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