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| author | Alexei Starovoitov <ast@kernel.org> | 2022-03-20 18:59:00 -0700 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2022-03-20 18:59:00 -0700 |
| commit | 46e9244b2563cc53acc63b57f5eb2999fa729c60 (patch) | |
| tree | a68caed04866465d23d56a0ce32220741231745a /net | |
| parent | 30630e44b6580f17724b6c5921a2a540bf06d6af (diff) | |
| parent | ce5236800116d18ac2c06c58f73930406e3ea4be (diff) | |
Merge branch 'Make 2-byte access to bpf_sk_lookup->remote_port endian-agnostic'
Jakub Sitnicki says:
====================
This patch set is a result of a discussion we had around the RFC patchset from
Ilya [1]. The fix for the narrow loads from the RFC series is still relevant,
but this series does not depend on it. Nor is it required to unbreak sk_lookup
tests on BE, if this series gets applied.
To summarize the takeaways from [1]:
1) we want to make 2-byte load from ctx->remote_port portable across LE and BE,
2) we keep the 4-byte load from ctx->remote_port as it is today - result varies
on endianess of the platform.
[1] https://lore.kernel.org/bpf/20220222182559.2865596-2-iii@linux.ibm.com/
v1 -> v2:
- Remove needless check that 4-byte load is from &ctx->remote_port offset
(Martin)
[v1]: https://lore.kernel.org/bpf/20220317165826.1099418-1-jakub@cloudflare.com/
====================
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'net')
| -rw-r--r-- | net/core/filter.c | 20 |
1 files changed, 18 insertions, 2 deletions
diff --git a/net/core/filter.c b/net/core/filter.c index 03655f2074ae..a7044e98765e 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -10989,13 +10989,24 @@ static bool sk_lookup_is_valid_access(int off, int size, case bpf_ctx_range(struct bpf_sk_lookup, local_ip4): case bpf_ctx_range_till(struct bpf_sk_lookup, remote_ip6[0], remote_ip6[3]): case bpf_ctx_range_till(struct bpf_sk_lookup, local_ip6[0], local_ip6[3]): - case offsetof(struct bpf_sk_lookup, remote_port) ... - offsetof(struct bpf_sk_lookup, local_ip4) - 1: case bpf_ctx_range(struct bpf_sk_lookup, local_port): case bpf_ctx_range(struct bpf_sk_lookup, ingress_ifindex): bpf_ctx_record_field_size(info, sizeof(__u32)); return bpf_ctx_narrow_access_ok(off, size, sizeof(__u32)); + case bpf_ctx_range(struct bpf_sk_lookup, remote_port): + /* Allow 4-byte access to 2-byte field for backward compatibility */ + if (size == sizeof(__u32)) + return true; + bpf_ctx_record_field_size(info, sizeof(__be16)); + return bpf_ctx_narrow_access_ok(off, size, sizeof(__be16)); + + case offsetofend(struct bpf_sk_lookup, remote_port) ... + offsetof(struct bpf_sk_lookup, local_ip4) - 1: + /* Allow access to zero padding for backward compatibility */ + bpf_ctx_record_field_size(info, sizeof(__u16)); + return bpf_ctx_narrow_access_ok(off, size, sizeof(__u16)); + default: return false; } @@ -11077,6 +11088,11 @@ static u32 sk_lookup_convert_ctx_access(enum bpf_access_type type, sport, 2, target_size)); break; + case offsetofend(struct bpf_sk_lookup, remote_port): + *target_size = 2; + *insn++ = BPF_MOV32_IMM(si->dst_reg, 0); + break; + case offsetof(struct bpf_sk_lookup, local_port): *insn++ = BPF_LDX_MEM(BPF_H, si->dst_reg, si->src_reg, bpf_target_off(struct bpf_sk_lookup_kern, |