Fix bug in previous patch: following data is permitted after '.' so it

must not be diagnosed as an error. The check for vanished socket can
only be applied when there is no data pending.

15 files changed, 57 insertions, 232 deletions

diff --git a/doc/doc-txt/ChangeLog b/doc/doc-txt/ChangeLog
index 4a8d41d66..db68bdae1 100644
--- a/doc/doc-txt/ChangeLog
+++ b/doc/doc-txt/ChangeLog
@@ -1,4 +1,4 @@
-$Cambridge: exim/doc/doc-txt/ChangeLog,v 1.502 2007/04/13 15:13:47 ph10 Exp $
+$Cambridge: exim/doc/doc-txt/ChangeLog,v 1.503 2007/04/16 10:31:58 ph10 Exp $
 
 Change log file for Exim from version 4.21
 -------------------------------------------
@@ -203,14 +203,16 @@ SC/03 Eximstats - V1.58 Fix to get <> and blackhole to show in edomain tables.
 PH/43 Yet another patch from the Sieve maintainer.
 
 PH/44 I found a way to check for a TCP/IP connection going away before sending
-      the response to the final '.' that terminates a message. At this time,
-      there should not be any pending input - the client should be waiting for
-      the response. Therefore, a select() can be used: if it shows that the
-      input is "ready", there is either input waiting, or the socket has been
-      closed. Both cases are errors. (It's a bit more complicated than this
-      because of buffering, but that's the essence of it.) Previously, Exim
+      the response to the final '.' that terminates a message, but only in the
+      case where the client has not sent further data following the '.'
+      (unfortunately, this is allowed). However, in many cases there won't be
+      any further data because there won't be any more messages to send. A call
+      to select() can be used: if it shows that the input is "ready", there is
+      either input waiting, or the socket has been closed. An attempt to read
+      the next input character can distinguish the two cases. Previously, Exim
       would have sent an OK response which the client would never have see.
-      This could lead to message repetition. This fix should cure that.
+      This could lead to message repetition. This fix should cure that, at
+      least in a lot of common cases.
 
 
 Exim version 4.66
diff --git a/src/src/receive.c b/src/src/receive.c
index 98a728b2f..e4c82d2fa 100644
--- a/src/src/receive.c
+++ b/src/src/receive.c
@@ -1,4 +1,4 @@
-/* $Cambridge: exim/src/src/receive.c,v 1.36 2007/04/13 15:13:47 ph10 Exp $ */
+/* $Cambridge: exim/src/src/receive.c,v 1.37 2007/04/16 10:31:58 ph10 Exp $ */
 
 /*************************************************
 *     Exim - an Internet mail transport agent    *
@@ -3436,21 +3436,26 @@ to cause a call to receive_bomb_out() if the log cannot be opened. */
 
 receive_call_bombout = TRUE;
 
-/* Before sending an SMTP response in a TCP/IP session, we check to see if
-there is unconsumed input (which there shouldn't be) or if the connection has
-gone away. This can be done because the end of a message is always a
-synchronization point. If the connection is still present, but there is no
-pending input, the result of a select() call will be zero. If, however, the
-connection has gone away, or if there is pending input, the result of select()
-will be non-zero. The two cases can be distinguished by trying to read the next
-input character. Of course, since TCP/IP is asynchronous, there is always a
-chance that the connection will vanish between the time of this test and the
-sending of the response, but the chance of this happening should be small.
+/* Before sending an SMTP response in a TCP/IP session, we check to see if the
+connection has gone away. This can only be done if there is no unconsumed input
+waiting in the local input buffer. We can test for this by calling
+receive_smtp_buffered(). RFC 2920 (pipelining) explicitly allows for additional
+input to be sent following the final dot, so the presence of following input is
+not an error.
 
-We also check for input that has already been received and is in the local
-input buffer (plain SMTP or TLS) by calling receive_smtp_buffered(). */
+If the connection is still present, but there is no unread input for the
+socket, the result of a select() call will be zero. If, however, the connection
+has gone away, or if there is pending input, the result of select() will be
+non-zero. The two cases can be distinguished by trying to read the next input
+character. If we succeed, we can unread it so that it remains in the local
+buffer for handling later. If not, the connection has been lost.
 
-if (smtp_input && sender_host_address != NULL && !sender_host_notsocket)
+Of course, since TCP/IP is asynchronous, there is always a chance that the
+connection will vanish between the time of this test and the sending of the
+response, but the chance of this happening should be small. */
+
+if (smtp_input && sender_host_address != NULL && !sender_host_notsocket &&
+    !receive_smtp_buffered())
   {
   struct timeval tv;
   fd_set select_check;
@@ -3459,47 +3464,39 @@ if (smtp_input && sender_host_address != NULL && !sender_host_notsocket)
   tv.tv_sec = 0;
   tv.tv_usec = 0;
 
-  if (select(fileno(smtp_in) + 1, &select_check, NULL, NULL, &tv) != 0 ||
-      receive_smtp_buffered())
+  if (select(fileno(smtp_in) + 1, &select_check, NULL, NULL, &tv) != 0)
     {
-    uschar *msg;
-    if ((RECEIVE_GETC)() == EOF)
-      {
-      msg = US"SMTP connection lost after final dot";
-      smtp_reply = US"";   /* No attempt to send a response */
-      }
-    else
+    int c = (RECEIVE_GETC)();
+    if (c != EOF) (RECEIVE_UNGETC)(c); else
       {
-      msg = US"Synchronization error (data after final dot)";
-      smtp_reply = US"550 Synchronization error (data after final dot)";
-      }
-
-    /* Overwrite the log line workspace */
+      uschar *msg = US"SMTP connection lost after final dot";
+      smtp_reply = US"";    /* No attempt to send a response */
+      smtp_yield = FALSE;   /* Nothing more on this connection */
 
-    sptr = 0;
-    s = string_cat(s, &size, &sptr, msg, Ustrlen(msg));
-    s = add_host_info_for_log(s, &size, &sptr);
-    s[sptr] = 0;
-    log_write(0, LOG_MAIN, "%s", s);
+      /* Re-use the log line workspace */
 
-    /* We now have to delete the files for this aborted message. */
+      sptr = 0;
+      s = string_cat(s, &size, &sptr, msg, Ustrlen(msg));
+      s = add_host_info_for_log(s, &size, &sptr);
+      s[sptr] = 0;
+      log_write(0, LOG_MAIN, "%s", s);
 
-    sprintf(CS spool_name, "%s/input/%s/%s-D", spool_directory, message_subdir,
-      message_id);
-    Uunlink(spool_name);
+      /* Delete the files for this aborted message. */
 
-    sprintf(CS spool_name, "%s/input/%s/%s-H", spool_directory, message_subdir,
-      message_id);
-    Uunlink(spool_name);
+      sprintf(CS spool_name, "%s/input/%s/%s-D", spool_directory,
+        message_subdir, message_id);
+      Uunlink(spool_name);
 
-    sprintf(CS spool_name, "%s/msglog/%s/%s", spool_directory, message_subdir,
-      message_id);
-    Uunlink(spool_name);
+      sprintf(CS spool_name, "%s/input/%s/%s-H", spool_directory,
+        message_subdir, message_id);
+      Uunlink(spool_name);
 
-    /* Do not accept any more messages on this connection. */
+      sprintf(CS spool_name, "%s/msglog/%s/%s", spool_directory,
+        message_subdir, message_id);
+      Uunlink(spool_name);
 
-    smtp_yield = FALSE;
-    goto TIDYUP;
+      goto TIDYUP;
+      }
     }
   }
 
diff --git a/test/log/0559 b/test/log/0559
index 077691e95..fcae1cf93 100644
--- a/test/log/0559
+++ b/test/log/0559
@@ -1,4 +1,2 @@
 1999-03-02 09:44:33 exim x.yz daemon started: pid=pppp, no queue runs, listening for SMTP on port 1225
 1999-03-02 09:44:33 10HmaX-0005vi-00 SMTP connection lost after final dot H=(abcd) [127.0.0.1] P=esmtp
-1999-03-02 09:44:33 exim x.yz daemon started: pid=pppp, no queue runs, listening for SMTP on port 1225
-1999-03-02 09:44:33 10HmaY-0005vi-00 Synchronization error (data after final dot) H=(abcd) [127.0.0.1] P=esmtp
diff --git a/test/log/2029 b/test/log/2029
index 737b6977b..0e16a7b24 100644
--- a/test/log/2029
+++ b/test/log/2029
@@ -1,5 +1,3 @@
 1999-03-02 09:44:33 exim x.yz daemon started: pid=pppp, no queue runs, listening for SMTP on port 1225
 1999-03-02 09:44:33 10HmaX-0005vi-00 TLS recv error on connection from [127.0.0.1]: A TLS packet with unexpected length was received.
 1999-03-02 09:44:33 10HmaX-0005vi-00 SMTP connection lost after final dot H=[127.0.0.1] P=smtps
-1999-03-02 09:44:33 exim x.yz daemon started: pid=pppp, no queue runs, listening for SMTP on port 1225
-1999-03-02 09:44:33 10HmaY-0005vi-00 Synchronization error (data after final dot) H=[127.0.0.1] P=smtps
diff --git a/test/log/2150 b/test/log/2150
index 41ada4435..01c430781 100644
--- a/test/log/2150
+++ b/test/log/2150
@@ -1,4 +1,2 @@
 1999-03-02 09:44:33 exim x.yz daemon started: pid=pppp, no queue runs, listening for SMTP on port 1225
 1999-03-02 09:44:33 10HmaX-0005vi-00 SMTP connection lost after final dot H=[127.0.0.1] P=smtps
-1999-03-02 09:44:33 exim x.yz daemon started: pid=pppp, no queue runs, listening for SMTP on port 1225
-1999-03-02 09:44:33 10HmaY-0005vi-00 Synchronization error (data after final dot) H=[127.0.0.1] P=smtps
diff --git a/test/scripts/0000-Basic/0300 b/test/scripts/0000-Basic/0300
index de3be1095..053aec804 100644
--- a/test/scripts/0000-Basic/0300
+++ b/test/scripts/0000-Basic/0300
@@ -23,9 +23,8 @@ rset\r\nmail from:<userx@test.ex>\r\nrcpt to:<userx@test.ex>\r\ndata
 ??? 250
 ??? 354
 the message
-.
+.\r\nmail from:<userx@test.ex>
 +++ 1
-mail from:<userx@test.ex>
 rcpt to:<userx@test.ex>\r\ndata\r\nthe message\r\nsecond line
 ??? 250
 ??? 250
diff --git a/test/scripts/0000-Basic/0301 b/test/scripts/0000-Basic/0301
index f84244f05..4add8f42c 100644
--- a/test/scripts/0000-Basic/0301
+++ b/test/scripts/0000-Basic/0301
@@ -26,9 +26,8 @@ mail from:<userx@test.ex>\r\nrcpt to:<userx@test.ex>\r\ndata
 ??? 250
 ??? 354
 the message
-.
+.\r\nmail from:<userx@test.ex>\r\nrcpt to:<userx@test.ex>\r\ndata\r\nthe message
 ??? 250
-mail from:<userx@test.ex>\r\nrcpt to:<userx@test.ex>\r\ndata\r\nthe message
 ??? 250
 ??? 250
 ??? 354
diff --git a/test/scripts/0000-Basic/0559 b/test/scripts/0000-Basic/0559
index 01d7d99af..3729f25ab 100644
--- a/test/scripts/0000-Basic/0559
+++ b/test/scripts/0000-Basic/0559
@@ -20,25 +20,3 @@ This is a test message.
 ****
 sleep 1
 killdaemon
-#
-# Also check for next input sent too soon
-#
-exim -DSERVER=server -bd -oX PORT_D
-****
-client -t5 127.0.0.1 PORT_D
-??? 220
-ehlo abcd
-??? 250-
-??? 250-
-??? 250-
-??? 250
-mail from:<userx@test.ex>\r\nrcpt to:<userx@test.ex>\r\ndata
-??? 250
-??? 250
-??? 354
-This is a test message.
-.\r\nrset
-??? 550
-****
-sleep 1
-killdaemon
diff --git a/test/scripts/2000-GnuTLS/2029 b/test/scripts/2000-GnuTLS/2029
index e371e68d7..c2b35497b 100644
--- a/test/scripts/2000-GnuTLS/2029
+++ b/test/scripts/2000-GnuTLS/2029
@@ -28,30 +28,3 @@ This is a test message.
 ****
 sleep 1
 killdaemon
-#
-# Also check for next input sent too soon
-#
-exim -DSERVER=server -bd -oX PORT_D
-****
-client-gnutls 127.0.0.1 PORT_D
-??? 220
-ehlo abcd
-??? 250-
-??? 250-
-??? 250-
-??? 250-
-??? 250
-starttls
-??? 220
-mail from:<userx@test.ex>
-??? 250
-rcpt to:<userx@test.ex>
-??? 250
-data
-??? 354
-This is a test message.
-.\r\nrset
-+++ 1
-****
-sleep 1
-killdaemon
diff --git a/test/scripts/2100-OpenSSL/2150 b/test/scripts/2100-OpenSSL/2150
index cfc6a20d7..91cd38276 100644
--- a/test/scripts/2100-OpenSSL/2150
+++ b/test/scripts/2100-OpenSSL/2150
@@ -26,30 +26,3 @@ This is a test message.
 ****
 sleep 1
 killdaemon
-#
-# Also check for next input sent too soon
-#
-exim -DSERVER=server -bd -oX PORT_D
-****
-client-gnutls 127.0.0.1 PORT_D
-??? 220
-ehlo abcd
-??? 250-
-??? 250-
-??? 250-
-??? 250-
-??? 250
-starttls
-??? 220
-mail from:<userx@test.ex>
-??? 250
-rcpt to:<userx@test.ex>
-??? 250
-data
-??? 354
-This is a test message.
-.\r\nrset
-+++ 1
-****
-sleep 1
-killdaemon
diff --git a/test/stdout/0300 b/test/stdout/0300
index 8dd5a3cc1..a41df39d3 100644
--- a/test/stdout/0300
+++ b/test/stdout/0300
@@ -27,9 +27,8 @@ Connecting to 127.0.0.1 port 1225 ... connected
 ??? 354
 <<< 354 Enter message, ending with "." on a line by itself
 >>> the message
->>> .
+>>> .\r\nmail from:<userx@test.ex>
 +++ 1
->>> mail from:<userx@test.ex>
 >>> rcpt to:<userx@test.ex>\r\ndata\r\nthe message\r\nsecond line
 ??? 250
 <<< 250 OK id=10HmaX-0005vi-00
diff --git a/test/stdout/0301 b/test/stdout/0301
index 964f0c17b..198962d06 100644
--- a/test/stdout/0301
+++ b/test/stdout/0301
@@ -36,10 +36,9 @@ Connecting to 127.0.0.1 port 1225 ... connected
 ??? 354
 <<< 354 Enter message, ending with "." on a line by itself
 >>> the message
->>> .
+>>> .\r\nmail from:<userx@test.ex>\r\nrcpt to:<userx@test.ex>\r\ndata\r\nthe message
 ??? 250
 <<< 250 OK id=10HmaX-0005vi-00
->>> mail from:<userx@test.ex>\r\nrcpt to:<userx@test.ex>\r\ndata\r\nthe message
 ??? 250
 <<< 250 OK
 ??? 250
diff --git a/test/stdout/0559 b/test/stdout/0559
index eee1b2e43..71f5c4541 100644
--- a/test/stdout/0559
+++ b/test/stdout/0559
@@ -21,27 +21,3 @@ Connecting to 127.0.0.1 port 1225 ... connected
 >>> .
 +++ 1
 End of script
-Connecting to 127.0.0.1 port 1225 ... connected
-??? 220
-<<< 220 myhost.test.ex ESMTP Exim x.yz Tue, 2 Mar 1999 09:44:33 +0000
->>> ehlo abcd
-??? 250-
-<<< 250-myhost.test.ex Hello abcd [127.0.0.1]
-??? 250-
-<<< 250-SIZE 52428800
-??? 250-
-<<< 250-PIPELINING
-??? 250
-<<< 250 HELP
->>> mail from:<userx@test.ex>\r\nrcpt to:<userx@test.ex>\r\ndata
-??? 250
-<<< 250 OK
-??? 250
-<<< 250 Accepted
-??? 354
-<<< 354 Enter message, ending with "." on a line by itself
->>> This is a test message.
->>> .\r\nrset
-??? 550
-<<< 550 Synchronization error (data after final dot)
-End of script
diff --git a/test/stdout/2029 b/test/stdout/2029
index dd1bdaef8..1efa5cd7c 100644
--- a/test/stdout/2029
+++ b/test/stdout/2029
@@ -30,35 +30,3 @@ Succeeded in starting TLS
 >>> .
 +++ 1
 End of script
-Connecting to 127.0.0.1 port 1225 ... connected
-??? 220
-<<< 220 myhost.test.ex ESMTP Exim x.yz Tue, 2 Mar 1999 09:44:33 +0000
->>> ehlo abcd
-??? 250-
-<<< 250-myhost.test.ex Hello abcd [127.0.0.1]
-??? 250-
-<<< 250-SIZE 52428800
-??? 250-
-<<< 250-PIPELINING
-??? 250-
-<<< 250-STARTTLS
-??? 250
-<<< 250 HELP
->>> starttls
-??? 220
-<<< 220 TLS go ahead
-Attempting to start TLS
-Succeeded in starting TLS
->>> mail from:<userx@test.ex>
-??? 250
-<<< 250 OK
->>> rcpt to:<userx@test.ex>
-??? 250
-<<< 250 Accepted
->>> data
-??? 354
-<<< 354 Enter message, ending with "." on a line by itself
->>> This is a test message.
->>> .\r\nrset
-+++ 1
-End of script
diff --git a/test/stdout/2150 b/test/stdout/2150
index dd1bdaef8..1efa5cd7c 100644
--- a/test/stdout/2150
+++ b/test/stdout/2150
@@ -30,35 +30,3 @@ Succeeded in starting TLS
 >>> .
 +++ 1
 End of script
-Connecting to 127.0.0.1 port 1225 ... connected
-??? 220
-<<< 220 myhost.test.ex ESMTP Exim x.yz Tue, 2 Mar 1999 09:44:33 +0000
->>> ehlo abcd
-??? 250-
-<<< 250-myhost.test.ex Hello abcd [127.0.0.1]
-??? 250-
-<<< 250-SIZE 52428800
-??? 250-
-<<< 250-PIPELINING
-??? 250-
-<<< 250-STARTTLS
-??? 250
-<<< 250 HELP
->>> starttls
-??? 220
-<<< 220 TLS go ahead
-Attempting to start TLS
-Succeeded in starting TLS
->>> mail from:<userx@test.ex>
-??? 250
-<<< 250 OK
->>> rcpt to:<userx@test.ex>
-??? 250
-<<< 250 Accepted
->>> data
-??? 354
-<<< 354 Enter message, ending with "." on a line by itself
->>> This is a test message.
->>> .\r\nrset
-+++ 1
-End of script