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_SK_LOOKUP: 82 xattr.expected_attach_type = BPF_SK_LOOKUP; 83 break; 84 case BPF_PROG_TYPE_KPROBE: 85 xattr.kern_version = get_kernel_version(); 86 break; 87 case BPF_PROG_TYPE_UNSPEC: 88 case BPF_PROG_TYPE_SOCKET_FILTER: 89 case BPF_PROG_TYPE_SCHED_CLS: 90 case BPF_PROG_TYPE_SCHED_ACT: 91 case BPF_PROG_TYPE_TRACEPOINT: 92 case BPF_PROG_TYPE_XDP: 93 case BPF_PROG_TYPE_PERF_EVENT: 94 case BPF_PROG_TYPE_CGROUP_SKB: 95 case BPF_PROG_TYPE_CGROUP_SOCK: 96 case BPF_PROG_TYPE_LWT_IN: 97 case BPF_PROG_TYPE_LWT_OUT: 98 case BPF_PROG_TYPE_LWT_XMIT: 99 case BPF_PROG_TYPE_SOCK_OPS: 100 case BPF_PROG_TYPE_SK_SKB: 101 case BPF_PROG_TYPE_CGROUP_DEVICE: 102 case BPF_PROG_TYPE_SK_MSG: 103 case BPF_PROG_TYPE_RAW_TRACEPOINT: 104 case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE: 105 case BPF_PROG_TYPE_LWT_SEG6LOCAL: 106 case BPF_PROG_TYPE_LIRC_MODE2: 107 case BPF_PROG_TYPE_SK_REUSEPORT: 108 case BPF_PROG_TYPE_FLOW_DISSECTOR: 109 case BPF_PROG_TYPE_CGROUP_SYSCTL: 110 case BPF_PROG_TYPE_CGROUP_SOCKOPT: 111 case BPF_PROG_TYPE_TRACING: 112 case BPF_PROG_TYPE_STRUCT_OPS: 113 case BPF_PROG_TYPE_EXT: 114 case BPF_PROG_TYPE_LSM: 115 default: 116 break; 117 } 118 119 xattr.prog_type = prog_type; 120 xattr.insns = insns; 121 xattr.insns_cnt = insns_cnt; 122 xattr.license = "GPL"; 123 xattr.prog_ifindex = ifindex; 124 125 fd = bpf_load_program_xattr(&xattr, buf, buf_len); 126 if (fd >= 0) 127 close(fd); 128 } 129 130 bool bpf_probe_prog_type(enum bpf_prog_type prog_type, __u32 ifindex) 131 { 132 struct bpf_insn insns[2] = { 133 BPF_MOV64_IMM(BPF_REG_0, 0), 134 BPF_EXIT_INSN() 135 }; 136 137 if (ifindex && prog_type == BPF_PROG_TYPE_SCHED_CLS) 138 /* nfp returns -EINVAL on exit(0) with TC offload */ 139 insns[0].imm = 2; 140 141 errno = 0; 142 probe_load(prog_type, insns, ARRAY_SIZE(insns), NULL, 0, ifindex); 143 144 return errno != EINVAL && errno != EOPNOTSUPP; 145 } 146 147 int libbpf__load_raw_btf(const char *raw_types, size_t types_len, 148 const char *str_sec, size_t str_len) 149 { 150 struct btf_header hdr = { 151 .magic = BTF_MAGIC, 152 .version = BTF_VERSION, 153 .hdr_len = sizeof(struct btf_header), 154 .type_len = types_len, 155 .str_off = types_len, 156 .str_len = str_len, 157 }; 158 int btf_fd, btf_len; 159 __u8 *raw_btf; 160 161 btf_len = hdr.hdr_len + hdr.type_len + hdr.str_len; 162 raw_btf = malloc(btf_len); 163 if (!raw_btf) 164 return -ENOMEM; 165 166 memcpy(raw_btf, &hdr, sizeof(hdr)); 167 memcpy(raw_btf + hdr.hdr_len, raw_types, hdr.type_len); 168 memcpy(raw_btf + hdr.hdr_len + hdr.type_len, str_sec, hdr.str_len); 169 170 btf_fd = bpf_load_btf(raw_btf, btf_len, NULL, 0, false); 171 172 free(raw_btf); 173 return btf_fd; 174 } 175 176 static int load_sk_storage_btf(void) 177 { 178 const char strs[] = "\0bpf_spin_lock\0val\0cnt\0l"; 179 /* struct bpf_spin_lock { 180 * int val; 181 * }; 182 * struct val { 183 * int cnt; 184 * struct bpf_spin_lock l; 185 * }; 186 */ 187 __u32 types[] = { 188 /* int */ 189 BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4), /* [1] */ 190 /* struct bpf_spin_lock */ /* [2] */ 191 BTF_TYPE_ENC(1, BTF_INFO_ENC(BTF_KIND_STRUCT, 0, 1), 4), 192 BTF_MEMBER_ENC(15, 1, 0), /* int val; */ 193 /* struct val */ /* [3] */ 194 BTF_TYPE_ENC(15, BTF_INFO_ENC(BTF_KIND_STRUCT, 0, 2), 8), 195 BTF_MEMBER_ENC(19, 1, 0), /* int cnt; */ 196 BTF_MEMBER_ENC(23, 2, 32),/* struct bpf_spin_lock l; */ 197 }; 198 199 return libbpf__load_raw_btf((char *)types, sizeof(types), 200 strs, sizeof(strs)); 201 } 202 203 bool bpf_probe_map_type(enum bpf_map_type map_type, __u32 ifindex) 204 { 205 int key_size, value_size, max_entries, map_flags; 206 __u32 btf_key_type_id = 0, btf_value_type_id = 0; 207 struct bpf_create_map_attr attr = {}; 208 int fd = -1, btf_fd = -1, fd_inner; 209 210 key_size = sizeof(__u32); 211 value_size = sizeof(__u32); 212 max_entries = 1; 213 map_flags = 0; 214 215 switch (map_type) { 216 case BPF_MAP_TYPE_STACK_TRACE: 217 value_size = sizeof(__u64); 218 break; 219 case BPF_MAP_TYPE_LPM_TRIE: 220 key_size = sizeof(__u64); 221 value_size = sizeof(__u64); 222 map_flags = BPF_F_NO_PREALLOC; 223 break; 224 case BPF_MAP_TYPE_CGROUP_STORAGE: 225 case BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE: 226 key_size = sizeof(struct bpf_cgroup_storage_key); 227 value_size = sizeof(__u64); 228 max_entries = 0; 229 break; 230 case BPF_MAP_TYPE_QUEUE: 231 case BPF_MAP_TYPE_STACK: 232 key_size = 0; 233 break; 234 case BPF_MAP_TYPE_SK_STORAGE: 235 btf_key_type_id = 1; 236 btf_value_type_id = 3; 237 value_size = 8; 238 max_entries = 0; 239 map_flags = BPF_F_NO_PREALLOC; 240 btf_fd = load_sk_storage_btf(); 241 if (btf_fd < 0) 242 return false; 243 break; 244 case BPF_MAP_TYPE_RINGBUF: 245 key_size = 0; 246 value_size = 0; 247 max_entries = 4096; 248 break; 249 case BPF_MAP_TYPE_UNSPEC: 250 case BPF_MAP_TYPE_HASH: 251 case BPF_MAP_TYPE_ARRAY: 252 case BPF_MAP_TYPE_PROG_ARRAY: 253 case BPF_MAP_TYPE_PERF_EVENT_ARRAY: 254 case BPF_MAP_TYPE_PERCPU_HASH: 255 case BPF_MAP_TYPE_PERCPU_ARRAY: 256 case BPF_MAP_TYPE_CGROUP_ARRAY: 257 case BPF_MAP_TYPE_LRU_HASH: 258 case BPF_MAP_TYPE_LRU_PERCPU_HASH: 259 case BPF_MAP_TYPE_ARRAY_OF_MAPS: 260 case BPF_MAP_TYPE_HASH_OF_MAPS: 261 case BPF_MAP_TYPE_DEVMAP: 262 case BPF_MAP_TYPE_DEVMAP_HASH: 263 case BPF_MAP_TYPE_SOCKMAP: 264 case BPF_MAP_TYPE_CPUMAP: 265 case BPF_MAP_TYPE_XSKMAP: 266 case BPF_MAP_TYPE_SOCKHASH: 267 case BPF_MAP_TYPE_REUSEPORT_SOCKARRAY: 268 case BPF_MAP_TYPE_STRUCT_OPS: 269 default: 270 break; 271 } 272 273 if (map_type == BPF_MAP_TYPE_ARRAY_OF_MAPS || 274 map_type == BPF_MAP_TYPE_HASH_OF_MAPS) { 275 /* TODO: probe for device, once libbpf has a function to create 276 * map-in-map for offload 277 */ 278 if (ifindex) 279 return false; 280 281 fd_inner = bpf_create_map(BPF_MAP_TYPE_HASH, 282 sizeof(__u32), sizeof(__u32), 1, 0); 283 if (fd_inner < 0) 284 return false; 285 fd = bpf_create_map_in_map(map_type, NULL, sizeof(__u32), 286 fd_inner, 1, 0); 287 close(fd_inner); 288 } else { 289 /* Note: No other restriction on map type probes for offload */ 290 attr.map_type = map_type; 291 attr.key_size = key_size; 292 attr.value_size = value_size; 293 attr.max_entries = max_entries; 294 attr.map_flags = map_flags; 295 attr.map_ifindex = ifindex; 296 if (btf_fd >= 0) { 297 attr.btf_fd = btf_fd; 298 attr.btf_key_type_id = btf_key_type_id; 299 attr.btf_value_type_id = btf_value_type_id; 300 } 301 302 fd = bpf_create_map_xattr(&attr); 303 } 304 if (fd >= 0) 305 close(fd); 306 if (btf_fd >= 0) 307 close(btf_fd); 308 309 return fd >= 0; 310 } 311 312 bool bpf_probe_helper(enum bpf_func_id id, enum bpf_prog_type prog_type, 313 __u32 ifindex) 314 { 315 struct bpf_insn insns[2] = { 316 BPF_EMIT_CALL(id), 317 BPF_EXIT_INSN() 318 }; 319 char buf[4096] = {}; 320 bool res; 321 322 probe_load(prog_type, insns, ARRAY_SIZE(insns), buf, sizeof(buf), 323 ifindex); 324 res = !grep(buf, "invalid func ") && !grep(buf, "unknown func "); 325 326 if (ifindex) { 327 switch (get_vendor_id(ifindex)) { 328 case 0x19ee: /* Netronome specific */ 329 res = res && !grep(buf, "not supported by FW") && 330 !grep(buf, "unsupported function id"); 331 break; 332 default: 333 break; 334 } 335 } 336 337 return res; 338 } 339 340 /* 341 * Probe for availability of kernel commit (5.3): 342 * 343 * c04c0d2b968a ("bpf: increase complexity limit and maximum program size") 344 */ 345 bool bpf_probe_large_insn_limit(__u32 ifindex) 346 { 347 struct bpf_insn insns[BPF_MAXINSNS + 1]; 348 int i; 349 350 for (i = 0; i < BPF_MAXINSNS; i++) 351 insns[i] = BPF_MOV64_IMM(BPF_REG_0, 1); 352 insns[BPF_MAXINSNS] = BPF_EXIT_INSN(); 353 354 errno = 0; 355 probe_load(BPF_PROG_TYPE_SCHED_CLS, insns, ARRAY_SIZE(insns), NULL, 0, 356 ifindex); 357 358 return errno != E2BIG && errno != EINVAL; 359 } 360