The recently added VRF support in Linux leverages the bind-to-device
API for programs to specify an L3 domain for a socket. While
SO_BINDTODEVICE has been around for ages, not every ipv4/ipv6 capable
program has support for it. Even for those programs that do support it,
the API requires processes to be started as root (CAP_NET_RAW) which
is not desirable from a general security perspective.
This patch set leverages Daniel Mack's work to attach bpf programs to
a cgroup:
https://www.mail-archive.com/netdev@vger.kernel.org/msg134028.html
to provide a capability to set sk_bound_dev_if for all AF_INET{6}
sockets opened by a process in a cgroup when the sockets are allocated.
This capability enables running any program in a VRF context and is key
to deploying Management VRF, a fundamental configuration for networking
gear, with any Linux OS installation.
David Ahern (3):
bpf: Refactor cgroups code in prep for new type
bpf: Add new cgroups prog type to enable sock modifications
samples: bpf: add userspace example for modifying sk_bound_dev_if
include/linux/filter.h | 2 +-
include/uapi/linux/bpf.h | 15 +++++++
kernel/bpf/cgroup.c | 36 ++++++++++++++---
kernel/bpf/syscall.c | 32 +++++++++------
net/core/filter.c | 92 +++++++++++++++++++++++++++++++++++++++++++
net/core/sock.c | 7 ++++
samples/bpf/Makefile | 2 +
samples/bpf/bpf_helpers.h | 2 +
samples/bpf/test_cgrp2_sock.c | 84 +++++++++++++++++++++++++++++++++++++++
9 files changed, 253 insertions(+), 19 deletions(-)
create mode 100644 samples/bpf/test_cgrp2_sock.c
--
2.1.4
