* Holy war on strlen: use IsEmptyStr where apropriate.
[citadel.git] / citadel / citserver.c
1 /* 
2  * $Id$
3  *
4  * Main source module for the Citadel server
5  *
6  */
7
8 #include "sysdep.h"
9 #include <stdlib.h>
10 #include <unistd.h>
11 #include <stdio.h>
12 #include <fcntl.h>
13 #include <signal.h>
14 #include <sys/types.h>
15 #include <sys/stat.h>
16
17
18 #if TIME_WITH_SYS_TIME
19 # include <sys/time.h>
20 # include <time.h>
21 #else
22 # if HAVE_SYS_TIME_H
23 #  include <sys/time.h>
24 # else
25 #  include <time.h>
26 # endif
27 #endif
28
29 #include <ctype.h>
30 #include <string.h>
31 #include <dirent.h>
32 #include <errno.h>
33 #include <limits.h>
34 #include <netdb.h>
35 #include <sys/types.h>
36 #include <sys/socket.h>
37 #include <netinet/in.h>
38 #include <arpa/inet.h>
39 #include "citadel.h"
40 #include "server.h"
41 #include "sysdep_decls.h"
42 #include "citserver.h"
43 #include "config.h"
44 #include "database.h"
45 #include "housekeeping.h"
46 #include "user_ops.h"
47 #include "msgbase.h"
48 #include "support.h"
49 #include "locate_host.h"
50 #include "room_ops.h"
51 #include "file_ops.h"
52 #include "policy.h"
53 #include "control.h"
54 #include "tools.h"
55 #include "euidindex.h"
56 #include "serv_network.h"       /* Needed for destroy_network_queue_room called from master_cleanup */
57
58 #ifndef HAVE_SNPRINTF
59 #include "snprintf.h"
60 #endif
61
62 struct CitContext *ContextList = NULL;
63 struct CitContext* next_session = NULL;
64 char *unique_session_numbers;
65 int ScheduledShutdown = 0;
66 int do_defrag = 0;
67 time_t server_startup_time;
68
69 /*
70  * Various things that need to be initialized at startup
71  */
72 void master_startup(void) {
73         struct timeval tv;
74         unsigned int seed;
75         FILE *urandom;
76         struct ctdlroom qrbuf;
77         
78         lprintf(CTDL_DEBUG, "master_startup() started\n");
79         time(&server_startup_time);
80
81         lprintf(CTDL_INFO, "Opening databases\n");
82         open_databases();
83
84         if (do_defrag) {
85                 defrag_databases();
86         }
87
88         check_ref_counts();
89
90         lprintf(CTDL_INFO, "Creating base rooms (if necessary)\n");
91         create_room(config.c_baseroom,  0, "", 0, 1, 0, VIEW_BBS);
92         create_room(AIDEROOM,           3, "", 0, 1, 0, VIEW_BBS);
93         create_room(SYSCONFIGROOM,      3, "", 0, 1, 0, VIEW_BBS);
94         create_room(config.c_twitroom,  0, "", 0, 1, 0, VIEW_BBS);
95
96         /* The "Local System Configuration" room doesn't need to be visible */
97         if (lgetroom(&qrbuf, SYSCONFIGROOM) == 0) {
98                 qrbuf.QRflags2 |= QR2_SYSTEM;
99                 lputroom(&qrbuf);
100         }
101
102         lprintf(CTDL_INFO, "Seeding the pseudo-random number generator...\n");
103         urandom = fopen("/dev/urandom", "r");
104         if (urandom != NULL) {
105                 fread(&seed, sizeof seed, 1, urandom);
106                 fclose(urandom);
107         }
108         else {
109                 gettimeofday(&tv, NULL);
110                 seed = tv.tv_usec;
111         }
112         srandom(seed);
113
114         lprintf(CTDL_INFO, "Initializing ipgm secret\n");
115         get_config();
116         config.c_ipgm_secret = rand();
117         put_config();
118
119         lprintf(CTDL_DEBUG, "master_startup() finished\n");
120 }
121
122
123 /*
124  * Cleanup routine to be called when the server is shutting down.
125  */
126 void master_cleanup(int exitcode) {
127         struct CleanupFunctionHook *fcn;
128         struct MaintenanceThreadHook *m_fcn;
129         static int already_cleaning_up = 0;
130
131         if (already_cleaning_up) while(1) sleep(1);
132         already_cleaning_up = 1;
133
134         /* Run any cleanup routines registered by loadable modules */
135         for (fcn = CleanupHookTable; fcn != NULL; fcn = fcn->next) {
136                 (*fcn->h_function_pointer)();
137         }
138
139         /* Close the AdjRefCount queue file */
140         AdjRefCount(-1, 0);
141
142         for (m_fcn = MaintenanceThreadHookTable; m_fcn != NULL; m_fcn = m_fcn->next) {
143                 lprintf(CTDL_INFO, "Waiting for maintenance thread \"%s\" to shut down\n", m_fcn->name);
144                 pthread_join(m_fcn->MaintenanceThread_tid, NULL);
145         }
146         
147
148         /* Close databases */
149         lprintf(CTDL_INFO, "Closing databases\n");
150         close_databases();
151
152         /* flush the networker stuff */
153         destroy_network_queue_room();
154
155         /* Do system-dependent stuff */
156         sysdep_master_cleanup();
157         
158 #ifdef DEBUG_MEMORY_LEAKS
159         dump_heap();
160 #endif
161
162         /* If the operator requested a halt but not an exit, halt here. */
163         if (shutdown_and_halt) {
164                 lprintf(CTDL_NOTICE, "citserver: Halting server without exiting.\n");
165                 fflush(stdout); fflush(stderr);
166                 while(1) {
167                         sleep(32767);
168                 }
169         }
170         
171         release_control();
172
173         /* Now go away. */
174         lprintf(CTDL_NOTICE, "citserver: Exiting with status %d\n", exitcode);
175         fflush(stdout); fflush(stderr);
176         
177         if (restart_server != 0)
178                 exit(1);
179         exit(exitcode);
180 }
181
182
183
184 /*
185  * Terminate a session.
186  */
187 void RemoveContext (struct CitContext *con)
188 {
189         if (con==NULL) {
190                 lprintf(CTDL_ERR,
191                         "WARNING: RemoveContext() called with NULL!\n");
192                 return;
193         }
194         lprintf(CTDL_DEBUG, "RemoveContext() session %d\n", con->cs_pid);
195
196         /* Run any cleanup routines registered by loadable modules.
197          * Note: We have to "become_session()" because the cleanup functions
198          *       might make references to "CC" assuming it's the right one.
199          */
200         become_session(con);
201         PerformSessionHooks(EVT_STOP);
202         become_session(NULL);
203
204         /* Now handle all of the administrivia. */
205         lprintf(CTDL_DEBUG, "Calling logout(%d)\n", con->cs_pid);
206         logout(con);
207
208         lprintf(CTDL_NOTICE, "[%3d] Session ended.\n", con->cs_pid);
209
210         /* If the client is still connected, blow 'em away. */
211         lprintf(CTDL_DEBUG, "Closing socket %d\n", con->client_socket);
212         close(con->client_socket);
213
214         lprintf(CTDL_DEBUG, "Done with RemoveContext()\n");
215 }
216
217
218
219
220
221 /*
222  * cmd_info()  -  tell the client about this server
223  */
224 void cmd_info(void) {
225         cprintf("%d Server info:\n", LISTING_FOLLOWS);
226         cprintf("%d\n", CC->cs_pid);
227         cprintf("%s\n", config.c_nodename);
228         cprintf("%s\n", config.c_humannode);
229         cprintf("%s\n", config.c_fqdn);
230         cprintf("%s\n", CITADEL);
231         cprintf("%d\n", REV_LEVEL);
232         cprintf("%s\n", config.c_site_location);
233         cprintf("%s\n", config.c_sysadm);
234         cprintf("%d\n", SERVER_TYPE);
235         cprintf("%s\n", config.c_moreprompt);
236         cprintf("1\n"); /* 1 = yes, this system supports floors */
237         cprintf("1\n"); /* 1 = we support the extended paging options */
238         cprintf("%s\n", CC->cs_nonce);
239         cprintf("1\n"); /* 1 = yes, this system supports the QNOP command */
240
241 #ifdef HAVE_LDAP
242         cprintf("1\n"); /* 1 = yes, this server is LDAP-enabled */
243 #else
244         cprintf("0\n"); /* 1 = no, this server is not LDAP-enabled */
245 #endif
246
247         if (config.c_auth_mode == 1) {
248                 cprintf("1\n"); /* "create new user" never works with host auth */
249         }
250         else {
251                 cprintf("%d\n", config.c_disable_newu); /* otherwise, site defined */
252         }
253
254         cprintf("%s\n", config.c_default_cal_zone);
255
256         cprintf("000\n");
257 }
258
259
260 /*
261  * returns an asterisk if there are any instant messages waiting,
262  * space otherwise.
263  */
264 char CtdlCheckExpress(void) {
265         if (CC->FirstExpressMessage == NULL) {
266                 return(' ');
267         }
268         else {
269                 return('*');
270         }
271 }
272
273 void cmd_time(void)
274 {
275    time_t tv;
276    struct tm tmp;
277    
278    tv = time(NULL);
279    localtime_r(&tv, &tmp);
280    
281    /* timezone and daylight global variables are not portable. */
282 #ifdef HAVE_STRUCT_TM_TM_GMTOFF
283    cprintf("%d %ld|%ld|%d\n", CIT_OK, (long)tv, tmp.tm_gmtoff, tmp.tm_isdst);
284 #else
285    cprintf("%d %ld|%ld|%d\n", CIT_OK, (long)tv, timezone, tmp.tm_isdst);
286 #endif
287 }
288
289
290 /*
291  * Check originating host against the public_clients file.  This determines
292  * whether the client is allowed to change the hostname for this session
293  * (for example, to show the location of the user rather than the location
294  * of the client).
295  */
296 int is_public_client(void)
297 {
298         char buf[1024];
299         char addrbuf[1024];
300         FILE *fp;
301         int i;
302         struct stat statbuf;
303         static time_t pc_timestamp = 0;
304         static char public_clients[SIZ];
305         static char public_clients_file[SIZ];
306
307         snprintf(public_clients_file, 
308                          sizeof public_clients_file,
309                          "%s/public_clients",
310                          ctdl_etc_dir);
311
312         /*
313          * Check the time stamp on the public_clients file.  If it's been
314          * updated since the last time we were here (or if this is the first
315          * time we've been through the loop), read its contents and learn
316          * the IP addresses of the listed hosts.
317          */
318         if (stat(public_clients_file, &statbuf) != 0) {
319                 /* No public_clients file exists, so bail out */
320                 lprintf(CTDL_WARNING, "Warning: '%s' does not exist\n", 
321                                 public_clients_file);
322                 return(0);
323         }
324
325         if (statbuf.st_mtime > pc_timestamp) {
326                 begin_critical_section(S_PUBLIC_CLIENTS);
327                 lprintf(CTDL_INFO, "Loading %s\n", public_clients_file);
328
329                 safestrncpy(public_clients, "127.0.0.1", sizeof public_clients);
330                 if (hostname_to_dotted_quad(addrbuf, config.c_fqdn) == 0) {
331                         strcat(public_clients, "|");
332                         strcat(public_clients, addrbuf);
333                 }
334
335                 fp = fopen(public_clients_file, "r");
336                 if (fp != NULL) while (fgets(buf, sizeof buf, fp)!=NULL) {
337                         for (i=0; i<strlen(buf); ++i) {
338                                 if (buf[i] == '#') buf[i] = 0;
339                         }
340                         while (isspace((buf[strlen(buf)-1]))) {
341                                 buf[strlen(buf)-1] = 0;
342                         }
343                         if (hostname_to_dotted_quad(addrbuf, buf) == 0) {
344                                 if ((strlen(public_clients) +
345                                    strlen(addrbuf) + 2)
346                                    < sizeof(public_clients)) {
347                                         strcat(public_clients, "|");
348                                         strcat(public_clients, addrbuf);
349                                 }
350                         }
351                 }
352                 fclose(fp);
353                 pc_timestamp = time(NULL);
354                 end_critical_section(S_PUBLIC_CLIENTS);
355         }
356
357         lprintf(CTDL_DEBUG, "Checking whether %s is a local or public client\n",
358                 CC->cs_addr);
359         for (i=0; i<num_parms(public_clients); ++i) {
360                 extract_token(addrbuf, public_clients, i, '|', sizeof addrbuf);
361                 if (!strcasecmp(CC->cs_addr, addrbuf)) {
362                         lprintf(CTDL_DEBUG, "... yes it is.\n");
363                         return(1);
364                 }
365         }
366
367         /* No hits.  This is not a public client. */
368         lprintf(CTDL_DEBUG, "... no it isn't.\n");
369         return(0);
370 }
371
372
373 /*
374  * the client is identifying itself to the server
375  */
376 void cmd_iden(char *argbuf)
377 {
378         int dev_code;
379         int cli_code;
380         int rev_level;
381         char desc[128];
382         char from_host[128];
383         struct in_addr addr;
384         int do_lookup = 0;
385
386         if (num_parms(argbuf)<4) {
387                 cprintf("%d usage error\n", ERROR + ILLEGAL_VALUE);
388                 return;
389         }
390
391         dev_code = extract_int(argbuf,0);
392         cli_code = extract_int(argbuf,1);
393         rev_level = extract_int(argbuf,2);
394         extract_token(desc, argbuf, 3, '|', sizeof desc);
395
396         safestrncpy(from_host, config.c_fqdn, sizeof from_host);
397         from_host[sizeof from_host - 1] = 0;
398         if (num_parms(argbuf)>=5) extract_token(from_host, argbuf, 4, '|', sizeof from_host);
399
400         CC->cs_clientdev = dev_code;
401         CC->cs_clienttyp = cli_code;
402         CC->cs_clientver = rev_level;
403         safestrncpy(CC->cs_clientname, desc, sizeof CC->cs_clientname);
404         CC->cs_clientname[31] = 0;
405
406         if (!IsEmptyStr(from_host)) {
407                 if (CC->is_local_socket) do_lookup = 1;
408                 else if (is_public_client()) do_lookup = 1;
409         }
410
411         if (do_lookup) {
412                 lprintf(CTDL_DEBUG, "Looking up hostname '%s'\n", from_host);
413                 if ((addr.s_addr = inet_addr(from_host)) != -1) {
414                         locate_host(CC->cs_host, sizeof CC->cs_host,
415                                 CC->cs_addr, sizeof CC->cs_addr,
416                                 &addr);
417                 }
418                 else {
419                         safestrncpy(CC->cs_host, from_host, sizeof CC->cs_host);
420                         CC->cs_host[sizeof CC->cs_host - 1] = 0;
421                 }
422         }
423
424         lprintf(CTDL_NOTICE, "Client %d/%d/%01d.%02d (%s) from %s\n",
425                 dev_code,
426                 cli_code,
427                 (rev_level / 100),
428                 (rev_level % 100),
429                 desc,
430                 CC->cs_host);
431         cprintf("%d Ok\n",CIT_OK);
432 }
433
434
435 /*
436  * display system messages or help
437  */
438 void cmd_mesg(char *mname)
439 {
440         FILE *mfp;
441         char targ[256];
442         char buf[256];
443         char buf2[256];
444         char *dirs[2];
445         DIR *dp;
446         struct dirent *d;
447
448         extract_token(buf, mname, 0, '|', sizeof buf);
449
450         dirs[0] = strdup(ctdl_message_dir);
451         dirs[1] = strdup(ctdl_hlp_dir);
452
453         snprintf(buf2, sizeof buf2, "%s.%d.%d",
454                 buf, CC->cs_clientdev, CC->cs_clienttyp);
455
456         /* If the client requested "?" then produce a listing */
457         if (!strcmp(buf, "?")) {
458                 cprintf("%d %s\n", LISTING_FOLLOWS, buf);
459                 dp = opendir(dirs[1]);
460                 if (dp != NULL) {
461                         while (d = readdir(dp), d != NULL) {
462                                 if (d->d_name[0] != '.') {
463                                         cprintf(" %s\n", d->d_name);
464                                 }
465                         }
466                         closedir(dp);
467                 }
468                 cprintf("000\n");
469                 free(dirs[0]);
470                 free(dirs[1]);
471                 return;
472         }
473
474         /* Otherwise, look for the requested file by name. */
475         else {
476                 mesg_locate(targ, sizeof targ, buf2, 2, (const char **)dirs);
477                 if (IsEmptyStr(targ)) {
478                         snprintf(buf2, sizeof buf2, "%s.%d",
479                                                         buf, CC->cs_clientdev);
480                         mesg_locate(targ, sizeof targ, buf2, 2,
481                                                         (const char **)dirs);
482                         if (IsEmptyStr(targ)) {
483                                 mesg_locate(targ, sizeof targ, buf, 2,
484                                                         (const char **)dirs);
485                         }       
486                 }
487         }
488
489         free(dirs[0]);
490         free(dirs[1]);
491
492         if (IsEmptyStr(targ)) {
493                 cprintf("%d '%s' not found.  (Searching in %s and %s)\n",
494                         ERROR + FILE_NOT_FOUND,
495                         mname,
496                         ctdl_message_dir,
497                         ctdl_hlp_dir
498                 );
499                 return;
500         }
501
502         mfp = fopen(targ, "r");
503         if (mfp==NULL) {
504                 cprintf("%d Cannot open '%s': %s\n",
505                         ERROR + INTERNAL_ERROR, targ, strerror(errno));
506                 return;
507         }
508         cprintf("%d %s\n", LISTING_FOLLOWS,buf);
509
510         while (fgets(buf, (sizeof buf - 1), mfp) != NULL) {
511                 buf[strlen(buf)-1] = 0;
512                 do_help_subst(buf);
513                 cprintf("%s\n",buf);
514         }
515
516         fclose(mfp);
517         cprintf("000\n");
518 }
519
520
521 /*
522  * enter system messages or help
523  */
524 void cmd_emsg(char *mname)
525 {
526         FILE *mfp;
527         char targ[256];
528         char buf[256];
529         char *dirs[2];
530         int a;
531
532         unbuffer_output();
533
534         if (CtdlAccessCheck(ac_aide)) return;
535
536         extract_token(buf, mname, 0, '|', sizeof buf);
537         for (a=0; a<strlen(buf); ++a) {         /* security measure */
538                 if (buf[a] == '/') buf[a] = '.';
539         }
540
541         dirs[0] = strdup(ctdl_message_dir);
542         dirs[1] = strdup(ctdl_hlp_dir);
543
544         mesg_locate(targ, sizeof targ, buf, 2, (const char**)dirs);
545         free(dirs[0]);
546         free(dirs[1]);
547
548         if (IsEmptyStr(targ)) {
549                 snprintf(targ, sizeof targ, 
550                                  "%s/%s",
551                                  ctdl_hlp_dir, buf);
552         }
553
554         mfp = fopen(targ,"w");
555         if (mfp==NULL) {
556                 cprintf("%d Cannot open '%s': %s\n",
557                         ERROR + INTERNAL_ERROR, targ, strerror(errno));
558                 return;
559         }
560         cprintf("%d %s\n", SEND_LISTING, targ);
561
562         while (client_getln(buf, sizeof buf), strcmp(buf, "000")) {
563                 fprintf(mfp, "%s\n", buf);
564         }
565
566         fclose(mfp);
567 }
568
569
570 /* Don't show the names of private rooms unless the viewing
571  * user also knows the rooms.
572  */
573 void GenerateRoomDisplay(char *real_room,
574                         struct CitContext *viewed,
575                         struct CitContext *viewer) {
576
577         int ra;
578
579         strcpy(real_room, viewed->room.QRname);
580         if (viewed->room.QRflags & QR_MAILBOX) {
581                 strcpy(real_room, &real_room[11]);
582         }
583         if (viewed->room.QRflags & QR_PRIVATE) {
584                 CtdlRoomAccess(&viewed->room, &viewer->user, &ra, NULL);
585                 if ( (ra & UA_KNOWN) == 0) {
586                         strcpy(real_room, "<private room>");
587                 }
588         }
589
590         if (viewed->cs_flags & CS_CHAT) {
591                 while (strlen(real_room) < 14)
592                         strcat(real_room, " ");
593
594                 strcpy(&real_room[14], "<chat>");
595         }
596
597 }
598
599 /*
600  * Convenience function.
601  */
602 int CtdlAccessCheck(int required_level) {
603
604         if (CC->internal_pgm) return(0);
605         if (required_level >= ac_internal) {
606                 cprintf("%d This is not a user-level command.\n",
607                         ERROR + HIGHER_ACCESS_REQUIRED);
608                 return(-1);
609         }
610
611         if ((required_level >= ac_logged_in) && (CC->logged_in == 0)) {
612                 cprintf("%d Not logged in.\n", ERROR + NOT_LOGGED_IN);
613                 return(-1);
614         }
615
616         if (CC->user.axlevel >= 6) return(0);
617         if (required_level >= ac_aide) {
618                 cprintf("%d This command requires Aide access.\n",
619                         ERROR + HIGHER_ACCESS_REQUIRED);
620                 return(-1);
621         }
622
623         if (is_room_aide()) return(0);
624         if (required_level >= ac_room_aide) {
625                 cprintf("%d This command requires Aide or Room Aide access.\n",
626                         ERROR + HIGHER_ACCESS_REQUIRED);
627                 return(-1);
628         }
629
630         /* shhh ... succeed quietly */
631         return(0);
632 }
633
634
635
636 /*
637  * Terminate another running session
638  */
639 void cmd_term(char *cmdbuf)
640 {
641         int session_num;
642         struct CitContext *ccptr;
643         int found_it = 0;
644         int allowed = 0;
645
646         session_num = extract_int(cmdbuf, 0);
647         if (session_num == CC->cs_pid) {
648                 cprintf("%d You can't kill your own session.\n", ERROR + ILLEGAL_VALUE);
649                 return;
650         }
651
652         lprintf(CTDL_DEBUG, "Locating session to kill\n");
653         begin_critical_section(S_SESSION_TABLE);
654         for (ccptr = ContextList; ccptr != NULL; ccptr = ccptr->next) {
655                 if (session_num == ccptr->cs_pid) {
656                         found_it = 1;
657                         if ((ccptr->user.usernum == CC->user.usernum)
658                            || (CC->user.axlevel >= 6)) {
659                                 allowed = 1;
660                                 ccptr->kill_me = 1;
661                         }
662                         else {
663                                 allowed = 0;
664                         }
665                 }
666         }
667         end_critical_section(S_SESSION_TABLE);
668
669         if (found_it) {
670                 if (allowed) {
671                         cprintf("%d Session terminated.\n", CIT_OK);
672                 }
673                 else {
674                         cprintf("%d You are not allowed to do that.\n",
675                                 ERROR + HIGHER_ACCESS_REQUIRED);
676                 }
677         }
678         else {
679                 cprintf("%d No such session.\n", ERROR + ILLEGAL_VALUE);
680         }
681 }
682
683
684
685
686
687 /* 
688  * get the paginator prompt
689  */
690 void cmd_more(void) {
691         cprintf("%d %s\n", CIT_OK, config.c_moreprompt);
692 }
693
694 /*
695  * echo 
696  */
697 void cmd_echo(char *etext)
698 {
699         cprintf("%d %s\n", CIT_OK, etext);
700 }
701
702
703
704 /* 
705  * identify as internal program
706  */
707 void cmd_ipgm(char *argbuf)
708 {
709         int secret;
710
711         secret = extract_int(argbuf, 0);
712
713         /* For security reasons, we do NOT allow this command to run
714          * over the network.  Local sockets only.
715          */
716         if (!CC->is_local_socket) {
717                 sleep(5);
718                 cprintf("%d Authentication failed.\n",
719                         ERROR + PASSWORD_REQUIRED);
720         }
721         else if (secret == config.c_ipgm_secret) {
722                 CC->internal_pgm = 1;
723                 strcpy(CC->curr_user, "<internal program>");
724                 CC->cs_flags = CC->cs_flags|CS_STEALTH;
725                 cprintf("%d Authenticated as an internal program.\n", CIT_OK);
726         }
727         else {
728                 sleep(5);
729                 cprintf("%d Authentication failed.\n",
730                         ERROR + PASSWORD_REQUIRED);
731                 lprintf(CTDL_ERR, "Warning: ipgm authentication failed.\n");
732                 CC->kill_me = 1;
733         }
734
735         /* Now change the ipgm secret for the next round.
736          * (Disabled because it breaks concurrent scripts.  The fact that
737          * we no longer accept IPGM over the network should be sufficient
738          * to prevent brute-force attacks.  If you don't agree, uncomment
739          * this block.)
740         get_config();
741         config.c_ipgm_secret = rand();
742         put_config();
743         */
744 }
745
746
747 /*
748  * Shut down the server
749  */
750 void cmd_down(char *argbuf) {
751         char *Reply ="%d Shutting down server.  Goodbye.\n";
752
753         if (CtdlAccessCheck(ac_aide)) return;
754
755         if (!IsEmptyStr(argbuf))
756         {
757                 int state = CIT_OK;
758                 restart_server = extract_int(argbuf, 0);
759                 
760                 if (restart_server > 0)
761                         Reply = "%d Restarting server.  See you soon.\n";
762                 if ((restart_server > 0) && !running_as_daemon)
763                 {
764                         lprintf(CTDL_ERR, "The user requested restart, but not running as deamon! Geronimooooooo!\n");
765                         Reply = "%d Warning, not running in deamon mode. maybe we will come up again, but don't lean on it.\n";
766                         state = ERROR;
767                 }
768                 cprintf(Reply, state);
769         }
770         else
771         {
772                 cprintf(Reply, CIT_OK);
773         }
774         time_to_die = 1;
775 }
776
777 /*
778  * Halt the server without exiting the server process.
779  */
780 void cmd_halt(void) {
781
782         if (CtdlAccessCheck(ac_aide)) return;
783
784         cprintf("%d Halting server.  Goodbye.\n", CIT_OK);
785         time_to_die = 1;
786         shutdown_and_halt = 1;
787 }
788
789 /*
790  * Schedule or cancel a server shutdown
791  */
792 void cmd_scdn(char *argbuf)
793 {
794         int new_state;
795         int state = CIT_OK;
796         char *Reply = "%d %d\n";
797
798         if (CtdlAccessCheck(ac_aide)) return;
799
800         new_state = extract_int(argbuf, 0);
801         if ((new_state == 2) || (new_state == 3))
802         {
803                 restart_server = 1;
804                 if (!running_as_daemon)
805                 {
806                         lprintf(CTDL_ERR, "The user requested restart, but not running as deamon! Geronimooooooo!\n");
807                         Reply = "%d %d Warning, not running in deamon mode. maybe we will come up again, but don't lean on it.\n";
808                         state = ERROR;
809                 }
810
811                 restart_server = extract_int(argbuf, 0);
812                 new_state -= 2;
813         }
814         if ((new_state == 0) || (new_state == 1)) {
815                 ScheduledShutdown = new_state;
816         }
817         cprintf(Reply, state, ScheduledShutdown);
818 }
819
820
821 /*
822  * Set or unset asynchronous protocol mode
823  */
824 void cmd_asyn(char *argbuf)
825 {
826         int new_state;
827
828         new_state = extract_int(argbuf, 0);
829         if ((new_state == 0) || (new_state == 1)) {
830                 CC->is_async = new_state;
831         }
832         cprintf("%d %d\n", CIT_OK, CC->is_async);
833 }
834
835
836 /*
837  * Generate a "nonce" for APOP-style authentication.
838  *
839  * RFC 1725 et al specify a PID to be placed in front of the nonce.
840  * Quoth BTX: That would be stupid.
841  */
842 void generate_nonce(struct CitContext *con) {
843         struct timeval tv;
844
845         memset(con->cs_nonce, NONCE_SIZE, 0);
846         gettimeofday(&tv, NULL);
847         memset(con->cs_nonce, NONCE_SIZE, 0);
848         snprintf(con->cs_nonce, NONCE_SIZE, "<%d%ld@%s>",
849                 rand(), (long)tv.tv_usec, config.c_fqdn);
850 }
851
852
853
854
855 /*
856  * Back-end function for starting a session
857  */
858 void begin_session(struct CitContext *con)
859 {
860         socklen_t len;
861         struct sockaddr_in sin;
862
863         /* 
864          * Initialize some variables specific to our context.
865          */
866         con->logged_in = 0;
867         con->internal_pgm = 0;
868         con->download_fp = NULL;
869         con->upload_fp = NULL;
870         con->FirstExpressMessage = NULL;
871         time(&con->lastcmd);
872         time(&con->lastidle);
873         strcpy(con->lastcmdname, "    ");
874         strcpy(con->cs_clientname, "(unknown)");
875         strcpy(con->curr_user, NLI);
876         strcpy(con->net_node, "");
877         strcpy(con->fake_username, "");
878         strcpy(con->fake_hostname, "");
879         strcpy(con->fake_roomname, "");
880         generate_nonce(con);
881         safestrncpy(con->cs_host, config.c_fqdn, sizeof con->cs_host);
882         safestrncpy(con->cs_addr, "", sizeof con->cs_addr);
883         con->cs_host[sizeof con->cs_host - 1] = 0;
884         len = sizeof sin;
885         if (!CC->is_local_socket) {
886                 if (!getpeername(con->client_socket, (struct sockaddr *) &sin, &len)) {
887                         locate_host(con->cs_host, sizeof con->cs_host,
888                                 con->cs_addr, sizeof con->cs_addr,
889                                 &sin.sin_addr
890                         );
891                 }
892         }
893         else {
894                 strcpy(con->cs_host, "");
895         }
896         con->cs_flags = 0;
897         con->upload_type = UPL_FILE;
898         con->dl_is_net = 0;
899
900         con->nologin = 0;
901         if ((config.c_maxsessions > 0)&&(num_sessions > config.c_maxsessions)) {
902                 con->nologin = 1;
903         }
904
905         lprintf(CTDL_NOTICE, "Session started.\n");
906
907         /* Run any session startup routines registered by loadable modules */
908         PerformSessionHooks(EVT_START);
909 }
910
911
912 void citproto_begin_session() {
913         if (CC->nologin==1) {
914                 cprintf("%d %s: Too many users are already online (maximum is %d)\n",
915                         ERROR + MAX_SESSIONS_EXCEEDED,
916                         config.c_nodename, config.c_maxsessions
917                 );
918                 CC->kill_me = 1;
919         }
920         else {
921                 cprintf("%d %s Citadel server ready.\n",
922                         CIT_OK, config.c_nodename);
923         }
924 }
925
926
927
928
929 /*
930  * This loop recognizes all server commands.
931  */
932 void do_command_loop(void) {
933         char cmdbuf[SIZ];
934
935         time(&CC->lastcmd);
936         memset(cmdbuf, 0, sizeof cmdbuf); /* Clear it, just in case */
937         if (client_getln(cmdbuf, sizeof cmdbuf) < 1) {
938                 lprintf(CTDL_ERR, "Client disconnected: ending session.\n");
939                 CC->kill_me = 1;
940                 return;
941         }
942
943         /* Log the server command, but don't show passwords... */
944         if ( (strncasecmp(cmdbuf, "PASS", 4))
945            && (strncasecmp(cmdbuf, "SETP", 4)) ) {
946                 lprintf(CTDL_INFO, "%s\n", cmdbuf);
947         }
948         else {
949                 lprintf(CTDL_INFO, "<password command sent>\n");
950         }
951
952         buffer_output();
953
954         /*
955          * Let other clients see the last command we executed, and
956          * update the idle time, but not NOOP, QNOP, PEXP, GEXP, RWHO, or TIME.
957          */
958         if ( (strncasecmp(cmdbuf, "NOOP", 4))
959            && (strncasecmp(cmdbuf, "QNOP", 4))
960            && (strncasecmp(cmdbuf, "PEXP", 4))
961            && (strncasecmp(cmdbuf, "GEXP", 4))
962            && (strncasecmp(cmdbuf, "RWHO", 4))
963            && (strncasecmp(cmdbuf, "TIME", 4)) ) {
964                 strcpy(CC->lastcmdname, "    ");
965                 safestrncpy(CC->lastcmdname, cmdbuf, sizeof(CC->lastcmdname));
966                 time(&CC->lastidle);
967         }
968                 
969         if ((strncasecmp(cmdbuf, "ENT0", 4))
970            && (strncasecmp(cmdbuf, "MESG", 4))
971            && (strncasecmp(cmdbuf, "MSGS", 4)))
972         {
973            CC->cs_flags &= ~CS_POSTING;
974         }
975                    
976         if (!strncasecmp(cmdbuf, "NOOP", 4)) {
977                 cprintf("%d%cok\n", CIT_OK, CtdlCheckExpress() );
978         }
979         
980         else if (!strncasecmp(cmdbuf, "QNOP", 4)) {
981                 /* do nothing, this command returns no response */
982         }
983
984         else if (!strncasecmp(cmdbuf,"QUIT",4)) {
985                 cprintf("%d Goodbye.\n", CIT_OK);
986                 CC->kill_me = 1;
987         }
988
989         else if (!strncasecmp(cmdbuf,"ASYN",4)) {
990                 cmd_asyn(&cmdbuf[5]);
991         }
992
993         else if (!strncasecmp(cmdbuf,"LOUT",4)) {
994                 if (CC->logged_in) logout(CC);
995                 cprintf("%d logged out.\n", CIT_OK);
996         }
997
998         else if (!strncasecmp(cmdbuf,"USER",4)) {
999                 cmd_user(&cmdbuf[5]);
1000         }
1001
1002         else if (!strncasecmp(cmdbuf,"PASS",4)) {
1003                 cmd_pass(&cmdbuf[5]);
1004         }
1005
1006         else if (!strncasecmp(cmdbuf,"NEWU",4)) {
1007                 cmd_newu(&cmdbuf[5]);
1008         }
1009
1010         else if (!strncasecmp(cmdbuf,"CREU",4)) {
1011                 cmd_creu(&cmdbuf[5]);
1012         }
1013
1014         else if (!strncasecmp(cmdbuf,"SETP",4)) {
1015                 cmd_setp(&cmdbuf[5]);
1016         }
1017
1018         else if (!strncasecmp(cmdbuf,"LRMS",4)) {
1019                 cmd_lrms(&cmdbuf[5]);
1020         }
1021
1022         else if (!strncasecmp(cmdbuf,"LKRA",4)) {
1023                 cmd_lkra(&cmdbuf[5]);
1024         }
1025
1026         else if (!strncasecmp(cmdbuf,"LKRN",4)) {
1027                 cmd_lkrn(&cmdbuf[5]);
1028         }
1029
1030         else if (!strncasecmp(cmdbuf,"LKRO",4)) {
1031                 cmd_lkro(&cmdbuf[5]);
1032         }
1033
1034         else if (!strncasecmp(cmdbuf,"LZRM",4)) {
1035                 cmd_lzrm(&cmdbuf[5]);
1036         }
1037
1038         else if (!strncasecmp(cmdbuf,"LPRM",4)) {
1039                 cmd_lprm(&cmdbuf[5]);
1040         }
1041
1042         else if (!strncasecmp(cmdbuf,"GETU",4)) {
1043                 cmd_getu();
1044         }
1045
1046         else if (!strncasecmp(cmdbuf,"SETU",4)) {
1047                 cmd_setu(&cmdbuf[5]);
1048         }
1049
1050         else if (!strncasecmp(cmdbuf,"GOTO",4)) {
1051                 cmd_goto(&cmdbuf[5]);
1052         }
1053
1054         else if (!strncasecmp(cmdbuf,"MSGS",4)) {
1055                 cmd_msgs(&cmdbuf[5]);
1056         }
1057
1058         else if (!strncasecmp(cmdbuf,"WHOK",4)) {
1059                 cmd_whok();
1060         }
1061
1062         else if (!strncasecmp(cmdbuf,"RDIR",4)) {
1063                 cmd_rdir();
1064         }
1065
1066         else if (!strncasecmp(cmdbuf,"EUID",4)) {
1067                 cmd_euid(&cmdbuf[5]);
1068         }
1069
1070         else if (!strncasecmp(cmdbuf,"MSG0",4)) {
1071                 cmd_msg0(&cmdbuf[5]);
1072         }
1073
1074         else if (!strncasecmp(cmdbuf,"MSG2",4)) {
1075                 cmd_msg2(&cmdbuf[5]);
1076         }
1077
1078         else if (!strncasecmp(cmdbuf,"MSG3",4)) {
1079                 cmd_msg3(&cmdbuf[5]);
1080         }
1081
1082         else if (!strncasecmp(cmdbuf,"MSG4",4)) {
1083                 cmd_msg4(&cmdbuf[5]);
1084         }
1085
1086         else if (!strncasecmp(cmdbuf,"MSGP",4)) {
1087                 cmd_msgp(&cmdbuf[5]);
1088         }
1089
1090         else if (!strncasecmp(cmdbuf,"OPNA",4)) {
1091                 cmd_opna(&cmdbuf[5]);
1092         }
1093
1094         else if (!strncasecmp(cmdbuf,"DLAT",4)) {
1095                 cmd_dlat(&cmdbuf[5]);
1096         }
1097
1098         else if (!strncasecmp(cmdbuf,"INFO",4)) {
1099                 cmd_info();
1100         }
1101
1102         else if (!strncasecmp(cmdbuf,"SLRP",4)) {
1103                 cmd_slrp(&cmdbuf[5]);
1104         }
1105
1106         else if (!strncasecmp(cmdbuf,"INVT",4)) {
1107                 cmd_invt_kick(&cmdbuf[5],1);
1108         }
1109
1110         else if (!strncasecmp(cmdbuf,"KICK",4)) {
1111                 cmd_invt_kick(&cmdbuf[5],0);
1112         }
1113
1114         else if (!strncasecmp(cmdbuf,"GETR",4)) {
1115                 cmd_getr();
1116         }
1117
1118         else if (!strncasecmp(cmdbuf,"SETR",4)) {
1119                 cmd_setr(&cmdbuf[5]);
1120         }
1121
1122         else if (!strncasecmp(cmdbuf,"GETA",4)) {
1123                 cmd_geta();
1124         }
1125
1126         else if (!strncasecmp(cmdbuf,"SETA",4)) {
1127                 cmd_seta(&cmdbuf[5]);
1128         }
1129
1130         else if (!strncasecmp(cmdbuf,"ENT0",4)) {
1131                 cmd_ent0(&cmdbuf[5]);
1132         }
1133
1134         else if (!strncasecmp(cmdbuf,"RINF",4)) {
1135                 cmd_rinf();
1136         }
1137
1138         else if (!strncasecmp(cmdbuf,"DELE",4)) {
1139                 cmd_dele(&cmdbuf[5]);
1140         }
1141
1142         else if (!strncasecmp(cmdbuf,"KILL",4)) {
1143                 cmd_kill(&cmdbuf[5]);
1144         }
1145
1146         else if (!strncasecmp(cmdbuf,"CRE8",4)) {
1147                 cmd_cre8(&cmdbuf[5]);
1148         }
1149
1150         else if (!strncasecmp(cmdbuf,"MOVE",4)) {
1151                 cmd_move(&cmdbuf[5]);
1152         }
1153
1154         else if (!strncasecmp(cmdbuf,"FORG",4)) {
1155                 cmd_forg();
1156         }
1157
1158         else if (!strncasecmp(cmdbuf,"MESG",4)) {
1159                 cmd_mesg(&cmdbuf[5]);
1160         }
1161
1162         else if (!strncasecmp(cmdbuf,"EMSG",4)) {
1163                 cmd_emsg(&cmdbuf[5]);
1164         }
1165
1166         else if (!strncasecmp(cmdbuf,"GNUR",4)) {
1167                 cmd_gnur();
1168         }
1169
1170         else if (!strncasecmp(cmdbuf,"VALI",4)) {
1171                 cmd_vali(&cmdbuf[5]);
1172         }
1173
1174         else if (!strncasecmp(cmdbuf,"EINF",4)) {
1175                 cmd_einf(&cmdbuf[5]);
1176         }
1177
1178         else if (!strncasecmp(cmdbuf,"LIST",4)) {
1179                 cmd_list(&cmdbuf[5]);
1180         }
1181
1182         else if (!strncasecmp(cmdbuf,"CHEK",4)) {
1183                 cmd_chek();
1184         }
1185
1186         else if (!strncasecmp(cmdbuf,"DELF",4)) {
1187                 cmd_delf(&cmdbuf[5]);
1188         }
1189
1190         else if (!strncasecmp(cmdbuf,"MOVF",4)) {
1191                 cmd_movf(&cmdbuf[5]);
1192         }
1193
1194         else if (!strncasecmp(cmdbuf,"NETF",4)) {
1195                 cmd_netf(&cmdbuf[5]);
1196         }
1197
1198         else if (!strncasecmp(cmdbuf,"OPEN",4)) {
1199                 cmd_open(&cmdbuf[5]);
1200         }
1201
1202         else if (!strncasecmp(cmdbuf,"CLOS",4)) {
1203                 cmd_clos();
1204         }
1205
1206         else if (!strncasecmp(cmdbuf,"UOPN",4)) {
1207                 cmd_uopn(&cmdbuf[5]);
1208         }
1209
1210         else if (!strncasecmp(cmdbuf,"UCLS",4)) {
1211                 cmd_ucls(&cmdbuf[5]);
1212         }
1213
1214         else if (!strncasecmp(cmdbuf,"READ",4)) {
1215                 cmd_read(&cmdbuf[5]);
1216         }
1217
1218         else if (!strncasecmp(cmdbuf,"WRIT",4)) {
1219                 cmd_writ(&cmdbuf[5]);
1220         }
1221
1222         else if (!strncasecmp(cmdbuf,"QUSR",4)) {
1223                 cmd_qusr(&cmdbuf[5]);
1224         }
1225
1226         else if (!strncasecmp(cmdbuf,"ECHO",4)) {
1227                 cmd_echo(&cmdbuf[5]);
1228         }
1229
1230         else if (!strncasecmp(cmdbuf,"OIMG",4)) {
1231                 cmd_oimg(&cmdbuf[5]);
1232         }
1233
1234         else if (!strncasecmp(cmdbuf,"MORE",4)) {
1235                 cmd_more();
1236         }
1237
1238         else if (!strncasecmp(cmdbuf,"NDOP",4)) {
1239                 cmd_ndop(&cmdbuf[5]);
1240         }
1241
1242         else if (!strncasecmp(cmdbuf,"NUOP",4)) {
1243                 cmd_nuop(&cmdbuf[5]);
1244         }
1245
1246         else if (!strncasecmp(cmdbuf,"LFLR",4)) {
1247                 cmd_lflr();
1248         }
1249
1250         else if (!strncasecmp(cmdbuf,"CFLR",4)) {
1251                 cmd_cflr(&cmdbuf[5]);
1252         }
1253
1254         else if (!strncasecmp(cmdbuf,"KFLR",4)) {
1255                 cmd_kflr(&cmdbuf[5]);
1256         }
1257
1258         else if (!strncasecmp(cmdbuf,"EFLR",4)) {
1259                 cmd_eflr(&cmdbuf[5]);
1260         }
1261
1262         else if (!strncasecmp(cmdbuf,"IDEN",4)) {
1263                 cmd_iden(&cmdbuf[5]);
1264         }
1265
1266         else if (!strncasecmp(cmdbuf,"IPGM",4)) {
1267                 cmd_ipgm(&cmdbuf[5]);
1268         }
1269
1270         else if (!strncasecmp(cmdbuf,"TERM",4)) {
1271                 cmd_term(&cmdbuf[5]);
1272         }
1273
1274         else if (!strncasecmp(cmdbuf,"DOWN",4)) {
1275                 cmd_down(&cmdbuf[5]);
1276         }
1277
1278         else if (!strncasecmp(cmdbuf,"HALT",4)) {
1279                 cmd_halt();
1280         }
1281
1282         else if (!strncasecmp(cmdbuf,"SCDN",4)) {
1283                 cmd_scdn(&cmdbuf[5]);
1284         }
1285
1286         else if (!strncasecmp(cmdbuf, "UIMG", 4)) {
1287                 cmd_uimg(&cmdbuf[5]);
1288         }
1289
1290         else if (!strncasecmp(cmdbuf, "TIME", 4)) {
1291                 cmd_time();
1292         }
1293
1294         else if (!strncasecmp(cmdbuf, "AGUP", 4)) {
1295                 cmd_agup(&cmdbuf[5]);
1296         }
1297
1298         else if (!strncasecmp(cmdbuf, "ASUP", 4)) {
1299                 cmd_asup(&cmdbuf[5]);
1300         }
1301
1302         else if (!strncasecmp(cmdbuf, "GPEX", 4)) {
1303                 cmd_gpex(&cmdbuf[5]);
1304         }
1305
1306         else if (!strncasecmp(cmdbuf, "SPEX", 4)) {
1307                 cmd_spex(&cmdbuf[5]);
1308         }
1309
1310         else if (!strncasecmp(cmdbuf, "CONF", 4)) {
1311                 cmd_conf(&cmdbuf[5]);
1312         }
1313
1314         else if (!strncasecmp(cmdbuf, "SEEN", 4)) {
1315                 cmd_seen(&cmdbuf[5]);
1316         }
1317
1318         else if (!strncasecmp(cmdbuf, "GTSN", 4)) {
1319                 cmd_gtsn(&cmdbuf[5]);
1320         }
1321
1322         else if (!strncasecmp(cmdbuf, "VIEW", 4)) {
1323                 cmd_view(&cmdbuf[5]);
1324         }
1325
1326         else if (!strncasecmp(cmdbuf, "ISME", 4)) {
1327                 cmd_isme(&cmdbuf[5]);
1328         }
1329
1330         else if (!DLoader_Exec_Cmd(cmdbuf)) {
1331                 cprintf("%d Unrecognized or unsupported command.\n",
1332                         ERROR + CMD_NOT_SUPPORTED);
1333                }
1334
1335         unbuffer_output();
1336
1337         /* Run any after-each-command routines registered by modules */
1338         PerformSessionHooks(EVT_CMD);
1339 }
1340
1341
1342 /*
1343  * This loop performs all asynchronous functions.
1344  */
1345 void do_async_loop(void) {
1346         PerformSessionHooks(EVT_ASYNC);
1347 }