[Patch bpf-next v8 13/16] udp: implement udp_bpf_recvmsg() for sockmap
From: Cong Wang <hidden>
Date: 2021-03-31 02:33:46
Also in:
netdev
Subsystem:
bpf [l7 framework] (sockmap), networking [general], the rest · Maintainers:
John Fastabend, Jakub Sitnicki, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
From: Cong Wang <redacted> We have to implement udp_bpf_recvmsg() to replace the ->recvmsg() to retrieve skmsg from ingress_msg. Cc: John Fastabend <john.fastabend@gmail.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Jakub Sitnicki <jakub@cloudflare.com> Cc: Lorenz Bauer <redacted> Signed-off-by: Cong Wang <redacted> --- 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 6001f93cd3a0..7d5c4ebf42fe 100644
--- a/net/ipv4/udp_bpf.c
+++ b/net/ipv4/udp_bpf.c@@ -4,6 +4,68 @@ #include <linux/skmsg.h> #include <net/sock.h> #include <net/udp.h> +#include <net/inet_common.h> + +#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)
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2.25.1