/* * uid.c -- UIDL handling for POP3 servers without LAST * * For license terms, see the file COPYING in this directory. */ #include "config.h" #include #include #include #include #if defined(STDC_HEADERS) #include #include #endif #if defined(HAVE_UNISTD_H) #include #endif #include "fetchmail.h" #include "i18n.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 initialize_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: some comparisons (those used for DNS address lists) 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 */ { struct stat statbuf; FILE *tmpfp; struct query *ctl; /* make sure lists are initially empty */ for (ctl = hostlist; ctl; ctl = ctl->next) ctl->skipped = ctl->oldsaved = ctl->newsaved = (struct idlist *)NULL; errno = 0; /* * Croak if the uidl directory does not exist. * This probably means an NFS mount failed and we can't * see a uidl file that ought to be there. * Question: is this a portable check? It's not clear * that all implementations of lstat() will return ENOTDIR * rather than plain ENOENT in this case... */ if (lstat(idfile, &statbuf) < 0) { if (errno == ENOTDIR) { report(stderr, _("lstat: %s: %s\n"), idfile, strerror(errno)); exit(PS_IOERR); } } /* let's get stored message UIDs from previous queries */ if ((tmpfp = fopen(idfile, "r")) != (FILE *)NULL) { char buf[POPBUFSIZE+1]; char *host = NULL; /* pacify -Wall */ char *user; char *id; char *atsign; /* temp pointer used in parsing user and host */ char *delimp1; char saveddelim1; char *delimp2; char saveddelim2 = '\0'; /* pacify -Wall */ while (fgets(buf, POPBUFSIZE, tmpfp) != (char *)NULL) { /* * At this point, we assume the bug has two fields -- a user@host * part, and an ID part. Either field may contain spurious @ signs. * The previous version of this code presumed one could split at * the rightmost '@'. This is not correct, as InterMail puts an * '@' in the UIDL. */ /* first, skip leading spaces */ user = buf + strspn(buf, " \t"); /* * First, we split the buf into a userhost part and an id * part ... but id doesn't necessarily start with a '<', * espescially if the POP server returns an X-UIDL header * instead of a Message-ID, as GMX's (www.gmx.net) POP3 * StreamProxy V1.0 does. */ if ((id = strchr(user, ' ')) != NULL ) { for (delimp1 = id; delimp1 >= user; delimp1--) if ((*delimp1 != ' ') && (*delimp1 != '\t')) break; /* * It should be safe to assume that id starts after * the " " - after all, we're writing the " " * ourselves in write_saved_lists() :-) */ id = id + strspn(id, " "); delimp1++; /* but what if there is only white space ?!? */ saveddelim1 = *delimp1; /* save char after token */ *delimp1 = '\0'; /* delimit token with \0 */ if (id != NULL) { /* now remove trailing white space chars from id */ if ((delimp2 = strpbrk(id, " \t\n")) != NULL ) { saveddelim2 = *delimp2; *delimp2 = '\0'; } atsign = strrchr(user, '@'); if (atsign) { *atsign = '\0'; host = atsign + 1; } 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, id, UID_SEEN); break; } } /* if it's not in a host we're querying, ** save it anyway */ if (ctl == (struct query *)NULL) { /* restore string */ *delimp1 = saveddelim1; *atsign = '@'; if (delimp2 != NULL) { *delimp2 = saveddelim2; } save_str(&scratchlist, buf, UID_SEEN); } } } } fclose(tmpfp); /* not checking should be safe, mode was "r" */ } if (outlevel >= O_DEBUG) { struct idlist *idp; int uidlcount = 0; for (ctl = hostlist; ctl; ctl = ctl->next) if (ctl->server.uidl) { report_build(stdout, _("Old UID list from %s:"), ctl->server.pollname); for (idp = ctl->oldsaved; idp; idp = idp->next) report_build(stdout, " %s", idp->id); if (!idp) report_build(stdout, _(" ")); report_complete(stdout, "\n"); uidlcount++; } if (uidlcount) { report_build(stdout, _("Scratch list of UIDs:")); for (idp = scratchlist; idp; idp = idp->next) report_build(stdout, " %s", idp->id); if (!idp) report_build(stdout, _(" ")); report_complete(stdout, "\n"); } } } #endif /* POP3_ENABLE */ struct idlist *save_str(struct idlist **idl, const char *str, flag status) /* 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.status.mark = status; (*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, const flag caseblind) /* is a given ID in the given list? (comparison may be caseblind) */ { if (*idl == (struct idlist *)NULL || str == (char *) NULL) return(0); else if (!caseblind && strcmp(str, (*idl)->id) == 0) return(1); else if (caseblind && strcasecmp(str, (*idl)->id) == 0) return(1); else return(str_in_list(&(*idl)->next, str, caseblind)); } 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( strcmp( 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( strcmp( str, walk->id) == 0 ) ret = nr; return ret; } void str_set_mark( struct idlist **idl, const char *str, const flag val) /* update the mark on an of an id to given value */ { int nr; struct idlist *walk; if (!str) return; for(walk = *idl, nr = 0; walk; nr ++, walk = walk->next) if (strcmp(str, walk->id) == 0) walk->val.status.mark = val; } 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.status.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 */ { struct idlist *idp; for (idp = *idl; idp; idp = idp->next) if (idp->val.status.num == num) { idp->val.status.mark = UID_DELETED; return(1); } return(0); } struct idlist *copy_str_list(struct idlist *idl) /* copy the given UID list */ { struct idlist *newnode ; if (idl == (struct idlist *)NULL) return(NULL); else { newnode = (struct idlist *)xmalloc(sizeof(struct idlist)); memcpy(newnode, idl, sizeof(struct idlist)); newnode->next = copy_str_list(idl->next); return(newnode); } } void append_str_list(struct idlist **idl, struct idlist **nidl) /* append nidl to idl (does not copy *) */ { if ((*nidl) == (struct idlist *)NULL || *nidl == *idl) return; else 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.status.mark == UID_DELETED) idl->val.status.mark = UID_EXPUNGED; } void uid_swap_lists(struct query *ctl) /* finish a query */ { /* debugging code */ if (ctl->server.uidl && outlevel >= O_DEBUG) { struct idlist *idp; report_build(stdout, _("New UID list from %s:"), ctl->server.pollname); for (idp = ctl->newsaved; idp; idp = idp->next) report_build(stdout, " %s = %d", idp->id, idp->val.status.mark); if (!idp) report_build(stdout, _(" ")); report_complete(stdout, "\n"); } /* * Don't swap UID lists unless we've actually seen UIDLs. * This is necessary in order to keep UIDL information * from being heedlessly deleted later on. */ if (ctl->newsaved) { /* old state of mailbox may now be irrelevant */ if (outlevel >= O_DEBUG) report(stdout, _("swapping UID lists\n")); free_str_list(&ctl->oldsaved); free_str_list(&scratchlist); ctl->oldsaved = ctl->newsaved; ctl->newsaved = (struct idlist *) NULL; } else if (outlevel >= O_DEBUG) report(stdout, _("not swapping UID lists, no UIDs seen this query\n")); } 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) { for (idp = ctl->oldsaved; idp; idp = idp->next) if (idp->val.status.mark == UID_SEEN || idp->val.status.mark == UID_DELETED) idcount++; } /* either nuke the file or write updated last-seen IDs */ if (!idcount && !scratchlist) { if (outlevel >= O_DEBUG) report(stdout, _("Deleting fetchids file.\n")); unlink(idfile); } else { if (outlevel >= O_DEBUG) report(stdout, _("Writing fetchids file.\n")); if ((tmpfp = fopen(idfile, "w")) != (FILE *)NULL) { for (ctl = hostlist; ctl; ctl = ctl->next) { for (idp = ctl->oldsaved; idp; idp = idp->next) if (idp->val.status.mark == UID_SEEN || idp->val.status.mark == UID_DELETED) 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 */