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| author | Martin KaFai Lau <kafai@fb.com> | 2020-09-25 03:03:56 +0300 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2020-09-25 23:58:01 +0300 |
| commit | a5fa25adf03d4b063aece74ba70ccbb3a71af122 (patch) | |
| tree | 654f3b361da1fc52c2f57ee3c9b01a30caa89139 /include | |
| parent | 1df8f55a37bd286a3d40192980050bc3d7d78887 (diff) | |
| download | linux-a5fa25adf03d4b063aece74ba70ccbb3a71af122.tar.xz | |
bpf: Change bpf_sk_release and bpf_sk_*cgroup_id to accept ARG_PTR_TO_BTF_ID_SOCK_COMMON
The previous patch allows the networking bpf prog to use the
bpf_skc_to_*() helpers to get a PTR_TO_BTF_ID socket pointer,
e.g. "struct tcp_sock *". It allows the bpf prog to read all the
fields of the tcp_sock.
This patch changes the bpf_sk_release() and bpf_sk_*cgroup_id()
to take ARG_PTR_TO_BTF_ID_SOCK_COMMON such that they will
work with the pointer returned by the bpf_skc_to_*() helpers
also. For example, the following will work:
sk = bpf_skc_lookup_tcp(skb, tuple, tuplen, BPF_F_CURRENT_NETNS, 0);
if (!sk)
return;
tp = bpf_skc_to_tcp_sock(sk);
if (!tp) {
bpf_sk_release(sk);
return;
}
lsndtime = tp->lsndtime;
/* Pass tp to bpf_sk_release() will also work */
bpf_sk_release(tp);
Since PTR_TO_BTF_ID could be NULL, the helper taking
ARG_PTR_TO_BTF_ID_SOCK_COMMON has to check for NULL at runtime.
A btf_id of "struct sock" may not always mean a fullsock. Regardless
the helper's running context may get a non-fullsock or not,
considering fullsock check/handling is pretty cheap, it is better to
keep the same verifier expectation on helper that takes ARG_PTR_TO_BTF_ID*
will be able to handle the minisock situation. In the bpf_sk_*cgroup_id()
case, it will try to get a fullsock by using sk_to_full_sk() as its
skb variant bpf_sk"b"_*cgroup_id() has already been doing.
bpf_sk_release can already handle minisock, so nothing special has to
be done.
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200925000356.3856047-1-kafai@fb.com
Diffstat (limited to 'include')
| -rw-r--r-- | include/uapi/linux/bpf.h | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index a22812561064..c96a56d9c3be 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -2512,7 +2512,7 @@ union bpf_attr { * result is from *reuse*\ **->socks**\ [] using the hash of the * tuple. * - * long bpf_sk_release(struct bpf_sock *sock) + * long bpf_sk_release(void *sock) * Description * Release the reference held by *sock*. *sock* must be a * non-**NULL** pointer that was returned from @@ -3234,11 +3234,11 @@ union bpf_attr { * * **-EOVERFLOW** if an overflow happened: The same object will be tried again. * - * u64 bpf_sk_cgroup_id(struct bpf_sock *sk) + * u64 bpf_sk_cgroup_id(void *sk) * Description * Return the cgroup v2 id of the socket *sk*. * - * *sk* must be a non-**NULL** pointer to a full socket, e.g. one + * *sk* must be a non-**NULL** pointer to a socket, e.g. one * returned from **bpf_sk_lookup_xxx**\ (), * **bpf_sk_fullsock**\ (), etc. The format of returned id is * same as in **bpf_skb_cgroup_id**\ (). @@ -3248,7 +3248,7 @@ union bpf_attr { * Return * The id is returned or 0 in case the id could not be retrieved. * - * u64 bpf_sk_ancestor_cgroup_id(struct bpf_sock *sk, int ancestor_level) + * u64 bpf_sk_ancestor_cgroup_id(void *sk, int ancestor_level) * Description * Return id of cgroup v2 that is ancestor of cgroup associated * with the *sk* at the *ancestor_level*. The root cgroup is at |