1 // SPDX-License-Identifier: GPL-2.0 2 /* Copyright (c) 2021 Facebook */ 3 #include "vmlinux.h" 4 5 #include <bpf/bpf_helpers.h> 6 #include <bpf/bpf_tracing.h> 7 #include <bpf/bpf_core_read.h> 8 9 #define ATTR __always_inline 10 #include "test_jhash.h" 11 12 struct { 13 __uint(type, BPF_MAP_TYPE_ARRAY); 14 __type(key, u32); 15 __type(value, u32); 16 __uint(max_entries, 256); 17 } array1 SEC(".maps"); 18 19 struct { 20 __uint(type, BPF_MAP_TYPE_ARRAY); 21 __type(key, u32); 22 __type(value, u32); 23 __uint(max_entries, 256); 24 } array2 SEC(".maps"); 25 26 static __noinline int randmap(int v, const struct net_device *dev) 27 { 28 struct bpf_map *map = (struct bpf_map *)&array1; 29 int key = bpf_get_prandom_u32() & 0xff; 30 int *val; 31 32 if (bpf_get_prandom_u32() & 1) 33 map = (struct bpf_map *)&array2; 34 35 val = bpf_map_lookup_elem(map, &key); 36 if (val) 37 *val = bpf_get_prandom_u32() + v + dev->mtu; 38 39 return 0; 40 } 41 42 SEC("tp_btf/xdp_devmap_xmit") 43 int BPF_PROG(tp_xdp_devmap_xmit_multi, const struct net_device 44 *from_dev, const struct net_device *to_dev, int sent, int drops, 45 int err) 46 { 47 return randmap(from_dev->ifindex, from_dev); 48 } 49 50 SEC("fentry/eth_type_trans") 51 int BPF_PROG(fentry_eth_type_trans, struct sk_buff *skb, 52 struct net_device *dev, unsigned short protocol) 53 { 54 return randmap(dev->ifindex + skb->len, dev); 55 } 56 57 SEC("fexit/eth_type_trans") 58 int BPF_PROG(fexit_eth_type_trans, struct sk_buff *skb, 59 struct net_device *dev, unsigned short protocol) 60 { 61 return randmap(dev->ifindex + skb->len, dev); 62 } 63 64 volatile const int never; 65 66 struct __sk_bUfF /* it will not exist in vmlinux */ { 67 int len; 68 } __attribute__((preserve_access_index)); 69 70 struct bpf_testmod_test_read_ctx /* it exists in bpf_testmod */ { 71 size_t len; 72 } __attribute__((preserve_access_index)); 73 74 SEC("tc") 75 int balancer_ingress(struct __sk_buff *ctx) 76 { 77 void *data_end = (void *)(long)ctx->data_end; 78 void *data = (void *)(long)ctx->data; 79 void *ptr; 80 int ret = 0, nh_off, i = 0; 81 82 nh_off = 14; 83 84 /* pragma unroll doesn't work on large loops */ 85 #define C do { \ 86 ptr = data + i; \ 87 if (ptr + nh_off > data_end) \ 88 break; \ 89 ctx->tc_index = jhash(ptr, nh_off, ctx->cb[0] + i++); \ 90 if (never) { \ 91 /* below is a dead code with unresolvable CO-RE relo */ \ 92 i += ((struct __sk_bUfF *)ctx)->len; \ 93 /* this CO-RE relo may or may not resolve 94 * depending on whether bpf_testmod is loaded. 95 */ \ 96 i += ((struct bpf_testmod_test_read_ctx *)ctx)->len; \ 97 } \ 98 } while (0); 99 #define C30 C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;C; 100 C30;C30;C30; /* 90 calls */ 101 return 0; 102 } 103 104 char LICENSE[] SEC("license") = "GPL"; 105