diff options
Diffstat (limited to '')
| -rw-r--r-- | tools/testing/selftests/bpf/progs/test_tc_neigh_fib.c | 158 |
1 files changed, 158 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/progs/test_tc_neigh_fib.c b/tools/testing/selftests/bpf/progs/test_tc_neigh_fib.c new file mode 100644 index 000000000000..ec4cce19362d --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_tc_neigh_fib.c @@ -0,0 +1,158 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <stdint.h> +#include <stdbool.h> +#include <stddef.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 ctx_ptr +# define ctx_ptr(field) (void *)(long)(field) +#endif + +#define AF_INET 2 +#define AF_INET6 10 + +static __always_inline int fill_fib_params_v4(struct __sk_buff *skb, + struct bpf_fib_lookup *fib_params) +{ + 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 -1; + + ip4h = (struct iphdr *)(data + sizeof(struct ethhdr)); + if ((void *)(ip4h + 1) > data_end) + return -1; + + fib_params->family = AF_INET; + fib_params->tos = ip4h->tos; + fib_params->l4_protocol = ip4h->protocol; + fib_params->sport = 0; + fib_params->dport = 0; + fib_params->tot_len = bpf_ntohs(ip4h->tot_len); + fib_params->ipv4_src = ip4h->saddr; + fib_params->ipv4_dst = ip4h->daddr; + + return 0; +} + +static __always_inline int fill_fib_params_v6(struct __sk_buff *skb, + struct bpf_fib_lookup *fib_params) +{ + struct in6_addr *src = (struct in6_addr *)fib_params->ipv6_src; + struct in6_addr *dst = (struct in6_addr *)fib_params->ipv6_dst; + 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 -1; + + ip6h = (struct ipv6hdr *)(data + sizeof(struct ethhdr)); + if ((void *)(ip6h + 1) > data_end) + return -1; + + fib_params->family = AF_INET6; + fib_params->flowinfo = 0; + fib_params->l4_protocol = ip6h->nexthdr; + fib_params->sport = 0; + fib_params->dport = 0; + fib_params->tot_len = bpf_ntohs(ip6h->payload_len); + *src = ip6h->saddr; + *dst = ip6h->daddr; + + return 0; +} + +SEC("tc") +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; +} + +static __always_inline int tc_redir(struct __sk_buff *skb) +{ + struct bpf_fib_lookup fib_params = { .ifindex = skb->ingress_ifindex }; + __u8 zero[ETH_ALEN * 2]; + int ret = -1; + + switch (skb->protocol) { + case __bpf_constant_htons(ETH_P_IP): + ret = fill_fib_params_v4(skb, &fib_params); + break; + case __bpf_constant_htons(ETH_P_IPV6): + ret = fill_fib_params_v6(skb, &fib_params); + break; + } + + if (ret) + return TC_ACT_OK; + + ret = bpf_fib_lookup(skb, &fib_params, sizeof(fib_params), 0); + if (ret == BPF_FIB_LKUP_RET_NOT_FWDED || ret < 0) + return TC_ACT_OK; + + __builtin_memset(&zero, 0, sizeof(zero)); + if (bpf_skb_store_bytes(skb, 0, &zero, sizeof(zero), 0) < 0) + return TC_ACT_SHOT; + + if (ret == BPF_FIB_LKUP_RET_NO_NEIGH) { + struct bpf_redir_neigh nh_params = {}; + + nh_params.nh_family = fib_params.family; + __builtin_memcpy(&nh_params.ipv6_nh, &fib_params.ipv6_dst, + sizeof(nh_params.ipv6_nh)); + + return bpf_redirect_neigh(fib_params.ifindex, &nh_params, + sizeof(nh_params), 0); + + } else if (ret == BPF_FIB_LKUP_RET_SUCCESS) { + void *data_end = ctx_ptr(skb->data_end); + struct ethhdr *eth = ctx_ptr(skb->data); + + if (eth + 1 > data_end) + return TC_ACT_SHOT; + + __builtin_memcpy(eth->h_dest, fib_params.dmac, ETH_ALEN); + __builtin_memcpy(eth->h_source, fib_params.smac, ETH_ALEN); + + return bpf_redirect(fib_params.ifindex, 0); + } + + return TC_ACT_SHOT; +} + +/* these are identical, but keep them separate for compatibility with the + * section names expected by test_tc_redirect.sh + */ +SEC("tc") +int tc_dst(struct __sk_buff *skb) +{ + return tc_redir(skb); +} + +SEC("tc") +int tc_src(struct __sk_buff *skb) +{ + return tc_redir(skb); +} + +char __license[] SEC("license") = "GPL"; |