citadel/server/modules/instmsg/serv_instmsg.c

   1 /*
   2  * This module handles instant messaging between users.
   3  *
   4  * Copyright (c) 1987-2022 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 <stdlib.h>
  16 #include <unistd.h>
  17 #include <stdio.h>
  18 #include <fcntl.h>
  19 #include <signal.h>
  20 #include <pwd.h>
  21 #include <errno.h>
  22 #include <sys/types.h>
  23 #include <time.h>
  24 #include <sys/wait.h>
  25 #include <string.h>
  26 #include <limits.h>
  27 #include <libcitadel.h>
  28 #include "../../sysdep.h"
  29 #include "../../citadel.h"
  30 #include "../../server.h"
  31 #include "../../context.h"
  32 #include "../../citserver.h"
  33 #include "../../support.h"
  34 #include "../../config.h"
  35 #include "../../msgbase.h"
  36 #include "../../user_ops.h"
  37 #include "../../ctdl_module.h"
  38 #include "serv_instmsg.h"
  39
  40 struct imlog {
  41         struct imlog *next;
  42         long usernums[2];
  43         char usernames[2][128];
  44         time_t lastmsg;
  45         int last_serial;
  46         StrBuf *conversation;
  47 };
  48
  49 struct imlog *imlist = NULL;
  50
  51 /*
  52  * This function handles the logging of instant messages to disk.
  53  */
  54 void log_instant_message(struct CitContext *me, struct CitContext *them, char *msgtext, int serial_number)
  55 {
  56         long usernums[2];
  57         long t;
  58         struct imlog *iptr = NULL;
  59         struct imlog *this_im = NULL;
  60
  61         memset(usernums, 0, sizeof usernums);
  62         usernums[0] = me->user.usernum;
  63         usernums[1] = them->user.usernum;
  64
  65         /* Always put the lower user number first, so we can use the array as a hash value which
  66          * represents a pair of users.  For a broadcast message one of the users will be 0.
  67          */
  68         if (usernums[0] > usernums[1]) {
  69                 t = usernums[0];
  70                 usernums[0] = usernums[1];
  71                 usernums[1] = t;
  72         }
  73
  74         begin_critical_section(S_IM_LOGS);
  75
  76         /* Look for an existing conversation in the hash table.
  77          * If not found, create a new one.
  78          */
  79
  80         this_im = NULL;
  81         for (iptr = imlist; iptr != NULL; iptr = iptr->next) {
  82                 if ((iptr->usernums[0] == usernums[0]) && (iptr->usernums[1] == usernums[1])) {
  83                         /* Existing conversation */
  84                         this_im = iptr;
  85                 }
  86         }
  87         if (this_im == NULL) {
  88                 /* New conversation */
  89                 this_im = malloc(sizeof(struct imlog));
  90                 memset(this_im, 0, sizeof (struct imlog));
  91                 this_im->usernums[0] = usernums[0];
  92                 this_im->usernums[1] = usernums[1];
  93                 /* usernames[] and usernums[] might not be in the same order.  This is not an error. */
  94                 if (me) {
  95                         safestrncpy(this_im->usernames[0], me->user.fullname, sizeof this_im->usernames[0]);
  96                 }
  97                 if (them) {
  98                         safestrncpy(this_im->usernames[1], them->user.fullname, sizeof this_im->usernames[1]);
  99                 }
 100                 this_im->conversation = NewStrBuf();
 101                 this_im->next = imlist;
 102                 imlist = this_im;
 103                 StrBufAppendBufPlain(this_im->conversation, HKEY("<html><body>\r\n"), 0);
 104         }
 105
 106         /* Since it's possible for this function to get called more than once if a user is logged
 107          * in on multiple sessions, we use the message's serial number to keep track of whether
 108          * we've already logged it.
 109          */
 110         if (this_im->last_serial != serial_number)
 111         {
 112                 this_im->lastmsg = time(NULL);          /* Touch the timestamp so we know when to flush */
 113                 this_im->last_serial = serial_number;
 114                 StrBufAppendBufPlain(this_im->conversation, HKEY("<p><b>"), 0);
 115                 StrBufAppendBufPlain(this_im->conversation, me->user.fullname, -1, 0);
 116                 StrBufAppendBufPlain(this_im->conversation, HKEY(":</b> "), 0);
 117                 StrEscAppend(this_im->conversation, NULL, msgtext, 0, 0);
 118                 StrBufAppendBufPlain(this_im->conversation, HKEY("</p>\r\n"), 0);
 119         }
 120         end_critical_section(S_IM_LOGS);
 121 }
 122
 123
 124 /*
 125  * Delete any remaining instant messages
 126  */
 127 void delete_instant_messages(void) {
 128         struct ExpressMessage *ptr;
 129
 130         begin_critical_section(S_SESSION_TABLE);
 131         while (CC->FirstExpressMessage != NULL) {
 132                 ptr = CC->FirstExpressMessage->next;
 133                 if (CC->FirstExpressMessage->text != NULL)
 134                         free(CC->FirstExpressMessage->text);
 135                 free(CC->FirstExpressMessage);
 136                 CC->FirstExpressMessage = ptr;
 137         }
 138         end_critical_section(S_SESSION_TABLE);
 139 }
 140
 141
 142 /*
 143  * Retrieve instant messages
 144  */
 145 void cmd_gexp(char *argbuf) {
 146         struct ExpressMessage *ptr;
 147
 148         if (CC->FirstExpressMessage == NULL) {
 149                 cprintf("%d No instant messages waiting.\n", ERROR + MESSAGE_NOT_FOUND);
 150                 return;
 151         }
 152
 153         begin_critical_section(S_SESSION_TABLE);
 154         ptr = CC->FirstExpressMessage;
 155         CC->FirstExpressMessage = CC->FirstExpressMessage->next;
 156         end_critical_section(S_SESSION_TABLE);
 157
 158         cprintf("%d %d|%ld|%d|%s|%s|%s\n",
 159                 LISTING_FOLLOWS,
 160                 ((ptr->next != NULL) ? 1 : 0),          /* more msgs? */
 161                 (long)ptr->timestamp,                   /* time sent */
 162                 ptr->flags,                             /* flags */
 163                 ptr->sender,                            /* sender of msg */
 164                 CtdlGetConfigStr("c_nodename"),         /* static for now (and possibly deprecated) */
 165                 ptr->sender_email                       /* email or jid of sender */
 166         );
 167
 168         if (ptr->text != NULL) {
 169                 memfmout(ptr->text, "\n");
 170                 free(ptr->text);
 171         }
 172
 173         cprintf("000\n");
 174         free(ptr);
 175 }
 176
 177
 178 /*
 179  * Asynchronously deliver instant messages
 180  */
 181 void cmd_gexp_async(void) {
 182
 183         /* Only do this if the session can handle asynchronous protocol */
 184         if (CC->is_async == 0) return;
 185
 186         /* And don't do it if there's nothing to send. */
 187         if (CC->FirstExpressMessage == NULL) return;
 188
 189         cprintf("%d instant msg\n", ASYNC_MSG + ASYNC_GEXP);
 190 }
 191
 192
 193 /*
 194  * Back end support function for send_instant_message() and company
 195  */
 196 void add_xmsg_to_context(struct CitContext *ccptr, struct ExpressMessage *newmsg)
 197 {
 198         struct ExpressMessage *findend;
 199
 200         if (ccptr->FirstExpressMessage == NULL) {
 201                 ccptr->FirstExpressMessage = newmsg;
 202         }
 203         else {
 204                 findend = ccptr->FirstExpressMessage;
 205                 while (findend->next != NULL) {
 206                         findend = findend->next;
 207                 }
 208                 findend->next = newmsg;
 209         }
 210
 211         /* If the target context is a session which can handle asynchronous
 212          * messages, go ahead and set the flag for that.
 213          */
 214         set_async_waiting(ccptr);
 215 }
 216
 217
 218 /*
 219  * This is the back end to the instant message sending function.
 220  * Returns the number of users to which the message was sent.
 221  * Sending a zero-length message tests for recipients without sending messages.
 222  */
 223 int send_instant_message(char *lun, char *lem, char *x_user, char *x_msg)
 224 {
 225         int message_sent = 0;           /* number of successful sends */
 226         struct CitContext *ccptr;
 227         struct ExpressMessage *newmsg = NULL;
 228         int do_send = 0;                /* 1 = send message; 0 = only check for valid recipient */
 229         static int serial_number = 0;   /* this keeps messages from getting logged twice */
 230
 231         if (!IsEmptyStr(x_msg)) {
 232                 do_send = 1;
 233         }
 234
 235         /* find the target user's context and append the message */
 236         begin_critical_section(S_SESSION_TABLE);
 237         ++serial_number;
 238         for (ccptr = ContextList; ccptr != NULL; ccptr = ccptr->next) {
 239
 240                 if ( ((!strcasecmp(ccptr->user.fullname, x_user))
 241                     || (!strcasecmp(x_user, "broadcast")))
 242                     && (ccptr->can_receive_im)
 243                     && ((ccptr->disable_exp == 0)
 244                     || (CC->user.axlevel >= AxAideU)) ) {
 245                         if (do_send) {
 246                                 newmsg = (struct ExpressMessage *) malloc(sizeof (struct ExpressMessage));
 247                                 memset(newmsg, 0, sizeof (struct ExpressMessage));
 248                                 time(&(newmsg->timestamp));
 249                                 safestrncpy(newmsg->sender, lun, sizeof newmsg->sender);
 250                                 safestrncpy(newmsg->sender_email, lem, sizeof newmsg->sender_email);
 251                                 if (!strcasecmp(x_user, "broadcast")) {
 252                                         newmsg->flags |= EM_BROADCAST;
 253                                 }
 254                                 newmsg->text = strdup(x_msg);
 255
 256                                 add_xmsg_to_context(ccptr, newmsg);
 257
 258                                 /* and log it ... */
 259                                 if (ccptr != CC) {
 260                                         log_instant_message(CC, ccptr, newmsg->text, serial_number);
 261                                 }
 262                         }
 263                         ++message_sent;
 264                 }
 265         }
 266         end_critical_section(S_SESSION_TABLE);
 267         return (message_sent);
 268 }
 269
 270
 271 /*
 272  * send instant messages
 273  */
 274 void cmd_sexp(char *argbuf)
 275 {
 276         int message_sent = 0;
 277         char x_user[USERNAME_SIZE];
 278         char x_msg[1024];
 279         char *lem;
 280         char *x_big_msgbuf = NULL;
 281
 282         if ((!(CC->logged_in)) && (!(CC->internal_pgm))) {
 283                 cprintf("%d Not logged in.\n", ERROR + NOT_LOGGED_IN);
 284                 return;
 285         }
 286
 287         lem = CC->cs_principal_id;
 288
 289         extract_token(x_user, argbuf, 0, '|', sizeof x_user);
 290         extract_token(x_msg, argbuf, 1, '|', sizeof x_msg);
 291
 292         if (!x_user[0]) {
 293                 cprintf("%d You were not previously paged.\n", ERROR + NO_SUCH_USER);
 294                 return;
 295         }
 296         if ((!strcasecmp(x_user, "broadcast")) && (CC->user.axlevel < AxAideU)) {
 297                 cprintf("%d Higher access required to send a broadcast.\n",
 298                         ERROR + HIGHER_ACCESS_REQUIRED);
 299                 return;
 300         }
 301         /* This loop handles text-transfer pages */
 302         if (!strcmp(x_msg, "-")) {
 303                 message_sent = PerformXmsgHooks(CC->user.fullname, lem, x_user, "");
 304                 if (message_sent == 0) {
 305                         if (CtdlGetUser(NULL, x_user))
 306                                 cprintf("%d '%s' does not exist.\n",
 307                                                 ERROR + NO_SUCH_USER, x_user);
 308                         else
 309                                 cprintf("%d '%s' is not logged in "
 310                                                 "or is not accepting pages.\n",
 311                                                 ERROR + RESOURCE_NOT_OPEN, x_user);
 312                         return;
 313                 }
 314                 unbuffer_output();
 315                 cprintf("%d Transmit message (will deliver to %d users)\n",
 316                         SEND_LISTING, message_sent);
 317                 x_big_msgbuf = malloc(SIZ);
 318                 memset(x_big_msgbuf, 0, SIZ);
 319                 while (client_getln(x_msg, sizeof x_msg) >= 0 && strcmp(x_msg, "000")) {
 320                         x_big_msgbuf = realloc(x_big_msgbuf,
 321                                strlen(x_big_msgbuf) + strlen(x_msg) + 4);
 322                         if (!IsEmptyStr(x_big_msgbuf))
 323                            if (x_big_msgbuf[strlen(x_big_msgbuf)] != '\n')
 324                                 strcat(x_big_msgbuf, "\n");
 325                         strcat(x_big_msgbuf, x_msg);
 326                 }
 327                 PerformXmsgHooks(CC->user.fullname, lem, x_user, x_big_msgbuf);
 328                 free(x_big_msgbuf);
 329
 330                 /* This loop handles inline pages */
 331         } else {
 332                 message_sent = PerformXmsgHooks(CC->user.fullname, lem, x_user, x_msg);
 333
 334                 if (message_sent > 0) {
 335                         if (!IsEmptyStr(x_msg)) {
 336                                 cprintf("%d Message sent", CIT_OK);
 337                         }
 338                         else {
 339                                 cprintf("%d Ok to send message", CIT_OK);
 340                         }
 341                         if (message_sent > 1) {
 342                                 cprintf(" to %d users", message_sent);
 343                         }
 344                         cprintf(".\n");
 345                 } else {
 346                         if (CtdlGetUser(NULL, x_user)) {
 347                                 cprintf("%d '%s' does not exist.\n", ERROR + NO_SUCH_USER, x_user);
 348                         }
 349                         else {
 350                                 cprintf("%d '%s' is not logged in or is not accepting instant messages.\n",
 351                                                 ERROR + RESOURCE_NOT_OPEN, x_user);
 352                         }
 353                 }
 354
 355
 356         }
 357 }
 358
 359
 360 /*
 361  * Enter or exit paging-disabled mode
 362  */
 363 void cmd_dexp(char *argbuf)
 364 {
 365         int new_state;
 366
 367         if (CtdlAccessCheck(ac_logged_in)) return;
 368
 369         new_state = extract_int(argbuf, 0);
 370         if ((new_state == 0) || (new_state == 1)) {
 371                 CC->disable_exp = new_state;
 372         }
 373
 374         cprintf("%d %d\n", CIT_OK, CC->disable_exp);
 375 }
 376
 377
 378 /*
 379  * Request client termination
 380  */
 381 void cmd_reqt(char *argbuf) {
 382         struct CitContext *ccptr;
 383         int sessions = 0;
 384         int which_session;
 385         struct ExpressMessage *newmsg;
 386
 387         if (CtdlAccessCheck(ac_aide)) return;
 388         which_session = extract_int(argbuf, 0);
 389
 390         begin_critical_section(S_SESSION_TABLE);
 391         for (ccptr = ContextList; ccptr != NULL; ccptr = ccptr->next) {
 392                 if ((ccptr->cs_pid == which_session) || (which_session == 0)) {
 393
 394                         newmsg = (struct ExpressMessage *)
 395                                 malloc(sizeof (struct ExpressMessage));
 396                         memset(newmsg, 0,
 397                                 sizeof (struct ExpressMessage));
 398                         time(&(newmsg->timestamp));
 399                         safestrncpy(newmsg->sender, CC->user.fullname,
 400                                     sizeof newmsg->sender);
 401                         newmsg->flags |= EM_GO_AWAY;
 402                         newmsg->text = strdup("Automatic logoff requested.");
 403
 404                         add_xmsg_to_context(ccptr, newmsg);
 405                         ++sessions;
 406
 407                 }
 408         }
 409         end_critical_section(S_SESSION_TABLE);
 410         cprintf("%d Sent termination request to %d sessions.\n", CIT_OK, sessions);
 411 }
 412
 413
 414 /*
 415  * This is the back end for flush_conversations_to_disk()
 416  * At this point we've isolated a single conversation (struct imlog)
 417  * and are ready to write it to disk.
 418  */
 419 void flush_individual_conversation(struct imlog *im) {
 420         struct CtdlMessage *msg;
 421         long msgnum = 0;
 422         char roomname[ROOMNAMELEN];
 423         StrBuf *MsgBuf, *FullMsgBuf;
 424
 425         StrBufAppendBufPlain(im->conversation, HKEY(
 426                 "</body>\r\n"
 427                 "</html>\r\n"
 428                 ), 0
 429         );
 430
 431         MsgBuf = StrBufQuotedPrintableEncode(im->conversation);
 432         FlushStrBuf(im->conversation);
 433         FullMsgBuf = NewStrBufPlain(NULL, StrLength(im->conversation) + 100);
 434
 435         StrBufAppendBufPlain(FullMsgBuf, HKEY(
 436                 "Content-type: text/html; charset=UTF-8\r\n"
 437                 "Content-Transfer-Encoding: quoted-printable\r\n"
 438                 "\r\n"
 439                 ), 0
 440         );
 441         StrBufAppendBuf (FullMsgBuf, MsgBuf, 0);
 442         FreeStrBuf(&MsgBuf);
 443
 444         msg = malloc(sizeof(struct CtdlMessage));
 445         memset(msg, 0, sizeof(struct CtdlMessage));
 446         msg->cm_magic = CTDLMESSAGE_MAGIC;
 447         msg->cm_anon_type = MES_NORMAL;
 448         msg->cm_format_type = FMT_RFC822;
 449         if (!IsEmptyStr(im->usernames[0])) {
 450                 CM_SetField(msg, eAuthor, im->usernames[0], strlen(im->usernames[0]));
 451         } else {
 452                 CM_SetField(msg, eAuthor, HKEY("Citadel"));
 453         }
 454         if (!IsEmptyStr(im->usernames[1])) {
 455                 CM_SetField(msg, eRecipient, im->usernames[1], strlen(im->usernames[1]));
 456         }
 457
 458         CM_SetField(msg, eOriginalRoom, HKEY(PAGELOGROOM));
 459         CM_SetAsFieldSB(msg, eMesageText, &FullMsgBuf); /* we own this memory now */
 460
 461         /* Start with usernums[1] because it's guaranteed to be higher than usernums[0],
 462          * so if there's only one party, usernums[0] will be zero but usernums[1] won't.
 463          * Create the room if necessary.  Note that we create as a type 5 room rather
 464          * than 4, which indicates that it's a personal room but we've already supplied
 465          * the namespace prefix.
 466          *
 467          * In the unlikely event that usernums[1] is zero, a room with an invalid namespace
 468          * prefix will be created.  That's ok because the auto-purger will clean it up later.
 469          */
 470         snprintf(roomname, sizeof roomname, "%010ld.%s", im->usernums[1], PAGELOGROOM);
 471         CtdlCreateRoom(roomname, 5, "", 0, 1, 1, VIEW_BBS);
 472         msgnum = CtdlSubmitMsg(msg, NULL, roomname);
 473         CM_Free(msg);
 474
 475         /* If there is a valid user number in usernums[0], save a copy for them too. */
 476         if (im->usernums[0] > 0) {
 477                 snprintf(roomname, sizeof roomname, "%010ld.%s", im->usernums[0], PAGELOGROOM);
 478                 CtdlCreateRoom(roomname, 5, "", 0, 1, 1, VIEW_BBS);
 479                 CtdlSaveMsgPointerInRoom(roomname, msgnum, 0, NULL);
 480         }
 481
 482         /* Finally, if we're logging instant messages globally, do that now. */
 483         if (!IsEmptyStr(CtdlGetConfigStr("c_logpages"))) {
 484                 CtdlCreateRoom(CtdlGetConfigStr("c_logpages"), 3, "", 0, 1, 1, VIEW_BBS);
 485                 CtdlSaveMsgPointerInRoom(CtdlGetConfigStr("c_logpages"), msgnum, 0, NULL);
 486         }
 487
 488 }
 489
 490 /*
 491  * Locate instant message conversations which have gone idle
 492  * (or, if the server is shutting down, locate *all* conversations)
 493  * and flush them to disk (in the participants' log rooms, etc.)
 494  */
 495 void flush_conversations_to_disk(time_t if_older_than) {
 496
 497         struct imlog *flush_these = NULL;
 498         struct imlog *dont_flush_these = NULL;
 499         struct imlog *imptr = NULL;
 500         struct CitContext *nptr;
 501         int nContexts, i;
 502
 503         nptr = CtdlGetContextArray(&nContexts) ;        /* Make a copy of the current wholist */
 504
 505         begin_critical_section(S_IM_LOGS);
 506         while (imlist)
 507         {
 508                 imptr = imlist;
 509                 imlist = imlist->next;
 510
 511                 /* For a two party conversation, if one party has logged out, force flush. */
 512                 if (nptr) {
 513                         int user0_is_still_online = 0;
 514                         int user1_is_still_online = 0;
 515                         for (i=0; i<nContexts; i++)  {
 516                                 if (nptr[i].user.usernum == imptr->usernums[0]) ++user0_is_still_online;
 517                                 if (nptr[i].user.usernum == imptr->usernums[1]) ++user1_is_still_online;
 518                         }
 519                         if (imptr->usernums[0] != imptr->usernums[1]) {         /* two party conversation */
 520                                 if ((!user0_is_still_online) || (!user1_is_still_online)) {
 521                                         imptr->lastmsg = 0L;    /* force flush */
 522                                 }
 523                         }
 524                         else {          /* one party conversation (yes, people do IM themselves) */
 525                                 if (!user0_is_still_online) {
 526                                         imptr->lastmsg = 0L;    /* force flush */
 527                                 }
 528                         }
 529                 }
 530
 531                 /* Now test this conversation to see if it qualifies for flushing. */
 532                 if ((time(NULL) - imptr->lastmsg) > if_older_than)
 533                 {
 534                         /* This conversation qualifies.  Move it to the list of ones to flush. */
 535                         imptr->next = flush_these;
 536                         flush_these = imptr;
 537                 }
 538                 else  {
 539                         /* Move it to the list of ones not to flush. */
 540                         imptr->next = dont_flush_these;
 541                         dont_flush_these = imptr;
 542                 }
 543         }
 544         imlist = dont_flush_these;
 545         end_critical_section(S_IM_LOGS);
 546         free(nptr);
 547
 548         /* We are now outside of the critical section, and we are the only thread holding a
 549          * pointer to a linked list of conversations to be flushed to disk.
 550          */
 551         while (flush_these) {
 552
 553                 flush_individual_conversation(flush_these);     /* This will free the string buffer */
 554                 imptr = flush_these;
 555                 flush_these = flush_these->next;
 556                 free(imptr);
 557         }
 558 }
 559
 560
 561 void instmsg_timer(void) {
 562         flush_conversations_to_disk(300);       /* Anything that hasn't peeped in more than 5 minutes */
 563 }
 564
 565
 566 void instmsg_shutdown(void) {
 567         flush_conversations_to_disk(0);         /* Get it ALL onto disk NOW. */
 568 }
 569
 570
 571 // Initialization function, called from modules_init.c
 572 char *ctdl_module_init_instmsg(void) {
 573         if (!threading) {
 574                 CtdlRegisterProtoHook(cmd_gexp, "GEXP", "Get instant messages");
 575                 CtdlRegisterProtoHook(cmd_sexp, "SEXP", "Send an instant message");
 576                 CtdlRegisterProtoHook(cmd_dexp, "DEXP", "Disable instant messages");
 577                 CtdlRegisterProtoHook(cmd_reqt, "REQT", "Request client termination");
 578                 CtdlRegisterSessionHook(cmd_gexp_async, EVT_ASYNC, PRIO_ASYNC + 1);
 579                 CtdlRegisterSessionHook(delete_instant_messages, EVT_STOP, PRIO_STOP + 1);
 580                 CtdlRegisterXmsgHook(send_instant_message, XMSG_PRI_LOCAL);
 581                 CtdlRegisterSessionHook(instmsg_timer, EVT_TIMER, PRIO_CLEANUP + 400);
 582                 CtdlRegisterSessionHook(instmsg_shutdown, EVT_SHUTDOWN, PRIO_SHUTDOWN + 10);
 583         }
 584
 585         /* return our module name for the log */
 586         return "instmsg";
 587 }