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/types.h> 26 #include <linux/ip.h> 27 #include <linux/in.h> 28 29 #include <net/inet_sock.h> 30 #include <net/snmp.h> 31 32 struct sock; 33 34 struct inet_skb_parm 35 { 36 struct ip_options opt; /* Compiled IP options */ 37 unsigned char flags; 38 39 #define IPSKB_FORWARDED 1 40 #define IPSKB_XFRM_TUNNEL_SIZE 2 41 #define IPSKB_XFRM_TRANSFORMED 4 42 #define IPSKB_FRAG_COMPLETE 8 43 #define IPSKB_REROUTED 16 44 }; 45 46 struct ipcm_cookie 47 { 48 __be32 addr; 49 int oif; 50 struct ip_options *opt; 51 }; 52 53 #define IPCB(skb) ((struct inet_skb_parm*)((skb)->cb)) 54 55 struct ip_ra_chain 56 { 57 struct ip_ra_chain *next; 58 struct sock *sk; 59 void (*destructor)(struct sock *); 60 }; 61 62 extern struct ip_ra_chain *ip_ra_chain; 63 extern rwlock_t ip_ra_lock; 64 65 /* IP flags. */ 66 #define IP_CE 0x8000 /* Flag: "Congestion" */ 67 #define IP_DF 0x4000 /* Flag: "Don't Fragment" */ 68 #define IP_MF 0x2000 /* Flag: "More Fragments" */ 69 #define IP_OFFSET 0x1FFF /* "Fragment Offset" part */ 70 71 #define IP_FRAG_TIME (30 * HZ) /* fragment lifetime */ 72 73 struct msghdr; 74 struct net_device; 75 struct packet_type; 76 struct rtable; 77 struct sk_buff; 78 struct sockaddr; 79 80 extern void ip_mc_dropsocket(struct sock *); 81 extern void ip_mc_dropdevice(struct net_device *dev); 82 extern int igmp_mc_proc_init(void); 83 84 /* 85 * Functions provided by ip.c 86 */ 87 88 extern int ip_build_and_send_pkt(struct sk_buff *skb, struct sock *sk, 89 __be32 saddr, __be32 daddr, 90 struct ip_options *opt); 91 extern int ip_rcv(struct sk_buff *skb, struct net_device *dev, 92 struct packet_type *pt, struct net_device *orig_dev); 93 extern int ip_local_deliver(struct sk_buff *skb); 94 extern int ip_mr_input(struct sk_buff *skb); 95 extern int ip_output(struct sk_buff *skb); 96 extern int ip_mc_output(struct sk_buff *skb); 97 extern int ip_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *)); 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, struct sock *sk, 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(__be32 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 __wsum 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 no_pmtu_disc; 150 }; 151 152 extern struct ipv4_config ipv4_config; 153 DECLARE_SNMP_STAT(struct ipstats_mib, ip_statistics); 154 #define IP_INC_STATS(field) SNMP_INC_STATS(ip_statistics, field) 155 #define IP_INC_STATS_BH(field) SNMP_INC_STATS_BH(ip_statistics, field) 156 #define IP_INC_STATS_USER(field) SNMP_INC_STATS_USER(ip_statistics, field) 157 DECLARE_SNMP_STAT(struct linux_mib, net_statistics); 158 #define NET_INC_STATS(field) SNMP_INC_STATS(net_statistics, field) 159 #define NET_INC_STATS_BH(field) SNMP_INC_STATS_BH(net_statistics, field) 160 #define NET_INC_STATS_USER(field) SNMP_INC_STATS_USER(net_statistics, field) 161 #define NET_ADD_STATS_BH(field, adnd) SNMP_ADD_STATS_BH(net_statistics, field, adnd) 162 #define NET_ADD_STATS_USER(field, adnd) SNMP_ADD_STATS_USER(net_statistics, field, adnd) 163 164 extern int sysctl_local_port_range[2]; 165 extern int sysctl_ip_default_ttl; 166 extern int sysctl_ip_nonlocal_bind; 167 168 /* From ip_fragment.c */ 169 extern int sysctl_ipfrag_high_thresh; 170 extern int sysctl_ipfrag_low_thresh; 171 extern int sysctl_ipfrag_time; 172 extern int sysctl_ipfrag_secret_interval; 173 extern int sysctl_ipfrag_max_dist; 174 175 /* From inetpeer.c */ 176 extern int inet_peer_threshold; 177 extern int inet_peer_minttl; 178 extern int inet_peer_maxttl; 179 extern int inet_peer_gc_mintime; 180 extern int inet_peer_gc_maxtime; 181 182 /* From ip_output.c */ 183 extern int sysctl_ip_dynaddr; 184 185 extern void ipfrag_init(void); 186 187 #ifdef CONFIG_INET 188 #include <net/dst.h> 189 190 /* The function in 2.2 was invalid, producing wrong result for 191 * check=0xFEFF. It was noticed by Arthur Skawina _year_ ago. --ANK(000625) */ 192 static inline 193 int ip_decrease_ttl(struct iphdr *iph) 194 { 195 u32 check = (__force u32)iph->check; 196 check += (__force u32)htons(0x0100); 197 iph->check = (__force __sum16)(check + (check>=0xFFFF)); 198 return --iph->ttl; 199 } 200 201 static inline 202 int ip_dont_fragment(struct sock *sk, struct dst_entry *dst) 203 { 204 return (inet_sk(sk)->pmtudisc == IP_PMTUDISC_DO || 205 (inet_sk(sk)->pmtudisc == IP_PMTUDISC_WANT && 206 !(dst_metric(dst, RTAX_LOCK)&(1<<RTAX_MTU)))); 207 } 208 209 extern void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more); 210 211 static inline void ip_select_ident(struct iphdr *iph, struct dst_entry *dst, struct sock *sk) 212 { 213 if (iph->frag_off & htons(IP_DF)) { 214 /* This is only to work around buggy Windows95/2000 215 * VJ compression implementations. If the ID field 216 * does not change, they drop every other packet in 217 * a TCP stream using header compression. 218 */ 219 iph->id = (sk && inet_sk(sk)->daddr) ? 220 htons(inet_sk(sk)->id++) : 0; 221 } else 222 __ip_select_ident(iph, dst, 0); 223 } 224 225 static inline void ip_select_ident_more(struct iphdr *iph, struct dst_entry *dst, struct sock *sk, int more) 226 { 227 if (iph->frag_off & htons(IP_DF)) { 228 if (sk && inet_sk(sk)->daddr) { 229 iph->id = htons(inet_sk(sk)->id); 230 inet_sk(sk)->id += 1 + more; 231 } else 232 iph->id = 0; 233 } else 234 __ip_select_ident(iph, dst, more); 235 } 236 237 /* 238 * Map a multicast IP onto multicast MAC for type ethernet. 239 */ 240 241 static inline void ip_eth_mc_map(__be32 naddr, char *buf) 242 { 243 __u32 addr=ntohl(naddr); 244 buf[0]=0x01; 245 buf[1]=0x00; 246 buf[2]=0x5e; 247 buf[5]=addr&0xFF; 248 addr>>=8; 249 buf[4]=addr&0xFF; 250 addr>>=8; 251 buf[3]=addr&0x7F; 252 } 253 254 /* 255 * Map a multicast IP onto multicast MAC for type IP-over-InfiniBand. 256 * Leave P_Key as 0 to be filled in by driver. 257 */ 258 259 static inline void ip_ib_mc_map(__be32 naddr, char *buf) 260 { 261 __u32 addr; 262 buf[0] = 0; /* Reserved */ 263 buf[1] = 0xff; /* Multicast QPN */ 264 buf[2] = 0xff; 265 buf[3] = 0xff; 266 addr = ntohl(naddr); 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, __be32 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 compat_ip_setsockopt(struct sock *sk, int level, 360 int optname, char __user *optval, int optlen); 361 extern int compat_ip_getsockopt(struct sock *sk, int level, 362 int optname, char __user *optval, int __user *optlen); 363 extern int ip_ra_control(struct sock *sk, unsigned char on, void (*destructor)(struct sock *)); 364 365 extern int ip_recv_error(struct sock *sk, struct msghdr *msg, int len); 366 extern void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err, 367 __be16 port, u32 info, u8 *payload); 368 extern void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 dport, 369 u32 info); 370 371 /* sysctl helpers - any sysctl which holds a value that ends up being 372 * fed into the routing cache should use these handlers. 373 */ 374 int ipv4_doint_and_flush(ctl_table *ctl, int write, 375 struct file* filp, void __user *buffer, 376 size_t *lenp, loff_t *ppos); 377 int ipv4_doint_and_flush_strategy(ctl_table *table, int __user *name, int nlen, 378 void __user *oldval, size_t __user *oldlenp, 379 void __user *newval, size_t newlen, 380 void **context); 381 #ifdef CONFIG_PROC_FS 382 extern int ip_misc_proc_init(void); 383 #endif 384 385 extern struct ctl_table ipv4_table[]; 386 387 #endif /* _IP_H */ 388