]> code.citadel.org Git - citadel.git/blobdiff - citadel/sysdep.c
* We now have a housekeeping thread and a housekeeping queue.
[citadel.git] / citadel / sysdep.c
index 0a0b185788d043a5f4c1e23751b9a5e720dc9233..2a74ce9cb16f7139d274673f9efd447787219941 100644 (file)
@@ -14,6 +14,7 @@
  */
 
 
+#include "sysdep.h"
 #include <stdlib.h>
 #include <unistd.h>
 #include <stdio.h>
 #include <errno.h>
 #include <stdarg.h>
 #include <syslog.h>
+#include <grp.h>
+#ifdef __GNUC__
+#include <malloc.h>
+#endif
+#ifdef HAVE_PTHREAD_H
 #include <pthread.h>
+#endif
 #include "citadel.h"
 #include "server.h"
 #include "sysdep_decls.h"
@@ -103,6 +110,15 @@ void *tracked_malloc(size_t tsize, char *tfile, int tline) {
        return ptr;
        }
 
+char *tracked_strdup(const char *orig, char *tfile, int tline) {
+       char *s;
+
+       s = tracked_malloc( (strlen(orig)+1), tfile, tline);
+       if (s == NULL) return NULL;
+
+       strcpy(s, orig);
+       return s;
+}
 
 void tracked_free(void *ptr) {
        struct TheHeap *hptr, *freeme;
@@ -147,10 +163,40 @@ void dump_tracked() {
                cprintf("%20s %5d\n",
                        hptr->h_file, hptr->h_line);
                }
+#ifdef __GNUC__
+        malloc_stats();
+#endif
+
        cprintf("000\n");
        }
 #endif
 
+static pthread_t main_thread_id;
+
+#ifndef HAVE_PTHREAD_CANCEL
+/*
+ * signal handler to fake thread cancellation; only required on BSDI as far
+ * as I know.
+ */
+static RETSIGTYPE cancel_thread(int signum) {
+       pthread_exit(NULL);
+       }
+#endif
+
+/*
+ * we used to use master_cleanup() as a signal handler to shut down the server.
+ * however, master_cleanup() and the functions it calls do some things that
+ * aren't such a good idea to do from a signal handler: acquiring mutexes,
+ * playing with signal masks on BSDI systems, etc. so instead we install the
+ * following signal handler to set a global variable to inform the main loop
+ * that it's time to call master_cleanup() and exit.
+ */
+
+static volatile int time_to_die = 0;
+
+static RETSIGTYPE signal_cleanup(int signum) {
+       time_to_die = 1;
+       }
 
 
 /*
@@ -175,13 +221,17 @@ void init_sysdep(void) {
 
        /*
         * The action for unexpected signals and exceptions should be to
-        * call master_cleanup() to gracefully shut down the server.
+        * call signal_cleanup() to gracefully shut down the server.
         */
-       signal(SIGINT, (void(*)(int))master_cleanup);
-       signal(SIGQUIT, (void(*)(int))master_cleanup);
-       signal(SIGHUP, (void(*)(int))master_cleanup);
-       signal(SIGTERM, (void(*)(int))master_cleanup);
+       signal(SIGINT, signal_cleanup);
+       signal(SIGQUIT, signal_cleanup);
+       signal(SIGHUP, signal_cleanup);
+       signal(SIGTERM, signal_cleanup);
        signal(SIGPIPE, SIG_IGN);
+       main_thread_id = pthread_self();
+#ifndef HAVE_PTHREAD_CANCEL /* fake it - only BSDI afaik */
+       signal(SIGUSR1, cancel_thread);
+#endif
        }
 
 
@@ -190,12 +240,30 @@ void init_sysdep(void) {
  */
 void begin_critical_section(int which_one)
 {
+#ifdef HAVE_PTHREAD_CANCEL
        int oldval;
+#else
+       sigset_t set;
+#endif
 
        /* lprintf(8, "begin_critical_section(%d)\n", which_one); */
 
-       /* Don't get interrupted during the critical section */
-       pthread_setcanceltype(PTHREAD_CANCEL_DEFERRED, &oldval);
+       if (!pthread_equal(pthread_self(), main_thread_id)) {
+               /* Keep a count of how many critical sections this thread has
+                * open, so that end_critical_section() doesn't enable
+                * cancellation prematurely. */
+               CC->n_crit++;
+#ifdef HAVE_PTHREAD_CANCEL
+               /* Don't get interrupted during the critical section */
+               pthread_setcanceltype(PTHREAD_CANCEL_DEFERRED, &oldval);
+#else
+               /* We're faking cancellation with signals. Block SIGUSR1 while
+                * we're in the critical section. */
+               sigemptyset(&set);
+               sigaddset(&set, SIGUSR1);
+               pthread_sigmask(SIG_BLOCK, &set, NULL);
+#endif
+               }
 
        /* Obtain a semaphore */
        pthread_mutex_lock(&Critters[which_one]);
@@ -207,19 +275,34 @@ void begin_critical_section(int which_one)
  */
 void end_critical_section(int which_one)
 {
+#ifdef HAVE_PTHREAD_CANCEL
        int oldval;
+#else
+       sigset_t set;
+#endif
 
        /* lprintf(8, "  end_critical_section(%d)\n", which_one); */
 
        /* Let go of the semaphore */
        pthread_mutex_unlock(&Critters[which_one]);
 
-       /* If a cancel was sent during the critical section, do it now.
-        * Then re-enable thread cancellation.
-        */
-       pthread_testcancel();
-       pthread_setcanceltype(PTHREAD_CANCEL_ASYNCHRONOUS, &oldval);
-       pthread_testcancel();
+       if (!pthread_equal(pthread_self(), main_thread_id))
+       if (!--CC->n_crit) {
+#ifdef HAVE_PTHREAD_CANCEL
+               /* If a cancel was sent during the critical section, do it now.
+                * Then re-enable thread cancellation.
+                */
+               pthread_testcancel();
+               pthread_setcanceltype(PTHREAD_CANCEL_ASYNCHRONOUS, &oldval);
+               pthread_testcancel();
+#else
+               /* We're faking it. Unblock SIGUSR1; signals sent during the
+                * critical section should now be able to kill us. */
+               sigemptyset(&set);
+               sigaddset(&set, SIGUSR1);
+               pthread_sigmask(SIG_UNBLOCK, &set, NULL);
+#endif
+               }
 
        }
 
@@ -309,7 +392,6 @@ struct CitContext *MyContext(void) {
 struct CitContext *CreateNewContext(void) {
        struct CitContext *me;
 
-       lprintf(9, "CreateNewContext: calling malloc()\n");
        me = (struct CitContext *) mallok(sizeof(struct CitContext));
        if (me == NULL) {
                lprintf(1, "citserver: can't allocate memory!!\n");
@@ -329,11 +411,15 @@ struct CitContext *CreateNewContext(void) {
  */
 void InitMyContext(struct CitContext *con)
 {
+#ifdef HAVE_PTHREAD_CANCEL
        int oldval;
+#endif
 
        con->mythread = pthread_self();
+#ifdef HAVE_PTHREAD_CANCEL
        pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, &oldval);
        pthread_setcanceltype(PTHREAD_CANCEL_ASYNCHRONOUS, &oldval);
+#endif
        if (pthread_setspecific(MyConKey, (void *)con) != 0) {
                lprintf(1, "ERROR!  pthread_setspecific() failed: %s\n",
                        strerror(errno));
@@ -348,8 +434,6 @@ void RemoveContext(struct CitContext *con)
        struct CitContext *ptr;
 
        lprintf(7, "Starting RemoveContext()\n");
-       lprintf(9, "Session count before RemoveContext is %d\n",
-               session_count());
        if (con==NULL) {
                lprintf(7, "WARNING: RemoveContext() called with null!\n");
                return;
@@ -363,7 +447,6 @@ void RemoveContext(struct CitContext *con)
        lprintf(7, "Closing socket %d\n", con->client_socket);
        close(con->client_socket);
 
-       lprintf(9, "Dereferencing session context\n");
        if (ContextList==con) {
                ContextList = ContextList->next;
                }
@@ -375,14 +458,8 @@ void RemoveContext(struct CitContext *con)
                        }
                }
 
-       lprintf(9, "Freeing session context...\n");     
        phree(con);
-       lprintf(9, "...done.\n");
        end_critical_section(S_SESSION_TABLE);
-
-       lprintf(9, "Session count after RemoveContext is %d\n",
-               session_count());
-
        lprintf(7, "Done with RemoveContext\n");
        }
 
@@ -395,15 +472,12 @@ int session_count(void) {
        struct CitContext *ptr;
        int TheCount = 0;
 
-       lprintf(9, "session_count() starting\n");
        begin_critical_section(S_SESSION_TABLE);
        for (ptr = ContextList; ptr != NULL; ptr = ptr->next) {
                ++TheCount;
-               lprintf(9, "Counted session %3d (%d)\n", ptr->cs_pid, TheCount);
                }
        end_critical_section(S_SESSION_TABLE);
 
-       lprintf(9, "session_count() finishing\n");
        return(TheCount);
        }
 
@@ -554,7 +628,6 @@ void kill_session(int session_to_kill) {
        struct CitContext *ptr;
        THREAD killme = 0;
 
-       lprintf(9, "kill_session() scanning for thread to cancel...\n");
        begin_critical_section(S_SESSION_TABLE);
        for (ptr = ContextList; ptr != NULL; ptr = ptr->next) {
                if (ptr->cs_pid == session_to_kill) {
@@ -562,11 +635,21 @@ void kill_session(int session_to_kill) {
                        }
                }
        end_critical_section(S_SESSION_TABLE);
-       lprintf(9, "kill_session() finished scanning.\n");
 
        if (killme != 0) {
-               lprintf(9, "calling pthread_cancel()\n");
+#ifdef HAVE_PTHREAD_CANCEL
                pthread_cancel(killme);
+#else
+               pthread_kill(killme, SIGUSR1);
+#ifdef __FreeBSD__
+               /* there's a very stupid bug in the user threads package on
+                  FreeBSD 3.1 which prevents a signal from being properly
+                  dispatched to a thread that's in a blocking syscall. the
+                  first signal interrupts the syscall, the second one actually
+                  gets delivered. */
+               pthread_kill(killme, SIGUSR1);
+#endif
+#endif
                }
        }
 
@@ -701,11 +784,16 @@ int main(int argc, char **argv)
        int alen;                       /* Data for master socket */
        int ssock;                      /* Descriptor for master socket */
        THREAD SessThread;              /* Thread descriptor */
+       THREAD HousekeepingThread;      /* Thread descriptor */
         pthread_attr_t attr;           /* Thread attributes */
        struct CitContext *con;         /* Temporary context pointer */
        char tracefile[128];            /* Name of file to log traces to */
        int a, i;                       /* General-purpose variables */
-       char convbuf[128];
+       fd_set readfds;
+       struct timeval tv;
+       struct passwd *pw;
+       int drop_root_perms = 1;
+       char *moddir;
         
        /* specify default port name and trace file */
        strcpy(tracefile, "");
@@ -729,30 +817,43 @@ int main(int argc, char **argv)
 
                /* -x specifies the desired logging level */
                else if (!strncmp(argv[a], "-x", 2)) {
-                       strcpy(convbuf, argv[a]);
-                       verbosity = atoi(&convbuf[2]);
+                       verbosity = atoi(&argv[a][2]);
                        }
 
                else if (!strncmp(argv[a], "-h", 2)) {
-                       strcpy(convbuf, argv[a]);
-                       strcpy(bbs_home_directory, &convbuf[2]);
+                       safestrncpy(bbs_home_directory, &argv[a][2],
+                                   sizeof bbs_home_directory);
                        home_specified = 1;
                        }
 
+               else if (!strncmp(argv[a], "-f", 2)) {
+                       do_defrag = 1;
+                       }
+
+               /* -r tells the server not to drop root permissions. don't use
+                * this unless you know what you're doing. this should be
+                * removed in the next release if it proves unnecessary. */
+               else if (!strcmp(argv[a], "-r"))
+                       drop_root_perms = 0;
+
                /* any other parameter makes it crash and burn */
                else {
-                       lprintf(1, "citserver: usage: ");
-                       lprintf(1, "citserver [-tTraceFile]");
-                       lprintf(1, " [-d] [-xLogLevel] [-hHomeDir]\n");
+                       lprintf(1,      "citserver: usage: "
+                                       "citserver [-tTraceFile] [-d] [-f]"
+                                       " [-xLogLevel] [-hHomeDir]\n");
                        exit(1);
                        }
 
                }
 
        /* Tell 'em who's in da house */
-       lprintf(1, "Multithreaded message server for %s\n", CITADEL);
-       lprintf(1, "Copyright (C) 1987-1998 by Art Cancro.  ");
-       lprintf(1, "All rights reserved.\n\n");
+       lprintf(1,
+"\nMultithreaded message server for Citadel/UX\n"
+"Copyright (C) 1987-1999 by the Citadel/UX development team.\n"
+"Citadel/UX is free software, covered by the GNU General Public License, and\n"
+"you are welcome to change it and/or distribute copies of it under certain\n"
+"conditions.  There is absolutely no warranty for this software.  Please\n"
+"read the 'COPYING.txt' file for details.\n\n");
 
        /* Initialize... */
        init_sysdep();
@@ -761,13 +862,6 @@ int main(int argc, char **argv)
        lprintf(7, "Loading citadel.config\n");
        get_config();
 
-        lprintf(7, "Initializing loadable modules\n");
-        DLoader_Init("./modules");
-        lprintf(9, "Modules done initializing.\n");
-
-       /* Do non system dependent startup functions */
-       master_startup();
-
        /*
         * Bind the server to our favourite port.
         * There is no need to check for errors, because ig_tcp_server()
@@ -778,18 +872,66 @@ int main(int argc, char **argv)
        lprintf(7, "Listening on socket %d\n", msock);
 
        /*
-        * Now that we've bound the socket, change to the BBS user id
-       lprintf(7, "Changing uid to %d\n", BBSUID);
-       if (setuid(BBSUID) != 0) {
-               lprintf(3, "setuid() failed: %s", strerror(errno));
+        * Now that we've bound the socket, change to the BBS user id and its
+        * corresponding group ids
+        */
+       if (drop_root_perms) {
+               if ((pw = getpwuid(BBSUID)) == NULL)
+                       lprintf(1, "WARNING: getpwuid(%d): %s\n"
+                                  "Group IDs will be incorrect.\n", BBSUID,
+                               strerror(errno));
+               else {
+                       initgroups(pw->pw_name, pw->pw_gid);
+                       if (setgid(pw->pw_gid))
+                               lprintf(3, "setgid(%d): %s\n", pw->pw_gid,
+                                       strerror(errno));
+                       }
+               lprintf(7, "Changing uid to %d\n", BBSUID);
+               if (setuid(BBSUID) != 0) {
+                       lprintf(3, "setuid() failed: %s\n", strerror(errno));
+                       }
                }
+
+       /*
+        * Do non system dependent startup functions.
         */
+       master_startup();
+
+       /*
+        * Load any server-side modules (plugins) available here.
+        */
+       lprintf(7, "Initializing loadable modules\n");
+       if ((moddir = malloc(strlen(bbs_home_directory) + 9)) != NULL) {
+               sprintf(moddir, "%s/modules", bbs_home_directory);
+               DLoader_Init(moddir);
+               free(moddir);
+               }
+
+       lprintf(7, "Starting housekeeper thread\n");
+       pthread_attr_init(&attr);
+               pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
+       if (pthread_create(&HousekeepingThread, &attr,
+          (void* (*)(void*)) housekeeping_loop, NULL) != 0) {
+               lprintf(1, "Can't create housekeeping thead: %s\n",
+                       strerror(errno));
+       }
 
        /* 
         * Endless loop.  Listen on the master socket.  When a connection
         * comes in, create a socket, a context, and a thread.
         */     
-       while (1) {
+       while (!time_to_die) {
+               /* we need to check if a signal has been delivered. because
+                * syscalls may be restartable across signals, we call
+                * select with a timeout of 1 second and repeatedly check for
+                * time_to_die... */
+               FD_ZERO(&readfds);
+               FD_SET(msock, &readfds);
+               tv.tv_sec = 1;
+               tv.tv_usec = 0;
+               if (select(msock + 1, &readfds, NULL, NULL, &tv) <= 0)
+                       continue;
+               alen = sizeof fsin;
                ssock = accept(msock, (struct sockaddr *)&fsin, &alen);
                if (ssock < 0) {
                        lprintf(2, "citserver: accept() failed: %s\n",
@@ -797,24 +939,20 @@ int main(int argc, char **argv)
                        }
                else {
                        lprintf(7, "citserver: Client socket %d\n", ssock);
-                       lprintf(9, "creating context\n");
                        con = CreateNewContext();
                        con->client_socket = ssock;
 
                        /* Set the SO_REUSEADDR socket option */
-                       lprintf(9, "setting socket options\n");
                        i = 1;
                        setsockopt(ssock, SOL_SOCKET, SO_REUSEADDR,
                                &i, sizeof(i));
 
                        /* set attributes for the new thread */
-                       lprintf(9, "setting thread attributes\n");
                        pthread_attr_init(&attr);
                        pthread_attr_setdetachstate(&attr,
                                PTHREAD_CREATE_DETACHED);
 
                        /* now create the thread */
-                       lprintf(9, "creating thread\n");
                        if (pthread_create(&SessThread, &attr,
                                           (void* (*)(void*)) sd_context_loop,
                                           con)
@@ -824,16 +962,9 @@ int main(int argc, char **argv)
                                        strerror(errno));
                                }
 
-                       /* detach the thread 
-                        * (defunct -- now done at thread creation time)
-                        * if (pthread_detach(&SessThread) != 0) {
-                        *      lprintf(1,
-                        *              "citserver: can't detach thread: %s\n",
-                        *              strerror(errno));
-                        *      }
-                        */
-                       lprintf(9, "done!\n");
                        }
                }
+       master_cleanup();
+       return 0;
        }