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-rw-r--r--net/netfilter/nft_dynset.c265
1 files changed, 265 insertions, 0 deletions
diff --git a/net/netfilter/nft_dynset.c b/net/netfilter/nft_dynset.c
new file mode 100644
index 000000000000..513a8ef60a59
--- /dev/null
+++ b/net/netfilter/nft_dynset.c
@@ -0,0 +1,265 @@
+/*
+ * Copyright (c) 2015 Patrick McHardy <kaber@trash.net>
+ *
+ * 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 <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.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_tables_core.h>
+
+struct nft_dynset {
+ struct nft_set *set;
+ struct nft_set_ext_tmpl tmpl;
+ enum nft_dynset_ops op:8;
+ enum nft_registers sreg_key:8;
+ enum nft_registers sreg_data:8;
+ u64 timeout;
+ struct nft_expr *expr;
+ struct nft_set_binding binding;
+};
+
+static void *nft_dynset_new(struct nft_set *set, const struct nft_expr *expr,
+ struct nft_regs *regs)
+{
+ const struct nft_dynset *priv = nft_expr_priv(expr);
+ struct nft_set_ext *ext;
+ u64 timeout;
+ void *elem;
+
+ if (set->size && !atomic_add_unless(&set->nelems, 1, set->size))
+ return NULL;
+
+ timeout = priv->timeout ? : set->timeout;
+ elem = nft_set_elem_init(set, &priv->tmpl,
+ &regs->data[priv->sreg_key],
+ &regs->data[priv->sreg_data],
+ timeout, GFP_ATOMIC);
+ if (elem == NULL) {
+ if (set->size)
+ atomic_dec(&set->nelems);
+ return NULL;
+ }
+
+ ext = nft_set_elem_ext(set, elem);
+ if (priv->expr != NULL)
+ nft_expr_clone(nft_set_ext_expr(ext), priv->expr);
+
+ return elem;
+}
+
+static void nft_dynset_eval(const struct nft_expr *expr,
+ struct nft_regs *regs,
+ const struct nft_pktinfo *pkt)
+{
+ const struct nft_dynset *priv = nft_expr_priv(expr);
+ struct nft_set *set = priv->set;
+ const struct nft_set_ext *ext;
+ const struct nft_expr *sexpr;
+ u64 timeout;
+
+ if (set->ops->update(set, &regs->data[priv->sreg_key], nft_dynset_new,
+ expr, regs, &ext)) {
+ sexpr = NULL;
+ if (nft_set_ext_exists(ext, NFT_SET_EXT_EXPR))
+ sexpr = nft_set_ext_expr(ext);
+
+ if (priv->op == NFT_DYNSET_OP_UPDATE &&
+ nft_set_ext_exists(ext, NFT_SET_EXT_EXPIRATION)) {
+ timeout = priv->timeout ? : set->timeout;
+ *nft_set_ext_expiration(ext) = jiffies + timeout;
+ } else if (sexpr == NULL)
+ goto out;
+
+ if (sexpr != NULL)
+ sexpr->ops->eval(sexpr, regs, pkt);
+ return;
+ }
+out:
+ regs->verdict.code = NFT_BREAK;
+}
+
+static const struct nla_policy nft_dynset_policy[NFTA_DYNSET_MAX + 1] = {
+ [NFTA_DYNSET_SET_NAME] = { .type = NLA_STRING },
+ [NFTA_DYNSET_SET_ID] = { .type = NLA_U32 },
+ [NFTA_DYNSET_OP] = { .type = NLA_U32 },
+ [NFTA_DYNSET_SREG_KEY] = { .type = NLA_U32 },
+ [NFTA_DYNSET_SREG_DATA] = { .type = NLA_U32 },
+ [NFTA_DYNSET_TIMEOUT] = { .type = NLA_U64 },
+ [NFTA_DYNSET_EXPR] = { .type = NLA_NESTED },
+};
+
+static int nft_dynset_init(const struct nft_ctx *ctx,
+ const struct nft_expr *expr,
+ const struct nlattr * const tb[])
+{
+ struct nft_dynset *priv = nft_expr_priv(expr);
+ struct nft_set *set;
+ u64 timeout;
+ int err;
+
+ if (tb[NFTA_DYNSET_SET_NAME] == NULL ||
+ tb[NFTA_DYNSET_OP] == NULL ||
+ tb[NFTA_DYNSET_SREG_KEY] == NULL)
+ return -EINVAL;
+
+ set = nf_tables_set_lookup(ctx->table, tb[NFTA_DYNSET_SET_NAME]);
+ if (IS_ERR(set)) {
+ if (tb[NFTA_DYNSET_SET_ID])
+ set = nf_tables_set_lookup_byid(ctx->net,
+ tb[NFTA_DYNSET_SET_ID]);
+ if (IS_ERR(set))
+ return PTR_ERR(set);
+ }
+
+ if (set->flags & NFT_SET_CONSTANT)
+ return -EBUSY;
+
+ priv->op = ntohl(nla_get_be32(tb[NFTA_DYNSET_OP]));
+ switch (priv->op) {
+ case NFT_DYNSET_OP_ADD:
+ break;
+ case NFT_DYNSET_OP_UPDATE:
+ if (!(set->flags & NFT_SET_TIMEOUT))
+ return -EOPNOTSUPP;
+ break;
+ default:
+ return -EOPNOTSUPP;
+ }
+
+ timeout = 0;
+ if (tb[NFTA_DYNSET_TIMEOUT] != NULL) {
+ if (!(set->flags & NFT_SET_TIMEOUT))
+ return -EINVAL;
+ timeout = be64_to_cpu(nla_get_be64(tb[NFTA_DYNSET_TIMEOUT]));
+ }
+
+ priv->sreg_key = nft_parse_register(tb[NFTA_DYNSET_SREG_KEY]);
+ err = nft_validate_register_load(priv->sreg_key, set->klen);;
+ if (err < 0)
+ return err;
+
+ if (tb[NFTA_DYNSET_SREG_DATA] != NULL) {
+ if (!(set->flags & NFT_SET_MAP))
+ return -EINVAL;
+ if (set->dtype == NFT_DATA_VERDICT)
+ return -EOPNOTSUPP;
+
+ priv->sreg_data = nft_parse_register(tb[NFTA_DYNSET_SREG_DATA]);
+ err = nft_validate_register_load(priv->sreg_data, set->dlen);
+ if (err < 0)
+ return err;
+ } else if (set->flags & NFT_SET_MAP)
+ return -EINVAL;
+
+ if (tb[NFTA_DYNSET_EXPR] != NULL) {
+ if (!(set->flags & NFT_SET_EVAL))
+ return -EINVAL;
+ if (!(set->flags & NFT_SET_ANONYMOUS))
+ return -EOPNOTSUPP;
+
+ priv->expr = nft_expr_init(ctx, tb[NFTA_DYNSET_EXPR]);
+ if (IS_ERR(priv->expr))
+ return PTR_ERR(priv->expr);
+
+ err = -EOPNOTSUPP;
+ if (!(priv->expr->ops->type->flags & NFT_EXPR_STATEFUL))
+ goto err1;
+ } else if (set->flags & NFT_SET_EVAL)
+ return -EINVAL;
+
+ nft_set_ext_prepare(&priv->tmpl);
+ nft_set_ext_add_length(&priv->tmpl, NFT_SET_EXT_KEY, set->klen);
+ if (set->flags & NFT_SET_MAP)
+ nft_set_ext_add_length(&priv->tmpl, NFT_SET_EXT_DATA, set->dlen);
+ if (priv->expr != NULL)
+ nft_set_ext_add_length(&priv->tmpl, NFT_SET_EXT_EXPR,
+ priv->expr->ops->size);
+ if (set->flags & NFT_SET_TIMEOUT) {
+ if (timeout || set->timeout)
+ nft_set_ext_add(&priv->tmpl, NFT_SET_EXT_EXPIRATION);
+ }
+
+ priv->timeout = timeout;
+
+ err = nf_tables_bind_set(ctx, set, &priv->binding);
+ if (err < 0)
+ goto err1;
+
+ priv->set = set;
+ return 0;
+
+err1:
+ if (priv->expr != NULL)
+ nft_expr_destroy(ctx, priv->expr);
+ return err;
+}
+
+static void nft_dynset_destroy(const struct nft_ctx *ctx,
+ const struct nft_expr *expr)
+{
+ struct nft_dynset *priv = nft_expr_priv(expr);
+
+ nf_tables_unbind_set(ctx, priv->set, &priv->binding);
+ if (priv->expr != NULL)
+ nft_expr_destroy(ctx, priv->expr);
+}
+
+static int nft_dynset_dump(struct sk_buff *skb, const struct nft_expr *expr)
+{
+ const struct nft_dynset *priv = nft_expr_priv(expr);
+
+ if (nft_dump_register(skb, NFTA_DYNSET_SREG_KEY, priv->sreg_key))
+ goto nla_put_failure;
+ if (priv->set->flags & NFT_SET_MAP &&
+ nft_dump_register(skb, NFTA_DYNSET_SREG_DATA, priv->sreg_data))
+ goto nla_put_failure;
+ if (nla_put_be32(skb, NFTA_DYNSET_OP, htonl(priv->op)))
+ goto nla_put_failure;
+ if (nla_put_string(skb, NFTA_DYNSET_SET_NAME, priv->set->name))
+ goto nla_put_failure;
+ if (nla_put_be64(skb, NFTA_DYNSET_TIMEOUT, cpu_to_be64(priv->timeout)))
+ goto nla_put_failure;
+ if (priv->expr && nft_expr_dump(skb, NFTA_DYNSET_EXPR, priv->expr))
+ goto nla_put_failure;
+ return 0;
+
+nla_put_failure:
+ return -1;
+}
+
+static struct nft_expr_type nft_dynset_type;
+static const struct nft_expr_ops nft_dynset_ops = {
+ .type = &nft_dynset_type,
+ .size = NFT_EXPR_SIZE(sizeof(struct nft_dynset)),
+ .eval = nft_dynset_eval,
+ .init = nft_dynset_init,
+ .destroy = nft_dynset_destroy,
+ .dump = nft_dynset_dump,
+};
+
+static struct nft_expr_type nft_dynset_type __read_mostly = {
+ .name = "dynset",
+ .ops = &nft_dynset_ops,
+ .policy = nft_dynset_policy,
+ .maxattr = NFTA_DYNSET_MAX,
+ .owner = THIS_MODULE,
+};
+
+int __init nft_dynset_module_init(void)
+{
+ return nft_register_expr(&nft_dynset_type);
+}
+
+void nft_dynset_module_exit(void)
+{
+ nft_unregister_expr(&nft_dynset_type);
+}
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.