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(enum bpf_map_type map_type, int key_size, 61 int value_size, int max_entries, __u32 map_flags) 62 { 63 union bpf_attr attr; 64 65 memset(&attr, '\0', sizeof(attr)); 66 67 attr.map_type = map_type; 68 attr.key_size = key_size; 69 attr.value_size = value_size; 70 attr.max_entries = max_entries; 71 attr.map_flags = map_flags; 72 73 return sys_bpf(BPF_MAP_CREATE, &attr, sizeof(attr)); 74 } 75 76 int bpf_create_map_in_map(enum bpf_map_type map_type, int key_size, 77 int inner_map_fd, int max_entries, __u32 map_flags) 78 { 79 union bpf_attr attr; 80 81 memset(&attr, '\0', sizeof(attr)); 82 83 attr.map_type = map_type; 84 attr.key_size = key_size; 85 attr.value_size = 4; 86 attr.inner_map_fd = inner_map_fd; 87 attr.max_entries = max_entries; 88 attr.map_flags = map_flags; 89 90 return sys_bpf(BPF_MAP_CREATE, &attr, sizeof(attr)); 91 } 92 93 int bpf_load_program(enum bpf_prog_type type, const struct bpf_insn *insns, 94 size_t insns_cnt, const char *license, 95 __u32 kern_version, char *log_buf, size_t log_buf_sz) 96 { 97 int fd; 98 union bpf_attr attr; 99 100 bzero(&attr, sizeof(attr)); 101 attr.prog_type = type; 102 attr.insn_cnt = (__u32)insns_cnt; 103 attr.insns = ptr_to_u64(insns); 104 attr.license = ptr_to_u64(license); 105 attr.log_buf = ptr_to_u64(NULL); 106 attr.log_size = 0; 107 attr.log_level = 0; 108 attr.kern_version = kern_version; 109 110 fd = sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr)); 111 if (fd >= 0 || !log_buf || !log_buf_sz) 112 return fd; 113 114 /* Try again with log */ 115 attr.log_buf = ptr_to_u64(log_buf); 116 attr.log_size = log_buf_sz; 117 attr.log_level = 1; 118 log_buf[0] = 0; 119 return sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr)); 120 } 121 122 int bpf_verify_program(enum bpf_prog_type type, const struct bpf_insn *insns, 123 size_t insns_cnt, int strict_alignment, 124 const char *license, __u32 kern_version, 125 char *log_buf, size_t log_buf_sz, int log_level) 126 { 127 union bpf_attr attr; 128 129 bzero(&attr, sizeof(attr)); 130 attr.prog_type = type; 131 attr.insn_cnt = (__u32)insns_cnt; 132 attr.insns = ptr_to_u64(insns); 133 attr.license = ptr_to_u64(license); 134 attr.log_buf = ptr_to_u64(log_buf); 135 attr.log_size = log_buf_sz; 136 attr.log_level = log_level; 137 log_buf[0] = 0; 138 attr.kern_version = kern_version; 139 attr.prog_flags = strict_alignment ? BPF_F_STRICT_ALIGNMENT : 0; 140 141 return sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr)); 142 } 143 144 int bpf_map_update_elem(int fd, const void *key, const void *value, 145 __u64 flags) 146 { 147 union bpf_attr attr; 148 149 bzero(&attr, sizeof(attr)); 150 attr.map_fd = fd; 151 attr.key = ptr_to_u64(key); 152 attr.value = ptr_to_u64(value); 153 attr.flags = flags; 154 155 return sys_bpf(BPF_MAP_UPDATE_ELEM, &attr, sizeof(attr)); 156 } 157 158 int bpf_map_lookup_elem(int fd, const void *key, void *value) 159 { 160 union bpf_attr attr; 161 162 bzero(&attr, sizeof(attr)); 163 attr.map_fd = fd; 164 attr.key = ptr_to_u64(key); 165 attr.value = ptr_to_u64(value); 166 167 return sys_bpf(BPF_MAP_LOOKUP_ELEM, &attr, sizeof(attr)); 168 } 169 170 int bpf_map_delete_elem(int fd, const void *key) 171 { 172 union bpf_attr attr; 173 174 bzero(&attr, sizeof(attr)); 175 attr.map_fd = fd; 176 attr.key = ptr_to_u64(key); 177 178 return sys_bpf(BPF_MAP_DELETE_ELEM, &attr, sizeof(attr)); 179 } 180 181 int bpf_map_get_next_key(int fd, const void *key, void *next_key) 182 { 183 union bpf_attr attr; 184 185 bzero(&attr, sizeof(attr)); 186 attr.map_fd = fd; 187 attr.key = ptr_to_u64(key); 188 attr.next_key = ptr_to_u64(next_key); 189 190 return sys_bpf(BPF_MAP_GET_NEXT_KEY, &attr, sizeof(attr)); 191 } 192 193 int bpf_obj_pin(int fd, const char *pathname) 194 { 195 union bpf_attr attr; 196 197 bzero(&attr, sizeof(attr)); 198 attr.pathname = ptr_to_u64((void *)pathname); 199 attr.bpf_fd = fd; 200 201 return sys_bpf(BPF_OBJ_PIN, &attr, sizeof(attr)); 202 } 203 204 int bpf_obj_get(const char *pathname) 205 { 206 union bpf_attr attr; 207 208 bzero(&attr, sizeof(attr)); 209 attr.pathname = ptr_to_u64((void *)pathname); 210 211 return sys_bpf(BPF_OBJ_GET, &attr, sizeof(attr)); 212 } 213 214 int bpf_prog_attach(int prog_fd, int target_fd, enum bpf_attach_type type, 215 unsigned int flags) 216 { 217 union bpf_attr attr; 218 219 bzero(&attr, sizeof(attr)); 220 attr.target_fd = target_fd; 221 attr.attach_bpf_fd = prog_fd; 222 attr.attach_type = type; 223 attr.attach_flags = flags; 224 225 return sys_bpf(BPF_PROG_ATTACH, &attr, sizeof(attr)); 226 } 227 228 int bpf_prog_detach(int target_fd, enum bpf_attach_type type) 229 { 230 union bpf_attr attr; 231 232 bzero(&attr, sizeof(attr)); 233 attr.target_fd = target_fd; 234 attr.attach_type = type; 235 236 return sys_bpf(BPF_PROG_DETACH, &attr, sizeof(attr)); 237 } 238 239 int bpf_prog_test_run(int prog_fd, int repeat, void *data, __u32 size, 240 void *data_out, __u32 *size_out, __u32 *retval, 241 __u32 *duration) 242 { 243 union bpf_attr attr; 244 int ret; 245 246 bzero(&attr, sizeof(attr)); 247 attr.test.prog_fd = prog_fd; 248 attr.test.data_in = ptr_to_u64(data); 249 attr.test.data_out = ptr_to_u64(data_out); 250 attr.test.data_size_in = size; 251 attr.test.repeat = repeat; 252 253 ret = sys_bpf(BPF_PROG_TEST_RUN, &attr, sizeof(attr)); 254 if (size_out) 255 *size_out = attr.test.data_size_out; 256 if (retval) 257 *retval = attr.test.retval; 258 if (duration) 259 *duration = attr.test.duration; 260 return ret; 261 } 262 263 int bpf_prog_get_next_id(__u32 start_id, __u32 *next_id) 264 { 265 union bpf_attr attr; 266 int err; 267 268 bzero(&attr, sizeof(attr)); 269 attr.start_id = start_id; 270 271 err = sys_bpf(BPF_PROG_GET_NEXT_ID, &attr, sizeof(attr)); 272 if (!err) 273 *next_id = attr.next_id; 274 275 return err; 276 } 277 278 int bpf_map_get_next_id(__u32 start_id, __u32 *next_id) 279 { 280 union bpf_attr attr; 281 int err; 282 283 bzero(&attr, sizeof(attr)); 284 attr.start_id = start_id; 285 286 err = sys_bpf(BPF_MAP_GET_NEXT_ID, &attr, sizeof(attr)); 287 if (!err) 288 *next_id = attr.next_id; 289 290 return err; 291 } 292 293 int bpf_prog_get_fd_by_id(__u32 id) 294 { 295 union bpf_attr attr; 296 297 bzero(&attr, sizeof(attr)); 298 attr.prog_id = id; 299 300 return sys_bpf(BPF_PROG_GET_FD_BY_ID, &attr, sizeof(attr)); 301 } 302 303 int bpf_map_get_fd_by_id(__u32 id) 304 { 305 union bpf_attr attr; 306 307 bzero(&attr, sizeof(attr)); 308 attr.map_id = id; 309 310 return sys_bpf(BPF_MAP_GET_FD_BY_ID, &attr, sizeof(attr)); 311 } 312 313 int bpf_obj_get_info_by_fd(int prog_fd, void *info, __u32 *info_len) 314 { 315 union bpf_attr attr; 316 int err; 317 318 bzero(&attr, sizeof(attr)); 319 attr.info.bpf_fd = prog_fd; 320 attr.info.info_len = *info_len; 321 attr.info.info = ptr_to_u64(info); 322 323 err = sys_bpf(BPF_OBJ_GET_INFO_BY_FD, &attr, sizeof(attr)); 324 if (!err) 325 *info_len = attr.info.info_len; 326 327 return err; 328 } 329