This patch adds synproxy stateful object support.
Signed-off-by: Fernando Fernandez Mancera <ffmanc...@riseup.net>
---
include/libnftnl/object.h | 6 ++
include/linux/netfilter/nf_tables.h | 3 +-
include/obj.h | 6 ++
src/Makefile.am | 1 +
src/obj/synproxy.c | 161 ++++++++++++++++++++++++++++
src/object.c | 1 +
6 files changed, 177 insertions(+), 1 deletion(-)
create mode 100644 src/obj/synproxy.c
diff --git a/include/libnftnl/object.h b/include/libnftnl/object.h
index cce0713..c5ea88e 100644
--- a/include/libnftnl/object.h
+++ b/include/libnftnl/object.h
@@ -86,6 +86,12 @@ enum {
NFTNL_OBJ_LIMIT_FLAGS,
};
+enum {
+ NFTNL_OBJ_SYNPROXY_MSS = NFTNL_OBJ_BASE,
+ NFTNL_OBJ_SYNPROXY_WSCALE,
+ NFTNL_OBJ_SYNPROXY_FLAGS,
+};
+
enum {
NFTNL_OBJ_TUNNEL_ID = NFTNL_OBJ_BASE,
NFTNL_OBJ_TUNNEL_IPV4_SRC,
diff --git a/include/linux/netfilter/nf_tables.h
b/include/linux/netfilter/nf_tables.h
index 75e083e..2e49bc6 100644
--- a/include/linux/netfilter/nf_tables.h
+++ b/include/linux/netfilter/nf_tables.h
@@ -1481,7 +1481,8 @@ enum nft_ct_expectation_attributes {
#define NFT_OBJECT_CT_TIMEOUT 7
#define NFT_OBJECT_SECMARK 8
#define NFT_OBJECT_CT_EXPECT 9
-#define __NFT_OBJECT_MAX 10
+#define NFT_OBJECT_SYNPROXY 10
+#define __NFT_OBJECT_MAX 11
#define NFT_OBJECT_MAX (__NFT_OBJECT_MAX - 1)
/**
diff --git a/include/obj.h b/include/obj.h
index 9394d79..10f806c 100644
--- a/include/obj.h
+++ b/include/obj.h
@@ -56,6 +56,11 @@ struct nftnl_obj {
uint32_t type;
uint32_t flags;
} limit;
+ struct nftnl_obj_synproxy {
+ uint16_t mss;
+ uint8_t wscale;
+ uint32_t flags;
+ } synproxy;
struct nftnl_obj_tunnel {
uint32_t id;
uint32_t src_v4;
@@ -108,6 +113,7 @@ extern struct obj_ops obj_ops_ct_helper;
extern struct obj_ops obj_ops_ct_timeout;
extern struct obj_ops obj_ops_ct_expect;
extern struct obj_ops obj_ops_limit;
+extern struct obj_ops obj_ops_synproxy;
extern struct obj_ops obj_ops_tunnel;
extern struct obj_ops obj_ops_secmark;
diff --git a/src/Makefile.am b/src/Makefile.am
index f16422c..90b1967 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -64,6 +64,7 @@ libnftnl_la_SOURCES = utils.c \
obj/quota.c \
obj/tunnel.c \
obj/limit.c \
+ obj/synproxy.c \
obj/ct_timeout.c \
obj/secmark.c \
obj/ct_expect.c \
diff --git a/src/obj/synproxy.c b/src/obj/synproxy.c
new file mode 100644
index 0000000..56ebc85
--- /dev/null
+++ b/src/obj/synproxy.c
@@ -0,0 +1,161 @@
+#include <stdio.h>
+#include <stdint.h>
+#include <arpa/inet.h>
+#include <errno.h>
+#include <inttypes.h>
+
+#include <linux/netfilter/nf_tables.h>
+
+#include "internal.h"
+#include <libmnl/libmnl.h>
+#include <libnftnl/object.h>
+
+#include "obj.h"
+
+static int nftnl_obj_synproxy_set(struct nftnl_obj *e, uint16_t type,
+ const void *data, uint32_t data_len)
+{
+ struct nftnl_obj_synproxy *synproxy = nftnl_obj_data(e);
+
+ switch (type) {
+ case NFTNL_OBJ_SYNPROXY_MSS:
+ synproxy->mss = *((uint16_t *)data);
+ break;
+ case NFTNL_OBJ_SYNPROXY_WSCALE:
+ synproxy->wscale = *((uint8_t *)data);
+ break;
+ case NFTNL_OBJ_SYNPROXY_FLAGS:
+ synproxy->flags = *((uint32_t *)data);
+ break;
+ default:
+ return -1;
+ }
+ return 0;
+}
+
+static const void *nftnl_obj_synproxy_get(const struct nftnl_obj *e,
+ uint16_t type, uint32_t *data_len)
+{
+ struct nftnl_obj_synproxy *synproxy = nftnl_obj_data(e);
+
+ switch (type) {
+ case NFTNL_OBJ_SYNPROXY_MSS:
+ *data_len = sizeof(synproxy->mss);
+ return &synproxy->mss;
+ case NFTNL_OBJ_SYNPROXY_WSCALE:
+ *data_len = sizeof(synproxy->wscale);
+ return &synproxy->wscale;
+ case NFTNL_OBJ_SYNPROXY_FLAGS:
+ *data_len = sizeof(synproxy->flags);
+ return &synproxy->flags;
+ }
+ return NULL;
+}
+
+static int nftnl_obj_synproxy_cb(const struct nlattr *attr, void *data)
+{
+ int type = mnl_attr_get_type(attr);
+ const struct nlattr **tb = data;
+
+ if (mnl_attr_type_valid(attr, NFTA_SYNPROXY_MAX) < 0)
+ return MNL_CB_OK;
+
+ switch (type) {
+ case NFTA_SYNPROXY_MSS:
+ if (mnl_attr_validate(attr, MNL_TYPE_U16) < 0)
+ abi_breakage();
+ break;
+ case NFTA_SYNPROXY_WSCALE:
+ if (mnl_attr_validate(attr, MNL_TYPE_U8) < 0)
+ abi_breakage();
+ break;
+ case NFTA_SYNPROXY_FLAGS:
+ if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0)
+ abi_breakage();
+ break;
+ }
+
+ tb[type] = attr;
+ return MNL_CB_OK;
+}
+
+static void nftnl_obj_synproxy_build(struct nlmsghdr *nlh,
+ const struct nftnl_obj *e)
+{
+ struct nftnl_obj_synproxy *synproxy = nftnl_obj_data(e);
+
+ if (e->flags & (1 << NFTNL_OBJ_SYNPROXY_MSS))
+ mnl_attr_put_u16(nlh, NFTA_SYNPROXY_MSS, htons(synproxy->mss));
+ if (e->flags & (1 << NFTNL_OBJ_SYNPROXY_WSCALE))
+ mnl_attr_put_u8(nlh, NFTA_SYNPROXY_WSCALE, synproxy->wscale);
+ if (e->flags & (1 << NFTNL_OBJ_SYNPROXY_FLAGS))
+ mnl_attr_put_u32(nlh, NFTA_SYNPROXY_FLAGS,
+ htonl(synproxy->flags));
+}
+
+static int nftnl_obj_synproxy_parse(struct nftnl_obj *e, struct nlattr *attr)
+{
+ struct nftnl_obj_synproxy *synproxy = nftnl_obj_data(e);
+ struct nlattr *tb[NFTA_SYNPROXY_MAX + 1] = {};
+
+ if (mnl_attr_parse_nested(attr, nftnl_obj_synproxy_cb, tb) < 0)
+ return -1;
+
+ if (tb[NFTA_SYNPROXY_MSS]) {
+ synproxy->mss = ntohs(mnl_attr_get_u16(tb[NFTA_SYNPROXY_MSS]));
+ e->flags |= (1 << NFTNL_OBJ_SYNPROXY_MSS);
+ }
+ if (tb[NFTA_SYNPROXY_WSCALE]) {
+ synproxy->wscale = mnl_attr_get_u8(tb[NFTA_SYNPROXY_WSCALE]);
+ e->flags |= (1 << NFTNL_OBJ_SYNPROXY_WSCALE);
+ }
+ if (tb[NFTA_SYNPROXY_FLAGS]) {
+ synproxy->flags =
ntohl(mnl_attr_get_u32(tb[NFTA_SYNPROXY_FLAGS]));
+ e->flags |= (1 << NFTNL_OBJ_SYNPROXY_FLAGS);
+ }
+
+ return 0;
+}
+
+static int nftnl_obj_synproxy_snprintf_default(char *buf, size_t size,
+ const struct nftnl_obj *e)
+{
+ struct nftnl_obj_synproxy *synproxy = nftnl_obj_data(e);
+ int ret, offset = 0, len = size;
+
+ if (e->flags & (1 << NFTNL_OBJ_SYNPROXY_MSS) &&
+ e->flags & (1 << NFTNL_OBJ_SYNPROXY_WSCALE)) {
+ ret = snprintf(buf, len, "mss %u wscale %u ", synproxy->mss,
+ synproxy->wscale);
+ SNPRINTF_BUFFER_SIZE(ret, len, offset);
+ }
+
+ return offset;
+}
+
+static int nftnl_obj_synproxy_snprintf(char *buf, size_t len, uint32_t type,
+ uint32_t flags,
+ const struct nftnl_obj *e)
+{
+ switch (type) {
+ case NFTNL_OUTPUT_DEFAULT:
+ return nftnl_obj_synproxy_snprintf_default(buf, len, e);
+ case NFTNL_OUTPUT_XML:
+ case NFTNL_OUTPUT_JSON:
+ default:
+ break;
+ }
+ return -1;
+}
+
+struct obj_ops obj_ops_synproxy = {
+ .name = "synproxy",
+ .type = NFT_OBJECT_SYNPROXY,
+ .alloc_len = sizeof(struct nftnl_obj_synproxy),
+ .max_attr = NFTA_SYNPROXY_MAX,
+ .set = nftnl_obj_synproxy_set,
+ .get = nftnl_obj_synproxy_get,
+ .parse = nftnl_obj_synproxy_parse,
+ .build = nftnl_obj_synproxy_build,
+ .snprintf = nftnl_obj_synproxy_snprintf,
+};
diff --git a/src/object.c b/src/object.c
index d8c87ee..ed8e36d 100644
--- a/src/object.c
+++ b/src/object.c
@@ -34,6 +34,7 @@ static struct obj_ops *obj_ops[__NFT_OBJECT_MAX] = {
[NFT_OBJECT_CT_TIMEOUT] = &obj_ops_ct_timeout,
[NFT_OBJECT_SECMARK] = &obj_ops_secmark,
[NFT_OBJECT_CT_EXPECT] = &obj_ops_ct_expect,
+ [NFT_OBJECT_SYNPROXY] = &obj_ops_synproxy,
};
static struct obj_ops *nftnl_obj_ops_lookup(uint32_t type)
--
2.20.1
