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 = DEFAULT_VERBOSITY; /* 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);
180 * we used to use master_cleanup() as a signal handler to shut down the server.
181 * however, master_cleanup() and the functions it calls do some things that
182 * aren't such a good idea to do from a signal handler: acquiring mutexes,
183 * playing with signal masks on BSDI systems, etc. so instead we install the
184 * following signal handler to set a global variable to inform the main loop
185 * that it's time to call master_cleanup() and exit.
188 static volatile int time_to_die = 0;
190 static RETSIGTYPE signal_cleanup(int signum) {
196 * Some initialization stuff...
198 void init_sysdep(void) {
201 /* Set up a bunch of semaphores to be used for critical sections */
202 for (a=0; a<MAX_SEMAPHORES; ++a) {
203 pthread_mutex_init(&Critters[a], NULL);
207 * Set up a place to put thread-specific data.
208 * We only need a single pointer per thread - it points to the
209 * thread's CitContext structure in the ContextList linked list.
211 if (pthread_key_create(&MyConKey, NULL) != 0) {
212 lprintf(1, "Can't create TSD key!! %s\n", strerror(errno));
216 * The action for unexpected signals and exceptions should be to
217 * call signal_cleanup() to gracefully shut down the server.
219 signal(SIGINT, signal_cleanup);
220 signal(SIGQUIT, signal_cleanup);
221 signal(SIGHUP, signal_cleanup);
222 signal(SIGTERM, signal_cleanup);
225 * Do not shut down the server on broken pipe signals, otherwise the
226 * whole Citadel service would come down whenever a single client
229 signal(SIGPIPE, SIG_IGN);
234 * Obtain a semaphore lock to begin a critical section.
236 void begin_critical_section(int which_one)
238 pthread_mutex_lock(&Critters[which_one]);
242 * Release a semaphore lock to end a critical section.
244 void end_critical_section(int which_one)
246 pthread_mutex_unlock(&Critters[which_one]);
252 * This is a generic function to set up a master socket for listening on
253 * a TCP port. The server shuts down if the bind fails.
255 int ig_tcp_server(int port_number, int queue_len)
257 struct sockaddr_in sin;
260 memset(&sin, 0, sizeof(sin));
261 sin.sin_family = AF_INET;
262 sin.sin_addr.s_addr = INADDR_ANY;
264 if (port_number == 0) {
266 "citserver: No port number specified. Run setup.\n");
270 sin.sin_port = htons((u_short)port_number);
272 s = socket(PF_INET, SOCK_STREAM, (getprotobyname("tcp")->p_proto));
274 lprintf(1, "citserver: Can't create a socket: %s\n",
279 /* Set the SO_REUSEADDR socket option, because it makes sense. */
281 setsockopt(s, SOL_SOCKET, SO_REUSEADDR, &i, sizeof(i));
283 if (bind(s, (struct sockaddr *)&sin, sizeof(sin)) < 0) {
284 lprintf(1, "citserver: Can't bind: %s\n", strerror(errno));
288 if (listen(s, queue_len) < 0) {
289 lprintf(1, "citserver: Can't listen: %s\n", strerror(errno));
299 * Return a pointer to the CitContext structure bound to the thread which
300 * called this function. If there's no such binding (for example, if it's
301 * called by the housekeeper thread) then a generic 'master' CC is returned.
303 struct CitContext *MyContext(void) {
304 struct CitContext *retCC;
305 retCC = (struct CitContext *) pthread_getspecific(MyConKey);
306 if (retCC == NULL) retCC = &masterCC;
312 * Initialize a new context and place it in the list.
314 struct CitContext *CreateNewContext(void) {
315 struct CitContext *me, *ptr;
318 me = (struct CitContext *) mallok(sizeof(struct CitContext));
320 lprintf(1, "citserver: can't allocate memory!!\n");
323 memset(me, 0, sizeof(struct CitContext));
325 /* The new context will be created already in the CON_EXECUTING state
326 * in order to prevent another thread from grabbing it while it's
329 me->state = CON_EXECUTING;
331 begin_critical_section(S_SESSION_TABLE);
333 /* obtain a unique session number */
334 for (ptr = ContextList; ptr != NULL; ptr = ptr->next) {
335 if (ptr->cs_pid == num) {
342 me->next = ContextList;
345 end_critical_section(S_SESSION_TABLE);
352 * Return the number of sessions currently running.
353 * (This should probably be moved out of sysdep.c)
355 int session_count(void) {
356 struct CitContext *ptr;
359 begin_critical_section(S_SESSION_TABLE);
360 for (ptr = ContextList; ptr != NULL; ptr = ptr->next) {
363 end_critical_section(S_SESSION_TABLE);
370 * client_write() ... Send binary data to the client.
372 void client_write(char *buf, int nbytes)
374 int bytes_written = 0;
376 while (bytes_written < nbytes) {
377 retval = write(CC->client_socket, &buf[bytes_written],
378 nbytes - bytes_written);
380 lprintf(2, "client_write() failed: %s\n",
385 bytes_written = bytes_written + retval;
391 * cprintf() ... Send formatted printable data to the client. It is
392 * implemented in terms of client_write() but remains in
393 * sysdep.c in case we port to somewhere without va_args...
395 void cprintf(const char *format, ...) {
399 va_start(arg_ptr, format);
400 if (vsnprintf(buf, sizeof buf, format, arg_ptr) == -1)
401 buf[sizeof buf - 2] = '\n';
402 client_write(buf, strlen(buf));
408 * Read data from the client socket.
410 * 1 Requested number of bytes has been read.
411 * 0 Request timed out.
412 * If the socket breaks, the session is immediately terminated.
414 int client_read_to(char *buf, int bytes, int timeout)
424 FD_SET(CC->client_socket, &rfds);
428 retval = select( (CC->client_socket)+1,
429 &rfds, NULL, NULL, &tv);
431 if (FD_ISSET(CC->client_socket, &rfds) == 0) {
435 rlen = read(CC->client_socket, &buf[len], bytes-len);
437 lprintf(2, "client_read() failed: %s\n",
448 * Read data from the client socket with default timeout.
449 * (This is implemented in terms of client_read_to() and could be
450 * justifiably moved out of sysdep.c)
452 int client_read(char *buf, int bytes)
454 return(client_read_to(buf, bytes, config.c_sleeping));
459 * client_gets() ... Get a LF-terminated line of text from the client.
460 * (This is implemented in terms of client_read() and could be
461 * justifiably moved out of sysdep.c)
463 int client_gets(char *buf)
467 /* Read one character at a time.
470 retval = client_read(&buf[i], 1);
471 if (retval != 1 || buf[i] == '\n' || i == 255)
475 /* If we got a long line, discard characters until the newline.
478 while (buf[i] != '\n' && retval == 1)
479 retval = client_read(&buf[i], 1);
481 /* Strip the trailing newline and any trailing nonprintables (cr's)
484 while ((strlen(buf)>0)&&(!isprint(buf[strlen(buf)-1])))
485 buf[strlen(buf)-1] = 0;
492 * The system-dependent part of master_cleanup() - close the master socket.
494 void sysdep_master_cleanup(void) {
495 lprintf(7, "Closing master socket %d\n", msock);
501 * Terminate another session.
502 * FIX ... now we need some way to wake that session up so it knows it
503 * needs to terminate.
505 void kill_session(int session_to_kill) {
506 struct CitContext *ptr;
508 begin_critical_section(S_SESSION_TABLE);
509 for (ptr = ContextList; ptr != NULL; ptr = ptr->next) {
510 if (ptr->cs_pid == session_to_kill) {
514 end_critical_section(S_SESSION_TABLE);
521 * Start running as a daemon. Only close stdio if do_close_stdio is set.
523 void start_daemon(int do_close_stdio) {
524 if (do_close_stdio) {
529 signal(SIGHUP,SIG_IGN);
530 signal(SIGINT,SIG_IGN);
531 signal(SIGQUIT,SIG_IGN);
532 if (fork()!=0) exit(0);
538 * Tie in to the 'netsetup' program.
540 * (We're going to hope that netsetup never feeds more than 4096 bytes back.)
542 void cmd_nset(char *cmdbuf)
549 char netsetup_args[3][256];
551 if (CC->usersupp.axlevel < 6) {
552 cprintf("%d Higher access required.\n",
553 ERROR + HIGHER_ACCESS_REQUIRED);
557 for (a=1; a<=3; ++a) {
558 if (num_parms(cmdbuf) >= a) {
559 extract(netsetup_args[a-1], cmdbuf, a-1);
560 for (b=0; b<strlen(netsetup_args[a-1]); ++b) {
561 if (netsetup_args[a-1][b] == 34) {
562 netsetup_args[a-1][b] = '_';
567 netsetup_args[a-1][0] = 0;
571 sprintf(fbuf, "./netsetup \"%s\" \"%s\" \"%s\" </dev/null 2>&1",
572 netsetup_args[0], netsetup_args[1], netsetup_args[2]);
573 netsetup = popen(fbuf, "r");
574 if (netsetup == NULL) {
575 cprintf("%d %s\n", ERROR, strerror(errno));
580 while (ch = getc(netsetup), (ch > 0)) {
581 fbuf[strlen(fbuf)+1] = 0;
582 fbuf[strlen(fbuf)] = ch;
585 retcode = pclose(netsetup);
588 for (a=0; a<strlen(fbuf); ++a) {
589 if (fbuf[a] < 32) fbuf[a] = 32;
592 cprintf("%d %s\n", ERROR, fbuf);
596 cprintf("%d Command succeeded. Output follows:\n", LISTING_FOLLOWS);
598 if (fbuf[strlen(fbuf)-1] != 10) cprintf("\n");
605 * Generic routine to convert a login name to a full name (gecos)
606 * Returns nonzero if a conversion took place
608 int convert_login(char NameToConvert[]) {
612 pw = getpwnam(NameToConvert);
617 strcpy(NameToConvert, pw->pw_gecos);
618 for (a=0; a<strlen(NameToConvert); ++a) {
619 if (NameToConvert[a] == ',') NameToConvert[a] = 0;
628 * Purge all sessions which have the 'kill_me' flag set.
629 * This function has code to prevent it from running more than once every
630 * few seconds, because running it after every single unbind would waste a lot
631 * of CPU time and keep the context list locked too much.
633 void dead_session_purge(void) {
634 static time_t last_purge = 0;
635 struct CitContext *ptr, *rem;
637 if ( (time(NULL) - last_purge) < 5 ) return; /* Too soon, go away */
641 begin_critical_section(S_SESSION_TABLE);
642 for (ptr = ContextList; ptr != NULL; ptr = ptr->next) {
643 if ( (ptr->state == CON_IDLE) && (ptr->kill_me) ) {
647 end_critical_section(S_SESSION_TABLE);
649 /* RemoveContext() enters its own S_SESSION_TABLE critical
650 * section, so we have to do it like this.
652 if (rem != NULL) RemoveContext(rem);
654 } while (rem != NULL);
661 * Here's where it all begins.
663 int main(int argc, char **argv)
665 pthread_t HousekeepingThread; /* Thread descriptor */
666 pthread_attr_t attr; /* Thread attributes */
667 char tracefile[128]; /* Name of file to log traces to */
668 int a, i; /* General-purpose variables */
670 int drop_root_perms = 1;
673 /* specify default port name and trace file */
674 strcpy(tracefile, "");
676 /* parse command-line arguments */
677 for (a=1; a<argc; ++a) {
679 /* -t specifies where to log trace messages to */
680 if (!strncmp(argv[a], "-t", 2)) {
681 strcpy(tracefile, argv[a]);
682 strcpy(tracefile, &tracefile[2]);
683 freopen(tracefile, "r", stdin);
684 freopen(tracefile, "w", stdout);
685 freopen(tracefile, "w", stderr);
688 /* run in the background if -d was specified */
689 else if (!strcmp(argv[a], "-d")) {
690 start_daemon( (strlen(tracefile) > 0) ? 0 : 1 ) ;
693 /* -x specifies the desired logging level */
694 else if (!strncmp(argv[a], "-x", 2)) {
695 verbosity = atoi(&argv[a][2]);
698 else if (!strncmp(argv[a], "-h", 2)) {
699 safestrncpy(bbs_home_directory, &argv[a][2],
700 sizeof bbs_home_directory);
704 else if (!strncmp(argv[a], "-f", 2)) {
708 /* -r tells the server not to drop root permissions. don't use
709 * this unless you know what you're doing. this should be
710 * removed in the next release if it proves unnecessary. */
711 else if (!strcmp(argv[a], "-r"))
714 /* any other parameter makes it crash and burn */
716 lprintf(1, "citserver: usage: "
717 "citserver [-tTraceFile] [-d] [-f]"
718 " [-xLogLevel] [-hHomeDir]\n");
724 /* Tell 'em who's in da house */
726 "\nMultithreaded message server for Citadel/UX\n"
727 "Copyright (C) 1987-1999 by the Citadel/UX development team.\n"
728 "Citadel/UX is free software, covered by the GNU General Public License, and\n"
729 "you are welcome to change it and/or distribute copies of it under certain\n"
730 "conditions. There is absolutely no warranty for this software. Please\n"
731 "read the 'COPYING.txt' file for details.\n\n");
735 openlog("citserver",LOG_PID,LOG_USER);
737 /* Load site-specific parameters */
738 lprintf(7, "Loading citadel.config\n");
742 * Bind the server to our favourite port.
743 * There is no need to check for errors, because ig_tcp_server()
744 * exits if it doesn't succeed.
746 lprintf(7, "Attempting to bind to port %d...\n", config.c_port_number);
747 msock = ig_tcp_server(config.c_port_number, 5);
748 lprintf(7, "Listening on socket %d\n", msock);
751 * Now that we've bound the socket, change to the BBS user id and its
752 * corresponding group ids
754 if (drop_root_perms) {
755 if ((pw = getpwuid(BBSUID)) == NULL)
756 lprintf(1, "WARNING: getpwuid(%d): %s\n"
757 "Group IDs will be incorrect.\n", BBSUID,
760 initgroups(pw->pw_name, pw->pw_gid);
761 if (setgid(pw->pw_gid))
762 lprintf(3, "setgid(%d): %s\n", pw->pw_gid,
765 lprintf(7, "Changing uid to %d\n", BBSUID);
766 if (setuid(BBSUID) != 0) {
767 lprintf(3, "setuid() failed: %s\n", strerror(errno));
772 * Do non system dependent startup functions.
777 * Load any server-side modules (plugins) available here.
779 lprintf(7, "Initializing loadable modules\n");
780 if ((moddir = malloc(strlen(bbs_home_directory) + 9)) != NULL) {
781 sprintf(moddir, "%s/modules", bbs_home_directory);
782 DLoader_Init(moddir);
786 lprintf(7, "Starting housekeeper thread\n");
787 pthread_attr_init(&attr);
788 pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
789 if (pthread_create(&HousekeepingThread, &attr,
790 (void* (*)(void*)) housekeeping_loop, NULL) != 0) {
791 lprintf(1, "Can't create housekeeping thead: %s\n",
797 * The rescan pipe exists so that worker threads can be woken up and
798 * told to re-scan the context list for fd's to listen on. This is
799 * necessary, for example, when a context is about to go idle and needs
800 * to get back on that list.
803 lprintf(1, "Can't create rescan pipe!\n");
808 * Now create a bunch of worker threads.
810 for (i=0; i<(NUM_WORKER_THREADS-1); ++i) {
811 pthread_attr_init(&attr);
812 pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
813 if (pthread_create(&HousekeepingThread, &attr,
814 (void* (*)(void*)) worker_thread, NULL) != 0) {
815 lprintf(1, "Can't create worker thead: %s\n",
820 /* Now this thread can become a worker as well. */
833 * This loop just keeps going and going and going...
835 void worker_thread(void) {
840 struct CitContext *ptr;
841 struct CitContext *bind_me = NULL;
844 struct CitContext *con= NULL; /* Temporary context pointer */
845 struct sockaddr_in fsin; /* Data for master socket */
846 int alen; /* Data for master socket */
847 int ssock; /* Descriptor for client socket */
849 while (!time_to_die) {
852 * In a stupid environment, we would have all idle threads
853 * calling select() and then they'd all wake up at once. We
854 * solve this problem by putting the select() in a critical
855 * section, so only one thread has the opportunity to wake
856 * up. If we wake up on the master socket, create a new
857 * session context; otherwise, just bind the thread to the
858 * context we want and go on our merry way.
861 begin_critical_section(S_I_WANNA_SELECT);
862 SETUP_FD: FD_ZERO(&readfds);
863 FD_SET(msock, &readfds);
865 FD_SET(rescan[0], &readfds);
866 if (rescan[0] > highest) highest = rescan[0];
869 begin_critical_section(S_SESSION_TABLE);
870 for (ptr = ContextList; ptr != NULL; ptr = ptr->next) {
871 if (ptr->state == CON_IDLE) {
872 FD_SET(ptr->client_socket, &readfds);
873 if (ptr->client_socket > highest)
874 highest = ptr->client_socket;
878 end_critical_section(S_SESSION_TABLE);
880 retval = select(highest + 1, &readfds, NULL, NULL, NULL);
882 /* Now figure out who made this select() unblock.
883 * First, check for an error or exit condition.
886 end_critical_section(S_I_WANNA_SELECT);
887 lprintf(9, "Exiting (%s)\n", errno);
891 /* Next, check to see if it's a new client connecting
892 * on the master socket.
894 else if (FD_ISSET(msock, &readfds)) {
896 ssock = accept(msock, (struct sockaddr *)&fsin, &alen);
898 lprintf(2, "citserver: accept() failed: %s\n",
902 lprintf(7, "citserver: New client socket %d\n",
905 /* New context will be created already set up
906 * in the CON_EXECUTING state.
908 con = CreateNewContext();
910 /* Assign our new socket number to it. */
911 con->client_socket = ssock;
913 /* Set the SO_REUSEADDR socket option */
915 setsockopt(ssock, SOL_SOCKET, SO_REUSEADDR,
918 pthread_setspecific(MyConKey, (void *)con);
920 /* do_command_loop(); */
921 pthread_setspecific(MyConKey, (void *)NULL);
922 con->state = CON_IDLE;
927 /* If the rescan pipe went active, someone is telling this
928 * thread that the &readfds needs to be refreshed with more
931 else if (FD_ISSET(rescan[0], &readfds)) {
932 read(rescan[0], &junk, 1);
936 /* It must be a client socket. Find a context that has data
937 * waiting on its socket *and* is in the CON_IDLE state.
941 begin_critical_section(S_SESSION_TABLE);
942 for (ptr = ContextList;
943 ( (ptr != NULL) && (bind_me == NULL) );
945 if ( (FD_ISSET(ptr->client_socket, &readfds))
946 && (ptr->state == CON_IDLE) ) {
950 if (bind_me != NULL) {
951 /* Found one. Stake a claim to it before
952 * letting anyone else touch the context list.
954 bind_me->state = CON_EXECUTING;
957 end_critical_section(S_SESSION_TABLE);
958 end_critical_section(S_I_WANNA_SELECT);
960 /* We're bound to a session, now do *one* command */
961 if (bind_me != NULL) {
962 pthread_setspecific(MyConKey, (void *)bind_me);
964 pthread_setspecific(MyConKey, (void *)NULL);
965 bind_me->state = CON_IDLE;
966 if (bind_me->kill_me == 1) {
967 RemoveContext(bind_me);
969 write(rescan[1], &junk, 1);
972 lprintf(9, "Thread %02d found nothing to do!\n",
977 dead_session_purge();