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 enum nft_registers sreg_key:8; 20 enum nft_registers sreg_data:8; 21 bool invert; 22 u64 timeout; 23 struct nft_expr *expr; 24 struct nft_set_binding binding; 25 }; 26 27 static int nft_expr_clone(struct nft_expr *dst, struct nft_expr *src) 28 { 29 int err; 30 31 if (src->ops->clone) { 32 dst->ops = src->ops; 33 err = src->ops->clone(dst, src); 34 if (err < 0) 35 return err; 36 } else { 37 memcpy(dst, src, src->ops->size); 38 } 39 40 __module_get(src->ops->type->owner); 41 return 0; 42 } 43 44 static void *nft_dynset_new(struct nft_set *set, const struct nft_expr *expr, 45 struct nft_regs *regs) 46 { 47 const struct nft_dynset *priv = nft_expr_priv(expr); 48 struct nft_set_ext *ext; 49 u64 timeout; 50 void *elem; 51 52 if (!atomic_add_unless(&set->nelems, 1, set->size)) 53 return NULL; 54 55 timeout = priv->timeout ? : set->timeout; 56 elem = nft_set_elem_init(set, &priv->tmpl, 57 ®s->data[priv->sreg_key], NULL, 58 ®s->data[priv->sreg_data], 59 timeout, 0, GFP_ATOMIC); 60 if (elem == NULL) 61 goto err1; 62 63 ext = nft_set_elem_ext(set, elem); 64 if (priv->expr != NULL && 65 nft_expr_clone(nft_set_ext_expr(ext), priv->expr) < 0) 66 goto err2; 67 68 return elem; 69 70 err2: 71 nft_set_elem_destroy(set, elem, false); 72 err1: 73 if (set->size) 74 atomic_dec(&set->nelems); 75 return NULL; 76 } 77 78 void nft_dynset_eval(const struct nft_expr *expr, 79 struct nft_regs *regs, const struct nft_pktinfo *pkt) 80 { 81 const struct nft_dynset *priv = nft_expr_priv(expr); 82 struct nft_set *set = priv->set; 83 const struct nft_set_ext *ext; 84 const struct nft_expr *sexpr; 85 u64 timeout; 86 87 if (priv->op == NFT_DYNSET_OP_DELETE) { 88 set->ops->delete(set, ®s->data[priv->sreg_key]); 89 return; 90 } 91 92 if (set->ops->update(set, ®s->data[priv->sreg_key], nft_dynset_new, 93 expr, regs, &ext)) { 94 sexpr = NULL; 95 if (nft_set_ext_exists(ext, NFT_SET_EXT_EXPR)) 96 sexpr = nft_set_ext_expr(ext); 97 98 if (priv->op == NFT_DYNSET_OP_UPDATE && 99 nft_set_ext_exists(ext, NFT_SET_EXT_EXPIRATION)) { 100 timeout = priv->timeout ? : set->timeout; 101 *nft_set_ext_expiration(ext) = get_jiffies_64() + timeout; 102 } 103 104 if (sexpr != NULL) 105 sexpr->ops->eval(sexpr, regs, pkt); 106 107 if (priv->invert) 108 regs->verdict.code = NFT_BREAK; 109 return; 110 } 111 112 if (!priv->invert) 113 regs->verdict.code = NFT_BREAK; 114 } 115 116 static const struct nla_policy nft_dynset_policy[NFTA_DYNSET_MAX + 1] = { 117 [NFTA_DYNSET_SET_NAME] = { .type = NLA_STRING, 118 .len = NFT_SET_MAXNAMELEN - 1 }, 119 [NFTA_DYNSET_SET_ID] = { .type = NLA_U32 }, 120 [NFTA_DYNSET_OP] = { .type = NLA_U32 }, 121 [NFTA_DYNSET_SREG_KEY] = { .type = NLA_U32 }, 122 [NFTA_DYNSET_SREG_DATA] = { .type = NLA_U32 }, 123 [NFTA_DYNSET_TIMEOUT] = { .type = NLA_U64 }, 124 [NFTA_DYNSET_EXPR] = { .type = NLA_NESTED }, 125 [NFTA_DYNSET_FLAGS] = { .type = NLA_U32 }, 126 }; 127 128 static int nft_dynset_init(const struct nft_ctx *ctx, 129 const struct nft_expr *expr, 130 const struct nlattr * const tb[]) 131 { 132 struct nft_dynset *priv = nft_expr_priv(expr); 133 u8 genmask = nft_genmask_next(ctx->net); 134 struct nft_set *set; 135 u64 timeout; 136 int err; 137 138 lockdep_assert_held(&ctx->net->nft.commit_mutex); 139 140 if (tb[NFTA_DYNSET_SET_NAME] == NULL || 141 tb[NFTA_DYNSET_OP] == NULL || 142 tb[NFTA_DYNSET_SREG_KEY] == NULL) 143 return -EINVAL; 144 145 if (tb[NFTA_DYNSET_FLAGS]) { 146 u32 flags = ntohl(nla_get_be32(tb[NFTA_DYNSET_FLAGS])); 147 148 if (flags & ~NFT_DYNSET_F_INV) 149 return -EINVAL; 150 if (flags & NFT_DYNSET_F_INV) 151 priv->invert = true; 152 } 153 154 set = nft_set_lookup_global(ctx->net, ctx->table, 155 tb[NFTA_DYNSET_SET_NAME], 156 tb[NFTA_DYNSET_SET_ID], genmask); 157 if (IS_ERR(set)) 158 return PTR_ERR(set); 159 160 if (set->ops->update == NULL) 161 return -EOPNOTSUPP; 162 163 if (set->flags & NFT_SET_CONSTANT) 164 return -EBUSY; 165 166 priv->op = ntohl(nla_get_be32(tb[NFTA_DYNSET_OP])); 167 switch (priv->op) { 168 case NFT_DYNSET_OP_ADD: 169 case NFT_DYNSET_OP_DELETE: 170 break; 171 case NFT_DYNSET_OP_UPDATE: 172 if (!(set->flags & NFT_SET_TIMEOUT)) 173 return -EOPNOTSUPP; 174 break; 175 default: 176 return -EOPNOTSUPP; 177 } 178 179 timeout = 0; 180 if (tb[NFTA_DYNSET_TIMEOUT] != NULL) { 181 if (!(set->flags & NFT_SET_TIMEOUT)) 182 return -EINVAL; 183 timeout = msecs_to_jiffies(be64_to_cpu(nla_get_be64( 184 tb[NFTA_DYNSET_TIMEOUT]))); 185 } 186 187 priv->sreg_key = nft_parse_register(tb[NFTA_DYNSET_SREG_KEY]); 188 err = nft_validate_register_load(priv->sreg_key, set->klen); 189 if (err < 0) 190 return err; 191 192 if (tb[NFTA_DYNSET_SREG_DATA] != NULL) { 193 if (!(set->flags & NFT_SET_MAP)) 194 return -EINVAL; 195 if (set->dtype == NFT_DATA_VERDICT) 196 return -EOPNOTSUPP; 197 198 priv->sreg_data = nft_parse_register(tb[NFTA_DYNSET_SREG_DATA]); 199 err = nft_validate_register_load(priv->sreg_data, set->dlen); 200 if (err < 0) 201 return err; 202 } else if (set->flags & NFT_SET_MAP) 203 return -EINVAL; 204 205 if (tb[NFTA_DYNSET_EXPR] != NULL) { 206 if (!(set->flags & NFT_SET_EVAL)) 207 return -EINVAL; 208 209 priv->expr = nft_expr_init(ctx, tb[NFTA_DYNSET_EXPR]); 210 if (IS_ERR(priv->expr)) 211 return PTR_ERR(priv->expr); 212 213 err = -EOPNOTSUPP; 214 if (!(priv->expr->ops->type->flags & NFT_EXPR_STATEFUL)) 215 goto err1; 216 217 if (priv->expr->ops->type->flags & NFT_EXPR_GC) { 218 if (set->flags & NFT_SET_TIMEOUT) 219 goto err1; 220 if (!set->ops->gc_init) 221 goto err1; 222 set->ops->gc_init(set); 223 } 224 } 225 226 nft_set_ext_prepare(&priv->tmpl); 227 nft_set_ext_add_length(&priv->tmpl, NFT_SET_EXT_KEY, set->klen); 228 if (set->flags & NFT_SET_MAP) 229 nft_set_ext_add_length(&priv->tmpl, NFT_SET_EXT_DATA, set->dlen); 230 if (priv->expr != NULL) 231 nft_set_ext_add_length(&priv->tmpl, NFT_SET_EXT_EXPR, 232 priv->expr->ops->size); 233 if (set->flags & NFT_SET_TIMEOUT) { 234 if (timeout || set->timeout) 235 nft_set_ext_add(&priv->tmpl, NFT_SET_EXT_EXPIRATION); 236 } 237 238 priv->timeout = timeout; 239 240 err = nf_tables_bind_set(ctx, set, &priv->binding); 241 if (err < 0) 242 goto err1; 243 244 if (set->size == 0) 245 set->size = 0xffff; 246 247 priv->set = set; 248 return 0; 249 250 err1: 251 if (priv->expr != NULL) 252 nft_expr_destroy(ctx, priv->expr); 253 return err; 254 } 255 256 static void nft_dynset_deactivate(const struct nft_ctx *ctx, 257 const struct nft_expr *expr, 258 enum nft_trans_phase phase) 259 { 260 struct nft_dynset *priv = nft_expr_priv(expr); 261 262 nf_tables_deactivate_set(ctx, priv->set, &priv->binding, phase); 263 } 264 265 static void nft_dynset_activate(const struct nft_ctx *ctx, 266 const struct nft_expr *expr) 267 { 268 struct nft_dynset *priv = nft_expr_priv(expr); 269 270 priv->set->use++; 271 } 272 273 static void nft_dynset_destroy(const struct nft_ctx *ctx, 274 const struct nft_expr *expr) 275 { 276 struct nft_dynset *priv = nft_expr_priv(expr); 277 278 if (priv->expr != NULL) 279 nft_expr_destroy(ctx, priv->expr); 280 281 nf_tables_destroy_set(ctx, priv->set); 282 } 283 284 static int nft_dynset_dump(struct sk_buff *skb, const struct nft_expr *expr) 285 { 286 const struct nft_dynset *priv = nft_expr_priv(expr); 287 u32 flags = priv->invert ? NFT_DYNSET_F_INV : 0; 288 289 if (nft_dump_register(skb, NFTA_DYNSET_SREG_KEY, priv->sreg_key)) 290 goto nla_put_failure; 291 if (priv->set->flags & NFT_SET_MAP && 292 nft_dump_register(skb, NFTA_DYNSET_SREG_DATA, priv->sreg_data)) 293 goto nla_put_failure; 294 if (nla_put_be32(skb, NFTA_DYNSET_OP, htonl(priv->op))) 295 goto nla_put_failure; 296 if (nla_put_string(skb, NFTA_DYNSET_SET_NAME, priv->set->name)) 297 goto nla_put_failure; 298 if (nla_put_be64(skb, NFTA_DYNSET_TIMEOUT, 299 cpu_to_be64(jiffies_to_msecs(priv->timeout)), 300 NFTA_DYNSET_PAD)) 301 goto nla_put_failure; 302 if (priv->expr && nft_expr_dump(skb, NFTA_DYNSET_EXPR, priv->expr)) 303 goto nla_put_failure; 304 if (nla_put_be32(skb, NFTA_DYNSET_FLAGS, htonl(flags))) 305 goto nla_put_failure; 306 return 0; 307 308 nla_put_failure: 309 return -1; 310 } 311 312 static const struct nft_expr_ops nft_dynset_ops = { 313 .type = &nft_dynset_type, 314 .size = NFT_EXPR_SIZE(sizeof(struct nft_dynset)), 315 .eval = nft_dynset_eval, 316 .init = nft_dynset_init, 317 .destroy = nft_dynset_destroy, 318 .activate = nft_dynset_activate, 319 .deactivate = nft_dynset_deactivate, 320 .dump = nft_dynset_dump, 321 }; 322 323 struct nft_expr_type nft_dynset_type __read_mostly = { 324 .name = "dynset", 325 .ops = &nft_dynset_ops, 326 .policy = nft_dynset_policy, 327 .maxattr = NFTA_DYNSET_MAX, 328 .owner = THIS_MODULE, 329 }; 330