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_map_update_elem(int fd, const void *key, const void *value, 121 __u64 flags) 122 { 123 union bpf_attr attr; 124 125 bzero(&attr, sizeof(attr)); 126 attr.map_fd = fd; 127 attr.key = ptr_to_u64(key); 128 attr.value = ptr_to_u64(value); 129 attr.flags = flags; 130 131 return sys_bpf(BPF_MAP_UPDATE_ELEM, &attr, sizeof(attr)); 132 } 133 134 int bpf_map_lookup_elem(int fd, const void *key, void *value) 135 { 136 union bpf_attr attr; 137 138 bzero(&attr, sizeof(attr)); 139 attr.map_fd = fd; 140 attr.key = ptr_to_u64(key); 141 attr.value = ptr_to_u64(value); 142 143 return sys_bpf(BPF_MAP_LOOKUP_ELEM, &attr, sizeof(attr)); 144 } 145 146 int bpf_map_delete_elem(int fd, const void *key) 147 { 148 union bpf_attr attr; 149 150 bzero(&attr, sizeof(attr)); 151 attr.map_fd = fd; 152 attr.key = ptr_to_u64(key); 153 154 return sys_bpf(BPF_MAP_DELETE_ELEM, &attr, sizeof(attr)); 155 } 156 157 int bpf_map_get_next_key(int fd, const void *key, void *next_key) 158 { 159 union bpf_attr attr; 160 161 bzero(&attr, sizeof(attr)); 162 attr.map_fd = fd; 163 attr.key = ptr_to_u64(key); 164 attr.next_key = ptr_to_u64(next_key); 165 166 return sys_bpf(BPF_MAP_GET_NEXT_KEY, &attr, sizeof(attr)); 167 } 168 169 int bpf_obj_pin(int fd, const char *pathname) 170 { 171 union bpf_attr attr; 172 173 bzero(&attr, sizeof(attr)); 174 attr.pathname = ptr_to_u64((void *)pathname); 175 attr.bpf_fd = fd; 176 177 return sys_bpf(BPF_OBJ_PIN, &attr, sizeof(attr)); 178 } 179 180 int bpf_obj_get(const char *pathname) 181 { 182 union bpf_attr attr; 183 184 bzero(&attr, sizeof(attr)); 185 attr.pathname = ptr_to_u64((void *)pathname); 186 187 return sys_bpf(BPF_OBJ_GET, &attr, sizeof(attr)); 188 } 189 190 int bpf_prog_attach(int prog_fd, int target_fd, enum bpf_attach_type type, 191 unsigned int flags) 192 { 193 union bpf_attr attr; 194 195 bzero(&attr, sizeof(attr)); 196 attr.target_fd = target_fd; 197 attr.attach_bpf_fd = prog_fd; 198 attr.attach_type = type; 199 attr.attach_flags = flags; 200 201 return sys_bpf(BPF_PROG_ATTACH, &attr, sizeof(attr)); 202 } 203 204 int bpf_prog_detach(int target_fd, enum bpf_attach_type type) 205 { 206 union bpf_attr attr; 207 208 bzero(&attr, sizeof(attr)); 209 attr.target_fd = target_fd; 210 attr.attach_type = type; 211 212 return sys_bpf(BPF_PROG_DETACH, &attr, sizeof(attr)); 213 } 214 215 int bpf_prog_test_run(int prog_fd, int repeat, void *data, __u32 size, 216 void *data_out, __u32 *size_out, __u32 *retval, 217 __u32 *duration) 218 { 219 union bpf_attr attr; 220 int ret; 221 222 bzero(&attr, sizeof(attr)); 223 attr.test.prog_fd = prog_fd; 224 attr.test.data_in = ptr_to_u64(data); 225 attr.test.data_out = ptr_to_u64(data_out); 226 attr.test.data_size_in = size; 227 attr.test.repeat = repeat; 228 229 ret = sys_bpf(BPF_PROG_TEST_RUN, &attr, sizeof(attr)); 230 if (size_out) 231 *size_out = attr.test.data_size_out; 232 if (retval) 233 *retval = attr.test.retval; 234 if (duration) 235 *duration = attr.test.duration; 236 return ret; 237 } 238