From: Cong Wang <cong.w...@bytedance.com> Currently sockmap only fully supports TCP, UDP is partially supported as it is only allowed to add into sockmap. This patch extends sockmap with: 1) full UDP support; 2) full AF_UNIX dgram support; 3) cross protocol support. Our goal is to allow socket splice between AF_UNIX dgram and UDP.
On the high level, ->sendmsg_locked() and ->read_sock() are required for each protocol to support sockmap redirection, and in order to do sock proto update, a new ops ->update_proto() is introduced, which is also required to implement. It is slightly harder for AF_UNIX, as it does not have a full struct proto implementation and redirection. In order to support cross protocol, we have to make skb independent of protocols, which is extremely hard given how creatively UDP uses dev_scratch. Fortunately, we can pass skmsg instead of skb when redirecting to ingress, the only thing needs to add is a new ->recvmsg() to retrieve skmsg. On the egress side, a new skb is allocated behind skb_send_sock_locked(), it comes for free. Another big barrier is skb CB, which was hard-coded as TCP_CB(), I switch it to skb ext to solve this problem. Please see patch 3 for more details. This patchset passed all tests, the existing ones and the new ones I add within this patchset. --- Cong Wang (19): bpf: rename BPF_STREAM_PARSER to BPF_SOCK_MAP skmsg: get rid of struct sk_psock_parser skmsg: use skb ext instead of TCP_SKB_CB sock_map: rename skb_parser and skb_verdict sock_map: introduce BPF_SK_SKB_VERDICT sock: introduce sk_prot->update_proto() udp: implement ->sendmsg_locked() udp: implement ->read_sock() for sockmap udp: add ->read_sock() and ->sendmsg_locked() to ipv6 af_unix: implement ->sendmsg_locked for dgram socket af_unix: implement ->read_sock() for sockmap af_unix: implement ->update_proto() af_unix: set TCP_ESTABLISHED for datagram sockets too skmsg: extract __tcp_bpf_recvmsg() and tcp_bpf_wait_data() udp: implement udp_bpf_recvmsg() for sockmap af_unix: implement unix_dgram_bpf_recvmsg() sock_map: update sock type checks selftests/bpf: add test cases for unix and udp sockmap selftests/bpf: add test case for redirection between udp and unix MAINTAINERS | 1 + include/linux/bpf.h | 4 +- include/linux/bpf_types.h | 2 +- include/linux/skbuff.h | 4 + include/linux/skmsg.h | 90 +++- include/net/af_unix.h | 13 + include/net/ipv6.h | 1 + include/net/sock.h | 3 + include/net/tcp.h | 33 +- include/net/udp.h | 9 +- include/uapi/linux/bpf.h | 1 + kernel/bpf/syscall.c | 1 + net/Kconfig | 14 +- net/core/Makefile | 2 +- net/core/filter.c | 3 +- net/core/skbuff.c | 7 + net/core/skmsg.c | 223 +++++--- net/core/sock_map.c | 128 ++--- net/ipv4/Makefile | 2 +- net/ipv4/af_inet.c | 2 + net/ipv4/tcp_bpf.c | 130 +---- net/ipv4/tcp_ipv4.c | 3 + net/ipv4/udp.c | 68 ++- net/ipv4/udp_bpf.c | 78 ++- net/ipv6/af_inet6.c | 2 + net/ipv6/tcp_ipv6.c | 3 + net/ipv6/udp.c | 30 +- net/tls/tls_sw.c | 4 +- net/unix/Makefile | 1 + net/unix/af_unix.c | 105 +++- net/unix/unix_bpf.c | 99 ++++ tools/bpf/bpftool/common.c | 1 + tools/bpf/bpftool/prog.c | 1 + tools/include/uapi/linux/bpf.h | 1 + .../selftests/bpf/prog_tests/sockmap_listen.c | 475 +++++++++++++++++- .../selftests/bpf/progs/test_sockmap_listen.c | 24 +- 36 files changed, 1233 insertions(+), 335 deletions(-) create mode 100644 net/unix/unix_bpf.c -- 2.25.1
