+/*************************************************
+* Reap SMTP specific responses *
+*************************************************/
+static int
+smtp_discard_responses(smtp_context * sx, smtp_transport_options_block * ob,
+ int count)
+{
+uschar flushbuffer[4096];
+
+while (count-- > 0)
+ {
+ if (!smtp_read_response(sx, flushbuffer, sizeof(flushbuffer),
+ '2', ob->command_timeout)
+ && (errno != 0 || flushbuffer[0] == 0))
+ break;
+ }
+return count;
+}
+
+
+/* Return boolean success */
+
+static BOOL
+smtp_reap_banner(smtp_context * sx)
+{
+BOOL good_response = smtp_read_response(sx, sx->buffer, sizeof(sx->buffer),
+ '2', (SOB sx->conn_args.ob)->command_timeout);
+#ifdef EXPERIMENTAL_DSN_INFO
+sx->smtp_greeting = string_copy(sx->buffer);
+#endif
+return good_response;
+}
+
+static BOOL
+smtp_reap_ehlo(smtp_context * sx)
+{
+if (!smtp_read_response(sx, sx->buffer, sizeof(sx->buffer), '2',
+ (SOB sx->conn_args.ob)->command_timeout))
+ {
+ if (errno != 0 || sx->buffer[0] == 0 || sx->lmtp)
+ {
+#ifdef EXPERIMENTAL_DSN_INFO
+ sx->helo_response = string_copy(sx->buffer);
+#endif
+ return FALSE;
+ }
+ sx->esmtp = FALSE;
+ }
+#ifdef EXPERIMENTAL_DSN_INFO
+sx->helo_response = string_copy(sx->buffer);
+#endif
+#ifndef DISABLE_EVENT
+(void) event_raise(sx->conn_args.tblock->event_action,
+ US"smtp:ehlo", sx->buffer);
+#endif
+return TRUE;
+}
+
+
+
+#ifndef DISABLE_PIPE_CONNECT
+static uschar *
+ehlo_cache_key(const smtp_context * sx)
+{
+host_item * host = sx->conn_args.host;
+return Ustrchr(host->address, ':')
+ ? string_sprintf("[%s]:%d.EHLO", host->address,
+ host->port == PORT_NONE ? sx->port : host->port)
+ : string_sprintf("%s:%d.EHLO", host->address,
+ host->port == PORT_NONE ? sx->port : host->port);
+}
+
+static void
+write_ehlo_cache_entry(const smtp_context * sx)
+{
+open_db dbblock, * dbm_file;
+
+if ((dbm_file = dbfn_open(US"misc", O_RDWR, &dbblock, TRUE, TRUE)))
+ {
+ uschar * ehlo_resp_key = ehlo_cache_key(sx);
+ dbdata_ehlo_resp er = { .data = sx->ehlo_resp };
+
+ HDEBUG(D_transport) debug_printf("writing clr %04x/%04x cry %04x/%04x\n",
+ sx->ehlo_resp.cleartext_features, sx->ehlo_resp.cleartext_auths,
+ sx->ehlo_resp.crypted_features, sx->ehlo_resp.crypted_auths);
+
+ dbfn_write(dbm_file, ehlo_resp_key, &er, (int)sizeof(er));
+ dbfn_close(dbm_file);
+ }
+}
+
+static void
+invalidate_ehlo_cache_entry(smtp_context * sx)
+{
+open_db dbblock, * dbm_file;
+
+if ( sx->early_pipe_active
+ && (dbm_file = dbfn_open(US"misc", O_RDWR, &dbblock, TRUE, TRUE)))
+ {
+ uschar * ehlo_resp_key = ehlo_cache_key(sx);
+ dbfn_delete(dbm_file, ehlo_resp_key);
+ dbfn_close(dbm_file);
+ }
+}
+
+static BOOL
+read_ehlo_cache_entry(smtp_context * sx)
+{
+open_db dbblock;
+open_db * dbm_file;
+
+if (!(dbm_file = dbfn_open(US"misc", O_RDONLY, &dbblock, FALSE, TRUE)))
+ { DEBUG(D_transport) debug_printf("ehlo-cache: no misc DB\n"); }
+else
+ {
+ uschar * ehlo_resp_key = ehlo_cache_key(sx);
+ dbdata_ehlo_resp * er;
+
+ if (!(er = dbfn_read(dbm_file, ehlo_resp_key)))
+ { DEBUG(D_transport) debug_printf("no ehlo-resp record\n"); }
+ else if (time(NULL) - er->time_stamp > retry_data_expire)
+ {
+ DEBUG(D_transport) debug_printf("ehlo-resp record too old\n");
+ dbfn_close(dbm_file);
+ if ((dbm_file = dbfn_open(US"misc", O_RDWR, &dbblock, TRUE, TRUE)))
+ dbfn_delete(dbm_file, ehlo_resp_key);
+ }
+ else
+ {
+ sx->ehlo_resp = er->data;
+ dbfn_close(dbm_file);
+ DEBUG(D_transport) debug_printf(
+ "EHLO response bits from cache: cleartext 0x%04x/0x%04x crypted 0x%04x/0x%04x\n",
+ er->data.cleartext_features, er->data.cleartext_auths,
+ er->data.crypted_features, er->data.crypted_auths);
+ return TRUE;
+ }
+ dbfn_close(dbm_file);
+ }
+return FALSE;
+}
+
+
+
+/* Return an auths bitmap for the set of AUTH methods offered by the server
+which match our authenticators. */
+
+static unsigned short
+study_ehlo_auths(smtp_context * sx)
+{
+uschar * names;
+auth_instance * au;
+uschar authnum;
+unsigned short authbits = 0;
+
+if (!sx->esmtp) return 0;
+if (!regex_AUTH) regex_AUTH = regex_must_compile(AUTHS_REGEX, FALSE, TRUE);
+if (!regex_match_and_setup(regex_AUTH, sx->buffer, 0, -1)) return 0;
+expand_nmax = -1; /* reset */
+names = string_copyn(expand_nstring[1], expand_nlength[1]);
+
+for (au = auths, authnum = 0; au; au = au->next, authnum++) if (au->client)
+ {
+ const uschar * list = names;
+ uschar * s;
+ for (int sep = ' '; s = string_nextinlist(&list, &sep, NULL, 0); )
+ if (strcmpic(au->public_name, s) == 0)
+ { authbits |= BIT(authnum); break; }
+ }
+
+DEBUG(D_transport)
+ debug_printf("server offers %s AUTH, methods '%s', bitmap 0x%04x\n",
+ tls_out.active.sock >= 0 ? "crypted" : "plaintext", names, authbits);
+
+if (tls_out.active.sock >= 0)
+ sx->ehlo_resp.crypted_auths = authbits;
+else
+ sx->ehlo_resp.cleartext_auths = authbits;
+return authbits;
+}
+
+
+
+
+/* Wait for and check responses for early-pipelining.
+
+Called from the lower-level smtp_read_response() function
+used for general code that assume synchronisation, if context
+flags indicate outstanding early-pipelining commands. Also
+called fom sync_responses() which handles pipelined commands.
+
+Arguments:
+ sx smtp connection context
+ countp number of outstanding responses, adjusted on return
+
+Return:
+ OK all well
+ DEFER error on first read of TLS'd conn
+ FAIL SMTP error in response
+*/
+int
+smtp_reap_early_pipe(smtp_context * sx, int * countp)
+{
+BOOL pending_BANNER = sx->pending_BANNER;
+BOOL pending_EHLO = sx->pending_EHLO;
+int rc = FAIL;
+
+sx->pending_BANNER = FALSE; /* clear early to avoid recursion */
+sx->pending_EHLO = FALSE;
+
+if (pending_BANNER)
+ {
+ DEBUG(D_transport) debug_printf("%s expect banner\n", __FUNCTION__);
+ (*countp)--;
+ if (!smtp_reap_banner(sx))
+ {
+ DEBUG(D_transport) debug_printf("bad banner\n");
+ if (tls_out.active.sock >= 0) rc = DEFER;
+ goto fail;
+ }
+ }
+
+if (pending_EHLO)
+ {
+ unsigned peer_offered;
+ unsigned short authbits = 0, * ap;
+
+ DEBUG(D_transport) debug_printf("%s expect ehlo\n", __FUNCTION__);
+ (*countp)--;
+ if (!smtp_reap_ehlo(sx))
+ {
+ DEBUG(D_transport) debug_printf("bad response for EHLO\n");
+ if (tls_out.active.sock >= 0) rc = DEFER;
+ goto fail;
+ }
+
+ /* Compare the actual EHLO response to the cached value we assumed;
+ on difference, dump or rewrite the cache and arrange for a retry. */
+
+ ap = tls_out.active.sock < 0
+ ? &sx->ehlo_resp.cleartext_auths : &sx->ehlo_resp.crypted_auths;
+
+ peer_offered = ehlo_response(sx->buffer,
+ (tls_out.active.sock < 0 ? OPTION_TLS : 0)
+ | OPTION_CHUNKING | OPTION_PRDR | OPTION_DSN | OPTION_PIPE | OPTION_SIZE
+ | OPTION_UTF8 | OPTION_EARLY_PIPE
+ );
+ if ( peer_offered != sx->peer_offered
+ || (authbits = study_ehlo_auths(sx)) != *ap)
+ {
+ HDEBUG(D_transport)
+ debug_printf("EHLO %s extensions changed, 0x%04x/0x%04x -> 0x%04x/0x%04x\n",
+ tls_out.active.sock < 0 ? "cleartext" : "crypted",
+ sx->peer_offered, *ap, peer_offered, authbits);
+ *(tls_out.active.sock < 0
+ ? &sx->ehlo_resp.cleartext_features : &sx->ehlo_resp.crypted_features) = peer_offered;
+ *ap = authbits;
+ if (peer_offered & OPTION_EARLY_PIPE)
+ write_ehlo_cache_entry(sx);
+ else
+ invalidate_ehlo_cache_entry(sx);
+
+ return OK; /* just carry on */
+ }
+ }
+return OK;
+
+fail:
+ invalidate_ehlo_cache_entry(sx);
+ (void) smtp_discard_responses(sx, sx->conn_args.ob, *countp);
+ return rc;
+}
+#endif
+
+
git://git.exim.org / users / heiko / exim.git / blobdiff