1 /* 2 * common eBPF ELF operations. 3 * 4 * Copyright (C) 2013-2015 Alexei Starovoitov <ast@kernel.org> 5 * Copyright (C) 2015 Wang Nan <wangnan0@huawei.com> 6 * Copyright (C) 2015 Huawei Inc. 7 * 8 * This program is free software; you can redistribute it and/or 9 * modify it under the terms of the GNU Lesser General Public 10 * License as published by the Free Software Foundation; 11 * version 2.1 of the License (not later!) 12 * 13 * This program is distributed in the hope that it will be useful, 14 * but WITHOUT ANY WARRANTY; without even the implied warranty of 15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 * GNU Lesser General Public License for more details. 17 * 18 * You should have received a copy of the GNU Lesser General Public 19 * License along with this program; if not, see <http://www.gnu.org/licenses> 20 */ 21 22 #include <stdlib.h> 23 #include <memory.h> 24 #include <unistd.h> 25 #include <asm/unistd.h> 26 #include <linux/bpf.h> 27 #include "bpf.h" 28 29 /* 30 * When building perf, unistd.h is overridden. __NR_bpf is 31 * required to be defined explicitly. 32 */ 33 #ifndef __NR_bpf 34 # if defined(__i386__) 35 # define __NR_bpf 357 36 # elif defined(__x86_64__) 37 # define __NR_bpf 321 38 # elif defined(__aarch64__) 39 # define __NR_bpf 280 40 # elif defined(__sparc__) 41 # define __NR_bpf 349 42 # elif defined(__s390__) 43 # define __NR_bpf 351 44 # else 45 # error __NR_bpf not defined. libbpf does not support your arch. 46 # endif 47 #endif 48 49 static inline __u64 ptr_to_u64(const void *ptr) 50 { 51 return (__u64) (unsigned long) ptr; 52 } 53 54 static inline int sys_bpf(enum bpf_cmd cmd, union bpf_attr *attr, 55 unsigned int size) 56 { 57 return syscall(__NR_bpf, cmd, attr, size); 58 } 59 60 int bpf_create_map_node(enum bpf_map_type map_type, int key_size, 61 int value_size, int max_entries, __u32 map_flags, 62 int node) 63 { 64 union bpf_attr attr; 65 66 memset(&attr, '\0', sizeof(attr)); 67 68 attr.map_type = map_type; 69 attr.key_size = key_size; 70 attr.value_size = value_size; 71 attr.max_entries = max_entries; 72 attr.map_flags = map_flags; 73 if (node >= 0) { 74 attr.map_flags |= BPF_F_NUMA_NODE; 75 attr.numa_node = node; 76 } 77 78 return sys_bpf(BPF_MAP_CREATE, &attr, sizeof(attr)); 79 } 80 81 int bpf_create_map(enum bpf_map_type map_type, int key_size, 82 int value_size, int max_entries, __u32 map_flags) 83 { 84 return bpf_create_map_node(map_type, key_size, value_size, 85 max_entries, map_flags, -1); 86 } 87 88 int bpf_create_map_in_map_node(enum bpf_map_type map_type, int key_size, 89 int inner_map_fd, int max_entries, 90 __u32 map_flags, int node) 91 { 92 union bpf_attr attr; 93 94 memset(&attr, '\0', sizeof(attr)); 95 96 attr.map_type = map_type; 97 attr.key_size = key_size; 98 attr.value_size = 4; 99 attr.inner_map_fd = inner_map_fd; 100 attr.max_entries = max_entries; 101 attr.map_flags = map_flags; 102 if (node >= 0) { 103 attr.map_flags |= BPF_F_NUMA_NODE; 104 attr.numa_node = node; 105 } 106 107 return sys_bpf(BPF_MAP_CREATE, &attr, sizeof(attr)); 108 } 109 110 int bpf_create_map_in_map(enum bpf_map_type map_type, int key_size, 111 int inner_map_fd, int max_entries, __u32 map_flags) 112 { 113 return bpf_create_map_in_map_node(map_type, key_size, inner_map_fd, 114 max_entries, map_flags, -1); 115 } 116 117 int bpf_load_program(enum bpf_prog_type type, const struct bpf_insn *insns, 118 size_t insns_cnt, const char *license, 119 __u32 kern_version, char *log_buf, size_t log_buf_sz) 120 { 121 int fd; 122 union bpf_attr attr; 123 124 bzero(&attr, sizeof(attr)); 125 attr.prog_type = type; 126 attr.insn_cnt = (__u32)insns_cnt; 127 attr.insns = ptr_to_u64(insns); 128 attr.license = ptr_to_u64(license); 129 attr.log_buf = ptr_to_u64(NULL); 130 attr.log_size = 0; 131 attr.log_level = 0; 132 attr.kern_version = kern_version; 133 134 fd = sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr)); 135 if (fd >= 0 || !log_buf || !log_buf_sz) 136 return fd; 137 138 /* Try again with log */ 139 attr.log_buf = ptr_to_u64(log_buf); 140 attr.log_size = log_buf_sz; 141 attr.log_level = 1; 142 log_buf[0] = 0; 143 return sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr)); 144 } 145 146 int bpf_verify_program(enum bpf_prog_type type, const struct bpf_insn *insns, 147 size_t insns_cnt, int strict_alignment, 148 const char *license, __u32 kern_version, 149 char *log_buf, size_t log_buf_sz, int log_level) 150 { 151 union bpf_attr attr; 152 153 bzero(&attr, sizeof(attr)); 154 attr.prog_type = type; 155 attr.insn_cnt = (__u32)insns_cnt; 156 attr.insns = ptr_to_u64(insns); 157 attr.license = ptr_to_u64(license); 158 attr.log_buf = ptr_to_u64(log_buf); 159 attr.log_size = log_buf_sz; 160 attr.log_level = log_level; 161 log_buf[0] = 0; 162 attr.kern_version = kern_version; 163 attr.prog_flags = strict_alignment ? BPF_F_STRICT_ALIGNMENT : 0; 164 165 return sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr)); 166 } 167 168 int bpf_map_update_elem(int fd, const void *key, const void *value, 169 __u64 flags) 170 { 171 union bpf_attr attr; 172 173 bzero(&attr, sizeof(attr)); 174 attr.map_fd = fd; 175 attr.key = ptr_to_u64(key); 176 attr.value = ptr_to_u64(value); 177 attr.flags = flags; 178 179 return sys_bpf(BPF_MAP_UPDATE_ELEM, &attr, sizeof(attr)); 180 } 181 182 int bpf_map_lookup_elem(int fd, const void *key, void *value) 183 { 184 union bpf_attr attr; 185 186 bzero(&attr, sizeof(attr)); 187 attr.map_fd = fd; 188 attr.key = ptr_to_u64(key); 189 attr.value = ptr_to_u64(value); 190 191 return sys_bpf(BPF_MAP_LOOKUP_ELEM, &attr, sizeof(attr)); 192 } 193 194 int bpf_map_delete_elem(int fd, const void *key) 195 { 196 union bpf_attr attr; 197 198 bzero(&attr, sizeof(attr)); 199 attr.map_fd = fd; 200 attr.key = ptr_to_u64(key); 201 202 return sys_bpf(BPF_MAP_DELETE_ELEM, &attr, sizeof(attr)); 203 } 204 205 int bpf_map_get_next_key(int fd, const void *key, void *next_key) 206 { 207 union bpf_attr attr; 208 209 bzero(&attr, sizeof(attr)); 210 attr.map_fd = fd; 211 attr.key = ptr_to_u64(key); 212 attr.next_key = ptr_to_u64(next_key); 213 214 return sys_bpf(BPF_MAP_GET_NEXT_KEY, &attr, sizeof(attr)); 215 } 216 217 int bpf_obj_pin(int fd, const char *pathname) 218 { 219 union bpf_attr attr; 220 221 bzero(&attr, sizeof(attr)); 222 attr.pathname = ptr_to_u64((void *)pathname); 223 attr.bpf_fd = fd; 224 225 return sys_bpf(BPF_OBJ_PIN, &attr, sizeof(attr)); 226 } 227 228 int bpf_obj_get(const char *pathname) 229 { 230 union bpf_attr attr; 231 232 bzero(&attr, sizeof(attr)); 233 attr.pathname = ptr_to_u64((void *)pathname); 234 235 return sys_bpf(BPF_OBJ_GET, &attr, sizeof(attr)); 236 } 237 238 int bpf_prog_attach(int prog_fd, int target_fd, enum bpf_attach_type type, 239 unsigned int flags) 240 { 241 union bpf_attr attr; 242 243 bzero(&attr, sizeof(attr)); 244 attr.target_fd = target_fd; 245 attr.attach_bpf_fd = prog_fd; 246 attr.attach_type = type; 247 attr.attach_flags = flags; 248 249 return sys_bpf(BPF_PROG_ATTACH, &attr, sizeof(attr)); 250 } 251 252 int bpf_prog_detach(int target_fd, enum bpf_attach_type type) 253 { 254 union bpf_attr attr; 255 256 bzero(&attr, sizeof(attr)); 257 attr.target_fd = target_fd; 258 attr.attach_type = type; 259 260 return sys_bpf(BPF_PROG_DETACH, &attr, sizeof(attr)); 261 } 262 263 int bpf_prog_test_run(int prog_fd, int repeat, void *data, __u32 size, 264 void *data_out, __u32 *size_out, __u32 *retval, 265 __u32 *duration) 266 { 267 union bpf_attr attr; 268 int ret; 269 270 bzero(&attr, sizeof(attr)); 271 attr.test.prog_fd = prog_fd; 272 attr.test.data_in = ptr_to_u64(data); 273 attr.test.data_out = ptr_to_u64(data_out); 274 attr.test.data_size_in = size; 275 attr.test.repeat = repeat; 276 277 ret = sys_bpf(BPF_PROG_TEST_RUN, &attr, sizeof(attr)); 278 if (size_out) 279 *size_out = attr.test.data_size_out; 280 if (retval) 281 *retval = attr.test.retval; 282 if (duration) 283 *duration = attr.test.duration; 284 return ret; 285 } 286 287 int bpf_prog_get_next_id(__u32 start_id, __u32 *next_id) 288 { 289 union bpf_attr attr; 290 int err; 291 292 bzero(&attr, sizeof(attr)); 293 attr.start_id = start_id; 294 295 err = sys_bpf(BPF_PROG_GET_NEXT_ID, &attr, sizeof(attr)); 296 if (!err) 297 *next_id = attr.next_id; 298 299 return err; 300 } 301 302 int bpf_map_get_next_id(__u32 start_id, __u32 *next_id) 303 { 304 union bpf_attr attr; 305 int err; 306 307 bzero(&attr, sizeof(attr)); 308 attr.start_id = start_id; 309 310 err = sys_bpf(BPF_MAP_GET_NEXT_ID, &attr, sizeof(attr)); 311 if (!err) 312 *next_id = attr.next_id; 313 314 return err; 315 } 316 317 int bpf_prog_get_fd_by_id(__u32 id) 318 { 319 union bpf_attr attr; 320 321 bzero(&attr, sizeof(attr)); 322 attr.prog_id = id; 323 324 return sys_bpf(BPF_PROG_GET_FD_BY_ID, &attr, sizeof(attr)); 325 } 326 327 int bpf_map_get_fd_by_id(__u32 id) 328 { 329 union bpf_attr attr; 330 331 bzero(&attr, sizeof(attr)); 332 attr.map_id = id; 333 334 return sys_bpf(BPF_MAP_GET_FD_BY_ID, &attr, sizeof(attr)); 335 } 336 337 int bpf_obj_get_info_by_fd(int prog_fd, void *info, __u32 *info_len) 338 { 339 union bpf_attr attr; 340 int err; 341 342 bzero(&attr, sizeof(attr)); 343 attr.info.bpf_fd = prog_fd; 344 attr.info.info_len = *info_len; 345 attr.info.info = ptr_to_u64(info); 346 347 err = sys_bpf(BPF_OBJ_GET_INFO_BY_FD, &attr, sizeof(attr)); 348 if (!err) 349 *info_len = attr.info.info_len; 350 351 return err; 352 } 353