diff options
author | Daniel Borkmann <daniel@iogearbox.net> | 2020-09-30 17:18:20 +0200 |
---|---|---|
committer | Alexei Starovoitov <ast@kernel.org> | 2020-09-30 11:50:35 -0700 |
commit | eef4a011f35d3aa657d4995c53ccb240d9eaea73 (patch) | |
tree | 3115443403643360337a3687c68186f44dda004a /tools/testing/selftests/bpf/progs | |
parent | faef26fa444dc44eeff70c9a63ebe7fef00b6c37 (diff) |
bpf, selftests: Add redirect_neigh selftest
Add a small test that exercises the new redirect_neigh() helper for the
IPv4 and IPv6 case.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/0fc7d9c5f9a6cc1c65b0d3be83b44b1ec9889f43.1601477936.git.daniel@iogearbox.net
Diffstat (limited to 'tools/testing/selftests/bpf/progs')
-rw-r--r-- | tools/testing/selftests/bpf/progs/test_tc_neigh.c | 144 |
1 files changed, 144 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/progs/test_tc_neigh.c b/tools/testing/selftests/bpf/progs/test_tc_neigh.c new file mode 100644 index 000000000000..889a72c3024f --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_tc_neigh.c @@ -0,0 +1,144 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <stdint.h> +#include <stdbool.h> + +#include <linux/bpf.h> +#include <linux/stddef.h> +#include <linux/pkt_cls.h> +#include <linux/if_ether.h> +#include <linux/in.h> +#include <linux/ip.h> +#include <linux/ipv6.h> + +#include <bpf/bpf_helpers.h> +#include <bpf/bpf_endian.h> + +#ifndef barrier_data +# define barrier_data(ptr) asm volatile("": :"r"(ptr) :"memory") +#endif + +#ifndef ctx_ptr +# define ctx_ptr(field) (void *)(long)(field) +#endif + +#define dst_to_src_tmp 0xeeddddeeU +#define src_to_dst_tmp 0xeeffffeeU + +#define ip4_src 0xac100164 /* 172.16.1.100 */ +#define ip4_dst 0xac100264 /* 172.16.2.100 */ + +#define ip6_src { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, \ + 0x00, 0x01, 0xde, 0xad, 0xbe, 0xef, 0xca, 0xfe } +#define ip6_dst { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, \ + 0x00, 0x02, 0xde, 0xad, 0xbe, 0xef, 0xca, 0xfe } + +#ifndef v6_equal +# define v6_equal(a, b) (a.s6_addr32[0] == b.s6_addr32[0] && \ + a.s6_addr32[1] == b.s6_addr32[1] && \ + a.s6_addr32[2] == b.s6_addr32[2] && \ + a.s6_addr32[3] == b.s6_addr32[3]) +#endif + +static __always_inline bool is_remote_ep_v4(struct __sk_buff *skb, + __be32 addr) +{ + void *data_end = ctx_ptr(skb->data_end); + void *data = ctx_ptr(skb->data); + struct iphdr *ip4h; + + if (data + sizeof(struct ethhdr) > data_end) + return false; + + ip4h = (struct iphdr *)(data + sizeof(struct ethhdr)); + if ((void *)(ip4h + 1) > data_end) + return false; + + return ip4h->daddr == addr; +} + +static __always_inline bool is_remote_ep_v6(struct __sk_buff *skb, + struct in6_addr addr) +{ + void *data_end = ctx_ptr(skb->data_end); + void *data = ctx_ptr(skb->data); + struct ipv6hdr *ip6h; + + if (data + sizeof(struct ethhdr) > data_end) + return false; + + ip6h = (struct ipv6hdr *)(data + sizeof(struct ethhdr)); + if ((void *)(ip6h + 1) > data_end) + return false; + + return v6_equal(ip6h->daddr, addr); +} + +SEC("chk_neigh") int tc_chk(struct __sk_buff *skb) +{ + void *data_end = ctx_ptr(skb->data_end); + void *data = ctx_ptr(skb->data); + __u32 *raw = data; + + if (data + sizeof(struct ethhdr) > data_end) + return TC_ACT_SHOT; + + return !raw[0] && !raw[1] && !raw[2] ? TC_ACT_SHOT : TC_ACT_OK; +} + +SEC("dst_ingress") int tc_dst(struct __sk_buff *skb) +{ + int idx = dst_to_src_tmp; + __u8 zero[ETH_ALEN * 2]; + bool redirect = false; + + switch (skb->protocol) { + case __bpf_constant_htons(ETH_P_IP): + redirect = is_remote_ep_v4(skb, __bpf_constant_htonl(ip4_src)); + break; + case __bpf_constant_htons(ETH_P_IPV6): + redirect = is_remote_ep_v6(skb, (struct in6_addr)ip6_src); + break; + } + + if (!redirect) + return TC_ACT_OK; + + barrier_data(&idx); + idx = bpf_ntohl(idx); + + __builtin_memset(&zero, 0, sizeof(zero)); + if (bpf_skb_store_bytes(skb, 0, &zero, sizeof(zero), 0) < 0) + return TC_ACT_SHOT; + + return bpf_redirect_neigh(idx, 0); +} + +SEC("src_ingress") int tc_src(struct __sk_buff *skb) +{ + int idx = src_to_dst_tmp; + __u8 zero[ETH_ALEN * 2]; + bool redirect = false; + + switch (skb->protocol) { + case __bpf_constant_htons(ETH_P_IP): + redirect = is_remote_ep_v4(skb, __bpf_constant_htonl(ip4_dst)); + break; + case __bpf_constant_htons(ETH_P_IPV6): + redirect = is_remote_ep_v6(skb, (struct in6_addr)ip6_dst); + break; + } + + if (!redirect) + return TC_ACT_OK; + + barrier_data(&idx); + idx = bpf_ntohl(idx); + + __builtin_memset(&zero, 0, sizeof(zero)); + if (bpf_skb_store_bytes(skb, 0, &zero, sizeof(zero), 0) < 0) + return TC_ACT_SHOT; + + return bpf_redirect_neigh(idx, 0); +} + +char __license[] SEC("license") = "GPL"; |