2 * Citadel context management stuff.
3 * Here's where we (hopefully) have all the code that manipulates contexts.
5 * Copyright (c) 1987-2015 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"
20 #include "citserver.h"
22 #include "locate_host.h"
29 pthread_key_t MyConKey; /* TSD key for MyContext() */
33 CitContext *ContextList = NULL;
35 time_t last_purge = 0; /* Last dead session purge */
36 int num_sessions = 0; /* Current number of sessions */
39 /* Flag for single user mode */
40 static int want_single_user = 0;
42 /* Try to go single user */
44 int CtdlTrySingleUser(void)
48 begin_critical_section(S_SINGLE_USER);
56 end_critical_section(S_SINGLE_USER);
60 void CtdlEndSingleUser(void)
62 begin_critical_section(S_SINGLE_USER);
64 end_critical_section(S_SINGLE_USER);
68 int CtdlWantSingleUser(void)
70 return want_single_user;
73 int CtdlIsSingleUser(void)
77 /* check for only one context here */
78 if (num_sessions == 1)
89 * Locate a context by its session number and terminate it if the user is able.
90 * User can NOT terminate their current session.
91 * User CAN terminate any other session that has them logged in.
92 * Aide CAN terminate any session except the current one.
94 int CtdlTerminateOtherSession (int session_num)
96 struct CitContext *CCC = CC;
101 if (session_num == CCC->cs_pid) return TERM_NOTALLOWED;
103 aide = ( (CCC->user.axlevel >= AxAideU) || (CCC->internal_pgm) ) ;
105 syslog(LOG_DEBUG, "context: locating session to kill");
106 begin_critical_section(S_SESSION_TABLE);
107 for (ccptr = ContextList; ccptr != NULL; ccptr = ccptr->next) {
108 if (session_num == ccptr->cs_pid) {
110 if ((ccptr->user.usernum == CCC->user.usernum) || aide) {
117 if (((ret & TERM_FOUND) != 0) && ((ret & TERM_ALLOWED) != 0))
119 if (ccptr->user.usernum == CCC->user.usernum)
120 ccptr->kill_me = KILLME_ADMIN_TERMINATE;
122 ccptr->kill_me = KILLME_IDLE;
123 end_critical_section(S_SESSION_TABLE);
126 end_critical_section(S_SESSION_TABLE);
134 * Check to see if the user who we just sent mail to is logged in. If yes,
135 * bump the 'new mail' counter for their session. That enables them to
136 * receive a new mail notification without having to hit the database.
138 void BumpNewMailCounter(long which_user)
140 CtdlBumpNewMailCounter(which_user);
143 void CtdlBumpNewMailCounter(long which_user)
147 begin_critical_section(S_SESSION_TABLE);
149 for (ptr = ContextList; ptr != NULL; ptr = ptr->next) {
150 if (ptr->user.usernum == which_user) {
155 end_critical_section(S_SESSION_TABLE);
160 * Check to see if a user is currently logged in
161 * Take care with what you do as a result of this test.
162 * The user may not have been logged in when this function was called BUT
163 * because of threading the user might be logged in before you test the result.
165 int CtdlIsUserLoggedIn (char *user_name)
170 begin_critical_section (S_SESSION_TABLE);
171 for (cptr = ContextList; cptr != NULL; cptr = cptr->next) {
172 if (!strcasecmp(cptr->user.fullname, user_name)) {
177 end_critical_section(S_SESSION_TABLE);
184 * Check to see if a user is currently logged in.
185 * Basically same as CtdlIsUserLoggedIn() but uses the user number instead.
186 * Take care with what you do as a result of this test.
187 * The user may not have been logged in when this function was called BUT
188 * because of threading the user might be logged in before you test the result.
190 int CtdlIsUserLoggedInByNum (long usernum)
195 begin_critical_section(S_SESSION_TABLE);
196 for (cptr = ContextList; cptr != NULL; cptr = cptr->next) {
197 if (cptr->user.usernum == usernum) {
201 end_critical_section(S_SESSION_TABLE);
208 * Return a pointer to the CitContext structure bound to the thread which
209 * called this function. If there's no such binding (for example, if it's
210 * called by the housekeeper thread) then a generic 'master' CC is returned.
212 * This function is used *VERY* frequently and must be kept small.
214 CitContext *MyContext(void) {
215 register CitContext *c;
216 return ((c = (CitContext *) pthread_getspecific(MyConKey), c == NULL) ? &masterCC : c);
223 * Terminate idle sessions. This function pounds through the session table
224 * comparing the current time to each session's time-of-last-command. If an
225 * idle session is found it is terminated, then the search restarts at the
226 * beginning because the pointer to our place in the list becomes invalid.
228 void terminate_idle_sessions(void)
236 begin_critical_section(S_SESSION_TABLE);
237 for (ccptr = ContextList; ccptr != NULL; ccptr = ccptr->next) {
240 && (CtdlGetConfigLong("c_sleeping") > 0)
241 && (now - (ccptr->lastcmd) > CtdlGetConfigLong("c_sleeping"))
243 if (!ccptr->dont_term) {
244 ccptr->kill_me = KILLME_IDLE;
252 end_critical_section(S_SESSION_TABLE);
254 syslog(LOG_INFO, "context: scheduled %d idle sessions for termination", killed);
256 if (longrunners > 0) {
257 syslog(LOG_INFO, "context: did not terminate %d protected idle sessions", longrunners);
263 * During shutdown, close the sockets of any sessions still connected.
265 void terminate_all_sessions(void)
270 begin_critical_section(S_SESSION_TABLE);
271 for (ccptr = ContextList; ccptr != NULL; ccptr = ccptr->next) {
272 if (ccptr->client_socket != -1)
274 syslog(LOG_INFO, "context: terminate_all_sessions() is murdering %s CC[%d]", ccptr->curr_user, ccptr->cs_pid);
275 close(ccptr->client_socket);
276 ccptr->client_socket = -1;
280 end_critical_section(S_SESSION_TABLE);
282 syslog(LOG_INFO, "context: flushed %d stuck sessions", killed);
289 * Terminate a session.
291 void RemoveContext (CitContext *con)
295 syslog(LOG_ERR, "context: RemoveContext() called with NULL, this should not happen");
298 c = con->ServiceName;
302 syslog(LOG_DEBUG, "context: RemoveContext(%s) session %d", c, con->cs_pid);
305 /* Run any cleanup routines registered by loadable modules.
306 * Note: We have to "become_session()" because the cleanup functions
307 * might make references to "CC" assuming it's the right one.
311 PerformSessionHooks(EVT_STOP);
312 client_close(); /* If the client is still connected, blow 'em away. */
313 become_session(NULL);
315 syslog(LOG_INFO, "context: [%3d]SRV[%s] Session ended.", con->cs_pid, c);
318 * If the client is still connected, blow 'em away.
319 * if the socket is 0 or -1, its already gone or was never there.
321 if (con->client_socket > 0)
323 syslog(LOG_INFO, "context: closing socket %d", con->client_socket);
324 close(con->client_socket);
327 /* If using AUTHMODE_LDAP, free the DN */
332 FreeStrBuf(&con->StatusMessage);
333 FreeStrBuf(&con->MigrateBuf);
334 FreeStrBuf(&con->RecvBuf.Buf);
335 if (con->cached_msglist) {
336 free(con->cached_msglist);
339 syslog(LOG_DEBUG, "context: done with RemoveContext()");
345 * Initialize a new context and place it in the list. The session number
346 * used to be the PID (which is why it's called cs_pid), but that was when we
347 * had one process per session. Now we just assign them sequentially, starting
348 * at 1 (don't change it to 0 because masterCC uses 0).
350 CitContext *CreateNewContext(void) {
353 me = (CitContext *) malloc(sizeof(CitContext));
355 syslog(LOG_ERR, "citserver: malloc() failed: %s", strerror(errno));
358 memset(me, 0, sizeof(CitContext));
360 /* Give the context a name. Hopefully makes it easier to track */
361 strcpy (me->user.fullname, "SYS_notauth");
363 /* The new context will be created already in the CON_EXECUTING state
364 * in order to prevent another thread from grabbing it while it's
367 me->state = CON_EXECUTING;
369 * Generate a unique session number and insert this context into
372 me->MigrateBuf = NewStrBuf();
374 me->RecvBuf.Buf = NewStrBuf();
376 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. */
379 begin_critical_section(S_SESSION_TABLE);
380 me->cs_pid = ++next_pid;
382 me->next = ContextList;
384 if (me->next != NULL) {
388 end_critical_section(S_SESSION_TABLE);
394 * Initialize a new context and place it in the list. The session number
395 * used to be the PID (which is why it's called cs_pid), but that was when we
396 * had one process per session. Now we just assign them sequentially, starting
397 * at 1 (don't change it to 0 because masterCC uses 0).
399 CitContext *CloneContext(CitContext *CloneMe) {
402 me = (CitContext *) malloc(sizeof(CitContext));
404 syslog(LOG_ERR, "citserver: malloc() failed: %s", strerror(errno));
407 memcpy(me, CloneMe, sizeof(CitContext));
409 memset(&me->RecvBuf, 0, sizeof(IOBuffer));
410 memset(&me->SendBuf, 0, sizeof(IOBuffer));
411 memset(&me->SBuf, 0, sizeof(IOBuffer));
412 me->MigrateBuf = NULL;
413 me->sMigrateBuf = NULL;
414 me->redirect_buffer = NULL;
419 me->download_fp = NULL;
420 me->upload_fp = NULL;
421 /// TODO: what about the room/user?
423 me->openid_data = NULL;
425 me->session_specific_data = NULL;
429 me->cached_msglist = NULL;
430 me->download_fp = NULL;
431 me->upload_fp = NULL;
432 me->client_socket = 0;
434 me->MigrateBuf = NewStrBuf();
435 me->RecvBuf.Buf = NewStrBuf();
437 begin_critical_section(S_SESSION_TABLE);
439 me->cs_pid = ++next_pid;
441 me->next = ContextList;
442 me->lastcmd = time(NULL); /* set lastcmd to now to prevent idle timer infanticide */
444 if (me->next != NULL) {
449 end_critical_section(S_SESSION_TABLE);
455 * Return an array containing a copy of the context list.
456 * This allows worker threads to perform "for each context" operations without
457 * having to lock and traverse the live list.
459 CitContext *CtdlGetContextArray(int *count)
462 CitContext *nptr, *cptr;
464 nContexts = num_sessions;
465 nptr = malloc(sizeof(CitContext) * nContexts);
470 begin_critical_section(S_SESSION_TABLE);
471 for (cptr = ContextList, i=0; cptr != NULL && i < nContexts; cptr = cptr->next, i++) {
472 memcpy(&nptr[i], cptr, sizeof (CitContext));
474 end_critical_section (S_SESSION_TABLE);
483 * Back-end function for starting a session
485 void begin_session(CitContext *con)
488 * Initialize some variables specific to our context.
491 con->internal_pgm = 0;
492 con->download_fp = NULL;
493 con->upload_fp = NULL;
494 con->cached_msglist = NULL;
495 con->cached_num_msgs = 0;
496 con->FirstExpressMessage = NULL;
498 time(&con->lastidle);
499 strcpy(con->lastcmdname, " ");
500 strcpy(con->cs_clientname, "(unknown)");
501 strcpy(con->curr_user, NLI);
502 *con->net_node = '\0';
503 *con->fake_username = '\0';
504 *con->fake_hostname = '\0';
505 *con->fake_roomname = '\0';
506 *con->cs_clientinfo = '\0';
507 safestrncpy(con->cs_host, CtdlGetConfigStr("c_fqdn"), sizeof con->cs_host);
508 safestrncpy(con->cs_addr, "", sizeof con->cs_addr);
509 con->cs_UDSclientUID = -1;
510 con->cs_host[sizeof con->cs_host - 1] = 0;
511 if (!CC->is_local_socket) {
512 locate_host(con->cs_host, sizeof con->cs_host,
513 con->cs_addr, sizeof con->cs_addr,
520 #ifdef HAVE_STRUCT_UCRED
522 /* as http://www.wsinnovations.com/softeng/articles/uds.html told us... */
523 struct ucred credentials;
524 socklen_t ucred_length = sizeof(struct ucred);
526 /*fill in the user data structure */
527 if(getsockopt(con->client_socket, SOL_SOCKET, SO_PEERCRED, &credentials, &ucred_length)) {
528 syslog(LOG_ERR, "context: could obtain credentials from unix domain socket");
532 /* the process ID of the process on the other side of the socket */
533 /* credentials.pid; */
535 /* the effective UID of the process on the other side of the socket */
536 con->cs_UDSclientUID = credentials.uid;
538 /* the effective primary GID of the process on the other side of the socket */
539 /* credentials.gid; */
541 /* To get supplemental groups, we will have to look them up in our account
542 database, after a reverse lookup on the UID to get the account name.
543 We can take this opportunity to check to see if this is a legit account.
545 snprintf(con->cs_clientinfo, sizeof(con->cs_clientinfo),
546 "PID: "F_PID_T"; UID: "F_UID_T"; GID: "F_XPID_T" ",
555 con->upload_type = UPL_FILE;
559 if (((CtdlGetConfigInt("c_maxsessions") > 0)&&(num_sessions > CtdlGetConfigInt("c_maxsessions"))) || CtdlWantSingleUser()) {
563 if (!CC->is_local_socket) {
564 syslog(LOG_INFO, "context: session (%s) started from %s (%s)", con->ServiceName, con->cs_host, con->cs_addr);
567 syslog(LOG_INFO, "context: session (%s) started via local socket with uid=%d", con->ServiceName, con->cs_UDSclientUID);
570 /* Run any session startup routines registered by loadable modules */
571 PerformSessionHooks(EVT_START);
576 * This function fills in a context and its user field correctly
577 * Then creates/loads that user
579 void CtdlFillSystemContext(CitContext *context, char *name)
584 memset(context, 0, sizeof(CitContext));
585 context->internal_pgm = 1;
587 strcpy (sysname, "SYS_");
588 strcat (sysname, name);
589 len = cutuserkey(sysname);
590 memcpy(context->curr_user, sysname, len + 1);
591 context->client_socket = (-1);
592 context->state = CON_SYS;
593 context->ServiceName = name;
595 /* internal_create_user has the side effect of loading the user regardless of wether they
596 * already existed or needed to be created
598 internal_create_user (sysname, len, &(context->user), -1) ;
600 /* Check to see if the system user needs upgrading */
601 if (context->user.usernum == 0)
602 { /* old system user with number 0, upgrade it */
603 context->user.usernum = get_new_user_number();
604 syslog(LOG_INFO, "context: upgrading system user \"%s\" from user number 0 to user number %ld", context->user.fullname, context->user.usernum);
605 /* add user to the database */
606 CtdlPutUser(&(context->user));
607 cdb_store(CDB_USERSBYNUMBER, &(context->user.usernum), sizeof(long), context->user.fullname, strlen(context->user.fullname)+1);
613 * Cleanup any contexts that are left lying around
615 void context_cleanup(void)
617 CitContext *ptr = NULL;
618 CitContext *rem = NULL;
621 * Clean up the contexts.
622 * There are no threads so no critical_section stuff is needed.
626 /* We need to update the ContextList because some modules may want to itterate it
627 * Question is should we NULL it before iterating here or should we just keep updating it
628 * as we remove items?
630 * Answer is to NULL it first to prevent modules from doing any actions on the list at all
634 /* Remove the session from the active list */
638 syslog(LOG_DEBUG, "context: context_cleanup() purging session %d", ptr->cs_pid);
648 * Purge all sessions which have the 'kill_me' flag set.
649 * This function has code to prevent it from running more than once every
650 * few seconds, because running it after every single unbind would waste a lot
651 * of CPU time and keep the context list locked too much. To force it to run
652 * anyway, set "force" to nonzero.
654 void dead_session_purge(int force) {
655 CitContext *ptr, *ptr2; /* general-purpose utility pointer */
656 CitContext *rem = NULL; /* list of sessions to be destroyed */
659 if ( (time(NULL) - last_purge) < 5 ) {
660 return; /* Too soon, go away */
665 if (try_critical_section(S_SESSION_TABLE))
673 if ( (ptr2->state == CON_IDLE) && (ptr2->kill_me) ) {
674 /* Remove the session from the active list */
676 ptr2->prev->next = ptr2->next;
679 ContextList = ptr2->next;
682 ptr2->next->prev = ptr2->prev;
686 /* And put it on our to-be-destroyed list */
691 end_critical_section(S_SESSION_TABLE);
693 /* Now that we no longer have the session list locked, we can take
694 * our time and destroy any sessions on the to-be-killed list, which
695 * is allocated privately on this thread's stack.
697 while (rem != NULL) {
698 syslog(LOG_DEBUG, "context: dead_session_purge() purging session %d, reason=%d", rem->cs_pid, rem->kill_me);
711 * masterCC is the context we use when not attached to a session. This
712 * function initializes it.
714 void InitializeMasterCC(void) {
715 memset(&masterCC, 0, sizeof(struct CitContext));
716 masterCC.internal_pgm = 1;
725 * Set the "async waiting" flag for a session, if applicable
727 void set_async_waiting(struct CitContext *ccptr)
729 syslog(LOG_DEBUG, "context: setting async_waiting flag for session %d", ccptr->cs_pid);
730 if (ccptr->is_async) {
731 ccptr->async_waiting++;
732 if (ccptr->state == CON_IDLE) {
733 ccptr->state = CON_READY;
739 void DebugSessionEnable(const int n)
743 CTDL_MODULE_INIT(session)
746 CtdlRegisterDebugFlagHook(HKEY("session"), DebugSessionEnable, &DebugSession);