X-Git-Url: http://pileus.org/git/?a=blobdiff_plain;f=imap.c;h=cb87eda5378f258f20955c3524f2f84c6d29cd0e;hb=d31db10231e9ed89f64fdf6e0fb7cae182aa377e;hp=7440abb09529717b28a3b27337006649a2343320;hpb=2cabbf89f9f696a4786476a4eda7a59a1c16d486;p=~andy%2Ffetchmail diff --git a/imap.c b/imap.c index 7440abb0..cb87eda5 100644 --- a/imap.c +++ b/imap.c @@ -8,6 +8,7 @@ #include "config.h" #include #include +#include #include #if defined(STDC_HEADERS) #include @@ -24,16 +25,161 @@ #define IMAP4 0 /* IMAP4 rev 0, RFC1730 */ #define IMAP4rev1 1 /* IMAP4 rev 1, RFC2060 */ -static int count = 0, recentcount = 0, unseen = 0, deletions = 0; -static int recentcount_ok = 0; -static unsigned int startcount = 1; -static int expunged, expunge_period, saved_timeout = 0; -static int imap_version, preauth; -static flag do_idle, has_idle; +/* global variables: please reinitialize them explicitly for proper + * working in daemon mode */ + +/* TODO: session variables to be initialized before server greeting */ +static int preauth = FALSE; + +/* session variables initialized in capa_probe() or imap_getauth() */ static char capabilities[MSGBUFSIZE+1]; +static int imap_version = IMAP4; +static flag do_idle = FALSE, has_idle = FALSE; +static int expunge_period = 1; + +/* mailbox variables initialized in imap_getrange() */ +static int count = 0, oldcount = 0, recentcount = 0, unseen = 0, deletions = 0; +static unsigned int startcount = 1; +static int expunged = 0; static unsigned int *unseen_messages; -static int imap_ok(int sock, char *argbuf) +/* for "IMAP> EXPUNGE" */ +static int actual_deletions = 0; + +/* for "IMAP> IDLE" */ +static int saved_timeout = 0, idle_timeout = 0; +static time_t idle_start_time = 0; + +static int imap_untagged_response(int sock, const char *buf) +/* interpret untagged status responses */ +{ + /* For each individual check, use a BLANK before the word to avoid + * confusion with the \Recent flag or similar */ + if (stage == STAGE_GETAUTH + && !strncmp(buf, "* CAPABILITY", 12)) + { + strlcpy(capabilities, buf + 12, sizeof(capabilities)); + } + else if (stage == STAGE_GETAUTH + && !strncmp(buf, "* PREAUTH", 9)) + { + preauth = TRUE; + } + else if (stage != STAGE_LOGOUT + && !strncmp(buf, "* BYE", 5)) + { + /* log the unexpected bye from server as we expect the + * connection to be cut-off after this */ + if (outlevel > O_SILENT) + report(stderr, GT_("Received BYE response from IMAP server: %s"), buf + 5); + } + else if (strstr(buf, " EXISTS")) + { + char *t; unsigned long u; + errno = 0; + u = strtoul(buf+2, &t, 10); + /* + * Don't trust the message count passed by the server. + * Without this check, it might be possible to do a + * DNS-spoofing attack that would pass back a ridiculous + * count, and allocate a malloc area that would overlap + * a portion of the stack. + */ + if (errno /* strtoul failed */ + || t == buf+2 /* no valid data */ + || u > (unsigned long)(INT_MAX/sizeof(int)) /* too large */) + { + report(stderr, GT_("bogus message count in \"%s\"!"), buf); + return(PS_PROTOCOL); + } + count = u; /* safe as long as count <= INT_MAX - checked above */ + + if ((recentcount = count - oldcount) < 0) + recentcount = 0; + + /* + * Nasty kluge to handle RFC2177 IDLE. If we know we're idling + * we can't wait for the tag matching the IDLE; we have to tell the + * server the IDLE is finished by shipping back a DONE when we + * see an EXISTS. Only after that will a tagged response be + * shipped. The idling flag also gets cleared on a timeout. + */ + if (stage == STAGE_IDLE) + { + /* If IDLE isn't supported, we were only sending NOOPs anyway. */ + if (has_idle) + { + /* we do our own write and report here to disable tagging */ + SockWrite(sock, "DONE\r\n", 6); + if (outlevel >= O_MONITOR) + report(stdout, "IMAP> DONE\n"); + } + + mytimeout = saved_timeout; + stage = STAGE_GETRANGE; + } + } + /* we now compute recentcount as a difference between + * new and old EXISTS, hence disable RECENT check */ +# if 0 + else if (strstr(buf, " RECENT")) + { + /* fixme: use strto[u]l and error checking */ + recentcount = atoi(buf+2); + } +# endif + else if (strstr(buf, " EXPUNGE")) + { + unsigned long u; char *t; + /* the response "* 10 EXPUNGE" means that the currently + * tenth (i.e. only one) message has been deleted */ + errno = 0; + u = strtoul(buf+2, &t, 10); + if (errno /* conversion error */ || t == buf+2 /* no number found */) { + report(stderr, GT_("bogus EXPUNGE count in \"%s\"!"), buf); + return PS_PROTOCOL; + } + if (u > 0) + { + if (count > 0) + count--; + if (oldcount > 0) + oldcount--; + /* We do expect an EXISTS response immediately + * after this, so this updation of recentcount is + * just a precaution! */ + if ((recentcount = count - oldcount) < 0) + recentcount = 0; + actual_deletions++; + } + } + /* + * The server may decide to make the mailbox read-only, + * which causes fetchmail to go into a endless loop + * fetching the same message over and over again. + * + * However, for check_only, we use EXAMINE which will + * mark the mailbox read-only as per the RFC. + * + * This checks for the condition and aborts if + * the mailbox is read-only. + * + * See RFC 2060 section 6.3.1 (SELECT). + * See RFC 2060 section 6.3.2 (EXAMINE). + */ + else if (stage == STAGE_GETRANGE + && !check_only && strstr(buf, "[READ-ONLY]")) + { + return(PS_LOCKBUSY); + } + else + { + return(PS_UNTAGGED); + } + return(PS_SUCCESS); +} + +static int imap_response(int sock, char *argbuf, struct RecvSplit *rs) /* parse command response */ { char buf[MSGBUFSIZE+1]; @@ -42,7 +188,11 @@ static int imap_ok(int sock, char *argbuf) int ok; char *cp; - if ((ok = gen_recv(sock, buf, sizeof(buf)))) + if (rs) + ok = gen_recv_split(sock, buf, sizeof(buf), rs); + else + ok = gen_recv(sock, buf, sizeof(buf)); + if (ok != PS_SUCCESS) return(ok); /* all tokens in responses are caseblind */ @@ -50,79 +200,33 @@ static int imap_ok(int sock, char *argbuf) if (islower((unsigned char)*cp)) *cp = toupper((unsigned char)*cp); - /* interpret untagged status responses */ - if (strstr(buf, "* CAPABILITY")) - { - strlcpy(capabilities, buf + 12, sizeof(capabilities)); - } - else if (strstr(buf, "EXISTS")) - { - count = atoi(buf+2); - /* - * Don't trust the message count passed by the server. - * Without this check, it might be possible to do a - * DNS-spoofing attack that would pass back a ridiculous - * count, and allocate a malloc area that would overlap - * a portion of the stack. - */ - if (count > INT_MAX/sizeof(int)) - { - report(stderr, GT_("bogus message count!")); - return(PS_PROTOCOL); - } - - /* - * Nasty kluge to handle RFC2177 IDLE. If we know we're idling - * we can't wait for the tag matching the IDLE; we have to tell the - * server the IDLE is finished by shipping back a DONE when we - * see an EXISTS. Only after that will a tagged response be - * shipped. The idling flag also gets cleared on a timeout. - */ - if (stage == STAGE_IDLE) + /* untagged responses start with "* " */ + if (buf[0] == '*' && buf[1] == ' ') { + ok = imap_untagged_response(sock, buf); + if (ok == PS_UNTAGGED) { - /* If IDLE isn't supported, we were only sending NOOPs anyway. */ - if (has_idle) + if (argbuf && stage != STAGE_IDLE && tag[0] != '\0') { - /* we do our own write and report here to disable tagging */ - SockWrite(sock, "DONE\r\n", 6); - if (outlevel >= O_MONITOR) - report(stdout, "IMAP> DONE\n"); + /* if there is an unmatched response, pass it back to + * the calling function for further analysis. The + * calling function should call imap_response() again + * to read the remaining response */ + strcpy(argbuf, buf); + return(ok); } - - mytimeout = saved_timeout; - stage = STAGE_FETCH; } + else if (ok != PS_SUCCESS) + return(ok); } - /* a space is required to avoid confusion with the \Recent flag */ - else if (strstr(buf, " RECENT")) + + if (stage == STAGE_IDLE) { - recentcount_ok = 1; - recentcount = atoi(buf+2); + /* reduce the timeout: servers may not reset their timeout + * when they send some information asynchronously */ + mytimeout = idle_timeout - (time((time_t *) NULL) - idle_start_time); + if (mytimeout <= 0) + return(PS_IDLETIMEOUT); } - else if (strstr(buf, "EXPUNGE") && !strstr(buf, "OK")) - { - count -= atoi(buf+2); - if (count < 0) - count = 0; - } - else if (strstr(buf, "PREAUTH")) - preauth = TRUE; - /* - * The server may decide to make the mailbox read-only, - * which causes fetchmail to go into a endless loop - * fetching the same message over and over again. - * - * However, for check_only, we use EXAMINE which will - * mark the mailbox read-only as per the RFC. - * - * This checks for the condition and aborts if - * the mailbox is read-only. - * - * See RFC 2060 section 6.3.1 (SELECT). - * See RFC 2060 section 6.3.2 (EXAMINE). - */ - else if (!check_only && strstr(buf, "[READ-ONLY]")) - return(PS_LOCKBUSY); } while (tag[0] != '\0' && strncmp(buf, tag, strlen(tag))); @@ -154,6 +258,8 @@ static int imap_ok(int sock, char *argbuf) { if (stage == STAGE_GETAUTH) return(PS_AUTHFAIL); /* RFC2060, 6.2.2 */ + else if (stage == STAGE_GETSIZES) + return(PS_SUCCESS); /* see comments in imap_getpartialsizes() */ else return(PS_ERROR); } @@ -162,13 +268,19 @@ static int imap_ok(int sock, char *argbuf) } } +static int imap_ok(int sock, char *argbuf) +/* parse command response */ +{ + int ok; + + while ((ok = imap_response(sock, argbuf, NULL)) == PS_UNTAGGED) + ; /* wait for the tagged response */ + return(ok); +} + #ifdef NTLM_ENABLE #include "ntlm.h" -static tSmbNtlmAuthRequest request; -static tSmbNtlmAuthChallenge challenge; -static tSmbNtlmAuthResponse response; - /* * NTLM support by Grant Edwards. * @@ -182,67 +294,25 @@ static tSmbNtlmAuthResponse response; static int do_imap_ntlm(int sock, struct query *ctl) { - char msgbuf[2048]; - int result,len; + int result; gen_send(sock, "AUTHENTICATE NTLM"); - if ((result = gen_recv(sock, msgbuf, sizeof msgbuf))) - return result; - - if (msgbuf[0] != '+') - return PS_AUTHFAIL; - - buildSmbNtlmAuthRequest(&request,ctl->remotename,NULL); - - if (outlevel >= O_DEBUG) - dumpSmbNtlmAuthRequest(stdout, &request); - - memset(msgbuf,0,sizeof msgbuf); - to64frombits (msgbuf, (unsigned char*)&request, SmbLength(&request)); - - if (outlevel >= O_MONITOR) - report(stdout, "IMAP> %s\n", msgbuf); - - strcat(msgbuf,"\r\n"); - SockWrite (sock, msgbuf, strlen (msgbuf)); - - if ((gen_recv(sock, msgbuf, sizeof msgbuf))) - return result; - - len = from64tobits ((char*)&challenge, msgbuf, sizeof(challenge)); - - if (outlevel >= O_DEBUG) - dumpSmbNtlmAuthChallenge(stdout, &challenge); - - buildSmbNtlmAuthResponse(&challenge, &response,ctl->remotename,ctl->password); - - if (outlevel >= O_DEBUG) - dumpSmbNtlmAuthResponse(stdout, &response); - - memset(msgbuf,0,sizeof msgbuf); - to64frombits (msgbuf, (unsigned char*)&response, SmbLength(&response)); - - if (outlevel >= O_MONITOR) - report(stdout, "IMAP> %s\n", msgbuf); - - strcat(msgbuf,"\r\n"); - SockWrite (sock, msgbuf, strlen (msgbuf)); - - if ((result = gen_recv (sock, msgbuf, sizeof msgbuf))) + if ((result = ntlm_helper(sock, ctl, "IMAP"))) return result; - - if (strstr (msgbuf, "OK")) + + result = imap_ok (sock, NULL); + if (result == PS_SUCCESS) return PS_SUCCESS; else return PS_AUTHFAIL; } #endif /* NTLM */ -static int imap_canonicalize(char *result, char *raw, int maxlen) +static void imap_canonicalize(char *result, char *raw, size_t maxlen) /* encode an IMAP password as per RFC1730's quoting conventions */ { - int i, j; + size_t i, j; j = 0; for (i = 0; i < strlen(raw) && i < maxlen; i++) @@ -252,11 +322,9 @@ static int imap_canonicalize(char *result, char *raw, int maxlen) result[j++] = raw[i]; } result[j] = '\0'; - - return(i); } -static void capa_probe(int sock, struct query *ctl) +static int capa_probe(int sock, struct query *ctl) /* set capability variables from a CAPA probe */ { int ok; @@ -269,7 +337,7 @@ static void capa_probe(int sock, struct query *ctl) /* capability checks are supposed to be caseblind */ for (cp = capabilities; *cp; cp++) - *cp = toupper(*cp); + *cp = toupper((unsigned char)*cp); /* UW-IMAP server 10.173 notifies in all caps, but RFC2060 says we should expect a response in mixed-case */ @@ -292,32 +360,52 @@ static void capa_probe(int sock, struct query *ctl) if (outlevel >= O_DEBUG) report(stdout, GT_("Protocol identified as IMAP2 or IMAP2BIS\n")); } + else + return ok; /* * Handle idling. We depend on coming through here on startup * and after each timeout (including timeouts during idles). */ + do_idle = ctl->idle; if (ctl->idle) { - do_idle = TRUE; if (strstr(capabilities, "IDLE")) - { has_idle = TRUE; - } + else + has_idle = FALSE; if (outlevel >= O_VERBOSE) report(stdout, GT_("will idle after poll\n")); } peek_capable = (imap_version >= IMAP4); + + return PS_SUCCESS; +} + +static int do_authcert (int sock, const char *command, const char *name) +/* do authentication "external" (authentication provided by client cert) */ +{ + char buf[256]; + + if (name && name[0]) + { + size_t len = strlen(name); + if ((len / 3) + ((len % 3) ? 4 : 0) < sizeof(buf)) + to64frombits (buf, name, strlen(name)); + else + return PS_AUTHFAIL; /* buffer too small. */ + } + else + buf[0]=0; + return gen_transact(sock, "%s EXTERNAL %s",command,buf); } static int imap_getauth(int sock, struct query *ctl, char *greeting) /* apply for connection authorization */ { int ok = 0; -#ifdef SSL_ENABLE - flag did_stls = FALSE; -#endif /* SSL_ENABLE */ + (void)greeting; /* * Assumption: expunges are cheap, so we want to do them @@ -328,7 +416,8 @@ static int imap_getauth(int sock, struct query *ctl, char *greeting) else expunge_period = 1; - capa_probe(sock, ctl); + if ((ok = capa_probe(sock, ctl))) + return ok; /* * If either (a) we saw a PREAUTH token in the greeting, or @@ -341,44 +430,68 @@ static int imap_getauth(int sock, struct query *ctl, char *greeting) } #ifdef SSL_ENABLE - if ((!ctl->sslproto || !strcmp(ctl->sslproto,"tls1")) - && !ctl->use_ssl - && strstr(capabilities, "STARTTLS")) - { - char *realhost; - - realhost = ctl->server.via ? ctl->server.via : ctl->server.pollname; - ok = gen_transact(sock, "STARTTLS"); - - /* We use "tls1" instead of ctl->sslproto, as we want STARTTLS, - * not other SSL protocols - */ - if (ok == PS_SUCCESS && - SSLOpen(sock,ctl->sslcert,ctl->sslkey,"tls1",ctl->sslcertck, ctl->sslcertpath,ctl->sslfingerprint,realhost,ctl->server.pollname) == -1) - { - if (!ctl->sslproto && !ctl->wehaveauthed) - { - ctl->sslproto = xstrdup(""); - /* repoll immediately */ - return(PS_REPOLL); - } - report(stderr, - GT_("SSL connection failed.\n")); - return(PS_AUTHFAIL); - } - did_stls = TRUE; - - /* - * RFC 2595 says this: - * - * "Once TLS has been started, the client MUST discard cached - * information about server capabilities and SHOULD re-issue the - * CAPABILITY command. This is necessary to protect against - * man-in-the-middle attacks which alter the capabilities list prior - * to STARTTLS. The server MAY advertise different capabilities - * after STARTTLS." - */ - capa_probe(sock, ctl); + if (maybe_tls(ctl)) { + char *commonname; + + commonname = ctl->server.pollname; + if (ctl->server.via) + commonname = ctl->server.via; + if (ctl->sslcommonname) + commonname = ctl->sslcommonname; + + if (strstr(capabilities, "STARTTLS") + || must_tls(ctl)) /* if TLS is mandatory, ignore capabilities */ + { + /* Use "tls1" rather than ctl->sslproto because tls1 is the only + * protocol that will work with STARTTLS. Don't need to worry + * whether TLS is mandatory or opportunistic unless SSLOpen() fails + * (see below). */ + if (gen_transact(sock, "STARTTLS") == PS_SUCCESS + && (set_timeout(mytimeout), SSLOpen(sock, ctl->sslcert, ctl->sslkey, "tls1", ctl->sslcertck, + ctl->sslcertfile, ctl->sslcertpath, ctl->sslfingerprint, commonname, + ctl->server.pollname, &ctl->remotename)) != -1) + { + /* + * RFC 2595 says this: + * + * "Once TLS has been started, the client MUST discard cached + * information about server capabilities and SHOULD re-issue the + * CAPABILITY command. This is necessary to protect against + * man-in-the-middle attacks which alter the capabilities list prior + * to STARTTLS. The server MAY advertise different capabilities + * after STARTTLS." + * + * Now that we're confident in our TLS connection we can + * guarantee a secure capability re-probe. + */ + if ((ok = capa_probe(sock, ctl))) + return ok; + if (outlevel >= O_VERBOSE) + { + report(stdout, GT_("%s: upgrade to TLS succeeded.\n"), commonname); + } + } else if (must_tls(ctl)) { + /* Config required TLS but we couldn't guarantee it, so we must + * stop. */ + set_timeout(0); + report(stderr, GT_("%s: upgrade to TLS failed.\n"), commonname); + return PS_SOCKET; + } else { + set_timeout(0); + if (outlevel >= O_VERBOSE) { + report(stdout, GT_("%s: opportunistic upgrade to TLS failed, trying to continue\n"), commonname); + } + /* We don't know whether the connection is in a working state, so + * test by issuing a NOOP. */ + if (gen_transact(sock, "NOOP") != PS_SUCCESS) { + /* Not usable. Empty sslproto to force an unencrypted + * connection on the next attempt, and repoll. */ + ctl->sslproto = xstrdup(""); + return PS_REPOLL; + } + /* Usable. Proceed with authenticating insecurely. */ + } + } } #endif /* SSL_ENABLE */ @@ -388,19 +501,45 @@ static int imap_getauth(int sock, struct query *ctl, char *greeting) */ ok = PS_AUTHFAIL; -#ifdef GSSAPI + /* Yahoo hack - we'll just try ID if it was offered by the server, + * and IGNORE errors. */ + { + char *tmp = strstr(capabilities, " ID"); + if (tmp && !isalnum((unsigned char)tmp[3]) && strstr(ctl->server.via ? ctl->server.via : ctl->server.pollname, "yahoo.com")) { + (void)gen_transact(sock, "ID (\"guid\" \"1\")"); + } + } + if ((ctl->server.authenticate == A_ANY + || ctl->server.authenticate == A_EXTERNAL) + && strstr(capabilities, "AUTH=EXTERNAL")) + { + ok = do_authcert(sock, "AUTHENTICATE", ctl->remotename); + if (ok) + { + /* SASL cancellation of authentication */ + gen_send(sock, "*"); + if (ctl->server.authenticate != A_ANY) + return ok; + } else { + return ok; + } + } + +#ifdef GSSAPI + if (((ctl->server.authenticate == A_ANY && check_gss_creds("imap", ctl->server.truename) == PS_SUCCESS) || ctl->server.authenticate == A_GSSAPI) && strstr(capabilities, "AUTH=GSSAPI")) - if(ok = do_gssauth(sock, "AUTHENTICATE", "imap", ctl->server.truename, ctl->remotename)) + { + if ((ok = do_gssauth(sock, "AUTHENTICATE", "imap", + ctl->server.truename, ctl->remotename))) { - /* SASL cancellation of authentication */ - gen_send(sock, "*"); - if(ctl->server.authenticate != A_ANY) + if (ctl->server.authenticate != A_ANY) return ok; - } - else + } else { return ok; + } + } #endif /* GSSAPI */ #ifdef KERBEROS_V4 @@ -431,8 +570,6 @@ static int imap_getauth(int sock, struct query *ctl, char *greeting) { if ((ok = do_cram_md5 (sock, "AUTHENTICATE", ctl, NULL))) { - /* SASL cancellation of authentication */ - gen_send(sock, "*"); if(ctl->server.authenticate != A_ANY) return ok; } @@ -468,8 +605,6 @@ static int imap_getauth(int sock, struct query *ctl, char *greeting) && strstr (capabilities, "AUTH=NTLM")) { if ((ok = do_imap_ntlm(sock, ctl))) { - /* SASL cancellation of authentication */ - gen_send(sock, "*"); if(ctl->server.authenticate != A_ANY) return ok; } @@ -508,31 +643,21 @@ static int imap_getauth(int sock, struct query *ctl, char *greeting) size_t rnl, pwl; rnl = 2 * strlen(ctl->remotename) + 1; pwl = 2 * strlen(ctl->password) + 1; - remotename = xmalloc(rnl); - password = xmalloc(pwl); + remotename = (char *)xmalloc(rnl); + password = (char *)xmalloc(pwl); imap_canonicalize(remotename, ctl->remotename, rnl); imap_canonicalize(password, ctl->password, pwl); snprintf(shroud, sizeof (shroud), "\"%s\"", password); ok = gen_transact(sock, "LOGIN \"%s\" \"%s\"", remotename, password); + memset(shroud, 0x55, sizeof(shroud)); shroud[0] = '\0'; + memset(password, 0x55, strlen(password)); free(password); free(remotename); -#ifdef SSL_ENABLE - /* this is for servers which claim to support TLS, but actually - * don't! */ - if (did_stls && ok == PS_SOCKET && !ctl->sslproto && !ctl->wehaveauthed) - { - ctl->sslproto = xstrdup(""); - /* repoll immediately */ - ok = PS_REPOLL; - } -#endif if (ok) { - /* SASL cancellation of authentication */ - gen_send(sock, "*"); if(ctl->server.authenticate != A_ANY) return ok; } @@ -548,15 +673,26 @@ static int internal_expunge(int sock) { int ok; - recentcount_ok = 0; + actual_deletions = 0; if ((ok = gen_transact(sock, "EXPUNGE"))) return(ok); - /* some servers do not report RECENT after an EXPUNGE. in this case, - * the previous value of recentcount is just ignored. */ - if (!recentcount_ok) - recentcount = 0; + /* if there is a mismatch between the number of mails which should + * have been expunged and the number of mails actually expunged, + * another email client may be deleting mails. Quit here, + * otherwise fetchmail gets out-of-sync with the imap server, + * reports the wrong size to the SMTP server on MAIL FROM: and + * triggers a "message ... was not the expected length" error on + * every subsequent mail */ + if (deletions > 0 && deletions != actual_deletions) + { + report(stderr, + GT_("mail expunge mismatch (%d actual != %d expected)\n"), + actual_deletions, deletions); + deletions = 0; + return(PS_ERROR); + } expunged += deletions; deletions = 0; @@ -573,14 +709,15 @@ static int imap_idle(int sock) { int ok; - stage = STAGE_IDLE; saved_timeout = mytimeout; if (has_idle) { /* special timeout to terminate the IDLE and re-issue it * at least every 28 minutes: * (the server may have an inactivity timeout) */ - mytimeout = 1680; /* 28 min */ + mytimeout = idle_timeout = 1680; /* 28 min */ + time(&idle_start_time); + stage = STAGE_IDLE; /* enter IDLE mode */ ok = gen_transact(sock, "IDLE"); @@ -589,37 +726,151 @@ static int imap_idle(int sock) SockWrite(sock, "DONE\r\n", 6); if (outlevel >= O_MONITOR) report(stdout, "IMAP> DONE\n"); - } else - /* not idle timeout */ - return ok; + /* reset stage and timeout here: we are not idling any more */ + mytimeout = saved_timeout; + stage = STAGE_GETRANGE; + /* get OK IDLE message */ + ok = imap_ok(sock, NULL); + } } else { /* no idle support, fake it */ - /* when faking an idle, we can't assume the server will - * send us the new messages out of the blue (RFC2060); - * this timeout is potentially the delay before we notice - * new mail (can be small since NOOP checking is cheap) */ - mytimeout = 28; + /* Note: stage and timeout have not been changed here as NOOP + * does not idle */ ok = gen_transact(sock, "NOOP"); - /* if there's an error (not likely) or we just found mail (stage - * has changed, timeout has also been restored), we're done */ - if (ok != 0 || stage != STAGE_IDLE) - return(ok); - /* wait (briefly) for an unsolicited status update */ - ok = imap_ok(sock, NULL); - /* again, this is new mail or an error */ - if (ok != PS_IDLETIMEOUT) - return(ok); + /* no error, but no new mail either */ + if (ok == PS_SUCCESS && recentcount == 0) + { + /* There are some servers who do send new mail + * notification out of the blue. This is in compliance + * with RFC 2060 section 5.3. Wait for that with a low + * timeout */ + mytimeout = idle_timeout = 28; + time(&idle_start_time); + stage = STAGE_IDLE; + /* We are waiting for notification; no tag needed */ + tag[0] = '\0'; + /* wait (briefly) for an unsolicited status update */ + ok = imap_ok(sock, NULL); + if (ok == PS_IDLETIMEOUT) { + /* no notification came; ok */ + ok = PS_SUCCESS; + } + } } /* restore normal timeout value */ + set_timeout(0); mytimeout = saved_timeout; - stage = STAGE_FETCH; + stage = STAGE_GETRANGE; - /* get OK IDLE message */ - if (has_idle) - return imap_ok(sock, NULL); + return(ok); +} - return PS_SUCCESS; +static int imap_search(int sock, struct query *ctl, int count) +/* search for unseen messages */ +{ + int ok; + char buf[MSGBUFSIZE+1], *cp; + + /* Don't count deleted messages. Enabled only for IMAP4 servers or + * higher and only when keeping mails. This flag will have an + * effect only when user has marked some unread mails for deletion + * using another e-mail client. */ + flag skipdeleted = (imap_version >= IMAP4) && ctl->keep; + const char *undeleted; + + /* structure to keep the end portion of the incomplete response */ + struct RecvSplit rs; + + /* startcount is higher than count so that if there are no + * unseen messages, imap_getsizes() will not need to do + * anything! */ + startcount = count + 1; + + for (;;) + { + undeleted = (skipdeleted ? " UNDELETED" : ""); + gen_send(sock, "SEARCH UNSEEN%s", undeleted); + gen_recv_split_init("* SEARCH", &rs); + while ((ok = imap_response(sock, buf, &rs)) == PS_UNTAGGED) + { + if ((cp = strstr(buf, "* SEARCH"))) + { + char *ep; + + cp += 8; /* skip "* SEARCH" */ + while (*cp && unseen < count) + { + /* skip whitespace */ + while (*cp && isspace((unsigned char)*cp)) + cp++; + if (*cp) + { + unsigned long um; + + errno = 0; + um = strtoul(cp,&ep,10); + if (errno == 0 && ep > cp + && um <= INT_MAX && um <= (unsigned)count) + { + unseen_messages[unseen++] = um; + if (outlevel >= O_DEBUG) + report(stdout, GT_("%lu is unseen\n"), um); + if (startcount > um) + startcount = um; + } + cp = ep; + } + } + } + } + if (ok != PS_ERROR) /* success or non-protocol error */ + return(ok); + + /* there is a protocol error. try a different search command. */ + if (skipdeleted) + { + /* retry with "SEARCH UNSEEN" */ + skipdeleted = FALSE; + continue; + } + /* try with "FETCH 1:n FLAGS" */ + break; + } + + if (count == 1) + gen_send(sock, "FETCH %d FLAGS", count); + else + gen_send(sock, "FETCH %d:%d FLAGS", 1, count); + while ((ok = imap_response(sock, buf, NULL)) == PS_UNTAGGED) + { + unsigned int num; + int consumed; + + /* expected response format: + * IMAP< * 1 FETCH (FLAGS (\Seen)) + * IMAP< * 2 FETCH (FLAGS (\Seen \Deleted)) + * IMAP< * 3 FETCH (FLAGS ()) + * IMAP< * 4 FETCH (FLAGS (\Recent)) + * IMAP< * 5 FETCH (UID 10 FLAGS (\Recent)) + */ + if (unseen < count + && sscanf(buf, "* %u %n", &num, &consumed) == 1 + && 0 == strncasecmp(buf+consumed, "FETCH", 5) + && isspace((unsigned char)buf[consumed+5]) + && num >= 1 && num <= (unsigned)count + && strstr(buf, "FLAGS ") + && !strstr(buf, "\\SEEN") + && !strstr(buf, "\\DELETED")) + { + unseen_messages[unseen++] = num; + if (outlevel >= O_DEBUG) + report(stdout, GT_("%u is unseen\n"), num); + if (startcount > num) + startcount = num; + } + } + return(ok); } static int imap_getrange(int sock, @@ -629,36 +880,20 @@ static int imap_getrange(int sock, /* get range of messages to be fetched */ { int ok; - char buf[MSGBUFSIZE+1], *cp; /* find out how many messages are waiting */ *bytes = -1; if (pass > 1) { - /* - * We have to have an expunge here, otherwise the re-poll will - * infinite-loop picking up un-expunged messages -- unless the - * expunge period is one and we've been nuking each message - * just after deletion. - */ - ok = 0; - if (deletions) { - ok = internal_expunge(sock); - if (ok) - { - report(stderr, GT_("expunge failed\n")); - return(ok); - } - } - - /* + /* deleted mails have already been expunged by + * end_mailbox_poll(). + * * recentcount is already set here by the last imap command which - * returned RECENT on detecting new mail. if recentcount is 0, wait + * returned EXISTS on detecting new mail. if recentcount is 0, wait * for new mail. - */ - - /* this is a while loop because imap_idle() might return on other + * + * this is a while loop because imap_idle() might return on other * mailbox changes also */ while (recentcount == 0 && do_idle) { smtp_close(ctl, 1); @@ -679,10 +914,15 @@ static int imap_getrange(int sock, } else { - count = 0; + oldcount = count = 0; ok = gen_transact(sock, check_only ? "EXAMINE \"%s\"" : "SELECT \"%s\"", folder ? folder : "INBOX"); + /* imap_ok returns PS_LOCKBUSY for READ-ONLY folders, + * which we can safely use in fetchall keep only */ + if (ok == PS_LOCKBUSY && ctl->fetchall && ctl-> keep) + ok = 0; + if (ok != 0) { report(stderr, GT_("mailbox selection failed\n")); @@ -693,16 +933,6 @@ static int imap_getrange(int sock, "%d messages waiting after first poll\n", count), count); - /* no messages? then we may need to idle until we get some */ - while (count == 0 && do_idle) { - ok = imap_idle(sock); - if (ok) - { - report(stderr, GT_("re-poll failed\n")); - return(ok); - } - } - /* * We should have an expunge here to * a) avoid fetching deleted mails during 'fetchall' @@ -721,9 +951,26 @@ static int imap_getrange(int sock, "%d messages waiting after expunge\n", count), count); } + + if (count == 0 && do_idle) + { + /* no messages? then we may need to idle until we get some */ + while (count == 0) { + ok = imap_idle(sock); + if (ok) + { + report(stderr, GT_("re-poll failed\n")); + return(ok); + } + } + if (outlevel >= O_DEBUG) + report(stdout, ngettext("%d message waiting after re-poll\n", + "%d messages waiting after re-poll\n", + count), count); + } } - *countp = count; + *countp = oldcount = count; recentcount = 0; startcount = 1; @@ -732,56 +979,16 @@ static int imap_getrange(int sock, { if (unseen_messages) free(unseen_messages); - unseen_messages = xmalloc(count * sizeof(unsigned int)); + unseen_messages = (unsigned int *)xmalloc(count * sizeof(unsigned int)); memset(unseen_messages, 0, count * sizeof(unsigned int)); unseen = 0; - /* don't count deleted messages, in case user enabled keep last time */ - gen_send(sock, "SEARCH UNSEEN NOT DELETED"); - do { - ok = gen_recv(sock, buf, sizeof(buf)); - if (ok != 0) - { - report(stderr, GT_("search for unseen messages failed\n")); - return(PS_PROTOCOL); - } - else if ((cp = strstr(buf, "* SEARCH"))) - { - char *ep; - - cp += 8; /* skip "* SEARCH" */ - /* startcount is higher than count so that if there are no - * unseen messages, imap_getsizes() will not need to do - * anything! */ - startcount = count + 1; - - while (*cp && unseen < count) - { - /* skip whitespace */ - while (*cp && isspace((unsigned char)*cp)) - cp++; - if (*cp) - { - unsigned int um; - /* - * Message numbers are between 1 and 2^32 inclusive, - * so unsigned int is large enough. - */ - um=(unsigned int)strtol(cp,&ep,10); - if (um <= count) - { - unseen_messages[unseen++] = um; - if (outlevel >= O_DEBUG) - report(stdout, GT_("%u is unseen\n"), um); - if (startcount > um) - startcount = um; - } - cp = ep; - } - } - } - } while - (tag[0] != '\0' && strncmp(buf, tag, strlen(tag))); + ok = imap_search(sock, ctl, count); + if (ok != 0) + { + report(stderr, GT_("search for unseen messages failed\n")); + return(ok); + } if (outlevel >= O_DEBUG && unseen > 0) report(stdout, GT_("%u is first unseen\n"), startcount); @@ -789,7 +996,6 @@ static int imap_getrange(int sock, unseen = -1; *newp = unseen; - count = 0; expunged = 0; deletions = 0; @@ -800,6 +1006,7 @@ static int imap_getpartialsizes(int sock, int first, int last, int *sizes) /* capture the sizes of messages #first-#last */ { char buf [MSGBUFSIZE+1]; + int ok; /* * Some servers (as in, PMDF5.1-9.1 under OpenVMS 6.1) @@ -831,7 +1038,7 @@ static int imap_getpartialsizes(int sock, int first, int last, int *sizes) * * 1 FETCH (BODY ("TEXT" "PLAIN" ("CHARSET" "US-ASCII") NIL NIL "7BIT" 35 3)) * A006 OK FETCH completed. * - * To get around this, we terminate the read loop on a NO and count + * To get around this, we treat the final NO as success and count * on the fact that the sizes array has been preinitialized with a * known-bad size value. */ @@ -846,32 +1053,32 @@ static int imap_getpartialsizes(int sock, int first, int last, int *sizes) gen_send(sock, "FETCH %d:%d RFC822.SIZE", first, last); else /* no unseen messages! */ return(PS_SUCCESS); - for (;;) + while ((ok = imap_response(sock, buf, NULL)) == PS_UNTAGGED) { - unsigned int num, size; - int ok; - char *cp; - - if ((ok = gen_recv(sock, buf, sizeof(buf)))) - return(ok); - /* we want response matching to be case-insensitive */ - for (cp = buf; *cp; cp++) - *cp = toupper(*cp); - /* an untagged NO means that a message was not readable */ - if (strstr(buf, "* NO")) - ; - else if (strstr(buf, "OK") || strstr(buf, "NO")) - break; - else if (sscanf(buf, "* %u FETCH (RFC822.SIZE %u)", &num, &size) == 2) + unsigned int size; + int num; + int consumed; + char *ptr; + + /* expected response formats: + * IMAP> A0005 FETCH 1 RFC822.SIZE + * IMAP< * 1 FETCH (RFC822.SIZE 1187) + * IMAP< * 1 FETCH (UID 16 RFC822.SIZE 1447) + */ + if (sscanf(buf, "* %d %n", &num, &consumed) == 1 + && 0 == strncasecmp(buf + consumed, "FETCH", 5) + && isspace((unsigned char)buf[consumed + 5]) + && (ptr = strstr(buf, "RFC822.SIZE ")) + && sscanf(ptr, "RFC822.SIZE %u", &size) == 1) { if (num >= first && num <= last) - sizes[num - first] = size; + sizes[num - first] = size; else - report(stderr, "Warning: ignoring bogus data for message sizes returned by the server.\n"); + report(stderr, + GT_("Warning: ignoring bogus data for message sizes returned by the server.\n")); } } - - return(PS_SUCCESS); + return(ok); } static int imap_getsizes(int sock, int count, int *sizes) @@ -886,6 +1093,8 @@ static int imap_is_old(int sock, struct query *ctl, int number) flag seen = TRUE; int i; + (void)sock; + (void)ctl; /* * Expunges change the fetch numbers, but unseen_messages contains * indices from before any expungees were done. So neither the @@ -894,7 +1103,7 @@ static int imap_is_old(int sock, struct query *ctl, int number) seen = TRUE; for (i = 0; i < unseen; i++) - if (unseen_messages[i] == number) + if (unseen_messages[i] == (unsigned)number) { seen = FALSE; break; @@ -903,6 +1112,7 @@ static int imap_is_old(int sock, struct query *ctl, int number) return(seen); } +#if 0 static char *skip_token(char *ptr) { while(isspace((unsigned char)*ptr)) ptr++; @@ -910,13 +1120,17 @@ static char *skip_token(char *ptr) while(isspace((unsigned char)*ptr)) ptr++; return(ptr); } +#endif static int imap_fetch_headers(int sock, struct query *ctl,int number,int *lenp) /* request headers of nth message */ { char buf [MSGBUFSIZE+1]; int num; + int ok; + char *ptr; + (void)ctl; /* expunges change the fetch numbers */ number -= expunged; @@ -927,37 +1141,50 @@ static int imap_fetch_headers(int sock, struct query *ctl,int number,int *lenp) gen_send(sock, "FETCH %d RFC822.HEADER", number); /* looking for FETCH response */ - for (;;) + if ((ok = imap_response(sock, buf, NULL)) == PS_UNTAGGED) { - int ok; - char *ptr; - - if ((ok = gen_recv(sock, buf, sizeof(buf)))) - return(ok); - ptr = skip_token(buf); /* either "* " or "AXXXX " */ - if (sscanf(ptr, "%d FETCH (%*s {%d}", &num, lenp) == 2) - break; - /* try to recover from chronically fucked-up M$ Exchange servers */ - else if (!strncmp(ptr, "NO", 2)) + int consumed; + /* expected response formats: + * IMAP> A0006 FETCH 1 RFC822.HEADER + * IMAP< * 1 FETCH (RFC822.HEADER {1360} + * IMAP< * 1 FETCH (UID 16 RFC822.HEADER {1360} + * IMAP< * 1 FETCH (UID 16 RFC822.SIZE 4029 RFC822.HEADER {1360} + */ + if (sscanf(buf, "* %d %n", &num, &consumed) == 1 + && 0 == strncasecmp(buf + consumed, "FETCH", 5) + && isspace((unsigned char)buf[5+consumed]) + && num == number + && (ptr = strstr(buf, "RFC822.HEADER")) + && sscanf(ptr, "RFC822.HEADER {%d}%n", lenp, &consumed) == 1 + && ptr[consumed-1] == '}') { - /* wait for a tagged response */ - if (strstr (buf, "* NO")) - imap_ok (sock, 0); - return(PS_TRANSIENT); + return(PS_SUCCESS); } - else if (!strncmp(ptr, "BAD", 3)) + + /* wait for a tagged response */ + imap_ok (sock, 0); + + /* try to recover for some responses */ + if (!strncmp(buf, "* NO", 4) || + !strncmp(buf, "* BAD", 5) || + strstr(buf, "FETCH ()")) { - /* wait for a tagged response */ - if (strstr (buf, "* BAD")) - imap_ok (sock, 0); - return(PS_TRANSIENT); + return(PS_TRANSIENT); } - } - if (num != number) + /* a response which does not match any of the above */ + if (outlevel > O_SILENT) + report(stderr, GT_("Incorrect FETCH response: %s.\n"), buf); return(PS_ERROR); - else - return(PS_SUCCESS); + } + else if (ok == PS_SUCCESS) + { + /* an unexpected tagged response */ + if (outlevel > O_SILENT) + report(stderr, GT_("Incorrect FETCH response: %s.\n"), buf); + return(PS_TRANSIENT); + } + return(ok); } static int imap_fetch_body(int sock, struct query *ctl, int number, int *lenp) @@ -966,6 +1193,7 @@ static int imap_fetch_body(int sock, struct query *ctl, int number, int *lenp) char buf [MSGBUFSIZE+1], *cp; int num; + (void)ctl; /* expunges change the fetch numbers */ number -= expunged; @@ -1016,6 +1244,20 @@ static int imap_fetch_body(int sock, struct query *ctl, int number, int *lenp) if (num != number) return(PS_ERROR); + /* Understand "NIL" as length => no body present + * (MS Exchange, BerliOS Bug #11980) */ + if (strstr(buf+10, "NIL)")) { + *lenp = 0; + return PS_SUCCESS; + } + + /* Understand the empty string. Seen on Yahoo. */ + /* XXX FIXME: we should be able to handle strings here. */ + if (strstr(buf+10, "\"\")")) { + *lenp = 0; + return PS_SUCCESS; + } + /* * Try to extract a length from the FETCH response. RFC2060 requires * it to be present, but at least one IMAP server (Novell GroupWise) @@ -1023,44 +1265,48 @@ static int imap_fetch_body(int sock, struct query *ctl, int number, int *lenp) * server called dbmail that returns huge garbage lengths. */ if ((cp = strchr(buf, '{'))) { + long l; char *t; errno = 0; - *lenp = (int)strtol(cp + 1, (char **)NULL, 10); - if (errno == ERANGE && (*lenp == LONG_MAX || *lenp == LONG_MIN)) - *lenp = -1; /* length is too big/small for us to handle */ - } - else + ++ cp; + l = strtol(cp, &t, 10); + if (errno || t == cp || (t && !strchr(t, '}')) /* parse error */ + || l < 0 || l > INT_MAX /* range check */) { + *lenp = -1; + } else { + *lenp = l; + } + } else { *lenp = -1; /* missing length part in FETCH reponse */ + } - return(PS_SUCCESS); + return PS_SUCCESS; } -static int imap_trail(int sock, struct query *ctl, int number) +static int imap_trail(int sock, struct query *ctl, const char *tag) /* discard tail of FETCH response after reading message text */ { /* expunges change the fetch numbers */ /* number -= expunged; */ - for (;;) - { - char buf[MSGBUFSIZE+1]; - int ok; - - if ((ok = gen_recv(sock, buf, sizeof(buf)))) - return(ok); - - /* UW IMAP returns "OK FETCH", Cyrus returns "OK Completed" */ - if (strstr(buf, "OK")) - break; - } + (void)ctl; + (void)tag; - return(PS_SUCCESS); + return imap_ok(sock, NULL); } static int imap_delete(int sock, struct query *ctl, int number) /* set delete flag for given message */ { int ok; + /* Select which flags to set on message deletion: */ + const char delflags_seen[] = "\\Seen \\Deleted"; + static const char *delflags; + /* Which environment variable to look for: */ + + /* DEFAULT since many fetchmail versions <= 6.3.X */ + delflags = delflags_seen; + (void)ctl; /* expunges change the fetch numbers */ number -= expunged; @@ -1068,17 +1314,18 @@ static int imap_delete(int sock, struct query *ctl, int number) * Use SILENT if possible as a minor throughput optimization. * Note: this has been dropped from IMAP4rev1. * - * We set Seen because there are some IMAP servers (notably HP - * OpenMail) that do message-receipt DSNs, but only when the seen - * bit is set. This is the appropriate time -- we get here right + * We set \Seen because there are some IMAP servers (notably HP + * OpenMail and MS Exchange) do message-receipt DSNs, + * but only when the seen bit gets set. + * This is the appropriate time -- we get here right * after the local SMTP response that says delivery was * successful. */ if ((ok = gen_transact(sock, imap_version == IMAP4 - ? "STORE %d +FLAGS.SILENT (\\Seen \\Deleted)" - : "STORE %d +FLAGS (\\Seen \\Deleted)", - number))) + ? "STORE %d +FLAGS.SILENT (%s)" + : "STORE %d +FLAGS (%s)", + number, delflags))) return(ok); else deletions++; @@ -1090,7 +1337,10 @@ static int imap_delete(int sock, struct query *ctl, int number) * the next session. */ if (NUM_NONZERO(expunge_period) && (deletions % expunge_period) == 0) - internal_expunge(sock); + { + if ((ok = internal_expunge(sock))) + return(ok); + } return(PS_SUCCESS); } @@ -1098,6 +1348,11 @@ static int imap_delete(int sock, struct query *ctl, int number) static int imap_mark_seen(int sock, struct query *ctl, int number) /* mark the given message as seen */ { + (void)ctl; + + /* expunges change the message numbers */ + number -= expunged; + return(gen_transact(sock, imap_version == IMAP4 ? "STORE %d +FLAGS.SILENT (\\Seen)" @@ -1105,9 +1360,19 @@ static int imap_mark_seen(int sock, struct query *ctl, int number) number)); } +static int imap_end_mailbox_poll(int sock, struct query *ctl) +/* cleanup mailbox before we idle or switch to another one */ +{ + (void)ctl; + if (deletions) + internal_expunge(sock); + return(PS_SUCCESS); +} + static int imap_logout(int sock, struct query *ctl) /* send logout command */ { + (void)ctl; /* if any un-expunged deletions remain, ship an expunge now */ if (deletions) internal_expunge(sock); @@ -1124,8 +1389,8 @@ static int imap_logout(int sock, struct query *ctl) static const struct method imap = { "IMAP", /* Internet Message Access Protocol */ - "imap", - "imaps", + "imap", /* service (plain and TLS) */ + "imaps", /* service (SSL) */ TRUE, /* this is a tagged protocol */ FALSE, /* no message delimiter */ imap_ok, /* parse command response */ @@ -1139,6 +1404,7 @@ static const struct method imap = imap_trail, /* eat message trailer */ imap_delete, /* delete the message */ imap_mark_seen, /* how to mark a message as seen */ + imap_end_mailbox_poll, /* end-of-mailbox processing */ imap_logout, /* expunge and exit */ TRUE, /* yes, we can re-poll */ };