lib/netlink-protocol.h

   1 /*
   2  * Copyright (c) 2008, 2010, 2011 Nicira, Inc.
   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_PROTOCOL_H
  18 #define NETLINK_PROTOCOL_H 1
  19
  20 /* Netlink protocol definitions.
  21  *
  22  * Netlink is a message framing format described in RFC 3549 and used heavily
  23  * in Linux to access the network stack.  Open vSwitch uses AF_NETLINK sockets
  24  * for this purpose on Linux.  But on all platforms, Open vSwitch uses Netlink
  25  * message framing internally for certain purposes.
  26  *
  27  * This header provides access to the Netlink message framing definitions
  28  * regardless of platform.  On Linux, it includes the proper headers directly;
  29  * on other platforms it directly defines the structures and macros itself.
  30  */
  31
  32 #include <stdint.h>
  33 #include <sys/socket.h>
  34 #include "util.h"
  35
  36 #ifdef HAVE_NETLINK
  37 #include <linux/netlink.h>
  38 #include <linux/genetlink.h>
  39
  40 #else
  41 #define NETLINK_GENERIC         16
  42
  43 struct sockaddr_nl {
  44     sa_family_t nl_family;
  45     unsigned short int nl_pad;
  46     uint32_t nl_pid;
  47     uint32_t nl_groups;
  48 };
  49 BUILD_ASSERT_DECL(sizeof(struct sockaddr_nl) == 12);
  50
  51 /* nlmsg_flags bits. */
  52 #define NLM_F_REQUEST           0x001
  53 #define NLM_F_MULTI             0x002
  54 #define NLM_F_ACK               0x004
  55 #define NLM_F_ECHO              0x008
  56
  57 #define NLM_F_ROOT              0x100
  58 #define NLM_F_MATCH             0x200
  59 #define NLM_F_ATOMIC            0x400
  60 #define NLM_F_DUMP              (NLM_F_ROOT | NLM_F_MATCH)
  61
  62 /* nlmsg_type values. */
  63 #define NLMSG_NOOP              1
  64 #define NLMSG_ERROR             2
  65 #define NLMSG_DONE              3
  66 #define NLMSG_OVERRUN           4
  67
  68 #define NLMSG_MIN_TYPE          0x10
  69
  70 struct nlmsghdr {
  71     uint32_t nlmsg_len;
  72     uint16_t nlmsg_type;
  73     uint16_t nlmsg_flags;
  74     uint32_t nlmsg_seq;
  75     uint32_t nlmsg_pid;
  76 };
  77 BUILD_ASSERT_DECL(sizeof(struct nlmsghdr) == 16);
  78
  79 #define NLMSG_ALIGNTO 4
  80 #define NLMSG_ALIGN(SIZE) ROUND_UP(SIZE, NLMSG_ALIGNTO)
  81 #define NLMSG_HDRLEN ((int) NLMSG_ALIGN(sizeof(struct nlmsghdr)))
  82
  83 struct nlmsgerr
  84 {
  85         int error;
  86         struct nlmsghdr msg;
  87 };
  88 BUILD_ASSERT_DECL(sizeof(struct nlmsgerr) == 20);
  89
  90 struct genlmsghdr {
  91     uint8_t cmd;
  92     uint8_t version;
  93     uint16_t reserved;
  94 };
  95 BUILD_ASSERT_DECL(sizeof(struct genlmsghdr) == 4);
  96
  97 #define GENL_HDRLEN NLMSG_ALIGN(sizeof(struct genlmsghdr))
  98
  99 struct nlattr {
 100     uint16_t nla_len;
 101     uint16_t nla_type;
 102 };
 103 BUILD_ASSERT_DECL(sizeof(struct nlattr) == 4);
 104
 105 #define NLA_ALIGNTO 4
 106 #define NLA_ALIGN(SIZE) ROUND_UP(SIZE, NLA_ALIGNTO)
 107 #define NLA_HDRLEN ((int) NLA_ALIGN(sizeof(struct nlattr)))
 108
 109 #define GENL_MIN_ID     NLMSG_MIN_TYPE
 110 #define GENL_MAX_ID     1023
 111
 112 #define GENL_ID_CTRL            NLMSG_MIN_TYPE
 113
 114 enum {
 115         CTRL_CMD_UNSPEC,
 116         CTRL_CMD_NEWFAMILY,
 117         CTRL_CMD_DELFAMILY,
 118         CTRL_CMD_GETFAMILY,
 119         CTRL_CMD_NEWOPS,
 120         CTRL_CMD_DELOPS,
 121         CTRL_CMD_GETOPS,
 122         __CTRL_CMD_MAX,
 123 };
 124
 125 #define CTRL_CMD_MAX (__CTRL_CMD_MAX - 1)
 126
 127 enum {
 128         CTRL_ATTR_UNSPEC,
 129         CTRL_ATTR_FAMILY_ID,
 130         CTRL_ATTR_FAMILY_NAME,
 131         CTRL_ATTR_VERSION,
 132         CTRL_ATTR_HDRSIZE,
 133         CTRL_ATTR_MAXATTR,
 134         CTRL_ATTR_OPS,
 135         __CTRL_ATTR_MAX,
 136 };
 137
 138 #define CTRL_ATTR_MAX (__CTRL_ATTR_MAX - 1)
 139
 140 enum {
 141         CTRL_ATTR_OP_UNSPEC,
 142         CTRL_ATTR_OP_ID,
 143         CTRL_ATTR_OP_FLAGS,
 144         __CTRL_ATTR_OP_MAX,
 145 };
 146
 147 #define CTRL_ATTR_OP_MAX (__CTRL_ATTR_OP_MAX - 1)
 148 #endif  /* !HAVE_NETLINK */
 149
 150 /* These were introduced all together in 2.6.24. */
 151 #ifndef NLA_TYPE_MASK
 152 #define NLA_F_NESTED        (1 << 15)
 153 #define NLA_F_NET_BYTEORDER (1 << 14)
 154 #define NLA_TYPE_MASK       ~(NLA_F_NESTED | NLA_F_NET_BYTEORDER)
 155 #endif
 156
 157 /* These were introduced all together in 2.6.14.  (We want our programs to
 158  * support the newer kernel features even if compiled with older headers.) */
 159 #ifndef NETLINK_ADD_MEMBERSHIP
 160 #define NETLINK_ADD_MEMBERSHIP 1
 161 #define NETLINK_DROP_MEMBERSHIP 2
 162 #endif
 163
 164 /* These were introduced all together in 2.6.23.  (We want our programs to
 165  * support the newer kernel features even if compiled with older headers.) */
 166 #ifndef CTRL_ATTR_MCAST_GRP_MAX
 167
 168 #undef CTRL_ATTR_MAX
 169 #define CTRL_ATTR_MAX 7
 170 #define CTRL_ATTR_MCAST_GROUPS 7
 171
 172 enum {
 173     CTRL_ATTR_MCAST_GRP_UNSPEC,
 174     CTRL_ATTR_MCAST_GRP_NAME,
 175     CTRL_ATTR_MCAST_GRP_ID,
 176     __CTRL_ATTR_MCAST_GRP_MAX,
 177 };
 178
 179 #define CTRL_ATTR_MCAST_GRP_MAX (__CTRL_ATTR_MCAST_GRP_MAX - 1)
 180 #endif /* CTRL_ATTR_MCAST_GRP_MAX */
 181
 182 #endif /* netlink-protocol.h */