On Fri, 3 Sep 2021 15:30:13 +0300 Arseny Krasnov wrote: > This patchset implements support of MSG_EOR bit for SEQPACKET > AF_VSOCK sockets over virtio transport. > First we need to define 'messages' and 'records' like this: > Message is result of sending calls: 'write()', 'send()', 'sendmsg()' > etc. It has fixed maximum length, and it bounds are visible using > return from receive calls: 'read()', 'recv()', 'recvmsg()' etc. > Current implementation based on message definition above. > Record has unlimited length, it consists of multiple message, > and bounds of record are visible via MSG_EOR flag returned from > 'recvmsg()' call. Sender passes MSG_EOR to sending system call and > receiver will see MSG_EOR when corresponding message will be processed. > Idea of patchset comes from POSIX: it says that SEQPACKET > supports record boundaries which are visible for receiver using > MSG_EOR bit. So, it looks like MSG_EOR is enough thing for SEQPACKET > and we don't need to maintain boundaries of corresponding send - > receive system calls. But, for 'sendXXX()' and 'recXXX()' POSIX says, > that all these calls operates with messages, e.g. 'sendXXX()' sends > message, while 'recXXX()' reads messages and for SEQPACKET, 'recXXX()' > must read one entire message from socket, dropping all out of size > bytes. Thus, both message boundaries and MSG_EOR bit must be supported > to follow POSIX rules. > To support MSG_EOR new bit was added along with existing > 'VIRTIO_VSOCK_SEQ_EOR': 'VIRTIO_VSOCK_SEQ_EOM'(end-of-message) - now it > works in the same way as 'VIRTIO_VSOCK_SEQ_EOR'. But 'VIRTIO_VSOCK_SEQ_EOR' > is used to mark 'MSG_EOR' bit passed from userspace. > This patchset includes simple test for MSG_EOR. Assuming you want this merged to net-next: # Form letter - net-next is closed We have already sent the networking pull request for 5.15 and therefore net-next is closed for new drivers, features, code refactoring and optimizations. We are currently accepting bug fixes only. Please repost when net-next reopens after 5.15-rc1 is cut. Look out for the announcement on the mailing list or check: http://vger.kernel.org/~davem/net-next.html RFC patches sent for review only are obviously welcome at any time.
