| Message ID | 20210323131006.2460058-1-arseny.krasnov@kaspersky.com |
|---|---|
| State | New |
| Headers | show |
| Series | virtio/vsock: introduce SOCK_SEQPACKET support | expand |
On Tue, Mar 23, 2021 at 04:10:03PM +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> >--- > v6 -> v7: > 'seqpacket_get_len' callback now removed, length of message is returned > by 'seqpacket_dequeue' callback. > > include/net/af_vsock.h | 4 ++ > net/vmw_vsock/af_vsock.c | 88 +++++++++++++++++++++++++++++++++++++++- > 2 files changed, 91 insertions(+), 1 deletion(-) > >diff --git a/include/net/af_vsock.h b/include/net/af_vsock.h >index b1c717286993..74ac8a4c4168 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. */ >+ int (*seqpacket_dequeue)(struct vsock_sock *vsk, struct msghdr *msg, >+ int flags, bool *msg_ready, size_t *record_len); >+ Why not using ssize_t as return value and return the length or a negative value in case of error? In this way we can remove the 'record_len' parameter. > /* 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 0bc661e54262..fa0c37f97330 100644 >--- a/net/vmw_vsock/af_vsock.c >+++ b/net/vmw_vsock/af_vsock.c >@@ -1973,6 +1973,89 @@ 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; >+ const struct iovec *orig_iov; >+ unsigned long orig_nr_segs; >+ bool msg_ready; >+ struct vsock_sock *vsk; >+ size_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); >+ orig_nr_segs = msg->msg_iter.nr_segs; >+ orig_iov = msg->msg_iter.iov; >+ msg_ready = false; >+ record_len = 0; >+ >+ while (1) { >+ err = vsock_wait_data(sk, &wait, timeout, NULL, 0); >+ >+ if (err <= 0) { >+ /* In case of any loop break(timeout, signal >+ * interrupt or shutdown), we report user that >+ * nothing was copied. >+ */ >+ err = 0; >+ break; >+ } >+ >+ err = transport->seqpacket_dequeue(vsk, msg, flags, &msg_ready, &record_len); >+ >+ if (err < 0) { >+ if (err == -EAGAIN) { >+ iov_iter_init(&msg->msg_iter, READ, >+ orig_iov, orig_nr_segs, >+ len); >+ /* Clear 'MSG_EOR' here, because dequeue >+ * callback above set it again if it was >+ * set by sender. This 'MSG_EOR' is from >+ * dropped record. >+ */ >+ msg->msg_flags &= ~MSG_EOR; >+ record_len = 0; >+ continue; >+ } >+ >+ err = -ENOMEM; >+ break; >+ } >+ >+ if (msg_ready) >+ break; >+ } >+ >+ if (sk->sk_err) >+ err = -sk->sk_err; >+ else if (sk->sk_shutdown & RCV_SHUTDOWN) >+ err = 0; >+ >+ if (msg_ready) { If 'err' is not 0, should we skip this branch? >+ /* User sets MSG_TRUNC, so return real length of >+ * packet. >+ */ >+ if (flags & MSG_TRUNC) >+ err = record_len; >+ else >+ err = len - msg->msg_iter.count; >+ >+ /* 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) >@@ -2028,7 +2111,10 @@ 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 25.03.2021 12:34, Stefano Garzarella wrote: > On Tue, Mar 23, 2021 at 04:10:03PM +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> >> --- >> v6 -> v7: >> 'seqpacket_get_len' callback now removed, length of message is returned >> by 'seqpacket_dequeue' callback. >> >> include/net/af_vsock.h | 4 ++ >> net/vmw_vsock/af_vsock.c | 88 +++++++++++++++++++++++++++++++++++++++- >> 2 files changed, 91 insertions(+), 1 deletion(-) >> >> diff --git a/include/net/af_vsock.h b/include/net/af_vsock.h >> index b1c717286993..74ac8a4c4168 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. */ >> + int (*seqpacket_dequeue)(struct vsock_sock *vsk, struct msghdr *msg, >> + int flags, bool *msg_ready, size_t *record_len); >> + > Why not using ssize_t as return value and return the length or a > negative value in case of error? > > In this way we can remove the 'record_len' parameter. Ok, i think it is possible > >> /* 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 0bc661e54262..fa0c37f97330 100644 >> --- a/net/vmw_vsock/af_vsock.c >> +++ b/net/vmw_vsock/af_vsock.c >> @@ -1973,6 +1973,89 @@ 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; >> + const struct iovec *orig_iov; >> + unsigned long orig_nr_segs; >> + bool msg_ready; >> + struct vsock_sock *vsk; >> + size_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); >> + orig_nr_segs = msg->msg_iter.nr_segs; >> + orig_iov = msg->msg_iter.iov; >> + msg_ready = false; >> + record_len = 0; >> + >> + while (1) { >> + err = vsock_wait_data(sk, &wait, timeout, NULL, 0); >> + >> + if (err <= 0) { >> + /* In case of any loop break(timeout, signal >> + * interrupt or shutdown), we report user that >> + * nothing was copied. >> + */ >> + err = 0; >> + break; >> + } >> + >> + err = transport->seqpacket_dequeue(vsk, msg, flags, &msg_ready, &record_len); >> + >> + if (err < 0) { >> + if (err == -EAGAIN) { >> + iov_iter_init(&msg->msg_iter, READ, >> + orig_iov, orig_nr_segs, >> + len); >> + /* Clear 'MSG_EOR' here, because dequeue >> + * callback above set it again if it was >> + * set by sender. This 'MSG_EOR' is from >> + * dropped record. >> + */ >> + msg->msg_flags &= ~MSG_EOR; >> + record_len = 0; >> + continue; >> + } >> + >> + err = -ENOMEM; >> + break; >> + } >> + >> + if (msg_ready) >> + break; >> + } >> + >> + if (sk->sk_err) >> + err = -sk->sk_err; >> + else if (sk->sk_shutdown & RCV_SHUTDOWN) >> + err = 0; >> + >> + if (msg_ready) { > If 'err' is not 0, should we skip this branch? Ack > >> + /* User sets MSG_TRUNC, so return real length of >> + * packet. >> + */ >> + if (flags & MSG_TRUNC) >> + err = record_len; >> + else >> + err = len - msg->msg_iter.count; >> + >> + /* 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) >> @@ -2028,7 +2111,10 @@ 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..74ac8a4c4168 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. */ + int (*seqpacket_dequeue)(struct vsock_sock *vsk, struct msghdr *msg, + int flags, bool *msg_ready, size_t *record_len); + /* 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 0bc661e54262..fa0c37f97330 100644 --- a/net/vmw_vsock/af_vsock.c +++ b/net/vmw_vsock/af_vsock.c @@ -1973,6 +1973,89 @@ 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; + const struct iovec *orig_iov; + unsigned long orig_nr_segs; + bool msg_ready; + struct vsock_sock *vsk; + size_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); + orig_nr_segs = msg->msg_iter.nr_segs; + orig_iov = msg->msg_iter.iov; + msg_ready = false; + record_len = 0; + + while (1) { + err = vsock_wait_data(sk, &wait, timeout, NULL, 0); + + if (err <= 0) { + /* In case of any loop break(timeout, signal + * interrupt or shutdown), we report user that + * nothing was copied. + */ + err = 0; + break; + } + + err = transport->seqpacket_dequeue(vsk, msg, flags, &msg_ready, &record_len); + + if (err < 0) { + if (err == -EAGAIN) { + iov_iter_init(&msg->msg_iter, READ, + orig_iov, orig_nr_segs, + len); + /* Clear 'MSG_EOR' here, because dequeue + * callback above set it again if it was + * set by sender. This 'MSG_EOR' is from + * dropped record. + */ + msg->msg_flags &= ~MSG_EOR; + record_len = 0; + continue; + } + + err = -ENOMEM; + break; + } + + if (msg_ready) + break; + } + + if (sk->sk_err) + err = -sk->sk_err; + else if (sk->sk_shutdown & RCV_SHUTDOWN) + err = 0; + + if (msg_ready) { + /* User sets MSG_TRUNC, so return real length of + * packet. + */ + if (flags & MSG_TRUNC) + err = record_len; + else + err = len - msg->msg_iter.count; + + /* 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) @@ -2028,7 +2111,10 @@ 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> --- v6 -> v7: 'seqpacket_get_len' callback now removed, length of message is returned by 'seqpacket_dequeue' callback. include/net/af_vsock.h | 4 ++ net/vmw_vsock/af_vsock.c | 88 +++++++++++++++++++++++++++++++++++++++- 2 files changed, 91 insertions(+), 1 deletion(-)