| Message ID | 20210413124250.3400313-1-arseny.krasnov@kaspersky.com (mailing list archive) |
|---|---|
| State | RFC |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | virtio/vsock: introduce SOCK_SEQPACKET support | expand |
| Context | Check | Description |
|---|---|---|
| netdev/tree_selection | success | Guessing tree name failed - patch did not apply |
On Tue, Apr 13, 2021 at 03:42:47PM +0300, Arseny Krasnov wrote: >This adds receive loop for SEQPACKET. It looks like receive loop for >STREAM, but there is a little bit difference: >1) It doesn't call notify callbacks. >2) It doesn't care about 'SO_SNDLOWAT' and 'SO_RCVLOWAT' values, because > there is no sense for these values in SEQPACKET case. >3) It waits until whole record is received or error is found during > receiving. >4) It processes and sets 'MSG_TRUNC' flag. > >So to avoid extra conditions for two types of socket inside one loop, two >independent functions were created. > >Signed-off-by: Arseny Krasnov <arseny.krasnov@kaspersky.com> >--- >v7 -> v8: > - Length of message is now not returned by callback, it returns only > length of data read by each call. > - Previous case, when EAGAIN is return and dequeue loop restarted now > removed(in this simplified version we consider that message could not > be corrupted). > - MSG_TRUNC in input flags is now handled by callback. > > include/net/af_vsock.h | 4 +++ > net/vmw_vsock/af_vsock.c | 66 +++++++++++++++++++++++++++++++++++++++- > 2 files changed, 69 insertions(+), 1 deletion(-) > >diff --git a/include/net/af_vsock.h b/include/net/af_vsock.h >index b1c717286993..5175f5a52ce1 100644 >--- a/include/net/af_vsock.h >+++ b/include/net/af_vsock.h >@@ -135,6 +135,10 @@ struct vsock_transport { > bool (*stream_is_active)(struct vsock_sock *); > bool (*stream_allow)(u32 cid, u32 port); > >+ /* SEQ_PACKET. */ >+ ssize_t (*seqpacket_dequeue)(struct vsock_sock *vsk, struct msghdr *msg, >+ int flags, bool *msg_ready); >+ > /* Notification. */ > int (*notify_poll_in)(struct vsock_sock *, size_t, bool *); > int (*notify_poll_out)(struct vsock_sock *, size_t, bool *); >diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c >index c4f6bfa1e381..d9fb4f9a3063 100644 >--- a/net/vmw_vsock/af_vsock.c >+++ b/net/vmw_vsock/af_vsock.c >@@ -1974,6 +1974,67 @@ static int __vsock_stream_recvmsg(struct sock *sk, struct msghdr *msg, > return err; > } > >+static int __vsock_seqpacket_recvmsg(struct sock *sk, struct msghdr *msg, >+ size_t len, int flags) >+{ >+ const struct vsock_transport *transport; >+ bool msg_ready; >+ struct vsock_sock *vsk; >+ ssize_t record_len; >+ long timeout; >+ int err = 0; >+ DEFINE_WAIT(wait); >+ >+ vsk = vsock_sk(sk); >+ transport = vsk->transport; >+ >+ timeout = sock_rcvtimeo(sk, flags & MSG_DONTWAIT); >+ msg_ready = false; >+ record_len = 0; >+ >+ while (1) { >+ ssize_t tmp_record_len; Maybe better a name like `partial_len`, `fragment_len`, or just `read`. >+ >+ if (vsock_wait_data(sk, &wait, timeout, NULL, 0) <= 0) { >+ /* In case of any loop break(timeout, signal >+ * interrupt or shutdown), we report user that >+ * nothing was copied. >+ */ >+ err = 0; >+ break; >+ } >+ >+ tmp_record_len = transport->seqpacket_dequeue(vsk, msg, flags, &msg_ready); I think we can avoid to pass 'flags' down to the transports. We can require that seqpacket_dequeue() should always return the real size of the packet received, and then check below if 'MSG_TRUNC' was set... >+ >+ if (tmp_record_len < 0) { >+ err = -ENOMEM; >+ break; >+ } >+ >+ record_len += tmp_record_len; >+ >+ if (msg_ready) >+ break; >+ } >+ >+ if (sk->sk_err) >+ err = -sk->sk_err; >+ else if (sk->sk_shutdown & RCV_SHUTDOWN) >+ err = 0; >+ >+ if (msg_ready && err == 0) { >+ err = record_len; >+ >+ /* Always set MSG_TRUNC if real length of packet is >+ * bigger than user's buffer. >+ */ ...here: if (flags & MSG_TRUNC && record_len > len) >+ if (record_len > len) >+ msg->msg_flags |= MSG_TRUNC; >+ } >+ >+ return err; >+} >+ > static int > vsock_connectible_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, > int flags) >@@ -2029,7 +2090,10 @@ vsock_connectible_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, > goto out; > } > >- err = __vsock_stream_recvmsg(sk, msg, len, flags); >+ if (sk->sk_type == SOCK_STREAM) >+ err = __vsock_stream_recvmsg(sk, msg, len, flags); >+ else >+ err = __vsock_seqpacket_recvmsg(sk, msg, len, flags); > > out: > release_sock(sk); >-- ) >2.25.1 >
On 21.04.2021 11:37, Stefano Garzarella wrote: > On Tue, Apr 13, 2021 at 03:42:47PM +0300, Arseny Krasnov wrote: >> This adds receive loop for SEQPACKET. It looks like receive loop for >> STREAM, but there is a little bit difference: >> 1) It doesn't call notify callbacks. >> 2) It doesn't care about 'SO_SNDLOWAT' and 'SO_RCVLOWAT' values, because >> there is no sense for these values in SEQPACKET case. >> 3) It waits until whole record is received or error is found during >> receiving. >> 4) It processes and sets 'MSG_TRUNC' flag. >> >> So to avoid extra conditions for two types of socket inside one loop, two >> independent functions were created. >> >> Signed-off-by: Arseny Krasnov <arseny.krasnov@kaspersky.com> >> --- >> v7 -> v8: >> - Length of message is now not returned by callback, it returns only >> length of data read by each call. >> - Previous case, when EAGAIN is return and dequeue loop restarted now >> removed(in this simplified version we consider that message could not >> be corrupted). >> - MSG_TRUNC in input flags is now handled by callback. >> >> include/net/af_vsock.h | 4 +++ >> net/vmw_vsock/af_vsock.c | 66 +++++++++++++++++++++++++++++++++++++++- >> 2 files changed, 69 insertions(+), 1 deletion(-) >> >> diff --git a/include/net/af_vsock.h b/include/net/af_vsock.h >> index b1c717286993..5175f5a52ce1 100644 >> --- a/include/net/af_vsock.h >> +++ b/include/net/af_vsock.h >> @@ -135,6 +135,10 @@ struct vsock_transport { >> bool (*stream_is_active)(struct vsock_sock *); >> bool (*stream_allow)(u32 cid, u32 port); >> >> + /* SEQ_PACKET. */ >> + ssize_t (*seqpacket_dequeue)(struct vsock_sock *vsk, struct msghdr *msg, >> + int flags, bool *msg_ready); >> + >> /* Notification. */ >> int (*notify_poll_in)(struct vsock_sock *, size_t, bool *); >> int (*notify_poll_out)(struct vsock_sock *, size_t, bool *); >> diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c >> index c4f6bfa1e381..d9fb4f9a3063 100644 >> --- a/net/vmw_vsock/af_vsock.c >> +++ b/net/vmw_vsock/af_vsock.c >> @@ -1974,6 +1974,67 @@ static int __vsock_stream_recvmsg(struct sock *sk, struct msghdr *msg, >> return err; >> } >> >> +static int __vsock_seqpacket_recvmsg(struct sock *sk, struct msghdr *msg, >> + size_t len, int flags) >> +{ >> + const struct vsock_transport *transport; >> + bool msg_ready; >> + struct vsock_sock *vsk; >> + ssize_t record_len; >> + long timeout; >> + int err = 0; >> + DEFINE_WAIT(wait); >> + >> + vsk = vsock_sk(sk); >> + transport = vsk->transport; >> + >> + timeout = sock_rcvtimeo(sk, flags & MSG_DONTWAIT); >> + msg_ready = false; >> + record_len = 0; >> + >> + while (1) { >> + ssize_t tmp_record_len; > Maybe better a name like `partial_len`, `fragment_len`, or just `read`. Ack > >> + >> + if (vsock_wait_data(sk, &wait, timeout, NULL, 0) <= 0) { >> + /* In case of any loop break(timeout, signal >> + * interrupt or shutdown), we report user that >> + * nothing was copied. >> + */ >> + err = 0; >> + break; >> + } >> + >> + tmp_record_len = transport->seqpacket_dequeue(vsk, msg, flags, &msg_ready); > I think we can avoid to pass 'flags' down to the transports. > > We can require that seqpacket_dequeue() should always return the real > size of the packet received, and then check below if 'MSG_TRUNC' was > set... Ack > >> + >> + if (tmp_record_len < 0) { >> + err = -ENOMEM; >> + break; >> + } >> + >> + record_len += tmp_record_len; >> + >> + if (msg_ready) >> + break; >> + } >> + >> + if (sk->sk_err) >> + err = -sk->sk_err; >> + else if (sk->sk_shutdown & RCV_SHUTDOWN) >> + err = 0; >> + >> + if (msg_ready && err == 0) { >> + err = record_len; >> + >> + /* Always set MSG_TRUNC if real length of packet is >> + * bigger than user's buffer. >> + */ > ...here: > if (flags & MSG_TRUNC && record_len > len) > >> + if (record_len > len) >> + msg->msg_flags |= MSG_TRUNC; >> + } >> + >> + return err; >> +} >> + >> static int >> vsock_connectible_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, >> int flags) >> @@ -2029,7 +2090,10 @@ vsock_connectible_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, >> goto out; >> } >> >> - err = __vsock_stream_recvmsg(sk, msg, len, flags); >> + if (sk->sk_type == SOCK_STREAM) >> + err = __vsock_stream_recvmsg(sk, msg, len, flags); >> + else >> + err = __vsock_seqpacket_recvmsg(sk, msg, len, flags); >> >> out: >> release_sock(sk); >> -- ) >> 2.25.1 >> >
diff --git a/include/net/af_vsock.h b/include/net/af_vsock.h index b1c717286993..5175f5a52ce1 100644 --- a/include/net/af_vsock.h +++ b/include/net/af_vsock.h @@ -135,6 +135,10 @@ struct vsock_transport { bool (*stream_is_active)(struct vsock_sock *); bool (*stream_allow)(u32 cid, u32 port); + /* SEQ_PACKET. */ + ssize_t (*seqpacket_dequeue)(struct vsock_sock *vsk, struct msghdr *msg, + int flags, bool *msg_ready); + /* Notification. */ int (*notify_poll_in)(struct vsock_sock *, size_t, bool *); int (*notify_poll_out)(struct vsock_sock *, size_t, bool *); diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c index c4f6bfa1e381..d9fb4f9a3063 100644 --- a/net/vmw_vsock/af_vsock.c +++ b/net/vmw_vsock/af_vsock.c @@ -1974,6 +1974,67 @@ static int __vsock_stream_recvmsg(struct sock *sk, struct msghdr *msg, return err; } +static int __vsock_seqpacket_recvmsg(struct sock *sk, struct msghdr *msg, + size_t len, int flags) +{ + const struct vsock_transport *transport; + bool msg_ready; + struct vsock_sock *vsk; + ssize_t record_len; + long timeout; + int err = 0; + DEFINE_WAIT(wait); + + vsk = vsock_sk(sk); + transport = vsk->transport; + + timeout = sock_rcvtimeo(sk, flags & MSG_DONTWAIT); + msg_ready = false; + record_len = 0; + + while (1) { + ssize_t tmp_record_len; + + if (vsock_wait_data(sk, &wait, timeout, NULL, 0) <= 0) { + /* In case of any loop break(timeout, signal + * interrupt or shutdown), we report user that + * nothing was copied. + */ + err = 0; + break; + } + + tmp_record_len = transport->seqpacket_dequeue(vsk, msg, flags, &msg_ready); + + if (tmp_record_len < 0) { + err = -ENOMEM; + break; + } + + record_len += tmp_record_len; + + if (msg_ready) + break; + } + + if (sk->sk_err) + err = -sk->sk_err; + else if (sk->sk_shutdown & RCV_SHUTDOWN) + err = 0; + + if (msg_ready && err == 0) { + err = record_len; + + /* Always set MSG_TRUNC if real length of packet is + * bigger than user's buffer. + */ + if (record_len > len) + msg->msg_flags |= MSG_TRUNC; + } + + return err; +} + static int vsock_connectible_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, int flags) @@ -2029,7 +2090,10 @@ vsock_connectible_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, goto out; } - err = __vsock_stream_recvmsg(sk, msg, len, flags); + if (sk->sk_type == SOCK_STREAM) + err = __vsock_stream_recvmsg(sk, msg, len, flags); + else + err = __vsock_seqpacket_recvmsg(sk, msg, len, flags); out: release_sock(sk);
This adds receive loop for SEQPACKET. It looks like receive loop for STREAM, but there is a little bit difference: 1) It doesn't call notify callbacks. 2) It doesn't care about 'SO_SNDLOWAT' and 'SO_RCVLOWAT' values, because there is no sense for these values in SEQPACKET case. 3) It waits until whole record is received or error is found during receiving. 4) It processes and sets 'MSG_TRUNC' flag. So to avoid extra conditions for two types of socket inside one loop, two independent functions were created. Signed-off-by: Arseny Krasnov <arseny.krasnov@kaspersky.com> --- v7 -> v8: - Length of message is now not returned by callback, it returns only length of data read by each call. - Previous case, when EAGAIN is return and dequeue loop restarted now removed(in this simplified version we consider that message could not be corrupted). - MSG_TRUNC in input flags is now handled by callback. include/net/af_vsock.h | 4 +++ net/vmw_vsock/af_vsock.c | 66 +++++++++++++++++++++++++++++++++++++++- 2 files changed, 69 insertions(+), 1 deletion(-)