receive flow processing

7 files changed, 372 insertions, 128 deletions

diff --git a/src/src/functions.h b/src/src/functions.h
index b5e3098dc..0b77aa1fe 100644
--- a/src/src/functions.h
+++ b/src/src/functions.h
@@ -100,6 +100,7 @@ extern int     auth_xtextdecode(uschar *, uschar **);
 
 extern uschar *b64encode(uschar *, int);
 extern int     b64decode(uschar *, uschar **);
+extern int     bdat_getc(void);
 extern void    bits_clear(unsigned int *, size_t, int *);
 extern void    bits_set(unsigned int *, size_t, int *);
 
diff --git a/src/src/globals.c b/src/src/globals.c
index 2e3fe4074..c86b9478d 100644
--- a/src/src/globals.c
+++ b/src/src/globals.c
@@ -185,6 +185,8 @@ incoming TCP/IP. The defaults use stdin. We never need these for any
 stand-alone tests. */
 
 #ifndef STAND_ALONE
+int (*lwr_receive_getc)(void)  = stdin_getc;
+int (*lwr_receive_ungetc)(int) = stdin_ungetc;
 int (*receive_getc)(void)      = stdin_getc;
 int (*receive_ungetc)(int)     = stdin_ungetc;
 int (*receive_feof)(void)      = stdin_feof;
@@ -495,6 +497,8 @@ int     check_spool_space      = 0;
 
 uschar *chunking_advertise_hosts = US"*";
 unsigned chunking_datasize     = 0;
+unsigned chunking_data_left    = 0;
+BOOL    chunking_offered       = FALSE;
 chunking_state_t chunking_state= CHUNKING_NOT_OFFERED;
 
 uschar *client_authenticator   = NULL;
diff --git a/src/src/globals.h b/src/src/globals.h
index 184a144f2..c5767d73a 100644
--- a/src/src/globals.h
+++ b/src/src/globals.h
@@ -138,6 +138,8 @@ extern uschar  *dsn_advertise_hosts;   /* host for which TLS is advertised */
 /* Input-reading functions for messages, so we can use special ones for
 incoming TCP/IP. */
 
+extern int (*lwr_receive_getc)(void);
+extern int (*lwr_receive_ungetc)(int);
 extern int (*receive_getc)(void);
 extern int (*receive_ungetc)(int);
 extern int (*receive_feof)(void);
@@ -269,6 +271,8 @@ extern int     check_spool_inodes;     /* Minimum for message acceptance */
 extern int     check_spool_space;      /* Minimum for message acceptance */
 extern uschar *chunking_advertise_hosts;    /* RFC 3030 CHUNKING */
 extern unsigned chunking_datasize;
+extern unsigned chunking_data_left;
+extern BOOL    chunking_offered;
 extern chunking_state_t chunking_state;
 extern uschar *client_authenticator;        /* Authenticator name used for smtp delivery */
 extern uschar *client_authenticated_id;     /* "login" name used for SMTP AUTH */
diff --git a/src/src/macros.h b/src/src/macros.h
index dbc49f01e..f567c7ec2 100644
--- a/src/src/macros.h
+++ b/src/src/macros.h
@@ -320,6 +320,13 @@ for having to swallow the rest of an SMTP message is whether the value is
 #define END_NOTENDED   3    /* Message reading not yet ended */
 #define END_SIZE       4    /* Reading ended because message too big */
 #define END_WERROR     5    /* Write error while reading the message */
+#define END_PROTOCOL   6    /* Protocol error in CHUNKING sequence */
+
+/* result codes for bdat_getc() (which can also return EOF) */
+
+#define EOD (-2)
+#define ERR (-3)
+
 
 /* Bit masks for debug and log selectors */
 
diff --git a/src/src/receive.c b/src/src/receive.c
index f6bdf4742..9ff339d39 100644
--- a/src/src/receive.c
+++ b/src/src/receive.c
@@ -770,16 +770,13 @@ Arguments:
 
 Returns:    One of the END_xxx values indicating why it stopped reading
 */
-/*XXX CHUNKING: maybe a variant routing specialised for BDAT, assuming
-string RFC compliance ie. CRLF always?  We still have to strip the CR
-but we are not dealing with variant lunacy or looking for the end-dot */
 
 static int
 read_message_data_smtp(FILE *fout)
 {
 int ch_state = 0;
 int ch;
-register int linelength = 0;
+int linelength = 0;
 
 while ((ch = (receive_getc)()) != EOF)
   {
@@ -869,7 +866,7 @@ while ((ch = (receive_getc)()) != EOF)
 
   message_size++;
   linelength++;
-  if (fout != NULL)
+  if (fout)
     {
     if (fputc(ch, fout) == EOF) return END_WERROR;
     if (message_size > thismessage_size_limit) return END_SIZE;
@@ -878,7 +875,7 @@ while ((ch = (receive_getc)()) != EOF)
     (void) cutthrough_put_nl();
   else
     {
-    uschar c= ch;
+    uschar c = ch;
     (void) cutthrough_puts(&c, 1);
     }
   }
@@ -892,6 +889,63 @@ return END_EOF;
 
 
 
+/* Variant of the above read_message_data_smtp() specialised for RFC 3030
+CHUNKING.  We assume that the incoming has proper CRLF, so only have to scan
+for and strip CR.  On the downside there are more protocol reasons to stop.
+
+Arguments:
+  fout      a FILE to which to write the message; NULL if skipping
+
+Returns:    One of the END_xxx values indicating why it stopped reading
+*/
+
+static int
+read_message_bdat_smtp(FILE *fout)
+{
+int ch;
+int linelength = 0;
+
+for (;;) switch (ch = bdat_getc())
+  {
+  case EOF: return END_EOF;
+  case EOD: return END_DOT;
+  case ERR: return END_PROTOCOL;
+
+  case '\r':
+    body_linecount++;
+    if (linelength > max_received_linelength)
+      max_received_linelength = linelength;
+    linelength = -1;
+    break;
+
+  case 0:
+    body_zerocount++;
+    /*FALLTHROUGH*/
+  default:
+    message_size++;
+    linelength++;
+    if (fout)
+      {
+      if (fputc(ch, fout) == EOF) return END_WERROR;
+      if (message_size > thismessage_size_limit) return END_SIZE;
+      }
+#ifdef notyet
+    if(ch == '\n')
+      (void) cutthrough_put_nl();
+    else
+      {
+      uschar c = ch;
+      (void) cutthrough_puts(&c, 1);
+      }
+#endif
+    break;
+  }
+/*NOTREACHED*/
+}
+
+
+
+
 /*************************************************
 *             Swallow SMTP message               *
 *************************************************/
@@ -908,6 +962,7 @@ Returns:     nothing
 void
 receive_swallow_smtp(void)
 {
+/*XXX CHUNKING: not enough.  read chunks until RSET? */
 if (message_ended >= END_NOTENDED)
   message_ended = read_message_data_smtp(NULL);
 }
@@ -1616,7 +1671,6 @@ next->text. */
 
 for (;;)
   {
-/*XXX CHUNKING: account for BDAT size & last, and do more chunks as needed */
   int ch = (receive_getc)();
 
   /* If we hit EOF on a SMTP connection, it's an error, since incoming
@@ -2835,7 +2889,14 @@ if (filter_test != FTEST_NONE)
   return message_ended == END_DOT;
   }
 
-/*XXX CHUNKING: need to cancel cutthrough under BDAT, for now */
+/*XXX CHUNKING: need to cancel cutthrough under BDAT, for now.  In future,
+think more if it could be handled.  Cannot do onward CHUNKING unless
+inbound is, but inbound chunking ought to be ok with outbound plain.
+Could we do onward CHUNKING given inbound CHUNKING?
+*/
+if (chunking_state > CHUNKING_OFFERED)
+  cancel_cutthrough_connection("chunking active");
+
 /* Cutthrough delivery:
 We have to create the Received header now rather than at the end of reception,
 so the timestamp behaviour is a change to the normal case.
@@ -2933,8 +2994,9 @@ if (!ferror(data_file) && !(receive_feof)() && message_ended != END_DOT)
   {
   if (smtp_input)
     {
-/*XXX CHUNKING: main data read, for message body */
-    message_ended = read_message_data_smtp(data_file);
+    message_ended = chunking_state > CHUNKING_OFFERED
+      ? read_message_bdat_smtp(data_file)
+      : read_message_data_smtp(data_file);
     receive_linecount++;                /* The terminating "." line */
     }
   else message_ended = read_message_data(data_file);
@@ -2942,51 +3004,64 @@ if (!ferror(data_file) && !(receive_feof)() && message_ended != END_DOT)
   receive_linecount += body_linecount;  /* For BSMTP errors mainly */
   message_linecount += body_linecount;
 
-  /* Handle premature termination of SMTP */
-
-  if (smtp_input && message_ended == END_EOF)
+  switch (message_ended)
     {
-    Uunlink(spool_name);                     /* Lose data file when closed */
-    cancel_cutthrough_connection("sender closed connection");
-    message_id[0] = 0;                       /* Indicate no message accepted */
-    smtp_reply = handle_lost_connection(US"");
-    smtp_yield = FALSE;
-    goto TIDYUP;                             /* Skip to end of function */
-    }
+    /* Handle premature termination of SMTP */
 
-  /* Handle message that is too big. Don't use host_or_ident() in the log
-  message; we want to see the ident value even for non-remote messages. */
+    case END_EOF:
+      if (smtp_input)
+	{
+	Uunlink(spool_name);                 /* Lose data file when closed */
+	cancel_cutthrough_connection("sender closed connection");
+	message_id[0] = 0;                   /* Indicate no message accepted */
+	smtp_reply = handle_lost_connection(US"");
+	smtp_yield = FALSE;
+	goto TIDYUP;                         /* Skip to end of function */
+	}
+      break;
 
-  if (message_ended == END_SIZE)
-    {
-    Uunlink(spool_name);                /* Lose the data file when closed */
-    cancel_cutthrough_connection("mail too big");
-    if (smtp_input) receive_swallow_smtp();  /* Swallow incoming SMTP */
+    /* Handle message that is too big. Don't use host_or_ident() in the log
+    message; we want to see the ident value even for non-remote messages. */
 
-    log_write(L_size_reject, LOG_MAIN|LOG_REJECT, "rejected from <%s>%s%s%s%s: "
-      "message too big: read=%d max=%d",
-      sender_address,
-      (sender_fullhost == NULL)? "" : " H=",
-      (sender_fullhost == NULL)? US"" : sender_fullhost,
-      (sender_ident == NULL)? "" : " U=",
-      (sender_ident == NULL)? US"" : sender_ident,
-      message_size,
-      thismessage_size_limit);
+    case END_SIZE:
+      Uunlink(spool_name);                /* Lose the data file when closed */
+      cancel_cutthrough_connection("mail too big");
+      if (smtp_input) receive_swallow_smtp();  /* Swallow incoming SMTP */
 
-    if (smtp_input)
-      {
-      smtp_reply = US"552 Message size exceeds maximum permitted";
-      message_id[0] = 0;               /* Indicate no message accepted */
-      goto TIDYUP;                     /* Skip to end of function */
-      }
-    else
-      {
-      fseek(data_file, (long int)SPOOL_DATA_START_OFFSET, SEEK_SET);
-      give_local_error(ERRMESS_TOOBIG,
-        string_sprintf("message too big (max=%d)", thismessage_size_limit),
-        US"message rejected: ", error_rc, data_file, header_list);
-      /* Does not return */
-      }
+      log_write(L_size_reject, LOG_MAIN|LOG_REJECT, "rejected from <%s>%s%s%s%s: "
+	"message too big: read=%d max=%d",
+	sender_address,
+	(sender_fullhost == NULL)? "" : " H=",
+	(sender_fullhost == NULL)? US"" : sender_fullhost,
+	(sender_ident == NULL)? "" : " U=",
+	(sender_ident == NULL)? US"" : sender_ident,
+	message_size,
+	thismessage_size_limit);
+
+      if (smtp_input)
+	{
+	smtp_reply = US"552 Message size exceeds maximum permitted";
+	message_id[0] = 0;               /* Indicate no message accepted */
+	goto TIDYUP;                     /* Skip to end of function */
+	}
+      else
+	{
+	fseek(data_file, (long int)SPOOL_DATA_START_OFFSET, SEEK_SET);
+	give_local_error(ERRMESS_TOOBIG,
+	  string_sprintf("message too big (max=%d)", thismessage_size_limit),
+	  US"message rejected: ", error_rc, data_file, header_list);
+	/* Does not return */
+	}
+      break;
+
+    /* Handle bad BDAT protocol sequence */
+
+    case END_PROTOCOL:
+      Uunlink(spool_name);		/* Lose the data file when closed */
+      cancel_cutthrough_connection("sender protocol error");
+      smtp_reply = US"";		/* Response already sent */
+      message_id[0] = 0;		/* Indicate no message accepted */
+      goto TIDYUP;			/* Skip to end of function */
     }
   }
 
@@ -3169,9 +3244,8 @@ user_msg = NULL;
 enable_dollar_recipients = TRUE;
 
 if (recipients_count == 0)
-  {
-  blackholed_by = recipients_discarded? US"MAIL ACL" : US"RCPT ACL";
-  }
+  blackholed_by = recipients_discarded ? US"MAIL ACL" : US"RCPT ACL";
+
 else
   {
   /* Handle interactive SMTP messages */
@@ -3187,18 +3261,15 @@ else
       dkim_exim_verify_finish();
 
       /* Check if we must run the DKIM ACL */
-      if ((acl_smtp_dkim != NULL) &&
-          (dkim_verify_signers != NULL) &&
-          (dkim_verify_signers[0] != '\0'))
+      if (acl_smtp_dkim && dkim_verify_signers && *dkim_verify_signers)
         {
         uschar *dkim_verify_signers_expanded =
           expand_string(dkim_verify_signers);
-        if (dkim_verify_signers_expanded == NULL)
-          {
+        if (!dkim_verify_signers_expanded)
           log_write(0, LOG_MAIN|LOG_PANIC,
             "expansion of dkim_verify_signers option failed: %s",
             expand_string_message);
-          }
+
         else
           {
           int sep = 0;
@@ -3207,28 +3278,23 @@ else
           uschar *seen_items = NULL;
           int     seen_items_size = 0;
           int     seen_items_offset = 0;
-          uschar itembuf[256];
           /* Default to OK when no items are present */
           rc = OK;
-          while ((item = string_nextinlist(&ptr, &sep,
-                                           itembuf,
-                                           sizeof(itembuf))))
+          while ((item = string_nextinlist(&ptr, &sep, NULL, 0)))
             {
             /* Prevent running ACL for an empty item */
-            if (!item || (item[0] == '\0')) continue;
+            if (!item || !*item) continue;
 
             /* Only run ACL once for each domain or identity,
 	    no matter how often it appears in the expanded list. */
             if (seen_items)
               {
               uschar *seen_item = NULL;
-              uschar seen_item_buf[256];
               const uschar *seen_items_list = seen_items;
               BOOL seen_this_item = FALSE;
 
               while ((seen_item = string_nextinlist(&seen_items_list, &sep,
-                                                    seen_item_buf,
-                                                    sizeof(seen_item_buf))))
+                                                    NULL, 0)))
 		if (Ustrcmp(seen_item,item) == 0)
 		  {
 		  seen_this_item = TRUE;
@@ -3787,7 +3853,7 @@ if (sender_host_authenticated)
 
 #ifndef DISABLE_PRDR
 if (prdr_requested)
-  s = string_append(s, &size, &sptr, 1, US" PRDR");
+  s = string_catn(s, &size, &sptr, US" PRDR", 5);
 #endif
 
 #ifdef SUPPORT_PROXY
@@ -3795,6 +3861,9 @@ if (proxy_session && LOGGING(proxy))
   s = string_append(s, &size, &sptr, 2, US" PRX=", proxy_local_address);
 #endif
 
+if (chunking_state > CHUNKING_OFFERED)
+  s = string_catn(s, &size, &sptr, US" K", 2);
+
 sprintf(CS big_buffer, "%d", msg_size);
 s = string_append(s, &size, &sptr, 2, US" S=", big_buffer);
 
@@ -4093,8 +4162,15 @@ if (smtp_input)
 
       /* Default OK response */
 
+      else if (chunking_state > CHUNKING_OFFERED)
+	{
+        smtp_printf("250- %u byte chunk, total %d\r\n250 OK id=%s\r\n",
+	    chunking_datasize, message_size+message_linecount, message_id);
+	chunking_state = CHUNKING_OFFERED;
+	}
       else
         smtp_printf("250 OK id=%s\r\n", message_id);
+
       if (host_checking)
         fprintf(stdout,
           "\n**** SMTP testing: that is not a real message id!\n\n");
diff --git a/src/src/smtp_in.c b/src/src/smtp_in.c
index b00537eb5..d4b3e565a 100644
--- a/src/src/smtp_in.c
+++ b/src/src/smtp_in.c
@@ -291,6 +291,13 @@ static int     smtp_had_eof;
 static int     smtp_had_error;
 
 
+/* forward declarations */
+int bdat_ungetc(int ch);
+static int smtp_read_command(BOOL check_sync);
+static int synprot_error(int type, int code, uschar *data, uschar *errmess);
+static void smtp_quit_handler(uschar **, uschar **);
+static void smtp_rset_handler(void);
+
 /*************************************************
 *          SMTP version of getc()                *
 *************************************************/
@@ -339,6 +346,118 @@ return *smtp_inptr++;
 
 
 
+/* Get a byte from the smtp input, in CHUNKING mode.  Handle ack of the
+previous BDAT chunk and getting new ones when we run out.  Uses the
+underlying smtp_getc or tls_getc both for that and for getting the
+(buffered) data byte.  EOD signals (an expected) no further data.
+ERR signals a protocol error, and EOF a closed input stream.
+
+Called from read_bdat_smtp() in receive.c for the message body, but also
+by the headers read loop in receive_msg(); manipulates chunking_state
+to handle the BDAT command/response.
+Placed here due to the correlation with the above smtp_getc(), which it wraps,
+and also by the need to do smtp command/response handling.
+
+Arguments:  none
+Returns:    the next character or ERR, EOD or EOF
+*/
+
+int
+bdat_getc(void)
+{
+uschar * user_msg = NULL;
+uschar * log_msg;
+
+for(;;)
+  {
+  if (chunking_data_left-- > 0)
+    return lwr_receive_getc();
+
+  receive_getc = lwr_receive_getc;
+  receive_ungetc = lwr_receive_ungetc;
+
+  /* If not the last, ack the received chunk.  The last response is delayed
+  until after the data ACL decides on it */
+  /*XXX find that "last response" and append the chunk size */
+
+  if (chunking_state == CHUNKING_LAST)
+    return EOD;
+
+  chunking_state = CHUNKING_OFFERED;
+  smtp_printf("250 %u byte chunk received\r\n", chunking_datasize);
+
+  /* Expect another BDAT cmd from input. RFC 3030 says nothing about
+  QUIT, RSET or NOOP but handling them seems obvious */
+
+next_cmd:
+  switch(smtp_read_command(TRUE))
+    {
+    default:
+      (void) synprot_error(L_smtp_protocol_error, 503, NULL,
+	US"only BDAT permissible after non-LAST BDAT");
+
+  repeat_until_rset:
+      switch(smtp_read_command(TRUE))
+	{
+	case QUIT_CMD:	smtp_quit_handler(&user_msg, &log_msg);	/*FALLTHROUGH */
+	case EOF_CMD:	return EOF;
+	case RSET_CMD:	smtp_rset_handler(); return ERR;
+	default:	if (synprot_error(L_smtp_protocol_error, 503, NULL,
+					  US"only RSET accepted now") > 0)
+			  return EOF;
+			goto repeat_until_rset;
+	}
+
+    case QUIT_CMD:
+      smtp_quit_handler(&user_msg, &log_msg);
+      /*FALLTHROUGH*/
+    case EOF_CMD:
+      return EOF;
+
+    case RSET_CMD:
+      smtp_rset_handler();
+      return ERR;
+
+    case NOOP_CMD:
+      HAD(SCH_NOOP);
+      smtp_printf("250 OK\r\n");
+      goto next_cmd;
+
+    case BDAT_CMD:
+      {
+      int n;
+
+      if (sscanf(CS smtp_cmd_data, "%u %n", &chunking_datasize, &n) < 1)
+	{
+	(void) synprot_error(L_smtp_protocol_error, 501, NULL,
+	  US"missing size for BDAT command");
+	return ERR;
+	}
+      chunking_state = strcmpic(smtp_cmd_data+n, US"LAST") == 0
+	? CHUNKING_LAST : CHUNKING_ACTIVE;
+      chunking_data_left = chunking_datasize;
+
+      if (chunking_datasize == 0)
+	if (chunking_state == CHUNKING_LAST)
+	  return EOD;
+	else
+	  {
+	  (void) synprot_error(L_smtp_protocol_error, 504, NULL,
+	    US"zero size for BDAT command");
+	  goto repeat_until_rset;
+	  }
+
+      receive_getc = bdat_getc;
+      receive_ungetc = bdat_ungetc;
+      break;	/* to top of main loop */
+      }
+    }
+  }
+}
+
+
+
+
 /*************************************************
 *          SMTP version of ungetc()              *
 *************************************************/
@@ -355,11 +474,18 @@ Returns:       the character
 int
 smtp_ungetc(int ch)
 {
-*(--smtp_inptr) = ch;
+*--smtp_inptr = ch;
 return ch;
 }
 
 
+int
+bdat_ungetc(int ch)
+{
+chunking_data_left++;
+return lwr_receive_ungetc(ch);
+}
+
 
 
 /*************************************************
@@ -1527,7 +1653,6 @@ authenticated_sender = NULL;
 bmi_run = 0;
 bmi_verdicts = NULL;
 #endif
-chunking_state = CHUNKING_NOT_OFFERED;
 #ifndef DISABLE_DKIM
 dkim_signers = NULL;
 dkim_disable_verify = FALSE;
@@ -3239,6 +3364,43 @@ return 0;
 
 
 
+static void
+smtp_quit_handler(uschar ** user_msgp, uschar ** log_msgp)
+{
+HAD(SCH_QUIT);
+incomplete_transaction_log(US"QUIT");
+if (acl_smtp_quit != NULL)
+  {
+  int rc = acl_check(ACL_WHERE_QUIT, NULL, acl_smtp_quit, user_msgp, log_msgp);
+  if (rc == ERROR)
+    log_write(0, LOG_MAIN|LOG_PANIC, "ACL for QUIT returned ERROR: %s",
+      *log_msgp);
+  }
+if (*user_msgp)
+  smtp_respond(US"221", 3, TRUE, *user_msgp);
+else
+  smtp_printf("221 %s closing connection\r\n", smtp_active_hostname);
+
+#ifdef SUPPORT_TLS
+tls_close(TRUE, TRUE);
+#endif
+
+log_write(L_smtp_connection, LOG_MAIN, "%s closed by QUIT",
+  smtp_get_connection_info());
+}
+
+
+static void
+smtp_rset_handler(void)
+{
+HAD(SCH_RSET);
+incomplete_transaction_log(US"RSET");
+smtp_printf("250 Reset OK\r\n");
+cmd_list[CMD_LIST_RSET].is_mail_cmd = FALSE;
+}
+
+
+
 /*************************************************
 *       Initialize for SMTP incoming message     *
 *************************************************/
@@ -3285,6 +3447,8 @@ for the host). Note: we do NOT reset AUTH at this point. */
 smtp_reset(reset_point);
 message_ended = END_NOTSTARTED;
 
+chunking_state = chunking_offered ? CHUNKING_OFFERED : CHUNKING_NOT_OFFERED;
+
 cmd_list[CMD_LIST_RSET].is_mail_cmd = TRUE;
 cmd_list[CMD_LIST_HELO].is_mail_cmd = TRUE;
 cmd_list[CMD_LIST_EHLO].is_mail_cmd = TRUE;
@@ -3775,6 +3939,7 @@ while (done <= 0)
         {
         s = string_catn(s, &size, &ptr, smtp_code, 3);
         s = string_catn(s, &size, &ptr, US"-CHUNKING\r\n", 11);
+	chunking_offered = TRUE;
 	chunking_state = CHUNKING_OFFERED;
         }
 
@@ -4546,12 +4711,18 @@ while (done <= 0)
 
       if (sscanf(CS smtp_cmd_data, "%u %n", &chunking_datasize, &n) < 1)
 	{
-	done = synprot_error(L_smtp_protocol_error, 503, NULL,
+	done = synprot_error(L_smtp_protocol_error, 501, NULL,
 	  US"missing size for BDAT command");
 	break;
 	}
       chunking_state = strcmpic(smtp_cmd_data+n, US"LAST") == 0
 	? CHUNKING_LAST : CHUNKING_ACTIVE;
+      chunking_data_left = chunking_datasize;
+
+      lwr_receive_getc = receive_getc;
+      lwr_receive_ungetc = receive_ungetc;
+      receive_getc = bdat_getc;
+      receive_ungetc = bdat_ungetc;
 
       DEBUG(D_any)
         debug_printf("chunking state %d\n", (int)chunking_state);
@@ -4594,45 +4765,45 @@ while (done <= 0)
       break;
       }
 
-    /* No go-ahead output for BDAT */
-
-    if (smtp_connection_had[smtp_ch_index-1] == SCH_BDAT)
-      {
+    if (chunking_state > CHUNKING_OFFERED)
+      {				/* No predata ACL or go-ahead output for BDAT */
       rc = OK;
-      break;
       }
-
-    /* If there is an ACL, re-check the synchronization afterwards, since the
-    ACL may have delayed.  To handle cutthrough delivery enforce a dummy call
-    to get the DATA command sent. */
-
-    if (acl_smtp_predata == NULL && cutthrough.fd < 0)
-      rc = OK;
     else
       {
-      uschar * acl= acl_smtp_predata ? acl_smtp_predata : US"accept";
-      enable_dollar_recipients = TRUE;
-      rc = acl_check(ACL_WHERE_PREDATA, NULL, acl, &user_msg,
-        &log_msg);
-      enable_dollar_recipients = FALSE;
-      if (rc == OK && !check_sync()) goto SYNC_FAILURE;
-      }
+      /* If there is an ACL, re-check the synchronization afterwards, since the
+      ACL may have delayed.  To handle cutthrough delivery enforce a dummy call
+      to get the DATA command sent. */
 
-    if (rc == OK)
-      {
-      uschar * code;
-      code = US"354";
-      if (user_msg == NULL)
-        smtp_printf("%s Enter message, ending with \".\" on a line by itself\r\n", code);
-      else smtp_user_msg(code, user_msg);
-      done = 3;
-      message_ended = END_NOTENDED;   /* Indicate in middle of data */
+      if (acl_smtp_predata == NULL && cutthrough.fd < 0)
+	rc = OK;
+      else
+	{
+	uschar * acl = acl_smtp_predata ? acl_smtp_predata : US"accept";
+	enable_dollar_recipients = TRUE;
+	rc = acl_check(ACL_WHERE_PREDATA, NULL, acl, &user_msg,
+	  &log_msg);
+	enable_dollar_recipients = FALSE;
+	if (rc == OK && !check_sync())
+	  goto SYNC_FAILURE;
+
+	if (rc != OK)
+	  {	/* Either the ACL failed the address, or it was deferred. */
+	  done = smtp_handle_acl_fail(ACL_WHERE_PREDATA, rc, user_msg, log_msg);
+	  break;
+	  }
+	}
+
+      if (user_msg)
+	smtp_user_msg(US"354", user_msg);
+      else
+	smtp_printf(
+	  "354 Enter message, ending with \".\" on a line by itself\r\n");
       }
 
-    /* Either the ACL failed the address, or it was deferred. */
+    done = 3;
+    message_ended = END_NOTENDED;   /* Indicate in middle of data */
 
-    else
-      done = smtp_handle_acl_fail(ACL_WHERE_PREDATA, rc, user_msg, log_msg);
     break;
 
 
@@ -4868,37 +5039,15 @@ while (done <= 0)
     message. */
 
     case QUIT_CMD:
-    HAD(SCH_QUIT);
-    incomplete_transaction_log(US"QUIT");
-    if (acl_smtp_quit != NULL)
-      {
-      rc = acl_check(ACL_WHERE_QUIT, NULL, acl_smtp_quit, &user_msg, &log_msg);
-      if (rc == ERROR)
-        log_write(0, LOG_MAIN|LOG_PANIC, "ACL for QUIT returned ERROR: %s",
-          log_msg);
-      }
-    if (user_msg == NULL)
-      smtp_printf("221 %s closing connection\r\n", smtp_active_hostname);
-    else
-      smtp_respond(US"221", 3, TRUE, user_msg);
-
-    #ifdef SUPPORT_TLS
-    tls_close(TRUE, TRUE);
-    #endif
-
+    smtp_quit_handler(&user_msg, &log_msg);
     done = 2;
-    log_write(L_smtp_connection, LOG_MAIN, "%s closed by QUIT",
-      smtp_get_connection_info());
     break;
 
 
     case RSET_CMD:
-    HAD(SCH_RSET);
-    incomplete_transaction_log(US"RSET");
+    smtp_rset_handler();
     smtp_reset(reset_point);
     toomany = FALSE;
-    smtp_printf("250 Reset OK\r\n");
-    cmd_list[CMD_LIST_RSET].is_mail_cmd = FALSE;
     break;
 
 
@@ -4925,7 +5074,7 @@ while (done <= 0)
           verify_check_host(&tls_advertise_hosts) != FAIL)
         Ustrcat(buffer, " STARTTLS");
       #endif
-      Ustrcat(buffer, " HELO EHLO MAIL RCPT DATA");
+      Ustrcat(buffer, " HELO EHLO MAIL RCPT DATA BDAT");
       Ustrcat(buffer, " NOOP QUIT RSET HELP");
       if (acl_smtp_etrn != NULL) Ustrcat(buffer, " ETRN");
       if (acl_smtp_expn != NULL) Ustrcat(buffer, " EXPN");
diff --git a/src/src/structs.h b/src/src/structs.h
index 2b449a648..b49f4b574 100644
--- a/src/src/structs.h
+++ b/src/src/structs.h
@@ -51,7 +51,10 @@ typedef struct ugid_block {
   BOOL    initgroups;
 } ugid_block;
 
-typedef enum {CHUNKING_NOT_OFFERED, CHUNKING_OFFERED, CHUNKING_ACTIVE, CHUNKING_LAST} chunking_state_t;
+typedef enum {	CHUNKING_NOT_OFFERED = -1,
+		CHUNKING_OFFERED,
+		CHUNKING_ACTIVE,
+		CHUNKING_LAST} chunking_state_t;
 
 /* Structure for holding information about a host for use mainly by routers,
 but also used when checking lists of hosts and when transporting. Looking up