citadel/server/serv_extensions.c

   1 // This began as a framework written by Brian Costello (btx) that loaded server extensions as dynamic modules.
   2 // We don't do it that way anymore but the concept lives on as a high degree of modularity in the server.
   3 // The functions in this file handle registration and execution of the server hooks used by static linked modules.
   4 //
   5 // Copyright (c) 1987-2021 by the citadel.org team
   6 //
   7 // This program is open source software; you can redistribute it and/or modify
   8 // it under the terms of the GNU General Public License, version 3.
   9
  10 #include <stdlib.h>
  11 #include <unistd.h>
  12 #include <stdio.h>
  13 #include <sys/stat.h>
  14 #include <libcitadel.h>
  15 #include "sysdep_decls.h"
  16 #include "modules/crypto/serv_crypto.h" /* Needed until a universal crypto startup hook is implimented for CtdlStartTLS */
  17 #include "serv_extensions.h"
  18 #include "ctdl_module.h"
  19 #include "config.h"
  20
  21
  22 /*
  23  * Structure defentitions for hook tables
  24  */
  25
  26 typedef struct FixedOutputHook FixedOutputHook;
  27 struct FixedOutputHook {
  28         FixedOutputHook *next;
  29         char content_type[64];
  30         void (*h_function_pointer) (char *, int);
  31 };
  32 FixedOutputHook *FixedOutputTable = NULL;
  33
  34
  35 /*
  36  * SessionFunctionHook extensions are used for any type of hook for which
  37  * the context in which it's being called (which is determined by the event
  38  * type) will make it obvious for the hook function to know where to look for
  39  * pertinent data.
  40  */
  41 typedef struct SessionFunctionHook SessionFunctionHook;
  42 struct SessionFunctionHook {
  43         SessionFunctionHook *next;
  44         int Priority;
  45         void (*h_function_pointer) (void);
  46         int eventtype;
  47 };
  48 SessionFunctionHook *SessionHookTable = NULL;
  49
  50
  51 /*
  52  * UserFunctionHook extensions are used for any type of hook which implements
  53  * an operation on a user or username (potentially) other than the one
  54  * operating the current session.
  55  */
  56 typedef struct UserFunctionHook UserFunctionHook;
  57 struct UserFunctionHook {
  58         UserFunctionHook *next;
  59         void (*h_function_pointer) (struct ctdluser *usbuf);
  60         int eventtype;
  61 };
  62 UserFunctionHook *UserHookTable = NULL;
  63
  64
  65 /*
  66  * MessageFunctionHook extensions are used for hooks which implement handlers
  67  * for various types of message operations (save, read, etc.)
  68  */
  69 typedef struct MessageFunctionHook MessageFunctionHook;
  70 struct MessageFunctionHook {
  71         MessageFunctionHook *next;
  72         int (*h_function_pointer) (struct CtdlMessage *msg, struct recptypes *recps);
  73         int eventtype;
  74 };
  75 MessageFunctionHook *MessageHookTable = NULL;
  76
  77
  78 /*
  79  * DeleteFunctionHook extensions are used for hooks which get called when a
  80  * message is about to be deleted.
  81  */
  82 typedef struct DeleteFunctionHook DeleteFunctionHook;
  83 struct DeleteFunctionHook {
  84         DeleteFunctionHook *next;
  85         void (*h_function_pointer) (char *target_room, long msgnum);
  86 };
  87 DeleteFunctionHook *DeleteHookTable = NULL;
  88
  89
  90 /*
  91  * ExpressMessageFunctionHook extensions are used for hooks which implement
  92  * the sending of an instant message through various channels.  Any function
  93  * registered should return the number of recipients to whom the message was
  94  * successfully transmitted.
  95  */
  96 typedef struct XmsgFunctionHook XmsgFunctionHook;
  97 struct XmsgFunctionHook {
  98         XmsgFunctionHook *next;
  99         int (*h_function_pointer) (char *, char *, char *, char *);
 100         int order;
 101 };
 102 XmsgFunctionHook *XmsgHookTable = NULL;
 103
 104
 105 /*
 106  * RoomFunctionHook extensions are used for hooks which impliment room
 107  * processing functions when new messages are added.
 108  */
 109 typedef struct RoomFunctionHook RoomFunctionHook;
 110 struct RoomFunctionHook {
 111         RoomFunctionHook *next;
 112         int (*fcn_ptr) (struct ctdlroom *);
 113 };
 114 RoomFunctionHook *RoomHookTable = NULL;
 115
 116 ServiceFunctionHook *ServiceHookTable = NULL;
 117
 118 typedef struct ProtoFunctionHook ProtoFunctionHook;
 119 struct ProtoFunctionHook {
 120         void (*handler) (char *cmdbuf);
 121         const char *cmd;
 122         const char *desc;
 123 };
 124
 125 HashList *ProtoHookList = NULL;
 126
 127
 128 #define ERR_PORT (1 << 1)
 129
 130
 131 static StrBuf *portlist = NULL;
 132 static StrBuf *errormessages = NULL;
 133
 134
 135 long   DetailErrorFlags;
 136 ConstStr Empty = {HKEY("")};
 137 char *ErrSubject = "Startup Problems";
 138 ConstStr ErrGeneral[] = {
 139         {HKEY("Citadel had trouble on starting up. ")},
 140         {HKEY(" This means, Citadel won't be the service provider for a specific service you configured it to.\n\n"
 141               "If you don't want Citadel to provide these services, turn them off in WebCit via: ")},
 142         {HKEY("To make both ways actualy take place restart the citserver with \"sendcommand down\"\n\n"
 143               "The errors returned by the system were:\n")},
 144         {HKEY("You can recheck the above if you follow this faq item:\n"
 145               "http://www.citadel.org/doku.php?id=faq:mastering_your_os:net#netstat")}
 146 };
 147
 148 ConstStr ErrPortShort = { HKEY("We couldn't bind all ports you configured to be provided by Citadel Server.\n")};
 149 ConstStr ErrPortWhere = { HKEY("\"Admin->System Preferences->Network\".\n\nThe failed ports and sockets are: ")};
 150 ConstStr ErrPortHint  = { HKEY("If you want Citadel to provide you with that functionality, "
 151                                "check the output of \"netstat -lnp\" on Linux, or \"netstat -na\" on BSD"
 152                                " and disable the program that binds these ports.\n")};
 153
 154
 155 void LogPrintMessages(long err) {
 156         StrBuf *Message;
 157         StrBuf *List, *DetailList;
 158         ConstStr *Short, *Where, *Hint;
 159
 160
 161         Message = NewStrBufPlain(NULL, StrLength(portlist) + StrLength(errormessages));
 162
 163         DetailErrorFlags = DetailErrorFlags & ~err;
 164
 165         switch (err)
 166         {
 167         case ERR_PORT:
 168                 Short = &ErrPortShort;
 169                 Where = &ErrPortWhere;
 170                 Hint  = &ErrPortHint;
 171                 List  = portlist;
 172                 DetailList = errormessages;
 173                 break;
 174         default:
 175                 Short = &Empty;
 176                 Where = &Empty;
 177                 Hint  = &Empty;
 178                 List  = NULL;
 179                 DetailList = NULL;
 180         }
 181
 182         StrBufAppendBufPlain(Message, CKEY(ErrGeneral[0]), 0);
 183         StrBufAppendBufPlain(Message, CKEY(*Short), 0);
 184         StrBufAppendBufPlain(Message, CKEY(ErrGeneral[1]), 0);
 185         StrBufAppendBufPlain(Message, CKEY(*Where), 0);
 186         StrBufAppendBuf(Message, List, 0);
 187         StrBufAppendBufPlain(Message, HKEY("\n\n"), 0);
 188         StrBufAppendBufPlain(Message, CKEY(*Hint), 0);
 189         StrBufAppendBufPlain(Message, HKEY("\n\n"), 0);
 190         StrBufAppendBufPlain(Message, CKEY(ErrGeneral[2]), 0);
 191         StrBufAppendBuf(Message, DetailList, 0);
 192         StrBufAppendBufPlain(Message, HKEY("\n\n"), 0);
 193         StrBufAppendBufPlain(Message, CKEY(ErrGeneral[3]), 0);
 194
 195         syslog(LOG_ERR, "extensions: %s", ChrPtr(Message));
 196         syslog(LOG_ERR, "extensions: %s", ErrSubject);
 197         quickie_message("Citadel", NULL, NULL, AIDEROOM, ChrPtr(Message), FMT_FIXED, ErrSubject);
 198
 199         FreeStrBuf(&Message);
 200         FreeStrBuf(&List);
 201         FreeStrBuf(&DetailList);
 202 }
 203
 204
 205 void AddPortError(char *Port, char *ErrorMessage) {
 206         long len;
 207
 208         DetailErrorFlags |= ERR_PORT;
 209
 210         len = StrLength(errormessages);
 211         if (len > 0) StrBufAppendBufPlain(errormessages, HKEY("; "), 0);
 212         else errormessages = NewStrBuf();
 213         StrBufAppendBufPlain(errormessages, ErrorMessage, -1, 0);
 214
 215
 216         len = StrLength(portlist);
 217         if (len > 0) StrBufAppendBufPlain(portlist, HKEY(";"), 0);
 218         else portlist = NewStrBuf();
 219         StrBufAppendBufPlain(portlist, Port, -1, 0);
 220 }
 221
 222
 223 int DLoader_Exec_Cmd(char *cmdbuf) {
 224         void *vP;
 225         ProtoFunctionHook *p;
 226
 227         if (GetHash(ProtoHookList, cmdbuf, 4, &vP) && (vP != NULL)) {
 228                 p = (ProtoFunctionHook*) vP;
 229                 p->handler(&cmdbuf[5]);
 230                 return 1;
 231         }
 232         return 0;
 233 }
 234
 235
 236 void CtdlRegisterProtoHook(void (*handler) (char *), char *cmd, char *desc) {
 237         ProtoFunctionHook *p;
 238
 239         if (ProtoHookList == NULL)
 240                 ProtoHookList = NewHash (1, FourHash);
 241
 242
 243         p = (ProtoFunctionHook *)
 244                 malloc(sizeof(ProtoFunctionHook));
 245
 246         if (p == NULL) {
 247                 fprintf(stderr, "can't malloc new ProtoFunctionHook\n");
 248                 exit(EXIT_FAILURE);
 249         }
 250         p->handler = handler;
 251         p->cmd = cmd;
 252         p->desc = desc;
 253
 254         Put(ProtoHookList, cmd, 4, p, NULL);
 255         syslog(LOG_DEBUG, "extensions: registered server command %s (%s)", cmd, desc);
 256 }
 257
 258
 259 void CtdlRegisterSessionHook(void (*fcn_ptr) (void), int EventType, int Priority)
 260 {
 261         SessionFunctionHook *newfcn;
 262
 263         newfcn = (SessionFunctionHook *)
 264             malloc(sizeof(SessionFunctionHook));
 265         newfcn->Priority = Priority;
 266         newfcn->h_function_pointer = fcn_ptr;
 267         newfcn->eventtype = EventType;
 268
 269         SessionFunctionHook **pfcn;
 270         pfcn = &SessionHookTable;
 271         while ((*pfcn != NULL) &&
 272                ((*pfcn)->Priority < newfcn->Priority) &&
 273                ((*pfcn)->next != NULL))
 274                 pfcn = &(*pfcn)->next;
 275
 276         newfcn->next = *pfcn;
 277         *pfcn = newfcn;
 278
 279         syslog(LOG_DEBUG, "extensions: registered a new session function (type %d Priority %d)", EventType, Priority);
 280 }
 281
 282
 283 void CtdlRegisterUserHook(void (*fcn_ptr) (ctdluser *), int EventType)
 284 {
 285
 286         UserFunctionHook *newfcn;
 287
 288         newfcn = (UserFunctionHook *)
 289             malloc(sizeof(UserFunctionHook));
 290         newfcn->next = UserHookTable;
 291         newfcn->h_function_pointer = fcn_ptr;
 292         newfcn->eventtype = EventType;
 293         UserHookTable = newfcn;
 294
 295         syslog(LOG_DEBUG, "extensions: registered a new user function (type %d)",
 296                    EventType);
 297 }
 298
 299
 300 void CtdlRegisterMessageHook(int (*handler)(struct CtdlMessage *, struct recptypes *), int EventType)
 301 {
 302
 303         MessageFunctionHook *newfcn;
 304
 305         newfcn = (MessageFunctionHook *)
 306             malloc(sizeof(MessageFunctionHook));
 307         newfcn->next = MessageHookTable;
 308         newfcn->h_function_pointer = handler;
 309         newfcn->eventtype = EventType;
 310         MessageHookTable = newfcn;
 311
 312         syslog(LOG_DEBUG, "extensions: registered a new message function (type %d)", EventType);
 313 }
 314
 315
 316 void CtdlRegisterRoomHook(int (*fcn_ptr)(struct ctdlroom *))
 317 {
 318         RoomFunctionHook *newfcn;
 319
 320         newfcn = (RoomFunctionHook *)
 321             malloc(sizeof(RoomFunctionHook));
 322         newfcn->next = RoomHookTable;
 323         newfcn->fcn_ptr = fcn_ptr;
 324         RoomHookTable = newfcn;
 325
 326         syslog(LOG_DEBUG, "extensions: registered a new room function");
 327 }
 328
 329
 330 void CtdlRegisterDeleteHook(void (*handler)(char *, long) )
 331 {
 332         DeleteFunctionHook *newfcn;
 333
 334         newfcn = (DeleteFunctionHook *)
 335             malloc(sizeof(DeleteFunctionHook));
 336         newfcn->next = DeleteHookTable;
 337         newfcn->h_function_pointer = handler;
 338         DeleteHookTable = newfcn;
 339
 340         syslog(LOG_DEBUG, "extensions: registered a new delete function");
 341 }
 342
 343
 344 void CtdlRegisterFixedOutputHook(char *content_type, void (*handler)(char *, int) )
 345 {
 346         FixedOutputHook *newfcn;
 347
 348         newfcn = (FixedOutputHook *)
 349             malloc(sizeof(FixedOutputHook));
 350         newfcn->next = FixedOutputTable;
 351         newfcn->h_function_pointer = handler;
 352         safestrncpy(newfcn->content_type, content_type, sizeof newfcn->content_type);
 353         FixedOutputTable = newfcn;
 354
 355         syslog(LOG_DEBUG, "extensions: registered a new fixed output function for %s", newfcn->content_type);
 356 }
 357
 358
 359 /* returns nonzero if we found a hook and used it */
 360 int PerformFixedOutputHooks(char *content_type, char *content, int content_length)
 361 {
 362         FixedOutputHook *fcn;
 363
 364         for (fcn = FixedOutputTable; fcn != NULL; fcn = fcn->next) {
 365                 if (!strcasecmp(content_type, fcn->content_type)) {
 366                         (*fcn->h_function_pointer) (content, content_length);
 367                         return(1);
 368                 }
 369         }
 370         return(0);
 371 }
 372
 373
 374 void CtdlRegisterXmsgHook(int (*fcn_ptr) (char *, char *, char *, char *), int order)
 375 {
 376
 377         XmsgFunctionHook *newfcn;
 378
 379         newfcn = (XmsgFunctionHook *) malloc(sizeof(XmsgFunctionHook));
 380         newfcn->next = XmsgHookTable;
 381         newfcn->order = order;
 382         newfcn->h_function_pointer = fcn_ptr;
 383         XmsgHookTable = newfcn;
 384         syslog(LOG_DEBUG, "extensions: registered a new x-msg function (priority %d)", order);
 385 }
 386
 387
 388 void CtdlRegisterServiceHook(int tcp_port,
 389                              char *sockpath,
 390                              void (*h_greeting_function) (void),
 391                              void (*h_command_function) (void),
 392                              void (*h_async_function) (void),
 393                              const char *ServiceName)
 394 {
 395         ServiceFunctionHook *newfcn;
 396         char *message;
 397
 398         newfcn = (ServiceFunctionHook *) malloc(sizeof(ServiceFunctionHook));
 399         message = (char*) malloc (SIZ + SIZ);
 400
 401         newfcn->next = ServiceHookTable;
 402         newfcn->tcp_port = tcp_port;
 403         newfcn->sockpath = sockpath;
 404         newfcn->h_greeting_function = h_greeting_function;
 405         newfcn->h_command_function = h_command_function;
 406         newfcn->h_async_function = h_async_function;
 407         newfcn->ServiceName = ServiceName;
 408
 409         if (sockpath != NULL) {
 410                 newfcn->msock = ctdl_uds_server(sockpath, CtdlGetConfigInt("c_maxsessions"));
 411                 snprintf(message, SIZ, "extensions: unix domain socket '%s': ", sockpath);
 412         }
 413         else if (tcp_port <= 0) {       /* port -1 to disable */
 414                 syslog(LOG_INFO, "extensions: service %s has been manually disabled, skipping", ServiceName);
 415                 free (message);
 416                 free(newfcn);
 417                 return;
 418         }
 419         else {
 420                 newfcn->msock = ctdl_tcp_server(CtdlGetConfigStr("c_ip_addr"), tcp_port, CtdlGetConfigInt("c_maxsessions"));
 421                 snprintf(message, SIZ, "extensions: TCP port %s:%d: (%s) ",
 422                          CtdlGetConfigStr("c_ip_addr"), tcp_port, ServiceName);
 423         }
 424
 425         if (newfcn->msock > 0) {
 426                 ServiceHookTable = newfcn;
 427                 strcat(message, "registered.");
 428                 syslog(LOG_INFO, "%s", message);
 429         }
 430         else {
 431                 AddPortError(message, "failed");
 432                 strcat(message, "FAILED.");
 433                 syslog(LOG_ERR, "%s", message);
 434                 free(newfcn);
 435         }
 436         free(message);
 437 }
 438
 439
 440 // During shutdown we can close all of the listening sockets.
 441 void CtdlShutdownServiceHooks(void) {
 442         ServiceFunctionHook *cur;
 443
 444         cur = ServiceHookTable;
 445         while (cur != NULL) {
 446                 if (cur->msock != -1) {
 447                         close(cur->msock);
 448                         cur->msock = -1;
 449                         if (cur->sockpath != NULL){
 450                                 syslog(LOG_INFO, "extensions: [%s] closed unix domain socket %s", cur->ServiceName, cur->sockpath);
 451                                 unlink(cur->sockpath);
 452                         } else {
 453                                 syslog(LOG_INFO, "extensions: [%s] closing service", cur->ServiceName);
 454                         }
 455                 }
 456                 cur = cur->next;
 457         }
 458 }
 459
 460
 461 void PerformSessionHooks(int EventType) {
 462         SessionFunctionHook *fcn = NULL;
 463
 464         for (fcn = SessionHookTable; fcn != NULL; fcn = fcn->next) {
 465                 if (fcn->eventtype == EventType) {
 466                         if (EventType == EVT_TIMER) {
 467                                 pthread_setspecific(MyConKey, NULL);    /* for every hook */
 468                         }
 469                         (*fcn->h_function_pointer) ();
 470                 }
 471         }
 472 }
 473
 474
 475 void PerformUserHooks(ctdluser *usbuf, int EventType) {
 476         UserFunctionHook *fcn = NULL;
 477
 478         for (fcn = UserHookTable; fcn != NULL; fcn = fcn->next) {
 479                 if (fcn->eventtype == EventType) {
 480                         (*fcn->h_function_pointer) (usbuf);
 481                 }
 482         }
 483 }
 484
 485
 486 int PerformMessageHooks(struct CtdlMessage *msg, struct recptypes *recps, int EventType) {
 487         MessageFunctionHook *fcn = NULL;
 488         int total_retval = 0;
 489
 490         /* Other code may elect to protect this message from server-side
 491          * handlers; if this is the case, don't do anything.
 492          */
 493         if (msg->cm_flags & CM_SKIP_HOOKS) {
 494                 return(0);
 495         }
 496
 497         /* Otherwise, run all the hooks appropriate to this event type.
 498          */
 499         for (fcn = MessageHookTable; fcn != NULL; fcn = fcn->next) {
 500                 if (fcn->eventtype == EventType) {
 501                         total_retval = total_retval + (*fcn->h_function_pointer) (msg, recps);
 502                 }
 503         }
 504
 505         /* Return the sum of the return codes from the hook functions.  If
 506          * this is an EVT_BEFORESAVE event, a nonzero return code will cause
 507          * the save operation to abort.
 508          */
 509         return total_retval;
 510 }
 511
 512
 513 int PerformRoomHooks(struct ctdlroom *target_room) {
 514         RoomFunctionHook *fcn;
 515         int total_retval = 0;
 516
 517         syslog(LOG_DEBUG, "extensions: performing room hooks for <%s>", target_room->QRname);
 518
 519         for (fcn = RoomHookTable; fcn != NULL; fcn = fcn->next) {
 520                 total_retval = total_retval + (*fcn->fcn_ptr) (target_room);
 521         }
 522
 523         /* Return the sum of the return codes from the hook functions.
 524          */
 525         return total_retval;
 526 }
 527
 528
 529 void PerformDeleteHooks(char *room, long msgnum) {
 530         DeleteFunctionHook *fcn;
 531
 532         for (fcn = DeleteHookTable; fcn != NULL; fcn = fcn->next) {
 533                 (*fcn->h_function_pointer) (room, msgnum);
 534         }
 535 }
 536
 537
 538 int PerformXmsgHooks(char *sender, char *sender_email, char *recp, char *msg) {
 539         XmsgFunctionHook *fcn;
 540         int total_sent = 0;
 541         int p;
 542
 543         for (p=0; p<MAX_XMSG_PRI; ++p) {
 544                 for (fcn = XmsgHookTable; fcn != NULL; fcn = fcn->next) {
 545                         if (fcn->order == p) {
 546                                 total_sent +=
 547                                         (*fcn->h_function_pointer)
 548                                                 (sender, sender_email, recp, msg);
 549                         }
 550                 }
 551                 /* Break out of the loop if a higher-priority function
 552                  * successfully delivered the message.  This prevents duplicate
 553                  * deliveries to local users simultaneously signed onto
 554                  * remote services.
 555                  */
 556                 if (total_sent) break;
 557         }
 558         return total_sent;
 559 }
 560
 561
 562 /*
 563  * "Start TLS" function that is (hopefully) adaptable for any protocol
 564  */
 565 void CtdlModuleStartCryptoMsgs(char *ok_response, char *nosup_response, char *error_response) {
 566 #ifdef HAVE_OPENSSL
 567         CtdlStartTLS (ok_response, nosup_response, error_response);
 568 #endif
 569 }
 570
 571
 572 CTDL_MODULE_INIT(modules) {
 573         return "modules";
 574 }