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 # else 41 # error __NR_bpf not defined. libbpf does not support your arch. 42 # endif 43 #endif 44 45 static inline __u64 ptr_to_u64(const void *ptr) 46 { 47 return (__u64) (unsigned long) ptr; 48 } 49 50 static inline int sys_bpf(enum bpf_cmd cmd, union bpf_attr *attr, 51 unsigned int size) 52 { 53 return syscall(__NR_bpf, cmd, attr, size); 54 } 55 56 int bpf_create_map(enum bpf_map_type map_type, int key_size, 57 int value_size, int max_entries, __u32 map_flags) 58 { 59 union bpf_attr attr; 60 61 memset(&attr, '\0', sizeof(attr)); 62 63 attr.map_type = map_type; 64 attr.key_size = key_size; 65 attr.value_size = value_size; 66 attr.max_entries = max_entries; 67 attr.map_flags = map_flags; 68 69 return sys_bpf(BPF_MAP_CREATE, &attr, sizeof(attr)); 70 } 71 72 int bpf_create_map_in_map(enum bpf_map_type map_type, int key_size, 73 int inner_map_fd, int max_entries, __u32 map_flags) 74 { 75 union bpf_attr attr; 76 77 memset(&attr, '\0', sizeof(attr)); 78 79 attr.map_type = map_type; 80 attr.key_size = key_size; 81 attr.value_size = 4; 82 attr.inner_map_fd = inner_map_fd; 83 attr.max_entries = max_entries; 84 attr.map_flags = map_flags; 85 86 return sys_bpf(BPF_MAP_CREATE, &attr, sizeof(attr)); 87 } 88 89 int bpf_load_program(enum bpf_prog_type type, const struct bpf_insn *insns, 90 size_t insns_cnt, const char *license, 91 __u32 kern_version, char *log_buf, size_t log_buf_sz) 92 { 93 int fd; 94 union bpf_attr attr; 95 96 bzero(&attr, sizeof(attr)); 97 attr.prog_type = type; 98 attr.insn_cnt = (__u32)insns_cnt; 99 attr.insns = ptr_to_u64(insns); 100 attr.license = ptr_to_u64(license); 101 attr.log_buf = ptr_to_u64(NULL); 102 attr.log_size = 0; 103 attr.log_level = 0; 104 attr.kern_version = kern_version; 105 106 fd = sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr)); 107 if (fd >= 0 || !log_buf || !log_buf_sz) 108 return fd; 109 110 /* Try again with log */ 111 attr.log_buf = ptr_to_u64(log_buf); 112 attr.log_size = log_buf_sz; 113 attr.log_level = 1; 114 log_buf[0] = 0; 115 return sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr)); 116 } 117 118 int bpf_map_update_elem(int fd, const void *key, const void *value, 119 __u64 flags) 120 { 121 union bpf_attr attr; 122 123 bzero(&attr, sizeof(attr)); 124 attr.map_fd = fd; 125 attr.key = ptr_to_u64(key); 126 attr.value = ptr_to_u64(value); 127 attr.flags = flags; 128 129 return sys_bpf(BPF_MAP_UPDATE_ELEM, &attr, sizeof(attr)); 130 } 131 132 int bpf_map_lookup_elem(int fd, const void *key, void *value) 133 { 134 union bpf_attr attr; 135 136 bzero(&attr, sizeof(attr)); 137 attr.map_fd = fd; 138 attr.key = ptr_to_u64(key); 139 attr.value = ptr_to_u64(value); 140 141 return sys_bpf(BPF_MAP_LOOKUP_ELEM, &attr, sizeof(attr)); 142 } 143 144 int bpf_map_delete_elem(int fd, const void *key) 145 { 146 union bpf_attr attr; 147 148 bzero(&attr, sizeof(attr)); 149 attr.map_fd = fd; 150 attr.key = ptr_to_u64(key); 151 152 return sys_bpf(BPF_MAP_DELETE_ELEM, &attr, sizeof(attr)); 153 } 154 155 int bpf_map_get_next_key(int fd, const void *key, void *next_key) 156 { 157 union bpf_attr attr; 158 159 bzero(&attr, sizeof(attr)); 160 attr.map_fd = fd; 161 attr.key = ptr_to_u64(key); 162 attr.next_key = ptr_to_u64(next_key); 163 164 return sys_bpf(BPF_MAP_GET_NEXT_KEY, &attr, sizeof(attr)); 165 } 166 167 int bpf_obj_pin(int fd, const char *pathname) 168 { 169 union bpf_attr attr; 170 171 bzero(&attr, sizeof(attr)); 172 attr.pathname = ptr_to_u64((void *)pathname); 173 attr.bpf_fd = fd; 174 175 return sys_bpf(BPF_OBJ_PIN, &attr, sizeof(attr)); 176 } 177 178 int bpf_obj_get(const char *pathname) 179 { 180 union bpf_attr attr; 181 182 bzero(&attr, sizeof(attr)); 183 attr.pathname = ptr_to_u64((void *)pathname); 184 185 return sys_bpf(BPF_OBJ_GET, &attr, sizeof(attr)); 186 } 187 188 int bpf_prog_attach(int prog_fd, int target_fd, enum bpf_attach_type type, 189 unsigned int flags) 190 { 191 union bpf_attr attr; 192 193 bzero(&attr, sizeof(attr)); 194 attr.target_fd = target_fd; 195 attr.attach_bpf_fd = prog_fd; 196 attr.attach_type = type; 197 attr.attach_flags = flags; 198 199 return sys_bpf(BPF_PROG_ATTACH, &attr, sizeof(attr)); 200 } 201 202 int bpf_prog_detach(int target_fd, enum bpf_attach_type type) 203 { 204 union bpf_attr attr; 205 206 bzero(&attr, sizeof(attr)); 207 attr.target_fd = target_fd; 208 attr.attach_type = type; 209 210 return sys_bpf(BPF_PROG_DETACH, &attr, sizeof(attr)); 211 } 212 213 int bpf_prog_test_run(int prog_fd, int repeat, void *data, __u32 size, 214 void *data_out, __u32 *size_out, __u32 *retval, 215 __u32 *duration) 216 { 217 union bpf_attr attr; 218 int ret; 219 220 bzero(&attr, sizeof(attr)); 221 attr.test.prog_fd = prog_fd; 222 attr.test.data_in = ptr_to_u64(data); 223 attr.test.data_out = ptr_to_u64(data_out); 224 attr.test.data_size_in = size; 225 attr.test.repeat = repeat; 226 227 ret = sys_bpf(BPF_PROG_TEST_RUN, &attr, sizeof(attr)); 228 if (size_out) 229 *size_out = attr.test.data_size_out; 230 if (retval) 231 *retval = attr.test.retval; 232 if (duration) 233 *duration = attr.test.duration; 234 return ret; 235 } 236