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 IS_ENABLED(CONFIG_IPV6) 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_long_t udp_memory_allocated; 109 110 /* sysctl variables for udp */ 111 extern long 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 static inline __wsum udp_csum(struct sk_buff *skb) 148 { 149 __wsum csum = csum_partial(skb_transport_header(skb), 150 sizeof(struct udphdr), skb->csum); 151 152 for (skb = skb_shinfo(skb)->frag_list; skb; skb = skb->next) { 153 csum = csum_add(csum, skb->csum); 154 } 155 return csum; 156 } 157 158 /* hash routines shared between UDPv4/6 and UDP-Litev4/6 */ 159 static inline void udp_lib_hash(struct sock *sk) 160 { 161 BUG(); 162 } 163 164 extern void udp_lib_unhash(struct sock *sk); 165 extern void udp_lib_rehash(struct sock *sk, u16 new_hash); 166 167 static inline void udp_lib_close(struct sock *sk, long timeout) 168 { 169 sk_common_release(sk); 170 } 171 172 extern int udp_lib_get_port(struct sock *sk, unsigned short snum, 173 int (*)(const struct sock *,const struct sock *), 174 unsigned int hash2_nulladdr); 175 176 /* net/ipv4/udp.c */ 177 extern int udp_get_port(struct sock *sk, unsigned short snum, 178 int (*saddr_cmp)(const struct sock *, 179 const struct sock *)); 180 extern void udp_err(struct sk_buff *, u32); 181 extern int udp_sendmsg(struct kiocb *iocb, struct sock *sk, 182 struct msghdr *msg, size_t len); 183 extern void udp_flush_pending_frames(struct sock *sk); 184 extern int udp_rcv(struct sk_buff *skb); 185 extern int udp_ioctl(struct sock *sk, int cmd, unsigned long arg); 186 extern int udp_disconnect(struct sock *sk, int flags); 187 extern unsigned int udp_poll(struct file *file, struct socket *sock, 188 poll_table *wait); 189 extern int udp_lib_getsockopt(struct sock *sk, int level, int optname, 190 char __user *optval, int __user *optlen); 191 extern int udp_lib_setsockopt(struct sock *sk, int level, int optname, 192 char __user *optval, unsigned int optlen, 193 int (*push_pending_frames)(struct sock *)); 194 extern struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport, 195 __be32 daddr, __be16 dport, 196 int dif); 197 extern struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport, 198 __be32 daddr, __be16 dport, 199 int dif, struct udp_table *tbl); 200 extern struct sock *udp6_lib_lookup(struct net *net, const struct in6_addr *saddr, __be16 sport, 201 const struct in6_addr *daddr, __be16 dport, 202 int dif); 203 extern struct sock *__udp6_lib_lookup(struct net *net, const struct in6_addr *saddr, __be16 sport, 204 const struct in6_addr *daddr, __be16 dport, 205 int dif, struct udp_table *tbl); 206 207 /* 208 * SNMP statistics for UDP and UDP-Lite 209 */ 210 #define UDP_INC_STATS_USER(net, field, is_udplite) do { \ 211 if (is_udplite) SNMP_INC_STATS_USER((net)->mib.udplite_statistics, field); \ 212 else SNMP_INC_STATS_USER((net)->mib.udp_statistics, field); } while(0) 213 #define UDP_INC_STATS_BH(net, field, is_udplite) do { \ 214 if (is_udplite) SNMP_INC_STATS_BH((net)->mib.udplite_statistics, field); \ 215 else SNMP_INC_STATS_BH((net)->mib.udp_statistics, field); } while(0) 216 217 #define UDP6_INC_STATS_BH(net, field, is_udplite) do { \ 218 if (is_udplite) SNMP_INC_STATS_BH((net)->mib.udplite_stats_in6, field);\ 219 else SNMP_INC_STATS_BH((net)->mib.udp_stats_in6, field); \ 220 } while(0) 221 #define UDP6_INC_STATS_USER(net, field, __lite) do { \ 222 if (__lite) SNMP_INC_STATS_USER((net)->mib.udplite_stats_in6, field); \ 223 else SNMP_INC_STATS_USER((net)->mib.udp_stats_in6, field); \ 224 } while(0) 225 226 #if IS_ENABLED(CONFIG_IPV6) 227 #define UDPX_INC_STATS_BH(sk, field) \ 228 do { \ 229 if ((sk)->sk_family == AF_INET) \ 230 UDP_INC_STATS_BH(sock_net(sk), field, 0); \ 231 else \ 232 UDP6_INC_STATS_BH(sock_net(sk), field, 0); \ 233 } while (0); 234 #else 235 #define UDPX_INC_STATS_BH(sk, field) UDP_INC_STATS_BH(sock_net(sk), field, 0) 236 #endif 237 238 /* /proc */ 239 int udp_seq_open(struct inode *inode, struct file *file); 240 241 struct udp_seq_afinfo { 242 char *name; 243 sa_family_t family; 244 struct udp_table *udp_table; 245 const struct file_operations *seq_fops; 246 struct seq_operations seq_ops; 247 }; 248 249 struct udp_iter_state { 250 struct seq_net_private p; 251 sa_family_t family; 252 int bucket; 253 struct udp_table *udp_table; 254 }; 255 256 #ifdef CONFIG_PROC_FS 257 extern int udp_proc_register(struct net *net, struct udp_seq_afinfo *afinfo); 258 extern void udp_proc_unregister(struct net *net, struct udp_seq_afinfo *afinfo); 259 260 extern int udp4_proc_init(void); 261 extern void udp4_proc_exit(void); 262 #endif 263 264 extern void udp_init(void); 265 266 extern int udp4_ufo_send_check(struct sk_buff *skb); 267 extern struct sk_buff *udp4_ufo_fragment(struct sk_buff *skb, 268 netdev_features_t features); 269 #endif /* _UDP_H */ 270