| Message ID | 20210323130716.2459195-1-arseny.krasnov@kaspersky.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | virtio/vsock: introduce SOCK_SEQPACKET support | expand |
Hi Arseny, On Tue, Mar 23, 2021 at 04:07:13PM +0300, Arseny Krasnov wrote: > This patchset implements support of SOCK_SEQPACKET for virtio >transport. > As SOCK_SEQPACKET guarantees to save record boundaries, so to >do it, two new packet operations were added: first for start of record > and second to mark end of record(SEQ_BEGIN and SEQ_END later). Also, >both operations carries metadata - to maintain boundaries and payload >integrity. Metadata is introduced by adding special header with two >fields - message id and message length: > > struct virtio_vsock_seq_hdr { > __le32 msg_id; > __le32 msg_len; > } __attribute__((packed)); > > This header is transmitted as payload of SEQ_BEGIN and SEQ_END >packets(buffer of second virtio descriptor in chain) in the same way as >data transmitted in RW packets. Payload was chosen as buffer for this >header to avoid touching first virtio buffer which carries header of >packet, because someone could check that size of this buffer is equal >to size of packet header. To send record, packet with start marker is >sent first(it's header carries length of record and id),then all data >is sent as usual 'RW' packets and finally SEQ_END is sent(it carries >id of message, which is equal to id of SEQ_BEGIN), also after sending >SEQ_END id is incremented. On receiver's side,size of record is known >from packet with start record marker. To check that no packets were >dropped by transport, 'msg_id's of two sequential SEQ_BEGIN and SEQ_END >are checked to be equal and length of data between two markers is >compared to then length in SEQ_BEGIN header. > Now as packets of one socket are not reordered neither on >vsock nor on vhost transport layers, such markers allows to restore >original record on receiver's side. If user's buffer is smaller that >record length, when all out of size data is dropped. > Maximum length of datagram is not limited as in stream socket, >because same credit logic is used. Difference with stream socket is >that user is not woken up until whole record is received or error >occurred. Implementation also supports 'MSG_EOR' and 'MSG_TRUNC' flags. > Tests also implemented. > > Thanks to stsp2@yandex.ru for encouragements and initial design >recommendations. > > Arseny Krasnov (22): > af_vsock: update functions for connectible socket > af_vsock: separate wait data loop > af_vsock: separate receive data loop > af_vsock: implement SEQPACKET receive loop > af_vsock: separate wait space loop > af_vsock: implement send logic for SEQPACKET > af_vsock: rest of SEQPACKET support > af_vsock: update comments for stream sockets > virtio/vsock: set packet's type in virtio_transport_send_pkt_info() > virtio/vsock: simplify credit update function API > virtio/vsock: dequeue callback for SOCK_SEQPACKET > virtio/vsock: fetch length for SEQPACKET record > virtio/vsock: add SEQPACKET receive logic > virtio/vsock: rest of SOCK_SEQPACKET support > virtio/vsock: SEQPACKET support feature bit > virtio/vsock: setup SEQPACKET ops for transport > vhost/vsock: setup SEQPACKET ops for transport > vsock/loopback: setup SEQPACKET ops for transport > vhost/vsock: SEQPACKET feature bit support > virtio/vsock: SEQPACKET feature bit support > vsock_test: add SOCK_SEQPACKET tests > virtio/vsock: update trace event for SEQPACKET > > drivers/vhost/vsock.c | 21 +- > include/linux/virtio_vsock.h | 21 + > include/net/af_vsock.h | 9 + > .../events/vsock_virtio_transport_common.h | 48 +- > include/uapi/linux/virtio_vsock.h | 19 + > net/vmw_vsock/af_vsock.c | 581 +++++++++++------ > net/vmw_vsock/virtio_transport.c | 17 + > net/vmw_vsock/virtio_transport_common.c | 379 +++++++++-- > net/vmw_vsock/vsock_loopback.c | 12 + > tools/testing/vsock/util.c | 32 +- > tools/testing/vsock/util.h | 3 + > tools/testing/vsock/vsock_test.c | 126 ++++ > 12 files changed, 1015 insertions(+), 253 deletions(-) > > v6 -> v7: > General changelog: > - virtio transport callback for message length now removed > from transport. Length of record is returned by dequeue > callback. > > - function which tries to get message length now returns 0 > when rx queue is empty. Also length of current message in > progress is set to 0, when message processed or error > happens. > > - patches for virtio feature bit moved after patches with > transport ops. > > Per patch changelog: > see every patch after '---' line. I reviewed the series and I left some comments, I think we are at a good point, but we should have the specification accepted before merging this series to avoid having to change the implementation later. What do you think? Thanks, Stefano
On 25.03.2021 13:52, Stefano Garzarella wrote: > Hi Arseny, > > On Tue, Mar 23, 2021 at 04:07:13PM +0300, Arseny Krasnov wrote: >> This patchset implements support of SOCK_SEQPACKET for virtio >> transport. >> As SOCK_SEQPACKET guarantees to save record boundaries, so to >> do it, two new packet operations were added: first for start of record >> and second to mark end of record(SEQ_BEGIN and SEQ_END later). Also, >> both operations carries metadata - to maintain boundaries and payload >> integrity. Metadata is introduced by adding special header with two >> fields - message id and message length: >> >> struct virtio_vsock_seq_hdr { >> __le32 msg_id; >> __le32 msg_len; >> } __attribute__((packed)); >> >> This header is transmitted as payload of SEQ_BEGIN and SEQ_END >> packets(buffer of second virtio descriptor in chain) in the same way as >> data transmitted in RW packets. Payload was chosen as buffer for this >> header to avoid touching first virtio buffer which carries header of >> packet, because someone could check that size of this buffer is equal >> to size of packet header. To send record, packet with start marker is >> sent first(it's header carries length of record and id),then all data >> is sent as usual 'RW' packets and finally SEQ_END is sent(it carries >> id of message, which is equal to id of SEQ_BEGIN), also after sending >> SEQ_END id is incremented. On receiver's side,size of record is known > >from packet with start record marker. To check that no packets were >> dropped by transport, 'msg_id's of two sequential SEQ_BEGIN and SEQ_END >> are checked to be equal and length of data between two markers is >> compared to then length in SEQ_BEGIN header. >> Now as packets of one socket are not reordered neither on >> vsock nor on vhost transport layers, such markers allows to restore >> original record on receiver's side. If user's buffer is smaller that >> record length, when all out of size data is dropped. >> Maximum length of datagram is not limited as in stream socket, >> because same credit logic is used. Difference with stream socket is >> that user is not woken up until whole record is received or error >> occurred. Implementation also supports 'MSG_EOR' and 'MSG_TRUNC' flags. >> Tests also implemented. >> >> Thanks to stsp2@yandex.ru for encouragements and initial design >> recommendations. >> >> Arseny Krasnov (22): >> af_vsock: update functions for connectible socket >> af_vsock: separate wait data loop >> af_vsock: separate receive data loop >> af_vsock: implement SEQPACKET receive loop >> af_vsock: separate wait space loop >> af_vsock: implement send logic for SEQPACKET >> af_vsock: rest of SEQPACKET support >> af_vsock: update comments for stream sockets >> virtio/vsock: set packet's type in virtio_transport_send_pkt_info() >> virtio/vsock: simplify credit update function API >> virtio/vsock: dequeue callback for SOCK_SEQPACKET >> virtio/vsock: fetch length for SEQPACKET record >> virtio/vsock: add SEQPACKET receive logic >> virtio/vsock: rest of SOCK_SEQPACKET support >> virtio/vsock: SEQPACKET support feature bit >> virtio/vsock: setup SEQPACKET ops for transport >> vhost/vsock: setup SEQPACKET ops for transport >> vsock/loopback: setup SEQPACKET ops for transport >> vhost/vsock: SEQPACKET feature bit support >> virtio/vsock: SEQPACKET feature bit support >> vsock_test: add SOCK_SEQPACKET tests >> virtio/vsock: update trace event for SEQPACKET >> >> drivers/vhost/vsock.c | 21 +- >> include/linux/virtio_vsock.h | 21 + >> include/net/af_vsock.h | 9 + >> .../events/vsock_virtio_transport_common.h | 48 +- >> include/uapi/linux/virtio_vsock.h | 19 + >> net/vmw_vsock/af_vsock.c | 581 +++++++++++------ >> net/vmw_vsock/virtio_transport.c | 17 + >> net/vmw_vsock/virtio_transport_common.c | 379 +++++++++-- >> net/vmw_vsock/vsock_loopback.c | 12 + >> tools/testing/vsock/util.c | 32 +- >> tools/testing/vsock/util.h | 3 + >> tools/testing/vsock/vsock_test.c | 126 ++++ >> 12 files changed, 1015 insertions(+), 253 deletions(-) >> >> v6 -> v7: >> General changelog: >> - virtio transport callback for message length now removed >> from transport. Length of record is returned by dequeue >> callback. >> >> - function which tries to get message length now returns 0 >> when rx queue is empty. Also length of current message in >> progress is set to 0, when message processed or error >> happens. >> >> - patches for virtio feature bit moved after patches with >> transport ops. >> >> Per patch changelog: >> see every patch after '---' line. > I reviewed the series and I left some comments, I think we are at a good > point, but we should have the specification accepted before merging this > series to avoid having to change the implementation later. I'll prepare new version of specification patch > > What do you think? Agree, Thank You > > Thanks, > Stefano > >
This patchset implements support of SOCK_SEQPACKET for virtio transport. As SOCK_SEQPACKET guarantees to save record boundaries, so to do it, two new packet operations were added: first for start of record and second to mark end of record(SEQ_BEGIN and SEQ_END later). Also, both operations carries metadata - to maintain boundaries and payload integrity. Metadata is introduced by adding special header with two fields - message id and message length: struct virtio_vsock_seq_hdr { __le32 msg_id; __le32 msg_len; } __attribute__((packed)); This header is transmitted as payload of SEQ_BEGIN and SEQ_END packets(buffer of second virtio descriptor in chain) in the same way as data transmitted in RW packets. Payload was chosen as buffer for this header to avoid touching first virtio buffer which carries header of packet, because someone could check that size of this buffer is equal to size of packet header. To send record, packet with start marker is sent first(it's header carries length of record and id),then all data is sent as usual 'RW' packets and finally SEQ_END is sent(it carries id of message, which is equal to id of SEQ_BEGIN), also after sending SEQ_END id is incremented. On receiver's side,size of record is known from packet with start record marker. To check that no packets were dropped by transport, 'msg_id's of two sequential SEQ_BEGIN and SEQ_END are checked to be equal and length of data between two markers is compared to then length in SEQ_BEGIN header. Now as packets of one socket are not reordered neither on vsock nor on vhost transport layers, such markers allows to restore original record on receiver's side. If user's buffer is smaller that record length, when all out of size data is dropped. Maximum length of datagram is not limited as in stream socket, because same credit logic is used. Difference with stream socket is that user is not woken up until whole record is received or error occurred. Implementation also supports 'MSG_EOR' and 'MSG_TRUNC' flags. Tests also implemented. Thanks to stsp2@yandex.ru for encouragements and initial design recommendations. Arseny Krasnov (22): af_vsock: update functions for connectible socket af_vsock: separate wait data loop af_vsock: separate receive data loop af_vsock: implement SEQPACKET receive loop af_vsock: separate wait space loop af_vsock: implement send logic for SEQPACKET af_vsock: rest of SEQPACKET support af_vsock: update comments for stream sockets virtio/vsock: set packet's type in virtio_transport_send_pkt_info() virtio/vsock: simplify credit update function API virtio/vsock: dequeue callback for SOCK_SEQPACKET virtio/vsock: fetch length for SEQPACKET record virtio/vsock: add SEQPACKET receive logic virtio/vsock: rest of SOCK_SEQPACKET support virtio/vsock: SEQPACKET support feature bit virtio/vsock: setup SEQPACKET ops for transport vhost/vsock: setup SEQPACKET ops for transport vsock/loopback: setup SEQPACKET ops for transport vhost/vsock: SEQPACKET feature bit support virtio/vsock: SEQPACKET feature bit support vsock_test: add SOCK_SEQPACKET tests virtio/vsock: update trace event for SEQPACKET drivers/vhost/vsock.c | 21 +- include/linux/virtio_vsock.h | 21 + include/net/af_vsock.h | 9 + .../events/vsock_virtio_transport_common.h | 48 +- include/uapi/linux/virtio_vsock.h | 19 + net/vmw_vsock/af_vsock.c | 581 +++++++++++------ net/vmw_vsock/virtio_transport.c | 17 + net/vmw_vsock/virtio_transport_common.c | 379 +++++++++-- net/vmw_vsock/vsock_loopback.c | 12 + tools/testing/vsock/util.c | 32 +- tools/testing/vsock/util.h | 3 + tools/testing/vsock/vsock_test.c | 126 ++++ 12 files changed, 1015 insertions(+), 253 deletions(-) v6 -> v7: General changelog: - virtio transport callback for message length now removed from transport. Length of record is returned by dequeue callback. - function which tries to get message length now returns 0 when rx queue is empty. Also length of current message in progress is set to 0, when message processed or error happens. - patches for virtio feature bit moved after patches with transport ops. Per patch changelog: see every patch after '---' line. v5 -> v6: General changelog: - virtio transport specific callbacks which send SEQ_BEGIN or SEQ_END now hidden inside virtio transport. Only enqueue, dequeue and record length callbacks are provided by transport. - virtio feature bit for SEQPACKET socket support introduced: VIRTIO_VSOCK_F_SEQPACKET. - 'msg_cnt' field in 'struct virtio_vsock_seq_hdr' renamed to 'msg_id' and used as id. Per patch changelog: - 'af_vsock: separate wait data loop': 1) Commit message updated. 2) 'prepare_to_wait()' moved inside while loop(thanks to Jorgen Hansen). Marked 'Reviewed-by' with 1), but as 2) I removed R-b. - 'af_vsock: separate receive data loop': commit message updated. Marked 'Reviewed-by' with that fix. - 'af_vsock: implement SEQPACKET receive loop': style fixes. - 'af_vsock: rest of SEQPACKET support': 1) 'module_put()' added when transport callback check failed. 2) Now only 'seqpacket_allow()' callback called to check support of SEQPACKET by transport. - 'af_vsock: update comments for stream sockets': commit message updated. Marked 'Reviewed-by' with that fix. - 'virtio/vsock: set packet's type in send': 1) Commit message updated. 2) Parameter 'type' from 'virtio_transport_send_credit_update()' also removed in this patch instead of in next. - 'virtio/vsock: dequeue callback for SOCK_SEQPACKET': SEQPACKET related state wrapped to special struct. - 'virtio/vsock: update trace event for SEQPACKET': format strings now not broken by new lines. v4 -> v5: - patches reorganized: 1) Setting of packet's type in 'virtio_transport_send_pkt_info()' is moved to separate patch. 2) Simplifying of 'virtio_transport_send_credit_update()' is moved to separate patch and before main virtio/vsock patches. - style problem fixed - in 'af_vsock: separate receive data loop' extra 'release_sock()' removed - added trace event fields for SEQPACKET - in 'af_vsock: separate wait data loop': 1) 'vsock_wait_data()' removed 'goto out;' 2) Comment for invalid data amount is changed. - in 'af_vsock: rest of SEQPACKET support', 'new_transport' pointer check is moved after 'try_module_get()' - in 'af_vsock: update comments for stream sockets', 'connect-oriented' replaced with 'connection-oriented' - in 'loopback/vsock: setup SEQPACKET ops for transport', 'loopback/vsock' replaced with 'vsock/loopback' v3 -> v4: - SEQPACKET specific metadata moved from packet header to payload and called 'virtio_vsock_seq_hdr' - record integrity check: 1) SEQ_END operation was added, which marks end of record. 2) Both SEQ_BEGIN and SEQ_END carries counter which is incremented on every marker send. - af_vsock.c: socket operations for STREAM and SEQPACKET call same functions instead of having own "gates" differs only by names: 'vsock_seqpacket/stream_getsockopt()' now replaced with 'vsock_connectible_getsockopt()'. - af_vsock.c: 'seqpacket_dequeue' callback returns error and flag that record ready. There is no need to return number of copied bytes, because case when record received successfully is checked at virtio transport layer, when SEQ_END is processed. Also user doesn't need number of copied bytes, because 'recv()' from SEQPACKET could return error, length of users's buffer or length of whole record(both are known in af_vsock.c). - af_vsock.c: both wait loops in af_vsock.c(for data and space) moved to separate functions because now both called from several places. - af_vsock.c: 'vsock_assign_transport()' checks that 'new_transport' pointer is not NULL and returns 'ESOCKTNOSUPPORT' instead of 'ENODEV' if failed to use transport. - tools/testing/vsock/vsock_test.c: rename tests v2 -> v3: - patches reorganized: split for prepare and implementation patches - local variables are declared in "Reverse Christmas tree" manner - virtio_transport_common.c: valid leXX_to_cpu() for vsock header fields access - af_vsock.c: 'vsock_connectible_*sockopt()' added as shared code between stream and seqpacket sockets. - af_vsock.c: loops in '__vsock_*_recvmsg()' refactored. - af_vsock.c: 'vsock_wait_data()' refactored. v1 -> v2: - patches reordered: af_vsock.c related changes now before virtio vsock - patches reorganized: more small patches, where +/- are not mixed - tests for SOCK_SEQPACKET added - all commit messages updated - af_vsock.c: 'vsock_pre_recv_check()' inlined to 'vsock_connectible_recvmsg()' - af_vsock.c: 'vsock_assign_transport()' returns ENODEV if transport was not found - virtio_transport_common.c: transport callback for seqpacket dequeue - virtio_transport_common.c: simplified 'virtio_transport_recv_connected()' - virtio_transport_common.c: send reset on socket and packet type mismatch. Signed-off-by: Arseny Krasnov <arseny.krasnov@kaspersky.com>