smtp transport: message_linelength_limit option. Bug 1684

6 files changed, 46 insertions, 17 deletions

diff --git a/src/src/configure.default b/src/src/configure.default
index 57af99c14..7d54e11eb 100644
--- a/src/src/configure.default
+++ b/src/src/configure.default
@@ -808,13 +808,9 @@ begin transports
 
 
 # This transport is used for delivering messages over SMTP connections.
-# Refuse to send any message with over-long lines, which could have
-# been received other than via SMTP. The use of message_size_limit to
-# enforce this is a red herring.
 
 remote_smtp:
   driver = smtp
-  message_size_limit = ${if > {$max_received_linelength}{998} {1}{0}}
 .ifdef _HAVE_TLS
   tls_resumption_hosts = *
 #endif
@@ -832,7 +828,6 @@ remote_smtp:
 
 smarthost_smtp:
   driver = smtp
-  message_size_limit = ${if > {$max_received_linelength}{998} {1}{0}}
   multi_domain
   #
 .ifdef _HAVE_TLS
diff --git a/src/src/deliver.c b/src/src/deliver.c
index 3dcd7f949..67d711b7e 100644
--- a/src/src/deliver.c
+++ b/src/src/deliver.c
@@ -5380,7 +5380,8 @@ Returns:       nothing
 static void
 print_dsn_diagnostic_code(const address_item *addr, FILE *f)
 {
-uschar *s = testflag(addr, af_pass_message) ? addr->message : NULL;
+uschar * s = testflag(addr, af_pass_message) ? addr->message : NULL;
+unsigned cnt;
 
 /* af_pass_message and addr->message set ? print remote host answer */
 if (s)
@@ -5392,19 +5393,32 @@ if (s)
   if (!(s = Ustrstr(addr->message, ": ")))
     return;				/* not found, bail out */
   s += 2;  /* skip ": " */
-  fprintf(f, "Diagnostic-Code: smtp; ");
+  cnt = fprintf(f, "Diagnostic-Code: smtp; ");
   }
 /* no message available. do nothing */
 else return;
 
 while (*s)
+  {
+  if (cnt > 950)	/* RFC line length limit: 998 */
+    {
+    DEBUG(D_deliver) debug_printf("print_dsn_diagnostic_code() truncated line\n");
+    fputs("[truncated]", f);
+    break;
+    }
+
   if (*s == '\\' && s[1] == 'n')
     {
     fputs("\n ", f);    /* as defined in RFC 3461 */
     s += 2;
+    cnt += 2;
     }
   else
+    {
     fputc(*s++, f);
+    cnt++;
+    }
+  }
 
 fputc('\n', f);
 }
@@ -7831,11 +7845,11 @@ wording. */
 	    fprintf(fp, "Remote-MTA: X-ip; [%s]%s\n", hu->address, p);
 	    }
 	  if ((s = addr->smtp_greeting) && *s)
-	    fprintf(fp, "X-Remote-MTA-smtp-greeting: X-str; %s\n", s);
+	    fprintf(fp, "X-Remote-MTA-smtp-greeting: X-str; %.900s\n", s);
 	  if ((s = addr->helo_response) && *s)
-	    fprintf(fp, "X-Remote-MTA-helo-response: X-str; %s\n", s);
+	    fprintf(fp, "X-Remote-MTA-helo-response: X-str; %.900s\n", s);
 	  if ((s = addr->message) && *s)
-	    fprintf(fp, "X-Exim-Diagnostic: X-str; %s\n", s);
+	    fprintf(fp, "X-Exim-Diagnostic: X-str; %.900s\n", s);
 	  }
 #endif
 	  print_dsn_diagnostic_code(addr, fp);
diff --git a/src/src/smtp_in.c b/src/src/smtp_in.c
index 412ef4df0..2b4323bec 100644
--- a/src/src/smtp_in.c
+++ b/src/src/smtp_in.c
@@ -5173,9 +5173,9 @@ while (done <= 0)
 	recipients_list[recipients_count-1].orcpt = orcpt;
 	recipients_list[recipients_count-1].dsn_flags = dsn_flags;
 
-	DEBUG(D_receive) debug_printf("DSN: orcpt: %s  flags: %d\n",
+	/* DEBUG(D_receive) debug_printf("DSN: orcpt: %s  flags: %d\n",
 	  recipients_list[recipients_count-1].orcpt,
-	  recipients_list[recipients_count-1].dsn_flags);
+	  recipients_list[recipients_count-1].dsn_flags); */
 	}
 
       /* The recipient was discarded */
@@ -5190,8 +5190,8 @@ while (done <= 0)
 	discarded = TRUE;
 	log_write(0, LOG_MAIN|LOG_REJECT, "%s F=<%s> RCPT %s: "
 	  "discarded by %s ACL%s%s", host_and_ident(TRUE),
-	  sender_address_unrewritten? sender_address_unrewritten : sender_address,
-	  smtp_cmd_argument, f.recipients_discarded? "MAIL" : "RCPT",
+	  sender_address_unrewritten ? sender_address_unrewritten : sender_address,
+	  smtp_cmd_argument, f.recipients_discarded ? "MAIL" : "RCPT",
 	  log_msg ? US": " : US"", log_msg ? log_msg : US"");
 	}
 
diff --git a/src/src/spool_out.c b/src/src/spool_out.c
index 5d658fd74..9a514b331 100644
--- a/src/src/spool_out.c
+++ b/src/src/spool_out.c
@@ -277,9 +277,9 @@ if (message_smtputf8)
 #endif
 
 /* Write the dsn flags to the spool header file */
-DEBUG(D_deliver) debug_printf("DSN: Write SPOOL: -dsn_envid %s\n", dsn_envid);
+/* DEBUG(D_deliver) debug_printf("DSN: Write SPOOL: -dsn_envid %s\n", dsn_envid); */
 if (dsn_envid) fprintf(fp, "-dsn_envid %s\n", dsn_envid);
-DEBUG(D_deliver) debug_printf("DSN: Write SPOOL  :-dsn_ret %d\n", dsn_ret);
+/* DEBUG(D_deliver) debug_printf("DSN: Write SPOOL: -dsn_ret %d\n", dsn_ret); */
 if (dsn_ret) fprintf(fp, "-dsn_ret %d\n", dsn_ret);
 
 /* To complete the envelope, write out the tree of non-recipients, followed by
@@ -293,7 +293,7 @@ for (int i = 0; i < recipients_count; i++)
   {
   recipient_item *r = recipients_list + i;
 
-  DEBUG(D_deliver) debug_printf("DSN: Flags: 0x%x\n", r->dsn_flags);
+  /* DEBUG(D_deliver) debug_printf("DSN: Flags: 0x%x\n", r->dsn_flags); */
 
   if (r->pno < 0 && !r->errors_to && r->dsn_flags == 0)
     fprintf(fp, "%s\n", r->address);
diff --git a/src/src/transports/smtp.c b/src/src/transports/smtp.c
index f47c6d92f..12a199464 100644
--- a/src/src/transports/smtp.c
+++ b/src/src/transports/smtp.c
@@ -111,6 +111,7 @@ optionlist smtp_transport_options[] = {
   { "lmtp_ignore_quota",    opt_bool,	   LOFF(lmtp_ignore_quota) },
   { "max_rcpt",             opt_int | opt_public,
       OPT_OFF(transport_instance, max_addresses) },
+  { "message_linelength_limit", opt_int,   LOFF(message_linelength_limit) },
   { "multi_domain",         opt_expand_bool | opt_public,
       OPT_OFF(transport_instance, multi_domain) },
   { "port",                 opt_stringptr, LOFF(port) },
@@ -207,6 +208,7 @@ smtp_transport_options_block smtp_transport_option_defaults = {
   .size_addition =		1024,
   .hosts_max_try =		5,
   .hosts_max_try_hardlimit =	50,
+  .message_linelength_limit =	998,
   .address_retry_include_sender = TRUE,
   .allow_localhost =		FALSE,
   .authenticated_sender_force =	FALSE,
@@ -4524,6 +4526,23 @@ DEBUG(D_transport)
       cutthrough.cctx.sock >= 0 ? cutthrough.cctx.sock : 0);
   }
 
+/* Check the restrictions on line length */
+
+debug_printf("%s %d: max_received_linelength %u message_linelength_limit %u\n", __FUNCTION__, __LINE__, max_received_linelength, ob->message_linelength_limit);
+if (max_received_linelength > ob->message_linelength_limit)
+  {
+  struct timeval now;
+  gettimeofday(&now, NULL);
+
+  for (address_item * addr = addrlist; addr; addr = addr->next)
+    if (addr->transport_return == DEFER)
+      addr->transport_return = PENDING_DEFER;
+
+  set_errno_nohost(addrlist, ERRNO_SMTPFORMAT,
+    US"message has lines too long for transport", FAIL, TRUE, &now);
+  goto END_TRANSPORT;
+  }
+
 /* Set the flag requesting that these hosts be added to the waiting
 database if the delivery fails temporarily or if we are running with
 queue_smtp or a 2-stage queue run. This gets unset for certain
diff --git a/src/src/transports/smtp.h b/src/src/transports/smtp.h
index 037105a00..607a3772d 100644
--- a/src/src/transports/smtp.h
+++ b/src/src/transports/smtp.h
@@ -62,6 +62,7 @@ typedef struct {
   int     size_addition;
   int     hosts_max_try;
   int     hosts_max_try_hardlimit;
+  int	  message_linelength_limit;
   BOOL    address_retry_include_sender;
   BOOL    allow_localhost;
   BOOL    authenticated_sender_force;