udp_diag: Implement the get_exact dumping functionality

Do the same as TCP does -- lookup a socket in the given udp_table,
check cookie, fill the reply message with existing inet socket dumping
helper and send one back.

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

1 files changed, 51 insertions, 1 deletions

diff --git a/net/ipv4/udp_diag.c b/net/ipv4/udp_diag.c
index 75e4e4ada545..caa164dcd30f 100644
--- a/net/ipv4/udp_diag.c
+++ b/net/ipv4/udp_diag.c
@@ -21,7 +21,57 @@
 static int udp_dump_one(struct udp_table *tbl, struct sk_buff *in_skb,
                 const struct nlmsghdr *nlh, struct inet_diag_req *req)
 {
-        return 0;
+        int err = -EINVAL;
+        struct sock *sk;
+        struct sk_buff *rep;
+
+        if (req->sdiag_family == AF_INET)
+                sk = __udp4_lib_lookup(&init_net,
+                                req->id.idiag_src[0], req->id.idiag_sport,
+                                req->id.idiag_dst[0], req->id.idiag_dport,
+                                req->id.idiag_if, tbl);
+        else if (req->sdiag_family == AF_INET6)
+                sk = __udp6_lib_lookup(&init_net,
+                                (struct in6_addr *)req->id.idiag_src,
+                                req->id.idiag_sport,
+                                (struct in6_addr *)req->id.idiag_dst,
+                                req->id.idiag_dport,
+                                req->id.idiag_if, tbl);
+        else
+                goto out_nosk;
+
+        err = -ENOENT;
+        if (sk == NULL)
+                goto out_nosk;
+
+        err = inet_diag_check_cookie(sk, req);
+        if (err)
+                goto out;
+
+        err = -ENOMEM;
+        rep = alloc_skb(NLMSG_SPACE((sizeof(struct inet_diag_msg) +
+                                     sizeof(struct inet_diag_meminfo) +
+                                     64)), GFP_KERNEL);
+        if (!rep)
+                goto out;
+
+        err = inet_sk_diag_fill(sk, NULL, rep, req,
+                           NETLINK_CB(in_skb).pid,
+                           nlh->nlmsg_seq, 0, nlh);
+        if (err < 0) {
+                WARN_ON(err == -EMSGSIZE);
+                kfree_skb(rep);
+                goto out;
+        }
+        err = netlink_unicast(sock_diag_nlsk, rep, NETLINK_CB(in_skb).pid,
+                              MSG_DONTWAIT);
+        if (err > 0)
+                err = 0;
+out:
+        if (sk)
+                sock_put(sk);
+out_nosk:
+        return err;
 }
 
 static void udp_dump(struct udp_table *table, struct sk_buff *skb, struct netlink_callback *cb,