1 // SPDX-License-Identifier: GPL-2.0 2 #define KBUILD_MODNAME "foo" 3 #include <string.h> 4 #include <linux/in.h> 5 #include <linux/if_ether.h> 6 #include <linux/if_packet.h> 7 #include <linux/ip.h> 8 #include <linux/ipv6.h> 9 10 #include <linux/bpf.h> 11 #include <bpf/bpf_helpers.h> 12 #include <bpf/bpf_endian.h> 13 14 /* One map use devmap, another one use devmap_hash for testing */ 15 struct { 16 __uint(type, BPF_MAP_TYPE_DEVMAP); 17 __uint(key_size, sizeof(int)); 18 __uint(value_size, sizeof(int)); 19 __uint(max_entries, 1024); 20 } map_all SEC(".maps"); 21 22 struct { 23 __uint(type, BPF_MAP_TYPE_DEVMAP_HASH); 24 __uint(key_size, sizeof(int)); 25 __uint(value_size, sizeof(struct bpf_devmap_val)); 26 __uint(max_entries, 128); 27 } map_egress SEC(".maps"); 28 29 /* map to store egress interfaces mac addresses */ 30 struct { 31 __uint(type, BPF_MAP_TYPE_HASH); 32 __type(key, __u32); 33 __type(value, __be64); 34 __uint(max_entries, 128); 35 } mac_map SEC(".maps"); 36 37 /* map to store redirect flags for each protocol*/ 38 struct { 39 __uint(type, BPF_MAP_TYPE_HASH); 40 __type(key, __u16); 41 __type(value, __u64); 42 __uint(max_entries, 16); 43 } redirect_flags SEC(".maps"); 44 45 SEC("xdp") 46 int xdp_redirect_map_multi_prog(struct xdp_md *ctx) 47 { 48 void *data_end = (void *)(long)ctx->data_end; 49 void *data = (void *)(long)ctx->data; 50 int if_index = ctx->ingress_ifindex; 51 struct ethhdr *eth = data; 52 __u64 *flags_from_map; 53 __u16 h_proto; 54 __u64 nh_off; 55 __u64 flags; 56 57 nh_off = sizeof(*eth); 58 if (data + nh_off > data_end) 59 return XDP_DROP; 60 61 h_proto = bpf_htons(eth->h_proto); 62 63 flags_from_map = bpf_map_lookup_elem(&redirect_flags, &h_proto); 64 65 /* Default flags for IPv4 : (BPF_F_BROADCAST | BPF_F_EXCLUDE_INGRESS) */ 66 if (h_proto == ETH_P_IP) { 67 flags = flags_from_map ? *flags_from_map : BPF_F_BROADCAST | BPF_F_EXCLUDE_INGRESS; 68 return bpf_redirect_map(&map_all, 0, flags); 69 } 70 /* Default flags for IPv6 : 0 */ 71 if (h_proto == ETH_P_IPV6) { 72 flags = flags_from_map ? *flags_from_map : 0; 73 return bpf_redirect_map(&map_all, if_index, flags); 74 } 75 /* Default flags for others BPF_F_BROADCAST : 0 */ 76 else { 77 flags = flags_from_map ? *flags_from_map : BPF_F_BROADCAST; 78 return bpf_redirect_map(&map_all, 0, flags); 79 } 80 } 81 82 /* The following 2 progs are for 2nd devmap prog testing */ 83 SEC("xdp") 84 int xdp_redirect_map_all_prog(struct xdp_md *ctx) 85 { 86 return bpf_redirect_map(&map_egress, 0, 87 BPF_F_BROADCAST | BPF_F_EXCLUDE_INGRESS); 88 } 89 90 SEC("xdp/devmap") 91 int xdp_devmap_prog(struct xdp_md *ctx) 92 { 93 void *data_end = (void *)(long)ctx->data_end; 94 void *data = (void *)(long)ctx->data; 95 __u32 key = ctx->egress_ifindex; 96 struct ethhdr *eth = data; 97 __u64 nh_off; 98 __be64 *mac; 99 100 nh_off = sizeof(*eth); 101 if (data + nh_off > data_end) 102 return XDP_DROP; 103 104 mac = bpf_map_lookup_elem(&mac_map, &key); 105 if (mac) 106 __builtin_memcpy(eth->h_source, mac, ETH_ALEN); 107 108 return XDP_PASS; 109 } 110 111 char _license[] SEC("license") = "GPL"; 112