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(*((u16 *)val)); 129 break; 130 case 4: 131 data->val32 = ntohl(*((u32 *)val)); 132 break; 133 case 8: 134 data->val64 = be64_to_cpu(*((u64 *)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 .offload = nft_cmp_offload, 197 }; 198 199 static int nft_cmp_fast_init(const struct nft_ctx *ctx, 200 const struct nft_expr *expr, 201 const struct nlattr * const tb[]) 202 { 203 struct nft_cmp_fast_expr *priv = nft_expr_priv(expr); 204 struct nft_data_desc desc; 205 struct nft_data data; 206 int err; 207 208 err = nft_data_init(NULL, &data, sizeof(data), &desc, 209 tb[NFTA_CMP_DATA]); 210 if (err < 0) 211 return err; 212 213 err = nft_parse_register_load(tb[NFTA_CMP_SREG], &priv->sreg, desc.len); 214 if (err < 0) 215 return err; 216 217 desc.len *= BITS_PER_BYTE; 218 219 priv->mask = nft_cmp_fast_mask(desc.len); 220 priv->data = data.data[0] & priv->mask; 221 priv->len = desc.len; 222 priv->inv = ntohl(nla_get_be32(tb[NFTA_CMP_OP])) != NFT_CMP_EQ; 223 return 0; 224 } 225 226 static int nft_cmp_fast_offload(struct nft_offload_ctx *ctx, 227 struct nft_flow_rule *flow, 228 const struct nft_expr *expr) 229 { 230 const struct nft_cmp_fast_expr *priv = nft_expr_priv(expr); 231 struct nft_cmp_expr cmp = { 232 .data = { 233 .data = { 234 [0] = priv->data, 235 }, 236 }, 237 .sreg = priv->sreg, 238 .len = priv->len / BITS_PER_BYTE, 239 .op = priv->inv ? NFT_CMP_NEQ : NFT_CMP_EQ, 240 }; 241 242 return __nft_cmp_offload(ctx, flow, &cmp); 243 } 244 245 static int nft_cmp_fast_dump(struct sk_buff *skb, const struct nft_expr *expr) 246 { 247 const struct nft_cmp_fast_expr *priv = nft_expr_priv(expr); 248 enum nft_cmp_ops op = priv->inv ? NFT_CMP_NEQ : NFT_CMP_EQ; 249 struct nft_data data; 250 251 if (nft_dump_register(skb, NFTA_CMP_SREG, priv->sreg)) 252 goto nla_put_failure; 253 if (nla_put_be32(skb, NFTA_CMP_OP, htonl(op))) 254 goto nla_put_failure; 255 256 data.data[0] = priv->data; 257 if (nft_data_dump(skb, NFTA_CMP_DATA, &data, 258 NFT_DATA_VALUE, priv->len / BITS_PER_BYTE) < 0) 259 goto nla_put_failure; 260 return 0; 261 262 nla_put_failure: 263 return -1; 264 } 265 266 const struct nft_expr_ops nft_cmp_fast_ops = { 267 .type = &nft_cmp_type, 268 .size = NFT_EXPR_SIZE(sizeof(struct nft_cmp_fast_expr)), 269 .eval = NULL, /* inlined */ 270 .init = nft_cmp_fast_init, 271 .dump = nft_cmp_fast_dump, 272 .offload = nft_cmp_fast_offload, 273 }; 274 275 static u32 nft_cmp_mask(u32 bitlen) 276 { 277 return (__force u32)cpu_to_le32(~0U >> (sizeof(u32) * BITS_PER_BYTE - bitlen)); 278 } 279 280 static void nft_cmp16_fast_mask(struct nft_data *data, unsigned int bitlen) 281 { 282 int len = bitlen / BITS_PER_BYTE; 283 int i, words = len / sizeof(u32); 284 285 for (i = 0; i < words; i++) { 286 data->data[i] = 0xffffffff; 287 bitlen -= sizeof(u32) * BITS_PER_BYTE; 288 } 289 290 if (len % sizeof(u32)) 291 data->data[i++] = nft_cmp_mask(bitlen); 292 293 for (; i < 4; i++) 294 data->data[i] = 0; 295 } 296 297 static int nft_cmp16_fast_init(const struct nft_ctx *ctx, 298 const struct nft_expr *expr, 299 const struct nlattr * const tb[]) 300 { 301 struct nft_cmp16_fast_expr *priv = nft_expr_priv(expr); 302 struct nft_data_desc desc; 303 int err; 304 305 err = nft_data_init(NULL, &priv->data, sizeof(priv->data), &desc, 306 tb[NFTA_CMP_DATA]); 307 if (err < 0) 308 return err; 309 310 err = nft_parse_register_load(tb[NFTA_CMP_SREG], &priv->sreg, desc.len); 311 if (err < 0) 312 return err; 313 314 nft_cmp16_fast_mask(&priv->mask, desc.len * BITS_PER_BYTE); 315 priv->inv = ntohl(nla_get_be32(tb[NFTA_CMP_OP])) != NFT_CMP_EQ; 316 priv->len = desc.len; 317 318 return 0; 319 } 320 321 static int nft_cmp16_fast_offload(struct nft_offload_ctx *ctx, 322 struct nft_flow_rule *flow, 323 const struct nft_expr *expr) 324 { 325 const struct nft_cmp16_fast_expr *priv = nft_expr_priv(expr); 326 struct nft_cmp_expr cmp = { 327 .data = priv->data, 328 .sreg = priv->sreg, 329 .len = priv->len, 330 .op = priv->inv ? NFT_CMP_NEQ : NFT_CMP_EQ, 331 }; 332 333 return __nft_cmp_offload(ctx, flow, &cmp); 334 } 335 336 static int nft_cmp16_fast_dump(struct sk_buff *skb, const struct nft_expr *expr) 337 { 338 const struct nft_cmp16_fast_expr *priv = nft_expr_priv(expr); 339 enum nft_cmp_ops op = priv->inv ? NFT_CMP_NEQ : NFT_CMP_EQ; 340 341 if (nft_dump_register(skb, NFTA_CMP_SREG, priv->sreg)) 342 goto nla_put_failure; 343 if (nla_put_be32(skb, NFTA_CMP_OP, htonl(op))) 344 goto nla_put_failure; 345 346 if (nft_data_dump(skb, NFTA_CMP_DATA, &priv->data, 347 NFT_DATA_VALUE, priv->len) < 0) 348 goto nla_put_failure; 349 return 0; 350 351 nla_put_failure: 352 return -1; 353 } 354 355 356 const struct nft_expr_ops nft_cmp16_fast_ops = { 357 .type = &nft_cmp_type, 358 .size = NFT_EXPR_SIZE(sizeof(struct nft_cmp16_fast_expr)), 359 .eval = NULL, /* inlined */ 360 .init = nft_cmp16_fast_init, 361 .dump = nft_cmp16_fast_dump, 362 .offload = nft_cmp16_fast_offload, 363 }; 364 365 static const struct nft_expr_ops * 366 nft_cmp_select_ops(const struct nft_ctx *ctx, const struct nlattr * const tb[]) 367 { 368 struct nft_data_desc desc; 369 struct nft_data data; 370 enum nft_cmp_ops op; 371 u8 sreg; 372 int err; 373 374 if (tb[NFTA_CMP_SREG] == NULL || 375 tb[NFTA_CMP_OP] == NULL || 376 tb[NFTA_CMP_DATA] == NULL) 377 return ERR_PTR(-EINVAL); 378 379 op = ntohl(nla_get_be32(tb[NFTA_CMP_OP])); 380 switch (op) { 381 case NFT_CMP_EQ: 382 case NFT_CMP_NEQ: 383 case NFT_CMP_LT: 384 case NFT_CMP_LTE: 385 case NFT_CMP_GT: 386 case NFT_CMP_GTE: 387 break; 388 default: 389 return ERR_PTR(-EINVAL); 390 } 391 392 err = nft_data_init(NULL, &data, sizeof(data), &desc, 393 tb[NFTA_CMP_DATA]); 394 if (err < 0) 395 return ERR_PTR(err); 396 397 if (desc.type != NFT_DATA_VALUE) 398 goto err1; 399 400 sreg = ntohl(nla_get_be32(tb[NFTA_CMP_SREG])); 401 402 if (op == NFT_CMP_EQ || op == NFT_CMP_NEQ) { 403 if (desc.len <= sizeof(u32)) 404 return &nft_cmp_fast_ops; 405 else if (desc.len <= sizeof(data) && 406 ((sreg >= NFT_REG_1 && sreg <= NFT_REG_4) || 407 (sreg >= NFT_REG32_00 && sreg <= NFT_REG32_12 && sreg % 2 == 0))) 408 return &nft_cmp16_fast_ops; 409 } 410 return &nft_cmp_ops; 411 err1: 412 nft_data_release(&data, desc.type); 413 return ERR_PTR(-EINVAL); 414 } 415 416 struct nft_expr_type nft_cmp_type __read_mostly = { 417 .name = "cmp", 418 .select_ops = nft_cmp_select_ops, 419 .policy = nft_cmp_policy, 420 .maxattr = NFTA_CMP_MAX, 421 .owner = THIS_MODULE, 422 }; 423