1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (c) 2008-2009 Patrick McHardy <[email protected]> 4 * 5 * Development of this code funded by Astaro AG (http://www.astaro.com/) 6 */ 7 8 #include <linux/kernel.h> 9 #include <linux/init.h> 10 #include <linux/module.h> 11 #include <linux/netlink.h> 12 #include <linux/netfilter.h> 13 #include <linux/if_arp.h> 14 #include <linux/netfilter/nf_tables.h> 15 #include <net/netfilter/nf_tables_core.h> 16 #include <net/netfilter/nf_tables_offload.h> 17 #include <net/netfilter/nf_tables.h> 18 19 struct nft_cmp_expr { 20 struct nft_data data; 21 u8 sreg; 22 u8 len; 23 enum nft_cmp_ops op:8; 24 }; 25 26 void nft_cmp_eval(const struct nft_expr *expr, 27 struct nft_regs *regs, 28 const struct nft_pktinfo *pkt) 29 { 30 const struct nft_cmp_expr *priv = nft_expr_priv(expr); 31 int d; 32 33 d = memcmp(®s->data[priv->sreg], &priv->data, priv->len); 34 switch (priv->op) { 35 case NFT_CMP_EQ: 36 if (d != 0) 37 goto mismatch; 38 break; 39 case NFT_CMP_NEQ: 40 if (d == 0) 41 goto mismatch; 42 break; 43 case NFT_CMP_LT: 44 if (d == 0) 45 goto mismatch; 46 fallthrough; 47 case NFT_CMP_LTE: 48 if (d > 0) 49 goto mismatch; 50 break; 51 case NFT_CMP_GT: 52 if (d == 0) 53 goto mismatch; 54 fallthrough; 55 case NFT_CMP_GTE: 56 if (d < 0) 57 goto mismatch; 58 break; 59 } 60 return; 61 62 mismatch: 63 regs->verdict.code = NFT_BREAK; 64 } 65 66 static const struct nla_policy nft_cmp_policy[NFTA_CMP_MAX + 1] = { 67 [NFTA_CMP_SREG] = { .type = NLA_U32 }, 68 [NFTA_CMP_OP] = { .type = NLA_U32 }, 69 [NFTA_CMP_DATA] = { .type = NLA_NESTED }, 70 }; 71 72 static int nft_cmp_init(const struct nft_ctx *ctx, const struct nft_expr *expr, 73 const struct nlattr * const tb[]) 74 { 75 struct nft_cmp_expr *priv = nft_expr_priv(expr); 76 struct nft_data_desc desc; 77 int err; 78 79 err = nft_data_init(NULL, &priv->data, sizeof(priv->data), &desc, 80 tb[NFTA_CMP_DATA]); 81 if (err < 0) 82 return err; 83 84 if (desc.type != NFT_DATA_VALUE) { 85 err = -EINVAL; 86 nft_data_release(&priv->data, desc.type); 87 return err; 88 } 89 90 err = nft_parse_register_load(tb[NFTA_CMP_SREG], &priv->sreg, desc.len); 91 if (err < 0) 92 return err; 93 94 priv->op = ntohl(nla_get_be32(tb[NFTA_CMP_OP])); 95 priv->len = desc.len; 96 return 0; 97 } 98 99 static int nft_cmp_dump(struct sk_buff *skb, const struct nft_expr *expr) 100 { 101 const struct nft_cmp_expr *priv = nft_expr_priv(expr); 102 103 if (nft_dump_register(skb, NFTA_CMP_SREG, priv->sreg)) 104 goto nla_put_failure; 105 if (nla_put_be32(skb, NFTA_CMP_OP, htonl(priv->op))) 106 goto nla_put_failure; 107 108 if (nft_data_dump(skb, NFTA_CMP_DATA, &priv->data, 109 NFT_DATA_VALUE, priv->len) < 0) 110 goto nla_put_failure; 111 return 0; 112 113 nla_put_failure: 114 return -1; 115 } 116 117 union nft_cmp_offload_data { 118 u16 val16; 119 u32 val32; 120 u64 val64; 121 }; 122 123 static void nft_payload_n2h(union nft_cmp_offload_data *data, 124 const u8 *val, u32 len) 125 { 126 switch (len) { 127 case 2: 128 data->val16 = ntohs(*((__be16 *)val)); 129 break; 130 case 4: 131 data->val32 = ntohl(*((__be32 *)val)); 132 break; 133 case 8: 134 data->val64 = be64_to_cpu(*((__be64 *)val)); 135 break; 136 default: 137 WARN_ON_ONCE(1); 138 break; 139 } 140 } 141 142 static int __nft_cmp_offload(struct nft_offload_ctx *ctx, 143 struct nft_flow_rule *flow, 144 const struct nft_cmp_expr *priv) 145 { 146 struct nft_offload_reg *reg = &ctx->regs[priv->sreg]; 147 union nft_cmp_offload_data _data, _datamask; 148 u8 *mask = (u8 *)&flow->match.mask; 149 u8 *key = (u8 *)&flow->match.key; 150 u8 *data, *datamask; 151 152 if (priv->op != NFT_CMP_EQ || priv->len > reg->len) 153 return -EOPNOTSUPP; 154 155 if (reg->flags & NFT_OFFLOAD_F_NETWORK2HOST) { 156 nft_payload_n2h(&_data, (u8 *)&priv->data, reg->len); 157 nft_payload_n2h(&_datamask, (u8 *)®->mask, reg->len); 158 data = (u8 *)&_data; 159 datamask = (u8 *)&_datamask; 160 } else { 161 data = (u8 *)&priv->data; 162 datamask = (u8 *)®->mask; 163 } 164 165 memcpy(key + reg->offset, data, reg->len); 166 memcpy(mask + reg->offset, datamask, reg->len); 167 168 flow->match.dissector.used_keys |= BIT(reg->key); 169 flow->match.dissector.offset[reg->key] = reg->base_offset; 170 171 if (reg->key == FLOW_DISSECTOR_KEY_META && 172 reg->offset == offsetof(struct nft_flow_key, meta.ingress_iftype) && 173 nft_reg_load16(priv->data.data) != ARPHRD_ETHER) 174 return -EOPNOTSUPP; 175 176 nft_offload_update_dependency(ctx, &priv->data, reg->len); 177 178 return 0; 179 } 180 181 static int nft_cmp_offload(struct nft_offload_ctx *ctx, 182 struct nft_flow_rule *flow, 183 const struct nft_expr *expr) 184 { 185 const struct nft_cmp_expr *priv = nft_expr_priv(expr); 186 187 return __nft_cmp_offload(ctx, flow, priv); 188 } 189 190 static const struct nft_expr_ops nft_cmp_ops = { 191 .type = &nft_cmp_type, 192 .size = NFT_EXPR_SIZE(sizeof(struct nft_cmp_expr)), 193 .eval = nft_cmp_eval, 194 .init = nft_cmp_init, 195 .dump = nft_cmp_dump, 196 .reduce = NFT_REDUCE_READONLY, 197 .offload = nft_cmp_offload, 198 }; 199 200 /* Calculate the mask for the nft_cmp_fast expression. On big endian the 201 * mask needs to include the *upper* bytes when interpreting that data as 202 * something smaller than the full u32, therefore a cpu_to_le32 is done. 203 */ 204 static u32 nft_cmp_fast_mask(unsigned int len) 205 { 206 __le32 mask = cpu_to_le32(~0U >> (sizeof_field(struct nft_cmp_fast_expr, 207 data) * BITS_PER_BYTE - len)); 208 209 return (__force u32)mask; 210 } 211 212 static int nft_cmp_fast_init(const struct nft_ctx *ctx, 213 const struct nft_expr *expr, 214 const struct nlattr * const tb[]) 215 { 216 struct nft_cmp_fast_expr *priv = nft_expr_priv(expr); 217 struct nft_data_desc desc; 218 struct nft_data data; 219 int err; 220 221 err = nft_data_init(NULL, &data, sizeof(data), &desc, 222 tb[NFTA_CMP_DATA]); 223 if (err < 0) 224 return err; 225 226 err = nft_parse_register_load(tb[NFTA_CMP_SREG], &priv->sreg, desc.len); 227 if (err < 0) 228 return err; 229 230 desc.len *= BITS_PER_BYTE; 231 232 priv->mask = nft_cmp_fast_mask(desc.len); 233 priv->data = data.data[0] & priv->mask; 234 priv->len = desc.len; 235 priv->inv = ntohl(nla_get_be32(tb[NFTA_CMP_OP])) != NFT_CMP_EQ; 236 return 0; 237 } 238 239 static int nft_cmp_fast_offload(struct nft_offload_ctx *ctx, 240 struct nft_flow_rule *flow, 241 const struct nft_expr *expr) 242 { 243 const struct nft_cmp_fast_expr *priv = nft_expr_priv(expr); 244 struct nft_cmp_expr cmp = { 245 .data = { 246 .data = { 247 [0] = priv->data, 248 }, 249 }, 250 .sreg = priv->sreg, 251 .len = priv->len / BITS_PER_BYTE, 252 .op = priv->inv ? NFT_CMP_NEQ : NFT_CMP_EQ, 253 }; 254 255 return __nft_cmp_offload(ctx, flow, &cmp); 256 } 257 258 static int nft_cmp_fast_dump(struct sk_buff *skb, const struct nft_expr *expr) 259 { 260 const struct nft_cmp_fast_expr *priv = nft_expr_priv(expr); 261 enum nft_cmp_ops op = priv->inv ? NFT_CMP_NEQ : NFT_CMP_EQ; 262 struct nft_data data; 263 264 if (nft_dump_register(skb, NFTA_CMP_SREG, priv->sreg)) 265 goto nla_put_failure; 266 if (nla_put_be32(skb, NFTA_CMP_OP, htonl(op))) 267 goto nla_put_failure; 268 269 data.data[0] = priv->data; 270 if (nft_data_dump(skb, NFTA_CMP_DATA, &data, 271 NFT_DATA_VALUE, priv->len / BITS_PER_BYTE) < 0) 272 goto nla_put_failure; 273 return 0; 274 275 nla_put_failure: 276 return -1; 277 } 278 279 const struct nft_expr_ops nft_cmp_fast_ops = { 280 .type = &nft_cmp_type, 281 .size = NFT_EXPR_SIZE(sizeof(struct nft_cmp_fast_expr)), 282 .eval = NULL, /* inlined */ 283 .init = nft_cmp_fast_init, 284 .dump = nft_cmp_fast_dump, 285 .reduce = NFT_REDUCE_READONLY, 286 .offload = nft_cmp_fast_offload, 287 }; 288 289 static u32 nft_cmp_mask(u32 bitlen) 290 { 291 return (__force u32)cpu_to_le32(~0U >> (sizeof(u32) * BITS_PER_BYTE - bitlen)); 292 } 293 294 static void nft_cmp16_fast_mask(struct nft_data *data, unsigned int bitlen) 295 { 296 int len = bitlen / BITS_PER_BYTE; 297 int i, words = len / sizeof(u32); 298 299 for (i = 0; i < words; i++) { 300 data->data[i] = 0xffffffff; 301 bitlen -= sizeof(u32) * BITS_PER_BYTE; 302 } 303 304 if (len % sizeof(u32)) 305 data->data[i++] = nft_cmp_mask(bitlen); 306 307 for (; i < 4; i++) 308 data->data[i] = 0; 309 } 310 311 static int nft_cmp16_fast_init(const struct nft_ctx *ctx, 312 const struct nft_expr *expr, 313 const struct nlattr * const tb[]) 314 { 315 struct nft_cmp16_fast_expr *priv = nft_expr_priv(expr); 316 struct nft_data_desc desc; 317 int err; 318 319 err = nft_data_init(NULL, &priv->data, sizeof(priv->data), &desc, 320 tb[NFTA_CMP_DATA]); 321 if (err < 0) 322 return err; 323 324 err = nft_parse_register_load(tb[NFTA_CMP_SREG], &priv->sreg, desc.len); 325 if (err < 0) 326 return err; 327 328 nft_cmp16_fast_mask(&priv->mask, desc.len * BITS_PER_BYTE); 329 priv->inv = ntohl(nla_get_be32(tb[NFTA_CMP_OP])) != NFT_CMP_EQ; 330 priv->len = desc.len; 331 332 return 0; 333 } 334 335 static int nft_cmp16_fast_offload(struct nft_offload_ctx *ctx, 336 struct nft_flow_rule *flow, 337 const struct nft_expr *expr) 338 { 339 const struct nft_cmp16_fast_expr *priv = nft_expr_priv(expr); 340 struct nft_cmp_expr cmp = { 341 .data = priv->data, 342 .sreg = priv->sreg, 343 .len = priv->len, 344 .op = priv->inv ? NFT_CMP_NEQ : NFT_CMP_EQ, 345 }; 346 347 return __nft_cmp_offload(ctx, flow, &cmp); 348 } 349 350 static int nft_cmp16_fast_dump(struct sk_buff *skb, const struct nft_expr *expr) 351 { 352 const struct nft_cmp16_fast_expr *priv = nft_expr_priv(expr); 353 enum nft_cmp_ops op = priv->inv ? NFT_CMP_NEQ : NFT_CMP_EQ; 354 355 if (nft_dump_register(skb, NFTA_CMP_SREG, priv->sreg)) 356 goto nla_put_failure; 357 if (nla_put_be32(skb, NFTA_CMP_OP, htonl(op))) 358 goto nla_put_failure; 359 360 if (nft_data_dump(skb, NFTA_CMP_DATA, &priv->data, 361 NFT_DATA_VALUE, priv->len) < 0) 362 goto nla_put_failure; 363 return 0; 364 365 nla_put_failure: 366 return -1; 367 } 368 369 370 const struct nft_expr_ops nft_cmp16_fast_ops = { 371 .type = &nft_cmp_type, 372 .size = NFT_EXPR_SIZE(sizeof(struct nft_cmp16_fast_expr)), 373 .eval = NULL, /* inlined */ 374 .init = nft_cmp16_fast_init, 375 .dump = nft_cmp16_fast_dump, 376 .reduce = NFT_REDUCE_READONLY, 377 .offload = nft_cmp16_fast_offload, 378 }; 379 380 static const struct nft_expr_ops * 381 nft_cmp_select_ops(const struct nft_ctx *ctx, const struct nlattr * const tb[]) 382 { 383 struct nft_data_desc desc; 384 struct nft_data data; 385 enum nft_cmp_ops op; 386 u8 sreg; 387 int err; 388 389 if (tb[NFTA_CMP_SREG] == NULL || 390 tb[NFTA_CMP_OP] == NULL || 391 tb[NFTA_CMP_DATA] == NULL) 392 return ERR_PTR(-EINVAL); 393 394 op = ntohl(nla_get_be32(tb[NFTA_CMP_OP])); 395 switch (op) { 396 case NFT_CMP_EQ: 397 case NFT_CMP_NEQ: 398 case NFT_CMP_LT: 399 case NFT_CMP_LTE: 400 case NFT_CMP_GT: 401 case NFT_CMP_GTE: 402 break; 403 default: 404 return ERR_PTR(-EINVAL); 405 } 406 407 err = nft_data_init(NULL, &data, sizeof(data), &desc, 408 tb[NFTA_CMP_DATA]); 409 if (err < 0) 410 return ERR_PTR(err); 411 412 if (desc.type != NFT_DATA_VALUE) 413 goto err1; 414 415 sreg = ntohl(nla_get_be32(tb[NFTA_CMP_SREG])); 416 417 if (op == NFT_CMP_EQ || op == NFT_CMP_NEQ) { 418 if (desc.len <= sizeof(u32)) 419 return &nft_cmp_fast_ops; 420 else if (desc.len <= sizeof(data) && 421 ((sreg >= NFT_REG_1 && sreg <= NFT_REG_4) || 422 (sreg >= NFT_REG32_00 && sreg <= NFT_REG32_12 && sreg % 2 == 0))) 423 return &nft_cmp16_fast_ops; 424 } 425 return &nft_cmp_ops; 426 err1: 427 nft_data_release(&data, desc.type); 428 return ERR_PTR(-EINVAL); 429 } 430 431 struct nft_expr_type nft_cmp_type __read_mostly = { 432 .name = "cmp", 433 .select_ops = nft_cmp_select_ops, 434 .policy = nft_cmp_policy, 435 .maxattr = NFTA_CMP_MAX, 436 .owner = THIS_MODULE, 437 }; 438