TFO: use enum for client status

[exim.git] / src / src / smtp_out.c

diff --git a/src/src/smtp_out.c b/src/src/smtp_out.c
index c4f32a0c2eea0482488d5baeb2d2040535c373a2..f02863a5410bda5867577a3a25190d3b8ca117c9 100644 (file)
--- a/src/src/smtp_out.c
+++ b/src/src/smtp_out.c
@@ -2,7 +2,7 @@
 *     Exim - an Internet mail transport agent    *
 *************************************************/
 
 *     Exim - an Internet mail transport agent    *
 *************************************************/
 

-/* Copyright (c) University of Cambridge 1995 - 2016 */
+/* Copyright (c) University of Cambridge 1995 - 2018 */

 /* See the file NOTICE for conditions of use and distribution. */
 
 /* A number of functions for driving outgoing SMTP calls. */
 /* See the file NOTICE for conditions of use and distribution. */
 
 /* A number of functions for driving outgoing SMTP calls. */


@@ -45,7 +45,7 @@ if (!istring) return TRUE;
 
 if (!(expint = expand_string(istring)))
   {
 
 if (!(expint = expand_string(istring)))
   {

-  if (expand_string_forcedfail) return TRUE;
+  if (f.expand_string_forcedfail) return TRUE;

   addr->transport_return = PANIC;
   addr->message = string_sprintf("failed to expand \"interface\" "
       "option for %s: %s", msg, expand_string_message);
   addr->transport_return = PANIC;
   addr->message = string_sprintf("failed to expand \"interface\" "
       "option for %s: %s", msg, expand_string_message);


@@ -140,9 +140,69 @@ return TRUE;
 
 
 
 
 
 

+#ifdef TCP_FASTOPEN
+static void
+tfo_out_check(int sock)
+{
+# if defined(TCP_INFO) && defined(EXIM_HAVE_TCPI_UNACKED)
+struct tcp_info tinfo;
+socklen_t len = sizeof(tinfo);
+
+if (getsockopt(sock, IPPROTO_TCP, TCP_INFO, &tinfo, &len) == 0)
+  {
+  switch (tcp_out_fastopen)
+    {
+      /* This is a somewhat dubious detection method; totally undocumented so likely
+      to fail in future kernels.  There seems to be no documented way.  What we really
+      want to know is if the server sent smtp-banner data before our ACK of his SYN,ACK
+      hit him.  What this (possibly?) detects is whether we sent a TFO cookie with our
+      SYN, as distinct from a TFO request.  This gets a false-positive when the server
+      key is rotated; we send the old one (which this test sees) but the server returns
+      the new one and does not send its SMTP banner before we ACK his SYN,ACK.
+       To force that rotation case:
+       '# echo -n "00000000-00000000-00000000-0000000" >/proc/sys/net/ipv4/tcp_fastopen_key'
+      The kernel seems to be counting unack'd packets. */
+
+    case TFO_ATTEMPTED:
+      if (tinfo.tcpi_unacked > 1)
+       {
+       DEBUG(D_transport|D_v)
+         debug_printf("TCP_FASTOPEN tcpi_unacked %d\n", tinfo.tcpi_unacked);
+       tcp_out_fastopen = TFO_USED;
+       }
+      break;
+
+#ifdef notdef          /* This seems to always fire, meaning that we cannot tell
+                       whether the server accepted data we sent.  For now assume
+                       that it did. */
+
+      /* If there was data-on-SYN but we had to retrasnmit it, declare no TFO */
+
+    case TFO_USED:
+      if (!(tinfo.tcpi_options & TCPI_OPT_SYN_DATA))
+       {
+       DEBUG(D_transport|D_v) debug_printf("TFO: had to retransmit\n");
+       tcp_out_fastopen = TFO_NOT_USED;
+       }
+      break;
+#endif
+    }
+
+  }
+# endif
+}
+#endif
+
+
+/* Arguments as for smtp_connect(), plus
+  early_data   if non-NULL, data to be sent - preferably in the TCP SYN segment
+
+Returns:      connected socket number, or -1 with errno set
+*/
+

 int
 smtp_sock_connect(host_item * host, int host_af, int port, uschar * interface,
 int
 smtp_sock_connect(host_item * host, int host_af, int port, uschar * interface,

-  transport_instance * tb, int timeout)
+  transport_instance * tb, int timeout, const blob * early_data)

 {
 smtp_transport_options_block * ob =
   (smtp_transport_options_block *)tb->options_block;
 {
 smtp_transport_options_block * ob =
   (smtp_transport_options_block *)tb->options_block;


@@ -152,7 +212,8 @@ int dscp_level;
 int dscp_option;
 int sock;
 int save_errno = 0;
 int dscp_option;
 int sock;
 int save_errno = 0;

-BOOL fastopen = FALSE;
+const blob * fastopen_blob = NULL;
+

 
 #ifndef DISABLE_EVENT
 deliver_host_address = host->address;
 
 #ifndef DISABLE_EVENT
 deliver_host_address = host->address;


@@ -185,10 +246,6 @@ if (dscp && dscp_lookup(dscp, host_af, &dscp_level, &dscp_option, &dscp_value))
     (void) setsockopt(sock, dscp_level, dscp_option, &dscp_value, sizeof(dscp_value));
   }
 
     (void) setsockopt(sock, dscp_level, dscp_option, &dscp_value, sizeof(dscp_value));
   }
 

-#ifdef TCP_FASTOPEN
-if (verify_check_given_host (&ob->hosts_try_fastopen, host) == OK) fastopen = TRUE;
-#endif
-

 /* Bind to a specific interface if requested. Caller must ensure the interface
 is the same type (IPv4 or IPv6) as the outgoing address. */
 
 /* Bind to a specific interface if requested. Caller must ensure the interface
 is the same type (IPv4 or IPv6) as the outgoing address. */
 


@@ -201,10 +258,22 @@ if (interface && ip_bind(sock, host_af, interface, 0) < 0)
   }
 
 /* Connect to the remote host, and add keepalive to the socket before returning
   }
 
 /* Connect to the remote host, and add keepalive to the socket before returning

-it, if requested. */
+it, if requested.  If the build supports TFO, request it - and if the caller
+requested some early-data then include that in the TFO request. */

 
 

-else if (ip_connect(sock, host_af, host->address, port, timeout, fastopen) < 0)
-  save_errno = errno;
+else
+  {
+#ifdef TCP_FASTOPEN
+  if (verify_check_given_host(CUSS &ob->hosts_try_fastopen, host) == OK)
+    fastopen_blob = early_data ? early_data : &tcp_fastopen_nodata;
+#endif
+
+  if (ip_connect(sock, host_af, host->address, port, timeout, fastopen_blob) < 0)
+    save_errno = errno;
+  else if (early_data && !fastopen_blob && early_data->data && early_data->len)
+    if (send(sock, early_data->data, early_data->len, 0) < 0)
+      save_errno = errno;
+  }

 
 /* Either bind() or connect() failed */
 
 
 /* Either bind() or connect() failed */
 


@@ -239,10 +308,31 @@ else
     return -1;
     }
   if (ob->keepalive) ip_keepalive(sock, host->address, TRUE);
     return -1;
     }
   if (ob->keepalive) ip_keepalive(sock, host->address, TRUE);

+#ifdef TCP_FASTOPEN
+  if (fastopen_blob) tfo_out_check(sock);
+#endif

   return sock;
   }
 }
 
   return sock;
   }
 }
 

+
+
+
+
+void
+smtp_port_for_connect(host_item * host, int port)
+{
+if (host->port != PORT_NONE)
+  {
+  HDEBUG(D_transport|D_acl|D_v)
+    debug_printf_indent("Transport port=%d replaced by host-specific port=%d\n", port,
+      host->port);
+  port = host->port;
+  }
+else host->port = port;    /* Set the port actually used */
+}
+
+

 /*************************************************
 *           Connect to remote host               *
 *************************************************/
 /*************************************************
 *           Connect to remote host               *
 *************************************************/


@@ -252,15 +342,9 @@ detected by checking for a colon in the address. AF_INET6 is defined even on
 non-IPv6 systems, to enable the code to be less messy. However, on such systems
 host->address will always be an IPv4 address.
 
 non-IPv6 systems, to enable the code to be less messy. However, on such systems
 host->address will always be an IPv4 address.
 

-The port field in the host item is used if it is set (usually router from SRV
-records or elsewhere). In other cases, the default passed as an argument is
-used, and the host item is updated with its value.
-

 Arguments:
 Arguments:

-  host        host item containing name and address (and sometimes port)
+  host        host item containing name and address and port

   host_af     AF_INET or AF_INET6
   host_af     AF_INET or AF_INET6

-  port        default remote port to connect to, in host byte order, for those
-                hosts whose port setting is PORT_NONE

   interface   outgoing interface address or NULL
   timeout     timeout value or 0
   tb          transport
   interface   outgoing interface address or NULL
   timeout     timeout value or 0
   tb          transport


@@ -269,23 +353,15 @@ Returns:      connected socket number, or -1 with errno set
 */
 
 int
 */
 
 int

-smtp_connect(host_item *host, int host_af, int port, uschar *interface,
+smtp_connect(host_item *host, int host_af, uschar *interface,

   int timeout, transport_instance * tb)
 {
   int timeout, transport_instance * tb)
 {

+int port = host->port;

 #ifdef SUPPORT_SOCKS
 smtp_transport_options_block * ob =
   (smtp_transport_options_block *)tb->options_block;
 #endif
 
 #ifdef SUPPORT_SOCKS
 smtp_transport_options_block * ob =
   (smtp_transport_options_block *)tb->options_block;
 #endif
 

-if (host->port != PORT_NONE)
-  {
-  HDEBUG(D_transport|D_acl|D_v)
-    debug_printf_indent("Transport port=%d replaced by host-specific port=%d\n", port,
-      host->port);
-  port = host->port;
-  }
-else host->port = port;    /* Set the port actually used */
-

 callout_address = string_sprintf("[%s]:%d", host->address, port);
 
 HDEBUG(D_transport|D_acl|D_v)
 callout_address = string_sprintf("[%s]:%d", host->address, port);
 
 HDEBUG(D_transport|D_acl|D_v)


@@ -305,7 +381,7 @@ if (ob->socks_proxy)
   return socks_sock_connect(host, host_af, port, interface, tb, timeout);
 #endif
 
   return socks_sock_connect(host, host_af, port, interface, tb, timeout);
 #endif
 

-return smtp_sock_connect(host, host_af, port, interface, tb, timeout);
+return smtp_sock_connect(host, host_af, port, interface, tb, timeout, NULL);

 }
 
 
 }
 
 


@@ -319,7 +395,7 @@ pipelining.
 
 Argument:
   outblock   the SMTP output block
 
 Argument:
   outblock   the SMTP output block

-  mode      more-expected, or plain
+  mode      further data expected, or plain

 
 Returns:     TRUE if OK, FALSE on error, with errno set
 */
 
 Returns:     TRUE if OK, FALSE on error, with errno set
 */


@@ -329,18 +405,19 @@ flush_buffer(smtp_outblock * outblock, int mode)
 {
 int rc;
 int n = outblock->ptr - outblock->buffer;
 {
 int rc;
 int n = outblock->ptr - outblock->buffer;

+BOOL more = mode == SCMD_MORE;

 
 HDEBUG(D_transport|D_acl) debug_printf_indent("cmd buf flush %d bytes%s\n", n,
 
 HDEBUG(D_transport|D_acl) debug_printf_indent("cmd buf flush %d bytes%s\n", n,

-  mode == SCMD_MORE ? " (more expected)" : "");
+  more ? " (more expected)" : "");

 
 #ifdef SUPPORT_TLS
 
 #ifdef SUPPORT_TLS

-if (tls_out.active == outblock->sock)
-  rc = tls_write(FALSE, outblock->buffer, n);
+if (outblock->cctx->tls_ctx)
+  rc = tls_write(outblock->cctx->tls_ctx, outblock->buffer, n, more);

 else
 #endif
 else
 #endif

-  rc = send(outblock->sock, outblock->buffer, n,
+  rc = send(outblock->cctx->sock, outblock->buffer, n,

 #ifdef MSG_MORE
 #ifdef MSG_MORE

-           mode == SCMD_MORE ? MSG_MORE : 0
+           more ? MSG_MORE : 0

 #else
            0
 #endif
 #else
            0
 #endif


@@ -367,7 +444,7 @@ return TRUE;
 any error message.
 
 Arguments:
 any error message.
 
 Arguments:

-  outblock   contains buffer for pipelining, and socket
+  sx        SMTP connection, contains buffer for pipelining, and socket

   mode       buffer, write-with-more-likely, write
   format     a format, starting with one of
              of HELO, MAIL FROM, RCPT TO, DATA, ".", or QUIT.
   mode       buffer, write-with-more-likely, write
   format     a format, starting with one of
              of HELO, MAIL FROM, RCPT TO, DATA, ".", or QUIT.


@@ -380,8 +457,9 @@ Returns:     0 if command added to pipelining buffer, with nothing transmitted
 */
 
 int
 */
 
 int

-smtp_write_command(smtp_outblock * outblock, int mode, const char *format, ...)
+smtp_write_command(void * sx, int mode, const char *format, ...)

 {
 {

+smtp_outblock * outblock = &((smtp_context *)sx)->outblock;

 int count;
 int rc = 0;
 va_list ap;
 int count;
 int rc = 0;
 va_list ap;


@@ -469,7 +547,7 @@ read_response_line(smtp_inblock *inblock, uschar *buffer, int size, int timeout)
 uschar *p = buffer;
 uschar *ptr = inblock->ptr;
 uschar *ptrend = inblock->ptrend;
 uschar *p = buffer;
 uschar *ptr = inblock->ptr;
 uschar *ptrend = inblock->ptrend;

-int sock = inblock->sock;
+client_conn_ctx * cctx = inblock->cctx;

 
 /* Loop for reading multiple packets or reading another packet after emptying
 a previously-read one. */
 
 /* Loop for reading multiple packets or reading another packet after emptying
 a previously-read one. */


@@ -507,7 +585,7 @@ for (;;)
 
   /* Need to read a new input packet. */
 
 
   /* Need to read a new input packet. */
 

-  if((rc = ip_recv(sock, inblock->buffer, inblock->buffersize, timeout)) <= 0)
+  if((rc = ip_recv(cctx, inblock->buffer, inblock->buffersize, timeout)) <= 0)

     {
     DEBUG(D_deliver|D_transport|D_acl)
       debug_printf_indent(errno ? "  SMTP(%s)<<\n" : "  SMTP(closed)<<\n",
     {
     DEBUG(D_deliver|D_transport|D_acl)
       debug_printf_indent(errno ? "  SMTP(%s)<<\n" : "  SMTP(closed)<<\n",


@@ -546,7 +624,8 @@ also returned after a reading error. In this case buffer[0] will be zero, and
 the error code will be in errno.
 
 Arguments:
 the error code will be in errno.
 
 Arguments:

-  inblock   the SMTP input block (contains holding buffer, socket, etc.)
+  sx        the SMTP connection (contains input block with holding buffer,
+               socket, etc.)

   buffer    where to put the response
   size      the size of the buffer
   okdigit   the expected first digit of the response
   buffer    where to put the response
   size      the size of the buffer
   okdigit   the expected first digit of the response


@@ -556,9 +635,10 @@ Returns:    TRUE if a valid, non-error response was received; else FALSE
 */
 
 BOOL
 */
 
 BOOL

-smtp_read_response(smtp_inblock *inblock, uschar *buffer, int size, int okdigit,
+smtp_read_response(void * sx, uschar *buffer, int size, int okdigit,

    int timeout)
 {
    int timeout)
 {

+smtp_inblock * inblock = &((smtp_context *)sx)->inblock;

 uschar *ptr = buffer;
 int count;
 
 uschar *ptr = buffer;
 int count;