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 const struct nft_expr_ops nft_bitwise_ops = { 282 .type = &nft_bitwise_type, 283 .size = NFT_EXPR_SIZE(sizeof(struct nft_bitwise)), 284 .eval = nft_bitwise_eval, 285 .init = nft_bitwise_init, 286 .dump = nft_bitwise_dump, 287 .offload = nft_bitwise_offload, 288 }; 289 290 static int 291 nft_bitwise_extract_u32_data(const struct nlattr * const tb, u32 *out) 292 { 293 struct nft_data_desc desc; 294 struct nft_data data; 295 int err = 0; 296 297 err = nft_data_init(NULL, &data, sizeof(data), &desc, tb); 298 if (err < 0) 299 return err; 300 301 if (desc.type != NFT_DATA_VALUE || desc.len != sizeof(u32)) { 302 err = -EINVAL; 303 goto err; 304 } 305 *out = data.data[0]; 306 err: 307 nft_data_release(&data, desc.type); 308 return err; 309 } 310 311 static int nft_bitwise_fast_init(const struct nft_ctx *ctx, 312 const struct nft_expr *expr, 313 const struct nlattr * const tb[]) 314 { 315 struct nft_bitwise_fast_expr *priv = nft_expr_priv(expr); 316 int err; 317 318 err = nft_parse_register_load(tb[NFTA_BITWISE_SREG], &priv->sreg, 319 sizeof(u32)); 320 if (err < 0) 321 return err; 322 323 err = nft_parse_register_store(ctx, tb[NFTA_BITWISE_DREG], &priv->dreg, 324 NULL, NFT_DATA_VALUE, sizeof(u32)); 325 if (err < 0) 326 return err; 327 328 if (tb[NFTA_BITWISE_DATA]) 329 return -EINVAL; 330 331 if (!tb[NFTA_BITWISE_MASK] || 332 !tb[NFTA_BITWISE_XOR]) 333 return -EINVAL; 334 335 err = nft_bitwise_extract_u32_data(tb[NFTA_BITWISE_MASK], &priv->mask); 336 if (err < 0) 337 return err; 338 339 err = nft_bitwise_extract_u32_data(tb[NFTA_BITWISE_XOR], &priv->xor); 340 if (err < 0) 341 return err; 342 343 return 0; 344 } 345 346 static int 347 nft_bitwise_fast_dump(struct sk_buff *skb, const struct nft_expr *expr) 348 { 349 const struct nft_bitwise_fast_expr *priv = nft_expr_priv(expr); 350 struct nft_data data; 351 352 if (nft_dump_register(skb, NFTA_BITWISE_SREG, priv->sreg)) 353 return -1; 354 if (nft_dump_register(skb, NFTA_BITWISE_DREG, priv->dreg)) 355 return -1; 356 if (nla_put_be32(skb, NFTA_BITWISE_LEN, htonl(sizeof(u32)))) 357 return -1; 358 if (nla_put_be32(skb, NFTA_BITWISE_OP, htonl(NFT_BITWISE_BOOL))) 359 return -1; 360 361 data.data[0] = priv->mask; 362 if (nft_data_dump(skb, NFTA_BITWISE_MASK, &data, 363 NFT_DATA_VALUE, sizeof(u32)) < 0) 364 return -1; 365 366 data.data[0] = priv->xor; 367 if (nft_data_dump(skb, NFTA_BITWISE_XOR, &data, 368 NFT_DATA_VALUE, sizeof(u32)) < 0) 369 return -1; 370 371 return 0; 372 } 373 374 static int nft_bitwise_fast_offload(struct nft_offload_ctx *ctx, 375 struct nft_flow_rule *flow, 376 const struct nft_expr *expr) 377 { 378 const struct nft_bitwise_fast_expr *priv = nft_expr_priv(expr); 379 struct nft_offload_reg *reg = &ctx->regs[priv->dreg]; 380 381 if (priv->xor || priv->sreg != priv->dreg || reg->len != sizeof(u32)) 382 return -EOPNOTSUPP; 383 384 reg->mask.data[0] = priv->mask; 385 return 0; 386 } 387 388 const struct nft_expr_ops nft_bitwise_fast_ops = { 389 .type = &nft_bitwise_type, 390 .size = NFT_EXPR_SIZE(sizeof(struct nft_bitwise_fast_expr)), 391 .eval = NULL, /* inlined */ 392 .init = nft_bitwise_fast_init, 393 .dump = nft_bitwise_fast_dump, 394 .offload = nft_bitwise_fast_offload, 395 }; 396 397 static const struct nft_expr_ops * 398 nft_bitwise_select_ops(const struct nft_ctx *ctx, 399 const struct nlattr * const tb[]) 400 { 401 int err; 402 u32 len; 403 404 if (!tb[NFTA_BITWISE_LEN] || 405 !tb[NFTA_BITWISE_SREG] || 406 !tb[NFTA_BITWISE_DREG]) 407 return ERR_PTR(-EINVAL); 408 409 err = nft_parse_u32_check(tb[NFTA_BITWISE_LEN], U8_MAX, &len); 410 if (err < 0) 411 return ERR_PTR(err); 412 413 if (len != sizeof(u32)) 414 return &nft_bitwise_ops; 415 416 if (tb[NFTA_BITWISE_OP] && 417 ntohl(nla_get_be32(tb[NFTA_BITWISE_OP])) != NFT_BITWISE_BOOL) 418 return &nft_bitwise_ops; 419 420 return &nft_bitwise_fast_ops; 421 } 422 423 struct nft_expr_type nft_bitwise_type __read_mostly = { 424 .name = "bitwise", 425 .select_ops = nft_bitwise_select_ops, 426 .policy = nft_bitwise_policy, 427 .maxattr = NFTA_BITWISE_MAX, 428 .owner = THIS_MODULE, 429 }; 430