net: diag: support SOCK_DESTROY for UDP sockets

This implements SOCK_DESTROY for UDP sockets similar to what was done
for TCP with commit c1e64e298b8ca ("net: diag: Support destroying TCP
sockets.") A process with a UDP socket targeted for destroy is awakened
and recvmsg fails with ECONNABORTED.

Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/net/udp.h b/include/net/udp.h
index 8894d71..ea53a87 100644 (file)
--- a/include/net/udp.h
+++ b/include/net/udp.h
@@ -251,6 +251,7 @@ int udp_get_port(struct sock *sk, unsigned short snum,
                 int (*saddr_cmp)(const struct sock *,
                                  const struct sock *));
 void udp_err(struct sk_buff *, u32);
+int udp_abort(struct sock *sk, int err);
 int udp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len);
 int udp_push_pending_frames(struct sock *sk);
 void udp_flush_pending_frames(struct sock *sk);

diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 8f5f7f6..e9ffc27 100644 (file)
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -2193,6 +2193,20 @@ unsigned int udp_poll(struct file *file, struct socket *sock, poll_table *wait)
 }
 EXPORT_SYMBOL(udp_poll);
 
+int udp_abort(struct sock *sk, int err)
+{
+       lock_sock(sk);
+
+       sk->sk_err = err;
+       sk->sk_error_report(sk);
+       udp_disconnect(sk, 0);
+
+       release_sock(sk);
+
+       return 0;
+}
+EXPORT_SYMBOL_GPL(udp_abort);
+
 struct proto udp_prot = {
        .name              = "UDP",
        .owner             = THIS_MODULE,
@@ -2224,6 +2238,7 @@ struct proto udp_prot = {
        .compat_getsockopt = compat_udp_getsockopt,
 #endif
        .clear_sk          = sk_prot_clear_portaddr_nulls,
+       .diag_destroy      = udp_abort,
 };
 EXPORT_SYMBOL(udp_prot);
 

diff --git a/net/ipv4/udp_diag.c b/net/ipv4/udp_diag.c
index 3d5ccf4..8a9f6e5 100644 (file)
--- a/net/ipv4/udp_diag.c
+++ b/net/ipv4/udp_diag.c
@@ -165,12 +165,88 @@ static void udp_diag_get_info(struct sock *sk, struct inet_diag_msg *r,
        r->idiag_wqueue = sk_wmem_alloc_get(sk);
 }
 
+#ifdef CONFIG_INET_DIAG_DESTROY
+static int __udp_diag_destroy(struct sk_buff *in_skb,
+                             const struct inet_diag_req_v2 *req,
+                             struct udp_table *tbl)
+{
+       struct net *net = sock_net(in_skb->sk);
+       struct sock *sk;
+       int err;
+
+       rcu_read_lock();
+
+       if (req->sdiag_family == AF_INET)
+               sk = __udp4_lib_lookup(net,
+                               req->id.idiag_dst[0], req->id.idiag_dport,
+                               req->id.idiag_src[0], req->id.idiag_sport,
+                               req->id.idiag_if, tbl, NULL);
+#if IS_ENABLED(CONFIG_IPV6)
+       else if (req->sdiag_family == AF_INET6) {
+               if (ipv6_addr_v4mapped((struct in6_addr *)req->id.idiag_dst) &&
+                   ipv6_addr_v4mapped((struct in6_addr *)req->id.idiag_src))
+                       sk = __udp4_lib_lookup(net,
+                                       req->id.idiag_dst[0], req->id.idiag_dport,
+                                       req->id.idiag_src[0], req->id.idiag_sport,
+                                       req->id.idiag_if, tbl, NULL);
+
+               else
+                       sk = __udp6_lib_lookup(net,
+                                       (struct in6_addr *)req->id.idiag_dst,
+                                       req->id.idiag_dport,
+                                       (struct in6_addr *)req->id.idiag_src,
+                                       req->id.idiag_sport,
+                                       req->id.idiag_if, tbl, NULL);
+       }
+#endif
+       else {
+               rcu_read_unlock();
+               return -EINVAL;
+       }
+
+       if (sk && !atomic_inc_not_zero(&sk->sk_refcnt))
+               sk = NULL;
+
+       rcu_read_unlock();
+
+       if (!sk)
+               return -ENOENT;
+
+       if (sock_diag_check_cookie(sk, req->id.idiag_cookie)) {
+               sock_put(sk);
+               return -ENOENT;
+       }
+
+       err = sock_diag_destroy(sk, ECONNABORTED);
+
+       sock_put(sk);
+
+       return err;
+}
+
+static int udp_diag_destroy(struct sk_buff *in_skb,
+                           const struct inet_diag_req_v2 *req)
+{
+       return __udp_diag_destroy(in_skb, req, &udp_table);
+}
+
+static int udplite_diag_destroy(struct sk_buff *in_skb,
+                               const struct inet_diag_req_v2 *req)
+{
+       return __udp_diag_destroy(in_skb, req, &udplite_table);
+}
+
+#endif
+
 static const struct inet_diag_handler udp_diag_handler = {
        .dump            = udp_diag_dump,
        .dump_one        = udp_diag_dump_one,
        .idiag_get_info  = udp_diag_get_info,
        .idiag_type      = IPPROTO_UDP,
        .idiag_info_size = 0,
+#ifdef CONFIG_INET_DIAG_DESTROY
+       .destroy         = udp_diag_destroy,
+#endif
 };
 
 static void udplite_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
@@ -192,6 +268,9 @@ static const struct inet_diag_handler udplite_diag_handler = {
        .idiag_get_info  = udp_diag_get_info,
        .idiag_type      = IPPROTO_UDPLITE,
        .idiag_info_size = 0,
+#ifdef CONFIG_INET_DIAG_DESTROY
+       .destroy         = udplite_diag_destroy,
+#endif
 };
 
 static int __init udp_diag_init(void)

diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index 81e2f98..16512cf 100644 (file)
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -1467,6 +1467,7 @@ struct proto udpv6_prot = {
        .compat_getsockopt = compat_udpv6_getsockopt,
 #endif
        .clear_sk          = udp_v6_clear_sk,
+       .diag_destroy      = udp_abort,
 };
 
 static struct inet_protosw udpv6_protosw = {