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 */ 42struct 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 */ 61struct 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 */ 75struct udp_table { 76 struct udp_hslot *hash; 77 struct udp_hslot *hash2; 78 unsigned int mask; 79 unsigned int log; 80}; 81extern struct udp_table udp_table; 82void udp_table_init(struct udp_table *, const char *); 83static 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 */ 92static inline struct udp_hslot *udp_hashslot2(struct udp_table *table, 93 unsigned int hash) 94{ 95 return &table->hash2[hash & table->mask]; 96} 97 98extern struct proto udp_prot; 99 100extern atomic_long_t udp_memory_allocated; 101 102/* sysctl variables for udp */ 103extern long sysctl_udp_mem[3]; 104extern int sysctl_udp_rmem_min; 105extern int sysctl_udp_wmem_min; 106 107struct sk_buff; 108 109/* 110 * Generic checksumming routines for UDP(-Lite) v4 and v6 111 */ 112static inline __sum16 __udp_lib_checksum_complete(struct sk_buff *skb) 113{ 114 return (UDP_SKB_CB(skb)->cscov == skb->len ? 115 __skb_checksum_complete(skb) : 116 __skb_checksum_complete_head(skb, UDP_SKB_CB(skb)->cscov)); 117} 118 119static inline int udp_lib_checksum_complete(struct sk_buff *skb) 120{ 121 return !skb_csum_unnecessary(skb) && 122 __udp_lib_checksum_complete(skb); 123} 124 125/** 126 * udp_csum_outgoing - compute UDPv4/v6 checksum over fragments 127 * @sk: socket we are writing to 128 * @skb: sk_buff containing the filled-in UDP header 129 * (checksum field must be zeroed out) 130 */ 131static inline __wsum udp_csum_outgoing(struct sock *sk, struct sk_buff *skb) 132{ 133 __wsum csum = csum_partial(skb_transport_header(skb), 134 sizeof(struct udphdr), 0); 135 skb_queue_walk(&sk->sk_write_queue, skb) { 136 csum = csum_add(csum, skb->csum); 137 } 138 return csum; 139} 140 141static inline __wsum udp_csum(struct sk_buff *skb) 142{ 143 __wsum csum = csum_partial(skb_transport_header(skb), 144 sizeof(struct udphdr), skb->csum); 145 146 for (skb = skb_shinfo(skb)->frag_list; skb; skb = skb->next) { 147 csum = csum_add(csum, skb->csum); 148 } 149 return csum; 150} 151 152static inline __sum16 udp_v4_check(int len, __be32 saddr, 153 __be32 daddr, __wsum base) 154{ 155 return csum_tcpudp_magic(saddr, daddr, len, IPPROTO_UDP, base); 156} 157 158void udp_set_csum(bool nocheck, struct sk_buff *skb, 159 __be32 saddr, __be32 daddr, int len); 160 161struct sk_buff **udp_gro_receive(struct sk_buff **head, struct sk_buff *skb, 162 struct udphdr *uh); 163int udp_gro_complete(struct sk_buff *skb, int nhoff); 164 165static inline struct udphdr *udp_gro_udphdr(struct sk_buff *skb) 166{ 167 struct udphdr *uh; 168 unsigned int hlen, off; 169 170 off = skb_gro_offset(skb); 171 hlen = off + sizeof(*uh); 172 uh = skb_gro_header_fast(skb, off); 173 if (skb_gro_header_hard(skb, hlen)) 174 uh = skb_gro_header_slow(skb, hlen, off); 175 176 return uh; 177} 178 179/* hash routines shared between UDPv4/6 and UDP-Litev4/6 */ 180static inline void udp_lib_hash(struct sock *sk) 181{ 182 BUG(); 183} 184 185void udp_lib_unhash(struct sock *sk); 186void udp_lib_rehash(struct sock *sk, u16 new_hash); 187 188static inline void udp_lib_close(struct sock *sk, long timeout) 189{ 190 sk_common_release(sk); 191} 192 193int udp_lib_get_port(struct sock *sk, unsigned short snum, 194 int (*)(const struct sock *, const struct sock *), 195 unsigned int hash2_nulladdr); 196 197static inline __be16 udp_flow_src_port(struct net *net, struct sk_buff *skb, 198 int min, int max, bool use_eth) 199{ 200 u32 hash; 201 202 if (min >= max) { 203 /* Use default range */ 204 inet_get_local_port_range(net, &min, &max); 205 } 206 207 hash = skb_get_hash(skb); 208 if (unlikely(!hash) && use_eth) { 209 /* Can't find a normal hash, caller has indicated an Ethernet 210 * packet so use that to compute a hash. 211 */ 212 hash = jhash(skb->data, 2 * ETH_ALEN, 213 (__force u32) skb->protocol); 214 } 215 216 /* Since this is being sent on the wire obfuscate hash a bit 217 * to minimize possbility that any useful information to an 218 * attacker is leaked. Only upper 16 bits are relevant in the 219 * computation for 16 bit port value. 220 */ 221 hash ^= hash << 16; 222 223 return htons((((u64) hash * (max - min)) >> 32) + min); 224} 225 226/* net/ipv4/udp.c */ 227void udp_v4_early_demux(struct sk_buff *skb); 228int udp_get_port(struct sock *sk, unsigned short snum, 229 int (*saddr_cmp)(const struct sock *, 230 const struct sock *)); 231void udp_err(struct sk_buff *, u32); 232int udp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, 233 size_t len); 234int udp_push_pending_frames(struct sock *sk); 235void udp_flush_pending_frames(struct sock *sk); 236void udp4_hwcsum(struct sk_buff *skb, __be32 src, __be32 dst); 237int udp_rcv(struct sk_buff *skb); 238int udp_ioctl(struct sock *sk, int cmd, unsigned long arg); 239int udp_disconnect(struct sock *sk, int flags); 240unsigned int udp_poll(struct file *file, struct socket *sock, poll_table *wait); 241struct sk_buff *skb_udp_tunnel_segment(struct sk_buff *skb, 242 netdev_features_t features, 243 bool is_ipv6); 244int udp_lib_getsockopt(struct sock *sk, int level, int optname, 245 char __user *optval, int __user *optlen); 246int udp_lib_setsockopt(struct sock *sk, int level, int optname, 247 char __user *optval, unsigned int optlen, 248 int (*push_pending_frames)(struct sock *)); 249struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport, 250 __be32 daddr, __be16 dport, int dif); 251struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport, 252 __be32 daddr, __be16 dport, int dif, 253 struct udp_table *tbl); 254struct sock *udp6_lib_lookup(struct net *net, 255 const struct in6_addr *saddr, __be16 sport, 256 const struct in6_addr *daddr, __be16 dport, 257 int dif); 258struct sock *__udp6_lib_lookup(struct net *net, 259 const struct in6_addr *saddr, __be16 sport, 260 const struct in6_addr *daddr, __be16 dport, 261 int dif, struct udp_table *tbl); 262 263/* 264 * SNMP statistics for UDP and UDP-Lite 265 */ 266#define UDP_INC_STATS_USER(net, field, is_udplite) do { \ 267 if (is_udplite) SNMP_INC_STATS_USER((net)->mib.udplite_statistics, field); \ 268 else SNMP_INC_STATS_USER((net)->mib.udp_statistics, field); } while(0) 269#define UDP_INC_STATS_BH(net, field, is_udplite) do { \ 270 if (is_udplite) SNMP_INC_STATS_BH((net)->mib.udplite_statistics, field); \ 271 else SNMP_INC_STATS_BH((net)->mib.udp_statistics, field); } while(0) 272 273#define UDP6_INC_STATS_BH(net, field, is_udplite) do { \ 274 if (is_udplite) SNMP_INC_STATS_BH((net)->mib.udplite_stats_in6, field);\ 275 else SNMP_INC_STATS_BH((net)->mib.udp_stats_in6, field); \ 276} while(0) 277#define UDP6_INC_STATS_USER(net, field, __lite) do { \ 278 if (__lite) SNMP_INC_STATS_USER((net)->mib.udplite_stats_in6, field); \ 279 else SNMP_INC_STATS_USER((net)->mib.udp_stats_in6, field); \ 280} while(0) 281 282#if IS_ENABLED(CONFIG_IPV6) 283#define UDPX_INC_STATS_BH(sk, field) \ 284do { \ 285 if ((sk)->sk_family == AF_INET) \ 286 UDP_INC_STATS_BH(sock_net(sk), field, 0); \ 287 else \ 288 UDP6_INC_STATS_BH(sock_net(sk), field, 0); \ 289} while (0) 290#else 291#define UDPX_INC_STATS_BH(sk, field) UDP_INC_STATS_BH(sock_net(sk), field, 0) 292#endif 293 294/* /proc */ 295int udp_seq_open(struct inode *inode, struct file *file); 296 297struct udp_seq_afinfo { 298 char *name; 299 sa_family_t family; 300 struct udp_table *udp_table; 301 const struct file_operations *seq_fops; 302 struct seq_operations seq_ops; 303}; 304 305struct udp_iter_state { 306 struct seq_net_private p; 307 sa_family_t family; 308 int bucket; 309 struct udp_table *udp_table; 310}; 311 312#ifdef CONFIG_PROC_FS 313int udp_proc_register(struct net *net, struct udp_seq_afinfo *afinfo); 314void udp_proc_unregister(struct net *net, struct udp_seq_afinfo *afinfo); 315 316int udp4_proc_init(void); 317void udp4_proc_exit(void); 318#endif 319 320int udpv4_offload_init(void); 321 322void udp_init(void); 323 324void udp_encap_enable(void); 325#if IS_ENABLED(CONFIG_IPV6) 326void udpv6_encap_enable(void); 327#endif 328#endif /* _UDP_H */ 329