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 */ 180