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 */
77 * This fd_set will be loaded up with all the master sockets, so we can
78 * quickly copy it into a working fd_set every time we need it.
86 * lprintf() ... Write logging information
88 void lprintf(int loglevel, const char *format, ...) {
92 va_start(arg_ptr, format);
93 vsprintf(buf, format, arg_ptr);
96 if (loglevel <= verbosity) {
97 fprintf(stderr, "%s", buf);
101 PerformLogHooks(loglevel, buf);
106 #ifdef DEBUG_MEMORY_LEAKS
107 void *tracked_malloc(size_t tsize, char *tfile, int tline) {
109 struct TheHeap *hptr;
113 lprintf(3, "DANGER! mallok(%d) at %s:%d failed!\n",
114 tsize, tfile, tline);
118 hptr = (struct TheHeap *) malloc(sizeof(struct TheHeap));
119 strcpy(hptr->h_file, tfile);
120 hptr->h_line = tline;
127 char *tracked_strdup(const char *orig, char *tfile, int tline) {
130 s = tracked_malloc( (strlen(orig)+1), tfile, tline);
131 if (s == NULL) return NULL;
137 void tracked_free(void *ptr) {
138 struct TheHeap *hptr, *freeme;
140 if (heap->h_ptr == ptr) {
146 for (hptr=heap; hptr->next!=NULL; hptr=hptr->next) {
147 if (hptr->next->h_ptr == ptr) {
149 hptr->next = hptr->next->next;
158 void *tracked_realloc(void *ptr, size_t size) {
160 struct TheHeap *hptr;
162 newptr = realloc(ptr, size);
164 for (hptr=heap; hptr!=NULL; hptr=hptr->next) {
165 if (hptr->h_ptr == ptr) hptr->h_ptr = newptr;
172 void dump_tracked() {
173 struct TheHeap *hptr;
175 cprintf("%d Here's what's allocated...\n", LISTING_FOLLOWS);
176 for (hptr=heap; hptr!=NULL; hptr=hptr->next) {
177 cprintf("%20s %5d\n",
178 hptr->h_file, hptr->h_line);
190 * we used to use master_cleanup() as a signal handler to shut down the server.
191 * however, master_cleanup() and the functions it calls do some things that
192 * aren't such a good idea to do from a signal handler: acquiring mutexes,
193 * playing with signal masks on BSDI systems, etc. so instead we install the
194 * following signal handler to set a global variable to inform the main loop
195 * that it's time to call master_cleanup() and exit.
198 static volatile int time_to_die = 0;
200 static RETSIGTYPE signal_cleanup(int signum) {
206 * Some initialization stuff...
208 void init_sysdep(void) {
211 /* Set up a bunch of semaphores to be used for critical sections */
212 for (a=0; a<MAX_SEMAPHORES; ++a) {
213 pthread_mutex_init(&Critters[a], NULL);
217 * Set up a place to put thread-specific data.
218 * We only need a single pointer per thread - it points to the
219 * thread's CitContext structure in the ContextList linked list.
221 if (pthread_key_create(&MyConKey, NULL) != 0) {
222 lprintf(1, "Can't create TSD key!! %s\n", strerror(errno));
226 * The action for unexpected signals and exceptions should be to
227 * call signal_cleanup() to gracefully shut down the server.
229 signal(SIGINT, signal_cleanup);
230 signal(SIGQUIT, signal_cleanup);
231 signal(SIGHUP, signal_cleanup);
232 signal(SIGTERM, signal_cleanup);
235 * Do not shut down the server on broken pipe signals, otherwise the
236 * whole Citadel service would come down whenever a single client
239 signal(SIGPIPE, SIG_IGN);
244 * Obtain a semaphore lock to begin a critical section.
246 void begin_critical_section(int which_one)
248 pthread_mutex_lock(&Critters[which_one]);
252 * Release a semaphore lock to end a critical section.
254 void end_critical_section(int which_one)
256 pthread_mutex_unlock(&Critters[which_one]);
262 * This is a generic function to set up a master socket for listening on
263 * a TCP port. The server shuts down if the bind fails.
265 int ig_tcp_server(int port_number, int queue_len)
267 struct sockaddr_in sin;
270 memset(&sin, 0, sizeof(sin));
271 sin.sin_family = AF_INET;
272 sin.sin_addr.s_addr = INADDR_ANY;
274 if (port_number == 0) {
276 "citserver: No port number specified. Run setup.\n");
280 sin.sin_port = htons((u_short)port_number);
282 s = socket(PF_INET, SOCK_STREAM, (getprotobyname("tcp")->p_proto));
284 lprintf(1, "citserver: Can't create a socket: %s\n",
289 /* Set the SO_REUSEADDR socket option, because it makes sense. */
291 setsockopt(s, SOL_SOCKET, SO_REUSEADDR, &i, sizeof(i));
293 if (bind(s, (struct sockaddr *)&sin, sizeof(sin)) < 0) {
294 lprintf(1, "citserver: Can't bind: %s\n", strerror(errno));
298 if (listen(s, queue_len) < 0) {
299 lprintf(1, "citserver: Can't listen: %s\n", strerror(errno));
309 * Return a pointer to the CitContext structure bound to the thread which
310 * called this function. If there's no such binding (for example, if it's
311 * called by the housekeeper thread) then a generic 'master' CC is returned.
313 struct CitContext *MyContext(void) {
314 struct CitContext *retCC;
315 retCC = (struct CitContext *) pthread_getspecific(MyConKey);
316 if (retCC == NULL) retCC = &masterCC;
322 * Initialize a new context and place it in the list.
324 struct CitContext *CreateNewContext(void) {
325 struct CitContext *me, *ptr;
329 me = (struct CitContext *) mallok(sizeof(struct CitContext));
331 lprintf(1, "citserver: can't allocate memory!!\n");
334 memset(me, 0, sizeof(struct CitContext));
336 /* The new context will be created already in the CON_EXECUTING state
337 * in order to prevent another thread from grabbing it while it's
340 me->state = CON_EXECUTING;
342 begin_critical_section(S_SESSION_TABLE);
344 /* obtain a unique session number */
347 for (ptr = ContextList; ptr != NULL; ptr = ptr->next) {
348 if (ptr->cs_pid == num) {
353 } while (startover == 1);
356 me->next = ContextList;
360 end_critical_section(S_SESSION_TABLE);
367 * client_write() ... Send binary data to the client.
369 void client_write(char *buf, int nbytes)
371 int bytes_written = 0;
373 while (bytes_written < nbytes) {
374 retval = write(CC->client_socket, &buf[bytes_written],
375 nbytes - bytes_written);
377 lprintf(2, "client_write() failed: %s\n",
382 bytes_written = bytes_written + retval;
388 * cprintf() ... Send formatted printable data to the client. It is
389 * implemented in terms of client_write() but remains in
390 * sysdep.c in case we port to somewhere without va_args...
392 void cprintf(const char *format, ...) {
396 va_start(arg_ptr, format);
397 if (vsnprintf(buf, sizeof buf, format, arg_ptr) == -1)
398 buf[sizeof buf - 2] = '\n';
399 client_write(buf, strlen(buf));
405 * Read data from the client socket.
407 * 1 Requested number of bytes has been read.
408 * 0 Request timed out.
409 * -1 The socket is broken.
410 * If the socket breaks, the session will be terminated.
412 int client_read_to(char *buf, int bytes, int timeout)
422 FD_SET(CC->client_socket, &rfds);
426 retval = select( (CC->client_socket)+1,
427 &rfds, NULL, NULL, &tv);
429 if (FD_ISSET(CC->client_socket, &rfds) == 0) {
433 rlen = read(CC->client_socket, &buf[len], bytes-len);
435 lprintf(2, "client_read() failed: %s\n",
446 * Read data from the client socket with default timeout.
447 * (This is implemented in terms of client_read_to() and could be
448 * justifiably moved out of sysdep.c)
450 int client_read(char *buf, int bytes)
452 return(client_read_to(buf, bytes, config.c_sleeping));
457 * client_gets() ... Get a LF-terminated line of text from the client.
458 * (This is implemented in terms of client_read() and could be
459 * justifiably moved out of sysdep.c)
461 int client_gets(char *buf)
465 /* Read one character at a time.
468 retval = client_read(&buf[i], 1);
469 if (retval != 1 || buf[i] == '\n' || i == 255)
473 /* If we got a long line, discard characters until the newline.
476 while (buf[i] != '\n' && retval == 1)
477 retval = client_read(&buf[i], 1);
479 /* Strip the trailing newline and any trailing nonprintables (cr's)
482 while ((strlen(buf)>0)&&(!isprint(buf[strlen(buf)-1])))
483 buf[strlen(buf)-1] = 0;
490 * The system-dependent part of master_cleanup() - close the master socket.
492 void sysdep_master_cleanup(void) {
493 lprintf(7, "Closing master socket %d\n", msock);
499 * Terminate another session.
500 * (This could justifiably be moved out of sysdep.c because it
501 * no longer does anything that is system-dependent.)
503 void kill_session(int session_to_kill) {
504 struct CitContext *ptr;
506 begin_critical_section(S_SESSION_TABLE);
507 for (ptr = ContextList; ptr != NULL; ptr = ptr->next) {
508 if (ptr->cs_pid == session_to_kill) {
512 end_critical_section(S_SESSION_TABLE);
519 * Start running as a daemon. Only close stdio if do_close_stdio is set.
521 void start_daemon(int do_close_stdio) {
522 if (do_close_stdio) {
527 signal(SIGHUP,SIG_IGN);
528 signal(SIGINT,SIG_IGN);
529 signal(SIGQUIT,SIG_IGN);
530 if (fork()!=0) exit(0);
536 * Tie in to the 'netsetup' program.
538 * (We're going to hope that netsetup never feeds more than 4096 bytes back.)
540 void cmd_nset(char *cmdbuf)
547 char netsetup_args[3][256];
549 if (CC->usersupp.axlevel < 6) {
550 cprintf("%d Higher access required.\n",
551 ERROR + HIGHER_ACCESS_REQUIRED);
555 for (a=1; a<=3; ++a) {
556 if (num_parms(cmdbuf) >= a) {
557 extract(netsetup_args[a-1], cmdbuf, a-1);
558 for (b=0; b<strlen(netsetup_args[a-1]); ++b) {
559 if (netsetup_args[a-1][b] == 34) {
560 netsetup_args[a-1][b] = '_';
565 netsetup_args[a-1][0] = 0;
569 sprintf(fbuf, "./netsetup \"%s\" \"%s\" \"%s\" </dev/null 2>&1",
570 netsetup_args[0], netsetup_args[1], netsetup_args[2]);
571 netsetup = popen(fbuf, "r");
572 if (netsetup == NULL) {
573 cprintf("%d %s\n", ERROR, strerror(errno));
578 while (ch = getc(netsetup), (ch > 0)) {
579 fbuf[strlen(fbuf)+1] = 0;
580 fbuf[strlen(fbuf)] = ch;
583 retcode = pclose(netsetup);
586 for (a=0; a<strlen(fbuf); ++a) {
587 if (fbuf[a] < 32) fbuf[a] = 32;
590 cprintf("%d %s\n", ERROR, fbuf);
594 cprintf("%d Command succeeded. Output follows:\n", LISTING_FOLLOWS);
596 if (fbuf[strlen(fbuf)-1] != 10) cprintf("\n");
603 * Generic routine to convert a login name to a full name (gecos)
604 * Returns nonzero if a conversion took place
606 int convert_login(char NameToConvert[]) {
610 pw = getpwnam(NameToConvert);
615 strcpy(NameToConvert, pw->pw_gecos);
616 for (a=0; a<strlen(NameToConvert); ++a) {
617 if (NameToConvert[a] == ',') NameToConvert[a] = 0;
626 * Purge all sessions which have the 'kill_me' flag set.
627 * This function has code to prevent it from running more than once every
628 * few seconds, because running it after every single unbind would waste a lot
629 * of CPU time and keep the context list locked too much.
631 * After that's done, we raise or lower the size of the worker thread pool
632 * if such an action is appropriate.
634 void dead_session_purge(void) {
635 struct CitContext *ptr, *rem;
639 if ( (time(NULL) - last_purge) < 5 ) return; /* Too soon, go away */
644 begin_critical_section(S_SESSION_TABLE);
645 for (ptr = ContextList; ptr != NULL; ptr = ptr->next) {
646 if ( (ptr->state == CON_IDLE) && (ptr->kill_me) ) {
650 end_critical_section(S_SESSION_TABLE);
652 /* RemoveContext() enters its own S_SESSION_TABLE critical
653 * section, so we have to do it like this.
656 lprintf(9, "Purging session %d\n", rem->cs_pid);
660 } while (rem != NULL);
663 /* Raise or lower the size of the worker thread pool if such
664 * an action is appropriate.
667 if ( (num_sessions > num_threads)
668 && (num_threads < config.c_max_workers) ) {
670 pthread_attr_init(&attr);
671 pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
672 if (pthread_create(&newthread, &attr,
673 (void* (*)(void*)) worker_thread, NULL) != 0) {
674 lprintf(1, "Can't create worker thead: %s\n",
680 else if ( (num_sessions < num_threads)
681 && (num_threads > config.c_min_workers) ) {
692 * Here's where it all begins.
694 int main(int argc, char **argv)
696 pthread_t HousekeepingThread; /* Thread descriptor */
697 pthread_attr_t attr; /* Thread attributes */
698 char tracefile[128]; /* Name of file to log traces to */
699 int a, i; /* General-purpose variables */
701 int drop_root_perms = 1;
704 /* specify default port name and trace file */
705 strcpy(tracefile, "");
707 /* parse command-line arguments */
708 for (a=1; a<argc; ++a) {
710 /* -t specifies where to log trace messages to */
711 if (!strncmp(argv[a], "-t", 2)) {
712 strcpy(tracefile, argv[a]);
713 strcpy(tracefile, &tracefile[2]);
714 freopen(tracefile, "r", stdin);
715 freopen(tracefile, "w", stdout);
716 freopen(tracefile, "w", stderr);
719 /* run in the background if -d was specified */
720 else if (!strcmp(argv[a], "-d")) {
721 start_daemon( (strlen(tracefile) > 0) ? 0 : 1 ) ;
724 /* -x specifies the desired logging level */
725 else if (!strncmp(argv[a], "-x", 2)) {
726 verbosity = atoi(&argv[a][2]);
729 else if (!strncmp(argv[a], "-h", 2)) {
730 safestrncpy(bbs_home_directory, &argv[a][2],
731 sizeof bbs_home_directory);
735 else if (!strncmp(argv[a], "-f", 2)) {
739 /* -r tells the server not to drop root permissions. don't use
740 * this unless you know what you're doing. this should be
741 * removed in the next release if it proves unnecessary. */
742 else if (!strcmp(argv[a], "-r"))
745 /* any other parameter makes it crash and burn */
747 lprintf(1, "citserver: usage: "
748 "citserver [-tTraceFile] [-d] [-f]"
749 " [-xLogLevel] [-hHomeDir]\n");
755 /* Tell 'em who's in da house */
757 "\nMultithreaded message server for Citadel/UX\n"
758 "Copyright (C) 1987-1999 by the Citadel/UX development team.\n"
759 "Citadel/UX is free software, covered by the GNU General Public License, and\n"
760 "you are welcome to change it and/or distribute copies of it under certain\n"
761 "conditions. There is absolutely no warranty for this software. Please\n"
762 "read the 'COPYING.txt' file for details.\n\n");
766 openlog("citserver",LOG_PID,LOG_USER);
768 /* Load site-specific parameters */
769 lprintf(7, "Loading citadel.config\n");
773 * Bind the server to our favourite port.
774 * There is no need to check for errors, because ig_tcp_server()
775 * exits if it doesn't succeed.
777 lprintf(7, "Attempting to bind to port %d...\n", config.c_port_number);
778 msock = ig_tcp_server(config.c_port_number, config.c_maxsessions);
779 lprintf(7, "Listening on socket %d\n", msock);
782 * Now that we've bound the socket, change to the BBS user id and its
783 * corresponding group ids
785 if (drop_root_perms) {
786 if ((pw = getpwuid(BBSUID)) == NULL)
787 lprintf(1, "WARNING: getpwuid(%d): %s\n"
788 "Group IDs will be incorrect.\n", BBSUID,
791 initgroups(pw->pw_name, pw->pw_gid);
792 if (setgid(pw->pw_gid))
793 lprintf(3, "setgid(%d): %s\n", pw->pw_gid,
796 lprintf(7, "Changing uid to %d\n", BBSUID);
797 if (setuid(BBSUID) != 0) {
798 lprintf(3, "setuid() failed: %s\n", strerror(errno));
803 * Do non system dependent startup functions.
808 * Load any server-side modules (plugins) available here.
810 lprintf(7, "Initializing loadable modules\n");
811 if ((moddir = malloc(strlen(bbs_home_directory) + 9)) != NULL) {
812 sprintf(moddir, "%s/modules", bbs_home_directory);
813 DLoader_Init(moddir);
817 lprintf(7, "Starting housekeeper thread\n");
818 pthread_attr_init(&attr);
819 pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
820 if (pthread_create(&HousekeepingThread, &attr,
821 (void* (*)(void*)) housekeeping_loop, NULL) != 0) {
822 lprintf(1, "Can't create housekeeping thead: %s\n",
828 * The rescan pipe exists so that worker threads can be woken up and
829 * told to re-scan the context list for fd's to listen on. This is
830 * necessary, for example, when a context is about to go idle and needs
831 * to get back on that list.
834 lprintf(1, "Can't create rescan pipe!\n");
839 * Now create a bunch of worker threads.
841 for (i=0; i<(config.c_min_workers-1); ++i) {
842 pthread_attr_init(&attr);
843 pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
844 if (pthread_create(&HousekeepingThread, &attr,
845 (void* (*)(void*)) worker_thread, NULL) != 0) {
846 lprintf(1, "Can't create worker thead: %s\n",
851 /* Now this thread can become a worker as well. */
864 * This loop just keeps going and going and going...
866 void worker_thread(void) {
871 struct CitContext *ptr;
872 struct CitContext *bind_me = NULL;
875 struct CitContext *con= NULL; /* Temporary context pointer */
876 struct sockaddr_in fsin; /* Data for master socket */
877 int alen; /* Data for master socket */
878 int ssock; /* Descriptor for client socket */
881 while (!time_to_die) {
884 * A naive implementation would have all idle threads
885 * calling select() and then they'd all wake up at once. We
886 * solve this problem by putting the select() in a critical
887 * section, so only one thread has the opportunity to wake
888 * up. If we wake up on the master socket, create a new
889 * session context; otherwise, just bind the thread to the
890 * context we want and go on our merry way.
893 begin_critical_section(S_I_WANNA_SELECT);
894 SETUP_FD: FD_ZERO(&readfds);
895 FD_SET(msock, &readfds);
897 FD_SET(rescan[0], &readfds);
898 if (rescan[0] > highest) highest = rescan[0];
901 begin_critical_section(S_SESSION_TABLE);
902 for (ptr = ContextList; ptr != NULL; ptr = ptr->next) {
903 if (ptr->state == CON_IDLE) {
904 FD_SET(ptr->client_socket, &readfds);
905 if (ptr->client_socket > highest)
906 highest = ptr->client_socket;
910 end_critical_section(S_SESSION_TABLE);
912 retval = select(highest + 1, &readfds, NULL, NULL, NULL);
914 /* Now figure out who made this select() unblock.
915 * First, check for an error or exit condition.
918 end_critical_section(S_I_WANNA_SELECT);
919 lprintf(9, "Exiting (%s)\n", strerror(errno));
923 /* Next, check to see if it's a new client connecting
924 * on the master socket.
926 else if (FD_ISSET(msock, &readfds)) {
928 ssock = accept(msock, (struct sockaddr *)&fsin, &alen);
930 lprintf(2, "citserver: accept() failed: %s\n",
934 lprintf(7, "citserver: New client socket %d\n",
937 /* New context will be created already set up
938 * in the CON_EXECUTING state.
940 con = CreateNewContext();
942 /* Assign our new socket number to it. */
943 con->client_socket = ssock;
945 /* Set the SO_REUSEADDR socket option */
947 setsockopt(ssock, SOL_SOCKET, SO_REUSEADDR,
950 pthread_setspecific(MyConKey, (void *)con);
952 /* do_command_loop(); */
953 pthread_setspecific(MyConKey, (void *)NULL);
954 con->state = CON_IDLE;
959 /* If the rescan pipe went active, someone is telling this
960 * thread that the &readfds needs to be refreshed with more
963 else if (FD_ISSET(rescan[0], &readfds)) {
964 read(rescan[0], &junk, 1);
968 /* It must be a client socket. Find a context that has data
969 * waiting on its socket *and* is in the CON_IDLE state.
973 begin_critical_section(S_SESSION_TABLE);
974 for (ptr = ContextList;
975 ( (ptr != NULL) && (bind_me == NULL) );
977 if ( (FD_ISSET(ptr->client_socket, &readfds))
978 && (ptr->state == CON_IDLE) ) {
982 if (bind_me != NULL) {
983 /* Found one. Stake a claim to it before
984 * letting anyone else touch the context list.
986 bind_me->state = CON_EXECUTING;
989 end_critical_section(S_SESSION_TABLE);
990 end_critical_section(S_I_WANNA_SELECT);
992 /* We're bound to a session, now do *one* command */
993 if (bind_me != NULL) {
994 pthread_setspecific(MyConKey, (void *)bind_me);
996 pthread_setspecific(MyConKey, (void *)NULL);
997 bind_me->state = CON_IDLE;
998 if (bind_me->kill_me == 1) {
999 RemoveContext(bind_me);
1001 write(rescan[1], &junk, 1);
1004 lprintf(9, "Thread found nothing to do!\n");
1008 dead_session_purge();
1011 /* If control reaches this point, the server is shutting down */