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) 1987-2023 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 // Structure defentitions for hook tables
  23 typedef struct FixedOutputHook FixedOutputHook;
  24 struct FixedOutputHook {
  25         FixedOutputHook *next;
  26         char content_type[64];
  27         void (*h_function_pointer) (char *, int);
  28 };
  29 FixedOutputHook *FixedOutputTable = NULL;
  30
  31
  32 // SessionFunctionHook extensions are used for any type of hook for which
  33 // the context in which it's being called (which is determined by the event
  34 // type) will make it obvious for the hook function to know where to look for
  35 // pertinent data.
  36 typedef struct SessionFunctionHook SessionFunctionHook;
  37 struct SessionFunctionHook {
  38         SessionFunctionHook *next;
  39         int Priority;
  40         void (*h_function_pointer) (void);
  41         int eventtype;
  42 };
  43 SessionFunctionHook *SessionHookTable = NULL;
  44
  45
  46 // UserFunctionHook extensions are used for any type of hook which implements
  47 // an operation on a user or username (potentially) other than the one
  48 // operating the current session.
  49 typedef struct UserFunctionHook UserFunctionHook;
  50 struct UserFunctionHook {
  51         UserFunctionHook *next;
  52         void (*h_function_pointer) (struct ctdluser *usbuf);
  53         int eventtype;
  54 };
  55 UserFunctionHook *UserHookTable = NULL;
  56
  57
  58 // MessageFunctionHook extensions are used for hooks which implement handlers
  59 // for various types of message operations (save, read, etc.)
  60 typedef struct MessageFunctionHook MessageFunctionHook;
  61 struct MessageFunctionHook {
  62         MessageFunctionHook *next;
  63         int (*h_function_pointer) (struct CtdlMessage *msg, struct recptypes *recps);
  64         int eventtype;
  65 };
  66 MessageFunctionHook *MessageHookTable = NULL;
  67
  68
  69 // DeleteFunctionHook extensions are used for hooks which get called when a
  70 // message is about to be deleted.
  71 typedef struct DeleteFunctionHook DeleteFunctionHook;
  72 struct DeleteFunctionHook {
  73         DeleteFunctionHook *next;
  74         void (*h_function_pointer) (char *target_room, long msgnum);
  75 };
  76 DeleteFunctionHook *DeleteHookTable = NULL;
  77
  78
  79 // ExpressMessageFunctionHook extensions are used for hooks which implement
  80 // the sending of an instant message through various channels.  Any function
  81 // registered should return the number of recipients to whom the message was
  82 // successfully transmitted.
  83 typedef struct XmsgFunctionHook XmsgFunctionHook;
  84 struct XmsgFunctionHook {
  85         XmsgFunctionHook *next;
  86         int (*h_function_pointer) (char *, char *, char *, char *);
  87         int order;
  88 };
  89 XmsgFunctionHook *XmsgHookTable = NULL;
  90
  91
  92 // RoomFunctionHook extensions are used for hooks which implement room
  93 // processing functions when new messages are added.
  94 typedef struct RoomFunctionHook RoomFunctionHook;
  95 struct RoomFunctionHook {
  96         RoomFunctionHook *next;
  97         int (*fcn_ptr) (struct ctdlroom *);
  98 };
  99 RoomFunctionHook *RoomHookTable = NULL;
 100
 101 ServiceFunctionHook *ServiceHookTable = NULL;
 102
 103 typedef struct ProtoFunctionHook ProtoFunctionHook;
 104 struct ProtoFunctionHook {
 105         void (*handler) (char *cmdbuf);
 106         const char *cmd;
 107         const char *desc;
 108 };
 109
 110 HashList *ProtoHookList = NULL;
 111
 112
 113 #define ERR_PORT (1 << 1)
 114
 115
 116 static StrBuf *portlist = NULL;
 117 static StrBuf *errormessages = NULL;
 118
 119
 120 long   DetailErrorFlags;
 121 ConstStr Empty = {HKEY("")};
 122 char *ErrSubject = "Startup Problems";
 123 ConstStr ErrGeneral[] = {
 124         {HKEY("Citadel had trouble on starting up. ")},
 125         {HKEY(" This means, Citadel won't be the service provider for a specific service you configured it to.\n\n"
 126               "If you don't want Citadel to provide these services, turn them off in WebCit via: ")},
 127         {HKEY("To make both ways actualy take place restart the citserver with \"sendcommand down\"\n\n"
 128               "The errors returned by the system were:\n")},
 129         {HKEY("You can recheck the above if you follow this faq item:\n"
 130               "http://www.citadel.org/doku.php?id=faq:mastering_your_os:net#netstat")}
 131 };
 132
 133 ConstStr ErrPortShort = { HKEY("We couldn't bind all ports you configured to be provided by Citadel Server.\n")};
 134 ConstStr ErrPortWhere = { HKEY("\"Admin->System Preferences->Network\".\n\nThe failed ports and sockets are: ")};
 135 ConstStr ErrPortHint  = { HKEY("If you want Citadel to provide you with that functionality, "
 136                                "check the output of \"netstat -lnp\" on Linux, or \"netstat -na\" on BSD"
 137                                " and disable the program that binds these ports.\n")};
 138
 139
 140 void LogPrintMessages(long err) {
 141         StrBuf *Message;
 142         StrBuf *List, *DetailList;
 143         ConstStr *Short, *Where, *Hint;
 144
 145
 146         Message = NewStrBufPlain(NULL, StrLength(portlist) + StrLength(errormessages));
 147
 148         DetailErrorFlags = DetailErrorFlags & ~err;
 149
 150         switch (err)
 151         {
 152         case ERR_PORT:
 153                 Short = &ErrPortShort;
 154                 Where = &ErrPortWhere;
 155                 Hint  = &ErrPortHint;
 156                 List  = portlist;
 157                 DetailList = errormessages;
 158                 break;
 159         default:
 160                 Short = &Empty;
 161                 Where = &Empty;
 162                 Hint  = &Empty;
 163                 List  = NULL;
 164                 DetailList = NULL;
 165         }
 166
 167         StrBufAppendBufPlain(Message, CKEY(ErrGeneral[0]), 0);
 168         StrBufAppendBufPlain(Message, CKEY(*Short), 0);
 169         StrBufAppendBufPlain(Message, CKEY(ErrGeneral[1]), 0);
 170         StrBufAppendBufPlain(Message, CKEY(*Where), 0);
 171         StrBufAppendBuf(Message, List, 0);
 172         StrBufAppendBufPlain(Message, HKEY("\n\n"), 0);
 173         StrBufAppendBufPlain(Message, CKEY(*Hint), 0);
 174         StrBufAppendBufPlain(Message, HKEY("\n\n"), 0);
 175         StrBufAppendBufPlain(Message, CKEY(ErrGeneral[2]), 0);
 176         StrBufAppendBuf(Message, DetailList, 0);
 177         StrBufAppendBufPlain(Message, HKEY("\n\n"), 0);
 178         StrBufAppendBufPlain(Message, CKEY(ErrGeneral[3]), 0);
 179
 180         syslog(LOG_ERR, "extensions: %s", ChrPtr(Message));
 181         syslog(LOG_ERR, "extensions: %s", ErrSubject);
 182         quickie_message("Citadel", NULL, NULL, AIDEROOM, ChrPtr(Message), FMT_FIXED, ErrSubject);
 183
 184         FreeStrBuf(&Message);
 185         FreeStrBuf(&List);
 186         FreeStrBuf(&DetailList);
 187 }
 188
 189
 190 void AddPortError(char *Port, char *ErrorMessage) {
 191         long len;
 192
 193         DetailErrorFlags |= ERR_PORT;
 194
 195         len = StrLength(errormessages);
 196         if (len > 0) StrBufAppendBufPlain(errormessages, HKEY("; "), 0);
 197         else errormessages = NewStrBuf();
 198         StrBufAppendBufPlain(errormessages, ErrorMessage, -1, 0);
 199
 200         len = StrLength(portlist);
 201         if (len > 0) StrBufAppendBufPlain(portlist, HKEY(";"), 0);
 202         else portlist = NewStrBuf();
 203         StrBufAppendBufPlain(portlist, Port, -1, 0);
 204 }
 205
 206
 207 int DLoader_Exec_Cmd(char *cmdbuf) {
 208         void *vP;
 209         ProtoFunctionHook *p;
 210
 211         if (GetHash(ProtoHookList, cmdbuf, 4, &vP) && (vP != NULL)) {
 212                 p = (ProtoFunctionHook*) vP;
 213                 p->handler(&cmdbuf[5]);
 214                 return 1;
 215         }
 216         return 0;
 217 }
 218
 219
 220 void CtdlRegisterProtoHook(void (*handler) (char *), char *cmd, char *desc) {
 221         ProtoFunctionHook *p;
 222
 223         if (ProtoHookList == NULL)
 224                 ProtoHookList = NewHash (1, FourHash);
 225
 226
 227         p = (ProtoFunctionHook *)
 228                 malloc(sizeof(ProtoFunctionHook));
 229
 230         if (p == NULL) {
 231                 fprintf(stderr, "can't malloc new ProtoFunctionHook\n");
 232                 exit(EXIT_FAILURE);
 233         }
 234         p->handler = handler;
 235         p->cmd = cmd;
 236         p->desc = desc;
 237
 238         Put(ProtoHookList, cmd, 4, p, NULL);
 239         syslog(LOG_DEBUG, "extensions: registered server command %s (%s)", cmd, desc);
 240 }
 241
 242
 243 void CtdlRegisterSessionHook(void (*fcn_ptr) (void), int EventType, int Priority) {
 244         SessionFunctionHook *newfcn;
 245
 246         newfcn = (SessionFunctionHook *) malloc(sizeof(SessionFunctionHook));
 247         newfcn->Priority = Priority;
 248         newfcn->h_function_pointer = fcn_ptr;
 249         newfcn->eventtype = EventType;
 250
 251         SessionFunctionHook **pfcn;
 252         pfcn = &SessionHookTable;
 253         while ((*pfcn != NULL) &&
 254                ((*pfcn)->Priority < newfcn->Priority) &&
 255                ((*pfcn)->next != NULL))
 256                 pfcn = &(*pfcn)->next;
 257
 258         newfcn->next = *pfcn;
 259         *pfcn = newfcn;
 260
 261         syslog(LOG_DEBUG, "extensions: registered a new session function (type %d Priority %d)", EventType, Priority);
 262 }
 263
 264
 265 void CtdlRegisterUserHook(void (*fcn_ptr) (ctdluser *), int EventType) {
 266
 267         UserFunctionHook *newfcn;
 268
 269         newfcn = (UserFunctionHook *) malloc(sizeof(UserFunctionHook));
 270         newfcn->next = UserHookTable;
 271         newfcn->h_function_pointer = fcn_ptr;
 272         newfcn->eventtype = EventType;
 273         UserHookTable = newfcn;
 274
 275         syslog(LOG_DEBUG, "extensions: registered a new user function (type %d)", EventType);
 276 }
 277
 278
 279 void CtdlRegisterMessageHook(int (*handler)(struct CtdlMessage *, struct recptypes *), int EventType) {
 280
 281         MessageFunctionHook *newfcn;
 282
 283         newfcn = (MessageFunctionHook *) malloc(sizeof(MessageFunctionHook));
 284         newfcn->next = MessageHookTable;
 285         newfcn->h_function_pointer = handler;
 286         newfcn->eventtype = EventType;
 287         MessageHookTable = newfcn;
 288
 289         syslog(LOG_DEBUG, "extensions: registered a new message function (type %d)", EventType);
 290 }
 291
 292
 293 void CtdlRegisterRoomHook(int (*fcn_ptr)(struct ctdlroom *)) {
 294         RoomFunctionHook *newfcn;
 295
 296         newfcn = (RoomFunctionHook *) malloc(sizeof(RoomFunctionHook));
 297         newfcn->next = RoomHookTable;
 298         newfcn->fcn_ptr = fcn_ptr;
 299         RoomHookTable = newfcn;
 300
 301         syslog(LOG_DEBUG, "extensions: registered a new room function");
 302 }
 303
 304
 305 void CtdlRegisterDeleteHook(void (*handler)(char *, long) ) {
 306         DeleteFunctionHook *newfcn;
 307
 308         newfcn = (DeleteFunctionHook *) malloc(sizeof(DeleteFunctionHook));
 309         newfcn->next = DeleteHookTable;
 310         newfcn->h_function_pointer = handler;
 311         DeleteHookTable = newfcn;
 312
 313         syslog(LOG_DEBUG, "extensions: registered a new delete function");
 314 }
 315
 316
 317 void CtdlRegisterFixedOutputHook(char *content_type, void (*handler)(char *, int) ) {
 318         FixedOutputHook *newfcn;
 319
 320         newfcn = (FixedOutputHook *) malloc(sizeof(FixedOutputHook));
 321         newfcn->next = FixedOutputTable;
 322         newfcn->h_function_pointer = handler;
 323         safestrncpy(newfcn->content_type, content_type, sizeof newfcn->content_type);
 324         FixedOutputTable = newfcn;
 325
 326         syslog(LOG_DEBUG, "extensions: registered a new fixed output function for %s", newfcn->content_type);
 327 }
 328
 329
 330 // returns nonzero if we found a hook and used it
 331 int PerformFixedOutputHooks(char *content_type, char *content, int content_length) {
 332         FixedOutputHook *fcn;
 333
 334         for (fcn = FixedOutputTable; fcn != NULL; fcn = fcn->next) {
 335                 if (!strcasecmp(content_type, fcn->content_type)) {
 336                         (*fcn->h_function_pointer) (content, content_length);
 337                         return(1);
 338                 }
 339         }
 340         return(0);
 341 }
 342
 343
 344 void CtdlRegisterXmsgHook(int (*fcn_ptr) (char *, char *, char *, char *), int order) {
 345
 346         XmsgFunctionHook *newfcn;
 347
 348         newfcn = (XmsgFunctionHook *) malloc(sizeof(XmsgFunctionHook));
 349         newfcn->next = XmsgHookTable;
 350         newfcn->order = order;
 351         newfcn->h_function_pointer = fcn_ptr;
 352         XmsgHookTable = newfcn;
 353         syslog(LOG_DEBUG, "extensions: registered a new x-msg function (priority %d)", order);
 354 }
 355
 356
 357 void CtdlRegisterServiceHook(int tcp_port,
 358                              char *sockpath,
 359                              void (*h_greeting_function) (void),
 360                              void (*h_command_function) (void),
 361                              void (*h_async_function) (void),
 362                              const char *ServiceName)
 363 {
 364         ServiceFunctionHook *newfcn;
 365         char *message;
 366
 367         newfcn = (ServiceFunctionHook *) malloc(sizeof(ServiceFunctionHook));
 368         message = (char*) malloc (SIZ + SIZ);
 369
 370         newfcn->next = ServiceHookTable;
 371         newfcn->tcp_port = tcp_port;
 372         newfcn->sockpath = sockpath;
 373         newfcn->h_greeting_function = h_greeting_function;
 374         newfcn->h_command_function = h_command_function;
 375         newfcn->h_async_function = h_async_function;
 376         newfcn->ServiceName = ServiceName;
 377
 378         if (sockpath != NULL) {
 379                 newfcn->msock = ctdl_uds_server(sockpath, CtdlGetConfigInt("c_maxsessions"));
 380                 snprintf(message, SIZ, "extensions: unix domain socket '%s': ", sockpath);
 381         }
 382         else if (tcp_port <= 0) {       // port -1 to disable
 383                 syslog(LOG_INFO, "extensions: service %s has been manually disabled, skipping", ServiceName);
 384                 free (message);
 385                 free(newfcn);
 386                 return;
 387         }
 388         else {
 389                 newfcn->msock = ctdl_tcp_server(CtdlGetConfigStr("c_ip_addr"), tcp_port, CtdlGetConfigInt("c_maxsessions"));
 390                 snprintf(message, SIZ, "extensions: TCP port %s:%d: (%s) ",
 391                          CtdlGetConfigStr("c_ip_addr"), tcp_port, ServiceName);
 392         }
 393
 394         if (newfcn->msock > 0) {
 395                 ServiceHookTable = newfcn;
 396                 strcat(message, "registered.");
 397                 syslog(LOG_INFO, "%s", message);
 398         }
 399         else {
 400                 AddPortError(message, "failed");
 401                 strcat(message, "FAILED.");
 402                 syslog(LOG_ERR, "%s", message);
 403                 free(newfcn);
 404         }
 405         free(message);
 406 }
 407
 408
 409 // During shutdown we can close all of the listening sockets.
 410 void CtdlShutdownServiceHooks(void) {
 411         ServiceFunctionHook *cur;
 412
 413         cur = ServiceHookTable;
 414         while (cur != NULL) {
 415                 if (cur->msock != -1) {
 416                         close(cur->msock);
 417                         cur->msock = -1;
 418                         if (cur->sockpath != NULL){
 419                                 syslog(LOG_INFO, "extensions: [%s] closed unix domain socket %s", cur->ServiceName, cur->sockpath);
 420                                 unlink(cur->sockpath);
 421                         }
 422                         else {
 423                                 syslog(LOG_INFO, "extensions: [%s] closing service", cur->ServiceName);
 424                         }
 425                 }
 426                 cur = cur->next;
 427         }
 428 }
 429
 430
 431 void PerformSessionHooks(int EventType) {
 432         SessionFunctionHook *fcn = NULL;
 433
 434         for (fcn = SessionHookTable; fcn != NULL; fcn = fcn->next) {
 435                 if (fcn->eventtype == EventType) {
 436                         if (EventType == EVT_TIMER) {
 437                                 pthread_setspecific(MyConKey, NULL);    // for every hook
 438                         }
 439                         (*fcn->h_function_pointer) ();
 440                 }
 441         }
 442 }
 443
 444
 445 void PerformUserHooks(ctdluser *usbuf, int EventType) {
 446         UserFunctionHook *fcn = NULL;
 447
 448         for (fcn = UserHookTable; fcn != NULL; fcn = fcn->next) {
 449                 if (fcn->eventtype == EventType) {
 450                         (*fcn->h_function_pointer) (usbuf);
 451                 }
 452         }
 453 }
 454
 455
 456 int PerformMessageHooks(struct CtdlMessage *msg, struct recptypes *recps, int EventType) {
 457         MessageFunctionHook *fcn = NULL;
 458         int total_retval = 0;
 459
 460         // Other code may elect to protect this message from server-side
 461         // handlers; if this is the case, don't do anything.
 462         if (msg->cm_flags & CM_SKIP_HOOKS) {
 463                 return(0);
 464         }
 465
 466         // Otherwise, run all the hooks appropriate to this event type.
 467         for (fcn = MessageHookTable; fcn != NULL; fcn = fcn->next) {
 468                 if (fcn->eventtype == EventType) {
 469                         total_retval = total_retval + (*fcn->h_function_pointer) (msg, recps);
 470                 }
 471         }
 472
 473         // Return the sum of the return codes from the hook functions.  If
 474         // this is an EVT_BEFORESAVE event, a nonzero return code will cause
 475         // the save operation to abort.
 476         return total_retval;
 477 }
 478
 479
 480 int PerformRoomHooks(struct ctdlroom *target_room) {
 481         RoomFunctionHook *fcn;
 482         int total_retval = 0;
 483
 484         syslog(LOG_DEBUG, "extensions: performing room hooks for <%s>", target_room->QRname);
 485
 486         for (fcn = RoomHookTable; fcn != NULL; fcn = fcn->next) {
 487                 total_retval = total_retval + (*fcn->fcn_ptr) (target_room);
 488         }
 489
 490         // Return the sum of the return codes from the hook functions.
 491         return total_retval;
 492 }
 493
 494
 495 void PerformDeleteHooks(char *room, long msgnum) {
 496         DeleteFunctionHook *fcn;
 497
 498         for (fcn = DeleteHookTable; fcn != NULL; fcn = fcn->next) {
 499                 (*fcn->h_function_pointer) (room, msgnum);
 500         }
 501 }
 502
 503
 504 int PerformXmsgHooks(char *sender, char *sender_email, char *recp, char *msg) {
 505         XmsgFunctionHook *fcn;
 506         int total_sent = 0;
 507         int p;
 508
 509         for (p=0; p<MAX_XMSG_PRI; ++p) {
 510                 for (fcn = XmsgHookTable; fcn != NULL; fcn = fcn->next) {
 511                         if (fcn->order == p) {
 512                                 total_sent +=
 513                                         (*fcn->h_function_pointer)
 514                                                 (sender, sender_email, recp, msg);
 515                         }
 516                 }
 517                 // Break out of the loop if a higher-priority function
 518                 // successfully delivered the message.  This prevents duplicate
 519                 // deliveries to local users simultaneously signed onto
 520                 // remote services.
 521                 if (total_sent) break;
 522         }
 523         return total_sent;
 524 }
 525
 526
 527 // "Start TLS" function that is (hopefully) adaptable for any protocol
 528 void CtdlModuleStartCryptoMsgs(char *ok_response, char *nosup_response, char *error_response) {
 529 #ifdef HAVE_OPENSSL
 530         CtdlStartTLS (ok_response, nosup_response, error_response);
 531 #endif
 532 }
 533
 534
 535 CTDL_MODULE_INIT(modules) {
 536         return "modules";
 537 }