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/*
* uid.c -- UIDL handling for POP3 servers without LAST
*
* For license terms, see the file COPYING in this directory.
*/
#include "config.h"
#include <stdio.h>
#include <limits.h>
#if defined(STDC_HEADERS)
#include <stdlib.h>
#include <string.h>
#endif
#if defined(HAVE_UNISTD_H)
#include <unistd.h>
#endif
#include "fetchmail.h"
/*
* Machinery for handling UID lists live here. This is mainly to support
* RFC1725-conformant POP3 servers without a LAST command, but may also be
* useful for making the IMAP4 querying logic UID-oriented, if a future
* revision of IMAP forces me to.
*
* These functions are also used by the rest of the code to maintain
* string lists.
*
* Here's the theory:
*
* At start of a query, we have a (possibly empty) list of UIDs to be
* considered seen in `oldsaved'. These are messages that were left in
* the mailbox and *not deleted* on previous queries (we don't need to
* remember the UIDs of deleted messages because ... well, they're gone!)
* This list is initially set up by initialized_saved_list() from the
* .fetchids file.
*
* Early in the query, during the execution of the protocol-specific
* getrange code, the driver expects that the host's `newsaved' member
* will be filled with a list of UIDs and message numbers representing
* the mailbox state. If this list is empty, the server did
* not respond to the request for a UID listing.
*
* Each time a message is fetched, we can check its UID against the
* `oldsaved' list to see if it is old.
*
* Each time a message-id is seen, we mark it with MARK_SEEN.
*
* Each time a message is deleted, we mark its id UID_DELETED in the
* `newsaved' member. When we want to assert that an expunge has been
* done on the server, we call expunge_uid() to register that all
* deleted messages are gone by marking them UID_EXPUNGED.
*
* At the end of the query, the `newsaved' member becomes the
* `oldsaved' list. The old `oldsaved' list is freed.
*
* At the end of the fetchmail run, seen and non-EXPUNGED members of all
* current `oldsaved' lists are flushed out to the .fetchids file to
* be picked up by the next run. If there are no un-expunged
* messages, the file is deleted.
*
* Note: all comparisons are caseblind!
*/
/* UIDs associated with un-queried hosts */
static struct idlist *scratchlist;
#ifdef POP3_ENABLE
void initialize_saved_lists(struct query *hostlist, const char *idfile)
/* read file of saved IDs and attach to each host */
{
int st;
FILE *tmpfp;
struct query *ctl;
/* make sure lists are initially empty */
for (ctl = hostlist; ctl; ctl = ctl->next)
ctl->oldsaved = ctl->newsaved = (struct idlist *)NULL;
/* let's get stored message UIDs from previous queries */
if ((tmpfp = fopen(idfile, "r")) != (FILE *)NULL) {
char buf[POPBUFSIZE+1],host[HOSTLEN+1],user[USERNAMELEN+1],id[IDLEN+1];
while (fgets(buf, POPBUFSIZE, tmpfp) != (char *)NULL)
{
/* possible lossage here with very old versions of sscanf(3)... */
if ((st = sscanf(buf, "%[^@]@%s %s\n", user, host, id)) == 3)
{
for (ctl = hostlist; ctl; ctl = ctl->next)
{
if (ctl->server.truename &&
strcasecmp(host, ctl->server.truename) == 0
&& strcasecmp(user, ctl->remotename) == 0)
{
save_str(&ctl->oldsaved, UID_KEPT, id);
break;
}
}
/* if it's not in a host we're querying, save it anyway */
if (ctl == (struct query *)NULL)
save_str(&scratchlist, UID_KEPT, buf);
}
}
fclose(tmpfp);
}
}
#endif /* POP3_ENABLE */
struct idlist *save_str(struct idlist **idl, int num, const char *str)
/* save a number/UID pair on the given UID list */
{
struct idlist **end;
/* do it nonrecursively so the list is in the right order */
for (end = idl; *end; end = &(*end)->next)
continue;
*end = (struct idlist *)xmalloc(sizeof(struct idlist));
(*end)->val.num = num;
(*end)->id = str ? xstrdup(str) : (char *)NULL;
(*end)->next = NULL;
return(*end);
}
void free_str_list(struct idlist **idl)
/* free the given UID list */
{
if (*idl == (struct idlist *)NULL)
return;
free_str_list(&(*idl)->next);
free ((*idl)->id);
free(*idl);
*idl = (struct idlist *)NULL;
}
void save_str_pair(struct idlist **idl, const char *str1, const char *str2)
/* save an ID pair on the given list */
{
struct idlist **end;
/* do it nonrecursively so the list is in the right order */
for (end = idl; *end; end = &(*end)->next)
continue;
*end = (struct idlist *)xmalloc(sizeof(struct idlist));
(*end)->id = str1 ? xstrdup(str1) : (char *)NULL;
if (str2)
(*end)->val.id2 = xstrdup(str2);
else
(*end)->val.id2 = (char *)NULL;
(*end)->next = (struct idlist *)NULL;
}
#ifdef __UNUSED__
void free_str_pair_list(struct idlist **idl)
/* free the given ID pair list */
{
if (*idl == (struct idlist *)NULL)
return;
free_idpair_list(&(*idl)->next);
free ((*idl)->id);
free ((*idl)->val.id2);
free(*idl);
*idl = (struct idlist *)NULL;
}
#endif
int str_in_list(struct idlist **idl, const char *str)
/* is a given ID in the given list? (comparison is caseblind) */
{
if (*idl == (struct idlist *)NULL || str == (char *) NULL)
return(0);
else if (strcasecmp(str, (*idl)->id) == 0)
return(1);
else
return(str_in_list(&(*idl)->next, str));
}
int str_nr_in_list( struct idlist **idl, const char *str )
/* return the position of str in idl */
{
int nr;
struct idlist *walk;
if ( !str )
return -1;
for( walk = *idl, nr = 0; walk; nr ++, walk = walk->next )
if( strcasecmp( str, walk->id) == 0 )
return nr;
return -1;
}
int str_nr_last_in_list( struct idlist **idl, const char *str)
/* return the last position of str in idl */
{
int nr, ret = -1;
struct idlist *walk;
if ( !str )
return -1;
for( walk = *idl, nr = 0; walk; nr ++, walk = walk->next )
if( strcasecmp( str, walk->id) == 0 )
ret = nr;
return ret;
}
int count_list( struct idlist **idl)
/* count the number of elements in the list */
{
if( !*idl )
return 0;
return 1 + count_list( &(*idl)->next );
}
char *str_from_nr_list(struct idlist **idl, int number)
/* return the number'th string in idl */
{
if( !*idl || number < 0)
return 0;
if( number == 0 )
return (*idl)->id;
return str_from_nr_list(&(*idl)->next, number-1);
}
char *str_find(struct idlist **idl, int number)
/* return the id of the given number in the given list. */
{
if (*idl == (struct idlist *) 0)
return((char *) 0);
else if (number == (*idl)->val.num)
return((*idl)->id);
else
return(str_find(&(*idl)->next, number));
}
char *idpair_find(struct idlist **idl, const char *id)
/* return the id of the given id in the given list (caseblind comparison) */
{
if (*idl == (struct idlist *) 0)
return((char *) 0);
else if (strcasecmp(id, (*idl)->id) == 0)
return((*idl)->val.id2 ? (*idl)->val.id2 : (*idl)->id);
else
return(idpair_find(&(*idl)->next, id));
}
int delete_str(struct idlist **idl, int num)
/* delete given message from given list */
{
#ifdef HARD_DELETE /* not used */
if (*idl == (struct idlist *)NULL)
return(0);
else if ((*idl)->val.num == num)
{
struct idlist *next = (*idl)->next;
free ((*idl)->id);
free(*idl);
*idl = next;
return(1);
}
else
return(delete_str(&(*idl)->next, num));
#else
struct idlist *idp;
for (idp = *idl; idp; idp = idp->next)
if (idp->val.num == num)
{
idp->val.num = UID_DELETED;
return(1);
}
return(0);
#endif /* HARD_DELETE */
}
void append_str_list(struct idlist **idl, struct idlist **nidl)
/* append nidl to idl (does not copy *) */
{
if ((*idl) == (struct idlist *)NULL)
*idl = *nidl;
else if ((*idl)->next == (struct idlist *)NULL)
(*idl)->next = *nidl;
else if ((*idl)->next != *nidl)
append_str_list(&(*idl)->next, nidl);
}
#ifdef POP3_ENABLE
void expunge_uids(struct query *ctl)
/* assert that all UIDs marked deleted have actually been expunged */
{
struct idlist *idl;
for (idl = ctl->newsaved; idl; idl = idl->next)
if (idl->val.num == UID_DELETED)
idl->val.num = UID_EXPUNGED;
}
void update_str_lists(struct query *ctl)
/* perform end-of-query actions on UID lists */
{
free_str_list(&ctl->oldsaved);
ctl->oldsaved = ctl->newsaved;
ctl->newsaved = (struct idlist *) NULL;
}
void write_saved_lists(struct query *hostlist, const char *idfile)
/* perform end-of-run write of seen-messages list */
{
int idcount;
FILE *tmpfp;
struct query *ctl;
struct idlist *idp;
/* if all lists are empty, nuke the file */
idcount = 0;
for (ctl = hostlist; ctl; ctl = ctl->next) {
if (ctl->oldsaved)
idcount++;
}
/* either nuke the file or write updated last-seen IDs */
if (!idcount)
unlink(idfile);
else
if ((tmpfp = fopen(idfile, "w")) != (FILE *)NULL) {
for (ctl = hostlist; ctl; ctl = ctl->next) {
for (idp = ctl->oldsaved; idp; idp = idp->next)
if (SAVE_UID(idp->val.num))
fprintf(tmpfp, "%s@%s %s\n",
ctl->remotename, ctl->server.truename, idp->id);
}
for (idp = scratchlist; idp; idp = idp->next)
fputs(idp->id, tmpfp);
fclose(tmpfp);
}
}
#endif /* POP3_ENABLE */
/* uid.c ends here */
These are the contents of the former NiCE NeXT User Group NeXTSTEP/OpenStep software archive, currently hosted by Netfuture.ch.