This patch adds support for the inner expression which allows you to
match on the inner tunnel headers, eg. VxLAN.
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
---
include/libnftnl/expr.h | 7 +
include/linux/netfilter/nf_tables.h | 32 ++++-
src/Makefile.am | 1 +
src/expr/inner.c | 214 ++++++++++++++++++++++++++++
src/expr_ops.c | 2 +
5 files changed, 254 insertions(+), 2 deletions(-)
create mode 100644 src/expr/inner.c
diff --git a/include/libnftnl/expr.h b/include/libnftnl/expr.h
index 00c63ab9d19b..9873228dd794 100644
--- a/include/libnftnl/expr.h
+++ b/include/libnftnl/expr.h
@@ -316,6 +316,13 @@ enum {
NFTNL_EXPR_LAST_SET,
};
+enum {
+ NFTNL_EXPR_INNER_TYPE = NFTNL_EXPR_BASE,
+ NFTNL_EXPR_INNER_FLAGS,
+ NFTNL_EXPR_INNER_HDRSIZE,
+ NFTNL_EXPR_INNER_EXPR,
+};
+
#ifdef __cplusplus
} /* extern "C" */
#endif
diff --git a/include/linux/netfilter/nf_tables.h b/include/linux/netfilter/nf_tables.h
index 0ae912054cf1..4608646f2103 100644
--- a/include/linux/netfilter/nf_tables.h
+++ b/include/linux/netfilter/nf_tables.h
@@ -753,13 +753,14 @@ enum nft_dynset_attributes {
* @NFT_PAYLOAD_LL_HEADER: link layer header
* @NFT_PAYLOAD_NETWORK_HEADER: network header
* @NFT_PAYLOAD_TRANSPORT_HEADER: transport header
- * @NFT_PAYLOAD_INNER_HEADER: inner header
+ * @NFT_PAYLOAD_INNER_HEADER: inner header / payload
*/
enum nft_payload_bases {
NFT_PAYLOAD_LL_HEADER,
NFT_PAYLOAD_NETWORK_HEADER,
NFT_PAYLOAD_TRANSPORT_HEADER,
NFT_PAYLOAD_INNER_HEADER,
+ NFT_PAYLOAD_TUN_HEADER,
};
/**
@@ -779,6 +780,31 @@ enum nft_payload_csum_flags {
NFT_PAYLOAD_L4CSUM_PSEUDOHDR = (1 << 0),
};
+enum nft_inner_type {
+ NFT_INNER_UNSPEC = 0,
+ NFT_INNER_VXLAN,
+};
+
+enum nft_inner_flags {
+ NFT_INNER_HDRSIZE = (1 << 0),
+ NFT_INNER_LL = (1 << 1),
+ NFT_INNER_NH = (1 << 2),
+ NFT_INNER_TH = (1 << 3),
+};
+#define NFT_INNER_MASK (NFT_INNER_HDRSIZE | NFT_INNER_LL | \
+ NFT_INNER_NH | NFT_INNER_TH)
+
+enum nft_inner_attributes {
+ NFTA_INNER_UNSPEC,
+ NFTA_INNER_NUM,
+ NFTA_INNER_TYPE,
+ NFTA_INNER_FLAGS,
+ NFTA_INNER_HDRSIZE,
+ NFTA_INNER_EXPR,
+ __NFTA_INNER_MAX
+};
+#define NFTA_INNER_MAX (__NFTA_INNER_MAX - 1)
+
/**
* enum nft_payload_attributes - nf_tables payload expression netlink attributes
*
@@ -898,7 +924,8 @@ enum nft_meta_keys {
NFT_META_OIF,
NFT_META_IIFNAME,
NFT_META_OIFNAME,
- NFT_META_IIFTYPE,
+ NFT_META_IFTYPE,
+#define NFT_META_IIFTYPE NFT_META_IFTYPE
NFT_META_OIFTYPE,
NFT_META_SKUID,
NFT_META_SKGID,
@@ -925,6 +952,7 @@ enum nft_meta_keys {
NFT_META_TIME_HOUR,
NFT_META_SDIF,
NFT_META_SDIFNAME,
+ __NFT_META_IIFTYPE,
};
/**
diff --git a/src/Makefile.am b/src/Makefile.am
index c3b0ab974bd2..3cd259c04d1c 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -40,6 +40,7 @@ libnftnl_la_SOURCES = utils.c \
expr/lookup.c \
expr/dynset.c \
expr/immediate.c \
+ expr/inner.c \
expr/match.c \
expr/meta.c \
expr/numgen.c \
diff --git a/src/expr/inner.c b/src/expr/inner.c
new file mode 100644
index 000000000000..7daae4f36adb
--- /dev/null
+++ b/src/expr/inner.c
@@ -0,0 +1,214 @@
+/*
+ * (C) 2012-2022 by Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
+ *
+ * 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 "internal.h"
+
+#include <stdio.h>
+#include <stdint.h>
+#include <string.h>
+#include <limits.h>
+#include <arpa/inet.h>
+#include <errno.h>
+#include <libmnl/libmnl.h>
+
+#include <linux/netfilter/nf_tables.h>
+
+#include <libnftnl/expr.h>
+#include <libnftnl/rule.h>
+
+struct nftnl_expr_inner {
+ uint32_t type;
+ uint32_t flags;
+ uint32_t hdrsize;
+ struct nftnl_expr *expr;
+};
+
+static void nftnl_expr_inner_free(const struct nftnl_expr *e)
+{
+ struct nftnl_expr_inner *inner = nftnl_expr_data(e);
+
+ if (inner->expr)
+ nftnl_expr_free(inner->expr);
+}
+
+static int
+nftnl_expr_inner_set(struct nftnl_expr *e, uint16_t type,
+ const void *data, uint32_t data_len)
+{
+ struct nftnl_expr_inner *inner = nftnl_expr_data(e);
+
+ switch(type) {
+ case NFTNL_EXPR_INNER_TYPE:
+ memcpy(&inner->type, data, sizeof(inner->type));
+ break;
+ case NFTNL_EXPR_INNER_FLAGS:
+ memcpy(&inner->flags, data, sizeof(inner->flags));
+ break;
+ case NFTNL_EXPR_INNER_HDRSIZE:
+ memcpy(&inner->hdrsize, data, sizeof(inner->hdrsize));
+ break;
+ case NFTNL_EXPR_INNER_EXPR:
+ if (inner->expr)
+ nftnl_expr_free(inner->expr);
+
+ inner->expr = (void *)data;
+ break;
+ default:
+ return -1;
+ }
+ return 0;
+}
+
+static const void *
+nftnl_expr_inner_get(const struct nftnl_expr *e, uint16_t type,
+ uint32_t *data_len)
+{
+ struct nftnl_expr_inner *inner = nftnl_expr_data(e);
+
+ switch(type) {
+ case NFTNL_EXPR_INNER_FLAGS:
+ *data_len = sizeof(inner->flags);
+ return &inner->flags;
+ case NFTNL_EXPR_INNER_TYPE:
+ *data_len = sizeof(inner->type);
+ return &inner->type;
+ case NFTNL_EXPR_INNER_HDRSIZE:
+ *data_len = sizeof(inner->hdrsize);
+ return &inner->hdrsize;
+ case NFTNL_EXPR_INNER_EXPR:
+ return inner->expr;
+ }
+ return NULL;
+}
+
+static void
+nftnl_expr_inner_build(struct nlmsghdr *nlh, const struct nftnl_expr *e)
+{
+ struct nftnl_expr_inner *inner = nftnl_expr_data(e);
+ struct nlattr *nest;
+
+ mnl_attr_put_u32(nlh, NFTA_INNER_NUM, htonl(0));
+ if (e->flags & (1 << NFTNL_EXPR_INNER_TYPE))
+ mnl_attr_put_u32(nlh, NFTA_INNER_TYPE, htonl(inner->type));
+ if (e->flags & (1 << NFTNL_EXPR_INNER_FLAGS))
+ mnl_attr_put_u32(nlh, NFTA_INNER_FLAGS, htonl(inner->flags));
+ if (e->flags & (1 << NFTNL_EXPR_INNER_HDRSIZE))
+ mnl_attr_put_u32(nlh, NFTA_INNER_HDRSIZE, htonl(inner->hdrsize));
+ if (e->flags & (1 << NFTNL_EXPR_INNER_EXPR)) {
+ nest = mnl_attr_nest_start(nlh, NFTA_INNER_EXPR);
+ nftnl_expr_build_payload(nlh, inner->expr);
+ mnl_attr_nest_end(nlh, nest);
+ }
+}
+
+static int nftnl_inner_parse_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_INNER_MAX) < 0)
+ return MNL_CB_OK;
+
+ switch(type) {
+ case NFTA_INNER_NUM:
+ case NFTA_INNER_TYPE:
+ case NFTA_INNER_HDRSIZE:
+ case NFTA_INNER_FLAGS:
+ if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0)
+ abi_breakage();
+ break;
+ case NFTA_INNER_EXPR:
+ if (mnl_attr_validate(attr, MNL_TYPE_NESTED) < 0)
+ abi_breakage();
+ break;
+ }
+
+ tb[type] = attr;
+
+ return MNL_CB_OK;
+}
+
+static int
+nftnl_expr_inner_parse(struct nftnl_expr *e, struct nlattr *attr)
+{
+ struct nftnl_expr_inner *inner = nftnl_expr_data(e);
+ struct nlattr *tb[NFTA_INNER_MAX + 1] = {};
+ struct nftnl_expr *expr;
+ int err;
+
+ err = mnl_attr_parse_nested(attr, nftnl_inner_parse_cb, tb);
+ if (err < 0)
+ return err;
+
+ if (tb[NFTA_INNER_HDRSIZE]) {
+ inner->hdrsize =
+ ntohl(mnl_attr_get_u32(tb[NFTA_INNER_HDRSIZE]));
+ e->flags |= (1 << NFTNL_EXPR_INNER_HDRSIZE);
+ }
+ if (tb[NFTA_INNER_FLAGS]) {
+ inner->flags =
+ ntohl(mnl_attr_get_u32(tb[NFTA_INNER_FLAGS]));
+ e->flags |= (1 << NFTNL_EXPR_INNER_FLAGS);
+ }
+ if (tb[NFTA_INNER_TYPE]) {
+ inner->type =
+ ntohl(mnl_attr_get_u32(tb[NFTA_INNER_TYPE]));
+ e->flags |= (1 << NFTNL_EXPR_INNER_TYPE);
+ }
+ if (tb[NFTA_INNER_EXPR]) {
+ expr = nftnl_expr_parse(tb[NFTA_INNER_EXPR]);
+ if (!expr)
+ return -1;
+
+ if (inner->expr)
+ nftnl_expr_free(inner->expr);
+
+ inner->expr = expr;
+ e->flags |= (1 << NFTNL_EXPR_INNER_EXPR);
+ }
+
+ return 0;
+}
+
+static int
+nftnl_expr_inner_snprintf(char *buf, size_t remain, uint32_t flags,
+ const struct nftnl_expr *e)
+{
+ struct nftnl_expr_inner *inner = nftnl_expr_data(e);
+ uint32_t offset = 0;
+ int ret;
+
+ ret = snprintf(buf, remain, "type %u hdrsize %u flags %x [",
+ inner->type, inner->hdrsize, inner->flags);
+ SNPRINTF_BUFFER_SIZE(ret, remain, offset);
+
+ ret = snprintf(buf + offset, remain, " %s ", inner->expr->ops->name);
+ SNPRINTF_BUFFER_SIZE(ret, remain, offset);
+
+ ret = nftnl_expr_snprintf(buf + offset, remain, inner->expr,
+ NFTNL_OUTPUT_DEFAULT, 0);
+ SNPRINTF_BUFFER_SIZE(ret, remain, offset);
+
+ ret = snprintf(buf + offset, remain, "] ");
+ SNPRINTF_BUFFER_SIZE(ret, remain, offset);
+
+ return offset;
+}
+
+struct expr_ops expr_ops_inner = {
+ .name = "inner",
+ .alloc_len = sizeof(struct nftnl_expr_inner),
+ .max_attr = NFTA_INNER_MAX,
+ .free = nftnl_expr_inner_free,
+ .set = nftnl_expr_inner_set,
+ .get = nftnl_expr_inner_get,
+ .parse = nftnl_expr_inner_parse,
+ .build = nftnl_expr_inner_build,
+ .output = nftnl_expr_inner_snprintf,
+};
diff --git a/src/expr_ops.c b/src/expr_ops.c
index 7248e4f98b0a..b85f47209725 100644
--- a/src/expr_ops.c
+++ b/src/expr_ops.c
@@ -14,6 +14,7 @@ extern struct expr_ops expr_ops_dup;
extern struct expr_ops expr_ops_exthdr;
extern struct expr_ops expr_ops_fwd;
extern struct expr_ops expr_ops_immediate;
+extern struct expr_ops expr_ops_inner;
extern struct expr_ops expr_ops_last;
extern struct expr_ops expr_ops_limit;
extern struct expr_ops expr_ops_log;
@@ -58,6 +59,7 @@ static struct expr_ops *expr_ops[] = {
&expr_ops_exthdr,
&expr_ops_fwd,
&expr_ops_immediate,
+ &expr_ops_inner,
&expr_ops_last,
&expr_ops_limit,
&expr_ops_log,
--
2.30.2
