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
  33 /**
  34  *      struct udp_skb_cb  -  UDP(-Lite) private variables
  35  *
  36  *      @header:      private variables used by IPv4/IPv6
  37  *      @cscov:       checksum coverage length (UDP-Lite only)
  38  *      @partial_cov: if set indicates partial csum coverage
  39  */
  40 struct udp_skb_cb {
  41         union {
  42                 struct inet_skb_parm    h4;
  43 #if defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE)
  44                 struct inet6_skb_parm   h6;
  45 #endif
  46         } header;
  47         __u16           cscov;
  48         __u8            partial_cov;
  49 };
  50 #define UDP_SKB_CB(__skb)       ((struct udp_skb_cb *)((__skb)->cb))
  51
  52 extern struct hlist_head udp_hash[UDP_HTABLE_SIZE];
  53 extern rwlock_t udp_hash_lock;
  54
  55
  56 /* Note: this must match 'valbool' in sock_setsockopt */
  57 #define UDP_CSUM_NOXMIT         1
  58
  59 /* Used by SunRPC/xprt layer. */
  60 #define UDP_CSUM_NORCV          2
  61
  62 /* Default, as per the RFC, is to always do csums. */
  63 #define UDP_CSUM_DEFAULT        0
  64
  65 extern struct proto udp_prot;
  66
  67 struct sk_buff;
  68
  69 /*
  70  *      Generic checksumming routines for UDP(-Lite) v4 and v6
  71  */
  72 static inline u16  __udp_lib_checksum_complete(struct sk_buff *skb)
  73 {
  74         if (! UDP_SKB_CB(skb)->partial_cov)
  75                 return __skb_checksum_complete(skb);
  76         return  csum_fold(skb_checksum(skb, 0, UDP_SKB_CB(skb)->cscov,
  77                           skb->csum));
  78 }
  79
  80 static __inline__ int udp_lib_checksum_complete(struct sk_buff *skb)
  81 {
  82         return skb->ip_summed != CHECKSUM_UNNECESSARY &&
  83                 __udp_lib_checksum_complete(skb);
  84 }
  85
  86 /**
  87  *      udp_csum_outgoing  -  compute UDPv4/v6 checksum over fragments
  88  *      @sk:    socket we are writing to
  89  *      @skb:   sk_buff containing the filled-in UDP header
  90  *              (checksum field must be zeroed out)
  91  */
  92 static inline __wsum udp_csum_outgoing(struct sock *sk, struct sk_buff *skb)
  93 {
  94         __wsum csum = csum_partial(skb->h.raw, sizeof(struct udphdr), 0);
  95
  96         skb_queue_walk(&sk->sk_write_queue, skb) {
  97                 csum = csum_add(csum, skb->csum);
  98         }
  99         return csum;
 100 }
 101
 102 /* hash routines shared between UDPv4/6 and UDP-Litev4/6 */
 103 static inline void udp_lib_hash(struct sock *sk)
 104 {
 105         BUG();
 106 }
 107
 108 static inline void udp_lib_unhash(struct sock *sk)
 109 {
 110         write_lock_bh(&udp_hash_lock);
 111         if (sk_del_node_init(sk)) {
 112                 inet_sk(sk)->num = 0;
 113                 sock_prot_dec_use(sk->sk_prot);
 114         }
 115         write_unlock_bh(&udp_hash_lock);
 116 }
 117
 118 static inline void udp_lib_close(struct sock *sk, long timeout)
 119 {
 120         sk_common_release(sk);
 121 }
 122
 123
 124 /* net/ipv4/udp.c */
 125 extern int      udp_get_port(struct sock *sk, unsigned short snum,
 126                              int (*saddr_cmp)(const struct sock *, const struct sock *));
 127 extern void     udp_err(struct sk_buff *, u32);
 128
 129 extern int      udp_sendmsg(struct kiocb *iocb, struct sock *sk,
 130                             struct msghdr *msg, size_t len);
 131
 132 extern int      udp_rcv(struct sk_buff *skb);
 133 extern int      udp_ioctl(struct sock *sk, int cmd, unsigned long arg);
 134 extern int      udp_disconnect(struct sock *sk, int flags);
 135 extern unsigned int udp_poll(struct file *file, struct socket *sock,
 136                              poll_table *wait);
 137
 138 DECLARE_SNMP_STAT(struct udp_mib, udp_statistics);
 139 /*
 140  *      SNMP statistics for UDP and UDP-Lite
 141  */
 142 #define UDP_INC_STATS_USER(field, is_udplite)                          do {   \
 143         if (is_udplite) SNMP_INC_STATS_USER(udplite_statistics, field);       \
 144         else            SNMP_INC_STATS_USER(udp_statistics, field);  }  while(0)
 145 #define UDP_INC_STATS_BH(field, is_udplite)                            do  {  \
 146         if (is_udplite) SNMP_INC_STATS_BH(udplite_statistics, field);         \
 147         else            SNMP_INC_STATS_BH(udp_statistics, field);    }  while(0)
 148
 149 /* /proc */
 150 struct udp_seq_afinfo {
 151         struct module           *owner;
 152         char                    *name;
 153         sa_family_t             family;
 154         struct hlist_head       *hashtable;
 155         int                     (*seq_show) (struct seq_file *m, void *v);
 156         struct file_operations  *seq_fops;
 157 };
 158
 159 struct udp_iter_state {
 160         sa_family_t             family;
 161         struct hlist_head       *hashtable;
 162         int                     bucket;
 163         struct seq_operations   seq_ops;
 164 };
 165
 166 #ifdef CONFIG_PROC_FS
 167 extern int udp_proc_register(struct udp_seq_afinfo *afinfo);
 168 extern void udp_proc_unregister(struct udp_seq_afinfo *afinfo);
 169
 170 extern int  udp4_proc_init(void);
 171 extern void udp4_proc_exit(void);
 172 #endif
 173 #endif  /* _UDP_H */