src/lxc/rtnl.h

   1 /*
   2  * lxc: linux Container library
   3  *
   4  * (C) Copyright IBM Corp. 2007, 2008
   5  *
   6  * Authors:
   7  * Daniel Lezcano <daniel.lezcano at free.fr>
   8  *
   9  * This library is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU Lesser General Public
  11  * License as published by the Free Software Foundation; either
  12  * version 2.1 of the License, or (at your option) any later version.
  13  *
  14  * This library is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17  * Lesser General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU Lesser General Public
  20  * License along with this library; if not, write to the Free Software
  21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  22  */
  23
  24 #ifndef __LXC_RTNL_H
  25 #define __LXC_RTNL_H
  26
  27 /*
  28  * Use this as a good size to allocate route netlink messages
  29  */
  30 #define RTNLMSG_GOOD_SIZE NLMSG_GOOD_SIZE
  31 #define RTNLMSG_DATA(glh) ((void *)(NLMSG_DATA(glh) + RTNL_HDRLEN))
  32
  33 /*
  34  * struct genl_handler : the structure which store the netlink handler
  35  *  and the family number
  36  *
  37  * @nlh: the netlink socket handler
  38  */
  39 struct rtnl_handler {
  40         struct nl_handler nlh;
  41 };
  42
  43 /*
  44  * struct rtnlmsg : the struct containing the route netlink message
  45  *  format
  46  *
  47  * @nlmsghdr: a netlink message header
  48  * @rtnlmsghdr: a route netlink message header pointer
  49  *
  50  */
  51 struct rtnlmsg {
  52         struct nlmsghdr nlmsghdr;
  53 };
  54
  55 /*
  56  * rtnetlink_open : open a route netlink socket
  57  *
  58  * @handler: a struct rtnl_handler pointer
  59  *
  60  * Returns 0 on success, < 0 otherwise
  61  */
  62 extern int rtnetlink_open(struct rtnl_handler *handler);
  63
  64 /*
  65  * genetlink_close : close a route netlink socket
  66  *
  67  * @handler: the handler of the socket to be closed
  68  *
  69  * Returns 0 on success, < 0 otherwise
  70  */
  71 extern int rtnetlink_close(struct rtnl_handler *handler);
  72
  73 /*
  74  * rtnetlink_rcv : receive a route netlink socket, it is up
  75  *  to the caller to manage the allocation of the route netlink message
  76  *
  77  * @handler: the handler of the route netlink socket
  78  * @rtnlmsg: the pointer to a route netlink message pre-allocated
  79  *
  80  * Returns 0 on success, < 0 otherwise
  81  */
  82 extern int rtnetlink_rcv(struct rtnl_handler *handler, struct rtnlmsg *rtnlmsg);
  83
  84 /*
  85  * rtnetlink_send : send a route netlink socket, it is up
  86  *  to the caller to manage the allocation of the route netlink message
  87  *
  88  * @handler: the handler of the route netlink socket
  89  * @rtnlmsg: the pointer to a netlink message pre-allocated
  90  *
  91  * Returns 0 on success, < 0 otherwise
  92  */
  93 extern int rtnetlink_send(struct rtnl_handler *handler,
  94                           struct rtnlmsg *rtnlmsg);
  95
  96 struct genlmsg *genlmsg_alloc(size_t size);
  97
  98 extern void rtnlmsg_free(struct rtnlmsg *rtnlmsg);
  99
 100 /*
 101  * rtnetlink_transaction : send and receive a route netlink message in one shot
 102  *
 103  * @handler: the handler of the route netlink socket
 104  * @request: a route netlink message containing the request to be sent
 105  * @answer: a pre-allocated route netlink message to receive the response
 106  *
 107  * Returns 0 on success, < 0 otherwise
 108  */
 109 extern int rtnetlink_transaction(struct rtnl_handler *handler,
 110                                  struct rtnlmsg *request,
 111                                  struct rtnlmsg *answer);
 112
 113 #endif /* __LXC_RTNL_H */