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 IP module. 7 * 8 * Version: @(#)ip.h 1.0.2 05/07/93 9 * 10 * Authors: Ross Biro 11 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> 12 * Alan Cox, <gw4pts@gw4pts.ampr.org> 13 * 14 * Changes: 15 * Mike McLagan : Routing by source 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 _IP_H 23 #define _IP_H 24 25 #include <linux/config.h> 26 #include <linux/types.h> 27 #include <linux/ip.h> 28 #include <linux/in.h> 29 30 #include <net/inet_sock.h> 31 #include <net/snmp.h> 32 33 struct sock; 34 35 struct inet_skb_parm 36 { 37 struct ip_options opt; /* Compiled IP options */ 38 unsigned char flags; 39 40 #define IPSKB_FORWARDED 1 41 #define IPSKB_XFRM_TUNNEL_SIZE 2 42 #define IPSKB_XFRM_TRANSFORMED 4 43 #define IPSKB_FRAG_COMPLETE 8 44 #define IPSKB_REROUTED 16 45 }; 46 47 struct ipcm_cookie 48 { 49 u32 addr; 50 int oif; 51 struct ip_options *opt; 52 }; 53 54 #define IPCB(skb) ((struct inet_skb_parm*)((skb)->cb)) 55 56 struct ip_ra_chain 57 { 58 struct ip_ra_chain *next; 59 struct sock *sk; 60 void (*destructor)(struct sock *); 61 }; 62 63 extern struct ip_ra_chain *ip_ra_chain; 64 extern rwlock_t ip_ra_lock; 65 66 /* IP flags. */ 67 #define IP_CE 0x8000 /* Flag: "Congestion" */ 68 #define IP_DF 0x4000 /* Flag: "Don't Fragment" */ 69 #define IP_MF 0x2000 /* Flag: "More Fragments" */ 70 #define IP_OFFSET 0x1FFF /* "Fragment Offset" part */ 71 72 #define IP_FRAG_TIME (30 * HZ) /* fragment lifetime */ 73 74 struct msghdr; 75 struct net_device; 76 struct packet_type; 77 struct rtable; 78 struct sk_buff; 79 struct sockaddr; 80 81 extern void ip_mc_dropsocket(struct sock *); 82 extern void ip_mc_dropdevice(struct net_device *dev); 83 extern int igmp_mc_proc_init(void); 84 85 /* 86 * Functions provided by ip.c 87 */ 88 89 extern int ip_build_and_send_pkt(struct sk_buff *skb, struct sock *sk, 90 u32 saddr, u32 daddr, 91 struct ip_options *opt); 92 extern int ip_rcv(struct sk_buff *skb, struct net_device *dev, 93 struct packet_type *pt, struct net_device *orig_dev); 94 extern int ip_local_deliver(struct sk_buff *skb); 95 extern int ip_mr_input(struct sk_buff *skb); 96 extern int ip_output(struct sk_buff *skb); 97 extern int ip_mc_output(struct sk_buff *skb); 98 extern int ip_do_nat(struct sk_buff *skb); 99 extern void ip_send_check(struct iphdr *ip); 100 extern int ip_queue_xmit(struct sk_buff *skb, int ipfragok); 101 extern void ip_init(void); 102 extern int ip_append_data(struct sock *sk, 103 int getfrag(void *from, char *to, int offset, int len, 104 int odd, struct sk_buff *skb), 105 void *from, int len, int protolen, 106 struct ipcm_cookie *ipc, 107 struct rtable *rt, 108 unsigned int flags); 109 extern int ip_generic_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb); 110 extern ssize_t ip_append_page(struct sock *sk, struct page *page, 111 int offset, size_t size, int flags); 112 extern int ip_push_pending_frames(struct sock *sk); 113 extern void ip_flush_pending_frames(struct sock *sk); 114 115 /* datagram.c */ 116 extern int ip4_datagram_connect(struct sock *sk, 117 struct sockaddr *uaddr, int addr_len); 118 119 /* 120 * Map a multicast IP onto multicast MAC for type Token Ring. 121 * This conforms to RFC1469 Option 2 Multicasting i.e. 122 * using a functional address to transmit / receive 123 * multicast packets. 124 */ 125 126 static inline void ip_tr_mc_map(u32 addr, char *buf) 127 { 128 buf[0]=0xC0; 129 buf[1]=0x00; 130 buf[2]=0x00; 131 buf[3]=0x04; 132 buf[4]=0x00; 133 buf[5]=0x00; 134 } 135 136 struct ip_reply_arg { 137 struct kvec iov[1]; 138 u32 csum; 139 int csumoffset; /* u16 offset of csum in iov[0].iov_base */ 140 /* -1 if not needed */ 141 }; 142 143 void ip_send_reply(struct sock *sk, struct sk_buff *skb, struct ip_reply_arg *arg, 144 unsigned int len); 145 146 struct ipv4_config 147 { 148 int log_martians; 149 int autoconfig; 150 int no_pmtu_disc; 151 }; 152 153 extern struct ipv4_config ipv4_config; 154 DECLARE_SNMP_STAT(struct ipstats_mib, ip_statistics); 155 #define IP_INC_STATS(field) SNMP_INC_STATS(ip_statistics, field) 156 #define IP_INC_STATS_BH(field) SNMP_INC_STATS_BH(ip_statistics, field) 157 #define IP_INC_STATS_USER(field) SNMP_INC_STATS_USER(ip_statistics, field) 158 DECLARE_SNMP_STAT(struct linux_mib, net_statistics); 159 #define NET_INC_STATS(field) SNMP_INC_STATS(net_statistics, field) 160 #define NET_INC_STATS_BH(field) SNMP_INC_STATS_BH(net_statistics, field) 161 #define NET_INC_STATS_USER(field) SNMP_INC_STATS_USER(net_statistics, field) 162 #define NET_ADD_STATS_BH(field, adnd) SNMP_ADD_STATS_BH(net_statistics, field, adnd) 163 #define NET_ADD_STATS_USER(field, adnd) SNMP_ADD_STATS_USER(net_statistics, field, adnd) 164 165 extern int sysctl_local_port_range[2]; 166 extern int sysctl_ip_default_ttl; 167 extern int sysctl_ip_nonlocal_bind; 168 169 /* From ip_fragment.c */ 170 extern int sysctl_ipfrag_high_thresh; 171 extern int sysctl_ipfrag_low_thresh; 172 extern int sysctl_ipfrag_time; 173 extern int sysctl_ipfrag_secret_interval; 174 extern int sysctl_ipfrag_max_dist; 175 176 /* From inetpeer.c */ 177 extern int inet_peer_threshold; 178 extern int inet_peer_minttl; 179 extern int inet_peer_maxttl; 180 extern int inet_peer_gc_mintime; 181 extern int inet_peer_gc_maxtime; 182 183 /* From ip_output.c */ 184 extern int sysctl_ip_dynaddr; 185 186 extern void ipfrag_init(void); 187 188 #ifdef CONFIG_INET 189 #include <net/dst.h> 190 191 /* The function in 2.2 was invalid, producing wrong result for 192 * check=0xFEFF. It was noticed by Arthur Skawina _year_ ago. --ANK(000625) */ 193 static inline 194 int ip_decrease_ttl(struct iphdr *iph) 195 { 196 u32 check = iph->check; 197 check += htons(0x0100); 198 iph->check = check + (check>=0xFFFF); 199 return --iph->ttl; 200 } 201 202 static inline 203 int ip_dont_fragment(struct sock *sk, struct dst_entry *dst) 204 { 205 return (inet_sk(sk)->pmtudisc == IP_PMTUDISC_DO || 206 (inet_sk(sk)->pmtudisc == IP_PMTUDISC_WANT && 207 !(dst_metric(dst, RTAX_LOCK)&(1<<RTAX_MTU)))); 208 } 209 210 extern void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more); 211 212 static inline void ip_select_ident(struct iphdr *iph, struct dst_entry *dst, struct sock *sk) 213 { 214 if (iph->frag_off & htons(IP_DF)) { 215 /* This is only to work around buggy Windows95/2000 216 * VJ compression implementations. If the ID field 217 * does not change, they drop every other packet in 218 * a TCP stream using header compression. 219 */ 220 iph->id = (sk && inet_sk(sk)->daddr) ? 221 htons(inet_sk(sk)->id++) : 0; 222 } else 223 __ip_select_ident(iph, dst, 0); 224 } 225 226 static inline void ip_select_ident_more(struct iphdr *iph, struct dst_entry *dst, struct sock *sk, int more) 227 { 228 if (iph->frag_off & htons(IP_DF)) { 229 if (sk && inet_sk(sk)->daddr) { 230 iph->id = htons(inet_sk(sk)->id); 231 inet_sk(sk)->id += 1 + more; 232 } else 233 iph->id = 0; 234 } else 235 __ip_select_ident(iph, dst, more); 236 } 237 238 /* 239 * Map a multicast IP onto multicast MAC for type ethernet. 240 */ 241 242 static inline void ip_eth_mc_map(u32 addr, char *buf) 243 { 244 addr=ntohl(addr); 245 buf[0]=0x01; 246 buf[1]=0x00; 247 buf[2]=0x5e; 248 buf[5]=addr&0xFF; 249 addr>>=8; 250 buf[4]=addr&0xFF; 251 addr>>=8; 252 buf[3]=addr&0x7F; 253 } 254 255 /* 256 * Map a multicast IP onto multicast MAC for type IP-over-InfiniBand. 257 * Leave P_Key as 0 to be filled in by driver. 258 */ 259 260 static inline void ip_ib_mc_map(u32 addr, char *buf) 261 { 262 buf[0] = 0; /* Reserved */ 263 buf[1] = 0xff; /* Multicast QPN */ 264 buf[2] = 0xff; 265 buf[3] = 0xff; 266 addr = ntohl(addr); 267 buf[4] = 0xff; 268 buf[5] = 0x12; /* link local scope */ 269 buf[6] = 0x40; /* IPv4 signature */ 270 buf[7] = 0x1b; 271 buf[8] = 0; /* P_Key */ 272 buf[9] = 0; 273 buf[10] = 0; 274 buf[11] = 0; 275 buf[12] = 0; 276 buf[13] = 0; 277 buf[14] = 0; 278 buf[15] = 0; 279 buf[19] = addr & 0xff; 280 addr >>= 8; 281 buf[18] = addr & 0xff; 282 addr >>= 8; 283 buf[17] = addr & 0xff; 284 addr >>= 8; 285 buf[16] = addr & 0x0f; 286 } 287 288 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 289 #include <linux/ipv6.h> 290 #endif 291 292 static __inline__ void inet_reset_saddr(struct sock *sk) 293 { 294 inet_sk(sk)->rcv_saddr = inet_sk(sk)->saddr = 0; 295 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 296 if (sk->sk_family == PF_INET6) { 297 struct ipv6_pinfo *np = inet6_sk(sk); 298 299 memset(&np->saddr, 0, sizeof(np->saddr)); 300 memset(&np->rcv_saddr, 0, sizeof(np->rcv_saddr)); 301 } 302 #endif 303 } 304 305 #endif 306 307 extern int ip_call_ra_chain(struct sk_buff *skb); 308 309 /* 310 * Functions provided by ip_fragment.o 311 */ 312 313 enum ip_defrag_users 314 { 315 IP_DEFRAG_LOCAL_DELIVER, 316 IP_DEFRAG_CALL_RA_CHAIN, 317 IP_DEFRAG_CONNTRACK_IN, 318 IP_DEFRAG_CONNTRACK_OUT, 319 IP_DEFRAG_VS_IN, 320 IP_DEFRAG_VS_OUT, 321 IP_DEFRAG_VS_FWD 322 }; 323 324 struct sk_buff *ip_defrag(struct sk_buff *skb, u32 user); 325 extern int ip_frag_nqueues; 326 extern atomic_t ip_frag_mem; 327 328 /* 329 * Functions provided by ip_forward.c 330 */ 331 332 extern int ip_forward(struct sk_buff *skb); 333 extern int ip_net_unreachable(struct sk_buff *skb); 334 335 /* 336 * Functions provided by ip_options.c 337 */ 338 339 extern void ip_options_build(struct sk_buff *skb, struct ip_options *opt, u32 daddr, struct rtable *rt, int is_frag); 340 extern int ip_options_echo(struct ip_options *dopt, struct sk_buff *skb); 341 extern void ip_options_fragment(struct sk_buff *skb); 342 extern int ip_options_compile(struct ip_options *opt, struct sk_buff *skb); 343 extern int ip_options_get(struct ip_options **optp, 344 unsigned char *data, int optlen); 345 extern int ip_options_get_from_user(struct ip_options **optp, 346 unsigned char __user *data, int optlen); 347 extern void ip_options_undo(struct ip_options * opt); 348 extern void ip_forward_options(struct sk_buff *skb); 349 extern int ip_options_rcv_srr(struct sk_buff *skb); 350 351 /* 352 * Functions provided by ip_sockglue.c 353 */ 354 355 extern void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb); 356 extern int ip_cmsg_send(struct msghdr *msg, struct ipcm_cookie *ipc); 357 extern int ip_setsockopt(struct sock *sk, int level, int optname, char __user *optval, int optlen); 358 extern int ip_getsockopt(struct sock *sk, int level, int optname, char __user *optval, int __user *optlen); 359 extern int ip_ra_control(struct sock *sk, unsigned char on, void (*destructor)(struct sock *)); 360 361 extern int ip_recv_error(struct sock *sk, struct msghdr *msg, int len); 362 extern void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err, 363 u16 port, u32 info, u8 *payload); 364 extern void ip_local_error(struct sock *sk, int err, u32 daddr, u16 dport, 365 u32 info); 366 367 /* sysctl helpers - any sysctl which holds a value that ends up being 368 * fed into the routing cache should use these handlers. 369 */ 370 int ipv4_doint_and_flush(ctl_table *ctl, int write, 371 struct file* filp, void __user *buffer, 372 size_t *lenp, loff_t *ppos); 373 int ipv4_doint_and_flush_strategy(ctl_table *table, int __user *name, int nlen, 374 void __user *oldval, size_t __user *oldlenp, 375 void __user *newval, size_t newlen, 376 void **context); 377 #ifdef CONFIG_PROC_FS 378 extern int ip_misc_proc_init(void); 379 #endif 380 381 extern struct ctl_table ipv4_table[]; 382 383 #endif /* _IP_H */ 384