release/src/router/dnsmasq/src/helper.c

   1 /* dnsmasq is Copyright (c) 2000-2013 Simon Kelley
   2
   3    This program is free software; you can redistribute it and/or modify
   4    it under the terms of the GNU General Public License as published by
   5    the Free Software Foundation; version 2 dated June, 1991, or
   6    (at your option) version 3 dated 29 June, 2007.
   7
   8    This program is distributed in the hope that it will be useful,
   9    but WITHOUT ANY WARRANTY; without even the implied warranty of
  10    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11    GNU General Public License for more details.
  12
  13    You should have received a copy of the GNU General Public License
  14    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  15 */
  16
  17 #include "dnsmasq.h"
  18
  19 #ifdef HAVE_SCRIPT
  20
  21 /* This file has code to fork a helper process which recieves data via a pipe
  22    shared with the main process and which is responsible for calling a script when
  23    DHCP leases change.
  24
  25    The helper process is forked before the main process drops root, so it retains root
  26    privs to pass on to the script. For this reason it tries to be paranoid about
  27    data received from the main process, in case that has been compromised. We don't
  28    want the helper to give an attacker root. In particular, the script to be run is
  29    not settable via the pipe, once the fork has taken place it is not alterable by the
  30    main process.
  31 */
  32
  33 static void my_setenv(const char *name, const char *value, int *error);
  34 static unsigned char *grab_extradata(unsigned char *buf, unsigned char *end,  char *env, int *err);
  35
  36 #ifdef HAVE_LUASCRIPT
  37 #define LUA_COMPAT_ALL
  38 #include <lua.h>
  39 #include <lualib.h>
  40 #include <lauxlib.h>
  41
  42 #ifndef lua_open
  43 #define lua_open()     luaL_newstate()
  44 #endif
  45
  46 lua_State *lua;
  47
  48 static unsigned char *grab_extradata_lua(unsigned char *buf, unsigned char *end, char *field);
  49 #endif
  50
  51
  52 struct script_data
  53 {
  54   int flags;
  55   int action, hwaddr_len, hwaddr_type;
  56   int clid_len, hostname_len, ed_len;
  57   struct in_addr addr, giaddr;
  58   unsigned int remaining_time;
  59 #ifdef HAVE_BROKEN_RTC
  60   unsigned int length;
  61 #else
  62   time_t expires;
  63 #endif
  64 #ifdef HAVE_DHCP6
  65   struct in6_addr addr6;
  66   int iaid, vendorclass_count;
  67 #endif
  68   unsigned char hwaddr[DHCP_CHADDR_MAX];
  69   char interface[IF_NAMESIZE];
  70 };
  71
  72 static struct script_data *buf = NULL;
  73 static size_t bytes_in_buf = 0, buf_size = 0;
  74
  75 int create_helper(int event_fd, int err_fd, uid_t uid, gid_t gid, long max_fd)
  76 {
  77   pid_t pid;
  78   int i, pipefd[2];
  79   struct sigaction sigact;
  80
  81   /* create the pipe through which the main program sends us commands,
  82      then fork our process. */
  83   if (pipe(pipefd) == -1 || !fix_fd(pipefd[1]) || (pid = fork()) == -1)
  84     {
  85       send_event(err_fd, EVENT_PIPE_ERR, errno, NULL);
  86       _exit(0);
  87     }
  88
  89   if (pid != 0)
  90     {
  91       close(pipefd[0]); /* close reader side */
  92       return pipefd[1];
  93     }
  94
  95   /* ignore SIGTERM, so that we can clean up when the main process gets hit
  96      and SIGALRM so that we can use sleep() */
  97   sigact.sa_handler = SIG_IGN;
  98   sigact.sa_flags = 0;
  99   sigemptyset(&sigact.sa_mask);
 100   sigaction(SIGTERM, &sigact, NULL);
 101   sigaction(SIGALRM, &sigact, NULL);
 102
 103   if (!option_bool(OPT_DEBUG) && uid != 0)
 104     {
 105       gid_t dummy;
 106       if (setgroups(0, &dummy) == -1 ||
 107           setgid(gid) == -1 ||
 108           setuid(uid) == -1)
 109         {
 110           if (option_bool(OPT_NO_FORK))
 111             /* send error to daemon process if no-fork */
 112             send_event(event_fd, EVENT_USER_ERR, errno, daemon->scriptuser);
 113           else
 114             {
 115               /* kill daemon */
 116               send_event(event_fd, EVENT_DIE, 0, NULL);
 117               /* return error */
 118               send_event(err_fd, EVENT_USER_ERR, errno, daemon->scriptuser);
 119             }
 120           _exit(0);
 121         }
 122     }
 123
 124   /* close all the sockets etc, we don't need them here.
 125      Don't close err_fd, in case the lua-init fails.
 126      Note that we have to do this before lua init
 127      so we don't close any lua fds. */
 128   for (max_fd--; max_fd >= 0; max_fd--)
 129     if (max_fd != STDOUT_FILENO && max_fd != STDERR_FILENO &&
 130         max_fd != STDIN_FILENO && max_fd != pipefd[0] &&
 131         max_fd != event_fd && max_fd != err_fd)
 132       close(max_fd);
 133
 134 #ifdef HAVE_LUASCRIPT
 135   if (daemon->luascript)
 136     {
 137       const char *lua_err = NULL;
 138       lua = lua_open();
 139       luaL_openlibs(lua);
 140
 141       /* get Lua to load our script file */
 142       if (luaL_dofile(lua, daemon->luascript) != 0)
 143         lua_err = lua_tostring(lua, -1);
 144       else
 145         {
 146           lua_getglobal(lua, "lease");
 147           if (lua_type(lua, -1) != LUA_TFUNCTION)
 148             lua_err = _("lease() function missing in Lua script");
 149         }
 150
 151       if (lua_err)
 152         {
 153           if (option_bool(OPT_NO_FORK) || option_bool(OPT_DEBUG))
 154             /* send error to daemon process if no-fork */
 155             send_event(event_fd, EVENT_LUA_ERR, 0, (char *)lua_err);
 156           else
 157             {
 158               /* kill daemon */
 159               send_event(event_fd, EVENT_DIE, 0, NULL);
 160               /* return error */
 161               send_event(err_fd, EVENT_LUA_ERR, 0, (char *)lua_err);
 162             }
 163           _exit(0);
 164         }
 165
 166       lua_pop(lua, 1);  /* remove nil from stack */
 167       lua_getglobal(lua, "init");
 168       if (lua_type(lua, -1) == LUA_TFUNCTION)
 169         lua_call(lua, 0, 0);
 170       else
 171         lua_pop(lua, 1);  /* remove nil from stack */
 172     }
 173 #endif
 174
 175   /* All init done, close our copy of the error pipe, so that main process can return */
 176   if (err_fd != -1)
 177     close(err_fd);
 178
 179   /* loop here */
 180   while(1)
 181     {
 182       struct script_data data;
 183       char *p, *action_str, *hostname = NULL, *domain = NULL;
 184       unsigned char *buf = (unsigned char *)daemon->namebuff;
 185       unsigned char *end, *extradata, *alloc_buff = NULL;
 186       int is6, err = 0;
 187
 188       free(alloc_buff);
 189
 190       /* we read zero bytes when pipe closed: this is our signal to exit */
 191       if (!read_write(pipefd[0], (unsigned char *)&data, sizeof(data), 1))
 192         {
 193 #ifdef HAVE_LUASCRIPT
 194           if (daemon->luascript)
 195             {
 196               lua_getglobal(lua, "shutdown");
 197               if (lua_type(lua, -1) == LUA_TFUNCTION)
 198                 lua_call(lua, 0, 0);
 199             }
 200 #endif
 201           _exit(0);
 202         }
 203
 204       is6 = !!(data.flags & (LEASE_TA | LEASE_NA));
 205
 206       if (data.action == ACTION_DEL)
 207         action_str = "del";
 208       else if (data.action == ACTION_ADD)
 209         action_str = "add";
 210       else if (data.action == ACTION_OLD || data.action == ACTION_OLD_HOSTNAME)
 211         action_str = "old";
 212       else if (data.action == ACTION_TFTP)
 213         {
 214           action_str = "tftp";
 215           is6 = (data.flags != AF_INET);
 216         }
 217       else
 218         continue;
 219
 220
 221       /* stringify MAC into dhcp_buff */
 222       p = daemon->dhcp_buff;
 223       if (data.hwaddr_type != ARPHRD_ETHER || data.hwaddr_len == 0)
 224         p += sprintf(p, "%.2x-", data.hwaddr_type);
 225       for (i = 0; (i < data.hwaddr_len) && (i < DHCP_CHADDR_MAX); i++)
 226         {
 227           p += sprintf(p, "%.2x", data.hwaddr[i]);
 228           if (i != data.hwaddr_len - 1)
 229             p += sprintf(p, ":");
 230         }
 231
 232       /* supplied data may just exceed normal buffer (unlikely) */
 233       if ((data.hostname_len + data.ed_len + data.clid_len) > MAXDNAME &&
 234           !(alloc_buff = buf = malloc(data.hostname_len + data.ed_len + data.clid_len)))
 235         continue;
 236
 237       if (!read_write(pipefd[0], buf,
 238                       data.hostname_len + data.ed_len + data.clid_len, 1))
 239         continue;
 240
 241       /* CLID into packet */
 242       for (p = daemon->packet, i = 0; i < data.clid_len; i++)
 243         {
 244           p += sprintf(p, "%.2x", buf[i]);
 245           if (i != data.clid_len - 1)
 246               p += sprintf(p, ":");
 247         }
 248
 249 #ifdef HAVE_DHCP6
 250       if (is6)
 251         {
 252           /* or IAID and server DUID for IPv6 */
 253           sprintf(daemon->dhcp_buff3, "%s%u", data.flags & LEASE_TA ? "T" : "", data.iaid);
 254           for (p = daemon->dhcp_packet.iov_base, i = 0; i < daemon->duid_len; i++)
 255             {
 256               p += sprintf(p, "%.2x", daemon->duid[i]);
 257               if (i != daemon->duid_len - 1)
 258                 p += sprintf(p, ":");
 259             }
 260
 261         }
 262 #endif
 263
 264       buf += data.clid_len;
 265
 266       if (data.hostname_len != 0)
 267         {
 268           char *dot;
 269           hostname = (char *)buf;
 270           hostname[data.hostname_len - 1] = 0;
 271           if (data.action != ACTION_TFTP)
 272             {
 273               if (!legal_hostname(hostname))
 274                 hostname = NULL;
 275               else if ((dot = strchr(hostname, '.')))
 276                 {
 277                   domain = dot+1;
 278                   *dot = 0;
 279                 }
 280             }
 281         }
 282
 283       extradata = buf + data.hostname_len;
 284
 285       if (!is6)
 286         inet_ntop(AF_INET, &data.addr, daemon->addrbuff, ADDRSTRLEN);
 287 #ifdef HAVE_DHCP6
 288       else
 289         inet_ntop(AF_INET6, &data.addr6, daemon->addrbuff, ADDRSTRLEN);
 290 #endif
 291
 292       /* file length */
 293       if (data.action == ACTION_TFTP)
 294         sprintf(is6 ? daemon->packet : daemon->dhcp_buff, "%u", data.iaid);
 295
 296 #ifdef HAVE_LUASCRIPT
 297       if (daemon->luascript)
 298         {
 299           if (data.action == ACTION_TFTP)
 300             {
 301               lua_getglobal(lua, "tftp");
 302               if (lua_type(lua, -1) != LUA_TFUNCTION)
 303                 lua_pop(lua, 1); /* tftp function optional */
 304               else
 305                 {
 306                   lua_pushstring(lua, action_str); /* arg1 - action */
 307                   lua_newtable(lua);               /* arg2 - data table */
 308                   lua_pushstring(lua, daemon->addrbuff);
 309                   lua_setfield(lua, -2, "destination_address");
 310                   lua_pushstring(lua, hostname);
 311                   lua_setfield(lua, -2, "file_name");
 312                   lua_pushstring(lua, is6 ? daemon->packet : daemon->dhcp_buff);
 313                   lua_setfield(lua, -2, "file_size");
 314                   lua_call(lua, 2, 0);  /* pass 2 values, expect 0 */
 315                 }
 316             }
 317           else
 318             {
 319               lua_getglobal(lua, "lease");     /* function to call */
 320               lua_pushstring(lua, action_str); /* arg1 - action */
 321               lua_newtable(lua);               /* arg2 - data table */
 322
 323               if (is6)
 324                 {
 325                   lua_pushstring(lua, daemon->packet);
 326                   lua_setfield(lua, -2, "client_duid");
 327                   lua_pushstring(lua, daemon->dhcp_packet.iov_base);
 328                   lua_setfield(lua, -2, "server_duid");
 329                   lua_pushstring(lua, daemon->dhcp_buff3);
 330                   lua_setfield(lua, -2, "iaid");
 331                 }
 332
 333               if (!is6 && data.clid_len != 0)
 334                 {
 335                   lua_pushstring(lua, daemon->packet);
 336                   lua_setfield(lua, -2, "client_id");
 337                 }
 338
 339               if (strlen(data.interface) != 0)
 340                 {
 341                   lua_pushstring(lua, data.interface);
 342                   lua_setfield(lua, -2, "interface");
 343                 }
 344
 345 #ifdef HAVE_BROKEN_RTC
 346               lua_pushnumber(lua, data.length);
 347               lua_setfield(lua, -2, "lease_length");
 348 #else
 349               lua_pushnumber(lua, data.expires);
 350               lua_setfield(lua, -2, "lease_expires");
 351 #endif
 352
 353               if (hostname)
 354                 {
 355                   lua_pushstring(lua, hostname);
 356                   lua_setfield(lua, -2, "hostname");
 357                 }
 358
 359               if (domain)
 360                 {
 361                   lua_pushstring(lua, domain);
 362                   lua_setfield(lua, -2, "domain");
 363                 }
 364
 365               end = extradata + data.ed_len;
 366               buf = extradata;
 367
 368               if (!is6)
 369                 buf = grab_extradata_lua(buf, end, "vendor_class");
 370 #ifdef HAVE_DHCP6
 371               else  if (data.vendorclass_count != 0)
 372                 {
 373                   sprintf(daemon->dhcp_buff2, "vendor_class_id");
 374                   buf = grab_extradata_lua(buf, end, daemon->dhcp_buff2);
 375                   for (i = 0; i < data.vendorclass_count - 1; i++)
 376                     {
 377                       sprintf(daemon->dhcp_buff2, "vendor_class%i", i);
 378                       buf = grab_extradata_lua(buf, end, daemon->dhcp_buff2);
 379                     }
 380                 }
 381 #endif
 382
 383               buf = grab_extradata_lua(buf, end, "supplied_hostname");
 384
 385               if (!is6)
 386                 {
 387                   buf = grab_extradata_lua(buf, end, "cpewan_oui");
 388                   buf = grab_extradata_lua(buf, end, "cpewan_serial");
 389                   buf = grab_extradata_lua(buf, end, "cpewan_class");
 390                   buf = grab_extradata_lua(buf, end, "circuit_id");
 391                   buf = grab_extradata_lua(buf, end, "subscriber_id");
 392                   buf = grab_extradata_lua(buf, end, "remote_id");
 393                 }
 394
 395               buf = grab_extradata_lua(buf, end, "tags");
 396
 397               if (is6)
 398                 buf = grab_extradata_lua(buf, end, "relay_address");
 399               else if (data.giaddr.s_addr != 0)
 400                 {
 401                   lua_pushstring(lua, inet_ntoa(data.giaddr));
 402                   lua_setfield(lua, -2, "relay_address");
 403                 }
 404
 405               for (i = 0; buf; i++)
 406                 {
 407                   sprintf(daemon->dhcp_buff2, "user_class%i", i);
 408                   buf = grab_extradata_lua(buf, end, daemon->dhcp_buff2);
 409                 }
 410
 411               if (data.action != ACTION_DEL && data.remaining_time != 0)
 412                 {
 413                   lua_pushnumber(lua, data.remaining_time);
 414                   lua_setfield(lua, -2, "time_remaining");
 415                 }
 416
 417               if (data.action == ACTION_OLD_HOSTNAME && hostname)
 418                 {
 419                   lua_pushstring(lua, hostname);
 420                   lua_setfield(lua, -2, "old_hostname");
 421                 }
 422
 423               if (!is6 || data.hwaddr_len != 0)
 424                 {
 425                   lua_pushstring(lua, daemon->dhcp_buff);
 426                   lua_setfield(lua, -2, "mac_address");
 427                 }
 428
 429               lua_pushstring(lua, daemon->addrbuff);
 430               lua_setfield(lua, -2, "ip_address");
 431
 432               lua_call(lua, 2, 0);      /* pass 2 values, expect 0 */
 433             }
 434         }
 435 #endif
 436
 437       /* no script, just lua */
 438       if (!daemon->lease_change_command)
 439         continue;
 440
 441       /* possible fork errors are all temporary resource problems */
 442       while ((pid = fork()) == -1 && (errno == EAGAIN || errno == ENOMEM))
 443         sleep(2);
 444
 445       if (pid == -1)
 446         continue;
 447
 448       /* wait for child to complete */
 449       if (pid != 0)
 450         {
 451           /* reap our children's children, if necessary */
 452           while (1)
 453             {
 454               int status;
 455               pid_t rc = wait(&status);
 456
 457               if (rc == pid)
 458                 {
 459                   /* On error send event back to main process for logging */
 460                   if (WIFSIGNALED(status))
 461                     send_event(event_fd, EVENT_KILLED, WTERMSIG(status), NULL);
 462                   else if (WIFEXITED(status) && WEXITSTATUS(status) != 0)
 463                     send_event(event_fd, EVENT_EXITED, WEXITSTATUS(status), NULL);
 464                   break;
 465                 }
 466
 467               if (rc == -1 && errno != EINTR)
 468                 break;
 469             }
 470
 471           continue;
 472         }
 473
 474       if (data.action != ACTION_TFTP)
 475         {
 476 #ifdef HAVE_DHCP6
 477           if (is6)
 478             {
 479               my_setenv("DNSMASQ_IAID", daemon->dhcp_buff3, &err);
 480               my_setenv("DNSMASQ_SERVER_DUID", daemon->dhcp_packet.iov_base, &err);
 481               if (data.hwaddr_len != 0)
 482                 my_setenv("DNSMASQ_MAC", daemon->dhcp_buff, &err);
 483             }
 484 #endif
 485
 486           if (!is6 && data.clid_len != 0)
 487             my_setenv("DNSMASQ_CLIENT_ID", daemon->packet, &err);
 488
 489           if (strlen(data.interface) != 0)
 490             my_setenv("DNSMASQ_INTERFACE", data.interface, &err);
 491
 492 #ifdef HAVE_BROKEN_RTC
 493           sprintf(daemon->dhcp_buff2, "%u", data.length);
 494           my_setenv("DNSMASQ_LEASE_LENGTH", daemon->dhcp_buff2, &err);
 495 #else
 496           sprintf(daemon->dhcp_buff2, "%lu", (unsigned long)data.expires);
 497           my_setenv("DNSMASQ_LEASE_EXPIRES", daemon->dhcp_buff2, &err);
 498 #endif
 499
 500           if (domain)
 501             my_setenv("DNSMASQ_DOMAIN", domain, &err);
 502
 503           end = extradata + data.ed_len;
 504           buf = extradata;
 505
 506           if (!is6)
 507             buf = grab_extradata(buf, end, "DNSMASQ_VENDOR_CLASS", &err);
 508 #ifdef HAVE_DHCP6
 509           else
 510             {
 511               if (data.vendorclass_count != 0)
 512                 {
 513                   buf = grab_extradata(buf, end, "DNSMASQ_VENDOR_CLASS_ID", &err);
 514                   for (i = 0; i < data.vendorclass_count - 1; i++)
 515                     {
 516                       sprintf(daemon->dhcp_buff2, "DNSMASQ_VENDOR_CLASS%i", i);
 517                       buf = grab_extradata(buf, end, daemon->dhcp_buff2, &err);
 518                     }
 519                 }
 520             }
 521 #endif
 522
 523           buf = grab_extradata(buf, end, "DNSMASQ_SUPPLIED_HOSTNAME", &err);
 524
 525           if (!is6)
 526             {
 527               buf = grab_extradata(buf, end, "DNSMASQ_CPEWAN_OUI", &err);
 528               buf = grab_extradata(buf, end, "DNSMASQ_CPEWAN_SERIAL", &err);
 529               buf = grab_extradata(buf, end, "DNSMASQ_CPEWAN_CLASS", &err);
 530               buf = grab_extradata(buf, end, "DNSMASQ_CIRCUIT_ID", &err);
 531               buf = grab_extradata(buf, end, "DNSMASQ_SUBSCRIBER_ID", &err);
 532               buf = grab_extradata(buf, end, "DNSMASQ_REMOTE_ID", &err);
 533             }
 534
 535           buf = grab_extradata(buf, end, "DNSMASQ_TAGS", &err);
 536
 537           if (is6)
 538             buf = grab_extradata(buf, end, "DNSMASQ_RELAY_ADDRESS", &err);
 539           else if (data.giaddr.s_addr != 0)
 540             my_setenv("DNSMASQ_RELAY_ADDRESS", inet_ntoa(data.giaddr), &err);
 541
 542           for (i = 0; buf; i++)
 543             {
 544               sprintf(daemon->dhcp_buff2, "DNSMASQ_USER_CLASS%i", i);
 545               buf = grab_extradata(buf, end, daemon->dhcp_buff2, &err);
 546             }
 547
 548           if (data.action != ACTION_DEL && data.remaining_time != 0)
 549             {
 550               sprintf(daemon->dhcp_buff2, "%u", data.remaining_time);
 551               my_setenv("DNSMASQ_TIME_REMAINING", daemon->dhcp_buff2, &err);
 552             }
 553
 554           if (data.action == ACTION_OLD_HOSTNAME && hostname)
 555             {
 556               my_setenv("DNSMASQ_OLD_HOSTNAME", hostname, &err);
 557               hostname = NULL;
 558             }
 559         }
 560
 561       if (option_bool(OPT_LOG_OPTS))
 562         my_setenv("DNSMASQ_LOG_DHCP", "1", &err);
 563
 564       /* we need to have the event_fd around if exec fails */
 565       if ((i = fcntl(event_fd, F_GETFD)) != -1)
 566         fcntl(event_fd, F_SETFD, i | FD_CLOEXEC);
 567       close(pipefd[0]);
 568
 569       p =  strrchr(daemon->lease_change_command, '/');
 570       if (err == 0)
 571         {
 572           execl(daemon->lease_change_command,
 573                 p ? p+1 : daemon->lease_change_command,
 574                 action_str, is6 ? daemon->packet : daemon->dhcp_buff,
 575                 daemon->addrbuff, hostname, (char*)NULL);
 576           err = errno;
 577         }
 578       /* failed, send event so the main process logs the problem */
 579       send_event(event_fd, EVENT_EXEC_ERR, err, NULL);
 580       _exit(0);
 581     }
 582 }
 583
 584 static void my_setenv(const char *name, const char *value, int *error)
 585 {
 586   if (*error == 0 && setenv(name, value, 1) != 0)
 587     *error = errno;
 588 }
 589
 590 static unsigned char *grab_extradata(unsigned char *buf, unsigned char *end,  char *env, int *err)
 591 {
 592   unsigned char *next;
 593
 594   if (!buf || (buf == end))
 595     return NULL;
 596
 597   for (next = buf; *next != 0; next++)
 598     if (next == end)
 599       return NULL;
 600
 601   if (next != buf)
 602     {
 603       char *p;
 604       /* No "=" in value */
 605       if ((p = strchr((char *)buf, '=')))
 606         *p = 0;
 607       my_setenv(env, (char *)buf, err);
 608     }
 609
 610   return next + 1;
 611 }
 612
 613 #ifdef HAVE_LUASCRIPT
 614 static unsigned char *grab_extradata_lua(unsigned char *buf, unsigned char *end, char *field)
 615 {
 616   unsigned char *next;
 617
 618   if (!buf || (buf == end))
 619     return NULL;
 620
 621   for (next = buf; *next != 0; next++)
 622     if (next == end)
 623       return NULL;
 624
 625   if (next != buf)
 626     {
 627       lua_pushstring(lua,  (char *)buf);
 628       lua_setfield(lua, -2, field);
 629     }
 630
 631   return next + 1;
 632 }
 633 #endif
 634
 635 static void buff_alloc(size_t size)
 636 {
 637   if (size > buf_size)
 638     {
 639       struct script_data *new;
 640
 641       /* start with reasonable size, will almost never need extending. */
 642       if (size < sizeof(struct script_data) + 200)
 643         size = sizeof(struct script_data) + 200;
 644
 645       if (!(new = whine_malloc(size)))
 646         return;
 647       if (buf)
 648         free(buf);
 649       buf = new;
 650       buf_size = size;
 651     }
 652 }
 653
 654 /* pack up lease data into a buffer */
 655 void queue_script(int action, struct dhcp_lease *lease, char *hostname, time_t now)
 656 {
 657   unsigned char *p;
 658   unsigned int hostname_len = 0, clid_len = 0, ed_len = 0;
 659   int fd = daemon->dhcpfd;
 660 #ifdef HAVE_DHCP6
 661   if (!daemon->dhcp)
 662     fd = daemon->dhcp6fd;
 663 #endif
 664
 665   /* no script */
 666   if (daemon->helperfd == -1)
 667     return;
 668
 669   if (lease->extradata)
 670     ed_len = lease->extradata_len;
 671   if (lease->clid)
 672     clid_len = lease->clid_len;
 673   if (hostname)
 674     hostname_len = strlen(hostname) + 1;
 675
 676   buff_alloc(sizeof(struct script_data) +  clid_len + ed_len + hostname_len);
 677
 678   buf->action = action;
 679   buf->flags = lease->flags;
 680 #ifdef HAVE_DHCP6
 681   buf->vendorclass_count = lease->vendorclass_count;
 682   buf->addr6 = lease->addr6;
 683   buf->iaid = lease->iaid;
 684 #endif
 685   buf->hwaddr_len = lease->hwaddr_len;
 686   buf->hwaddr_type = lease->hwaddr_type;
 687   buf->clid_len = clid_len;
 688   buf->ed_len = ed_len;
 689   buf->hostname_len = hostname_len;
 690   buf->addr = lease->addr;
 691   buf->giaddr = lease->giaddr;
 692   memcpy(buf->hwaddr, lease->hwaddr, DHCP_CHADDR_MAX);
 693   if (!indextoname(fd, lease->last_interface, buf->interface))
 694     buf->interface[0] = 0;
 695
 696 #ifdef HAVE_BROKEN_RTC
 697   buf->length = lease->length;
 698 #else
 699   buf->expires = lease->expires;
 700 #endif
 701
 702   if (lease->expires != 0)
 703     buf->remaining_time = (unsigned int)difftime(lease->expires, now);
 704   else
 705     buf->remaining_time = 0;
 706
 707   p = (unsigned char *)(buf+1);
 708   if (clid_len != 0)
 709     {
 710       memcpy(p, lease->clid, clid_len);
 711       p += clid_len;
 712     }
 713   if (hostname_len != 0)
 714     {
 715       memcpy(p, hostname, hostname_len);
 716       p += hostname_len;
 717     }
 718   if (ed_len != 0)
 719     {
 720       memcpy(p, lease->extradata, ed_len);
 721       p += ed_len;
 722     }
 723   bytes_in_buf = p - (unsigned char *)buf;
 724 }
 725
 726 #ifdef HAVE_TFTP
 727 /* This nastily re-uses DHCP-fields for TFTP stuff */
 728 void queue_tftp(off_t file_len, char *filename, union mysockaddr *peer)
 729 {
 730   unsigned int filename_len;
 731
 732   /* no script */
 733   if (daemon->helperfd == -1)
 734     return;
 735
 736   filename_len = strlen(filename) + 1;
 737   buff_alloc(sizeof(struct script_data) +  filename_len);
 738   memset(buf, 0, sizeof(struct script_data));
 739
 740   buf->action = ACTION_TFTP;
 741   buf->hostname_len = filename_len;
 742   buf->iaid = file_len;
 743
 744   if ((buf->flags = peer->sa.sa_family) == AF_INET)
 745     buf->addr = peer->in.sin_addr;
 746 #ifdef HAVE_IPV6
 747   else
 748     buf->addr6 = peer->in6.sin6_addr;
 749 #endif
 750
 751   memcpy((unsigned char *)(buf+1), filename, filename_len);
 752
 753   bytes_in_buf = sizeof(struct script_data) +  filename_len;
 754 }
 755 #endif
 756
 757 int helper_buf_empty(void)
 758 {
 759   return bytes_in_buf == 0;
 760 }
 761
 762 void helper_write(void)
 763 {
 764   ssize_t rc;
 765
 766   if (bytes_in_buf == 0)
 767     return;
 768
 769   if ((rc = write(daemon->helperfd, buf, bytes_in_buf)) != -1)
 770     {
 771       if (bytes_in_buf != (size_t)rc)
 772         memmove(buf, buf + rc, bytes_in_buf - rc);
 773       bytes_in_buf -= rc;
 774     }
 775   else
 776     {
 777       if (errno == EAGAIN || errno == EINTR)
 778         return;
 779       bytes_in_buf = 0;
 780     }
 781 }
 782
 783 #endif
 784
 785
 786