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-rw-r--r--net/netfilter/nft_nat.c408
1 files changed, 408 insertions, 0 deletions
diff --git a/net/netfilter/nft_nat.c b/net/netfilter/nft_nat.c
new file mode 100644
index 000000000..ba7bcce72
--- /dev/null
+++ b/net/netfilter/nft_nat.c
@@ -0,0 +1,408 @@
+// 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 {
+ u8 sreg_addr_min;
+ u8 sreg_addr_max;
+ u8 sreg_proto_min;
+ u8 sreg_proto_max;
+ 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, &regs->data[priv->sreg_addr_min],
+ sizeof(range->min_addr.ip6));
+ memcpy(range->max_addr.ip6, &regs->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(&regs->data[priv->sreg_proto_min]);
+ range->max_proto.all = (__force __be16)
+ nft_reg_load16(&regs->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;
+
+ if (ctx->family != NFPROTO_IPV4 &&
+ ctx->family != NFPROTO_IPV6 &&
+ ctx->family != NFPROTO_INET)
+ return -EOPNOTSUPP;
+
+ 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]) {
+ err = nft_parse_register_load(tb[NFTA_NAT_REG_ADDR_MIN],
+ &priv->sreg_addr_min, alen);
+ if (err < 0)
+ return err;
+
+ if (tb[NFTA_NAT_REG_ADDR_MAX]) {
+ err = nft_parse_register_load(tb[NFTA_NAT_REG_ADDR_MAX],
+ &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_proto.all);
+ if (tb[NFTA_NAT_REG_PROTO_MIN]) {
+ err = nft_parse_register_load(tb[NFTA_NAT_REG_PROTO_MIN],
+ &priv->sreg_proto_min, plen);
+ if (err < 0)
+ return err;
+
+ if (tb[NFTA_NAT_REG_PROTO_MAX]) {
+ err = nft_parse_register_load(tb[NFTA_NAT_REG_PROTO_MAX],
+ &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,
+ .reduce = NFT_REDUCE_READONLY,
+};
+
+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) ||
+ priv->family == NFPROTO_INET)
+ 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,
+ .reduce = NFT_REDUCE_READONLY,
+};
+
+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");
generated by cgit v1.2.3 (git 2.39.1) at 2024-06-02 01:41:02 +0000