linux/net/ipv4/udp_bpf.c
Lorenz Bauer edc6741cc6 bpf: Add sockmap hooks for UDP sockets
Add basic psock hooks for UDP sockets. This allows adding and
removing sockets, as well as automatic removal on unhash and close.

Signed-off-by: Lorenz Bauer <lmb@cloudflare.com>
Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20200309111243.6982-8-lmb@cloudflare.com
2020-03-09 22:34:58 +01:00

54 lines
1.4 KiB
C

// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2020 Cloudflare Ltd https://cloudflare.com */
#include <linux/skmsg.h>
#include <net/sock.h>
#include <net/udp.h>
enum {
UDP_BPF_IPV4,
UDP_BPF_IPV6,
UDP_BPF_NUM_PROTS,
};
static struct proto *udpv6_prot_saved __read_mostly;
static DEFINE_SPINLOCK(udpv6_prot_lock);
static struct proto udp_bpf_prots[UDP_BPF_NUM_PROTS];
static void udp_bpf_rebuild_protos(struct proto *prot, const struct proto *base)
{
*prot = *base;
prot->unhash = sock_map_unhash;
prot->close = sock_map_close;
}
static void udp_bpf_check_v6_needs_rebuild(struct sock *sk, struct proto *ops)
{
if (sk->sk_family == AF_INET6 &&
unlikely(ops != smp_load_acquire(&udpv6_prot_saved))) {
spin_lock_bh(&udpv6_prot_lock);
if (likely(ops != udpv6_prot_saved)) {
udp_bpf_rebuild_protos(&udp_bpf_prots[UDP_BPF_IPV6], ops);
smp_store_release(&udpv6_prot_saved, ops);
}
spin_unlock_bh(&udpv6_prot_lock);
}
}
static int __init udp_bpf_v4_build_proto(void)
{
udp_bpf_rebuild_protos(&udp_bpf_prots[UDP_BPF_IPV4], &udp_prot);
return 0;
}
core_initcall(udp_bpf_v4_build_proto);
struct proto *udp_bpf_get_proto(struct sock *sk, struct sk_psock *psock)
{
int family = sk->sk_family == AF_INET ? UDP_BPF_IPV4 : UDP_BPF_IPV6;
if (!psock->sk_proto)
udp_bpf_check_v6_needs_rebuild(sk, READ_ONCE(sk->sk_prot));
return &udp_bpf_prots[family];
}