From 5d77dca82839ef016a93ad7acd7058b14d967752 Mon Sep 17 00:00:00 2001 From: David Ahern Date: Tue, 23 Aug 2016 21:06:33 -0700 Subject: [PATCH] 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 Signed-off-by: David S. Miller --- include/net/udp.h | 1 + net/ipv4/udp.c | 15 +++++++++ net/ipv4/udp_diag.c | 79 +++++++++++++++++++++++++++++++++++++++++++++ net/ipv6/udp.c | 1 + 4 files changed, 96 insertions(+) diff --git a/include/net/udp.h b/include/net/udp.h index 8894d7144189..ea53a87d880f 100644 --- 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 8f5f7f6026f7..e9ffc27b23d0 100644 --- 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 3d5ccf4b1412..8a9f6e535caa 100644 --- 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 81e2f98b958d..16512cf06e73 100644 --- 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 = {