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)
131 * Return a pointer to the CitContext structure bound to the thread which
132 * called this function. If there's no such binding (for example, if it's
133 * called by the housekeeper thread) then a generic 'master' CC is returned.
135 * This function is used *VERY* frequently and must be kept small.
137 CitContext *MyContext(void) {
139 register CitContext *c;
141 return ((c = (CitContext *) citthread_getspecific(MyConKey),
142 c == NULL) ? &masterCC : c
150 * Terminate a session.
152 void RemoveContext (CitContext *con)
155 CtdlLogPrintf(CTDL_ERR,
156 "WARNING: RemoveContext() called with NULL!\n");
159 CtdlLogPrintf(CTDL_DEBUG, "RemoveContext() session %d\n", con->cs_pid);
161 /* Run any cleanup routines registered by loadable modules.
162 * Note: We have to "become_session()" because the cleanup functions
163 * might make references to "CC" assuming it's the right one.
167 PerformSessionHooks(EVT_STOP);
168 become_session(NULL);
170 CtdlLogPrintf(CTDL_NOTICE, "[%3d] Session ended.\n", con->cs_pid);
172 /* If the client is still connected, blow 'em away. */
173 CtdlLogPrintf(CTDL_DEBUG, "Closing socket %d\n", con->client_socket);
174 close(con->client_socket);
176 /* If using AUTHMODE_LDAP, free the DN */
182 CtdlLogPrintf(CTDL_DEBUG, "Done with RemoveContext()\n");
189 * Initialize a new context and place it in the list. The session number
190 * used to be the PID (which is why it's called cs_pid), but that was when we
191 * had one process per session. Now we just assign them sequentially, starting
192 * at 1 (don't change it to 0 because masterCC uses 0).
194 CitContext *CreateNewContext(void) {
196 static int next_pid = 0;
198 me = (CitContext *) malloc(sizeof(CitContext));
200 CtdlLogPrintf(CTDL_ALERT, "citserver: can't allocate memory!!\n");
203 memset(me, 0, sizeof(CitContext));
205 /* Give the contaxt a name. Hopefully makes it easier to track */
206 strcpy (me->user.fullname, "SYS_notauth");
208 /* The new context will be created already in the CON_EXECUTING state
209 * in order to prevent another thread from grabbing it while it's
212 me->state = CON_EXECUTING;
214 * Generate a unique session number and insert this context into
217 begin_critical_section(S_SESSION_TABLE);
218 me->cs_pid = ++next_pid;
220 me->next = ContextList;
222 if (me->next != NULL) {
226 end_critical_section(S_SESSION_TABLE);
231 CitContext *CtdlGetContextArray(int *count)
234 CitContext *nptr, *cptr;
236 nContexts = num_sessions;
237 nptr = malloc(sizeof(CitContext) * nContexts);
240 begin_critical_section(S_SESSION_TABLE);
241 for (cptr = ContextList, i=0; cptr != NULL && i < nContexts; cptr = cptr->next, i++)
242 memcpy(&nptr[i], cptr, sizeof (CitContext));
243 end_critical_section (S_SESSION_TABLE);
252 * This function fills in a context and its user field correctly
253 * Then creates/loads that user
255 void CtdlFillSystemContext(CitContext *context, char *name)
257 char sysname[USERNAME_SIZE];
259 memset(context, 0, sizeof(CitContext));
260 context->internal_pgm = 1;
262 strcpy (sysname, "SYS_");
263 strcat (sysname, name);
264 /* internal_create_user has the side effect of loading the user regardless of wether they
265 * already existed or needed to be created
267 internal_create_user (sysname, &(context->user), -1) ;
269 /* Check to see if the system user needs upgrading */
270 if (context->user.usernum == 0)
271 { /* old system user with number 0, upgrade it */
272 context->user.usernum = get_new_user_number();
273 CtdlLogPrintf(CTDL_DEBUG, "Upgrading system user \"%s\" from user number 0 to user number %d\n", context->user.fullname, context->user.usernum);
274 /* add user to the database */
275 CtdlPutUser(&(context->user));
276 cdb_store(CDB_USERSBYNUMBER, &(context->user.usernum), sizeof(long), context->user.fullname, strlen(context->user.fullname)+1);
281 * Cleanup any contexts that are left lying around
283 void context_cleanup(void)
285 CitContext *ptr = NULL;
286 CitContext *rem = NULL;
289 * Clean up the contexts.
290 * There are no threads so no critical_section stuff is needed.
294 /* We need to update the ContextList because some modules may want to itterate it
295 * Question is should we NULL it before iterating here or should we just keep updating it
296 * as we remove items?
298 * Answer is to NULL it first to prevent modules from doing any actions on the list at all
302 /* Remove the session from the active list */
306 CtdlLogPrintf(CTDL_DEBUG, "Purging session %d\n", ptr->cs_pid);
316 * Terminate another session.
317 * (This could justifiably be moved out of sysdep.c because it
318 * no longer does anything that is system-dependent.)
320 void kill_session(int session_to_kill) {
323 begin_critical_section(S_SESSION_TABLE);
324 for (ptr = ContextList; ptr != NULL; ptr = ptr->next) {
325 if (ptr->cs_pid == session_to_kill) {
329 end_critical_section(S_SESSION_TABLE);
333 * Purge all sessions which have the 'kill_me' flag set.
334 * This function has code to prevent it from running more than once every
335 * few seconds, because running it after every single unbind would waste a lot
336 * of CPU time and keep the context list locked too much. To force it to run
337 * anyway, set "force" to nonzero.
339 void dead_session_purge(int force) {
340 CitContext *ptr, *ptr2; /* general-purpose utility pointer */
341 CitContext *rem = NULL; /* list of sessions to be destroyed */
344 if ( (time(NULL) - last_purge) < 5 ) {
345 return; /* Too soon, go away */
350 if (try_critical_section(S_SESSION_TABLE))
358 if ( (ptr2->state == CON_IDLE) && (ptr2->kill_me) ) {
359 /* Remove the session from the active list */
361 ptr2->prev->next = ptr2->next;
364 ContextList = ptr2->next;
367 ptr2->next->prev = ptr2->prev;
371 /* And put it on our to-be-destroyed list */
376 end_critical_section(S_SESSION_TABLE);
378 /* Now that we no longer have the session list locked, we can take
379 * our time and destroy any sessions on the to-be-killed list, which
380 * is allocated privately on this thread's stack.
382 while (rem != NULL) {
383 CtdlLogPrintf(CTDL_DEBUG, "Purging session %d\n", rem->cs_pid);
396 * masterCC is the context we use when not attached to a session. This
397 * function initializes it.
399 void InitializeMasterCC(void) {
400 memset(&masterCC, 0, sizeof( CitContext));
401 masterCC.internal_pgm = 1;
409 * Bind a thread to a context. (It's inline merely to speed things up.)
411 INLINE void become_session(CitContext *which_con) {
412 citthread_setspecific(MyConKey, (void *)which_con );