rtnlutil: Introduce rtnl utility

The rtnl utility will encapsulate a collection of functions for rtnl ops.

Makefile.am

@@ -204,6 +204,7 @@ src_iwd_SOURCES = src/main.c linux/nl80211.h src/iwd.h src/missing.h \
 					src/manager.c \
 					src/erp.h src/erp.c \
 					src/fils.h src/fils.c \
+					src/rtnutil.h src/rtnlutil.c \
 					$(eap_sources) \
 					$(builtin_sources)
 src_iwd_LDADD = $(ell_ldadd) -ldl

src/rtnlutil.c

@@ -0,0 +1,76 @@
+/*
+ *
+ *  Wireless daemon for Linux
+ *
+ *  Copyright (C) 2019  Intel Corporation. All rights reserved.
+ *
+ *  This library is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU Lesser General Public
+ *  License as published by the Free Software Foundation; either
+ *  version 2.1 of the License, or (at your option) any later version.
+ *
+ *  This library is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *  Lesser General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Lesser General Public
+ *  License along with this library; if not, write to the Free Software
+ *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <sys/socket.h>
+#include <linux/rtnetlink.h>
+
+#include <ell/ell.h>
+
+#include "src/rtnlutil.h"
+
+static size_t rta_add_u8(void *rta_buf, unsigned short type, uint8_t value)
+{
+	struct rtattr *rta = rta_buf;
+
+	rta->rta_len = RTA_LENGTH(sizeof(uint8_t));
+	rta->rta_type = type;
+	*((uint8_t *) RTA_DATA(rta)) = value;
+
+	return RTA_SPACE(sizeof(uint8_t));
+}
+
+uint32_t rtnl_set_linkmode_and_operstate(struct l_netlink *rtnl, int ifindex,
+					uint8_t linkmode, uint8_t operstate,
+					l_netlink_command_func_t cb,
+					void *user_data,
+					l_netlink_destroy_func_t destroy)
+{
+	struct ifinfomsg *rtmmsg;
+	void *rta_buf;
+	size_t bufsize;
+	uint32_t id;
+
+	bufsize = NLMSG_ALIGN(sizeof(struct ifinfomsg)) +
+		RTA_SPACE(sizeof(uint8_t)) + RTA_SPACE(sizeof(uint8_t));
+
+	rtmmsg = l_malloc(bufsize);
+	memset(rtmmsg, 0, bufsize);
+
+	rtmmsg->ifi_family = AF_UNSPEC;
+	rtmmsg->ifi_index = ifindex;
+
+	rta_buf = (void *) rtmmsg + NLMSG_ALIGN(sizeof(struct ifinfomsg));
+
+	rta_buf += rta_add_u8(rta_buf, IFLA_LINKMODE, linkmode);
+	rta_buf += rta_add_u8(rta_buf, IFLA_OPERSTATE, operstate);
+
+	id = l_netlink_send(rtnl, RTM_SETLINK, 0, rtmmsg,
+					rta_buf - (void *) rtmmsg,
+					cb, user_data, destroy);
+	l_free(rtmmsg);
+
+	return id;
+}

src/rtnlutil.h

@@ -0,0 +1,27 @@
+/*
+ *
+ *  Wireless daemon for Linux
+ *
+ *  Copyright (C) 2019  Intel Corporation. All rights reserved.
+ *
+ *  This library is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU Lesser General Public
+ *  License as published by the Free Software Foundation; either
+ *  version 2.1 of the License, or (at your option) any later version.
+ *
+ *  This library is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *  Lesser General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Lesser General Public
+ *  License along with this library; if not, write to the Free Software
+ *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ */
+
+uint32_t rtnl_set_linkmode_and_operstate(struct l_netlink *rtnl, int ifindex,
+					uint8_t linkmode, uint8_t operstate,
+					l_netlink_command_func_t cb,
+					void *user_data,
+					l_netlink_destroy_func_t destroy);