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 /* GET request flag.*/
  51 #define NLM_F_ROOT              0x100
  52 #define NLM_F_MATCH             0x200
  53 #define NLM_F_ATOMIC            0x400
  54 #define NLM_F_DUMP              (NLM_F_ROOT | NLM_F_MATCH)
  55
  56 /* NEW request flags. */
  57 #define NLM_F_REPLACE           0x100
  58 #define NLM_F_EXCL              0x200
  59 #define NLM_F_CREATE            0x400
  60
  61 /* nlmsg_type values. */
  62 #define NLMSG_NOOP              1
  63 #define NLMSG_ERROR             2
  64 #define NLMSG_DONE              3
  65 #define NLMSG_OVERRUN           4
  66
  67 #define NLMSG_MIN_TYPE          0x10
  68
  69 #define MAX_LINKS               32
  70
  71 struct nlmsghdr {
  72     uint32_t nlmsg_len;
  73     uint16_t nlmsg_type;
  74     uint16_t nlmsg_flags;
  75     uint32_t nlmsg_seq;
  76     uint32_t nlmsg_pid;
  77 };
  78 BUILD_ASSERT_DECL(sizeof(struct nlmsghdr) == 16);
  79
  80 #define NLMSG_ALIGNTO 4
  81 #define NLMSG_ALIGN(SIZE) ROUND_UP(SIZE, NLMSG_ALIGNTO)
  82 #define NLMSG_HDRLEN ((int) NLMSG_ALIGN(sizeof(struct nlmsghdr)))
  83
  84 struct nlmsgerr
  85 {
  86         int error;
  87         struct nlmsghdr msg;
  88 };
  89 BUILD_ASSERT_DECL(sizeof(struct nlmsgerr) == 20);
  90
  91 struct genlmsghdr {
  92     uint8_t cmd;
  93     uint8_t version;
  94     uint16_t reserved;
  95 };
  96 BUILD_ASSERT_DECL(sizeof(struct genlmsghdr) == 4);
  97
  98 #define GENL_HDRLEN NLMSG_ALIGN(sizeof(struct genlmsghdr))
  99
 100 struct nlattr {
 101     uint16_t nla_len;
 102     uint16_t nla_type;
 103 };
 104 BUILD_ASSERT_DECL(sizeof(struct nlattr) == 4);
 105
 106 #define NLA_ALIGNTO 4
 107 #define NLA_ALIGN(SIZE) ROUND_UP(SIZE, NLA_ALIGNTO)
 108 #define NLA_HDRLEN ((int) NLA_ALIGN(sizeof(struct nlattr)))
 109
 110 #define GENL_MIN_ID     NLMSG_MIN_TYPE
 111 #define GENL_MAX_ID     1023
 112
 113 #define GENL_ID_CTRL            NLMSG_MIN_TYPE
 114
 115 enum {
 116         CTRL_CMD_UNSPEC,
 117         CTRL_CMD_NEWFAMILY,
 118         CTRL_CMD_DELFAMILY,
 119         CTRL_CMD_GETFAMILY,
 120         CTRL_CMD_NEWOPS,
 121         CTRL_CMD_DELOPS,
 122         CTRL_CMD_GETOPS,
 123         __CTRL_CMD_MAX,
 124 };
 125
 126 #define CTRL_CMD_MAX (__CTRL_CMD_MAX - 1)
 127
 128 enum {
 129         CTRL_ATTR_UNSPEC,
 130         CTRL_ATTR_FAMILY_ID,
 131         CTRL_ATTR_FAMILY_NAME,
 132         CTRL_ATTR_VERSION,
 133         CTRL_ATTR_HDRSIZE,
 134         CTRL_ATTR_MAXATTR,
 135         CTRL_ATTR_OPS,
 136         __CTRL_ATTR_MAX,
 137 };
 138
 139 #define CTRL_ATTR_MAX (__CTRL_ATTR_MAX - 1)
 140
 141 enum {
 142         CTRL_ATTR_OP_UNSPEC,
 143         CTRL_ATTR_OP_ID,
 144         CTRL_ATTR_OP_FLAGS,
 145         __CTRL_ATTR_OP_MAX,
 146 };
 147
 148 #define CTRL_ATTR_OP_MAX (__CTRL_ATTR_OP_MAX - 1)
 149 #endif  /* !HAVE_NETLINK */
 150
 151 /* These were introduced all together in 2.6.24. */
 152 #ifndef NLA_TYPE_MASK
 153 #define NLA_F_NESTED        (1 << 15)
 154 #define NLA_F_NET_BYTEORDER (1 << 14)
 155 #define NLA_TYPE_MASK       ~(NLA_F_NESTED | NLA_F_NET_BYTEORDER)
 156 #endif
 157
 158 /* These were introduced all together in 2.6.14.  (We want our programs to
 159  * support the newer kernel features even if compiled with older headers.) */
 160 #ifndef NETLINK_ADD_MEMBERSHIP
 161 #define NETLINK_ADD_MEMBERSHIP 1
 162 #define NETLINK_DROP_MEMBERSHIP 2
 163 #endif
 164
 165 /* This was introduced in v4.2.  (We want our programs to support the newer
 166  * kernel features even if compiled with older headers.) */
 167 #ifndef NETLINK_LISTEN_ALL_NSID
 168 #define NETLINK_LISTEN_ALL_NSID 8
 169 #endif
 170
 171 /* These were introduced all together in 2.6.23.  (We want our programs to
 172  * support the newer kernel features even if compiled with older headers.) */
 173 #ifndef CTRL_ATTR_MCAST_GRP_MAX
 174
 175 #undef CTRL_ATTR_MAX
 176 #define CTRL_ATTR_MAX 7
 177 #define CTRL_ATTR_MCAST_GROUPS 7
 178
 179 enum {
 180     CTRL_ATTR_MCAST_GRP_UNSPEC,
 181     CTRL_ATTR_MCAST_GRP_NAME,
 182     CTRL_ATTR_MCAST_GRP_ID,
 183     __CTRL_ATTR_MCAST_GRP_MAX,
 184 };
 185
 186 #define CTRL_ATTR_MCAST_GRP_MAX (__CTRL_ATTR_MCAST_GRP_MAX - 1)
 187 #endif /* CTRL_ATTR_MCAST_GRP_MAX */
 188
 189 #endif /* netlink-protocol.h */