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