2 * uid.c -- UIDL handling for POP3 servers without LAST
4 * For license terms, see the file COPYING in this directory.
11 #if defined(STDC_HEADERS)
15 #if defined(HAVE_UNISTD_H)
19 #include "fetchmail.h"
22 * Machinery for handling UID lists live here. This is mainly to support
23 * RFC1725-conformant POP3 servers without a LAST command, but may also be
24 * useful for making the IMAP4 querying logic UID-oriented, if a future
25 * revision of IMAP forces me to.
27 * These functions are also used by the rest of the code to maintain
32 * At start of a query, we have a (possibly empty) list of UIDs to be
33 * considered seen in `oldsaved'. These are messages that were left in
34 * the mailbox and *not deleted* on previous queries (we don't need to
35 * remember the UIDs of deleted messages because ... well, they're gone!)
36 * This list is initially set up by initialized_saved_list() from the
39 * Early in the query, during the execution of the protocol-specific
40 * getrange code, the driver expects that the host's `newsaved' member
41 * will be filled with a list of UIDs and message numbers representing
42 * the mailbox state. If this list is empty, the server did
43 * not respond to the request for a UID listing.
45 * Each time a message is fetched, we can check its UID against the
46 * `oldsaved' list to see if it is old.
48 * Each time a message-id is seen, we mark it with MARK_SEEN.
50 * Each time a message is deleted, we mark its id UID_DELETED in the
51 * `newsaved' member. When we want to assert that an expunge has been
52 * done on the server, we call expunge_uid() to register that all
53 * deleted messages are gone by marking them UID_EXPUNGED.
55 * At the end of the query, the `newsaved' member becomes the
56 * `oldsaved' list. The old `oldsaved' list is freed.
58 * At the end of the fetchmail run, seen and non-EXPUNGED members of all
59 * current `oldsaved' lists are flushed out to the .fetchids file to
60 * be picked up by the next run. If there are no un-expunged
61 * messages, the file is deleted.
63 * Note: all comparisons are caseblind!
66 /* UIDs associated with un-queried hosts */
67 static struct idlist *scratchlist;
70 void initialize_saved_lists(struct query *hostlist, const char *idfile)
71 /* read file of saved IDs and attach to each host */
77 /* make sure lists are initially empty */
78 for (ctl = hostlist; ctl; ctl = ctl->next)
79 ctl->oldsaved = ctl->newsaved = (struct idlist *)NULL;
81 /* let's get stored message UIDs from previous queries */
82 if ((tmpfp = fopen(idfile, "r")) != (FILE *)NULL) {
83 char buf[POPBUFSIZE+1],host[HOSTLEN+1],user[USERNAMELEN+1],id[IDLEN+1];
85 while (fgets(buf, POPBUFSIZE, tmpfp) != (char *)NULL)
87 /* possible lossage here with very old versions of sscanf(3)... */
88 if ((st = sscanf(buf, "%[^@]@%s %s\n", user, host, id)) == 3)
90 for (ctl = hostlist; ctl; ctl = ctl->next)
92 if (ctl->server.truename &&
93 strcasecmp(host, ctl->server.truename) == 0
94 && strcasecmp(user, ctl->remotename) == 0)
96 save_str(&ctl->oldsaved, id, UID_SEEN);
101 /* if it's not in a host we're querying, save it anyway */
102 if (ctl == (struct query *)NULL)
103 save_str(&scratchlist, buf, UID_SEEN);
109 #endif /* POP3_ENABLE */
111 struct idlist *save_str(struct idlist **idl, const char *str, flag status)
112 /* save a number/UID pair on the given UID list */
116 /* do it nonrecursively so the list is in the right order */
117 for (end = idl; *end; end = &(*end)->next)
120 *end = (struct idlist *)xmalloc(sizeof(struct idlist));
121 (*end)->val.status.mark = status;
122 (*end)->id = str ? xstrdup(str) : (char *)NULL;
128 void free_str_list(struct idlist **idl)
129 /* free the given UID list */
131 if (*idl == (struct idlist *)NULL)
134 free_str_list(&(*idl)->next);
137 *idl = (struct idlist *)NULL;
140 void save_str_pair(struct idlist **idl, const char *str1, const char *str2)
141 /* save an ID pair on the given list */
145 /* do it nonrecursively so the list is in the right order */
146 for (end = idl; *end; end = &(*end)->next)
149 *end = (struct idlist *)xmalloc(sizeof(struct idlist));
150 (*end)->id = str1 ? xstrdup(str1) : (char *)NULL;
152 (*end)->val.id2 = xstrdup(str2);
154 (*end)->val.id2 = (char *)NULL;
155 (*end)->next = (struct idlist *)NULL;
159 void free_str_pair_list(struct idlist **idl)
160 /* free the given ID pair list */
162 if (*idl == (struct idlist *)NULL)
165 free_idpair_list(&(*idl)->next);
167 free ((*idl)->val.id2);
169 *idl = (struct idlist *)NULL;
173 int str_in_list(struct idlist **idl, const char *str)
174 /* is a given ID in the given list? (comparison is caseblind) */
176 if (*idl == (struct idlist *)NULL || str == (char *) NULL)
178 else if (strcasecmp(str, (*idl)->id) == 0)
181 return(str_in_list(&(*idl)->next, str));
184 int str_nr_in_list( struct idlist **idl, const char *str )
185 /* return the position of str in idl */
191 for( walk = *idl, nr = 0; walk; nr ++, walk = walk->next )
192 if( strcasecmp( str, walk->id) == 0 )
197 int str_nr_last_in_list( struct idlist **idl, const char *str)
198 /* return the last position of str in idl */
204 for( walk = *idl, nr = 0; walk; nr ++, walk = walk->next )
205 if( strcasecmp( str, walk->id) == 0 )
210 int count_list( struct idlist **idl)
211 /* count the number of elements in the list */
215 return 1 + count_list( &(*idl)->next );
218 char *str_from_nr_list(struct idlist **idl, int number)
219 /* return the number'th string in idl */
221 if( !*idl || number < 0)
225 return str_from_nr_list(&(*idl)->next, number-1);
229 char *str_find(struct idlist **idl, int number)
230 /* return the id of the given number in the given list. */
232 if (*idl == (struct idlist *) 0)
234 else if (number == (*idl)->val.status.num)
237 return(str_find(&(*idl)->next, number));
240 char *idpair_find(struct idlist **idl, const char *id)
241 /* return the id of the given id in the given list (caseblind comparison) */
243 if (*idl == (struct idlist *) 0)
245 else if (strcasecmp(id, (*idl)->id) == 0)
246 return((*idl)->val.id2 ? (*idl)->val.id2 : (*idl)->id);
248 return(idpair_find(&(*idl)->next, id));
251 int delete_str(struct idlist **idl, int num)
252 /* delete given message from given list */
256 for (idp = *idl; idp; idp = idp->next)
257 if (idp->val.status.num == num)
259 idp->val.status.mark = UID_DELETED;
265 void append_str_list(struct idlist **idl, struct idlist **nidl)
266 /* append nidl to idl (does not copy *) */
268 if ((*idl) == (struct idlist *)NULL)
270 else if ((*idl)->next == (struct idlist *)NULL)
271 (*idl)->next = *nidl;
272 else if ((*idl)->next != *nidl)
273 append_str_list(&(*idl)->next, nidl);
277 void expunge_uids(struct query *ctl)
278 /* assert that all UIDs marked deleted have actually been expunged */
282 for (idl = ctl->newsaved; idl; idl = idl->next)
283 if (idl->val.status.mark == UID_DELETED)
284 idl->val.status.mark = UID_EXPUNGED;
287 void update_str_lists(struct query *ctl)
288 /* perform end-of-query actions on UID lists */
290 free_str_list(&ctl->oldsaved);
291 ctl->oldsaved = ctl->newsaved;
292 ctl->newsaved = (struct idlist *) NULL;
295 void write_saved_lists(struct query *hostlist, const char *idfile)
296 /* perform end-of-run write of seen-messages list */
303 /* if all lists are empty, nuke the file */
305 for (ctl = hostlist; ctl; ctl = ctl->next) {
310 /* either nuke the file or write updated last-seen IDs */
314 if ((tmpfp = fopen(idfile, "w")) != (FILE *)NULL) {
315 for (ctl = hostlist; ctl; ctl = ctl->next) {
316 for (idp = ctl->oldsaved; idp; idp = idp->next)
317 if (idp->val.status.mark == UID_SEEN
318 || idp->val.status.mark == UID_DELETED)
319 fprintf(tmpfp, "%s@%s %s\n",
320 ctl->remotename, ctl->server.truename, idp->id);
322 for (idp = scratchlist; idp; idp = idp->next)
323 fputs(idp->id, tmpfp);
327 #endif /* POP3_ENABLE */
329 /* uid.c ends here */