lib/netlink-socket.h

   1 /*
   2  * Copyright (c) 2008, 2009, 2010, 2011 Nicira Networks.
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at:
   7  *
   8  *     http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16
  17 #ifndef NETLINK_SOCKET_H
  18 #define NETLINK_SOCKET_H 1
  19
  20 /* Netlink socket definitions.
  21  *
  22  * Netlink is a datagram-based network protocol primarily for communication
  23  * between user processes and the kernel, and mainly on Linux.  Netlink is
  24  * specified in RFC 3549, "Linux Netlink as an IP Services Protocol".
  25  *
  26  * Netlink is not suitable for use in physical networks of heterogeneous
  27  * machines because host byte order is used throughout.
  28  *
  29  * This header file defines functions for working with Netlink sockets, which
  30  * are Linux-specific.  For Netlink protocol definitions, see
  31  * netlink-protocol.h.  For helper functions for working with Netlink messages,
  32  * see netlink.h.
  33  */
  34
  35 #include <stdbool.h>
  36 #include <stddef.h>
  37 #include <stdint.h>
  38 #include <sys/uio.h>
  39
  40 struct ofpbuf;
  41 struct nl_sock;
  42
  43 #ifndef HAVE_NETLINK
  44 #error "netlink-socket.h is only for hosts that support Netlink sockets"
  45 #endif
  46
  47 /* Netlink sockets. */
  48 int nl_sock_create(int protocol, struct nl_sock **);
  49 int nl_sock_clone(const struct nl_sock *, struct nl_sock **);
  50 void nl_sock_destroy(struct nl_sock *);
  51
  52 int nl_sock_join_mcgroup(struct nl_sock *, unsigned int multicast_group);
  53 int nl_sock_leave_mcgroup(struct nl_sock *, unsigned int multicast_group);
  54
  55 int nl_sock_send(struct nl_sock *, const struct ofpbuf *, bool wait);
  56 int nl_sock_sendv(struct nl_sock *sock, const struct iovec iov[], size_t n_iov,
  57                   bool wait);
  58 int nl_sock_recv(struct nl_sock *, struct ofpbuf **, bool wait);
  59 int nl_sock_transact(struct nl_sock *, const struct ofpbuf *request,
  60                      struct ofpbuf **reply);
  61
  62 int nl_sock_drain(struct nl_sock *);
  63
  64 void nl_sock_wait(const struct nl_sock *, short int events);
  65
  66 /* Table dumping. */
  67 struct nl_dump {
  68     struct nl_sock *sock;       /* Socket being dumped. */
  69     uint32_t seq;               /* Expected nlmsg_seq for replies. */
  70     struct ofpbuf *buffer;      /* Receive buffer currently being iterated. */
  71     int status;                 /* 0=OK, EOF=done, or positive errno value. */
  72 };
  73
  74 void nl_dump_start(struct nl_dump *, struct nl_sock *,
  75                    const struct ofpbuf *request);
  76 bool nl_dump_next(struct nl_dump *, struct ofpbuf *reply);
  77 int nl_dump_done(struct nl_dump *);
  78
  79 /* Miscellaneous */
  80 int nl_lookup_genl_family(const char *name, int *number);
  81
  82 #endif /* netlink-socket.h */