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 5
  48
  49 #define REQUEST_TIMEOUT 3
  50 #define REQUEST_RETRIES 5
  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         debug(dhcp_client, "request timeout (retries %d)",
 604                                         dhcp_client->retry_times);
 605
 606         dhcp_client->retry_times++;
 607
 608         start_request(dhcp_client);
 609
 610         return FALSE;
 611 }
 612
 613 static gboolean listener_event(GIOChannel *channel, GIOCondition condition,
 614                                                         gpointer user_data);
 615
 616 static int switch_listening_mode(GDHCPClient *dhcp_client,
 617                                         ListenMode listen_mode)
 618 {
 619         GIOChannel *listener_channel;
 620         int listener_sockfd;
 621
 622         debug(dhcp_client, "switch listening mode (%d ==> %d)",
 623                                 dhcp_client->listen_mode, listen_mode);
 624
 625         if (dhcp_client->listen_mode == listen_mode)
 626                 return 0;
 627
 628         if (dhcp_client->listen_mode != L_NONE) {
 629                 g_source_remove(dhcp_client->listener_watch);
 630                 dhcp_client->listener_channel = NULL;
 631                 dhcp_client->listen_mode = L_NONE;
 632                 dhcp_client->listener_sockfd = -1;
 633                 dhcp_client->listener_watch = 0;
 634         }
 635
 636         if (listen_mode == L_NONE)
 637                 return 0;
 638
 639         if (listen_mode == L2)
 640                 listener_sockfd = dhcp_l2_socket(dhcp_client->ifindex);
 641         else if (listen_mode == L3)
 642                 listener_sockfd = dhcp_l3_socket(CLIENT_PORT,
 643                                                 dhcp_client->interface);
 644         else
 645                 return -EIO;
 646
 647         if (listener_sockfd < 0)
 648                 return -EIO;
 649
 650         listener_channel = g_io_channel_unix_new(listener_sockfd);
 651         if (listener_channel == NULL) {
 652                 /* Failed to create listener channel */
 653                 close(listener_sockfd);
 654                 return -EIO;
 655         }
 656
 657         dhcp_client->listen_mode = listen_mode;
 658         dhcp_client->listener_sockfd = listener_sockfd;
 659         dhcp_client->listener_channel = listener_channel;
 660
 661         g_io_channel_set_close_on_unref(listener_channel, TRUE);
 662         dhcp_client->listener_watch =
 663                         g_io_add_watch_full(listener_channel,
 664                                                 G_PRIORITY_HIGH, G_IO_IN,
 665                                                 listener_event, dhcp_client,
 666                                                                 NULL);
 667         g_io_channel_unref(dhcp_client->listener_channel);
 668
 669         return 0;
 670 }
 671
 672 static void start_request(GDHCPClient *dhcp_client)
 673 {
 674         debug(dhcp_client, "start request (retries %d)",
 675                                         dhcp_client->retry_times);
 676
 677         if (dhcp_client->retry_times == REQUEST_RETRIES) {
 678                 dhcp_client->state = INIT_SELECTING;
 679
 680                 if (dhcp_client->no_lease_cb != NULL)
 681                         dhcp_client->no_lease_cb(dhcp_client,
 682                                         dhcp_client->no_lease_data);
 683
 684                 return;
 685         }
 686
 687         if (dhcp_client->retry_times == 0) {
 688                 dhcp_client->state = REQUESTING;
 689                 switch_listening_mode(dhcp_client, L2);
 690         }
 691
 692         send_select(dhcp_client);
 693
 694         dhcp_client->timeout = g_timeout_add_seconds_full(G_PRIORITY_HIGH,
 695                                                         REQUEST_TIMEOUT,
 696                                                         request_timeout,
 697                                                         dhcp_client,
 698                                                         NULL);
 699 }
 700
 701 static uint32_t get_lease(struct dhcp_packet *packet)
 702 {
 703         uint8_t *option_u8;
 704         uint32_t lease_seconds;
 705
 706         option_u8 = dhcp_get_option(packet, DHCP_LEASE_TIME);
 707         if (option_u8 == NULL)
 708                 return 3600;
 709
 710         lease_seconds = dhcp_get_unaligned((uint32_t *) option_u8);
 711         lease_seconds = ntohl(lease_seconds);
 712         /* paranoia: must not be prone to overflows */
 713         lease_seconds &= 0x0fffffff;
 714         if (lease_seconds < 10)
 715                 lease_seconds = 10;
 716
 717         return lease_seconds;
 718 }
 719
 720 static void restart_dhcp(GDHCPClient *dhcp_client, int retry_times)
 721 {
 722         debug(dhcp_client, "restart DHCP (retries %d)", retry_times);
 723
 724         if (dhcp_client->timeout > 0) {
 725                 g_source_remove(dhcp_client->timeout);
 726                 dhcp_client->timeout = 0;
 727         }
 728
 729         dhcp_client->retry_times = retry_times;
 730         dhcp_client->requested_ip = 0;
 731         switch_listening_mode(dhcp_client, L2);
 732
 733         g_dhcp_client_start(dhcp_client);
 734 }
 735
 736 static gboolean start_rebound_timeout(gpointer user_data)
 737 {
 738         GDHCPClient *dhcp_client = user_data;
 739
 740         debug(dhcp_client, "start rebound timeout");
 741
 742         switch_listening_mode(dhcp_client, L2);
 743
 744         dhcp_client->lease_seconds >>= 1;
 745
 746         /* We need to have enough time to receive ACK package*/
 747         if (dhcp_client->lease_seconds <= 6) {
 748
 749                 /* ip need to be cleared */
 750                 if (dhcp_client->lease_lost_cb != NULL)
 751                         dhcp_client->lease_lost_cb(dhcp_client,
 752                                         dhcp_client->lease_lost_data);
 753
 754                 restart_dhcp(dhcp_client, 0);
 755         } else {
 756                 send_rebound(dhcp_client);
 757
 758                 dhcp_client->timeout =
 759                                 g_timeout_add_seconds_full(G_PRIORITY_HIGH,
 760                                                 dhcp_client->lease_seconds >> 1,
 761                                                         start_rebound_timeout,
 762                                                                 dhcp_client,
 763                                                                 NULL);
 764         }
 765
 766         return FALSE;
 767 }
 768
 769 static void start_rebound(GDHCPClient *dhcp_client)
 770 {
 771         debug(dhcp_client, "start rebound");
 772
 773         dhcp_client->state = REBINDING;
 774
 775         dhcp_client->timeout = g_timeout_add_seconds_full(G_PRIORITY_HIGH,
 776                                                 dhcp_client->lease_seconds >> 1,
 777                                                         start_rebound_timeout,
 778                                                                 dhcp_client,
 779                                                                 NULL);
 780 }
 781
 782 static gboolean start_renew_timeout(gpointer user_data)
 783 {
 784         GDHCPClient *dhcp_client = user_data;
 785
 786         debug(dhcp_client, "start renew timeout");
 787
 788         dhcp_client->state = RENEWING;
 789
 790         dhcp_client->lease_seconds >>= 1;
 791
 792         switch_listening_mode(dhcp_client, L3);
 793         if (dhcp_client->lease_seconds <= 60)
 794                 start_rebound(dhcp_client);
 795         else {
 796                 send_renew(dhcp_client);
 797
 798                 dhcp_client->timeout =
 799                                 g_timeout_add_seconds_full(G_PRIORITY_HIGH,
 800                                                 dhcp_client->lease_seconds >> 1,
 801                                                         start_renew_timeout,
 802                                                                 dhcp_client,
 803                                                                 NULL);
 804         }
 805
 806         return FALSE;
 807 }
 808
 809 static void start_bound(GDHCPClient *dhcp_client)
 810 {
 811         debug(dhcp_client, "start bound");
 812
 813         dhcp_client->state = BOUND;
 814
 815         dhcp_client->timeout = g_timeout_add_seconds_full(G_PRIORITY_HIGH,
 816                                         dhcp_client->lease_seconds >> 1,
 817                                         start_renew_timeout, dhcp_client,
 818                                                         NULL);
 819 }
 820
 821 static gboolean restart_dhcp_timeout(gpointer user_data)
 822 {
 823         GDHCPClient *dhcp_client = user_data;
 824
 825         debug(dhcp_client, "restart DHCP timeout");
 826
 827         dhcp_client->ack_retry_times++;
 828
 829         restart_dhcp(dhcp_client, dhcp_client->ack_retry_times);
 830
 831         return FALSE;
 832 }
 833
 834 static char *get_ip(uint32_t ip)
 835 {
 836         struct in_addr addr;
 837
 838         addr.s_addr = ip;
 839
 840         return g_strdup(inet_ntoa(addr));
 841 }
 842
 843 /* get a rough idea of how long an option will be */
 844 static const uint8_t len_of_option_as_string[] = {
 845         [OPTION_IP] = sizeof("255.255.255.255 "),
 846         [OPTION_STRING] = 1,
 847         [OPTION_U8] = sizeof("255 "),
 848         [OPTION_U16] = sizeof("65535 "),
 849         [OPTION_U32] = sizeof("4294967295 "),
 850 };
 851
 852 static int sprint_nip(char *dest, const char *pre, const uint8_t *ip)
 853 {
 854         return sprintf(dest, "%s%u.%u.%u.%u", pre, ip[0], ip[1], ip[2], ip[3]);
 855 }
 856
 857 /* Create "opt_value1 option_value2 ..." string */
 858 static char *malloc_option_value_string(uint8_t *option, GDHCPOptionType type)
 859 {
 860         unsigned upper_length;
 861         int len, optlen;
 862         char *dest, *ret;
 863
 864         len = option[OPT_LEN - OPT_DATA];
 865         type &= OPTION_TYPE_MASK;
 866         optlen = dhcp_option_lengths[type];
 867         if (optlen == 0)
 868                 return NULL;
 869         upper_length = len_of_option_as_string[type] *
 870                         ((unsigned)len / (unsigned)optlen);
 871         dest = ret = malloc(upper_length + 1);
 872         if (ret == NULL)
 873                 return NULL;
 874
 875         while (len >= optlen) {
 876                 switch (type) {
 877                 case OPTION_IP:
 878                         dest += sprint_nip(dest, "", option);
 879                         break;
 880                 case OPTION_U16: {
 881                         uint16_t val_u16 = dhcp_get_unaligned(
 882                                                 (uint16_t *) option);
 883                         dest += sprintf(dest, "%u", ntohs(val_u16));
 884                         break;
 885                 }
 886                 case OPTION_U32: {
 887                         uint32_t val_u32 = dhcp_get_unaligned(
 888                                                 (uint32_t *) option);
 889                         dest += sprintf(dest, type == OPTION_U32 ? "%lu" :
 890                                         "%ld", (unsigned long) ntohl(val_u32));
 891                         break;
 892                 }
 893                 case OPTION_STRING:
 894                         memcpy(dest, option, len);
 895                         dest[len] = '\0';
 896                         return ret;
 897                 default:
 898                         break;
 899                 }
 900                 option += optlen;
 901                 len -= optlen;
 902                 if (len <= 0)
 903                         break;
 904                 *dest++ = ' ';
 905                 *dest = '\0';
 906         }
 907
 908         return ret;
 909 }
 910
 911 static GList *get_option_value_list(char *value)
 912 {
 913         char *pos = value;
 914         GList *list = NULL;
 915
 916         while ((pos = strchr(pos, ' ')) != NULL) {
 917                 *pos = '\0';
 918
 919                 list =  g_list_append(list, g_strdup(value));
 920
 921                 value = ++pos;
 922         }
 923
 924         list =  g_list_append(list, g_strdup(value));
 925
 926         return list;
 927 }
 928
 929 static void get_request(GDHCPClient *dhcp_client, struct dhcp_packet *packet)
 930 {
 931         GDHCPOptionType type;
 932         GList *list, *value_list;
 933         char *option_value;
 934         uint8_t *option;
 935         uint8_t code;
 936
 937         for (list = dhcp_client->request_list; list; list = list->next) {
 938                 code = (uint8_t) GPOINTER_TO_INT(list->data);
 939
 940                 option = dhcp_get_option(packet, code);
 941                 if (option == NULL) {
 942                         g_hash_table_remove(dhcp_client->code_value_hash,
 943                                                 GINT_TO_POINTER((int) code));
 944                         continue;
 945                 }
 946
 947                 type =  dhcp_get_code_type(code);
 948
 949                 option_value = malloc_option_value_string(option, type);
 950                 if (option_value == NULL)
 951                         g_hash_table_remove(dhcp_client->code_value_hash,
 952                                                 GINT_TO_POINTER((int) code));
 953
 954                 value_list = get_option_value_list(option_value);
 955
 956                 g_free(option_value);
 957
 958                 if (value_list == NULL)
 959                         g_hash_table_remove(dhcp_client->code_value_hash,
 960                                                 GINT_TO_POINTER((int) code));
 961                 else
 962                         g_hash_table_insert(dhcp_client->code_value_hash,
 963                                 GINT_TO_POINTER((int) code), value_list);
 964         }
 965 }
 966
 967 static gboolean listener_event(GIOChannel *channel, GIOCondition condition,
 968                                                         gpointer user_data)
 969 {
 970         GDHCPClient *dhcp_client = user_data;
 971         struct dhcp_packet packet;
 972         uint8_t *message_type, *option_u8;
 973         int re;
 974
 975         if (condition & (G_IO_NVAL | G_IO_ERR | G_IO_HUP)) {
 976                 dhcp_client->listener_watch = 0;
 977                 return FALSE;
 978         }
 979
 980         if (dhcp_client->listen_mode == L_NONE)
 981                 return FALSE;
 982
 983         if (dhcp_client->listen_mode == L2)
 984                 re = dhcp_recv_l2_packet(&packet, dhcp_client->listener_sockfd);
 985         else if (dhcp_client->listen_mode == L3)
 986                 re = dhcp_recv_l3_packet(&packet, dhcp_client->listener_sockfd);
 987         else
 988                 re = -EIO;
 989
 990         if (re < 0)
 991                 return TRUE;
 992
 993         if (check_package_owner(dhcp_client, &packet) == FALSE)
 994                 return TRUE;
 995
 996         message_type = dhcp_get_option(&packet, DHCP_MESSAGE_TYPE);
 997         if (message_type == NULL)
 998                 /* No message type option, ignore pakcage */
 999                 return TRUE;
1000
1001         debug(dhcp_client, "received DHCP packet (current state %d)",
1002                                                         dhcp_client->state);
1003
1004         switch (dhcp_client->state) {
1005         case INIT_SELECTING:
1006                 if (*message_type != DHCPOFFER)
1007                         return TRUE;
1008
1009                 g_source_remove(dhcp_client->timeout);
1010                 dhcp_client->timeout = 0;
1011                 dhcp_client->retry_times = 0;
1012
1013                 option_u8 = dhcp_get_option(&packet, DHCP_SERVER_ID);
1014                 dhcp_client->server_ip =
1015                                 dhcp_get_unaligned((uint32_t *) option_u8);
1016                 dhcp_client->requested_ip = packet.yiaddr;
1017
1018                 dhcp_client->state = REQUESTING;
1019
1020                 start_request(dhcp_client);
1021
1022                 return TRUE;
1023         case REQUESTING:
1024         case RENEWING:
1025         case REBINDING:
1026                 if (*message_type == DHCPACK) {
1027                         dhcp_client->retry_times = 0;
1028
1029                         if (dhcp_client->timeout > 0)
1030                                 g_source_remove(dhcp_client->timeout);
1031                         dhcp_client->timeout = 0;
1032
1033                         dhcp_client->lease_seconds = get_lease(&packet);
1034
1035                         get_request(dhcp_client, &packet);
1036
1037                         switch_listening_mode(dhcp_client, L_NONE);
1038
1039                         g_free(dhcp_client->assigned_ip);
1040                         dhcp_client->assigned_ip = get_ip(packet.yiaddr);
1041
1042                         /* Address should be set up here */
1043                         if (dhcp_client->lease_available_cb != NULL)
1044                                 dhcp_client->lease_available_cb(dhcp_client,
1045                                         dhcp_client->lease_available_data);
1046
1047                         start_bound(dhcp_client);
1048                 } else if (*message_type == DHCPNAK) {
1049                         dhcp_client->retry_times = 0;
1050
1051                         if (dhcp_client->timeout > 0)
1052                                 g_source_remove(dhcp_client->timeout);
1053
1054                         dhcp_client->timeout = g_timeout_add_seconds_full(
1055                                                         G_PRIORITY_HIGH, 3,
1056                                                         restart_dhcp_timeout,
1057                                                         dhcp_client,
1058                                                         NULL);
1059                 }
1060
1061                 break;
1062         default:
1063                 break;
1064         }
1065
1066         debug(dhcp_client, "processed DHCP packet (new state %d)",
1067                                                         dhcp_client->state);
1068
1069         return TRUE;
1070 }
1071
1072 static gboolean discover_timeout(gpointer user_data)
1073 {
1074         GDHCPClient *dhcp_client = user_data;
1075
1076         dhcp_client->retry_times++;
1077
1078         g_dhcp_client_start(dhcp_client);
1079
1080         return FALSE;
1081 }
1082
1083 int g_dhcp_client_start(GDHCPClient *dhcp_client)
1084 {
1085         int re;
1086
1087         if (dhcp_client->retry_times == DISCOVER_RETRIES) {
1088                 if (dhcp_client->no_lease_cb != NULL)
1089                         dhcp_client->no_lease_cb(dhcp_client,
1090                                         dhcp_client->no_lease_data);
1091
1092                 return 0;
1093         }
1094
1095         if (dhcp_client->retry_times == 0) {
1096                 g_free(dhcp_client->assigned_ip);
1097                 dhcp_client->assigned_ip = NULL;
1098
1099                 dhcp_client->state = INIT_SELECTING;
1100                 re = switch_listening_mode(dhcp_client, L2);
1101                 if (re != 0)
1102                         return re;
1103
1104                 dhcp_client->xid = rand();
1105         }
1106
1107         send_discover(dhcp_client, 0);
1108
1109         dhcp_client->timeout = g_timeout_add_seconds_full(G_PRIORITY_HIGH,
1110                                                         DISCOVER_TIMEOUT,
1111                                                         discover_timeout,
1112                                                         dhcp_client,
1113                                                         NULL);
1114         return 0;
1115 }
1116
1117 void g_dhcp_client_stop(GDHCPClient *dhcp_client)
1118 {
1119         switch_listening_mode(dhcp_client, L_NONE);
1120
1121         if (dhcp_client->state == BOUND ||
1122                         dhcp_client->state == RENEWING ||
1123                                 dhcp_client->state == REBINDING)
1124                 send_release(dhcp_client, dhcp_client->server_ip,
1125                                         dhcp_client->requested_ip);
1126
1127         if (dhcp_client->timeout > 0) {
1128                 g_source_remove(dhcp_client->timeout);
1129                 dhcp_client->timeout = 0;
1130         }
1131
1132         if (dhcp_client->listener_watch > 0) {
1133                 g_source_remove(dhcp_client->listener_watch);
1134                 dhcp_client->listener_watch = 0;
1135         }
1136
1137         dhcp_client->listener_channel = NULL;
1138
1139         dhcp_client->retry_times = 0;
1140         dhcp_client->ack_retry_times = 0;
1141
1142         dhcp_client->requested_ip = 0;
1143         dhcp_client->state = RELEASED;
1144         dhcp_client->lease_seconds = 0;
1145 }
1146
1147 GList *g_dhcp_client_get_option(GDHCPClient *dhcp_client,
1148                                         unsigned char option_code)
1149 {
1150         return g_hash_table_lookup(dhcp_client->code_value_hash,
1151                                         GINT_TO_POINTER((int) option_code));
1152 }
1153
1154 void g_dhcp_client_register_event(GDHCPClient *dhcp_client,
1155                                         GDHCPClientEvent event,
1156                                         GDHCPClientEventFunc func,
1157                                                         gpointer data)
1158 {
1159         switch (event) {
1160         case G_DHCP_CLIENT_EVENT_LEASE_AVAILABLE:
1161                 dhcp_client->lease_available_cb = func;
1162                 dhcp_client->lease_available_data = data;
1163                 return;
1164         case G_DHCP_CLIENT_EVENT_NO_LEASE:
1165                 dhcp_client->no_lease_cb = func;
1166                 dhcp_client->no_lease_data = data;
1167                 return;
1168         case G_DHCP_CLIENT_EVENT_LEASE_LOST:
1169                 dhcp_client->lease_lost_cb = func;
1170                 dhcp_client->lease_lost_data = data;
1171                 return;
1172         case G_DHCP_CLIENT_EVENT_ADDRESS_CONFLICT:
1173                 dhcp_client->address_conflict_cb = func;
1174                 dhcp_client->address_conflict_data = data;
1175                 return;
1176         }
1177 }
1178
1179 int g_dhcp_client_get_index(GDHCPClient *dhcp_client)
1180 {
1181         return dhcp_client->ifindex;
1182 }
1183
1184 char *g_dhcp_client_get_address(GDHCPClient *dhcp_client)
1185 {
1186         return g_strdup(dhcp_client->assigned_ip);
1187 }
1188
1189 GDHCPClientError g_dhcp_client_set_request(GDHCPClient *dhcp_client,
1190                                                 unsigned char option_code)
1191 {
1192         if (g_list_find(dhcp_client->request_list,
1193                         GINT_TO_POINTER((int) option_code)) == NULL)
1194                 dhcp_client->request_list = g_list_prepend(
1195                                         dhcp_client->request_list,
1196                                         (GINT_TO_POINTER((int) option_code)));
1197
1198         return G_DHCP_CLIENT_ERROR_NONE;
1199 }
1200
1201 static uint8_t *alloc_dhcp_option(int code, const char *str, int extra)
1202 {
1203         uint8_t *storage;
1204         int len = strnlen(str, 255);
1205
1206         storage = malloc(len + extra + OPT_DATA);
1207         storage[OPT_CODE] = code;
1208         storage[OPT_LEN] = len + extra;
1209         memcpy(storage + extra + OPT_DATA, str, len);
1210
1211         return storage;
1212 }
1213
1214 /* Now only support send hostname */
1215 GDHCPClientError g_dhcp_client_set_send(GDHCPClient *dhcp_client,
1216                 unsigned char option_code, const char *option_value)
1217 {
1218         uint8_t *binary_option;
1219
1220         if (option_code == G_DHCP_HOST_NAME && option_value != NULL) {
1221                 binary_option = alloc_dhcp_option(option_code,
1222                                                         option_value, 0);
1223
1224                 g_hash_table_insert(dhcp_client->send_value_hash,
1225                         GINT_TO_POINTER((int) option_code), binary_option);
1226         }
1227
1228         return G_DHCP_CLIENT_ERROR_NONE;
1229 }
1230
1231 GDHCPClient *g_dhcp_client_ref(GDHCPClient *dhcp_client)
1232 {
1233         if (dhcp_client == NULL)
1234                 return NULL;
1235
1236         g_atomic_int_inc(&dhcp_client->ref_count);
1237
1238         return dhcp_client;
1239 }
1240
1241 void g_dhcp_client_unref(GDHCPClient *dhcp_client)
1242 {
1243         if (dhcp_client == NULL)
1244                 return;
1245
1246         if (g_atomic_int_dec_and_test(&dhcp_client->ref_count) == FALSE)
1247                 return;
1248
1249         g_dhcp_client_stop(dhcp_client);
1250
1251         g_free(dhcp_client->interface);
1252         g_free(dhcp_client->assigned_ip);
1253
1254         g_list_free(dhcp_client->request_list);
1255         g_list_free(dhcp_client->require_list);
1256
1257         g_hash_table_destroy(dhcp_client->code_value_hash);
1258         g_hash_table_destroy(dhcp_client->send_value_hash);
1259
1260         g_free(dhcp_client);
1261 }
1262
1263 void g_dhcp_client_set_debug(GDHCPClient *dhcp_client,
1264                                 GDHCPDebugFunc func, gpointer user_data)
1265 {
1266         if (dhcp_client == NULL)
1267                 return;
1268
1269         dhcp_client->debug_func = func;
1270         dhcp_client->debug_data = user_data;
1271 }