--- /dev/null
+/*
+ * Copyright (c) 2008-2009 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/netlink.h>
+#include <linux/netfilter.h>
+#include <linux/netfilter/nf_tables.h>
+#include <net/netfilter/nf_tables_core.h>
+#include <net/netfilter/nf_tables.h>
+
+struct nft_cmp_expr {
+ struct nft_data data;
+ enum nft_registers sreg:8;
+ u8 len;
+ enum nft_cmp_ops op:8;
+};
+
+static void nft_cmp_eval(const struct nft_expr *expr,
+ struct nft_regs *regs,
+ const struct nft_pktinfo *pkt)
+{
+ const struct nft_cmp_expr *priv = nft_expr_priv(expr);
+ int d;
+
+ d = memcmp(®s->data[priv->sreg], &priv->data, priv->len);
+ switch (priv->op) {
+ case NFT_CMP_EQ:
+ if (d != 0)
+ goto mismatch;
+ break;
+ case NFT_CMP_NEQ:
+ if (d == 0)
+ goto mismatch;
+ break;
+ case NFT_CMP_LT:
+ if (d == 0)
+ goto mismatch;
+ case NFT_CMP_LTE:
+ if (d > 0)
+ goto mismatch;
+ break;
+ case NFT_CMP_GT:
+ if (d == 0)
+ goto mismatch;
+ case NFT_CMP_GTE:
+ if (d < 0)
+ goto mismatch;
+ break;
+ }
+ return;
+
+mismatch:
+ regs->verdict.code = NFT_BREAK;
+}
+
+static const struct nla_policy nft_cmp_policy[NFTA_CMP_MAX + 1] = {
+ [NFTA_CMP_SREG] = { .type = NLA_U32 },
+ [NFTA_CMP_OP] = { .type = NLA_U32 },
+ [NFTA_CMP_DATA] = { .type = NLA_NESTED },
+};
+
+static int nft_cmp_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
+ const struct nlattr * const tb[])
+{
+ struct nft_cmp_expr *priv = nft_expr_priv(expr);
+ struct nft_data_desc desc;
+ int err;
+
+ err = nft_data_init(NULL, &priv->data, sizeof(priv->data), &desc,
+ tb[NFTA_CMP_DATA]);
+ BUG_ON(err < 0);
+
+ priv->sreg = nft_parse_register(tb[NFTA_CMP_SREG]);
+ err = nft_validate_register_load(priv->sreg, desc.len);
+ if (err < 0)
+ return err;
+
+ priv->op = ntohl(nla_get_be32(tb[NFTA_CMP_OP]));
+ priv->len = desc.len;
+ return 0;
+}
+
+static int nft_cmp_dump(struct sk_buff *skb, const struct nft_expr *expr)
+{
+ const struct nft_cmp_expr *priv = nft_expr_priv(expr);
+
+ if (nft_dump_register(skb, NFTA_CMP_SREG, priv->sreg))
+ goto nla_put_failure;
+ if (nla_put_be32(skb, NFTA_CMP_OP, htonl(priv->op)))
+ goto nla_put_failure;
+
+ if (nft_data_dump(skb, NFTA_CMP_DATA, &priv->data,
+ NFT_DATA_VALUE, priv->len) < 0)
+ goto nla_put_failure;
+ return 0;
+
+nla_put_failure:
+ return -1;
+}
+
+static struct nft_expr_type nft_cmp_type;
+static const struct nft_expr_ops nft_cmp_ops = {
+ .type = &nft_cmp_type,
+ .size = NFT_EXPR_SIZE(sizeof(struct nft_cmp_expr)),
+ .eval = nft_cmp_eval,
+ .init = nft_cmp_init,
+ .dump = nft_cmp_dump,
+};
+
+static int nft_cmp_fast_init(const struct nft_ctx *ctx,
+ const struct nft_expr *expr,
+ const struct nlattr * const tb[])
+{
+ struct nft_cmp_fast_expr *priv = nft_expr_priv(expr);
+ struct nft_data_desc desc;
+ struct nft_data data;
+ u32 mask;
+ int err;
+
+ err = nft_data_init(NULL, &data, sizeof(data), &desc,
+ tb[NFTA_CMP_DATA]);
+ BUG_ON(err < 0);
+
+ priv->sreg = nft_parse_register(tb[NFTA_CMP_SREG]);
+ err = nft_validate_register_load(priv->sreg, desc.len);
+ if (err < 0)
+ return err;
+
+ desc.len *= BITS_PER_BYTE;
+ mask = nft_cmp_fast_mask(desc.len);
+
+ priv->data = data.data[0] & mask;
+ priv->len = desc.len;
+ return 0;
+}
+
+static int nft_cmp_fast_dump(struct sk_buff *skb, const struct nft_expr *expr)
+{
+ const struct nft_cmp_fast_expr *priv = nft_expr_priv(expr);
+ struct nft_data data;
+
+ if (nft_dump_register(skb, NFTA_CMP_SREG, priv->sreg))
+ goto nla_put_failure;
+ if (nla_put_be32(skb, NFTA_CMP_OP, htonl(NFT_CMP_EQ)))
+ goto nla_put_failure;
+
+ data.data[0] = priv->data;
+ if (nft_data_dump(skb, NFTA_CMP_DATA, &data,
+ NFT_DATA_VALUE, priv->len / BITS_PER_BYTE) < 0)
+ goto nla_put_failure;
+ return 0;
+
+nla_put_failure:
+ return -1;
+}
+
+const struct nft_expr_ops nft_cmp_fast_ops = {
+ .type = &nft_cmp_type,
+ .size = NFT_EXPR_SIZE(sizeof(struct nft_cmp_fast_expr)),
+ .eval = NULL, /* inlined */
+ .init = nft_cmp_fast_init,
+ .dump = nft_cmp_fast_dump,
+};
+
+static const struct nft_expr_ops *
+nft_cmp_select_ops(const struct nft_ctx *ctx, const struct nlattr * const tb[])
+{
+ struct nft_data_desc desc;
+ struct nft_data data;
+ enum nft_cmp_ops op;
+ int err;
+
+ if (tb[NFTA_CMP_SREG] == NULL ||
+ tb[NFTA_CMP_OP] == NULL ||
+ tb[NFTA_CMP_DATA] == NULL)
+ return ERR_PTR(-EINVAL);
+
+ op = ntohl(nla_get_be32(tb[NFTA_CMP_OP]));
+ switch (op) {
+ case NFT_CMP_EQ:
+ case NFT_CMP_NEQ:
+ case NFT_CMP_LT:
+ case NFT_CMP_LTE:
+ case NFT_CMP_GT:
+ case NFT_CMP_GTE:
+ break;
+ default:
+ return ERR_PTR(-EINVAL);
+ }
+
+ err = nft_data_init(NULL, &data, sizeof(data), &desc,
+ tb[NFTA_CMP_DATA]);
+ if (err < 0)
+ return ERR_PTR(err);
+
+ if (desc.len <= sizeof(u32) && op == NFT_CMP_EQ)
+ return &nft_cmp_fast_ops;
+ else
+ return &nft_cmp_ops;
+}
+
+static struct nft_expr_type nft_cmp_type __read_mostly = {
+ .name = "cmp",
+ .select_ops = nft_cmp_select_ops,
+ .policy = nft_cmp_policy,
+ .maxattr = NFTA_CMP_MAX,
+ .owner = THIS_MODULE,
+};
+
+int __init nft_cmp_module_init(void)
+{
+ return nft_register_expr(&nft_cmp_type);
+}
+
+void nft_cmp_module_exit(void)
+{
+ nft_unregister_expr(&nft_cmp_type);
+}
Code Review / kvmfornfv.git / blobdiff