diff options
| author |   Yonghong Song <yhs@fb.com> | 2020-06-23 16:08:09 -0700 |
|---|---|---|
| committer |   Alexei Starovoitov <ast@kernel.org> | 2020-06-24 18:37:59 -0700 |
| commit | af7ec13833619e17f03aa73a785a2f871da6d66b (patch) | |
| tree | 80a186e36a8007eeebb720adca3d59654d31fe86 /tools/include | |
| parent | bpf: Allow tracing programs to use bpf_jiffies64() helper (diff) | |
| download | linux-dev-af7ec13833619e17f03aa73a785a2f871da6d66b.tar.xz linux-dev-af7ec13833619e17f03aa73a785a2f871da6d66b.zip | |
bpf: Add bpf_skc_to_tcp6_sock() helper
The helper is used in tracing programs to cast a socket
pointer to a tcp6_sock pointer.
The return value could be NULL if the casting is illegal.
A new helper return type RET_PTR_TO_BTF_ID_OR_NULL is added
so the verifier is able to deduce proper return types for the helper.
Different from the previous BTF_ID based helpers,
the bpf_skc_to_tcp6_sock() argument can be several possible
btf_ids. More specifically, all possible socket data structures
with sock_common appearing in the first in the memory layout.
This patch only added socket types related to tcp and udp.
All possible argument btf_id and return value btf_id
for helper bpf_skc_to_tcp6_sock() are pre-calculcated and
cached. In the future, it is even possible to precompute
these btf_id's at kernel build time.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20200623230809.3988195-1-yhs@fb.com
Diffstat (limited to 'tools/include')
| -rw-r--r-- | tools/include/uapi/linux/bpf.h | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index d9737d51dd19..e90ad07b291a 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -3255,6 +3255,12 @@ union bpf_attr { * case of **BPF_CSUM_LEVEL_QUERY**, the current skb->csum_level * is returned or the error code -EACCES in case the skb is not * subject to CHECKSUM_UNNECESSARY. + * + * struct tcp6_sock *bpf_skc_to_tcp6_sock(void *sk) + * Description + * Dynamically cast a *sk* pointer to a *tcp6_sock* pointer. + * Return + * *sk* if casting is valid, or NULL otherwise. */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \ @@ -3392,7 +3398,8 @@ union bpf_attr { FN(ringbuf_submit), \ FN(ringbuf_discard), \ FN(ringbuf_query), \ - FN(csum_level), + FN(csum_level), \ + FN(skc_to_tcp6_sock), /* integer value in 'imm' field of BPF_CALL instruction selects which helper * function eBPF program intends to call |