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 /** 67 * struct udp_table - UDP table 68 * 69 * @hash: hash table, sockets are hashed on (local port) 70 * @hash2: hash table, sockets are hashed on (local port, local address) 71 * @mask: number of slots in hash tables, minus 1 72 * @log: log2(number of slots in hash table) 73 */ 74 struct udp_table { 75 struct udp_hslot *hash; 76 struct udp_hslot *hash2; 77 unsigned int mask; 78 unsigned int log; 79 }; 80 extern struct udp_table udp_table; 81 extern void udp_table_init(struct udp_table *, const char *); 82 static inline struct udp_hslot *udp_hashslot(struct udp_table *table, 83 struct net *net, unsigned num) 84 { 85 return &table->hash[udp_hashfn(net, num, table->mask)]; 86 } 87 /* 88 * For secondary hash, net_hash_mix() is performed before calling 89 * udp_hashslot2(), this explains difference with udp_hashslot() 90 */ 91 static inline struct udp_hslot *udp_hashslot2(struct udp_table *table, 92 unsigned int hash) 93 { 94 return &table->hash2[hash & table->mask]; 95 } 96 97 /* Note: this must match 'valbool' in sock_setsockopt */ 98 #define UDP_CSUM_NOXMIT 1 99 100 /* Used by SunRPC/xprt layer. */ 101 #define UDP_CSUM_NORCV 2 102 103 /* Default, as per the RFC, is to always do csums. */ 104 #define UDP_CSUM_DEFAULT 0 105 106 extern struct proto udp_prot; 107 108 extern atomic_t udp_memory_allocated; 109 110 /* sysctl variables for udp */ 111 extern int sysctl_udp_mem[3]; 112 extern int sysctl_udp_rmem_min; 113 extern int sysctl_udp_wmem_min; 114 115 struct sk_buff; 116 117 /* 118 * Generic checksumming routines for UDP(-Lite) v4 and v6 119 */ 120 static inline __sum16 __udp_lib_checksum_complete(struct sk_buff *skb) 121 { 122 return __skb_checksum_complete_head(skb, UDP_SKB_CB(skb)->cscov); 123 } 124 125 static inline int udp_lib_checksum_complete(struct sk_buff *skb) 126 { 127 return !skb_csum_unnecessary(skb) && 128 __udp_lib_checksum_complete(skb); 129 } 130 131 /** 132 * udp_csum_outgoing - compute UDPv4/v6 checksum over fragments 133 * @sk: socket we are writing to 134 * @skb: sk_buff containing the filled-in UDP header 135 * (checksum field must be zeroed out) 136 */ 137 static inline __wsum udp_csum_outgoing(struct sock *sk, struct sk_buff *skb) 138 { 139 __wsum csum = csum_partial(skb_transport_header(skb), 140 sizeof(struct udphdr), 0); 141 skb_queue_walk(&sk->sk_write_queue, skb) { 142 csum = csum_add(csum, skb->csum); 143 } 144 return csum; 145 } 146 147 /* hash routines shared between UDPv4/6 and UDP-Litev4/6 */ 148 static inline void udp_lib_hash(struct sock *sk) 149 { 150 BUG(); 151 } 152 153 extern void udp_lib_unhash(struct sock *sk); 154 155 static inline void udp_lib_close(struct sock *sk, long timeout) 156 { 157 sk_common_release(sk); 158 } 159 160 extern int udp_lib_get_port(struct sock *sk, unsigned short snum, 161 int (*)(const struct sock *,const struct sock *), 162 unsigned int hash2_nulladdr); 163 164 /* net/ipv4/udp.c */ 165 extern int udp_get_port(struct sock *sk, unsigned short snum, 166 int (*saddr_cmp)(const struct sock *, const struct sock *)); 167 extern void udp_err(struct sk_buff *, u32); 168 169 extern int udp_sendmsg(struct kiocb *iocb, struct sock *sk, 170 struct msghdr *msg, size_t len); 171 extern void udp_flush_pending_frames(struct sock *sk); 172 173 extern int udp_rcv(struct sk_buff *skb); 174 extern int udp_ioctl(struct sock *sk, int cmd, unsigned long arg); 175 extern int udp_disconnect(struct sock *sk, int flags); 176 extern unsigned int udp_poll(struct file *file, struct socket *sock, 177 poll_table *wait); 178 extern int udp_lib_getsockopt(struct sock *sk, int level, int optname, 179 char __user *optval, int __user *optlen); 180 extern int udp_lib_setsockopt(struct sock *sk, int level, int optname, 181 char __user *optval, unsigned int optlen, 182 int (*push_pending_frames)(struct sock *)); 183 184 extern struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport, 185 __be32 daddr, __be16 dport, 186 int dif); 187 188 /* 189 * SNMP statistics for UDP and UDP-Lite 190 */ 191 #define UDP_INC_STATS_USER(net, field, is_udplite) do { \ 192 if (is_udplite) SNMP_INC_STATS_USER((net)->mib.udplite_statistics, field); \ 193 else SNMP_INC_STATS_USER((net)->mib.udp_statistics, field); } while(0) 194 #define UDP_INC_STATS_BH(net, field, is_udplite) do { \ 195 if (is_udplite) SNMP_INC_STATS_BH((net)->mib.udplite_statistics, field); \ 196 else SNMP_INC_STATS_BH((net)->mib.udp_statistics, field); } while(0) 197 198 #define UDP6_INC_STATS_BH(net, field, is_udplite) do { \ 199 if (is_udplite) SNMP_INC_STATS_BH((net)->mib.udplite_stats_in6, field);\ 200 else SNMP_INC_STATS_BH((net)->mib.udp_stats_in6, field); \ 201 } while(0) 202 #define UDP6_INC_STATS_USER(net, field, __lite) do { \ 203 if (__lite) SNMP_INC_STATS_USER((net)->mib.udplite_stats_in6, field); \ 204 else SNMP_INC_STATS_USER((net)->mib.udp_stats_in6, field); \ 205 } while(0) 206 207 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 208 #define UDPX_INC_STATS_BH(sk, field) \ 209 do { \ 210 if ((sk)->sk_family == AF_INET) \ 211 UDP_INC_STATS_BH(sock_net(sk), field, 0); \ 212 else \ 213 UDP6_INC_STATS_BH(sock_net(sk), field, 0); \ 214 } while (0); 215 #else 216 #define UDPX_INC_STATS_BH(sk, field) UDP_INC_STATS_BH(sock_net(sk), field, 0) 217 #endif 218 219 /* /proc */ 220 struct udp_seq_afinfo { 221 char *name; 222 sa_family_t family; 223 struct udp_table *udp_table; 224 struct file_operations seq_fops; 225 struct seq_operations seq_ops; 226 }; 227 228 struct udp_iter_state { 229 struct seq_net_private p; 230 sa_family_t family; 231 int bucket; 232 struct udp_table *udp_table; 233 }; 234 235 #ifdef CONFIG_PROC_FS 236 extern int udp_proc_register(struct net *net, struct udp_seq_afinfo *afinfo); 237 extern void udp_proc_unregister(struct net *net, struct udp_seq_afinfo *afinfo); 238 239 extern int udp4_proc_init(void); 240 extern void udp4_proc_exit(void); 241 #endif 242 243 extern void udp_init(void); 244 245 extern int udp4_ufo_send_check(struct sk_buff *skb); 246 extern struct sk_buff *udp4_ufo_fragment(struct sk_buff *skb, int features); 247 #endif /* _UDP_H */ 248