[PATCH 8/8] net: Implement socketat.

Add a system call for creating sockets in a specified network namespace.

Signed-off-by: Eric W. Biederman <ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>
---
 net/socket.c |   26 ++++++++++++++++++++++++--
 1 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/net/socket.c b/net/socket.c
index 2270b94..1116f3c 100644
--- a/net/socket.c
+++ b/net/socket.c

@@ -1269,7 +1269,7 @@ int sock_create_kern(int family, int type, int protocol, struct socket **res)
 }
 EXPORT_SYMBOL(sock_create_kern);
 
-SYSCALL_DEFINE3(socket, int, family, int, type, int, protocol)
+static int do_socket(struct net *net, int family, int type, int protocol)
 {
 	int retval;
 	struct socket *sock;

@@ -1289,7 +1289,7 @@ SYSCALL_DEFINE3(socket, int, family, int, type, int, protocol)
 	if (SOCK_NONBLOCK != O_NONBLOCK && (flags & SOCK_NONBLOCK))
 		flags = (flags & ~SOCK_NONBLOCK) | O_NONBLOCK;
 
-	retval = sock_create(family, type, protocol, &sock);
+	retval = __sock_create(net, family, type, protocol, &sock, 0);
 	if (retval < 0)
 		goto out;
 

@@ -1306,6 +1306,28 @@ out_release:
 	return retval;
 }
 
+SYSCALL_DEFINE3(socket, int, family, int, type, int, protocol)
+{
+	return do_socket(current->nsproxy->net_ns, family, type, protocol);
+}
+
+SYSCALL_DEFINE4(socketat, int, fd, int, family, int, type, int, protocol)
+{
+	struct net *net;
+	int retval;
+
+	if (fd == -1) {
+		net = get_net(current->nsproxy->net_ns);
+	} else {
+		net = get_net_ns_by_fd(fd);
+		if (IS_ERR(net))
+			return  PTR_ERR(net);
+	}
+	retval = do_socket(net, family, type, protocol);
+	put_net(net);
+	return retval;
+}
+
 /*
  *	Create a pair of connected sockets.
  */

-- 
1.6.5.2.143.g8cc62

On 09/23/2010 12:51 PM, Eric W. Biederman wrote:

Add a system call for creating sockets in a specified network namespace.

What for?

On Thu, 2010-09-23 at 12:56 +0400, Pavel Emelyanov wrote:

On 09/23/2010 12:51 PM, Eric W. Biederman wrote:

quoted

Add a system call for creating sockets in a specified network namespace.

What for?

I can see many uses if my understanding is correct..
ex, from mother namespace:
fdx = open socket at namespace blah
from mother namespace, read/write/poll fdx 
(eg add route with netlink socket)

cheers,
jamal

On 09/23/2010 03:19 PM, jamal wrote:

On Thu, 2010-09-23 at 12:56 +0400, Pavel Emelyanov wrote:

quoted

On 09/23/2010 12:51 PM, Eric W. Biederman wrote:

quoted

Add a system call for creating sockets in a specified network namespace.

What for?

I can see many uses if my understanding is correct..
ex, from mother namespace:
fdx = open socket at namespace blah
from mother namespace, read/write/poll fdx 
(eg add route with netlink socket)

This particular usecase is unneeded once you have the "enter" ability.

cheers,
jamal