From: Cong Wang <xiyou.wangcong@gmail.com>
To: netdev@vger.kernel.org
Cc: bpf@vger.kernel.org, jiang.wang@bytedance.com,
duanxiongchun@bytedance.com, wangdongdong.6@bytedance.com,
Cong Wang <cong.wang@bytedance.com>,
John Fastabend <john.fastabend@gmail.com>,
Daniel Borkmann <daniel@iogearbox.net>,
Jakub Sitnicki <jakub@cloudflare.com>,
Lorenz Bauer <lmb@cloudflare.com>
Subject: [Patch bpf-next v3 05/10] af_unix: implement unix_dgram_bpf_recvmsg()
Date: Sun, 25 Apr 2021 19:49:56 -0700 [thread overview]
Message-ID: <20210426025001.7899-6-xiyou.wangcong@gmail.com> (raw)
In-Reply-To: <20210426025001.7899-1-xiyou.wangcong@gmail.com>
From: Cong Wang <cong.wang@bytedance.com>
We have to implement unix_dgram_bpf_recvmsg() to replace the
original ->recvmsg() to retrieve skmsg from ingress_msg.
AF_UNIX is again special here because the lack of
sk_prot->recvmsg(). I simply add a special case inside
unix_dgram_recvmsg() to call sk->sk_prot->recvmsg() directly.
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Jakub Sitnicki <jakub@cloudflare.com>
Cc: Lorenz Bauer <lmb@cloudflare.com>
Signed-off-by: Cong Wang <cong.wang@bytedance.com>
---
include/net/af_unix.h | 3 +++
net/unix/af_unix.c | 21 ++++++++++++++++---
net/unix/unix_bpf.c | 49 +++++++++++++++++++++++++++++++++++++++++++
3 files changed, 70 insertions(+), 3 deletions(-)
diff --git a/include/net/af_unix.h b/include/net/af_unix.h
index cca645846af1..e524c82794c9 100644
--- a/include/net/af_unix.h
+++ b/include/net/af_unix.h
@@ -82,6 +82,9 @@ static inline struct unix_sock *unix_sk(const struct sock *sk)
long unix_inq_len(struct sock *sk);
long unix_outq_len(struct sock *sk);
+int __unix_dgram_recvmsg(struct sock *sk, struct msghdr *msg, size_t size,
+ int nonblock, int flags, int *addr_len);
+
#ifdef CONFIG_SYSCTL
int unix_sysctl_register(struct net *net);
void unix_sysctl_unregister(struct net *net);
diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index c4afc5fbe137..08458fa9f48b 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -2088,11 +2088,11 @@ static void unix_copy_addr(struct msghdr *msg, struct sock *sk)
}
}
-static int unix_dgram_recvmsg(struct socket *sock, struct msghdr *msg,
- size_t size, int flags)
+int __unix_dgram_recvmsg(struct sock *sk, struct msghdr *msg, size_t size,
+ int nonblock, int flags, int *addr_len)
{
struct scm_cookie scm;
- struct sock *sk = sock->sk;
+ struct socket *sock = sk->sk_socket;
struct unix_sock *u = unix_sk(sk);
struct sk_buff *skb, *last;
long timeo;
@@ -2195,6 +2195,21 @@ static int unix_dgram_recvmsg(struct socket *sock, struct msghdr *msg,
return err;
}
+static int unix_dgram_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
+ int flags)
+{
+ struct sock *sk = sock->sk;
+ int addr_len = 0;
+
+#ifdef CONFIG_BPF_SYSCALL
+ if (sk->sk_prot != &unix_proto)
+ return sk->sk_prot->recvmsg(sk, msg, size, flags & MSG_DONTWAIT,
+ flags & ~MSG_DONTWAIT, &addr_len);
+#endif
+ return __unix_dgram_recvmsg(sk, msg, size, flags & MSG_DONTWAIT,
+ flags, &addr_len);
+}
+
static int unix_read_sock(struct sock *sk, read_descriptor_t *desc,
sk_read_actor_t recv_actor)
{
diff --git a/net/unix/unix_bpf.c b/net/unix/unix_bpf.c
index b1582a659427..b2c34aeb848f 100644
--- a/net/unix/unix_bpf.c
+++ b/net/unix/unix_bpf.c
@@ -6,6 +6,54 @@
#include <net/sock.h>
#include <net/af_unix.h>
+static int unix_dgram_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;
+
+ psock = sk_psock_get(sk);
+ if (unlikely(!psock))
+ return __unix_dgram_recvmsg(sk, msg, len, nonblock, flags,
+ addr_len);
+
+ lock_sock(sk);
+ if (!skb_queue_empty(&sk->sk_receive_queue) &&
+ sk_psock_queue_empty(psock)) {
+ ret = __unix_dgram_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 = __unix_dgram_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;
+}
+
static struct proto *unix_prot_saved __read_mostly;
static DEFINE_SPINLOCK(unix_prot_lock);
static struct proto unix_bpf_prot;
@@ -14,6 +62,7 @@ static void unix_bpf_rebuild_protos(struct proto *prot, const struct proto *base
{
*prot = *base;
prot->close = sock_map_close;
+ prot->recvmsg = unix_dgram_bpf_recvmsg;
}
static void unix_bpf_check_needs_rebuild(struct proto *ops)
--
2.25.1
next prev parent reply other threads:[~2021-04-26 2:50 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-26 2:49 [Patch bpf-next v3 00/10] sockmap: add sockmap support to Unix datagram socket Cong Wang
2021-04-26 2:49 ` [Patch bpf-next v3 01/10] sock_map: relax config dependency to CONFIG_NET Cong Wang
2021-04-26 2:49 ` [Patch bpf-next v3 02/10] af_unix: implement ->read_sock() for sockmap Cong Wang
2021-05-05 17:14 ` Jakub Sitnicki
2021-05-07 1:00 ` Cong Wang
2021-05-11 5:34 ` John Fastabend
2021-05-18 4:46 ` Cong Wang
2021-05-18 5:11 ` John Fastabend
2021-04-26 2:49 ` [Patch bpf-next v3 03/10] af_unix: implement ->psock_update_sk_prot() Cong Wang
2021-05-06 13:04 ` Jakub Sitnicki
2021-05-07 0:55 ` Cong Wang
2021-04-26 2:49 ` [Patch bpf-next v3 04/10] af_unix: set TCP_ESTABLISHED for datagram sockets too Cong Wang
2021-05-07 8:18 ` Jakub Sitnicki
2021-05-08 20:41 ` Cong Wang
2021-04-26 2:49 ` Cong Wang [this message]
2021-05-07 13:29 ` [Patch bpf-next v3 05/10] af_unix: implement unix_dgram_bpf_recvmsg() Jakub Sitnicki
2021-05-08 20:43 ` Cong Wang
2021-04-26 2:49 ` [Patch bpf-next v3 06/10] sock_map: update sock type checks for AF_UNIX Cong Wang
2021-04-26 2:49 ` [Patch bpf-next v3 07/10] selftests/bpf: factor out udp_socketpair() Cong Wang
2021-04-26 2:49 ` [Patch bpf-next v3 08/10] selftests/bpf: factor out add_to_sockmap() Cong Wang
2021-04-26 2:50 ` [Patch bpf-next v3 09/10] selftests/bpf: add a test case for unix sockmap Cong Wang
2021-04-26 2:50 ` [Patch bpf-next v3 10/10] selftests/bpf: add test cases for redirection between udp and unix Cong Wang
2021-05-07 14:07 ` [Patch bpf-next v3 00/10] sockmap: add sockmap support to Unix datagram socket Jakub Sitnicki
2021-05-08 22:27 ` Cong Wang
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