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 <linux/bug.h> 27 #include <net/inet_sock.h> 28 #include <net/sock.h> 29 #include <net/snmp.h> 30 #include <net/ip.h> 31 #include <linux/ipv6.h> 32 #include <linux/seq_file.h> 33 #include <linux/poll.h> 34 35 /** 36 * struct udp_skb_cb - UDP(-Lite) private variables 37 * 38 * @header: private variables used by IPv4/IPv6 39 * @cscov: checksum coverage length (UDP-Lite only) 40 * @partial_cov: if set indicates partial csum coverage 41 */ 42 struct udp_skb_cb { 43 union { 44 struct inet_skb_parm h4; 45 #if IS_ENABLED(CONFIG_IPV6) 46 struct inet6_skb_parm h6; 47 #endif 48 } header; 49 __u16 cscov; 50 __u8 partial_cov; 51 }; 52 #define UDP_SKB_CB(__skb) ((struct udp_skb_cb *)((__skb)->cb)) 53 54 /** 55 * struct udp_hslot - UDP hash slot 56 * 57 * @head: head of list of sockets 58 * @count: number of sockets in 'head' list 59 * @lock: spinlock protecting changes to head/count 60 */ 61 struct udp_hslot { 62 struct hlist_nulls_head head; 63 int count; 64 spinlock_t lock; 65 } __attribute__((aligned(2 * sizeof(long)))); 66 67 /** 68 * struct udp_table - UDP table 69 * 70 * @hash: hash table, sockets are hashed on (local port) 71 * @hash2: hash table, sockets are hashed on (local port, local address) 72 * @mask: number of slots in hash tables, minus 1 73 * @log: log2(number of slots in hash table) 74 */ 75 struct udp_table { 76 struct udp_hslot *hash; 77 struct udp_hslot *hash2; 78 unsigned int mask; 79 unsigned int log; 80 }; 81 extern struct udp_table udp_table; 82 void udp_table_init(struct udp_table *, const char *); 83 static inline struct udp_hslot *udp_hashslot(struct udp_table *table, 84 struct net *net, unsigned int num) 85 { 86 return &table->hash[udp_hashfn(net, num, table->mask)]; 87 } 88 /* 89 * For secondary hash, net_hash_mix() is performed before calling 90 * udp_hashslot2(), this explains difference with udp_hashslot() 91 */ 92 static inline struct udp_hslot *udp_hashslot2(struct udp_table *table, 93 unsigned int hash) 94 { 95 return &table->hash2[hash & table->mask]; 96 } 97 98 /* Note: this must match 'valbool' in sock_setsockopt */ 99 #define UDP_CSUM_NOXMIT 1 100 101 /* Used by SunRPC/xprt layer. */ 102 #define UDP_CSUM_NORCV 2 103 104 /* Default, as per the RFC, is to always do csums. */ 105 #define UDP_CSUM_DEFAULT 0 106 107 extern struct proto udp_prot; 108 109 extern atomic_long_t udp_memory_allocated; 110 111 /* sysctl variables for udp */ 112 extern long sysctl_udp_mem[3]; 113 extern int sysctl_udp_rmem_min; 114 extern int sysctl_udp_wmem_min; 115 116 struct sk_buff; 117 118 /* 119 * Generic checksumming routines for UDP(-Lite) v4 and v6 120 */ 121 static inline __sum16 __udp_lib_checksum_complete(struct sk_buff *skb) 122 { 123 return __skb_checksum_complete_head(skb, UDP_SKB_CB(skb)->cscov); 124 } 125 126 static inline int udp_lib_checksum_complete(struct sk_buff *skb) 127 { 128 return !skb_csum_unnecessary(skb) && 129 __udp_lib_checksum_complete(skb); 130 } 131 132 /** 133 * udp_csum_outgoing - compute UDPv4/v6 checksum over fragments 134 * @sk: socket we are writing to 135 * @skb: sk_buff containing the filled-in UDP header 136 * (checksum field must be zeroed out) 137 */ 138 static inline __wsum udp_csum_outgoing(struct sock *sk, struct sk_buff *skb) 139 { 140 __wsum csum = csum_partial(skb_transport_header(skb), 141 sizeof(struct udphdr), 0); 142 skb_queue_walk(&sk->sk_write_queue, skb) { 143 csum = csum_add(csum, skb->csum); 144 } 145 return csum; 146 } 147 148 static inline __wsum udp_csum(struct sk_buff *skb) 149 { 150 __wsum csum = csum_partial(skb_transport_header(skb), 151 sizeof(struct udphdr), skb->csum); 152 153 for (skb = skb_shinfo(skb)->frag_list; skb; skb = skb->next) { 154 csum = csum_add(csum, skb->csum); 155 } 156 return csum; 157 } 158 159 /* hash routines shared between UDPv4/6 and UDP-Litev4/6 */ 160 static inline void udp_lib_hash(struct sock *sk) 161 { 162 BUG(); 163 } 164 165 void udp_lib_unhash(struct sock *sk); 166 void udp_lib_rehash(struct sock *sk, u16 new_hash); 167 168 static inline void udp_lib_close(struct sock *sk, long timeout) 169 { 170 sk_common_release(sk); 171 } 172 173 int udp_lib_get_port(struct sock *sk, unsigned short snum, 174 int (*)(const struct sock *, const struct sock *), 175 unsigned int hash2_nulladdr); 176 177 /* net/ipv4/udp.c */ 178 void udp_v4_early_demux(struct sk_buff *skb); 179 int udp_get_port(struct sock *sk, unsigned short snum, 180 int (*saddr_cmp)(const struct sock *, 181 const struct sock *)); 182 void udp_err(struct sk_buff *, u32); 183 int udp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, 184 size_t len); 185 int udp_push_pending_frames(struct sock *sk); 186 void udp_flush_pending_frames(struct sock *sk); 187 void udp4_hwcsum(struct sk_buff *skb, __be32 src, __be32 dst); 188 int udp_rcv(struct sk_buff *skb); 189 int udp_ioctl(struct sock *sk, int cmd, unsigned long arg); 190 int udp_disconnect(struct sock *sk, int flags); 191 unsigned int udp_poll(struct file *file, struct socket *sock, poll_table *wait); 192 struct sk_buff *skb_udp_tunnel_segment(struct sk_buff *skb, 193 netdev_features_t features); 194 int udp_lib_getsockopt(struct sock *sk, int level, int optname, 195 char __user *optval, int __user *optlen); 196 int udp_lib_setsockopt(struct sock *sk, int level, int optname, 197 char __user *optval, unsigned int optlen, 198 int (*push_pending_frames)(struct sock *)); 199 struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport, 200 __be32 daddr, __be16 dport, int dif); 201 struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport, 202 __be32 daddr, __be16 dport, int dif, 203 struct udp_table *tbl); 204 struct sock *udp6_lib_lookup(struct net *net, 205 const struct in6_addr *saddr, __be16 sport, 206 const struct in6_addr *daddr, __be16 dport, 207 int dif); 208 struct sock *__udp6_lib_lookup(struct net *net, 209 const struct in6_addr *saddr, __be16 sport, 210 const struct in6_addr *daddr, __be16 dport, 211 int dif, struct udp_table *tbl); 212 213 /* 214 * SNMP statistics for UDP and UDP-Lite 215 */ 216 #define UDP_INC_STATS_USER(net, field, is_udplite) do { \ 217 if (is_udplite) SNMP_INC_STATS_USER((net)->mib.udplite_statistics, field); \ 218 else SNMP_INC_STATS_USER((net)->mib.udp_statistics, field); } while(0) 219 #define UDP_INC_STATS_BH(net, field, is_udplite) do { \ 220 if (is_udplite) SNMP_INC_STATS_BH((net)->mib.udplite_statistics, field); \ 221 else SNMP_INC_STATS_BH((net)->mib.udp_statistics, field); } while(0) 222 223 #define UDP6_INC_STATS_BH(net, field, is_udplite) do { \ 224 if (is_udplite) SNMP_INC_STATS_BH((net)->mib.udplite_stats_in6, field);\ 225 else SNMP_INC_STATS_BH((net)->mib.udp_stats_in6, field); \ 226 } while(0) 227 #define UDP6_INC_STATS_USER(net, field, __lite) do { \ 228 if (__lite) SNMP_INC_STATS_USER((net)->mib.udplite_stats_in6, field); \ 229 else SNMP_INC_STATS_USER((net)->mib.udp_stats_in6, field); \ 230 } while(0) 231 232 #if IS_ENABLED(CONFIG_IPV6) 233 #define UDPX_INC_STATS_BH(sk, field) \ 234 do { \ 235 if ((sk)->sk_family == AF_INET) \ 236 UDP_INC_STATS_BH(sock_net(sk), field, 0); \ 237 else \ 238 UDP6_INC_STATS_BH(sock_net(sk), field, 0); \ 239 } while (0) 240 #else 241 #define UDPX_INC_STATS_BH(sk, field) UDP_INC_STATS_BH(sock_net(sk), field, 0) 242 #endif 243 244 /* /proc */ 245 int udp_seq_open(struct inode *inode, struct file *file); 246 247 struct udp_seq_afinfo { 248 char *name; 249 sa_family_t family; 250 struct udp_table *udp_table; 251 const struct file_operations *seq_fops; 252 struct seq_operations seq_ops; 253 }; 254 255 struct udp_iter_state { 256 struct seq_net_private p; 257 sa_family_t family; 258 int bucket; 259 struct udp_table *udp_table; 260 }; 261 262 #ifdef CONFIG_PROC_FS 263 int udp_proc_register(struct net *net, struct udp_seq_afinfo *afinfo); 264 void udp_proc_unregister(struct net *net, struct udp_seq_afinfo *afinfo); 265 266 int udp4_proc_init(void); 267 void udp4_proc_exit(void); 268 #endif 269 270 int udpv4_offload_init(void); 271 272 void udp_init(void); 273 274 void udp_encap_enable(void); 275 #if IS_ENABLED(CONFIG_IPV6) 276 void udpv6_encap_enable(void); 277 #endif 278 #endif /* _UDP_H */ 279