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This is an omnibus commit which moves the Citadel Server from crusty old GNU Autotool...
[citadel.git] / citadel / server / internet_addressing.c
1 // This file contains functions which handle the mapping of Internet addresses
2 // to users on the Citadel system.
3 //
4 // Copyright (c) 1987-2022 by the citadel.org team
5 //
6 // This program is open source software; you can redistribute it and/or modify
7 // it under the terms of the GNU General Public License version 3.
8 //
9 // This program is distributed in the hope that it will be useful,
10 // but WITHOUT ANY WARRANTY; without even the implied warranty of
11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12 // GNU General Public License for more details.
13
14 #include "sysdep.h"
15 #include <stdlib.h>
16 #include <unistd.h>
17 #include <stdio.h>
18 #include <fcntl.h>
19 #include <ctype.h>
20 #include <signal.h>
21 #include <pwd.h>
22 #include <errno.h>
23 #include <sys/types.h>
24 #include <time.h>
25 #include <sys/wait.h>
26 #include <string.h>
27 #include <limits.h>
28 #include <libcitadel.h>
29 #include "citadel.h"
30 #include "server.h"
31 #include "sysdep_decls.h"
32 #include "citserver.h"
33 #include "support.h"
34 #include "config.h"
35 #include "msgbase.h"
36 #include "internet_addressing.h"
37 #include "user_ops.h"
38 #include "room_ops.h"
39 #include "parsedate.h"
40 #include "database.h"
41 #include "ctdl_module.h"
42 #ifdef HAVE_ICONV
43 #include <iconv.h>
44
45 // This is the non-define version in case it is needed for debugging
46 #if 0
47 inline void FindNextEnd (char *bptr, char *end)
48 {
49         /* Find the next ?Q? */
50         end = strchr(bptr + 2, '?');
51         if (end == NULL) return NULL;
52         if (((*(end + 1) == 'B') || (*(end + 1) == 'Q')) && 
53             (*(end + 2) == '?')) {
54                 /* skip on to the end of the cluster, the next ?= */
55                 end = strstr(end + 3, "?=");
56         }
57         else
58                 /* sort of half valid encoding, try to find an end. */
59                 end = strstr(bptr, "?=");
60 }
61 #endif
62
63 #define FindNextEnd(bptr, end) { \
64         end = strchr(bptr + 2, '?'); \
65         if (end != NULL) { \
66                 if (((*(end + 1) == 'B') || (*(end + 1) == 'Q')) && (*(end + 2) == '?')) { \
67                         end = strstr(end + 3, "?="); \
68                 } else end = strstr(bptr, "?="); \
69         } \
70 }
71
72 // Handle subjects with RFC2047 encoding such as:
73 // =?koi8-r?B?78bP0s3Mxc7JxSDXz9rE1dvO2c3JINvB0sHNySDP?=
74 void utf8ify_rfc822_string(char *buf) {
75         char *start, *end, *next, *nextend, *ptr;
76         char newbuf[1024];
77         char charset[128];
78         char encoding[16];
79         char istr[1024];
80         iconv_t ic = (iconv_t)(-1) ;
81         char *ibuf;                     // Buffer of characters to be converted
82         char *obuf;                     // Buffer for converted characters
83         size_t ibuflen;                 // Length of input buffer
84         size_t obuflen;                 // Length of output buffer
85         char *isav;                     // Saved pointer to input buffer
86         char *osav;                     // Saved pointer to output buffer
87         int passes = 0;
88         int i, len, delta;
89         int illegal_non_rfc2047_encoding = 0;
90
91         // Sometimes, badly formed messages contain strings which were simply
92         // written out directly in some foreign character set instead of
93         // using RFC2047 encoding.  This is illegal but we will attempt to
94         // handle it anyway by converting from a user-specified default
95         // charset to UTF-8 if we see any nonprintable characters.
96         len = strlen(buf);
97         for (i=0; i<len; ++i) {
98                 if ((buf[i] < 32) || (buf[i] > 126)) {
99                         illegal_non_rfc2047_encoding = 1;
100                         i = len;        // take a shortcut, it won't be more than one.
101                 }
102         }
103         if (illegal_non_rfc2047_encoding) {
104                 const char *default_header_charset = "iso-8859-1";
105                 if ( (strcasecmp(default_header_charset, "UTF-8")) && (strcasecmp(default_header_charset, "us-ascii")) ) {
106                         ctdl_iconv_open("UTF-8", default_header_charset, &ic);
107                         if (ic != (iconv_t)(-1) ) {
108                                 ibuf = malloc(1024);
109                                 isav = ibuf;
110                                 safestrncpy(ibuf, buf, 1024);
111                                 ibuflen = strlen(ibuf);
112                                 obuflen = 1024;
113                                 obuf = (char *) malloc(obuflen);
114                                 osav = obuf;
115                                 iconv(ic, &ibuf, &ibuflen, &obuf, &obuflen);
116                                 osav[1024-obuflen] = 0;
117                                 strcpy(buf, osav);
118                                 free(osav);
119                                 iconv_close(ic);
120                                 free(isav);
121                         }
122                 }
123         }
124
125         // pre evaluate the first pair
126         nextend = end = NULL;
127         len = strlen(buf);
128         start = strstr(buf, "=?");
129         if (start != NULL) 
130                 FindNextEnd (start, end);
131
132         while ((start != NULL) && (end != NULL)) {
133                 next = strstr(end, "=?");
134                 if (next != NULL)
135                         FindNextEnd(next, nextend);
136                 if (nextend == NULL)
137                         next = NULL;
138
139                 // did we find two partitions
140                 if ((next != NULL) && ((next - end) > 2)) {
141                         ptr = end + 2;
142                         while ((ptr < next) && 
143                                (isspace(*ptr) ||
144                                 (*ptr == '\r') ||
145                                 (*ptr == '\n') || 
146                                 (*ptr == '\t')))
147                                 ptr ++;
148                         // did we find a gab just filled with blanks?
149                         if (ptr == next) {
150                                 memmove(end + 2, next, len - (next - start));
151
152                                 // now terminate the gab at the end
153                                 delta = (next - end) - 2;
154                                 len -= delta;
155                                 buf[len] = '\0';
156
157                                 // move next to its new location.
158                                 next -= delta;
159                                 nextend -= delta;
160                         }
161                 }
162                 // our next-pair is our new first pair now.
163                 start = next;
164                 end = nextend;
165         }
166
167         // Now we handle foreign character sets properly encoded in RFC2047 format.
168         start = strstr(buf, "=?");
169         FindNextEnd((start != NULL)? start : buf, end);
170         while (start != NULL && end != NULL && end > start) {
171                 extract_token(charset, start, 1, '?', sizeof charset);
172                 extract_token(encoding, start, 2, '?', sizeof encoding);
173                 extract_token(istr, start, 3, '?', sizeof istr);
174
175                 ibuf = malloc(1024);
176                 isav = ibuf;
177                 if (!strcasecmp(encoding, "B")) {       // base64
178                         ibuflen = CtdlDecodeBase64(ibuf, istr, strlen(istr));
179                 }
180                 else if (!strcasecmp(encoding, "Q")) {  // quoted-printable
181                         size_t len;
182                         unsigned long pos;
183                         
184                         len = strlen(istr);
185                         pos = 0;
186                         while (pos < len) {
187                                 if (istr[pos] == '_') istr[pos] = ' ';
188                                 pos++;
189                         }
190                         ibuflen = CtdlDecodeQuotedPrintable(ibuf, istr, len);
191                 }
192                 else {
193                         strcpy(ibuf, istr);             // unknown encoding
194                         ibuflen = strlen(istr);
195                 }
196
197                 ctdl_iconv_open("UTF-8", charset, &ic);
198                 if (ic != (iconv_t)(-1) ) {
199                         obuflen = 1024;
200                         obuf = (char *) malloc(obuflen);
201                         osav = obuf;
202                         iconv(ic, &ibuf, &ibuflen, &obuf, &obuflen);
203                         osav[1024-obuflen] = 0;
204
205                         end = start;
206                         end++;
207                         strcpy(start, "");
208                         remove_token(end, 0, '?');
209                         remove_token(end, 0, '?');
210                         remove_token(end, 0, '?');
211                         remove_token(end, 0, '?');
212                         strcpy(end, &end[1]);
213
214                         snprintf(newbuf, sizeof newbuf, "%s%s%s", buf, osav, end);
215                         strcpy(buf, newbuf);
216                         free(osav);
217                         iconv_close(ic);
218                 }
219                 else {
220                         end = start;
221                         end++;
222                         strcpy(start, "");
223                         remove_token(end, 0, '?');
224                         remove_token(end, 0, '?');
225                         remove_token(end, 0, '?');
226                         remove_token(end, 0, '?');
227                         strcpy(end, &end[1]);
228
229                         snprintf(newbuf, sizeof newbuf, "%s(unreadable)%s", buf, end);
230                         strcpy(buf, newbuf);
231                 }
232
233                 free(isav);
234
235                 // Since spammers will go to all sorts of absurd lengths to get their
236                 // messages through, there are LOTS of corrupt headers out there.
237                 // So, prevent a really badly formed RFC2047 header from throwing
238                 // this function into an infinite loop.
239                 ++passes;
240                 if (passes > 20) return;
241
242                 start = strstr(buf, "=?");
243                 FindNextEnd((start != NULL)? start : buf, end);
244         }
245
246 }
247 #else
248 inline void utf8ify_rfc822_string(char *a){};
249
250 #endif
251
252
253 char *inetcfg = NULL;
254
255 // Return nonzero if the supplied name is an alias for this host.
256 int CtdlHostAlias(char *fqdn) {
257         int config_lines;
258         int i;
259         char buf[256];
260         char host[256], type[256];
261         int found = 0;
262
263         if (fqdn == NULL)                                       return(hostalias_nomatch);
264         if (IsEmptyStr(fqdn))                                   return(hostalias_nomatch);
265         if (!strcasecmp(fqdn, "localhost"))                     return(hostalias_localhost);
266         if (!strcasecmp(fqdn, CtdlGetConfigStr("c_fqdn")))      return(hostalias_localhost);
267         if (!strcasecmp(fqdn, CtdlGetConfigStr("c_nodename")))  return(hostalias_localhost);
268         if (inetcfg == NULL)                                    return(hostalias_nomatch);
269
270         config_lines = num_tokens(inetcfg, '\n');
271         for (i=0; i<config_lines; ++i) {
272                 extract_token(buf, inetcfg, i, '\n', sizeof buf);
273                 extract_token(host, buf, 0, '|', sizeof host);
274                 extract_token(type, buf, 1, '|', sizeof type);
275
276                 found = 0;
277
278                 // Process these in a specific order, in case there are multiple matches.
279                 // We want localhost to override masq, for example.
280
281                 if ( (!strcasecmp(type, "masqdomain")) && (!strcasecmp(fqdn, host))) {
282                         found = hostalias_masq;
283                 }
284
285                 if ( (!strcasecmp(type, "localhost")) && (!strcasecmp(fqdn, host))) {
286                         found = hostalias_localhost;
287                 }
288
289                 // "directory" used to be a distributed version of "localhost" but they're both the same now
290                 if ( (!strcasecmp(type, "directory")) && (!strcasecmp(fqdn, host))) {
291                         found = hostalias_localhost;
292                 }
293
294                 if (found) return(found);
295         }
296         return(hostalias_nomatch);
297 }
298
299
300 // Determine whether a given Internet address belongs to the current user
301 int CtdlIsMe(char *addr, int addr_buf_len) {
302         struct recptypes *recp;
303         int i;
304
305         recp = validate_recipients(addr, NULL, 0);
306         if (recp == NULL) return(0);
307
308         if (recp->num_local == 0) {
309                 free_recipients(recp);
310                 return(0);
311         }
312
313         for (i=0; i<recp->num_local; ++i) {
314                 extract_token(addr, recp->recp_local, i, '|', addr_buf_len);
315                 if (!strcasecmp(addr, CC->user.fullname)) {
316                         free_recipients(recp);
317                         return(1);
318                 }
319         }
320
321         free_recipients(recp);
322         return(0);
323 }
324
325
326 // If the last item in a list of recipients was truncated to a partial address,
327 // remove it completely in order to avoid choking library functions.
328 void sanitize_truncated_recipient(char *str) {
329         if (!str) return;
330         if (num_tokens(str, ',') < 2) return;
331
332         int len = strlen(str);
333         if (len < 900) return;
334         if (len > 998) str[998] = 0;
335
336         char *cptr = strrchr(str, ',');
337         if (!cptr) return;
338
339         char *lptr = strchr(cptr, '<');
340         char *rptr = strchr(cptr, '>');
341
342         if ( (lptr) && (rptr) && (rptr > lptr) ) return;
343
344         *cptr = 0;
345 }
346
347
348 // This function is self explanatory.
349 // (What can I say, I'm in a weird mood today...)
350 void remove_any_whitespace_to_the_left_or_right_of_at_symbol(char *name) {
351         char *ptr;
352         if (!name) return;
353
354         for (ptr=name; *ptr; ++ptr) {
355                 while ( (isspace(*ptr)) && (*(ptr+1)=='@') ) {
356                         strcpy(ptr, ptr+1);
357                         if (ptr > name) --ptr;
358                 }
359                 while ( (*ptr=='@') && (*(ptr+1)!=0) && (isspace(*(ptr+1))) ) {
360                         strcpy(ptr+1, ptr+2);
361                 }
362         }
363 }
364
365
366 // values that can be returned by expand_aliases()
367 enum {
368         EA_ERROR,               // Can't send message due to bad address
369         EA_MULTIPLE,            // Alias expanded into multiple recipients -- run me again!
370         EA_LOCAL,               // Local message, do no network processing
371         EA_INTERNET,            // Convert msg and send as Internet mail
372         EA_SKIP                 // This recipient has been invalidated -- skip it!
373 };
374
375
376 // Process alias and routing info for email addresses
377 int expand_aliases(char *name, char *aliases) {
378         int a;
379         char aaa[SIZ];
380         int at = 0;
381
382         if (aliases) {
383                 int num_aliases = num_tokens(aliases, '\n');
384                 for (a=0; a<num_aliases; ++a) {
385                         extract_token(aaa, aliases, a, '\n', sizeof aaa);
386                         char *bar = strchr(aaa, '|');
387                         if (bar) {
388                                 bar[0] = 0;
389                                 ++bar;
390                                 striplt(aaa);
391                                 striplt(bar);
392                                 if ( (!IsEmptyStr(aaa)) && (!strcasecmp(name, aaa)) ) {
393                                         syslog(LOG_DEBUG, "internet_addressing: global alias <%s> to <%s>", name, bar);
394                                         strcpy(name, bar);
395                                 }
396                         }
397                 }
398                 if (strchr(name, ',')) {
399                         return(EA_MULTIPLE);
400                 }
401         }
402
403         char original_name[256];                                // Now go for the regular aliases
404         safestrncpy(original_name, name, sizeof original_name);
405
406         // should these checks still be here, or maybe move them to split_recps() ?
407         striplt(name);
408         remove_any_whitespace_to_the_left_or_right_of_at_symbol(name);
409         stripallbut(name, '<', '>');
410
411         // Hit the email address directory
412         if (CtdlDirectoryLookup(aaa, name, sizeof aaa) == 0) {
413                 strcpy(name, aaa);
414         }
415
416         if (strcasecmp(original_name, name)) {
417                 syslog(LOG_INFO, "internet_addressing: directory alias <%s> to <%s>", original_name, name);
418         }
419
420         // Change "user @ xxx" to "user" if xxx is an alias for this host
421         for (a=0; name[a] != '\0'; ++a) {
422                 if (name[a] == '@') {
423                         if (CtdlHostAlias(&name[a+1]) == hostalias_localhost) {
424                                 name[a] = 0;
425                                 syslog(LOG_DEBUG, "internet_addressing: host is local, recipient is <%s>", name);
426                                 break;
427                         }
428                 }
429         }
430
431         // Is this a local or remote recipient?
432         at = haschar(name, '@');
433         if (at == 0) {
434                 return(EA_LOCAL);                       // no @'s = local address
435         }
436         else if (at == 1) {
437                 return(EA_INTERNET);                    // one @ = internet address
438         }
439         else {
440                 return(EA_ERROR);                       // more than one @ = badly formed address
441         }
442 }
443
444
445 // Return a supplied list of email addresses as an array, removing superfluous information and syntax.
446 // If an existing Array is supplied as "append_to" it will do so; otherwise a new Array is allocated.
447 Array *split_recps(char *addresses, Array *append_to) {
448
449         if (IsEmptyStr(addresses)) {            // nothing supplied, nothing returned
450                 return(NULL);
451         }
452
453         // Copy the supplied address list into our own memory space, because we are going to modify it.
454         char *a = strdup(addresses);
455         if (a == NULL) {
456                 syslog(LOG_ERR, "internet_addressing: malloc() failed: %m");
457                 return(NULL);
458         }
459
460         // Strip out anything in double quotes
461         char *l = NULL;
462         char *r = NULL;
463         do {
464                 l = strchr(a, '\"');
465                 r = strrchr(a, '\"');
466                 if (r > l) {
467                         strcpy(l, r+1);
468                 }
469         } while (r > l);
470
471         // Transform all qualifying delimiters to commas
472         char *t;
473         for (t=a; t[0]; ++t) {
474                 if ((t[0]==';') || (t[0]=='|')) {
475                         t[0]=',';
476                 }
477         }
478
479         // Tokenize the recipients into an array.  No single recipient should be larger than 256 bytes.
480         Array *recipients_array = NULL;
481         if (append_to) {
482                 recipients_array = append_to;                   // Append to an existing array of recipients
483         }
484         else {
485                 recipients_array = array_new(256);              // This is a new array of recipients
486         }
487
488         int num_addresses = num_tokens(a, ',');
489         int i;
490         for (i=0; i<num_addresses; ++i) {
491                 char this_address[256];
492                 extract_token(this_address, a, i, ',', sizeof this_address);
493                 striplt(this_address);                          // strip leading and trailing whitespace
494                 stripout(this_address, '(', ')');               // remove any portion in parentheses
495                 stripallbut(this_address, '<', '>');            // if angle brackets are present, keep only what is inside them
496                 if (!IsEmptyStr(this_address)) {
497                         array_append(recipients_array, this_address);
498                 }
499         }
500
501         free(a);                                                // We don't need this buffer anymore.
502         return(recipients_array);                               // Return the completed array to the caller.
503 }
504
505
506 // Validate recipients, count delivery types and errors, and handle aliasing
507 //
508 // Returns 0 if all addresses are ok, ret->num_error = -1 if no addresses 
509 // were specified, or the number of addresses found invalid.
510 //
511 // Caller needs to free the result using free_recipients()
512 //
513 struct recptypes *validate_recipients(char *supplied_recipients, const char *RemoteIdentifier, int Flags) {
514         struct recptypes *ret;
515         char *recipients = NULL;
516         char append[SIZ];
517         long len;
518         int mailtype;
519         int invalid;
520         struct ctdluser tempUS;
521         struct ctdlroom original_room;
522         int err = 0;
523         char errmsg[SIZ];
524         char *org_recp;
525         char this_recp[256];
526
527         ret = (struct recptypes *) malloc(sizeof(struct recptypes));                    // Initialize
528         if (ret == NULL) return(NULL);
529         memset(ret, 0, sizeof(struct recptypes));                                       // set all values to null/zero
530
531         if (supplied_recipients == NULL) {
532                 recipients = strdup("");
533         }
534         else {
535                 recipients = strdup(supplied_recipients);
536         }
537
538         len = strlen(recipients) + 1024;                                                // allocate memory
539         ret->errormsg = malloc(len);
540         ret->recp_local = malloc(len);
541         ret->recp_internet = malloc(len);
542         ret->recp_room = malloc(len);
543         ret->display_recp = malloc(len);
544         ret->recp_orgroom = malloc(len);
545
546         ret->errormsg[0] = 0;
547         ret->recp_local[0] = 0;
548         ret->recp_internet[0] = 0;
549         ret->recp_room[0] = 0;
550         ret->recp_orgroom[0] = 0;
551         ret->display_recp[0] = 0;
552         ret->recptypes_magic = RECPTYPES_MAGIC;
553
554         Array *recp_array = split_recps(supplied_recipients, NULL);
555
556         char *aliases = CtdlGetSysConfig(GLOBAL_ALIASES);                               // First hit the Global Alias Table
557
558         int r;
559         for (r=0; (recp_array && r<array_len(recp_array)); ++r) {
560                 org_recp = (char *)array_get_element_at(recp_array, r);
561                 strncpy(this_recp, org_recp, sizeof this_recp);
562
563                 int i;
564                 for (i=0; i<3; ++i) {                                           // pass three times through the aliaser
565                         mailtype = expand_aliases(this_recp, aliases);
566         
567                         // If an alias expanded to multiple recipients, strip off those recipients and append them
568                         // to the end of the array.  This loop will hit those again when it gets there.
569                         if (mailtype == EA_MULTIPLE) {
570                                 recp_array = split_recps(this_recp, recp_array);
571                         }
572                 }
573
574                 // This loop searches for duplicate recipients in the final list and marks them to be skipped.
575                 int j;
576                 for (j=0; j<r; ++j) {
577                         if (!strcasecmp(this_recp, (char *)array_get_element_at(recp_array, j) )) {
578                                 mailtype = EA_SKIP;
579                         }
580                 }
581
582                 syslog(LOG_DEBUG, "Recipient #%d of type %d is <%s>", r, mailtype, this_recp);
583                 invalid = 0;
584                 errmsg[0] = 0;
585                 switch(mailtype) {
586                 case EA_LOCAL:                                  // There are several types of "local" recipients.
587
588                         // Old BBS conventions require mail to "sysop" to go somewhere.  Send it to the admin room.
589                         if (!strcasecmp(this_recp, "sysop")) {
590                                 ++ret->num_room;
591                                 strcpy(this_recp, CtdlGetConfigStr("c_aideroom"));
592                                 if (!IsEmptyStr(ret->recp_room)) {
593                                         strcat(ret->recp_room, "|");
594                                 }
595                                 strcat(ret->recp_room, this_recp);
596                         }
597
598                         // This handles rooms which can receive posts via email.
599                         else if (!strncasecmp(this_recp, "room_", 5)) {
600                                 original_room = CC->room;                               // Remember where we parked
601
602                                 char mail_to_room[ROOMNAMELEN];
603                                 char *m;
604                                 strncpy(mail_to_room, &this_recp[5], sizeof mail_to_room);
605                                 for (m = mail_to_room; *m; ++m) {
606                                         if (m[0] == '_') m[0]=' ';
607                                 }
608                                 if (!CtdlGetRoom(&CC->room, mail_to_room)) {            // Find the room they asked for
609
610                                         err = CtdlDoIHavePermissionToPostInThisRoom(    // check for write permissions to room
611                                                 errmsg, 
612                                                 sizeof errmsg, 
613                                                 Flags,
614                                                 0                                       // 0 means "this is not a reply"
615                                         );
616                                         if (err) {
617                                                 ++ret->num_error;
618                                                 invalid = 1;
619                                         } 
620                                         else {
621                                                 ++ret->num_room;
622                                                 if (!IsEmptyStr(ret->recp_room)) {
623                                                         strcat(ret->recp_room, "|");
624                                                 }
625                                                 strcat(ret->recp_room, CC->room.QRname);
626         
627                                                 if (!IsEmptyStr(ret->recp_orgroom)) {
628                                                         strcat(ret->recp_orgroom, "|");
629                                                 }
630                                                 strcat(ret->recp_orgroom, this_recp);
631         
632                                         }
633                                 }
634                                 else {                                                  // no such room exists
635                                         ++ret->num_error;
636                                         invalid = 1;
637                                 }
638                                                 
639                                 // Restore this session's original room location.
640                                 CC->room = original_room;
641
642                         }
643
644                         // This handles the most common case, which is mail to a user's inbox.
645                         else if (CtdlGetUser(&tempUS, this_recp) == 0) {
646                                 ++ret->num_local;
647                                 strcpy(this_recp, tempUS.fullname);
648                                 if (!IsEmptyStr(ret->recp_local)) {
649                                         strcat(ret->recp_local, "|");
650                                 }
651                                 strcat(ret->recp_local, this_recp);
652                         }
653
654                         // No match for this recipient
655                         else {
656                                 ++ret->num_error;
657                                 invalid = 1;
658                         }
659                         break;
660                 case EA_INTERNET:
661                         // Yes, you're reading this correctly: if the target domain points back to the local system,
662                         // the address is invalid.  That's because if the address were valid, we would have
663                         // already translated it to a local address by now.
664                         if (IsDirectory(this_recp, 0)) {
665                                 ++ret->num_error;
666                                 invalid = 1;
667                         }
668                         else {
669                                 ++ret->num_internet;
670                                 if (!IsEmptyStr(ret->recp_internet)) {
671                                         strcat(ret->recp_internet, "|");
672                                 }
673                                 strcat(ret->recp_internet, this_recp);
674                         }
675                         break;
676                 case EA_MULTIPLE:
677                 case EA_SKIP:
678                         // no action required, anything in this slot has already been processed elsewhere
679                         break;
680                 case EA_ERROR:
681                         ++ret->num_error;
682                         invalid = 1;
683                         break;
684                 }
685                 if (invalid) {
686                         if (IsEmptyStr(errmsg)) {
687                                 snprintf(append, sizeof append, "Invalid recipient: %s", this_recp);
688                         }
689                         else {
690                                 snprintf(append, sizeof append, "%s", errmsg);
691                         }
692                         if ( (strlen(ret->errormsg) + strlen(append) + 3) < SIZ) {
693                                 if (!IsEmptyStr(ret->errormsg)) {
694                                         strcat(ret->errormsg, "; ");
695                                 }
696                                 strcat(ret->errormsg, append);
697                         }
698                 }
699                 else {
700                         if (IsEmptyStr(ret->display_recp)) {
701                                 strcpy(append, this_recp);
702                         }
703                         else {
704                                 snprintf(append, sizeof append, ", %s", this_recp);
705                         }
706                         if ( (strlen(ret->display_recp)+strlen(append)) < SIZ) {
707                                 strcat(ret->display_recp, append);
708                         }
709                 }
710         }
711
712         if (aliases != NULL) {          // ok, we're done with the global alias list now
713                 free(aliases);
714         }
715
716         if ( (ret->num_local + ret->num_internet + ret->num_room + ret->num_error) == 0) {
717                 ret->num_error = (-1);
718                 strcpy(ret->errormsg, "No recipients specified.");
719         }
720
721         syslog(LOG_DEBUG, "internet_addressing: validate_recipients() = %d local, %d room, %d SMTP, %d error",
722                 ret->num_local, ret->num_room, ret->num_internet, ret->num_error
723         );
724
725         free(recipients);
726         if (recp_array) {
727                 array_free(recp_array);
728         }
729
730         return(ret);
731 }
732
733
734 // Destructor for recptypes
735 void free_recipients(struct recptypes *valid) {
736
737         if (valid == NULL) {
738                 return;
739         }
740
741         if (valid->recptypes_magic != RECPTYPES_MAGIC) {
742                 syslog(LOG_ERR, "internet_addressing: attempt to call free_recipients() on some other data type!");
743                 abort();
744         }
745
746         if (valid->errormsg != NULL)            free(valid->errormsg);
747         if (valid->recp_local != NULL)          free(valid->recp_local);
748         if (valid->recp_internet != NULL)       free(valid->recp_internet);
749         if (valid->recp_room != NULL)           free(valid->recp_room);
750         if (valid->recp_orgroom != NULL)        free(valid->recp_orgroom);
751         if (valid->display_recp != NULL)        free(valid->display_recp);
752         if (valid->bounce_to != NULL)           free(valid->bounce_to);
753         if (valid->envelope_from != NULL)       free(valid->envelope_from);
754         if (valid->sending_room != NULL)        free(valid->sending_room);
755         free(valid);
756 }
757
758
759 char *qp_encode_email_addrs(char *source) {
760         char *user, *node, *name;
761         const char headerStr[] = "=?UTF-8?Q?";
762         char *Encoded;
763         char *EncodedName;
764         char *nPtr;
765         int need_to_encode = 0;
766         long SourceLen;
767         long EncodedMaxLen;
768         long nColons = 0;
769         long *AddrPtr;
770         long *AddrUtf8;
771         long nAddrPtrMax = 50;
772         long nmax;
773         int InQuotes = 0;
774         int i, n;
775
776         if (source == NULL) return source;
777         if (IsEmptyStr(source)) return source;
778         syslog(LOG_DEBUG, "internet_addressing: qp_encode_email_addrs <%s>", source);
779
780         AddrPtr = malloc (sizeof (long) * nAddrPtrMax);
781         AddrUtf8 = malloc (sizeof (long) * nAddrPtrMax);
782         memset(AddrUtf8, 0, sizeof (long) * nAddrPtrMax);
783         *AddrPtr = 0;
784         i = 0;
785         while (!IsEmptyStr (&source[i])) {
786                 if (nColons >= nAddrPtrMax){
787                         long *ptr;
788
789                         ptr = (long *) malloc(sizeof (long) * nAddrPtrMax * 2);
790                         memcpy (ptr, AddrPtr, sizeof (long) * nAddrPtrMax);
791                         free (AddrPtr), AddrPtr = ptr;
792
793                         ptr = (long *) malloc(sizeof (long) * nAddrPtrMax * 2);
794                         memset(&ptr[nAddrPtrMax], 0, sizeof (long) * nAddrPtrMax);
795
796                         memcpy (ptr, AddrUtf8, sizeof (long) * nAddrPtrMax);
797                         free (AddrUtf8), AddrUtf8 = ptr;
798                         nAddrPtrMax *= 2;                               
799                 }
800                 if (((unsigned char) source[i] < 32) || ((unsigned char) source[i] > 126)) {
801                         need_to_encode = 1;
802                         AddrUtf8[nColons] = 1;
803                 }
804                 if (source[i] == '"') {
805                         InQuotes = !InQuotes;
806                 }
807                 if (!InQuotes && source[i] == ',') {
808                         AddrPtr[nColons] = i;
809                         nColons++;
810                 }
811                 i++;
812         }
813         if (need_to_encode == 0) {
814                 free(AddrPtr);
815                 free(AddrUtf8);
816                 return source;
817         }
818
819         SourceLen = i;
820         EncodedMaxLen = nColons * (sizeof(headerStr) + 3) + SourceLen * 3;
821         Encoded = (char*) malloc (EncodedMaxLen);
822
823         for (i = 0; i < nColons; i++) {
824                 source[AddrPtr[i]++] = '\0';
825         }
826         // TODO: if libidn, this might get larger
827         user = malloc(SourceLen + 1);
828         node = malloc(SourceLen + 1);
829         name = malloc(SourceLen + 1);
830
831         nPtr = Encoded;
832         *nPtr = '\0';
833         for (i = 0; i < nColons && nPtr != NULL; i++) {
834                 nmax = EncodedMaxLen - (nPtr - Encoded);
835                 if (AddrUtf8[i]) {
836                         process_rfc822_addr(&source[AddrPtr[i]], user, node, name);
837                         // TODO: libIDN here !
838                         if (IsEmptyStr(name)) {
839                                 n = snprintf(nPtr, nmax, (i==0)?"%s@%s" : ",%s@%s", user, node);
840                         }
841                         else {
842                                 EncodedName = rfc2047encode(name, strlen(name));                        
843                                 n = snprintf(nPtr, nmax, (i==0)?"%s <%s@%s>" : ",%s <%s@%s>", EncodedName, user, node);
844                                 free(EncodedName);
845                         }
846                 }
847                 else { 
848                         n = snprintf(nPtr, nmax, (i==0)?"%s" : ",%s", &source[AddrPtr[i]]);
849                 }
850                 if (n > 0 )
851                         nPtr += n;
852                 else { 
853                         char *ptr, *nnPtr;
854                         ptr = (char*) malloc(EncodedMaxLen * 2);
855                         memcpy(ptr, Encoded, EncodedMaxLen);
856                         nnPtr = ptr + (nPtr - Encoded), nPtr = nnPtr;
857                         free(Encoded), Encoded = ptr;
858                         EncodedMaxLen *= 2;
859                         i--; // do it once more with properly lengthened buffer
860                 }
861         }
862         for (i = 0; i < nColons; i++)
863                 source[--AddrPtr[i]] = ',';
864
865         free(user);
866         free(node);
867         free(name);
868         free(AddrUtf8);
869         free(AddrPtr);
870         return Encoded;
871 }
872
873
874 // Unfold a multi-line field into a single line, removing multi-whitespaces
875 void unfold_rfc822_field(char **field, char **FieldEnd) 
876 {
877         int quote = 0;
878         char *pField = *field;
879         char *sField;
880         char *pFieldEnd = *FieldEnd;
881
882         while (isspace(*pField))
883                 pField++;
884         // remove leading/trailing whitespace
885         ;
886
887         while (isspace(*pFieldEnd))
888                 pFieldEnd --;
889
890         *FieldEnd = pFieldEnd;
891         // convert non-space whitespace to spaces, and remove double blanks
892         for (sField = *field = pField; 
893              sField < pFieldEnd; 
894              pField++, sField++)
895         {
896                 if ((*sField=='\r') || (*sField=='\n'))
897                 {
898                         int offset = 1;
899                         while ( ( (*(sField + offset) == '\r') || (*(sField + offset) == '\n' )) && (sField + offset < pFieldEnd) ) {
900                                 offset ++;
901                         }
902                         sField += offset;
903                         *pField = *sField;
904                 }
905                 else {
906                         if (*sField=='\"') quote = 1 - quote;
907                         if (!quote) {
908                                 if (isspace(*sField)) {
909                                         *pField = ' ';
910                                         pField++;
911                                         sField++;
912                                         
913                                         while ((sField < pFieldEnd) && 
914                                                isspace(*sField))
915                                                 sField++;
916                                         *pField = *sField;
917                                 }
918                                 else *pField = *sField;
919                         }
920                         else *pField = *sField;
921                 }
922         }
923         *pField = '\0';
924         *FieldEnd = pField - 1;
925 }
926
927
928 // Split an RFC822-style address into userid, host, and full name
929 //
930 // Note: This still handles obsolete address syntaxes such as user%node@node and ...node!user
931 //       We should probably remove that.
932 void process_rfc822_addr(const char *rfc822, char *user, char *node, char *name) {
933         int a;
934
935         strcpy(user, "");
936         strcpy(node, CtdlGetConfigStr("c_fqdn"));
937         strcpy(name, "");
938
939         if (rfc822 == NULL) return;
940
941         // extract full name - first, it's From minus <userid>
942         strcpy(name, rfc822);
943         stripout(name, '<', '>');
944
945         // strip anything to the left of a bang
946         while ((!IsEmptyStr(name)) && (haschar(name, '!') > 0))
947                 strcpy(name, &name[1]);
948
949         // and anything to the right of a @ or %
950         for (a = 0; name[a] != '\0'; ++a) {
951                 if (name[a] == '@') {
952                         name[a] = 0;
953                         break;
954                 }
955                 if (name[a] == '%') {
956                         name[a] = 0;
957                         break;
958                 }
959         }
960
961         // but if there are parentheses, that changes the rules...
962         if ((haschar(rfc822, '(') == 1) && (haschar(rfc822, ')') == 1)) {
963                 strcpy(name, rfc822);
964                 stripallbut(name, '(', ')');
965         }
966
967         // but if there are a set of quotes, that supersedes everything
968         if (haschar(rfc822, 34) == 2) {
969                 strcpy(name, rfc822);
970                 while ((!IsEmptyStr(name)) && (name[0] != 34)) {
971                         strcpy(&name[0], &name[1]);
972                 }
973                 strcpy(&name[0], &name[1]);
974                 for (a = 0; name[a] != '\0'; ++a)
975                         if (name[a] == 34) {
976                                 name[a] = 0;
977                                 break;
978                         }
979         }
980         // extract user id
981         strcpy(user, rfc822);
982
983         // first get rid of anything in parens
984         stripout(user, '(', ')');
985
986         // if there's a set of angle brackets, strip it down to that
987         if ((haschar(user, '<') == 1) && (haschar(user, '>') == 1)) {
988                 stripallbut(user, '<', '>');
989         }
990
991         // strip anything to the left of a bang
992         while ((!IsEmptyStr(user)) && (haschar(user, '!') > 0))
993                 strcpy(user, &user[1]);
994
995         // and anything to the right of a @ or %
996         for (a = 0; user[a] != '\0'; ++a) {
997                 if (user[a] == '@') {
998                         user[a] = 0;
999                         break;
1000                 }
1001                 if (user[a] == '%') {
1002                         user[a] = 0;
1003                         break;
1004                 }
1005         }
1006
1007
1008         // extract node name
1009         strcpy(node, rfc822);
1010
1011         // first get rid of anything in parens
1012         stripout(node, '(', ')');
1013
1014         // if there's a set of angle brackets, strip it down to that
1015         if ((haschar(node, '<') == 1) && (haschar(node, '>') == 1)) {
1016                 stripallbut(node, '<', '>');
1017         }
1018
1019         // If no node specified, tack ours on instead
1020         if (
1021                 (haschar(node, '@')==0)
1022                 && (haschar(node, '%')==0)
1023                 && (haschar(node, '!')==0)
1024         ) {
1025                 strcpy(node, CtdlGetConfigStr("c_nodename"));
1026         }
1027         else {
1028
1029                 // strip anything to the left of a @
1030                 while ((!IsEmptyStr(node)) && (haschar(node, '@') > 0))
1031                         strcpy(node, &node[1]);
1032         
1033                 // strip anything to the left of a %
1034                 while ((!IsEmptyStr(node)) && (haschar(node, '%') > 0))
1035                         strcpy(node, &node[1]);
1036         
1037                 // reduce multiple system bang paths to node!user
1038                 while ((!IsEmptyStr(node)) && (haschar(node, '!') > 1))
1039                         strcpy(node, &node[1]);
1040         
1041                 // now get rid of the user portion of a node!user string
1042                 for (a = 0; node[a] != '\0'; ++a)
1043                         if (node[a] == '!') {
1044                                 node[a] = 0;
1045                                 break;
1046                         }
1047         }
1048
1049         // strip leading and trailing spaces in all strings
1050         striplt(user);
1051         striplt(node);
1052         striplt(name);
1053
1054         // If we processed a string that had the address in angle brackets
1055         // but no name outside the brackets, we now have an empty name.  In
1056         // this case, use the user portion of the address as the name.
1057         if ((IsEmptyStr(name)) && (!IsEmptyStr(user))) {
1058                 strcpy(name, user);
1059         }
1060 }
1061
1062
1063 // convert_field() is a helper function for convert_internet_message().
1064 // Given start/end positions for an rfc822 field, it converts it to a Citadel
1065 // field if it wants to, and unfolds it if necessary.
1066 //
1067 // Returns 1 if the field was converted and inserted into the Citadel message
1068 // structure, implying that the source field should be removed from the
1069 // message text.
1070 int convert_field(struct CtdlMessage *msg, const char *beg, const char *end) {
1071         char *key, *value, *valueend;
1072         long len;
1073         const char *pos;
1074         int i;
1075         const char *colonpos = NULL;
1076         int processed = 0;
1077         char user[1024];
1078         char node[1024];
1079         char name[1024];
1080         char addr[1024];
1081         time_t parsed_date;
1082         long valuelen;
1083
1084         for (pos = end; pos >= beg; pos--) {
1085                 if (*pos == ':') colonpos = pos;
1086         }
1087
1088         if (colonpos == NULL) return(0);        /* no colon? not a valid header line */
1089
1090         len = end - beg;
1091         key = malloc(len + 2);
1092         memcpy(key, beg, len + 1);
1093         key[len] = '\0';
1094         valueend = key + len;
1095         * ( key + (colonpos - beg) ) = '\0';
1096         value = &key[(colonpos - beg) + 1];
1097         // printf("Header: [%s]\nValue: [%s]\n", key, value);
1098         unfold_rfc822_field(&value, &valueend);
1099         valuelen = valueend - value + 1;
1100         // printf("UnfoldedValue: [%s]\n", value);
1101
1102         // Here's the big rfc822-to-citadel loop.
1103
1104         // Date/time is converted into a unix timestamp.  If the conversion
1105         // fails, we replace it with the time the message arrived locally.
1106         if (!strcasecmp(key, "Date")) {
1107                 parsed_date = parsedate(value);
1108                 if (parsed_date < 0L) parsed_date = time(NULL);
1109
1110                 if (CM_IsEmpty(msg, eTimestamp))
1111                         CM_SetFieldLONG(msg, eTimestamp, parsed_date);
1112                 processed = 1;
1113         }
1114
1115         else if (!strcasecmp(key, "From")) {
1116                 process_rfc822_addr(value, user, node, name);
1117                 syslog(LOG_DEBUG, "internet_addressing: converted to <%s@%s> (%s)", user, node, name);
1118                 snprintf(addr, sizeof(addr), "%s@%s", user, node);
1119                 if (CM_IsEmpty(msg, eAuthor) && !IsEmptyStr(name)) {
1120                         CM_SetField(msg, eAuthor, name, -1);
1121                 }
1122                 if (CM_IsEmpty(msg, erFc822Addr) && !IsEmptyStr(addr)) {
1123                         CM_SetField(msg, erFc822Addr, addr, -1);
1124                 }
1125                 processed = 1;
1126         }
1127
1128         else if (!strcasecmp(key, "Subject")) {
1129                 if (CM_IsEmpty(msg, eMsgSubject))
1130                         CM_SetField(msg, eMsgSubject, value, valuelen);
1131                 processed = 1;
1132         }
1133
1134         else if (!strcasecmp(key, "List-ID")) {
1135                 if (CM_IsEmpty(msg, eListID))
1136                         CM_SetField(msg, eListID, value, valuelen);
1137                 processed = 1;
1138         }
1139
1140         else if (!strcasecmp(key, "To")) {
1141                 if (CM_IsEmpty(msg, eRecipient))
1142                         CM_SetField(msg, eRecipient, value, valuelen);
1143                 processed = 1;
1144         }
1145
1146         else if (!strcasecmp(key, "CC")) {
1147                 if (CM_IsEmpty(msg, eCarbonCopY))
1148                         CM_SetField(msg, eCarbonCopY, value, valuelen);
1149                 processed = 1;
1150         }
1151
1152         else if (!strcasecmp(key, "Message-ID")) {
1153                 if (!CM_IsEmpty(msg, emessageId)) {
1154                         syslog(LOG_WARNING, "internet_addressing: duplicate message id");
1155                 }
1156                 else {
1157                         char *pValue;
1158                         long pValueLen;
1159
1160                         pValue = value;
1161                         pValueLen = valuelen;
1162                         // Strip angle brackets
1163                         while (haschar(pValue, '<') > 0) {
1164                                 pValue ++;
1165                                 pValueLen --;
1166                         }
1167
1168                         for (i = 0; i <= pValueLen; ++i)
1169                                 if (pValue[i] == '>') {
1170                                         pValueLen = i;
1171                                         break;
1172                                 }
1173
1174                         CM_SetField(msg, emessageId, pValue, pValueLen);
1175                 }
1176
1177                 processed = 1;
1178         }
1179
1180         else if (!strcasecmp(key, "Return-Path")) {
1181                 if (CM_IsEmpty(msg, eMessagePath))
1182                         CM_SetField(msg, eMessagePath, value, valuelen);
1183                 processed = 1;
1184         }
1185
1186         else if (!strcasecmp(key, "Envelope-To")) {
1187                 if (CM_IsEmpty(msg, eenVelopeTo))
1188                         CM_SetField(msg, eenVelopeTo, value, valuelen);
1189                 processed = 1;
1190         }
1191
1192         else if (!strcasecmp(key, "References")) {
1193                 CM_SetField(msg, eWeferences, value, valuelen);
1194                 processed = 1;
1195         }
1196
1197         else if (!strcasecmp(key, "Reply-To")) {
1198                 CM_SetField(msg, eReplyTo, value, valuelen);
1199                 processed = 1;
1200         }
1201
1202         else if (!strcasecmp(key, "In-reply-to")) {
1203                 if (CM_IsEmpty(msg, eWeferences)) // References: supersedes In-reply-to:
1204                         CM_SetField(msg, eWeferences, value, valuelen);
1205                 processed = 1;
1206         }
1207
1208
1209
1210         // Clean up and move on.
1211         free(key);      // Don't free 'value', it's actually the same buffer
1212         return processed;
1213 }
1214
1215
1216 // Convert RFC822 references format (References) to Citadel references format (Weferences)
1217 void convert_references_to_wefewences(char *str) {
1218         int bracket_nesting = 0;
1219         char *ptr = str;
1220         char *moveptr = NULL;
1221         char ch;
1222
1223         while(*ptr) {
1224                 ch = *ptr;
1225                 if (ch == '>') {
1226                         --bracket_nesting;
1227                         if (bracket_nesting < 0) bracket_nesting = 0;
1228                 }
1229                 if ((ch == '>') && (bracket_nesting == 0) && (*(ptr+1)) && (ptr>str) ) {
1230                         *ptr = '|';
1231                         ++ptr;
1232                 }
1233                 else if (bracket_nesting > 0) {
1234                         ++ptr;
1235                 }
1236                 else {
1237                         moveptr = ptr;
1238                         while (*moveptr) {
1239                                 *moveptr = *(moveptr+1);
1240                                 ++moveptr;
1241                         }
1242                 }
1243                 if (ch == '<') ++bracket_nesting;
1244         }
1245
1246 }
1247
1248
1249 // Convert an RFC822 message (headers + body) to a CtdlMessage structure.
1250 // NOTE: the supplied buffer becomes part of the CtdlMessage structure, and
1251 // will be deallocated when CM_Free() is called.  Therefore, the
1252 // supplied buffer should be DEREFERENCED.  It should not be freed or used
1253 // again.
1254 struct CtdlMessage *convert_internet_message(char *rfc822) {
1255         StrBuf *RFCBuf = NewStrBufPlain(rfc822, -1);
1256         free (rfc822);
1257         return convert_internet_message_buf(&RFCBuf);
1258 }
1259
1260
1261 struct CtdlMessage *convert_internet_message_buf(StrBuf **rfc822)
1262 {
1263         struct CtdlMessage *msg;
1264         const char *pos, *beg, *end, *totalend;
1265         int done, alldone = 0;
1266         int converted;
1267         StrBuf *OtherHeaders;
1268
1269         msg = malloc(sizeof(struct CtdlMessage));
1270         if (msg == NULL) return msg;
1271
1272         memset(msg, 0, sizeof(struct CtdlMessage));
1273         msg->cm_magic = CTDLMESSAGE_MAGIC;      // self check
1274         msg->cm_anon_type = 0;                  // never anonymous
1275         msg->cm_format_type = FMT_RFC822;       // internet message
1276
1277         pos = ChrPtr(*rfc822);
1278         totalend = pos + StrLength(*rfc822);
1279         done = 0;
1280         OtherHeaders = NewStrBufPlain(NULL, StrLength(*rfc822));
1281
1282         while (!alldone) {
1283
1284                 /* Locate beginning and end of field, keeping in mind that
1285                  * some fields might be multiline
1286                  */
1287                 end = beg = pos;
1288
1289                 while ((end < totalend) && 
1290                        (end == beg) && 
1291                        (done == 0) ) 
1292                 {
1293
1294                         if ( (*pos=='\n') && ((*(pos+1))!=0x20) && ((*(pos+1))!=0x09) )
1295                         {
1296                                 end = pos;
1297                         }
1298
1299                         /* done with headers? */
1300                         if ((*pos=='\n') &&
1301                             ( (*(pos+1)=='\n') ||
1302                               (*(pos+1)=='\r')) ) 
1303                         {
1304                                 alldone = 1;
1305                         }
1306
1307                         if (pos >= (totalend - 1) )
1308                         {
1309                                 end = pos;
1310                                 done = 1;
1311                         }
1312
1313                         ++pos;
1314
1315                 }
1316
1317                 /* At this point we have a field.  Are we interested in it? */
1318                 converted = convert_field(msg, beg, end);
1319
1320                 /* Strip the field out of the RFC822 header if we used it */
1321                 if (!converted) {
1322                         StrBufAppendBufPlain(OtherHeaders, beg, end - beg, 0);
1323                         StrBufAppendBufPlain(OtherHeaders, HKEY("\n"), 0);
1324                 }
1325
1326                 /* If we've hit the end of the message, bail out */
1327                 if (pos >= totalend)
1328                         alldone = 1;
1329         }
1330         StrBufAppendBufPlain(OtherHeaders, HKEY("\n"), 0);
1331         if (pos < totalend)
1332                 StrBufAppendBufPlain(OtherHeaders, pos, totalend - pos, 0);
1333         FreeStrBuf(rfc822);
1334         CM_SetAsFieldSB(msg, eMesageText, &OtherHeaders);
1335
1336         /* Follow-up sanity checks... */
1337
1338         /* If there's no timestamp on this message, set it to now. */
1339         if (CM_IsEmpty(msg, eTimestamp)) {
1340                 CM_SetFieldLONG(msg, eTimestamp, time(NULL));
1341         }
1342
1343         /* If a W (references, or rather, Wefewences) field is present, we
1344          * have to convert it from RFC822 format to Citadel format.
1345          */
1346         if (!CM_IsEmpty(msg, eWeferences)) {
1347                 /// todo: API!
1348                 convert_references_to_wefewences(msg->cm_fields[eWeferences]);
1349         }
1350
1351         return msg;
1352 }
1353
1354
1355 /*
1356  * Look for a particular header field in an RFC822 message text.  If the
1357  * requested field is found, it is unfolded (if necessary) and returned to
1358  * the caller.  The field name is stripped out, leaving only its contents.
1359  * The caller is responsible for freeing the returned buffer.  If the requested
1360  * field is not present, or anything else goes wrong, it returns NULL.
1361  */
1362 char *rfc822_fetch_field(const char *rfc822, const char *fieldname) {
1363         char *fieldbuf = NULL;
1364         const char *end_of_headers;
1365         const char *field_start;
1366         const char *ptr;
1367         char *cont;
1368         char fieldhdr[SIZ];
1369
1370         /* Should never happen, but sometimes we get stupid */
1371         if (rfc822 == NULL) return(NULL);
1372         if (fieldname == NULL) return(NULL);
1373
1374         snprintf(fieldhdr, sizeof fieldhdr, "%s:", fieldname);
1375
1376         /* Locate the end of the headers, so we don't run past that point */
1377         end_of_headers = cbmstrcasestr(rfc822, "\n\r\n");
1378         if (end_of_headers == NULL) {
1379                 end_of_headers = cbmstrcasestr(rfc822, "\n\n");
1380         }
1381         if (end_of_headers == NULL) return (NULL);
1382
1383         field_start = cbmstrcasestr(rfc822, fieldhdr);
1384         if (field_start == NULL) return(NULL);
1385         if (field_start > end_of_headers) return(NULL);
1386
1387         fieldbuf = malloc(SIZ);
1388         strcpy(fieldbuf, "");
1389
1390         ptr = field_start;
1391         ptr = cmemreadline(ptr, fieldbuf, SIZ-strlen(fieldbuf) );
1392         while ( (isspace(ptr[0])) && (ptr < end_of_headers) ) {
1393                 strcat(fieldbuf, " ");
1394                 cont = &fieldbuf[strlen(fieldbuf)];
1395                 ptr = cmemreadline(ptr, cont, SIZ-strlen(fieldbuf) );
1396                 striplt(cont);
1397         }
1398
1399         strcpy(fieldbuf, &fieldbuf[strlen(fieldhdr)]);
1400         striplt(fieldbuf);
1401
1402         return(fieldbuf);
1403 }
1404
1405
1406 /*****************************************************************************
1407  *                      DIRECTORY MANAGEMENT FUNCTIONS                       *
1408  *****************************************************************************/
1409
1410 /*
1411  * Generate the index key for an Internet e-mail address to be looked up
1412  * in the database.
1413  */
1414 void directory_key(char *key, char *addr) {
1415         int i;
1416         int keylen = 0;
1417
1418         for (i=0; !IsEmptyStr(&addr[i]); ++i) {
1419                 if (!isspace(addr[i])) {
1420                         key[keylen++] = tolower(addr[i]);
1421                 }
1422         }
1423         key[keylen++] = 0;
1424
1425         syslog(LOG_DEBUG, "internet_addressing: directory key is <%s>", key);
1426 }
1427
1428
1429 /*
1430  * Return nonzero if the supplied address is in one of "our" domains
1431  */
1432 int IsDirectory(char *addr, int allow_masq_domains) {
1433         char domain[256];
1434         int h;
1435
1436         extract_token(domain, addr, 1, '@', sizeof domain);
1437         striplt(domain);
1438
1439         h = CtdlHostAlias(domain);
1440
1441         if ( (h == hostalias_masq) && allow_masq_domains)
1442                 return(1);
1443         
1444         if (h == hostalias_localhost) {
1445                 return(1);
1446         }
1447         else {
1448                 return(0);
1449         }
1450 }
1451
1452
1453 /*
1454  * Add an Internet e-mail address to the directory for a user
1455  */
1456 int CtdlDirectoryAddUser(char *internet_addr, char *citadel_addr) {
1457         char key[SIZ];
1458
1459         if (IsDirectory(internet_addr, 0) == 0) {
1460                 return 0;
1461         }
1462         syslog(LOG_DEBUG, "internet_addressing: create directory entry: %s --> %s", internet_addr, citadel_addr);
1463         directory_key(key, internet_addr);
1464         cdb_store(CDB_DIRECTORY, key, strlen(key), citadel_addr, strlen(citadel_addr)+1 );
1465         return 1;
1466 }
1467
1468
1469 /*
1470  * Delete an Internet e-mail address from the directory.
1471  *
1472  * (NOTE: we don't actually use or need the citadel_addr variable; it's merely
1473  * here because the callback API expects to be able to send it.)
1474  */
1475 int CtdlDirectoryDelUser(char *internet_addr, char *citadel_addr) {
1476         char key[SIZ];
1477         
1478         syslog(LOG_DEBUG, "internet_addressing: delete directory entry: %s --> %s", internet_addr, citadel_addr);
1479         directory_key(key, internet_addr);
1480         return cdb_delete(CDB_DIRECTORY, key, strlen(key) ) == 0;
1481 }
1482
1483
1484 /*
1485  * Look up an Internet e-mail address in the directory.
1486  * On success: returns 0, and Citadel address stored in 'target'
1487  * On failure: returns nonzero
1488  */
1489 int CtdlDirectoryLookup(char *target, char *internet_addr, size_t targbuflen) {
1490         struct cdbdata *cdbrec;
1491         char key[SIZ];
1492
1493         /* Dump it in there unchanged, just for kicks */
1494         if (target != NULL) {
1495                 safestrncpy(target, internet_addr, targbuflen);
1496         }
1497
1498         /* Only do lookups for addresses with hostnames in them */
1499         if (num_tokens(internet_addr, '@') != 2) return(-1);
1500
1501         /* Only do lookups for domains in the directory */
1502         if (IsDirectory(internet_addr, 0) == 0) return(-1);
1503
1504         directory_key(key, internet_addr);
1505         cdbrec = cdb_fetch(CDB_DIRECTORY, key, strlen(key) );
1506         if (cdbrec != NULL) {
1507                 if (target != NULL) {
1508                         safestrncpy(target, cdbrec->ptr, targbuflen);
1509                 }
1510                 cdb_free(cdbrec);
1511                 return(0);
1512         }
1513
1514         return(-1);
1515 }
1516
1517
1518 /*
1519  * Harvest any email addresses that someone might want to have in their
1520  * "collected addresses" book.
1521  */
1522 char *harvest_collected_addresses(struct CtdlMessage *msg) {
1523         char *coll = NULL;
1524         char addr[256];
1525         char user[256], node[256], name[256];
1526         int is_harvestable;
1527         int i, j, h;
1528         eMsgField field = 0;
1529
1530         if (msg == NULL) return(NULL);
1531
1532         is_harvestable = 1;
1533         strcpy(addr, "");       
1534         if (!CM_IsEmpty(msg, eAuthor)) {
1535                 strcat(addr, msg->cm_fields[eAuthor]);
1536         }
1537         if (!CM_IsEmpty(msg, erFc822Addr)) {
1538                 strcat(addr, " <");
1539                 strcat(addr, msg->cm_fields[erFc822Addr]);
1540                 strcat(addr, ">");
1541                 if (IsDirectory(msg->cm_fields[erFc822Addr], 0)) {
1542                         is_harvestable = 0;
1543                 }
1544         }
1545
1546         if (is_harvestable) {
1547                 coll = strdup(addr);
1548         }
1549         else {
1550                 coll = strdup("");
1551         }
1552
1553         if (coll == NULL) return(NULL);
1554
1555         /* Scan both the R (To) and Y (CC) fields */
1556         for (i = 0; i < 2; ++i) {
1557                 if (i == 0) field = eRecipient;
1558                 if (i == 1) field = eCarbonCopY;
1559
1560                 if (!CM_IsEmpty(msg, field)) {
1561                         for (j=0; j<num_tokens(msg->cm_fields[field], ','); ++j) {
1562                                 extract_token(addr, msg->cm_fields[field], j, ',', sizeof addr);
1563                                 if (strstr(addr, "=?") != NULL)
1564                                         utf8ify_rfc822_string(addr);
1565                                 process_rfc822_addr(addr, user, node, name);
1566                                 h = CtdlHostAlias(node);
1567                                 if (h != hostalias_localhost) {
1568                                         coll = realloc(coll, strlen(coll) + strlen(addr) + 4);
1569                                         if (coll == NULL) return(NULL);
1570                                         if (!IsEmptyStr(coll)) {
1571                                                 strcat(coll, ",");
1572                                         }
1573                                         striplt(addr);
1574                                         strcat(coll, addr);
1575                                 }
1576                         }
1577                 }
1578         }
1579
1580         if (IsEmptyStr(coll)) {
1581                 free(coll);
1582                 return(NULL);
1583         }
1584         return(coll);
1585 }
1586
1587
1588 /*
1589  * Helper function for CtdlRebuildDirectoryIndex()
1590  */
1591 void CtdlRebuildDirectoryIndex_backend(char *username, void *data) {
1592
1593         int j = 0;
1594         struct ctdluser usbuf;
1595
1596         if (CtdlGetUser(&usbuf, username) != 0) {
1597                 return;
1598         }
1599
1600         if ( (!IsEmptyStr(usbuf.fullname)) && (!IsEmptyStr(usbuf.emailaddrs)) ) {
1601                 for (j=0; j<num_tokens(usbuf.emailaddrs, '|'); ++j) {
1602                         char one_email[512];
1603                         extract_token(one_email, usbuf.emailaddrs, j, '|', sizeof one_email);
1604                         CtdlDirectoryAddUser(one_email, usbuf.fullname);
1605                 }
1606         }
1607 }
1608
1609
1610 /*
1611  * Initialize the directory database (erasing anything already there)
1612  */
1613 void CtdlRebuildDirectoryIndex(void) {
1614         syslog(LOG_INFO, "internet_addressing: rebuilding email address directory index");
1615         cdb_trunc(CDB_DIRECTORY);
1616         ForEachUser(CtdlRebuildDirectoryIndex_backend, NULL);
1617 }
1618
1619
1620 // Configure Internet email addresses for a user account, updating the Directory Index in the process
1621 void CtdlSetEmailAddressesForUser(char *requested_user, char *new_emailaddrs) {
1622         struct ctdluser usbuf;
1623         int i;
1624         char buf[SIZ];
1625
1626         if (CtdlGetUserLock(&usbuf, requested_user) != 0) {     // We can lock because the DirectoryIndex functions don't lock.
1627                 return;                                         // Silently fail here if the specified user does not exist.
1628         }
1629
1630         syslog(LOG_DEBUG, "internet_addressing: setting email addresses for <%s> to <%s>", usbuf.fullname, new_emailaddrs);
1631
1632         // Delete all of the existing directory index records for the user (easier this way)
1633         for (i=0; i<num_tokens(usbuf.emailaddrs, '|'); ++i) {
1634                 extract_token(buf, usbuf.emailaddrs, i, '|', sizeof buf);
1635                 CtdlDirectoryDelUser(buf, requested_user);
1636         }
1637
1638         strcpy(usbuf.emailaddrs, new_emailaddrs);               // make it official.
1639
1640         // Index all of the new email addresses (they've already been sanitized)
1641         for (i=0; i<num_tokens(usbuf.emailaddrs, '|'); ++i) {
1642                 extract_token(buf, usbuf.emailaddrs, i, '|', sizeof buf);
1643                 CtdlDirectoryAddUser(buf, requested_user);
1644         }
1645
1646         CtdlPutUserLock(&usbuf);
1647 }
1648
1649
1650 /*
1651  * Auto-generate an Internet email address for a user account
1652  */
1653 void AutoGenerateEmailAddressForUser(struct ctdluser *user) {
1654         char synthetic_email_addr[1024];
1655         int i, j;
1656         int u = 0;
1657
1658         for (i=0; u==0; ++i) {
1659                 if (i == 0) {
1660                         // first try just converting the user name to lowercase and replacing spaces with underscores
1661                         snprintf(synthetic_email_addr, sizeof synthetic_email_addr, "%s@%s", user->fullname, CtdlGetConfigStr("c_fqdn"));
1662                         for (j=0; ((synthetic_email_addr[j] != '\0')&&(synthetic_email_addr[j] != '@')); j++) {
1663                                 synthetic_email_addr[j] = tolower(synthetic_email_addr[j]);
1664                                 if (!isalnum(synthetic_email_addr[j])) {
1665                                         synthetic_email_addr[j] = '_';
1666                                 }
1667                         }
1668                 }
1669                 else if (i == 1) {
1670                         // then try 'ctdl' followed by the user number
1671                         snprintf(synthetic_email_addr, sizeof synthetic_email_addr, "ctdl%08lx@%s", user->usernum, CtdlGetConfigStr("c_fqdn"));
1672                 }
1673                 else if (i > 1) {
1674                         // oof.  just keep trying other numbers until we find one
1675                         snprintf(synthetic_email_addr, sizeof synthetic_email_addr, "ctdl%08x@%s", i, CtdlGetConfigStr("c_fqdn"));
1676                 }
1677                 u = CtdlDirectoryLookup(NULL, synthetic_email_addr, 0);
1678                 syslog(LOG_DEBUG, "user_ops: address <%s> lookup returned <%d>", synthetic_email_addr, u);
1679         }
1680
1681         CtdlSetEmailAddressesForUser(user->fullname, synthetic_email_addr);
1682         strncpy(CC->user.emailaddrs, synthetic_email_addr, sizeof(user->emailaddrs));
1683         syslog(LOG_DEBUG, "user_ops: auto-generated email address <%s> for <%s>", synthetic_email_addr, user->fullname);
1684 }
1685
1686
1687 // Determine whether the supplied email address is subscribed to the supplied room's mailing list service.
1688 int is_email_subscribed_to_list(char *email, char *room_name) {
1689         struct ctdlroom room;
1690         long roomnum;
1691         char *roomnetconfig;
1692         int found_it = 0;
1693
1694         if (CtdlGetRoom(&room, room_name)) {
1695                 return(0);                                      // room not found, so definitely not subscribed
1696         }
1697
1698         // If this room has the QR2_SMTP_PUBLIC flag set, anyone may email a post to this room, even non-subscribers.
1699         if (room.QRflags2 & QR2_SMTP_PUBLIC) {
1700                 return(1);
1701         }
1702
1703         roomnum = room.QRnumber;
1704         roomnetconfig = LoadRoomNetConfigFile(roomnum);
1705         if (roomnetconfig == NULL) {
1706                 return(0);
1707         }
1708
1709         // We're going to do a very sloppy match here and simply search for the specified email address
1710         // anywhere in the room's netconfig.  If you don't like this, fix it yourself.
1711         if (bmstrcasestr(roomnetconfig, email)) {
1712                 found_it = 1;
1713         }
1714         else {
1715                 found_it = 0;
1716         }
1717
1718         free(roomnetconfig);
1719         return(found_it);
1720 }