lib/netlink-protocol.h

   1 /*
   2  * Copyright (c) 2008, 2010, 2011, 2014 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_NETFILTER       12
  42 #define NETLINK_GENERIC         16
  43
  44 /* nlmsg_flags bits. */
  45 #define NLM_F_REQUEST           0x001
  46 #define NLM_F_MULTI             0x002
  47 #define NLM_F_ACK               0x004
  48 #define NLM_F_ECHO              0x008
  49
  50 #define NLM_F_ROOT              0x100
  51 #define NLM_F_MATCH             0x200
  52 #define NLM_F_EXCL              0x200
  53 #define NLM_F_ATOMIC            0x400
  54 #define NLM_F_CREATE            0x400
  55 #define NLM_F_DUMP              (NLM_F_ROOT | NLM_F_MATCH)
  56
  57 /* nlmsg_type values. */
  58 #define NLMSG_NOOP              1
  59 #define NLMSG_ERROR             2
  60 #define NLMSG_DONE              3
  61 #define NLMSG_OVERRUN           4
  62
  63 #define NLMSG_MIN_TYPE          0x10
  64
  65 #define MAX_LINKS               32
  66
  67 struct nlmsghdr {
  68     uint32_t nlmsg_len;
  69     uint16_t nlmsg_type;
  70     uint16_t nlmsg_flags;
  71     uint32_t nlmsg_seq;
  72     uint32_t nlmsg_pid;
  73 };
  74 BUILD_ASSERT_DECL(sizeof(struct nlmsghdr) == 16);
  75
  76 #define NLMSG_ALIGNTO 4
  77 #define NLMSG_ALIGN(SIZE) ROUND_UP(SIZE, NLMSG_ALIGNTO)
  78 #define NLMSG_HDRLEN ((int) NLMSG_ALIGN(sizeof(struct nlmsghdr)))
  79
  80 struct nlmsgerr
  81 {
  82         int error;
  83         struct nlmsghdr msg;
  84 };
  85 BUILD_ASSERT_DECL(sizeof(struct nlmsgerr) == 20);
  86
  87 struct genlmsghdr {
  88     uint8_t cmd;
  89     uint8_t version;
  90     uint16_t reserved;
  91 };
  92 BUILD_ASSERT_DECL(sizeof(struct genlmsghdr) == 4);
  93
  94 #define GENL_HDRLEN NLMSG_ALIGN(sizeof(struct genlmsghdr))
  95
  96 struct nlattr {
  97     uint16_t nla_len;
  98     uint16_t nla_type;
  99 };
 100 BUILD_ASSERT_DECL(sizeof(struct nlattr) == 4);
 101
 102 #define NLA_ALIGNTO 4
 103 #define NLA_ALIGN(SIZE) ROUND_UP(SIZE, NLA_ALIGNTO)
 104 #define NLA_HDRLEN ((int) NLA_ALIGN(sizeof(struct nlattr)))
 105
 106 #define GENL_MIN_ID     NLMSG_MIN_TYPE
 107 #define GENL_MAX_ID     1023
 108
 109 #define GENL_ID_CTRL            NLMSG_MIN_TYPE
 110
 111 enum {
 112         CTRL_CMD_UNSPEC,
 113         CTRL_CMD_NEWFAMILY,
 114         CTRL_CMD_DELFAMILY,
 115         CTRL_CMD_GETFAMILY,
 116         CTRL_CMD_NEWOPS,
 117         CTRL_CMD_DELOPS,
 118         CTRL_CMD_GETOPS,
 119         __CTRL_CMD_MAX,
 120 };
 121
 122 #define CTRL_CMD_MAX (__CTRL_CMD_MAX - 1)
 123
 124 enum {
 125         CTRL_ATTR_UNSPEC,
 126         CTRL_ATTR_FAMILY_ID,
 127         CTRL_ATTR_FAMILY_NAME,
 128         CTRL_ATTR_VERSION,
 129         CTRL_ATTR_HDRSIZE,
 130         CTRL_ATTR_MAXATTR,
 131         CTRL_ATTR_OPS,
 132         __CTRL_ATTR_MAX,
 133 };
 134
 135 #define CTRL_ATTR_MAX (__CTRL_ATTR_MAX - 1)
 136
 137 enum {
 138         CTRL_ATTR_OP_UNSPEC,
 139         CTRL_ATTR_OP_ID,
 140         CTRL_ATTR_OP_FLAGS,
 141         __CTRL_ATTR_OP_MAX,
 142 };
 143
 144 #define CTRL_ATTR_OP_MAX (__CTRL_ATTR_OP_MAX - 1)
 145 #endif  /* !HAVE_NETLINK */
 146
 147 /* These were introduced all together in 2.6.24. */
 148 #ifndef NLA_TYPE_MASK
 149 #define NLA_F_NESTED        (1 << 15)
 150 #define NLA_F_NET_BYTEORDER (1 << 14)
 151 #define NLA_TYPE_MASK       ~(NLA_F_NESTED | NLA_F_NET_BYTEORDER)
 152 #endif
 153
 154 /* These were introduced all together in 2.6.14.  (We want our programs to
 155  * support the newer kernel features even if compiled with older headers.) */
 156 #ifndef NETLINK_ADD_MEMBERSHIP
 157 #define NETLINK_ADD_MEMBERSHIP 1
 158 #define NETLINK_DROP_MEMBERSHIP 2
 159 #endif
 160
 161 /* This was introduced in v4.2.  (We want our programs to support the newer
 162  * kernel features even if compiled with older headers.) */
 163 #ifndef NETLINK_LISTEN_ALL_NSID
 164 #define NETLINK_LISTEN_ALL_NSID 8
 165 #endif
 166
 167 /* These were introduced all together in 2.6.23.  (We want our programs to
 168  * support the newer kernel features even if compiled with older headers.) */
 169 #ifndef CTRL_ATTR_MCAST_GRP_MAX
 170
 171 #undef CTRL_ATTR_MAX
 172 #define CTRL_ATTR_MAX 7
 173 #define CTRL_ATTR_MCAST_GROUPS 7
 174
 175 enum {
 176     CTRL_ATTR_MCAST_GRP_UNSPEC,
 177     CTRL_ATTR_MCAST_GRP_NAME,
 178     CTRL_ATTR_MCAST_GRP_ID,
 179     __CTRL_ATTR_MCAST_GRP_MAX,
 180 };
 181
 182 #define CTRL_ATTR_MCAST_GRP_MAX (__CTRL_ATTR_MCAST_GRP_MAX - 1)
 183 #endif /* CTRL_ATTR_MCAST_GRP_MAX */
 184
 185 #endif /* netlink-protocol.h */