2 * $Id: sysdep.c 7989 2009-10-31 15:29:37Z davew $
4 * Citadel context management stuff.
5 * See COPYING for copyright information.
7 * Here's where we (hopefully) have all the code that manipulates contexts.
18 #include <sys/types.h>
21 #include <sys/socket.h>
23 #include <sys/syslog.h>
25 #if TIME_WITH_SYS_TIME
26 # include <sys/time.h>
30 # include <sys/time.h>
37 #include <sys/resource.h>
38 #include <netinet/in.h>
39 #include <netinet/tcp.h>
40 #include <arpa/inet.h>
48 #include <libcitadel.h>
51 #include "sysdep_decls.h"
52 #include "citserver.h"
56 #include "housekeeping.h"
57 #include "modules/crypto/serv_crypto.h" /* Needed for init_ssl, client_write_ssl, client_read_ssl, destruct_ssl */
60 #ifdef HAVE_SYS_SELECT_H
61 #include <sys/select.h>
68 #include "ctdl_module.h"
75 citthread_key_t MyConKey; /* TSD key for MyContext() */
79 CitContext *ContextList = NULL;
81 time_t last_purge = 0; /* Last dead session purge */
82 int num_sessions = 0; /* Current number of sessions */
84 /* Flag for single user mode */
85 static int want_single_user = 0;
87 /* Try to go single user */
89 int CtdlTrySingleUser(void)
93 begin_critical_section(S_SINGLE_USER);
101 end_critical_section(S_SINGLE_USER);
105 void CtdlEndSingleUser(void)
107 begin_critical_section(S_SINGLE_USER);
108 want_single_user = 0;
109 end_critical_section(S_SINGLE_USER);
113 int CtdlWantSingleUser(void)
115 return want_single_user;
118 int CtdlIsSingleUser(void)
120 if (want_single_user)
122 /* check for only one context here */
123 if (num_sessions == 1)
133 * Check to see if the user who we just sent mail to is logged in. If yes,
134 * bump the 'new mail' counter for their session. That enables them to
135 * receive a new mail notification without having to hit the database.
137 void BumpNewMailCounter(long which_user)
139 CtdlBumpNewMailCounter(which_user);
142 void CtdlBumpNewMailCounter(long which_user)
146 begin_critical_section(S_SESSION_TABLE);
148 for (ptr = ContextList; ptr != NULL; ptr = ptr->next) {
149 if (ptr->user.usernum == which_user) {
154 end_critical_section(S_SESSION_TABLE);
159 * Check to see if a user is currently logged in
160 * Take care with what you do as a result of this test.
161 * The user may not have been logged in when this function was called BUT
162 * because of threading the user might be logged in before you test the result.
164 int CtdlIsUserLoggedIn (char *user_name)
169 begin_critical_section (S_SESSION_TABLE);
170 for (cptr = ContextList; cptr != NULL; cptr = cptr->next) {
171 if (!strcasecmp(cptr->user.fullname, user_name)) {
176 end_critical_section(S_SESSION_TABLE);
183 * Check to see if a user is currently logged in.
184 * Basically same as CtdlIsUserLoggedIn() but uses the user number instead.
185 * Take care with what you do as a result of this test.
186 * The user may not have been logged in when this function was called BUT
187 * because of threading the user might be logged in before you test the result.
189 int CtdlIsUserLoggedInByNum (long usernum)
194 begin_critical_section(S_SESSION_TABLE);
195 for (cptr = ContextList; cptr != NULL; cptr = cptr->next) {
196 if (cptr->user.usernum == usernum) {
200 end_critical_section(S_SESSION_TABLE);
207 * Return a pointer to the CitContext structure bound to the thread which
208 * called this function. If there's no such binding (for example, if it's
209 * called by the housekeeper thread) then a generic 'master' CC is returned.
211 * This function is used *VERY* frequently and must be kept small.
213 CitContext *MyContext(void) {
215 register CitContext *c;
217 return ((c = (CitContext *) citthread_getspecific(MyConKey),
218 c == NULL) ? &masterCC : c
226 * Terminate idle sessions. This function pounds through the session table
227 * comparing the current time to each session's time-of-last-command. If an
228 * idle session is found it is terminated, then the search restarts at the
229 * beginning because the pointer to our place in the list becomes invalid.
231 void terminate_idle_sessions(void)
241 begin_critical_section(S_SESSION_TABLE);
242 for (ccptr = ContextList; ccptr != NULL; ccptr = ccptr->next) {
244 && (config.c_sleeping > 0)
245 && (now - (ccptr->lastcmd) > config.c_sleeping) ) {
246 if (!ccptr->dont_term) {
254 end_critical_section(S_SESSION_TABLE);
256 CtdlLogPrintf(CTDL_INFO, "Terminated %d idle sessions\n", killed);
258 CtdlLogPrintf(CTDL_INFO, "Didn't terminate %d protected idle sessions;\n", killed);
264 * Terminate a session.
266 void RemoveContext (CitContext *con)
269 CtdlLogPrintf(CTDL_ERR,
270 "WARNING: RemoveContext() called with NULL!\n");
273 CtdlLogPrintf(CTDL_DEBUG, "RemoveContext() session %d\n", con->cs_pid);
275 /* Run any cleanup routines registered by loadable modules.
276 * Note: We have to "become_session()" because the cleanup functions
277 * might make references to "CC" assuming it's the right one.
281 PerformSessionHooks(EVT_STOP);
282 become_session(NULL);
284 CtdlLogPrintf(CTDL_NOTICE, "[%3d] Session ended.\n", con->cs_pid);
286 /* If the client is still connected, blow 'em away. */
287 CtdlLogPrintf(CTDL_DEBUG, "Closing socket %d\n", con->client_socket);
288 close(con->client_socket);
290 /* If using AUTHMODE_LDAP, free the DN */
296 CtdlLogPrintf(CTDL_DEBUG, "Done with RemoveContext()\n");
303 * Initialize a new context and place it in the list. The session number
304 * used to be the PID (which is why it's called cs_pid), but that was when we
305 * had one process per session. Now we just assign them sequentially, starting
306 * at 1 (don't change it to 0 because masterCC uses 0).
308 CitContext *CreateNewContext(void) {
310 static int next_pid = 0;
312 me = (CitContext *) malloc(sizeof(CitContext));
314 CtdlLogPrintf(CTDL_ALERT, "citserver: can't allocate memory!!\n");
317 memset(me, 0, sizeof(CitContext));
319 /* Give the contaxt a name. Hopefully makes it easier to track */
320 strcpy (me->user.fullname, "SYS_notauth");
322 /* The new context will be created already in the CON_EXECUTING state
323 * in order to prevent another thread from grabbing it while it's
326 me->state = CON_EXECUTING;
328 * Generate a unique session number and insert this context into
331 begin_critical_section(S_SESSION_TABLE);
332 me->cs_pid = ++next_pid;
334 me->next = ContextList;
336 if (me->next != NULL) {
340 end_critical_section(S_SESSION_TABLE);
345 CitContext *CtdlGetContextArray(int *count)
348 CitContext *nptr, *cptr;
350 nContexts = num_sessions;
351 nptr = malloc(sizeof(CitContext) * nContexts);
354 begin_critical_section(S_SESSION_TABLE);
355 for (cptr = ContextList, i=0; cptr != NULL && i < nContexts; cptr = cptr->next, i++)
356 memcpy(&nptr[i], cptr, sizeof (CitContext));
357 end_critical_section (S_SESSION_TABLE);
366 * This function fills in a context and its user field correctly
367 * Then creates/loads that user
369 void CtdlFillSystemContext(CitContext *context, char *name)
371 char sysname[USERNAME_SIZE];
373 memset(context, 0, sizeof(CitContext));
374 context->internal_pgm = 1;
376 strcpy (sysname, "SYS_");
377 strcat (sysname, name);
378 /* internal_create_user has the side effect of loading the user regardless of wether they
379 * already existed or needed to be created
381 internal_create_user (sysname, &(context->user), -1) ;
383 /* Check to see if the system user needs upgrading */
384 if (context->user.usernum == 0)
385 { /* old system user with number 0, upgrade it */
386 context->user.usernum = get_new_user_number();
387 CtdlLogPrintf(CTDL_DEBUG, "Upgrading system user \"%s\" from user number 0 to user number %d\n", context->user.fullname, context->user.usernum);
388 /* add user to the database */
389 CtdlPutUser(&(context->user));
390 cdb_store(CDB_USERSBYNUMBER, &(context->user.usernum), sizeof(long), context->user.fullname, strlen(context->user.fullname)+1);
395 * Cleanup any contexts that are left lying around
397 void context_cleanup(void)
399 CitContext *ptr = NULL;
400 CitContext *rem = NULL;
403 * Clean up the contexts.
404 * There are no threads so no critical_section stuff is needed.
408 /* We need to update the ContextList because some modules may want to itterate it
409 * Question is should we NULL it before iterating here or should we just keep updating it
410 * as we remove items?
412 * Answer is to NULL it first to prevent modules from doing any actions on the list at all
416 /* Remove the session from the active list */
420 CtdlLogPrintf(CTDL_DEBUG, "Purging session %d\n", ptr->cs_pid);
430 * Terminate another session.
431 * (This could justifiably be moved out of sysdep.c because it
432 * no longer does anything that is system-dependent.)
434 void kill_session(int session_to_kill) {
437 begin_critical_section(S_SESSION_TABLE);
438 for (ptr = ContextList; ptr != NULL; ptr = ptr->next) {
439 if (ptr->cs_pid == session_to_kill) {
443 end_critical_section(S_SESSION_TABLE);
447 * Purge all sessions which have the 'kill_me' flag set.
448 * This function has code to prevent it from running more than once every
449 * few seconds, because running it after every single unbind would waste a lot
450 * of CPU time and keep the context list locked too much. To force it to run
451 * anyway, set "force" to nonzero.
453 void dead_session_purge(int force) {
454 CitContext *ptr, *ptr2; /* general-purpose utility pointer */
455 CitContext *rem = NULL; /* list of sessions to be destroyed */
458 if ( (time(NULL) - last_purge) < 5 ) {
459 return; /* Too soon, go away */
464 if (try_critical_section(S_SESSION_TABLE))
472 if ( (ptr2->state == CON_IDLE) && (ptr2->kill_me) ) {
473 /* Remove the session from the active list */
475 ptr2->prev->next = ptr2->next;
478 ContextList = ptr2->next;
481 ptr2->next->prev = ptr2->prev;
485 /* And put it on our to-be-destroyed list */
490 end_critical_section(S_SESSION_TABLE);
492 /* Now that we no longer have the session list locked, we can take
493 * our time and destroy any sessions on the to-be-killed list, which
494 * is allocated privately on this thread's stack.
496 while (rem != NULL) {
497 CtdlLogPrintf(CTDL_DEBUG, "Purging session %d\n", rem->cs_pid);
510 * masterCC is the context we use when not attached to a session. This
511 * function initializes it.
513 void InitializeMasterCC(void) {
514 memset(&masterCC, 0, sizeof( CitContext));
515 masterCC.internal_pgm = 1;
523 * Bind a thread to a context. (It's inline merely to speed things up.)
525 INLINE void become_session(CitContext *which_con) {
526 citthread_setspecific(MyConKey, (void *)which_con );