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