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, sizeof(u32)); 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 = { 97 .type = NFT_DATA_VALUE, 98 .size = sizeof(priv->mask), 99 .len = priv->len, 100 }; 101 struct nft_data_desc xor = { 102 .type = NFT_DATA_VALUE, 103 .size = sizeof(priv->xor), 104 .len = priv->len, 105 }; 106 int err; 107 108 if (tb[NFTA_BITWISE_DATA]) 109 return -EINVAL; 110 111 if (!tb[NFTA_BITWISE_MASK] || 112 !tb[NFTA_BITWISE_XOR]) 113 return -EINVAL; 114 115 err = nft_data_init(NULL, &priv->mask, &mask, tb[NFTA_BITWISE_MASK]); 116 if (err < 0) 117 return err; 118 119 err = nft_data_init(NULL, &priv->xor, &xor, tb[NFTA_BITWISE_XOR]); 120 if (err < 0) 121 goto err_xor_err; 122 123 return 0; 124 125 err_xor_err: 126 nft_data_release(&priv->mask, mask.type); 127 128 return err; 129 } 130 131 static int nft_bitwise_init_shift(struct nft_bitwise *priv, 132 const struct nlattr *const tb[]) 133 { 134 struct nft_data_desc desc = { 135 .type = NFT_DATA_VALUE, 136 .size = sizeof(priv->data), 137 .len = sizeof(u32), 138 }; 139 int err; 140 141 if (tb[NFTA_BITWISE_MASK] || 142 tb[NFTA_BITWISE_XOR]) 143 return -EINVAL; 144 145 if (!tb[NFTA_BITWISE_DATA]) 146 return -EINVAL; 147 148 err = nft_data_init(NULL, &priv->data, &desc, tb[NFTA_BITWISE_DATA]); 149 if (err < 0) 150 return err; 151 152 if (priv->data.data[0] >= BITS_PER_TYPE(u32)) { 153 nft_data_release(&priv->data, desc.type); 154 return -EINVAL; 155 } 156 157 return 0; 158 } 159 160 static int nft_bitwise_init(const struct nft_ctx *ctx, 161 const struct nft_expr *expr, 162 const struct nlattr * const tb[]) 163 { 164 struct nft_bitwise *priv = nft_expr_priv(expr); 165 u32 len; 166 int err; 167 168 err = nft_parse_u32_check(tb[NFTA_BITWISE_LEN], U8_MAX, &len); 169 if (err < 0) 170 return err; 171 172 priv->len = len; 173 174 err = nft_parse_register_load(tb[NFTA_BITWISE_SREG], &priv->sreg, 175 priv->len); 176 if (err < 0) 177 return err; 178 179 err = nft_parse_register_store(ctx, tb[NFTA_BITWISE_DREG], 180 &priv->dreg, NULL, NFT_DATA_VALUE, 181 priv->len); 182 if (err < 0) 183 return err; 184 185 if (tb[NFTA_BITWISE_OP]) { 186 priv->op = ntohl(nla_get_be32(tb[NFTA_BITWISE_OP])); 187 switch (priv->op) { 188 case NFT_BITWISE_BOOL: 189 case NFT_BITWISE_LSHIFT: 190 case NFT_BITWISE_RSHIFT: 191 break; 192 default: 193 return -EOPNOTSUPP; 194 } 195 } else { 196 priv->op = NFT_BITWISE_BOOL; 197 } 198 199 switch(priv->op) { 200 case NFT_BITWISE_BOOL: 201 err = nft_bitwise_init_bool(priv, tb); 202 break; 203 case NFT_BITWISE_LSHIFT: 204 case NFT_BITWISE_RSHIFT: 205 err = nft_bitwise_init_shift(priv, tb); 206 break; 207 } 208 209 return err; 210 } 211 212 static int nft_bitwise_dump_bool(struct sk_buff *skb, 213 const struct nft_bitwise *priv) 214 { 215 if (nft_data_dump(skb, NFTA_BITWISE_MASK, &priv->mask, 216 NFT_DATA_VALUE, priv->len) < 0) 217 return -1; 218 219 if (nft_data_dump(skb, NFTA_BITWISE_XOR, &priv->xor, 220 NFT_DATA_VALUE, priv->len) < 0) 221 return -1; 222 223 return 0; 224 } 225 226 static int nft_bitwise_dump_shift(struct sk_buff *skb, 227 const struct nft_bitwise *priv) 228 { 229 if (nft_data_dump(skb, NFTA_BITWISE_DATA, &priv->data, 230 NFT_DATA_VALUE, sizeof(u32)) < 0) 231 return -1; 232 return 0; 233 } 234 235 static int nft_bitwise_dump(struct sk_buff *skb, const struct nft_expr *expr) 236 { 237 const struct nft_bitwise *priv = nft_expr_priv(expr); 238 int err = 0; 239 240 if (nft_dump_register(skb, NFTA_BITWISE_SREG, priv->sreg)) 241 return -1; 242 if (nft_dump_register(skb, NFTA_BITWISE_DREG, priv->dreg)) 243 return -1; 244 if (nla_put_be32(skb, NFTA_BITWISE_LEN, htonl(priv->len))) 245 return -1; 246 if (nla_put_be32(skb, NFTA_BITWISE_OP, htonl(priv->op))) 247 return -1; 248 249 switch (priv->op) { 250 case NFT_BITWISE_BOOL: 251 err = nft_bitwise_dump_bool(skb, priv); 252 break; 253 case NFT_BITWISE_LSHIFT: 254 case NFT_BITWISE_RSHIFT: 255 err = nft_bitwise_dump_shift(skb, priv); 256 break; 257 } 258 259 return err; 260 } 261 262 static struct nft_data zero; 263 264 static int nft_bitwise_offload(struct nft_offload_ctx *ctx, 265 struct nft_flow_rule *flow, 266 const struct nft_expr *expr) 267 { 268 const struct nft_bitwise *priv = nft_expr_priv(expr); 269 struct nft_offload_reg *reg = &ctx->regs[priv->dreg]; 270 271 if (priv->op != NFT_BITWISE_BOOL) 272 return -EOPNOTSUPP; 273 274 if (memcmp(&priv->xor, &zero, sizeof(priv->xor)) || 275 priv->sreg != priv->dreg || priv->len != reg->len) 276 return -EOPNOTSUPP; 277 278 memcpy(®->mask, &priv->mask, sizeof(priv->mask)); 279 280 return 0; 281 } 282 283 static bool nft_bitwise_reduce(struct nft_regs_track *track, 284 const struct nft_expr *expr) 285 { 286 const struct nft_bitwise *priv = nft_expr_priv(expr); 287 const struct nft_bitwise *bitwise; 288 unsigned int regcount; 289 u8 dreg; 290 int i; 291 292 if (!track->regs[priv->sreg].selector) 293 return false; 294 295 bitwise = nft_expr_priv(track->regs[priv->dreg].selector); 296 if (track->regs[priv->sreg].selector == track->regs[priv->dreg].selector && 297 track->regs[priv->sreg].num_reg == 0 && 298 track->regs[priv->dreg].bitwise && 299 track->regs[priv->dreg].bitwise->ops == expr->ops && 300 priv->sreg == bitwise->sreg && 301 priv->dreg == bitwise->dreg && 302 priv->op == bitwise->op && 303 priv->len == bitwise->len && 304 !memcmp(&priv->mask, &bitwise->mask, sizeof(priv->mask)) && 305 !memcmp(&priv->xor, &bitwise->xor, sizeof(priv->xor)) && 306 !memcmp(&priv->data, &bitwise->data, sizeof(priv->data))) { 307 track->cur = expr; 308 return true; 309 } 310 311 if (track->regs[priv->sreg].bitwise || 312 track->regs[priv->sreg].num_reg != 0) { 313 nft_reg_track_cancel(track, priv->dreg, priv->len); 314 return false; 315 } 316 317 if (priv->sreg != priv->dreg) { 318 nft_reg_track_update(track, track->regs[priv->sreg].selector, 319 priv->dreg, priv->len); 320 } 321 322 dreg = priv->dreg; 323 regcount = DIV_ROUND_UP(priv->len, NFT_REG32_SIZE); 324 for (i = 0; i < regcount; i++, dreg++) 325 track->regs[priv->dreg].bitwise = expr; 326 327 return false; 328 } 329 330 static const struct nft_expr_ops nft_bitwise_ops = { 331 .type = &nft_bitwise_type, 332 .size = NFT_EXPR_SIZE(sizeof(struct nft_bitwise)), 333 .eval = nft_bitwise_eval, 334 .init = nft_bitwise_init, 335 .dump = nft_bitwise_dump, 336 .reduce = nft_bitwise_reduce, 337 .offload = nft_bitwise_offload, 338 }; 339 340 static int 341 nft_bitwise_extract_u32_data(const struct nlattr * const tb, u32 *out) 342 { 343 struct nft_data data; 344 struct nft_data_desc desc = { 345 .type = NFT_DATA_VALUE, 346 .size = sizeof(data), 347 .len = sizeof(u32), 348 }; 349 int err; 350 351 err = nft_data_init(NULL, &data, &desc, tb); 352 if (err < 0) 353 return err; 354 355 *out = data.data[0]; 356 357 return 0; 358 } 359 360 static int nft_bitwise_fast_init(const struct nft_ctx *ctx, 361 const struct nft_expr *expr, 362 const struct nlattr * const tb[]) 363 { 364 struct nft_bitwise_fast_expr *priv = nft_expr_priv(expr); 365 int err; 366 367 err = nft_parse_register_load(tb[NFTA_BITWISE_SREG], &priv->sreg, 368 sizeof(u32)); 369 if (err < 0) 370 return err; 371 372 err = nft_parse_register_store(ctx, tb[NFTA_BITWISE_DREG], &priv->dreg, 373 NULL, NFT_DATA_VALUE, sizeof(u32)); 374 if (err < 0) 375 return err; 376 377 if (tb[NFTA_BITWISE_DATA]) 378 return -EINVAL; 379 380 if (!tb[NFTA_BITWISE_MASK] || 381 !tb[NFTA_BITWISE_XOR]) 382 return -EINVAL; 383 384 err = nft_bitwise_extract_u32_data(tb[NFTA_BITWISE_MASK], &priv->mask); 385 if (err < 0) 386 return err; 387 388 err = nft_bitwise_extract_u32_data(tb[NFTA_BITWISE_XOR], &priv->xor); 389 if (err < 0) 390 return err; 391 392 return 0; 393 } 394 395 static int 396 nft_bitwise_fast_dump(struct sk_buff *skb, const struct nft_expr *expr) 397 { 398 const struct nft_bitwise_fast_expr *priv = nft_expr_priv(expr); 399 struct nft_data data; 400 401 if (nft_dump_register(skb, NFTA_BITWISE_SREG, priv->sreg)) 402 return -1; 403 if (nft_dump_register(skb, NFTA_BITWISE_DREG, priv->dreg)) 404 return -1; 405 if (nla_put_be32(skb, NFTA_BITWISE_LEN, htonl(sizeof(u32)))) 406 return -1; 407 if (nla_put_be32(skb, NFTA_BITWISE_OP, htonl(NFT_BITWISE_BOOL))) 408 return -1; 409 410 data.data[0] = priv->mask; 411 if (nft_data_dump(skb, NFTA_BITWISE_MASK, &data, 412 NFT_DATA_VALUE, sizeof(u32)) < 0) 413 return -1; 414 415 data.data[0] = priv->xor; 416 if (nft_data_dump(skb, NFTA_BITWISE_XOR, &data, 417 NFT_DATA_VALUE, sizeof(u32)) < 0) 418 return -1; 419 420 return 0; 421 } 422 423 static int nft_bitwise_fast_offload(struct nft_offload_ctx *ctx, 424 struct nft_flow_rule *flow, 425 const struct nft_expr *expr) 426 { 427 const struct nft_bitwise_fast_expr *priv = nft_expr_priv(expr); 428 struct nft_offload_reg *reg = &ctx->regs[priv->dreg]; 429 430 if (priv->xor || priv->sreg != priv->dreg || reg->len != sizeof(u32)) 431 return -EOPNOTSUPP; 432 433 reg->mask.data[0] = priv->mask; 434 return 0; 435 } 436 437 static bool nft_bitwise_fast_reduce(struct nft_regs_track *track, 438 const struct nft_expr *expr) 439 { 440 const struct nft_bitwise_fast_expr *priv = nft_expr_priv(expr); 441 const struct nft_bitwise_fast_expr *bitwise; 442 443 if (!track->regs[priv->sreg].selector) 444 return false; 445 446 bitwise = nft_expr_priv(track->regs[priv->dreg].selector); 447 if (track->regs[priv->sreg].selector == track->regs[priv->dreg].selector && 448 track->regs[priv->dreg].bitwise && 449 track->regs[priv->dreg].bitwise->ops == expr->ops && 450 priv->sreg == bitwise->sreg && 451 priv->dreg == bitwise->dreg && 452 priv->mask == bitwise->mask && 453 priv->xor == bitwise->xor) { 454 track->cur = expr; 455 return true; 456 } 457 458 if (track->regs[priv->sreg].bitwise) { 459 nft_reg_track_cancel(track, priv->dreg, NFT_REG32_SIZE); 460 return false; 461 } 462 463 if (priv->sreg != priv->dreg) { 464 track->regs[priv->dreg].selector = 465 track->regs[priv->sreg].selector; 466 } 467 track->regs[priv->dreg].bitwise = expr; 468 469 return false; 470 } 471 472 const struct nft_expr_ops nft_bitwise_fast_ops = { 473 .type = &nft_bitwise_type, 474 .size = NFT_EXPR_SIZE(sizeof(struct nft_bitwise_fast_expr)), 475 .eval = NULL, /* inlined */ 476 .init = nft_bitwise_fast_init, 477 .dump = nft_bitwise_fast_dump, 478 .reduce = nft_bitwise_fast_reduce, 479 .offload = nft_bitwise_fast_offload, 480 }; 481 482 static const struct nft_expr_ops * 483 nft_bitwise_select_ops(const struct nft_ctx *ctx, 484 const struct nlattr * const tb[]) 485 { 486 int err; 487 u32 len; 488 489 if (!tb[NFTA_BITWISE_LEN] || 490 !tb[NFTA_BITWISE_SREG] || 491 !tb[NFTA_BITWISE_DREG]) 492 return ERR_PTR(-EINVAL); 493 494 err = nft_parse_u32_check(tb[NFTA_BITWISE_LEN], U8_MAX, &len); 495 if (err < 0) 496 return ERR_PTR(err); 497 498 if (len != sizeof(u32)) 499 return &nft_bitwise_ops; 500 501 if (tb[NFTA_BITWISE_OP] && 502 ntohl(nla_get_be32(tb[NFTA_BITWISE_OP])) != NFT_BITWISE_BOOL) 503 return &nft_bitwise_ops; 504 505 return &nft_bitwise_fast_ops; 506 } 507 508 struct nft_expr_type nft_bitwise_type __read_mostly = { 509 .name = "bitwise", 510 .select_ops = nft_bitwise_select_ops, 511 .policy = nft_bitwise_policy, 512 .maxattr = NFTA_BITWISE_MAX, 513 .owner = THIS_MODULE, 514 }; 515 516 bool nft_expr_reduce_bitwise(struct nft_regs_track *track, 517 const struct nft_expr *expr) 518 { 519 const struct nft_expr *last = track->last; 520 const struct nft_expr *next; 521 522 if (expr == last) 523 return false; 524 525 next = nft_expr_next(expr); 526 if (next->ops == &nft_bitwise_ops) 527 return nft_bitwise_reduce(track, next); 528 else if (next->ops == &nft_bitwise_fast_ops) 529 return nft_bitwise_fast_reduce(track, next); 530 531 return false; 532 } 533 EXPORT_SYMBOL_GPL(nft_expr_reduce_bitwise); 534