Recast more internal string routines to use growable-strings

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

diff --git a/src/src/smtp_out.c b/src/src/smtp_out.c
index db33ac66e26990c7ba0be6222ff0dd58106ee604..9bd90c77a7cacf3d6abe360404f17b866000f2e3 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);


@@ -140,8 +140,66 @@ 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);
+
+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_NODATA:
+    if (  getsockopt(sock, IPPROTO_TCP, TCP_INFO, &tinfo, &len) == 0
+       && tinfo.tcpi_state == TCP_SYN_SENT
+       && 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_NODATA;
+      }
+    break;
+
+    /* When called after waiting for received data we should be able
+    to tell if data we sent was accepted. */
+
+  case TFO_ATTEMPTED_DATA:
+    if (  getsockopt(sock, IPPROTO_TCP, TCP_INFO, &tinfo, &len) == 0
+       && tinfo.tcpi_state == TCP_ESTABLISHED
+       )
+      if (tinfo.tcpi_options & TCPI_OPT_SYN_DATA)
+       {
+       DEBUG(D_transport|D_v) debug_printf("TFO: data was acked\n");
+       tcp_out_fastopen = TFO_USED_DATA;
+       }
+      else
+       {
+       DEBUG(D_transport|D_v) debug_printf("TFO: had to retransmit\n");
+       tcp_out_fastopen = TFO_NOT_USED;
+       }
+    break;
+  }
+# endif
+}
+#endif
+
+

 /* Arguments as for smtp_connect(), plus
 /* Arguments as for smtp_connect(), plus

-  early_data   if non-NULL, data to be sent - preferably in the TCP SYN segment
+  early_data   if non-NULL, idenmpotent data to be sent -
+               preferably in the TCP SYN segment

 
 Returns:      connected socket number, or -1 with errno set
 */
 
 Returns:      connected socket number, or -1 with errno set
 */


@@ -158,6 +216,8 @@ int dscp_level;
 int dscp_option;
 int sock;
 int save_errno = 0;
 int dscp_option;
 int sock;
 int save_errno = 0;

+const blob * fastopen_blob = NULL;
+

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


@@ -203,22 +263,29 @@ if (interface && ip_bind(sock, host_af, interface, 0) < 0)
 
 /* Connect to the remote host, and add keepalive to the socket before returning
 it, if requested.  If the build supports TFO, request it - and if the caller
 
 /* Connect to the remote host, and add keepalive to the socket before returning
 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. */
+requested some early-data then include that in the TFO request.  If there is
+early-data but no TFO support, send it after connecting. */

 
 else
   {
 
 else
   {

-  const blob * fastopen = NULL;
-

 #ifdef TCP_FASTOPEN
 #ifdef TCP_FASTOPEN

-  if (verify_check_given_host(&ob->hosts_try_fastopen, host) == OK)
-    fastopen = early_data ? early_data : &tcp_fastopen_nodata;
+  if (verify_check_given_host(CUSS &ob->hosts_try_fastopen, host) == OK)
+    fastopen_blob = early_data ? early_data : &tcp_fastopen_nodata;

 #endif
 
 #endif
 

-  if (ip_connect(sock, host_af, host->address, port, timeout, fastopen) < 0)
+  if (ip_connect(sock, host_af, host->address, port, timeout, fastopen_blob) < 0)

     save_errno = errno;
     save_errno = errno;

-  else if (early_data && !fastopen && early_data->data && early_data->len)
+  else if (early_data && !fastopen_blob && early_data->data && early_data->len)
+    {
+    HDEBUG(D_transport|D_acl|D_v)
+      debug_printf("sending %ld nonTFO early-data\n", (long)early_data->len);
+
+#ifdef TCP_QUICKACK
+    (void) setsockopt(sock, IPPROTO_TCP, TCP_QUICKACK, US &off, sizeof(off));
+#endif

     if (send(sock, early_data->data, early_data->len, 0) < 0)
       save_errno = errno;
     if (send(sock, early_data->data, early_data->len, 0) < 0)
       save_errno = errno;

+    }

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


@@ -237,12 +304,13 @@ if (save_errno != 0)
   return -1;
   }
 
   return -1;
   }
 

-/* Both bind() and connect() succeeded */
+/* Both bind() and connect() succeeded, and any early-data */

 
 else
   {
   union sockaddr_46 interface_sock;
   EXIM_SOCKLEN_T size = sizeof(interface_sock);
 
 else
   {
   union sockaddr_46 interface_sock;
   EXIM_SOCKLEN_T size = sizeof(interface_sock);

+

   HDEBUG(D_transport|D_acl|D_v) debug_printf_indent("connected\n");
   if (getsockname(sock, (struct sockaddr *)(&interface_sock), &size) == 0)
     sending_ip_address = host_ntoa(-1, &interface_sock, NULL, &sending_port);
   HDEBUG(D_transport|D_acl|D_v) debug_printf_indent("connected\n");
   if (getsockname(sock, (struct sockaddr *)(&interface_sock), &size) == 0)
     sending_ip_address = host_ntoa(-1, &interface_sock, NULL, &sending_port);


@@ -253,7 +321,11 @@ else
     close(sock);
     return -1;
     }
     close(sock);
     return -1;
     }

+

   if (ob->keepalive) ip_keepalive(sock, host->address, TRUE);
   if (ob->keepalive) ip_keepalive(sock, host->address, TRUE);

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

   return sock;
   }
 }
   return sock;
   }
 }


@@ -286,45 +358,62 @@ non-IPv6 systems, to enable the code to be less messy. However, on such systems
 host->address will always be an IPv4 address.
 
 Arguments:
 host->address will always be an IPv4 address.
 
 Arguments:

-  host        host item containing name and address and port
-  host_af     AF_INET or AF_INET6
-  interface   outgoing interface address or NULL
-  timeout     timeout value or 0
-  tb          transport
+  sc         details for making connection: host, af, interface, transport
+  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
 
 Returns:      connected socket number, or -1 with errno set
 */
 
 int

-smtp_connect(host_item *host, int host_af, uschar *interface,
-  int timeout, transport_instance * tb)
+smtp_connect(smtp_connect_args * sc, const blob * early_data)

 {
 {

-int port = host->port;
-#ifdef SUPPORT_SOCKS
-smtp_transport_options_block * ob =
-  (smtp_transport_options_block *)tb->options_block;
-#endif
+int port = sc->host->port;
+smtp_transport_options_block * ob = sc->ob;

 
 

-callout_address = string_sprintf("[%s]:%d", host->address, port);
+callout_address = string_sprintf("[%s]:%d", sc->host->address, port);

 
 HDEBUG(D_transport|D_acl|D_v)
   {
   uschar * s = US" ";
 
 HDEBUG(D_transport|D_acl|D_v)
   {
   uschar * s = US" ";

-  if (interface) s = string_sprintf(" from %s ", interface);
+  if (sc->interface) s = string_sprintf(" from %s ", sc->interface);

 #ifdef SUPPORT_SOCKS
   if (ob->socks_proxy) s = string_sprintf("%svia proxy ", s);
 #endif
 #ifdef SUPPORT_SOCKS
   if (ob->socks_proxy) s = string_sprintf("%svia proxy ", s);
 #endif

-  debug_printf_indent("Connecting to %s %s%s... ", host->name, callout_address, s);
+  debug_printf_indent("Connecting to %s %s%s... ", sc->host->name, callout_address, s);

   }
 
 /* Create and connect the socket */
 
 #ifdef SUPPORT_SOCKS
 if (ob->socks_proxy)
   }
 
 /* Create and connect the socket */
 
 #ifdef SUPPORT_SOCKS
 if (ob->socks_proxy)

-  return socks_sock_connect(host, host_af, port, interface, tb, timeout);
+  {
+  int sock = socks_sock_connect(sc->host, sc->host_af, port, sc->interface,
+                               sc->tblock, ob->connect_timeout);
+  
+  if (sock >= 0)
+    {
+    if (early_data && early_data->data && early_data->len)
+      if (send(sock, early_data->data, early_data->len, 0) < 0)
+       {
+       int save_errno = errno;
+       HDEBUG(D_transport|D_acl|D_v)
+         {
+         debug_printf_indent("failed: %s", CUstrerror(save_errno));
+         if (save_errno == ETIMEDOUT)
+           debug_printf(" (timeout=%s)", readconf_printtime(ob->connect_timeout));
+         debug_printf("\n");
+         }
+       (void)close(sock);
+       sock = -1;
+       errno = save_errno;
+       }
+    }
+  return sock;
+  }

 #endif
 
 #endif
 

-return smtp_sock_connect(host, host_af, port, interface, tb, timeout, NULL);
+return smtp_sock_connect(sc->host, sc->host_af, port, sc->interface,
+                         sc->tblock, ob->connect_timeout, early_data);

 }
 
 
 }
 
 


@@ -354,17 +443,37 @@ HDEBUG(D_transport|D_acl) debug_printf_indent("cmd buf flush %d bytes%s\n", n,
   more ? " (more expected)" : "");
 
 #ifdef SUPPORT_TLS
   more ? " (more expected)" : "");
 
 #ifdef SUPPORT_TLS

-if (tls_out.active == outblock->sock)
-  rc = tls_write(FALSE, outblock->buffer, n, more);
+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,
+
+  {
+  if (outblock->conn_args)
+    {
+    blob early_data = { .data = outblock->buffer, .len = n };
+
+    /* We ignore the more-flag if we're doing a connect with early-data, which
+    means we won't get BDAT+data. A pity, but wise due to the idempotency
+    requirement: TFO with data can, in rare cases, replay the data to the
+    receiver. */
+
+    if (  (outblock->cctx->sock = smtp_connect(outblock->conn_args, &early_data))
+       < 0)
+      return FALSE;
+    outblock->conn_args = NULL;
+    rc = n;
+    }
+  else
+
+    rc = send(outblock->cctx->sock, outblock->buffer, n,

 #ifdef MSG_MORE
 #ifdef MSG_MORE

-           more ? MSG_MORE : 0
+             more ? MSG_MORE : 0

 #else
 #else

-           0
+             0

 #endif
 #endif

-          );
+            );
+  }

 
 if (rc <= 0)
   {
 
 if (rc <= 0)
   {


@@ -387,7 +496,7 @@ 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.


@@ -400,36 +509,37 @@ 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, ...)

 {
 {

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

 int rc = 0;
 int rc = 0;

-va_list ap;

 
 if (format)
   {
 
 if (format)
   {

+  gstring gs = { .size = big_buffer_size, .ptr = 0, .s = big_buffer };
+  va_list ap;
+

   va_start(ap, format);
   va_start(ap, format);

-  if (!string_vformat(big_buffer, big_buffer_size, CS format, ap))
+  if (!string_vformat(&gs, FALSE, CS format, ap))

     log_write(0, LOG_MAIN|LOG_PANIC_DIE, "overlong write_command in outgoing "
       "SMTP");
   va_end(ap);
     log_write(0, LOG_MAIN|LOG_PANIC_DIE, "overlong write_command in outgoing "
       "SMTP");
   va_end(ap);

-  count = Ustrlen(big_buffer);
+  string_from_gstring(&gs);

 
 

-  if (count > outblock->buffersize)
+  if (gs.ptr > outblock->buffersize)

     log_write(0, LOG_MAIN|LOG_PANIC_DIE, "overlong write_command in outgoing "
       "SMTP");
 
     log_write(0, LOG_MAIN|LOG_PANIC_DIE, "overlong write_command in outgoing "
       "SMTP");
 

-  if (count > outblock->buffersize - (outblock->ptr - outblock->buffer))
+  if (gs.ptr > outblock->buffersize - (outblock->ptr - outblock->buffer))

     {
     rc = outblock->cmd_count;                 /* flush resets */
     if (!flush_buffer(outblock, SCMD_FLUSH)) return -1;
     }
 
     {
     rc = outblock->cmd_count;                 /* flush resets */
     if (!flush_buffer(outblock, SCMD_FLUSH)) return -1;
     }
 

-  Ustrncpy(CS outblock->ptr, big_buffer, count);
-  outblock->ptr += count;
+  Ustrncpy(CS outblock->ptr, gs.s, gs.ptr);
+  outblock->ptr += gs.ptr;

   outblock->cmd_count++;
   outblock->cmd_count++;

-  count -= 2;
-  big_buffer[count] = 0;     /* remove \r\n for error message */
+  gs.ptr -= 2; string_from_gstring(&gs); /* remove \r\n for error message */

 
   /* We want to hide the actual data sent in AUTH transactions from reflections
   and logs. While authenticating, a flag is set in the outblock to enable this.
 
   /* We want to hide the actual data sent in AUTH transactions from reflections
   and logs. While authenticating, a flag is set in the outblock to enable this.


@@ -489,7 +599,7 @@ 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. */


@@ -527,7 +637,7 @@ 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",


@@ -566,7 +676,8 @@ 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


@@ -574,26 +685,37 @@ Arguments:
 
 Returns:    TRUE if a valid, non-error response was received; else FALSE
 */
 
 Returns:    TRUE if a valid, non-error response was received; else FALSE
 */

+/*XXX could move to smtp transport; no other users */

 
 BOOL
 
 BOOL

-smtp_read_response(smtp_inblock *inblock, uschar *buffer, int size, int okdigit,
+smtp_read_response(void * sx0, uschar *buffer, int size, int okdigit,

    int timeout)
 {
    int timeout)
 {

+smtp_context * sx = sx0;

 uschar *ptr = buffer;
 uschar *ptr = buffer;

-int count;
+int count = 0;

 
 errno = 0;  /* Ensure errno starts out zero */
 
 
 errno = 0;  /* Ensure errno starts out zero */
 

+#ifdef EXPERIMENTAL_PIPE_CONNECT
+if (sx->pending_BANNER || sx->pending_EHLO)
+  if (smtp_reap_early_pipe(sx, &count) != OK)
+    {
+    DEBUG(D_transport) debug_printf("failed reaping pipelined cmd responsess\n");
+    return FALSE;
+    }
+#endif
+

 /* This is a loop to read and concatenate the lines that make up a multi-line
 response. */
 
 for (;;)
   {
 /* This is a loop to read and concatenate the lines that make up a multi-line
 response. */
 
 for (;;)
   {

-  if ((count = read_response_line(inblock, ptr, size, timeout)) < 0)
+  if ((count = read_response_line(&sx->inblock, ptr, size, timeout)) < 0)

     return FALSE;
 
   HDEBUG(D_transport|D_acl|D_v)
     return FALSE;
 
   HDEBUG(D_transport|D_acl|D_v)

-    debug_printf_indent("  %s %s\n", (ptr == buffer)? "SMTP<<" : "      ", ptr);
+    debug_printf_indent("  %s %s\n", ptr == buffer ? "SMTP<<" : "      ", ptr);

 
   /* Check the format of the response: it must start with three digits; if
   these are followed by a space or end of line, the response is complete. If
 
   /* Check the format of the response: it must start with three digits; if
   these are followed by a space or end of line, the response is complete. If


@@ -627,6 +749,10 @@ for (;;)
   size -= count + 1;
   }
 
   size -= count + 1;
   }
 

+#ifdef TCP_FASTOPEN
+  tfo_out_check(sx->cctx.sock);
+#endif
+

 /* Return a value that depends on the SMTP return code. On some systems a
 non-zero value of errno has been seen at this point, so ensure it is zero,
 because the caller of this function looks at errno when FALSE is returned, to
 /* Return a value that depends on the SMTP return code. On some systems a
 non-zero value of errno has been seen at this point, so ensure it is zero,
 because the caller of this function looks at errno when FALSE is returned, to