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