LXR linux/include/linux/udp.h

   1/*
   2 * INET         An implementation of the TCP/IP protocol suite for the LINUX
   3 *              operating system.  INET is implemented using the  BSD Socket
   4 *              interface as the means of communication with the user level.
   5 *
   6 *              Definitions for the UDP protocol.
   7 *
   8 * Version:     @(#)udp.h       1.0.2   04/28/93
   9 *
  10 * Author:      Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
  11 *
  12 *              This program is free software; you can redistribute it and/or
  13 *              modify it under the terms of the GNU General Public License
  14 *              as published by the Free Software Foundation; either version
  15 *              2 of the License, or (at your option) any later version.
  16 */
  17#ifndef _LINUX_UDP_H
  18#define _LINUX_UDP_H
  19
  20#include <linux/types.h>
  21
  22struct udphdr {
  23        __be16  source;
  24        __be16  dest;
  25        __be16  len;
  26        __sum16 check;
  27};
  28
  29/* UDP socket options */
  30#define UDP_CORK        1       /* Never send partially complete segments */
  31#define UDP_ENCAP       100     /* Set the socket to accept encapsulated packets */
  32
  33/* UDP encapsulation types */
  34#define UDP_ENCAP_ESPINUDP_NON_IKE      1 /* draft-ietf-ipsec-nat-t-ike-00/01 */
  35#define UDP_ENCAP_ESPINUDP      2 /* draft-ietf-ipsec-udp-encaps-06 */
  36#define UDP_ENCAP_L2TPINUDP     3 /* rfc2661 */
  37
  38#ifdef __KERNEL__
  39#include <net/inet_sock.h>
  40#include <linux/skbuff.h>
  41#include <net/netns/hash.h>
  42
  43static inline struct udphdr *udp_hdr(const struct sk_buff *skb)
  44{
  45        return (struct udphdr *)skb_transport_header(skb);
  46}
  47
  48#define UDP_HTABLE_SIZE         128
  49
  50static inline int udp_hashfn(struct net *net, const unsigned num)
  51{
  52        return (num + net_hash_mix(net)) & (UDP_HTABLE_SIZE - 1);
  53}
  54
  55struct udp_sock {
  56        /* inet_sock has to be the first member */
  57        struct inet_sock inet;
  58        int              pending;       /* Any pending frames ? */
  59        unsigned int     corkflag;      /* Cork is required */
  60        __u16            encap_type;    /* Is this an Encapsulation socket? */
  61        /*
  62         * Following member retains the information to create a UDP header
  63         * when the socket is uncorked.
  64         */
  65        __u16            len;           /* total length of pending frames */
  66        /*
  67         * Fields specific to UDP-Lite.
  68         */
  69        __u16            pcslen;
  70        __u16            pcrlen;
  71/* indicator bits used by pcflag: */
  72#define UDPLITE_BIT      0x1            /* set by udplite proto init function */
  73#define UDPLITE_SEND_CC  0x2            /* set via udplite setsockopt         */
  74#define UDPLITE_RECV_CC  0x4            /* set via udplite setsocktopt        */
  75        __u8             pcflag;        /* marks socket as UDP-Lite if > 0    */
  76        __u8             unused[3];
  77        /*
  78         * For encapsulation sockets.
  79         */
  80        int (*encap_rcv)(struct sock *sk, struct sk_buff *skb);
  81};
  82
  83static inline struct udp_sock *udp_sk(const struct sock *sk)
  84{
  85        return (struct udp_sock *)sk;
  86}
  87
  88#define IS_UDPLITE(__sk) (udp_sk(__sk)->pcflag)
  89
  90#endif
  91
  92#endif  /* _LINUX_UDP_H */
  93