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 = nf_tables_obj_lookup(ctx->table, tb[NFTA_OBJREF_IMM_NAME], objtype, 42 genmask); 43 if (IS_ERR(obj)) 44 return -ENOENT; 45 46 nft_objref_priv(expr) = obj; 47 obj->use++; 48 49 return 0; 50 } 51 52 static int nft_objref_dump(struct sk_buff *skb, const struct nft_expr *expr) 53 { 54 const struct nft_object *obj = nft_objref_priv(expr); 55 56 if (nla_put_string(skb, NFTA_OBJREF_IMM_NAME, obj->name) || 57 nla_put_be32(skb, NFTA_OBJREF_IMM_TYPE, 58 htonl(obj->ops->type->type))) 59 goto nla_put_failure; 60 61 return 0; 62 63 nla_put_failure: 64 return -1; 65 } 66 67 static void nft_objref_destroy(const struct nft_ctx *ctx, 68 const struct nft_expr *expr) 69 { 70 struct nft_object *obj = nft_objref_priv(expr); 71 72 obj->use--; 73 } 74 75 static struct nft_expr_type nft_objref_type; 76 static const struct nft_expr_ops nft_objref_ops = { 77 .type = &nft_objref_type, 78 .size = NFT_EXPR_SIZE(sizeof(struct nft_object *)), 79 .eval = nft_objref_eval, 80 .init = nft_objref_init, 81 .destroy = nft_objref_destroy, 82 .dump = nft_objref_dump, 83 }; 84 85 struct nft_objref_map { 86 struct nft_set *set; 87 enum nft_registers sreg:8; 88 struct nft_set_binding binding; 89 }; 90 91 static void nft_objref_map_eval(const struct nft_expr *expr, 92 struct nft_regs *regs, 93 const struct nft_pktinfo *pkt) 94 { 95 struct nft_objref_map *priv = nft_expr_priv(expr); 96 const struct nft_set *set = priv->set; 97 const struct nft_set_ext *ext; 98 struct nft_object *obj; 99 bool found; 100 101 found = set->ops->lookup(nft_net(pkt), set, ®s->data[priv->sreg], 102 &ext); 103 if (!found) { 104 regs->verdict.code = NFT_BREAK; 105 return; 106 } 107 obj = *nft_set_ext_obj(ext); 108 obj->ops->eval(obj, regs, pkt); 109 } 110 111 static int nft_objref_map_init(const struct nft_ctx *ctx, 112 const struct nft_expr *expr, 113 const struct nlattr * const tb[]) 114 { 115 struct nft_objref_map *priv = nft_expr_priv(expr); 116 u8 genmask = nft_genmask_next(ctx->net); 117 struct nft_set *set; 118 int err; 119 120 set = nft_set_lookup_global(ctx->net, ctx->table, 121 tb[NFTA_OBJREF_SET_NAME], 122 tb[NFTA_OBJREF_SET_ID], genmask); 123 if (IS_ERR(set)) 124 return PTR_ERR(set); 125 126 if (!(set->flags & NFT_SET_OBJECT)) 127 return -EINVAL; 128 129 priv->sreg = nft_parse_register(tb[NFTA_OBJREF_SET_SREG]); 130 err = nft_validate_register_load(priv->sreg, set->klen); 131 if (err < 0) 132 return err; 133 134 priv->binding.flags = set->flags & NFT_SET_OBJECT; 135 136 err = nf_tables_bind_set(ctx, set, &priv->binding); 137 if (err < 0) 138 return err; 139 140 priv->set = set; 141 return 0; 142 } 143 144 static int nft_objref_map_dump(struct sk_buff *skb, const struct nft_expr *expr) 145 { 146 const struct nft_objref_map *priv = nft_expr_priv(expr); 147 148 if (nft_dump_register(skb, NFTA_OBJREF_SET_SREG, priv->sreg) || 149 nla_put_string(skb, NFTA_OBJREF_SET_NAME, priv->set->name)) 150 goto nla_put_failure; 151 152 return 0; 153 154 nla_put_failure: 155 return -1; 156 } 157 158 static void nft_objref_map_destroy(const struct nft_ctx *ctx, 159 const struct nft_expr *expr) 160 { 161 struct nft_objref_map *priv = nft_expr_priv(expr); 162 163 nf_tables_unbind_set(ctx, priv->set, &priv->binding); 164 } 165 166 static struct nft_expr_type nft_objref_type; 167 static const struct nft_expr_ops nft_objref_map_ops = { 168 .type = &nft_objref_type, 169 .size = NFT_EXPR_SIZE(sizeof(struct nft_objref_map)), 170 .eval = nft_objref_map_eval, 171 .init = nft_objref_map_init, 172 .destroy = nft_objref_map_destroy, 173 .dump = nft_objref_map_dump, 174 }; 175 176 static const struct nft_expr_ops * 177 nft_objref_select_ops(const struct nft_ctx *ctx, 178 const struct nlattr * const tb[]) 179 { 180 if (tb[NFTA_OBJREF_SET_SREG] && 181 (tb[NFTA_OBJREF_SET_NAME] || 182 tb[NFTA_OBJREF_SET_ID])) 183 return &nft_objref_map_ops; 184 else if (tb[NFTA_OBJREF_IMM_NAME] && 185 tb[NFTA_OBJREF_IMM_TYPE]) 186 return &nft_objref_ops; 187 188 return ERR_PTR(-EOPNOTSUPP); 189 } 190 191 static const struct nla_policy nft_objref_policy[NFTA_OBJREF_MAX + 1] = { 192 [NFTA_OBJREF_IMM_NAME] = { .type = NLA_STRING, 193 .len = NFT_OBJ_MAXNAMELEN - 1 }, 194 [NFTA_OBJREF_IMM_TYPE] = { .type = NLA_U32 }, 195 [NFTA_OBJREF_SET_SREG] = { .type = NLA_U32 }, 196 [NFTA_OBJREF_SET_NAME] = { .type = NLA_STRING, 197 .len = NFT_SET_MAXNAMELEN - 1 }, 198 [NFTA_OBJREF_SET_ID] = { .type = NLA_U32 }, 199 }; 200 201 static struct nft_expr_type nft_objref_type __read_mostly = { 202 .name = "objref", 203 .select_ops = nft_objref_select_ops, 204 .policy = nft_objref_policy, 205 .maxattr = NFTA_OBJREF_MAX, 206 .owner = THIS_MODULE, 207 }; 208 209 static int __init nft_objref_module_init(void) 210 { 211 return nft_register_expr(&nft_objref_type); 212 } 213 214 static void __exit nft_objref_module_exit(void) 215 { 216 nft_unregister_expr(&nft_objref_type); 217 } 218 219 module_init(nft_objref_module_init); 220 module_exit(nft_objref_module_exit); 221 222 MODULE_LICENSE("GPL"); 223 MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>"); 224 MODULE_ALIAS_NFT_EXPR("objref"); 225