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- // SPDX-License-Identifier: GPL-2.0-only
- /*
- * Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net>
- * Copyright (c) 2012 Pablo Neira Ayuso <pablo@netfilter.org>
- * Copyright (c) 2012 Intel Corporation
- */
- #include <linux/module.h>
- #include <linux/init.h>
- #include <linux/skbuff.h>
- #include <linux/ip.h>
- #include <linux/string.h>
- #include <linux/netlink.h>
- #include <linux/netfilter.h>
- #include <linux/netfilter_ipv4.h>
- #include <linux/netfilter/nfnetlink.h>
- #include <linux/netfilter/nf_tables.h>
- #include <net/netfilter/nf_conntrack.h>
- #include <net/netfilter/nf_nat.h>
- #include <net/netfilter/nf_tables.h>
- #include <net/ip.h>
- struct nft_nat {
- enum nft_registers sreg_addr_min:8;
- enum nft_registers sreg_addr_max:8;
- enum nft_registers sreg_proto_min:8;
- enum nft_registers sreg_proto_max:8;
- enum nf_nat_manip_type type:8;
- u8 family;
- u16 flags;
- };
- static void nft_nat_setup_addr(struct nf_nat_range2 *range,
- const struct nft_regs *regs,
- const struct nft_nat *priv)
- {
- switch (priv->family) {
- case AF_INET:
- range->min_addr.ip = (__force __be32)
- regs->data[priv->sreg_addr_min];
- range->max_addr.ip = (__force __be32)
- regs->data[priv->sreg_addr_max];
- break;
- case AF_INET6:
- memcpy(range->min_addr.ip6, ®s->data[priv->sreg_addr_min],
- sizeof(range->min_addr.ip6));
- memcpy(range->max_addr.ip6, ®s->data[priv->sreg_addr_max],
- sizeof(range->max_addr.ip6));
- break;
- }
- }
- static void nft_nat_setup_proto(struct nf_nat_range2 *range,
- const struct nft_regs *regs,
- const struct nft_nat *priv)
- {
- 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]);
- }
- static void nft_nat_setup_netmap(struct nf_nat_range2 *range,
- const struct nft_pktinfo *pkt,
- const struct nft_nat *priv)
- {
- struct sk_buff *skb = pkt->skb;
- union nf_inet_addr new_addr;
- __be32 netmask;
- int i, len = 0;
- switch (priv->type) {
- case NFT_NAT_SNAT:
- if (nft_pf(pkt) == NFPROTO_IPV4) {
- new_addr.ip = ip_hdr(skb)->saddr;
- len = sizeof(struct in_addr);
- } else {
- new_addr.in6 = ipv6_hdr(skb)->saddr;
- len = sizeof(struct in6_addr);
- }
- break;
- case NFT_NAT_DNAT:
- if (nft_pf(pkt) == NFPROTO_IPV4) {
- new_addr.ip = ip_hdr(skb)->daddr;
- len = sizeof(struct in_addr);
- } else {
- new_addr.in6 = ipv6_hdr(skb)->daddr;
- len = sizeof(struct in6_addr);
- }
- break;
- }
- for (i = 0; i < len / sizeof(__be32); i++) {
- netmask = ~(range->min_addr.ip6[i] ^ range->max_addr.ip6[i]);
- new_addr.ip6[i] &= ~netmask;
- new_addr.ip6[i] |= range->min_addr.ip6[i] & netmask;
- }
- range->min_addr = new_addr;
- range->max_addr = new_addr;
- }
- static void nft_nat_eval(const struct nft_expr *expr,
- struct nft_regs *regs,
- const struct nft_pktinfo *pkt)
- {
- const struct nft_nat *priv = nft_expr_priv(expr);
- enum ip_conntrack_info ctinfo;
- struct nf_conn *ct = nf_ct_get(pkt->skb, &ctinfo);
- struct nf_nat_range2 range;
- memset(&range, 0, sizeof(range));
- if (priv->sreg_addr_min) {
- nft_nat_setup_addr(&range, regs, priv);
- if (priv->flags & NF_NAT_RANGE_NETMAP)
- nft_nat_setup_netmap(&range, pkt, priv);
- }
- if (priv->sreg_proto_min)
- nft_nat_setup_proto(&range, regs, priv);
- range.flags = priv->flags;
- regs->verdict.code = nf_nat_setup_info(ct, &range, priv->type);
- }
- static const struct nla_policy nft_nat_policy[NFTA_NAT_MAX + 1] = {
- [NFTA_NAT_TYPE] = { .type = NLA_U32 },
- [NFTA_NAT_FAMILY] = { .type = NLA_U32 },
- [NFTA_NAT_REG_ADDR_MIN] = { .type = NLA_U32 },
- [NFTA_NAT_REG_ADDR_MAX] = { .type = NLA_U32 },
- [NFTA_NAT_REG_PROTO_MIN] = { .type = NLA_U32 },
- [NFTA_NAT_REG_PROTO_MAX] = { .type = NLA_U32 },
- [NFTA_NAT_FLAGS] = { .type = NLA_U32 },
- };
- static int nft_nat_validate(const struct nft_ctx *ctx,
- const struct nft_expr *expr,
- const struct nft_data **data)
- {
- struct nft_nat *priv = nft_expr_priv(expr);
- int err;
- err = nft_chain_validate_dependency(ctx->chain, NFT_CHAIN_T_NAT);
- if (err < 0)
- return err;
- switch (priv->type) {
- case NFT_NAT_SNAT:
- err = nft_chain_validate_hooks(ctx->chain,
- (1 << NF_INET_POST_ROUTING) |
- (1 << NF_INET_LOCAL_IN));
- break;
- case NFT_NAT_DNAT:
- err = nft_chain_validate_hooks(ctx->chain,
- (1 << NF_INET_PRE_ROUTING) |
- (1 << NF_INET_LOCAL_OUT));
- break;
- }
- return err;
- }
- static int nft_nat_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
- const struct nlattr * const tb[])
- {
- struct nft_nat *priv = nft_expr_priv(expr);
- unsigned int alen, plen;
- u32 family;
- int err;
- if (tb[NFTA_NAT_TYPE] == NULL ||
- (tb[NFTA_NAT_REG_ADDR_MIN] == NULL &&
- tb[NFTA_NAT_REG_PROTO_MIN] == NULL))
- return -EINVAL;
- switch (ntohl(nla_get_be32(tb[NFTA_NAT_TYPE]))) {
- case NFT_NAT_SNAT:
- priv->type = NF_NAT_MANIP_SRC;
- break;
- case NFT_NAT_DNAT:
- priv->type = NF_NAT_MANIP_DST;
- break;
- default:
- return -EOPNOTSUPP;
- }
- if (tb[NFTA_NAT_FAMILY] == NULL)
- return -EINVAL;
- family = ntohl(nla_get_be32(tb[NFTA_NAT_FAMILY]));
- if (ctx->family != NFPROTO_INET && ctx->family != family)
- return -EOPNOTSUPP;
- switch (family) {
- case NFPROTO_IPV4:
- alen = sizeof_field(struct nf_nat_range, min_addr.ip);
- break;
- case NFPROTO_IPV6:
- alen = sizeof_field(struct nf_nat_range, min_addr.ip6);
- break;
- default:
- if (tb[NFTA_NAT_REG_ADDR_MIN])
- return -EAFNOSUPPORT;
- break;
- }
- priv->family = family;
- if (tb[NFTA_NAT_REG_ADDR_MIN]) {
- priv->sreg_addr_min =
- nft_parse_register(tb[NFTA_NAT_REG_ADDR_MIN]);
- err = nft_validate_register_load(priv->sreg_addr_min, alen);
- if (err < 0)
- return err;
- if (tb[NFTA_NAT_REG_ADDR_MAX]) {
- priv->sreg_addr_max =
- nft_parse_register(tb[NFTA_NAT_REG_ADDR_MAX]);
- err = nft_validate_register_load(priv->sreg_addr_max,
- alen);
- if (err < 0)
- return err;
- } else {
- priv->sreg_addr_max = priv->sreg_addr_min;
- }
- priv->flags |= NF_NAT_RANGE_MAP_IPS;
- }
- plen = sizeof_field(struct nf_nat_range, min_addr.all);
- if (tb[NFTA_NAT_REG_PROTO_MIN]) {
- priv->sreg_proto_min =
- nft_parse_register(tb[NFTA_NAT_REG_PROTO_MIN]);
- err = nft_validate_register_load(priv->sreg_proto_min, plen);
- if (err < 0)
- return err;
- if (tb[NFTA_NAT_REG_PROTO_MAX]) {
- priv->sreg_proto_max =
- nft_parse_register(tb[NFTA_NAT_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;
- }
- priv->flags |= NF_NAT_RANGE_PROTO_SPECIFIED;
- }
- if (tb[NFTA_NAT_FLAGS]) {
- priv->flags |= ntohl(nla_get_be32(tb[NFTA_NAT_FLAGS]));
- if (priv->flags & ~NF_NAT_RANGE_MASK)
- return -EOPNOTSUPP;
- }
- return nf_ct_netns_get(ctx->net, family);
- }
- static int nft_nat_dump(struct sk_buff *skb, const struct nft_expr *expr)
- {
- const struct nft_nat *priv = nft_expr_priv(expr);
- switch (priv->type) {
- case NF_NAT_MANIP_SRC:
- if (nla_put_be32(skb, NFTA_NAT_TYPE, htonl(NFT_NAT_SNAT)))
- goto nla_put_failure;
- break;
- case NF_NAT_MANIP_DST:
- if (nla_put_be32(skb, NFTA_NAT_TYPE, htonl(NFT_NAT_DNAT)))
- goto nla_put_failure;
- break;
- }
- if (nla_put_be32(skb, NFTA_NAT_FAMILY, htonl(priv->family)))
- goto nla_put_failure;
- if (priv->sreg_addr_min) {
- if (nft_dump_register(skb, NFTA_NAT_REG_ADDR_MIN,
- priv->sreg_addr_min) ||
- nft_dump_register(skb, NFTA_NAT_REG_ADDR_MAX,
- priv->sreg_addr_max))
- goto nla_put_failure;
- }
- if (priv->sreg_proto_min) {
- if (nft_dump_register(skb, NFTA_NAT_REG_PROTO_MIN,
- priv->sreg_proto_min) ||
- nft_dump_register(skb, NFTA_NAT_REG_PROTO_MAX,
- priv->sreg_proto_max))
- goto nla_put_failure;
- }
- if (priv->flags != 0) {
- if (nla_put_be32(skb, NFTA_NAT_FLAGS, htonl(priv->flags)))
- goto nla_put_failure;
- }
- return 0;
- nla_put_failure:
- return -1;
- }
- static void
- nft_nat_destroy(const struct nft_ctx *ctx, const struct nft_expr *expr)
- {
- const struct nft_nat *priv = nft_expr_priv(expr);
- nf_ct_netns_put(ctx->net, priv->family);
- }
- static struct nft_expr_type nft_nat_type;
- static const struct nft_expr_ops nft_nat_ops = {
- .type = &nft_nat_type,
- .size = NFT_EXPR_SIZE(sizeof(struct nft_nat)),
- .eval = nft_nat_eval,
- .init = nft_nat_init,
- .destroy = nft_nat_destroy,
- .dump = nft_nat_dump,
- .validate = nft_nat_validate,
- };
- static struct nft_expr_type nft_nat_type __read_mostly = {
- .name = "nat",
- .ops = &nft_nat_ops,
- .policy = nft_nat_policy,
- .maxattr = NFTA_NAT_MAX,
- .owner = THIS_MODULE,
- };
- #ifdef CONFIG_NF_TABLES_INET
- static void nft_nat_inet_eval(const struct nft_expr *expr,
- struct nft_regs *regs,
- const struct nft_pktinfo *pkt)
- {
- const struct nft_nat *priv = nft_expr_priv(expr);
- if (priv->family == nft_pf(pkt))
- nft_nat_eval(expr, regs, pkt);
- }
- static const struct nft_expr_ops nft_nat_inet_ops = {
- .type = &nft_nat_type,
- .size = NFT_EXPR_SIZE(sizeof(struct nft_nat)),
- .eval = nft_nat_inet_eval,
- .init = nft_nat_init,
- .destroy = nft_nat_destroy,
- .dump = nft_nat_dump,
- .validate = nft_nat_validate,
- };
- static struct nft_expr_type nft_inet_nat_type __read_mostly = {
- .name = "nat",
- .family = NFPROTO_INET,
- .ops = &nft_nat_inet_ops,
- .policy = nft_nat_policy,
- .maxattr = NFTA_NAT_MAX,
- .owner = THIS_MODULE,
- };
- static int nft_nat_inet_module_init(void)
- {
- return nft_register_expr(&nft_inet_nat_type);
- }
- static void nft_nat_inet_module_exit(void)
- {
- nft_unregister_expr(&nft_inet_nat_type);
- }
- #else
- static int nft_nat_inet_module_init(void) { return 0; }
- static void nft_nat_inet_module_exit(void) { }
- #endif
- static int __init nft_nat_module_init(void)
- {
- int ret = nft_nat_inet_module_init();
- if (ret)
- return ret;
- ret = nft_register_expr(&nft_nat_type);
- if (ret)
- nft_nat_inet_module_exit();
- return ret;
- }
- static void __exit nft_nat_module_exit(void)
- {
- nft_nat_inet_module_exit();
- nft_unregister_expr(&nft_nat_type);
- }
- module_init(nft_nat_module_init);
- module_exit(nft_nat_module_exit);
- MODULE_LICENSE("GPL");
- MODULE_AUTHOR("Tomasz Bursztyka <tomasz.bursztyka@linux.intel.com>");
- MODULE_ALIAS_NFT_EXPR("nat");
- MODULE_DESCRIPTION("Network Address Translation support");
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