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 <cong.wang@bytedance.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20210331023237.41094-14-xiyou.wangcong@gmail.com
This commit is contained in:
Cong Wang 2021-03-30 19:32:34 -07:00 committed by Alexei Starovoitov
parent 2bc793e327
commit 1f5be6b3b0

View File

@ -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)