From 1f5be6b3b063767202f815d5571f7d03729f1282 Mon Sep 17 00:00:00 2001 From: Cong Wang Date: Tue, 30 Mar 2021 19:32:34 -0700 Subject: [PATCH] udp: Implement udp_bpf_recvmsg() for sockmap We have to implement udp_bpf_recvmsg() to replace the ->recvmsg() to retrieve skmsg from ingress_msg. Signed-off-by: Cong Wang Signed-off-by: Alexei Starovoitov Acked-by: John Fastabend Link: https://lore.kernel.org/bpf/20210331023237.41094-14-xiyou.wangcong@gmail.com --- net/ipv4/udp_bpf.c | 64 +++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 63 insertions(+), 1 deletion(-) diff --git a/net/ipv4/udp_bpf.c b/net/ipv4/udp_bpf.c index 6001f93cd3a086..7d5c4ebf42fe91 100644 --- a/net/ipv4/udp_bpf.c +++ b/net/ipv4/udp_bpf.c @@ -4,6 +4,68 @@ #include #include #include +#include + +#include "udp_impl.h" + +static struct proto *udpv6_prot_saved __read_mostly; + +static int sk_udp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, + int noblock, int flags, int *addr_len) +{ +#if IS_ENABLED(CONFIG_IPV6) + if (sk->sk_family == AF_INET6) + return udpv6_prot_saved->recvmsg(sk, msg, len, noblock, flags, + addr_len); +#endif + return udp_prot.recvmsg(sk, msg, len, noblock, flags, addr_len); +} + +static int udp_bpf_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, + int nonblock, int flags, int *addr_len) +{ + struct sk_psock *psock; + int copied, ret; + + if (unlikely(flags & MSG_ERRQUEUE)) + return inet_recv_error(sk, msg, len, addr_len); + + psock = sk_psock_get(sk); + if (unlikely(!psock)) + return sk_udp_recvmsg(sk, msg, len, nonblock, flags, addr_len); + + lock_sock(sk); + if (sk_psock_queue_empty(psock)) { + ret = sk_udp_recvmsg(sk, msg, len, nonblock, flags, addr_len); + goto out; + } + +msg_bytes_ready: + copied = sk_msg_recvmsg(sk, psock, msg, len, flags); + if (!copied) { + int data, err = 0; + long timeo; + + timeo = sock_rcvtimeo(sk, nonblock); + data = sk_msg_wait_data(sk, psock, flags, timeo, &err); + if (data) { + if (!sk_psock_queue_empty(psock)) + goto msg_bytes_ready; + ret = sk_udp_recvmsg(sk, msg, len, nonblock, flags, addr_len); + goto out; + } + if (err) { + ret = err; + goto out; + } + copied = -EAGAIN; + } + ret = copied; +out: + release_sock(sk); + sk_psock_put(sk, psock); + return ret; +} enum { UDP_BPF_IPV4, @@ -11,7 +73,6 @@ enum { 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]; @@ -20,6 +81,7 @@ 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; + prot->recvmsg = udp_bpf_recvmsg; } static void udp_bpf_check_v6_needs_rebuild(struct proto *ops)