-/*
- * Citadel context management stuff.
- * Here's where we (hopefully) have all the code that manipulates contexts.
- *
- * Copyright (c) 1987-2011 by the citadel.org team
- *
- * This program is open source software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License, version 3.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- */
-
-#include "sysdep.h"
-#include <stdlib.h>
-#include <unistd.h>
-#include <stdio.h>
-#include <fcntl.h>
-#include <ctype.h>
-#include <signal.h>
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <sys/wait.h>
-#include <sys/socket.h>
-#include <syslog.h>
-#include <sys/syslog.h>
-/*
-#include <sys/syscall.h>
-*/
-
-#if TIME_WITH_SYS_TIME
-# include <sys/time.h>
-# include <time.h>
-#else
-# if HAVE_SYS_TIME_H
-# include <sys/time.h>
-# else
-# include <time.h>
-# endif
-#endif
-
-#include <limits.h>
-#include <sys/resource.h>
-#include <netinet/in.h>
-#include <netinet/tcp.h>
-#include <arpa/inet.h>
-#include <netdb.h>
-#include <sys/un.h>
-#include <string.h>
-#include <pwd.h>
-#include <errno.h>
-#include <stdarg.h>
-#include <grp.h>
-#include <libcitadel.h>
-#include "citadel.h"
-#include "server.h"
-#include "sysdep_decls.h"
-#include "citserver.h"
-#include "support.h"
-#include "config.h"
-#include "database.h"
-#include "housekeeping.h"
-#include "modules/crypto/serv_crypto.h" /* Needed for init_ssl, client_write_ssl, client_read_ssl, destruct_ssl */
-#include "ecrash.h"
-
-#ifdef HAVE_SYS_SELECT_H
-#include <sys/select.h>
-#endif
-
-#ifndef HAVE_SNPRINTF
-#include "snprintf.h"
-#endif
-
-#include "ctdl_module.h"
-#include "threads.h"
-#include "user_ops.h"
-#include "control.h"
-
-int DebugSession = 0;
-
-pthread_key_t MyConKey; /* TSD key for MyContext() */
-
-
-CitContext masterCC;
-CitContext *ContextList = NULL;
-
-time_t last_purge = 0; /* Last dead session purge */
-int num_sessions = 0; /* Current number of sessions */
-
-/* Flag for single user mode */
-static int want_single_user = 0;
-
-/* Try to go single user */
-
-int CtdlTrySingleUser(void)
-{
- int can_do = 0;
-
- begin_critical_section(S_SINGLE_USER);
- if (want_single_user)
- can_do = 0;
- else
- {
- can_do = 1;
- want_single_user = 1;
- }
- end_critical_section(S_SINGLE_USER);
- return can_do;
-}
-
-void CtdlEndSingleUser(void)
-{
- begin_critical_section(S_SINGLE_USER);
- want_single_user = 0;
- end_critical_section(S_SINGLE_USER);
-}
-
-
-int CtdlWantSingleUser(void)
-{
- return want_single_user;
-}
-
-int CtdlIsSingleUser(void)
-{
- if (want_single_user)
- {
- /* check for only one context here */
- if (num_sessions == 1)
- return TRUE;
- }
- return FALSE;
-}
-
-
-
-
-
-/*
- * Locate a context by its session number and terminate it if the user is able.
- * User can NOT terminate their current session.
- * User CAN terminate any other session that has them logged in.
- * Aide CAN terminate any session except the current one.
- */
-int CtdlTerminateOtherSession (int session_num)
-{
- int ret = 0;
- CitContext *ccptr;
-
- if (session_num == CC->cs_pid) {
- return TERM_NOTALLOWED;
- }
-
- CONM_syslog(LOG_DEBUG, "Locating session to kill\n");
- begin_critical_section(S_SESSION_TABLE);
- for (ccptr = ContextList; ccptr != NULL; ccptr = ccptr->next) {
- if (session_num == ccptr->cs_pid) {
- ret |= TERM_FOUND;
- if ((ccptr->user.usernum == CC->user.usernum)
- || (CC->user.axlevel >= AxAideU)) {
- ret |= TERM_ALLOWED;
- ccptr->kill_me = KILLME_ADMIN_TERMINATE;
- }
- }
- }
- end_critical_section(S_SESSION_TABLE);
- return ret;
-}
-
-
-
-/*
- * Check to see if the user who we just sent mail to is logged in. If yes,
- * bump the 'new mail' counter for their session. That enables them to
- * receive a new mail notification without having to hit the database.
- */
-void BumpNewMailCounter(long which_user)
-{
- CtdlBumpNewMailCounter(which_user);
-}
-
-void CtdlBumpNewMailCounter(long which_user)
-{
- CitContext *ptr;
-
- begin_critical_section(S_SESSION_TABLE);
-
- for (ptr = ContextList; ptr != NULL; ptr = ptr->next) {
- if (ptr->user.usernum == which_user) {
- ptr->newmail += 1;
- }
- }
-
- end_critical_section(S_SESSION_TABLE);
-}
-
-
-/*
- * Check to see if a user is currently logged in
- * Take care with what you do as a result of this test.
- * The user may not have been logged in when this function was called BUT
- * because of threading the user might be logged in before you test the result.
- */
-int CtdlIsUserLoggedIn (char *user_name)
-{
- CitContext *cptr;
- int ret = 0;
-
- begin_critical_section (S_SESSION_TABLE);
- for (cptr = ContextList; cptr != NULL; cptr = cptr->next) {
- if (!strcasecmp(cptr->user.fullname, user_name)) {
- ret = 1;
- break;
- }
- }
- end_critical_section(S_SESSION_TABLE);
- return ret;
-}
-
-
-
-/*
- * Check to see if a user is currently logged in.
- * Basically same as CtdlIsUserLoggedIn() but uses the user number instead.
- * Take care with what you do as a result of this test.
- * The user may not have been logged in when this function was called BUT
- * because of threading the user might be logged in before you test the result.
- */
-int CtdlIsUserLoggedInByNum (long usernum)
-{
- CitContext *cptr;
- int ret = 0;
-
- begin_critical_section(S_SESSION_TABLE);
- for (cptr = ContextList; cptr != NULL; cptr = cptr->next) {
- if (cptr->user.usernum == usernum) {
- ret = 1;
- }
- }
- end_critical_section(S_SESSION_TABLE);
- return ret;
-}
-
-
-
-/*
- * Return a pointer to the CitContext structure bound to the thread which
- * called this function. If there's no such binding (for example, if it's
- * called by the housekeeper thread) then a generic 'master' CC is returned.
- *
- * This function is used *VERY* frequently and must be kept small.
- */
-CitContext *MyContext(void) {
- register CitContext *c;
- return ((c = (CitContext *) pthread_getspecific(MyConKey), c == NULL) ? &masterCC : c);
-}
-
-
-
-
-/*
- * Terminate idle sessions. This function pounds through the session table
- * comparing the current time to each session's time-of-last-command. If an
- * idle session is found it is terminated, then the search restarts at the
- * beginning because the pointer to our place in the list becomes invalid.
- */
-void terminate_idle_sessions(void)
-{
- CitContext *ccptr;
- time_t now;
- int killed = 0;
- int longrunners = 0;
-
- now = time(NULL);
- begin_critical_section(S_SESSION_TABLE);
- for (ccptr = ContextList; ccptr != NULL; ccptr = ccptr->next) {
- if (
- (ccptr != CC)
- && (config.c_sleeping > 0)
- && (now - (ccptr->lastcmd) > config.c_sleeping)
- ) {
- if (!ccptr->dont_term) {
- ccptr->kill_me = KILLME_IDLE;
- ++killed;
- }
- else {
- ++longrunners;
- }
- }
- }
- end_critical_section(S_SESSION_TABLE);
- if (killed > 0)
- CON_syslog(LOG_INFO, "Scheduled %d idle sessions for termination\n", killed);
- if (longrunners > 0)
- CON_syslog(LOG_INFO, "Didn't terminate %d protected idle sessions", longrunners);
-}
-
-
-/*
- * During shutdown, close the sockets of any sessions still connected.
- */
-void terminate_all_sessions(void)
-{
- CitContext *ccptr;
- int killed = 0;
-
- begin_critical_section(S_SESSION_TABLE);
- for (ccptr = ContextList; ccptr != NULL; ccptr = ccptr->next) {
- if (ccptr->client_socket != -1)
- {
- CON_syslog(LOG_INFO, "terminate_all_sessions() is murdering %s", ccptr->curr_user);
- close(ccptr->client_socket);
- ccptr->client_socket = -1;
- killed++;
- }
- }
- end_critical_section(S_SESSION_TABLE);
- if (killed > 0) {
- CON_syslog(LOG_INFO, "Flushed %d stuck sessions\n", killed);
- }
-}
-
-
-
-/*
- * Terminate a session.
- */
-void RemoveContext (CitContext *con)
-{
- const char *c;
- if (con == NULL) {
- CONM_syslog(LOG_ERR, "WARNING: RemoveContext() called with NULL!");
- return;
- }
- c = con->ServiceName;
- if (c == NULL) {
- c = "WTF?";
- }
- CON_syslog(LOG_DEBUG, "RemoveContext(%s) session %d", c, con->cs_pid);
-/// cit_backtrace();
-
- /* Run any cleanup routines registered by loadable modules.
- * Note: We have to "become_session()" because the cleanup functions
- * might make references to "CC" assuming it's the right one.
- */
- become_session(con);
- CtdlUserLogout();
- PerformSessionHooks(EVT_STOP);
- client_close(); /* If the client is still connected, blow 'em away. */
- become_session(NULL);
-
- CON_syslog(LOG_NOTICE, "[%3d]SRV[%s] Session ended.", con->cs_pid, c);
-
- /*
- * If the client is still connected, blow 'em away.
- * if the socket is 0 or -1, its already gone or was never there.
- */
- if (con->client_socket > 0)
- {
- CON_syslog(LOG_NOTICE, "Closing socket %d", con->client_socket);
- close(con->client_socket);
- }
-
- /* If using AUTHMODE_LDAP, free the DN */
- if (con->ldap_dn) {
- free(con->ldap_dn);
- con->ldap_dn = NULL;
- }
- FreeStrBuf(&con->StatusMessage);
- FreeStrBuf(&con->MigrateBuf);
- FreeStrBuf(&con->RecvBuf.Buf);
- if (con->cached_msglist) {
- free(con->cached_msglist);
- }
-
- CONM_syslog(LOG_DEBUG, "Done with RemoveContext()");
-}
-
-
-
-/*
- * Initialize a new context and place it in the list. The session number
- * used to be the PID (which is why it's called cs_pid), but that was when we
- * had one process per session. Now we just assign them sequentially, starting
- * at 1 (don't change it to 0 because masterCC uses 0).
- */
-CitContext *CreateNewContext(void) {
- CitContext *me;
- static int next_pid = 0;
-
- me = (CitContext *) malloc(sizeof(CitContext));
- if (me == NULL) {
- CONM_syslog(LOG_ALERT, "citserver: can't allocate memory!!\n");
- return NULL;
- }
- memset(me, 0, sizeof(CitContext));
-
- /* Give the context a name. Hopefully makes it easier to track */
- strcpy (me->user.fullname, "SYS_notauth");
-
- /* The new context will be created already in the CON_EXECUTING state
- * in order to prevent another thread from grabbing it while it's
- * being set up.
- */
- me->state = CON_EXECUTING;
- /*
- * Generate a unique session number and insert this context into
- * the list.
- */
- me->MigrateBuf = NewStrBuf();
-
- me->RecvBuf.Buf = NewStrBuf();
-
- 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. */
-
-
- begin_critical_section(S_SESSION_TABLE);
- me->cs_pid = ++next_pid;
- me->prev = NULL;
- me->next = ContextList;
- ContextList = me;
- if (me->next != NULL) {
- me->next->prev = me;
- }
- ++num_sessions;
- end_critical_section(S_SESSION_TABLE);
- return (me);
-}
-
-
-/*
- * Initialize a new context and place it in the list. The session number
- * used to be the PID (which is why it's called cs_pid), but that was when we
- * had one process per session. Now we just assign them sequentially, starting
- * at 1 (don't change it to 0 because masterCC uses 0).
- */
-CitContext *CloneContext(CitContext *CloneMe) {
- CitContext *me;
- static int next_pid = 0;
-
- me = (CitContext *) malloc(sizeof(CitContext));
- if (me == NULL) {
- CONM_syslog(LOG_ALERT, "citserver: can't allocate memory!!\n");
- return NULL;
- }
- memcpy(me, CloneMe, sizeof(CitContext));
-
- memset(&me->RecvBuf, 0, sizeof(IOBuffer));
- memset(&me->SendBuf, 0, sizeof(IOBuffer));
- memset(&me->SBuf, 0, sizeof(IOBuffer));
- me->MigrateBuf = NULL;
- me->sMigrateBuf = NULL;
- me->redirect_buffer = NULL;
-#ifdef HAVE_OPENSSL
- me->ssl = NULL;
-#endif
-
- me->download_fp = NULL;
- me->upload_fp = NULL;
- /// TODO: what about the room/user?
- me->ma = NULL;
- me->openid_data = NULL;
- me->ldap_dn = NULL;
- me->session_specific_data = NULL;
-
- me->download_fp = NULL;
- me->upload_fp = NULL;
- me->client_socket = 0;
-
- me->MigrateBuf = NewStrBuf();
- me->RecvBuf.Buf = NewStrBuf();
-
- begin_critical_section(S_SESSION_TABLE);
- {
- me->cs_pid = ++next_pid;
- me->prev = NULL;
- me->next = ContextList;
- me->lastcmd = time(NULL); /* set lastcmd to now to prevent idle timer infanticide */
- ContextList = me;
- if (me->next != NULL) {
- me->next->prev = me;
- }
- ++num_sessions;
- }
- end_critical_section(S_SESSION_TABLE);
- return (me);
-}
-
-
-/*
- * Return an array containing a copy of the context list.
- * This allows worker threads to perform "for each context" operations without
- * having to lock and traverse the live list.
- */
-CitContext *CtdlGetContextArray(int *count)
-{
- int nContexts, i;
- CitContext *nptr, *cptr;
-
- nContexts = num_sessions;
- nptr = malloc(sizeof(CitContext) * nContexts);
- if (!nptr) {
- *count = 0;
- return NULL;
- }
- begin_critical_section(S_SESSION_TABLE);
- for (cptr = ContextList, i=0; cptr != NULL && i < nContexts; cptr = cptr->next, i++) {
- memcpy(&nptr[i], cptr, sizeof (CitContext));
- }
- end_critical_section (S_SESSION_TABLE);
-
- *count = i;
- return nptr;
-}
-
-
-
-/*
- * This function fills in a context and its user field correctly
- * Then creates/loads that user
- */
-void CtdlFillSystemContext(CitContext *context, char *name)
-{
- char sysname[SIZ];
- long len;
-
- memset(context, 0, sizeof(CitContext));
- context->internal_pgm = 1;
- context->cs_pid = 0;
- strcpy (sysname, "SYS_");
- strcat (sysname, name);
- len = cutuserkey(sysname);
- memcpy(context->curr_user, sysname, len + 1);
- context->client_socket = (-1);
- context->state = CON_SYS;
- context->ServiceName = name;
-
- /* internal_create_user has the side effect of loading the user regardless of wether they
- * already existed or needed to be created
- */
- internal_create_user (sysname, len, &(context->user), -1) ;
-
- /* Check to see if the system user needs upgrading */
- if (context->user.usernum == 0)
- { /* old system user with number 0, upgrade it */
- context->user.usernum = get_new_user_number();
- CON_syslog(LOG_INFO, "Upgrading system user \"%s\" from user number 0 to user number %ld\n", context->user.fullname, context->user.usernum);
- /* add user to the database */
- CtdlPutUser(&(context->user));
- cdb_store(CDB_USERSBYNUMBER, &(context->user.usernum), sizeof(long), context->user.fullname, strlen(context->user.fullname)+1);
- }
-}
-
-
-/*
- * Cleanup any contexts that are left lying around
- */
-void context_cleanup(void)
-{
- CitContext *ptr = NULL;
- CitContext *rem = NULL;
-
- /*
- * Clean up the contexts.
- * There are no threads so no critical_section stuff is needed.
- */
- ptr = ContextList;
-
- /* We need to update the ContextList because some modules may want to itterate it
- * Question is should we NULL it before iterating here or should we just keep updating it
- * as we remove items?
- *
- * Answer is to NULL it first to prevent modules from doing any actions on the list at all
- */
- ContextList=NULL;
- while (ptr != NULL){
- /* Remove the session from the active list */
- rem = ptr->next;
- --num_sessions;
-
- CON_syslog(LOG_DEBUG, "context_cleanup(): purging session %d\n", ptr->cs_pid);
- RemoveContext(ptr);
- free (ptr);
- ptr = rem;
- }
-}
-
-
-
-/*
- * Purge all sessions which have the 'kill_me' flag set.
- * This function has code to prevent it from running more than once every
- * few seconds, because running it after every single unbind would waste a lot
- * of CPU time and keep the context list locked too much. To force it to run
- * anyway, set "force" to nonzero.
- */
-void dead_session_purge(int force) {
- CitContext *ptr, *ptr2; /* general-purpose utility pointer */
- CitContext *rem = NULL; /* list of sessions to be destroyed */
-
- if (force == 0) {
- if ( (time(NULL) - last_purge) < 5 ) {
- return; /* Too soon, go away */
- }
- }
- time(&last_purge);
-
- if (try_critical_section(S_SESSION_TABLE))
- return;
-
- ptr = ContextList;
- while (ptr) {
- ptr2 = ptr;
- ptr = ptr->next;
-
- if ( (ptr2->state == CON_IDLE) && (ptr2->kill_me) ) {
- /* Remove the session from the active list */
- if (ptr2->prev) {
- ptr2->prev->next = ptr2->next;
- }
- else {
- ContextList = ptr2->next;
- }
- if (ptr2->next) {
- ptr2->next->prev = ptr2->prev;
- }
-
- --num_sessions;
- /* And put it on our to-be-destroyed list */
- ptr2->next = rem;
- rem = ptr2;
- }
- }
- end_critical_section(S_SESSION_TABLE);
-
- /* Now that we no longer have the session list locked, we can take
- * our time and destroy any sessions on the to-be-killed list, which
- * is allocated privately on this thread's stack.
- */
- while (rem != NULL) {
- CON_syslog(LOG_DEBUG, "dead_session_purge(): purging session %d, reason=%d\n", rem->cs_pid, rem->kill_me);
- RemoveContext(rem);
- ptr = rem;
- rem = rem->next;
- free(ptr);
- }
-}
-
-
-
-
-
-/*
- * masterCC is the context we use when not attached to a session. This
- * function initializes it.
- */
-void InitializeMasterCC(void) {
- memset(&masterCC, 0, sizeof(struct CitContext));
- masterCC.internal_pgm = 1;
- masterCC.cs_pid = 0;
-}
-
-
-
-
-
-/*
- * Set the "async waiting" flag for a session, if applicable
- */
-void set_async_waiting(struct CitContext *ccptr)
-{
- CON_syslog(LOG_DEBUG, "Setting async_waiting flag for session %d\n", ccptr->cs_pid);
- if (ccptr->is_async) {
- ccptr->async_waiting++;
- if (ccptr->state == CON_IDLE) {
- ccptr->state = CON_READY;
- }
- }
-}
-
-
-void DebugSessionEnable(const int n)
-{
- DebugSession = n;
-}
-CTDL_MODULE_INIT(session)
-{
- if (!threading) {
- CtdlRegisterDebugFlagHook(HKEY("session"), DebugSessionEnable, &DebugSession);
- }
- return "session";
-}