1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (c) 2015 Patrick McHardy <kaber@trash.net> 4 */ 5 6 #include <linux/kernel.h> 7 #include <linux/module.h> 8 #include <linux/init.h> 9 #include <linux/netlink.h> 10 #include <linux/netfilter.h> 11 #include <linux/netfilter/nf_tables.h> 12 #include <net/netfilter/nf_tables.h> 13 #include <net/netfilter/nf_tables_core.h> 14 15 struct nft_dynset { 16 struct nft_set *set; 17 struct nft_set_ext_tmpl tmpl; 18 enum nft_dynset_ops op:8; 19 u8 sreg_key; 20 u8 sreg_data; 21 bool invert; 22 bool expr:1, 23 override_exprs:1; 24 u8 num_exprs; 25 u64 timeout; 26 struct nft_expr *expr_array[NFT_SET_EXPR_MAX]; 27 struct nft_set_binding binding; 28 }; 29 30 static int nft_dynset_expr_setup(const struct nft_dynset *priv, 31 const struct nft_set_ext *ext) 32 { 33 struct nft_set_elem_expr *elem_expr = nft_set_ext_expr(ext); 34 struct nft_ctx ctx = { 35 .net = read_pnet(&priv->set->net), 36 .family = priv->set->table->family, 37 }; 38 struct nft_expr *expr; 39 int i; 40 41 for (i = 0; i < priv->num_exprs; i++) { 42 expr = nft_setelem_expr_at(elem_expr, elem_expr->size); 43 if (nft_expr_clone(expr, priv->expr_array[i], GFP_ATOMIC) < 0) 44 goto err_out; 45 46 elem_expr->size += priv->expr_array[i]->ops->size; 47 } 48 49 return 0; 50 err_out: 51 nft_set_elem_expr_destroy(&ctx, elem_expr); 52 53 return -1; 54 } 55 56 struct nft_elem_priv *nft_dynset_new(struct nft_set *set, 57 const struct nft_expr *expr, 58 struct nft_regs *regs) 59 { 60 const struct nft_dynset *priv = nft_expr_priv(expr); 61 struct nft_set_ext *ext; 62 void *elem_priv; 63 u64 timeout; 64 65 if (!atomic_add_unless(&set->nelems, 1, set->size)) 66 return NULL; 67 68 timeout = priv->timeout ? : READ_ONCE(set->timeout); 69 elem_priv = nft_set_elem_init(set, &priv->tmpl, 70 ®s->data[priv->sreg_key], NULL, 71 ®s->data[priv->sreg_data], 72 timeout, 0, GFP_ATOMIC); 73 if (IS_ERR(elem_priv)) 74 goto err1; 75 76 ext = nft_set_elem_ext(set, elem_priv); 77 if (priv->num_exprs && nft_dynset_expr_setup(priv, ext) < 0) 78 goto err2; 79 80 return elem_priv; 81 82 err2: 83 nft_set_elem_destroy(set, elem_priv, false); 84 err1: 85 if (set->size) 86 atomic_dec(&set->nelems); 87 return NULL; 88 } 89 90 void nft_dynset_eval(const struct nft_expr *expr, 91 struct nft_regs *regs, const struct nft_pktinfo *pkt) 92 { 93 const struct nft_dynset *priv = nft_expr_priv(expr); 94 struct nft_set *set = priv->set; 95 const struct nft_set_ext *ext; 96 u64 timeout; 97 98 if (priv->op == NFT_DYNSET_OP_DELETE) { 99 set->ops->delete(set, ®s->data[priv->sreg_key]); 100 return; 101 } 102 103 ext = set->ops->update(set, ®s->data[priv->sreg_key], expr, regs); 104 if (ext) { 105 if (priv->op == NFT_DYNSET_OP_UPDATE && 106 nft_set_ext_exists(ext, NFT_SET_EXT_TIMEOUT) && 107 READ_ONCE(nft_set_ext_timeout(ext)->timeout) != 0) { 108 timeout = priv->timeout ? : READ_ONCE(set->timeout); 109 WRITE_ONCE(nft_set_ext_timeout(ext)->expiration, get_jiffies_64() + timeout); 110 } 111 112 nft_set_elem_update_expr(ext, regs, pkt); 113 114 if (priv->invert) 115 regs->verdict.code = NFT_BREAK; 116 return; 117 } 118 119 if (!priv->invert) 120 regs->verdict.code = NFT_BREAK; 121 } 122 123 static void nft_dynset_ext_add_expr(struct nft_dynset *priv) 124 { 125 u8 size = 0; 126 int i; 127 128 for (i = 0; i < priv->num_exprs; i++) 129 size += priv->expr_array[i]->ops->size; 130 131 nft_set_ext_add_length(&priv->tmpl, NFT_SET_EXT_EXPRESSIONS, 132 sizeof(struct nft_set_elem_expr) + size); 133 } 134 135 static struct nft_expr * 136 nft_dynset_expr_alloc(const struct nft_ctx *ctx, const struct nft_set *set, 137 const struct nlattr *attr, int pos) 138 { 139 struct nft_expr *expr; 140 int err; 141 142 expr = nft_set_elem_expr_alloc(ctx, set, attr); 143 if (IS_ERR(expr)) 144 return expr; 145 146 if (set->exprs[pos] && set->exprs[pos]->ops != expr->ops) { 147 err = -EOPNOTSUPP; 148 goto err_dynset_expr; 149 } 150 151 return expr; 152 153 err_dynset_expr: 154 nft_expr_destroy(ctx, expr); 155 return ERR_PTR(err); 156 } 157 158 static const struct nla_policy nft_dynset_policy[NFTA_DYNSET_MAX + 1] = { 159 [NFTA_DYNSET_SET_NAME] = { .type = NLA_STRING, 160 .len = NFT_SET_MAXNAMELEN - 1 }, 161 [NFTA_DYNSET_SET_ID] = { .type = NLA_U32 }, 162 [NFTA_DYNSET_OP] = NLA_POLICY_MAX(NLA_BE32, 255), 163 [NFTA_DYNSET_SREG_KEY] = { .type = NLA_U32 }, 164 [NFTA_DYNSET_SREG_DATA] = { .type = NLA_U32 }, 165 [NFTA_DYNSET_TIMEOUT] = { .type = NLA_U64 }, 166 [NFTA_DYNSET_EXPR] = { .type = NLA_NESTED }, 167 [NFTA_DYNSET_FLAGS] = NLA_POLICY_MASK(NLA_BE32, NFT_DYNSET_F_INV | 168 NFT_DYNSET_F_EXPR), 169 [NFTA_DYNSET_EXPRESSIONS] = { .type = NLA_NESTED }, 170 }; 171 172 static int nft_dynset_init(const struct nft_ctx *ctx, 173 const struct nft_expr *expr, 174 const struct nlattr * const tb[]) 175 { 176 struct nftables_pernet *nft_net = nft_pernet(ctx->net); 177 struct nft_dynset *priv = nft_expr_priv(expr); 178 u8 genmask = nft_genmask_next(ctx->net); 179 struct nft_set *set; 180 u64 timeout; 181 int err, i; 182 183 lockdep_assert_held(&nft_net->commit_mutex); 184 185 if (tb[NFTA_DYNSET_SET_NAME] == NULL || 186 tb[NFTA_DYNSET_OP] == NULL || 187 tb[NFTA_DYNSET_SREG_KEY] == NULL) 188 return -EINVAL; 189 190 if (tb[NFTA_DYNSET_FLAGS]) { 191 u32 flags = ntohl(nla_get_be32(tb[NFTA_DYNSET_FLAGS])); 192 if (flags & ~(NFT_DYNSET_F_INV | NFT_DYNSET_F_EXPR)) 193 return -EOPNOTSUPP; 194 if (flags & NFT_DYNSET_F_INV) 195 priv->invert = true; 196 if (flags & NFT_DYNSET_F_EXPR) 197 priv->expr = true; 198 } 199 200 set = nft_set_lookup_global(ctx->net, ctx->table, 201 tb[NFTA_DYNSET_SET_NAME], 202 tb[NFTA_DYNSET_SET_ID], genmask); 203 if (IS_ERR(set)) 204 return PTR_ERR(set); 205 206 if (set->flags & NFT_SET_OBJECT) 207 return -EOPNOTSUPP; 208 209 if (set->ops->update == NULL) 210 return -EOPNOTSUPP; 211 212 if (set->flags & NFT_SET_CONSTANT) 213 return -EBUSY; 214 215 priv->op = ntohl(nla_get_be32(tb[NFTA_DYNSET_OP])); 216 if (priv->op > NFT_DYNSET_OP_DELETE) 217 return -EOPNOTSUPP; 218 219 timeout = 0; 220 if (tb[NFTA_DYNSET_TIMEOUT] != NULL) { 221 if (!(set->flags & NFT_SET_TIMEOUT)) 222 return -EOPNOTSUPP; 223 224 err = nf_msecs_to_jiffies64(tb[NFTA_DYNSET_TIMEOUT], &timeout); 225 if (err) 226 return err; 227 } 228 229 err = nft_parse_register_load(ctx, tb[NFTA_DYNSET_SREG_KEY], &priv->sreg_key, 230 set->klen); 231 if (err < 0) 232 return err; 233 234 if (tb[NFTA_DYNSET_SREG_DATA] != NULL) { 235 if (!(set->flags & NFT_SET_MAP)) 236 return -EOPNOTSUPP; 237 if (set->dtype == NFT_DATA_VERDICT) 238 return -EOPNOTSUPP; 239 240 err = nft_parse_register_load(ctx, tb[NFTA_DYNSET_SREG_DATA], 241 &priv->sreg_data, set->dlen); 242 if (err < 0) 243 return err; 244 } else if (set->flags & NFT_SET_MAP) 245 return -EINVAL; 246 247 if ((tb[NFTA_DYNSET_EXPR] || tb[NFTA_DYNSET_EXPRESSIONS]) && 248 !(set->flags & NFT_SET_EVAL)) 249 return -EINVAL; 250 251 if (tb[NFTA_DYNSET_EXPR]) { 252 struct nft_expr *dynset_expr; 253 254 dynset_expr = nft_dynset_expr_alloc(ctx, set, 255 tb[NFTA_DYNSET_EXPR], 0); 256 if (IS_ERR(dynset_expr)) 257 return PTR_ERR(dynset_expr); 258 259 priv->num_exprs++; 260 priv->expr_array[0] = dynset_expr; 261 priv->override_exprs = true; 262 263 if (set->num_exprs > 1 || 264 (set->num_exprs == 1 && 265 dynset_expr->ops != set->exprs[0]->ops)) { 266 err = -EOPNOTSUPP; 267 goto err_expr_free; 268 } 269 } else if (tb[NFTA_DYNSET_EXPRESSIONS]) { 270 struct nft_expr *dynset_expr; 271 struct nlattr *tmp; 272 int left; 273 274 if (!priv->expr) 275 return -EINVAL; 276 277 i = 0; 278 nla_for_each_nested(tmp, tb[NFTA_DYNSET_EXPRESSIONS], left) { 279 if (i == NFT_SET_EXPR_MAX) { 280 err = -E2BIG; 281 goto err_expr_free; 282 } 283 if (nla_type(tmp) != NFTA_LIST_ELEM) { 284 err = -EINVAL; 285 goto err_expr_free; 286 } 287 dynset_expr = nft_dynset_expr_alloc(ctx, set, tmp, i); 288 if (IS_ERR(dynset_expr)) { 289 err = PTR_ERR(dynset_expr); 290 goto err_expr_free; 291 } 292 priv->expr_array[i] = dynset_expr; 293 priv->num_exprs++; 294 priv->override_exprs = true; 295 296 if (set->num_exprs) { 297 if (i >= set->num_exprs) { 298 err = -EINVAL; 299 goto err_expr_free; 300 } 301 if (dynset_expr->ops != set->exprs[i]->ops) { 302 err = -EOPNOTSUPP; 303 goto err_expr_free; 304 } 305 } 306 i++; 307 } 308 if (set->num_exprs && set->num_exprs != i) { 309 err = -EOPNOTSUPP; 310 goto err_expr_free; 311 } 312 } else if (set->num_exprs > 0) { 313 for (i = 0; i < set->num_exprs; i++) 314 priv->expr_array[i] = set->exprs[i]; 315 316 priv->num_exprs = set->num_exprs; 317 } 318 319 nft_set_ext_prepare(&priv->tmpl); 320 nft_set_ext_add_length(&priv->tmpl, NFT_SET_EXT_KEY, set->klen); 321 if (set->flags & NFT_SET_MAP) 322 nft_set_ext_add_length(&priv->tmpl, NFT_SET_EXT_DATA, set->dlen); 323 324 if (priv->num_exprs) 325 nft_dynset_ext_add_expr(priv); 326 327 if (set->flags & NFT_SET_TIMEOUT && 328 (timeout || READ_ONCE(set->timeout))) 329 nft_set_ext_add(&priv->tmpl, NFT_SET_EXT_TIMEOUT); 330 331 priv->timeout = timeout; 332 333 err = nf_tables_bind_set(ctx, set, &priv->binding); 334 if (err < 0) 335 goto err_expr_free; 336 337 if (set->size == 0) 338 set->size = 0xffff; 339 340 priv->set = set; 341 return 0; 342 343 err_expr_free: 344 if (priv->override_exprs) { 345 for (i = 0; i < priv->num_exprs; i++) 346 nft_expr_destroy(ctx, priv->expr_array[i]); 347 } 348 return err; 349 } 350 351 static void nft_dynset_deactivate(const struct nft_ctx *ctx, 352 const struct nft_expr *expr, 353 enum nft_trans_phase phase) 354 { 355 struct nft_dynset *priv = nft_expr_priv(expr); 356 357 nf_tables_deactivate_set(ctx, priv->set, &priv->binding, phase); 358 } 359 360 static void nft_dynset_activate(const struct nft_ctx *ctx, 361 const struct nft_expr *expr) 362 { 363 struct nft_dynset *priv = nft_expr_priv(expr); 364 365 nf_tables_activate_set(ctx, priv->set); 366 } 367 368 static void nft_dynset_destroy(const struct nft_ctx *ctx, 369 const struct nft_expr *expr) 370 { 371 struct nft_dynset *priv = nft_expr_priv(expr); 372 int i; 373 374 if (priv->override_exprs) { 375 for (i = 0; i < priv->num_exprs; i++) 376 nft_expr_destroy(ctx, priv->expr_array[i]); 377 } 378 nf_tables_destroy_set(ctx, priv->set); 379 } 380 381 static int nft_dynset_dump(struct sk_buff *skb, 382 const struct nft_expr *expr, bool reset) 383 { 384 const struct nft_dynset *priv = nft_expr_priv(expr); 385 u32 flags = priv->invert ? NFT_DYNSET_F_INV : 0; 386 int i; 387 388 if (nft_dump_register(skb, NFTA_DYNSET_SREG_KEY, priv->sreg_key)) 389 goto nla_put_failure; 390 if (priv->set->flags & NFT_SET_MAP && 391 nft_dump_register(skb, NFTA_DYNSET_SREG_DATA, priv->sreg_data)) 392 goto nla_put_failure; 393 if (nla_put_be32(skb, NFTA_DYNSET_OP, htonl(priv->op))) 394 goto nla_put_failure; 395 if (nla_put_string(skb, NFTA_DYNSET_SET_NAME, priv->set->name)) 396 goto nla_put_failure; 397 if (nla_put_be64(skb, NFTA_DYNSET_TIMEOUT, 398 nf_jiffies64_to_msecs(priv->timeout), 399 NFTA_DYNSET_PAD)) 400 goto nla_put_failure; 401 if (priv->set->num_exprs == 0 || priv->override_exprs) { 402 if (priv->num_exprs == 1) { 403 if (nft_expr_dump(skb, NFTA_DYNSET_EXPR, 404 priv->expr_array[0], reset)) 405 goto nla_put_failure; 406 } else if (priv->num_exprs > 1) { 407 struct nlattr *nest; 408 409 nest = nla_nest_start_noflag(skb, NFTA_DYNSET_EXPRESSIONS); 410 if (!nest) 411 goto nla_put_failure; 412 413 for (i = 0; i < priv->num_exprs; i++) { 414 if (nft_expr_dump(skb, NFTA_LIST_ELEM, 415 priv->expr_array[i], reset)) 416 goto nla_put_failure; 417 } 418 nla_nest_end(skb, nest); 419 } 420 } 421 if (nla_put_be32(skb, NFTA_DYNSET_FLAGS, htonl(flags))) 422 goto nla_put_failure; 423 return 0; 424 425 nla_put_failure: 426 return -1; 427 } 428 429 static const struct nft_expr_ops nft_dynset_ops = { 430 .type = &nft_dynset_type, 431 .size = NFT_EXPR_SIZE(sizeof(struct nft_dynset)), 432 .eval = nft_dynset_eval, 433 .init = nft_dynset_init, 434 .destroy = nft_dynset_destroy, 435 .activate = nft_dynset_activate, 436 .deactivate = nft_dynset_deactivate, 437 .dump = nft_dynset_dump, 438 }; 439 440 struct nft_expr_type nft_dynset_type __read_mostly = { 441 .name = "dynset", 442 .ops = &nft_dynset_ops, 443 .policy = nft_dynset_policy, 444 .maxattr = NFTA_DYNSET_MAX, 445 .owner = THIS_MODULE, 446 }; 447