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-rw-r--r--net/netfilter/nft_masq.c307
1 files changed, 307 insertions, 0 deletions
diff --git a/net/netfilter/nft_masq.c b/net/netfilter/nft_masq.c
new file mode 100644
index 000000000..026b4f87d
--- /dev/null
+++ b/net/netfilter/nft_masq.c
@@ -0,0 +1,307 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2014 Arturo Borrero Gonzalez <arturo@debian.org>
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/netlink.h>
+#include <linux/netfilter.h>
+#include <linux/netfilter/nf_tables.h>
+#include <net/netfilter/nf_tables.h>
+#include <net/netfilter/nf_nat.h>
+#include <net/netfilter/nf_nat_masquerade.h>
+
+struct nft_masq {
+ u32 flags;
+ u8 sreg_proto_min;
+ u8 sreg_proto_max;
+};
+
+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 = sizeof_field(struct nf_nat_range, min_proto.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]) {
+ err = nft_parse_register_load(tb[NFTA_MASQ_REG_PROTO_MIN],
+ &priv->sreg_proto_min, plen);
+ if (err < 0)
+ return err;
+
+ if (tb[NFTA_MASQ_REG_PROTO_MAX]) {
+ err = nft_parse_register_load(tb[NFTA_MASQ_REG_PROTO_MAX],
+ &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(
+ &regs->data[priv->sreg_proto_min]);
+ range.max_proto.all = (__force __be16)nft_reg_load16(
+ &regs->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,
+ .reduce = NFT_REDUCE_READONLY,
+};
+
+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(
+ &regs->data[priv->sreg_proto_min]);
+ range.max_proto.all = (__force __be16)nft_reg_load16(
+ &regs->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,
+ .reduce = NFT_REDUCE_READONLY,
+};
+
+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)
+{
+ return nft_register_expr(&nft_masq_ipv6_type);
+}
+
+static void nft_masq_module_exit_ipv6(void)
+{
+ nft_unregister_expr(&nft_masq_ipv6_type);
+}
+#else
+static inline int nft_masq_module_init_ipv6(void) { return 0; }
+static inline void nft_masq_module_exit_ipv6(void) {}
+#endif
+
+#ifdef CONFIG_NF_TABLES_INET
+static void nft_masq_inet_eval(const struct nft_expr *expr,
+ struct nft_regs *regs,
+ const struct nft_pktinfo *pkt)
+{
+ switch (nft_pf(pkt)) {
+ case NFPROTO_IPV4:
+ return nft_masq_ipv4_eval(expr, regs, pkt);
+ case NFPROTO_IPV6:
+ return nft_masq_ipv6_eval(expr, regs, pkt);
+ }
+
+ WARN_ON_ONCE(1);
+}
+
+static void
+nft_masq_inet_destroy(const struct nft_ctx *ctx, const struct nft_expr *expr)
+{
+ nf_ct_netns_put(ctx->net, NFPROTO_INET);
+}
+
+static struct nft_expr_type nft_masq_inet_type;
+static const struct nft_expr_ops nft_masq_inet_ops = {
+ .type = &nft_masq_inet_type,
+ .size = NFT_EXPR_SIZE(sizeof(struct nft_masq)),
+ .eval = nft_masq_inet_eval,
+ .init = nft_masq_init,
+ .destroy = nft_masq_inet_destroy,
+ .dump = nft_masq_dump,
+ .validate = nft_masq_validate,
+ .reduce = NFT_REDUCE_READONLY,
+};
+
+static struct nft_expr_type nft_masq_inet_type __read_mostly = {
+ .family = NFPROTO_INET,
+ .name = "masq",
+ .ops = &nft_masq_inet_ops,
+ .policy = nft_masq_policy,
+ .maxattr = NFTA_MASQ_MAX,
+ .owner = THIS_MODULE,
+};
+
+static int __init nft_masq_module_init_inet(void)
+{
+ return nft_register_expr(&nft_masq_inet_type);
+}
+
+static void nft_masq_module_exit_inet(void)
+{
+ nft_unregister_expr(&nft_masq_inet_type);
+}
+#else
+static inline int nft_masq_module_init_inet(void) { return 0; }
+static inline void nft_masq_module_exit_inet(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_masq_module_init_inet();
+ if (ret < 0) {
+ nft_masq_module_exit_ipv6();
+ return ret;
+ }
+
+ ret = nft_register_expr(&nft_masq_ipv4_type);
+ if (ret < 0) {
+ nft_masq_module_exit_inet();
+ nft_masq_module_exit_ipv6();
+ return ret;
+ }
+
+ ret = nf_nat_masquerade_inet_register_notifiers();
+ if (ret < 0) {
+ nft_masq_module_exit_ipv6();
+ nft_masq_module_exit_inet();
+ 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_masq_module_exit_inet();
+ nft_unregister_expr(&nft_masq_ipv4_type);
+ nf_nat_masquerade_inet_unregister_notifiers();
+}
+
+module_init(nft_masq_module_init);
+module_exit(nft_masq_module_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Arturo Borrero Gonzalez <arturo@debian.org>");
+MODULE_ALIAS_NFT_EXPR("masq");
+MODULE_DESCRIPTION("Netfilter nftables masquerade expression support");
generated by cgit v1.2.3 (git 2.39.1) at 2024-06-09 16:07:12 +0000