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.
9 * Wherever possible, we use function wrappers and type definitions to create
10 * abstractions that are platform-independent from the calling side.
12 * Eventually we'll try porting to a different platform and either have
13 * multiple variants of this file or simply load it up with #ifdefs.
24 #include <sys/types.h>
26 #include <sys/socket.h>
29 #include <netinet/in.h>
45 #include "sysdep_decls.h"
46 #include "citserver.h"
50 #include "housekeeping.h"
51 #include "dynloader.h"
54 #ifdef HAVE_SYS_SELECT_H
55 #include <sys/select.h>
62 #ifdef DEBUG_MEMORY_LEAKS
63 struct TheHeap *heap = NULL;
66 pthread_mutex_t Critters[MAX_SEMAPHORES]; /* Things needing locking */
67 pthread_key_t MyConKey; /* TSD key for MyContext() */
69 int msock; /* master listening socket */
70 int verbosity = 9; /* Logging level */
72 struct CitContext masterCC;
73 int rescan[2]; /* The Rescan Pipe */
76 * lprintf() ... Write logging information
78 void lprintf(int loglevel, const char *format, ...) {
82 va_start(arg_ptr, format);
83 vsprintf(buf, format, arg_ptr);
86 if (loglevel <= verbosity) {
87 fprintf(stderr, "%s", buf);
91 PerformLogHooks(loglevel, buf);
96 #ifdef DEBUG_MEMORY_LEAKS
97 void *tracked_malloc(size_t tsize, char *tfile, int tline) {
103 lprintf(3, "DANGER! mallok(%d) at %s:%d failed!\n",
104 tsize, tfile, tline);
108 hptr = (struct TheHeap *) malloc(sizeof(struct TheHeap));
109 strcpy(hptr->h_file, tfile);
110 hptr->h_line = tline;
117 char *tracked_strdup(const char *orig, char *tfile, int tline) {
120 s = tracked_malloc( (strlen(orig)+1), tfile, tline);
121 if (s == NULL) return NULL;
127 void tracked_free(void *ptr) {
128 struct TheHeap *hptr, *freeme;
130 if (heap->h_ptr == ptr) {
136 for (hptr=heap; hptr->next!=NULL; hptr=hptr->next) {
137 if (hptr->next->h_ptr == ptr) {
139 hptr->next = hptr->next->next;
148 void *tracked_realloc(void *ptr, size_t size) {
150 struct TheHeap *hptr;
152 newptr = realloc(ptr, size);
154 for (hptr=heap; hptr!=NULL; hptr=hptr->next) {
155 if (hptr->h_ptr == ptr) hptr->h_ptr = newptr;
162 void dump_tracked() {
163 struct TheHeap *hptr;
165 cprintf("%d Here's what's allocated...\n", LISTING_FOLLOWS);
166 for (hptr=heap; hptr!=NULL; hptr=hptr->next) {
167 cprintf("%20s %5d\n",
168 hptr->h_file, hptr->h_line);
178 static pthread_t main_thread_id;
180 #ifndef HAVE_PTHREAD_CANCEL
182 * signal handler to fake thread cancellation; only required on BSDI as far
185 static RETSIGTYPE cancel_thread(int signum) {
191 * we used to use master_cleanup() as a signal handler to shut down the server.
192 * however, master_cleanup() and the functions it calls do some things that
193 * aren't such a good idea to do from a signal handler: acquiring mutexes,
194 * playing with signal masks on BSDI systems, etc. so instead we install the
195 * following signal handler to set a global variable to inform the main loop
196 * that it's time to call master_cleanup() and exit.
199 static volatile int time_to_die = 0;
201 static RETSIGTYPE signal_cleanup(int signum) {
207 * Some initialization stuff...
209 void init_sysdep(void) {
212 /* Set up a bunch of semaphores to be used for critical sections */
213 for (a=0; a<MAX_SEMAPHORES; ++a) {
214 pthread_mutex_init(&Critters[a], NULL);
218 * Set up a place to put thread-specific data.
219 * We only need a single pointer per thread - it points to the
220 * thread's CitContext structure in the ContextList linked list.
222 if (pthread_key_create(&MyConKey, NULL) != 0) {
223 lprintf(1, "Can't create TSD key!! %s\n", strerror(errno));
227 * The action for unexpected signals and exceptions should be to
228 * call signal_cleanup() to gracefully shut down the server.
230 signal(SIGINT, signal_cleanup);
231 signal(SIGQUIT, signal_cleanup);
232 signal(SIGHUP, signal_cleanup);
233 signal(SIGTERM, signal_cleanup);
234 signal(SIGPIPE, SIG_IGN);
235 main_thread_id = pthread_self();
236 #ifndef HAVE_PTHREAD_CANCEL /* fake it - only BSDI afaik */
237 signal(SIGUSR1, cancel_thread);
243 * Obtain a semaphore lock to begin a critical section.
245 void begin_critical_section(int which_one)
247 pthread_mutex_lock(&Critters[which_one]);
251 * Release a semaphore lock to end a critical section.
253 void end_critical_section(int which_one)
255 pthread_mutex_unlock(&Critters[which_one]);
261 * This is a generic function to set up a master socket for listening on
262 * a TCP port. The server shuts down if the bind fails.
264 int ig_tcp_server(int port_number, int queue_len)
266 struct sockaddr_in sin;
269 memset(&sin, 0, sizeof(sin));
270 sin.sin_family = AF_INET;
271 sin.sin_addr.s_addr = INADDR_ANY;
273 if (port_number == 0) {
275 "citserver: No port number specified. Run setup.\n");
279 sin.sin_port = htons((u_short)port_number);
281 s = socket(PF_INET, SOCK_STREAM, (getprotobyname("tcp")->p_proto));
283 lprintf(1, "citserver: Can't create a socket: %s\n",
288 /* Set the SO_REUSEADDR socket option, because it makes sense. */
290 setsockopt(s, SOL_SOCKET, SO_REUSEADDR, &i, sizeof(i));
292 if (bind(s, (struct sockaddr *)&sin, sizeof(sin)) < 0) {
293 lprintf(1, "citserver: Can't bind: %s\n", strerror(errno));
297 if (listen(s, queue_len) < 0) {
298 lprintf(1, "citserver: Can't listen: %s\n", strerror(errno));
308 * Return a pointer to a thread's own CitContext structure (new)
310 struct CitContext *MyContext(void) {
311 struct CitContext *retCC;
312 retCC = (struct CitContext *) pthread_getspecific(MyConKey);
313 if (retCC == NULL) retCC = &masterCC;
319 * Wedge our way into the context list.
321 struct CitContext *CreateNewContext(void) {
322 struct CitContext *me;
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);
338 me->next = ContextList;
340 end_critical_section(S_SESSION_TABLE);
345 * Remove a context from the context list.
347 void RemoveContext(struct CitContext *con)
349 struct CitContext *ptr = NULL;
350 struct CitContext *ToFree = NULL;
352 lprintf(7, "Starting RemoveContext()\n");
354 lprintf(5, "WARNING: RemoveContext() called with NULL!\n");
359 * session_count() starts its own S_SESSION_TABLE critical section;
360 * so do not call it from within this loop.
362 begin_critical_section(S_SESSION_TABLE);
364 if (ContextList == con) {
365 ToFree = ContextList;
366 ContextList = ContextList->next;
369 for (ptr = ContextList; ptr != NULL; ptr = ptr->next) {
370 if (ptr->next == con) {
372 ptr->next = ptr->next->next;
378 end_critical_section(S_SESSION_TABLE);
380 lprintf(7, "Closing socket %d\n", ToFree->client_socket);
381 close(ToFree->client_socket);
383 /* Tell the housekeeping thread to check to see if this is the time
384 * to initiate a scheduled shutdown event.
386 enter_housekeeping_cmd("SCHED_SHUTDOWN");
388 /* Free up the memory used by this context */
391 lprintf(7, "Done with RemoveContext\n");
396 * Return the number of sessions currently running.
397 * (This should probably be moved out of sysdep.c)
399 int session_count(void) {
400 struct CitContext *ptr;
403 begin_critical_section(S_SESSION_TABLE);
404 for (ptr = ContextList; ptr != NULL; ptr = ptr->next) {
407 end_critical_section(S_SESSION_TABLE);
414 * client_write() ... Send binary data to the client.
416 void client_write(char *buf, int nbytes)
418 int bytes_written = 0;
420 while (bytes_written < nbytes) {
421 retval = write(CC->client_socket, &buf[bytes_written],
422 nbytes - bytes_written);
424 lprintf(2, "client_write() failed: %s\n",
428 bytes_written = bytes_written + retval;
434 * cprintf() ... Send formatted printable data to the client. It is
435 * implemented in terms of client_write() but remains in
436 * sysdep.c in case we port to somewhere without va_args...
438 void cprintf(const char *format, ...) {
442 va_start(arg_ptr, format);
443 if (vsnprintf(buf, sizeof buf, format, arg_ptr) == -1)
444 buf[sizeof buf - 2] = '\n';
445 client_write(buf, strlen(buf));
451 * Read data from the client socket.
453 * 1 Requested number of bytes has been read.
454 * 0 Request timed out.
455 * If the socket breaks, the session is immediately terminated.
457 int client_read_to(char *buf, int bytes, int timeout)
467 FD_SET(CC->client_socket, &rfds);
471 retval = select( (CC->client_socket)+1,
472 &rfds, NULL, NULL, &tv);
474 if (FD_ISSET(CC->client_socket, &rfds) == 0) {
478 rlen = read(CC->client_socket, &buf[len], bytes-len);
480 lprintf(2, "client_read() failed: %s\n",
490 * Read data from the client socket with default timeout.
491 * (This is implemented in terms of client_read_to() and could be
492 * justifiably moved out of sysdep.c)
494 int client_read(char *buf, int bytes)
496 return(client_read_to(buf, bytes, config.c_sleeping));
501 * client_gets() ... Get a LF-terminated line of text from the client.
502 * (This is implemented in terms of client_read() and could be
503 * justifiably moved out of sysdep.c)
505 int client_gets(char *buf)
509 /* Read one character at a time.
512 retval = client_read(&buf[i], 1);
513 if (retval != 1 || buf[i] == '\n' || i == 255)
517 /* If we got a long line, discard characters until the newline.
520 while (buf[i] != '\n' && retval == 1)
521 retval = client_read(&buf[i], 1);
523 /* Strip the trailing newline and any trailing nonprintables (cr's)
526 while ((strlen(buf)>0)&&(!isprint(buf[strlen(buf)-1])))
527 buf[strlen(buf)-1] = 0;
534 * The system-dependent part of master_cleanup() - close the master socket.
536 void sysdep_master_cleanup(void) {
537 lprintf(7, "Closing master socket %d\n", msock);
543 * Terminate another session.
545 void kill_session(int session_to_kill) {
546 struct CitContext *ptr;
548 begin_critical_section(S_SESSION_TABLE);
549 for (ptr = ContextList; ptr != NULL; ptr = ptr->next) {
550 if (ptr->cs_pid == session_to_kill) {
551 ptr->state = CON_DYING;
554 end_critical_section(S_SESSION_TABLE);
561 * Start running as a daemon. Only close stdio if do_close_stdio is set.
563 void start_daemon(int do_close_stdio) {
564 if (do_close_stdio) {
569 signal(SIGHUP,SIG_IGN);
570 signal(SIGINT,SIG_IGN);
571 signal(SIGQUIT,SIG_IGN);
572 if (fork()!=0) exit(0);
578 * Tie in to the 'netsetup' program.
580 * (We're going to hope that netsetup never feeds more than 4096 bytes back.)
582 void cmd_nset(char *cmdbuf)
589 char netsetup_args[3][256];
591 if (CC->usersupp.axlevel < 6) {
592 cprintf("%d Higher access required.\n",
593 ERROR + HIGHER_ACCESS_REQUIRED);
597 for (a=1; a<=3; ++a) {
598 if (num_parms(cmdbuf) >= a) {
599 extract(netsetup_args[a-1], cmdbuf, a-1);
600 for (b=0; b<strlen(netsetup_args[a-1]); ++b) {
601 if (netsetup_args[a-1][b] == 34) {
602 netsetup_args[a-1][b] = '_';
607 netsetup_args[a-1][0] = 0;
611 sprintf(fbuf, "./netsetup \"%s\" \"%s\" \"%s\" </dev/null 2>&1",
612 netsetup_args[0], netsetup_args[1], netsetup_args[2]);
613 netsetup = popen(fbuf, "r");
614 if (netsetup == NULL) {
615 cprintf("%d %s\n", ERROR, strerror(errno));
620 while (ch = getc(netsetup), (ch > 0)) {
621 fbuf[strlen(fbuf)+1] = 0;
622 fbuf[strlen(fbuf)] = ch;
625 retcode = pclose(netsetup);
628 for (a=0; a<strlen(fbuf); ++a) {
629 if (fbuf[a] < 32) fbuf[a] = 32;
632 cprintf("%d %s\n", ERROR, fbuf);
636 cprintf("%d Command succeeded. Output follows:\n", LISTING_FOLLOWS);
638 if (fbuf[strlen(fbuf)-1] != 10) cprintf("\n");
645 * Generic routine to convert a login name to a full name (gecos)
646 * Returns nonzero if a conversion took place
648 int convert_login(char NameToConvert[]) {
652 pw = getpwnam(NameToConvert);
657 strcpy(NameToConvert, pw->pw_gecos);
658 for (a=0; a<strlen(NameToConvert); ++a) {
659 if (NameToConvert[a] == ',') NameToConvert[a] = 0;
671 * Here's where it all begins.
673 int main(int argc, char **argv)
675 THREAD HousekeepingThread; /* Thread descriptor */
676 pthread_attr_t attr; /* Thread attributes */
677 char tracefile[128]; /* Name of file to log traces to */
678 int a, i; /* General-purpose variables */
680 int drop_root_perms = 1;
683 /* specify default port name and trace file */
684 strcpy(tracefile, "");
686 /* parse command-line arguments */
687 for (a=1; a<argc; ++a) {
689 /* -t specifies where to log trace messages to */
690 if (!strncmp(argv[a], "-t", 2)) {
691 strcpy(tracefile, argv[a]);
692 strcpy(tracefile, &tracefile[2]);
693 freopen(tracefile, "r", stdin);
694 freopen(tracefile, "w", stdout);
695 freopen(tracefile, "w", stderr);
698 /* run in the background if -d was specified */
699 else if (!strcmp(argv[a], "-d")) {
700 start_daemon( (strlen(tracefile) > 0) ? 0 : 1 ) ;
703 /* -x specifies the desired logging level */
704 else if (!strncmp(argv[a], "-x", 2)) {
705 verbosity = atoi(&argv[a][2]);
708 else if (!strncmp(argv[a], "-h", 2)) {
709 safestrncpy(bbs_home_directory, &argv[a][2],
710 sizeof bbs_home_directory);
714 else if (!strncmp(argv[a], "-f", 2)) {
718 /* -r tells the server not to drop root permissions. don't use
719 * this unless you know what you're doing. this should be
720 * removed in the next release if it proves unnecessary. */
721 else if (!strcmp(argv[a], "-r"))
724 /* any other parameter makes it crash and burn */
726 lprintf(1, "citserver: usage: "
727 "citserver [-tTraceFile] [-d] [-f]"
728 " [-xLogLevel] [-hHomeDir]\n");
734 /* Tell 'em who's in da house */
736 "\nMultithreaded message server for Citadel/UX\n"
737 "Copyright (C) 1987-1999 by the Citadel/UX development team.\n"
738 "Citadel/UX is free software, covered by the GNU General Public License, and\n"
739 "you are welcome to change it and/or distribute copies of it under certain\n"
740 "conditions. There is absolutely no warranty for this software. Please\n"
741 "read the 'COPYING.txt' file for details.\n\n");
745 openlog("citserver",LOG_PID,LOG_USER);
746 /* Load site-specific parameters */
747 lprintf(7, "Loading citadel.config\n");
751 * Bind the server to our favourite port.
752 * There is no need to check for errors, because ig_tcp_server()
753 * exits if it doesn't succeed.
755 lprintf(7, "Attempting to bind to port %d...\n", config.c_port_number);
756 msock = ig_tcp_server(config.c_port_number, 5);
757 lprintf(7, "Listening on socket %d\n", msock);
760 * Now that we've bound the socket, change to the BBS user id and its
761 * corresponding group ids
763 if (drop_root_perms) {
764 if ((pw = getpwuid(BBSUID)) == NULL)
765 lprintf(1, "WARNING: getpwuid(%d): %s\n"
766 "Group IDs will be incorrect.\n", BBSUID,
769 initgroups(pw->pw_name, pw->pw_gid);
770 if (setgid(pw->pw_gid))
771 lprintf(3, "setgid(%d): %s\n", pw->pw_gid,
774 lprintf(7, "Changing uid to %d\n", BBSUID);
775 if (setuid(BBSUID) != 0) {
776 lprintf(3, "setuid() failed: %s\n", strerror(errno));
781 * Do non system dependent startup functions.
786 * Load any server-side modules (plugins) available here.
788 lprintf(7, "Initializing loadable modules\n");
789 if ((moddir = malloc(strlen(bbs_home_directory) + 9)) != NULL) {
790 sprintf(moddir, "%s/modules", bbs_home_directory);
791 DLoader_Init(moddir);
795 lprintf(7, "Starting housekeeper thread\n");
796 pthread_attr_init(&attr);
797 pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
798 if (pthread_create(&HousekeepingThread, &attr,
799 (void* (*)(void*)) housekeeping_loop, NULL) != 0) {
800 lprintf(1, "Can't create housekeeping thead: %s\n",
806 * The rescan pipe exists so that worker threads can be woken up and
807 * told to re-scan the context list for fd's to listen on. This is
808 * necessary, for example, when a context is about to go idle and needs
809 * to get back on that list.
812 lprintf(1, "Can't create rescan pipe!\n");
817 * Now create a bunch of worker threads.
819 for (i=0; i<(NUM_WORKER_THREADS-1); ++i) {
820 pthread_attr_init(&attr);
821 pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
822 if (pthread_create(&HousekeepingThread, &attr,
823 (void* (*)(void*)) worker_thread, NULL) != 0) {
824 lprintf(1, "Can't create worker thead: %s\n",
829 /* Now this thread can become a worker as well. */
842 * This loop just keeps going and going and going...
844 void worker_thread(void) {
849 struct CitContext *ptr;
850 struct CitContext *bind_me = NULL;
853 struct CitContext *con= NULL; /* Temporary context pointer */
854 struct sockaddr_in fsin; /* Data for master socket */
855 int alen; /* Data for master socket */
856 int ssock; /* Descriptor for master socket */
858 while (!time_to_die) {
861 * In a stupid environment, we would have all idle threads
862 * calling select() and then they'd all wake up at once. We
863 * solve this problem by putting the select() in a critical
864 * section, so only one thread has the opportunity to wake
865 * up. If we wake up on the master socket, create a new
866 * session context; otherwise, just bind the thread to the
867 * context we want and go on our merry way.
870 begin_critical_section(S_I_WANNA_SELECT);
871 lprintf(9, "Worker thread %2d woke up\n", getpid());
875 FD_SET(msock, &readfds);
877 FD_SET(rescan[0], &readfds);
878 if (rescan[0] > highest) highest = rescan[0];
881 begin_critical_section(S_SESSION_TABLE);
882 for (ptr = ContextList; ptr != NULL; ptr = ptr->next) {
883 if (ptr->state == CON_IDLE) {
884 FD_SET(ptr->client_socket, &readfds);
885 if (ptr->client_socket > highest)
886 highest = ptr->client_socket;
890 end_critical_section(S_SESSION_TABLE);
892 lprintf(9, "Thread %2d can wake up on %d different fd's\n",
893 getpid(), numselect);
894 retval = select(highest + 1, &readfds, NULL, NULL, NULL);
895 lprintf(9, "select() returned %d\n", retval);
897 /* Now figure out who made this select() unblock.
898 * First, check for an error or exit condition.
901 end_critical_section(S_I_WANNA_SELECT);
902 lprintf(9, "Exiting (%s)\n", errno);
906 /* Next, check to see if it's a new client connecting
907 * on the master socket.
909 else if (FD_ISSET(msock, &readfds)) {
910 lprintf(9, "It's the master socket!\n");
912 ssock = accept(msock, (struct sockaddr *)&fsin, &alen);
914 lprintf(2, "citserver: accept() failed: %s\n",
918 lprintf(7, "citserver: New client socket %d\n",
921 /* New context will be created already set up
922 * in the CON_EXECUTING state.
924 con = CreateNewContext();
926 /* Assign our new socket number to it. */
927 con->client_socket = ssock;
929 /* Set the SO_REUSEADDR socket option */
931 setsockopt(ssock, SOL_SOCKET, SO_REUSEADDR,
934 pthread_setspecific(MyConKey, (void *)con);
936 /* do_command_loop(); */
937 pthread_setspecific(MyConKey, (void *)NULL);
938 con->state = CON_IDLE;
943 /* If the rescan pipe went active, someone is telling this
944 * thread that the &readfds needs to be refreshed with more
947 else if (FD_ISSET(rescan[0], &readfds)) {
948 lprintf(9, "rescanning\n");
949 read(rescan[0], &junk, 1);
953 /* It must be a client socket. Find a context that has data
954 * waiting on its socket *and* is in the CON_IDLE state.
958 begin_critical_section(S_SESSION_TABLE);
959 for (ptr = ContextList;
960 ( (ptr != NULL) && (bind_me == NULL) );
962 if ( (FD_ISSET(ptr->client_socket, &readfds))
963 && (ptr->state == CON_IDLE) ) {
967 if (bind_me != NULL) {
968 /* Found one. Stake a claim to it before
969 * letting anyone else touch the context list.
971 bind_me->state = CON_EXECUTING;
974 end_critical_section(S_SESSION_TABLE);
975 end_critical_section(S_I_WANNA_SELECT);
977 /* We're bound to a session, now do *one* command */
978 if (bind_me != NULL) {
979 lprintf(9, "Binding thread to session %d\n",
980 bind_me->client_socket);
981 pthread_setspecific(MyConKey, (void *)bind_me);
983 pthread_setspecific(MyConKey, (void *)NULL);
984 if (bind_me->state == CON_DYING) {
985 RemoveContext(bind_me);
988 bind_me->state = CON_IDLE;
990 write(rescan[1], &junk, 1);
993 lprintf(9, "Thread %02d found nothing to do!\n",