citadel/modules/instmsg/serv_instmsg.c

   1 /*
   2  * This module handles instant messaging between users.
   3  *
   4  * Copyright (c) 1987-2020 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 #include <time.h>
  25 #include <sys/wait.h>
  26 #include <string.h>
  27 #include <limits.h>
  28 #include <libcitadel.h>
  29 #include "citadel.h"
  30 #include "server.h"
  31 #include "serv_instmsg.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
  39 struct imlog {
  40         struct imlog *next;
  41         long usernums[2];
  42         char usernames[2][128];
  43         time_t lastmsg;
  44         int last_serial;
  45         StrBuf *conversation;
  46 };
  47
  48 struct imlog *imlist = NULL;
  49
  50 /*
  51  * This function handles the logging of instant messages to disk.
  52  */
  53 void log_instant_message(struct CitContext *me, struct CitContext *them, char *msgtext, int serial_number)
  54 {
  55         long usernums[2];
  56         long t;
  57         struct imlog *iptr = NULL;
  58         struct imlog *this_im = NULL;
  59
  60         memset(usernums, 0, sizeof usernums);
  61         usernums[0] = me->user.usernum;
  62         usernums[1] = them->user.usernum;
  63
  64         /* Always put the lower user number first, so we can use the array as a hash value which
  65          * represents a pair of users.  For a broadcast message one of the users will be 0.
  66          */
  67         if (usernums[0] > usernums[1]) {
  68                 t = usernums[0];
  69                 usernums[0] = usernums[1];
  70                 usernums[1] = t;
  71         }
  72
  73         begin_critical_section(S_IM_LOGS);
  74
  75         /* Look for an existing conversation in the hash table.
  76          * If not found, create a new one.
  77          */
  78
  79         this_im = NULL;
  80         for (iptr = imlist; iptr != NULL; iptr = iptr->next) {
  81                 if ((iptr->usernums[0] == usernums[0]) && (iptr->usernums[1] == usernums[1])) {
  82                         /* Existing conversation */
  83                         this_im = iptr;
  84                 }
  85         }
  86         if (this_im == NULL) {
  87                 /* New conversation */
  88                 this_im = malloc(sizeof(struct imlog));
  89                 memset(this_im, 0, sizeof (struct imlog));
  90                 this_im->usernums[0] = usernums[0];
  91                 this_im->usernums[1] = usernums[1];
  92                 /* usernames[] and usernums[] might not be in the same order.  This is not an error. */
  93                 if (me) {
  94                         safestrncpy(this_im->usernames[0], me->user.fullname, sizeof this_im->usernames[0]);
  95                 }
  96                 if (them) {
  97                         safestrncpy(this_im->usernames[1], them->user.fullname, sizeof this_im->usernames[1]);
  98                 }
  99                 this_im->conversation = NewStrBuf();
 100                 this_im->next = imlist;
 101                 imlist = this_im;
 102                 StrBufAppendBufPlain(this_im->conversation, HKEY("<html><body>\r\n"), 0);
 103         }
 104
 105         /* Since it's possible for this function to get called more than once if a user is logged
 106          * in on multiple sessions, we use the message's serial number to keep track of whether
 107          * we've already logged it.
 108          */
 109         if (this_im->last_serial != serial_number)
 110         {
 111                 this_im->lastmsg = time(NULL);          /* Touch the timestamp so we know when to flush */
 112                 this_im->last_serial = serial_number;
 113                 StrBufAppendBufPlain(this_im->conversation, HKEY("<p><b>"), 0);
 114                 StrBufAppendBufPlain(this_im->conversation, me->user.fullname, -1, 0);
 115                 StrBufAppendBufPlain(this_im->conversation, HKEY(":</b> "), 0);
 116                 StrEscAppend(this_im->conversation, NULL, msgtext, 0, 0);
 117                 StrBufAppendBufPlain(this_im->conversation, HKEY("</p>\r\n"), 0);
 118         }
 119         end_critical_section(S_IM_LOGS);
 120 }
 121
 122
 123 /*
 124  * Delete any remaining instant messages
 125  */
 126 void delete_instant_messages(void) {
 127         struct ExpressMessage *ptr;
 128
 129         begin_critical_section(S_SESSION_TABLE);
 130         while (CC->FirstExpressMessage != NULL) {
 131                 ptr = CC->FirstExpressMessage->next;
 132                 if (CC->FirstExpressMessage->text != NULL)
 133                         free(CC->FirstExpressMessage->text);
 134                 free(CC->FirstExpressMessage);
 135                 CC->FirstExpressMessage = ptr;
 136         }
 137         end_critical_section(S_SESSION_TABLE);
 138 }
 139
 140
 141 /*
 142  * Retrieve instant messages
 143  */
 144 void cmd_gexp(char *argbuf) {
 145         struct ExpressMessage *ptr;
 146
 147         if (CC->FirstExpressMessage == NULL) {
 148                 cprintf("%d No instant messages waiting.\n", ERROR + MESSAGE_NOT_FOUND);
 149                 return;
 150         }
 151
 152         begin_critical_section(S_SESSION_TABLE);
 153         ptr = CC->FirstExpressMessage;
 154         CC->FirstExpressMessage = CC->FirstExpressMessage->next;
 155         end_critical_section(S_SESSION_TABLE);
 156
 157         cprintf("%d %d|%ld|%d|%s|%s|%s\n",
 158                 LISTING_FOLLOWS,
 159                 ((ptr->next != NULL) ? 1 : 0),          /* more msgs? */
 160                 (long)ptr->timestamp,                   /* time sent */
 161                 ptr->flags,                             /* flags */
 162                 ptr->sender,                            /* sender of msg */
 163                 CtdlGetConfigStr("c_nodename"),         /* static for now (and possibly deprecated) */
 164                 ptr->sender_email                       /* email or jid of sender */
 165         );
 166
 167         if (ptr->text != NULL) {
 168                 memfmout(ptr->text, "\n");
 169                 free(ptr->text);
 170         }
 171
 172         cprintf("000\n");
 173         free(ptr);
 174 }
 175
 176
 177 /*
 178  * Asynchronously deliver instant messages
 179  */
 180 void cmd_gexp_async(void) {
 181
 182         /* Only do this if the session can handle asynchronous protocol */
 183         if (CC->is_async == 0) return;
 184
 185         /* And don't do it if there's nothing to send. */
 186         if (CC->FirstExpressMessage == NULL) return;
 187
 188         cprintf("%d instant msg\n", ASYNC_MSG + ASYNC_GEXP);
 189 }
 190
 191
 192 /*
 193  * Back end support function for send_instant_message() and company
 194  */
 195 void add_xmsg_to_context(struct CitContext *ccptr, struct ExpressMessage *newmsg)
 196 {
 197         struct ExpressMessage *findend;
 198
 199         if (ccptr->FirstExpressMessage == NULL) {
 200                 ccptr->FirstExpressMessage = newmsg;
 201         }
 202         else {
 203                 findend = ccptr->FirstExpressMessage;
 204                 while (findend->next != NULL) {
 205                         findend = findend->next;
 206                 }
 207                 findend->next = newmsg;
 208         }
 209
 210         /* If the target context is a session which can handle asynchronous
 211          * messages, go ahead and set the flag for that.
 212          */
 213         set_async_waiting(ccptr);
 214 }
 215
 216
 217 /*
 218  * This is the back end to the instant message sending function.
 219  * Returns the number of users to which the message was sent.
 220  * Sending a zero-length message tests for recipients without sending messages.
 221  */
 222 int send_instant_message(char *lun, char *lem, char *x_user, char *x_msg)
 223 {
 224         int message_sent = 0;           /* number of successful sends */
 225         struct CitContext *ccptr;
 226         struct ExpressMessage *newmsg = NULL;
 227         int do_send = 0;                /* 1 = send message; 0 = only check for valid recipient */
 228         static int serial_number = 0;   /* this keeps messages from getting logged twice */
 229
 230         if (!IsEmptyStr(x_msg)) {
 231                 do_send = 1;
 232         }
 233
 234         /* find the target user's context and append the message */
 235         begin_critical_section(S_SESSION_TABLE);
 236         ++serial_number;
 237         for (ccptr = ContextList; ccptr != NULL; ccptr = ccptr->next) {
 238
 239                 if ( ((!strcasecmp(ccptr->user.fullname, x_user))
 240                     || (!strcasecmp(x_user, "broadcast")))
 241                     && (ccptr->can_receive_im)
 242                     && ((ccptr->disable_exp == 0)
 243                     || (CC->user.axlevel >= AxAideU)) ) {
 244                         if (do_send) {
 245                                 newmsg = (struct ExpressMessage *) malloc(sizeof (struct ExpressMessage));
 246                                 memset(newmsg, 0, sizeof (struct ExpressMessage));
 247                                 time(&(newmsg->timestamp));
 248                                 safestrncpy(newmsg->sender, lun, sizeof newmsg->sender);
 249                                 safestrncpy(newmsg->sender_email, lem, sizeof newmsg->sender_email);
 250                                 if (!strcasecmp(x_user, "broadcast")) {
 251                                         newmsg->flags |= EM_BROADCAST;
 252                                 }
 253                                 newmsg->text = strdup(x_msg);
 254
 255                                 add_xmsg_to_context(ccptr, newmsg);
 256
 257                                 /* and log it ... */
 258                                 if (ccptr != CC) {
 259                                         log_instant_message(CC, ccptr, newmsg->text, serial_number);
 260                                 }
 261                         }
 262                         ++message_sent;
 263                 }
 264         }
 265         end_critical_section(S_SESSION_TABLE);
 266         return (message_sent);
 267 }
 268
 269
 270 /*
 271  * send instant messages
 272  */
 273 void cmd_sexp(char *argbuf)
 274 {
 275         int message_sent = 0;
 276         char x_user[USERNAME_SIZE];
 277         char x_msg[1024];
 278         char *lem;
 279         char *x_big_msgbuf = NULL;
 280
 281         if ((!(CC->logged_in)) && (!(CC->internal_pgm))) {
 282                 cprintf("%d Not logged in.\n", ERROR + NOT_LOGGED_IN);
 283                 return;
 284         }
 285
 286         lem = CC->cs_principal_id;
 287
 288         extract_token(x_user, argbuf, 0, '|', sizeof x_user);
 289         extract_token(x_msg, argbuf, 1, '|', sizeof x_msg);
 290
 291         if (!x_user[0]) {
 292                 cprintf("%d You were not previously paged.\n", ERROR + NO_SUCH_USER);
 293                 return;
 294         }
 295         if ((!strcasecmp(x_user, "broadcast")) && (CC->user.axlevel < AxAideU)) {
 296                 cprintf("%d Higher access required to send a broadcast.\n",
 297                         ERROR + HIGHER_ACCESS_REQUIRED);
 298                 return;
 299         }
 300         /* This loop handles text-transfer pages */
 301         if (!strcmp(x_msg, "-")) {
 302                 message_sent = PerformXmsgHooks(CC->user.fullname, lem, x_user, "");
 303                 if (message_sent == 0) {
 304                         if (CtdlGetUser(NULL, x_user))
 305                                 cprintf("%d '%s' does not exist.\n",
 306                                                 ERROR + NO_SUCH_USER, x_user);
 307                         else
 308                                 cprintf("%d '%s' is not logged in "
 309                                                 "or is not accepting pages.\n",
 310                                                 ERROR + RESOURCE_NOT_OPEN, x_user);
 311                         return;
 312                 }
 313                 unbuffer_output();
 314                 cprintf("%d Transmit message (will deliver to %d users)\n",
 315                         SEND_LISTING, message_sent);
 316                 x_big_msgbuf = malloc(SIZ);
 317                 memset(x_big_msgbuf, 0, SIZ);
 318                 while (client_getln(x_msg, sizeof x_msg) >= 0 && strcmp(x_msg, "000")) {
 319                         x_big_msgbuf = realloc(x_big_msgbuf,
 320                                strlen(x_big_msgbuf) + strlen(x_msg) + 4);
 321                         if (!IsEmptyStr(x_big_msgbuf))
 322                            if (x_big_msgbuf[strlen(x_big_msgbuf)] != '\n')
 323                                 strcat(x_big_msgbuf, "\n");
 324                         strcat(x_big_msgbuf, x_msg);
 325                 }
 326                 PerformXmsgHooks(CC->user.fullname, lem, x_user, x_big_msgbuf);
 327                 free(x_big_msgbuf);
 328
 329                 /* This loop handles inline pages */
 330         } else {
 331                 message_sent = PerformXmsgHooks(CC->user.fullname, lem, x_user, x_msg);
 332
 333                 if (message_sent > 0) {
 334                         if (!IsEmptyStr(x_msg)) {
 335                                 cprintf("%d Message sent", CIT_OK);
 336                         }
 337                         else {
 338                                 cprintf("%d Ok to send message", CIT_OK);
 339                         }
 340                         if (message_sent > 1) {
 341                                 cprintf(" to %d users", message_sent);
 342                         }
 343                         cprintf(".\n");
 344                 } else {
 345                         if (CtdlGetUser(NULL, x_user)) {
 346                                 cprintf("%d '%s' does not exist.\n", ERROR + NO_SUCH_USER, x_user);
 347                         }
 348                         else {
 349                                 cprintf("%d '%s' is not logged in or is not accepting instant messages.\n",
 350                                                 ERROR + RESOURCE_NOT_OPEN, x_user);
 351                         }
 352                 }
 353
 354
 355         }
 356 }
 357
 358
 359 /*
 360  * Enter or exit paging-disabled mode
 361  */
 362 void cmd_dexp(char *argbuf)
 363 {
 364         int new_state;
 365
 366         if (CtdlAccessCheck(ac_logged_in)) return;
 367
 368         new_state = extract_int(argbuf, 0);
 369         if ((new_state == 0) || (new_state == 1)) {
 370                 CC->disable_exp = new_state;
 371         }
 372
 373         cprintf("%d %d\n", CIT_OK, CC->disable_exp);
 374 }
 375
 376
 377 /*
 378  * Request client termination
 379  */
 380 void cmd_reqt(char *argbuf) {
 381         struct CitContext *ccptr;
 382         int sessions = 0;
 383         int which_session;
 384         struct ExpressMessage *newmsg;
 385
 386         if (CtdlAccessCheck(ac_aide)) return;
 387         which_session = extract_int(argbuf, 0);
 388
 389         begin_critical_section(S_SESSION_TABLE);
 390         for (ccptr = ContextList; ccptr != NULL; ccptr = ccptr->next) {
 391                 if ((ccptr->cs_pid == which_session) || (which_session == 0)) {
 392
 393                         newmsg = (struct ExpressMessage *)
 394                                 malloc(sizeof (struct ExpressMessage));
 395                         memset(newmsg, 0,
 396                                 sizeof (struct ExpressMessage));
 397                         time(&(newmsg->timestamp));
 398                         safestrncpy(newmsg->sender, CC->user.fullname,
 399                                     sizeof newmsg->sender);
 400                         newmsg->flags |= EM_GO_AWAY;
 401                         newmsg->text = strdup("Automatic logoff requested.");
 402
 403                         add_xmsg_to_context(ccptr, newmsg);
 404                         ++sessions;
 405
 406                 }
 407         }
 408         end_critical_section(S_SESSION_TABLE);
 409         cprintf("%d Sent termination request to %d sessions.\n", CIT_OK, sessions);
 410 }
 411
 412
 413 /*
 414  * This is the back end for flush_conversations_to_disk()
 415  * At this point we've isolated a single conversation (struct imlog)
 416  * and are ready to write it to disk.
 417  */
 418 void flush_individual_conversation(struct imlog *im) {
 419         struct CtdlMessage *msg;
 420         long msgnum = 0;
 421         char roomname[ROOMNAMELEN];
 422         StrBuf *MsgBuf, *FullMsgBuf;
 423
 424         StrBufAppendBufPlain(im->conversation, HKEY(
 425                 "</body>\r\n"
 426                 "</html>\r\n"
 427                 ), 0
 428         );
 429
 430         MsgBuf = StrBufRFC2047encodeMessage(im->conversation);
 431         FlushStrBuf(im->conversation);
 432         FullMsgBuf = NewStrBufPlain(NULL, StrLength(im->conversation) + 100);
 433
 434         StrBufAppendBufPlain(FullMsgBuf, HKEY(
 435                 "Content-type: text/html; charset=UTF-8\r\n"
 436                 "Content-Transfer-Encoding: quoted-printable\r\n"
 437                 "\r\n"
 438                 ), 0
 439         );
 440         StrBufAppendBuf (FullMsgBuf, MsgBuf, 0);
 441         FreeStrBuf(&MsgBuf);
 442
 443         msg = malloc(sizeof(struct CtdlMessage));
 444         memset(msg, 0, sizeof(struct CtdlMessage));
 445         msg->cm_magic = CTDLMESSAGE_MAGIC;
 446         msg->cm_anon_type = MES_NORMAL;
 447         msg->cm_format_type = FMT_RFC822;
 448         if (!IsEmptyStr(im->usernames[0])) {
 449                 CM_SetField(msg, eAuthor, im->usernames[0], strlen(im->usernames[0]));
 450         } else {
 451                 CM_SetField(msg, eAuthor, HKEY("Citadel"));
 452         }
 453         if (!IsEmptyStr(im->usernames[1])) {
 454                 CM_SetField(msg, eRecipient, im->usernames[1], strlen(im->usernames[1]));
 455         }
 456
 457         CM_SetField(msg, eOriginalRoom, HKEY(PAGELOGROOM));
 458         CM_SetAsFieldSB(msg, eMesageText, &FullMsgBuf); /* we own this memory now */
 459
 460         /* Start with usernums[1] because it's guaranteed to be higher than usernums[0],
 461          * so if there's only one party, usernums[0] will be zero but usernums[1] won't.
 462          * Create the room if necessary.  Note that we create as a type 5 room rather
 463          * than 4, which indicates that it's a personal room but we've already supplied
 464          * the namespace prefix.
 465          *
 466          * In the unlikely event that usernums[1] is zero, a room with an invalid namespace
 467          * prefix will be created.  That's ok because the auto-purger will clean it up later.
 468          */
 469         snprintf(roomname, sizeof roomname, "%010ld.%s", im->usernums[1], PAGELOGROOM);
 470         CtdlCreateRoom(roomname, 5, "", 0, 1, 1, VIEW_BBS);
 471         msgnum = CtdlSubmitMsg(msg, NULL, roomname);
 472         CM_Free(msg);
 473
 474         /* If there is a valid user number in usernums[0], save a copy for them too. */
 475         if (im->usernums[0] > 0) {
 476                 snprintf(roomname, sizeof roomname, "%010ld.%s", im->usernums[0], PAGELOGROOM);
 477                 CtdlCreateRoom(roomname, 5, "", 0, 1, 1, VIEW_BBS);
 478                 CtdlSaveMsgPointerInRoom(roomname, msgnum, 0, NULL);
 479         }
 480
 481         /* Finally, if we're logging instant messages globally, do that now. */
 482         if (!IsEmptyStr(CtdlGetConfigStr("c_logpages"))) {
 483                 CtdlCreateRoom(CtdlGetConfigStr("c_logpages"), 3, "", 0, 1, 1, VIEW_BBS);
 484                 CtdlSaveMsgPointerInRoom(CtdlGetConfigStr("c_logpages"), msgnum, 0, NULL);
 485         }
 486
 487 }
 488
 489 /*
 490  * Locate instant message conversations which have gone idle
 491  * (or, if the server is shutting down, locate *all* conversations)
 492  * and flush them to disk (in the participants' log rooms, etc.)
 493  */
 494 void flush_conversations_to_disk(time_t if_older_than) {
 495
 496         struct imlog *flush_these = NULL;
 497         struct imlog *dont_flush_these = NULL;
 498         struct imlog *imptr = NULL;
 499         struct CitContext *nptr;
 500         int nContexts, i;
 501
 502         nptr = CtdlGetContextArray(&nContexts) ;        /* Make a copy of the current wholist */
 503
 504         begin_critical_section(S_IM_LOGS);
 505         while (imlist)
 506         {
 507                 imptr = imlist;
 508                 imlist = imlist->next;
 509
 510                 /* For a two party conversation, if one party has logged out, force flush. */
 511                 if (nptr) {
 512                         int user0_is_still_online = 0;
 513                         int user1_is_still_online = 0;
 514                         for (i=0; i<nContexts; i++)  {
 515                                 if (nptr[i].user.usernum == imptr->usernums[0]) ++user0_is_still_online;
 516                                 if (nptr[i].user.usernum == imptr->usernums[1]) ++user1_is_still_online;
 517                         }
 518                         if (imptr->usernums[0] != imptr->usernums[1]) {         /* two party conversation */
 519                                 if ((!user0_is_still_online) || (!user1_is_still_online)) {
 520                                         imptr->lastmsg = 0L;    /* force flush */
 521                                 }
 522                         }
 523                         else {          /* one party conversation (yes, people do IM themselves) */
 524                                 if (!user0_is_still_online) {
 525                                         imptr->lastmsg = 0L;    /* force flush */
 526                                 }
 527                         }
 528                 }
 529
 530                 /* Now test this conversation to see if it qualifies for flushing. */
 531                 if ((time(NULL) - imptr->lastmsg) > if_older_than)
 532                 {
 533                         /* This conversation qualifies.  Move it to the list of ones to flush. */
 534                         imptr->next = flush_these;
 535                         flush_these = imptr;
 536                 }
 537                 else  {
 538                         /* Move it to the list of ones not to flush. */
 539                         imptr->next = dont_flush_these;
 540                         dont_flush_these = imptr;
 541                 }
 542         }
 543         imlist = dont_flush_these;
 544         end_critical_section(S_IM_LOGS);
 545         free(nptr);
 546
 547         /* We are now outside of the critical section, and we are the only thread holding a
 548          * pointer to a linked list of conversations to be flushed to disk.
 549          */
 550         while (flush_these) {
 551
 552                 flush_individual_conversation(flush_these);     /* This will free the string buffer */
 553                 imptr = flush_these;
 554                 flush_these = flush_these->next;
 555                 free(imptr);
 556         }
 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 void instmsg_shutdown(void) {
 566         flush_conversations_to_disk(0);         /* Get it ALL onto disk NOW. */
 567 }
 568
 569 CTDL_MODULE_INIT(instmsg)
 570 {
 571         if (!threading)
 572         {
 573                 CtdlRegisterProtoHook(cmd_gexp, "GEXP", "Get instant messages");
 574                 CtdlRegisterProtoHook(cmd_sexp, "SEXP", "Send an instant message");
 575                 CtdlRegisterProtoHook(cmd_dexp, "DEXP", "Disable instant messages");
 576                 CtdlRegisterProtoHook(cmd_reqt, "REQT", "Request client termination");
 577                 CtdlRegisterSessionHook(cmd_gexp_async, EVT_ASYNC, PRIO_ASYNC + 1);
 578                 CtdlRegisterSessionHook(delete_instant_messages, EVT_STOP, PRIO_STOP + 1);
 579                 CtdlRegisterXmsgHook(send_instant_message, XMSG_PRI_LOCAL);
 580                 CtdlRegisterSessionHook(instmsg_timer, EVT_TIMER, PRIO_CLEANUP + 400);
 581                 CtdlRegisterSessionHook(instmsg_shutdown, EVT_SHUTDOWN, PRIO_SHUTDOWN + 10);
 582         }
 583
 584         /* return our module name for the log */
 585         return "instmsg";
 586 }