Import Debian changes 4.92-8+deb10u3

[hcoop/debian/exim4.git] / src / ip.c

diff --git a/src/ip.c b/src/ip.c
index bf56466..552f7dc 100644 (file)
--- a/src/ip.c
+++ b/src/ip.c
@@ -2,7 +2,7 @@
 *     Exim - an Internet mail transport agent    *
 *************************************************/
 
 *     Exim - an Internet mail transport agent    *
 *************************************************/
 

-/* Copyright (c) University of Cambridge 1995 - 2017 */
+/* Copyright (c) University of Cambridge 1995 - 2018 */

 /* See the file NOTICE for conditions of use and distribution. */
 
 /* Functions for doing things with sockets. With the advent of IPv6 this has
 /* See the file NOTICE for conditions of use and distribution. */
 
 /* Functions for doing things with sockets. With the advent of IPv6 this has


@@ -160,6 +160,26 @@ return bind(sock, (struct sockaddr *)&sin, s_len);
 
 
 
 
 
 

+/*************************************************
+*************************************************/
+
+#ifdef EXIM_TFO_PROBE
+void
+tfo_probe(void)
+{
+# ifdef TCP_FASTOPEN
+int sock, backlog = 5;
+
+if (  (sock = socket(SOCK_STREAM, AF_INET, 0)) < 0
+   && setsockopt(sock, IPPROTO_TCP, TCP_FASTOPEN, &backlog, sizeof(backlog))
+   )
+  f.tcp_fastopen_ok = TRUE;
+close(sock);
+# endif
+}
+#endif
+
+

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


@@ -175,14 +195,15 @@ Arguments:
   address     the remote address, in text form
   port        the remote port
   timeout     a timeout (zero for indefinite timeout)
   address     the remote address, in text form
   port        the remote port
   timeout     a timeout (zero for indefinite timeout)

-  fastopen    TRUE iff TCP_FASTOPEN can be used
+  fastopen_blob    non-null iff TCP_FASTOPEN can be used; may indicate early-data to
+               be sent in SYN segment.  Any such data must be idempotent.

 
 Returns:      0 on success; -1 on failure, with errno set
 */
 
 int
 ip_connect(int sock, int af, const uschar *address, int port, int timeout,
 
 Returns:      0 on success; -1 on failure, with errno set
 */
 
 int
 ip_connect(int sock, int af, const uschar *address, int port, int timeout,

-  BOOL fastopen)
+  const blob * fastopen_blob)

 {
 struct sockaddr_in s_in4;
 struct sockaddr *s_ptr;
 {
 struct sockaddr_in s_in4;
 struct sockaddr *s_ptr;


@@ -222,40 +243,112 @@ timer, thereby allowing the inbuilt OS timeout to operate. */
 
 callout_address = string_sprintf("[%s]:%d", address, port);
 sigalrm_seen = FALSE;
 
 callout_address = string_sprintf("[%s]:%d", address, port);
 sigalrm_seen = FALSE;

-if (timeout > 0) alarm(timeout);
+if (timeout > 0) ALARM(timeout);

 
 

-#if defined(TCP_FASTOPEN) && defined(MSG_FASTOPEN)
+#ifdef TCP_FASTOPEN

 /* TCP Fast Open, if the system has a cookie from a previous call to
 this peer, can send data in the SYN packet.  The peer can send data
 before it gets our ACK of its SYN,ACK - the latter is useful for
 /* TCP Fast Open, if the system has a cookie from a previous call to
 this peer, can send data in the SYN packet.  The peer can send data
 before it gets our ACK of its SYN,ACK - the latter is useful for

-the SMTP banner.  Is there any usage where the former might be?
-We might extend the ip_connect() args for data if so.  For now,
-connect in FASTOPEN mode but with zero data.
-*/
+the SMTP banner.  Other (than SMTP) cases of TCP connections can
+possibly use the data-on-syn, so support that too. */

 
 

-if (fastopen)
+if (fastopen_blob && f.tcp_fastopen_ok)

   {
   {

-  if (  (rc = sendto(sock, NULL, 0, MSG_FASTOPEN, s_ptr, s_len)) < 0
-     && errno == EOPNOTSUPP
-     )
+# ifdef MSG_FASTOPEN
+  /* This is a Linux implementation.  It might be useable on FreeBSD; I have
+  not checked. */
+
+  if ((rc = sendto(sock, fastopen_blob->data, fastopen_blob->len,
+                   MSG_FASTOPEN | MSG_DONTWAIT, s_ptr, s_len)) >= 0)
+       /* seen for with-data, experimental TFO option, with-cookie case */
+       /* seen for with-data, proper TFO opt, with-cookie case */
+    {
+    DEBUG(D_transport|D_v)
+      debug_printf("TFO mode connection attempt to %s, %lu data\n",
+       address, (unsigned long)fastopen_blob->len);
+    /*XXX also seen on successful TFO, sigh */
+    tcp_out_fastopen = fastopen_blob->len > 0 ?  TFO_ATTEMPTED_DATA : TFO_ATTEMPTED_NODATA;
+    }
+  else if (errno == EINPROGRESS)       /* expected if we had no cookie for peer */
+       /* seen for no-data, proper TFO option, both cookie-request and with-cookie cases */
+       /*  apparently no visibility of the diffference at this point */
+       /* seen for with-data, proper TFO opt, cookie-req */
+       /*   with netwk delay, post-conn tcp_info sees unacked 1 for R, 2 for C; code in smtp_out.c */
+       /* ? older Experimental TFO option behaviour ? */
+    {                                  /* queue unsent data */
+    DEBUG(D_transport|D_v) debug_printf("TFO mode sendto, %s data: EINPROGRESS\n",
+      fastopen_blob->len > 0 ? "with"  : "no");
+    if (!fastopen_blob->data)
+      {
+      tcp_out_fastopen = TFO_ATTEMPTED_NODATA;         /* we tried; unknown if useful yet */
+      rc = 0;
+      }
+    else
+      rc = send(sock, fastopen_blob->data, fastopen_blob->len, 0);
+    }
+  else if(errno == EOPNOTSUPP)

     {
     DEBUG(D_transport)
       debug_printf("Tried TCP Fast Open but apparently not enabled by sysctl\n");
     {
     DEBUG(D_transport)
       debug_printf("Tried TCP Fast Open but apparently not enabled by sysctl\n");

-    rc = connect(sock, s_ptr, s_len);
+    goto legacy_connect;
+    }
+# endif
+# ifdef EXIM_TFO_CONNECTX
+  /* MacOS */
+  sa_endpoints_t ends = {
+    .sae_srcif = 0, .sae_srcaddr = NULL, .sae_srcaddrlen = 0,
+    .sae_dstaddr = s_ptr, .sae_dstaddrlen = s_len };
+  struct iovec iov = {
+    .iov_base = fastopen_blob->data, .iov_len = fastopen_blob->len };
+  size_t len;
+
+  if ((rc = connectx(sock, &ends, SAE_ASSOCID_ANY,
+            CONNECT_DATA_IDEMPOTENT, &iov, 1, &len, NULL)) == 0)
+    {
+    DEBUG(D_transport|D_v)
+      debug_printf("TFO mode connection attempt to %s, %lu data\n",
+       address, (unsigned long)fastopen_blob->len);
+    tcp_out_fastopen = fastopen_blob->len > 0 ?  TFO_ATTEMPTED_DATA : TFO_ATTEMPTED_NODATA;
+
+    if (len != fastopen_blob->len)
+      DEBUG(D_transport|D_v)
+       debug_printf(" only queued %lu data!\n", (unsigned long)len);
+    }
+  else if (errno == EINPROGRESS)
+    {
+    DEBUG(D_transport|D_v) debug_printf("TFO mode sendto, %s data: EINPROGRESS\n",
+      fastopen_blob->len > 0 ? "with"  : "no");
+    if (!fastopen_blob->data)
+      {
+      tcp_out_fastopen = TFO_ATTEMPTED_NODATA;         /* we tried; unknown if useful yet */
+      rc = 0;
+      }
+    else       /* assume that no data was queued; block in send */
+      rc = send(sock, fastopen_blob->data, fastopen_blob->len, 0);

     }
     }

+# endif

   }
 else
   }
 else

-#endif
-  rc = connect(sock, s_ptr, s_len);
+#endif /*TCP_FASTOPEN*/
+  {
+legacy_connect:
+  DEBUG(D_transport|D_v) if (fastopen_blob)
+    debug_printf("non-TFO mode connection attempt to %s, %lu data\n",
+      address, (unsigned long)fastopen_blob->len);
+  if ((rc = connect(sock, s_ptr, s_len)) >= 0)
+    if (  fastopen_blob && fastopen_blob->data && fastopen_blob->len
+       && send(sock, fastopen_blob->data, fastopen_blob->len, 0) < 0)
+       rc = -1;
+  }

 
 save_errno = errno;
 
 save_errno = errno;

-alarm(0);
+ALARM_CLR(0);

 
 /* There is a testing facility for simulating a connection timeout, as I
 can't think of any other way of doing this. It converts a connection refused
 into a timeout if the timeout is set to 999999. */
 
 
 /* There is a testing facility for simulating a connection timeout, as I
 can't think of any other way of doing this. It converts a connection refused
 into a timeout if the timeout is set to 999999. */
 

-if (running_in_test_harness  && save_errno == ECONNREFUSED && timeout == 999999)
+if (f.running_in_test_harness  && save_errno == ECONNREFUSED && timeout == 999999)

   {
   rc = -1;
   save_errno = EINTR;
   {
   rc = -1;
   save_errno = EINTR;


@@ -286,24 +379,25 @@ return -1;
 Arguments:
   type          SOCK_DGRAM or SOCK_STREAM
   af            AF_INET6 or AF_INET for the socket type
 Arguments:
   type          SOCK_DGRAM or SOCK_STREAM
   af            AF_INET6 or AF_INET for the socket type

-  address       the remote address, in text form
+  hostname     host name, or ip address (as text)

   portlo,porthi the remote port range
   timeout       a timeout
   portlo,porthi the remote port range
   timeout       a timeout

-  connhost     if not NULL, host_item filled in with connection details
+  connhost     if not NULL, host_item to be filled in with connection details

   errstr        pointer for allocated string on error
   errstr        pointer for allocated string on error

+  fastopen_blob        with SOCK_STREAM, if non-null, request TCP Fast Open.
+               Additionally, optional idempotent early-data to send

 
 Return:
   socket fd, or -1 on failure (having allocated an error string)
 */
 int
 ip_connectedsocket(int type, const uschar * hostname, int portlo, int porthi,
 
 Return:
   socket fd, or -1 on failure (having allocated an error string)
 */
 int
 ip_connectedsocket(int type, const uschar * hostname, int portlo, int porthi,

-       int timeout, host_item * connhost, uschar ** errstr)
+      int timeout, host_item * connhost, uschar ** errstr, const blob * fastopen_blob)

 {
 int namelen, port;
 host_item shost;
 host_item *h;
 int af = 0, fd, fd4 = -1, fd6 = -1;
 {
 int namelen, port;
 host_item shost;
 host_item *h;
 int af = 0, fd, fd4 = -1, fd6 = -1;

-BOOL fastopen = tcp_fastopen_ok && type == SOCK_STREAM;

 
 shost.next = NULL;
 shost.address = NULL;
 
 shost.next = NULL;
 shost.address = NULL;


@@ -359,7 +453,7 @@ for (h = &shost; h; h = h->next)
     }
 
   for(port = portlo; port <= porthi; port++)
     }
 
   for(port = portlo; port <= porthi; port++)

-    if (ip_connect(fd, af, h->address, port, timeout, fastopen) == 0)
+    if (ip_connect(fd, af, h->address, port, timeout, fastopen_blob) == 0)

       {
       if (fd != fd6) close(fd6);
       if (fd != fd4) close(fd4);
       {
       if (fd != fd6) close(fd6);
       if (fd != fd4) close(fd4);


@@ -381,6 +475,7 @@ bad:
 }
 
 
 }
 
 

+/*XXX TFO? */

 int
 ip_tcpsocket(const uschar * hostport, uschar ** errstr, int tmo)
 {
 int
 ip_tcpsocket(const uschar * hostport, uschar ** errstr, int tmo)
 {


@@ -401,7 +496,7 @@ if (scan != 3)
   }
 
 return ip_connectedsocket(SOCK_STREAM, hostname, portlow, porthigh,
   }
 
 return ip_connectedsocket(SOCK_STREAM, hostname, portlow, porthigh,

-                         tmo, NULL, errstr);
+                         tmo, NULL, errstr, NULL);

 }
 
 int
 }
 
 int


@@ -457,7 +552,7 @@ ip_keepalive(int sock, const uschar *address, BOOL torf)
 {
 int fodder = 1;
 if (setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE,
 {
 int fodder = 1;
 if (setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE,

-    (uschar *)(&fodder), sizeof(fodder)) != 0)
+    US (&fodder), sizeof(fodder)) != 0)

   log_write(0, LOG_MAIN, "setsockopt(SO_KEEPALIVE) on connection %s %s "
     "failed: %s", torf? "to":"from", address, strerror(errno));
 }
   log_write(0, LOG_MAIN, "setsockopt(SO_KEEPALIVE) on connection %s %s "
     "failed: %s", torf? "to":"from", address, strerror(errno));
 }


@@ -492,7 +587,7 @@ if (time_left <= 0)
 
 do
   {
 
 do
   {

-  struct timeval tv = { time_left, 0 };
+  struct timeval tv = { .tv_sec = time_left, .tv_usec = 0 };

   FD_ZERO (&select_inset);
   FD_SET (fd, &select_inset);
 
   FD_ZERO (&select_inset);
   FD_SET (fd, &select_inset);
 


@@ -536,7 +631,7 @@ getting interrupted, and the possibility of select() returning with a positive
 result but no ready descriptor. Is this in fact possible?
 
 Arguments:
 result but no ready descriptor. Is this in fact possible?
 
 Arguments:

-  sock        the socket
+  cctx        the connection context (socket fd, possibly TLS context)

   buffer      to read into
   bufsize     the buffer size
   timeout     the timeout
   buffer      to read into
   bufsize     the buffer size
   timeout     the timeout


@@ -546,24 +641,24 @@ Returns:      > 0 => that much data read
 */
 
 int
 */
 
 int

-ip_recv(int sock, uschar *buffer, int buffsize, int timeout)
+ip_recv(client_conn_ctx * cctx, uschar * buffer, int buffsize, int timeout)

 {
 int rc;
 
 {
 int rc;
 

-if (!fd_ready(sock, timeout))
+if (!fd_ready(cctx->sock, timeout))

   return -1;
 
 /* The socket is ready, read from it (via TLS if it's active). On EOF (i.e.
 close down of the connection), set errno to zero; otherwise leave it alone. */
 
 #ifdef SUPPORT_TLS
   return -1;
 
 /* The socket is ready, read from it (via TLS if it's active). On EOF (i.e.
 close down of the connection), set errno to zero; otherwise leave it alone. */
 
 #ifdef SUPPORT_TLS

-if (tls_out.active == sock)
-  rc = tls_read(FALSE, buffer, buffsize);
-else if (tls_in.active == sock)
-  rc = tls_read(TRUE, buffer, buffsize);
+if (cctx->tls_ctx)                                     /* client TLS */
+  rc = tls_read(cctx->tls_ctx, buffer, buffsize);
+else if (tls_in.active.sock == cctx->sock)             /* server TLS */
+  rc = tls_read(NULL, buffer, buffsize);

 else
 #endif
 else
 #endif

-  rc = recv(sock, buffer, buffsize, 0);
+  rc = recv(cctx->sock, buffer, buffsize, 0);

 
 if (rc > 0) return rc;
 if (rc == 0) errno = 0;
 
 if (rc > 0) return rc;
 if (rc == 0) errno = 0;