net/tipc/netlink.c

   1 /*
   2  * net/tipc/netlink.c: TIPC configuration handling
   3  *
   4  * Copyright (c) 2005-2006, Ericsson AB
   5  * Copyright (c) 2005, Wind River Systems
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions are met:
  10  *
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 3. Neither the names of the copyright holders nor the names of its
  17  *    contributors may be used to endorse or promote products derived from
  18  *    this software without specific prior written permission.
  19  *
  20  * Alternatively, this software may be distributed under the terms of the
  21  * GNU General Public License ("GPL") version 2 as published by the Free
  22  * Software Foundation.
  23  *
  24  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  25  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  27  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
  28  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  29  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  30  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  31  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  32  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  33  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  34  * POSSIBILITY OF SUCH DAMAGE.
  35  */
  36
  37 #include "core.h"
  38 #include "config.h"
  39 #include <net/genetlink.h>
  40
  41 static int handle_cmd(struct sk_buff *skb, struct genl_info *info)
  42 {
  43         struct sk_buff *rep_buf;
  44         struct nlmsghdr *rep_nlh;
  45         struct nlmsghdr *req_nlh = info->nlhdr;
  46         struct tipc_genlmsghdr *req_userhdr = info->userhdr;
  47         int hdr_space = NLMSG_SPACE(GENL_HDRLEN + TIPC_GENL_HDRLEN);
  48
  49         if ((req_userhdr->cmd & 0xC000) && (!capable(CAP_NET_ADMIN)))
  50                 rep_buf = tipc_cfg_reply_error_string(TIPC_CFG_NOT_NET_ADMIN);
  51         else
  52                 rep_buf = tipc_cfg_do_cmd(req_userhdr->dest,
  53                                           req_userhdr->cmd,
  54                                           NLMSG_DATA(req_nlh) + GENL_HDRLEN + TIPC_GENL_HDRLEN,
  55                                           NLMSG_PAYLOAD(req_nlh, GENL_HDRLEN + TIPC_GENL_HDRLEN),
  56                                           hdr_space);
  57
  58         if (rep_buf) {
  59                 skb_push(rep_buf, hdr_space);
  60                 rep_nlh = nlmsg_hdr(rep_buf);
  61                 memcpy(rep_nlh, req_nlh, hdr_space);
  62                 rep_nlh->nlmsg_len = rep_buf->len;
  63                 genlmsg_unicast(rep_buf, req_nlh->nlmsg_pid);
  64         }
  65
  66         return 0;
  67 }
  68
  69 static struct genl_family family = {
  70         .id             = GENL_ID_GENERATE,
  71         .name           = TIPC_GENL_NAME,
  72         .version        = TIPC_GENL_VERSION,
  73         .hdrsize        = TIPC_GENL_HDRLEN,
  74         .maxattr        = 0,
  75 };
  76
  77 static struct genl_ops ops = {
  78         .cmd            = TIPC_GENL_CMD,
  79         .doit           = handle_cmd,
  80 };
  81
  82 static int family_registered = 0;
  83
  84 int tipc_netlink_start(void)
  85 {
  86
  87
  88         if (genl_register_family(&family))
  89                 goto err;
  90
  91         family_registered = 1;
  92
  93         if (genl_register_ops(&family, &ops))
  94                 goto err_unregister;
  95
  96         return 0;
  97
  98  err_unregister:
  99         genl_unregister_family(&family);
 100         family_registered = 0;
 101  err:
 102         err("Failed to register netlink interface\n");
 103         return -EFAULT;
 104 }
 105
 106 void tipc_netlink_stop(void)
 107 {
 108         if (family_registered) {
 109                 genl_unregister_family(&family);
 110                 family_registered = 0;
 111         }
 112 }