X-Git-Url: https://git.exim.org/exim.git/blobdiff_plain/adb21834f3684b6484d8c2214ee4c3c9c504d632..5c161fa615ab4a2d40170fedd71d1b9a7f079ff6:/src/src/smtp_out.c

diff --git a/src/src/smtp_out.c b/src/src/smtp_out.c
index 4f8a84e2b..911dd537e 100644
--- a/src/src/smtp_out.c
+++ b/src/src/smtp_out.c
@@ -3,6 +3,7 @@
 *************************************************/
 
 /* Copyright (c) University of Cambridge 1995 - 2018 */
+/* Copyright (c) The Exim Maintainers 2020 */
 /* See the file NOTICE for conditions of use and distribution. */
 
 /* A number of functions for driving outgoing SMTP calls. */
@@ -52,8 +53,19 @@ if (!(expint = expand_string(istring)))
   return FALSE;
   }
 
-while (isspace(*expint)) expint++;
-if (*expint == 0) return TRUE;
+if (is_tainted(expint))
+  {
+  log_write(0, LOG_MAIN|LOG_PANIC,
+    "attempt to use tainted value '%s' from '%s' for interface",
+    expint, istring);
+  addr->transport_return = PANIC;
+  addr->message = string_sprintf("failed to expand \"interface\" "
+      "option for %s: configuration error", msg);
+  return FALSE;
+  }
+
+Uskip_whitespace(&expint);
+if (!*expint) return TRUE;
 
 while ((iface = string_nextinlist(&expint, &sep, big_buffer,
           big_buffer_size)))
@@ -144,7 +156,28 @@ return TRUE;
 static void
 tfo_out_check(int sock)
 {
-# if defined(TCP_INFO) && defined(EXIM_HAVE_TCPI_UNACKED)
+# ifdef __FreeBSD__
+struct tcp_info tinfo;
+int val;
+socklen_t len = sizeof(val);
+
+/* The observability as of 12.1 is not useful as a client, only telling us that
+a TFO option was used on SYN.  It could have been a TFO-R, or ignored by the
+server. */
+
+/*
+if (tcp_out_fastopen == TFO_ATTEMPTED_NODATA || tcp_out_fastopen == TFO_ATTEMPTED_DATA)
+  if (getsockopt(sock, IPPROTO_TCP, TCP_FASTOPEN, &val, &len) == 0 && val != 0) {}
+*/
+switch (tcp_out_fastopen)
+  {
+  case TFO_ATTEMPTED_NODATA:	tcp_out_fastopen = TFO_USED_NODATA; break;
+  case TFO_ATTEMPTED_DATA:	tcp_out_fastopen = TFO_USED_DATA; break;
+  default: break; /* compiler quietening */
+  }
+
+# else	/* Linux & Apple */
+#  if defined(TCP_INFO) && defined(EXIM_HAVE_TCPI_UNACKED)
 struct tcp_info tinfo;
 socklen_t len = sizeof(tinfo);
 
@@ -194,7 +227,8 @@ switch (tcp_out_fastopen)
 
   default: break; /* compiler quietening */
   }
-# endif
+#  endif
+# endif	/* Linux & Apple */
 }
 #endif
 
@@ -341,7 +375,7 @@ smtp_port_for_connect(host_item * host, int port)
 {
 if (host->port != PORT_NONE)
   {
-  HDEBUG(D_transport|D_acl|D_v)
+  HDEBUG(D_transport|D_acl|D_v) if (port != host->port)
     debug_printf_indent("Transport port=%d replaced by host-specific port=%d\n", port,
       host->port);
   port = host->port;
@@ -467,7 +501,7 @@ else
     rc = n;
     }
   else
-
+    {
     rc = send(outblock->cctx->sock, outblock->buffer, n,
 #ifdef MSG_MORE
 	      more ? MSG_MORE : 0
@@ -475,6 +509,17 @@ else
 	      0
 #endif
 	     );
+
+#if defined(__linux__)
+    /* This is a workaround for a current linux kernel bug: as of
+    5.6.8-200.fc31.x86_64  small (<MSS) writes get delayed by about 200ms,
+    This is despite NODELAY being active.
+    https://bugzilla.redhat.com/show_bug.cgi?id=1803806 */
+
+    if (!more)
+      setsockopt(outblock->cctx->sock, IPPROTO_TCP, TCP_CORK, &off, sizeof(off));
+#endif
+    }
   }
 
 if (rc <= 0)
@@ -521,8 +566,14 @@ if (format)
   gstring gs = { .size = big_buffer_size, .ptr = 0, .s = big_buffer };
   va_list ap;
 
+  /* Use taint-unchecked routines for writing into big_buffer, trusting that
+  we'll never expand the results.  Actually, the error-message use - leaving
+  the results in big_buffer for potential later use - is uncomfortably distant.
+  XXX Would be better to assume all smtp commands are short, use normal pool
+  alloc rather than big_buffer, and another global for the data-for-error. */
+
   va_start(ap, format);
-  if (!string_vformat(&gs, FALSE, CS format, ap))
+  if (!string_vformat(&gs, SVFMT_TAINT_NOCHK, CS format, ap))
     log_write(0, LOG_MAIN|LOG_PANIC_DIE, "overlong write_command in outgoing "
       "SMTP");
   va_end(ap);
@@ -538,7 +589,7 @@ if (format)
     if (!flush_buffer(outblock, SCMD_FLUSH)) return -1;
     }
 
-  Ustrncpy(CS outblock->ptr, gs.s, gs.ptr);
+  Ustrncpy(outblock->ptr, gs.s, gs.ptr);
   outblock->ptr += gs.ptr;
   outblock->cmd_count++;
   gs.ptr -= 2; string_from_gstring(&gs); /* remove \r\n for error message */
@@ -558,7 +609,7 @@ if (format)
       while (!isspace(*p)) p++;
       while (isspace(*p)) p++;
       }
-    while (*p != 0) *p++ = '*';
+    while (*p) *p++ = '*';
     }
 
   HDEBUG(D_transport|D_acl|D_v) debug_printf_indent("  SMTP>> %s\n", big_buffer);
@@ -700,7 +751,7 @@ time_t timelimit = time(NULL) + timeout;
 
 errno = 0;  /* Ensure errno starts out zero */
 
-#ifdef SUPPORT_PIPE_CONNECT
+#ifndef DISABLE_PIPE_CONNECT
 if (sx->pending_BANNER || sx->pending_EHLO)
   {
   int rc;