/* * Copyright (c) 2014 Arturo Borrero Gonzalez * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */ #include #include #include #include #include #include #include #include #include #include struct nft_masq { u32 flags; enum nft_registers sreg_proto_min:8; enum nft_registers sreg_proto_max:8; }; static const struct nla_policy nft_masq_policy[NFTA_MASQ_MAX + 1] = { [NFTA_MASQ_FLAGS] = { .type = NLA_U32 }, [NFTA_MASQ_REG_PROTO_MIN] = { .type = NLA_U32 }, [NFTA_MASQ_REG_PROTO_MAX] = { .type = NLA_U32 }, }; static int nft_masq_validate(const struct nft_ctx *ctx, const struct nft_expr *expr, const struct nft_data **data) { int err; err = nft_chain_validate_dependency(ctx->chain, NFT_CHAIN_T_NAT); if (err < 0) return err; return nft_chain_validate_hooks(ctx->chain, (1 << NF_INET_POST_ROUTING)); } static int nft_masq_init(const struct nft_ctx *ctx, const struct nft_expr *expr, const struct nlattr * const tb[]) { u32 plen = FIELD_SIZEOF(struct nf_nat_range, min_addr.all); struct nft_masq *priv = nft_expr_priv(expr); int err; if (tb[NFTA_MASQ_FLAGS]) { priv->flags = ntohl(nla_get_be32(tb[NFTA_MASQ_FLAGS])); if (priv->flags & ~NF_NAT_RANGE_MASK) return -EINVAL; } if (tb[NFTA_MASQ_REG_PROTO_MIN]) { priv->sreg_proto_min = nft_parse_register(tb[NFTA_MASQ_REG_PROTO_MIN]); err = nft_validate_register_load(priv->sreg_proto_min, plen); if (err < 0) return err; if (tb[NFTA_MASQ_REG_PROTO_MAX]) { priv->sreg_proto_max = nft_parse_register(tb[NFTA_MASQ_REG_PROTO_MAX]); err = nft_validate_register_load(priv->sreg_proto_max, plen); if (err < 0) return err; } else { priv->sreg_proto_max = priv->sreg_proto_min; } } return nf_ct_netns_get(ctx->net, ctx->family); } static int nft_masq_dump(struct sk_buff *skb, const struct nft_expr *expr) { const struct nft_masq *priv = nft_expr_priv(expr); if (priv->flags != 0 && nla_put_be32(skb, NFTA_MASQ_FLAGS, htonl(priv->flags))) goto nla_put_failure; if (priv->sreg_proto_min) { if (nft_dump_register(skb, NFTA_MASQ_REG_PROTO_MIN, priv->sreg_proto_min) || nft_dump_register(skb, NFTA_MASQ_REG_PROTO_MAX, priv->sreg_proto_max)) goto nla_put_failure; } return 0; nla_put_failure: return -1; } static void nft_masq_ipv4_eval(const struct nft_expr *expr, struct nft_regs *regs, const struct nft_pktinfo *pkt) { struct nft_masq *priv = nft_expr_priv(expr); struct nf_nat_range2 range; memset(&range, 0, sizeof(range)); range.flags = priv->flags; if (priv->sreg_proto_min) { range.min_proto.all = (__force __be16)nft_reg_load16( ®s->data[priv->sreg_proto_min]); range.max_proto.all = (__force __be16)nft_reg_load16( ®s->data[priv->sreg_proto_max]); } regs->verdict.code = nf_nat_masquerade_ipv4(pkt->skb, nft_hook(pkt), &range, nft_out(pkt)); } static void nft_masq_ipv4_destroy(const struct nft_ctx *ctx, const struct nft_expr *expr) { nf_ct_netns_put(ctx->net, NFPROTO_IPV4); } static struct nft_expr_type nft_masq_ipv4_type; static const struct nft_expr_ops nft_masq_ipv4_ops = { .type = &nft_masq_ipv4_type, .size = NFT_EXPR_SIZE(sizeof(struct nft_masq)), .eval = nft_masq_ipv4_eval, .init = nft_masq_init, .destroy = nft_masq_ipv4_destroy, .dump = nft_masq_dump, .validate = nft_masq_validate, }; static struct nft_expr_type nft_masq_ipv4_type __read_mostly = { .family = NFPROTO_IPV4, .name = "masq", .ops = &nft_masq_ipv4_ops, .policy = nft_masq_policy, .maxattr = NFTA_MASQ_MAX, .owner = THIS_MODULE, }; #ifdef CONFIG_NF_TABLES_IPV6 static void nft_masq_ipv6_eval(const struct nft_expr *expr, struct nft_regs *regs, const struct nft_pktinfo *pkt) { struct nft_masq *priv = nft_expr_priv(expr); struct nf_nat_range2 range; memset(&range, 0, sizeof(range)); range.flags = priv->flags; if (priv->sreg_proto_min) { range.min_proto.all = (__force __be16)nft_reg_load16( ®s->data[priv->sreg_proto_min]); range.max_proto.all = (__force __be16)nft_reg_load16( ®s->data[priv->sreg_proto_max]); } regs->verdict.code = nf_nat_masquerade_ipv6(pkt->skb, &range, nft_out(pkt)); } static void nft_masq_ipv6_destroy(const struct nft_ctx *ctx, const struct nft_expr *expr) { nf_ct_netns_put(ctx->net, NFPROTO_IPV6); } static struct nft_expr_type nft_masq_ipv6_type; static const struct nft_expr_ops nft_masq_ipv6_ops = { .type = &nft_masq_ipv6_type, .size = NFT_EXPR_SIZE(sizeof(struct nft_masq)), .eval = nft_masq_ipv6_eval, .init = nft_masq_init, .destroy = nft_masq_ipv6_destroy, .dump = nft_masq_dump, .validate = nft_masq_validate, }; static struct nft_expr_type nft_masq_ipv6_type __read_mostly = { .family = NFPROTO_IPV6, .name = "masq", .ops = &nft_masq_ipv6_ops, .policy = nft_masq_policy, .maxattr = NFTA_MASQ_MAX, .owner = THIS_MODULE, }; static int __init nft_masq_module_init_ipv6(void) { int ret = nft_register_expr(&nft_masq_ipv6_type); if (ret) return ret; ret = nf_nat_masquerade_ipv6_register_notifier(); if (ret < 0) nft_unregister_expr(&nft_masq_ipv6_type); return ret; } static void nft_masq_module_exit_ipv6(void) { nft_unregister_expr(&nft_masq_ipv6_type); nf_nat_masquerade_ipv6_unregister_notifier(); } #else static inline int nft_masq_module_init_ipv6(void) { return 0; } static inline void nft_masq_module_exit_ipv6(void) {} #endif static int __init nft_masq_module_init(void) { int ret; ret = nft_masq_module_init_ipv6(); if (ret < 0) return ret; ret = nft_register_expr(&nft_masq_ipv4_type); if (ret < 0) { nft_masq_module_exit_ipv6(); return ret; } ret = nf_nat_masquerade_ipv4_register_notifier(); if (ret < 0) { nft_masq_module_exit_ipv6(); nft_unregister_expr(&nft_masq_ipv4_type); return ret; } return ret; } static void __exit nft_masq_module_exit(void) { nft_masq_module_exit_ipv6(); nft_unregister_expr(&nft_masq_ipv4_type); nf_nat_masquerade_ipv4_unregister_notifier(); } module_init(nft_masq_module_init); module_exit(nft_masq_module_exit); MODULE_LICENSE("GPL"); MODULE_AUTHOR("Arturo Borrero Gonzalez "); MODULE_ALIAS_NFT_AF_EXPR(AF_INET6, "masq"); MODULE_ALIAS_NFT_AF_EXPR(AF_INET, "masq");