1 /* 2 * Copyright (c) 2012-2016 Pablo Neira Ayuso <pablo@netfilter.org> 3 * 4 * This program is free software; you can redistribute it and/or modify it 5 * under the terms and conditions of the GNU General Public License, 6 * version 2, as published by the Free Software Foundation. 7 */ 8 9 #include <linux/init.h> 10 #include <linux/module.h> 11 #include <linux/skbuff.h> 12 #include <linux/netlink.h> 13 #include <linux/netfilter.h> 14 #include <linux/netfilter/nf_tables.h> 15 #include <net/netfilter/nf_tables.h> 16 17 #define nft_objref_priv(expr) *((struct nft_object **)nft_expr_priv(expr)) 18 19 static void nft_objref_eval(const struct nft_expr *expr, 20 struct nft_regs *regs, 21 const struct nft_pktinfo *pkt) 22 { 23 struct nft_object *obj = nft_objref_priv(expr); 24 25 obj->ops->eval(obj, regs, pkt); 26 } 27 28 static int nft_objref_init(const struct nft_ctx *ctx, 29 const struct nft_expr *expr, 30 const struct nlattr * const tb[]) 31 { 32 struct nft_object *obj = nft_objref_priv(expr); 33 u8 genmask = nft_genmask_next(ctx->net); 34 u32 objtype; 35 36 if (!tb[NFTA_OBJREF_IMM_NAME] || 37 !tb[NFTA_OBJREF_IMM_TYPE]) 38 return -EINVAL; 39 40 objtype = ntohl(nla_get_be32(tb[NFTA_OBJREF_IMM_TYPE])); 41 obj = nft_obj_lookup(ctx->net, ctx->table, 42 tb[NFTA_OBJREF_IMM_NAME], objtype, 43 genmask); 44 if (IS_ERR(obj)) 45 return -ENOENT; 46 47 nft_objref_priv(expr) = obj; 48 obj->use++; 49 50 return 0; 51 } 52 53 static int nft_objref_dump(struct sk_buff *skb, const struct nft_expr *expr) 54 { 55 const struct nft_object *obj = nft_objref_priv(expr); 56 57 if (nla_put_string(skb, NFTA_OBJREF_IMM_NAME, obj->key.name) || 58 nla_put_be32(skb, NFTA_OBJREF_IMM_TYPE, 59 htonl(obj->ops->type->type))) 60 goto nla_put_failure; 61 62 return 0; 63 64 nla_put_failure: 65 return -1; 66 } 67 68 static void nft_objref_deactivate(const struct nft_ctx *ctx, 69 const struct nft_expr *expr, 70 enum nft_trans_phase phase) 71 { 72 struct nft_object *obj = nft_objref_priv(expr); 73 74 if (phase == NFT_TRANS_COMMIT) 75 return; 76 77 obj->use--; 78 } 79 80 static void nft_objref_activate(const struct nft_ctx *ctx, 81 const struct nft_expr *expr) 82 { 83 struct nft_object *obj = nft_objref_priv(expr); 84 85 obj->use++; 86 } 87 88 static struct nft_expr_type nft_objref_type; 89 static const struct nft_expr_ops nft_objref_ops = { 90 .type = &nft_objref_type, 91 .size = NFT_EXPR_SIZE(sizeof(struct nft_object *)), 92 .eval = nft_objref_eval, 93 .init = nft_objref_init, 94 .activate = nft_objref_activate, 95 .deactivate = nft_objref_deactivate, 96 .dump = nft_objref_dump, 97 }; 98 99 struct nft_objref_map { 100 struct nft_set *set; 101 enum nft_registers sreg:8; 102 struct nft_set_binding binding; 103 }; 104 105 static void nft_objref_map_eval(const struct nft_expr *expr, 106 struct nft_regs *regs, 107 const struct nft_pktinfo *pkt) 108 { 109 struct nft_objref_map *priv = nft_expr_priv(expr); 110 const struct nft_set *set = priv->set; 111 const struct nft_set_ext *ext; 112 struct nft_object *obj; 113 bool found; 114 115 found = set->ops->lookup(nft_net(pkt), set, ®s->data[priv->sreg], 116 &ext); 117 if (!found) { 118 regs->verdict.code = NFT_BREAK; 119 return; 120 } 121 obj = *nft_set_ext_obj(ext); 122 obj->ops->eval(obj, regs, pkt); 123 } 124 125 static int nft_objref_map_init(const struct nft_ctx *ctx, 126 const struct nft_expr *expr, 127 const struct nlattr * const tb[]) 128 { 129 struct nft_objref_map *priv = nft_expr_priv(expr); 130 u8 genmask = nft_genmask_next(ctx->net); 131 struct nft_set *set; 132 int err; 133 134 set = nft_set_lookup_global(ctx->net, ctx->table, 135 tb[NFTA_OBJREF_SET_NAME], 136 tb[NFTA_OBJREF_SET_ID], genmask); 137 if (IS_ERR(set)) 138 return PTR_ERR(set); 139 140 if (!(set->flags & NFT_SET_OBJECT)) 141 return -EINVAL; 142 143 priv->sreg = nft_parse_register(tb[NFTA_OBJREF_SET_SREG]); 144 err = nft_validate_register_load(priv->sreg, set->klen); 145 if (err < 0) 146 return err; 147 148 priv->binding.flags = set->flags & NFT_SET_OBJECT; 149 150 err = nf_tables_bind_set(ctx, set, &priv->binding); 151 if (err < 0) 152 return err; 153 154 priv->set = set; 155 return 0; 156 } 157 158 static int nft_objref_map_dump(struct sk_buff *skb, const struct nft_expr *expr) 159 { 160 const struct nft_objref_map *priv = nft_expr_priv(expr); 161 162 if (nft_dump_register(skb, NFTA_OBJREF_SET_SREG, priv->sreg) || 163 nla_put_string(skb, NFTA_OBJREF_SET_NAME, priv->set->name)) 164 goto nla_put_failure; 165 166 return 0; 167 168 nla_put_failure: 169 return -1; 170 } 171 172 static void nft_objref_map_deactivate(const struct nft_ctx *ctx, 173 const struct nft_expr *expr, 174 enum nft_trans_phase phase) 175 { 176 struct nft_objref_map *priv = nft_expr_priv(expr); 177 178 nf_tables_deactivate_set(ctx, priv->set, &priv->binding, phase); 179 } 180 181 static void nft_objref_map_activate(const struct nft_ctx *ctx, 182 const struct nft_expr *expr) 183 { 184 struct nft_objref_map *priv = nft_expr_priv(expr); 185 186 priv->set->use++; 187 } 188 189 static void nft_objref_map_destroy(const struct nft_ctx *ctx, 190 const struct nft_expr *expr) 191 { 192 struct nft_objref_map *priv = nft_expr_priv(expr); 193 194 nf_tables_destroy_set(ctx, priv->set); 195 } 196 197 static struct nft_expr_type nft_objref_type; 198 static const struct nft_expr_ops nft_objref_map_ops = { 199 .type = &nft_objref_type, 200 .size = NFT_EXPR_SIZE(sizeof(struct nft_objref_map)), 201 .eval = nft_objref_map_eval, 202 .init = nft_objref_map_init, 203 .activate = nft_objref_map_activate, 204 .deactivate = nft_objref_map_deactivate, 205 .destroy = nft_objref_map_destroy, 206 .dump = nft_objref_map_dump, 207 }; 208 209 static const struct nft_expr_ops * 210 nft_objref_select_ops(const struct nft_ctx *ctx, 211 const struct nlattr * const tb[]) 212 { 213 if (tb[NFTA_OBJREF_SET_SREG] && 214 (tb[NFTA_OBJREF_SET_NAME] || 215 tb[NFTA_OBJREF_SET_ID])) 216 return &nft_objref_map_ops; 217 else if (tb[NFTA_OBJREF_IMM_NAME] && 218 tb[NFTA_OBJREF_IMM_TYPE]) 219 return &nft_objref_ops; 220 221 return ERR_PTR(-EOPNOTSUPP); 222 } 223 224 static const struct nla_policy nft_objref_policy[NFTA_OBJREF_MAX + 1] = { 225 [NFTA_OBJREF_IMM_NAME] = { .type = NLA_STRING, 226 .len = NFT_OBJ_MAXNAMELEN - 1 }, 227 [NFTA_OBJREF_IMM_TYPE] = { .type = NLA_U32 }, 228 [NFTA_OBJREF_SET_SREG] = { .type = NLA_U32 }, 229 [NFTA_OBJREF_SET_NAME] = { .type = NLA_STRING, 230 .len = NFT_SET_MAXNAMELEN - 1 }, 231 [NFTA_OBJREF_SET_ID] = { .type = NLA_U32 }, 232 }; 233 234 static struct nft_expr_type nft_objref_type __read_mostly = { 235 .name = "objref", 236 .select_ops = nft_objref_select_ops, 237 .policy = nft_objref_policy, 238 .maxattr = NFTA_OBJREF_MAX, 239 .owner = THIS_MODULE, 240 }; 241 242 static int __init nft_objref_module_init(void) 243 { 244 return nft_register_expr(&nft_objref_type); 245 } 246 247 static void __exit nft_objref_module_exit(void) 248 { 249 nft_unregister_expr(&nft_objref_type); 250 } 251 252 module_init(nft_objref_module_init); 253 module_exit(nft_objref_module_exit); 254 255 MODULE_LICENSE("GPL"); 256 MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>"); 257 MODULE_ALIAS_NFT_EXPR("objref"); 258