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