Add skeleton code for CAPWAP Data Channel kernel module.

The IEEE802.11 data packets will embedded into CAPWAP Data Channel directly in
kernel mode. The CAPWAP Data Channel in usermode be used only for compatibility
reasons.

src/wtp/binding/ieee80211/wifi_nl80211.c

@@ -45,7 +45,7 @@ struct family_data {
 
 /* Compatibility functions */
 #ifdef HAVE_LIBNL_10 
-static uint32_t port_bitmap[32] = { 0 };
+static uint32_t g_portbitmap[32] = { 0 };
 
 static struct nl_sock* nl_socket_alloc_cb(void* cb) {
 	int i;
@@ -54,11 +54,11 @@ static struct nl_sock* nl_socket_alloc_cb(void* cb) {
 
 	handle = nl_handle_alloc_cb(cb);
 	for (i = 0; i < 1024; i++) {
-		if (port_bitmap[i / 32] & (1 << (i % 32))) {
+		if (g_portbitmap[i / 32] & (1 << (i % 32))) {
 			continue;
 		}
 
-		port_bitmap[i / 32] |= 1 << (i % 32);
+		g_portbitmap[i / 32] |= 1 << (i % 32);
 		pid += i << 22;
 		break;
 	}
@@ -71,7 +71,7 @@ static void nl_socket_free(struct nl_sock* handle) {
 	uint32_t port = nl_socket_get_local_port(handle);
 
 	port >>= 22;
-	port_bitmap[port / 32] &= ~(1 << (port % 32));
+	g_portbitmap[port / 32] &= ~(1 << (port % 32));
 
 	nl_handle_destroy(handle);
 }

src/wtp/wtp.c

@@ -8,6 +8,7 @@
 #include "capwap_dtls.h"
 #include "wtp_dfa.h"
 #include "wtp_radio.h"
+#include "wtp_kmod.h"
 
 #include <arpa/inet.h>
 #include <libconfig.h>
@@ -1390,21 +1391,38 @@ int main(int argc, char** argv) {
 					capwap_logging_info("Wait the initialization of radio interfaces");
 					wtp_wait_radio_ready();
 
-					/* */
-					capwap_logging_info("Startup WTP");
+					/* Connect WTP with kernel module */
+					value = wtp_kmod_init();
+					if (!value || !g_wtp.kmodrequest) {
+						if (!value) {
+							g_wtp.kmodconnect = 1;
+							capwap_logging_info("SmartCAPWAP kernel module connected");
+						}
 
-					/* Complete configuration WTP */
-					result = wtp_configure();
-					if (result == CAPWAP_SUCCESSFUL) {
-						/* Running WTP */
-						result = wtp_dfa_running();
+						/* */
+						capwap_logging_info("Startup WTP");
 
-						/* Close socket */
-						capwap_close_sockets(&g_wtp.net);
+						/* Complete configuration WTP */
+						result = wtp_configure();
+						if (result == CAPWAP_SUCCESSFUL) {
+							/* Running WTP */
+							result = wtp_dfa_running();
+
+							/* Close socket */
+							capwap_close_sockets(&g_wtp.net);
+						}
+
+						/* Disconnect kernel module */
+						if (g_wtp.kmodconnect) {
+							wtp_kmod_free();
+						}
+
+						/* */
+						capwap_logging_info("Terminate WTP");
+					} else {
+						capwap_logging_fatal("Unable to connect with kernel module");
 					}
 
-					capwap_logging_info("Terminate WTP");
-
 					/* Close radio */
 					wtp_radio_close();
 

src/wtp/wtp.h

@@ -56,6 +56,11 @@ struct wtp_t {
 	int standalone;
 	int running;
 
+	/* */
+	int kmodrequest;
+	int kmodconnect;
+
+	/* */
 	char wlanprefix[IFNAMSIZ];
 
 	/* */

src/wtp/wtp_kmod.c

@@ -0,0 +1,227 @@
+#include "wtp.h"
+#include "wtp_kmod.h"
+#include <netlink/genl/genl.h>
+#include <netlink/genl/family.h>
+#include <netlink/genl/ctrl.h>
+#include "nlsmartcapwap.h"
+
+/* Compatibility functions */
+#ifdef HAVE_LIBNL_10 
+#define nl_sock nl_handle
+static uint32_t g_portbitmap[32] = { 0 };
+
+static struct nl_sock* nl_socket_alloc_cb(void* cb) {
+	int i;
+	struct nl_sock* handle;
+	uint32_t pid = getpid() & 0x3FFFFF;
+
+	handle = nl_handle_alloc_cb(cb);
+	for (i = 0; i < 1024; i++) {
+		if (g_portbitmap[i / 32] & (1 << (i % 32))) {
+			continue;
+		}
+
+		g_portbitmap[i / 32] |= 1 << (i % 32);
+		pid += i << 22;
+		break;
+	}
+
+	nl_socket_set_local_port(handle, pid);
+	return handle;
+}
+
+static void nl_socket_free(struct nl_sock* handle) {
+	uint32_t port = nl_socket_get_local_port(handle);
+
+	port >>= 22;
+	g_portbitmap[port / 32] &= ~(1 << (port % 32));
+
+	nl_handle_destroy(handle);
+}
+#endif
+
+/* */
+struct wtp_kmod_handle {
+	struct nl_sock* nl;
+	struct nl_cb* nl_cb;
+	int nlsmartcapwap_id;
+};
+
+/* */
+typedef int (*wtp_kmod_valid_cb)(struct nl_msg* msg, void* data);
+
+/* */
+static struct wtp_kmod_handle g_kmodhandle;
+
+/* */
+static struct nl_sock* nl_create_handle(struct nl_cb* cb) {
+	struct nl_sock* handle;
+
+	handle = nl_socket_alloc_cb(cb);
+	if (!handle) {
+		return NULL;
+	}
+
+	if (genl_connect(handle)) {
+		nl_socket_free(handle);
+		return NULL;
+	}
+
+	return handle;
+}
+
+/* */
+static int wtp_kmod_no_seq_check(struct nl_msg* msg, void* arg) {
+	return NL_OK;
+}
+
+/* */
+static int wtp_kmod_error_handler(struct sockaddr_nl* nla, struct nlmsgerr* err, void* arg) {
+	*((int*)arg) = err->error;
+	return NL_STOP;
+}
+
+/* */
+static int wtp_kmod_finish_handler(struct nl_msg* msg, void* arg) {
+	*((int*)arg) = 0;
+	return NL_SKIP;
+}
+
+/* */
+static int wtp_kmod_ack_handler(struct nl_msg* msg, void* arg) {
+	*((int*)arg) = 0;
+	return NL_STOP;
+}
+
+/* */
+static int wtp_kmod_valid_handler(struct nl_msg* msg, void* data) {
+	struct nlattr* tb_msg[NLSMARTCAPWAP_ATTR_MAX + 1];
+	struct genlmsghdr* gnlh = nlmsg_data(nlmsg_hdr(msg));
+
+	nla_parse(tb_msg, NLSMARTCAPWAP_ATTR_MAX, genlmsg_attrdata(gnlh, 0), genlmsg_attrlen(gnlh, 0), NULL);
+
+	return NL_SKIP;
+}
+
+/* */
+static int wtp_kmod_send_and_recv(struct nl_sock* nl, struct nl_cb* nl_cb, struct nl_msg* msg, wtp_kmod_valid_cb valid_cb, void* data) {
+	int result;
+	struct nl_cb* cb;
+
+	/* Clone netlink callback */
+	cb = nl_cb_clone(nl_cb);
+	if (!cb) {
+		return -1;
+	}
+
+	/* Complete send message */
+	result = nl_send_auto_complete(nl, msg);
+	if (result < 0) {
+		nl_cb_put(cb);
+		return -1;
+	}
+
+	/* Customize message callback */
+	nl_cb_err(cb, NL_CB_CUSTOM, wtp_kmod_error_handler, &result);
+	nl_cb_set(cb, NL_CB_FINISH, NL_CB_CUSTOM, wtp_kmod_finish_handler, &result);
+	nl_cb_set(cb, NL_CB_ACK, NL_CB_CUSTOM, wtp_kmod_ack_handler, &result);
+
+	if (valid_cb) {
+		nl_cb_set(cb, NL_CB_VALID, NL_CB_CUSTOM, valid_cb, data);
+	}
+
+	result = 1;
+	while (result > 0) {
+		nl_recvmsgs(nl, cb);
+	}
+
+	nl_cb_put(cb);
+	return result;
+}
+
+/* */
+static int wtp_kmod_send_and_recv_msg(struct nl_msg* msg, wtp_kmod_valid_cb valid_cb, void* data) {
+	return wtp_kmod_send_and_recv(g_kmodhandle.nl, g_kmodhandle.nl_cb, msg, valid_cb, data);
+}
+
+/* */
+static int wtp_kmod_connect(void) {
+	int result;
+	struct nl_msg* msg;
+
+	/* */
+	msg = nlmsg_alloc();
+	if (!msg) {
+		return -1;
+	}
+
+	/* */
+	genlmsg_put(msg, 0, 0, g_kmodhandle.nlsmartcapwap_id, 0, 0, NLSMARTCAPWAP_CMD_CONNECT, 0);
+
+	/* */
+	result = wtp_kmod_send_and_recv_msg(msg, NULL, NULL);
+	if (result) {
+		if (result == -EALREADY) {
+			result = 0;
+		} else {
+			capwap_logging_warning("Unable to connect kernel module, error code: %d", result);
+		}
+	}
+
+	/* */
+	nlmsg_free(msg);
+	return result;
+}
+
+/* */
+int wtp_kmod_init(void) {
+	int result;
+
+	/* */
+	memset(&g_kmodhandle, 0, sizeof(struct wtp_kmod_handle));
+
+	/* Configure netlink callback */
+	g_kmodhandle.nl_cb = nl_cb_alloc(NL_CB_DEFAULT);
+	if (!g_kmodhandle.nl_cb) {
+		wtp_kmod_free();
+		return -1;
+	}
+
+	/* Create netlink socket */
+	g_kmodhandle.nl = nl_create_handle(g_kmodhandle.nl_cb);
+	if (!g_kmodhandle.nl) {
+		wtp_kmod_free();
+		return -1;
+	}
+
+	/* Get nlsmartcapwap netlink family */
+	g_kmodhandle.nlsmartcapwap_id = genl_ctrl_resolve(g_kmodhandle.nl, SMARTCAPWAP_GENL_NAME);
+	if (g_kmodhandle.nlsmartcapwap_id < 0) {
+		wtp_kmod_free();
+		return -1;
+	}
+
+	/* Configure callback function */
+	nl_cb_set(g_kmodhandle.nl_cb, NL_CB_SEQ_CHECK, NL_CB_CUSTOM, wtp_kmod_no_seq_check, NULL);
+	nl_cb_set(g_kmodhandle.nl_cb, NL_CB_VALID, NL_CB_CUSTOM, wtp_kmod_valid_handler, NULL);
+
+	/* Connect to kernel module */
+	result = wtp_kmod_connect();
+	if (result) {
+		wtp_kmod_free();
+		return result;
+	}
+
+	return 0;
+}
+
+/* */
+void wtp_kmod_free(void) {
+	if (g_kmodhandle.nl) {
+		nl_socket_free(g_kmodhandle.nl);
+	}
+
+	if (g_kmodhandle.nl_cb) {
+		nl_cb_put(g_kmodhandle.nl_cb);
+	}
+}

src/wtp/wtp_kmod.h

@@ -0,0 +1,8 @@
+#ifndef __WTP_KMOD_HEADER__
+#define __WTP_KMOD_HEADER__
+
+/* */
+int wtp_kmod_init(void);
+void wtp_kmod_free(void);
+
+#endif /* __WTP_KMOD_HEADER__ */