diff options
author | Lawrence Brakmo <brakmo@fb.com> | 2018-01-26 03:14:08 +0300 |
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committer | Alexei Starovoitov <ast@kernel.org> | 2018-01-26 03:41:14 +0300 |
commit | b73042b8a28e2603ac178295ab96c876ba5a97a1 (patch) | |
tree | c3db00b9c7a9b9816bb3392f9fa59f7d8b4a5e49 /include/linux/filter.h | |
parent | 34d367c59233464dbd1f07445c4665099a7128ec (diff) | |
download | linux-b73042b8a28e2603ac178295ab96c876ba5a97a1.tar.xz |
bpf: Add write access to tcp_sock and sock fields
This patch adds a macro, SOCK_OPS_SET_FIELD, for writing to
struct tcp_sock or struct sock fields. This required adding a new
field "temp" to struct bpf_sock_ops_kern for temporary storage that
is used by sock_ops_convert_ctx_access. It is used to store and recover
the contents of a register, so the register can be used to store the
address of the sk. Since we cannot overwrite the dst_reg because it
contains the pointer to ctx, nor the src_reg since it contains the value
we want to store, we need an extra register to contain the address
of the sk.
Also adds the macro SOCK_OPS_GET_OR_SET_FIELD that calls one of the
GET or SET macros depending on the value of the TYPE field.
Signed-off-by: Lawrence Brakmo <brakmo@fb.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'include/linux/filter.h')
-rw-r--r-- | include/linux/filter.h | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/include/linux/filter.h b/include/linux/filter.h index 425056c7f96c..daa5a676335f 100644 --- a/include/linux/filter.h +++ b/include/linux/filter.h @@ -1007,6 +1007,15 @@ struct bpf_sock_ops_kern { u32 replylong[4]; }; u32 is_fullsock; + u64 temp; /* temp and everything after is not + * initialized to 0 before calling + * the BPF program. New fields that + * should be initialized to 0 should + * be inserted before temp. + * temp is scratch storage used by + * sock_ops_convert_ctx_access + * as temporary storage of a register. + */ }; #endif /* __LINUX_FILTER_H__ */ |