text: /*
   * net/tipc/netlink.c: TIPC configuration handling
   *
   * Copyright (c) 2005-2006, Ericsson AB
   * Copyright (c) 2005-2007, Wind River Systems
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions are met:
   *
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in the
   *    documentation and/or other materials provided with the distribution.
   * 3. Neither the names of the copyright holders nor the names of its
   *    contributors may be used to endorse or promote products derived from
   *    this software without specific prior written permission.
   *
   * Alternatively, this software may be distributed under the terms of the
   * GNU General Public License ("GPL") version 2 as published by the Free
   * Software Foundation.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
   * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
   * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
   * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
   * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
   * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
   * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
   * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
   * POSSIBILITY OF SUCH DAMAGE.
   */
  
  #include "core.h"
  #include "config.h"
  #include <net/genetlink.h>
  
  static int handle_cmd(struct sk_buff *skb, struct genl_info *info)
  {
  	struct sk_buff *rep_buf;
  	struct nlmsghdr *rep_nlh;
  	struct nlmsghdr *req_nlh = info->nlhdr;
  	struct tipc_genlmsghdr *req_userhdr = info->userhdr;
  	int hdr_space = NLMSG_SPACE(GENL_HDRLEN + TIPC_GENL_HDRLEN);
  	u16 cmd;
  
  	if ((req_userhdr->cmd & 0xC000) && (!capable(CAP_NET_ADMIN)))
  		cmd = TIPC_CMD_NOT_NET_ADMIN;
  	else
  		cmd = req_userhdr->cmd;
  
  	rep_buf = tipc_cfg_do_cmd(req_userhdr->dest, cmd,
  			NLMSG_DATA(req_nlh) + GENL_HDRLEN + TIPC_GENL_HDRLEN,
  			NLMSG_PAYLOAD(req_nlh, GENL_HDRLEN + TIPC_GENL_HDRLEN),
  			hdr_space);
  
  	if (rep_buf) {
  		skb_push(rep_buf, hdr_space);
  		rep_nlh = nlmsg_hdr(rep_buf);
  		memcpy(rep_nlh, req_nlh, hdr_space);
  		rep_nlh->nlmsg_len = rep_buf->len;
  		genlmsg_unicast(&init_net, rep_buf, NETLINK_CB(skb).portid);
  	}
  
  	return 0;
  }
  
  static struct genl_family tipc_genl_family = {
  	.id		= GENL_ID_GENERATE,
  	.name		= TIPC_GENL_NAME,
  	.version	= TIPC_GENL_VERSION,
  	.hdrsize	= TIPC_GENL_HDRLEN,
  	.maxattr	= 0,
  };
  
  static struct genl_ops tipc_genl_ops = {
  	.cmd		= TIPC_GENL_CMD,
  	.doit		= handle_cmd,
  };
  
  static int tipc_genl_family_registered;
  
  int tipc_netlink_start(void)
  {
  	int res;
  
  	res = genl_register_family_with_ops(&tipc_genl_family,
  		&tipc_genl_ops, 1);
  	if (res) {
  		pr_err("Failed to register netlink interface\n");
  		return res;
  	}
  
  	tipc_genl_family_registered = 1;
  	return 0;
  }
  
  void tipc_netlink_stop(void)
  {
  	if (!tipc_genl_family_registered)
  		return;
  
  	genl_unregister_family(&tipc_genl_family);
  	tipc_genl_family_registered = 0;
  }
  