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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 | // SPDX-License-Identifier: GPL-2.0 /* Copyright (c) 2022 Facebook */ #include <string.h> #include <linux/bpf.h> #include <bpf/bpf_helpers.h> #include "bpf_misc.h" #include "errno.h" char _license[] SEC("license") = "GPL"; int pid, err, val; struct sample { int pid; int seq; long value; char comm[16]; }; struct { __uint(type, BPF_MAP_TYPE_RINGBUF); __uint(max_entries, 4096); } ringbuf SEC(".maps"); struct { __uint(type, BPF_MAP_TYPE_ARRAY); __uint(max_entries, 1); __type(key, __u32); __type(value, __u32); } array_map SEC(".maps"); SEC("tp/syscalls/sys_enter_nanosleep") int test_read_write(void *ctx) { char write_data[64] = "hello there, world!!"; char read_data[64] = {}, buf[64] = {}; struct bpf_dynptr ptr; int i; if (bpf_get_current_pid_tgid() >> 32 != pid) return 0; bpf_ringbuf_reserve_dynptr(&ringbuf, sizeof(write_data), 0, &ptr); /* Write data into the dynptr */ err = bpf_dynptr_write(&ptr, 0, write_data, sizeof(write_data), 0); /* Read the data that was written into the dynptr */ err = err ?: bpf_dynptr_read(read_data, sizeof(read_data), &ptr, 0, 0); /* Ensure the data we read matches the data we wrote */ for (i = 0; i < sizeof(read_data); i++) { if (read_data[i] != write_data[i]) { err = 1; break; } } bpf_ringbuf_discard_dynptr(&ptr, 0); return 0; } SEC("tp/syscalls/sys_enter_nanosleep") int test_data_slice(void *ctx) { __u32 key = 0, val = 235, *map_val; struct bpf_dynptr ptr; __u32 map_val_size; void *data; map_val_size = sizeof(*map_val); if (bpf_get_current_pid_tgid() >> 32 != pid) return 0; bpf_map_update_elem(&array_map, &key, &val, 0); map_val = bpf_map_lookup_elem(&array_map, &key); if (!map_val) { err = 1; return 0; } bpf_dynptr_from_mem(map_val, map_val_size, 0, &ptr); /* Try getting a data slice that is out of range */ data = bpf_dynptr_data(&ptr, map_val_size + 1, 1); if (data) { err = 2; return 0; } /* Try getting more bytes than available */ data = bpf_dynptr_data(&ptr, 0, map_val_size + 1); if (data) { err = 3; return 0; } data = bpf_dynptr_data(&ptr, 0, sizeof(__u32)); if (!data) { err = 4; return 0; } *(__u32 *)data = 999; err = bpf_probe_read_kernel(&val, sizeof(val), data); if (err) return 0; if (val != *(int *)data) err = 5; return 0; } static int ringbuf_callback(__u32 index, void *data) { struct sample *sample; struct bpf_dynptr *ptr = (struct bpf_dynptr *)data; sample = bpf_dynptr_data(ptr, 0, sizeof(*sample)); if (!sample) err = 2; else sample->pid += index; return 0; } SEC("tp/syscalls/sys_enter_nanosleep") int test_ringbuf(void *ctx) { struct bpf_dynptr ptr; struct sample *sample; if (bpf_get_current_pid_tgid() >> 32 != pid) return 0; val = 100; /* check that you can reserve a dynamic size reservation */ err = bpf_ringbuf_reserve_dynptr(&ringbuf, val, 0, &ptr); sample = err ? NULL : bpf_dynptr_data(&ptr, 0, sizeof(*sample)); if (!sample) { err = 1; goto done; } sample->pid = 10; /* Can pass dynptr to callback functions */ bpf_loop(10, ringbuf_callback, &ptr, 0); if (sample->pid != 55) err = 2; done: bpf_ringbuf_discard_dynptr(&ptr, 0); return 0; } |