Adding upstream version 3.4.23.upstream/3.4.23upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 2469 insertions, 0 deletions

diff --git a/src/smtp/smtp_proto.c b/src/smtp/smtp_proto.c
new file mode 100644
index 0000000..a43a326
--- /dev/null
+++ b/src/smtp/smtp_proto.c
@@ -0,0 +1,2469 @@
+/*++
+/* NAME
+/*	smtp_proto 3
+/* SUMMARY
+/*	client SMTP/LMTP protocol
+/* SYNOPSIS
+/*	#include "smtp.h"
+/*
+/*	int	smtp_helo(state)
+/*	SMTP_STATE *state;
+/*
+/*	int	smtp_xfer(state)
+/*	SMTP_STATE *state;
+/*
+/*	int	smtp_rset(state)
+/*	SMTP_STATE *state;
+/*
+/*	int	smtp_quit(state)
+/*	SMTP_STATE *state;
+/* DESCRIPTION
+/*	In the subsequent text, SMTP implies LMTP.
+/*	This module implements the client side of the SMTP protocol.
+/*
+/*	smtp_helo() performs the initial handshake with the SMTP server.
+/*	When TLS is enabled, this includes STARTTLS negotiations.
+/*
+/*	smtp_xfer() sends message envelope information followed by the
+/*	message data, and finishes the SMTP conversation. These operations
+/*	are combined in one function, in order to implement SMTP pipelining.
+/*	Recipients are marked as "done" in the mail queue file when
+/*	bounced or delivered. The message delivery status is updated
+/*	accordingly.
+/*
+/*	smtp_rset() sends a single RSET command and waits for the
+/*	response. In case of a negative reply it sets the
+/*	CANT_RSET_THIS_SESSION flag.
+/*
+/*	smtp_quit() sends a single QUIT command and waits for the
+/*	response if configured to do so. It always turns off connection
+/*	caching.
+/* DIAGNOSTICS
+/*	smtp_helo(), smtp_xfer(), smtp_rset() and smtp_quit() return
+/*	0 in case of success, -1 in case of failure. For smtp_xfer(),
+/*	smtp_rset() and smtp_quit(), success means the ability to
+/*	perform an SMTP conversation, not necessarily the ability
+/*	to deliver mail, or the achievement of server happiness.
+/*
+/*	In case of a rejected or failed connection, a connection
+/*	is marked as "bad, do not cache". Otherwise, connection
+/*	caching may be turned off (without being marked "bad") at
+/*	the discretion of the code that implements the individual
+/*	protocol steps.
+/*
+/*	Warnings: corrupt message file. A corrupt message is marked
+/*	as "corrupt" by changing its queue file permissions.
+/* BUGS
+/*	Some SMTP servers will abort when the number of recipients
+/*	for one message exceeds their capacity. This behavior violates
+/*	the SMTP protocol.
+/*	The only way around this is to limit the number of recipients
+/*	per transaction to an artificially-low value.
+/* SEE ALSO
+/*	smtp(3h) internal data structures
+/*	smtp_chat(3) query/reply SMTP support
+/*	smtp_trouble(3) error handlers
+/* LICENSE
+/* .ad
+/* .fi
+/*	The Secure Mailer license must be distributed with this software.
+/* AUTHOR(S)
+/*	Wietse Venema
+/*	IBM T.J. Watson Research
+/*	P.O. Box 704
+/*	Yorktown Heights, NY 10598, USA
+/*
+/*	Wietse Venema
+/*	Google, Inc.
+/*	111 8th Avenue
+/*	New York, NY 10011, USA
+/*
+/*	Pipelining code in cooperation with:
+/*	Jon Ribbens
+/*	Oaktree Internet Solutions Ltd.,
+/*	Internet House,
+/*	Canal Basin,
+/*	Coventry,
+/*	CV1 4LY, United Kingdom.
+/*
+/*	Connection caching in cooperation with:
+/*	Victor Duchovni
+/*	Morgan Stanley
+/*
+/*	TLS support originally by:
+/*	Lutz Jaenicke
+/*	BTU Cottbus
+/*	Allgemeine Elektrotechnik
+/*	Universitaetsplatz 3-4
+/*	D-03044 Cottbus, Germany
+/*--*/
+
+/* System library. */
+
+#include <sys_defs.h>
+#include <sys/stat.h>
+#include <sys/socket.h>			/* shutdown(2) */
+#include <netinet/in.h>			/* ntohs() */
+#include <string.h>
+#include <unistd.h>
+#include <stdlib.h>			/* 44BSD stdarg.h uses abort() */
+#include <stdarg.h>
+#include <time.h>
+
+#ifdef STRCASECMP_IN_STRINGS_H
+#include <strings.h>
+#endif
+
+/* Utility library. */
+
+#include <msg.h>
+#include <vstring.h>
+#include <vstream.h>
+#include <vstring_vstream.h>
+#include <stringops.h>
+#include <mymalloc.h>
+#include <iostuff.h>
+#include <split_at.h>
+#include <name_code.h>
+#include <name_mask.h>
+
+/* Global library. */
+
+#include <mail_params.h>
+#include <smtp_stream.h>
+#include <mail_queue.h>
+#include <recipient_list.h>
+#include <deliver_request.h>
+#include <defer.h>
+#include <bounce.h>
+#include <record.h>
+#include <rec_type.h>
+#include <off_cvt.h>
+#include <mark_corrupt.h>
+#include <quote_821_local.h>
+#include <quote_822_local.h>
+#include <mail_proto.h>
+#include <mime_state.h>
+#include <ehlo_mask.h>
+#include <maps.h>
+#include <tok822.h>
+#include <mail_addr_map.h>
+#include <ext_prop.h>
+#include <namadr_list.h>
+#include <match_parent_style.h>
+#include <lex_822.h>
+#include <dsn_mask.h>
+#include <xtext.h>
+#include <uxtext.h>
+#include <smtputf8.h>
+
+/* Application-specific. */
+
+#include "smtp.h"
+#include "smtp_sasl.h"
+
+ /*
+  * Sender and receiver state. A session does not necessarily go through a
+  * linear progression, but states are guaranteed to not jump backwards.
+  * Normal sessions go from MAIL->RCPT->DATA->DOT->QUIT->LAST. The states
+  * MAIL, RCPT, and DATA may also be followed by ABORT->QUIT->LAST.
+  * 
+  * When connection caching is enabled, the QUIT state is suppressed. Normal
+  * sessions proceed as MAIL->RCPT->DATA->DOT->LAST, while aborted sessions
+  * end with ABORT->LAST. The connection is left open for a limited time. An
+  * RSET probe should be sent before attempting to reuse an open connection
+  * for a new transaction.
+  * 
+  * The code to send an RSET probe is a special case with its own initial state
+  * and with its own dedicated state transitions. The session proceeds as
+  * RSET->LAST. This code is kept inside the main protocol engine for
+  * consistent error handling and error reporting. It is not to be confused
+  * with the code that sends RSET to abort a mail transaction in progress.
+  * 
+  * The code to send QUIT without message delivery transaction jumps into the
+  * main state machine. If this introduces complications, then we should
+  * introduce a second QUIT state with its own dedicated state transitions,
+  * just like we did for RSET probes.
+  * 
+  * By default, the receiver skips the QUIT response. Some SMTP servers
+  * disconnect after responding to ".", and some SMTP servers wait before
+  * responding to QUIT.
+  * 
+  * Client states that are associated with sending mail (up to and including
+  * SMTP_STATE_DOT) must have smaller numerical values than the non-sending
+  * states (SMTP_STATE_ABORT .. SMTP_STATE_LAST).
+  */
+#define SMTP_STATE_XFORWARD_NAME_ADDR 0
+#define SMTP_STATE_XFORWARD_PROTO_HELO 1
+#define SMTP_STATE_MAIL		2
+#define SMTP_STATE_RCPT		3
+#define SMTP_STATE_DATA		4
+#define SMTP_STATE_DOT		5
+#define SMTP_STATE_ABORT	6
+#define SMTP_STATE_RSET		7
+#define SMTP_STATE_QUIT		8
+#define SMTP_STATE_LAST		9
+
+int    *xfer_timeouts[SMTP_STATE_LAST] = {
+    &var_smtp_xfwd_tmout,		/* name/addr */
+    &var_smtp_xfwd_tmout,		/* helo/proto */
+    &var_smtp_mail_tmout,
+    &var_smtp_rcpt_tmout,
+    &var_smtp_data0_tmout,
+    &var_smtp_data2_tmout,
+    &var_smtp_rset_tmout,
+    &var_smtp_rset_tmout,
+    &var_smtp_quit_tmout,
+};
+
+char   *xfer_states[SMTP_STATE_LAST] = {
+    "sending XFORWARD name/address",
+    "sending XFORWARD protocol/helo_name",
+    "sending MAIL FROM",
+    "sending RCPT TO",
+    "sending DATA command",
+    "sending end of data -- message may be sent more than once",
+    "sending final RSET",
+    "sending RSET probe",
+    "sending QUIT",
+};
+
+char   *xfer_request[SMTP_STATE_LAST] = {
+    "XFORWARD name/address command",
+    "XFORWARD helo/protocol command",
+    "MAIL FROM command",
+    "RCPT TO command",
+    "DATA command",
+    "end of DATA command",
+    "final RSET command",
+    "RSET probe",
+    "QUIT command",
+};
+
+ /*
+  * Note: MIME downgrade never happens for mail that must be delivered with
+  * SMTPUTF8 (the sender requested SMTPUTF8, AND the delivery request
+  * involves at least one UTF-8 envelope address or header value.
+  */
+#define SMTP_MIME_DOWNGRADE(session, request) \
+    (var_disable_mime_oconv == 0 \
+     && (session->features & SMTP_FEATURE_8BITMIME) == 0 \
+     && strcmp(request->encoding, MAIL_ATTR_ENC_7BIT) != 0)
+
+#ifdef USE_TLS
+
+static int smtp_start_tls(SMTP_STATE *);
+
+#endif
+
+ /*
+  * Call-back information for header/body checks. We don't provide call-backs
+  * for actions that change the message delivery time or destination.
+  */
+static void smtp_hbc_logger(void *, const char *, const char *, const char *, const char *);
+static void smtp_text_out(void *, int, const char *, ssize_t, off_t);
+
+HBC_CALL_BACKS smtp_hbc_callbacks[1] = {
+    smtp_hbc_logger,
+    smtp_text_out,
+};
+
+static int smtp_vrfy_tgt;
+
+/* smtp_vrfy_init - initialize */
+
+void    smtp_vrfy_init(void)
+{
+    static const NAME_CODE vrfy_init_table[] = {
+	SMTP_VRFY_TGT_RCPT, SMTP_STATE_RCPT,
+	SMTP_VRFY_TGT_DATA, SMTP_STATE_DATA,
+	0,
+    };
+
+    if ((smtp_vrfy_tgt = name_code(vrfy_init_table, NAME_CODE_FLAG_NONE,
+				   var_smtp_vrfy_tgt)) == 0)
+	msg_fatal("bad protocol stage: \"%s = %s\"",
+		  VAR_SMTP_VRFY_TGT, var_smtp_vrfy_tgt);
+}
+
+/* smtp_helo - perform initial handshake with SMTP server */
+
+int     smtp_helo(SMTP_STATE *state)
+{
+    const char *myname = "smtp_helo";
+    SMTP_SESSION *session = state->session;
+    DELIVER_REQUEST *request = state->request;
+    SMTP_ITERATOR *iter = state->iterator;
+    SMTP_RESP *resp;
+    SMTP_RESP fake;
+    int     except;
+    char   *lines;
+    char   *words;
+    char   *word;
+    int     n;
+    static const NAME_CODE xforward_features[] = {
+	XFORWARD_NAME, SMTP_FEATURE_XFORWARD_NAME,
+	XFORWARD_ADDR, SMTP_FEATURE_XFORWARD_ADDR,
+	XFORWARD_PORT, SMTP_FEATURE_XFORWARD_PORT,
+	XFORWARD_PROTO, SMTP_FEATURE_XFORWARD_PROTO,
+	XFORWARD_HELO, SMTP_FEATURE_XFORWARD_HELO,
+	XFORWARD_IDENT, SMTP_FEATURE_XFORWARD_IDENT,
+	XFORWARD_DOMAIN, SMTP_FEATURE_XFORWARD_DOMAIN,
+	0, 0,
+    };
+    const char *ehlo_words;
+    int     discard_mask;
+    static const NAME_MASK pix_bug_table[] = {
+	PIX_BUG_DISABLE_ESMTP, SMTP_FEATURE_PIX_NO_ESMTP,
+	PIX_BUG_DELAY_DOTCRLF, SMTP_FEATURE_PIX_DELAY_DOTCRLF,
+	0,
+    };
+    const char *pix_bug_words;
+    const char *pix_bug_source;
+    int     pix_bug_mask;
+
+#ifdef USE_TLS
+    int     saved_features = session->features;
+    int     tls_helo_status;
+
+#endif
+    const char *NOCLOBBER where;
+
+    /*
+     * Skip the plaintext SMTP handshake when connecting in SMTPS mode.
+     */
+#ifdef USE_TLS
+    if (var_smtp_tls_wrappermode
+	&& (state->misc_flags & SMTP_MISC_FLAG_IN_STARTTLS) == 0) {
+	/* XXX Mix-up of per-session and per-request flags. */
+	state->misc_flags |= SMTP_MISC_FLAG_IN_STARTTLS;
+	smtp_stream_setup(state->session->stream, var_smtp_starttls_tmout,
+			  var_smtp_rec_deadline);
+	tls_helo_status = smtp_start_tls(state);
+	state->misc_flags &= ~SMTP_MISC_FLAG_IN_STARTTLS;
+	return (tls_helo_status);
+    }
+#endif
+
+    /*
+     * Prepare for disaster.
+     */
+    smtp_stream_setup(state->session->stream, var_smtp_helo_tmout,
+		      var_smtp_rec_deadline);
+    if ((except = vstream_setjmp(state->session->stream)) != 0)
+	return (smtp_stream_except(state, except, where));
+
+    /*
+     * If not recursing after STARTTLS, examine the server greeting banner
+     * and decide if we are going to send EHLO as the next command.
+     */
+    if (var_smtp_tls_wrappermode
+	|| (state->misc_flags & SMTP_MISC_FLAG_IN_STARTTLS) == 0) {
+
+	/*
+	 * Read and parse the server's SMTP greeting banner.
+	 */
+	where = "receiving the initial server greeting";
+	switch ((resp = smtp_chat_resp(session))->code / 100) {
+	case 2:
+	    break;
+	case 5:
+	    if (var_smtp_skip_5xx_greeting)
+		STR(resp->dsn_buf)[0] = '4';
+	    /* FALLTHROUGH */
+	default:
+	    return (smtp_site_fail(state, STR(iter->host), resp,
+				   "host %s refused to talk to me: %s",
+				   session->namaddr,
+				   translit(resp->str, "\n", " ")));
+	}
+
+	/*
+	 * If the policy table specifies a bogus TLS security level, fail
+	 * now.
+	 */
+#ifdef USE_TLS
+	if (state->tls->level == TLS_LEV_INVALID)
+	    /* Warning is already logged. */
+	    return (smtp_site_fail(state, DSN_BY_LOCAL_MTA,
+				   SMTP_RESP_FAKE(&fake, "4.7.0"),
+				   "client TLS configuration problem"));
+#endif
+
+	/*
+	 * XXX Some PIX firewall versions require flush before ".<CR><LF>" so
+	 * it does not span a packet boundary. This hurts performance so it
+	 * is not on by default.
+	 */
+	if (resp->str[strspn(resp->str, "20 *\t\n")] == 0) {
+	    /* Best effort only. Ignore errors. */
+	    if (smtp_pix_bug_maps != 0
+		&& (pix_bug_words =
+		    maps_find(smtp_pix_bug_maps,
+			      STR(iter->addr), 0)) != 0) {
+		pix_bug_source = VAR_LMTP_SMTP(PIX_BUG_MAPS);
+	    } else {
+		pix_bug_words = var_smtp_pix_bug_words;
+		pix_bug_source = VAR_LMTP_SMTP(PIX_BUG_WORDS);
+	    }
+	    if (*pix_bug_words) {
+		pix_bug_mask = name_mask_opt(pix_bug_source, pix_bug_table,
+					     pix_bug_words,
+				     NAME_MASK_ANY_CASE | NAME_MASK_IGNORE);
+		if ((pix_bug_mask & SMTP_FEATURE_PIX_DELAY_DOTCRLF)
+		    && request->msg_stats.incoming_arrival.tv_sec
+		    > vstream_ftime(state->session->stream) - var_smtp_pix_thresh)
+		    pix_bug_mask &= ~SMTP_FEATURE_PIX_DELAY_DOTCRLF;
+		msg_info("%s: enabling PIX workarounds: %s for %s",
+			 request->queue_id,
+			 str_name_mask("pix workaround bitmask",
+				       pix_bug_table, pix_bug_mask),
+			 session->namaddrport);
+		session->features |= pix_bug_mask;
+	    }
+	}
+
+	/*
+	 * See if we are talking to ourself. This should not be possible with
+	 * the way we implement DNS lookups. However, people are known to
+	 * sometimes screw up the naming service. And, mailer loops are still
+	 * possible when our own mailer routing tables are mis-configured.
+	 */
+	words = resp->str;
+	(void) mystrtok(&words, "- \t\n");
+	for (n = 0; (word = mystrtok(&words, " \t\n")) != 0; n++) {
+	    if (n == 0 && strcasecmp(word, var_myhostname) == 0) {
+		if (state->misc_flags & SMTP_MISC_FLAG_LOOP_DETECT)
+		    msg_warn("host %s greeted me with my own hostname %s",
+			     session->namaddrport, var_myhostname);
+	    } else if (strcasecmp(word, "ESMTP") == 0)
+		session->features |= SMTP_FEATURE_ESMTP;
+	}
+	if (smtp_mode) {
+	    if (var_smtp_always_ehlo
+		&& (session->features & SMTP_FEATURE_PIX_NO_ESMTP) == 0)
+		session->features |= SMTP_FEATURE_ESMTP;
+	    if (var_smtp_never_ehlo
+		|| (session->features & SMTP_FEATURE_PIX_NO_ESMTP) != 0)
+		session->features &= ~SMTP_FEATURE_ESMTP;
+	} else {
+	    session->features |= SMTP_FEATURE_ESMTP;
+	}
+    }
+
+    /*
+     * If recursing after STARTTLS, there is no server greeting banner.
+     * Always send EHLO as the next command.
+     */
+    else {
+	session->features |= SMTP_FEATURE_ESMTP;
+    }
+
+    /*
+     * Return the compliment. Fall back to SMTP if our ESMTP recognition
+     * heuristic failed.
+     */
+    if (smtp_mode) {
+	where = "performing the EHLO handshake";
+	if (session->features & SMTP_FEATURE_ESMTP) {
+	    smtp_chat_cmd(session, "EHLO %s", var_smtp_helo_name);
+	    if ((resp = smtp_chat_resp(session))->code / 100 != 2) {
+		if (resp->code == 421)
+		    return (smtp_site_fail(state, STR(iter->host), resp,
+					"host %s refused to talk to me: %s",
+					   session->namaddr,
+					   translit(resp->str, "\n", " ")));
+		else
+		    session->features &= ~SMTP_FEATURE_ESMTP;
+	    }
+	}
+	if ((session->features & SMTP_FEATURE_ESMTP) == 0) {
+	    where = "performing the HELO handshake";
+	    smtp_chat_cmd(session, "HELO %s", var_smtp_helo_name);
+	    if ((resp = smtp_chat_resp(session))->code / 100 != 2)
+		return (smtp_site_fail(state, STR(iter->host), resp,
+				       "host %s refused to talk to me: %s",
+				       session->namaddr,
+				       translit(resp->str, "\n", " ")));
+	}
+    } else {
+	where = "performing the LHLO handshake";
+	smtp_chat_cmd(session, "LHLO %s", var_smtp_helo_name);
+	if ((resp = smtp_chat_resp(session))->code / 100 != 2)
+	    return (smtp_site_fail(state, STR(iter->host), resp,
+				   "host %s refused to talk to me: %s",
+				   session->namaddr,
+				   translit(resp->str, "\n", " ")));
+    }
+
+    /*
+     * No early returns allowed, to ensure consistent handling of TLS and
+     * SASL policies.
+     */
+    if (session->features & SMTP_FEATURE_ESMTP) {
+
+	/*
+	 * Determine what server EHLO keywords to ignore, typically to avoid
+	 * inter-operability problems.
+	 */
+	if (smtp_ehlo_dis_maps == 0
+	    || (ehlo_words = maps_find(smtp_ehlo_dis_maps,
+				       STR(iter->addr), 0)) == 0)
+	    ehlo_words = var_smtp_ehlo_dis_words;
+	if (smtp_ehlo_dis_maps && smtp_ehlo_dis_maps->error) {
+	    msg_warn("%s: %s map lookup error for %s",
+		     session->state->request->queue_id,
+		     smtp_ehlo_dis_maps->title, STR(iter->addr));
+	    vstream_longjmp(session->stream, SMTP_ERR_DATA);
+	}
+	discard_mask = ehlo_mask(ehlo_words);
+	if (discard_mask && !(discard_mask & EHLO_MASK_SILENT))
+	    msg_info("discarding EHLO keywords: %s",
+		     str_ehlo_mask(discard_mask));
+
+	/*
+	 * Pick up some useful features offered by the SMTP server. XXX Until
+	 * we have a portable routine to convert from string to off_t with
+	 * proper overflow detection, ignore the message size limit
+	 * advertised by the SMTP server. Otherwise, we might do the wrong
+	 * thing when the server advertises a really huge message size limit.
+	 * 
+	 * XXX Allow for "code (SP|-) ehlo-keyword (SP|=) ehlo-param...",
+	 * because MicroSoft implemented AUTH based on an old draft.
+	 */
+	lines = resp->str;
+	for (n = 0; (words = mystrtok(&lines, "\n")) != 0; /* see below */ ) {
+	    if (mystrtok(&words, "- ")
+		&& (word = mystrtok(&words, " \t=")) != 0) {
+		if (n == 0) {
+		    if (session->helo != 0)
+			myfree(session->helo);
+
+		    /*
+		     * XXX: Keep the original case: we don't expect a single
+		     * SMTP server to randomly change the case of its helo
+		     * response. If different capitalization is detected, we
+		     * should assume disjoint TLS caches.
+		     */
+		    session->helo = mystrdup(word);
+		    if (strcasecmp(word, var_myhostname) == 0
+			&& (state->misc_flags & SMTP_MISC_FLAG_LOOP_DETECT) != 0) {
+			msg_warn("host %s replied to HELO/EHLO"
+				 " with my own hostname %s",
+				 session->namaddrport, var_myhostname);
+			if (session->features & SMTP_FEATURE_BEST_MX)
+			    return (smtp_site_fail(state, DSN_BY_LOCAL_MTA,
+					     SMTP_RESP_FAKE(&fake, "5.4.6"),
+					 "mail for %s loops back to myself",
+						   request->nexthop));
+			else
+			    return (smtp_site_fail(state, DSN_BY_LOCAL_MTA,
+					     SMTP_RESP_FAKE(&fake, "4.4.6"),
+					 "mail for %s loops back to myself",
+						   request->nexthop));
+		    }
+		} else if (strcasecmp(word, "8BITMIME") == 0) {
+		    if ((discard_mask & EHLO_MASK_8BITMIME) == 0)
+			session->features |= SMTP_FEATURE_8BITMIME;
+		} else if (strcasecmp(word, "PIPELINING") == 0) {
+		    if ((discard_mask & EHLO_MASK_PIPELINING) == 0)
+			session->features |= SMTP_FEATURE_PIPELINING;
+		} else if (strcasecmp(word, "XFORWARD") == 0) {
+		    if ((discard_mask & EHLO_MASK_XFORWARD) == 0)
+			while ((word = mystrtok(&words, " \t")) != 0)
+			    session->features |=
+				name_code(xforward_features,
+					  NAME_CODE_FLAG_NONE, word);
+		} else if (strcasecmp(word, "SIZE") == 0) {
+		    if ((discard_mask & EHLO_MASK_SIZE) == 0) {
+			session->features |= SMTP_FEATURE_SIZE;
+			if ((word = mystrtok(&words, " \t")) != 0) {
+			    if (!alldig(word))
+				msg_warn("bad EHLO SIZE limit \"%s\" from %s",
+					 word, session->namaddrport);
+			    else
+				session->size_limit = off_cvt_string(word);
+			}
+		    }
+#ifdef USE_TLS
+		} else if (strcasecmp(word, "STARTTLS") == 0) {
+		    /* Ignored later if we already sent STARTTLS. */
+		    if ((discard_mask & EHLO_MASK_STARTTLS) == 0)
+			session->features |= SMTP_FEATURE_STARTTLS;
+#endif
+#ifdef USE_SASL_AUTH
+		} else if (var_smtp_sasl_enable
+			   && strcasecmp(word, "AUTH") == 0) {
+		    if ((discard_mask & EHLO_MASK_AUTH) == 0)
+			smtp_sasl_helo_auth(session, words);
+#endif
+		} else if (strcasecmp(word, "DSN") == 0) {
+		    if ((discard_mask & EHLO_MASK_DSN) == 0)
+			session->features |= SMTP_FEATURE_DSN;
+		} else if (strcasecmp(word, "SMTPUTF8") == 0) {
+		    if ((discard_mask & EHLO_MASK_SMTPUTF8) == 0)
+			session->features |= SMTP_FEATURE_SMTPUTF8;
+		}
+		n++;
+	    }
+	}
+    }
+    if (msg_verbose)
+	msg_info("server features: 0x%x size %.0f",
+		 session->features, (double) session->size_limit);
+
+    /*
+     * Decide if this delivery requires SMTPUTF8 server support.
+     * 
+     * For now, we require that the remote SMTP server supports SMTPUTF8 when
+     * the sender requested SMTPUTF8 support.
+     * 
+     * XXX EAI Refine this to: the sender requested SMTPUTF8 support AND the
+     * delivery request involves at least one UTF-8 envelope address or
+     * header value.
+     * 
+     * If the sender requested SMTPUTF8 support but the delivery request
+     * involves no UTF-8 envelope address or header value, then we could
+     * still deliver such mail to a non-SMTPUTF8 server, except that we must
+     * either uxtext-encode ORCPT parameters or not send them. We cannot
+     * encode the ORCPT in xtext, because legacy SMTP requires that the
+     * unencoded address consist entirely of printable (graphic and white
+     * space) characters from the US-ASCII repertoire (RFC 3461 section 4). A
+     * correct uxtext encoder will produce a result that an xtext decoder
+     * will pass through unchanged.
+     * 
+     * XXX Should we try to encode headers with RFC 2047 when delivering to a
+     * non-SMTPUTF8 server? That could make life easier for mailing lists.
+     */
+#define DELIVERY_REQUIRES_SMTPUTF8 \
+	((request->smtputf8 & SMTPUTF8_FLAG_REQUESTED) \
+	&& (request->smtputf8 & ~SMTPUTF8_FLAG_REQUESTED))
+
+    /*
+     * Require that the server supports SMTPUTF8 when delivery requires
+     * SMTPUTF8.
+     * 
+     * Fix 20140706: moved this before negotiating TLS, AUTH, and so on.
+     */
+    if ((session->features & SMTP_FEATURE_SMTPUTF8) == 0
+	&& DELIVERY_REQUIRES_SMTPUTF8)
+	return (smtp_mesg_fail(state, DSN_BY_LOCAL_MTA,
+			       SMTP_RESP_FAKE(&fake, "5.6.7"),
+			       "SMTPUTF8 is required, "
+			       "but was not offered by host %s",
+			       session->namaddr));
+
+    /*
+     * Fix 20140706: don't do silly things when the remote server announces
+     * SMTPUTF8 but not 8BITMIME support. Our primary mission is to deliver
+     * mail, not to force people into compliance.
+     */
+    if ((session->features & SMTP_FEATURE_SMTPUTF8) != 0
+	&& (session->features & SMTP_FEATURE_8BITMIME) == 0) {
+	msg_info("host %s offers SMTPUTF8 support, but not 8BITMIME",
+		 session->namaddr);
+	session->features |= SMTP_FEATURE_8BITMIME;
+    }
+
+    /*
+     * We use SMTP command pipelining if the server said it supported it.
+     * Since we use blocking I/O, RFC 2197 says that we should inspect the
+     * TCP window size and not send more than this amount of information.
+     * Unfortunately this information is unavailable using the sockets
+     * interface. However, we *can* get the TCP send buffer size on the local
+     * TCP/IP stack. We should be able to fill this buffer without being
+     * blocked, and then the kernel will effectively do non-blocking I/O for
+     * us by automatically writing out the contents of its send buffer while
+     * we are reading in the responses. In addition to TCP buffering we have
+     * to be aware of application-level buffering by the vstream module,
+     * which is limited to a couple kbytes.
+     * 
+     * XXX No need to do this before and after STARTTLS, but it's not a big deal
+     * if we do.
+     * 
+     * XXX When TLS is turned on, the SMTP-level writes will be encapsulated as
+     * TLS messages. Thus, the TCP-level payload will be larger than the
+     * SMTP-level payload. This has implications for the PIPELINING engine.
+     * 
+     * To avoid deadlock, the PIPELINING engine needs to request a TCP send
+     * buffer size that can hold the unacknowledged commands plus the TLS
+     * encapsulation overhead.
+     * 
+     * The PIPELINING engine keeps the unacknowledged command size <= the
+     * default VSTREAM buffer size (to avoid small-write performance issues
+     * when the VSTREAM buffer size is at its default size). With a default
+     * VSTREAM buffer size of 4096 there is no reason to increase the
+     * unacknowledged command size as the TCP MSS increases. It's safer to
+     * spread the remote SMTP server's recipient processing load over time,
+     * than dumping a very large recipient list all at once.
+     * 
+     * For TLS encapsulation overhead we make a conservative guess: take the
+     * current protocol overhead of ~40 bytes, double the number for future
+     * proofing (~80 bytes), then round up the result to the nearest power of
+     * 2 (128 bytes). Plus, be prepared for worst-case compression that
+     * expands data by 1 kbyte, so that the worst-case SMTP payload per TLS
+     * message becomes 15 kbytes.
+     */
+#define PIPELINING_BUFSIZE	VSTREAM_BUFSIZE
+#ifdef USE_TLS
+#define TLS_WORST_PAYLOAD	16384
+#define TLS_WORST_COMP_OVERHD	1024
+#define TLS_WORST_PROTO_OVERHD	128
+#define TLS_WORST_SMTP_PAYLOAD	(TLS_WORST_PAYLOAD - TLS_WORST_COMP_OVERHD)
+#define TLS_WORST_TOTAL_OVERHD	(TLS_WORST_COMP_OVERHD + TLS_WORST_PROTO_OVERHD)
+#endif
+
+    if (session->features & SMTP_FEATURE_PIPELINING) {
+	SOCKOPT_SIZE optlen;
+	int     tcp_bufsize;
+	int     enc_overhead = 0;
+
+	optlen = sizeof(tcp_bufsize);
+	if (getsockopt(vstream_fileno(session->stream), SOL_SOCKET,
+		       SO_SNDBUF, (char *) &tcp_bufsize, &optlen) < 0)
+	    msg_fatal("%s: getsockopt: %m", myname);
+#ifdef USE_TLS
+	if (state->misc_flags & SMTP_MISC_FLAG_IN_STARTTLS)
+	    enc_overhead +=
+		(1 + (PIPELINING_BUFSIZE - 1)
+		 / TLS_WORST_SMTP_PAYLOAD) * TLS_WORST_TOTAL_OVERHD;
+#endif
+	if (tcp_bufsize < PIPELINING_BUFSIZE + enc_overhead) {
+	    tcp_bufsize = PIPELINING_BUFSIZE + enc_overhead;
+	    if (setsockopt(vstream_fileno(session->stream), SOL_SOCKET,
+			   SO_SNDBUF, (char *) &tcp_bufsize, optlen) < 0)
+		msg_fatal("%s: setsockopt: %m", myname);
+	}
+	if (msg_verbose)
+	    msg_info("Using %s PIPELINING, TCP send buffer size is %d, "
+		     "PIPELINING buffer size is %d",
+		     smtp_mode ? "ESMTP" : "LMTP",
+		     tcp_bufsize, PIPELINING_BUFSIZE);
+    }
+#ifdef USE_TLS
+
+    /*
+     * Skip this part if we already sent STARTTLS.
+     */
+    if ((state->misc_flags & SMTP_MISC_FLAG_IN_STARTTLS) == 0) {
+
+	/*
+	 * Optionally log unused STARTTLS opportunities.
+	 */
+	if ((session->features & SMTP_FEATURE_STARTTLS) &&
+	    var_smtp_tls_note_starttls_offer &&
+	    state->tls->level <= TLS_LEV_NONE)
+	    msg_info("Host offered STARTTLS: [%s]", STR(iter->host));
+
+	/*
+	 * Decide whether or not to send STARTTLS.
+	 */
+	if ((session->features & SMTP_FEATURE_STARTTLS) != 0
+	    && smtp_tls_ctx != 0 && state->tls->level >= TLS_LEV_MAY) {
+
+	    /*
+	     * Prepare for disaster.
+	     */
+	    smtp_stream_setup(state->session->stream, var_smtp_starttls_tmout,
+			      var_smtp_rec_deadline);
+	    if ((except = vstream_setjmp(state->session->stream)) != 0)
+		return (smtp_stream_except(state, except,
+					"receiving the STARTTLS response"));
+
+	    /*
+	     * Send STARTTLS. Recurse when the server accepts STARTTLS, after
+	     * resetting the SASL and EHLO features lists.
+	     * 
+	     * Reset the SASL mechanism list to avoid spurious warnings.
+	     * 
+	     * Use the smtp_sasl_tls_security_options feature to allow SASL
+	     * mechanisms that may not be allowed with plain-text
+	     * connections.
+	     */
+	    smtp_chat_cmd(session, "STARTTLS");
+	    if ((resp = smtp_chat_resp(session))->code / 100 == 2) {
+#ifdef USE_SASL_AUTH
+		if (session->features & SMTP_FEATURE_AUTH)
+		    smtp_sasl_cleanup(session);
+#endif
+		session->features = saved_features;
+		/* XXX Mix-up of per-session and per-request flags. */
+		state->misc_flags |= SMTP_MISC_FLAG_IN_STARTTLS;
+		tls_helo_status = smtp_start_tls(state);
+		state->misc_flags &= ~SMTP_MISC_FLAG_IN_STARTTLS;
+		return (tls_helo_status);
+	    }
+
+	    /*
+	     * Give up if we must use TLS but the server rejects STARTTLS
+	     * although support for it was announced in the EHLO response.
+	     */
+	    session->features &= ~SMTP_FEATURE_STARTTLS;
+	    if (TLS_REQUIRED(state->tls->level))
+		return (smtp_site_fail(state, STR(iter->host), resp,
+		    "TLS is required, but host %s refused to start TLS: %s",
+				       session->namaddr,
+				       translit(resp->str, "\n", " ")));
+	    /* Else try to continue in plain-text mode. */
+	}
+
+	/*
+	 * Give up if we must use TLS but can't for various reasons.
+	 * 
+	 * 200412 Be sure to provide the default clause at the bottom of this
+	 * block. When TLS is required we must never, ever, end up in
+	 * plain-text mode.
+	 */
+	if (TLS_REQUIRED(state->tls->level)) {
+	    if (!(session->features & SMTP_FEATURE_STARTTLS)) {
+		return (smtp_site_fail(state, DSN_BY_LOCAL_MTA,
+				       SMTP_RESP_FAKE(&fake, "4.7.4"),
+			  "TLS is required, but was not offered by host %s",
+				       session->namaddr));
+	    } else if (smtp_tls_ctx == 0) {
+		return (smtp_site_fail(state, DSN_BY_LOCAL_MTA,
+				       SMTP_RESP_FAKE(&fake, "4.7.5"),
+		     "TLS is required, but our TLS engine is unavailable"));
+	    } else {
+		msg_warn("%s: TLS is required but unavailable, don't know why",
+			 myname);
+		return (smtp_site_fail(state, DSN_BY_LOCAL_MTA,
+				       SMTP_RESP_FAKE(&fake, "4.7.0"),
+				       "TLS is required, but unavailable"));
+	    }
+	}
+    }
+#endif
+#ifdef USE_SASL_AUTH
+    if (var_smtp_sasl_enable && (session->features & SMTP_FEATURE_AUTH))
+	return (smtp_sasl_helo_login(state));
+#endif
+
+    return (0);
+}
+
+#ifdef USE_TLS
+
+/* smtp_start_tls - turn on TLS and recurse into the HELO dialog */
+
+static int smtp_start_tls(SMTP_STATE *state)
+{
+    SMTP_SESSION *session = state->session;
+    SMTP_ITERATOR *iter = state->iterator;
+    TLS_CLIENT_START_PROPS start_props;
+    VSTRING *serverid;
+    SMTP_RESP fake;
+    TLS_CLIENT_INIT_PROPS init_props;
+    VSTREAM *tlsproxy;
+    VSTRING *port_buf;
+
+    /*
+     * When the TLS handshake succeeds, we can reuse a connection only if TLS
+     * remains turned on for the lifetime of that connection. This requires
+     * that the TLS library state is maintained in some proxy process, for
+     * example, in tlsproxy(8). We then store the proxy file handle in the
+     * connection cache, and reuse that file handle.
+     * 
+     * Otherwise, we must turn off connection caching. We can't turn off TLS in
+     * one SMTP client process, save the open connection to a cache which is
+     * shared with all SMTP clients, migrate the connection to another SMTP
+     * client, and resume TLS there. When the TLS handshake fails, we can't
+     * reuse the SMTP connection either, because the conversation is in an
+     * unknown state.
+     */
+    if (state->tls->conn_reuse == 0)
+	DONT_CACHE_THIS_SESSION;
+
+    /*
+     * The following assumes sites that use TLS in a perverse configuration:
+     * multiple hosts per hostname, or even multiple hosts per IP address.
+     * All this without a shared TLS session cache, and they still want to
+     * use TLS session caching???
+     * 
+     * The TLS session cache records the trust chain verification status of
+     * cached sessions. Different transports may have different CAfile or
+     * CApath settings, perhaps to allow authenticated connections to sites
+     * with private CA certs without trusting said private certs for other
+     * sites. So we cannot assume that a trust chain valid for one transport
+     * is valid for another. Therefore the client session id must include
+     * either the transport name or the values of CAfile and CApath. We use
+     * the transport name.
+     * 
+     * XXX: We store only one session per lookup key. Ideally the the key maps
+     * 1-to-1 to a server TLS session cache. We use the IP address, port and
+     * ehlo response name to build a lookup key that works for split caches
+     * (that announce distinct names) behind a load balancer.
+     * 
+     * XXX: The TLS library will salt the serverid with further details of the
+     * protocol and cipher requirements including the server ehlo response.
+     * Deferring the helo to the digested suffix results in more predictable
+     * SSL session lookup key lengths.
+     */
+    serverid = vstring_alloc(10);
+    smtp_key_prefix(serverid, "&", state->iterator, SMTP_KEY_FLAG_SERVICE
+		    | SMTP_KEY_FLAG_CUR_NEXTHOP	/* With port */
+		    | SMTP_KEY_FLAG_HOSTNAME
+		    | SMTP_KEY_FLAG_ADDR);
+
+    if (state->tls->conn_reuse) {
+	TLS_CLIENT_PARAMS tls_params;
+
+	/*
+	 * Send all our wishes in one big request.
+	 */
+	TLS_PROXY_CLIENT_INIT_PROPS(&init_props,
+				    log_param = VAR_LMTP_SMTP(TLS_LOGLEVEL),
+				    log_level = var_smtp_tls_loglevel,
+				    verifydepth = var_smtp_tls_scert_vd,
+				    cache_type
+				    = LMTP_SMTP_SUFFIX(TLS_MGR_SCACHE),
+				    chain_files = var_smtp_tls_chain_files,
+				    cert_file = var_smtp_tls_cert_file,
+				    key_file = var_smtp_tls_key_file,
+				    dcert_file = var_smtp_tls_dcert_file,
+				    dkey_file = var_smtp_tls_dkey_file,
+				    eccert_file = var_smtp_tls_eccert_file,
+				    eckey_file = var_smtp_tls_eckey_file,
+				    CAfile = var_smtp_tls_CAfile,
+				    CApath = var_smtp_tls_CApath,
+				    mdalg = var_smtp_tls_fpt_dgst);
+	TLS_PROXY_CLIENT_START_PROPS(&start_props,
+				     timeout = var_smtp_starttls_tmout,
+				     tls_level = state->tls->level,
+				     nexthop = session->tls_nexthop,
+				     host = STR(iter->host),
+				     namaddr = session->namaddrport,
+				     sni = state->tls->sni,
+				     serverid = vstring_str(serverid),
+				     helo = session->helo,
+				     protocols = state->tls->protocols,
+				     cipher_grade = state->tls->grade,
+				     cipher_exclusions
+				     = vstring_str(state->tls->exclusions),
+				     matchargv = state->tls->matchargv,
+				     mdalg = var_smtp_tls_fpt_dgst,
+				     dane = state->tls->dane);
+
+	/*
+	 * The tlsproxy(8) server enforces timeouts that are larger than
+	 * those specified by the tlsproxy(8) client. These timeouts are a
+	 * safety net for the case that the tlsproxy(8) client fails to
+	 * enforce time limits. Normally, the tlsproxy(8) client would time
+	 * out and trigger a plaintext event in the tlsproxy(8) server, and
+	 * cause it to tear down the session.
+	 * 
+	 * However, the tlsproxy(8) server has no insight into the SMTP
+	 * protocol, and therefore it cannot by itself support different
+	 * timeouts at different SMTP protocol stages. Instead, we specify
+	 * the largest timeout (end-of-data) and rely on the SMTP client to
+	 * time out first, which normally results in a plaintext event in the
+	 * tlsproxy(8) server. Unfortunately, we cannot permit plaintext
+	 * events during the TLS handshake, so we specify a separate timeout
+	 * for that stage (the end-of-data timeout would be unreasonably
+	 * large anyway).
+	 */
+#define PROXY_OPEN_FLAGS \
+        (TLS_PROXY_FLAG_ROLE_CLIENT | TLS_PROXY_FLAG_SEND_CONTEXT)
+
+	port_buf = vstring_alloc(100);		/* minimize fragmentation */
+	vstring_sprintf(port_buf, "%d", ntohs(iter->port));
+	tlsproxy =
+	    tls_proxy_open(var_tlsproxy_service, PROXY_OPEN_FLAGS,
+			   session->stream, STR(iter->addr),
+			   STR(port_buf), var_smtp_starttls_tmout,
+			   var_smtp_data2_tmout, state->service,
+			   tls_proxy_client_param_from_config(&tls_params),
+			   &init_props, &start_props);
+	vstring_free(port_buf);
+
+	/*
+	 * To insert tlsproxy(8) between this process and the remote SMTP
+	 * server, we swap the file descriptors between the tlsproxy and
+	 * session->stream VSTREAMS, so that we don't lose all the
+	 * user-configurable session->stream attributes (such as longjump
+	 * buffers or timeouts).
+	 * 
+	 * TODO: the tlsproxy RPCs should return more error detail than a "NO"
+	 * result. OTOH, the in-process TLS engine does not return such info
+	 * either.
+	 * 
+	 * If the tlsproxy request fails we do not fall back to the in-process
+	 * TLS stack. Reason: the admin enabled connection reuse to respect
+	 * receiver policy; silently violating such policy would not be
+	 * useful.
+	 * 
+	 * We also don't fall back to the in-process TLS stack under low-traffic
+	 * conditions, to avoid frustrating attempts to debug a problem with
+	 * using the tlsproxy(8) service.
+	 */
+	if (tlsproxy == 0) {
+	    session->tls_context = 0;
+	} else {
+	    vstream_control(tlsproxy,
+			    CA_VSTREAM_CTL_DOUBLE,
+			    CA_VSTREAM_CTL_END);
+	    vstream_control(session->stream,
+			    CA_VSTREAM_CTL_SWAP_FD(tlsproxy),
+			    CA_VSTREAM_CTL_END);
+	    (void) vstream_fclose(tlsproxy);	/* direct-to-server stream! */
+
+	    /*
+	     * There must not be any pending data in the stream buffers
+	     * before we read the TLS context attributes.
+	     */
+	    vstream_fpurge(session->stream, VSTREAM_PURGE_BOTH);
+
+	    /*
+	     * After plumbing the plaintext stream, receive the TLS context
+	     * object. For this we use the same VSTREAM buffer that we also
+	     * use to receive subsequent SMTP commands, therefore we must be
+	     * prepared for the possibility that the remote SMTP server
+	     * starts talking immediately. The tlsproxy implementation sends
+	     * the TLS context before remote content. The attribute protocol
+	     * is robust enough that an adversary cannot insert their own TLS
+	     * context attributes.
+	     */
+	    session->tls_context = tls_proxy_context_receive(session->stream);
+	    if (session->tls_context) {
+		session->features |= SMTP_FEATURE_FROM_PROXY;
+		tls_log_summary(TLS_ROLE_CLIENT, TLS_USAGE_NEW,
+				session->tls_context);
+	    }
+	}
+    } else {					/* state->tls->conn_reuse */
+
+	/*
+	 * As of Postfix 2.5, tls_client_start() tries hard to always
+	 * complete the TLS handshake. It records the verification and match
+	 * status in the resulting TLScontext. It is now up to the
+	 * application to abort the TLS connection if it chooses.
+	 * 
+	 * XXX When tls_client_start() fails then we don't know what state the
+	 * SMTP connection is in, so we give up on this connection even if we
+	 * are not required to use TLS.
+	 * 
+	 * Large parameter lists are error-prone, so we emulate a language
+	 * feature that C does not have natively: named parameter lists.
+	 */
+	session->tls_context =
+	    TLS_CLIENT_START(&start_props,
+			     ctx = smtp_tls_ctx,
+			     stream = session->stream,
+			     fd = -1,
+			     timeout = var_smtp_starttls_tmout,
+			     tls_level = state->tls->level,
+			     nexthop = session->tls_nexthop,
+			     host = STR(iter->host),
+			     namaddr = session->namaddrport,
+			     sni = state->tls->sni,
+			     serverid = vstring_str(serverid),
+			     helo = session->helo,
+			     protocols = state->tls->protocols,
+			     cipher_grade = state->tls->grade,
+			     cipher_exclusions
+			     = vstring_str(state->tls->exclusions),
+			     matchargv = state->tls->matchargv,
+			     mdalg = var_smtp_tls_fpt_dgst,
+			     dane = state->tls->dane);
+
+	/*
+	 * At this point there must not be any pending data in the stream
+	 * buffers.
+	 */
+	vstream_fpurge(session->stream, VSTREAM_PURGE_BOTH);
+    }						/* state->tls->conn_reuse */
+
+    vstring_free(serverid);
+
+    if (session->tls_context == 0) {
+
+	/*
+	 * We must avoid further I/O, the peer is in an undefined state.
+	 */
+	DONT_USE_FORBIDDEN_SESSION;
+
+	/*
+	 * If TLS is optional, try delivery to the same server over a
+	 * plaintext connection. Otherwise we would defer mail forever with
+	 * destinations that have no alternate MX host.
+	 * 
+	 * Don't fall back to plaintext if we were willing to use SASL-over-TLS
+	 * authentication. If the server doesn't announce SASL support over
+	 * plaintext connections, then we don't want delivery to fail with
+	 * "relay access denied".
+	 * 
+	 * If TLS is opportunistic, don't throttle the destination, otherwise if
+	 * the mail is volume is high enough we may have difficulty ever
+	 * draining even the deferred mail, as new mail provides a constant
+	 * stream of negative feedback.
+	 */
+	if (PLAINTEXT_FALLBACK_OK_AFTER_STARTTLS_FAILURE)
+	    RETRY_AS_PLAINTEXT;
+	return (smtp_misc_fail(state, state->tls->level == TLS_LEV_MAY ?
+			       SMTP_NOTHROTTLE : SMTP_THROTTLE,
+			       DSN_BY_LOCAL_MTA,
+			       SMTP_RESP_FAKE(&fake, "4.7.5"),
+			       "Cannot start TLS: handshake failure"));
+    }
+
+    /*
+     * If we are verifying the server certificate and are not happy with the
+     * result, abort the delivery here. We have a usable TLS session with the
+     * server, so no need to disable I/O, ... we can even be polite and send
+     * "QUIT".
+     * 
+     * See src/tls/tls_level.c and src/tls/tls.h. Levels above "encrypt" require
+     * matching.  Levels >= "dane" require CA or DNSSEC trust.
+     * 
+     * When DANE TLSA records specify an end-entity certificate, the trust and
+     * match bits always coincide, but it is fine to report the wrong
+     * end-entity certificate as untrusted rather than unmatched.
+     */
+    if (TLS_MUST_TRUST(state->tls->level))
+	if (!TLS_CERT_IS_TRUSTED(session->tls_context))
+	    return (smtp_site_fail(state, DSN_BY_LOCAL_MTA,
+				   SMTP_RESP_FAKE(&fake, "4.7.5"),
+				   "Server certificate not trusted"));
+    if (TLS_MUST_MATCH(state->tls->level))
+	if (!TLS_CERT_IS_MATCHED(session->tls_context))
+	    return (smtp_site_fail(state, DSN_BY_LOCAL_MTA,
+				   SMTP_RESP_FAKE(&fake, "4.7.5"),
+				   "Server certificate not verified"));
+
+    /*
+     * At this point we have to re-negotiate the "EHLO" to reget the
+     * feature-list.
+     */
+    return (smtp_helo(state));
+}
+
+#endif
+
+/* smtp_hbc_logger - logging call-back for header/body checks */
+
+static void smtp_hbc_logger(void *context, const char *action,
+			            const char *where, const char *content,
+			            const char *text)
+{
+    const SMTP_STATE *state = (SMTP_STATE *) context;
+
+    if (*text) {
+	msg_info("%s: %s: %s %.60s: %s",
+		 state->request->queue_id, action, where, content, text);
+    } else {
+	msg_info("%s: %s: %s %.60s",
+		 state->request->queue_id, action, where, content);
+    }
+}
+
+/* smtp_text_out - output one header/body record */
+
+static void smtp_text_out(void *context, int rec_type,
+			          const char *text, ssize_t len,
+			          off_t unused_offset)
+{
+    SMTP_STATE *state = (SMTP_STATE *) context;
+    SMTP_SESSION *session = state->session;
+    ssize_t data_left;
+    const char *data_start;
+
+    /*
+     * Deal with an impedance mismatch between Postfix queue files (record
+     * length <= $message_line_length_limit) and SMTP (DATA record length <=
+     * $smtp_line_length_limit). The code below does a little too much work
+     * when the SMTP line length limit is disabled, but it avoids code
+     * duplication, and thus, it avoids testing and maintenance problems.
+     */
+    data_left = len;
+    data_start = text;
+    do {
+	if (state->space_left == var_smtp_line_limit
+	    && data_left > 0 && *data_start == '.')
+	    smtp_fputc('.', session->stream);
+	if (var_smtp_line_limit > 0 && data_left >= state->space_left) {
+	    smtp_fputs(data_start, state->space_left, session->stream);
+	    data_start += state->space_left;
+	    data_left -= state->space_left;
+	    state->space_left = var_smtp_line_limit;
+	    if (data_left > 0 || rec_type == REC_TYPE_CONT) {
+		smtp_fputc(' ', session->stream);
+		state->space_left -= 1;
+	    }
+	} else {
+	    if (rec_type == REC_TYPE_CONT) {
+		smtp_fwrite(data_start, data_left, session->stream);
+		state->space_left -= data_left;
+	    } else {
+		smtp_fputs(data_start, data_left, session->stream);
+		state->space_left = var_smtp_line_limit;
+	    }
+	    break;
+	}
+    } while (data_left > 0);
+}
+
+/* smtp_format_out - output one header/body record */
+
+static void PRINTFLIKE(3, 4) smtp_format_out(void *, int, const char *,...);
+
+static void smtp_format_out(void *context, int rec_type, const char *fmt,...)
+{
+    static VSTRING *vp;
+    va_list ap;
+
+    if (vp == 0)
+	vp = vstring_alloc(100);
+    va_start(ap, fmt);
+    vstring_vsprintf(vp, fmt, ap);
+    va_end(ap);
+    smtp_text_out(context, rec_type, vstring_str(vp), VSTRING_LEN(vp), 0);
+}
+
+/* smtp_header_out - output one message header */
+
+static void smtp_header_out(void *context, int unused_header_class,
+			            const HEADER_OPTS *unused_info,
+			            VSTRING *buf, off_t offset)
+{
+    char   *start = vstring_str(buf);
+    char   *line;
+    char   *next_line;
+
+    /*
+     * This code destroys the header. We could try to avoid clobbering it,
+     * but we're not going to use the data any further.
+     */
+    for (line = start; line; line = next_line) {
+	next_line = split_at(line, '\n');
+	smtp_text_out(context, REC_TYPE_NORM, line, next_line ?
+		      next_line - line - 1 : strlen(line), offset);
+    }
+}
+
+/* smtp_header_rewrite - rewrite message header before output */
+
+static void smtp_header_rewrite(void *context, int header_class,
+				        const HEADER_OPTS *header_info,
+				        VSTRING *buf, off_t offset)
+{
+    SMTP_STATE *state = (SMTP_STATE *) context;
+    int     did_rewrite = 0;
+    char   *line;
+    char   *start;
+    char   *next_line;
+    char   *end_line;
+    char   *result;
+
+    /*
+     * Apply optional header filtering.
+     */
+    if (smtp_header_checks) {
+	result = hbc_header_checks(context, smtp_header_checks, header_class,
+				   header_info, buf, offset);
+	if (result == 0)
+	    return;
+	if (result == HBC_CHECKS_STAT_ERROR) {
+	    msg_warn("%s: smtp header checks lookup error",
+		     state->request->queue_id);
+	    vstream_longjmp(state->session->stream, SMTP_ERR_DATA);
+	}
+	if (result != STR(buf)) {
+	    vstring_strcpy(buf, result);
+	    myfree(result);
+	}
+    }
+
+    /*
+     * Rewrite primary header addresses that match the smtp_generic_maps. The
+     * cleanup server already enforces that all headers have proper lengths
+     * and that all addresses are in proper form, so we don't have to repeat
+     * that.
+     */
+    if (smtp_generic_maps && header_info && header_class == MIME_HDR_PRIMARY
+	&& (header_info->flags & (HDR_OPT_SENDER | HDR_OPT_RECIP)) != 0) {
+	TOK822 *tree;
+	TOK822 **addr_list;
+	TOK822 **tpp;
+
+	tree = tok822_parse(vstring_str(buf)
+			    + strlen(header_info->name) + 1);
+	addr_list = tok822_grep(tree, TOK822_ADDR);
+	for (tpp = addr_list; *tpp; tpp++)
+	    did_rewrite |= smtp_map11_tree(tpp[0], smtp_generic_maps,
+				     smtp_ext_prop_mask & EXT_PROP_GENERIC);
+	if (did_rewrite) {
+	    vstring_truncate(buf, strlen(header_info->name));
+	    vstring_strcat(buf, ": ");
+	    tok822_externalize(buf, tree, TOK822_STR_HEAD);
+	}
+	myfree((void *) addr_list);
+	tok822_free_tree(tree);
+    }
+
+    /*
+     * Pass through unmodified headers without reconstruction.
+     */
+    if (did_rewrite == 0) {
+	smtp_header_out(context, header_class, header_info, buf, offset);
+	return;
+    }
+
+    /*
+     * A rewritten address list contains one address per line. The code below
+     * replaces newlines by spaces, to fit as many addresses on a line as
+     * possible (without rearranging the order of addresses). Prepending
+     * white space to the beginning of lines is delegated to the output
+     * routine.
+     * 
+     * Code derived from cleanup_fold_header().
+     */
+    for (line = start = vstring_str(buf); line != 0; line = next_line) {
+	end_line = line + strcspn(line, "\n");
+	if (line > start) {
+	    if (end_line - start < 70) {	/* TAB counts as one */
+		line[-1] = ' ';
+	    } else {
+		start = line;
+	    }
+	}
+	next_line = *end_line ? end_line + 1 : 0;
+    }
+
+    /*
+     * Prepend a tab to continued header lines that went through the address
+     * rewriting machinery. Just like smtp_header_out(), this code destroys
+     * the header. We could try to avoid clobbering it, but we're not going
+     * to use the data any further.
+     * 
+     * Code derived from cleanup_out_header().
+     */
+    for (line = start = vstring_str(buf); line != 0; line = next_line) {
+	next_line = split_at(line, '\n');
+	if (line == start || IS_SPACE_TAB(*line)) {
+	    smtp_text_out(state, REC_TYPE_NORM, line, next_line ?
+			  next_line - line - 1 : strlen(line), offset);
+	} else {
+	    smtp_format_out(state, REC_TYPE_NORM, "\t%s", line);
+	}
+    }
+}
+
+/* smtp_body_rewrite - rewrite message body before output */
+
+static void smtp_body_rewrite(void *context, int type,
+			              const char *buf, ssize_t len,
+			              off_t offset)
+{
+    SMTP_STATE *state = (SMTP_STATE *) context;
+    char   *result;
+
+    /*
+     * Apply optional body filtering.
+     */
+    if (smtp_body_checks) {
+	result = hbc_body_checks(context, smtp_body_checks, buf, len, offset);
+	if (result == buf) {
+	    smtp_text_out(state, type, buf, len, offset);
+	} else if (result == HBC_CHECKS_STAT_ERROR) {
+	    msg_warn("%s: smtp body checks lookup error",
+		     state->request->queue_id);
+	    vstream_longjmp(state->session->stream, SMTP_ERR_DATA);
+	} else if (result != 0) {
+	    smtp_text_out(state, type, result, strlen(result), offset);
+	    myfree(result);
+	}
+    }
+}
+
+/* smtp_mime_fail - MIME problem */
+
+static void smtp_mime_fail(SMTP_STATE *state, int mime_errs)
+{
+    const MIME_STATE_DETAIL *detail;
+    SMTP_RESP fake;
+
+    detail = mime_state_detail(mime_errs);
+    smtp_mesg_fail(state, DSN_BY_LOCAL_MTA,
+		   SMTP_RESP_FAKE(&fake, detail->dsn),
+		   "%s", detail->text);
+}
+
+/* smtp_loop - exercise the SMTP protocol engine */
+
+static int smtp_loop(SMTP_STATE *state, NOCLOBBER int send_state,
+		             NOCLOBBER int recv_state)
+{
+    const char *myname = "smtp_loop";
+    DELIVER_REQUEST *request = state->request;
+    SMTP_SESSION *session = state->session;
+    SMTP_ITERATOR *iter = state->iterator;
+    SMTP_RESP *resp;
+    RECIPIENT *rcpt;
+    VSTRING *next_command = vstring_alloc(100);
+    int    *NOCLOBBER survivors = 0;
+    NOCLOBBER int next_state;
+    NOCLOBBER int next_rcpt;
+    NOCLOBBER int send_rcpt;
+    NOCLOBBER int recv_rcpt;
+    NOCLOBBER int nrcpt;
+    NOCLOBBER int recv_done;
+    int     except;
+    int     rec_type;
+    NOCLOBBER int prev_type = 0;
+    NOCLOBBER int mail_from_rejected;
+    NOCLOBBER int downgrading;
+    int     mime_errs;
+    SMTP_RESP fake;
+    int     fail_status;
+
+    /*
+     * Macros for readability.
+     */
+#define REWRITE_ADDRESS(dst, src) do { \
+	vstring_strcpy(dst, src); \
+	if (*(src) && smtp_generic_maps) \
+	    smtp_map11_internal(dst, smtp_generic_maps, \
+		smtp_ext_prop_mask & EXT_PROP_GENERIC); \
+    } while (0)
+
+#define QUOTE_ADDRESS(dst, src) do { \
+	if (*(src) && var_smtp_quote_821_env) { \
+	    quote_821_local(dst, src); \
+	} else { \
+	    vstring_strcpy(dst, src); \
+	} \
+    } while (0)
+
+    /* Caution: changes to RETURN() also affect code outside the main loop. */
+
+#define RETURN(x) do { \
+	if (recv_state != SMTP_STATE_LAST) \
+	    DONT_CACHE_THIS_SESSION; \
+	vstring_free(next_command); \
+	if (survivors) \
+	    myfree((void *) survivors); \
+	if (session->mime_state) \
+	    session->mime_state = mime_state_free(session->mime_state); \
+	return (x); \
+    } while (0)
+
+#define SENDER_IS_AHEAD \
+	(recv_state < send_state || recv_rcpt != send_rcpt)
+
+#define SENDER_IN_WAIT_STATE \
+	(send_state == SMTP_STATE_DOT || send_state == SMTP_STATE_LAST)
+
+#define SENDING_MAIL \
+	(recv_state <= SMTP_STATE_DOT)
+
+#define CANT_RSET_THIS_SESSION \
+	(session->features |= SMTP_FEATURE_RSET_REJECTED)
+
+    /*
+     * Pipelining support requires two loops: one loop for sending and one
+     * for receiving. Each loop has its own independent state. Most of the
+     * time the sender can run ahead of the receiver by as much as the TCP
+     * send buffer permits. There are only two places where the sender must
+     * wait for status information from the receiver: once after sending DATA
+     * and once after sending QUIT.
+     * 
+     * The sender state advances until the TCP send buffer would overflow, or
+     * until the sender needs status information from the receiver. At that
+     * point the receiver starts processing responses. Once the receiver has
+     * caught up with the sender, the sender resumes sending commands. If the
+     * receiver detects a serious problem (MAIL FROM rejected, all RCPT TO
+     * commands rejected, DATA rejected) it forces the sender to abort the
+     * SMTP dialog with RSET and QUIT.
+     */
+    nrcpt = 0;
+    next_rcpt = send_rcpt = recv_rcpt = recv_done = 0;
+    mail_from_rejected = 0;
+
+    /*
+     * Prepare for disaster. This should not be needed because the design
+     * guarantees that no output is flushed before smtp_chat_resp() is
+     * called.
+     * 
+     * 1) Every SMTP command fits entirely in a VSTREAM output buffer.
+     * 
+     * 2) smtp_loop() never invokes smtp_chat_cmd() without making sure that
+     * there is sufficient space for the command in the output buffer.
+     * 
+     * 3) smtp_loop() flushes the output buffer to avoid server timeouts.
+     * 
+     * Changing any of these would violate the design, and would likely break
+     * SMTP pipelining.
+     * 
+     * We set up the error handler anyway (only upon entry to avoid wasting
+     * resources) because 1) there is code below that expects that VSTREAM
+     * timeouts are enabled, and 2) this allows us to detect if someone broke
+     * Postfix by introducing spurious flush before read operations.
+     */
+    if (send_state < SMTP_STATE_XFORWARD_NAME_ADDR
+	|| send_state > SMTP_STATE_QUIT)
+	msg_panic("%s: bad sender state %d (receiver state %d)",
+		  myname, send_state, recv_state);
+    smtp_stream_setup(session->stream, *xfer_timeouts[send_state],
+		      var_smtp_rec_deadline);
+    if ((except = vstream_setjmp(session->stream)) != 0) {
+	msg_warn("smtp_proto: spurious flush before read in send state %d",
+		 send_state);
+	RETURN(SENDING_MAIL ? smtp_stream_except(state, except,
+					     xfer_states[send_state]) : -1);
+    }
+
+    /*
+     * The main protocol loop.
+     */
+    do {
+
+	/*
+	 * Build the next command.
+	 */
+	switch (send_state) {
+
+	    /*
+	     * Sanity check.
+	     */
+	default:
+	    msg_panic("%s: bad sender state %d", myname, send_state);
+
+	    /*
+	     * Build the XFORWARD command. With properly sanitized
+	     * information, the command length stays within the 512 byte
+	     * command line length limit.
+	     * 
+	     * XXX smtpd_xforward_preset() initializes some fields as "unknown"
+	     * and some as null; historically, pickup(8) does not send any of
+	     * these, and the queue manager presets absent fields to "not
+	     * available" except for the rewrite context which is preset to
+	     * local by way of migration aid.  These definitions need to be
+	     * centralized for maintainability.
+	     */
+#ifndef CAN_FORWARD_CLIENT_NAME
+#define _ATTR_AVAIL_AND_KNOWN_(val) \
+	(DEL_REQ_ATTR_AVAIL(val) && strcasecmp((val), "unknown"))
+#define CAN_FORWARD_CLIENT_NAME	_ATTR_AVAIL_AND_KNOWN_
+#define CAN_FORWARD_CLIENT_ADDR	_ATTR_AVAIL_AND_KNOWN_
+#define CAN_FORWARD_CLIENT_PORT	_ATTR_AVAIL_AND_KNOWN_
+#define CAN_FORWARD_PROTO_NAME	_ATTR_AVAIL_AND_KNOWN_
+#define CAN_FORWARD_HELO_NAME	DEL_REQ_ATTR_AVAIL
+#define CAN_FORWARD_IDENT_NAME	DEL_REQ_ATTR_AVAIL
+#define CAN_FORWARD_RWR_CONTEXT	DEL_REQ_ATTR_AVAIL
+#endif
+
+	case SMTP_STATE_XFORWARD_NAME_ADDR:
+	    vstring_strcpy(next_command, XFORWARD_CMD);
+	    if ((session->features & SMTP_FEATURE_XFORWARD_NAME)
+		&& CAN_FORWARD_CLIENT_NAME(request->client_name)) {
+		vstring_strcat(next_command, " " XFORWARD_NAME "=");
+		xtext_quote_append(next_command, request->client_name, "");
+	    }
+	    if ((session->features & SMTP_FEATURE_XFORWARD_ADDR)
+		&& CAN_FORWARD_CLIENT_ADDR(request->client_addr)) {
+		vstring_strcat(next_command, " " XFORWARD_ADDR "=");
+		xtext_quote_append(next_command, request->client_addr, "");
+	    }
+	    if ((session->features & SMTP_FEATURE_XFORWARD_PORT)
+		&& CAN_FORWARD_CLIENT_PORT(request->client_port)) {
+		vstring_strcat(next_command, " " XFORWARD_PORT "=");
+		xtext_quote_append(next_command, request->client_port, "");
+	    }
+	    if (session->send_proto_helo)
+		next_state = SMTP_STATE_XFORWARD_PROTO_HELO;
+	    else
+		next_state = SMTP_STATE_MAIL;
+	    break;
+
+	case SMTP_STATE_XFORWARD_PROTO_HELO:
+	    vstring_strcpy(next_command, XFORWARD_CMD);
+	    if ((session->features & SMTP_FEATURE_XFORWARD_PROTO)
+		&& CAN_FORWARD_PROTO_NAME(request->client_proto)) {
+		vstring_strcat(next_command, " " XFORWARD_PROTO "=");
+		xtext_quote_append(next_command, request->client_proto, "");
+	    }
+	    if ((session->features & SMTP_FEATURE_XFORWARD_HELO)
+		&& CAN_FORWARD_HELO_NAME(request->client_helo)) {
+		vstring_strcat(next_command, " " XFORWARD_HELO "=");
+		xtext_quote_append(next_command, request->client_helo, "");
+	    }
+	    if ((session->features & SMTP_FEATURE_XFORWARD_IDENT)
+		&& CAN_FORWARD_IDENT_NAME(request->log_ident)) {
+		vstring_strcat(next_command, " " XFORWARD_IDENT "=");
+		xtext_quote_append(next_command, request->log_ident, "");
+	    }
+	    if ((session->features & SMTP_FEATURE_XFORWARD_DOMAIN)
+		&& CAN_FORWARD_RWR_CONTEXT(request->rewrite_context)) {
+		vstring_strcat(next_command, " " XFORWARD_DOMAIN "=");
+		xtext_quote_append(next_command,
+		     strcmp(request->rewrite_context, MAIL_ATTR_RWR_LOCAL) ?
+			      XFORWARD_DOM_REMOTE : XFORWARD_DOM_LOCAL, "");
+	    }
+	    next_state = SMTP_STATE_MAIL;
+	    break;
+
+	    /*
+	     * Build the MAIL FROM command.
+	     */
+	case SMTP_STATE_MAIL:
+	    request->msg_stats.reuse_count = session->reuse_count;
+	    GETTIMEOFDAY(&request->msg_stats.conn_setup_done);
+	    REWRITE_ADDRESS(session->scratch2, request->sender);
+	    QUOTE_ADDRESS(session->scratch, vstring_str(session->scratch2));
+	    vstring_sprintf(next_command, "MAIL FROM:<%s>",
+			    vstring_str(session->scratch));
+	    /* XXX Don't announce SIZE if we're going to MIME downgrade. */
+	    if (session->features & SMTP_FEATURE_SIZE	/* RFC 1870 */
+		&& !SMTP_MIME_DOWNGRADE(session, request))
+		vstring_sprintf_append(next_command, " SIZE=%lu",
+				       request->data_size);
+	    if (session->features & SMTP_FEATURE_8BITMIME) {	/* RFC 1652 */
+		if (strcmp(request->encoding, MAIL_ATTR_ENC_8BIT) == 0)
+		    vstring_strcat(next_command, " BODY=8BITMIME");
+		else if (strcmp(request->encoding, MAIL_ATTR_ENC_7BIT) == 0)
+		    vstring_strcat(next_command, " BODY=7BIT");
+		else if (strcmp(request->encoding, MAIL_ATTR_ENC_NONE) != 0)
+		    msg_warn("%s: unknown content encoding: %s",
+			     request->queue_id, request->encoding);
+	    }
+	    if (session->features & SMTP_FEATURE_DSN) {
+		if (request->dsn_envid[0]) {
+		    vstring_sprintf_append(next_command, " ENVID=");
+		    xtext_quote_append(next_command, request->dsn_envid, "+=");
+		}
+		if (request->dsn_ret)
+		    vstring_sprintf_append(next_command, " RET=%s",
+					   dsn_ret_str(request->dsn_ret));
+	    }
+
+	    /*
+	     * Request SMTPUTF8 when the remote SMTP server supports SMTPUTF8
+	     * and the sender requested SMTPUTF8 support.
+	     * 
+	     * If the sender requested SMTPUTF8 but the remote SMTP server does
+	     * not support SMTPUTF8, then we have already determined earlier
+	     * that delivering this message without SMTPUTF8 will not break
+	     * the SMTPUTF8 promise that was made to the sender.
+	     */
+	    if ((session->features & SMTP_FEATURE_SMTPUTF8) != 0
+		&& (request->smtputf8 & SMTPUTF8_FLAG_REQUESTED) != 0)
+		vstring_strcat(next_command, " SMTPUTF8");
+
+	    /*
+	     * We authenticate the local MTA only, but not the sender.
+	     */
+#ifdef USE_SASL_AUTH
+	    if (var_smtp_sasl_enable
+		&& var_smtp_dummy_mail_auth
+		&& (session->features & SMTP_FEATURE_AUTH))
+		vstring_strcat(next_command, " AUTH=<>");
+#endif
+
+	    /*
+	     * CVE-2009-3555 (TLS renegotiation). Try to detect a mail
+	     * hijacking attack that prepends malicious EHLO/MAIL/RCPT/DATA
+	     * commands to our TLS session.
+	     * 
+	     * For the attack to succeed, the remote SMTP server must reply to
+	     * the malicious EHLO/MAIL/RCPT/DATA commands after completing
+	     * TLS (re)negotiation, so that the replies arrive in our TLS
+	     * session (otherwise the Postfix SMTP client would time out
+	     * waiting for an answer). With some luck we can detect this
+	     * specific attack as a server MAIL reply that arrives before we
+	     * send our own MAIL command.
+	     * 
+	     * We don't apply this test to the HELO command because the result
+	     * would be very timing sensitive, and we don't apply this test
+	     * to RCPT and DATA replies because these may be pipelined for
+	     * legitimate reasons.
+	     */
+#ifdef USE_TLS
+	    if (var_smtp_tls_blk_early_mail_reply
+		&& (state->misc_flags & SMTP_MISC_FLAG_IN_STARTTLS) != 0
+		&& (vstream_peek(session->stream) > 0
+		    || peekfd(vstream_fileno(session->stream)) > 0))
+		session->features |= SMTP_FEATURE_EARLY_TLS_MAIL_REPLY;
+#endif
+
+	    /*
+	     * We now return to our regular broadcast.
+	     */
+	    next_state = SMTP_STATE_RCPT;
+	    break;
+
+	    /*
+	     * Build one RCPT TO command before we have seen the MAIL FROM
+	     * response.
+	     */
+	case SMTP_STATE_RCPT:
+	    rcpt = request->rcpt_list.info + send_rcpt;
+	    REWRITE_ADDRESS(session->scratch2, rcpt->address);
+	    QUOTE_ADDRESS(session->scratch, vstring_str(session->scratch2));
+	    vstring_sprintf(next_command, "RCPT TO:<%s>",
+			    vstring_str(session->scratch));
+	    if (session->features & SMTP_FEATURE_DSN) {
+		/* XXX DSN xtext encode address value not type. */
+		const char *orcpt_type_addr = rcpt->dsn_orcpt;
+
+		/* Fix 20140706: don't use empty rcpt->orig_addr. */
+		if (orcpt_type_addr[0] == 0 && rcpt->orig_addr[0] != 0) {
+		    quote_822_local(session->scratch, rcpt->orig_addr);
+		    vstring_sprintf(session->scratch2, "%s;%s",
+		    /* Fix 20140707: sender must request SMTPUTF8. */
+				    (request->smtputf8 != 0
+			      && !allascii(vstring_str(session->scratch))) ?
+				    "utf-8" : "rfc822",
+				    vstring_str(session->scratch));
+		    orcpt_type_addr = vstring_str(session->scratch2);
+		}
+		if (orcpt_type_addr[0] != 0) {
+		    /* Fix 20140706: don't send unquoted ORCPT. */
+		    /* Fix 20140707: quoting method must match orcpt type. */
+		    /* Fix 20140707: handle uxtext encoder errors. */
+		    if (strncasecmp(orcpt_type_addr, "utf-8;", 6) == 0) {
+			if (uxtext_quote(session->scratch,
+					 orcpt_type_addr, "+=") != 0)
+			    vstring_sprintf_append(next_command, " ORCPT=%s",
+					     vstring_str(session->scratch));
+		    } else {
+			xtext_quote(session->scratch, orcpt_type_addr, "=");
+			vstring_sprintf_append(next_command, " ORCPT=%s",
+					     vstring_str(session->scratch));
+		    }
+		}
+		if (rcpt->dsn_notify)
+		    vstring_sprintf_append(next_command, " NOTIFY=%s",
+					   dsn_notify_str(rcpt->dsn_notify));
+	    }
+	    if ((next_rcpt = send_rcpt + 1) == SMTP_RCPT_LEFT(state))
+		next_state = (DEL_REQ_TRACE_ONLY(request->flags)
+			      && smtp_vrfy_tgt == SMTP_STATE_RCPT) ?
+		    SMTP_STATE_ABORT : SMTP_STATE_DATA;
+	    break;
+
+	    /*
+	     * Build the DATA command before we have seen all the RCPT TO
+	     * responses.
+	     */
+	case SMTP_STATE_DATA:
+	    vstring_strcpy(next_command, "DATA");
+	    next_state = SMTP_STATE_DOT;
+	    break;
+
+	    /*
+	     * Build the "." command after we have seen the DATA response
+	     * (DATA is a protocol synchronization point).
+	     * 
+	     * Changing the connection caching state here is safe because it
+	     * affects none of the not-yet processed replies to
+	     * already-generated commands.
+	     */
+	case SMTP_STATE_DOT:
+	    vstring_strcpy(next_command, ".");
+	    if (THIS_SESSION_IS_EXPIRED)
+		DONT_CACHE_THIS_SESSION;
+	    next_state = THIS_SESSION_IS_CACHED ?
+		SMTP_STATE_LAST : SMTP_STATE_QUIT;
+	    break;
+
+	    /*
+	     * The SMTP_STATE_ABORT sender state is entered by the sender
+	     * when it has verified all recipients; or it is entered by the
+	     * receiver when all recipients are verified or rejected, and is
+	     * then left before the bottom of the main loop.
+	     * 
+	     * Changing the connection caching state here is safe because there
+	     * are no not-yet processed replies to already-generated
+	     * commands.
+	     */
+	case SMTP_STATE_ABORT:
+	    vstring_strcpy(next_command, "RSET");
+	    if (THIS_SESSION_IS_EXPIRED)
+		DONT_CACHE_THIS_SESSION;
+	    next_state = THIS_SESSION_IS_CACHED ?
+		SMTP_STATE_LAST : SMTP_STATE_QUIT;
+	    break;
+
+	    /*
+	     * Build the RSET command. This is entered as initial state from
+	     * smtp_rset() and has its own dedicated state transitions. It is
+	     * used to find out the status of a cached session before
+	     * attempting mail delivery.
+	     */
+	case SMTP_STATE_RSET:
+	    vstring_strcpy(next_command, "RSET");
+	    next_state = SMTP_STATE_LAST;
+	    break;
+
+	    /*
+	     * Build the QUIT command before we have seen the "." or RSET
+	     * response. This is entered as initial state from smtp_quit(),
+	     * or is reached near the end of any non-cached session.
+	     * 
+	     * Changing the connection caching state here is safe. If this
+	     * command is pipelined together with a preceding command, then
+	     * connection caching was already turned off. Do not clobber the
+	     * "bad connection" flag.
+	     */
+	case SMTP_STATE_QUIT:
+	    vstring_strcpy(next_command, "QUIT");
+	    next_state = SMTP_STATE_LAST;
+	    if (THIS_SESSION_IS_CACHED)
+		DONT_CACHE_THIS_SESSION;
+	    break;
+
+	    /*
+	     * The final sender state has no action associated with it.
+	     */
+	case SMTP_STATE_LAST:
+	    VSTRING_RESET(next_command);
+	    break;
+	}
+	VSTRING_TERMINATE(next_command);
+
+	/*
+	 * Process responses until the receiver has caught up. Vstreams
+	 * automatically flush buffered output when reading new data.
+	 * 
+	 * Flush unsent output if command pipelining is off or if no I/O
+	 * happened for a while. This limits the accumulation of client-side
+	 * delays in pipelined sessions.
+	 * 
+	 * The PIPELINING engine will flush the VSTREAM buffer if the sender
+	 * could otherwise produce more output than fits the PIPELINING
+	 * buffer. This generally works because we know exactly how much
+	 * output we produced since the last time that the sender and
+	 * receiver synchronized the SMTP state. However this logic is not
+	 * applicable after the sender enters the DATA phase, where it does
+	 * not synchronize with the receiver until the <CR><LF>.<CR><LF>.
+	 * Thus, the PIPELINING engine no longer knows how much data is
+	 * pending in the TCP send buffer. For this reason, if PIPELINING is
+	 * enabled, we always pipeline QUIT after <CR><LF>.<CR><LF>. This is
+	 * safe because once the receiver reads <CR><LF>.<CR><LF>, its TCP
+	 * stack either has already received the QUIT<CR><LF>, or else it
+	 * acknowledges all bytes up to and including <CR><LF>.<CR><LF>,
+	 * making room in the sender's TCP stack for QUIT<CR><LF>.
+	 */
+#define CHECK_PIPELINING_BUFSIZE \
+	(recv_state != SMTP_STATE_DOT || send_state != SMTP_STATE_QUIT)
+
+	if (SENDER_IN_WAIT_STATE
+	    || (SENDER_IS_AHEAD
+		&& ((session->features & SMTP_FEATURE_PIPELINING) == 0
+		    || (CHECK_PIPELINING_BUFSIZE
+			&& (VSTRING_LEN(next_command) + 2
+		    + vstream_bufstat(session->stream, VSTREAM_BST_OUT_PEND)
+			    > PIPELINING_BUFSIZE))
+		    || time((time_t *) 0)
+		    - vstream_ftime(session->stream) > 10))) {
+	    while (SENDER_IS_AHEAD) {
+
+		/*
+		 * Sanity check.
+		 */
+		if (recv_state < SMTP_STATE_XFORWARD_NAME_ADDR
+		    || recv_state > SMTP_STATE_QUIT)
+		    msg_panic("%s: bad receiver state %d (sender state %d)",
+			      myname, recv_state, send_state);
+
+		/*
+		 * Receive the next server response. Use the proper timeout,
+		 * and log the proper client state in case of trouble.
+		 * 
+		 * XXX If we lose the connection before sending end-of-data,
+		 * find out if the server sent a premature end-of-data reply.
+		 * If this read attempt fails, report "lost connection while
+		 * sending message body", not "lost connection while sending
+		 * end-of-data".
+		 * 
+		 * "except" becomes zero just above the protocol loop, and stays
+		 * zero or triggers an early return from the loop. In just
+		 * one case: loss of the connection when sending the message
+		 * body, we record the exception, and keep processing in the
+		 * hope of detecting a premature 5XX. We must be careful to
+		 * not clobber this non-zero value once it is set. The
+		 * variable need not survive longjmp() calls, since the only
+		 * setjmp() which does not return early is the one sets this
+		 * condition, subquent failures always return early.
+		 */
+#define LOST_CONNECTION_INSIDE_DATA (except == SMTP_ERR_EOF)
+
+		smtp_stream_setup(session->stream, *xfer_timeouts[recv_state],
+				  var_smtp_rec_deadline);
+		if (LOST_CONNECTION_INSIDE_DATA) {
+		    if (vstream_setjmp(session->stream) != 0)
+			RETURN(smtp_stream_except(state, SMTP_ERR_EOF,
+						  "sending message body"));
+		} else {
+		    if ((except = vstream_setjmp(session->stream)) != 0)
+			RETURN(SENDING_MAIL ? smtp_stream_except(state, except,
+					     xfer_states[recv_state]) : -1);
+		}
+		resp = smtp_chat_resp(session);
+
+		/*
+		 * Process the response.
+		 */
+		switch (recv_state) {
+
+		    /*
+		     * Process the XFORWARD response.
+		     */
+		case SMTP_STATE_XFORWARD_NAME_ADDR:
+		    if (resp->code / 100 != 2)
+			msg_warn("host %s said: %s (in reply to %s)",
+				 session->namaddrport,
+				 translit(resp->str, "\n", " "),
+			       xfer_request[SMTP_STATE_XFORWARD_NAME_ADDR]);
+		    if (session->send_proto_helo)
+			recv_state = SMTP_STATE_XFORWARD_PROTO_HELO;
+		    else
+			recv_state = SMTP_STATE_MAIL;
+		    break;
+
+		case SMTP_STATE_XFORWARD_PROTO_HELO:
+		    if (resp->code / 100 != 2)
+			msg_warn("host %s said: %s (in reply to %s)",
+				 session->namaddrport,
+				 translit(resp->str, "\n", " "),
+			      xfer_request[SMTP_STATE_XFORWARD_PROTO_HELO]);
+		    recv_state = SMTP_STATE_MAIL;
+		    break;
+
+		    /*
+		     * Process the MAIL FROM response. When the server
+		     * rejects the sender, set the mail_from_rejected flag so
+		     * that the receiver may apply a course correction.
+		     */
+		case SMTP_STATE_MAIL:
+		    if (resp->code / 100 != 2) {
+			smtp_mesg_fail(state, STR(iter->host), resp,
+				       "host %s said: %s (in reply to %s)",
+				       session->namaddr,
+				       translit(resp->str, "\n", " "),
+				       xfer_request[SMTP_STATE_MAIL]);
+			mail_from_rejected = 1;
+		    }
+
+		    /*
+		     * CVE-2009-3555 (TLS renegotiation). Whatever it was
+		     * that arrived before we sent our MAIL FROM command, it
+		     * was not a fatal-level TLS alert message. It could be a
+		     * warning-level TLS alert message, or a ChangeCipherSpec
+		     * message, but such messages are not normally sent in
+		     * the middle of a TLS session. We disconnect and try
+		     * again later.
+		     */
+#ifdef USE_TLS
+		    if (var_smtp_tls_blk_early_mail_reply
+			&& (session->features & SMTP_FEATURE_EARLY_TLS_MAIL_REPLY)) {
+			smtp_site_fail(state, DSN_BY_LOCAL_MTA,
+				       SMTP_RESP_FAKE(&fake, "4.7.0"),
+				       "unexpected server message");
+			msg_warn("server %s violates %s policy",
+				 session->namaddr,
+				 VAR_LMTP_SMTP(TLS_BLK_EARLY_MAIL_REPLY));
+			mail_from_rejected = 1;
+		    }
+#endif
+
+		    /*
+		     * We now return to our regular broadcast.
+		     */
+		    recv_state = SMTP_STATE_RCPT;
+		    break;
+
+		    /*
+		     * Process one RCPT TO response. If MAIL FROM was
+		     * rejected, ignore RCPT TO responses: all recipients are
+		     * dead already. When all recipients are rejected the
+		     * receiver may apply a course correction.
+		     * 
+		     * XXX 2821: Section 4.5.3.1 says that a 552 RCPT TO reply
+		     * must be treated as if the server replied with 452.
+		     * However, this causes "too much mail data" to be
+		     * treated as a recoverable error, which is wrong. I'll
+		     * stick with RFC 821.
+		     */
+		case SMTP_STATE_RCPT:
+		    if (!mail_from_rejected) {
+#ifdef notdef
+			if (resp->code == 552) {
+			    resp->code = 452;
+			    resp->dsn[0] = '4';
+			}
+#endif
+			rcpt = request->rcpt_list.info + recv_rcpt;
+			if (resp->code / 100 == 2) {
+			    if (!smtp_mode) {
+				if (survivors == 0)
+				    survivors = (int *)
+					mymalloc(request->rcpt_list.len
+						 * sizeof(int));
+				survivors[nrcpt] = recv_rcpt;
+			    }
+			    ++nrcpt;
+			    /* If trace-only, mark the recipient done. */
+			    if (DEL_REQ_TRACE_ONLY(request->flags)
+				&& smtp_vrfy_tgt == SMTP_STATE_RCPT) {
+				translit(resp->str, "\n", " ");
+				smtp_rcpt_done(state, resp, rcpt);
+			    }
+			} else {
+			    smtp_rcpt_fail(state, rcpt, STR(iter->host), resp,
+					"host %s said: %s (in reply to %s)",
+					   session->namaddr,
+					   translit(resp->str, "\n", " "),
+					   xfer_request[SMTP_STATE_RCPT]);
+			}
+		    }
+		    /* If trace-only, send RSET instead of DATA. */
+		    if (++recv_rcpt == SMTP_RCPT_LEFT(state))
+			recv_state = (DEL_REQ_TRACE_ONLY(request->flags)
+				      && smtp_vrfy_tgt == SMTP_STATE_RCPT) ?
+			    SMTP_STATE_ABORT : SMTP_STATE_DATA;
+		    /* XXX Also: record if non-delivering session. */
+		    break;
+
+		    /*
+		     * Process the DATA response. When the server rejects
+		     * DATA, set nrcpt to a negative value so that the
+		     * receiver can apply a course correction.
+		     */
+		case SMTP_STATE_DATA:
+		    recv_state = SMTP_STATE_DOT;
+		    if (resp->code / 100 != 3) {
+			if (nrcpt > 0)
+			    smtp_mesg_fail(state, STR(iter->host), resp,
+					"host %s said: %s (in reply to %s)",
+					   session->namaddr,
+					   translit(resp->str, "\n", " "),
+					   xfer_request[SMTP_STATE_DATA]);
+			nrcpt = -1;
+		    }
+
+		    /*
+		     * In the case of a successful address probe with target
+		     * equal to DATA, the remote server is now in the DATA
+		     * state, and therefore we must not make any further
+		     * attempt to send or receive on this connection. This
+		     * means that we cannot not reuse the general-purpose
+		     * course-correction logic below which sends RSET (and
+		     * perhaps QUIT). Instead we "jump" straight to the exit
+		     * and force an unceremonious disconnect.
+		     */
+		    else if (DEL_REQ_TRACE_ONLY(request->flags)
+			     && smtp_vrfy_tgt == SMTP_STATE_DATA) {
+			for (nrcpt = 0; nrcpt < recv_rcpt; nrcpt++) {
+			    rcpt = request->rcpt_list.info + nrcpt;
+			    if (!SMTP_RCPT_ISMARKED(rcpt)) {
+				translit(resp->str, "\n", " ");
+				SMTP_RESP_SET_DSN(resp, "2.0.0");
+				smtp_rcpt_done(state, resp, rcpt);
+			    }
+			}
+			DONT_CACHE_THIS_SESSION;
+			send_state = recv_state = SMTP_STATE_LAST;
+		    }
+		    break;
+
+		    /*
+		     * Process the end of message response. Ignore the
+		     * response when no recipient was accepted: all
+		     * recipients are dead already, and the next receiver
+		     * state is SMTP_STATE_LAST/QUIT regardless. Otherwise,
+		     * if the message transfer fails, bounce all remaining
+		     * recipients, else cross off the recipients that were
+		     * delivered.
+		     */
+		case SMTP_STATE_DOT:
+		    GETTIMEOFDAY(&request->msg_stats.deliver_done);
+		    if (smtp_mode) {
+			if (nrcpt > 0) {
+			    if (resp->code / 100 != 2) {
+				smtp_mesg_fail(state, STR(iter->host), resp,
+					"host %s said: %s (in reply to %s)",
+					       session->namaddr,
+					     translit(resp->str, "\n", " "),
+					       xfer_request[SMTP_STATE_DOT]);
+			    } else {
+				for (nrcpt = 0; nrcpt < recv_rcpt; nrcpt++) {
+				    rcpt = request->rcpt_list.info + nrcpt;
+				    if (!SMTP_RCPT_ISMARKED(rcpt)) {
+					translit(resp->str, "\n", " ");
+					smtp_rcpt_done(state, resp, rcpt);
+				    }
+				}
+			    }
+			}
+		    }
+
+		    /*
+		     * With LMTP we have one response per accepted RCPT TO
+		     * command. Stay in the SMTP_STATE_DOT state until we
+		     * have collected all responses.
+		     */
+		    else {
+			if (nrcpt > 0) {
+			    rcpt = request->rcpt_list.info
+				+ survivors[recv_done++];
+			    if (resp->code / 100 != 2) {
+				smtp_rcpt_fail(state, rcpt, STR(iter->host), resp,
+					"host %s said: %s (in reply to %s)",
+					       session->namaddr,
+					     translit(resp->str, "\n", " "),
+					       xfer_request[SMTP_STATE_DOT]);
+			    } else {
+				translit(resp->str, "\n", " ");
+				smtp_rcpt_done(state, resp, rcpt);
+			    }
+			}
+			if (msg_verbose)
+			    msg_info("%s: got %d of %d end-of-data replies",
+				     myname, recv_done, nrcpt);
+			if (recv_done < nrcpt)
+			    break;
+		    }
+
+		    /*
+		     * XXX Do not change the connection caching state here,
+		     * even if the connection caching timer expired between
+		     * generating the command and processing the reply,
+		     * otherwise the sender and receiver loops get out of
+		     * sync. The caller will call smtp_quit() if appropriate.
+		     */
+		    if (var_skip_quit_resp || THIS_SESSION_IS_CACHED
+			|| LOST_CONNECTION_INSIDE_DATA)
+			recv_state = SMTP_STATE_LAST;
+		    else
+			recv_state = SMTP_STATE_QUIT;
+		    break;
+
+		    /*
+		     * Receive the RSET response.
+		     * 
+		     * The SMTP_STATE_ABORT sender state is entered by the
+		     * sender when it has verified all recipients; or it is
+		     * entered by the receiver when all recipients are
+		     * verified or rejected, and is then left before the
+		     * bottom of the main loop.
+		     * 
+		     * XXX Do not change the connection caching state here, even
+		     * if the server rejected RSET or if the connection
+		     * caching timer expired between generating the command
+		     * and processing the reply, otherwise the sender and
+		     * receiver loops get out of sync. The caller will call
+		     * smtp_quit() if appropriate.
+		     */
+		case SMTP_STATE_ABORT:
+		    recv_state = (var_skip_quit_resp || THIS_SESSION_IS_CACHED ?
+				  SMTP_STATE_LAST : SMTP_STATE_QUIT);
+		    break;
+
+		    /*
+		     * This is the initial receiver state from smtp_rset().
+		     * It is used to find out the status of a cached session
+		     * before attempting mail delivery.
+		     */
+		case SMTP_STATE_RSET:
+		    if (resp->code / 100 != 2)
+			CANT_RSET_THIS_SESSION;
+		    recv_state = SMTP_STATE_LAST;
+		    break;
+
+		    /*
+		     * Receive, but otherwise ignore, the QUIT response.
+		     */
+		case SMTP_STATE_QUIT:
+		    recv_state = SMTP_STATE_LAST;
+		    break;
+		}
+	    }
+
+	    /*
+	     * At this point, the sender and receiver are fully synchronized.
+	     */
+
+	    /*
+	     * We know the server response to every command that was sent.
+	     * Apply a course correction if necessary: the sender wants to
+	     * send RCPT TO but MAIL FROM was rejected; the sender wants to
+	     * send DATA but all recipients were rejected; the sender wants
+	     * to deliver the message but DATA was rejected.
+	     */
+	    if ((send_state == SMTP_STATE_RCPT && mail_from_rejected)
+		|| (send_state == SMTP_STATE_DATA && nrcpt == 0)
+		|| (send_state == SMTP_STATE_DOT && nrcpt < 0)) {
+		send_state = recv_state = SMTP_STATE_ABORT;
+		send_rcpt = recv_rcpt = 0;
+		vstring_strcpy(next_command, "RSET");
+		if (THIS_SESSION_IS_EXPIRED)
+		    DONT_CACHE_THIS_SESSION;
+		next_state = THIS_SESSION_IS_CACHED ?
+		    SMTP_STATE_LAST : SMTP_STATE_QUIT;
+		/* XXX Also: record if non-delivering session. */
+		next_rcpt = 0;
+	    }
+	}
+
+	/*
+	 * Make the next sender state the current sender state.
+	 */
+	if (send_state == SMTP_STATE_LAST)
+	    continue;
+
+	/*
+	 * Special case if the server accepted the DATA command. If the
+	 * server accepted at least one recipient send the entire message.
+	 * Otherwise, just send "." as per RFC 2197.
+	 * 
+	 * XXX If there is a hard MIME error while downgrading to 7-bit mail,
+	 * disconnect ungracefully, because there is no other way to cancel a
+	 * transaction in progress.
+	 */
+	if (send_state == SMTP_STATE_DOT && nrcpt > 0) {
+
+	    smtp_stream_setup(session->stream, var_smtp_data1_tmout,
+			      var_smtp_rec_deadline);
+
+	    if ((except = vstream_setjmp(session->stream)) == 0) {
+
+		if (vstream_fseek(state->src, request->data_offset, SEEK_SET) < 0)
+		    msg_fatal("seek queue file: %m");
+
+		downgrading = SMTP_MIME_DOWNGRADE(session, request);
+
+		/*
+		 * XXX Don't downgrade just because generic_maps is turned
+		 * on.
+		 */
+#define SMTP_ANY_CHECKS (smtp_header_checks || smtp_body_checks)
+
+		if (downgrading || smtp_generic_maps || SMTP_ANY_CHECKS)
+		    session->mime_state = mime_state_alloc(downgrading ?
+							   MIME_OPT_DOWNGRADE
+						 | MIME_OPT_REPORT_NESTING :
+						      SMTP_ANY_CHECKS == 0 ?
+						     MIME_OPT_DISABLE_MIME :
+							   0,
+							   smtp_generic_maps
+						     || smtp_header_checks ?
+						       smtp_header_rewrite :
+							   smtp_header_out,
+						     (MIME_STATE_ANY_END) 0,
+							   smtp_body_checks ?
+							 smtp_body_rewrite :
+							   smtp_text_out,
+						     (MIME_STATE_ANY_END) 0,
+						   (MIME_STATE_ERR_PRINT) 0,
+							   (void *) state);
+		state->space_left = var_smtp_line_limit;
+
+		while ((rec_type = rec_get(state->src, session->scratch, 0)) > 0) {
+		    if (rec_type != REC_TYPE_NORM && rec_type != REC_TYPE_CONT)
+			break;
+		    if (session->mime_state == 0) {
+			smtp_text_out((void *) state, rec_type,
+				      vstring_str(session->scratch),
+				      VSTRING_LEN(session->scratch),
+				      (off_t) 0);
+		    } else {
+			mime_errs =
+			    mime_state_update(session->mime_state, rec_type,
+					      vstring_str(session->scratch),
+					      VSTRING_LEN(session->scratch));
+			if (mime_errs) {
+			    smtp_mime_fail(state, mime_errs);
+			    RETURN(0);
+			}
+		    }
+		    prev_type = rec_type;
+		}
+
+		if (session->mime_state) {
+
+		    /*
+		     * The cleanup server normally ends MIME content with a
+		     * normal text record. The following code is needed to
+		     * flush an internal buffer when someone submits 8-bit
+		     * mail not ending in newline via /usr/sbin/sendmail
+		     * while MIME input processing is turned off, and MIME
+		     * 8bit->7bit conversion is requested upon delivery.
+		     * 
+		     * Or some error while doing generic address mapping.
+		     */
+		    mime_errs =
+			mime_state_update(session->mime_state, rec_type, "", 0);
+		    if (mime_errs) {
+			smtp_mime_fail(state, mime_errs);
+			RETURN(0);
+		    }
+		} else if (prev_type == REC_TYPE_CONT)	/* missing newline */
+		    smtp_fputs("", 0, session->stream);
+		if (session->features & SMTP_FEATURE_PIX_DELAY_DOTCRLF) {
+		    smtp_flush(session->stream);/* hurts performance */
+		    sleep(var_smtp_pix_delay);	/* not to mention this */
+		}
+		if (vstream_ferror(state->src))
+		    msg_fatal("queue file read error");
+		if (rec_type != REC_TYPE_XTRA) {
+		    msg_warn("%s: bad record type: %d in message content",
+			     request->queue_id, rec_type);
+		    fail_status = smtp_mesg_fail(state, DSN_BY_LOCAL_MTA,
+					     SMTP_RESP_FAKE(&fake, "5.3.0"),
+					     "unreadable mail queue entry");
+		    /* Bailing out, abort stream with prejudice */
+		    (void) vstream_fpurge(session->stream, VSTREAM_PURGE_BOTH);
+		    DONT_USE_FORBIDDEN_SESSION;
+		    /* If bounce_append() succeeded, status is still 0 */
+		    if (state->status == 0)
+			(void) mark_corrupt(state->src);
+		    /* Don't override smtp_mesg_fail() here. */
+		    RETURN(fail_status);
+		}
+	    } else {
+		if (!LOST_CONNECTION_INSIDE_DATA)
+		    RETURN(smtp_stream_except(state, except,
+					      "sending message body"));
+
+		/*
+		 * We will clear the stream error flag to try and read a
+		 * premature 5XX response, so it is important to flush any
+		 * unwritten data. Otherwise, we will try to flush it again
+		 * before reading, which may incur an unnecessary delay and
+		 * will prevent the reading of any response that is not
+		 * already buffered (bundled with the DATA 354 response).
+		 * 
+		 * Not much point in sending QUIT at this point, skip right to
+		 * SMTP_STATE_LAST. The read engine above will likewise avoid
+		 * looking for a QUIT response.
+		 */
+		(void) vstream_fpurge(session->stream, VSTREAM_PURGE_WRITE);
+		next_state = SMTP_STATE_LAST;
+	    }
+	}
+
+	/*
+	 * Copy the next command to the buffer and update the sender state.
+	 */
+	if (except == 0) {
+	    smtp_chat_cmd(session, "%s", vstring_str(next_command));
+	} else {
+	    DONT_CACHE_THIS_SESSION;
+	}
+	send_state = next_state;
+	send_rcpt = next_rcpt;
+    } while (recv_state != SMTP_STATE_LAST);
+    RETURN(0);
+}
+
+/* smtp_xfer - send a batch of envelope information and the message data */
+
+int     smtp_xfer(SMTP_STATE *state)
+{
+    DELIVER_REQUEST *request = state->request;
+    SMTP_SESSION *session = state->session;
+    SMTP_RESP fake;
+    int     send_state;
+    int     recv_state;
+    int     send_name_addr;
+    int     result;
+
+    /*
+     * Sanity check. Recipients should be unmarked at this point.
+     */
+    if (SMTP_RCPT_LEFT(state) <= 0)
+	msg_panic("smtp_xfer: bad recipient count: %d",
+		  SMTP_RCPT_LEFT(state));
+    if (SMTP_RCPT_ISMARKED(request->rcpt_list.info))
+	msg_panic("smtp_xfer: bad recipient status: %d",
+		  request->rcpt_list.info->u.status);
+
+    /*
+     * See if we should even try to send this message at all. This code sits
+     * here rather than in the EHLO processing code, because of SMTP
+     * connection caching.
+     */
+    if (session->size_limit > 0 && session->size_limit < request->data_size) {
+	smtp_mesg_fail(state, DSN_BY_LOCAL_MTA,
+		       SMTP_RESP_FAKE(&fake, "5.3.4"),
+		    "message size %lu exceeds size limit %.0f of server %s",
+		       request->data_size, (double) session->size_limit,
+		       session->namaddr);
+	/* Redundant. We abort this delivery attempt. */
+	state->misc_flags |= SMTP_MISC_FLAG_COMPLETE_SESSION;
+	return (0);
+    }
+
+    /*
+     * Use XFORWARD to forward the origin of this email message across an
+     * SMTP-based content filter. Send client attribute information only if
+     * it exists (i.e. remote submission). Local submissions have no client
+     * attributes; the mail will appear to originate from the content filter
+     * which is acceptable.
+     */
+    send_name_addr =
+	var_smtp_send_xforward
+	&& (((session->features & SMTP_FEATURE_XFORWARD_NAME)
+	     && CAN_FORWARD_CLIENT_NAME(request->client_name))
+	    || ((session->features & SMTP_FEATURE_XFORWARD_ADDR)
+		&& CAN_FORWARD_CLIENT_ADDR(request->client_addr))
+	    || ((session->features & SMTP_FEATURE_XFORWARD_PORT)
+		&& CAN_FORWARD_CLIENT_PORT(request->client_port)));
+    session->send_proto_helo =
+	var_smtp_send_xforward
+	&& (((session->features & SMTP_FEATURE_XFORWARD_PROTO)
+	     && CAN_FORWARD_PROTO_NAME(request->client_proto))
+	    || ((session->features & SMTP_FEATURE_XFORWARD_HELO)
+		&& CAN_FORWARD_HELO_NAME(request->client_helo))
+	    || ((session->features & SMTP_FEATURE_XFORWARD_IDENT)
+		&& CAN_FORWARD_IDENT_NAME(request->log_ident))
+	    || ((session->features & SMTP_FEATURE_XFORWARD_DOMAIN)
+		&& CAN_FORWARD_RWR_CONTEXT(request->rewrite_context)));
+    if (send_name_addr)
+	recv_state = send_state = SMTP_STATE_XFORWARD_NAME_ADDR;
+    else if (session->send_proto_helo)
+	recv_state = send_state = SMTP_STATE_XFORWARD_PROTO_HELO;
+    else
+	recv_state = send_state = SMTP_STATE_MAIL;
+
+    /*
+     * Remember this session's "normal completion", even if the server 4xx-ed
+     * some or all recipients. Connection or handshake errors with a later MX
+     * host should not cause this destination be marked as unreachable.
+     */
+    result = smtp_loop(state, send_state, recv_state);
+
+    if (result == 0
+    /* Just in case */
+	&& vstream_ferror(session->stream) == 0
+	&& vstream_feof(session->stream) == 0)
+	state->misc_flags |= SMTP_MISC_FLAG_COMPLETE_SESSION;
+
+    return (result);
+}
+
+/* smtp_rset - send a lone RSET command */
+
+int     smtp_rset(SMTP_STATE *state)
+{
+
+    /*
+     * This works because SMTP_STATE_RSET is a dedicated sender/recipient
+     * entry state, with SMTP_STATE_LAST as next sender/recipient state.
+     */
+    return (smtp_loop(state, SMTP_STATE_RSET, SMTP_STATE_RSET));
+}
+
+/* smtp_quit - send a lone QUIT command */
+
+int     smtp_quit(SMTP_STATE *state)
+{
+
+    /*
+     * This works because SMTP_STATE_QUIT is the last state with a sender
+     * action, with SMTP_STATE_LAST as the next sender/recipient state.
+     */
+    return (smtp_loop(state, SMTP_STATE_QUIT, var_skip_quit_resp ?
+		      SMTP_STATE_LAST : SMTP_STATE_QUIT));
+}