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
  22 struct 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
  43 static 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
  50 static inline int udp_hashfn(struct net *net, const unsigned num)
  51 {
  52         return (num + net_hash_mix(net)) & (UDP_HTABLE_SIZE - 1);
  53 }
  54
  55 struct 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
  83 static 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 */