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 extern atomic_t udp_memory_allocated;
  69
  70 /* sysctl variables for udp */
  71 extern int sysctl_udp_mem[3];
  72 extern int sysctl_udp_rmem_min;
  73 extern int sysctl_udp_wmem_min;
  74
  75 struct sk_buff;
  76
  77 /*
  78  *      Generic checksumming routines for UDP(-Lite) v4 and v6
  79  */
  80 static inline __sum16 __udp_lib_checksum_complete(struct sk_buff *skb)
  81 {
  82         return __skb_checksum_complete_head(skb, UDP_SKB_CB(skb)->cscov);
  83 }
  84
  85 static inline int udp_lib_checksum_complete(struct sk_buff *skb)
  86 {
  87         return !skb_csum_unnecessary(skb) &&
  88                 __udp_lib_checksum_complete(skb);
  89 }
  90
  91 /**
  92  *      udp_csum_outgoing  -  compute UDPv4/v6 checksum over fragments
  93  *      @sk:    socket we are writing to
  94  *      @skb:   sk_buff containing the filled-in UDP header
  95  *              (checksum field must be zeroed out)
  96  */
  97 static inline __wsum udp_csum_outgoing(struct sock *sk, struct sk_buff *skb)
  98 {
  99         __wsum csum = csum_partial(skb_transport_header(skb),
 100                                    sizeof(struct udphdr), 0);
 101         skb_queue_walk(&sk->sk_write_queue, skb) {
 102                 csum = csum_add(csum, skb->csum);
 103         }
 104         return csum;
 105 }
 106
 107 /* hash routines shared between UDPv4/6 and UDP-Litev4/6 */
 108 static inline void udp_lib_hash(struct sock *sk)
 109 {
 110         BUG();
 111 }
 112
 113 static inline void udp_lib_unhash(struct sock *sk)
 114 {
 115         write_lock_bh(&udp_hash_lock);
 116         if (sk_del_node_init(sk)) {
 117                 inet_sk(sk)->num = 0;
 118                 sock_prot_inuse_add(sk->sk_prot, -1);
 119         }
 120         write_unlock_bh(&udp_hash_lock);
 121 }
 122
 123 static inline void udp_lib_close(struct sock *sk, long timeout)
 124 {
 125         sk_common_release(sk);
 126 }
 127
 128
 129 /* net/ipv4/udp.c */
 130 extern int      udp_get_port(struct sock *sk, unsigned short snum,
 131                              int (*saddr_cmp)(const struct sock *, const struct sock *));
 132 extern void     udp_err(struct sk_buff *, u32);
 133
 134 extern int      udp_sendmsg(struct kiocb *iocb, struct sock *sk,
 135                             struct msghdr *msg, size_t len);
 136
 137 extern int      udp_rcv(struct sk_buff *skb);
 138 extern int      udp_ioctl(struct sock *sk, int cmd, unsigned long arg);
 139 extern int      udp_disconnect(struct sock *sk, int flags);
 140 extern unsigned int udp_poll(struct file *file, struct socket *sock,
 141                              poll_table *wait);
 142 extern int      udp_lib_getsockopt(struct sock *sk, int level, int optname,
 143                                    char __user *optval, int __user *optlen);
 144 extern int      udp_lib_setsockopt(struct sock *sk, int level, int optname,
 145                                    char __user *optval, int optlen,
 146                                    int (*push_pending_frames)(struct sock *));
 147
 148 DECLARE_SNMP_STAT(struct udp_mib, udp_statistics);
 149 DECLARE_SNMP_STAT(struct udp_mib, udp_stats_in6);
 150
 151 /* UDP-Lite does not have a standardized MIB yet, so we inherit from UDP */
 152 DECLARE_SNMP_STAT(struct udp_mib, udplite_statistics);
 153 DECLARE_SNMP_STAT(struct udp_mib, udplite_stats_in6);
 154
 155 /*
 156  *      SNMP statistics for UDP and UDP-Lite
 157  */
 158 #define UDP_INC_STATS_USER(field, is_udplite)                          do {   \
 159         if (is_udplite) SNMP_INC_STATS_USER(udplite_statistics, field);       \
 160         else            SNMP_INC_STATS_USER(udp_statistics, field);  }  while(0)
 161 #define UDP_INC_STATS_BH(field, is_udplite)                            do  {  \
 162         if (is_udplite) SNMP_INC_STATS_BH(udplite_statistics, field);         \
 163         else            SNMP_INC_STATS_BH(udp_statistics, field);    }  while(0)
 164
 165 #define UDP6_INC_STATS_BH(field, is_udplite)                          do  {  \
 166         if (is_udplite) SNMP_INC_STATS_BH(udplite_stats_in6, field);         \
 167         else            SNMP_INC_STATS_BH(udp_stats_in6, field);    } while(0)
 168 #define UDP6_INC_STATS_USER(field, is_udplite)                         do {    \
 169         if (is_udplite) SNMP_INC_STATS_USER(udplite_stats_in6, field);         \
 170         else            SNMP_INC_STATS_USER(udp_stats_in6, field);    } while(0)
 171
 172 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
 173 #define UDPX_INC_STATS_BH(sk, field) \
 174         do { \
 175                 if ((sk)->sk_family == AF_INET) \
 176                         UDP_INC_STATS_BH(field, 0); \
 177                 else \
 178                         UDP6_INC_STATS_BH(field, 0); \
 179         } while (0);
 180 #else
 181 #define UDPX_INC_STATS_BH(sk, field) UDP_INC_STATS_BH(field, 0)
 182 #endif
 183
 184 /* /proc */
 185 struct udp_seq_afinfo {
 186         struct module           *owner;
 187         char                    *name;
 188         sa_family_t             family;
 189         struct hlist_head       *hashtable;
 190         int                     (*seq_show) (struct seq_file *m, void *v);
 191         struct file_operations  *seq_fops;
 192 };
 193
 194 struct udp_iter_state {
 195         sa_family_t             family;
 196         struct hlist_head       *hashtable;
 197         int                     bucket;
 198         struct seq_operations   seq_ops;
 199 };
 200
 201 #ifdef CONFIG_PROC_FS
 202 extern int udp_proc_register(struct udp_seq_afinfo *afinfo);
 203 extern void udp_proc_unregister(struct udp_seq_afinfo *afinfo);
 204
 205 extern int  udp4_proc_init(void);
 206 extern void udp4_proc_exit(void);
 207 #endif
 208
 209 extern void udp_init(void);
 210 #endif  /* _UDP_H */