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d105fa983c
Martin KaFai Lau says:
====================
This series adds __sk_buff->sk, "struct bpf_tcp_sock",
BPF_FUNC_sk_fullsock and BPF_FUNC_tcp_sock. Together, they provide
a common way to expose the members of "struct tcp_sock" and
"struct bpf_sock" for the bpf_prog to access.
The patch series first adds a bpf_sock pointer to __sk_buff
and a new helper BPF_FUNC_sk_fullsock.
It then adds BPF_FUNC_tcp_sock to get a bpf_tcp_sock
pointer from a bpf_sock pointer.
The current use case is to allow a cg_skb_bpf_prog to provide
per cgroup traffic policing/shaping.
Please see individual patch for details.
v2:
- Patch 1 depends on
commit d623876646 ("bpf: Fix narrow load on a bpf_sock returned from sk_lookup()")
in the bpf branch.
- Add sk_to_full_sk() to bpf_sk_fullsock() and bpf_tcp_sock()
such that there is a way to access the listener's sk and tcp_sk
when __sk_buff->sk is a request_sock.
The comments in the uapi bpf.h is updated accordingly.
- bpf_ctx_range_till() is used in bpf_sock_common_is_valid_access()
in patch 1. Saved a few lines.
- Patch 2 is new in v2 and it adds "state", "dst_ip4", "dst_ip6" and
"dst_port" to the bpf_sock. Narrow load is allowed on them.
The "state" (i.e. sk_state) has already been used in
INET_DIAG (e.g. ss -t) and getsockopt(TCP_INFO).
- While at it in the new patch 2, also allow narrow load on some
existing fields of the bpf_sock, which are "family", "type", "protocol"
and "src_port". Only allow loading from first byte for now.
i.e. does not allow narrow load starting from the 2nd byte.
- Add some narrow load tests to the test_verifier's sock.c
====================
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.