Pablo Neira Ayuso | c97d22e | 2016-11-28 00:05:38 +0100 | [diff] [blame] | 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->type->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, htonl(obj->type->type))) |
| 58 | goto nla_put_failure; |
| 59 | |
| 60 | return 0; |
| 61 | |
| 62 | nla_put_failure: |
| 63 | return -1; |
| 64 | } |
| 65 | |
| 66 | static void nft_objref_destroy(const struct nft_ctx *ctx, |
| 67 | const struct nft_expr *expr) |
| 68 | { |
| 69 | struct nft_object *obj = nft_objref_priv(expr); |
| 70 | |
| 71 | obj->use--; |
| 72 | } |
| 73 | |
| 74 | static struct nft_expr_type nft_objref_type; |
| 75 | static const struct nft_expr_ops nft_objref_ops = { |
| 76 | .type = &nft_objref_type, |
| 77 | .size = NFT_EXPR_SIZE(sizeof(struct nft_object *)), |
| 78 | .eval = nft_objref_eval, |
| 79 | .init = nft_objref_init, |
| 80 | .destroy = nft_objref_destroy, |
| 81 | .dump = nft_objref_dump, |
| 82 | }; |
| 83 | |
Pablo Neira Ayuso | 63aea29 | 2016-11-28 00:06:03 +0100 | [diff] [blame] | 84 | struct nft_objref_map { |
| 85 | struct nft_set *set; |
| 86 | enum nft_registers sreg:8; |
| 87 | struct nft_set_binding binding; |
| 88 | }; |
| 89 | |
| 90 | static void nft_objref_map_eval(const struct nft_expr *expr, |
| 91 | struct nft_regs *regs, |
| 92 | const struct nft_pktinfo *pkt) |
| 93 | { |
| 94 | struct nft_objref_map *priv = nft_expr_priv(expr); |
| 95 | const struct nft_set *set = priv->set; |
| 96 | const struct nft_set_ext *ext; |
| 97 | struct nft_object *obj; |
| 98 | bool found; |
| 99 | |
| 100 | found = set->ops->lookup(nft_net(pkt), set, ®s->data[priv->sreg], |
| 101 | &ext); |
| 102 | if (!found) { |
| 103 | regs->verdict.code = NFT_BREAK; |
| 104 | return; |
| 105 | } |
| 106 | obj = *nft_set_ext_obj(ext); |
| 107 | obj->type->eval(obj, regs, pkt); |
| 108 | } |
| 109 | |
| 110 | static int nft_objref_map_init(const struct nft_ctx *ctx, |
| 111 | const struct nft_expr *expr, |
| 112 | const struct nlattr * const tb[]) |
| 113 | { |
| 114 | struct nft_objref_map *priv = nft_expr_priv(expr); |
| 115 | u8 genmask = nft_genmask_next(ctx->net); |
| 116 | struct nft_set *set; |
| 117 | int err; |
| 118 | |
Pablo Neira Ayuso | c7a72e3 | 2017-03-06 17:46:20 +0100 | [diff] [blame] | 119 | set = nft_set_lookup(ctx->net, ctx->table, tb[NFTA_OBJREF_SET_NAME], |
| 120 | tb[NFTA_OBJREF_SET_ID], genmask); |
| 121 | if (IS_ERR(set)) |
| 122 | return PTR_ERR(set); |
Pablo Neira Ayuso | 63aea29 | 2016-11-28 00:06:03 +0100 | [diff] [blame] | 123 | |
| 124 | if (!(set->flags & NFT_SET_OBJECT)) |
| 125 | return -EINVAL; |
| 126 | |
| 127 | priv->sreg = nft_parse_register(tb[NFTA_OBJREF_SET_SREG]); |
| 128 | err = nft_validate_register_load(priv->sreg, set->klen); |
| 129 | if (err < 0) |
| 130 | return err; |
| 131 | |
| 132 | priv->binding.flags = set->flags & NFT_SET_OBJECT; |
| 133 | |
| 134 | err = nf_tables_bind_set(ctx, set, &priv->binding); |
| 135 | if (err < 0) |
| 136 | return err; |
| 137 | |
| 138 | priv->set = set; |
| 139 | return 0; |
| 140 | } |
| 141 | |
| 142 | static int nft_objref_map_dump(struct sk_buff *skb, const struct nft_expr *expr) |
| 143 | { |
| 144 | const struct nft_objref_map *priv = nft_expr_priv(expr); |
| 145 | |
| 146 | if (nft_dump_register(skb, NFTA_OBJREF_SET_SREG, priv->sreg) || |
| 147 | nla_put_string(skb, NFTA_OBJREF_SET_NAME, priv->set->name)) |
| 148 | goto nla_put_failure; |
| 149 | |
| 150 | return 0; |
| 151 | |
| 152 | nla_put_failure: |
| 153 | return -1; |
| 154 | } |
| 155 | |
| 156 | static void nft_objref_map_destroy(const struct nft_ctx *ctx, |
| 157 | const struct nft_expr *expr) |
| 158 | { |
| 159 | struct nft_objref_map *priv = nft_expr_priv(expr); |
| 160 | |
| 161 | nf_tables_unbind_set(ctx, priv->set, &priv->binding); |
| 162 | } |
| 163 | |
| 164 | static struct nft_expr_type nft_objref_type; |
| 165 | static const struct nft_expr_ops nft_objref_map_ops = { |
| 166 | .type = &nft_objref_type, |
| 167 | .size = NFT_EXPR_SIZE(sizeof(struct nft_objref_map)), |
| 168 | .eval = nft_objref_map_eval, |
| 169 | .init = nft_objref_map_init, |
| 170 | .destroy = nft_objref_map_destroy, |
| 171 | .dump = nft_objref_map_dump, |
| 172 | }; |
| 173 | |
| 174 | static const struct nft_expr_ops * |
| 175 | nft_objref_select_ops(const struct nft_ctx *ctx, |
| 176 | const struct nlattr * const tb[]) |
| 177 | { |
| 178 | if (tb[NFTA_OBJREF_SET_SREG] && |
| 179 | (tb[NFTA_OBJREF_SET_NAME] || |
| 180 | tb[NFTA_OBJREF_SET_ID])) |
| 181 | return &nft_objref_map_ops; |
| 182 | else if (tb[NFTA_OBJREF_IMM_NAME] && |
| 183 | tb[NFTA_OBJREF_IMM_TYPE]) |
| 184 | return &nft_objref_ops; |
| 185 | |
| 186 | return ERR_PTR(-EOPNOTSUPP); |
| 187 | } |
| 188 | |
Pablo Neira Ayuso | c97d22e | 2016-11-28 00:05:38 +0100 | [diff] [blame] | 189 | static const struct nla_policy nft_objref_policy[NFTA_OBJREF_MAX + 1] = { |
Liping Zhang | b2fbd04 | 2017-01-20 21:03:03 +0800 | [diff] [blame] | 190 | [NFTA_OBJREF_IMM_NAME] = { .type = NLA_STRING, |
| 191 | .len = NFT_OBJ_MAXNAMELEN - 1 }, |
Pablo Neira Ayuso | c97d22e | 2016-11-28 00:05:38 +0100 | [diff] [blame] | 192 | [NFTA_OBJREF_IMM_TYPE] = { .type = NLA_U32 }, |
Pablo Neira Ayuso | 63aea29 | 2016-11-28 00:06:03 +0100 | [diff] [blame] | 193 | [NFTA_OBJREF_SET_SREG] = { .type = NLA_U32 }, |
Liping Zhang | b2fbd04 | 2017-01-20 21:03:03 +0800 | [diff] [blame] | 194 | [NFTA_OBJREF_SET_NAME] = { .type = NLA_STRING, |
| 195 | .len = NFT_SET_MAXNAMELEN - 1 }, |
Pablo Neira Ayuso | 63aea29 | 2016-11-28 00:06:03 +0100 | [diff] [blame] | 196 | [NFTA_OBJREF_SET_ID] = { .type = NLA_U32 }, |
Pablo Neira Ayuso | c97d22e | 2016-11-28 00:05:38 +0100 | [diff] [blame] | 197 | }; |
| 198 | |
| 199 | static struct nft_expr_type nft_objref_type __read_mostly = { |
| 200 | .name = "objref", |
Pablo Neira Ayuso | 63aea29 | 2016-11-28 00:06:03 +0100 | [diff] [blame] | 201 | .select_ops = nft_objref_select_ops, |
Pablo Neira Ayuso | c97d22e | 2016-11-28 00:05:38 +0100 | [diff] [blame] | 202 | .policy = nft_objref_policy, |
| 203 | .maxattr = NFTA_OBJREF_MAX, |
| 204 | .owner = THIS_MODULE, |
| 205 | }; |
| 206 | |
| 207 | static int __init nft_objref_module_init(void) |
| 208 | { |
| 209 | return nft_register_expr(&nft_objref_type); |
| 210 | } |
| 211 | |
| 212 | static void __exit nft_objref_module_exit(void) |
| 213 | { |
| 214 | nft_unregister_expr(&nft_objref_type); |
| 215 | } |
| 216 | |
| 217 | module_init(nft_objref_module_init); |
| 218 | module_exit(nft_objref_module_exit); |
| 219 | |
| 220 | MODULE_LICENSE("GPL"); |
| 221 | MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>"); |
| 222 | MODULE_ALIAS_NFT_EXPR("objref"); |