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| author | Jakub Sitnicki <jakub@cloudflare.com> | 2022-01-30 14:55:18 +0300 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2022-01-31 23:39:12 +0300 |
| commit | 8f50f16ff39dd4e2d43d1548ca66925652f8aff7 (patch) | |
| tree | 7dd90826ccc6a7f26688e8f790140ff96e6b43ea /tools/testing/selftests/bpf/progs/test_sock_fields.c | |
| parent | 4421a582718ab81608d8486734c18083b822390d (diff) | |
| download | linux-8f50f16ff39dd4e2d43d1548ca66925652f8aff7.tar.xz | |
selftests/bpf: Extend verifier and bpf_sock tests for dst_port loads
Add coverage to the verifier tests and tests for reading bpf_sock fields to
ensure that 32-bit, 16-bit, and 8-bit loads from dst_port field are allowed
only at intended offsets and produce expected values.
While 16-bit and 8-bit access to dst_port field is straight-forward, 32-bit
wide loads need be allowed and produce a zero-padded 16-bit value for
backward compatibility.
Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>
Link: https://lore.kernel.org/r/20220130115518.213259-3-jakub@cloudflare.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'tools/testing/selftests/bpf/progs/test_sock_fields.c')
| -rw-r--r-- | tools/testing/selftests/bpf/progs/test_sock_fields.c | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/progs/test_sock_fields.c b/tools/testing/selftests/bpf/progs/test_sock_fields.c index 81b57b9aaaea..246f1f001813 100644 --- a/tools/testing/selftests/bpf/progs/test_sock_fields.c +++ b/tools/testing/selftests/bpf/progs/test_sock_fields.c @@ -12,6 +12,7 @@ enum bpf_linum_array_idx { EGRESS_LINUM_IDX, INGRESS_LINUM_IDX, + READ_SK_DST_PORT_LINUM_IDX, __NR_BPF_LINUM_ARRAY_IDX, }; @@ -250,4 +251,44 @@ int ingress_read_sock_fields(struct __sk_buff *skb) return CG_OK; } +static __noinline bool sk_dst_port__load_word(struct bpf_sock *sk) +{ + __u32 *word = (__u32 *)&sk->dst_port; + return word[0] == bpf_htonl(0xcafe0000); +} + +static __noinline bool sk_dst_port__load_half(struct bpf_sock *sk) +{ + __u16 *half = (__u16 *)&sk->dst_port; + return half[0] == bpf_htons(0xcafe); +} + +static __noinline bool sk_dst_port__load_byte(struct bpf_sock *sk) +{ + __u8 *byte = (__u8 *)&sk->dst_port; + return byte[0] == 0xca && byte[1] == 0xfe; +} + +SEC("cgroup_skb/egress") +int read_sk_dst_port(struct __sk_buff *skb) +{ + __u32 linum, linum_idx; + struct bpf_sock *sk; + + linum_idx = READ_SK_DST_PORT_LINUM_IDX; + + sk = skb->sk; + if (!sk) + RET_LOG(); + + if (!sk_dst_port__load_word(sk)) + RET_LOG(); + if (!sk_dst_port__load_half(sk)) + RET_LOG(); + if (!sk_dst_port__load_byte(sk)) + RET_LOG(); + + return CG_OK; +} + char _license[] SEC("license") = "GPL"; |