From 6458bde368cee77e798d05cccd2316db4d748c41 Mon Sep 17 00:00:00 2001 From: Ilya Leoshkevich Date: Tue, 29 Sep 2020 22:18:14 +0200 Subject: [PATCH] selftests/bpf: Fix endianness issues in sk_lookup/ctx_narrow_access This test makes a lot of narrow load checks while assuming little endian architecture, and therefore fails on s390. Fix by introducing LSB and LSW macros and using them to perform narrow loads. Fixes: 0ab5539f8584 ("selftests/bpf: Tests for BPF_SK_LOOKUP attach point") Signed-off-by: Ilya Leoshkevich Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20200929201814.44360-1-iii@linux.ibm.com --- tools/testing/selftests/bpf/progs/test_sk_lookup.c | 216 ++++++++++----------- 1 file changed, 101 insertions(+), 115 deletions(-) diff --git a/tools/testing/selftests/bpf/progs/test_sk_lookup.c b/tools/testing/selftests/bpf/progs/test_sk_lookup.c index bbf8296..1032b29 100644 --- a/tools/testing/selftests/bpf/progs/test_sk_lookup.c +++ b/tools/testing/selftests/bpf/progs/test_sk_lookup.c @@ -19,6 +19,17 @@ #define IP6(aaaa, bbbb, cccc, dddd) \ { bpf_htonl(aaaa), bpf_htonl(bbbb), bpf_htonl(cccc), bpf_htonl(dddd) } +/* Macros for least-significant byte and word accesses. */ +#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__ +#define LSE_INDEX(index, size) (index) +#else +#define LSE_INDEX(index, size) ((size) - (index) - 1) +#endif +#define LSB(value, index) \ + (((__u8 *)&(value))[LSE_INDEX((index), sizeof(value))]) +#define LSW(value, index) \ + (((__u16 *)&(value))[LSE_INDEX((index), sizeof(value) / 2)]) + #define MAX_SOCKS 32 struct { @@ -369,171 +380,146 @@ int ctx_narrow_access(struct bpf_sk_lookup *ctx) { struct bpf_sock *sk; int err, family; - __u16 *half; - __u8 *byte; bool v4; v4 = (ctx->family == AF_INET); /* Narrow loads from family field */ - byte = (__u8 *)&ctx->family; - half = (__u16 *)&ctx->family; - if (byte[0] != (v4 ? AF_INET : AF_INET6) || - byte[1] != 0 || byte[2] != 0 || byte[3] != 0) + if (LSB(ctx->family, 0) != (v4 ? AF_INET : AF_INET6) || + LSB(ctx->family, 1) != 0 || LSB(ctx->family, 2) != 0 || LSB(ctx->family, 3) != 0) return SK_DROP; - if (half[0] != (v4 ? AF_INET : AF_INET6)) + if (LSW(ctx->family, 0) != (v4 ? AF_INET : AF_INET6)) return SK_DROP; - byte = (__u8 *)&ctx->protocol; - if (byte[0] != IPPROTO_TCP || - byte[1] != 0 || byte[2] != 0 || byte[3] != 0) + /* Narrow loads from protocol field */ + if (LSB(ctx->protocol, 0) != IPPROTO_TCP || + LSB(ctx->protocol, 1) != 0 || LSB(ctx->protocol, 2) != 0 || LSB(ctx->protocol, 3) != 0) return SK_DROP; - half = (__u16 *)&ctx->protocol; - if (half[0] != IPPROTO_TCP) + if (LSW(ctx->protocol, 0) != IPPROTO_TCP) return SK_DROP; /* Narrow loads from remote_port field. Expect non-0 value. */ - byte = (__u8 *)&ctx->remote_port; - if (byte[0] == 0 && byte[1] == 0 && byte[2] == 0 && byte[3] == 0) + if (LSB(ctx->remote_port, 0) == 0 && LSB(ctx->remote_port, 1) == 0 && + LSB(ctx->remote_port, 2) == 0 && LSB(ctx->remote_port, 3) == 0) return SK_DROP; - half = (__u16 *)&ctx->remote_port; - if (half[0] == 0) + if (LSW(ctx->remote_port, 0) == 0) return SK_DROP; /* Narrow loads from local_port field. Expect DST_PORT. */ - byte = (__u8 *)&ctx->local_port; - if (byte[0] != ((DST_PORT >> 0) & 0xff) || - byte[1] != ((DST_PORT >> 8) & 0xff) || - byte[2] != 0 || byte[3] != 0) + if (LSB(ctx->local_port, 0) != ((DST_PORT >> 0) & 0xff) || + LSB(ctx->local_port, 1) != ((DST_PORT >> 8) & 0xff) || + LSB(ctx->local_port, 2) != 0 || LSB(ctx->local_port, 3) != 0) return SK_DROP; - half = (__u16 *)&ctx->local_port; - if (half[0] != DST_PORT) + if (LSW(ctx->local_port, 0) != DST_PORT) return SK_DROP; /* Narrow loads from IPv4 fields */ if (v4) { /* Expect non-0.0.0.0 in remote_ip4 */ - byte = (__u8 *)&ctx->remote_ip4; - if (byte[0] == 0 && byte[1] == 0 && - byte[2] == 0 && byte[3] == 0) + if (LSB(ctx->remote_ip4, 0) == 0 && LSB(ctx->remote_ip4, 1) == 0 && + LSB(ctx->remote_ip4, 2) == 0 && LSB(ctx->remote_ip4, 3) == 0) return SK_DROP; - half = (__u16 *)&ctx->remote_ip4; - if (half[0] == 0 && half[1] == 0) + if (LSW(ctx->remote_ip4, 0) == 0 && LSW(ctx->remote_ip4, 1) == 0) return SK_DROP; /* Expect DST_IP4 in local_ip4 */ - byte = (__u8 *)&ctx->local_ip4; - if (byte[0] != ((DST_IP4 >> 0) & 0xff) || - byte[1] != ((DST_IP4 >> 8) & 0xff) || - byte[2] != ((DST_IP4 >> 16) & 0xff) || - byte[3] != ((DST_IP4 >> 24) & 0xff)) + if (LSB(ctx->local_ip4, 0) != ((DST_IP4 >> 0) & 0xff) || + LSB(ctx->local_ip4, 1) != ((DST_IP4 >> 8) & 0xff) || + LSB(ctx->local_ip4, 2) != ((DST_IP4 >> 16) & 0xff) || + LSB(ctx->local_ip4, 3) != ((DST_IP4 >> 24) & 0xff)) return SK_DROP; - half = (__u16 *)&ctx->local_ip4; - if (half[0] != ((DST_IP4 >> 0) & 0xffff) || - half[1] != ((DST_IP4 >> 16) & 0xffff)) + if (LSW(ctx->local_ip4, 0) != ((DST_IP4 >> 0) & 0xffff) || + LSW(ctx->local_ip4, 1) != ((DST_IP4 >> 16) & 0xffff)) return SK_DROP; } else { /* Expect 0.0.0.0 IPs when family != AF_INET */ - byte = (__u8 *)&ctx->remote_ip4; - if (byte[0] != 0 || byte[1] != 0 && - byte[2] != 0 || byte[3] != 0) + if (LSB(ctx->remote_ip4, 0) != 0 || LSB(ctx->remote_ip4, 1) != 0 || + LSB(ctx->remote_ip4, 2) != 0 || LSB(ctx->remote_ip4, 3) != 0) return SK_DROP; - half = (__u16 *)&ctx->remote_ip4; - if (half[0] != 0 || half[1] != 0) + if (LSW(ctx->remote_ip4, 0) != 0 || LSW(ctx->remote_ip4, 1) != 0) return SK_DROP; - byte = (__u8 *)&ctx->local_ip4; - if (byte[0] != 0 || byte[1] != 0 && - byte[2] != 0 || byte[3] != 0) + if (LSB(ctx->local_ip4, 0) != 0 || LSB(ctx->local_ip4, 1) != 0 || + LSB(ctx->local_ip4, 2) != 0 || LSB(ctx->local_ip4, 3) != 0) return SK_DROP; - half = (__u16 *)&ctx->local_ip4; - if (half[0] != 0 || half[1] != 0) + if (LSW(ctx->local_ip4, 0) != 0 || LSW(ctx->local_ip4, 1) != 0) return SK_DROP; } /* Narrow loads from IPv6 fields */ if (!v4) { - /* Expenct non-:: IP in remote_ip6 */ - byte = (__u8 *)&ctx->remote_ip6; - if (byte[0] == 0 && byte[1] == 0 && - byte[2] == 0 && byte[3] == 0 && - byte[4] == 0 && byte[5] == 0 && - byte[6] == 0 && byte[7] == 0 && - byte[8] == 0 && byte[9] == 0 && - byte[10] == 0 && byte[11] == 0 && - byte[12] == 0 && byte[13] == 0 && - byte[14] == 0 && byte[15] == 0) + /* Expect non-:: IP in remote_ip6 */ + if (LSB(ctx->remote_ip6[0], 0) == 0 && LSB(ctx->remote_ip6[0], 1) == 0 && + LSB(ctx->remote_ip6[0], 2) == 0 && LSB(ctx->remote_ip6[0], 3) == 0 && + LSB(ctx->remote_ip6[1], 0) == 0 && LSB(ctx->remote_ip6[1], 1) == 0 && + LSB(ctx->remote_ip6[1], 2) == 0 && LSB(ctx->remote_ip6[1], 3) == 0 && + LSB(ctx->remote_ip6[2], 0) == 0 && LSB(ctx->remote_ip6[2], 1) == 0 && + LSB(ctx->remote_ip6[2], 2) == 0 && LSB(ctx->remote_ip6[2], 3) == 0 && + LSB(ctx->remote_ip6[3], 0) == 0 && LSB(ctx->remote_ip6[3], 1) == 0 && + LSB(ctx->remote_ip6[3], 2) == 0 && LSB(ctx->remote_ip6[3], 3) == 0) return SK_DROP; - half = (__u16 *)&ctx->remote_ip6; - if (half[0] == 0 && half[1] == 0 && - half[2] == 0 && half[3] == 0 && - half[4] == 0 && half[5] == 0 && - half[6] == 0 && half[7] == 0) + if (LSW(ctx->remote_ip6[0], 0) == 0 && LSW(ctx->remote_ip6[0], 1) == 0 && + LSW(ctx->remote_ip6[1], 0) == 0 && LSW(ctx->remote_ip6[1], 1) == 0 && + LSW(ctx->remote_ip6[2], 0) == 0 && LSW(ctx->remote_ip6[2], 1) == 0 && + LSW(ctx->remote_ip6[3], 0) == 0 && LSW(ctx->remote_ip6[3], 1) == 0) return SK_DROP; - /* Expect DST_IP6 in local_ip6 */ - byte = (__u8 *)&ctx->local_ip6; - if (byte[0] != ((DST_IP6[0] >> 0) & 0xff) || - byte[1] != ((DST_IP6[0] >> 8) & 0xff) || - byte[2] != ((DST_IP6[0] >> 16) & 0xff) || - byte[3] != ((DST_IP6[0] >> 24) & 0xff) || - byte[4] != ((DST_IP6[1] >> 0) & 0xff) || - byte[5] != ((DST_IP6[1] >> 8) & 0xff) || - byte[6] != ((DST_IP6[1] >> 16) & 0xff) || - byte[7] != ((DST_IP6[1] >> 24) & 0xff) || - byte[8] != ((DST_IP6[2] >> 0) & 0xff) || - byte[9] != ((DST_IP6[2] >> 8) & 0xff) || - byte[10] != ((DST_IP6[2] >> 16) & 0xff) || - byte[11] != ((DST_IP6[2] >> 24) & 0xff) || - byte[12] != ((DST_IP6[3] >> 0) & 0xff) || - byte[13] != ((DST_IP6[3] >> 8) & 0xff) || - byte[14] != ((DST_IP6[3] >> 16) & 0xff) || - byte[15] != ((DST_IP6[3] >> 24) & 0xff)) + if (LSB(ctx->local_ip6[0], 0) != ((DST_IP6[0] >> 0) & 0xff) || + LSB(ctx->local_ip6[0], 1) != ((DST_IP6[0] >> 8) & 0xff) || + LSB(ctx->local_ip6[0], 2) != ((DST_IP6[0] >> 16) & 0xff) || + LSB(ctx->local_ip6[0], 3) != ((DST_IP6[0] >> 24) & 0xff) || + LSB(ctx->local_ip6[1], 0) != ((DST_IP6[1] >> 0) & 0xff) || + LSB(ctx->local_ip6[1], 1) != ((DST_IP6[1] >> 8) & 0xff) || + LSB(ctx->local_ip6[1], 2) != ((DST_IP6[1] >> 16) & 0xff) || + LSB(ctx->local_ip6[1], 3) != ((DST_IP6[1] >> 24) & 0xff) || + LSB(ctx->local_ip6[2], 0) != ((DST_IP6[2] >> 0) & 0xff) || + LSB(ctx->local_ip6[2], 1) != ((DST_IP6[2] >> 8) & 0xff) || + LSB(ctx->local_ip6[2], 2) != ((DST_IP6[2] >> 16) & 0xff) || + LSB(ctx->local_ip6[2], 3) != ((DST_IP6[2] >> 24) & 0xff) || + LSB(ctx->local_ip6[3], 0) != ((DST_IP6[3] >> 0) & 0xff) || + LSB(ctx->local_ip6[3], 1) != ((DST_IP6[3] >> 8) & 0xff) || + LSB(ctx->local_ip6[3], 2) != ((DST_IP6[3] >> 16) & 0xff) || + LSB(ctx->local_ip6[3], 3) != ((DST_IP6[3] >> 24) & 0xff)) return SK_DROP; - half = (__u16 *)&ctx->local_ip6; - if (half[0] != ((DST_IP6[0] >> 0) & 0xffff) || - half[1] != ((DST_IP6[0] >> 16) & 0xffff) || - half[2] != ((DST_IP6[1] >> 0) & 0xffff) || - half[3] != ((DST_IP6[1] >> 16) & 0xffff) || - half[4] != ((DST_IP6[2] >> 0) & 0xffff) || - half[5] != ((DST_IP6[2] >> 16) & 0xffff) || - half[6] != ((DST_IP6[3] >> 0) & 0xffff) || - half[7] != ((DST_IP6[3] >> 16) & 0xffff)) + if (LSW(ctx->local_ip6[0], 0) != ((DST_IP6[0] >> 0) & 0xffff) || + LSW(ctx->local_ip6[0], 1) != ((DST_IP6[0] >> 16) & 0xffff) || + LSW(ctx->local_ip6[1], 0) != ((DST_IP6[1] >> 0) & 0xffff) || + LSW(ctx->local_ip6[1], 1) != ((DST_IP6[1] >> 16) & 0xffff) || + LSW(ctx->local_ip6[2], 0) != ((DST_IP6[2] >> 0) & 0xffff) || + LSW(ctx->local_ip6[2], 1) != ((DST_IP6[2] >> 16) & 0xffff) || + LSW(ctx->local_ip6[3], 0) != ((DST_IP6[3] >> 0) & 0xffff) || + LSW(ctx->local_ip6[3], 1) != ((DST_IP6[3] >> 16) & 0xffff)) return SK_DROP; } else { /* Expect :: IPs when family != AF_INET6 */ - byte = (__u8 *)&ctx->remote_ip6; - if (byte[0] != 0 || byte[1] != 0 || - byte[2] != 0 || byte[3] != 0 || - byte[4] != 0 || byte[5] != 0 || - byte[6] != 0 || byte[7] != 0 || - byte[8] != 0 || byte[9] != 0 || - byte[10] != 0 || byte[11] != 0 || - byte[12] != 0 || byte[13] != 0 || - byte[14] != 0 || byte[15] != 0) + if (LSB(ctx->remote_ip6[0], 0) != 0 || LSB(ctx->remote_ip6[0], 1) != 0 || + LSB(ctx->remote_ip6[0], 2) != 0 || LSB(ctx->remote_ip6[0], 3) != 0 || + LSB(ctx->remote_ip6[1], 0) != 0 || LSB(ctx->remote_ip6[1], 1) != 0 || + LSB(ctx->remote_ip6[1], 2) != 0 || LSB(ctx->remote_ip6[1], 3) != 0 || + LSB(ctx->remote_ip6[2], 0) != 0 || LSB(ctx->remote_ip6[2], 1) != 0 || + LSB(ctx->remote_ip6[2], 2) != 0 || LSB(ctx->remote_ip6[2], 3) != 0 || + LSB(ctx->remote_ip6[3], 0) != 0 || LSB(ctx->remote_ip6[3], 1) != 0 || + LSB(ctx->remote_ip6[3], 2) != 0 || LSB(ctx->remote_ip6[3], 3) != 0) return SK_DROP; - half = (__u16 *)&ctx->remote_ip6; - if (half[0] != 0 || half[1] != 0 || - half[2] != 0 || half[3] != 0 || - half[4] != 0 || half[5] != 0 || - half[6] != 0 || half[7] != 0) + if (LSW(ctx->remote_ip6[0], 0) != 0 || LSW(ctx->remote_ip6[0], 1) != 0 || + LSW(ctx->remote_ip6[1], 0) != 0 || LSW(ctx->remote_ip6[1], 1) != 0 || + LSW(ctx->remote_ip6[2], 0) != 0 || LSW(ctx->remote_ip6[2], 1) != 0 || + LSW(ctx->remote_ip6[3], 0) != 0 || LSW(ctx->remote_ip6[3], 1) != 0) return SK_DROP; - byte = (__u8 *)&ctx->local_ip6; - if (byte[0] != 0 || byte[1] != 0 || - byte[2] != 0 || byte[3] != 0 || - byte[4] != 0 || byte[5] != 0 || - byte[6] != 0 || byte[7] != 0 || - byte[8] != 0 || byte[9] != 0 || - byte[10] != 0 || byte[11] != 0 || - byte[12] != 0 || byte[13] != 0 || - byte[14] != 0 || byte[15] != 0) + if (LSB(ctx->local_ip6[0], 0) != 0 || LSB(ctx->local_ip6[0], 1) != 0 || + LSB(ctx->local_ip6[0], 2) != 0 || LSB(ctx->local_ip6[0], 3) != 0 || + LSB(ctx->local_ip6[1], 0) != 0 || LSB(ctx->local_ip6[1], 1) != 0 || + LSB(ctx->local_ip6[1], 2) != 0 || LSB(ctx->local_ip6[1], 3) != 0 || + LSB(ctx->local_ip6[2], 0) != 0 || LSB(ctx->local_ip6[2], 1) != 0 || + LSB(ctx->local_ip6[2], 2) != 0 || LSB(ctx->local_ip6[2], 3) != 0 || + LSB(ctx->local_ip6[3], 0) != 0 || LSB(ctx->local_ip6[3], 1) != 0 || + LSB(ctx->local_ip6[3], 2) != 0 || LSB(ctx->local_ip6[3], 3) != 0) return SK_DROP; - half = (__u16 *)&ctx->local_ip6; - if (half[0] != 0 || half[1] != 0 || - half[2] != 0 || half[3] != 0 || - half[4] != 0 || half[5] != 0 || - half[6] != 0 || half[7] != 0) + if (LSW(ctx->remote_ip6[0], 0) != 0 || LSW(ctx->remote_ip6[0], 1) != 0 || + LSW(ctx->remote_ip6[1], 0) != 0 || LSW(ctx->remote_ip6[1], 1) != 0 || + LSW(ctx->remote_ip6[2], 0) != 0 || LSW(ctx->remote_ip6[2], 1) != 0 || + LSW(ctx->remote_ip6[3], 0) != 0 || LSW(ctx->remote_ip6[3], 1) != 0) return SK_DROP; } -- 2.7.4