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 verbosity = DEFAULT_VERBOSITY; /* Logging level */
69 struct CitContext masterCC;
70 int rescan[2]; /* The Rescan Pipe */
71 time_t last_purge = 0; /* Last dead session purge */
72 int num_threads = 0; /* Current number of threads */
73 int num_sessions = 0; /* Current number of sessions */
75 fd_set masterfds; /* Master sockets etc. */
80 * lprintf() ... Write logging information
82 void lprintf(int loglevel, const char *format, ...) {
86 va_start(arg_ptr, format);
87 vsprintf(buf, format, arg_ptr);
90 if (loglevel <= verbosity) {
91 fprintf(stderr, "%s", buf);
95 PerformLogHooks(loglevel, buf);
100 #ifdef DEBUG_MEMORY_LEAKS
101 void *tracked_malloc(size_t tsize, char *tfile, int tline) {
103 struct TheHeap *hptr;
107 lprintf(3, "DANGER! mallok(%d) at %s:%d failed!\n",
108 tsize, tfile, tline);
112 hptr = (struct TheHeap *) malloc(sizeof(struct TheHeap));
113 strcpy(hptr->h_file, tfile);
114 hptr->h_line = tline;
121 char *tracked_strdup(const char *orig, char *tfile, int tline) {
124 s = tracked_malloc( (strlen(orig)+1), tfile, tline);
125 if (s == NULL) return NULL;
131 void tracked_free(void *ptr) {
132 struct TheHeap *hptr, *freeme;
134 if (heap->h_ptr == ptr) {
140 for (hptr=heap; hptr->next!=NULL; hptr=hptr->next) {
141 if (hptr->next->h_ptr == ptr) {
143 hptr->next = hptr->next->next;
152 void *tracked_realloc(void *ptr, size_t size) {
154 struct TheHeap *hptr;
156 newptr = realloc(ptr, size);
158 for (hptr=heap; hptr!=NULL; hptr=hptr->next) {
159 if (hptr->h_ptr == ptr) hptr->h_ptr = newptr;
166 void dump_tracked() {
167 struct TheHeap *hptr;
169 cprintf("%d Here's what's allocated...\n", LISTING_FOLLOWS);
170 for (hptr=heap; hptr!=NULL; hptr=hptr->next) {
171 cprintf("%20s %5d\n",
172 hptr->h_file, hptr->h_line);
184 * we used to use master_cleanup() as a signal handler to shut down the server.
185 * however, master_cleanup() and the functions it calls do some things that
186 * aren't such a good idea to do from a signal handler: acquiring mutexes,
187 * playing with signal masks on BSDI systems, etc. so instead we install the
188 * following signal handler to set a global variable to inform the main loop
189 * that it's time to call master_cleanup() and exit.
192 static volatile int time_to_die = 0;
194 static RETSIGTYPE signal_cleanup(int signum) {
200 * Some initialization stuff...
202 void init_sysdep(void) {
205 /* Set up a bunch of semaphores to be used for critical sections */
206 for (a=0; a<MAX_SEMAPHORES; ++a) {
207 pthread_mutex_init(&Critters[a], NULL);
211 * Set up a place to put thread-specific data.
212 * We only need a single pointer per thread - it points to the
213 * thread's CitContext structure in the ContextList linked list.
215 if (pthread_key_create(&MyConKey, NULL) != 0) {
216 lprintf(1, "Can't create TSD key!! %s\n", strerror(errno));
220 * The action for unexpected signals and exceptions should be to
221 * call signal_cleanup() to gracefully shut down the server.
223 signal(SIGINT, signal_cleanup);
224 signal(SIGQUIT, signal_cleanup);
225 signal(SIGHUP, signal_cleanup);
226 signal(SIGTERM, signal_cleanup);
229 * Do not shut down the server on broken pipe signals, otherwise the
230 * whole Citadel service would come down whenever a single client
233 signal(SIGPIPE, SIG_IGN);
238 * Obtain a semaphore lock to begin a critical section.
240 void begin_critical_section(int which_one)
242 pthread_mutex_lock(&Critters[which_one]);
246 * Release a semaphore lock to end a critical section.
248 void end_critical_section(int which_one)
250 pthread_mutex_unlock(&Critters[which_one]);
256 * This is a generic function to set up a master socket for listening on
257 * a TCP port. The server shuts down if the bind fails.
259 int ig_tcp_server(int port_number, int queue_len)
261 struct sockaddr_in sin;
264 memset(&sin, 0, sizeof(sin));
265 sin.sin_family = AF_INET;
266 sin.sin_addr.s_addr = INADDR_ANY;
268 if (port_number == 0) {
269 lprintf(1, "citserver: illegal port number specified\n");
273 sin.sin_port = htons((u_short)port_number);
275 s = socket(PF_INET, SOCK_STREAM, (getprotobyname("tcp")->p_proto));
277 lprintf(1, "citserver: Can't create a socket: %s\n",
282 /* Set the SO_REUSEADDR socket option, because it makes sense. */
284 setsockopt(s, SOL_SOCKET, SO_REUSEADDR, &i, sizeof(i));
286 if (bind(s, (struct sockaddr *)&sin, sizeof(sin)) < 0) {
287 lprintf(1, "citserver: Can't bind: %s\n", strerror(errno));
289 if (bind(s, (struct sockaddr *)&sin, sizeof(sin)) < 0) {
290 lprintf(1, "citserver: Can't bind: %s\n",
295 lprintf(1, "bind to alternate port %d ok\n",
296 htons(sin.sin_port) );
300 if (listen(s, queue_len) < 0) {
301 lprintf(1, "citserver: Can't listen: %s\n", strerror(errno));
311 * Return a pointer to the CitContext structure bound to the thread which
312 * called this function. If there's no such binding (for example, if it's
313 * called by the housekeeper thread) then a generic 'master' CC is returned.
315 struct CitContext *MyContext(void) {
316 struct CitContext *retCC;
317 retCC = (struct CitContext *) pthread_getspecific(MyConKey);
318 if (retCC == NULL) retCC = &masterCC;
324 * Initialize a new context and place it in the list.
326 struct CitContext *CreateNewContext(void) {
327 struct CitContext *me, *ptr;
331 me = (struct CitContext *) mallok(sizeof(struct CitContext));
333 lprintf(1, "citserver: can't allocate memory!!\n");
336 memset(me, 0, sizeof(struct CitContext));
338 /* The new context will be created already in the CON_EXECUTING state
339 * in order to prevent another thread from grabbing it while it's
342 me->state = CON_EXECUTING;
344 begin_critical_section(S_SESSION_TABLE);
346 /* obtain a unique session number */
349 for (ptr = ContextList; ptr != NULL; ptr = ptr->next) {
350 if (ptr->cs_pid == num) {
355 } while (startover == 1);
358 me->next = ContextList;
362 end_critical_section(S_SESSION_TABLE);
369 * client_write() ... Send binary data to the client.
371 void client_write(char *buf, int nbytes)
373 int bytes_written = 0;
375 while (bytes_written < nbytes) {
376 retval = write(CC->client_socket, &buf[bytes_written],
377 nbytes - bytes_written);
379 lprintf(2, "client_write() failed: %s\n",
384 bytes_written = bytes_written + retval;
390 * cprintf() ... Send formatted printable data to the client. It is
391 * implemented in terms of client_write() but remains in
392 * sysdep.c in case we port to somewhere without va_args...
394 void cprintf(const char *format, ...) {
398 va_start(arg_ptr, format);
399 if (vsnprintf(buf, sizeof buf, format, arg_ptr) == -1)
400 buf[sizeof buf - 2] = '\n';
401 client_write(buf, strlen(buf));
407 * Read data from the client socket.
409 * 1 Requested number of bytes has been read.
410 * 0 Request timed out.
411 * -1 The socket is broken.
412 * If the socket breaks, the session will be 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 /* FIX close all protocol master sockets here */
500 * Terminate another session.
501 * (This could justifiably be moved out of sysdep.c because it
502 * no longer does anything that is system-dependent.)
504 void kill_session(int session_to_kill) {
505 struct CitContext *ptr;
507 begin_critical_section(S_SESSION_TABLE);
508 for (ptr = ContextList; ptr != NULL; ptr = ptr->next) {
509 if (ptr->cs_pid == session_to_kill) {
513 end_critical_section(S_SESSION_TABLE);
520 * Start running as a daemon. Only close stdio if do_close_stdio is set.
522 void start_daemon(int do_close_stdio) {
523 if (do_close_stdio) {
528 signal(SIGHUP,SIG_IGN);
529 signal(SIGINT,SIG_IGN);
530 signal(SIGQUIT,SIG_IGN);
531 if (fork()!=0) exit(0);
537 * Tie in to the 'netsetup' program.
539 * (We're going to hope that netsetup never feeds more than 4096 bytes back.)
541 void cmd_nset(char *cmdbuf)
548 char netsetup_args[3][256];
550 if (CC->usersupp.axlevel < 6) {
551 cprintf("%d Higher access required.\n",
552 ERROR + HIGHER_ACCESS_REQUIRED);
556 for (a=1; a<=3; ++a) {
557 if (num_parms(cmdbuf) >= a) {
558 extract(netsetup_args[a-1], cmdbuf, a-1);
559 for (b=0; b<strlen(netsetup_args[a-1]); ++b) {
560 if (netsetup_args[a-1][b] == 34) {
561 netsetup_args[a-1][b] = '_';
566 netsetup_args[a-1][0] = 0;
570 sprintf(fbuf, "./netsetup \"%s\" \"%s\" \"%s\" </dev/null 2>&1",
571 netsetup_args[0], netsetup_args[1], netsetup_args[2]);
572 netsetup = popen(fbuf, "r");
573 if (netsetup == NULL) {
574 cprintf("%d %s\n", ERROR, strerror(errno));
579 while (ch = getc(netsetup), (ch > 0)) {
580 fbuf[strlen(fbuf)+1] = 0;
581 fbuf[strlen(fbuf)] = ch;
584 retcode = pclose(netsetup);
587 for (a=0; a<strlen(fbuf); ++a) {
588 if (fbuf[a] < 32) fbuf[a] = 32;
591 cprintf("%d %s\n", ERROR, fbuf);
595 cprintf("%d Command succeeded. Output follows:\n", LISTING_FOLLOWS);
597 if (fbuf[strlen(fbuf)-1] != 10) cprintf("\n");
604 * Generic routine to convert a login name to a full name (gecos)
605 * Returns nonzero if a conversion took place
607 int convert_login(char NameToConvert[]) {
611 pw = getpwnam(NameToConvert);
616 strcpy(NameToConvert, pw->pw_gecos);
617 for (a=0; a<strlen(NameToConvert); ++a) {
618 if (NameToConvert[a] == ',') NameToConvert[a] = 0;
627 * Purge all sessions which have the 'kill_me' flag set.
628 * This function has code to prevent it from running more than once every
629 * few seconds, because running it after every single unbind would waste a lot
630 * of CPU time and keep the context list locked too much.
632 * After that's done, we raise or lower the size of the worker thread pool
633 * if such an action is appropriate.
635 void dead_session_purge(void) {
636 struct CitContext *ptr, *rem;
640 if ( (time(NULL) - last_purge) < 5 ) return; /* Too soon, go away */
645 begin_critical_section(S_SESSION_TABLE);
646 for (ptr = ContextList; ptr != NULL; ptr = ptr->next) {
647 if ( (ptr->state == CON_IDLE) && (ptr->kill_me) ) {
651 end_critical_section(S_SESSION_TABLE);
653 /* RemoveContext() enters its own S_SESSION_TABLE critical
654 * section, so we have to do it like this.
657 lprintf(9, "Purging session %d\n", rem->cs_pid);
661 } while (rem != NULL);
664 /* Raise or lower the size of the worker thread pool if such
665 * an action is appropriate.
668 if ( (num_sessions > num_threads)
669 && (num_threads < config.c_max_workers) ) {
671 pthread_attr_init(&attr);
672 pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
673 if (pthread_create(&newthread, &attr,
674 (void* (*)(void*)) worker_thread, NULL) != 0) {
675 lprintf(1, "Can't create worker thead: %s\n",
681 else if ( (num_sessions < num_threads)
682 && (num_threads > config.c_min_workers) ) {
693 * Here's where it all begins.
695 int main(int argc, char **argv)
697 pthread_t HousekeepingThread; /* Thread descriptor */
698 pthread_attr_t attr; /* Thread attributes */
699 char tracefile[128]; /* Name of file to log traces to */
700 int a, i; /* General-purpose variables */
702 int drop_root_perms = 1;
704 struct ServiceFunctionHook *serviceptr;
706 /* specify default port name and trace file */
707 strcpy(tracefile, "");
709 /* parse command-line arguments */
710 for (a=1; a<argc; ++a) {
712 /* -t specifies where to log trace messages to */
713 if (!strncmp(argv[a], "-t", 2)) {
714 strcpy(tracefile, argv[a]);
715 strcpy(tracefile, &tracefile[2]);
716 freopen(tracefile, "r", stdin);
717 freopen(tracefile, "w", stdout);
718 freopen(tracefile, "w", stderr);
721 /* run in the background if -d was specified */
722 else if (!strcmp(argv[a], "-d")) {
723 start_daemon( (strlen(tracefile) > 0) ? 0 : 1 ) ;
726 /* -x specifies the desired logging level */
727 else if (!strncmp(argv[a], "-x", 2)) {
728 verbosity = atoi(&argv[a][2]);
731 else if (!strncmp(argv[a], "-h", 2)) {
732 safestrncpy(bbs_home_directory, &argv[a][2],
733 sizeof bbs_home_directory);
737 else if (!strncmp(argv[a], "-f", 2)) {
741 /* -r tells the server not to drop root permissions. don't use
742 * this unless you know what you're doing. this should be
743 * removed in the next release if it proves unnecessary. */
744 else if (!strcmp(argv[a], "-r"))
747 /* any other parameter makes it crash and burn */
749 lprintf(1, "citserver: usage: "
750 "citserver [-tTraceFile] [-d] [-f]"
751 " [-xLogLevel] [-hHomeDir]\n");
757 /* Tell 'em who's in da house */
759 "\nMultithreaded message server for Citadel/UX\n"
760 "Copyright (C) 1987-1999 by the Citadel/UX development team.\n"
761 "Citadel/UX is free software, covered by the GNU General Public License, and\n"
762 "you are welcome to change it and/or distribute copies of it under certain\n"
763 "conditions. There is absolutely no warranty for this software. Please\n"
764 "read the 'COPYING.txt' file for details.\n\n");
768 openlog("citserver",LOG_PID,LOG_USER);
770 /* Load site-specific parameters */
771 lprintf(7, "Loading citadel.config\n");
775 * Do non system dependent startup functions.
780 * Bind the server to our favorite ports.
782 CtdlRegisterServiceHook(config.c_port_number,
783 citproto_begin_session,
787 * Load any server-side modules (plugins) available here.
789 lprintf(7, "Initializing loadable modules\n");
790 if ((moddir = malloc(strlen(bbs_home_directory) + 9)) != NULL) {
791 sprintf(moddir, "%s/modules", bbs_home_directory);
792 DLoader_Init(moddir);
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 * Set up a fd_set containing all the master sockets to which we
809 * always listen. It's computationally less expensive to just copy
810 * this to a local fd_set when starting a new select() and then add
811 * the client sockets than it is to initialize a new one and then
812 * figure out what to put there.
816 FD_SET(rescan[0], &masterfds);
817 if (rescan[0] > masterhighest) masterhighest = rescan[0];
819 for (serviceptr = ServiceHookTable; serviceptr != NULL;
820 serviceptr = serviceptr->next ) {
821 serviceptr->msock = ig_tcp_server(
822 serviceptr->tcp_port, config.c_maxsessions);
823 if (serviceptr->msock >= 0) {
824 FD_SET(serviceptr->msock, &masterfds);
825 if (serviceptr->msock > masterhighest)
826 masterhighest = serviceptr->msock;
827 lprintf(7, "Bound to port %-5d (socket %d)\n",
828 serviceptr->tcp_port,
832 lprintf(1, "Unable to bind to port %d\n",
833 serviceptr->tcp_port);
839 * Now that we've bound the sockets, change to the BBS user id and its
840 * corresponding group ids
842 if (drop_root_perms) {
843 if ((pw = getpwuid(BBSUID)) == NULL)
844 lprintf(1, "WARNING: getpwuid(%d): %s\n"
845 "Group IDs will be incorrect.\n", BBSUID,
848 initgroups(pw->pw_name, pw->pw_gid);
849 if (setgid(pw->pw_gid))
850 lprintf(3, "setgid(%d): %s\n", pw->pw_gid,
853 lprintf(7, "Changing uid to %d\n", BBSUID);
854 if (setuid(BBSUID) != 0) {
855 lprintf(3, "setuid() failed: %s\n", strerror(errno));
860 * Create the housekeeper thread
862 lprintf(7, "Starting housekeeper thread\n");
863 pthread_attr_init(&attr);
864 pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
865 if (pthread_create(&HousekeepingThread, &attr,
866 (void* (*)(void*)) housekeeping_loop, NULL) != 0) {
867 lprintf(1, "Can't create housekeeping thead: %s\n",
873 * Now create a bunch of worker threads.
875 for (i=0; i<(config.c_min_workers-1); ++i) {
876 pthread_attr_init(&attr);
877 pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
878 if (pthread_create(&HousekeepingThread, &attr,
879 (void* (*)(void*)) worker_thread, NULL) != 0) {
880 lprintf(1, "Can't create worker thead: %s\n",
885 /* Now this thread can become a worker as well. */
893 * Bind a thread to a context.
895 inline void become_session(struct CitContext *which_con) {
896 pthread_setspecific(MyConKey, (void *)which_con );
902 * This loop just keeps going and going and going...
904 void worker_thread(void) {
908 struct CitContext *ptr;
909 struct CitContext *bind_me = NULL;
912 struct CitContext *con= NULL; /* Temporary context pointer */
913 struct ServiceFunctionHook *serviceptr;
914 struct sockaddr_in fsin; /* Data for master socket */
915 int alen; /* Data for master socket */
916 int ssock; /* Descriptor for client socket */
919 while (!time_to_die) {
922 * A naive implementation would have all idle threads
923 * calling select() and then they'd all wake up at once. We
924 * solve this problem by putting the select() in a critical
925 * section, so only one thread has the opportunity to wake
926 * up. If we wake up on the master socket, create a new
927 * session context; otherwise, just bind the thread to the
928 * context we want and go on our merry way.
931 begin_critical_section(S_I_WANNA_SELECT);
932 SETUP_FD: memcpy(&readfds, &masterfds, sizeof(fd_set) );
933 highest = masterhighest;
934 begin_critical_section(S_SESSION_TABLE);
935 for (ptr = ContextList; ptr != NULL; ptr = ptr->next) {
936 if (ptr->state == CON_IDLE) {
937 FD_SET(ptr->client_socket, &readfds);
938 if (ptr->client_socket > highest)
939 highest = ptr->client_socket;
942 end_critical_section(S_SESSION_TABLE);
944 retval = select(highest + 1, &readfds, NULL, NULL, NULL);
946 /* Now figure out who made this select() unblock.
947 * First, check for an error or exit condition.
950 end_critical_section(S_I_WANNA_SELECT);
951 lprintf(9, "Exiting (%s)\n", strerror(errno));
955 /* Next, check to see if it's a new client connecting
956 * on the master socket.
958 else for (serviceptr = ServiceHookTable; serviceptr != NULL;
959 serviceptr = serviceptr->next ) {
961 if (FD_ISSET(serviceptr->msock, &readfds)) {
963 ssock = accept(serviceptr->msock,
964 (struct sockaddr *)&fsin, &alen);
966 lprintf(2, "citserver: accept(): %s\n",
970 lprintf(7, "citserver: "
971 "New client socket %d\n",
974 /* New context will be created already
975 * set up in the CON_EXECUTING state.
977 con = CreateNewContext();
979 /* Assign new socket number to it. */
980 con->client_socket = ssock;
981 con->h_command_function =
982 serviceptr->h_command_function;
984 /* Set the SO_REUSEADDR socket option */
986 setsockopt(ssock, SOL_SOCKET,
992 serviceptr->h_greeting_function();
993 become_session(NULL);
994 con->state = CON_IDLE;
1000 /* If the rescan pipe went active, someone is telling this
1001 * thread that the &readfds needs to be refreshed with more
1004 if (!time_to_die) if (FD_ISSET(rescan[0], &readfds)) {
1005 read(rescan[0], &junk, 1);
1009 /* It must be a client socket. Find a context that has data
1010 * waiting on its socket *and* is in the CON_IDLE state.
1014 begin_critical_section(S_SESSION_TABLE);
1015 for (ptr = ContextList;
1016 ( (ptr != NULL) && (bind_me == NULL) );
1018 if ( (FD_ISSET(ptr->client_socket, &readfds))
1019 && (ptr->state == CON_IDLE) ) {
1023 if (bind_me != NULL) {
1024 /* Found one. Stake a claim to it before
1025 * letting anyone else touch the context list.
1027 bind_me->state = CON_EXECUTING;
1030 end_critical_section(S_SESSION_TABLE);
1031 end_critical_section(S_I_WANNA_SELECT);
1033 /* We're bound to a session, now do *one* command */
1034 if (bind_me != NULL) {
1035 become_session(bind_me);
1036 CC->h_command_function();
1037 become_session(NULL);
1038 bind_me->state = CON_IDLE;
1039 if (bind_me->kill_me == 1) {
1040 RemoveContext(bind_me);
1042 write(rescan[1], &junk, 1);
1045 lprintf(9, "Thread found nothing to do!\n");
1049 dead_session_purge();
1052 /* If control reaches this point, the server is shutting down */