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