include/linux/netlink.h

   1 /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
   2 #ifndef __LINUX_NETLINK_H
   3 #define __LINUX_NETLINK_H
   4
   5 #include <linux/kernel.h>
   6 #include <linux/socket.h> /* for __kernel_sa_family_t */
   7 #include <linux/types.h>
   8
   9 #define NETLINK_ROUTE           0       /* Routing/device hook                          */
  10 #define NETLINK_UNUSED          1       /* Unused number                                */
  11 #define NETLINK_USERSOCK        2       /* Reserved for user mode socket protocols      */
  12 #define NETLINK_FIREWALL        3       /* Unused number, formerly ip_queue             */
  13 #define NETLINK_SOCK_DIAG       4       /* socket monitoring                            */
  14 #define NETLINK_NFLOG           5       /* netfilter/iptables ULOG */
  15 #define NETLINK_XFRM            6       /* ipsec */
  16 #define NETLINK_SELINUX         7       /* SELinux event notifications */
  17 #define NETLINK_ISCSI           8       /* Open-iSCSI */
  18 #define NETLINK_AUDIT           9       /* auditing */
  19 #define NETLINK_FIB_LOOKUP      10
  20 #define NETLINK_CONNECTOR       11
  21 #define NETLINK_NETFILTER       12      /* netfilter subsystem */
  22 #define NETLINK_IP6_FW          13
  23 #define NETLINK_DNRTMSG         14      /* DECnet routing messages */
  24 #define NETLINK_KOBJECT_UEVENT  15      /* Kernel messages to userspace */
  25 #define NETLINK_GENERIC         16
  26 /* leave room for NETLINK_DM (DM Events) */
  27 #define NETLINK_SCSITRANSPORT   18      /* SCSI Transports */
  28 #define NETLINK_ECRYPTFS        19
  29 #define NETLINK_RDMA            20
  30 #define NETLINK_CRYPTO          21      /* Crypto layer */
  31 #define NETLINK_SMC             22      /* SMC monitoring */
  32
  33 #define NETLINK_INET_DIAG       NETLINK_SOCK_DIAG
  34
  35 #define MAX_LINKS 32
  36
  37 struct sockaddr_nl {
  38         __kernel_sa_family_t    nl_family;      /* AF_NETLINK   */
  39         unsigned short  nl_pad;         /* zero         */
  40         __u32           nl_pid;         /* port ID      */
  41         __u32           nl_groups;      /* multicast groups mask */
  42 };
  43
  44 struct nlmsghdr {
  45         __u32           nlmsg_len;      /* Length of message including header */
  46         __u16           nlmsg_type;     /* Message content */
  47         __u16           nlmsg_flags;    /* Additional flags */
  48         __u32           nlmsg_seq;      /* Sequence number */
  49         __u32           nlmsg_pid;      /* Sending process port ID */
  50 };
  51
  52 /* Flags values */
  53
  54 #define NLM_F_REQUEST           0x01    /* It is request message.       */
  55 #define NLM_F_MULTI             0x02    /* Multipart message, terminated by NLMSG_DONE */
  56 #define NLM_F_ACK               0x04    /* Reply with ack, with zero or error code */
  57 #define NLM_F_ECHO              0x08    /* Echo this request            */
  58 #define NLM_F_DUMP_INTR         0x10    /* Dump was inconsistent due to sequence change */
  59 #define NLM_F_DUMP_FILTERED     0x20    /* Dump was filtered as requested */
  60
  61 /* Modifiers to GET request */
  62 #define NLM_F_ROOT      0x100   /* specify tree root    */
  63 #define NLM_F_MATCH     0x200   /* return all matching  */
  64 #define NLM_F_ATOMIC    0x400   /* atomic GET           */
  65 #define NLM_F_DUMP      (NLM_F_ROOT|NLM_F_MATCH)
  66
  67 /* Modifiers to NEW request */
  68 #define NLM_F_REPLACE   0x100   /* Override existing            */
  69 #define NLM_F_EXCL      0x200   /* Do not touch, if it exists   */
  70 #define NLM_F_CREATE    0x400   /* Create, if it does not exist */
  71 #define NLM_F_APPEND    0x800   /* Add to end of list           */
  72
  73 /* Modifiers to DELETE request */
  74 #define NLM_F_NONREC    0x100   /* Do not delete recursively    */
  75
  76 /* Flags for ACK message */
  77 #define NLM_F_CAPPED    0x100   /* request was capped */
  78 #define NLM_F_ACK_TLVS  0x200   /* extended ACK TVLs were included */
  79
  80 /*
  81    4.4BSD ADD           NLM_F_CREATE|NLM_F_EXCL
  82    4.4BSD CHANGE        NLM_F_REPLACE
  83
  84    True CHANGE          NLM_F_CREATE|NLM_F_REPLACE
  85    Append               NLM_F_CREATE
  86    Check                NLM_F_EXCL
  87  */
  88
  89 #define NLMSG_ALIGNTO   4U
  90 #define NLMSG_ALIGN(len) ( ((len)+NLMSG_ALIGNTO-1) & ~(NLMSG_ALIGNTO-1) )
  91 #define NLMSG_HDRLEN     ((int) NLMSG_ALIGN(sizeof(struct nlmsghdr)))
  92 #define NLMSG_LENGTH(len) ((len) + NLMSG_HDRLEN)
  93 #define NLMSG_SPACE(len) NLMSG_ALIGN(NLMSG_LENGTH(len))
  94 #define NLMSG_DATA(nlh)  ((void*)(((char*)nlh) + NLMSG_LENGTH(0)))
  95 #define NLMSG_NEXT(nlh,len)      ((len) -= NLMSG_ALIGN((nlh)->nlmsg_len), \
  96                                   (struct nlmsghdr*)(((char*)(nlh)) + NLMSG_ALIGN((nlh)->nlmsg_len)))
  97 #define NLMSG_OK(nlh,len) ((len) >= (int)sizeof(struct nlmsghdr) && \
  98                            (nlh)->nlmsg_len >= sizeof(struct nlmsghdr) && \
  99                            (nlh)->nlmsg_len <= (len))
 100 #define NLMSG_PAYLOAD(nlh,len) ((nlh)->nlmsg_len - NLMSG_SPACE((len)))
 101
 102 #define NLMSG_NOOP              0x1     /* Nothing.             */
 103 #define NLMSG_ERROR             0x2     /* Error                */
 104 #define NLMSG_DONE              0x3     /* End of a dump        */
 105 #define NLMSG_OVERRUN           0x4     /* Data lost            */
 106
 107 #define NLMSG_MIN_TYPE          0x10    /* < 0x10: reserved control messages */
 108
 109 struct nlmsgerr {
 110         int             error;
 111         struct nlmsghdr msg;
 112         /*
 113          * followed by the message contents unless NETLINK_CAP_ACK was set
 114          * or the ACK indicates success (error == 0)
 115          * message length is aligned with NLMSG_ALIGN()
 116          */
 117         /*
 118          * followed by TLVs defined in enum nlmsgerr_attrs
 119          * if NETLINK_EXT_ACK was set
 120          */
 121 };
 122
 123 /**
 124  * enum nlmsgerr_attrs - nlmsgerr attributes
 125  * @NLMSGERR_ATTR_UNUSED: unused
 126  * @NLMSGERR_ATTR_MSG: error message string (string)
 127  * @NLMSGERR_ATTR_OFFS: offset of the invalid attribute in the original
 128  *       message, counting from the beginning of the header (u32)
 129  * @NLMSGERR_ATTR_COOKIE: arbitrary subsystem specific cookie to
 130  *      be used - in the success case - to identify a created
 131  *      object or operation or similar (binary)
 132  * @__NLMSGERR_ATTR_MAX: number of attributes
 133  * @NLMSGERR_ATTR_MAX: highest attribute number
 134  */
 135 enum nlmsgerr_attrs {
 136         NLMSGERR_ATTR_UNUSED,
 137         NLMSGERR_ATTR_MSG,
 138         NLMSGERR_ATTR_OFFS,
 139         NLMSGERR_ATTR_COOKIE,
 140
 141         __NLMSGERR_ATTR_MAX,
 142         NLMSGERR_ATTR_MAX = __NLMSGERR_ATTR_MAX - 1
 143 };
 144
 145 #define NETLINK_ADD_MEMBERSHIP          1
 146 #define NETLINK_DROP_MEMBERSHIP         2
 147 #define NETLINK_PKTINFO                 3
 148 #define NETLINK_BROADCAST_ERROR         4
 149 #define NETLINK_NO_ENOBUFS              5
 150 #define NETLINK_RX_RING                 6
 151 #define NETLINK_TX_RING                 7
 152 #define NETLINK_LISTEN_ALL_NSID         8
 153 #define NETLINK_LIST_MEMBERSHIPS        9
 154 #define NETLINK_CAP_ACK                 10
 155 #define NETLINK_EXT_ACK                 11
 156
 157 struct nl_pktinfo {
 158         __u32   group;
 159 };
 160
 161 struct nl_mmap_req {
 162         unsigned int    nm_block_size;
 163         unsigned int    nm_block_nr;
 164         unsigned int    nm_frame_size;
 165         unsigned int    nm_frame_nr;
 166 };
 167
 168 struct nl_mmap_hdr {
 169         unsigned int    nm_status;
 170         unsigned int    nm_len;
 171         __u32           nm_group;
 172         /* credentials */
 173         __u32           nm_pid;
 174         __u32           nm_uid;
 175         __u32           nm_gid;
 176 };
 177
 178 enum nl_mmap_status {
 179         NL_MMAP_STATUS_UNUSED,
 180         NL_MMAP_STATUS_RESERVED,
 181         NL_MMAP_STATUS_VALID,
 182         NL_MMAP_STATUS_COPY,
 183         NL_MMAP_STATUS_SKIP,
 184 };
 185
 186 #define NL_MMAP_MSG_ALIGNMENT           NLMSG_ALIGNTO
 187 #define NL_MMAP_MSG_ALIGN(sz)           __ALIGN_KERNEL(sz, NL_MMAP_MSG_ALIGNMENT)
 188 #define NL_MMAP_HDRLEN                  NL_MMAP_MSG_ALIGN(sizeof(struct nl_mmap_hdr))
 189
 190 #define NET_MAJOR 36            /* Major 36 is reserved for networking                                          */
 191
 192 enum {
 193         NETLINK_UNCONNECTED = 0,
 194         NETLINK_CONNECTED,
 195 };
 196
 197 /*
 198  *  <------- NLA_HDRLEN ------> <-- NLA_ALIGN(payload)-->
 199  * +---------------------+- - -+- - - - - - - - - -+- - -+
 200  * |        Header       | Pad |     Payload       | Pad |
 201  * |   (struct nlattr)   | ing |                   | ing |
 202  * +---------------------+- - -+- - - - - - - - - -+- - -+
 203  *  <-------------- nlattr->nla_len -------------->
 204  */
 205
 206 struct nlattr {
 207         __u16           nla_len;
 208         __u16           nla_type;
 209 };
 210
 211 /*
 212  * nla_type (16 bits)
 213  * +---+---+-------------------------------+
 214  * | N | O | Attribute Type                |
 215  * +---+---+-------------------------------+
 216  * N := Carries nested attributes
 217  * O := Payload stored in network byte order
 218  *
 219  * Note: The N and O flag are mutually exclusive.
 220  */
 221 #define NLA_F_NESTED            (1 << 15)
 222 #define NLA_F_NET_BYTEORDER     (1 << 14)
 223 #define NLA_TYPE_MASK           ~(NLA_F_NESTED | NLA_F_NET_BYTEORDER)
 224
 225 #define NLA_ALIGNTO             4
 226 #define NLA_ALIGN(len)          (((len) + NLA_ALIGNTO - 1) & ~(NLA_ALIGNTO - 1))
 227 #define NLA_HDRLEN              ((int) NLA_ALIGN(sizeof(struct nlattr)))
 228
 229 /* Generic 32 bitflags attribute content sent to the kernel.
 230  *
 231  * The value is a bitmap that defines the values being set
 232  * The selector is a bitmask that defines which value is legit
 233  *
 234  * Examples:
 235  *  value = 0x0, and selector = 0x1
 236  *  implies we are selecting bit 1 and we want to set its value to 0.
 237  *
 238  *  value = 0x2, and selector = 0x2
 239  *  implies we are selecting bit 2 and we want to set its value to 1.
 240  *
 241  */
 242 struct nla_bitfield32 {
 243         __u32 value;
 244         __u32 selector;
 245 };
 246
 247 #endif /* __LINUX_NETLINK_H */