sockets: add AF_VSOCK support

Add the AF_VSOCK address family so that qemu-ga will be able to use
virtio-vsock.

The AF_VSOCK address family uses <cid, port> address tuples.  The cid is
the unique identifier comparable to an IP address.  AF_VSOCK does not
use name resolution so it's easy to convert between struct sockaddr_vm
and strings.

This patch defines a VsockSocketAddress instead of trying to piggy-back
on InetSocketAddress.  This is cleaner in the long run since it avoids
lots of IPv4 vs IPv6 vs vsock special casing.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
* treat trailing commas as garbage when parsing (Eric Blake)
* add configure check instead of checking AF_VSOCK directly
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>

1 files changed, 31 insertions, 0 deletions

diff --git a/configure b/configure
index 6b7acb1ccb..fd6f898cbc 100755
--- a/configure
+++ b/configure
@@ -4674,6 +4674,33 @@ if compile_prog "" "" ; then
     have_rtnetlink=yes
 fi
 
+##########################################
+# check for usable AF_VSOCK environment
+have_af_vsock=no
+cat > $TMPC << EOF
+#include <errno.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#if !defined(AF_VSOCK)
+# error missing AF_VSOCK flag
+#endif
+#include <linux/vm_sockets.h>
+int main(void) {
+    int sock, ret;
+    struct sockaddr_vm svm;
+    socklen_t len = sizeof(svm);
+    sock = socket(AF_VSOCK, SOCK_STREAM, 0);
+    ret = getpeername(sock, (struct sockaddr *)&svm, &len);
+    if ((ret == -1) && (errno == ENOTCONN)) {
+        return 0;
+    }
+    return -1;
+}
+EOF
+if compile_prog "" "" ; then
+    have_af_vsock=yes
+fi
+
 #################################################
 # Sparc implicitly links with --relax, which is
 # incompatible with -r, so --no-relax should be
@@ -5662,6 +5689,10 @@ if test "$replication" = "yes" ; then
   echo "CONFIG_REPLICATION=y" >> $config_host_mak
 fi
 
+if test "$have_af_vsock" = "yes" ; then
+  echo "CONFIG_AF_VSOCK=y" >> $config_host_mak
+fi
+
 # Hold two types of flag:
 #   CONFIG_THREAD_SETNAME_BYTHREAD  - we've got a way of setting the name on
 #                                     a thread we have a handle to