122 {
1123         return g_hash_table_lookup(dhcp_client->code_value_hash,
1124                                         GINT_TO_POINTER((int) option_code));
1125 }
1126
1127 void g_dhcp_client_register_event(GDHCPClient *dhcp_client,
1128                                         GDHCPClientEvent event,
1129                                         GDHCPClientEventFunc func,
1130                                                         gpointer data)
1131 {
1132         switch (event) {
1133         case G_DHCP_CLIENT_EVENT_LEASE_AVAILABLE:
1134                 dhcp_client->lease_available_cb = func;
1135                 dhcp_client->lease_available_data = data;
1136                 return;
1137         case G_DHCP_CLIENT_EVENT_NO_LEASE:
1138                 dhcp_client->no_lease_cb = func;
1139                 dhcp_client->no_lease_data = data;
1140                 return;
1141         case G_DHCP_CLIENT_EVENT_LEASE_LOST:
1142                 dhcp_client->lease_lost_cb = func;
1143                 dhcp_client->lease_lost_data = data;
1144                 return;
1145         case G_DHCP_CLIENT_EVENT_ADDRESS_CONFLICT:
1146                 dhcp_client->address_conflict_cb = func;
1147                 dhcp_client->address_conflict_data = data;
1148                 return;
1149         }
1150 }
1151
1152 int g_dhcp_client_get_index(GDHCPClient *dhcp_client)
1153 {
1154         return dhcp_client->ifindex;
1155 }
1156
1157 char *g_dhcp_client_get_address(GDHCPClient *dhcp_client)
1158 {
1159         return g_strdup(dhcp_client->assigned_ip);
1160 }
1161
1162 GDHCPClientError g_dhcp_client_set_request(GDHCPClient *dhcp_client,
1163                                                 unsigned char option_code)
1164 {
1165         if (g_list_find(dhcp_client->request_list,
1166                         GINT_TO_POINTER((int) option_code)) == NULL)
1167                 dhcp_client->request_list = g_list_prepend(
1168                                         dhcp_client->request_list,
1169                                         (GINT_TO_POINTER((int) option_code)));
1170
1171         return G_DHCP_CLIENT_ERROR_NONE;
1172 }
1173
1174 static uint8_t *alloc_dhcp_option(int code, const char *str, int extra)
1175 {
1176         uint8_t *storage;
1177         int len = strnlen(str, 255);
1178
1179         storage = malloc(len + extra + OPT_DATA);
1180         storage[OPT_CODE] = code;
1181         storage[OPT_LEN] = len + extra;
1182         memcpy(storage + extra + OPT_DATA, str, len);
1183
1184         return storage;
1185 }
1186
1187 static const char *get_hostname(const char *host)
1188 {
1189         char local_host_name[HOST_NAME_MAX + 1];
1190
1191         if (g_strcmp0("<hostname>", host) != 0)
1192                 return g_strdup(host);
1193
1194         if (gethostname(local_host_name, HOST_NAME_MAX) != 0)
1195                 return NULL;
1196
1197         local_host_name[HOST_NAME_MAX] = 0;
1198
1199         return g_strdup(local_host_name);
1200 }
1201
1202 /* Now only support send hostname */
1203 GDHCPClientError g_dhcp_client_set_send(GDHCPClient *dhcp_client,
1204                 unsigned char option_code, const char *option_value)
1205 {
1206         uint8_t *binary_option;
1207         const char *hostname;
1208
1209         if (option_code == G_DHCP_HOST_NAME) {
1210                 hostname = get_hostname(option_value);
1211
1212                 binary_option = alloc_dhcp_option(option_code, hostname, 0);
1213
1214                 g_hash_table_insert(dhcp_client->send_value_hash,
1215                         GINT_TO_POINTER((int) option_code), binary_option);
1216         }
1217
1218         return G_DHCP_CLIENT_ERROR_NONE;
1219 }
1220
1221 GDHCPClient *g_dhcp_client_ref(GDHCPClient *dhcp_client)
1222 {
1223         if (dhcp_client == NULL)
1224                 return NULL;
1225
1226         g_atomic_int_inc(&dhcp_client->ref_count);
1227
1228         return dhcp_client;
1229 }
1230
1231 void g_dhcp_client_unref(GDHCPClient *dhcp_client)
1232 {
1233         if (dhcp_client == NULL)
1234                 return;
1235
1236         if (g_atomic_int_dec_and_test(&dhcp_client->ref_count) == FALSE)
1237                 return;
1238
1239         g_dhcp_client_stop(dhcp_client);
1240
1241         g_free(dhcp_client->interface);
1242         g_free(dhcp_client->assigned_ip);
1243
1244         g_list_free(dhcp_client->request_list);
1245         g_list_free(dhcp_client->require_list);
1246
1247         g_hash_table_destroy(dhcp_client->code_value_hash);
1248         g_hash_table_destroy(dhcp_client->send_value_hash);
1249
1250         g_free(dhcp_client);
1251 }
1252
1253 void g_dhcp_client_set_debug(GDHCPClient *dhcp_client,
1254                                 GDHCPDebugFunc func, gpointer user_data)
1255 {
1256         if (dhcp_client == NULL)
1257                 return;
1258
1259         dhcp_client->debug_func = func;
1260         dhcp_client->debug_data = user_data;
1261 }