1 // SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) 2 /* Copyright (c) 2019 Netronome Systems, Inc. */ 3 4 #include <errno.h> 5 #include <fcntl.h> 6 #include <string.h> 7 #include <stdlib.h> 8 #include <unistd.h> 9 #include <net/if.h> 10 #include <sys/utsname.h> 11 12 #include <linux/btf.h> 13 #include <linux/filter.h> 14 #include <linux/kernel.h> 15 16 #include "bpf.h" 17 #include "libbpf.h" 18 #include "libbpf_internal.h" 19 20 /* make sure libbpf doesn't use kernel-only integer typedefs */ 21 #pragma GCC poison u8 u16 u32 u64 s8 s16 s32 s64 22 23 static bool grep(const char *buffer, const char *pattern) 24 { 25 return !!strstr(buffer, pattern); 26 } 27 28 static int get_vendor_id(int ifindex) 29 { 30 char ifname[IF_NAMESIZE], path[64], buf[8]; 31 ssize_t len; 32 int fd; 33 34 if (!if_indextoname(ifindex, ifname)) 35 return -1; 36 37 snprintf(path, sizeof(path), "/sys/class/net/%s/device/vendor", ifname); 38 39 fd = open(path, O_RDONLY); 40 if (fd < 0) 41 return -1; 42 43 len = read(fd, buf, sizeof(buf)); 44 close(fd); 45 if (len < 0) 46 return -1; 47 if (len >= (ssize_t)sizeof(buf)) 48 return -1; 49 buf[len] = '\0'; 50 51 return strtol(buf, NULL, 0); 52 } 53 54 static int get_kernel_version(void) 55 { 56 int version, subversion, patchlevel; 57 struct utsname utsn; 58 59 /* Return 0 on failure, and attempt to probe with empty kversion */ 60 if (uname(&utsn)) 61 return 0; 62 63 if (sscanf(utsn.release, "%d.%d.%d", 64 &version, &subversion, &patchlevel) != 3) 65 return 0; 66 67 return (version << 16) + (subversion << 8) + patchlevel; 68 } 69 70 static void 71 probe_load(enum bpf_prog_type prog_type, const struct bpf_insn *insns, 72 size_t insns_cnt, char *buf, size_t buf_len, __u32 ifindex) 73 { 74 struct bpf_load_program_attr xattr = {}; 75 int fd; 76 77 switch (prog_type) { 78 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: 79 xattr.expected_attach_type = BPF_CGROUP_INET4_CONNECT; 80 break; 81 case BPF_PROG_TYPE_KPROBE: 82 xattr.kern_version = get_kernel_version(); 83 break; 84 case BPF_PROG_TYPE_UNSPEC: 85 case BPF_PROG_TYPE_SOCKET_FILTER: 86 case BPF_PROG_TYPE_SCHED_CLS: 87 case BPF_PROG_TYPE_SCHED_ACT: 88 case BPF_PROG_TYPE_TRACEPOINT: 89 case BPF_PROG_TYPE_XDP: 90 case BPF_PROG_TYPE_PERF_EVENT: 91 case BPF_PROG_TYPE_CGROUP_SKB: 92 case BPF_PROG_TYPE_CGROUP_SOCK: 93 case BPF_PROG_TYPE_LWT_IN: 94 case BPF_PROG_TYPE_LWT_OUT: 95 case BPF_PROG_TYPE_LWT_XMIT: 96 case BPF_PROG_TYPE_SOCK_OPS: 97 case BPF_PROG_TYPE_SK_SKB: 98 case BPF_PROG_TYPE_CGROUP_DEVICE: 99 case BPF_PROG_TYPE_SK_MSG: 100 case BPF_PROG_TYPE_RAW_TRACEPOINT: 101 case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE: 102 case BPF_PROG_TYPE_LWT_SEG6LOCAL: 103 case BPF_PROG_TYPE_LIRC_MODE2: 104 case BPF_PROG_TYPE_SK_REUSEPORT: 105 case BPF_PROG_TYPE_FLOW_DISSECTOR: 106 case BPF_PROG_TYPE_CGROUP_SYSCTL: 107 case BPF_PROG_TYPE_CGROUP_SOCKOPT: 108 case BPF_PROG_TYPE_TRACING: 109 case BPF_PROG_TYPE_STRUCT_OPS: 110 case BPF_PROG_TYPE_EXT: 111 case BPF_PROG_TYPE_LSM: 112 default: 113 break; 114 } 115 116 xattr.prog_type = prog_type; 117 xattr.insns = insns; 118 xattr.insns_cnt = insns_cnt; 119 xattr.license = "GPL"; 120 xattr.prog_ifindex = ifindex; 121 122 fd = bpf_load_program_xattr(&xattr, buf, buf_len); 123 if (fd >= 0) 124 close(fd); 125 } 126 127 bool bpf_probe_prog_type(enum bpf_prog_type prog_type, __u32 ifindex) 128 { 129 struct bpf_insn insns[2] = { 130 BPF_MOV64_IMM(BPF_REG_0, 0), 131 BPF_EXIT_INSN() 132 }; 133 134 if (ifindex && prog_type == BPF_PROG_TYPE_SCHED_CLS) 135 /* nfp returns -EINVAL on exit(0) with TC offload */ 136 insns[0].imm = 2; 137 138 errno = 0; 139 probe_load(prog_type, insns, ARRAY_SIZE(insns), NULL, 0, ifindex); 140 141 return errno != EINVAL && errno != EOPNOTSUPP; 142 } 143 144 int libbpf__load_raw_btf(const char *raw_types, size_t types_len, 145 const char *str_sec, size_t str_len) 146 { 147 struct btf_header hdr = { 148 .magic = BTF_MAGIC, 149 .version = BTF_VERSION, 150 .hdr_len = sizeof(struct btf_header), 151 .type_len = types_len, 152 .str_off = types_len, 153 .str_len = str_len, 154 }; 155 int btf_fd, btf_len; 156 __u8 *raw_btf; 157 158 btf_len = hdr.hdr_len + hdr.type_len + hdr.str_len; 159 raw_btf = malloc(btf_len); 160 if (!raw_btf) 161 return -ENOMEM; 162 163 memcpy(raw_btf, &hdr, sizeof(hdr)); 164 memcpy(raw_btf + hdr.hdr_len, raw_types, hdr.type_len); 165 memcpy(raw_btf + hdr.hdr_len + hdr.type_len, str_sec, hdr.str_len); 166 167 btf_fd = bpf_load_btf(raw_btf, btf_len, NULL, 0, false); 168 169 free(raw_btf); 170 return btf_fd; 171 } 172 173 static int load_sk_storage_btf(void) 174 { 175 const char strs[] = "\0bpf_spin_lock\0val\0cnt\0l"; 176 /* struct bpf_spin_lock { 177 * int val; 178 * }; 179 * struct val { 180 * int cnt; 181 * struct bpf_spin_lock l; 182 * }; 183 */ 184 __u32 types[] = { 185 /* int */ 186 BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4), /* [1] */ 187 /* struct bpf_spin_lock */ /* [2] */ 188 BTF_TYPE_ENC(1, BTF_INFO_ENC(BTF_KIND_STRUCT, 0, 1), 4), 189 BTF_MEMBER_ENC(15, 1, 0), /* int val; */ 190 /* struct val */ /* [3] */ 191 BTF_TYPE_ENC(15, BTF_INFO_ENC(BTF_KIND_STRUCT, 0, 2), 8), 192 BTF_MEMBER_ENC(19, 1, 0), /* int cnt; */ 193 BTF_MEMBER_ENC(23, 2, 32),/* struct bpf_spin_lock l; */ 194 }; 195 196 return libbpf__load_raw_btf((char *)types, sizeof(types), 197 strs, sizeof(strs)); 198 } 199 200 bool bpf_probe_map_type(enum bpf_map_type map_type, __u32 ifindex) 201 { 202 int key_size, value_size, max_entries, map_flags; 203 __u32 btf_key_type_id = 0, btf_value_type_id = 0; 204 struct bpf_create_map_attr attr = {}; 205 int fd = -1, btf_fd = -1, fd_inner; 206 207 key_size = sizeof(__u32); 208 value_size = sizeof(__u32); 209 max_entries = 1; 210 map_flags = 0; 211 212 switch (map_type) { 213 case BPF_MAP_TYPE_STACK_TRACE: 214 value_size = sizeof(__u64); 215 break; 216 case BPF_MAP_TYPE_LPM_TRIE: 217 key_size = sizeof(__u64); 218 value_size = sizeof(__u64); 219 map_flags = BPF_F_NO_PREALLOC; 220 break; 221 case BPF_MAP_TYPE_CGROUP_STORAGE: 222 case BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE: 223 key_size = sizeof(struct bpf_cgroup_storage_key); 224 value_size = sizeof(__u64); 225 max_entries = 0; 226 break; 227 case BPF_MAP_TYPE_QUEUE: 228 case BPF_MAP_TYPE_STACK: 229 key_size = 0; 230 break; 231 case BPF_MAP_TYPE_SK_STORAGE: 232 btf_key_type_id = 1; 233 btf_value_type_id = 3; 234 value_size = 8; 235 max_entries = 0; 236 map_flags = BPF_F_NO_PREALLOC; 237 btf_fd = load_sk_storage_btf(); 238 if (btf_fd < 0) 239 return false; 240 break; 241 case BPF_MAP_TYPE_UNSPEC: 242 case BPF_MAP_TYPE_HASH: 243 case BPF_MAP_TYPE_ARRAY: 244 case BPF_MAP_TYPE_PROG_ARRAY: 245 case BPF_MAP_TYPE_PERF_EVENT_ARRAY: 246 case BPF_MAP_TYPE_PERCPU_HASH: 247 case BPF_MAP_TYPE_PERCPU_ARRAY: 248 case BPF_MAP_TYPE_CGROUP_ARRAY: 249 case BPF_MAP_TYPE_LRU_HASH: 250 case BPF_MAP_TYPE_LRU_PERCPU_HASH: 251 case BPF_MAP_TYPE_ARRAY_OF_MAPS: 252 case BPF_MAP_TYPE_HASH_OF_MAPS: 253 case BPF_MAP_TYPE_DEVMAP: 254 case BPF_MAP_TYPE_DEVMAP_HASH: 255 case BPF_MAP_TYPE_SOCKMAP: 256 case BPF_MAP_TYPE_CPUMAP: 257 case BPF_MAP_TYPE_XSKMAP: 258 case BPF_MAP_TYPE_SOCKHASH: 259 case BPF_MAP_TYPE_REUSEPORT_SOCKARRAY: 260 case BPF_MAP_TYPE_STRUCT_OPS: 261 default: 262 break; 263 } 264 265 if (map_type == BPF_MAP_TYPE_ARRAY_OF_MAPS || 266 map_type == BPF_MAP_TYPE_HASH_OF_MAPS) { 267 /* TODO: probe for device, once libbpf has a function to create 268 * map-in-map for offload 269 */ 270 if (ifindex) 271 return false; 272 273 fd_inner = bpf_create_map(BPF_MAP_TYPE_HASH, 274 sizeof(__u32), sizeof(__u32), 1, 0); 275 if (fd_inner < 0) 276 return false; 277 fd = bpf_create_map_in_map(map_type, NULL, sizeof(__u32), 278 fd_inner, 1, 0); 279 close(fd_inner); 280 } else { 281 /* Note: No other restriction on map type probes for offload */ 282 attr.map_type = map_type; 283 attr.key_size = key_size; 284 attr.value_size = value_size; 285 attr.max_entries = max_entries; 286 attr.map_flags = map_flags; 287 attr.map_ifindex = ifindex; 288 if (btf_fd >= 0) { 289 attr.btf_fd = btf_fd; 290 attr.btf_key_type_id = btf_key_type_id; 291 attr.btf_value_type_id = btf_value_type_id; 292 } 293 294 fd = bpf_create_map_xattr(&attr); 295 } 296 if (fd >= 0) 297 close(fd); 298 if (btf_fd >= 0) 299 close(btf_fd); 300 301 return fd >= 0; 302 } 303 304 bool bpf_probe_helper(enum bpf_func_id id, enum bpf_prog_type prog_type, 305 __u32 ifindex) 306 { 307 struct bpf_insn insns[2] = { 308 BPF_EMIT_CALL(id), 309 BPF_EXIT_INSN() 310 }; 311 char buf[4096] = {}; 312 bool res; 313 314 probe_load(prog_type, insns, ARRAY_SIZE(insns), buf, sizeof(buf), 315 ifindex); 316 res = !grep(buf, "invalid func ") && !grep(buf, "unknown func "); 317 318 if (ifindex) { 319 switch (get_vendor_id(ifindex)) { 320 case 0x19ee: /* Netronome specific */ 321 res = res && !grep(buf, "not supported by FW") && 322 !grep(buf, "unsupported function id"); 323 break; 324 default: 325 break; 326 } 327 } 328 329 return res; 330 } 331 332 /* 333 * Probe for availability of kernel commit (5.3): 334 * 335 * c04c0d2b968a ("bpf: increase complexity limit and maximum program size") 336 */ 337 bool bpf_probe_large_insn_limit(__u32 ifindex) 338 { 339 struct bpf_insn insns[BPF_MAXINSNS + 1]; 340 int i; 341 342 for (i = 0; i < BPF_MAXINSNS; i++) 343 insns[i] = BPF_MOV64_IMM(BPF_REG_0, 1); 344 insns[BPF_MAXINSNS] = BPF_EXIT_INSN(); 345 346 errno = 0; 347 probe_load(BPF_PROG_TYPE_SCHED_CLS, insns, ARRAY_SIZE(insns), NULL, 0, 348 ifindex); 349 350 return errno != E2BIG && errno != EINVAL; 351 } 352