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); 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 extern int ip_finish_output(struct sk_buff *skb); 144 145 struct ipv4_config 146 { 147 int log_martians; 148 int autoconfig; 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 #ifdef CONFIG_INET 169 /* The function in 2.2 was invalid, producing wrong result for 170 * check=0xFEFF. It was noticed by Arthur Skawina _year_ ago. --ANK(000625) */ 171 static inline 172 int ip_decrease_ttl(struct iphdr *iph) 173 { 174 u32 check = iph->check; 175 check += htons(0x0100); 176 iph->check = check + (check>=0xFFFF); 177 return --iph->ttl; 178 } 179 180 static inline 181 int ip_dont_fragment(struct sock *sk, struct dst_entry *dst) 182 { 183 return (inet_sk(sk)->pmtudisc == IP_PMTUDISC_DO || 184 (inet_sk(sk)->pmtudisc == IP_PMTUDISC_WANT && 185 !(dst_metric(dst, RTAX_LOCK)&(1<<RTAX_MTU)))); 186 } 187 188 extern void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more); 189 190 static inline void ip_select_ident(struct iphdr *iph, struct dst_entry *dst, struct sock *sk) 191 { 192 if (iph->frag_off & htons(IP_DF)) { 193 /* This is only to work around buggy Windows95/2000 194 * VJ compression implementations. If the ID field 195 * does not change, they drop every other packet in 196 * a TCP stream using header compression. 197 */ 198 iph->id = (sk && inet_sk(sk)->daddr) ? 199 htons(inet_sk(sk)->id++) : 0; 200 } else 201 __ip_select_ident(iph, dst, 0); 202 } 203 204 static inline void ip_select_ident_more(struct iphdr *iph, struct dst_entry *dst, struct sock *sk, int more) 205 { 206 if (iph->frag_off & htons(IP_DF)) { 207 if (sk && inet_sk(sk)->daddr) { 208 iph->id = htons(inet_sk(sk)->id); 209 inet_sk(sk)->id += 1 + more; 210 } else 211 iph->id = 0; 212 } else 213 __ip_select_ident(iph, dst, more); 214 } 215 216 /* 217 * Map a multicast IP onto multicast MAC for type ethernet. 218 */ 219 220 static inline void ip_eth_mc_map(u32 addr, char *buf) 221 { 222 addr=ntohl(addr); 223 buf[0]=0x01; 224 buf[1]=0x00; 225 buf[2]=0x5e; 226 buf[5]=addr&0xFF; 227 addr>>=8; 228 buf[4]=addr&0xFF; 229 addr>>=8; 230 buf[3]=addr&0x7F; 231 } 232 233 /* 234 * Map a multicast IP onto multicast MAC for type IP-over-InfiniBand. 235 * Leave P_Key as 0 to be filled in by driver. 236 */ 237 238 static inline void ip_ib_mc_map(u32 addr, char *buf) 239 { 240 buf[0] = 0; /* Reserved */ 241 buf[1] = 0xff; /* Multicast QPN */ 242 buf[2] = 0xff; 243 buf[3] = 0xff; 244 addr = ntohl(addr); 245 buf[4] = 0xff; 246 buf[5] = 0x12; /* link local scope */ 247 buf[6] = 0x40; /* IPv4 signature */ 248 buf[7] = 0x1b; 249 buf[8] = 0; /* P_Key */ 250 buf[9] = 0; 251 buf[10] = 0; 252 buf[11] = 0; 253 buf[12] = 0; 254 buf[13] = 0; 255 buf[14] = 0; 256 buf[15] = 0; 257 buf[19] = addr & 0xff; 258 addr >>= 8; 259 buf[18] = addr & 0xff; 260 addr >>= 8; 261 buf[17] = addr & 0xff; 262 addr >>= 8; 263 buf[16] = addr & 0x0f; 264 } 265 266 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 267 #include <linux/ipv6.h> 268 #endif 269 270 static __inline__ void inet_reset_saddr(struct sock *sk) 271 { 272 inet_sk(sk)->rcv_saddr = inet_sk(sk)->saddr = 0; 273 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 274 if (sk->sk_family == PF_INET6) { 275 struct ipv6_pinfo *np = inet6_sk(sk); 276 277 memset(&np->saddr, 0, sizeof(np->saddr)); 278 memset(&np->rcv_saddr, 0, sizeof(np->rcv_saddr)); 279 } 280 #endif 281 } 282 283 #endif 284 285 extern int ip_call_ra_chain(struct sk_buff *skb); 286 287 /* 288 * Functions provided by ip_fragment.o 289 */ 290 291 enum ip_defrag_users 292 { 293 IP_DEFRAG_LOCAL_DELIVER, 294 IP_DEFRAG_CALL_RA_CHAIN, 295 IP_DEFRAG_CONNTRACK_IN, 296 IP_DEFRAG_CONNTRACK_OUT, 297 IP_DEFRAG_NAT_OUT, 298 IP_DEFRAG_VS_IN, 299 IP_DEFRAG_VS_OUT, 300 IP_DEFRAG_VS_FWD 301 }; 302 303 struct sk_buff *ip_defrag(struct sk_buff *skb, u32 user); 304 extern int ip_frag_nqueues; 305 extern atomic_t ip_frag_mem; 306 307 /* 308 * Functions provided by ip_forward.c 309 */ 310 311 extern int ip_forward(struct sk_buff *skb); 312 extern int ip_net_unreachable(struct sk_buff *skb); 313 314 /* 315 * Functions provided by ip_options.c 316 */ 317 318 extern void ip_options_build(struct sk_buff *skb, struct ip_options *opt, u32 daddr, struct rtable *rt, int is_frag); 319 extern int ip_options_echo(struct ip_options *dopt, struct sk_buff *skb); 320 extern void ip_options_fragment(struct sk_buff *skb); 321 extern int ip_options_compile(struct ip_options *opt, struct sk_buff *skb); 322 extern int ip_options_get(struct ip_options **optp, unsigned char *data, int optlen, int user); 323 extern void ip_options_undo(struct ip_options * opt); 324 extern void ip_forward_options(struct sk_buff *skb); 325 extern int ip_options_rcv_srr(struct sk_buff *skb); 326 327 /* 328 * Functions provided by ip_sockglue.c 329 */ 330 331 extern void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb); 332 extern int ip_cmsg_send(struct msghdr *msg, struct ipcm_cookie *ipc); 333 extern int ip_setsockopt(struct sock *sk, int level, int optname, char __user *optval, int optlen); 334 extern int ip_getsockopt(struct sock *sk, int level, int optname, char __user *optval, int __user *optlen); 335 extern int ip_ra_control(struct sock *sk, unsigned char on, void (*destructor)(struct sock *)); 336 337 extern int ip_recv_error(struct sock *sk, struct msghdr *msg, int len); 338 extern void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err, 339 u16 port, u32 info, u8 *payload); 340 extern void ip_local_error(struct sock *sk, int err, u32 daddr, u16 dport, 341 u32 info); 342 343 /* sysctl helpers - any sysctl which holds a value that ends up being 344 * fed into the routing cache should use these handlers. 345 */ 346 int ipv4_doint_and_flush(ctl_table *ctl, int write, 347 struct file* filp, void __user *buffer, 348 size_t *lenp, loff_t *ppos); 349 int ipv4_doint_and_flush_strategy(ctl_table *table, int __user *name, int nlen, 350 void __user *oldval, size_t __user *oldlenp, 351 void __user *newval, size_t newlen, 352 void **context); 353 354 #endif /* _IP_H */ 355