--- /dev/null
+/*
+ * Copyright (c) 2008 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.
+ *
+ * Development of this code funded by Astaro AG (http://www.astaro.com/)
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/list.h>
+#include <linux/jhash.h>
+#include <linux/netlink.h>
+#include <linux/netfilter.h>
+#include <linux/netfilter/nf_tables.h>
+#include <net/netfilter/nf_tables.h>
+
+struct nft_hash {
+ struct hlist_head *hash;
+ unsigned int hsize;
+ enum nft_registers sreg:8;
+ enum nft_registers dreg:8;
+ u8 klen;
+ u8 dlen;
+ u16 flags;
+};
+
+struct nft_hash_elem {
+ struct hlist_node hnode;
+ struct nft_data key;
+ struct nft_data data[];
+};
+
+static u32 nft_hash_rnd __read_mostly;
+static bool nft_hash_rnd_initted __read_mostly;
+
+static unsigned int nft_hash_data(const struct nft_data *data,
+ unsigned int hsize, unsigned int len)
+{
+ unsigned int h;
+
+ // FIXME: can we reasonably guarantee the upper bits are fixed?
+ h = jhash2(data->data, len >> 2, nft_hash_rnd);
+ return ((u64)h * hsize) >> 32;
+}
+
+static void nft_hash_eval(const struct nft_expr *expr,
+ struct nft_data data[NFT_REG_MAX + 1],
+ const struct nft_pktinfo *pkt)
+{
+ const struct nft_hash *priv = nft_expr_priv(expr);
+ const struct nft_hash_elem *elem;
+ const struct nft_data *key = &data[priv->sreg];
+ unsigned int h;
+
+ h = nft_hash_data(key, priv->hsize, priv->klen);
+ hlist_for_each_entry(elem, &priv->hash[h], hnode) {
+ if (nft_data_cmp(&elem->key, key, priv->klen))
+ continue;
+ if (priv->flags & NFT_HASH_MAP)
+ nft_data_copy(&data[priv->dreg], elem->data);
+ return;
+ }
+ data[NFT_REG_VERDICT].verdict = NFT_BREAK;
+}
+
+static void nft_hash_elem_destroy(const struct nft_expr *expr,
+ struct nft_hash_elem *elem)
+{
+ const struct nft_hash *priv = nft_expr_priv(expr);
+
+ nft_data_uninit(&elem->key, NFT_DATA_VALUE);
+ if (priv->flags & NFT_HASH_MAP)
+ nft_data_uninit(elem->data, nft_dreg_to_type(priv->dreg));
+ kfree(elem);
+}
+
+static const struct nla_policy nft_he_policy[NFTA_HE_MAX + 1] = {
+ [NFTA_HE_KEY] = { .type = NLA_NESTED },
+ [NFTA_HE_DATA] = { .type = NLA_NESTED },
+};
+
+static int nft_hash_elem_init(const struct nft_ctx *ctx,
+ const struct nft_expr *expr,
+ const struct nlattr *nla,
+ struct nft_hash_elem **new)
+{
+ struct nft_hash *priv = nft_expr_priv(expr);
+ struct nlattr *tb[NFTA_HE_MAX + 1];
+ struct nft_hash_elem *elem;
+ struct nft_data_desc d1, d2;
+ unsigned int size;
+ int err;
+
+ err = nla_parse_nested(tb, NFTA_HE_MAX, nla, nft_he_policy);
+ if (err < 0)
+ return err;
+
+ if (tb[NFTA_HE_KEY] == NULL)
+ return -EINVAL;
+ size = sizeof(*elem);
+
+ if (priv->flags & NFT_HASH_MAP) {
+ if (tb[NFTA_HE_DATA] == NULL)
+ return -EINVAL;
+ size += sizeof(elem->data[0]);
+ } else {
+ if (tb[NFTA_HE_DATA] != NULL)
+ return -EINVAL;
+ }
+
+ elem = kzalloc(size, GFP_KERNEL);
+ if (elem == NULL)
+ return -ENOMEM;
+
+ err = nft_data_init(ctx, &elem->key, &d1, tb[NFTA_HE_KEY]);
+ if (err < 0)
+ goto err1;
+ err = -EINVAL;
+ if (d1.type != NFT_DATA_VALUE || d1.len != priv->klen)
+ goto err2;
+
+ if (tb[NFTA_HE_DATA] != NULL) {
+ err = nft_data_init(ctx, elem->data, &d2, tb[NFTA_HE_DATA]);
+ if (err < 0)
+ goto err2;
+ err = nft_validate_data_load(ctx, priv->dreg, elem->data, d2.type);
+ if (err < 0)
+ goto err3;
+ }
+
+ *new = elem;
+ return 0;
+
+err3:
+ nft_data_uninit(elem->data, d2.type);
+err2:
+ nft_data_uninit(&elem->key, d1.type);
+err1:
+ kfree(elem);
+ return err;
+}
+
+static int nft_hash_elem_dump(struct sk_buff *skb, const struct nft_expr *expr,
+ const struct nft_hash_elem *elem)
+
+{
+ const struct nft_hash *priv = nft_expr_priv(expr);
+ struct nlattr *nest;
+
+ nest = nla_nest_start(skb, NFTA_LIST_ELEM);
+ if (nest == NULL)
+ goto nla_put_failure;
+
+ if (nft_data_dump(skb, NFTA_HE_KEY, &elem->key,
+ NFT_DATA_VALUE, priv->klen) < 0)
+ goto nla_put_failure;
+
+ if (priv->flags & NFT_HASH_MAP) {
+ if (nft_data_dump(skb, NFTA_HE_DATA, elem->data,
+ NFT_DATA_VALUE, priv->dlen) < 0)
+ goto nla_put_failure;
+ }
+
+ nla_nest_end(skb, nest);
+ return 0;
+
+nla_put_failure:
+ return -1;
+}
+
+static void nft_hash_destroy(const struct nft_ctx *ctx,
+ const struct nft_expr *expr)
+{
+ const struct nft_hash *priv = nft_expr_priv(expr);
+ const struct hlist_node *next;
+ struct nft_hash_elem *elem;
+ unsigned int i;
+
+ for (i = 0; i < priv->hsize; i++) {
+ hlist_for_each_entry_safe(elem, next, &priv->hash[i], hnode) {
+ hlist_del(&elem->hnode);
+ nft_hash_elem_destroy(expr, elem);
+ }
+ }
+ kfree(priv->hash);
+}
+
+static const struct nla_policy nft_hash_policy[NFTA_HASH_MAX + 1] = {
+ [NFTA_HASH_FLAGS] = { .type = NLA_U32 },
+ [NFTA_HASH_SREG] = { .type = NLA_U32 },
+ [NFTA_HASH_DREG] = { .type = NLA_U32 },
+ [NFTA_HASH_KLEN] = { .type = NLA_U32 },
+ [NFTA_HASH_ELEMENTS] = { .type = NLA_NESTED },
+};
+
+static int nft_hash_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
+ const struct nlattr * const tb[])
+{
+ struct nft_hash *priv = nft_expr_priv(expr);
+ struct nft_hash_elem *elem, *uninitialized_var(new);
+ const struct nlattr *nla;
+ unsigned int cnt, i;
+ unsigned int h;
+ int err, rem;
+
+ if (unlikely(!nft_hash_rnd_initted)) {
+ get_random_bytes(&nft_hash_rnd, 4);
+ nft_hash_rnd_initted = true;
+ }
+
+ if (tb[NFTA_HASH_SREG] == NULL ||
+ tb[NFTA_HASH_KLEN] == NULL ||
+ tb[NFTA_HASH_ELEMENTS] == NULL)
+ return -EINVAL;
+
+ if (tb[NFTA_HASH_FLAGS] != NULL) {
+ priv->flags = ntohl(nla_get_be32(tb[NFTA_HASH_FLAGS]));
+ if (priv->flags & ~NFT_HASH_MAP)
+ return -EINVAL;
+ }
+
+ priv->sreg = ntohl(nla_get_be32(tb[NFTA_HASH_SREG]));
+ err = nft_validate_input_register(priv->sreg);
+ if (err < 0)
+ return err;
+
+ if (tb[NFTA_HASH_DREG] != NULL) {
+ if (!(priv->flags & NFT_HASH_MAP))
+ return -EINVAL;
+ priv->dreg = ntohl(nla_get_be32(tb[NFTA_HASH_DREG]));
+ err = nft_validate_output_register(priv->dreg);
+ if (err < 0)
+ return err;
+ }
+
+ priv->klen = ntohl(nla_get_be32(tb[NFTA_HASH_KLEN]));
+ if (priv->klen == 0)
+ return -EINVAL;
+
+ cnt = 0;
+ nla_for_each_nested(nla, tb[NFTA_HASH_ELEMENTS], rem) {
+ if (nla_type(nla) != NFTA_LIST_ELEM)
+ return -EINVAL;
+ cnt++;
+ }
+
+ /* Aim for a load factor of 0.75 */
+ cnt = cnt * 4 / 3;
+
+ priv->hash = kcalloc(cnt, sizeof(struct hlist_head), GFP_KERNEL);
+ if (priv->hash == NULL)
+ return -ENOMEM;
+ priv->hsize = cnt;
+
+ for (i = 0; i < cnt; i++)
+ INIT_HLIST_HEAD(&priv->hash[i]);
+
+ err = -ENOMEM;
+ nla_for_each_nested(nla, tb[NFTA_HASH_ELEMENTS], rem) {
+ err = nft_hash_elem_init(ctx, expr, nla, &new);
+ if (err < 0)
+ goto err1;
+
+ h = nft_hash_data(&new->key, priv->hsize, priv->klen);
+ hlist_for_each_entry(elem, &priv->hash[h], hnode) {
+ if (nft_data_cmp(&elem->key, &new->key, priv->klen))
+ continue;
+ nft_hash_elem_destroy(expr, new);
+ err = -EEXIST;
+ goto err1;
+ }
+ hlist_add_head(&new->hnode, &priv->hash[h]);
+ }
+ return 0;
+
+err1:
+ nft_hash_destroy(ctx, expr);
+ return err;
+}
+
+static int nft_hash_dump(struct sk_buff *skb, const struct nft_expr *expr)
+{
+ const struct nft_hash *priv = nft_expr_priv(expr);
+ const struct nft_hash_elem *elem;
+ struct nlattr *list;
+ unsigned int i;
+
+ if (priv->flags)
+ if (nla_put_be32(skb, NFTA_HASH_FLAGS, htonl(priv->flags)))
+ goto nla_put_failure;
+ if (nla_put_be32(skb, NFTA_HASH_SREG, htonl(priv->sreg)))
+ goto nla_put_failure;
+ if (priv->flags & NFT_HASH_MAP)
+ if (nla_put_be32(skb, NFTA_HASH_DREG, htonl(priv->dreg)))
+ goto nla_put_failure;
+ if (nla_put_be32(skb, NFTA_HASH_KLEN, htonl(priv->klen)))
+ goto nla_put_failure;
+
+ list = nla_nest_start(skb, NFTA_HASH_ELEMENTS);
+ if (list == NULL)
+ goto nla_put_failure;
+
+ for (i = 0; i < priv->hsize; i++) {
+ hlist_for_each_entry(elem, &priv->hash[i], hnode) {
+ if (nft_hash_elem_dump(skb, expr, elem) < 0)
+ goto nla_put_failure;
+ }
+ }
+
+ nla_nest_end(skb, list);
+ return 0;
+
+nla_put_failure:
+ return -1;
+}
+
+static struct nft_expr_ops nft_hash_ops __read_mostly = {
+ .name = "hash",
+ .size = NFT_EXPR_SIZE(sizeof(struct nft_hash)),
+ .owner = THIS_MODULE,
+ .eval = nft_hash_eval,
+ .init = nft_hash_init,
+ .destroy = nft_hash_destroy,
+ .dump = nft_hash_dump,
+ .policy = nft_hash_policy,
+ .maxattr = NFTA_HASH_MAX,
+};
+
+static int __init nft_hash_module_init(void)
+{
+ return nft_register_expr(&nft_hash_ops);
+}
+
+static void __exit nft_hash_module_exit(void)
+{
+ nft_unregister_expr(&nft_hash_ops);
+}
+
+module_init(nft_hash_module_init);
+module_exit(nft_hash_module_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
+MODULE_ALIAS_NFT_EXPR("hash");
projects / karo-tx-linux.git / blobdiff