2 * Citadel context management stuff.
3 * Here's where we (hopefully) have all the code that manipulates contexts.
5 * Copyright (c) 1987-2011 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.
23 #include <sys/types.h>
26 #include <sys/socket.h>
28 #include <sys/syslog.h>
30 #include <sys/syscall.h>
33 #if TIME_WITH_SYS_TIME
34 # include <sys/time.h>
38 # include <sys/time.h>
45 #include <sys/resource.h>
46 #include <netinet/in.h>
47 #include <netinet/tcp.h>
48 #include <arpa/inet.h>
56 #include <libcitadel.h>
59 #include "sysdep_decls.h"
60 #include "citserver.h"
64 #include "housekeeping.h"
65 #include "modules/crypto/serv_crypto.h" /* Needed for init_ssl, client_write_ssl, client_read_ssl, destruct_ssl */
68 #ifdef HAVE_SYS_SELECT_H
69 #include <sys/select.h>
76 #include "ctdl_module.h"
83 pthread_key_t MyConKey; /* TSD key for MyContext() */
87 CitContext *ContextList = NULL;
89 time_t last_purge = 0; /* Last dead session purge */
90 int num_sessions = 0; /* Current number of sessions */
92 /* Flag for single user mode */
93 static int want_single_user = 0;
95 /* Try to go single user */
97 int CtdlTrySingleUser(void)
101 begin_critical_section(S_SINGLE_USER);
102 if (want_single_user)
107 want_single_user = 1;
109 end_critical_section(S_SINGLE_USER);
113 void CtdlEndSingleUser(void)
115 begin_critical_section(S_SINGLE_USER);
116 want_single_user = 0;
117 end_critical_section(S_SINGLE_USER);
121 int CtdlWantSingleUser(void)
123 return want_single_user;
126 int CtdlIsSingleUser(void)
128 if (want_single_user)
130 /* check for only one context here */
131 if (num_sessions == 1)
142 * Locate a context by its session number and terminate it if the user is able.
143 * User can NOT terminate their current session.
144 * User CAN terminate any other session that has them logged in.
145 * Aide CAN terminate any session except the current one.
147 int CtdlTerminateOtherSession (int session_num)
152 if (session_num == CC->cs_pid) {
153 return TERM_NOTALLOWED;
156 CONM_syslog(LOG_DEBUG, "Locating session to kill\n");
157 begin_critical_section(S_SESSION_TABLE);
158 for (ccptr = ContextList; ccptr != NULL; ccptr = ccptr->next) {
159 if (session_num == ccptr->cs_pid) {
161 if ((ccptr->user.usernum == CC->user.usernum)
162 || (CC->user.axlevel >= AxAideU)) {
164 ccptr->kill_me = KILLME_ADMIN_TERMINATE;
168 end_critical_section(S_SESSION_TABLE);
175 * Check to see if the user who we just sent mail to is logged in. If yes,
176 * bump the 'new mail' counter for their session. That enables them to
177 * receive a new mail notification without having to hit the database.
179 void BumpNewMailCounter(long which_user)
181 CtdlBumpNewMailCounter(which_user);
184 void CtdlBumpNewMailCounter(long which_user)
188 begin_critical_section(S_SESSION_TABLE);
190 for (ptr = ContextList; ptr != NULL; ptr = ptr->next) {
191 if (ptr->user.usernum == which_user) {
196 end_critical_section(S_SESSION_TABLE);
201 * Check to see if a user is currently logged in
202 * Take care with what you do as a result of this test.
203 * The user may not have been logged in when this function was called BUT
204 * because of threading the user might be logged in before you test the result.
206 int CtdlIsUserLoggedIn (char *user_name)
211 begin_critical_section (S_SESSION_TABLE);
212 for (cptr = ContextList; cptr != NULL; cptr = cptr->next) {
213 if (!strcasecmp(cptr->user.fullname, user_name)) {
218 end_critical_section(S_SESSION_TABLE);
225 * Check to see if a user is currently logged in.
226 * Basically same as CtdlIsUserLoggedIn() but uses the user number instead.
227 * Take care with what you do as a result of this test.
228 * The user may not have been logged in when this function was called BUT
229 * because of threading the user might be logged in before you test the result.
231 int CtdlIsUserLoggedInByNum (long usernum)
236 begin_critical_section(S_SESSION_TABLE);
237 for (cptr = ContextList; cptr != NULL; cptr = cptr->next) {
238 if (cptr->user.usernum == usernum) {
242 end_critical_section(S_SESSION_TABLE);
249 * Return a pointer to the CitContext structure bound to the thread which
250 * called this function. If there's no such binding (for example, if it's
251 * called by the housekeeper thread) then a generic 'master' CC is returned.
253 * This function is used *VERY* frequently and must be kept small.
255 CitContext *MyContext(void) {
256 register CitContext *c;
257 return ((c = (CitContext *) pthread_getspecific(MyConKey), c == NULL) ? &masterCC : c);
264 * Terminate idle sessions. This function pounds through the session table
265 * comparing the current time to each session's time-of-last-command. If an
266 * idle session is found it is terminated, then the search restarts at the
267 * beginning because the pointer to our place in the list becomes invalid.
269 void terminate_idle_sessions(void)
277 begin_critical_section(S_SESSION_TABLE);
278 for (ccptr = ContextList; ccptr != NULL; ccptr = ccptr->next) {
281 && (config.c_sleeping > 0)
282 && (now - (ccptr->lastcmd) > config.c_sleeping)
284 if (!ccptr->dont_term) {
285 ccptr->kill_me = KILLME_IDLE;
293 end_critical_section(S_SESSION_TABLE);
295 CON_syslog(LOG_INFO, "Scheduled %d idle sessions for termination\n", killed);
297 CON_syslog(LOG_INFO, "Didn't terminate %d protected idle sessions", longrunners);
302 * During shutdown, close the sockets of any sessions still connected.
304 void terminate_all_sessions(void)
309 begin_critical_section(S_SESSION_TABLE);
310 for (ccptr = ContextList; ccptr != NULL; ccptr = ccptr->next) {
311 if (ccptr->client_socket != -1)
313 CON_syslog(LOG_INFO, "terminate_all_sessions() is murdering %s", ccptr->curr_user);
314 close(ccptr->client_socket);
315 ccptr->client_socket = -1;
319 end_critical_section(S_SESSION_TABLE);
321 CON_syslog(LOG_INFO, "Flushed %d stuck sessions\n", killed);
328 * Terminate a session.
330 void RemoveContext (CitContext *con)
334 CONM_syslog(LOG_ERR, "WARNING: RemoveContext() called with NULL!");
337 c = con->ServiceName;
341 CON_syslog(LOG_DEBUG, "RemoveContext(%s) session %d", c, con->cs_pid);
344 /* Run any cleanup routines registered by loadable modules.
345 * Note: We have to "become_session()" because the cleanup functions
346 * might make references to "CC" assuming it's the right one.
350 PerformSessionHooks(EVT_STOP);
351 client_close(); /* If the client is still connected, blow 'em away. */
352 become_session(NULL);
354 CON_syslog(LOG_NOTICE, "[%3d]SRV[%s] Session ended.", con->cs_pid, c);
357 * If the client is still connected, blow 'em away.
358 * if the socket is 0 or -1, its already gone or was never there.
360 if (con->client_socket > 0)
362 CON_syslog(LOG_NOTICE, "Closing socket %d", con->client_socket);
363 close(con->client_socket);
366 /* If using AUTHMODE_LDAP, free the DN */
371 FreeStrBuf(&con->StatusMessage);
372 FreeStrBuf(&con->MigrateBuf);
373 FreeStrBuf(&con->RecvBuf.Buf);
374 if (con->cached_msglist) {
375 free(con->cached_msglist);
378 CONM_syslog(LOG_DEBUG, "Done with RemoveContext()");
384 * Initialize a new context and place it in the list. The session number
385 * used to be the PID (which is why it's called cs_pid), but that was when we
386 * had one process per session. Now we just assign them sequentially, starting
387 * at 1 (don't change it to 0 because masterCC uses 0).
389 CitContext *CreateNewContext(void) {
391 static int next_pid = 0;
393 me = (CitContext *) malloc(sizeof(CitContext));
395 CONM_syslog(LOG_ALERT, "citserver: can't allocate memory!!\n");
398 memset(me, 0, sizeof(CitContext));
400 /* Give the context a name. Hopefully makes it easier to track */
401 strcpy (me->user.fullname, "SYS_notauth");
403 /* The new context will be created already in the CON_EXECUTING state
404 * in order to prevent another thread from grabbing it while it's
407 me->state = CON_EXECUTING;
409 * Generate a unique session number and insert this context into
412 me->MigrateBuf = NewStrBuf();
414 me->RecvBuf.Buf = NewStrBuf();
416 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. */
419 begin_critical_section(S_SESSION_TABLE);
420 me->cs_pid = ++next_pid;
422 me->next = ContextList;
424 if (me->next != NULL) {
428 end_critical_section(S_SESSION_TABLE);
434 * Initialize a new context and place it in the list. The session number
435 * used to be the PID (which is why it's called cs_pid), but that was when we
436 * had one process per session. Now we just assign them sequentially, starting
437 * at 1 (don't change it to 0 because masterCC uses 0).
439 CitContext *CloneContext(CitContext *CloneMe) {
441 static int next_pid = 0;
443 me = (CitContext *) malloc(sizeof(CitContext));
445 CONM_syslog(LOG_ALERT, "citserver: can't allocate memory!!\n");
448 memcpy(me, CloneMe, sizeof(CitContext));
450 memset(&me->RecvBuf, 0, sizeof(IOBuffer));
451 memset(&me->SendBuf, 0, sizeof(IOBuffer));
452 memset(&me->SBuf, 0, sizeof(IOBuffer));
453 me->MigrateBuf = NULL;
454 me->sMigrateBuf = NULL;
455 me->redirect_buffer = NULL;
460 me->download_fp = NULL;
461 me->upload_fp = NULL;
462 /// TODO: what about the room/user?
464 me->openid_data = NULL;
466 me->session_specific_data = NULL;
468 me->download_fp = NULL;
469 me->upload_fp = NULL;
470 me->client_socket = 0;
472 me->MigrateBuf = NewStrBuf();
473 me->RecvBuf.Buf = NewStrBuf();
475 begin_critical_section(S_SESSION_TABLE);
477 me->cs_pid = ++next_pid;
479 me->next = ContextList;
480 me->lastcmd = time(NULL); /* set lastcmd to now to prevent idle timer infanticide */
482 if (me->next != NULL) {
487 end_critical_section(S_SESSION_TABLE);
493 * Return an array containing a copy of the context list.
494 * This allows worker threads to perform "for each context" operations without
495 * having to lock and traverse the live list.
497 CitContext *CtdlGetContextArray(int *count)
500 CitContext *nptr, *cptr;
502 nContexts = num_sessions;
503 nptr = malloc(sizeof(CitContext) * nContexts);
508 begin_critical_section(S_SESSION_TABLE);
509 for (cptr = ContextList, i=0; cptr != NULL && i < nContexts; cptr = cptr->next, i++) {
510 memcpy(&nptr[i], cptr, sizeof (CitContext));
512 end_critical_section (S_SESSION_TABLE);
521 * This function fills in a context and its user field correctly
522 * Then creates/loads that user
524 void CtdlFillSystemContext(CitContext *context, char *name)
529 memset(context, 0, sizeof(CitContext));
530 context->internal_pgm = 1;
532 strcpy (sysname, "SYS_");
533 strcat (sysname, name);
534 len = cutuserkey(sysname);
535 memcpy(context->curr_user, sysname, len + 1);
536 context->client_socket = (-1);
537 context->state = CON_SYS;
538 context->ServiceName = name;
540 /* internal_create_user has the side effect of loading the user regardless of wether they
541 * already existed or needed to be created
543 internal_create_user (sysname, len, &(context->user), -1) ;
545 /* Check to see if the system user needs upgrading */
546 if (context->user.usernum == 0)
547 { /* old system user with number 0, upgrade it */
548 context->user.usernum = get_new_user_number();
549 CON_syslog(LOG_INFO, "Upgrading system user \"%s\" from user number 0 to user number %ld\n", context->user.fullname, context->user.usernum);
550 /* add user to the database */
551 CtdlPutUser(&(context->user));
552 cdb_store(CDB_USERSBYNUMBER, &(context->user.usernum), sizeof(long), context->user.fullname, strlen(context->user.fullname)+1);
558 * Cleanup any contexts that are left lying around
560 void context_cleanup(void)
562 CitContext *ptr = NULL;
563 CitContext *rem = NULL;
566 * Clean up the contexts.
567 * There are no threads so no critical_section stuff is needed.
571 /* We need to update the ContextList because some modules may want to itterate it
572 * Question is should we NULL it before iterating here or should we just keep updating it
573 * as we remove items?
575 * Answer is to NULL it first to prevent modules from doing any actions on the list at all
579 /* Remove the session from the active list */
583 CON_syslog(LOG_DEBUG, "context_cleanup(): purging session %d\n", ptr->cs_pid);
593 * Purge all sessions which have the 'kill_me' flag set.
594 * This function has code to prevent it from running more than once every
595 * few seconds, because running it after every single unbind would waste a lot
596 * of CPU time and keep the context list locked too much. To force it to run
597 * anyway, set "force" to nonzero.
599 void dead_session_purge(int force) {
600 CitContext *ptr, *ptr2; /* general-purpose utility pointer */
601 CitContext *rem = NULL; /* list of sessions to be destroyed */
604 if ( (time(NULL) - last_purge) < 5 ) {
605 return; /* Too soon, go away */
610 if (try_critical_section(S_SESSION_TABLE))
618 if ( (ptr2->state == CON_IDLE) && (ptr2->kill_me) ) {
619 /* Remove the session from the active list */
621 ptr2->prev->next = ptr2->next;
624 ContextList = ptr2->next;
627 ptr2->next->prev = ptr2->prev;
631 /* And put it on our to-be-destroyed list */
636 end_critical_section(S_SESSION_TABLE);
638 /* Now that we no longer have the session list locked, we can take
639 * our time and destroy any sessions on the to-be-killed list, which
640 * is allocated privately on this thread's stack.
642 while (rem != NULL) {
643 CON_syslog(LOG_DEBUG, "dead_session_purge(): purging session %d, reason=%d\n", rem->cs_pid, rem->kill_me);
656 * masterCC is the context we use when not attached to a session. This
657 * function initializes it.
659 void InitializeMasterCC(void) {
660 memset(&masterCC, 0, sizeof(struct CitContext));
661 masterCC.internal_pgm = 1;
670 * Set the "async waiting" flag for a session, if applicable
672 void set_async_waiting(struct CitContext *ccptr)
674 CON_syslog(LOG_DEBUG, "Setting async_waiting flag for session %d\n", ccptr->cs_pid);
675 if (ccptr->is_async) {
676 ccptr->async_waiting++;
677 if (ccptr->state == CON_IDLE) {
678 ccptr->state = CON_READY;
684 void DebugSessionEnable(const int n)
688 CTDL_MODULE_INIT(session)
691 CtdlRegisterDebugFlagHook(HKEY("session"), DebugSessionEnable, &DebugSession);