citadel/modules/instmsg/serv_instmsg.c

   1 /*
   2  * This module handles instant messaging between users.
   3  *
   4  * Copyright (c) 1987-2018 by the citadel.org team
   5  *
   6  * This program is open source software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 3.
   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
  15 #include "sysdep.h"
  16 #include <stdlib.h>
  17 #include <unistd.h>
  18 #include <stdio.h>
  19 #include <fcntl.h>
  20 #include <signal.h>
  21 #include <pwd.h>
  22 #include <errno.h>
  23 #include <sys/types.h>
  24
  25 #if TIME_WITH_SYS_TIME
  26 # include <sys/time.h>
  27 # include <time.h>
  28 #else
  29 # if HAVE_SYS_TIME_H
  30 #  include <sys/time.h>
  31 # else
  32 #  include <time.h>
  33 # endif
  34 #endif
  35
  36 #include <sys/wait.h>
  37 #include <string.h>
  38 #include <limits.h>
  39 #include <libcitadel.h>
  40 #include "citadel.h"
  41 #include "server.h"
  42 #include "serv_instmsg.h"
  43 #include "citserver.h"
  44 #include "support.h"
  45 #include "config.h"
  46 #include "msgbase.h"
  47 #include "user_ops.h"
  48 #include "ctdl_module.h"
  49
  50 struct imlog {
  51         struct imlog *next;
  52         long usernums[2];
  53         char usernames[2][128];
  54         time_t lastmsg;
  55         int last_serial;
  56         StrBuf *conversation;
  57 };
  58
  59 struct imlog *imlist = NULL;
  60
  61 /*
  62  * This function handles the logging of instant messages to disk.
  63  */
  64 void log_instant_message(struct CitContext *me, struct CitContext *them, char *msgtext, int serial_number)
  65 {
  66         long usernums[2];
  67         long t;
  68         struct imlog *iptr = NULL;
  69         struct imlog *this_im = NULL;
  70
  71         memset(usernums, 0, sizeof usernums);
  72         usernums[0] = me->user.usernum;
  73         usernums[1] = them->user.usernum;
  74
  75         /* Always put the lower user number first, so we can use the array as a hash value which
  76          * represents a pair of users.  For a broadcast message one of the users will be 0.
  77          */
  78         if (usernums[0] > usernums[1]) {
  79                 t = usernums[0];
  80                 usernums[0] = usernums[1];
  81                 usernums[1] = t;
  82         }
  83
  84         begin_critical_section(S_IM_LOGS);
  85
  86         /* Look for an existing conversation in the hash table.
  87          * If not found, create a new one.
  88          */
  89
  90         this_im = NULL;
  91         for (iptr = imlist; iptr != NULL; iptr = iptr->next) {
  92                 if ((iptr->usernums[0] == usernums[0]) && (iptr->usernums[1] == usernums[1])) {
  93                         /* Existing conversation */
  94                         this_im = iptr;
  95                 }
  96         }
  97         if (this_im == NULL) {
  98                 /* New conversation */
  99                 this_im = malloc(sizeof(struct imlog));
 100                 memset(this_im, 0, sizeof (struct imlog));
 101                 this_im->usernums[0] = usernums[0];
 102                 this_im->usernums[1] = usernums[1];
 103                 /* usernames[] and usernums[] might not be in the same order.  This is not an error. */
 104                 if (me) {
 105                         safestrncpy(this_im->usernames[0], me->user.fullname, sizeof this_im->usernames[0]);
 106                 }
 107                 if (them) {
 108                         safestrncpy(this_im->usernames[1], them->user.fullname, sizeof this_im->usernames[1]);
 109                 }
 110                 this_im->conversation = NewStrBuf();
 111                 this_im->next = imlist;
 112                 imlist = this_im;
 113                 StrBufAppendBufPlain(this_im->conversation, HKEY("<html><body>\r\n"), 0);
 114         }
 115
 116         /* Since it's possible for this function to get called more than once if a user is logged
 117          * in on multiple sessions, we use the message's serial number to keep track of whether
 118          * we've already logged it.
 119          */
 120         if (this_im->last_serial != serial_number)
 121         {
 122                 this_im->lastmsg = time(NULL);          /* Touch the timestamp so we know when to flush */
 123                 this_im->last_serial = serial_number;
 124                 StrBufAppendBufPlain(this_im->conversation, HKEY("<p><b>"), 0);
 125                 StrBufAppendBufPlain(this_im->conversation, me->user.fullname, -1, 0);
 126                 StrBufAppendBufPlain(this_im->conversation, HKEY(":</b> "), 0);
 127                 StrEscAppend(this_im->conversation, NULL, msgtext, 0, 0);
 128                 StrBufAppendBufPlain(this_im->conversation, HKEY("</p>\r\n"), 0);
 129         }
 130         end_critical_section(S_IM_LOGS);
 131 }
 132
 133
 134 /*
 135  * Delete any remaining instant messages
 136  */
 137 void delete_instant_messages(void) {
 138         struct ExpressMessage *ptr;
 139
 140         begin_critical_section(S_SESSION_TABLE);
 141         while (CC->FirstExpressMessage != NULL) {
 142                 ptr = CC->FirstExpressMessage->next;
 143                 if (CC->FirstExpressMessage->text != NULL)
 144                         free(CC->FirstExpressMessage->text);
 145                 free(CC->FirstExpressMessage);
 146                 CC->FirstExpressMessage = ptr;
 147         }
 148         end_critical_section(S_SESSION_TABLE);
 149 }
 150
 151
 152 /*
 153  * Retrieve instant messages
 154  */
 155 void cmd_gexp(char *argbuf) {
 156         struct ExpressMessage *ptr;
 157
 158         if (CC->FirstExpressMessage == NULL) {
 159                 cprintf("%d No instant messages waiting.\n", ERROR + MESSAGE_NOT_FOUND);
 160                 return;
 161         }
 162
 163         begin_critical_section(S_SESSION_TABLE);
 164         ptr = CC->FirstExpressMessage;
 165         CC->FirstExpressMessage = CC->FirstExpressMessage->next;
 166         end_critical_section(S_SESSION_TABLE);
 167
 168         cprintf("%d %d|%ld|%d|%s|%s|%s\n",
 169                 LISTING_FOLLOWS,
 170                 ((ptr->next != NULL) ? 1 : 0),          /* more msgs? */
 171                 (long)ptr->timestamp,                   /* time sent */
 172                 ptr->flags,                             /* flags */
 173                 ptr->sender,                            /* sender of msg */
 174                 CtdlGetConfigStr("c_nodename"),         /* static for now (and possibly deprecated) */
 175                 ptr->sender_email                       /* email or jid of sender */
 176         );
 177
 178         if (ptr->text != NULL) {
 179                 memfmout(ptr->text, "\n");
 180                 free(ptr->text);
 181         }
 182
 183         cprintf("000\n");
 184         free(ptr);
 185 }
 186
 187
 188 /*
 189  * Asynchronously deliver instant messages
 190  */
 191 void cmd_gexp_async(void) {
 192
 193         /* Only do this if the session can handle asynchronous protocol */
 194         if (CC->is_async == 0) return;
 195
 196         /* And don't do it if there's nothing to send. */
 197         if (CC->FirstExpressMessage == NULL) return;
 198
 199         cprintf("%d instant msg\n", ASYNC_MSG + ASYNC_GEXP);
 200 }
 201
 202
 203 /*
 204  * Back end support function for send_instant_message() and company
 205  */
 206 void add_xmsg_to_context(struct CitContext *ccptr, struct ExpressMessage *newmsg)
 207 {
 208         struct ExpressMessage *findend;
 209
 210         if (ccptr->FirstExpressMessage == NULL) {
 211                 ccptr->FirstExpressMessage = newmsg;
 212         }
 213         else {
 214                 findend = ccptr->FirstExpressMessage;
 215                 while (findend->next != NULL) {
 216                         findend = findend->next;
 217                 }
 218                 findend->next = newmsg;
 219         }
 220
 221         /* If the target context is a session which can handle asynchronous
 222          * messages, go ahead and set the flag for that.
 223          */
 224         set_async_waiting(ccptr);
 225 }
 226
 227
 228 /*
 229  * This is the back end to the instant message sending function.
 230  * Returns the number of users to which the message was sent.
 231  * Sending a zero-length message tests for recipients without sending messages.
 232  */
 233 int send_instant_message(char *lun, char *lem, char *x_user, char *x_msg)
 234 {
 235         int message_sent = 0;           /* number of successful sends */
 236         struct CitContext *ccptr;
 237         struct ExpressMessage *newmsg = NULL;
 238         char *un;
 239         int do_send = 0;                /* 1 = send message; 0 = only check for valid recipient */
 240         static int serial_number = 0;   /* this keeps messages from getting logged twice */
 241
 242         if (!IsEmptyStr(x_msg)) {
 243                 do_send = 1;
 244         }
 245
 246         /* find the target user's context and append the message */
 247         begin_critical_section(S_SESSION_TABLE);
 248         ++serial_number;
 249         for (ccptr = ContextList; ccptr != NULL; ccptr = ccptr->next) {
 250
 251                 if (ccptr->fake_username[0]) {
 252                         un = ccptr->fake_username;
 253                 }
 254                 else {
 255                         un = ccptr->user.fullname;
 256                 }
 257
 258                 if ( ((!strcasecmp(un, x_user))
 259                     || (!strcasecmp(x_user, "broadcast")))
 260                     && (ccptr->can_receive_im)
 261                     && ((ccptr->disable_exp == 0)
 262                     || (CC->user.axlevel >= AxAideU)) ) {
 263                         if (do_send) {
 264                                 newmsg = (struct ExpressMessage *) malloc(sizeof (struct ExpressMessage));
 265                                 memset(newmsg, 0, sizeof (struct ExpressMessage));
 266                                 time(&(newmsg->timestamp));
 267                                 safestrncpy(newmsg->sender, lun, sizeof newmsg->sender);
 268                                 safestrncpy(newmsg->sender_email, lem, sizeof newmsg->sender_email);
 269                                 if (!strcasecmp(x_user, "broadcast")) {
 270                                         newmsg->flags |= EM_BROADCAST;
 271                                 }
 272                                 newmsg->text = strdup(x_msg);
 273
 274                                 add_xmsg_to_context(ccptr, newmsg);
 275
 276                                 /* and log it ... */
 277                                 if (ccptr != CC) {
 278                                         log_instant_message(CC, ccptr, newmsg->text, serial_number);
 279                                 }
 280                         }
 281                         ++message_sent;
 282                 }
 283         }
 284         end_critical_section(S_SESSION_TABLE);
 285         return (message_sent);
 286 }
 287
 288
 289 /*
 290  * send instant messages
 291  */
 292 void cmd_sexp(char *argbuf)
 293 {
 294         int message_sent = 0;
 295         char x_user[USERNAME_SIZE];
 296         char x_msg[1024];
 297         char *lun;
 298         char *lem;
 299         char *x_big_msgbuf = NULL;
 300
 301         if ((!(CC->logged_in)) && (!(CC->internal_pgm))) {
 302                 cprintf("%d Not logged in.\n", ERROR + NOT_LOGGED_IN);
 303                 return;
 304         }
 305         if (CC->fake_username[0]) {
 306                 lun = CC->fake_username;
 307         }
 308         else {
 309                 lun = CC->user.fullname;
 310         }
 311
 312         lem = CC->cs_inet_email;
 313
 314         extract_token(x_user, argbuf, 0, '|', sizeof x_user);
 315         extract_token(x_msg, argbuf, 1, '|', sizeof x_msg);
 316
 317         if (!x_user[0]) {
 318                 cprintf("%d You were not previously paged.\n", ERROR + NO_SUCH_USER);
 319                 return;
 320         }
 321         if ((!strcasecmp(x_user, "broadcast")) && (CC->user.axlevel < AxAideU)) {
 322                 cprintf("%d Higher access required to send a broadcast.\n",
 323                         ERROR + HIGHER_ACCESS_REQUIRED);
 324                 return;
 325         }
 326         /* This loop handles text-transfer pages */
 327         if (!strcmp(x_msg, "-")) {
 328                 message_sent = PerformXmsgHooks(lun, lem, x_user, "");
 329                 if (message_sent == 0) {
 330                         if (CtdlGetUser(NULL, x_user))
 331                                 cprintf("%d '%s' does not exist.\n",
 332                                                 ERROR + NO_SUCH_USER, x_user);
 333                         else
 334                                 cprintf("%d '%s' is not logged in "
 335                                                 "or is not accepting pages.\n",
 336                                                 ERROR + RESOURCE_NOT_OPEN, x_user);
 337                         return;
 338                 }
 339                 unbuffer_output();
 340                 cprintf("%d Transmit message (will deliver to %d users)\n",
 341                         SEND_LISTING, message_sent);
 342                 x_big_msgbuf = malloc(SIZ);
 343                 memset(x_big_msgbuf, 0, SIZ);
 344                 while (client_getln(x_msg, sizeof x_msg) >= 0 && strcmp(x_msg, "000")) {
 345                         x_big_msgbuf = realloc(x_big_msgbuf,
 346                                strlen(x_big_msgbuf) + strlen(x_msg) + 4);
 347                         if (!IsEmptyStr(x_big_msgbuf))
 348                            if (x_big_msgbuf[strlen(x_big_msgbuf)] != '\n')
 349                                 strcat(x_big_msgbuf, "\n");
 350                         strcat(x_big_msgbuf, x_msg);
 351                 }
 352                 PerformXmsgHooks(lun, lem, x_user, x_big_msgbuf);
 353                 free(x_big_msgbuf);
 354
 355                 /* This loop handles inline pages */
 356         } else {
 357                 message_sent = PerformXmsgHooks(lun, lem, x_user, x_msg);
 358
 359                 if (message_sent > 0) {
 360                         if (!IsEmptyStr(x_msg)) {
 361                                 cprintf("%d Message sent", CIT_OK);
 362                         }
 363                         else {
 364                                 cprintf("%d Ok to send message", CIT_OK);
 365                         }
 366                         if (message_sent > 1) {
 367                                 cprintf(" to %d users", message_sent);
 368                         }
 369                         cprintf(".\n");
 370                 } else {
 371                         if (CtdlGetUser(NULL, x_user)) {
 372                                 cprintf("%d '%s' does not exist.\n", ERROR + NO_SUCH_USER, x_user);
 373                         }
 374                         else {
 375                                 cprintf("%d '%s' is not logged in or is not accepting instant messages.\n",
 376                                                 ERROR + RESOURCE_NOT_OPEN, x_user);
 377                         }
 378                 }
 379
 380
 381         }
 382 }
 383
 384
 385 /*
 386  * Enter or exit paging-disabled mode
 387  */
 388 void cmd_dexp(char *argbuf)
 389 {
 390         int new_state;
 391
 392         if (CtdlAccessCheck(ac_logged_in)) return;
 393
 394         new_state = extract_int(argbuf, 0);
 395         if ((new_state == 0) || (new_state == 1)) {
 396                 CC->disable_exp = new_state;
 397         }
 398
 399         cprintf("%d %d\n", CIT_OK, CC->disable_exp);
 400 }
 401
 402
 403 /*
 404  * Request client termination
 405  */
 406 void cmd_reqt(char *argbuf) {
 407         struct CitContext *ccptr;
 408         int sessions = 0;
 409         int which_session;
 410         struct ExpressMessage *newmsg;
 411
 412         if (CtdlAccessCheck(ac_aide)) return;
 413         which_session = extract_int(argbuf, 0);
 414
 415         begin_critical_section(S_SESSION_TABLE);
 416         for (ccptr = ContextList; ccptr != NULL; ccptr = ccptr->next) {
 417                 if ((ccptr->cs_pid == which_session) || (which_session == 0)) {
 418
 419                         newmsg = (struct ExpressMessage *)
 420                                 malloc(sizeof (struct ExpressMessage));
 421                         memset(newmsg, 0,
 422                                 sizeof (struct ExpressMessage));
 423                         time(&(newmsg->timestamp));
 424                         safestrncpy(newmsg->sender, CC->user.fullname,
 425                                     sizeof newmsg->sender);
 426                         newmsg->flags |= EM_GO_AWAY;
 427                         newmsg->text = strdup("Automatic logoff requested.");
 428
 429                         add_xmsg_to_context(ccptr, newmsg);
 430                         ++sessions;
 431
 432                 }
 433         }
 434         end_critical_section(S_SESSION_TABLE);
 435         cprintf("%d Sent termination request to %d sessions.\n", CIT_OK, sessions);
 436 }
 437
 438
 439 /*
 440  * This is the back end for flush_conversations_to_disk()
 441  * At this point we've isolated a single conversation (struct imlog)
 442  * and are ready to write it to disk.
 443  */
 444 void flush_individual_conversation(struct imlog *im) {
 445         struct CtdlMessage *msg;
 446         long msgnum = 0;
 447         char roomname[ROOMNAMELEN];
 448         StrBuf *MsgBuf, *FullMsgBuf;
 449
 450         StrBufAppendBufPlain(im->conversation, HKEY(
 451                 "</body>\r\n"
 452                 "</html>\r\n"
 453                 ), 0
 454         );
 455
 456         MsgBuf = StrBufRFC2047encodeMessage(im->conversation);
 457         FlushStrBuf(im->conversation);
 458         FullMsgBuf = NewStrBufPlain(NULL, StrLength(im->conversation) + 100);
 459
 460         StrBufAppendBufPlain(FullMsgBuf, HKEY(
 461                 "Content-type: text/html; charset=UTF-8\r\n"
 462                 "Content-Transfer-Encoding: quoted-printable\r\n"
 463                 "\r\n"
 464                 ), 0
 465         );
 466         StrBufAppendBuf (FullMsgBuf, MsgBuf, 0);
 467         FreeStrBuf(&MsgBuf);
 468
 469         msg = malloc(sizeof(struct CtdlMessage));
 470         memset(msg, 0, sizeof(struct CtdlMessage));
 471         msg->cm_magic = CTDLMESSAGE_MAGIC;
 472         msg->cm_anon_type = MES_NORMAL;
 473         msg->cm_format_type = FMT_RFC822;
 474         if (!IsEmptyStr(im->usernames[0])) {
 475                 CM_SetField(msg, eAuthor, im->usernames[0], strlen(im->usernames[0]));
 476         } else {
 477                 CM_SetField(msg, eAuthor, HKEY("Citadel"));
 478         }
 479         if (!IsEmptyStr(im->usernames[1])) {
 480                 CM_SetField(msg, eRecipient, im->usernames[1], strlen(im->usernames[1]));
 481         }
 482
 483         CM_SetField(msg, eOriginalRoom, HKEY(PAGELOGROOM));
 484         CM_SetAsFieldSB(msg, eMesageText, &FullMsgBuf); /* we own this memory now */
 485
 486         /* Start with usernums[1] because it's guaranteed to be higher than usernums[0],
 487          * so if there's only one party, usernums[0] will be zero but usernums[1] won't.
 488          * Create the room if necessary.  Note that we create as a type 5 room rather
 489          * than 4, which indicates that it's a personal room but we've already supplied
 490          * the namespace prefix.
 491          *
 492          * In the unlikely event that usernums[1] is zero, a room with an invalid namespace
 493          * prefix will be created.  That's ok because the auto-purger will clean it up later.
 494          */
 495         snprintf(roomname, sizeof roomname, "%010ld.%s", im->usernums[1], PAGELOGROOM);
 496         CtdlCreateRoom(roomname, 5, "", 0, 1, 1, VIEW_BBS);
 497         msgnum = CtdlSubmitMsg(msg, NULL, roomname, 0);
 498         CM_Free(msg);
 499
 500         /* If there is a valid user number in usernums[0], save a copy for them too. */
 501         if (im->usernums[0] > 0) {
 502                 snprintf(roomname, sizeof roomname, "%010ld.%s", im->usernums[0], PAGELOGROOM);
 503                 CtdlCreateRoom(roomname, 5, "", 0, 1, 1, VIEW_BBS);
 504                 CtdlSaveMsgPointerInRoom(roomname, msgnum, 0, NULL);
 505         }
 506
 507         /* Finally, if we're logging instant messages globally, do that now. */
 508         if (!IsEmptyStr(CtdlGetConfigStr("c_logpages"))) {
 509                 CtdlCreateRoom(CtdlGetConfigStr("c_logpages"), 3, "", 0, 1, 1, VIEW_BBS);
 510                 CtdlSaveMsgPointerInRoom(CtdlGetConfigStr("c_logpages"), msgnum, 0, NULL);
 511         }
 512
 513 }
 514
 515 /*
 516  * Locate instant message conversations which have gone idle
 517  * (or, if the server is shutting down, locate *all* conversations)
 518  * and flush them to disk (in the participants' log rooms, etc.)
 519  */
 520 void flush_conversations_to_disk(time_t if_older_than) {
 521
 522         struct imlog *flush_these = NULL;
 523         struct imlog *dont_flush_these = NULL;
 524         struct imlog *imptr = NULL;
 525         struct CitContext *nptr;
 526         int nContexts, i;
 527
 528         nptr = CtdlGetContextArray(&nContexts) ;        /* Make a copy of the current wholist */
 529
 530         begin_critical_section(S_IM_LOGS);
 531         while (imlist)
 532         {
 533                 imptr = imlist;
 534                 imlist = imlist->next;
 535
 536                 /* For a two party conversation, if one party has logged out, force flush. */
 537                 if (nptr) {
 538                         int user0_is_still_online = 0;
 539                         int user1_is_still_online = 0;
 540                         for (i=0; i<nContexts; i++)  {
 541                                 if (nptr[i].user.usernum == imptr->usernums[0]) ++user0_is_still_online;
 542                                 if (nptr[i].user.usernum == imptr->usernums[1]) ++user1_is_still_online;
 543                         }
 544                         if (imptr->usernums[0] != imptr->usernums[1]) {         /* two party conversation */
 545                                 if ((!user0_is_still_online) || (!user1_is_still_online)) {
 546                                         imptr->lastmsg = 0L;    /* force flush */
 547                                 }
 548                         }
 549                         else {          /* one party conversation (yes, people do IM themselves) */
 550                                 if (!user0_is_still_online) {
 551                                         imptr->lastmsg = 0L;    /* force flush */
 552                                 }
 553                         }
 554                 }
 555
 556                 /* Now test this conversation to see if it qualifies for flushing. */
 557                 if ((time(NULL) - imptr->lastmsg) > if_older_than)
 558                 {
 559                         /* This conversation qualifies.  Move it to the list of ones to flush. */
 560                         imptr->next = flush_these;
 561                         flush_these = imptr;
 562                 }
 563                 else  {
 564                         /* Move it to the list of ones not to flush. */
 565                         imptr->next = dont_flush_these;
 566                         dont_flush_these = imptr;
 567                 }
 568         }
 569         imlist = dont_flush_these;
 570         end_critical_section(S_IM_LOGS);
 571         free(nptr);
 572
 573         /* We are now outside of the critical section, and we are the only thread holding a
 574          * pointer to a linked list of conversations to be flushed to disk.
 575          */
 576         while (flush_these) {
 577
 578                 flush_individual_conversation(flush_these);     /* This will free the string buffer */
 579                 imptr = flush_these;
 580                 flush_these = flush_these->next;
 581                 free(imptr);
 582         }
 583 }
 584
 585
 586
 587 void instmsg_timer(void) {
 588         flush_conversations_to_disk(300);       /* Anything that hasn't peeped in more than 5 minutes */
 589 }
 590
 591 void instmsg_shutdown(void) {
 592         flush_conversations_to_disk(0);         /* Get it ALL onto disk NOW. */
 593 }
 594
 595 CTDL_MODULE_INIT(instmsg)
 596 {
 597         if (!threading)
 598         {
 599                 CtdlRegisterProtoHook(cmd_gexp, "GEXP", "Get instant messages");
 600                 CtdlRegisterProtoHook(cmd_sexp, "SEXP", "Send an instant message");
 601                 CtdlRegisterProtoHook(cmd_dexp, "DEXP", "Disable instant messages");
 602                 CtdlRegisterProtoHook(cmd_reqt, "REQT", "Request client termination");
 603                 CtdlRegisterSessionHook(cmd_gexp_async, EVT_ASYNC, PRIO_ASYNC + 1);
 604                 CtdlRegisterSessionHook(delete_instant_messages, EVT_STOP, PRIO_STOP + 1);
 605                 CtdlRegisterXmsgHook(send_instant_message, XMSG_PRI_LOCAL);
 606                 CtdlRegisterSessionHook(instmsg_timer, EVT_TIMER, PRIO_CLEANUP + 400);
 607                 CtdlRegisterSessionHook(instmsg_shutdown, EVT_SHUTDOWN, PRIO_SHUTDOWN + 10);
 608         }
 609
 610         /* return our module name for the log */
 611         return "instmsg";
 612 }