diff options
Diffstat (limited to 'net/netfilter/nft_objref.c')
| -rw-r--r-- | net/netfilter/nft_objref.c | 226 |
1 files changed, 226 insertions, 0 deletions
diff --git a/net/netfilter/nft_objref.c b/net/netfilter/nft_objref.c new file mode 100644 index 000000000000..415a65ba2b85 --- /dev/null +++ b/net/netfilter/nft_objref.c @@ -0,0 +1,226 @@ +/* + * Copyright (c) 2012-2016 Pablo Neira Ayuso <pablo@netfilter.org> + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + */ + +#include <linux/init.h> +#include <linux/module.h> +#include <linux/skbuff.h> +#include <linux/netlink.h> +#include <linux/netfilter.h> +#include <linux/netfilter/nf_tables.h> +#include <net/netfilter/nf_tables.h> + +#define nft_objref_priv(expr) *((struct nft_object **)nft_expr_priv(expr)) + +static void nft_objref_eval(const struct nft_expr *expr, + struct nft_regs *regs, + const struct nft_pktinfo *pkt) +{ + struct nft_object *obj = nft_objref_priv(expr); + + obj->type->eval(obj, regs, pkt); +} + +static int nft_objref_init(const struct nft_ctx *ctx, + const struct nft_expr *expr, + const struct nlattr * const tb[]) +{ + struct nft_object *obj = nft_objref_priv(expr); + u8 genmask = nft_genmask_next(ctx->net); + u32 objtype; + + if (!tb[NFTA_OBJREF_IMM_NAME] || + !tb[NFTA_OBJREF_IMM_TYPE]) + return -EINVAL; + + objtype = ntohl(nla_get_be32(tb[NFTA_OBJREF_IMM_TYPE])); + obj = nf_tables_obj_lookup(ctx->table, tb[NFTA_OBJREF_IMM_NAME], objtype, + genmask); + if (IS_ERR(obj)) + return -ENOENT; + + nft_objref_priv(expr) = obj; + obj->use++; + + return 0; +} + +static int nft_objref_dump(struct sk_buff *skb, const struct nft_expr *expr) +{ + const struct nft_object *obj = nft_objref_priv(expr); + + if (nla_put_string(skb, NFTA_OBJREF_IMM_NAME, obj->name) || + nla_put_be32(skb, NFTA_OBJREF_IMM_TYPE, htonl(obj->type->type))) + goto nla_put_failure; + + return 0; + +nla_put_failure: + return -1; +} + +static void nft_objref_destroy(const struct nft_ctx *ctx, + const struct nft_expr *expr) +{ + struct nft_object *obj = nft_objref_priv(expr); + + obj->use--; +} + +static struct nft_expr_type nft_objref_type; +static const struct nft_expr_ops nft_objref_ops = { + .type = &nft_objref_type, + .size = NFT_EXPR_SIZE(sizeof(struct nft_object *)), + .eval = nft_objref_eval, + .init = nft_objref_init, + .destroy = nft_objref_destroy, + .dump = nft_objref_dump, +}; + +struct nft_objref_map { + struct nft_set *set; + enum nft_registers sreg:8; + struct nft_set_binding binding; +}; + +static void nft_objref_map_eval(const struct nft_expr *expr, + struct nft_regs *regs, + const struct nft_pktinfo *pkt) +{ + struct nft_objref_map *priv = nft_expr_priv(expr); + const struct nft_set *set = priv->set; + const struct nft_set_ext *ext; + struct nft_object *obj; + bool found; + + found = set->ops->lookup(nft_net(pkt), set, ®s->data[priv->sreg], + &ext); + if (!found) { + regs->verdict.code = NFT_BREAK; + return; + } + obj = *nft_set_ext_obj(ext); + obj->type->eval(obj, regs, pkt); +} + +static int nft_objref_map_init(const struct nft_ctx *ctx, + const struct nft_expr *expr, + const struct nlattr * const tb[]) +{ + struct nft_objref_map *priv = nft_expr_priv(expr); + u8 genmask = nft_genmask_next(ctx->net); + struct nft_set *set; + int err; + + set = nf_tables_set_lookup(ctx->table, tb[NFTA_OBJREF_SET_NAME], genmask); + if (IS_ERR(set)) { + if (tb[NFTA_OBJREF_SET_ID]) { + set = nf_tables_set_lookup_byid(ctx->net, + tb[NFTA_OBJREF_SET_ID], + genmask); + } + if (IS_ERR(set)) + return PTR_ERR(set); + } + + if (!(set->flags & NFT_SET_OBJECT)) + return -EINVAL; + + priv->sreg = nft_parse_register(tb[NFTA_OBJREF_SET_SREG]); + err = nft_validate_register_load(priv->sreg, set->klen); + if (err < 0) + return err; + + priv->binding.flags = set->flags & NFT_SET_OBJECT; + + err = nf_tables_bind_set(ctx, set, &priv->binding); + if (err < 0) + return err; + + priv->set = set; + return 0; +} + +static int nft_objref_map_dump(struct sk_buff *skb, const struct nft_expr *expr) +{ + const struct nft_objref_map *priv = nft_expr_priv(expr); + + if (nft_dump_register(skb, NFTA_OBJREF_SET_SREG, priv->sreg) || + nla_put_string(skb, NFTA_OBJREF_SET_NAME, priv->set->name)) + goto nla_put_failure; + + return 0; + +nla_put_failure: + return -1; +} + +static void nft_objref_map_destroy(const struct nft_ctx *ctx, + const struct nft_expr *expr) +{ + struct nft_objref_map *priv = nft_expr_priv(expr); + + nf_tables_unbind_set(ctx, priv->set, &priv->binding); +} + +static struct nft_expr_type nft_objref_type; +static const struct nft_expr_ops nft_objref_map_ops = { + .type = &nft_objref_type, + .size = NFT_EXPR_SIZE(sizeof(struct nft_objref_map)), + .eval = nft_objref_map_eval, + .init = nft_objref_map_init, + .destroy = nft_objref_map_destroy, + .dump = nft_objref_map_dump, +}; + +static const struct nft_expr_ops * +nft_objref_select_ops(const struct nft_ctx *ctx, + const struct nlattr * const tb[]) +{ + if (tb[NFTA_OBJREF_SET_SREG] && + (tb[NFTA_OBJREF_SET_NAME] || + tb[NFTA_OBJREF_SET_ID])) + return &nft_objref_map_ops; + else if (tb[NFTA_OBJREF_IMM_NAME] && + tb[NFTA_OBJREF_IMM_TYPE]) + return &nft_objref_ops; + + return ERR_PTR(-EOPNOTSUPP); +} + +static const struct nla_policy nft_objref_policy[NFTA_OBJREF_MAX + 1] = { + [NFTA_OBJREF_IMM_NAME] = { .type = NLA_STRING }, + [NFTA_OBJREF_IMM_TYPE] = { .type = NLA_U32 }, + [NFTA_OBJREF_SET_SREG] = { .type = NLA_U32 }, + [NFTA_OBJREF_SET_NAME] = { .type = NLA_STRING }, + [NFTA_OBJREF_SET_ID] = { .type = NLA_U32 }, +}; + +static struct nft_expr_type nft_objref_type __read_mostly = { + .name = "objref", + .select_ops = nft_objref_select_ops, + .policy = nft_objref_policy, + .maxattr = NFTA_OBJREF_MAX, + .owner = THIS_MODULE, +}; + +static int __init nft_objref_module_init(void) +{ + return nft_register_expr(&nft_objref_type); +} + +static void __exit nft_objref_module_exit(void) +{ + nft_unregister_expr(&nft_objref_type); +} + +module_init(nft_objref_module_init); +module_exit(nft_objref_module_exit); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>"); +MODULE_ALIAS_NFT_EXPR("objref"); |