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 /**
  54  *      struct udp_hslot - UDP hash slot
  55  *
  56  *      @head:  head of list of sockets
  57  *      @count: number of sockets in 'head' list
  58  *      @lock:  spinlock protecting changes to head/count
  59  */
  60 struct udp_hslot {
  61         struct hlist_nulls_head head;
  62         int                     count;
  63         spinlock_t              lock;
  64 } __attribute__((aligned(2 * sizeof(long))));
  65
  66 struct udp_table {
  67         struct udp_hslot        *hash;
  68         unsigned int mask;
  69         unsigned int log;
  70 };
  71 extern struct udp_table udp_table;
  72 extern void udp_table_init(struct udp_table *, const char *);
  73 static inline struct udp_hslot *udp_hashslot(struct udp_table *table,
  74                                              struct net *net, unsigned num)
  75 {
  76         return &table->hash[udp_hashfn(net, num, table->mask)];
  77 }
  78
  79 /* Note: this must match 'valbool' in sock_setsockopt */
  80 #define UDP_CSUM_NOXMIT         1
  81
  82 /* Used by SunRPC/xprt layer. */
  83 #define UDP_CSUM_NORCV          2
  84
  85 /* Default, as per the RFC, is to always do csums. */
  86 #define UDP_CSUM_DEFAULT        0
  87
  88 extern struct proto udp_prot;
  89
  90 extern atomic_t udp_memory_allocated;
  91
  92 /* sysctl variables for udp */
  93 extern int sysctl_udp_mem[3];
  94 extern int sysctl_udp_rmem_min;
  95 extern int sysctl_udp_wmem_min;
  96
  97 struct sk_buff;
  98
  99 /*
 100  *      Generic checksumming routines for UDP(-Lite) v4 and v6
 101  */
 102 static inline __sum16 __udp_lib_checksum_complete(struct sk_buff *skb)
 103 {
 104         return __skb_checksum_complete_head(skb, UDP_SKB_CB(skb)->cscov);
 105 }
 106
 107 static inline int udp_lib_checksum_complete(struct sk_buff *skb)
 108 {
 109         return !skb_csum_unnecessary(skb) &&
 110                 __udp_lib_checksum_complete(skb);
 111 }
 112
 113 /**
 114  *      udp_csum_outgoing  -  compute UDPv4/v6 checksum over fragments
 115  *      @sk:    socket we are writing to
 116  *      @skb:   sk_buff containing the filled-in UDP header
 117  *              (checksum field must be zeroed out)
 118  */
 119 static inline __wsum udp_csum_outgoing(struct sock *sk, struct sk_buff *skb)
 120 {
 121         __wsum csum = csum_partial(skb_transport_header(skb),
 122                                    sizeof(struct udphdr), 0);
 123         skb_queue_walk(&sk->sk_write_queue, skb) {
 124                 csum = csum_add(csum, skb->csum);
 125         }
 126         return csum;
 127 }
 128
 129 /* hash routines shared between UDPv4/6 and UDP-Litev4/6 */
 130 static inline void udp_lib_hash(struct sock *sk)
 131 {
 132         BUG();
 133 }
 134
 135 extern void udp_lib_unhash(struct sock *sk);
 136
 137 static inline void udp_lib_close(struct sock *sk, long timeout)
 138 {
 139         sk_common_release(sk);
 140 }
 141
 142 extern int      udp_lib_get_port(struct sock *sk, unsigned short snum,
 143                 int (*)(const struct sock*,const struct sock*));
 144
 145 /* net/ipv4/udp.c */
 146 extern int      udp_get_port(struct sock *sk, unsigned short snum,
 147                              int (*saddr_cmp)(const struct sock *, const struct sock *));
 148 extern void     udp_err(struct sk_buff *, u32);
 149
 150 extern int      udp_sendmsg(struct kiocb *iocb, struct sock *sk,
 151                             struct msghdr *msg, size_t len);
 152 extern void     udp_flush_pending_frames(struct sock *sk);
 153
 154 extern int      udp_rcv(struct sk_buff *skb);
 155 extern int      udp_ioctl(struct sock *sk, int cmd, unsigned long arg);
 156 extern int      udp_disconnect(struct sock *sk, int flags);
 157 extern unsigned int udp_poll(struct file *file, struct socket *sock,
 158                              poll_table *wait);
 159 extern int      udp_lib_getsockopt(struct sock *sk, int level, int optname,
 160                                    char __user *optval, int __user *optlen);
 161 extern int      udp_lib_setsockopt(struct sock *sk, int level, int optname,
 162                                    char __user *optval, unsigned int optlen,
 163                                    int (*push_pending_frames)(struct sock *));
 164
 165 extern struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport,
 166                                     __be32 daddr, __be16 dport,
 167                                     int dif);
 168
 169 /*
 170  *      SNMP statistics for UDP and UDP-Lite
 171  */
 172 #define UDP_INC_STATS_USER(net, field, is_udplite)            do { \
 173         if (is_udplite) SNMP_INC_STATS_USER((net)->mib.udplite_statistics, field);       \
 174         else            SNMP_INC_STATS_USER((net)->mib.udp_statistics, field);  }  while(0)
 175 #define UDP_INC_STATS_BH(net, field, is_udplite)              do { \
 176         if (is_udplite) SNMP_INC_STATS_BH((net)->mib.udplite_statistics, field);         \
 177         else            SNMP_INC_STATS_BH((net)->mib.udp_statistics, field);    }  while(0)
 178
 179 #define UDP6_INC_STATS_BH(net, field, is_udplite)           do { \
 180         if (is_udplite) SNMP_INC_STATS_BH((net)->mib.udplite_stats_in6, field);\
 181         else            SNMP_INC_STATS_BH((net)->mib.udp_stats_in6, field);  \
 182 } while(0)
 183 #define UDP6_INC_STATS_USER(net, field, __lite)             do { \
 184         if (__lite) SNMP_INC_STATS_USER((net)->mib.udplite_stats_in6, field);  \
 185         else        SNMP_INC_STATS_USER((net)->mib.udp_stats_in6, field);      \
 186 } while(0)
 187
 188 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
 189 #define UDPX_INC_STATS_BH(sk, field) \
 190         do { \
 191                 if ((sk)->sk_family == AF_INET) \
 192                         UDP_INC_STATS_BH(sock_net(sk), field, 0); \
 193                 else \
 194                         UDP6_INC_STATS_BH(sock_net(sk), field, 0); \
 195         } while (0);
 196 #else
 197 #define UDPX_INC_STATS_BH(sk, field) UDP_INC_STATS_BH(sock_net(sk), field, 0)
 198 #endif
 199
 200 /* /proc */
 201 struct udp_seq_afinfo {
 202         char                    *name;
 203         sa_family_t             family;
 204         struct udp_table        *udp_table;
 205         struct file_operations  seq_fops;
 206         struct seq_operations   seq_ops;
 207 };
 208
 209 struct udp_iter_state {
 210         struct seq_net_private  p;
 211         sa_family_t             family;
 212         int                     bucket;
 213         struct udp_table        *udp_table;
 214 };
 215
 216 #ifdef CONFIG_PROC_FS
 217 extern int udp_proc_register(struct net *net, struct udp_seq_afinfo *afinfo);
 218 extern void udp_proc_unregister(struct net *net, struct udp_seq_afinfo *afinfo);
 219
 220 extern int  udp4_proc_init(void);
 221 extern void udp4_proc_exit(void);
 222 #endif
 223
 224 extern void udp_init(void);
 225
 226 extern int udp4_ufo_send_check(struct sk_buff *skb);
 227 extern struct sk_buff *udp4_ufo_fragment(struct sk_buff *skb, int features);
 228 #endif  /* _UDP_H */