src/network.c

   1 /* $Id$
   2  * UDP Gateway utility network layer
   3  * Copyright (C) 2004 Jan Kratochvil <project-udpgate@jankratochvil.net>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; exactly version 2 of June 1991 is required
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  17  */
  18
  19
  20 #include "config.h"
  21
  22 #include <glib/gmessages.h>
  23 #include <glib/gmain.h>
  24 #include <sys/socket.h>
  25 #include <netinet/in.h>
  26 #include <glib/glist.h>
  27 #include <stdio.h>
  28 #include <stdlib.h>
  29 #include <sys/types.h>
  30 #include <signal.h>
  31 #include <errno.h>
  32 #include <glib/giochannel.h>
  33 #include <sys/ioctl.h>
  34 #include <string.h>
  35 #include <glib/galloca.h>
  36 #include <glib/gprintf.h>
  37 #include <glib/grand.h>
  38
  39 #include "network.h"
  40 #include "packet.h"
  41 #include "main.h"       /* for optarg_verbose */
  42
  43
  44 /* Config: */
  45 #define NETWORK_PATHNAME_PID "/var/run/udpgate.pid"
  46 #define SOCK_SOURCE_CHECK_EVENTS (G_IO_IN)      /* |G_IO_PRI */
  47 #define SOCK_SOURCE_CHECK_REVENTS (SOCK_SOURCE_CHECK_EVENTS)    /* |G_IO_ERR|G_IO_HUP|G_IO_NVAL */
  48 #define SERVER_INADDR 0x7F000001
  49 #undef  SERVER_INADDR
  50 #define SERVER_INADDR 0x511F02EA        /* paulina.vellum.cz = 81.31.2.234; host order */
  51 #define SERVER_PORT   9201      /* host order */
  52 #define PROBE_INADDR  SERVER_INADDR     /* host order */
  53 #define PROBE_PORT    8201      /* host order */
  54 #define CLIENT_TIMEOUT_SEC (5*60)
  55 #define PROBE_TIMEOUT_SEC (5)
  56
  57
  58 void (*network_notify_hostip)(guint32 hostip_guint32);
  59
  60
  61 struct client {
  62         GPollFD gpollfd;
  63         struct sockaddr_in sockaddr_in_from;
  64         guint timeout_id;
  65         };
  66
  67 static GSource *sock_gsource;
  68
  69 static GList *sock_client_list; /* of 'struct client *', incl. 'master' and 'probe' */
  70 static struct client *master;   /* no 'timeout' permitted */
  71 static struct client *probe;    /* 'timeout' permitted */
  72 static guint32 probe_unique;
  73
  74 static gboolean write_daemon_running(pid_t pid);
  75
  76 pid_t is_daemon_running(void)
  77 {
  78 FILE *f;
  79 char buf[LINE_MAX],*got;
  80 int pid_int;
  81
  82         if (sock_gsource)
  83                 return getpid();
  84
  85         if (!(f=fopen(NETWORK_PATHNAME_PID,"r")))
  86                 goto err;
  87         got=fgets(buf,sizeof(buf),f);
  88         fclose(f);      /* FIXME: error ignored */
  89         if (got!=buf) {
  90 err_unlink:
  91                 write_daemon_running((pid_t)-1);        /* unlink */
  92 err:
  93                 return (pid_t)-1;
  94                 }
  95         pid_int=atoi(buf);
  96         if (pid_int<=1)
  97                 goto err_unlink;
  98         if (kill((pid_t)pid_int,0)) {
  99                 if (errno==ESRCH)
 100                         goto err_unlink;
 101                 goto err;
 102                 }
 103         return (pid_t)pid_int;
 104 }
 105
 106 static gboolean write_daemon_running(pid_t pid)
 107 {
 108 FILE *f;
 109
 110         if (pid==(pid_t)-1) {
 111                 if (unlink(NETWORK_PATHNAME_PID)) {
 112                         if (errno!=ENOENT)
 113                                 g_warning(_("Error removing PID file \"%s\": %m"),NETWORK_PATHNAME_PID);
 114                         return FALSE;
 115                         }
 116                 return TRUE;
 117                 }
 118         if (!(f=fopen(NETWORK_PATHNAME_PID,"w"))) {
 119                 g_warning(_("Error writing PID %d to \"%s\": %m"),(int)pid,NETWORK_PATHNAME_PID);
 120                 return FALSE;
 121                 }
 122         fprintf(f,"%d\n",(int)pid);     /* errors ignored */
 123         fclose(f);      /* FIXME: error ignored */
 124         return TRUE;
 125 }
 126
 127 static void client_timeout_remove(struct client *client)
 128 {
 129         g_return_if_fail(client!=NULL);
 130         g_return_if_fail(client!=master);
 131
 132         if (client->timeout_id) {
 133 gboolean errgboolean;
 134
 135                 if (optarg_verbose)
 136                         g_message(_("Client fd %d removed timeout id %d"),client->gpollfd.fd,client->timeout_id);
 137                 errgboolean=g_source_remove(client->timeout_id);
 138                 g_assert(errgboolean==TRUE);
 139                 client->timeout_id=0;
 140                 }
 141 }
 142
 143 static gboolean client_touch_timeout(struct client *client);
 144
 145 static void client_touch(struct client *client)
 146 {
 147         g_return_if_fail(client!=NULL);
 148         g_return_if_fail(client!=master);
 149
 150         client_timeout_remove(client);
 151         client->timeout_id=g_timeout_add(
 152                         (client==probe ? PROBE_TIMEOUT_SEC*1000 : CLIENT_TIMEOUT_SEC*1000),     /* interval; msec */
 153                         (GSourceFunc)client_touch_timeout,      /* function */
 154                         client);        /* data */
 155         if (optarg_verbose)
 156                 g_message(_("Client fd %d new timeout id %d"),client->gpollfd.fd,client->timeout_id);
 157         g_assert(client->timeout_id!=0);
 158 }
 159
 160 static void client_destroy(struct client *client);
 161
 162 static gboolean client_touch_timeout(struct client *client)
 163 {
 164         g_return_val_if_fail(client!=NULL,FALSE);       /* FALSE=>should be removed */
 165         g_return_val_if_fail(client!=master,FALSE);     /* FALSE=>should be removed */
 166
 167         if (optarg_verbose)
 168                 g_message(_("Client fd %d timeout id %d occured/entered"),client->gpollfd.fd,client->timeout_id);
 169
 170         /* Do not destroy the timeout in client_destroy().
 171          * It would crash GLib - we remove it be returning FALSE from here.
 172          */
 173         g_assert(client->timeout_id!=0);
 174         client->timeout_id=0;
 175
 176         if (client==probe) {
 177                 network_stop();
 178                 /* Never destroy 'client' now - it has been destroyed by network_stop()! */
 179                 g_warning(_("No probe response from the server, stopping the daemon. Please check your public Internet connectivity."));
 180                 }
 181         else {
 182                 client_destroy(client);
 183                 }
 184
 185         if (optarg_verbose)
 186                 g_message(_("Client timeout occurance finish"));
 187
 188         return FALSE;   /* GSource should be removed */
 189 }
 190
 191 static void handle_master_probe(const void *packet,size_t gotlen,const struct sockaddr_in *sockaddr_in_from)
 192 {
 193 GHashTable *got_hash;
 194 gpointer got_unique_gpointer;
 195 gpointer hostip_gpointer;
 196 guint32 hostip_guint32;
 197
 198         g_return_if_fail(packet!=NULL);
 199         g_return_if_fail(sockaddr_in_from!=NULL);
 200
 201         if (!probe)
 202                 return;
 203
 204         if (!(got_hash=packet_disassembly(packet,gotlen)))
 205                 return;
 206         if (!(g_hash_table_lookup_extended(
 207                         got_hash,       /* hash_table */
 208                         GUINT_TO_POINTER(PACKET_ELEM_TYPE_DATA_GUINT32),        /* lookup_key */
 209                         NULL,   /* orig_key */
 210                         &got_unique_gpointer))) {
 211 err_packet_disassembly_destroy_got_hash:
 212                 packet_disassembly_destroy(got_hash);
 213                 return;
 214                 }
 215         if (GPOINTER_TO_UINT(got_unique_gpointer)!=probe_unique)
 216                 goto err_packet_disassembly_destroy_got_hash;
 217         if (!(g_hash_table_lookup_extended(
 218                         got_hash,       /* hash_table */
 219                         GUINT_TO_POINTER(PACKET_ELEM_TYPE_CLIENT_INADDR),       /* lookup_key */
 220                         NULL,   /* orig_key */
 221                         &hostip_gpointer)))
 222                 goto err_packet_disassembly_destroy_got_hash;
 223         hostip_guint32=GPOINTER_TO_UINT(hostip_gpointer);
 224         packet_disassembly_destroy(got_hash);
 225
 226         client_destroy(probe);
 227         if (network_notify_hostip)
 228                 (*network_notify_hostip)(hostip_guint32);
 229 }
 230
 231 static struct client *client_new(void);
 232
 233 static void handle_master(struct client *master)
 234 {
 235         g_return_if_fail(master!=NULL);
 236
 237         for (;;) {
 238 char packet[0x10000];
 239 ssize_t gotlen;
 240 struct sockaddr_in sockaddr_in_from;
 241 struct client *client=NULL      /* Prevent false positive: might be used uninitialized */;
 242 struct sockaddr_in sockaddr_in_server;
 243 socklen_t sockaddr_in_from_length;
 244 GList *clientl;
 245
 246                 sockaddr_in_from_length=sizeof(sockaddr_in_from);
 247                 if (-1==(gotlen=recvfrom(
 248                                 master->gpollfd.fd,     /* s */
 249                                 packet, /* buf */
 250                                 sizeof(packet), /* len */
 251                                 0,      /* flags */
 252                                 (struct sockaddr *)&sockaddr_in_from,   /* from */
 253                                 &sockaddr_in_from_length)))     /* fromlen */
 254                         break;
 255
 256                 if (sockaddr_in_from_length!=sizeof(sockaddr_in_from))  /* FIXME: errors reporting */
 257                         continue;
 258
 259                 if (packet_recognized(packet,gotlen)) {
 260                         handle_master_probe(packet,gotlen,&sockaddr_in_from);
 261                         continue;
 262                         }
 263
 264                 /* FIXME: Performance: Ugly search... */
 265                 for (clientl=sock_client_list;clientl;clientl=clientl->next) {
 266                         client=clientl->data;
 267                         if (client==master)
 268                                 continue;
 269                         if (1
 270                                         && client->sockaddr_in_from.sin_family     ==sockaddr_in_from.sin_family
 271                                         && client->sockaddr_in_from.sin_port       ==sockaddr_in_from.sin_port
 272                                         && client->sockaddr_in_from.sin_addr.s_addr==sockaddr_in_from.sin_addr.s_addr)
 273                                 break;
 274                         }
 275                 if (!clientl) {
 276                         client=client_new();
 277                         client->sockaddr_in_from=sockaddr_in_from;
 278                         }
 279                 client_touch(client);
 280                 UDPGATE_MEMZERO(&sockaddr_in_server);
 281                 sockaddr_in_server.sin_family=AF_INET;
 282                 sockaddr_in_server.sin_port=htons(SERVER_PORT);
 283                 sockaddr_in_server.sin_addr.s_addr=htonl(SERVER_INADDR);
 284                 /* FIXME: errors checking */
 285                 sendto(
 286                                 client->gpollfd.fd,     /* s */
 287                                 packet, /* msg */
 288                                 gotlen, /* len */
 289                                 0,      /* flags */
 290                                 (struct sockaddr *)&sockaddr_in_server, /* to */
 291                                 sizeof(sockaddr_in_server));    /* tolen */
 292                 }
 293 }
 294
 295 static void handle_probe(struct client *probe)
 296 {
 297         g_return_if_fail(probe!=NULL);
 298
 299         for (;;) {
 300 ssize_t gotlen;
 301 struct sockaddr_in sockaddr_in_from;
 302 char packet[0x10000];
 303 socklen_t sockaddr_in_from_length;
 304
 305                 sockaddr_in_from_length=sizeof(sockaddr_in_from);
 306                 if (-1==(gotlen=recvfrom(
 307                                 master->gpollfd.fd,     /* s */
 308                                 packet, /* buf */
 309                                 sizeof(packet), /* len */
 310                                 0,      /* flags */
 311                                 (struct sockaddr *)&sockaddr_in_from,   /* from */
 312                                 &sockaddr_in_from_length)))     /* fromlen */
 313                         break;
 314                 if (sockaddr_in_from_length!=sizeof(sockaddr_in_from))  /* FIXME: errors reporting */
 315                         continue;
 316
 317                 /* Probe socket should have no response; maybe some ICMP errors - ignored. */
 318                 }
 319 }
 320
 321 static void handle_client(struct client *client)
 322 {
 323         g_return_if_fail(client!=NULL);
 324         g_return_if_fail(master!=NULL);
 325
 326         for (;;) {
 327 ssize_t gotlen;
 328 struct sockaddr_in sockaddr_in_from;
 329 char packet [0x10000];
 330 socklen_t sockaddr_in_from_length;
 331
 332                 sockaddr_in_from_length=sizeof(sockaddr_in_from);
 333                 if (-1==(gotlen=recvfrom(
 334                                 client->gpollfd.fd,     /* s */
 335                                 packet, /* buf */
 336                                 sizeof(packet), /* len */
 337                                 0,      /* flags */
 338                                 (struct sockaddr *)&sockaddr_in_from,   /* from */
 339                                 &sockaddr_in_from_length)))     /* fromlen */
 340                         break;
 341                 if (sockaddr_in_from_length!=sizeof(sockaddr_in_from))  /* FIXME: errors reporting */
 342                         continue;
 343                 client_touch(client);
 344                 /* FIXME: errors checking */
 345                 sendto(
 346                                 master->gpollfd.fd,     /* s */
 347                                 packet, /* msg */
 348                                 gotlen, /* len */
 349                                 0,      /* flags */
 350                                 (struct sockaddr *)&client->sockaddr_in_from,   /* to */
 351                                 sizeof(client->sockaddr_in_from));      /* tolen */
 352                 }
 353 }
 354
 355 static gboolean sock_source_callback(gpointer data /* unused */)
 356 {
 357 GList *clientl;
 358
 359         for (clientl=sock_client_list;clientl;clientl=clientl->next) {
 360 struct client *client=clientl->data;
 361
 362                 if (client->gpollfd.revents&SOCK_SOURCE_CHECK_REVENTS) {
 363                         /**/ if (client==master)
 364                                 handle_master(client);
 365                         else if (client==probe)
 366                                 handle_probe(client);
 367                         else
 368                                 handle_client(client);
 369                         }
 370                 }
 371
 372         return TRUE; /* the source should be kept active */
 373 }
 374
 375 static gboolean sock_source_prepare(GSource *source,gint *timeout)
 376 {
 377         *timeout=-1;
 378
 379         return FALSE;
 380 }
 381
 382 static gboolean sock_source_check(GSource *source)
 383 {
 384 GList *clientl;
 385
 386         for (clientl=sock_client_list;clientl;clientl=clientl->next) {
 387 struct client *client=clientl->data;
 388
 389                 if (client->gpollfd.revents&SOCK_SOURCE_CHECK_REVENTS)
 390                         return TRUE;
 391                 }
 392         return FALSE;
 393 }
 394
 395 static gboolean sock_source_dispatch(GSource *source,GSourceFunc callback,gpointer user_data)
 396 {
 397         g_assert(callback!=NULL);
 398         return (*callback)(user_data);
 399 }
 400
 401 static GSourceFuncs sock_source_watch_funcs={
 402                 sock_source_prepare,
 403                 sock_source_check,
 404                 sock_source_dispatch,
 405                 NULL, /* finalize */
 406                 };
 407
 408 static void sock_gsource_destroy(void)
 409 {
 410         while (sock_client_list)
 411                 client_destroy(sock_client_list->data);
 412
 413         g_assert(master==NULL);
 414         g_assert(probe==NULL);
 415
 416         if (sock_gsource) {
 417                 g_source_destroy(sock_gsource);
 418                 sock_gsource=NULL;
 419                 }
 420
 421         write_daemon_running((pid_t)-1);        /* unlink; errors ignored */
 422 }
 423
 424 static gboolean sock_gsource_new(void)
 425 {
 426         if (sock_gsource)
 427                 return TRUE;
 428
 429         g_assert(sock_client_list==NULL);
 430
 431         /* attach sock_source_callback() to watch for any abnormalities
 432          * on our open pipe 'parentheart_fds' and terminate the child if parent dies.
 433          */
 434         if (!(sock_gsource=g_source_new(&sock_source_watch_funcs,sizeof(GSource)))) {
 435                 g_warning("g_source_new(): %m");
 436                 return FALSE;
 437                 }
 438         g_source_set_callback(
 439                         sock_gsource,  /* source */
 440                         sock_source_callback,  /* func */
 441                         NULL, /* data */
 442                         NULL);  /* notify */
 443         if (!g_source_attach(   /* returns 'guint' id */
 444                         sock_gsource,  /* source */
 445                         NULL)) {        /* context; NULL means 'default context' */
 446                 g_warning("g_source_attach(gsource,NULL): %m");
 447                 sock_gsource_destroy();
 448                 return FALSE;
 449                 }
 450         return TRUE;
 451 }
 452
 453 static struct client *client_new(void)
 454 {
 455 struct client *client;
 456 static unsigned long oneul=1;
 457 int sock;
 458
 459         if (!sock_gsource_new())
 460                 return FALSE;
 461
 462         if (-1==(sock=socket(AF_INET,SOCK_DGRAM,IPPROTO_UDP))) {
 463                 g_warning("socket(AF_INET,SOCK_DGRAM,IPPROTO_UDP): %m");
 464                 return NULL;
 465                 }
 466         if (ioctl(sock,FIONBIO,&oneul)) {       /* non-blocking mode */
 467                 g_warning("ioctl(sock,FIONBIO,&1): %m");
 468                 close(sock);    /* errors ignored */
 469                 return NULL;
 470                 }
 471
 472         udpgate_new(client);
 473         client->gpollfd.fd=sock;
 474         client->gpollfd.events=SOCK_SOURCE_CHECK_EVENTS;
 475         client->gpollfd.revents=0;
 476         client->timeout_id=0;
 477         sock_client_list=g_list_prepend(sock_client_list,client);
 478         g_source_add_poll(sock_gsource,&client->gpollfd);
 479
 480         if (optarg_verbose)
 481                 g_message(_("Client fd %d created"),client->gpollfd.fd);
 482
 483         return client;
 484 }
 485
 486 static void client_destroy(struct client *client)
 487 {
 488         g_return_if_fail(client!=NULL);
 489
 490         if (!sock_gsource_new())
 491                 return;
 492
 493         if (optarg_verbose)
 494                 g_message(_("Client fd %d timeout id %d destroy enter"),client->gpollfd.fd,client->timeout_id);
 495
 496         if (client==master) {
 497                 master=NULL;
 498                 g_assert(client->timeout_id==0);
 499                 }
 500         else {
 501                 if (client==probe)
 502                         probe=NULL;
 503                 client_timeout_remove(client);
 504                 }
 505
 506         g_source_remove_poll(sock_gsource,&client->gpollfd);
 507         sock_client_list=g_list_remove(sock_client_list,client);
 508         close(client->gpollfd.fd);      /* errors ignored */
 509
 510         if (optarg_verbose)
 511                 g_message(_("Client fd %d timeout id %d destroy finish"),client->gpollfd.fd,client->timeout_id);
 512
 513         g_free(client);
 514 }
 515
 516 static gboolean probe_send(struct client *probe,gint port_local)
 517 {
 518 struct sockaddr_in sockaddr_in_server;
 519 GHashTable *probe_hash;
 520 gpointer packet;
 521 size_t packet_length;
 522
 523         g_return_val_if_fail(probe!=NULL,FALSE);
 524
 525         probe_unique=g_random_int();
 526
 527         probe_hash=g_hash_table_new(
 528                         g_direct_hash,  /* hash_func */
 529                         g_direct_equal);        /* key_equal_func */
 530         g_hash_table_insert(probe_hash,GUINT_TO_POINTER(PACKET_ELEM_TYPE_CLIENT_PORT) ,GUINT_TO_POINTER(port_local));
 531         g_hash_table_insert(probe_hash,GUINT_TO_POINTER(PACKET_ELEM_TYPE_DATA_GUINT32),GUINT_TO_POINTER(probe_unique));
 532         packet=packet_assembly(&packet_length,probe_hash);
 533         g_hash_table_destroy(probe_hash);
 534         if (!packet)
 535                 return FALSE;
 536
 537         UDPGATE_MEMZERO(&sockaddr_in_server);
 538         sockaddr_in_server.sin_family=AF_INET;
 539         sockaddr_in_server.sin_port=htons(PROBE_PORT);
 540         sockaddr_in_server.sin_addr.s_addr=htonl(PROBE_INADDR);
 541         /* FIXME: errors checking */
 542         sendto(
 543                         probe->gpollfd.fd,      /* s */
 544                         packet, /* msg */
 545                         packet_length,  /* len */
 546                         0,      /* flags */
 547                         (struct sockaddr *)&sockaddr_in_server, /* to */
 548                         sizeof(sockaddr_in_server));    /* tolen */
 549
 550         return TRUE;
 551 }
 552
 553 static gboolean master_start(gint port)
 554 {
 555 struct sockaddr_in sockaddr_in;
 556
 557         g_return_val_if_fail(port>=0,FALSE);
 558         g_return_val_if_fail(master==NULL,FALSE);
 559
 560         /* Setup 'master': */
 561         if (!(master=client_new()))
 562                 return FALSE;
 563         UDPGATE_MEMZERO(&sockaddr_in);
 564         sockaddr_in.sin_family=AF_INET;
 565         sockaddr_in.sin_port=htons(port);
 566         sockaddr_in.sin_addr.s_addr=htonl(INADDR_ANY);
 567         if (bind(master->gpollfd.fd,(struct sockaddr *)&sockaddr_in,sizeof(sockaddr_in))) {
 568                 g_warning("bind(sock,{AF_INET,INADDR_ANY:%d}): %m",(int)port);
 569                 return FALSE;
 570                 }
 571         return TRUE;
 572 }
 573
 574 static gboolean probe_start(gint port)
 575 {
 576         g_return_val_if_fail(port>=0,FALSE);
 577         g_return_val_if_fail(probe==NULL,FALSE);
 578
 579         /* Setup 'probe': */
 580         if (!(probe=client_new()))
 581                 return FALSE;
 582         probe_send(probe,port);
 583         client_touch(probe);    /* timeout */
 584         return TRUE;
 585 }
 586
 587 gboolean network_start(gint port)
 588 {
 589 pid_t daemon_pid;
 590
 591         g_return_val_if_fail(port>=0,FALSE);
 592
 593         if ((pid_t)-1!=(daemon_pid=is_daemon_running())) {
 594                 g_warning(_("Cannot start network daemon: Daemon is already running on PID %d"),(int)daemon_pid);
 595                 return FALSE;
 596                 }
 597         if (!master_start(port)) {
 598                 sock_gsource_destroy();
 599                 return FALSE;
 600                 }
 601         if (!probe_start(port)) {
 602                 sock_gsource_destroy();
 603                 return FALSE;
 604                 }
 605         write_daemon_running(getpid()); /* errors ignored */
 606         if (network_notify_hostip)
 607                 (*network_notify_hostip)(0);
 608         return TRUE;
 609 }
 610
 611 gboolean optarg_port_set_string(const gchar *port_string)
 612 {
 613 char *endp;
 614 long port_long;
 615
 616         g_return_val_if_fail(port_string!=NULL,FALSE);
 617
 618         port_long=strtol(port_string,&endp,0);
 619         if (endp && *endp) {
 620                 g_warning(_("Invalid port specification, offending string: %s"),endp);
 621                 return FALSE;
 622                 }
 623         if (port_long<1 || port_long>=G_MAXINT || (endp && *endp)) {
 624                 g_warning(_("Invalid port integer number specification (%ld)"),port_long);
 625                 return FALSE;
 626                 }
 627         optarg_port=port_long;
 628         return TRUE;
 629 }
 630
 631 gboolean network_stop(void)
 632 {
 633 pid_t daemon_pid;
 634 int errno_save;
 635
 636         if ((pid_t)-1==(daemon_pid=is_daemon_running())) {
 637                 g_warning(_("Cannot stop network daemon: Daemon is not running"));
 638                 return FALSE;
 639                 }
 640         if (daemon_pid==getpid()) {
 641                 sock_gsource_destroy();
 642                 goto ok;
 643                 }
 644         errno=0;
 645         kill(daemon_pid,SIGKILL);
 646         errno_save=errno;
 647         write_daemon_running((pid_t)-1);        /* unlink; errors ignored */
 648         if (errno_save)  {
 649                 g_warning(udpgate_printf_alloca(_("Unable to stop the daemon at PID %d: %s"),
 650                                 (int)daemon_pid,strerror(errno_save)));
 651                 return FALSE;
 652                 }
 653 ok:
 654         if (network_notify_hostip)
 655                 (*network_notify_hostip)(0);
 656         return TRUE;
 657 }
 658
 659 static GMainLoop *gmainloop;
 660 static void network_detach_network_notify_hostip(guint32 hostip_guint32)
 661 {
 662         if (!hostip_guint32)
 663                 g_main_loop_quit(gmainloop);
 664 }
 665
 666 gboolean network_detach(void)
 667 {
 668 pid_t daemon_pid,forked_pid;
 669
 670         if ((pid_t)-1==(daemon_pid=is_daemon_running()))
 671                 return TRUE;
 672         if (getpid()!=daemon_pid)
 673                 return TRUE;
 674         if (!optarg_no_fork) {
 675                 if ((pid_t)-1==(forked_pid=fork())) {
 676                         g_warning("fork(2): %m");
 677                         return FALSE;
 678                         }
 679                 if (forked_pid) {
 680                         /* parent */
 681                         return TRUE;
 682                         }
 683                 write_daemon_running(getpid()); /* errors ignored */
 684                 optarg_verbose=0;
 685                 close(STDIN_FILENO);
 686                 close(STDOUT_FILENO);
 687                 close(STDERR_FILENO);
 688                 setpgrp();
 689                 setsid();
 690                 }
 691
 692         network_notify_hostip=network_detach_network_notify_hostip;
 693         gmainloop=g_main_loop_new(
 694                         NULL,   /* context */
 695                         TRUE);  /* is_running; ignored */
 696         g_main_loop_run(gmainloop);     /* loop */
 697         /* Unable to contact the server, aborting. */
 698         return FALSE;
 699 }