v2 -> v3:
* place BPF logic under static key in udp_sendmsg, udpv6_sendmsg;
* rebase.
v1 -> v2:
* return ENOTSUPP if bpf_prog rewrote IPv6-only with IPv4-mapped IPv6;
* add test for IPv4-mapped IPv6 use-case;
* fix build for CONFIG_CGROUP_BPF=n;
* rebase.
This path set adds BPF hooks for sys_sendmsg similar to existing hooks for
sys_bind and sys_connect.
Hooks allow to override source IP (including the case when it's set via
cmsg(3)) and destination IP:port for unconnected UDP (slow path). TCP and
connected UDP (fast path) are not affected. This makes UDP support
complete: connected UDP is handled by sys_connect hooks, unconnected by
sys_sendmsg ones.
Similar to sys_connect hooks, sys_sendmsg ones can be used to make system
calls such as sendmsg(2) and sendto(2) return EPERM.
Please see patch 0001 for more details.
Andrey Ignatov (5):
bpf: Hooks for sys_sendmsg
bpf: Sync bpf.h to tools/
libbpf: Support guessing sendmsg{4,6} progs
selftests/bpf: Prepare test_sock_addr for extension
selftests/bpf: Selftest for sys_sendmsg hooks
include/linux/bpf-cgroup.h | 23 +-
include/linux/filter.h | 1 +
include/uapi/linux/bpf.h | 8 +
kernel/bpf/cgroup.c | 11 +-
kernel/bpf/syscall.c | 8 +
net/core/filter.c | 39 +
net/ipv4/udp.c | 20 +-
net/ipv6/udp.c | 24 +
tools/include/uapi/linux/bpf.h | 8 +
tools/lib/bpf/libbpf.c | 2 +
tools/testing/selftests/bpf/Makefile | 2 +-
tools/testing/selftests/bpf/sendmsg4_prog.c | 49 ++
tools/testing/selftests/bpf/sendmsg6_prog.c | 60 ++
tools/testing/selftests/bpf/test_sock_addr.c | 1155 +++++++++++++++++++++-----
14 files changed, 1214 insertions(+), 196 deletions(-)
create mode 100644 tools/testing/selftests/bpf/sendmsg4_prog.c
create mode 100644 tools/testing/selftests/bpf/sendmsg6_prog.c
--
2.9.5
