From edc6741cc66059532ba621928e3f1b02a53a2f39 Mon Sep 17 00:00:00 2001 From: Lorenz Bauer Date: Mon, 9 Mar 2020 11:12:38 +0000 Subject: [PATCH] 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 Signed-off-by: Jakub Sitnicki Signed-off-by: Daniel Borkmann Acked-by: John Fastabend Link: https://lore.kernel.org/bpf/20200309111243.6982-8-lmb@cloudflare.com --- MAINTAINERS | 1 + include/net/udp.h | 5 +++++ net/ipv4/Makefile | 1 + net/ipv4/udp_bpf.c | 53 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 60 insertions(+) create mode 100644 net/ipv4/udp_bpf.c diff --git a/MAINTAINERS b/MAINTAINERS index c23884e084be..14554bde1c06 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -9370,6 +9370,7 @@ F: include/linux/skmsg.h F: net/core/skmsg.c F: net/core/sock_map.c F: net/ipv4/tcp_bpf.c +F: net/ipv4/udp_bpf.c LANTIQ / INTEL Ethernet drivers M: Hauke Mehrtens diff --git a/include/net/udp.h b/include/net/udp.h index e55d5f765807..a8fa6c0c6ded 100644 --- a/include/net/udp.h +++ b/include/net/udp.h @@ -503,4 +503,9 @@ static inline struct sk_buff *udp_rcv_segment(struct sock *sk, return segs; } +#ifdef CONFIG_BPF_STREAM_PARSER +struct sk_psock; +struct proto *udp_bpf_get_proto(struct sock *sk, struct sk_psock *psock); +#endif /* BPF_STREAM_PARSER */ + #endif /* _UDP_H */ diff --git a/net/ipv4/Makefile b/net/ipv4/Makefile index 9d97bace13c8..9e1a186a3671 100644 --- a/net/ipv4/Makefile +++ b/net/ipv4/Makefile @@ -61,6 +61,7 @@ obj-$(CONFIG_TCP_CONG_LP) += tcp_lp.o obj-$(CONFIG_TCP_CONG_YEAH) += tcp_yeah.o obj-$(CONFIG_TCP_CONG_ILLINOIS) += tcp_illinois.o obj-$(CONFIG_NET_SOCK_MSG) += tcp_bpf.o +obj-$(CONFIG_BPF_STREAM_PARSER) += udp_bpf.o obj-$(CONFIG_NETLABEL) += cipso_ipv4.o obj-$(CONFIG_XFRM) += xfrm4_policy.o xfrm4_state.o xfrm4_input.o \ 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 +#include +#include + +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]; +} -- 2.11.0