bpf: Add flags arg to bpf_dynptr_read and bpf_dynptr_write APIs

Commit 13bbbfbea7 ("bpf: Add bpf_dynptr_read and bpf_dynptr_write")
added the bpf_dynptr_write() and bpf_dynptr_read() APIs.

However, it will be needed for some dynptr types to pass in flags as
well (e.g. when writing to a skb, the user may like to invalidate the
hash or recompute the checksum).

This patch adds a "u64 flags" arg to the bpf_dynptr_read() and
bpf_dynptr_write() APIs before their UAPI signature freezes where
we then cannot change them anymore with a 5.19.x released kernel.

Fixes: 13bbbfbea7 ("bpf: Add bpf_dynptr_read and bpf_dynptr_write")
Signed-off-by: Joanne Koong <joannelkoong@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/r/20220706232547.4016651-1-joannelkoong@gmail.com
This commit is contained in:
Joanne Koong
2022-07-06 16:25:47 -07:00
committed by Daniel Borkmann
parent 0326195f52
commit f8d3da4ef8
5 changed files with 29 additions and 19 deletions

View File

@@ -5222,22 +5222,25 @@ union bpf_attr {
* Return
* Nothing. Always succeeds.
*
* long bpf_dynptr_read(void *dst, u32 len, struct bpf_dynptr *src, u32 offset)
* long bpf_dynptr_read(void *dst, u32 len, struct bpf_dynptr *src, u32 offset, u64 flags)
* Description
* Read *len* bytes from *src* into *dst*, starting from *offset*
* into *src*.
* *flags* is currently unused.
* Return
* 0 on success, -E2BIG if *offset* + *len* exceeds the length
* of *src*'s data, -EINVAL if *src* is an invalid dynptr.
* of *src*'s data, -EINVAL if *src* is an invalid dynptr or if
* *flags* is not 0.
*
* long bpf_dynptr_write(struct bpf_dynptr *dst, u32 offset, void *src, u32 len)
* long bpf_dynptr_write(struct bpf_dynptr *dst, u32 offset, void *src, u32 len, u64 flags)
* Description
* Write *len* bytes from *src* into *dst*, starting from *offset*
* into *dst*.
* *flags* is currently unused.
* Return
* 0 on success, -E2BIG if *offset* + *len* exceeds the length
* of *dst*'s data, -EINVAL if *dst* is an invalid dynptr or if *dst*
* is a read-only dynptr.
* is a read-only dynptr or if *flags* is not 0.
*
* void *bpf_dynptr_data(struct bpf_dynptr *ptr, u32 offset, u32 len)
* Description