X-Git-Url: http://pileus.org/git/?a=blobdiff_plain;f=uid.c;h=8a775b9c63f48b60997f834f2d0f4f86f92bbe20;hb=f6c7034fdbeb25d7d8eb0e62c0fe5de563eb7b55;hp=01b8999c495934c1de8dba958a7311ebe3a5cc48;hpb=473437ebe5a57fc2d4bfd782ecc004394f339033;p=~andy%2Ffetchmail diff --git a/uid.c b/uid.c index 01b8999c..8a775b9c 100644 --- a/uid.c +++ b/uid.c @@ -1,209 +1,474 @@ -/* Copyright 1993-95 by Carl Harris, Jr. Copyright 1996 by Eric S. Raymond - * All rights reserved. +/** + * \file uid.c -- UIDL handling for POP3 servers without LAST + * * For license terms, see the file COPYING in this directory. */ -/*********************************************************************** - module: uid.c - project: fetchmail - programmer: Eric S. Raymond - description: UID list handling - - ***********************************************************************/ - -#include +#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" +#include "sdump.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. (This would be bad. Server-side - * seen bits are better than UIDs, because they track messages seen by - * *all* clients.) + * RFC1725/RFC1939-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 `already seen'. These are messages that were left in + * 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 set up by initialized_saved_list() from the .fetchids - * file and hangs off the host's `saved' member. + * 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 `listed' member + * 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 current mailbox state. If this list is empty, the server did + * 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 - * `saved' list to see if it is old. If not, it should be downloaded - * (and possibly deleted). It should be downloaded anyway if --all - * is on. It should not be deleted if --keep is on. + * `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. * - * Each time a message is deleted, we remove its id from the `listed' - * member. + * 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. * - * At the end of the query, whatever remains in the `listed' member - * (because it was not deleted) becomes the `saved' list. The old - * `saved' list is freed. + * One disadvantage of UIDL is that all the UIDs have to be downloaded + * before a search for new messages can be done. Typically, new messages + * are appended to mailboxes. Hence, downloading all UIDs just to download + * a few new mails is a waste of bandwidth. If new messages are always at + * the end of the mailbox, fast UIDL will decrease the time required to + * download new mails. + * + * During fast UIDL, the UIDs of all messages are not downloaded! The first + * unseen message is searched for by using a binary search on UIDs. UIDs + * after the first unseen message are downloaded as and when needed. + * + * The advantages of fast UIDL are (this is noticeable only when the + * mailbox has too many mails): + * + * - There is no need to download the UIDs of all mails right at the start. + * - There is no need to save all the UIDs in memory separately in + * `newsaved' list. + * - There is no need to download the UIDs of seen mail (except for the + * first binary search). + * - The first new mail is downloaded considerably faster. + * + * The disadvantages are: + * + * - Since all UIDs are not downloaded, it is not possible to swap old and + * new list. The current state of the mailbox is essentially a merged state + * of old and new mails. + * - If an intermediate mail has been temporarily refused (say, due to 4xx + * code from the smtp server), this mail may not get downloaded. + * - If 'flush' is used, such intermediate mails will also get deleted. + * + * The first two disadvantages can be overcome by doing a linear search + * once in a while (say, every 10th poll). Also, with flush, fast UIDL + * should be disabled. + * + * Note: some comparisons (those used for DNS address lists) are caseblind! */ -/* UIDs associated with un-queried hosts */ +int dofastuidl = 0; + +#ifdef POP3_ENABLE +/** UIDs associated with un-queried hosts */ static struct idlist *scratchlist; -void initialize_saved_lists(hostlist, idfile) -/* read file of saved IDs and attach to each host */ -struct hostrec *hostlist; -char *idfile; +/** Read saved IDs from \a idfile and attach to each host in \a hostlist. */ +void initialize_saved_lists(struct query *hostlist, const char *idfile) { - int st; + struct stat statbuf; FILE *tmpfp; - struct hostrec *hostp; + struct query *ctl; /* make sure lists are initially empty */ - for (hostp = hostlist; hostp; hostp = hostp->next) - hostp->saved = hostp->current = (struct idlist *)NULL; + for (ctl = hostlist; ctl; ctl = ctl->next) { + ctl->skipped = (struct idlist *)NULL; + ctl->oldsaved = (struct idlist *)NULL; + ctl->newsaved = (struct idlist *)NULL; + ctl->oldsavedend = &ctl->oldsaved; + } + + 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], host[HOSTLEN+1], id[IDLEN+1]; + 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) { - if ((st = sscanf(buf, "%s %s\n", host, id)) == 2) + /* + * 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. + * + * this is one other trick. The userhost part + * may contain ' ' in the user part, at least in + * the lotus notes case. + * So we start looking for the '@' after which the + * host will follow with the ' ' separator with the id. + * + * XXX FIXME: There is a case this code cannot handle: + * the user name cannot have blanks after a '@'. + */ + if ((delimp1 = strchr(user, '@')) != NULL && + (id = strchr(delimp1,' ')) != NULL) { - for (hostp = hostlist; hostp; hostp = hostp->next) - { - if (strcmp(host, hostp->servername) == 0) - { - save_uid(&hostp->saved, -1, id); + 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 ?!? */ + /* we have at least one @, else we are not in this branch */ + saveddelim1 = *delimp1; /* save char after token */ + *delimp1 = '\0'; /* delimit token with \0 */ + + /* now remove trailing white space chars from id */ + if ((delimp2 = strpbrk(id, " \t\n")) != NULL ) { + saveddelim2 = *delimp2; + *delimp2 = '\0'; + } + + atsign = strrchr(user, '@'); + /* we have at least one @, else we are not in this branch */ + *atsign = '\0'; + host = atsign + 1; + + /* find proper list and save it */ + for (ctl = hostlist; ctl; ctl = ctl->next) { + if (strcasecmp(host, ctl->server.queryname) == 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. Otherwise we'd lose UIDL + * information any time we queried an explicit + * subset of hosts. + */ + 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 it's not in a host we're querying, save it anyway */ - if (hostp == (struct hostrec *)NULL) - save_uid(&scratchlist, -1, buf); + if (outlevel >= O_DEBUG) + { + struct idlist *idp; + + for (ctl = hostlist; ctl; ctl = ctl->next) + { + report_build(stdout, GT_("Old UID list from %s:"), + ctl->server.pollname); + idp = ctl->oldsaved; + if (!idp) + report_build(stdout, GT_(" ")); + else for (idp = ctl->oldsaved; idp; idp = idp->next) { + char *t = sdump(idp->id, strlen(idp->id)-1); + report_build(stdout, " %s\n", t); + free(t); + } + report_complete(stdout, "\n"); } + + report_build(stdout, GT_("Scratch list of UIDs:")); + if (!scratchlist) + report_build(stdout, GT_(" ")); + else for (idp = scratchlist; idp; idp = idp->next) { + char *t = sdump(idp->id, strlen(idp->id)-1); + report_build(stdout, " %s\n", t); + free(t); } - fclose(tmpfp); + report_complete(stdout, "\n"); } } -void save_uid(idl, num, str) -/* save a number/UID pair on the given UID list */ -struct idlist **idl; -int num; -char *str; +/** Assert that all UIDs marked deleted in query \a ctl have actually been +expunged. */ +void expunge_uids(struct query *ctl) { - struct idlist *new; + struct idlist *idl; - new = (struct idlist *)xmalloc(sizeof(struct idlist)); - new->num = num; - new->id = strdup(str); - new->next = *idl; - *idl = new; + for (idl = dofastuidl ? ctl->oldsaved : ctl->newsaved; idl; idl = idl->next) + if (idl->val.status.mark == UID_DELETED) + idl->val.status.mark = UID_EXPUNGED; } -void free_uid_list(idl) -/* free the given UID list */ -struct idlist **idl; +static const char *str_uidmark(int mark) { - if (*idl == (struct idlist *)NULL) - return; + static char buf[20]; - free_uid_list(&(*idl)->next); - free ((*idl)->id); - free(*idl); - *idl = (struct idlist *)NULL; + switch(mark) { + case UID_UNSEEN: + return "UNSEEN"; + case UID_SEEN: + return "SEEN"; + case UID_EXPUNGED: + return "EXPUNGED"; + case UID_DELETED: + return "DELETED"; + default: + if (snprintf(buf, sizeof(buf), "MARK=%d", mark) < 0) + return "ERROR"; + else + return buf; + } } -int uid_in_list(idl, str) -/* is a given ID in the given list? */ -struct idlist **idl; -char *str; +static void dump_list(const struct idlist *idp) { - if (*idl == (struct idlist *)NULL) - return(0); - else if (strcmp(str, (*idl)->id) == 0) - return(1); - else - return(uid_in_list(&(*idl)->next, str)); + if (!idp) { + report_build(stdout, GT_(" ")); + } else while (idp) { + char *t = sdump(idp->id, strlen(idp->id)); + report_build(stdout, " %s = %s%s", t, str_uidmark(idp->val.status.mark), idp->next ? "," : ""); + free(t); + idp = idp->next; + } } -int delete_uid(idl, str) -/* delete given UID from given list */ -struct idlist **idl; -char *str; +/* finish a query */ +void uid_swap_lists(struct query *ctl) { - if (*idl == (struct idlist *)NULL) - return(0); - else if (strcmp((*idl)->id, str) == 0) + /* debugging code */ + if (outlevel >= O_DEBUG) { - struct idlist *next = (*idl)->next; + if (dofastuidl) { + report_build(stdout, GT_("Merged UID list from %s:"), ctl->server.pollname); + dump_list(ctl->oldsaved); + } else { + report_build(stdout, GT_("New UID list from %s:"), ctl->server.pollname); + dump_list(ctl->newsaved); + } + report_complete(stdout, "\n"); + } - free ((*idl)->id); - free(*idl); - *idl = next; - return(1); + /* + * 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. + * + * Older versions of fetchmail did + * + * free_str_list(&scratchlist); + * + * after swap. This was wrong; we need to preserve the UIDL information + * from unqueried hosts. Unfortunately, not doing this means that + * under some circumstances UIDLs can end up being stored forever -- + * specifically, if a user description is removed from .fetchmailrc + * with UIDLs from that account in .fetchids, there is no way for + * them to ever get garbage-collected. + */ + if (ctl->newsaved) + { + /* old state of mailbox may now be irrelevant */ + struct idlist *temp = ctl->oldsaved; + if (outlevel >= O_DEBUG) + report(stdout, GT_("swapping UID lists\n")); + ctl->oldsaved = ctl->newsaved; + ctl->newsaved = (struct idlist *) NULL; + free_str_list(&temp); } - else - return(delete_uid(&(*idl)->next, str)); - return(0); + /* in fast uidl, there is no need to swap lists: the old state of + * mailbox cannot be discarded! */ + else if (outlevel >= O_DEBUG && !dofastuidl) + report(stdout, GT_("not swapping UID lists, no UIDs seen this query\n")); } -void update_uid_lists(hostp) -/* perform end-of-query actions on UID lists */ -struct hostrec *hostp; +/* finish a query which had errors */ +void uid_discard_new_list(struct query *ctl) { - /* - * Replace `saved' list with `current' list as modified by deletions. - */ - free_uid_list(&hostp->saved); - hostp->saved = hostp->current; + /* debugging code */ + if (outlevel >= O_DEBUG) + { + /* this is now a merged list! the mails which were seen in this + * poll are marked here. */ + report_build(stdout, GT_("Merged UID list from %s:"), ctl->server.pollname); + dump_list(ctl->oldsaved); + report_complete(stdout, "\n"); + } + + if (ctl->newsaved) + { + /* new state of mailbox is not reliable */ + if (outlevel >= O_DEBUG) + report(stdout, GT_("discarding new UID list\n")); + free_str_list(&ctl->newsaved); + ctl->newsaved = (struct idlist *) NULL; + } +} + +/** Reset the number associated with each id */ +void uid_reset_num(struct query *ctl) +{ + struct idlist *idp; + for (idp = ctl->oldsaved; idp; idp = idp->next) + idp->val.status.num = 0; } -void write_saved_lists(hostlist, idfile) -struct hostrec *hostlist; -char *idfile; +/** Write list of seen messages, at end of run. */ +void write_saved_lists(struct query *hostlist, const char *idfile) { - int st, idcount; + long idcount; FILE *tmpfp; - struct hostrec *hostp; + struct query *ctl; struct idlist *idp; /* if all lists are empty, nuke the file */ idcount = 0; - for (hostp = hostlist; hostp; hostp = hostp->next) { - if (hostp->saved) - idcount++; + 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) - unlink(idfile); - else - if ((tmpfp = fopen(idfile, "w")) != (FILE *)NULL) { - for (hostp = hostlist; hostp; hostp = hostp->next) { - for (idp = hostp->saved; idp; idp = idp->next) - fprintf(tmpfp, "%s %s\n", hostp->servername, idp->id); + if (!idcount && !scratchlist) + { + if (outlevel >= O_DEBUG) { + if (access(idfile, F_OK) == 0) + report(stdout, GT_("Deleting fetchids file.\n")); + } + if (unlink(idfile) && errno != ENOENT) + report(stderr, GT_("Error deleting %s: %s\n"), idfile, strerror(errno)); + } else { + char *newnam = (char *)xmalloc(strlen(idfile) + 2); + strcpy(newnam, idfile); + strcat(newnam, "_"); + if (outlevel >= O_DEBUG) + report(stdout, GT_("Writing fetchids file.\n")); + (void)unlink(newnam); /* remove file/link first */ + if ((tmpfp = fopen(newnam, "w")) != (FILE *)NULL) { + int errflg = 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) + if (fprintf(tmpfp, "%s@%s %s\n", + ctl->remotename, ctl->server.queryname, idp->id) < 0) { + int e = errno; + report(stderr, GT_("Write error on fetchids file %s: %s\n"), newnam, strerror(e)); + errflg = 1; + goto bailout; + } } for (idp = scratchlist; idp; idp = idp->next) - fputs(idp->id, tmpfp); + if (EOF == fputs(idp->id, tmpfp)) { + int e = errno; + report(stderr, GT_("Write error on fetchids file %s: %s\n"), newnam, strerror(e)); + errflg = 1; + goto bailout; + } + +bailout: + (void)fflush(tmpfp); /* return code ignored, we check ferror instead */ + errflg |= ferror(tmpfp); fclose(tmpfp); + /* if we could write successfully, move into place; + * otherwise, drop */ + if (errflg) { + report(stderr, GT_("Error writing to fetchids file %s, old file left in place.\n"), newnam); + unlink(newnam); + } else { + if (rename(newnam, idfile)) { + report(stderr, GT_("Cannot rename fetchids file %s to %s: %s\n"), newnam, idfile, strerror(errno)); + } + } + } else { + report(stderr, GT_("Cannot open fetchids file %s for writing: %s\n"), newnam, strerror(errno)); } + free(newnam); + } } +#endif /* POP3_ENABLE */ + +/* uid.c ends here */