LXR linux/include/net/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 module.
   7 *
   8 * Version:     @(#)udp.h       1.0.2   05/07/93
   9 *
  10 * Authors:     Ross Biro
  11 *              Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
  12 *
  13 * Fixes:
  14 *              Alan Cox        : Turned on udp checksums. I don't want to
  15 *                                chase 'memory corruption' bugs that aren't!
  16 *
  17 *              This program is free software; you can redistribute it and/or
  18 *              modify it under the terms of the GNU General Public License
  19 *              as published by the Free Software Foundation; either version
  20 *              2 of the License, or (at your option) any later version.
  21 */
  22#ifndef _UDP_H
  23#define _UDP_H
  24
  25#include <linux/list.h>
  26#include <net/inet_sock.h>
  27#include <net/sock.h>
  28#include <net/snmp.h>
  29#include <net/ip.h>
  30#include <linux/ipv6.h>
  31#include <linux/seq_file.h>
  32#include <linux/poll.h>
  33
  34/**
  35 *      struct udp_skb_cb  -  UDP(-Lite) private variables
  36 *
  37 *      @header:      private variables used by IPv4/IPv6
  38 *      @cscov:       checksum coverage length (UDP-Lite only)
  39 *      @partial_cov: if set indicates partial csum coverage
  40 */
  41struct udp_skb_cb {
  42        union {
  43                struct inet_skb_parm    h4;
  44#if defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE)
  45                struct inet6_skb_parm   h6;
  46#endif
  47        } header;
  48        __u16           cscov;
  49        __u8            partial_cov;
  50};
  51#define UDP_SKB_CB(__skb)       ((struct udp_skb_cb *)((__skb)->cb))
  52
  53struct udp_hslot {
  54        struct hlist_nulls_head head;
  55        spinlock_t              lock;
  56} __attribute__((aligned(2 * sizeof(long))));
  57struct udp_table {
  58        struct udp_hslot        hash[UDP_HTABLE_SIZE];
  59};
  60extern struct udp_table udp_table;
  61extern void udp_table_init(struct udp_table *);
  62
  63
  64/* Note: this must match 'valbool' in sock_setsockopt */
  65#define UDP_CSUM_NOXMIT         1
  66
  67/* Used by SunRPC/xprt layer. */
  68#define UDP_CSUM_NORCV          2
  69
  70/* Default, as per the RFC, is to always do csums. */
  71#define UDP_CSUM_DEFAULT        0
  72
  73extern struct proto udp_prot;
  74
  75extern atomic_t udp_memory_allocated;
  76
  77/* sysctl variables for udp */
  78extern int sysctl_udp_mem[3];
  79extern int sysctl_udp_rmem_min;
  80extern int sysctl_udp_wmem_min;
  81
  82struct sk_buff;
  83
  84/*
  85 *      Generic checksumming routines for UDP(-Lite) v4 and v6
  86 */
  87static inline __sum16 __udp_lib_checksum_complete(struct sk_buff *skb)
  88{
  89        return __skb_checksum_complete_head(skb, UDP_SKB_CB(skb)->cscov);
  90}
  91
  92static inline int udp_lib_checksum_complete(struct sk_buff *skb)
  93{
  94        return !skb_csum_unnecessary(skb) &&
  95                __udp_lib_checksum_complete(skb);
  96}
  97
  98/**
  99 *      udp_csum_outgoing  -  compute UDPv4/v6 checksum over fragments
 100 *      @sk:    socket we are writing to
 101 *      @skb:   sk_buff containing the filled-in UDP header
 102 *              (checksum field must be zeroed out)
 103 */
 104static inline __wsum udp_csum_outgoing(struct sock *sk, struct sk_buff *skb)
 105{
 106        __wsum csum = csum_partial(skb_transport_header(skb),
 107                                   sizeof(struct udphdr), 0);
 108        skb_queue_walk(&sk->sk_write_queue, skb) {
 109                csum = csum_add(csum, skb->csum);
 110        }
 111        return csum;
 112}
 113
 114/* hash routines shared between UDPv4/6 and UDP-Litev4/6 */
 115static inline void udp_lib_hash(struct sock *sk)
 116{
 117        BUG();
 118}
 119
 120extern void udp_lib_unhash(struct sock *sk);
 121
 122static inline void udp_lib_close(struct sock *sk, long timeout)
 123{
 124        sk_common_release(sk);
 125}
 126
 127extern int      udp_lib_get_port(struct sock *sk, unsigned short snum,
 128                int (*)(const struct sock*,const struct sock*));
 129
 130/* net/ipv4/udp.c */
 131extern int      udp_get_port(struct sock *sk, unsigned short snum,
 132                             int (*saddr_cmp)(const struct sock *, const struct sock *));
 133extern void     udp_err(struct sk_buff *, u32);
 134
 135extern int      udp_sendmsg(struct kiocb *iocb, struct sock *sk,
 136                            struct msghdr *msg, size_t len);
 137extern void     udp_flush_pending_frames(struct sock *sk);
 138
 139extern int      udp_rcv(struct sk_buff *skb);
 140extern int      udp_ioctl(struct sock *sk, int cmd, unsigned long arg);
 141extern int      udp_disconnect(struct sock *sk, int flags);
 142extern unsigned int udp_poll(struct file *file, struct socket *sock,
 143                             poll_table *wait);
 144extern int      udp_lib_getsockopt(struct sock *sk, int level, int optname,
 145                                   char __user *optval, int __user *optlen);
 146extern int      udp_lib_setsockopt(struct sock *sk, int level, int optname,
 147                                   char __user *optval, unsigned int optlen,
 148                                   int (*push_pending_frames)(struct sock *));
 149
 150extern struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport,
 151                                    __be32 daddr, __be16 dport,
 152                                    int dif);
 153
 154/*
 155 *      SNMP statistics for UDP and UDP-Lite
 156 */
 157#define UDP_INC_STATS_USER(net, field, is_udplite)            do { \
 158        if (is_udplite) SNMP_INC_STATS_USER((net)->mib.udplite_statistics, field);       \
 159        else            SNMP_INC_STATS_USER((net)->mib.udp_statistics, field);  }  while(0)
 160#define UDP_INC_STATS_BH(net, field, is_udplite)              do { \
 161        if (is_udplite) SNMP_INC_STATS_BH((net)->mib.udplite_statistics, field);         \
 162        else            SNMP_INC_STATS_BH((net)->mib.udp_statistics, field);    }  while(0)
 163
 164#define UDP6_INC_STATS_BH(net, field, is_udplite)           do { \
 165        if (is_udplite) SNMP_INC_STATS_BH((net)->mib.udplite_stats_in6, field);\
 166        else            SNMP_INC_STATS_BH((net)->mib.udp_stats_in6, field);  \
 167} while(0)
 168#define UDP6_INC_STATS_USER(net, field, __lite)             do { \
 169        if (__lite) SNMP_INC_STATS_USER((net)->mib.udplite_stats_in6, field);  \
 170        else        SNMP_INC_STATS_USER((net)->mib.udp_stats_in6, field);      \
 171} while(0)
 172
 173#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
 174#define UDPX_INC_STATS_BH(sk, field) \
 175        do { \
 176                if ((sk)->sk_family == AF_INET) \
 177                        UDP_INC_STATS_BH(sock_net(sk), field, 0); \
 178                else \
 179                        UDP6_INC_STATS_BH(sock_net(sk), field, 0); \
 180        } while (0);
 181#else
 182#define UDPX_INC_STATS_BH(sk, field) UDP_INC_STATS_BH(sock_net(sk), field, 0)
 183#endif
 184
 185/* /proc */
 186struct udp_seq_afinfo {
 187        char                    *name;
 188        sa_family_t             family;
 189        struct udp_table        *udp_table;
 190        struct file_operations  seq_fops;
 191        struct seq_operations   seq_ops;
 192};
 193
 194struct udp_iter_state {
 195        struct seq_net_private  p;
 196        sa_family_t             family;
 197        int                     bucket;
 198        struct udp_table        *udp_table;
 199};
 200
 201#ifdef CONFIG_PROC_FS
 202extern int udp_proc_register(struct net *net, struct udp_seq_afinfo *afinfo);
 203extern void udp_proc_unregister(struct net *net, struct udp_seq_afinfo *afinfo);
 204
 205extern int  udp4_proc_init(void);
 206extern void udp4_proc_exit(void);
 207#endif
 208
 209extern void udp_init(void);
 210
 211extern int udp4_ufo_send_check(struct sk_buff *skb);
 212extern struct sk_buff *udp4_ufo_fragment(struct sk_buff *skb, int features);
 213#endif  /* _UDP_H */
 214