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;
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 #ifdef HAVE_PTHREAD_CANCEL
253 /* lprintf(8, "begin_critical_section(%d)\n", which_one); */
255 if (!pthread_equal(pthread_self(), main_thread_id)) {
256 /* Keep a count of how many critical sections this thread has
257 * open, so that end_critical_section() doesn't enable
258 * cancellation prematurely. */
259 if (CC != NULL) CC->n_crit++;
260 #ifdef HAVE_PTHREAD_CANCEL
261 /* Don't get interrupted during the critical section */
262 pthread_setcanceltype(PTHREAD_CANCEL_DEFERRED, &oldval);
264 /* We're faking cancellation with signals. Block SIGUSR1 while
265 * we're in the critical section. */
267 sigaddset(&set, SIGUSR1);
268 pthread_sigmask(SIG_BLOCK, &set, NULL);
272 /* Obtain a semaphore */
273 pthread_mutex_lock(&Critters[which_one]);
278 * Release a semaphore lock to end a critical section.
280 void end_critical_section(int which_one)
282 #ifdef HAVE_PTHREAD_CANCEL
288 /* lprintf(8, " end_critical_section(%d)\n", which_one); */
290 /* Let go of the semaphore */
291 pthread_mutex_unlock(&Critters[which_one]);
293 if (!pthread_equal(pthread_self(), main_thread_id))
296 #ifdef HAVE_PTHREAD_CANCEL
297 /* If a cancel was sent during the critical section, do it now.
298 * Then re-enable thread cancellation.
300 pthread_testcancel();
301 pthread_setcanceltype(PTHREAD_CANCEL_ASYNCHRONOUS, &oldval);
302 pthread_testcancel();
304 /* We're faking it. Unblock SIGUSR1; signals sent during the
305 * critical section should now be able to kill us. */
307 sigaddset(&set, SIGUSR1);
308 pthread_sigmask(SIG_UNBLOCK, &set, NULL);
317 * This is a generic function to set up a master socket for listening on
318 * a TCP port. The server shuts down if the bind fails.
320 int ig_tcp_server(int port_number, int queue_len)
322 struct sockaddr_in sin;
325 memset(&sin, 0, sizeof(sin));
326 sin.sin_family = AF_INET;
327 sin.sin_addr.s_addr = INADDR_ANY;
329 if (port_number == 0) {
331 "citserver: No port number specified. Run setup.\n");
335 sin.sin_port = htons((u_short)port_number);
337 s = socket(PF_INET, SOCK_STREAM, (getprotobyname("tcp")->p_proto));
339 lprintf(1, "citserver: Can't create a socket: %s\n",
344 /* Set the SO_REUSEADDR socket option, because it makes sense. */
346 setsockopt(s, SOL_SOCKET, SO_REUSEADDR, &i, sizeof(i));
348 if (bind(s, (struct sockaddr *)&sin, sizeof(sin)) < 0) {
349 lprintf(1, "citserver: Can't bind: %s\n", strerror(errno));
353 if (listen(s, queue_len) < 0) {
354 lprintf(1, "citserver: Can't listen: %s\n", strerror(errno));
363 * Return a pointer to a thread's own CitContext structure (old)
364 * NOTE: this version of MyContext() is commented out because it is no longer
365 * in use. It was written before I discovered TSD keys. This
366 * version pounds through the context list until it finds the one matching
367 * the currently running thread. It remains here, commented out, in case it
368 * is needed for future ports to threading libraries which have the equivalent
369 * of pthread_self() but not pthread_key_create() and its ilk.
371 * struct CitContext *MyContext() {
372 * struct CitContext *ptr;
375 * me = pthread_self();
376 * for (ptr=ContextList; ptr!=NULL; ptr=ptr->next) {
377 * if (ptr->mythread == me) return(ptr);
384 * Return a pointer to a thread's own CitContext structure (new)
386 struct CitContext *MyContext(void) {
387 struct CitContext *retCC;
388 retCC = (struct CitContext *) pthread_getspecific(MyConKey);
389 if (retCC == NULL) retCC = &masterCC;
395 * Wedge our way into the context list.
397 struct CitContext *CreateNewContext(void) {
398 struct CitContext *me;
400 me = (struct CitContext *) mallok(sizeof(struct CitContext));
402 lprintf(1, "citserver: can't allocate memory!!\n");
405 memset(me, 0, sizeof(struct CitContext));
407 begin_critical_section(S_SESSION_TABLE);
408 me->next = ContextList;
410 end_critical_section(S_SESSION_TABLE);
415 * Add a thread's thread ID to the context
417 void InitMyContext(struct CitContext *con)
419 #ifdef HAVE_PTHREAD_CANCEL
423 con->mythread = pthread_self();
424 #ifdef HAVE_PTHREAD_CANCEL
425 pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, &oldval);
426 pthread_setcanceltype(PTHREAD_CANCEL_ASYNCHRONOUS, &oldval);
428 if (pthread_setspecific(MyConKey, (void *)con) != 0) {
429 lprintf(1, "ERROR! pthread_setspecific() failed: %s\n",
435 * Remove a context from the context list.
437 void RemoveContext(int con)
439 struct CitContext *ptr = NULL;
440 struct CitContext *ToFree = NULL;
442 lprintf(7, "Starting RemoveContext()\n");
444 lprintf(7, "WARNING: RemoveContext() called with 0!\n");
449 * session_count() starts its own S_SESSION_TABLE critical section;
450 * so do not call it from within this loop.
452 begin_critical_section(S_SESSION_TABLE);
454 if (ContextList->client_socket == con) {
455 ToFree = ContextList;
456 ContextList = ContextList->next;
459 for (ptr = ContextList; ptr != NULL; ptr = ptr->next) {
460 if (ptr->next->client_socket == con) {
462 ptr->next = ptr->next->next;
468 end_critical_section(S_SESSION_TABLE);
470 lprintf(7, "Closing socket %d\n", ToFree->client_socket);
471 close(ToFree->client_socket);
473 /* Tell the housekeeping thread to check to see if this is the time
474 * to initiate a scheduled shutdown event.
476 enter_housekeeping_cmd("SCHED_SHUTDOWN");
478 /* Free up the memory used by this context */
481 lprintf(7, "Done with RemoveContext\n");
486 * Return the number of sessions currently running.
487 * (This should probably be moved out of sysdep.c)
489 int session_count(void) {
490 struct CitContext *ptr;
493 begin_critical_section(S_SESSION_TABLE);
494 for (ptr = ContextList; ptr != NULL; ptr = ptr->next) {
497 end_critical_section(S_SESSION_TABLE);
504 * client_write() ... Send binary data to the client.
506 void client_write(char *buf, int nbytes)
508 int bytes_written = 0;
510 while (bytes_written < nbytes) {
511 retval = write(CC->client_socket, &buf[bytes_written],
512 nbytes - bytes_written);
514 lprintf(2, "client_write() failed: %s\n",
518 bytes_written = bytes_written + retval;
524 * cprintf() ... Send formatted printable data to the client. It is
525 * implemented in terms of client_write() but remains in
526 * sysdep.c in case we port to somewhere without va_args...
528 void cprintf(const char *format, ...) {
532 va_start(arg_ptr, format);
533 if (vsnprintf(buf, sizeof buf, format, arg_ptr) == -1)
534 buf[sizeof buf - 2] = '\n';
535 client_write(buf, strlen(buf));
541 * Read data from the client socket.
543 * 1 Requested number of bytes has been read.
544 * 0 Request timed out.
545 * If the socket breaks, the session is immediately terminated.
547 int client_read_to(char *buf, int bytes, int timeout)
557 FD_SET(CC->client_socket, &rfds);
561 retval = select( (CC->client_socket)+1,
562 &rfds, NULL, NULL, &tv);
563 if (FD_ISSET(CC->client_socket, &rfds) == 0) {
567 rlen = read(CC->client_socket, &buf[len], bytes-len);
569 lprintf(2, "client_read() failed: %s\n",
579 * Read data from the client socket with default timeout.
580 * (This is implemented in terms of client_read_to() and could be
581 * justifiably moved out of sysdep.c)
583 int client_read(char *buf, int bytes)
585 return(client_read_to(buf, bytes, config.c_sleeping));
590 * client_gets() ... Get a LF-terminated line of text from the client.
591 * (This is implemented in terms of client_read() and could be
592 * justifiably moved out of sysdep.c)
594 int client_gets(char *buf)
598 /* Read one character at a time.
601 retval = client_read(&buf[i], 1);
602 if (retval != 1 || buf[i] == '\n' || i == 255)
606 /* If we got a long line, discard characters until the newline.
609 while (buf[i] != '\n' && retval == 1)
610 retval = client_read(&buf[i], 1);
612 /* Strip the trailing newline and any trailing nonprintables (cr's)
615 while ((strlen(buf)>0)&&(!isprint(buf[strlen(buf)-1])))
616 buf[strlen(buf)-1] = 0;
623 * The system-dependent part of master_cleanup() - close the master socket.
625 void sysdep_master_cleanup(void) {
626 lprintf(7, "Closing master socket %d\n", msock);
631 * Cleanup routine to be called when one thread is shutting down.
633 void cleanup(int exit_code)
635 /* Terminate the thread.
636 * Its cleanup handler will call cleanup_stuff()
638 lprintf(7, "Calling pthread_exit()\n");
643 * Terminate another session.
645 void kill_session(int session_to_kill) {
646 struct CitContext *ptr;
649 begin_critical_section(S_SESSION_TABLE);
650 for (ptr = ContextList; ptr != NULL; ptr = ptr->next) {
651 if (ptr->cs_pid == session_to_kill) {
652 killme = ptr->mythread;
655 end_critical_section(S_SESSION_TABLE);
658 #ifdef HAVE_PTHREAD_CANCEL
659 pthread_cancel(killme);
661 pthread_kill(killme, SIGUSR1);
663 /* there's a very stupid bug in the user threads package on
664 FreeBSD 3.1 which prevents a signal from being properly
665 dispatched to a thread that's in a blocking syscall. the
666 first signal interrupts the syscall, the second one actually
668 pthread_kill(killme, SIGUSR1);
676 * The system-dependent wrapper around the main context loop.
678 void *sd_context_loop(struct CitContext *con) {
679 pthread_cleanup_push(*cleanup_stuff, NULL);
681 pthread_cleanup_pop(0);
687 * Start running as a daemon. Only close stdio if do_close_stdio is set.
689 void start_daemon(int do_close_stdio) {
690 if (do_close_stdio) {
695 signal(SIGHUP,SIG_IGN);
696 signal(SIGINT,SIG_IGN);
697 signal(SIGQUIT,SIG_IGN);
698 if (fork()!=0) exit(0);
704 * Tie in to the 'netsetup' program.
706 * (We're going to hope that netsetup never feeds more than 4096 bytes back.)
708 void cmd_nset(char *cmdbuf)
715 char netsetup_args[3][256];
717 if (CC->usersupp.axlevel < 6) {
718 cprintf("%d Higher access required.\n",
719 ERROR + HIGHER_ACCESS_REQUIRED);
723 for (a=1; a<=3; ++a) {
724 if (num_parms(cmdbuf) >= a) {
725 extract(netsetup_args[a-1], cmdbuf, a-1);
726 for (b=0; b<strlen(netsetup_args[a-1]); ++b) {
727 if (netsetup_args[a-1][b] == 34) {
728 netsetup_args[a-1][b] = '_';
733 netsetup_args[a-1][0] = 0;
737 sprintf(fbuf, "./netsetup \"%s\" \"%s\" \"%s\" </dev/null 2>&1",
738 netsetup_args[0], netsetup_args[1], netsetup_args[2]);
739 netsetup = popen(fbuf, "r");
740 if (netsetup == NULL) {
741 cprintf("%d %s\n", ERROR, strerror(errno));
746 while (ch = getc(netsetup), (ch > 0)) {
747 fbuf[strlen(fbuf)+1] = 0;
748 fbuf[strlen(fbuf)] = ch;
751 retcode = pclose(netsetup);
754 for (a=0; a<strlen(fbuf); ++a) {
755 if (fbuf[a] < 32) fbuf[a] = 32;
758 cprintf("%d %s\n", ERROR, fbuf);
762 cprintf("%d Command succeeded. Output follows:\n", LISTING_FOLLOWS);
764 if (fbuf[strlen(fbuf)-1] != 10) cprintf("\n");
771 * Generic routine to convert a login name to a full name (gecos)
772 * Returns nonzero if a conversion took place
774 int convert_login(char NameToConvert[]) {
778 pw = getpwnam(NameToConvert);
783 strcpy(NameToConvert, pw->pw_gecos);
784 for (a=0; a<strlen(NameToConvert); ++a) {
785 if (NameToConvert[a] == ',') NameToConvert[a] = 0;
797 * Here's where it all begins.
799 int main(int argc, char **argv)
801 struct sockaddr_in fsin; /* Data for master socket */
802 int alen; /* Data for master socket */
803 int ssock; /* Descriptor for master socket */
804 THREAD SessThread; /* Thread descriptor */
805 THREAD HousekeepingThread; /* Thread descriptor */
806 pthread_attr_t attr; /* Thread attributes */
807 struct CitContext *con; /* Temporary context pointer */
808 char tracefile[128]; /* Name of file to log traces to */
809 int a, i; /* General-purpose variables */
813 int drop_root_perms = 1;
816 /* specify default port name and trace file */
817 strcpy(tracefile, "");
819 /* parse command-line arguments */
820 for (a=1; a<argc; ++a) {
822 /* -t specifies where to log trace messages to */
823 if (!strncmp(argv[a], "-t", 2)) {
824 strcpy(tracefile, argv[a]);
825 strcpy(tracefile, &tracefile[2]);
826 freopen(tracefile, "r", stdin);
827 freopen(tracefile, "w", stdout);
828 freopen(tracefile, "w", stderr);
831 /* run in the background if -d was specified */
832 else if (!strcmp(argv[a], "-d")) {
833 start_daemon( (strlen(tracefile) > 0) ? 0 : 1 ) ;
836 /* -x specifies the desired logging level */
837 else if (!strncmp(argv[a], "-x", 2)) {
838 verbosity = atoi(&argv[a][2]);
841 else if (!strncmp(argv[a], "-h", 2)) {
842 safestrncpy(bbs_home_directory, &argv[a][2],
843 sizeof bbs_home_directory);
847 else if (!strncmp(argv[a], "-f", 2)) {
851 /* -r tells the server not to drop root permissions. don't use
852 * this unless you know what you're doing. this should be
853 * removed in the next release if it proves unnecessary. */
854 else if (!strcmp(argv[a], "-r"))
857 /* any other parameter makes it crash and burn */
859 lprintf(1, "citserver: usage: "
860 "citserver [-tTraceFile] [-d] [-f]"
861 " [-xLogLevel] [-hHomeDir]\n");
867 /* Tell 'em who's in da house */
869 "\nMultithreaded message server for Citadel/UX\n"
870 "Copyright (C) 1987-1999 by the Citadel/UX development team.\n"
871 "Citadel/UX is free software, covered by the GNU General Public License, and\n"
872 "you are welcome to change it and/or distribute copies of it under certain\n"
873 "conditions. There is absolutely no warranty for this software. Please\n"
874 "read the 'COPYING.txt' file for details.\n\n");
878 openlog("citserver",LOG_PID,LOG_USER);
879 /* Load site-specific parameters */
880 lprintf(7, "Loading citadel.config\n");
884 * Bind the server to our favourite port.
885 * There is no need to check for errors, because ig_tcp_server()
886 * exits if it doesn't succeed.
888 lprintf(7, "Attempting to bind to port %d...\n", config.c_port_number);
889 msock = ig_tcp_server(config.c_port_number, 5);
890 lprintf(7, "Listening on socket %d\n", msock);
893 * Now that we've bound the socket, change to the BBS user id and its
894 * corresponding group ids
896 if (drop_root_perms) {
897 if ((pw = getpwuid(BBSUID)) == NULL)
898 lprintf(1, "WARNING: getpwuid(%d): %s\n"
899 "Group IDs will be incorrect.\n", BBSUID,
902 initgroups(pw->pw_name, pw->pw_gid);
903 if (setgid(pw->pw_gid))
904 lprintf(3, "setgid(%d): %s\n", pw->pw_gid,
907 lprintf(7, "Changing uid to %d\n", BBSUID);
908 if (setuid(BBSUID) != 0) {
909 lprintf(3, "setuid() failed: %s\n", strerror(errno));
914 * Do non system dependent startup functions.
919 * Load any server-side modules (plugins) available here.
921 lprintf(7, "Initializing loadable modules\n");
922 if ((moddir = malloc(strlen(bbs_home_directory) + 9)) != NULL) {
923 sprintf(moddir, "%s/modules", bbs_home_directory);
924 DLoader_Init(moddir);
928 lprintf(7, "Starting housekeeper thread\n");
929 pthread_attr_init(&attr);
930 pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
931 if (pthread_create(&HousekeepingThread, &attr,
932 (void* (*)(void*)) housekeeping_loop, NULL) != 0) {
933 lprintf(1, "Can't create housekeeping thead: %s\n",
938 * Endless loop. Listen on the master socket. When a connection
939 * comes in, create a socket, a context, and a thread.
941 while (!time_to_die) {
942 /* we need to check if a signal has been delivered. because
943 * syscalls may be restartable across signals, we call
944 * select with a timeout of 1 second and repeatedly check for
947 FD_SET(msock, &readfds);
950 if (select(msock + 1, &readfds, NULL, NULL, &tv) <= 0)
953 ssock = accept(msock, (struct sockaddr *)&fsin, &alen);
955 lprintf(2, "citserver: accept() failed: %s\n",
959 lprintf(7, "citserver: Client socket %d\n", ssock);
960 con = CreateNewContext();
961 con->client_socket = ssock;
963 /* Set the SO_REUSEADDR socket option */
965 setsockopt(ssock, SOL_SOCKET, SO_REUSEADDR,
968 /* set attributes for the new thread */
969 pthread_attr_init(&attr);
970 pthread_attr_setdetachstate(&attr,
971 PTHREAD_CREATE_DETACHED);
973 /* now create the thread */
974 if (pthread_create(&SessThread, &attr,
975 (void* (*)(void*)) sd_context_loop,
979 "citserver: can't create thread: %s\n",