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  */
  41 struct 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
  53 extern struct hlist_head udp_hash[UDP_HTABLE_SIZE];
  54 extern rwlock_t udp_hash_lock;
  55
  56
  57 /* Note: this must match 'valbool' in sock_setsockopt */
  58 #define UDP_CSUM_NOXMIT         1
  59
  60 /* Used by SunRPC/xprt layer. */
  61 #define UDP_CSUM_NORCV          2
  62
  63 /* Default, as per the RFC, is to always do csums. */
  64 #define UDP_CSUM_DEFAULT        0
  65
  66 extern struct proto udp_prot;
  67
  68 struct sk_buff;
  69
  70 /*
  71  *      Generic checksumming routines for UDP(-Lite) v4 and v6
  72  */
  73 static inline __sum16 __udp_lib_checksum_complete(struct sk_buff *skb)
  74 {
  75         if (! UDP_SKB_CB(skb)->partial_cov)
  76                 return __skb_checksum_complete(skb);
  77         return csum_fold(skb_checksum(skb, 0, UDP_SKB_CB(skb)->cscov,
  78                                       skb->csum));
  79 }
  80
  81 static inline int udp_lib_checksum_complete(struct sk_buff *skb)
  82 {
  83         return skb->ip_summed != CHECKSUM_UNNECESSARY &&
  84                 __udp_lib_checksum_complete(skb);
  85 }
  86
  87 /**
  88  *      udp_csum_outgoing  -  compute UDPv4/v6 checksum over fragments
  89  *      @sk:    socket we are writing to
  90  *      @skb:   sk_buff containing the filled-in UDP header
  91  *              (checksum field must be zeroed out)
  92  */
  93 static inline __wsum udp_csum_outgoing(struct sock *sk, struct sk_buff *skb)
  94 {
  95         __wsum csum = csum_partial(skb->h.raw, sizeof(struct udphdr), 0);
  96
  97         skb_queue_walk(&sk->sk_write_queue, skb) {
  98                 csum = csum_add(csum, skb->csum);
  99         }
 100         return csum;
 101 }
 102
 103 /* hash routines shared between UDPv4/6 and UDP-Litev4/6 */
 104 static inline void udp_lib_hash(struct sock *sk)
 105 {
 106         BUG();
 107 }
 108
 109 static inline void udp_lib_unhash(struct sock *sk)
 110 {
 111         write_lock_bh(&udp_hash_lock);
 112         if (sk_del_node_init(sk)) {
 113                 inet_sk(sk)->num = 0;
 114                 sock_prot_dec_use(sk->sk_prot);
 115         }
 116         write_unlock_bh(&udp_hash_lock);
 117 }
 118
 119 static inline void udp_lib_close(struct sock *sk, long timeout)
 120 {
 121         sk_common_release(sk);
 122 }
 123
 124
 125 /* net/ipv4/udp.c */
 126 extern int      udp_get_port(struct sock *sk, unsigned short snum,
 127                              int (*saddr_cmp)(const struct sock *, const struct sock *));
 128 extern void     udp_err(struct sk_buff *, u32);
 129
 130 extern int      udp_sendmsg(struct kiocb *iocb, struct sock *sk,
 131                             struct msghdr *msg, size_t len);
 132
 133 extern int      udp_rcv(struct sk_buff *skb);
 134 extern int      udp_ioctl(struct sock *sk, int cmd, unsigned long arg);
 135 extern int      udp_disconnect(struct sock *sk, int flags);
 136 extern unsigned int udp_poll(struct file *file, struct socket *sock,
 137                              poll_table *wait);
 138 extern int      udp_lib_getsockopt(struct sock *sk, int level, int optname,
 139                                    char __user *optval, int __user *optlen);
 140 extern int      udp_lib_setsockopt(struct sock *sk, int level, int optname,
 141                                    char __user *optval, int optlen,
 142                                    int (*push_pending_frames)(struct sock *));
 143
 144 DECLARE_SNMP_STAT(struct udp_mib, udp_statistics);
 145 /*
 146  *      SNMP statistics for UDP and UDP-Lite
 147  */
 148 #define UDP_INC_STATS_USER(field, is_udplite)                          do {   \
 149         if (is_udplite) SNMP_INC_STATS_USER(udplite_statistics, field);       \
 150         else            SNMP_INC_STATS_USER(udp_statistics, field);  }  while(0)
 151 #define UDP_INC_STATS_BH(field, is_udplite)                            do  {  \
 152         if (is_udplite) SNMP_INC_STATS_BH(udplite_statistics, field);         \
 153         else            SNMP_INC_STATS_BH(udp_statistics, field);    }  while(0)
 154
 155 /* /proc */
 156 struct udp_seq_afinfo {
 157         struct module           *owner;
 158         char                    *name;
 159         sa_family_t             family;
 160         struct hlist_head       *hashtable;
 161         int                     (*seq_show) (struct seq_file *m, void *v);
 162         struct file_operations  *seq_fops;
 163 };
 164
 165 struct udp_iter_state {
 166         sa_family_t             family;
 167         struct hlist_head       *hashtable;
 168         int                     bucket;
 169         struct seq_operations   seq_ops;
 170 };
 171
 172 #ifdef CONFIG_PROC_FS
 173 extern int udp_proc_register(struct udp_seq_afinfo *afinfo);
 174 extern void udp_proc_unregister(struct udp_seq_afinfo *afinfo);
 175
 176 extern int  udp4_proc_init(void);
 177 extern void udp4_proc_exit(void);
 178 #endif
 179 #endif  /* _UDP_H */