1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net> 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/netfilter/nf_tables.h> 14 #include <net/netfilter/nf_tables_core.h> 15 #include <net/netfilter/nf_tables.h> 16 #include <net/netfilter/nf_tables_offload.h> 17 18 struct nft_bitwise { 19 u8 sreg; 20 u8 dreg; 21 enum nft_bitwise_ops op:8; 22 u8 len; 23 struct nft_data mask; 24 struct nft_data xor; 25 struct nft_data data; 26 }; 27 28 static void nft_bitwise_eval_bool(u32 *dst, const u32 *src, 29 const struct nft_bitwise *priv) 30 { 31 unsigned int i; 32 33 for (i = 0; i < DIV_ROUND_UP(priv->len, 4); i++) 34 dst[i] = (src[i] & priv->mask.data[i]) ^ priv->xor.data[i]; 35 } 36 37 static void nft_bitwise_eval_lshift(u32 *dst, const u32 *src, 38 const struct nft_bitwise *priv) 39 { 40 u32 shift = priv->data.data[0]; 41 unsigned int i; 42 u32 carry = 0; 43 44 for (i = DIV_ROUND_UP(priv->len, sizeof(u32)); i > 0; i--) { 45 dst[i - 1] = (src[i - 1] << shift) | carry; 46 carry = src[i - 1] >> (BITS_PER_TYPE(u32) - shift); 47 } 48 } 49 50 static void nft_bitwise_eval_rshift(u32 *dst, const u32 *src, 51 const struct nft_bitwise *priv) 52 { 53 u32 shift = priv->data.data[0]; 54 unsigned int i; 55 u32 carry = 0; 56 57 for (i = 0; i < DIV_ROUND_UP(priv->len, sizeof(u32)); i++) { 58 dst[i] = carry | (src[i] >> shift); 59 carry = src[i] << (BITS_PER_TYPE(u32) - shift); 60 } 61 } 62 63 void nft_bitwise_eval(const struct nft_expr *expr, 64 struct nft_regs *regs, const struct nft_pktinfo *pkt) 65 { 66 const struct nft_bitwise *priv = nft_expr_priv(expr); 67 const u32 *src = ®s->data[priv->sreg]; 68 u32 *dst = ®s->data[priv->dreg]; 69 70 switch (priv->op) { 71 case NFT_BITWISE_BOOL: 72 nft_bitwise_eval_bool(dst, src, priv); 73 break; 74 case NFT_BITWISE_LSHIFT: 75 nft_bitwise_eval_lshift(dst, src, priv); 76 break; 77 case NFT_BITWISE_RSHIFT: 78 nft_bitwise_eval_rshift(dst, src, priv); 79 break; 80 } 81 } 82 83 static const struct nla_policy nft_bitwise_policy[NFTA_BITWISE_MAX + 1] = { 84 [NFTA_BITWISE_SREG] = { .type = NLA_U32 }, 85 [NFTA_BITWISE_DREG] = { .type = NLA_U32 }, 86 [NFTA_BITWISE_LEN] = { .type = NLA_U32 }, 87 [NFTA_BITWISE_MASK] = { .type = NLA_NESTED }, 88 [NFTA_BITWISE_XOR] = { .type = NLA_NESTED }, 89 [NFTA_BITWISE_OP] = { .type = NLA_U32 }, 90 [NFTA_BITWISE_DATA] = { .type = NLA_NESTED }, 91 }; 92 93 static int nft_bitwise_init_bool(struct nft_bitwise *priv, 94 const struct nlattr *const tb[]) 95 { 96 struct nft_data_desc mask, xor; 97 int err; 98 99 if (tb[NFTA_BITWISE_DATA]) 100 return -EINVAL; 101 102 if (!tb[NFTA_BITWISE_MASK] || 103 !tb[NFTA_BITWISE_XOR]) 104 return -EINVAL; 105 106 err = nft_data_init(NULL, &priv->mask, sizeof(priv->mask), &mask, 107 tb[NFTA_BITWISE_MASK]); 108 if (err < 0) 109 return err; 110 if (mask.type != NFT_DATA_VALUE || mask.len != priv->len) { 111 err = -EINVAL; 112 goto err1; 113 } 114 115 err = nft_data_init(NULL, &priv->xor, sizeof(priv->xor), &xor, 116 tb[NFTA_BITWISE_XOR]); 117 if (err < 0) 118 goto err1; 119 if (xor.type != NFT_DATA_VALUE || xor.len != priv->len) { 120 err = -EINVAL; 121 goto err2; 122 } 123 124 return 0; 125 err2: 126 nft_data_release(&priv->xor, xor.type); 127 err1: 128 nft_data_release(&priv->mask, mask.type); 129 return err; 130 } 131 132 static int nft_bitwise_init_shift(struct nft_bitwise *priv, 133 const struct nlattr *const tb[]) 134 { 135 struct nft_data_desc d; 136 int err; 137 138 if (tb[NFTA_BITWISE_MASK] || 139 tb[NFTA_BITWISE_XOR]) 140 return -EINVAL; 141 142 if (!tb[NFTA_BITWISE_DATA]) 143 return -EINVAL; 144 145 err = nft_data_init(NULL, &priv->data, sizeof(priv->data), &d, 146 tb[NFTA_BITWISE_DATA]); 147 if (err < 0) 148 return err; 149 if (d.type != NFT_DATA_VALUE || d.len != sizeof(u32) || 150 priv->data.data[0] >= BITS_PER_TYPE(u32)) { 151 nft_data_release(&priv->data, d.type); 152 return -EINVAL; 153 } 154 155 return 0; 156 } 157 158 static int nft_bitwise_init(const struct nft_ctx *ctx, 159 const struct nft_expr *expr, 160 const struct nlattr * const tb[]) 161 { 162 struct nft_bitwise *priv = nft_expr_priv(expr); 163 u32 len; 164 int err; 165 166 err = nft_parse_u32_check(tb[NFTA_BITWISE_LEN], U8_MAX, &len); 167 if (err < 0) 168 return err; 169 170 priv->len = len; 171 172 err = nft_parse_register_load(tb[NFTA_BITWISE_SREG], &priv->sreg, 173 priv->len); 174 if (err < 0) 175 return err; 176 177 err = nft_parse_register_store(ctx, tb[NFTA_BITWISE_DREG], 178 &priv->dreg, NULL, NFT_DATA_VALUE, 179 priv->len); 180 if (err < 0) 181 return err; 182 183 if (tb[NFTA_BITWISE_OP]) { 184 priv->op = ntohl(nla_get_be32(tb[NFTA_BITWISE_OP])); 185 switch (priv->op) { 186 case NFT_BITWISE_BOOL: 187 case NFT_BITWISE_LSHIFT: 188 case NFT_BITWISE_RSHIFT: 189 break; 190 default: 191 return -EOPNOTSUPP; 192 } 193 } else { 194 priv->op = NFT_BITWISE_BOOL; 195 } 196 197 switch(priv->op) { 198 case NFT_BITWISE_BOOL: 199 err = nft_bitwise_init_bool(priv, tb); 200 break; 201 case NFT_BITWISE_LSHIFT: 202 case NFT_BITWISE_RSHIFT: 203 err = nft_bitwise_init_shift(priv, tb); 204 break; 205 } 206 207 return err; 208 } 209 210 static int nft_bitwise_dump_bool(struct sk_buff *skb, 211 const struct nft_bitwise *priv) 212 { 213 if (nft_data_dump(skb, NFTA_BITWISE_MASK, &priv->mask, 214 NFT_DATA_VALUE, priv->len) < 0) 215 return -1; 216 217 if (nft_data_dump(skb, NFTA_BITWISE_XOR, &priv->xor, 218 NFT_DATA_VALUE, priv->len) < 0) 219 return -1; 220 221 return 0; 222 } 223 224 static int nft_bitwise_dump_shift(struct sk_buff *skb, 225 const struct nft_bitwise *priv) 226 { 227 if (nft_data_dump(skb, NFTA_BITWISE_DATA, &priv->data, 228 NFT_DATA_VALUE, sizeof(u32)) < 0) 229 return -1; 230 return 0; 231 } 232 233 static int nft_bitwise_dump(struct sk_buff *skb, const struct nft_expr *expr) 234 { 235 const struct nft_bitwise *priv = nft_expr_priv(expr); 236 int err = 0; 237 238 if (nft_dump_register(skb, NFTA_BITWISE_SREG, priv->sreg)) 239 return -1; 240 if (nft_dump_register(skb, NFTA_BITWISE_DREG, priv->dreg)) 241 return -1; 242 if (nla_put_be32(skb, NFTA_BITWISE_LEN, htonl(priv->len))) 243 return -1; 244 if (nla_put_be32(skb, NFTA_BITWISE_OP, htonl(priv->op))) 245 return -1; 246 247 switch (priv->op) { 248 case NFT_BITWISE_BOOL: 249 err = nft_bitwise_dump_bool(skb, priv); 250 break; 251 case NFT_BITWISE_LSHIFT: 252 case NFT_BITWISE_RSHIFT: 253 err = nft_bitwise_dump_shift(skb, priv); 254 break; 255 } 256 257 return err; 258 } 259 260 static struct nft_data zero; 261 262 static int nft_bitwise_offload(struct nft_offload_ctx *ctx, 263 struct nft_flow_rule *flow, 264 const struct nft_expr *expr) 265 { 266 const struct nft_bitwise *priv = nft_expr_priv(expr); 267 struct nft_offload_reg *reg = &ctx->regs[priv->dreg]; 268 269 if (priv->op != NFT_BITWISE_BOOL) 270 return -EOPNOTSUPP; 271 272 if (memcmp(&priv->xor, &zero, sizeof(priv->xor)) || 273 priv->sreg != priv->dreg || priv->len != reg->len) 274 return -EOPNOTSUPP; 275 276 memcpy(®->mask, &priv->mask, sizeof(priv->mask)); 277 278 return 0; 279 } 280 281 static bool nft_bitwise_reduce(struct nft_regs_track *track, 282 const struct nft_expr *expr) 283 { 284 const struct nft_bitwise *priv = nft_expr_priv(expr); 285 const struct nft_bitwise *bitwise; 286 287 if (!track->regs[priv->sreg].selector) 288 return false; 289 290 bitwise = nft_expr_priv(expr); 291 if (track->regs[priv->sreg].selector == track->regs[priv->dreg].selector && 292 track->regs[priv->dreg].bitwise && 293 track->regs[priv->dreg].bitwise->ops == expr->ops && 294 priv->sreg == bitwise->sreg && 295 priv->dreg == bitwise->dreg && 296 priv->op == bitwise->op && 297 priv->len == bitwise->len && 298 !memcmp(&priv->mask, &bitwise->mask, sizeof(priv->mask)) && 299 !memcmp(&priv->xor, &bitwise->xor, sizeof(priv->xor)) && 300 !memcmp(&priv->data, &bitwise->data, sizeof(priv->data))) { 301 track->cur = expr; 302 return true; 303 } 304 305 if (track->regs[priv->sreg].bitwise) { 306 track->regs[priv->dreg].selector = NULL; 307 track->regs[priv->dreg].bitwise = NULL; 308 return false; 309 } 310 311 if (priv->sreg != priv->dreg) { 312 track->regs[priv->dreg].selector = 313 track->regs[priv->sreg].selector; 314 } 315 track->regs[priv->dreg].bitwise = expr; 316 317 return false; 318 } 319 320 static const struct nft_expr_ops nft_bitwise_ops = { 321 .type = &nft_bitwise_type, 322 .size = NFT_EXPR_SIZE(sizeof(struct nft_bitwise)), 323 .eval = nft_bitwise_eval, 324 .init = nft_bitwise_init, 325 .dump = nft_bitwise_dump, 326 .reduce = nft_bitwise_reduce, 327 .offload = nft_bitwise_offload, 328 }; 329 330 static int 331 nft_bitwise_extract_u32_data(const struct nlattr * const tb, u32 *out) 332 { 333 struct nft_data_desc desc; 334 struct nft_data data; 335 int err = 0; 336 337 err = nft_data_init(NULL, &data, sizeof(data), &desc, tb); 338 if (err < 0) 339 return err; 340 341 if (desc.type != NFT_DATA_VALUE || desc.len != sizeof(u32)) { 342 err = -EINVAL; 343 goto err; 344 } 345 *out = data.data[0]; 346 err: 347 nft_data_release(&data, desc.type); 348 return err; 349 } 350 351 static int nft_bitwise_fast_init(const struct nft_ctx *ctx, 352 const struct nft_expr *expr, 353 const struct nlattr * const tb[]) 354 { 355 struct nft_bitwise_fast_expr *priv = nft_expr_priv(expr); 356 int err; 357 358 err = nft_parse_register_load(tb[NFTA_BITWISE_SREG], &priv->sreg, 359 sizeof(u32)); 360 if (err < 0) 361 return err; 362 363 err = nft_parse_register_store(ctx, tb[NFTA_BITWISE_DREG], &priv->dreg, 364 NULL, NFT_DATA_VALUE, sizeof(u32)); 365 if (err < 0) 366 return err; 367 368 if (tb[NFTA_BITWISE_DATA]) 369 return -EINVAL; 370 371 if (!tb[NFTA_BITWISE_MASK] || 372 !tb[NFTA_BITWISE_XOR]) 373 return -EINVAL; 374 375 err = nft_bitwise_extract_u32_data(tb[NFTA_BITWISE_MASK], &priv->mask); 376 if (err < 0) 377 return err; 378 379 err = nft_bitwise_extract_u32_data(tb[NFTA_BITWISE_XOR], &priv->xor); 380 if (err < 0) 381 return err; 382 383 return 0; 384 } 385 386 static int 387 nft_bitwise_fast_dump(struct sk_buff *skb, const struct nft_expr *expr) 388 { 389 const struct nft_bitwise_fast_expr *priv = nft_expr_priv(expr); 390 struct nft_data data; 391 392 if (nft_dump_register(skb, NFTA_BITWISE_SREG, priv->sreg)) 393 return -1; 394 if (nft_dump_register(skb, NFTA_BITWISE_DREG, priv->dreg)) 395 return -1; 396 if (nla_put_be32(skb, NFTA_BITWISE_LEN, htonl(sizeof(u32)))) 397 return -1; 398 if (nla_put_be32(skb, NFTA_BITWISE_OP, htonl(NFT_BITWISE_BOOL))) 399 return -1; 400 401 data.data[0] = priv->mask; 402 if (nft_data_dump(skb, NFTA_BITWISE_MASK, &data, 403 NFT_DATA_VALUE, sizeof(u32)) < 0) 404 return -1; 405 406 data.data[0] = priv->xor; 407 if (nft_data_dump(skb, NFTA_BITWISE_XOR, &data, 408 NFT_DATA_VALUE, sizeof(u32)) < 0) 409 return -1; 410 411 return 0; 412 } 413 414 static int nft_bitwise_fast_offload(struct nft_offload_ctx *ctx, 415 struct nft_flow_rule *flow, 416 const struct nft_expr *expr) 417 { 418 const struct nft_bitwise_fast_expr *priv = nft_expr_priv(expr); 419 struct nft_offload_reg *reg = &ctx->regs[priv->dreg]; 420 421 if (priv->xor || priv->sreg != priv->dreg || reg->len != sizeof(u32)) 422 return -EOPNOTSUPP; 423 424 reg->mask.data[0] = priv->mask; 425 return 0; 426 } 427 428 static bool nft_bitwise_fast_reduce(struct nft_regs_track *track, 429 const struct nft_expr *expr) 430 { 431 const struct nft_bitwise_fast_expr *priv = nft_expr_priv(expr); 432 const struct nft_bitwise_fast_expr *bitwise; 433 434 if (!track->regs[priv->sreg].selector) 435 return false; 436 437 bitwise = nft_expr_priv(expr); 438 if (track->regs[priv->sreg].selector == track->regs[priv->dreg].selector && 439 track->regs[priv->dreg].bitwise && 440 track->regs[priv->dreg].bitwise->ops == expr->ops && 441 priv->sreg == bitwise->sreg && 442 priv->dreg == bitwise->dreg && 443 priv->mask == bitwise->mask && 444 priv->xor == bitwise->xor) { 445 track->cur = expr; 446 return true; 447 } 448 449 if (track->regs[priv->sreg].bitwise) { 450 track->regs[priv->dreg].selector = NULL; 451 track->regs[priv->dreg].bitwise = NULL; 452 return false; 453 } 454 455 if (priv->sreg != priv->dreg) { 456 track->regs[priv->dreg].selector = 457 track->regs[priv->sreg].selector; 458 } 459 track->regs[priv->dreg].bitwise = expr; 460 461 return false; 462 } 463 464 const struct nft_expr_ops nft_bitwise_fast_ops = { 465 .type = &nft_bitwise_type, 466 .size = NFT_EXPR_SIZE(sizeof(struct nft_bitwise_fast_expr)), 467 .eval = NULL, /* inlined */ 468 .init = nft_bitwise_fast_init, 469 .dump = nft_bitwise_fast_dump, 470 .reduce = nft_bitwise_fast_reduce, 471 .offload = nft_bitwise_fast_offload, 472 }; 473 474 static const struct nft_expr_ops * 475 nft_bitwise_select_ops(const struct nft_ctx *ctx, 476 const struct nlattr * const tb[]) 477 { 478 int err; 479 u32 len; 480 481 if (!tb[NFTA_BITWISE_LEN] || 482 !tb[NFTA_BITWISE_SREG] || 483 !tb[NFTA_BITWISE_DREG]) 484 return ERR_PTR(-EINVAL); 485 486 err = nft_parse_u32_check(tb[NFTA_BITWISE_LEN], U8_MAX, &len); 487 if (err < 0) 488 return ERR_PTR(err); 489 490 if (len != sizeof(u32)) 491 return &nft_bitwise_ops; 492 493 if (tb[NFTA_BITWISE_OP] && 494 ntohl(nla_get_be32(tb[NFTA_BITWISE_OP])) != NFT_BITWISE_BOOL) 495 return &nft_bitwise_ops; 496 497 return &nft_bitwise_fast_ops; 498 } 499 500 struct nft_expr_type nft_bitwise_type __read_mostly = { 501 .name = "bitwise", 502 .select_ops = nft_bitwise_select_ops, 503 .policy = nft_bitwise_policy, 504 .maxattr = NFTA_BITWISE_MAX, 505 .owner = THIS_MODULE, 506 }; 507 508 bool nft_expr_reduce_bitwise(struct nft_regs_track *track, 509 const struct nft_expr *expr) 510 { 511 const struct nft_expr *last = track->last; 512 const struct nft_expr *next; 513 514 if (expr == last) 515 return false; 516 517 next = nft_expr_next(expr); 518 if (next->ops == &nft_bitwise_ops) 519 return nft_bitwise_reduce(track, next); 520 else if (next->ops == &nft_bitwise_fast_ops) 521 return nft_bitwise_fast_reduce(track, next); 522 523 return false; 524 } 525