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 <net/inet_sock.h>
  21#include <linux/skbuff.h>
  22#include <net/netns/hash.h>
  23#include <uapi/linux/udp.h>
  24
  25static inline struct udphdr *udp_hdr(const struct sk_buff *skb)
  26{
  27        return (struct udphdr *)skb_transport_header(skb);
  28}
  29
  30#define UDP_HTABLE_SIZE_MIN             (CONFIG_BASE_SMALL ? 128 : 256)
  31
  32static inline int udp_hashfn(struct net *net, unsigned num, unsigned mask)
  33{
  34        return (num + net_hash_mix(net)) & mask;
  35}
  36
  37struct udp_sock {
  38        /* inet_sock has to be the first member */
  39        struct inet_sock inet;
  40#define udp_port_hash           inet.sk.__sk_common.skc_u16hashes[0]
  41#define udp_portaddr_hash       inet.sk.__sk_common.skc_u16hashes[1]
  42#define udp_portaddr_node       inet.sk.__sk_common.skc_portaddr_node
  43        int              pending;       /* Any pending frames ? */
  44        unsigned int     corkflag;      /* Cork is required */
  45        __u16            encap_type;    /* Is this an Encapsulation socket? */
  46        /*
  47         * Following member retains the information to create a UDP header
  48         * when the socket is uncorked.
  49         */
  50        __u16            len;           /* total length of pending frames */
  51        /*
  52         * Fields specific to UDP-Lite.
  53         */
  54        __u16            pcslen;
  55        __u16            pcrlen;
  56/* indicator bits used by pcflag: */
  57#define UDPLITE_BIT      0x1            /* set by udplite proto init function */
  58#define UDPLITE_SEND_CC  0x2            /* set via udplite setsockopt         */
  59#define UDPLITE_RECV_CC  0x4            /* set via udplite setsocktopt        */
  60        __u8             pcflag;        /* marks socket as UDP-Lite if > 0    */
  61        __u8             unused[3];
  62        /*
  63         * For encapsulation sockets.
  64         */
  65        int (*encap_rcv)(struct sock *sk, struct sk_buff *skb);
  66};
  67
  68static inline struct udp_sock *udp_sk(const struct sock *sk)
  69{
  70        return (struct udp_sock *)sk;
  71}
  72
  73#define udp_portaddr_for_each_entry(__sk, node, list) \
  74        hlist_nulls_for_each_entry(__sk, node, list, __sk_common.skc_portaddr_node)
  75
  76#define udp_portaddr_for_each_entry_rcu(__sk, node, list) \
  77        hlist_nulls_for_each_entry_rcu(__sk, node, list, __sk_common.skc_portaddr_node)
  78
  79#define IS_UDPLITE(__sk) (udp_sk(__sk)->pcflag)
  80
  81#endif  /* _LINUX_UDP_H */
  82