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