/* * 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");