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 a user is currently logged in
134 * Take care with what you do as a result of this test.
135 * The user may not have been logged in when this function was called BUT
136 * because of threading the user might be logged in before you test the result.
138 int CtdlIsUserLoggedIn (char *user_name)
143 begin_critical_section (S_SESSION_TABLE);
144 for (cptr = ContextList; cptr != NULL; cptr = cptr->next) {
145 if (!strcasecmp(cptr->user.fullname, user_name)) {
150 end_critical_section(S_SESSION_TABLE);
155 * Return a pointer to the CitContext structure bound to the thread which
156 * called this function. If there's no such binding (for example, if it's
157 * called by the housekeeper thread) then a generic 'master' CC is returned.
159 * This function is used *VERY* frequently and must be kept small.
161 CitContext *MyContext(void) {
163 register CitContext *c;
165 return ((c = (CitContext *) citthread_getspecific(MyConKey),
166 c == NULL) ? &masterCC : c
174 * Terminate a session.
176 void RemoveContext (CitContext *con)
179 CtdlLogPrintf(CTDL_ERR,
180 "WARNING: RemoveContext() called with NULL!\n");
183 CtdlLogPrintf(CTDL_DEBUG, "RemoveContext() session %d\n", con->cs_pid);
185 /* Run any cleanup routines registered by loadable modules.
186 * Note: We have to "become_session()" because the cleanup functions
187 * might make references to "CC" assuming it's the right one.
191 PerformSessionHooks(EVT_STOP);
192 become_session(NULL);
194 CtdlLogPrintf(CTDL_NOTICE, "[%3d] Session ended.\n", con->cs_pid);
196 /* If the client is still connected, blow 'em away. */
197 CtdlLogPrintf(CTDL_DEBUG, "Closing socket %d\n", con->client_socket);
198 close(con->client_socket);
200 /* If using AUTHMODE_LDAP, free the DN */
206 CtdlLogPrintf(CTDL_DEBUG, "Done with RemoveContext()\n");
213 * Initialize a new context and place it in the list. The session number
214 * used to be the PID (which is why it's called cs_pid), but that was when we
215 * had one process per session. Now we just assign them sequentially, starting
216 * at 1 (don't change it to 0 because masterCC uses 0).
218 CitContext *CreateNewContext(void) {
220 static int next_pid = 0;
222 me = (CitContext *) malloc(sizeof(CitContext));
224 CtdlLogPrintf(CTDL_ALERT, "citserver: can't allocate memory!!\n");
227 memset(me, 0, sizeof(CitContext));
229 /* Give the contaxt a name. Hopefully makes it easier to track */
230 strcpy (me->user.fullname, "SYS_notauth");
232 /* The new context will be created already in the CON_EXECUTING state
233 * in order to prevent another thread from grabbing it while it's
236 me->state = CON_EXECUTING;
238 * Generate a unique session number and insert this context into
241 begin_critical_section(S_SESSION_TABLE);
242 me->cs_pid = ++next_pid;
244 me->next = ContextList;
246 if (me->next != NULL) {
250 end_critical_section(S_SESSION_TABLE);
255 CitContext *CtdlGetContextArray(int *count)
258 CitContext *nptr, *cptr;
260 nContexts = num_sessions;
261 nptr = malloc(sizeof(CitContext) * nContexts);
264 begin_critical_section(S_SESSION_TABLE);
265 for (cptr = ContextList, i=0; cptr != NULL && i < nContexts; cptr = cptr->next, i++)
266 memcpy(&nptr[i], cptr, sizeof (CitContext));
267 end_critical_section (S_SESSION_TABLE);
276 * This function fills in a context and its user field correctly
277 * Then creates/loads that user
279 void CtdlFillSystemContext(CitContext *context, char *name)
281 char sysname[USERNAME_SIZE];
283 memset(context, 0, sizeof(CitContext));
284 context->internal_pgm = 1;
286 strcpy (sysname, "SYS_");
287 strcat (sysname, name);
288 /* internal_create_user has the side effect of loading the user regardless of wether they
289 * already existed or needed to be created
291 internal_create_user (sysname, &(context->user), -1) ;
293 /* Check to see if the system user needs upgrading */
294 if (context->user.usernum == 0)
295 { /* old system user with number 0, upgrade it */
296 context->user.usernum = get_new_user_number();
297 CtdlLogPrintf(CTDL_DEBUG, "Upgrading system user \"%s\" from user number 0 to user number %d\n", context->user.fullname, context->user.usernum);
298 /* add user to the database */
299 CtdlPutUser(&(context->user));
300 cdb_store(CDB_USERSBYNUMBER, &(context->user.usernum), sizeof(long), context->user.fullname, strlen(context->user.fullname)+1);
305 * Cleanup any contexts that are left lying around
307 void context_cleanup(void)
309 CitContext *ptr = NULL;
310 CitContext *rem = NULL;
313 * Clean up the contexts.
314 * There are no threads so no critical_section stuff is needed.
318 /* We need to update the ContextList because some modules may want to itterate it
319 * Question is should we NULL it before iterating here or should we just keep updating it
320 * as we remove items?
322 * Answer is to NULL it first to prevent modules from doing any actions on the list at all
326 /* Remove the session from the active list */
330 CtdlLogPrintf(CTDL_DEBUG, "Purging session %d\n", ptr->cs_pid);
340 * Terminate another session.
341 * (This could justifiably be moved out of sysdep.c because it
342 * no longer does anything that is system-dependent.)
344 void kill_session(int session_to_kill) {
347 begin_critical_section(S_SESSION_TABLE);
348 for (ptr = ContextList; ptr != NULL; ptr = ptr->next) {
349 if (ptr->cs_pid == session_to_kill) {
353 end_critical_section(S_SESSION_TABLE);
357 * Purge all sessions which have the 'kill_me' flag set.
358 * This function has code to prevent it from running more than once every
359 * few seconds, because running it after every single unbind would waste a lot
360 * of CPU time and keep the context list locked too much. To force it to run
361 * anyway, set "force" to nonzero.
363 void dead_session_purge(int force) {
364 CitContext *ptr, *ptr2; /* general-purpose utility pointer */
365 CitContext *rem = NULL; /* list of sessions to be destroyed */
368 if ( (time(NULL) - last_purge) < 5 ) {
369 return; /* Too soon, go away */
374 if (try_critical_section(S_SESSION_TABLE))
382 if ( (ptr2->state == CON_IDLE) && (ptr2->kill_me) ) {
383 /* Remove the session from the active list */
385 ptr2->prev->next = ptr2->next;
388 ContextList = ptr2->next;
391 ptr2->next->prev = ptr2->prev;
395 /* And put it on our to-be-destroyed list */
400 end_critical_section(S_SESSION_TABLE);
402 /* Now that we no longer have the session list locked, we can take
403 * our time and destroy any sessions on the to-be-killed list, which
404 * is allocated privately on this thread's stack.
406 while (rem != NULL) {
407 CtdlLogPrintf(CTDL_DEBUG, "Purging session %d\n", rem->cs_pid);
420 * masterCC is the context we use when not attached to a session. This
421 * function initializes it.
423 void InitializeMasterCC(void) {
424 memset(&masterCC, 0, sizeof( CitContext));
425 masterCC.internal_pgm = 1;
433 * Bind a thread to a context. (It's inline merely to speed things up.)
435 INLINE void become_session(CitContext *which_con) {
436 citthread_setspecific(MyConKey, (void *)which_con );