citadel/server/modules/instmsg/serv_instmsg.c

   1 // This module handles instant messaging between users.
   2 //
   3 // Copyright (c) 1987-2023 by the citadel.org team
   4 //
   5 // This program is open source software.  Use, duplication, or disclosure
   6 // is subject to the terms of the GNU General Public License, version 3.
   7
   8 #include <stdlib.h>
   9 #include <unistd.h>
  10 #include <stdio.h>
  11 #include <fcntl.h>
  12 #include <signal.h>
  13 #include <pwd.h>
  14 #include <errno.h>
  15 #include <sys/types.h>
  16 #include <time.h>
  17 #include <sys/wait.h>
  18 #include <string.h>
  19 #include <limits.h>
  20 #include <libcitadel.h>
  21 #include "../../sysdep.h"
  22 #include "../../citadel_defs.h"
  23 #include "../../server.h"
  24 #include "../../context.h"
  25 #include "../../citserver.h"
  26 #include "../../support.h"
  27 #include "../../config.h"
  28 #include "../../msgbase.h"
  29 #include "../../user_ops.h"
  30 #include "../../ctdl_module.h"
  31 #include "serv_instmsg.h"
  32
  33 struct imlog {
  34         struct imlog *next;
  35         long usernums[2];
  36         char usernames[2][128];
  37         time_t lastmsg;
  38         int last_serial;
  39         StrBuf *conversation;
  40 };
  41
  42 struct imlog *imlist = NULL;
  43
  44 // This function handles the logging of instant messages to disk.
  45 void log_instant_message(struct CitContext *me, struct CitContext *them, char *msgtext, int serial_number) {
  46         long usernums[2];
  47         long t;
  48         struct imlog *iptr = NULL;
  49         struct imlog *this_im = NULL;
  50
  51         memset(usernums, 0, sizeof usernums);
  52         usernums[0] = me->user.usernum;
  53         usernums[1] = them->user.usernum;
  54
  55         // Always put the lower user number first, so we can use the array as a hash value which
  56         // represents a pair of users.  For a broadcast message one of the users will be 0.
  57         if (usernums[0] > usernums[1]) {
  58                 t = usernums[0];
  59                 usernums[0] = usernums[1];
  60                 usernums[1] = t;
  61         }
  62
  63         begin_critical_section(S_IM_LOGS);
  64
  65         // Look for an existing conversation in the hash table.
  66         // If not found, create a new one.
  67
  68         this_im = NULL;
  69         for (iptr = imlist; iptr != NULL; iptr = iptr->next) {
  70                 if ((iptr->usernums[0] == usernums[0]) && (iptr->usernums[1] == usernums[1])) {
  71                         /* Existing conversation */
  72                         this_im = iptr;
  73                 }
  74         }
  75         if (this_im == NULL) {
  76                 // New conversation
  77                 this_im = malloc(sizeof(struct imlog));
  78                 memset(this_im, 0, sizeof (struct imlog));
  79                 this_im->usernums[0] = usernums[0];
  80                 this_im->usernums[1] = usernums[1];
  81                 // usernames[] and usernums[] might not be in the same order.  This is not an error.
  82                 if (me) {
  83                         safestrncpy(this_im->usernames[0], me->user.fullname, sizeof this_im->usernames[0]);
  84                 }
  85                 if (them) {
  86                         safestrncpy(this_im->usernames[1], them->user.fullname, sizeof this_im->usernames[1]);
  87                 }
  88                 this_im->conversation = NewStrBuf();
  89                 this_im->next = imlist;
  90                 imlist = this_im;
  91                 StrBufAppendBufPlain(this_im->conversation, HKEY("<html><body>\r\n"), 0);
  92         }
  93
  94         // Since it's possible for this function to get called more than once if a user is logged
  95         // in on multiple sessions, we use the message's serial number to keep track of whether
  96         // we've already logged it.
  97         if (this_im->last_serial != serial_number) {
  98                 this_im->lastmsg = time(NULL);          // Touch the timestamp so we know when to flush
  99                 this_im->last_serial = serial_number;
 100                 StrBufAppendBufPlain(this_im->conversation, HKEY("<p><b>"), 0);
 101                 StrBufAppendBufPlain(this_im->conversation, me->user.fullname, -1, 0);
 102                 StrBufAppendBufPlain(this_im->conversation, HKEY(":</b> "), 0);
 103                 StrEscAppend(this_im->conversation, NULL, msgtext, 0, 0);
 104                 StrBufAppendBufPlain(this_im->conversation, HKEY("</p>\r\n"), 0);
 105         }
 106         end_critical_section(S_IM_LOGS);
 107 }
 108
 109
 110 // Delete any remaining instant messages
 111 void delete_instant_messages(void) {
 112         struct ExpressMessage *ptr;
 113
 114         begin_critical_section(S_SESSION_TABLE);
 115         while (CC->FirstExpressMessage != NULL) {
 116                 ptr = CC->FirstExpressMessage->next;
 117                 if (CC->FirstExpressMessage->text != NULL)
 118                         free(CC->FirstExpressMessage->text);
 119                 free(CC->FirstExpressMessage);
 120                 CC->FirstExpressMessage = ptr;
 121         }
 122         end_critical_section(S_SESSION_TABLE);
 123 }
 124
 125
 126 // Retrieve instant messages
 127 void cmd_gexp(char *argbuf) {
 128         struct ExpressMessage *ptr;
 129
 130         if (CC->FirstExpressMessage == NULL) {
 131                 cprintf("%d No instant messages waiting.\n", ERROR + MESSAGE_NOT_FOUND);
 132                 return;
 133         }
 134
 135         begin_critical_section(S_SESSION_TABLE);
 136         ptr = CC->FirstExpressMessage;
 137         CC->FirstExpressMessage = CC->FirstExpressMessage->next;
 138         end_critical_section(S_SESSION_TABLE);
 139
 140         cprintf("%d %d|%ld|%d|%s|%s|%s\n",
 141                 LISTING_FOLLOWS,
 142                 ((ptr->next != NULL) ? 1 : 0),          // more msgs?
 143                 (long)ptr->timestamp,                   // time sent
 144                 ptr->flags,                             // flags
 145                 ptr->sender,                            // sender of msg
 146                 CtdlGetConfigStr("c_nodename"),         // static for now (and possibly deprecated)
 147                 ptr->sender_email                       // email or jid of sender
 148         );
 149
 150         if (ptr->text != NULL) {
 151                 memfmout(ptr->text, "\n");
 152                 free(ptr->text);
 153         }
 154
 155         cprintf("000\n");
 156         free(ptr);
 157 }
 158
 159
 160 // Asynchronously deliver instant messages
 161 void cmd_gexp_async(void) {
 162
 163         // Only do this if the session can handle asynchronous protocol
 164         if (CC->is_async == 0) return;
 165
 166         // And don't do it if there's nothing to send.
 167         if (CC->FirstExpressMessage == NULL) return;
 168
 169         cprintf("%d instant msg\n", ASYNC_MSG + ASYNC_GEXP);
 170 }
 171
 172
 173 // Back end support function for send_instant_message() and company
 174 void add_xmsg_to_context(struct CitContext *ccptr, struct ExpressMessage *newmsg) {
 175         struct ExpressMessage *findend;
 176
 177         if (ccptr->FirstExpressMessage == NULL) {
 178                 ccptr->FirstExpressMessage = newmsg;
 179         }
 180         else {
 181                 findend = ccptr->FirstExpressMessage;
 182                 while (findend->next != NULL) {
 183                         findend = findend->next;
 184                 }
 185                 findend->next = newmsg;
 186         }
 187
 188         // If the target context is a session which can handle asynchronous
 189         // messages, go ahead and set the flag for that.
 190         set_async_waiting(ccptr);
 191 }
 192
 193
 194 // This is the back end to the instant message sending function.
 195 // Returns the number of users to which the message was sent.
 196 // Sending a zero-length message tests for recipients without sending messages.
 197 int send_instant_message(char *lun, char *lem, char *x_user, char *x_msg) {
 198         int message_sent = 0;           // number of successful sends
 199         struct CitContext *ccptr;
 200         struct ExpressMessage *newmsg = NULL;
 201         int do_send = 0;                // 1 = send message; 0 = only check for valid recipient
 202         static int serial_number = 0;   // this keeps messages from getting logged twice
 203
 204         if (!IsEmptyStr(x_msg)) {
 205                 do_send = 1;
 206         }
 207
 208         // find the target user's context and append the message
 209         begin_critical_section(S_SESSION_TABLE);
 210         ++serial_number;
 211         for (ccptr = ContextList; ccptr != NULL; ccptr = ccptr->next) {
 212
 213                 if ( ((!strcasecmp(ccptr->user.fullname, x_user))
 214                     || (!strcasecmp(x_user, "broadcast")))
 215                     && (ccptr->can_receive_im)
 216                     && ((ccptr->disable_exp == 0)
 217                     || (CC->user.axlevel >= AxAideU)) ) {
 218                         if (do_send) {
 219                                 newmsg = (struct ExpressMessage *) malloc(sizeof (struct ExpressMessage));
 220                                 memset(newmsg, 0, sizeof (struct ExpressMessage));
 221                                 time(&(newmsg->timestamp));
 222                                 safestrncpy(newmsg->sender, lun, sizeof newmsg->sender);
 223                                 safestrncpy(newmsg->sender_email, lem, sizeof newmsg->sender_email);
 224                                 if (!strcasecmp(x_user, "broadcast")) {
 225                                         newmsg->flags |= EM_BROADCAST;
 226                                 }
 227                                 newmsg->text = strdup(x_msg);
 228
 229                                 add_xmsg_to_context(ccptr, newmsg);
 230
 231                                 // and log it ...
 232                                 if (ccptr != CC) {
 233                                         log_instant_message(CC, ccptr, newmsg->text, serial_number);
 234                                 }
 235                         }
 236                         ++message_sent;
 237                 }
 238         }
 239         end_critical_section(S_SESSION_TABLE);
 240         return (message_sent);
 241 }
 242
 243
 244 // send instant messages
 245 void cmd_sexp(char *argbuf) {
 246         int message_sent = 0;
 247         char x_user[USERNAME_SIZE];
 248         char x_msg[1024];
 249         char *lem;
 250         char *x_big_msgbuf = NULL;
 251
 252         if ((!(CC->logged_in)) && (!(CC->internal_pgm))) {
 253                 cprintf("%d Not logged in.\n", ERROR + NOT_LOGGED_IN);
 254                 return;
 255         }
 256
 257         lem = CC->cs_principal_id;
 258
 259         extract_token(x_user, argbuf, 0, '|', sizeof x_user);
 260         extract_token(x_msg, argbuf, 1, '|', sizeof x_msg);
 261
 262         if (!x_user[0]) {
 263                 cprintf("%d You were not previously paged.\n", ERROR + NO_SUCH_USER);
 264                 return;
 265         }
 266         if ((!strcasecmp(x_user, "broadcast")) && (CC->user.axlevel < AxAideU)) {
 267                 cprintf("%d Higher access required to send a broadcast.\n",
 268                         ERROR + HIGHER_ACCESS_REQUIRED);
 269                 return;
 270         }
 271         // This loop handles text-transfer pages
 272         if (!strcmp(x_msg, "-")) {
 273                 message_sent = PerformXmsgHooks(CC->user.fullname, lem, x_user, "");
 274                 if (message_sent == 0) {
 275                         if (CtdlGetUser(NULL, x_user))
 276                                 cprintf("%d '%s' does not exist.\n", ERROR + NO_SUCH_USER, x_user);
 277                         else
 278                                 cprintf("%d '%s' is not logged in or is not accepting messages.\n", ERROR + RESOURCE_NOT_OPEN, x_user);
 279                         return;
 280                 }
 281                 unbuffer_output();
 282                 cprintf("%d Transmit message (will deliver to %d users)\n", SEND_LISTING, message_sent);
 283                 x_big_msgbuf = malloc(SIZ);
 284                 memset(x_big_msgbuf, 0, SIZ);
 285                 while (client_getln(x_msg, sizeof x_msg) >= 0 && strcmp(x_msg, "000")) {
 286                         x_big_msgbuf = realloc(x_big_msgbuf, strlen(x_big_msgbuf) + strlen(x_msg) + 4);
 287                         if (!IsEmptyStr(x_big_msgbuf))
 288                            if (x_big_msgbuf[strlen(x_big_msgbuf)] != '\n')
 289                                 strcat(x_big_msgbuf, "\n");
 290                         strcat(x_big_msgbuf, x_msg);
 291                 }
 292                 PerformXmsgHooks(CC->user.fullname, lem, x_user, x_big_msgbuf);
 293                 free(x_big_msgbuf);
 294
 295                 // This loop handles inline pages
 296         }
 297         else {
 298                 message_sent = PerformXmsgHooks(CC->user.fullname, lem, x_user, x_msg);
 299
 300                 if (message_sent > 0) {
 301                         if (!IsEmptyStr(x_msg)) {
 302                                 cprintf("%d Message sent", CIT_OK);
 303                         }
 304                         else {
 305                                 cprintf("%d Ok to send message", CIT_OK);
 306                         }
 307                         if (message_sent > 1) {
 308                                 cprintf(" to %d users", message_sent);
 309                         }
 310                         cprintf(".\n");
 311                 }
 312                 else {
 313                         if (CtdlGetUser(NULL, x_user)) {
 314                                 cprintf("%d '%s' does not exist.\n", ERROR + NO_SUCH_USER, x_user);
 315                         }
 316                         else {
 317                                 cprintf("%d '%s' is not logged in or is not accepting messages.\n", ERROR + RESOURCE_NOT_OPEN, x_user);
 318                         }
 319                 }
 320         }
 321 }
 322
 323
 324 // Enter or exit paging-disabled mode
 325 void cmd_dexp(char *argbuf) {
 326         int new_state;
 327
 328         if (CtdlAccessCheck(ac_logged_in)) return;
 329
 330         new_state = extract_int(argbuf, 0);
 331         if ((new_state == 0) || (new_state == 1)) {
 332                 CC->disable_exp = new_state;
 333         }
 334
 335         cprintf("%d %d\n", CIT_OK, CC->disable_exp);
 336 }
 337
 338
 339 // Request client termination
 340 void cmd_reqt(char *argbuf) {
 341         struct CitContext *ccptr;
 342         int sessions = 0;
 343         int which_session;
 344         struct ExpressMessage *newmsg;
 345
 346         if (CtdlAccessCheck(ac_aide)) return;
 347         which_session = extract_int(argbuf, 0);
 348
 349         begin_critical_section(S_SESSION_TABLE);
 350         for (ccptr = ContextList; ccptr != NULL; ccptr = ccptr->next) {
 351                 if ((ccptr->cs_pid == which_session) || (which_session == 0)) {
 352
 353                         newmsg = (struct ExpressMessage *)
 354                                 malloc(sizeof (struct ExpressMessage));
 355                         memset(newmsg, 0,
 356                                 sizeof (struct ExpressMessage));
 357                         time(&(newmsg->timestamp));
 358                         safestrncpy(newmsg->sender, CC->user.fullname,
 359                                     sizeof newmsg->sender);
 360                         newmsg->flags |= EM_GO_AWAY;
 361                         newmsg->text = strdup("Automatic logoff requested.");
 362
 363                         add_xmsg_to_context(ccptr, newmsg);
 364                         ++sessions;
 365
 366                 }
 367         }
 368         end_critical_section(S_SESSION_TABLE);
 369         cprintf("%d Sent termination request to %d sessions.\n", CIT_OK, sessions);
 370 }
 371
 372
 373 // This is the back end for flush_conversations_to_disk()
 374 // At this point we've isolated a single conversation (struct imlog)
 375 // and are ready to write it to disk.
 376 void flush_individual_conversation(struct imlog *im) {
 377         struct CtdlMessage *msg;
 378         long msgnum = 0;
 379         char roomname[ROOMNAMELEN];
 380         StrBuf *MsgBuf, *FullMsgBuf;
 381
 382         StrBufAppendBufPlain(im->conversation, HKEY(
 383                 "</body>\r\n"
 384                 "</html>\r\n"
 385                 ), 0
 386         );
 387
 388         MsgBuf = StrBufQuotedPrintableEncode(im->conversation);
 389         FlushStrBuf(im->conversation);
 390         FullMsgBuf = NewStrBufPlain(NULL, StrLength(im->conversation) + 100);
 391
 392         StrBufAppendBufPlain(FullMsgBuf, HKEY(
 393                 "Content-type: text/html; charset=UTF-8\r\n"
 394                 "Content-Transfer-Encoding: quoted-printable\r\n"
 395                 "\r\n"
 396                 ), 0
 397         );
 398         StrBufAppendBuf (FullMsgBuf, MsgBuf, 0);
 399         FreeStrBuf(&MsgBuf);
 400
 401         msg = malloc(sizeof(struct CtdlMessage));
 402         memset(msg, 0, sizeof(struct CtdlMessage));
 403         msg->cm_magic = CTDLMESSAGE_MAGIC;
 404         msg->cm_anon_type = MES_NORMAL;
 405         msg->cm_format_type = FMT_RFC822;
 406         if (!IsEmptyStr(im->usernames[0])) {
 407                 CM_SetField(msg, eAuthor, im->usernames[0]);
 408         }
 409         else {
 410                 CM_SetField(msg, eAuthor, "Citadel");
 411         }
 412         if (!IsEmptyStr(im->usernames[1])) {
 413                 CM_SetField(msg, eRecipient, im->usernames[1]);
 414         }
 415
 416         CM_SetField(msg, eOriginalRoom, PAGELOGROOM);
 417         CM_SetAsFieldSB(msg, eMesageText, &FullMsgBuf); /* we own this memory now */
 418
 419         // Start with usernums[1] because it's guaranteed to be higher than usernums[0],
 420         // so if there's only one party, usernums[0] will be zero but usernums[1] won't.
 421         // Create the room if necessary.  Note that we create as a type 5 room rather
 422         // than 4, which indicates that it's a personal room but we've already supplied
 423         // the namespace prefix.
 424         //
 425         // In the unlikely event that usernums[1] is zero, a room with an invalid namespace
 426         // prefix will be created.  That's ok because the auto-purger will clean it up later.
 427         //
 428         snprintf(roomname, sizeof roomname, "%010ld.%s", im->usernums[1], PAGELOGROOM);
 429         CtdlCreateRoom(roomname, 5, "", 0, 1, 1, VIEW_BBS);
 430         msgnum = CtdlSubmitMsg(msg, NULL, roomname);
 431         CM_Free(msg);
 432
 433         // If there is a valid user number in usernums[0], save a copy for them too.
 434         if (im->usernums[0] > 0) {
 435                 snprintf(roomname, sizeof roomname, "%010ld.%s", im->usernums[0], PAGELOGROOM);
 436                 CtdlCreateRoom(roomname, 5, "", 0, 1, 1, VIEW_BBS);
 437                 CtdlSaveMsgPointerInRoom(roomname, msgnum, 0, NULL);
 438         }
 439
 440         // Finally, if we're logging instant messages globally, do that now.
 441         if (!IsEmptyStr(CtdlGetConfigStr("c_logpages"))) {
 442                 CtdlCreateRoom(CtdlGetConfigStr("c_logpages"), 3, "", 0, 1, 1, VIEW_BBS);
 443                 CtdlSaveMsgPointerInRoom(CtdlGetConfigStr("c_logpages"), msgnum, 0, NULL);
 444         }
 445
 446 }
 447
 448 // Locate instant message conversations which have gone idle
 449 // (or, if the server is shutting down, locate *all* conversations)
 450 // and flush them to disk (in the participants' log rooms, etc.)
 451 void flush_conversations_to_disk(time_t if_older_than) {
 452
 453         struct imlog *flush_these = NULL;
 454         struct imlog *dont_flush_these = NULL;
 455         struct imlog *imptr = NULL;
 456         struct CitContext *nptr;
 457         int nContexts, i;
 458
 459         nptr = CtdlGetContextArray(&nContexts) ;        // Make a copy of the current wholist
 460
 461         begin_critical_section(S_IM_LOGS);
 462         while (imlist) {
 463                 imptr = imlist;
 464                 imlist = imlist->next;
 465
 466                 // For a two party conversation, if one party has logged out, force flush.
 467                 if (nptr) {
 468                         int user0_is_still_online = 0;
 469                         int user1_is_still_online = 0;
 470                         for (i=0; i<nContexts; i++)  {
 471                                 if (nptr[i].user.usernum == imptr->usernums[0]) ++user0_is_still_online;
 472                                 if (nptr[i].user.usernum == imptr->usernums[1]) ++user1_is_still_online;
 473                         }
 474                         if (imptr->usernums[0] != imptr->usernums[1]) {         // two party conversation
 475                                 if ((!user0_is_still_online) || (!user1_is_still_online)) {
 476                                         imptr->lastmsg = 0L;                    // force flush
 477                                 }
 478                         }
 479                         else {          // one party conversation (yes, people do IM themselves)
 480                                 if (!user0_is_still_online) {
 481                                         imptr->lastmsg = 0L;    // force flush
 482                                 }
 483                         }
 484                 }
 485
 486                 // Now test this conversation to see if it qualifies for flushing.
 487                 if ((time(NULL) - imptr->lastmsg) > if_older_than) {
 488                         // This conversation qualifies.  Move it to the list of ones to flush.
 489                         imptr->next = flush_these;
 490                         flush_these = imptr;
 491                 }
 492                 else  {
 493                         // Move it to the list of ones not to flush.
 494                         imptr->next = dont_flush_these;
 495                         dont_flush_these = imptr;
 496                 }
 497         }
 498         imlist = dont_flush_these;
 499         end_critical_section(S_IM_LOGS);
 500         free(nptr);
 501
 502         // We are now outside of the critical section, and we are the only thread holding a
 503         // pointer to a linked list of conversations to be flushed to disk.
 504         while (flush_these) {
 505
 506                 flush_individual_conversation(flush_these);     // This will free the string buffer
 507                 imptr = flush_these;
 508                 flush_these = flush_these->next;
 509                 free(imptr);
 510         }
 511 }
 512
 513
 514 void instmsg_timer(void) {
 515         flush_conversations_to_disk(300);       // Anything that hasn't peeped in more than 5 minutes
 516 }
 517
 518
 519 void instmsg_shutdown(void) {
 520         flush_conversations_to_disk(0);         // Get it ALL onto disk NOW.
 521 }
 522
 523
 524 // Initialization function, called from modules_init.c
 525 char *ctdl_module_init_instmsg(void) {
 526         if (!threading) {
 527                 CtdlRegisterProtoHook(cmd_gexp, "GEXP", "Get instant messages");
 528                 CtdlRegisterProtoHook(cmd_sexp, "SEXP", "Send an instant message");
 529                 CtdlRegisterProtoHook(cmd_dexp, "DEXP", "Disable instant messages");
 530                 CtdlRegisterProtoHook(cmd_reqt, "REQT", "Request client termination");
 531                 CtdlRegisterSessionHook(cmd_gexp_async, EVT_ASYNC, PRIO_ASYNC + 1);
 532                 CtdlRegisterSessionHook(delete_instant_messages, EVT_STOP, PRIO_STOP + 1);
 533                 CtdlRegisterXmsgHook(send_instant_message, XMSG_PRI_LOCAL);
 534                 CtdlRegisterSessionHook(instmsg_timer, EVT_TIMER, PRIO_CLEANUP + 400);
 535                 CtdlRegisterSessionHook(instmsg_shutdown, EVT_SHUTDOWN, PRIO_SHUTDOWN + 10);
 536         }
 537
 538         // return our module name for the log
 539         return "instmsg";
 540 }