diff options
Diffstat (limited to 'net/unix/unix_bpf.c')
| -rw-r--r-- | net/unix/unix_bpf.c | 44 |
1 files changed, 35 insertions, 9 deletions
diff --git a/net/unix/unix_bpf.c b/net/unix/unix_bpf.c index 452376c6f419..e0d30d6d22ac 100644 --- a/net/unix/unix_bpf.c +++ b/net/unix/unix_bpf.c @@ -1,11 +1,12 @@ // SPDX-License-Identifier: GPL-2.0 /* Copyright (c) 2021 Cong Wang <cong.wang@bytedance.com> */ -#include <linux/skmsg.h> #include <linux/bpf.h> -#include <net/sock.h> +#include <linux/skmsg.h> #include <net/af_unix.h> +#include "af_unix.h" + #define unix_sk_has_data(__sk, __psock) \ ({ !skb_queue_empty(&__sk->sk_receive_queue) || \ !skb_queue_empty(&__psock->ingress_skb) || \ @@ -48,13 +49,18 @@ static int __unix_recvmsg(struct sock *sk, struct msghdr *msg, } static int unix_bpf_recvmsg(struct sock *sk, struct msghdr *msg, - size_t len, int nonblock, int flags, - int *addr_len) + size_t len, int flags, int *addr_len) { struct unix_sock *u = unix_sk(sk); struct sk_psock *psock; int copied; + if (flags & MSG_OOB) + return -EOPNOTSUPP; + + if (!len) + return 0; + psock = sk_psock_get(sk); if (unlikely(!psock)) return __unix_recvmsg(sk, msg, len, flags); @@ -73,7 +79,7 @@ msg_bytes_ready: long timeo; int data; - timeo = sock_rcvtimeo(sk, nonblock); + timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT); data = unix_msg_wait_data(sk, psock, timeo); if (data) { if (!sk_psock_queue_empty(psock)) @@ -146,25 +152,45 @@ int unix_dgram_bpf_update_proto(struct sock *sk, struct sk_psock *psock, bool re if (restore) { sk->sk_write_space = psock->saved_write_space; - WRITE_ONCE(sk->sk_prot, psock->sk_proto); + sock_replace_proto(sk, psock->sk_proto); return 0; } unix_dgram_bpf_check_needs_rebuild(psock->sk_proto); - WRITE_ONCE(sk->sk_prot, &unix_dgram_bpf_prot); + sock_replace_proto(sk, &unix_dgram_bpf_prot); return 0; } int unix_stream_bpf_update_proto(struct sock *sk, struct sk_psock *psock, bool restore) { + struct sock *sk_pair; + + /* Restore does not decrement the sk_pair reference yet because we must + * keep the a reference to the socket until after an RCU grace period + * and any pending sends have completed. + */ if (restore) { sk->sk_write_space = psock->saved_write_space; - WRITE_ONCE(sk->sk_prot, psock->sk_proto); + sock_replace_proto(sk, psock->sk_proto); return 0; } + /* psock_update_sk_prot can be called multiple times if psock is + * added to multiple maps and/or slots in the same map. There is + * also an edge case where replacing a psock with itself can trigger + * an extra psock_update_sk_prot during the insert process. So it + * must be safe to do multiple calls. Here we need to ensure we don't + * increment the refcnt through sock_hold many times. There will only + * be a single matching destroy operation. + */ + if (!psock->sk_pair) { + sk_pair = unix_peer(sk); + sock_hold(sk_pair); + psock->sk_pair = sk_pair; + } + unix_stream_bpf_check_needs_rebuild(psock->sk_proto); - WRITE_ONCE(sk->sk_prot, &unix_stream_bpf_prot); + sock_replace_proto(sk, &unix_stream_bpf_prot); return 0; } |