+/*************************************************
+* 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;
+#if defined(__linux__) && defined(TCP_QUICKACK)
+ { /* Hack to get QUICKACK disabled; has to be right after 3whs, and has to on->off */
+ int sock = sx->cctx.sock;
+ struct pollfd p = {.fd = sock, .events = POLLOUT};
+ if (poll(&p, 1, 1000) >= 0) /* retval test solely for compiler quitening */
+ {
+ (void) setsockopt(sock, IPPROTO_TCP, TCP_QUICKACK, US &on, sizeof(on));
+ (void) setsockopt(sock, IPPROTO_TCP, TCP_QUICKACK, US &off, sizeof(off));
+ }
+ }
+#endif
+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, NULL);
+#endif
+return TRUE;
+}
+
+
+#if !defined(DISABLE_TLS) && !defined(DISABLE_TLS_RESUME)
+
+/* Grab a string differentiating server behind a loadbalancer, for TLS
+resumption when such servers do not share a session-cache */
+
+static void
+ehlo_response_lbserver(smtp_context * sx, const uschar * name_extract)
+{
+const uschar * s;
+uschar * save_item = iterate_item;
+
+if (sx->conn_args.have_lbserver)
+ return;
+iterate_item = sx->buffer;
+s = expand_cstring(name_extract);
+iterate_item = save_item;
+sx->conn_args.host_lbserver = s && !*s ? NULL : s;
+sx->conn_args.have_lbserver = TRUE;
+}
+#endif
+
+
+
+/******************************************************************************/
+
+#ifndef DISABLE_ESMTP_LIMITS
+/* If TLS, or TLS not offered, called with the EHLO response in the buffer.
+Check it for a LIMITS keyword and parse values into the smtp context structure.
+
+We don't bother with peers that we won't talk TLS to, even though they can,
+just ignore their LIMITS advice (if any) and treat them as if they do not.
+This saves us dealing with a duplicate set of values. */
+
+static void
+ehlo_response_limits_read(smtp_context * sx)
+{
+uschar * match;
+
+/* matches up to just after the first space after the keyword */
+
+if (regex_match(regex_LIMITS, sx->buffer, -1, &match))
+ for (const uschar * s = sx->buffer + Ustrlen(match); *s; )
+ {
+ while (isspace(*s)) s++;
+ if (*s == '\n') break;
+
+ if (strncmpic(s, US"MAILMAX=", 8) == 0)
+ {
+ sx->peer_limit_mail = atoi(CS (s += 8));
+ while (isdigit(*s)) s++;
+ }
+ else if (strncmpic(s, US"RCPTMAX=", 8) == 0)
+ {
+ sx->peer_limit_rcpt = atoi(CS (s += 8));
+ while (isdigit(*s)) s++;
+ }
+ else if (strncmpic(s, US"RCPTDOMAINMAX=", 14) == 0)
+ {
+ sx->peer_limit_rcptdom = atoi(CS (s += 14));
+ while (isdigit(*s)) s++;
+ }
+ else
+ while (*s && !isspace(*s)) s++;
+ }
+}
+
+/* Apply given values to the current connection */
+static void
+ehlo_limits_apply(smtp_context * sx,
+ unsigned limit_mail, unsigned limit_rcpt, unsigned limit_rcptdom)
+{
+if (limit_mail && limit_mail < sx->max_mail) sx->max_mail = limit_mail;
+if (limit_rcpt && limit_rcpt < sx->max_rcpt) sx->max_rcpt = limit_rcpt;
+if (limit_rcptdom)
+ {
+ DEBUG(D_transport) debug_printf("will treat as !multi_domain\n");
+ sx->single_rcpt_domain = TRUE;
+ }
+}
+
+/* Apply values from EHLO-resp to the current connection */
+static void
+ehlo_response_limits_apply(smtp_context * sx)
+{
+ehlo_limits_apply(sx, sx->peer_limit_mail, sx->peer_limit_rcpt,
+ sx->peer_limit_rcptdom);
+}
+
+/* Apply values read from cache to the current connection */
+static void
+ehlo_cache_limits_apply(smtp_context * sx)
+{
+# ifndef DISABLE_PIPE_CONNECT
+ehlo_limits_apply(sx, sx->ehlo_resp.limit_mail, sx->ehlo_resp.limit_rcpt,
+ sx->ehlo_resp.limit_rcptdom);
+# endif
+}
+#endif /*EXPERIMENTAL_ESMTP_LIMITS*/
+
+/******************************************************************************/
+
+#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);
+}
+
+/* Cache EHLO-response info for use by early-pipe.
+Called
+- During a normal flow on EHLO response (either cleartext or under TLS),
+ when we are willing to do PIPECONNECT and it is offered
+- During an early-pipe flow on receiving the actual EHLO response and noting
+ disparity versus the cached info used, when PIPECONNECT is still being offered
+
+We assume that suitable values have been set in the sx.ehlo_resp structure for
+features and auths; we handle the copy of limits. */
+
+static void
+write_ehlo_cache_entry(smtp_context * sx)
+{
+open_db dbblock, * dbm_file;
+
+# ifndef DISABLE_ESMTP_LIMITS
+sx->ehlo_resp.limit_mail = sx->peer_limit_mail;
+sx->ehlo_resp.limit_rcpt = sx->peer_limit_rcpt;
+sx->ehlo_resp.limit_rcptdom = sx->peer_limit_rcptdom;
+# endif
+
+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)
+# ifndef DISABLE_ESMTP_LIMITS
+ if (sx->ehlo_resp.limit_mail || sx->ehlo_resp.limit_rcpt || sx->ehlo_resp.limit_rcptdom)
+ debug_printf("writing clr %04x/%04x cry %04x/%04x lim %05d/%05d/%05d\n",
+ sx->ehlo_resp.cleartext_features, sx->ehlo_resp.cleartext_auths,
+ sx->ehlo_resp.crypted_features, sx->ehlo_resp.crypted_auths,
+ sx->ehlo_resp.limit_mail, sx->ehlo_resp.limit_rcpt,
+ sx->ehlo_resp.limit_rcptdom);
+ else
+# endif
+ 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);
+ HDEBUG(D_transport)
+ {
+ dbdata_ehlo_resp * er;
+
+ if (!(er = dbfn_read_enforce_length(dbm_file, ehlo_resp_key, sizeof(dbdata_ehlo_resp))))
+ debug_printf("no ehlo-resp record!\n");
+ else
+ debug_printf("ehlo-resp record is %d seconds old\n", time(NULL) - er->time_stamp);
+ }
+
+ 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_enforce_length(dbm_file, ehlo_resp_key, sizeof(dbdata_ehlo_resp))))
+ { 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
+ {
+ DEBUG(D_transport)
+# ifndef DISABLE_ESMTP_LIMITS
+ if (er->data.limit_mail || er->data.limit_rcpt || er->data.limit_rcptdom)
+ debug_printf("EHLO response bits from cache:"
+ " cleartext 0x%04x/0x%04x crypted 0x%04x/0x%04x lim %05d/%05d/%05d\n",
+ er->data.cleartext_features, er->data.cleartext_auths,
+ er->data.crypted_features, er->data.crypted_auths,
+ er->data.limit_mail, er->data.limit_rcpt, er->data.limit_rcptdom);
+ else
+# endif
+ 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);
+
+ sx->ehlo_resp = er->data;
+# ifndef DISABLE_ESMTP_LIMITS
+ ehlo_cache_limits_apply(sx);
+# endif
+ dbfn_close(dbm_file);
+ 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 client-side 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, MCS_NOFLAGS, 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', usable-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)
+ {
+ const uschar * s;
+
+ 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;
+ }
+ /*XXX EXPERIMENTAL_ESMTP_LIMITS ? */
+
+# ifndef DISABLE_TLS_RESUME
+ GET_OPTION("host_name_extract");
+ s = ((smtp_transport_options_block *)sx->conn_args.ob)->host_name_extract;
+ if (!s) s = HNE_DEFAULT;
+ ehlo_response_lbserver(sx, s);
+# endif
+ }
+
+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 extensions and AUTH methods 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
+ );
+# ifndef DISABLE_ESMTP_LIMITS
+ if (tls_out.active.sock >= 0 || !(peer_offered & OPTION_TLS))
+ ehlo_response_limits_read(sx);
+# endif
+ 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);
+ if (peer_offered & OPTION_EARLY_PIPE)
+ {
+ *(tls_out.active.sock < 0
+ ? &sx->ehlo_resp.cleartext_features : &sx->ehlo_resp.crypted_features) =
+ peer_offered;
+ *ap = authbits;
+ write_ehlo_cache_entry(sx);
+ }
+ else
+ {
+ invalidate_ehlo_cache_entry(sx);
+ sx->early_pipe_active = FALSE; /* cancel further early-pipe on this conn */
+ }
+
+ return OK; /* just carry on */
+ }
+# ifndef DISABLE_ESMTP_LIMITS
+ /* If we are handling LIMITS, compare the actual EHLO LIMITS values with the
+ cached values and invalidate cache if different. OK to carry on with
+ connect since values are advisory. */
+ {
+ if ( (tls_out.active.sock >= 0 || !(peer_offered & OPTION_TLS))
+ && ( sx->peer_limit_mail != sx->ehlo_resp.limit_mail
+ || sx->peer_limit_rcpt != sx->ehlo_resp.limit_rcpt
+ || sx->peer_limit_rcptdom != sx->ehlo_resp.limit_rcptdom
+ ) )
+ {
+ HDEBUG(D_transport)
+ {
+ debug_printf("EHLO LIMITS changed:");
+ if (sx->peer_limit_mail != sx->ehlo_resp.limit_mail)
+ debug_printf(" MAILMAX %u -> %u\n", sx->ehlo_resp.limit_mail, sx->peer_limit_mail);
+ else if (sx->peer_limit_rcpt != sx->ehlo_resp.limit_rcpt)
+ debug_printf(" RCPTMAX %u -> %u\n", sx->ehlo_resp.limit_rcpt, sx->peer_limit_rcpt);
+ else
+ debug_printf(" RCPTDOMAINMAX %u -> %u\n", sx->ehlo_resp.limit_rcptdom, sx->peer_limit_rcptdom);
+ }
+ invalidate_ehlo_cache_entry(sx);
+ }
+ }
+# endif
+ }
+return OK;
+
+fail:
+ invalidate_ehlo_cache_entry(sx);
+ (void) smtp_discard_responses(sx, sx->conn_args.ob, *countp);
+ return rc;
+}
+#endif /*!DISABLE_PIPE_CONNECT*/
+
+