2 * Citadel context management stuff.
3 * Here's where we (hopefully) have all the code that manipulates contexts.
5 * Copyright (c) 1987-2018 by the citadel.org team
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.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
16 #include "ctdl_module.h"
17 #include "serv_extensions.h"
19 #include "citserver.h"
21 #include "locate_host.h"
26 pthread_key_t MyConKey; /* TSD key for MyContext() */
28 CitContext *ContextList = NULL;
29 time_t last_purge = 0; /* Last dead session purge */
30 int num_sessions = 0; /* Current number of sessions */
33 /* Flag for single user mode */
34 static int want_single_user = 0;
36 /* Try to go single user */
38 int CtdlTrySingleUser(void)
42 begin_critical_section(S_SINGLE_USER);
50 end_critical_section(S_SINGLE_USER);
55 void CtdlEndSingleUser(void)
57 begin_critical_section(S_SINGLE_USER);
59 end_critical_section(S_SINGLE_USER);
63 int CtdlWantSingleUser(void)
65 return want_single_user;
69 int CtdlIsSingleUser(void)
73 /* check for only one context here */
74 if (num_sessions == 1)
82 * Locate a context by its session number and terminate it if the user is able.
83 * User can NOT terminate their current session.
84 * User CAN terminate any other session that has them logged in.
85 * Aide CAN terminate any session except the current one.
87 int CtdlTerminateOtherSession (int session_num)
89 struct CitContext *CCC = CC;
94 if (session_num == CCC->cs_pid) return TERM_NOTALLOWED;
96 aide = ( (CCC->user.axlevel >= AxAideU) || (CCC->internal_pgm) ) ;
98 syslog(LOG_DEBUG, "context: locating session to kill");
99 begin_critical_section(S_SESSION_TABLE);
100 for (ccptr = ContextList; ccptr != NULL; ccptr = ccptr->next) {
101 if (session_num == ccptr->cs_pid) {
103 if ((ccptr->user.usernum == CCC->user.usernum) || aide) {
110 if (((ret & TERM_FOUND) != 0) && ((ret & TERM_ALLOWED) != 0))
112 if (ccptr->user.usernum == CCC->user.usernum)
113 ccptr->kill_me = KILLME_ADMIN_TERMINATE;
115 ccptr->kill_me = KILLME_IDLE;
116 end_critical_section(S_SESSION_TABLE);
119 end_critical_section(S_SESSION_TABLE);
127 * Check to see if the user who we just sent mail to is logged in. If yes,
128 * bump the 'new mail' counter for their session. That enables them to
129 * receive a new mail notification without having to hit the database.
131 void BumpNewMailCounter(long which_user)
133 CtdlBumpNewMailCounter(which_user);
136 void CtdlBumpNewMailCounter(long which_user)
140 begin_critical_section(S_SESSION_TABLE);
142 for (ptr = ContextList; ptr != NULL; ptr = ptr->next) {
143 if (ptr->user.usernum == which_user) {
148 end_critical_section(S_SESSION_TABLE);
153 * Check to see if a user is currently logged in
154 * Take care with what you do as a result of this test.
155 * The user may not have been logged in when this function was called BUT
156 * because of threading the user might be logged in before you test the result.
158 int CtdlIsUserLoggedIn (char *user_name)
163 begin_critical_section (S_SESSION_TABLE);
164 for (cptr = ContextList; cptr != NULL; cptr = cptr->next) {
165 if (!strcasecmp(cptr->user.fullname, user_name)) {
170 end_critical_section(S_SESSION_TABLE);
177 * Check to see if a user is currently logged in.
178 * Basically same as CtdlIsUserLoggedIn() but uses the user number instead.
179 * Take care with what you do as a result of this test.
180 * The user may not have been logged in when this function was called BUT
181 * because of threading the user might be logged in before you test the result.
183 int CtdlIsUserLoggedInByNum (long usernum)
188 begin_critical_section(S_SESSION_TABLE);
189 for (cptr = ContextList; cptr != NULL; cptr = cptr->next) {
190 if (cptr->user.usernum == usernum) {
194 end_critical_section(S_SESSION_TABLE);
201 * Return a pointer to the CitContext structure bound to the thread which
202 * called this function. If there's no such binding (for example, if it's
203 * called by the housekeeper thread) then a generic 'master' CC is returned.
205 * This function is used *VERY* frequently and must be kept small.
207 CitContext *MyContext(void) {
208 register CitContext *c;
209 return ((c = (CitContext *) pthread_getspecific(MyConKey), c == NULL) ? &masterCC : c);
216 * Terminate idle sessions. This function pounds through the session table
217 * comparing the current time to each session's time-of-last-command. If an
218 * idle session is found it is terminated, then the search restarts at the
219 * beginning because the pointer to our place in the list becomes invalid.
221 void terminate_idle_sessions(void)
229 begin_critical_section(S_SESSION_TABLE);
230 for (ccptr = ContextList; ccptr != NULL; ccptr = ccptr->next) {
233 && (CtdlGetConfigLong("c_sleeping") > 0)
234 && (now - (ccptr->lastcmd) > CtdlGetConfigLong("c_sleeping"))
236 if (!ccptr->dont_term) {
237 ccptr->kill_me = KILLME_IDLE;
245 end_critical_section(S_SESSION_TABLE);
247 syslog(LOG_INFO, "context: scheduled %d idle sessions for termination", killed);
249 if (longrunners > 0) {
250 syslog(LOG_INFO, "context: did not terminate %d protected idle sessions", longrunners);
256 * During shutdown, close the sockets of any sessions still connected.
258 void terminate_all_sessions(void)
263 begin_critical_section(S_SESSION_TABLE);
264 for (ccptr = ContextList; ccptr != NULL; ccptr = ccptr->next) {
265 if (ccptr->client_socket != -1)
267 syslog(LOG_INFO, "context: terminate_all_sessions() is murdering %s CC[%d]", ccptr->curr_user, ccptr->cs_pid);
268 close(ccptr->client_socket);
269 ccptr->client_socket = -1;
273 end_critical_section(S_SESSION_TABLE);
275 syslog(LOG_INFO, "context: flushed %d stuck sessions", killed);
282 * Terminate a session.
284 void RemoveContext (CitContext *con)
288 syslog(LOG_ERR, "context: RemoveContext() called with NULL, this should not happen");
291 c = con->ServiceName;
295 syslog(LOG_DEBUG, "context: RemoveContext(%s) session %d", c, con->cs_pid);
298 /* Run any cleanup routines registered by loadable modules.
299 * Note: We have to "become_session()" because the cleanup functions
300 * might make references to "CC" assuming it's the right one.
304 PerformSessionHooks(EVT_STOP);
305 client_close(); /* If the client is still connected, blow 'em away. */
306 become_session(NULL);
308 syslog(LOG_INFO, "context: [%3d]SRV[%s] Session ended.", con->cs_pid, c);
311 * If the client is still connected, blow 'em away.
312 * if the socket is 0 or -1, its already gone or was never there.
314 if (con->client_socket > 0)
316 syslog(LOG_INFO, "context: closing socket %d", con->client_socket);
317 close(con->client_socket);
320 /* If using AUTHMODE_LDAP, free the DN */
325 FreeStrBuf(&con->StatusMessage);
326 FreeStrBuf(&con->MigrateBuf);
327 FreeStrBuf(&con->RecvBuf.Buf);
328 if (con->cached_msglist) {
329 free(con->cached_msglist);
332 syslog(LOG_DEBUG, "context: done with RemoveContext()");
338 * Initialize a new context and place it in the list. The session number
339 * used to be the PID (which is why it's called cs_pid), but that was when we
340 * had one process per session. Now we just assign them sequentially, starting
341 * at 1 (don't change it to 0 because masterCC uses 0).
343 CitContext *CreateNewContext(void) {
346 me = (CitContext *) malloc(sizeof(CitContext));
348 syslog(LOG_ERR, "citserver: malloc() failed: %m");
351 memset(me, 0, sizeof(CitContext));
353 /* Give the context a name. Hopefully makes it easier to track */
354 strcpy (me->user.fullname, "SYS_notauth");
356 /* The new context will be created already in the CON_EXECUTING state
357 * in order to prevent another thread from grabbing it while it's
360 me->state = CON_EXECUTING;
362 * Generate a unique session number and insert this context into
365 me->MigrateBuf = NewStrBuf();
367 me->RecvBuf.Buf = NewStrBuf();
369 me->lastcmd = time(NULL); /* set lastcmd to now to prevent idle timer infanticide TODO: if we have a valid IO, use that to set the timer. */
372 begin_critical_section(S_SESSION_TABLE);
373 me->cs_pid = ++next_pid;
375 me->next = ContextList;
377 if (me->next != NULL) {
381 end_critical_section(S_SESSION_TABLE);
387 * Initialize a new context and place it in the list. The session number
388 * used to be the PID (which is why it's called cs_pid), but that was when we
389 * had one process per session. Now we just assign them sequentially, starting
390 * at 1 (don't change it to 0 because masterCC uses 0).
392 CitContext *CloneContext(CitContext *CloneMe) {
395 me = (CitContext *) malloc(sizeof(CitContext));
397 syslog(LOG_ERR, "citserver: malloc() failed: %m");
400 memcpy(me, CloneMe, sizeof(CitContext));
402 memset(&me->RecvBuf, 0, sizeof(IOBuffer));
403 memset(&me->SendBuf, 0, sizeof(IOBuffer));
404 memset(&me->SBuf, 0, sizeof(IOBuffer));
405 me->MigrateBuf = NULL;
406 me->sMigrateBuf = NULL;
407 me->redirect_buffer = NULL;
412 me->download_fp = NULL;
413 me->upload_fp = NULL;
414 /// TODO: what about the room/user?
416 me->openid_data = NULL;
418 me->session_specific_data = NULL;
422 me->cached_msglist = NULL;
423 me->download_fp = NULL;
424 me->upload_fp = NULL;
425 me->client_socket = 0;
427 me->MigrateBuf = NewStrBuf();
428 me->RecvBuf.Buf = NewStrBuf();
430 begin_critical_section(S_SESSION_TABLE);
432 me->cs_pid = ++next_pid;
434 me->next = ContextList;
435 me->lastcmd = time(NULL); /* set lastcmd to now to prevent idle timer infanticide */
437 if (me->next != NULL) {
442 end_critical_section(S_SESSION_TABLE);
448 * Return an array containing a copy of the context list.
449 * This allows worker threads to perform "for each context" operations without
450 * having to lock and traverse the live list.
452 CitContext *CtdlGetContextArray(int *count)
455 CitContext *nptr, *cptr;
457 nContexts = num_sessions;
458 nptr = malloc(sizeof(CitContext) * nContexts);
463 begin_critical_section(S_SESSION_TABLE);
464 for (cptr = ContextList, i=0; cptr != NULL && i < nContexts; cptr = cptr->next, i++) {
465 memcpy(&nptr[i], cptr, sizeof (CitContext));
467 end_critical_section (S_SESSION_TABLE);
476 * Back-end function for starting a session
478 void begin_session(CitContext *con)
481 * Initialize some variables specific to our context.
484 con->internal_pgm = 0;
485 con->download_fp = NULL;
486 con->upload_fp = NULL;
487 con->cached_msglist = NULL;
488 con->cached_num_msgs = 0;
489 con->FirstExpressMessage = NULL;
491 time(&con->lastidle);
492 strcpy(con->lastcmdname, " ");
493 strcpy(con->cs_clientname, "(unknown)");
494 strcpy(con->curr_user, NLI);
495 *con->fake_username = '\0';
496 *con->fake_hostname = '\0';
497 *con->fake_roomname = '\0';
498 *con->cs_clientinfo = '\0';
499 safestrncpy(con->cs_host, CtdlGetConfigStr("c_fqdn"), sizeof con->cs_host);
500 safestrncpy(con->cs_addr, "", sizeof con->cs_addr);
501 con->cs_UDSclientUID = -1;
502 con->cs_host[sizeof con->cs_host - 1] = 0;
503 if (!CC->is_local_socket) {
504 locate_host(con->cs_host, sizeof con->cs_host,
505 con->cs_addr, sizeof con->cs_addr,
512 #ifdef HAVE_STRUCT_UCRED
514 /* as http://www.wsinnovations.com/softeng/articles/uds.html told us... */
515 struct ucred credentials;
516 socklen_t ucred_length = sizeof(struct ucred);
518 /*fill in the user data structure */
519 if(getsockopt(con->client_socket, SOL_SOCKET, SO_PEERCRED, &credentials, &ucred_length)) {
520 syslog(LOG_ERR, "context: could obtain credentials from unix domain socket");
524 /* the process ID of the process on the other side of the socket */
525 /* credentials.pid; */
527 /* the effective UID of the process on the other side of the socket */
528 con->cs_UDSclientUID = credentials.uid;
530 /* the effective primary GID of the process on the other side of the socket */
531 /* credentials.gid; */
533 /* To get supplemental groups, we will have to look them up in our account
534 database, after a reverse lookup on the UID to get the account name.
535 We can take this opportunity to check to see if this is a legit account.
537 snprintf(con->cs_clientinfo, sizeof(con->cs_clientinfo),
538 "PID: "F_PID_T"; UID: "F_UID_T"; GID: "F_XPID_T" ",
547 con->upload_type = UPL_FILE;
550 if (((CtdlGetConfigInt("c_maxsessions") > 0)&&(num_sessions > CtdlGetConfigInt("c_maxsessions"))) || CtdlWantSingleUser()) {
554 if (!CC->is_local_socket) {
555 syslog(LOG_INFO, "context: session (%s) started from %s (%s)", con->ServiceName, con->cs_host, con->cs_addr);
558 syslog(LOG_INFO, "context: session (%s) started via local socket with uid=%d", con->ServiceName, con->cs_UDSclientUID);
561 /* Run any session startup routines registered by loadable modules */
562 PerformSessionHooks(EVT_START);
567 * This function fills in a context and its user field correctly
568 * Then creates/loads that user
570 void CtdlFillSystemContext(CitContext *context, char *name)
575 memset(context, 0, sizeof(CitContext));
576 context->internal_pgm = 1;
578 strcpy (sysname, "SYS_");
579 strcat (sysname, name);
580 len = cutuserkey(sysname);
581 memcpy(context->curr_user, sysname, len + 1);
582 context->client_socket = (-1);
583 context->state = CON_SYS;
584 context->ServiceName = name;
586 /* internal_create_user has the side effect of loading the user regardless of whether they
587 * already existed or needed to be created
589 internal_create_user(sysname, &(context->user), -1) ;
591 /* Check to see if the system user needs upgrading */
592 if (context->user.usernum == 0)
593 { /* old system user with number 0, upgrade it */
594 context->user.usernum = get_new_user_number();
595 syslog(LOG_INFO, "context: upgrading system user \"%s\" from user number 0 to user number %ld", context->user.fullname, context->user.usernum);
596 /* add user to the database */
597 CtdlPutUser(&(context->user));
598 cdb_store(CDB_USERSBYNUMBER, &(context->user.usernum), sizeof(long), context->user.fullname, strlen(context->user.fullname)+1);
604 * Cleanup any contexts that are left lying around
606 void context_cleanup(void)
608 CitContext *ptr = NULL;
609 CitContext *rem = NULL;
612 * Clean up the contexts.
613 * There are no threads so no critical_section stuff is needed.
617 /* We need to update the ContextList because some modules may want to itterate it
618 * Question is should we NULL it before iterating here or should we just keep updating it
619 * as we remove items?
621 * Answer is to NULL it first to prevent modules from doing any actions on the list at all
625 /* Remove the session from the active list */
629 syslog(LOG_DEBUG, "context: context_cleanup() purging session %d", ptr->cs_pid);
639 * Purge all sessions which have the 'kill_me' flag set.
640 * This function has code to prevent it from running more than once every
641 * few seconds, because running it after every single unbind would waste a lot
642 * of CPU time and keep the context list locked too much. To force it to run
643 * anyway, set "force" to nonzero.
645 void dead_session_purge(int force) {
646 CitContext *ptr, *ptr2; /* general-purpose utility pointer */
647 CitContext *rem = NULL; /* list of sessions to be destroyed */
650 if ( (time(NULL) - last_purge) < 5 ) {
651 return; /* Too soon, go away */
656 if (try_critical_section(S_SESSION_TABLE))
664 if ( (ptr2->state == CON_IDLE) && (ptr2->kill_me) ) {
665 /* Remove the session from the active list */
667 ptr2->prev->next = ptr2->next;
670 ContextList = ptr2->next;
673 ptr2->next->prev = ptr2->prev;
677 /* And put it on our to-be-destroyed list */
682 end_critical_section(S_SESSION_TABLE);
684 /* Now that we no longer have the session list locked, we can take
685 * our time and destroy any sessions on the to-be-killed list, which
686 * is allocated privately on this thread's stack.
688 while (rem != NULL) {
689 syslog(LOG_DEBUG, "context: dead_session_purge() purging session %d, reason=%d", rem->cs_pid, rem->kill_me);
702 * masterCC is the context we use when not attached to a session. This
703 * function initializes it.
705 void InitializeMasterCC(void) {
706 memset(&masterCC, 0, sizeof(struct CitContext));
707 masterCC.internal_pgm = 1;
716 * Set the "async waiting" flag for a session, if applicable
718 void set_async_waiting(struct CitContext *ccptr)
720 syslog(LOG_DEBUG, "context: setting async_waiting flag for session %d", ccptr->cs_pid);
721 if (ccptr->is_async) {
722 ccptr->async_waiting++;
723 if (ccptr->state == CON_IDLE) {
724 ccptr->state = CON_READY;
730 CTDL_MODULE_INIT(session)