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 # else 43 # error __NR_bpf not defined. libbpf does not support your arch. 44 # endif 45 #endif 46 47 static inline __u64 ptr_to_u64(const void *ptr) 48 { 49 return (__u64) (unsigned long) ptr; 50 } 51 52 static inline int sys_bpf(enum bpf_cmd cmd, union bpf_attr *attr, 53 unsigned int size) 54 { 55 return syscall(__NR_bpf, cmd, attr, size); 56 } 57 58 int bpf_create_map(enum bpf_map_type map_type, int key_size, 59 int value_size, int max_entries, __u32 map_flags) 60 { 61 union bpf_attr attr; 62 63 memset(&attr, '\0', sizeof(attr)); 64 65 attr.map_type = map_type; 66 attr.key_size = key_size; 67 attr.value_size = value_size; 68 attr.max_entries = max_entries; 69 attr.map_flags = map_flags; 70 71 return sys_bpf(BPF_MAP_CREATE, &attr, sizeof(attr)); 72 } 73 74 int bpf_create_map_in_map(enum bpf_map_type map_type, int key_size, 75 int inner_map_fd, int max_entries, __u32 map_flags) 76 { 77 union bpf_attr attr; 78 79 memset(&attr, '\0', sizeof(attr)); 80 81 attr.map_type = map_type; 82 attr.key_size = key_size; 83 attr.value_size = 4; 84 attr.inner_map_fd = inner_map_fd; 85 attr.max_entries = max_entries; 86 attr.map_flags = map_flags; 87 88 return sys_bpf(BPF_MAP_CREATE, &attr, sizeof(attr)); 89 } 90 91 int bpf_load_program(enum bpf_prog_type type, const struct bpf_insn *insns, 92 size_t insns_cnt, const char *license, 93 __u32 kern_version, char *log_buf, size_t log_buf_sz) 94 { 95 int fd; 96 union bpf_attr attr; 97 98 bzero(&attr, sizeof(attr)); 99 attr.prog_type = type; 100 attr.insn_cnt = (__u32)insns_cnt; 101 attr.insns = ptr_to_u64(insns); 102 attr.license = ptr_to_u64(license); 103 attr.log_buf = ptr_to_u64(NULL); 104 attr.log_size = 0; 105 attr.log_level = 0; 106 attr.kern_version = kern_version; 107 108 fd = sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr)); 109 if (fd >= 0 || !log_buf || !log_buf_sz) 110 return fd; 111 112 /* Try again with log */ 113 attr.log_buf = ptr_to_u64(log_buf); 114 attr.log_size = log_buf_sz; 115 attr.log_level = 1; 116 log_buf[0] = 0; 117 return sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr)); 118 } 119 120 int bpf_verify_program(enum bpf_prog_type type, const struct bpf_insn *insns, 121 size_t insns_cnt, int strict_alignment, 122 const char *license, __u32 kern_version, 123 char *log_buf, size_t log_buf_sz, int log_level) 124 { 125 union bpf_attr attr; 126 127 bzero(&attr, sizeof(attr)); 128 attr.prog_type = type; 129 attr.insn_cnt = (__u32)insns_cnt; 130 attr.insns = ptr_to_u64(insns); 131 attr.license = ptr_to_u64(license); 132 attr.log_buf = ptr_to_u64(log_buf); 133 attr.log_size = log_buf_sz; 134 attr.log_level = log_level; 135 log_buf[0] = 0; 136 attr.kern_version = kern_version; 137 attr.prog_flags = strict_alignment ? BPF_F_STRICT_ALIGNMENT : 0; 138 139 return sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr)); 140 } 141 142 int bpf_map_update_elem(int fd, const void *key, const void *value, 143 __u64 flags) 144 { 145 union bpf_attr attr; 146 147 bzero(&attr, sizeof(attr)); 148 attr.map_fd = fd; 149 attr.key = ptr_to_u64(key); 150 attr.value = ptr_to_u64(value); 151 attr.flags = flags; 152 153 return sys_bpf(BPF_MAP_UPDATE_ELEM, &attr, sizeof(attr)); 154 } 155 156 int bpf_map_lookup_elem(int fd, const void *key, void *value) 157 { 158 union bpf_attr attr; 159 160 bzero(&attr, sizeof(attr)); 161 attr.map_fd = fd; 162 attr.key = ptr_to_u64(key); 163 attr.value = ptr_to_u64(value); 164 165 return sys_bpf(BPF_MAP_LOOKUP_ELEM, &attr, sizeof(attr)); 166 } 167 168 int bpf_map_delete_elem(int fd, const void *key) 169 { 170 union bpf_attr attr; 171 172 bzero(&attr, sizeof(attr)); 173 attr.map_fd = fd; 174 attr.key = ptr_to_u64(key); 175 176 return sys_bpf(BPF_MAP_DELETE_ELEM, &attr, sizeof(attr)); 177 } 178 179 int bpf_map_get_next_key(int fd, const void *key, void *next_key) 180 { 181 union bpf_attr attr; 182 183 bzero(&attr, sizeof(attr)); 184 attr.map_fd = fd; 185 attr.key = ptr_to_u64(key); 186 attr.next_key = ptr_to_u64(next_key); 187 188 return sys_bpf(BPF_MAP_GET_NEXT_KEY, &attr, sizeof(attr)); 189 } 190 191 int bpf_obj_pin(int fd, const char *pathname) 192 { 193 union bpf_attr attr; 194 195 bzero(&attr, sizeof(attr)); 196 attr.pathname = ptr_to_u64((void *)pathname); 197 attr.bpf_fd = fd; 198 199 return sys_bpf(BPF_OBJ_PIN, &attr, sizeof(attr)); 200 } 201 202 int bpf_obj_get(const char *pathname) 203 { 204 union bpf_attr attr; 205 206 bzero(&attr, sizeof(attr)); 207 attr.pathname = ptr_to_u64((void *)pathname); 208 209 return sys_bpf(BPF_OBJ_GET, &attr, sizeof(attr)); 210 } 211 212 int bpf_prog_attach(int prog_fd, int target_fd, enum bpf_attach_type type, 213 unsigned int flags) 214 { 215 union bpf_attr attr; 216 217 bzero(&attr, sizeof(attr)); 218 attr.target_fd = target_fd; 219 attr.attach_bpf_fd = prog_fd; 220 attr.attach_type = type; 221 attr.attach_flags = flags; 222 223 return sys_bpf(BPF_PROG_ATTACH, &attr, sizeof(attr)); 224 } 225 226 int bpf_prog_detach(int target_fd, enum bpf_attach_type type) 227 { 228 union bpf_attr attr; 229 230 bzero(&attr, sizeof(attr)); 231 attr.target_fd = target_fd; 232 attr.attach_type = type; 233 234 return sys_bpf(BPF_PROG_DETACH, &attr, sizeof(attr)); 235 } 236 237 int bpf_prog_test_run(int prog_fd, int repeat, void *data, __u32 size, 238 void *data_out, __u32 *size_out, __u32 *retval, 239 __u32 *duration) 240 { 241 union bpf_attr attr; 242 int ret; 243 244 bzero(&attr, sizeof(attr)); 245 attr.test.prog_fd = prog_fd; 246 attr.test.data_in = ptr_to_u64(data); 247 attr.test.data_out = ptr_to_u64(data_out); 248 attr.test.data_size_in = size; 249 attr.test.repeat = repeat; 250 251 ret = sys_bpf(BPF_PROG_TEST_RUN, &attr, sizeof(attr)); 252 if (size_out) 253 *size_out = attr.test.data_size_out; 254 if (retval) 255 *retval = attr.test.retval; 256 if (duration) 257 *duration = attr.test.duration; 258 return ret; 259 } 260 261 int bpf_prog_get_next_id(__u32 start_id, __u32 *next_id) 262 { 263 union bpf_attr attr; 264 int err; 265 266 bzero(&attr, sizeof(attr)); 267 attr.start_id = start_id; 268 269 err = sys_bpf(BPF_PROG_GET_NEXT_ID, &attr, sizeof(attr)); 270 if (!err) 271 *next_id = attr.next_id; 272 273 return err; 274 } 275 276 int bpf_map_get_next_id(__u32 start_id, __u32 *next_id) 277 { 278 union bpf_attr attr; 279 int err; 280 281 bzero(&attr, sizeof(attr)); 282 attr.start_id = start_id; 283 284 err = sys_bpf(BPF_MAP_GET_NEXT_ID, &attr, sizeof(attr)); 285 if (!err) 286 *next_id = attr.next_id; 287 288 return err; 289 } 290 291 int bpf_prog_get_fd_by_id(__u32 id) 292 { 293 union bpf_attr attr; 294 295 bzero(&attr, sizeof(attr)); 296 attr.prog_id = id; 297 298 return sys_bpf(BPF_PROG_GET_FD_BY_ID, &attr, sizeof(attr)); 299 } 300 301 int bpf_map_get_fd_by_id(__u32 id) 302 { 303 union bpf_attr attr; 304 305 bzero(&attr, sizeof(attr)); 306 attr.map_id = id; 307 308 return sys_bpf(BPF_MAP_GET_FD_BY_ID, &attr, sizeof(attr)); 309 } 310 311 int bpf_obj_get_info_by_fd(int prog_fd, void *info, __u32 *info_len) 312 { 313 union bpf_attr attr; 314 int err; 315 316 bzero(&attr, sizeof(attr)); 317 bzero(info, *info_len); 318 attr.info.bpf_fd = prog_fd; 319 attr.info.info_len = *info_len; 320 attr.info.info = ptr_to_u64(info); 321 322 err = sys_bpf(BPF_OBJ_GET_INFO_BY_FD, &attr, sizeof(attr)); 323 if (!err) 324 *info_len = attr.info.info_len; 325 326 return err; 327 } 328