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 #include <linux/skbuff.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 static inline unsigned int ip_hdrlen(const struct sk_buff *skb) 48 { 49 return ip_hdr(skb)->ihl * 4; 50 } 51 52 struct ipcm_cookie 53 { 54 __be32 addr; 55 int oif; 56 struct ip_options *opt; 57 }; 58 59 #define IPCB(skb) ((struct inet_skb_parm*)((skb)->cb)) 60 61 struct ip_ra_chain 62 { 63 struct ip_ra_chain *next; 64 struct sock *sk; 65 void (*destructor)(struct sock *); 66 }; 67 68 extern struct ip_ra_chain *ip_ra_chain; 69 extern rwlock_t ip_ra_lock; 70 71 /* IP flags. */ 72 #define IP_CE 0x8000 /* Flag: "Congestion" */ 73 #define IP_DF 0x4000 /* Flag: "Don't Fragment" */ 74 #define IP_MF 0x2000 /* Flag: "More Fragments" */ 75 #define IP_OFFSET 0x1FFF /* "Fragment Offset" part */ 76 77 #define IP_FRAG_TIME (30 * HZ) /* fragment lifetime */ 78 79 struct msghdr; 80 struct net_device; 81 struct packet_type; 82 struct rtable; 83 struct sockaddr; 84 85 extern int igmp_mc_proc_init(void); 86 87 /* 88 * Functions provided by ip.c 89 */ 90 91 extern int ip_build_and_send_pkt(struct sk_buff *skb, struct sock *sk, 92 __be32 saddr, __be32 daddr, 93 struct ip_options *opt); 94 extern int ip_rcv(struct sk_buff *skb, struct net_device *dev, 95 struct packet_type *pt, struct net_device *orig_dev); 96 extern int ip_local_deliver(struct sk_buff *skb); 97 extern int ip_mr_input(struct sk_buff *skb); 98 extern int ip_output(struct sk_buff *skb); 99 extern int ip_mc_output(struct sk_buff *skb); 100 extern int ip_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *)); 101 extern int ip_do_nat(struct sk_buff *skb); 102 extern void ip_send_check(struct iphdr *ip); 103 extern int __ip_local_out(struct sk_buff *skb); 104 extern int ip_local_out(struct sk_buff *skb); 105 extern int ip_queue_xmit(struct sk_buff *skb, int ipfragok); 106 extern void ip_init(void); 107 extern int ip_append_data(struct sock *sk, 108 int getfrag(void *from, char *to, int offset, int len, 109 int odd, struct sk_buff *skb), 110 void *from, int len, int protolen, 111 struct ipcm_cookie *ipc, 112 struct rtable *rt, 113 unsigned int flags); 114 extern int ip_generic_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb); 115 extern ssize_t ip_append_page(struct sock *sk, struct page *page, 116 int offset, size_t size, int flags); 117 extern int ip_push_pending_frames(struct sock *sk); 118 extern void ip_flush_pending_frames(struct sock *sk); 119 120 /* datagram.c */ 121 extern int ip4_datagram_connect(struct sock *sk, 122 struct sockaddr *uaddr, int addr_len); 123 124 /* 125 * Map a multicast IP onto multicast MAC for type Token Ring. 126 * This conforms to RFC1469 Option 2 Multicasting i.e. 127 * using a functional address to transmit / receive 128 * multicast packets. 129 */ 130 131 static inline void ip_tr_mc_map(__be32 addr, char *buf) 132 { 133 buf[0]=0xC0; 134 buf[1]=0x00; 135 buf[2]=0x00; 136 buf[3]=0x04; 137 buf[4]=0x00; 138 buf[5]=0x00; 139 } 140 141 struct ip_reply_arg { 142 struct kvec iov[1]; 143 __wsum csum; 144 int csumoffset; /* u16 offset of csum in iov[0].iov_base */ 145 /* -1 if not needed */ 146 int bound_dev_if; 147 }; 148 149 void ip_send_reply(struct sock *sk, struct sk_buff *skb, struct ip_reply_arg *arg, 150 unsigned int len); 151 152 struct ipv4_config 153 { 154 int log_martians; 155 int no_pmtu_disc; 156 }; 157 158 extern struct ipv4_config ipv4_config; 159 #define IP_INC_STATS(net, field) SNMP_INC_STATS((net)->mib.ip_statistics, field) 160 #define IP_INC_STATS_BH(net, field) SNMP_INC_STATS_BH((net)->mib.ip_statistics, field) 161 #define IP_ADD_STATS_BH(net, field, val) SNMP_ADD_STATS_BH((net)->mib.ip_statistics, field, val) 162 #define NET_INC_STATS(net, field) SNMP_INC_STATS((net)->mib.net_statistics, field) 163 #define NET_INC_STATS_BH(net, field) SNMP_INC_STATS_BH((net)->mib.net_statistics, field) 164 #define NET_INC_STATS_USER(net, field) SNMP_INC_STATS_USER((net)->mib.net_statistics, field) 165 #define NET_ADD_STATS_BH(net, field, adnd) SNMP_ADD_STATS_BH((net)->mib.net_statistics, field, adnd) 166 #define NET_ADD_STATS_USER(net, field, adnd) SNMP_ADD_STATS_USER((net)->mib.net_statistics, field, adnd) 167 168 extern unsigned long snmp_fold_field(void *mib[], int offt); 169 extern int snmp_mib_init(void *ptr[2], size_t mibsize); 170 extern void snmp_mib_free(void *ptr[2]); 171 172 extern void inet_get_local_port_range(int *low, int *high); 173 174 extern int sysctl_ip_default_ttl; 175 extern int sysctl_ip_nonlocal_bind; 176 177 extern struct ctl_path net_ipv4_ctl_path[]; 178 179 /* From inetpeer.c */ 180 extern int inet_peer_threshold; 181 extern int inet_peer_minttl; 182 extern int inet_peer_maxttl; 183 extern int inet_peer_gc_mintime; 184 extern int inet_peer_gc_maxtime; 185 186 /* From ip_output.c */ 187 extern int sysctl_ip_dynaddr; 188 189 extern void ipfrag_init(void); 190 191 #ifdef CONFIG_INET 192 #include <net/dst.h> 193 194 /* The function in 2.2 was invalid, producing wrong result for 195 * check=0xFEFF. It was noticed by Arthur Skawina _year_ ago. --ANK(000625) */ 196 static inline 197 int ip_decrease_ttl(struct iphdr *iph) 198 { 199 u32 check = (__force u32)iph->check; 200 check += (__force u32)htons(0x0100); 201 iph->check = (__force __sum16)(check + (check>=0xFFFF)); 202 return --iph->ttl; 203 } 204 205 static inline 206 int ip_dont_fragment(struct sock *sk, struct dst_entry *dst) 207 { 208 return (inet_sk(sk)->pmtudisc == IP_PMTUDISC_DO || 209 (inet_sk(sk)->pmtudisc == IP_PMTUDISC_WANT && 210 !(dst_metric_locked(dst, RTAX_MTU)))); 211 } 212 213 extern void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more); 214 215 static inline void ip_select_ident(struct iphdr *iph, struct dst_entry *dst, struct sock *sk) 216 { 217 if (iph->frag_off & htons(IP_DF)) { 218 /* This is only to work around buggy Windows95/2000 219 * VJ compression implementations. If the ID field 220 * does not change, they drop every other packet in 221 * a TCP stream using header compression. 222 */ 223 iph->id = (sk && inet_sk(sk)->daddr) ? 224 htons(inet_sk(sk)->id++) : 0; 225 } else 226 __ip_select_ident(iph, dst, 0); 227 } 228 229 static inline void ip_select_ident_more(struct iphdr *iph, struct dst_entry *dst, struct sock *sk, int more) 230 { 231 if (iph->frag_off & htons(IP_DF)) { 232 if (sk && inet_sk(sk)->daddr) { 233 iph->id = htons(inet_sk(sk)->id); 234 inet_sk(sk)->id += 1 + more; 235 } else 236 iph->id = 0; 237 } else 238 __ip_select_ident(iph, dst, more); 239 } 240 241 /* 242 * Map a multicast IP onto multicast MAC for type ethernet. 243 */ 244 245 static inline void ip_eth_mc_map(__be32 naddr, char *buf) 246 { 247 __u32 addr=ntohl(naddr); 248 buf[0]=0x01; 249 buf[1]=0x00; 250 buf[2]=0x5e; 251 buf[5]=addr&0xFF; 252 addr>>=8; 253 buf[4]=addr&0xFF; 254 addr>>=8; 255 buf[3]=addr&0x7F; 256 } 257 258 /* 259 * Map a multicast IP onto multicast MAC for type IP-over-InfiniBand. 260 * Leave P_Key as 0 to be filled in by driver. 261 */ 262 263 static inline void ip_ib_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf) 264 { 265 __u32 addr; 266 unsigned char scope = broadcast[5] & 0xF; 267 268 buf[0] = 0; /* Reserved */ 269 buf[1] = 0xff; /* Multicast QPN */ 270 buf[2] = 0xff; 271 buf[3] = 0xff; 272 addr = ntohl(naddr); 273 buf[4] = 0xff; 274 buf[5] = 0x10 | scope; /* scope from broadcast address */ 275 buf[6] = 0x40; /* IPv4 signature */ 276 buf[7] = 0x1b; 277 buf[8] = broadcast[8]; /* P_Key */ 278 buf[9] = broadcast[9]; 279 buf[10] = 0; 280 buf[11] = 0; 281 buf[12] = 0; 282 buf[13] = 0; 283 buf[14] = 0; 284 buf[15] = 0; 285 buf[19] = addr & 0xff; 286 addr >>= 8; 287 buf[18] = addr & 0xff; 288 addr >>= 8; 289 buf[17] = addr & 0xff; 290 addr >>= 8; 291 buf[16] = addr & 0x0f; 292 } 293 294 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 295 #include <linux/ipv6.h> 296 #endif 297 298 static __inline__ void inet_reset_saddr(struct sock *sk) 299 { 300 inet_sk(sk)->rcv_saddr = inet_sk(sk)->saddr = 0; 301 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 302 if (sk->sk_family == PF_INET6) { 303 struct ipv6_pinfo *np = inet6_sk(sk); 304 305 memset(&np->saddr, 0, sizeof(np->saddr)); 306 memset(&np->rcv_saddr, 0, sizeof(np->rcv_saddr)); 307 } 308 #endif 309 } 310 311 #endif 312 313 extern int ip_call_ra_chain(struct sk_buff *skb); 314 315 /* 316 * Functions provided by ip_fragment.c 317 */ 318 319 enum ip_defrag_users 320 { 321 IP_DEFRAG_LOCAL_DELIVER, 322 IP_DEFRAG_CALL_RA_CHAIN, 323 IP_DEFRAG_CONNTRACK_IN, 324 IP_DEFRAG_CONNTRACK_OUT, 325 IP_DEFRAG_VS_IN, 326 IP_DEFRAG_VS_OUT, 327 IP_DEFRAG_VS_FWD 328 }; 329 330 int ip_defrag(struct sk_buff *skb, u32 user); 331 int ip_frag_mem(struct net *net); 332 int ip_frag_nqueues(struct net *net); 333 334 /* 335 * Functions provided by ip_forward.c 336 */ 337 338 extern int ip_forward(struct sk_buff *skb); 339 340 /* 341 * Functions provided by ip_options.c 342 */ 343 344 extern void ip_options_build(struct sk_buff *skb, struct ip_options *opt, __be32 daddr, struct rtable *rt, int is_frag); 345 extern int ip_options_echo(struct ip_options *dopt, struct sk_buff *skb); 346 extern void ip_options_fragment(struct sk_buff *skb); 347 extern int ip_options_compile(struct net *net, 348 struct ip_options *opt, struct sk_buff *skb); 349 extern int ip_options_get(struct net *net, struct ip_options **optp, 350 unsigned char *data, int optlen); 351 extern int ip_options_get_from_user(struct net *net, struct ip_options **optp, 352 unsigned char __user *data, int optlen); 353 extern void ip_options_undo(struct ip_options * opt); 354 extern void ip_forward_options(struct sk_buff *skb); 355 extern int ip_options_rcv_srr(struct sk_buff *skb); 356 357 /* 358 * Functions provided by ip_sockglue.c 359 */ 360 361 extern void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb); 362 extern int ip_cmsg_send(struct net *net, 363 struct msghdr *msg, struct ipcm_cookie *ipc); 364 extern int ip_setsockopt(struct sock *sk, int level, int optname, char __user *optval, int optlen); 365 extern int ip_getsockopt(struct sock *sk, int level, int optname, char __user *optval, int __user *optlen); 366 extern int compat_ip_setsockopt(struct sock *sk, int level, 367 int optname, char __user *optval, int optlen); 368 extern int compat_ip_getsockopt(struct sock *sk, int level, 369 int optname, char __user *optval, int __user *optlen); 370 extern int ip_ra_control(struct sock *sk, unsigned char on, void (*destructor)(struct sock *)); 371 372 extern int ip_recv_error(struct sock *sk, struct msghdr *msg, int len); 373 extern void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err, 374 __be16 port, u32 info, u8 *payload); 375 extern void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 dport, 376 u32 info); 377 378 /* sysctl helpers - any sysctl which holds a value that ends up being 379 * fed into the routing cache should use these handlers. 380 */ 381 int ipv4_doint_and_flush(ctl_table *ctl, int write, 382 struct file* filp, void __user *buffer, 383 size_t *lenp, loff_t *ppos); 384 int ipv4_doint_and_flush_strategy(ctl_table *table, int __user *name, int nlen, 385 void __user *oldval, size_t __user *oldlenp, 386 void __user *newval, size_t newlen); 387 #ifdef CONFIG_PROC_FS 388 extern int ip_misc_proc_init(void); 389 #endif 390 391 #endif /* _IP_H */ 392