SPDX: license tags (mostly by guesswork)

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

diff --git a/src/src/ip.c b/src/src/ip.c
index ff76b3871b4e89e98cabc5d6807e340407e99bb1..2ac2b267d1b6348d648a93c70b0cf79509f27bbe 100644 (file)
--- a/src/src/ip.c
+++ b/src/src/ip.c
@@ -3,7 +3,9 @@
 *************************************************/
 
 /* Copyright (c) University of Cambridge 1995 - 2018 */
 *************************************************/
 
 /* Copyright (c) University of Cambridge 1995 - 2018 */

+/* Copyright (c) The Exim Maintainers 2020 - 2021 */

 /* See the file NOTICE for conditions of use and distribution. */
 /* See the file NOTICE for conditions of use and distribution. */

+/* SPDX-License-Identifier: GPL-2.0-only */

 
 /* Functions for doing things with sockets. With the advent of IPv6 this has
 got messier, so that it's worth pulling out the code into separate functions
 
 /* Functions for doing things with sockets. With the advent of IPv6 this has
 got messier, so that it's worth pulling out the code into separate functions


@@ -14,6 +16,12 @@ different places in the code where sockets are used. */
 #include "exim.h"
 
 
 #include "exim.h"
 
 

+#if defined(TCP_FASTOPEN)
+# if defined(MSG_FASTOPEN) || defined(EXIM_TFO_CONNECTX) || defined(EXIM_TFO_FREEBSD)
+#  define EXIM_SUPPORT_TFO
+# endif
+#endif
+

 /*************************************************
 *             Create a socket                    *
 *************************************************/
 /*************************************************
 *             Create a socket                    *
 *************************************************/


@@ -120,8 +128,6 @@ if (af == AF_INET6)
   return sizeof(sin->v6);
   }
 else
   return sizeof(sin->v6);
   }
 else

-#else     /* HAVE_IPv6 */
-af = af;  /* Avoid compiler warning */

 #endif    /* HAVE_IPV6 */
 
 /* Setup code when using IPv4 socket. The wildcard address is "". */
 #endif    /* HAVE_IPV6 */
 
 /* Setup code when using IPv4 socket. The wildcard address is "". */


@@ -160,26 +166,6 @@ 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           *
 *************************************************/


@@ -222,8 +208,6 @@ if (af == AF_INET6)
   s_len = sizeof(s_in6);
   }
 else
   s_len = sizeof(s_in6);
   }
 else

-#else     /* HAVE_IPV6 */
-af = af;  /* Avoid compiler warning */

 #endif    /* HAVE_IPV6 */
 
 /* For an IPv4 address, use an IPv4 sockaddr structure, even on a system with
 #endif    /* HAVE_IPV6 */
 
 /* For an IPv4 address, use an IPv4 sockaddr structure, even on a system with


@@ -245,7 +229,7 @@ callout_address = string_sprintf("[%s]:%d", address, port);
 sigalrm_seen = FALSE;
 if (timeout > 0) ALARM(timeout);
 
 sigalrm_seen = FALSE;
 if (timeout > 0) ALARM(timeout);
 

-#ifdef TCP_FASTOPEN
+#ifdef EXIM_SUPPORT_TFO

 /* 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


@@ -255,8 +239,7 @@ possibly use the data-on-syn, so support that too. */
 if (fastopen_blob && f.tcp_fastopen_ok)
   {
 # ifdef MSG_FASTOPEN
 if (fastopen_blob && f.tcp_fastopen_ok)
   {
 # ifdef MSG_FASTOPEN

-  /* This is a Linux implementation.  It might be useable on FreeBSD; I have
-  not checked. */
+  /* This is a Linux implementation. */

 
   if ((rc = sendto(sock, fastopen_blob->data, fastopen_blob->len,
                    MSG_FASTOPEN | MSG_DONTWAIT, s_ptr, s_len)) >= 0)
 
   if ((rc = sendto(sock, fastopen_blob->data, fastopen_blob->len,
                    MSG_FASTOPEN | MSG_DONTWAIT, s_ptr, s_len)) >= 0)


@@ -264,36 +247,60 @@ if (fastopen_blob && f.tcp_fastopen_ok)
        /* seen for with-data, proper TFO opt, with-cookie case */
     {
     DEBUG(D_transport|D_v)
        /* 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",
+      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;
     }
        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 */
+  else switch (errno)
+    {
+    case 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 ? */
        /* 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);
+      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                                     /* queue unsent data */
+       rc = send(sock, fastopen_blob->data, fastopen_blob->len, 0);
+      break;
+
+    case EOPNOTSUPP:
+      DEBUG(D_transport)
+       debug_printf("Tried TCP Fast Open but apparently not enabled by sysctl\n");
+      goto legacy_connect;
+
+    case EPIPE:
+      DEBUG(D_transport)
+       debug_printf("Tried TCP Fast Open but kernel too old to support it\n");
+      goto legacy_connect;

     }
     }

-  else if(errno == EOPNOTSUPP)
+
+# elif defined(EXIM_TFO_FREEBSD)
+  /* Re: https://people.freebsd.org/~pkelsey/tfo-tools/tfo-client.c */
+
+  if (setsockopt(sock, IPPROTO_TCP, TCP_FASTOPEN, &on, sizeof(on)) < 0)

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

-# endif
-# ifdef EXIM_TFO_CONNECTX
+  if ((rc = sendto(sock, fastopen_blob->data, fastopen_blob->len, 0,
+                   s_ptr, s_len)) >= 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;
+    }
+
+# elif defined(EXIM_TFO_CONNECTX)

   /* MacOS */
   sa_endpoints_t ends = {
     .sae_srcif = 0, .sae_srcaddr = NULL, .sae_srcaddrlen = 0,
   /* MacOS */
   sa_endpoints_t ends = {
     .sae_srcif = 0, .sae_srcaddr = NULL, .sae_srcaddrlen = 0,


@@ -306,7 +313,7 @@ if (fastopen_blob && f.tcp_fastopen_ok)
             CONNECT_DATA_IDEMPOTENT, &iov, 1, &len, NULL)) == 0)
     {
     DEBUG(D_transport|D_v)
             CONNECT_DATA_IDEMPOTENT, &iov, 1, &len, NULL)) == 0)
     {
     DEBUG(D_transport|D_v)

-      debug_printf("TFO mode connection attempt to %s, %lu data\n",
+      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;
 
        address, (unsigned long)fastopen_blob->len);
     tcp_out_fastopen = fastopen_blob->len > 0 ?  TFO_ATTEMPTED_DATA : TFO_ATTEMPTED_NODATA;
 


@@ -316,7 +323,7 @@ if (fastopen_blob && f.tcp_fastopen_ok)
     }
   else if (errno == EINPROGRESS)
     {
     }
   else if (errno == EINPROGRESS)
     {

-    DEBUG(D_transport|D_v) debug_printf("TFO mode sendto, %s data: EINPROGRESS\n",
+    DEBUG(D_transport|D_v) debug_printf(" TFO mode connectx, %s data: EINPROGRESS\n",

       fastopen_blob->len > 0 ? "with"  : "no");
     if (!fastopen_blob->data)
       {
       fastopen_blob->len > 0 ? "with"  : "no");
     if (!fastopen_blob->data)
       {


@@ -329,11 +336,14 @@ if (fastopen_blob && f.tcp_fastopen_ok)
 # endif
   }
 else
 # endif
   }
 else

-#endif /*TCP_FASTOPEN*/
+#endif /*EXIM_SUPPORT_TFO*/

   {
   {

+#if defined(EXIM_SUPPORT_TFO) && !defined(EXIM_TFO_CONNECTX)

 legacy_connect:
 legacy_connect:

+#endif
+

   DEBUG(D_transport|D_v) if (fastopen_blob)
   DEBUG(D_transport|D_v) if (fastopen_blob)

-    debug_printf("non-TFO mode connection attempt to %s, %lu data\n",
+    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
       address, (unsigned long)fastopen_blob->len);
   if ((rc = connect(sock, s_ptr, s_len)) >= 0)
     if (  fastopen_blob && fastopen_blob->data && fastopen_blob->len


@@ -454,8 +464,8 @@ for (host_item * h = &shost; h; h = h->next)
   for (int port = portlo; port <= porthi; port++)
     if (ip_connect(fd, af, h->address, port, timeout, fastopen_blob) == 0)
       {
   for (int port = portlo; port <= porthi; port++)
     if (ip_connect(fd, af, h->address, port, timeout, fastopen_blob) == 0)
       {

-      if (fd != fd6) close(fd6);
-      if (fd != fd4) close(fd4);
+      if (fd6 >= 0 && fd != fd6) close(fd6);
+      if (fd4 >= 0 && fd != fd4) close(fd4);

       if (connhost)
        {
        h->port = port;
       if (connhost)
        {
        h->port = port;


@@ -476,7 +486,8 @@ bad:
 
 /*XXX TFO? */
 int
 
 /*XXX TFO? */
 int

-ip_tcpsocket(const uschar * hostport, uschar ** errstr, int tmo)
+ip_tcpsocket(const uschar * hostport, uschar ** errstr, int tmo,
+  host_item * connhost)

 {
 int scan;
 uschar hostname[256];
 {
 int scan;
 uschar hostname[256];


@@ -495,7 +506,7 @@ if (scan != 3)
   }
 
 return ip_connectedsocket(SOCK_STREAM, hostname, portlow, porthigh,
   }
 
 return ip_connectedsocket(SOCK_STREAM, hostname, portlow, porthigh,

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

 }
 
 int
 }
 
 int


@@ -512,7 +523,7 @@ if ((sock = socket(AF_UNIX, SOCK_STREAM, 0)) < 0)
 
 callout_address = string_copy(path);
 server.sun_family = AF_UNIX;
 
 callout_address = string_copy(path);
 server.sun_family = AF_UNIX;

-Ustrncpy(server.sun_path, path, sizeof(server.sun_path)-1);
+Ustrncpy(US server.sun_path, path, sizeof(server.sun_path)-1);

 server.sun_path[sizeof(server.sun_path)-1] = '\0';
 if (connect(sock, (struct sockaddr *) &server, sizeof(server)) < 0)
   {
 server.sun_path[sizeof(server.sun_path)-1] = '\0';
 if (connect(sock, (struct sockaddr *) &server, sizeof(server)) < 0)
   {


@@ -525,11 +536,18 @@ if (connect(sock, (struct sockaddr *) &server, sizeof(server)) < 0)
 return sock;
 }
 
 return sock;
 }
 

+/* spec is either an absolute path (with a leading /), or
+a host (name or IP) and port (whitespace-separated).
+The port can be a range, dash-separated, or a single number.
+
+For a TCP socket, optionally fill in a  host_item.
+*/

 int
 int

-ip_streamsocket(const uschar * spec, uschar ** errstr, int tmo)
+ip_streamsocket(const uschar * spec, uschar ** errstr, int tmo,
+  host_item * connhost)

 {
 return *spec == '/'
 {
 return *spec == '/'

-  ? ip_unixsocket(spec, errstr) : ip_tcpsocket(spec, errstr, tmo);
+  ? ip_unixsocket(spec, errstr) : ip_tcpsocket(spec, errstr, tmo, connhost);

 }
 
 /*************************************************
 }
 
 /*************************************************


@@ -565,17 +583,14 @@ if (setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE,
 /*
 Arguments:
   fd          the file descriptor
 /*
 Arguments:
   fd          the file descriptor

-  timeout     the timeout, seconds
+  timelimit   the timeout endpoint, seconds-since-epoch

 Returns:      TRUE => ready for i/o
               FALSE => timed out, or other error
 */
 BOOL
 Returns:      TRUE => ready for i/o
               FALSE => timed out, or other error
 */
 BOOL

-fd_ready(int fd, int timeout)
+fd_ready(int fd, time_t timelimit)

 {
 {

-fd_set select_inset;
-time_t start_recv = time(NULL);
-int time_left = timeout;
-int rc;
+int rc, time_left = timelimit - time(NULL);

 
 if (time_left <= 0)
   {
 
 if (time_left <= 0)
   {


@@ -586,12 +601,8 @@ if (time_left <= 0)
 
 do
   {
 
 do
   {

-  struct timeval tv = { .tv_sec = time_left, .tv_usec = 0 };
-  FD_ZERO (&select_inset);
-  FD_SET (fd, &select_inset);
-

   /*DEBUG(D_transport) debug_printf("waiting for data on fd\n");*/
   /*DEBUG(D_transport) debug_printf("waiting for data on fd\n");*/

-  rc = select(fd + 1, (SELECT_ARG2_TYPE *)&select_inset, NULL, NULL, &tv);
+  rc = poll_one_fd(fd, POLLIN, time_left * 1000);

 
   /* If some interrupt arrived, just retry. We presume this to be rare,
   but it can happen (e.g. the SIGUSR1 signal sent by exiwhat causes
 
   /* If some interrupt arrived, just retry. We presume this to be rare,
   but it can happen (e.g. the SIGUSR1 signal sent by exiwhat causes


@@ -608,8 +619,7 @@ do
     DEBUG(D_transport) debug_printf("EINTR while waiting for socket data\n");
 
     /* Watch out, 'continue' jumps to the condition, not to the loops top */
     DEBUG(D_transport) debug_printf("EINTR while waiting for socket data\n");
 
     /* Watch out, 'continue' jumps to the condition, not to the loops top */

-    time_left = timeout - (time(NULL) - start_recv);
-    if (time_left > 0) continue;
+    if ((time_left = timelimit - time(NULL)) > 0) continue;

     }
 
   if (rc <= 0)
     }
 
   if (rc <= 0)


@@ -621,7 +631,7 @@ do
   /* Checking the FD_ISSET is not enough, if we're interrupted, the
   select_inset may still contain the 'input'. */
   }
   /* Checking the FD_ISSET is not enough, if we're interrupted, the
   select_inset may still contain the 'input'. */
   }

-while (rc < 0 || !FD_ISSET(fd, &select_inset));
+while (rc < 0);

 return TRUE;
 }
 
 return TRUE;
 }
 


@@ -633,24 +643,24 @@ Arguments:
   cctx        the connection context (socket fd, possibly TLS context)
   buffer      to read into
   bufsize     the buffer size
   cctx        the connection context (socket fd, possibly TLS context)
   buffer      to read into
   bufsize     the buffer size

-  timeout     the timeout
+  timelimit   the timeout endpoint, seconds-since-epoch

 
 Returns:      > 0 => that much data read
               <= 0 on error or EOF; errno set - zero for EOF
 */
 
 int
 
 Returns:      > 0 => that much data read
               <= 0 on error or EOF; errno set - zero for EOF
 */
 
 int

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

 {
 int rc;
 
 {
 int rc;
 

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

   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. */
 
   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
+#ifndef DISABLE_TLS

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