Support for the nft hash expression within libnftnl.
Signed-off-by: Laura Garcia Liebana <nevola@xxxxxxxxx>
---
include/buffer.h | 2 +
include/libnftnl/expr.h | 16 ++
include/linux/netfilter/nf_tables.h | 20 +++
src/Makefile.am | 1 +
src/expr/hash.c | 295 ++++++++++++++++++++++++++++++++++++
src/expr_ops.c | 2 +
6 files changed, 336 insertions(+)
create mode 100644 src/expr/hash.c
diff --git a/include/buffer.h b/include/buffer.h
index 36f0ee3..c76bd4d 100644
--- a/include/buffer.h
+++ b/include/buffer.h
@@ -90,5 +90,7 @@ int nftnl_buf_reg(struct nftnl_buf *b, int type, union nftnl_data_reg *reg,
#define REPLACE "replace"
#define FLUSH "flush"
#define EVERY "every"
+#define MODULUS "modulus"
+#define SEED "seed"
#endif
diff --git a/include/libnftnl/expr.h b/include/libnftnl/expr.h
index 6aa7756..811c254 100644
--- a/include/libnftnl/expr.h
+++ b/include/libnftnl/expr.h
@@ -54,6 +54,14 @@ enum {
};
enum {
+ NFTNL_EXPR_HASH_SREG = NFTNL_EXPR_BASE,
+ NFTNL_EXPR_HASH_DREG,
+ NFTNL_EXPR_HASH_LEN,
+ NFTNL_EXPR_HASH_MODULUS,
+ NFTNL_EXPR_HASH_SEED,
+};
+
+enum {
NFTNL_EXPR_META_KEY = NFTNL_EXPR_BASE,
NFTNL_EXPR_META_DREG,
NFTNL_EXPR_META_SREG,
@@ -245,6 +253,14 @@ enum {
};
enum {
+ NFT_EXPR_HASH_SREG = NFT_RULE_EXPR_ATTR_BASE,
+ NFT_EXPR_HASH_DREG,
+ NFT_EXPR_HASH_LEN,
+ NFT_EXPR_HASH_MODULUS,
+ NFT_EXPR_HASH_SEED,
+};
+
+enum {
NFT_EXPR_META_KEY = NFT_RULE_EXPR_ATTR_BASE,
NFT_EXPR_META_DREG,
NFT_EXPR_META_SREG,
diff --git a/include/linux/netfilter/nf_tables.h b/include/linux/netfilter/nf_tables.h
index 6fe5fc8..7b574c7 100644
--- a/include/linux/netfilter/nf_tables.h
+++ b/include/linux/netfilter/nf_tables.h
@@ -681,6 +681,26 @@ enum nft_nth_attributes {
#define NFTA_NTH_MAX (__NFTA_NTH_MAX - 1)
/**
+ * enum nft_hash_attributes - nf_tables hash expression attributes
+ *
+ * @NFTA_HASH_SREG: source register (NLA_U32)
+ * @NFTA_HASH_DREG: destination register (NLA_U32)
+ * @NFTA_HASH_LEN: data length (NLA_U32)
+ * @NFTA_HASH_MODULUS: Modulus value (NLA_U32)
+ * @NFTA_HASH_SEED: hash initial value (NLA_U32)
+ */
+enum nft_hash_attributes {
+ NFTA_HASH_UNSPEC,
+ NFTA_HASH_SREG,
+ NFTA_HASH_DREG,
+ NFTA_HASH_LEN,
+ NFTA_HASH_MODULUS,
+ NFTA_HASH_SEED,
+ __NFTA_HASH_MAX
+};
+#define NFTA_HASH_MAX (__NFTA_HASH_MAX - 1)
+
+/**
* enum nft_meta_keys - nf_tables meta expression keys
*
* @NFT_META_LEN: packet length (skb->len)
diff --git a/src/Makefile.am b/src/Makefile.am
index 69b61ef..a01970d 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -39,6 +39,7 @@ libnftnl_la_SOURCES = utils.c \
expr/match.c \
expr/meta.c \
expr/nth.c \
+ expr/hash.c \
expr/nat.c \
expr/payload.c \
expr/queue.c \
diff --git a/src/expr/hash.c b/src/expr/hash.c
new file mode 100644
index 0000000..1383b07
--- /dev/null
+++ b/src/expr/hash.c
@@ -0,0 +1,295 @@
+/*
+ * (C) 2016 by Laura Garcia <nevola@xxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published
+ * by the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ */
+
+#include <stdio.h>
+#include <stdint.h>
+#include <string.h>
+#include <arpa/inet.h>
+#include <errno.h>
+#include <linux/netfilter/nf_tables.h>
+
+#include "internal.h"
+#include <libmnl/libmnl.h>
+#include <libnftnl/expr.h>
+#include <libnftnl/rule.h>
+
+
+struct nftnl_expr_hash {
+ enum nft_registers sreg;
+ enum nft_registers dreg;
+ unsigned int len;
+ unsigned int modulus;
+ unsigned int seed;
+};
+
+static int
+nftnl_expr_hash_set(struct nftnl_expr *e, uint16_t type,
+ const void *data, uint32_t data_len)
+{
+ struct nftnl_expr_hash *hash = nftnl_expr_data(e);
+
+ switch (type) {
+ case NFTNL_EXPR_HASH_SREG:
+ hash->sreg = *((uint32_t *)data);
+ break;
+ case NFTNL_EXPR_HASH_DREG:
+ hash->dreg = *((uint32_t *)data);
+ break;
+ case NFTNL_EXPR_HASH_LEN:
+ hash->len = *((unsigned int *)data);
+ break;
+ case NFTNL_EXPR_HASH_MODULUS:
+ hash->modulus = *((unsigned int *)data);
+ break;
+ case NFTNL_EXPR_HASH_SEED:
+ hash->seed = *((unsigned int *)data);
+ break;
+ default:
+ return -1;
+ }
+ return 0;
+}
+
+static const void *
+nftnl_expr_hash_get(const struct nftnl_expr *e, uint16_t type,
+ uint32_t *data_len)
+{
+ struct nftnl_expr_hash *hash = nftnl_expr_data(e);
+
+ switch (type) {
+ case NFTNL_EXPR_HASH_SREG:
+ *data_len = sizeof(hash->sreg);
+ return &hash->sreg;
+ case NFTNL_EXPR_HASH_DREG:
+ *data_len = sizeof(hash->dreg);
+ return &hash->dreg;
+ case NFTNL_EXPR_HASH_LEN:
+ *data_len = sizeof(hash->len);
+ return &hash->len;
+ case NFTNL_EXPR_HASH_MODULUS:
+ *data_len = sizeof(hash->modulus);
+ return &hash->modulus;
+ case NFTNL_EXPR_HASH_SEED:
+ *data_len = sizeof(hash->seed);
+ return &hash->seed;
+ }
+ return NULL;
+}
+
+static int nftnl_expr_hash_cb(const struct nlattr *attr, void *data)
+{
+ const struct nlattr **tb = data;
+ int type = mnl_attr_get_type(attr);
+
+ if (mnl_attr_type_valid(attr, NFTA_HASH_MAX) < 0)
+ return MNL_CB_OK;
+
+ switch (type) {
+ case NFTA_HASH_SREG:
+ case NFTA_HASH_DREG:
+ case NFTA_HASH_LEN:
+ case NFTA_HASH_MODULUS:
+ case NFTA_HASH_SEED:
+ if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0)
+ abi_breakage();
+ break;
+ }
+
+ tb[type] = attr;
+ return MNL_CB_OK;
+}
+
+static void
+nftnl_expr_hash_build(struct nlmsghdr *nlh, const struct nftnl_expr *e)
+{
+ struct nftnl_expr_hash *hash = nftnl_expr_data(e);
+
+ if (e->flags & (1 << NFTNL_EXPR_HASH_SREG))
+ mnl_attr_put_u32(nlh, NFTA_HASH_SREG, htonl(hash->sreg));
+ if (e->flags & (1 << NFTNL_EXPR_HASH_DREG))
+ mnl_attr_put_u32(nlh, NFTA_HASH_DREG, htonl(hash->dreg));
+ if (e->flags & (1 << NFTNL_EXPR_HASH_LEN))
+ mnl_attr_put_u32(nlh, NFTA_HASH_LEN, htonl(hash->len));
+ if (e->flags & (1 << NFTNL_EXPR_HASH_MODULUS))
+ mnl_attr_put_u32(nlh, NFTA_HASH_MODULUS, htonl(hash->modulus));
+ if (e->flags & (1 << NFTNL_EXPR_HASH_SEED))
+ mnl_attr_put_u32(nlh, NFTA_HASH_SEED, htonl(hash->seed));
+
+}
+
+static int
+nftnl_expr_hash_parse(struct nftnl_expr *e, struct nlattr *attr)
+{
+ struct nftnl_expr_hash *hash = nftnl_expr_data(e);
+ struct nlattr *tb[NFTA_HASH_MAX+1] = {};
+ int ret = 0;
+
+ if (mnl_attr_parse_nested(attr, nftnl_expr_hash_cb, tb) < 0)
+ return -1;
+
+ if (tb[NFTA_HASH_SREG]) {
+ hash->sreg = ntohl(mnl_attr_get_u32(tb[NFTA_HASH_SREG]));
+ e->flags |= (1 << NFTNL_EXPR_HASH_SREG);
+ }
+ if (tb[NFTA_HASH_DREG]) {
+ hash->dreg = ntohl(mnl_attr_get_u32(tb[NFTA_HASH_DREG]));
+ e->flags |= (1 << NFTNL_EXPR_HASH_DREG);
+ }
+ if (tb[NFTA_HASH_LEN]) {
+ hash->len = ntohl(mnl_attr_get_u32(tb[NFTA_HASH_LEN]));
+ e->flags |= (1 << NFTNL_EXPR_HASH_LEN);
+ }
+ if (tb[NFTA_HASH_MODULUS]) {
+ hash->modulus = ntohl(mnl_attr_get_u32(tb[NFTA_HASH_MODULUS]));
+ e->flags |= (1 << NFTNL_EXPR_HASH_MODULUS);
+ }
+ if (tb[NFTA_HASH_SEED]) {
+ hash->seed = ntohl(mnl_attr_get_u32(tb[NFTA_HASH_SEED]));
+ e->flags |= (1 << NFTNL_EXPR_HASH_SEED);
+ }
+
+ return ret;
+}
+
+static int nftnl_expr_hash_json_parse(struct nftnl_expr *e, json_t *root,
+ struct nftnl_parse_err *err)
+{
+#ifdef JSON_PARSING
+ uint32_t sreg, dreg, len, modulus, seed;
+
+ if (nftnl_jansson_parse_reg(root, "sreg", NFTNL_TYPE_U32,
+ &sreg, err) == 0)
+ nftnl_expr_set_u32(e, NFTNL_EXPR_HASH_SREG, sreg);
+
+ if (nftnl_jansson_parse_reg(root, "dreg", NFTNL_TYPE_U32,
+ &dreg, err) == 0)
+ nftnl_expr_set_u32(e, NFTNL_EXPR_HASH_DREG, dreg);
+
+ if (nftnl_jansson_parse_val(root, "len", NFTNL_TYPE_U32,
+ &len, err) == 0)
+ nftnl_expr_set_u32(e, NFTNL_EXPR_HASH_LEN, len);
+
+ if (nftnl_jansson_parse_val(root, "modulus", NFTNL_TYPE_U32,
+ &modulus, err) == 0)
+ nftnl_expr_set_u32(e, NFTNL_EXPR_HASH_MODULUS, modulus);
+
+ if (nftnl_jansson_parse_val(root, "seed", NFTNL_TYPE_U32,
+ &seed, err) == 0)
+ nftnl_expr_set_u32(e, NFTNL_EXPR_HASH_SEED, seed);
+
+ return 0;
+#else
+ errno = EOPNOTSUPP;
+ return -1;
+#endif
+}
+
+
+static int nftnl_expr_hash_xml_parse(struct nftnl_expr *e,
+ mxml_node_t *tree,
+ struct nftnl_parse_err *err)
+{
+#ifdef XML_PARSING
+ uint32_t sreg, dreg, len, modulus, seed;
+
+ if (nftnl_mxml_reg_parse(tree, "sreg", &sreg, MXML_DESCEND_FIRST,
+ NFTNL_XML_MAND, err) == 0)
+ nftnl_expr_set_u32(e, NFTNL_EXPR_HASH_SREG, sreg);
+
+ if (nftnl_mxml_reg_parse(tree, "dreg", &dreg, MXML_DESCEND_FIRST,
+ NFTNL_XML_MAND, err) == 0)
+ nftnl_expr_set_u32(e, NFTNL_EXPR_HASH_DREG, dreg);
+
+ if (nftnl_mxml_num_parse(tree, "len", MXML_DESCEND_FIRST, BASE_DEC,
+ &len, NFTNL_TYPE_U32, NFTNL_XML_MAND,
+ err) == 0)
+ nftnl_expr_set_u32(e, NFTNL_EXPR_HASH_LEN, len);
+
+ if (nftnl_mxml_num_parse(tree, "modulus", MXML_DESCEND_FIRST, BASE_DEC,
+ &modulus, NFTNL_TYPE_U32, NFTNL_XML_MAND,
+ err) == 0)
+ nftnl_expr_set_u32(e, NFTNL_EXPR_HASH_MODULUS, modulus);
+
+ if (nftnl_mxml_num_parse(tree, "seed", MXML_DESCEND_FIRST, BASE_DEC,
+ &seed, NFTNL_TYPE_U32, NFTNL_XML_MAND,
+ err) == 0)
+ nftnl_expr_set_u32(e, NFTNL_EXPR_HASH_SEED, seed);
+
+ return 0;
+#else
+ errno = EOPNOTSUPP;
+ return -1;
+#endif
+}
+
+static int
+nftnl_expr_hash_snprintf_default(char *buf, size_t size,
+ const struct nftnl_expr *e)
+{
+ struct nftnl_expr_hash *hash = nftnl_expr_data(e);
+ int len = size, offset = 0, ret;
+
+ ret = snprintf(buf, len, "reg %u = jhash(reg %u, %u, %u) %% modulus %u",
+ hash->dreg, hash->sreg, hash->len, hash->seed,
+ hash->modulus);
+ SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
+
+ return offset;
+}
+
+static int nftnl_expr_hash_export(char *buf, size_t size,
+ const struct nftnl_expr *e, int type)
+{
+ struct nftnl_expr_hash *hash = nftnl_expr_data(e);
+
+ NFTNL_BUF_INIT(b, buf, size);
+
+ if (e->flags & (1 << NFTNL_EXPR_HASH_SREG))
+ nftnl_buf_u32(&b, type, hash->sreg, SREG);
+ if (e->flags & (1 << NFTNL_EXPR_HASH_DREG))
+ nftnl_buf_u32(&b, type, hash->dreg, DREG);
+ if (e->flags & (1 << NFTNL_EXPR_HASH_LEN))
+ nftnl_buf_u32(&b, type, hash->len, LEN);
+ if (e->flags & (1 << NFTNL_EXPR_HASH_MODULUS))
+ nftnl_buf_u32(&b, type, hash->modulus, MODULUS);
+ if (e->flags & (1 << NFTNL_EXPR_HASH_SEED))
+ nftnl_buf_u32(&b, type, hash->seed, SEED);
+
+ return nftnl_buf_done(&b);
+}
+
+static int
+nftnl_expr_hash_snprintf(char *buf, size_t len, uint32_t type,
+ uint32_t flags, const struct nftnl_expr *e)
+{
+ switch (type) {
+ case NFTNL_OUTPUT_DEFAULT:
+ return nftnl_expr_hash_snprintf_default(buf, len, e);
+ case NFTNL_OUTPUT_XML:
+ case NFTNL_OUTPUT_JSON:
+ return nftnl_expr_hash_export(buf, len, e, type);
+ default:
+ break;
+ }
+ return -1;
+}
+
+struct expr_ops expr_ops_hash = {
+ .name = "hash",
+ .alloc_len = sizeof(struct nftnl_expr_hash),
+ .max_attr = NFTA_HASH_MAX,
+ .set = nftnl_expr_hash_set,
+ .get = nftnl_expr_hash_get,
+ .parse = nftnl_expr_hash_parse,
+ .build = nftnl_expr_hash_build,
+ .snprintf = nftnl_expr_hash_snprintf,
+ .xml_parse = nftnl_expr_hash_xml_parse,
+ .json_parse = nftnl_expr_hash_json_parse,
+};
diff --git a/src/expr_ops.c b/src/expr_ops.c
index 928bb5e..fe584fd 100644
--- a/src/expr_ops.c
+++ b/src/expr_ops.c
@@ -20,6 +20,7 @@ extern struct expr_ops expr_ops_masq;
extern struct expr_ops expr_ops_match;
extern struct expr_ops expr_ops_meta;
extern struct expr_ops expr_ops_nth;
+extern struct expr_ops expr_ops_hash;
extern struct expr_ops expr_ops_nat;
extern struct expr_ops expr_ops_payload;
extern struct expr_ops expr_ops_redir;
@@ -45,6 +46,7 @@ static struct expr_ops *expr_ops[] = {
&expr_ops_match,
&expr_ops_meta,
&expr_ops_nth,
+ &expr_ops_hash,
&expr_ops_nat,
&expr_ops_payload,
&expr_ops_redir,
--
2.8.1
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