[Patch bpf v2 3/4] net: implement ->sock_is_readable for UDP and AF_UNIX
flat view
STALE1837d
From: Cong Wang <hidden>
Date: 2021-09-28 00:22:34
Also in:
bpf
Subsystem:
bpf [l7 framework] (sockmap), networking [general], networking [unix sockets], the rest, user datagram protocol (udp) · Maintainers:
John Fastabend, Jakub Sitnicki, Jiayuan Chen, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Kuniyuki Iwashima, Linus Torvalds, Willem de Bruijn
From: Cong Wang <redacted> Yucong noticed we can't poll() sockets in sockmap even when they are the destination sockets of redirections. This is because we never poll any psock queues in ->poll(), except for TCP. Now we can overwrite >sock_is_readable() and implement and invoke it for UDP and AF_UNIX sockets. Reported-by: Yucong Sun <redacted> 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> --- include/linux/skmsg.h | 1 + net/core/skmsg.c | 14 ++++++++++++++ net/ipv4/udp.c | 2 ++ net/ipv4/udp_bpf.c | 1 + net/unix/af_unix.c | 4 ++++ net/unix/unix_bpf.c | 2 ++ 6 files changed, 24 insertions(+)
diff --git a/include/linux/skmsg.h b/include/linux/skmsg.h
index 8f577739fc36..a25434207dca 100644
--- a/include/linux/skmsg.h
+++ b/include/linux/skmsg.h@@ -128,6 +128,7 @@ int sk_msg_memcopy_from_iter(struct sock *sk, struct iov_iter *from, struct sk_msg *msg, u32 bytes); int sk_msg_recvmsg(struct sock *sk, struct sk_psock *psock, struct msghdr *msg, int len, int flags); +bool sk_msg_is_readable(struct sock *sk); static inline void sk_msg_check_to_free(struct sk_msg *msg, u32 i, u32 bytes) {
diff --git a/net/core/skmsg.c b/net/core/skmsg.c
index 2d6249b28928..93ae48581ad2 100644
--- a/net/core/skmsg.c
+++ b/net/core/skmsg.c@@ -474,6 +474,20 @@ int sk_msg_recvmsg(struct sock *sk, struct sk_psock *psock, struct msghdr *msg, } EXPORT_SYMBOL_GPL(sk_msg_recvmsg); +bool sk_msg_is_readable(struct sock *sk) +{ + struct sk_psock *psock; + bool empty = true; + + psock = sk_psock_get_checked(sk); + if (IS_ERR_OR_NULL(psock)) + return false; + empty = sk_psock_queue_empty(psock); + sk_psock_put(sk, psock); + return !empty; +} +EXPORT_SYMBOL_GPL(sk_msg_is_readable); + static struct sk_msg *sk_psock_create_ingress_msg(struct sock *sk, struct sk_buff *skb) {
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 8851c9463b4b..9f49c0967504 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c@@ -2866,6 +2866,8 @@ __poll_t udp_poll(struct file *file, struct socket *sock, poll_table *wait) !(sk->sk_shutdown & RCV_SHUTDOWN) && first_packet_length(sk) == -1) mask &= ~(EPOLLIN | EPOLLRDNORM); + if (sk_is_readable(sk)) + mask |= EPOLLIN | EPOLLRDNORM; return mask; }
diff --git a/net/ipv4/udp_bpf.c b/net/ipv4/udp_bpf.c
index 7a1d5f473878..bbe6569c9ad3 100644
--- a/net/ipv4/udp_bpf.c
+++ b/net/ipv4/udp_bpf.c@@ -114,6 +114,7 @@ static void udp_bpf_rebuild_protos(struct proto *prot, const struct proto *base) *prot = *base; prot->close = sock_map_close; prot->recvmsg = udp_bpf_recvmsg; + prot->sock_is_readable = sk_msg_is_readable; } static void udp_bpf_check_v6_needs_rebuild(struct proto *ops)
diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index 92345c9bb60c..f1cbaa0ccf6b 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c@@ -3014,6 +3014,8 @@ static __poll_t unix_poll(struct file *file, struct socket *sock, poll_table *wa /* readable? */ if (!skb_queue_empty_lockless(&sk->sk_receive_queue)) mask |= EPOLLIN | EPOLLRDNORM; + if (sk_is_readable(sk)) + mask |= EPOLLIN | EPOLLRDNORM; /* Connection-based need to check for termination and startup */ if ((sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET) &&
@@ -3053,6 +3055,8 @@ static __poll_t unix_dgram_poll(struct file *file, struct socket *sock, /* readable? */ if (!skb_queue_empty_lockless(&sk->sk_receive_queue)) mask |= EPOLLIN | EPOLLRDNORM; + if (sk_is_readable(sk)) + mask |= EPOLLIN | EPOLLRDNORM; /* Connection-based need to check for termination and startup */ if (sk->sk_type == SOCK_SEQPACKET) {
diff --git a/net/unix/unix_bpf.c b/net/unix/unix_bpf.c
index b927e2baae50..452376c6f419 100644
--- a/net/unix/unix_bpf.c
+++ b/net/unix/unix_bpf.c@@ -102,6 +102,7 @@ static void unix_dgram_bpf_rebuild_protos(struct proto *prot, const struct proto *prot = *base; prot->close = sock_map_close; prot->recvmsg = unix_bpf_recvmsg; + prot->sock_is_readable = sk_msg_is_readable; } static void unix_stream_bpf_rebuild_protos(struct proto *prot,
@@ -110,6 +111,7 @@ static void unix_stream_bpf_rebuild_protos(struct proto *prot, *prot = *base; prot->close = sock_map_close; prot->recvmsg = unix_bpf_recvmsg; + prot->sock_is_readable = sk_msg_is_readable; prot->unhash = sock_map_unhash; }
--
2.30.2