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() */
78 struct CitContext masterCC;
79 struct CitContext *ContextList = NULL;
80 // struct CitContext* next_session = NULL;
82 time_t last_purge = 0; /* Last dead session purge */
83 int num_sessions = 0; /* Current number of sessions */
85 /* Flag for single user mode */
86 static int want_single_user = 0;
88 /* Try to go single user */
90 int CtdlTrySingleUser(void)
94 begin_critical_section(S_SINGLE_USER);
100 want_single_user = 1;
102 end_critical_section(S_SINGLE_USER);
106 void CtdlEndSingleUser(void)
108 begin_critical_section(S_SINGLE_USER);
109 want_single_user = 0;
110 end_critical_section(S_SINGLE_USER);
114 int CtdlWantSingleUser(void)
116 return want_single_user;
119 int CtdlIsSingleUser(void)
121 if (want_single_user)
123 /* check for only one context here */
124 if (num_sessions == 1)
132 * Return a pointer to the CitContext structure bound to the thread which
133 * called this function. If there's no such binding (for example, if it's
134 * called by the housekeeper thread) then a generic 'master' CC is returned.
136 * This function is used *VERY* frequently and must be kept small.
138 struct CitContext *MyContext(void) {
140 register struct CitContext *c;
142 return ((c = (struct CitContext *) citthread_getspecific(MyConKey),
143 c == NULL) ? &masterCC : c
151 * Terminate a session.
153 void RemoveContext (struct CitContext *con)
156 CtdlLogPrintf(CTDL_ERR,
157 "WARNING: RemoveContext() called with NULL!\n");
160 CtdlLogPrintf(CTDL_DEBUG, "RemoveContext() session %d\n", con->cs_pid);
162 /* Run any cleanup routines registered by loadable modules.
163 * Note: We have to "become_session()" because the cleanup functions
164 * might make references to "CC" assuming it's the right one.
168 PerformSessionHooks(EVT_STOP);
169 become_session(NULL);
171 CtdlLogPrintf(CTDL_NOTICE, "[%3d] Session ended.\n", con->cs_pid);
173 /* If the client is still connected, blow 'em away. */
174 CtdlLogPrintf(CTDL_DEBUG, "Closing socket %d\n", con->client_socket);
175 close(con->client_socket);
177 /* If using AUTHMODE_LDAP, free the DN */
183 CtdlLogPrintf(CTDL_DEBUG, "Done with RemoveContext()\n");
191 * Initialize a new context and place it in the list. The session number
192 * used to be the PID (which is why it's called cs_pid), but that was when we
193 * had one process per session. Now we just assign them sequentially, starting
194 * at 1 (don't change it to 0 because masterCC uses 0).
196 struct CitContext *CreateNewContext(void) {
197 struct CitContext *me;
198 static int next_pid = 0;
200 me = (struct CitContext *) malloc(sizeof(struct CitContext));
202 CtdlLogPrintf(CTDL_ALERT, "citserver: can't allocate memory!!\n");
206 memset(me, 0, sizeof(struct CitContext));
208 /* Give the contaxt a name. Hopefully makes it easier to track */
209 strcpy (me->user.fullname, "SYS_notauth");
211 /* The new context will be created already in the CON_EXECUTING state
212 * in order to prevent another thread from grabbing it while it's
215 me->state = CON_EXECUTING;
217 * Generate a unique session number and insert this context into
220 begin_critical_section(S_SESSION_TABLE);
221 me->cs_pid = ++next_pid;
223 me->next = ContextList;
225 if (me->next != NULL) {
229 end_critical_section(S_SESSION_TABLE);
234 struct CitContext *CtdlGetContextArray(int *count)
237 struct CitContext *nptr, *cptr;
239 nContexts = num_sessions;
240 nptr = malloc(sizeof(struct CitContext) * nContexts);
243 begin_critical_section(S_SESSION_TABLE);
244 for (cptr = ContextList, i=0; cptr != NULL && i < nContexts; cptr = cptr->next, i++)
245 memcpy(&nptr[i], cptr, sizeof (struct CitContext));
246 end_critical_section (S_SESSION_TABLE);
255 * This function fills in a context and its user field correctly
256 * Then creates/loads that user
258 void CtdlFillSystemContext(struct CitContext *context, char *name)
260 char sysname[USERNAME_SIZE];
262 memset(context, 0, sizeof(struct CitContext));
263 context->internal_pgm = 1;
265 strcpy (sysname, "SYS_");
266 strcat (sysname, name);
267 /* internal_create_user has the side effect of loading the user regardless of wether they
268 * already existed or needed to be created
270 internal_create_user (sysname, &(context->user), -1) ;
272 /* Check to see if the system user needs upgrading */
273 if (context->user.usernum == 0)
274 { /* old system user with number 0, upgrade it */
275 context->user.usernum = get_new_user_number();
276 CtdlLogPrintf(CTDL_DEBUG, "Upgrading system user \"%s\" from user number 0 to user number %d\n", context->user.fullname, context->user.usernum);
277 /* add user to the database */
278 CtdlPutUser(&(context->user));
279 cdb_store(CDB_USERSBYNUMBER, &(context->user.usernum), sizeof(long), context->user.fullname, strlen(context->user.fullname)+1);
284 * Cleanup any contexts that are left lying around
286 void context_cleanup(void)
288 struct CitContext *ptr = NULL;
289 struct CitContext *rem = NULL;
292 * Clean up the contexts.
293 * There are no threads so no critical_section stuff is needed.
297 /* We need to update the ContextList because some modules may want to itterate it
298 * Question is should we NULL it before iterating here or should we just keep updating it
299 * as we remove items?
301 * Answer is to NULL it first to prevent modules from doing any actions on the list at all
305 /* Remove the session from the active list */
309 CtdlLogPrintf(CTDL_DEBUG, "Purging session %d\n", ptr->cs_pid);
319 * Terminate another session.
320 * (This could justifiably be moved out of sysdep.c because it
321 * no longer does anything that is system-dependent.)
323 void kill_session(int session_to_kill) {
324 struct CitContext *ptr;
326 begin_critical_section(S_SESSION_TABLE);
327 for (ptr = ContextList; ptr != NULL; ptr = ptr->next) {
328 if (ptr->cs_pid == session_to_kill) {
332 end_critical_section(S_SESSION_TABLE);
336 * Purge all sessions which have the 'kill_me' flag set.
337 * This function has code to prevent it from running more than once every
338 * few seconds, because running it after every single unbind would waste a lot
339 * of CPU time and keep the context list locked too much. To force it to run
340 * anyway, set "force" to nonzero.
342 void dead_session_purge(int force) {
343 struct CitContext *ptr, *ptr2; /* general-purpose utility pointer */
344 struct CitContext *rem = NULL; /* list of sessions to be destroyed */
347 if ( (time(NULL) - last_purge) < 5 ) {
348 return; /* Too soon, go away */
353 if (try_critical_section(S_SESSION_TABLE))
361 if ( (ptr2->state == CON_IDLE) && (ptr2->kill_me) ) {
362 /* Remove the session from the active list */
364 ptr2->prev->next = ptr2->next;
367 ContextList = ptr2->next;
370 ptr2->next->prev = ptr2->prev;
374 /* And put it on our to-be-destroyed list */
379 end_critical_section(S_SESSION_TABLE);
381 /* Now that we no longer have the session list locked, we can take
382 * our time and destroy any sessions on the to-be-killed list, which
383 * is allocated privately on this thread's stack.
385 while (rem != NULL) {
386 CtdlLogPrintf(CTDL_DEBUG, "Purging session %d\n", rem->cs_pid);
399 * masterCC is the context we use when not attached to a session. This
400 * function initializes it.
402 void InitializeMasterCC(void) {
403 memset(&masterCC, 0, sizeof(struct CitContext));
404 masterCC.internal_pgm = 1;
412 * Bind a thread to a context. (It's inline merely to speed things up.)
414 INLINE void become_session(struct CitContext *which_con) {
415 citthread_setspecific(MyConKey, (void *)which_con );