unix_diag: Unix socket name NLA

Report the sun_path when requested as NLA. With leading '\0' if
present but without the leading AF_UNIX bits.

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

1 files changed, 20 insertions, 0 deletions

diff --git a/net/unix/diag.c b/net/unix/diag.c
index d7bd48c49ee5..161ce6c05e31 100644
--- a/net/unix/diag.c
+++ b/net/unix/diag.c
@@ -10,6 +10,22 @@
 #define UNIX_DIAG_PUT(skb, attrtype, attrlen) \
         RTA_DATA(__RTA_PUT(skb, attrtype, attrlen))
 
+static int sk_diag_dump_name(struct sock *sk, struct sk_buff *nlskb)
+{
+        struct unix_address *addr = unix_sk(sk)->addr;
+        char *s;
+
+        if (addr) {
+                s = UNIX_DIAG_PUT(nlskb, UNIX_DIAG_NAME, addr->len - sizeof(short));
+                memcpy(s, addr->name->sun_path, addr->len - sizeof(short));
+        }
+
+        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)
 {
@@ -28,6 +44,10 @@ static int sk_diag_fill(struct sock *sk, struct sk_buff *skb, struct unix_diag_r
         rep->udiag_ino = sk_ino;
         sock_diag_save_cookie(sk, rep->udiag_cookie);
 
+        if ((req->udiag_show & UDIAG_SHOW_NAME) &&
+                        sk_diag_dump_name(sk, skb))
+                goto nlmsg_failure;
+
         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
         return skb->len;