2 * Citadel/UX "system dependent" stuff.
3 * See copyright.txt for copyright information.
7 * Here's where we (hopefully) have all the parts of the Citadel server that
8 * would need to be altered to run the server in a non-POSIX environment.
10 * Eventually we'll try porting to a different platform and either have
11 * multiple variants of this file or simply load it up with #ifdefs.
22 #include <sys/types.h>
24 #include <sys/socket.h>
27 #include <netinet/in.h>
43 #include "sysdep_decls.h"
44 #include "citserver.h"
48 #include "housekeeping.h"
49 #include "dynloader.h"
52 #ifdef HAVE_SYS_SELECT_H
53 #include <sys/select.h>
60 #ifdef DEBUG_MEMORY_LEAKS
61 struct TheHeap *heap = NULL;
64 pthread_mutex_t Critters[MAX_SEMAPHORES]; /* Things needing locking */
65 pthread_key_t MyConKey; /* TSD key for MyContext() */
67 int msock; /* master listening socket */
68 int verbosity = DEFAULT_VERBOSITY; /* Logging level */
70 struct CitContext masterCC;
71 int rescan[2]; /* The Rescan Pipe */
72 time_t last_purge = 0; /* Last dead session purge */
73 int num_threads = 0; /* Current number of threads */
74 int num_sessions = 0; /* Current number of sessions */
76 fd_set masterfds; /* Master sockets etc. */
81 * lprintf() ... Write logging information
83 void lprintf(int loglevel, const char *format, ...) {
87 va_start(arg_ptr, format);
88 vsprintf(buf, format, arg_ptr);
91 if (loglevel <= verbosity) {
92 fprintf(stderr, "%s", buf);
96 PerformLogHooks(loglevel, buf);
101 #ifdef DEBUG_MEMORY_LEAKS
102 void *tracked_malloc(size_t tsize, char *tfile, int tline) {
104 struct TheHeap *hptr;
108 lprintf(3, "DANGER! mallok(%d) at %s:%d failed!\n",
109 tsize, tfile, tline);
113 hptr = (struct TheHeap *) malloc(sizeof(struct TheHeap));
114 strcpy(hptr->h_file, tfile);
115 hptr->h_line = tline;
122 char *tracked_strdup(const char *orig, char *tfile, int tline) {
125 s = tracked_malloc( (strlen(orig)+1), tfile, tline);
126 if (s == NULL) return NULL;
132 void tracked_free(void *ptr) {
133 struct TheHeap *hptr, *freeme;
135 if (heap->h_ptr == ptr) {
141 for (hptr=heap; hptr->next!=NULL; hptr=hptr->next) {
142 if (hptr->next->h_ptr == ptr) {
144 hptr->next = hptr->next->next;
153 void *tracked_realloc(void *ptr, size_t size) {
155 struct TheHeap *hptr;
157 newptr = realloc(ptr, size);
159 for (hptr=heap; hptr!=NULL; hptr=hptr->next) {
160 if (hptr->h_ptr == ptr) hptr->h_ptr = newptr;
167 void dump_tracked() {
168 struct TheHeap *hptr;
170 cprintf("%d Here's what's allocated...\n", LISTING_FOLLOWS);
171 for (hptr=heap; hptr!=NULL; hptr=hptr->next) {
172 cprintf("%20s %5d\n",
173 hptr->h_file, hptr->h_line);
185 * we used to use master_cleanup() as a signal handler to shut down the server.
186 * however, master_cleanup() and the functions it calls do some things that
187 * aren't such a good idea to do from a signal handler: acquiring mutexes,
188 * playing with signal masks on BSDI systems, etc. so instead we install the
189 * following signal handler to set a global variable to inform the main loop
190 * that it's time to call master_cleanup() and exit.
193 static volatile int time_to_die = 0;
195 static RETSIGTYPE signal_cleanup(int signum) {
201 * Some initialization stuff...
203 void init_sysdep(void) {
206 /* Set up a bunch of semaphores to be used for critical sections */
207 for (a=0; a<MAX_SEMAPHORES; ++a) {
208 pthread_mutex_init(&Critters[a], NULL);
212 * Set up a place to put thread-specific data.
213 * We only need a single pointer per thread - it points to the
214 * thread's CitContext structure in the ContextList linked list.
216 if (pthread_key_create(&MyConKey, NULL) != 0) {
217 lprintf(1, "Can't create TSD key!! %s\n", strerror(errno));
221 * The action for unexpected signals and exceptions should be to
222 * call signal_cleanup() to gracefully shut down the server.
224 signal(SIGINT, signal_cleanup);
225 signal(SIGQUIT, signal_cleanup);
226 signal(SIGHUP, signal_cleanup);
227 signal(SIGTERM, signal_cleanup);
230 * Do not shut down the server on broken pipe signals, otherwise the
231 * whole Citadel service would come down whenever a single client
234 signal(SIGPIPE, SIG_IGN);
239 * Obtain a semaphore lock to begin a critical section.
241 void begin_critical_section(int which_one)
243 pthread_mutex_lock(&Critters[which_one]);
247 * Release a semaphore lock to end a critical section.
249 void end_critical_section(int which_one)
251 pthread_mutex_unlock(&Critters[which_one]);
257 * This is a generic function to set up a master socket for listening on
258 * a TCP port. The server shuts down if the bind fails.
260 int ig_tcp_server(int port_number, int queue_len)
262 struct sockaddr_in sin;
265 memset(&sin, 0, sizeof(sin));
266 sin.sin_family = AF_INET;
267 sin.sin_addr.s_addr = INADDR_ANY;
269 if (port_number == 0) {
271 "citserver: No port number specified. Run setup.\n");
275 sin.sin_port = htons((u_short)port_number);
277 s = socket(PF_INET, SOCK_STREAM, (getprotobyname("tcp")->p_proto));
279 lprintf(1, "citserver: Can't create a socket: %s\n",
284 /* Set the SO_REUSEADDR socket option, because it makes sense. */
286 setsockopt(s, SOL_SOCKET, SO_REUSEADDR, &i, sizeof(i));
288 if (bind(s, (struct sockaddr *)&sin, sizeof(sin)) < 0) {
289 lprintf(1, "citserver: Can't bind: %s\n", strerror(errno));
293 if (listen(s, queue_len) < 0) {
294 lprintf(1, "citserver: Can't listen: %s\n", strerror(errno));
304 * Return a pointer to the CitContext structure bound to the thread which
305 * called this function. If there's no such binding (for example, if it's
306 * called by the housekeeper thread) then a generic 'master' CC is returned.
308 struct CitContext *MyContext(void) {
309 struct CitContext *retCC;
310 retCC = (struct CitContext *) pthread_getspecific(MyConKey);
311 if (retCC == NULL) retCC = &masterCC;
317 * Initialize a new context and place it in the list.
319 struct CitContext *CreateNewContext(void) {
320 struct CitContext *me, *ptr;
324 me = (struct CitContext *) mallok(sizeof(struct CitContext));
326 lprintf(1, "citserver: can't allocate memory!!\n");
329 memset(me, 0, sizeof(struct CitContext));
331 /* The new context will be created already in the CON_EXECUTING state
332 * in order to prevent another thread from grabbing it while it's
335 me->state = CON_EXECUTING;
337 begin_critical_section(S_SESSION_TABLE);
339 /* obtain a unique session number */
342 for (ptr = ContextList; ptr != NULL; ptr = ptr->next) {
343 if (ptr->cs_pid == num) {
348 } while (startover == 1);
351 me->next = ContextList;
355 end_critical_section(S_SESSION_TABLE);
362 * client_write() ... Send binary data to the client.
364 void client_write(char *buf, int nbytes)
366 int bytes_written = 0;
368 while (bytes_written < nbytes) {
369 retval = write(CC->client_socket, &buf[bytes_written],
370 nbytes - bytes_written);
372 lprintf(2, "client_write() failed: %s\n",
377 bytes_written = bytes_written + retval;
383 * cprintf() ... Send formatted printable data to the client. It is
384 * implemented in terms of client_write() but remains in
385 * sysdep.c in case we port to somewhere without va_args...
387 void cprintf(const char *format, ...) {
391 va_start(arg_ptr, format);
392 if (vsnprintf(buf, sizeof buf, format, arg_ptr) == -1)
393 buf[sizeof buf - 2] = '\n';
394 client_write(buf, strlen(buf));
400 * Read data from the client socket.
402 * 1 Requested number of bytes has been read.
403 * 0 Request timed out.
404 * -1 The socket is broken.
405 * If the socket breaks, the session will be terminated.
407 int client_read_to(char *buf, int bytes, int timeout)
417 FD_SET(CC->client_socket, &rfds);
421 retval = select( (CC->client_socket)+1,
422 &rfds, NULL, NULL, &tv);
424 if (FD_ISSET(CC->client_socket, &rfds) == 0) {
428 rlen = read(CC->client_socket, &buf[len], bytes-len);
430 lprintf(2, "client_read() failed: %s\n",
441 * Read data from the client socket with default timeout.
442 * (This is implemented in terms of client_read_to() and could be
443 * justifiably moved out of sysdep.c)
445 int client_read(char *buf, int bytes)
447 return(client_read_to(buf, bytes, config.c_sleeping));
452 * client_gets() ... Get a LF-terminated line of text from the client.
453 * (This is implemented in terms of client_read() and could be
454 * justifiably moved out of sysdep.c)
456 int client_gets(char *buf)
460 /* Read one character at a time.
463 retval = client_read(&buf[i], 1);
464 if (retval != 1 || buf[i] == '\n' || i == 255)
468 /* If we got a long line, discard characters until the newline.
471 while (buf[i] != '\n' && retval == 1)
472 retval = client_read(&buf[i], 1);
474 /* Strip the trailing newline and any trailing nonprintables (cr's)
477 while ((strlen(buf)>0)&&(!isprint(buf[strlen(buf)-1])))
478 buf[strlen(buf)-1] = 0;
485 * The system-dependent part of master_cleanup() - close the master socket.
487 void sysdep_master_cleanup(void) {
488 lprintf(7, "Closing master socket %d\n", msock);
494 * Terminate another session.
495 * (This could justifiably be moved out of sysdep.c because it
496 * no longer does anything that is system-dependent.)
498 void kill_session(int session_to_kill) {
499 struct CitContext *ptr;
501 begin_critical_section(S_SESSION_TABLE);
502 for (ptr = ContextList; ptr != NULL; ptr = ptr->next) {
503 if (ptr->cs_pid == session_to_kill) {
507 end_critical_section(S_SESSION_TABLE);
514 * Start running as a daemon. Only close stdio if do_close_stdio is set.
516 void start_daemon(int do_close_stdio) {
517 if (do_close_stdio) {
522 signal(SIGHUP,SIG_IGN);
523 signal(SIGINT,SIG_IGN);
524 signal(SIGQUIT,SIG_IGN);
525 if (fork()!=0) exit(0);
531 * Tie in to the 'netsetup' program.
533 * (We're going to hope that netsetup never feeds more than 4096 bytes back.)
535 void cmd_nset(char *cmdbuf)
542 char netsetup_args[3][256];
544 if (CC->usersupp.axlevel < 6) {
545 cprintf("%d Higher access required.\n",
546 ERROR + HIGHER_ACCESS_REQUIRED);
550 for (a=1; a<=3; ++a) {
551 if (num_parms(cmdbuf) >= a) {
552 extract(netsetup_args[a-1], cmdbuf, a-1);
553 for (b=0; b<strlen(netsetup_args[a-1]); ++b) {
554 if (netsetup_args[a-1][b] == 34) {
555 netsetup_args[a-1][b] = '_';
560 netsetup_args[a-1][0] = 0;
564 sprintf(fbuf, "./netsetup \"%s\" \"%s\" \"%s\" </dev/null 2>&1",
565 netsetup_args[0], netsetup_args[1], netsetup_args[2]);
566 netsetup = popen(fbuf, "r");
567 if (netsetup == NULL) {
568 cprintf("%d %s\n", ERROR, strerror(errno));
573 while (ch = getc(netsetup), (ch > 0)) {
574 fbuf[strlen(fbuf)+1] = 0;
575 fbuf[strlen(fbuf)] = ch;
578 retcode = pclose(netsetup);
581 for (a=0; a<strlen(fbuf); ++a) {
582 if (fbuf[a] < 32) fbuf[a] = 32;
585 cprintf("%d %s\n", ERROR, fbuf);
589 cprintf("%d Command succeeded. Output follows:\n", LISTING_FOLLOWS);
591 if (fbuf[strlen(fbuf)-1] != 10) cprintf("\n");
598 * Generic routine to convert a login name to a full name (gecos)
599 * Returns nonzero if a conversion took place
601 int convert_login(char NameToConvert[]) {
605 pw = getpwnam(NameToConvert);
610 strcpy(NameToConvert, pw->pw_gecos);
611 for (a=0; a<strlen(NameToConvert); ++a) {
612 if (NameToConvert[a] == ',') NameToConvert[a] = 0;
621 * Purge all sessions which have the 'kill_me' flag set.
622 * This function has code to prevent it from running more than once every
623 * few seconds, because running it after every single unbind would waste a lot
624 * of CPU time and keep the context list locked too much.
626 * After that's done, we raise or lower the size of the worker thread pool
627 * if such an action is appropriate.
629 void dead_session_purge(void) {
630 struct CitContext *ptr, *rem;
634 if ( (time(NULL) - last_purge) < 5 ) return; /* Too soon, go away */
639 begin_critical_section(S_SESSION_TABLE);
640 for (ptr = ContextList; ptr != NULL; ptr = ptr->next) {
641 if ( (ptr->state == CON_IDLE) && (ptr->kill_me) ) {
645 end_critical_section(S_SESSION_TABLE);
647 /* RemoveContext() enters its own S_SESSION_TABLE critical
648 * section, so we have to do it like this.
651 lprintf(9, "Purging session %d\n", rem->cs_pid);
655 } while (rem != NULL);
658 /* Raise or lower the size of the worker thread pool if such
659 * an action is appropriate.
662 if ( (num_sessions > num_threads)
663 && (num_threads < config.c_max_workers) ) {
665 pthread_attr_init(&attr);
666 pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
667 if (pthread_create(&newthread, &attr,
668 (void* (*)(void*)) worker_thread, NULL) != 0) {
669 lprintf(1, "Can't create worker thead: %s\n",
675 else if ( (num_sessions < num_threads)
676 && (num_threads > config.c_min_workers) ) {
687 * Here's where it all begins.
689 int main(int argc, char **argv)
691 pthread_t HousekeepingThread; /* Thread descriptor */
692 pthread_attr_t attr; /* Thread attributes */
693 char tracefile[128]; /* Name of file to log traces to */
694 int a, i; /* General-purpose variables */
696 int drop_root_perms = 1;
698 struct ServiceFunctionHook *serviceptr;
700 /* specify default port name and trace file */
701 strcpy(tracefile, "");
703 /* parse command-line arguments */
704 for (a=1; a<argc; ++a) {
706 /* -t specifies where to log trace messages to */
707 if (!strncmp(argv[a], "-t", 2)) {
708 strcpy(tracefile, argv[a]);
709 strcpy(tracefile, &tracefile[2]);
710 freopen(tracefile, "r", stdin);
711 freopen(tracefile, "w", stdout);
712 freopen(tracefile, "w", stderr);
715 /* run in the background if -d was specified */
716 else if (!strcmp(argv[a], "-d")) {
717 start_daemon( (strlen(tracefile) > 0) ? 0 : 1 ) ;
720 /* -x specifies the desired logging level */
721 else if (!strncmp(argv[a], "-x", 2)) {
722 verbosity = atoi(&argv[a][2]);
725 else if (!strncmp(argv[a], "-h", 2)) {
726 safestrncpy(bbs_home_directory, &argv[a][2],
727 sizeof bbs_home_directory);
731 else if (!strncmp(argv[a], "-f", 2)) {
735 /* -r tells the server not to drop root permissions. don't use
736 * this unless you know what you're doing. this should be
737 * removed in the next release if it proves unnecessary. */
738 else if (!strcmp(argv[a], "-r"))
741 /* any other parameter makes it crash and burn */
743 lprintf(1, "citserver: usage: "
744 "citserver [-tTraceFile] [-d] [-f]"
745 " [-xLogLevel] [-hHomeDir]\n");
751 /* Tell 'em who's in da house */
753 "\nMultithreaded message server for Citadel/UX\n"
754 "Copyright (C) 1987-1999 by the Citadel/UX development team.\n"
755 "Citadel/UX is free software, covered by the GNU General Public License, and\n"
756 "you are welcome to change it and/or distribute copies of it under certain\n"
757 "conditions. There is absolutely no warranty for this software. Please\n"
758 "read the 'COPYING.txt' file for details.\n\n");
762 openlog("citserver",LOG_PID,LOG_USER);
764 /* Load site-specific parameters */
765 lprintf(7, "Loading citadel.config\n");
769 * Bind the server to our favourite port.
770 * There is no need to check for errors, because ig_tcp_server()
771 * exits if it doesn't succeed.
773 lprintf(7, "Attempting to bind to port %d...\n", config.c_port_number);
774 msock = ig_tcp_server(config.c_port_number, config.c_maxsessions);
775 lprintf(7, "Listening on socket %d\n", msock);
778 * Now that we've bound the socket, change to the BBS user id and its
779 * corresponding group ids
781 if (drop_root_perms) {
782 if ((pw = getpwuid(BBSUID)) == NULL)
783 lprintf(1, "WARNING: getpwuid(%d): %s\n"
784 "Group IDs will be incorrect.\n", BBSUID,
787 initgroups(pw->pw_name, pw->pw_gid);
788 if (setgid(pw->pw_gid))
789 lprintf(3, "setgid(%d): %s\n", pw->pw_gid,
792 lprintf(7, "Changing uid to %d\n", BBSUID);
793 if (setuid(BBSUID) != 0) {
794 lprintf(3, "setuid() failed: %s\n", strerror(errno));
799 * Do non system dependent startup functions.
804 * Load any server-side modules (plugins) available here.
806 lprintf(7, "Initializing loadable modules\n");
807 if ((moddir = malloc(strlen(bbs_home_directory) + 9)) != NULL) {
808 sprintf(moddir, "%s/modules", bbs_home_directory);
809 DLoader_Init(moddir);
813 lprintf(7, "Starting housekeeper thread\n");
814 pthread_attr_init(&attr);
815 pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
816 if (pthread_create(&HousekeepingThread, &attr,
817 (void* (*)(void*)) housekeeping_loop, NULL) != 0) {
818 lprintf(1, "Can't create housekeeping thead: %s\n",
824 * The rescan pipe exists so that worker threads can be woken up and
825 * told to re-scan the context list for fd's to listen on. This is
826 * necessary, for example, when a context is about to go idle and needs
827 * to get back on that list.
830 lprintf(1, "Can't create rescan pipe!\n");
835 * Set up a fd_set containing all the master sockets to which we
836 * always listen. It's computationally less expensive to just copy
837 * this to a local fd_set when starting a new select() and then add
838 * the client sockets than it is to initialize a new one and then
839 * figure out what to put there.
842 FD_SET(msock, &masterfds);
843 masterhighest = msock;
844 FD_SET(rescan[0], &masterfds);
845 if (rescan[0] > masterhighest) masterhighest = rescan[0];
847 for (serviceptr = ServiceHookTable; serviceptr != NULL;
848 serviceptr = serviceptr->next ) {
849 FD_SET(serviceptr->tcp_port, &masterfds);
850 if (serviceptr->tcp_port > masterhighest)
851 masterhighest = serviceptr->tcp_port;
856 * Now create a bunch of worker threads.
858 for (i=0; i<(config.c_min_workers-1); ++i) {
859 pthread_attr_init(&attr);
860 pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
861 if (pthread_create(&HousekeepingThread, &attr,
862 (void* (*)(void*)) worker_thread, NULL) != 0) {
863 lprintf(1, "Can't create worker thead: %s\n",
868 /* Now this thread can become a worker as well. */
881 * This loop just keeps going and going and going...
883 void worker_thread(void) {
887 struct CitContext *ptr;
888 struct CitContext *bind_me = NULL;
891 struct CitContext *con= NULL; /* Temporary context pointer */
892 struct sockaddr_in fsin; /* Data for master socket */
893 int alen; /* Data for master socket */
894 int ssock; /* Descriptor for client socket */
897 while (!time_to_die) {
900 * A naive implementation would have all idle threads
901 * calling select() and then they'd all wake up at once. We
902 * solve this problem by putting the select() in a critical
903 * section, so only one thread has the opportunity to wake
904 * up. If we wake up on the master socket, create a new
905 * session context; otherwise, just bind the thread to the
906 * context we want and go on our merry way.
909 begin_critical_section(S_I_WANNA_SELECT);
910 SETUP_FD: memcpy(&readfds, &masterfds, sizeof(fd_set) );
911 highest = masterhighest;
912 begin_critical_section(S_SESSION_TABLE);
913 for (ptr = ContextList; ptr != NULL; ptr = ptr->next) {
914 if (ptr->state == CON_IDLE) {
915 FD_SET(ptr->client_socket, &readfds);
916 if (ptr->client_socket > highest)
917 highest = ptr->client_socket;
920 end_critical_section(S_SESSION_TABLE);
922 retval = select(highest + 1, &readfds, NULL, NULL, NULL);
924 /* Now figure out who made this select() unblock.
925 * First, check for an error or exit condition.
928 end_critical_section(S_I_WANNA_SELECT);
929 lprintf(9, "Exiting (%s)\n", strerror(errno));
933 /* Next, check to see if it's a new client connecting
934 * on the master socket.
936 else if (FD_ISSET(msock, &readfds)) {
938 ssock = accept(msock, (struct sockaddr *)&fsin, &alen);
940 lprintf(2, "citserver: accept() failed: %s\n",
944 lprintf(7, "citserver: New client socket %d\n",
947 /* New context will be created already set up
948 * in the CON_EXECUTING state.
950 con = CreateNewContext();
952 /* Assign our new socket number to it. */
953 con->client_socket = ssock;
954 con->client_protocol = config.c_port_number;
956 /* Set the SO_REUSEADDR socket option */
958 setsockopt(ssock, SOL_SOCKET, SO_REUSEADDR,
961 pthread_setspecific(MyConKey, (void *)con);
963 pthread_setspecific(MyConKey, (void *)NULL);
964 con->state = CON_IDLE;
969 /* If the rescan pipe went active, someone is telling this
970 * thread that the &readfds needs to be refreshed with more
973 else if (FD_ISSET(rescan[0], &readfds)) {
974 read(rescan[0], &junk, 1);
978 /* It must be a client socket. Find a context that has data
979 * waiting on its socket *and* is in the CON_IDLE state.
983 begin_critical_section(S_SESSION_TABLE);
984 for (ptr = ContextList;
985 ( (ptr != NULL) && (bind_me == NULL) );
987 if ( (FD_ISSET(ptr->client_socket, &readfds))
988 && (ptr->state == CON_IDLE) ) {
992 if (bind_me != NULL) {
993 /* Found one. Stake a claim to it before
994 * letting anyone else touch the context list.
996 bind_me->state = CON_EXECUTING;
999 end_critical_section(S_SESSION_TABLE);
1000 end_critical_section(S_I_WANNA_SELECT);
1002 /* We're bound to a session, now do *one* command */
1003 if (bind_me != NULL) {
1004 pthread_setspecific(MyConKey, (void *)bind_me);
1006 pthread_setspecific(MyConKey, (void *)NULL);
1007 bind_me->state = CON_IDLE;
1008 if (bind_me->kill_me == 1) {
1009 RemoveContext(bind_me);
1011 write(rescan[1], &junk, 1);
1014 lprintf(9, "Thread found nothing to do!\n");
1018 dead_session_purge();
1021 /* If control reaches this point, the server is shutting down */