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
  30static inline struct udphdr *inner_udp_hdr(const struct sk_buff *skb)
  31{
  32        return (struct udphdr *)skb_inner_transport_header(skb);
  33}
  34
  35#define UDP_HTABLE_SIZE_MIN             (CONFIG_BASE_SMALL ? 128 : 256)
  36
  37static inline u32 udp_hashfn(const struct net *net, u32 num, u32 mask)
  38{
  39        return (num + net_hash_mix(net)) & mask;
  40}
  41
  42struct udp_sock {
  43        /* inet_sock has to be the first member */
  44        struct inet_sock inet;
  45#define udp_port_hash           inet.sk.__sk_common.skc_u16hashes[0]
  46#define udp_portaddr_hash       inet.sk.__sk_common.skc_u16hashes[1]
  47#define udp_portaddr_node       inet.sk.__sk_common.skc_portaddr_node
  48        int              pending;       /* Any pending frames ? */
  49        unsigned int     corkflag;      /* Cork is required */
  50        __u8             encap_type;    /* Is this an Encapsulation socket? */
  51        unsigned char    no_check6_tx:1,/* Send zero UDP6 checksums on TX? */
  52                         no_check6_rx:1;/* Allow zero UDP6 checksums on RX? */
  53        /*
  54         * Following member retains the information to create a UDP header
  55         * when the socket is uncorked.
  56         */
  57        __u16            len;           /* total length of pending frames */
  58        __u16            gso_size;
  59        /*
  60         * Fields specific to UDP-Lite.
  61         */
  62        __u16            pcslen;
  63        __u16            pcrlen;
  64/* indicator bits used by pcflag: */
  65#define UDPLITE_BIT      0x1            /* set by udplite proto init function */
  66#define UDPLITE_SEND_CC  0x2            /* set via udplite setsockopt         */
  67#define UDPLITE_RECV_CC  0x4            /* set via udplite setsocktopt        */
  68        __u8             pcflag;        /* marks socket as UDP-Lite if > 0    */
  69        __u8             unused[3];
  70        /*
  71         * For encapsulation sockets.
  72         */
  73        int (*encap_rcv)(struct sock *sk, struct sk_buff *skb);
  74        void (*encap_destroy)(struct sock *sk);
  75
  76        /* GRO functions for UDP socket */
  77        struct sk_buff **       (*gro_receive)(struct sock *sk,
  78                                               struct sk_buff **head,
  79                                               struct sk_buff *skb);
  80        int                     (*gro_complete)(struct sock *sk,
  81                                                struct sk_buff *skb,
  82                                                int nhoff);
  83
  84        /* udp_recvmsg try to use this before splicing sk_receive_queue */
  85        struct sk_buff_head     reader_queue ____cacheline_aligned_in_smp;
  86
  87        /* This field is dirtied by udp_recvmsg() */
  88        int             forward_deficit;
  89};
  90
  91#define UDP_MAX_SEGMENTS        (1 << 6UL)
  92
  93static inline struct udp_sock *udp_sk(const struct sock *sk)
  94{
  95        return (struct udp_sock *)sk;
  96}
  97
  98static inline void udp_set_no_check6_tx(struct sock *sk, bool val)
  99{
 100        udp_sk(sk)->no_check6_tx = val;
 101}
 102
 103static inline void udp_set_no_check6_rx(struct sock *sk, bool val)
 104{
 105        udp_sk(sk)->no_check6_rx = val;
 106}
 107
 108static inline bool udp_get_no_check6_tx(struct sock *sk)
 109{
 110        return udp_sk(sk)->no_check6_tx;
 111}
 112
 113static inline bool udp_get_no_check6_rx(struct sock *sk)
 114{
 115        return udp_sk(sk)->no_check6_rx;
 116}
 117
 118#define udp_portaddr_for_each_entry(__sk, list) \
 119        hlist_for_each_entry(__sk, list, __sk_common.skc_portaddr_node)
 120
 121#define udp_portaddr_for_each_entry_rcu(__sk, list) \
 122        hlist_for_each_entry_rcu(__sk, list, __sk_common.skc_portaddr_node)
 123
 124#define IS_UDPLITE(__sk) (__sk->sk_protocol == IPPROTO_UDPLITE)
 125
 126#endif  /* _LINUX_UDP_H */
 127