On Thu, 2016-08-18 at 19:29 -0700, David Ahern wrote:
> 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 giving the process notice that
> it should close the socket.
>
> Signed-off-by: David Ahern <d...@cumulusnetworks.com>
> ---
> include/net/udp.h | 8 ++++++++
> net/ipv4/udp.c | 58
> +++++++++++++++++++++++++++++++++++++++++++++++++++++
> net/ipv4/udp_diag.c | 55 ++++++++++++++++++++++++++++++++++++++++++++++++++
> net/ipv6/udp.c | 45 +++++++++++++++++++++++++++++++++++++++++
> 4 files changed, 166 insertions(+)
>
> diff --git a/include/net/udp.h b/include/net/udp.h
> index 8894d7144189..5c3443634b4d 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);
> @@ -274,6 +275,9 @@ struct sock *__udp4_lib_lookup(struct net *net, __be32
> saddr, __be16 sport,
> struct udp_table *tbl, struct sk_buff *skb);
> struct sock *udp4_lib_lookup_skb(struct sk_buff *skb,
> __be16 sport, __be16 dport);
> +struct sock *udp4_lib_lookup_full(struct net *net, __be32 saddr,
> + __be16 sport, __be32 daddr, __be16 dport,
> + int dif, struct udp_table *table);
> struct sock *udp6_lib_lookup(struct net *net,
> const struct in6_addr *saddr, __be16 sport,
> const struct in6_addr *daddr, __be16 dport,
> @@ -286,6 +290,10 @@ struct sock *__udp6_lib_lookup(struct net *net,
> struct sock *udp6_lib_lookup_skb(struct sk_buff *skb,
> __be16 sport, __be16 dport);
>
> +struct sock *udp6_lib_lookup_full(struct net *net,
> + const struct in6_addr *saddr, __be16 sport,
> + const struct in6_addr *daddr, __be16 dport,
> + int dif, struct udp_table *table);
> /*
> * SNMP statistics for UDP and UDP-Lite
> */
> diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
> index e61f7cd65d08..e5b72a7165e1 100644
> --- a/net/ipv4/udp.c
> +++ b/net/ipv4/udp.c
> @@ -594,6 +594,47 @@ struct sock *udp4_lib_lookup(struct net *net, __be32
> saddr, __be16 sport,
> EXPORT_SYMBOL_GPL(udp4_lib_lookup);
> #endif
>
> +/* caller should hold rcu lock */
> +struct sock *udp4_lib_lookup_full(struct net *net, __be32 saddr,
> + __be16 sport, __be32 daddr, __be16 dport,
> + int dif, struct udp_table *table)
> +{
> + struct sock *sk;
> + int i;
> +
> + for (i = 0; i <= table->mask; i++) {
> + struct udp_hslot *hslot = &table->hash[i];
> +
> + sk_for_each_rcu(sk, &hslot->head) {
> + struct inet_sock *inet;
> +
> + if (!net_eq(sock_net(sk), net) ||
> + ipv6_only_sock(sk))
> + continue;
> +
> + if (dif && sk->sk_bound_dev_if != dif)
> + continue;
> +
> + if (sk->sk_family != PF_INET)
> + continue;
> +
> + if (udp_sk(sk)->udp_port_hash != ntohs(sport))
> + continue;
> +
> + inet = inet_sk(sk);
> + if (inet->inet_rcv_saddr != saddr ||
> + inet->inet_daddr != daddr ||
> + inet->inet_dport != dport)
> + continue;
> +
> + return sk;
> + }
> + }
> +
> + return NULL;
> +}
Why are you iterating the whole table ?
Normally, udp_hashfn(net, ntohs(dport), udptable->mask) slot should be
enough to find all sockets bound to dport.
