netlink.h

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#ifndef _UAPI__LINUX_NETLINK_H
#define _UAPI__LINUX_NETLINK_H

#include <linux/socket.h> /* for __kernel_sa_family_t */
#include <linux/types.h>

#define NETLINK_ROUTE       0   /* Routing/device hook              */
#define NETLINK_UNUSED      1   /* Unused number                */
#define NETLINK_USERSOCK    2   /* Reserved for user mode socket protocols  */
#define NETLINK_FIREWALL    3   /* Unused number, formerly ip_queue     */
#define NETLINK_SOCK_DIAG   4   /* socket monitoring                */
#define NETLINK_NFLOG       5   /* netfilter/iptables ULOG */
#define NETLINK_XFRM        6   /* ipsec */
#define NETLINK_SELINUX     7   /* SELinux event notifications */
#define NETLINK_ISCSI       8   /* Open-iSCSI */
#define NETLINK_AUDIT       9   /* auditing */
#define NETLINK_FIB_LOOKUP  10  
#define NETLINK_CONNECTOR   11
#define NETLINK_NETFILTER   12  /* netfilter subsystem */
#define NETLINK_IP6_FW      13
#define NETLINK_DNRTMSG     14  /* DECnet routing messages */
#define NETLINK_KOBJECT_UEVENT  15  /* Kernel messages to userspace */
#define NETLINK_GENERIC     16
/* leave room for NETLINK_DM (DM Events) */
#define NETLINK_SCSITRANSPORT   18  /* SCSI Transports */
#define NETLINK_ECRYPTFS    19
#define NETLINK_RDMA        20
#define NETLINK_CRYPTO      21  /* Crypto layer */

#define NETLINK_INET_DIAG   NETLINK_SOCK_DIAG

#define MAX_LINKS 32        

struct sockaddr_nl {
    __kernel_sa_family_t    nl_family;  /* AF_NETLINK   */
    unsigned short  nl_pad;     /* zero     */
    __u32       nl_pid;     /* port ID  */
        __u32       nl_groups;  /* multicast groups mask */
};

struct nlmsghdr {
    __u32       nlmsg_len;  /* Length of message including header */
    __u16       nlmsg_type; /* Message content */
    __u16       nlmsg_flags;    /* Additional flags */
    __u32       nlmsg_seq;  /* Sequence number */
    __u32       nlmsg_pid;  /* Sending process port ID */
};

/* Flags values */

#define NLM_F_REQUEST       1   /* It is request message.   */
#define NLM_F_MULTI     2   /* Multipart message, terminated by NLMSG_DONE */
#define NLM_F_ACK       4   /* Reply with ack, with zero or error code */
#define NLM_F_ECHO      8   /* Echo this request        */
#define NLM_F_DUMP_INTR     16  /* Dump was inconsistent due to sequence change */

/* Modifiers to GET request */
#define NLM_F_ROOT  0x100   /* specify tree root    */
#define NLM_F_MATCH 0x200   /* return all matching  */
#define NLM_F_ATOMIC    0x400   /* atomic GET       */
#define NLM_F_DUMP  (NLM_F_ROOT|NLM_F_MATCH)

/* Modifiers to NEW request */
#define NLM_F_REPLACE   0x100   /* Override existing        */
#define NLM_F_EXCL  0x200   /* Do not touch, if it exists   */
#define NLM_F_CREATE    0x400   /* Create, if it does not exist */
#define NLM_F_APPEND    0x800   /* Add to end of list       */

/*
   4.4BSD ADD       NLM_F_CREATE|NLM_F_EXCL
   4.4BSD CHANGE    NLM_F_REPLACE

   True CHANGE      NLM_F_CREATE|NLM_F_REPLACE
   Append       NLM_F_CREATE
   Check        NLM_F_EXCL
 */

#define NLMSG_ALIGNTO   4U
#define NLMSG_ALIGN(len) ( ((len)+NLMSG_ALIGNTO-1) & ~(NLMSG_ALIGNTO-1) )
#define NLMSG_HDRLEN     ((int) NLMSG_ALIGN(sizeof(struct nlmsghdr)))
#define NLMSG_LENGTH(len) ((len)+NLMSG_ALIGN(NLMSG_HDRLEN))
#define NLMSG_SPACE(len) NLMSG_ALIGN(NLMSG_LENGTH(len))
#define NLMSG_DATA(nlh)  ((void*)(((char*)nlh) + NLMSG_LENGTH(0)))
#define NLMSG_NEXT(nlh,len)  ((len) -= NLMSG_ALIGN((nlh)->nlmsg_len), \
                  (struct nlmsghdr*)(((char*)(nlh)) + NLMSG_ALIGN((nlh)->nlmsg_len)))
#define NLMSG_OK(nlh,len) ((len) >= (int)sizeof(struct nlmsghdr) && \
               (nlh)->nlmsg_len >= sizeof(struct nlmsghdr) && \
               (nlh)->nlmsg_len <= (len))
#define NLMSG_PAYLOAD(nlh,len) ((nlh)->nlmsg_len - NLMSG_SPACE((len)))

#define NLMSG_NOOP      0x1 /* Nothing.     */
#define NLMSG_ERROR     0x2 /* Error        */
#define NLMSG_DONE      0x3 /* End of a dump    */
#define NLMSG_OVERRUN       0x4 /* Data lost        */

#define NLMSG_MIN_TYPE      0x10    /* < 0x10: reserved control messages */

struct nlmsgerr {
    int     error;
    struct nlmsghdr msg;
};

#define NETLINK_ADD_MEMBERSHIP  1
#define NETLINK_DROP_MEMBERSHIP 2
#define NETLINK_PKTINFO     3
#define NETLINK_BROADCAST_ERROR 4
#define NETLINK_NO_ENOBUFS  5

struct nl_pktinfo {
    __u32   group;
};

#define NET_MAJOR 36        /* Major 36 is reserved for networking                      */

enum {
    NETLINK_UNCONNECTED = 0,
    NETLINK_CONNECTED,
};

/*
 *  <------- NLA_HDRLEN ------> <-- NLA_ALIGN(payload)-->
 * +---------------------+- - -+- - - - - - - - - -+- - -+
 * |        Header       | Pad |     Payload       | Pad |
 * |   (struct nlattr)   | ing |                   | ing |
 * +---------------------+- - -+- - - - - - - - - -+- - -+
 *  <-------------- nlattr->nla_len -------------->
 */

struct nlattr {
    __u16           nla_len;
    __u16           nla_type;
};

/*
 * nla_type (16 bits)
 * +---+---+-------------------------------+
 * | N | O | Attribute Type                |
 * +---+---+-------------------------------+
 * N := Carries nested attributes
 * O := Payload stored in network byte order
 *
 * Note: The N and O flag are mutually exclusive.
 */
#define NLA_F_NESTED        (1 << 15)
#define NLA_F_NET_BYTEORDER (1 << 14)
#define NLA_TYPE_MASK       ~(NLA_F_NESTED | NLA_F_NET_BYTEORDER)

#define NLA_ALIGNTO     4
#define NLA_ALIGN(len)      (((len) + NLA_ALIGNTO - 1) & ~(NLA_ALIGNTO - 1))
#define NLA_HDRLEN      ((int) NLA_ALIGN(sizeof(struct nlattr)))


#endif /* _UAPI__LINUX_NETLINK_H */