unix_diag: Unix peer inode NLA

Report the peer socket inode ID as NLA. With this it's finally
possible to find out the other end of an interesting unix connection.

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/linux/unix_diag.h b/include/linux/unix_diag.h
index 3e53adb..2d74a86 100644 (file)
--- a/include/linux/unix_diag.h
+++ b/include/linux/unix_diag.h
@@ -13,6 +13,7 @@ struct unix_diag_req {
 
 #define UDIAG_SHOW_NAME                0x00000001      /* show name (not path) */
 #define UDIAG_SHOW_VFS         0x00000002      /* show VFS inode info */
+#define UDIAG_SHOW_PEER                0x00000004      /* show peer socket info */
 
 struct unix_diag_msg {
        __u8    udiag_family;
@@ -27,6 +28,7 @@ struct unix_diag_msg {
 enum {
        UNIX_DIAG_NAME,
        UNIX_DIAG_VFS,
+       UNIX_DIAG_PEER,
 
        UNIX_DIAG_MAX,
 };

diff --git a/net/unix/diag.c b/net/unix/diag.c
index 83799ef..0e0fda7 100644 (file)
--- a/net/unix/diag.c
+++ b/net/unix/diag.c
@@ -43,6 +43,26 @@ rtattr_failure:
        return -EMSGSIZE;
 }
 
+static int sk_diag_dump_peer(struct sock *sk, struct sk_buff *nlskb)
+{
+       struct sock *peer;
+       int ino;
+
+       peer = unix_peer_get(sk);
+       if (peer) {
+               unix_state_lock(peer);
+               ino = sock_i_ino(peer);
+               unix_state_unlock(peer);
+               sock_put(peer);
+
+               RTA_PUT_U32(nlskb, UNIX_DIAG_PEER, ino);
+       }
+
+       return 0;
+rtattr_failure:
+       return -EMSGSIZE;
+}
+
 static int sk_diag_fill(struct sock *sk, struct sk_buff *skb, struct unix_diag_req *req,
                u32 pid, u32 seq, u32 flags, int sk_ino)
 {
@@ -69,6 +89,10 @@ static int sk_diag_fill(struct sock *sk, struct sk_buff *skb, struct unix_diag_r
                        sk_diag_dump_vfs(sk, skb))
                goto nlmsg_failure;
 
+       if ((req->udiag_show & UDIAG_SHOW_PEER) &&
+                       sk_diag_dump_peer(sk, skb))
+               goto nlmsg_failure;
+
        nlh->nlmsg_len = skb_tail_pointer(skb) - b;
        return skb->len;