diff options
Diffstat (limited to 'net/ipv4/udp_bpf.c')
| -rw-r--r-- | net/ipv4/udp_bpf.c | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/net/ipv4/udp_bpf.c b/net/ipv4/udp_bpf.c new file mode 100644 index 000000000000..eddd973e6575 --- /dev/null +++ b/net/ipv4/udp_bpf.c @@ -0,0 +1,53 @@ +// 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]; +} |