1 /* 2 * Copyright (c) 2015 Patrick McHardy <kaber@trash.net> 3 * 4 * This program is free software; you can redistribute it and/or modify 5 * it under the terms of the GNU General Public License version 2 as 6 * published by the Free Software Foundation. 7 * 8 */ 9 10 #include <linux/kernel.h> 11 #include <linux/module.h> 12 #include <linux/init.h> 13 #include <linux/netlink.h> 14 #include <linux/netfilter.h> 15 #include <linux/netfilter/nf_tables.h> 16 #include <net/netfilter/nf_tables.h> 17 #include <net/netfilter/nf_tables_core.h> 18 19 struct nft_dynset { 20 struct nft_set *set; 21 struct nft_set_ext_tmpl tmpl; 22 enum nft_dynset_ops op:8; 23 enum nft_registers sreg_key:8; 24 enum nft_registers sreg_data:8; 25 u64 timeout; 26 struct nft_expr *expr; 27 struct nft_set_binding binding; 28 }; 29 30 static void *nft_dynset_new(struct nft_set *set, const struct nft_expr *expr, 31 struct nft_regs *regs) 32 { 33 const struct nft_dynset *priv = nft_expr_priv(expr); 34 struct nft_set_ext *ext; 35 u64 timeout; 36 void *elem; 37 38 if (set->size && !atomic_add_unless(&set->nelems, 1, set->size)) 39 return NULL; 40 41 timeout = priv->timeout ? : set->timeout; 42 elem = nft_set_elem_init(set, &priv->tmpl, 43 ®s->data[priv->sreg_key], 44 ®s->data[priv->sreg_data], 45 timeout, GFP_ATOMIC); 46 if (elem == NULL) { 47 if (set->size) 48 atomic_dec(&set->nelems); 49 return NULL; 50 } 51 52 ext = nft_set_elem_ext(set, elem); 53 if (priv->expr != NULL && 54 nft_expr_clone(nft_set_ext_expr(ext), priv->expr) < 0) 55 return NULL; 56 57 return elem; 58 } 59 60 static void nft_dynset_eval(const struct nft_expr *expr, 61 struct nft_regs *regs, 62 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 const struct nft_expr *sexpr; 68 u64 timeout; 69 70 if (set->ops->update(set, ®s->data[priv->sreg_key], nft_dynset_new, 71 expr, regs, &ext)) { 72 sexpr = NULL; 73 if (nft_set_ext_exists(ext, NFT_SET_EXT_EXPR)) 74 sexpr = nft_set_ext_expr(ext); 75 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) = jiffies + timeout; 80 } else if (sexpr == NULL) 81 goto out; 82 83 if (sexpr != NULL) 84 sexpr->ops->eval(sexpr, regs, pkt); 85 return; 86 } 87 out: 88 regs->verdict.code = NFT_BREAK; 89 } 90 91 static const struct nla_policy nft_dynset_policy[NFTA_DYNSET_MAX + 1] = { 92 [NFTA_DYNSET_SET_NAME] = { .type = NLA_STRING }, 93 [NFTA_DYNSET_SET_ID] = { .type = NLA_U32 }, 94 [NFTA_DYNSET_OP] = { .type = NLA_U32 }, 95 [NFTA_DYNSET_SREG_KEY] = { .type = NLA_U32 }, 96 [NFTA_DYNSET_SREG_DATA] = { .type = NLA_U32 }, 97 [NFTA_DYNSET_TIMEOUT] = { .type = NLA_U64 }, 98 [NFTA_DYNSET_EXPR] = { .type = NLA_NESTED }, 99 }; 100 101 static int nft_dynset_init(const struct nft_ctx *ctx, 102 const struct nft_expr *expr, 103 const struct nlattr * const tb[]) 104 { 105 struct nft_dynset *priv = nft_expr_priv(expr); 106 u8 genmask = nft_genmask_next(ctx->net); 107 struct nft_set *set; 108 u64 timeout; 109 int err; 110 111 if (tb[NFTA_DYNSET_SET_NAME] == NULL || 112 tb[NFTA_DYNSET_OP] == NULL || 113 tb[NFTA_DYNSET_SREG_KEY] == NULL) 114 return -EINVAL; 115 116 set = nf_tables_set_lookup(ctx->table, tb[NFTA_DYNSET_SET_NAME], 117 genmask); 118 if (IS_ERR(set)) { 119 if (tb[NFTA_DYNSET_SET_ID]) 120 set = nf_tables_set_lookup_byid(ctx->net, 121 tb[NFTA_DYNSET_SET_ID], 122 genmask); 123 if (IS_ERR(set)) 124 return PTR_ERR(set); 125 } 126 127 if (set->flags & NFT_SET_CONSTANT) 128 return -EBUSY; 129 130 priv->op = ntohl(nla_get_be32(tb[NFTA_DYNSET_OP])); 131 switch (priv->op) { 132 case NFT_DYNSET_OP_ADD: 133 break; 134 case NFT_DYNSET_OP_UPDATE: 135 if (!(set->flags & NFT_SET_TIMEOUT)) 136 return -EOPNOTSUPP; 137 break; 138 default: 139 return -EOPNOTSUPP; 140 } 141 142 timeout = 0; 143 if (tb[NFTA_DYNSET_TIMEOUT] != NULL) { 144 if (!(set->flags & NFT_SET_TIMEOUT)) 145 return -EINVAL; 146 timeout = msecs_to_jiffies(be64_to_cpu(nla_get_be64( 147 tb[NFTA_DYNSET_TIMEOUT]))); 148 } 149 150 priv->sreg_key = nft_parse_register(tb[NFTA_DYNSET_SREG_KEY]); 151 err = nft_validate_register_load(priv->sreg_key, set->klen);; 152 if (err < 0) 153 return err; 154 155 if (tb[NFTA_DYNSET_SREG_DATA] != NULL) { 156 if (!(set->flags & NFT_SET_MAP)) 157 return -EINVAL; 158 if (set->dtype == NFT_DATA_VERDICT) 159 return -EOPNOTSUPP; 160 161 priv->sreg_data = nft_parse_register(tb[NFTA_DYNSET_SREG_DATA]); 162 err = nft_validate_register_load(priv->sreg_data, set->dlen); 163 if (err < 0) 164 return err; 165 } else if (set->flags & NFT_SET_MAP) 166 return -EINVAL; 167 168 if (tb[NFTA_DYNSET_EXPR] != NULL) { 169 if (!(set->flags & NFT_SET_EVAL)) 170 return -EINVAL; 171 if (!(set->flags & NFT_SET_ANONYMOUS)) 172 return -EOPNOTSUPP; 173 174 priv->expr = nft_expr_init(ctx, tb[NFTA_DYNSET_EXPR]); 175 if (IS_ERR(priv->expr)) 176 return PTR_ERR(priv->expr); 177 178 err = -EOPNOTSUPP; 179 if (!(priv->expr->ops->type->flags & NFT_EXPR_STATEFUL)) 180 goto err1; 181 } else if (set->flags & NFT_SET_EVAL) 182 return -EINVAL; 183 184 nft_set_ext_prepare(&priv->tmpl); 185 nft_set_ext_add_length(&priv->tmpl, NFT_SET_EXT_KEY, set->klen); 186 if (set->flags & NFT_SET_MAP) 187 nft_set_ext_add_length(&priv->tmpl, NFT_SET_EXT_DATA, set->dlen); 188 if (priv->expr != NULL) 189 nft_set_ext_add_length(&priv->tmpl, NFT_SET_EXT_EXPR, 190 priv->expr->ops->size); 191 if (set->flags & NFT_SET_TIMEOUT) { 192 if (timeout || set->timeout) 193 nft_set_ext_add(&priv->tmpl, NFT_SET_EXT_EXPIRATION); 194 } 195 196 priv->timeout = timeout; 197 198 err = nf_tables_bind_set(ctx, set, &priv->binding); 199 if (err < 0) 200 goto err1; 201 202 priv->set = set; 203 return 0; 204 205 err1: 206 if (priv->expr != NULL) 207 nft_expr_destroy(ctx, priv->expr); 208 return err; 209 } 210 211 static void nft_dynset_destroy(const struct nft_ctx *ctx, 212 const struct nft_expr *expr) 213 { 214 struct nft_dynset *priv = nft_expr_priv(expr); 215 216 nf_tables_unbind_set(ctx, priv->set, &priv->binding); 217 if (priv->expr != NULL) 218 nft_expr_destroy(ctx, priv->expr); 219 } 220 221 static int nft_dynset_dump(struct sk_buff *skb, const struct nft_expr *expr) 222 { 223 const struct nft_dynset *priv = nft_expr_priv(expr); 224 225 if (nft_dump_register(skb, NFTA_DYNSET_SREG_KEY, priv->sreg_key)) 226 goto nla_put_failure; 227 if (priv->set->flags & NFT_SET_MAP && 228 nft_dump_register(skb, NFTA_DYNSET_SREG_DATA, priv->sreg_data)) 229 goto nla_put_failure; 230 if (nla_put_be32(skb, NFTA_DYNSET_OP, htonl(priv->op))) 231 goto nla_put_failure; 232 if (nla_put_string(skb, NFTA_DYNSET_SET_NAME, priv->set->name)) 233 goto nla_put_failure; 234 if (nla_put_be64(skb, NFTA_DYNSET_TIMEOUT, 235 cpu_to_be64(jiffies_to_msecs(priv->timeout)), 236 NFTA_DYNSET_PAD)) 237 goto nla_put_failure; 238 if (priv->expr && nft_expr_dump(skb, NFTA_DYNSET_EXPR, priv->expr)) 239 goto nla_put_failure; 240 return 0; 241 242 nla_put_failure: 243 return -1; 244 } 245 246 static struct nft_expr_type nft_dynset_type; 247 static const struct nft_expr_ops nft_dynset_ops = { 248 .type = &nft_dynset_type, 249 .size = NFT_EXPR_SIZE(sizeof(struct nft_dynset)), 250 .eval = nft_dynset_eval, 251 .init = nft_dynset_init, 252 .destroy = nft_dynset_destroy, 253 .dump = nft_dynset_dump, 254 }; 255 256 static struct nft_expr_type nft_dynset_type __read_mostly = { 257 .name = "dynset", 258 .ops = &nft_dynset_ops, 259 .policy = nft_dynset_policy, 260 .maxattr = NFTA_DYNSET_MAX, 261 .owner = THIS_MODULE, 262 }; 263 264 int __init nft_dynset_module_init(void) 265 { 266 return nft_register_expr(&nft_dynset_type); 267 } 268 269 void nft_dynset_module_exit(void) 270 { 271 nft_unregister_expr(&nft_dynset_type); 272 } 273
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