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 #include <net/flow.h> 33 34 struct sock; 35 36 struct inet_skb_parm 37 { 38 struct ip_options opt; /* Compiled IP options */ 39 unsigned char flags; 40 41 #define IPSKB_FORWARDED 1 42 #define IPSKB_XFRM_TUNNEL_SIZE 2 43 #define IPSKB_XFRM_TRANSFORMED 4 44 #define IPSKB_FRAG_COMPLETE 8 45 #define IPSKB_REROUTED 16 46 }; 47 48 static inline unsigned int ip_hdrlen(const struct sk_buff *skb) 49 { 50 return ip_hdr(skb)->ihl * 4; 51 } 52 53 struct ipcm_cookie 54 { 55 __be32 addr; 56 int oif; 57 struct ip_options *opt; 58 }; 59 60 #define IPCB(skb) ((struct inet_skb_parm*)((skb)->cb)) 61 62 struct ip_ra_chain 63 { 64 struct ip_ra_chain *next; 65 struct sock *sk; 66 void (*destructor)(struct sock *); 67 }; 68 69 extern struct ip_ra_chain *ip_ra_chain; 70 extern rwlock_t ip_ra_lock; 71 72 /* IP flags. */ 73 #define IP_CE 0x8000 /* Flag: "Congestion" */ 74 #define IP_DF 0x4000 /* Flag: "Don't Fragment" */ 75 #define IP_MF 0x2000 /* Flag: "More Fragments" */ 76 #define IP_OFFSET 0x1FFF /* "Fragment Offset" part */ 77 78 #define IP_FRAG_TIME (30 * HZ) /* fragment lifetime */ 79 80 struct msghdr; 81 struct net_device; 82 struct packet_type; 83 struct rtable; 84 struct sockaddr; 85 86 extern int igmp_mc_proc_init(void); 87 88 /* 89 * Functions provided by ip.c 90 */ 91 92 extern int ip_build_and_send_pkt(struct sk_buff *skb, struct sock *sk, 93 __be32 saddr, __be32 daddr, 94 struct ip_options *opt); 95 extern int ip_rcv(struct sk_buff *skb, struct net_device *dev, 96 struct packet_type *pt, struct net_device *orig_dev); 97 extern int ip_local_deliver(struct sk_buff *skb); 98 extern int ip_mr_input(struct sk_buff *skb); 99 extern int ip_output(struct sk_buff *skb); 100 extern int ip_mc_output(struct sk_buff *skb); 101 extern int ip_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *)); 102 extern int ip_do_nat(struct sk_buff *skb); 103 extern void ip_send_check(struct iphdr *ip); 104 extern int __ip_local_out(struct sk_buff *skb); 105 extern int ip_local_out(struct sk_buff *skb); 106 extern int ip_queue_xmit(struct sk_buff *skb, int ipfragok); 107 extern void ip_init(void); 108 extern int ip_append_data(struct sock *sk, 109 int getfrag(void *from, char *to, int offset, int len, 110 int odd, struct sk_buff *skb), 111 void *from, int len, int protolen, 112 struct ipcm_cookie *ipc, 113 struct rtable *rt, 114 unsigned int flags); 115 extern int ip_generic_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb); 116 extern ssize_t ip_append_page(struct sock *sk, struct page *page, 117 int offset, size_t size, int flags); 118 extern int ip_push_pending_frames(struct sock *sk); 119 extern void ip_flush_pending_frames(struct sock *sk); 120 121 /* datagram.c */ 122 extern int ip4_datagram_connect(struct sock *sk, 123 struct sockaddr *uaddr, int addr_len); 124 125 /* 126 * Map a multicast IP onto multicast MAC for type Token Ring. 127 * This conforms to RFC1469 Option 2 Multicasting i.e. 128 * using a functional address to transmit / receive 129 * multicast packets. 130 */ 131 132 static inline void ip_tr_mc_map(__be32 addr, char *buf) 133 { 134 buf[0]=0xC0; 135 buf[1]=0x00; 136 buf[2]=0x00; 137 buf[3]=0x04; 138 buf[4]=0x00; 139 buf[5]=0x00; 140 } 141 142 struct ip_reply_arg { 143 struct kvec iov[1]; 144 int flags; 145 __wsum csum; 146 int csumoffset; /* u16 offset of csum in iov[0].iov_base */ 147 /* -1 if not needed */ 148 int bound_dev_if; 149 }; 150 151 #define IP_REPLY_ARG_NOSRCCHECK 1 152 153 static inline __u8 ip_reply_arg_flowi_flags(const struct ip_reply_arg *arg) 154 { 155 return (arg->flags & IP_REPLY_ARG_NOSRCCHECK) ? FLOWI_FLAG_ANYSRC : 0; 156 } 157 158 void ip_send_reply(struct sock *sk, struct sk_buff *skb, struct ip_reply_arg *arg, 159 unsigned int len); 160 161 struct ipv4_config 162 { 163 int log_martians; 164 int no_pmtu_disc; 165 }; 166 167 extern struct ipv4_config ipv4_config; 168 #define IP_INC_STATS(net, field) SNMP_INC_STATS((net)->mib.ip_statistics, field) 169 #define IP_INC_STATS_BH(net, field) SNMP_INC_STATS_BH((net)->mib.ip_statistics, field) 170 #define IP_ADD_STATS_BH(net, field, val) SNMP_ADD_STATS_BH((net)->mib.ip_statistics, field, val) 171 #define NET_INC_STATS(net, field) SNMP_INC_STATS((net)->mib.net_statistics, field) 172 #define NET_INC_STATS_BH(net, field) SNMP_INC_STATS_BH((net)->mib.net_statistics, field) 173 #define NET_INC_STATS_USER(net, field) SNMP_INC_STATS_USER((net)->mib.net_statistics, field) 174 #define NET_ADD_STATS_BH(net, field, adnd) SNMP_ADD_STATS_BH((net)->mib.net_statistics, field, adnd) 175 #define NET_ADD_STATS_USER(net, field, adnd) SNMP_ADD_STATS_USER((net)->mib.net_statistics, field, adnd) 176 177 extern unsigned long snmp_fold_field(void *mib[], int offt); 178 extern int snmp_mib_init(void *ptr[2], size_t mibsize); 179 extern void snmp_mib_free(void *ptr[2]); 180 181 extern struct local_ports { 182 seqlock_t lock; 183 int range[2]; 184 } sysctl_local_ports; 185 extern void inet_get_local_port_range(int *low, int *high); 186 187 extern int sysctl_ip_default_ttl; 188 extern int sysctl_ip_nonlocal_bind; 189 190 extern struct ctl_path net_ipv4_ctl_path[]; 191 192 /* From inetpeer.c */ 193 extern int inet_peer_threshold; 194 extern int inet_peer_minttl; 195 extern int inet_peer_maxttl; 196 extern int inet_peer_gc_mintime; 197 extern int inet_peer_gc_maxtime; 198 199 /* From ip_output.c */ 200 extern int sysctl_ip_dynaddr; 201 202 extern void ipfrag_init(void); 203 204 extern void ip_static_sysctl_init(void); 205 206 #ifdef CONFIG_INET 207 #include <net/dst.h> 208 209 /* The function in 2.2 was invalid, producing wrong result for 210 * check=0xFEFF. It was noticed by Arthur Skawina _year_ ago. --ANK(000625) */ 211 static inline 212 int ip_decrease_ttl(struct iphdr *iph) 213 { 214 u32 check = (__force u32)iph->check; 215 check += (__force u32)htons(0x0100); 216 iph->check = (__force __sum16)(check + (check>=0xFFFF)); 217 return --iph->ttl; 218 } 219 220 static inline 221 int ip_dont_fragment(struct sock *sk, struct dst_entry *dst) 222 { 223 return (inet_sk(sk)->pmtudisc == IP_PMTUDISC_DO || 224 (inet_sk(sk)->pmtudisc == IP_PMTUDISC_WANT && 225 !(dst_metric_locked(dst, RTAX_MTU)))); 226 } 227 228 extern void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more); 229 230 static inline void ip_select_ident(struct iphdr *iph, struct dst_entry *dst, struct sock *sk) 231 { 232 if (iph->frag_off & htons(IP_DF)) { 233 /* This is only to work around buggy Windows95/2000 234 * VJ compression implementations. If the ID field 235 * does not change, they drop every other packet in 236 * a TCP stream using header compression. 237 */ 238 iph->id = (sk && inet_sk(sk)->daddr) ? 239 htons(inet_sk(sk)->id++) : 0; 240 } else 241 __ip_select_ident(iph, dst, 0); 242 } 243 244 static inline void ip_select_ident_more(struct iphdr *iph, struct dst_entry *dst, struct sock *sk, int more) 245 { 246 if (iph->frag_off & htons(IP_DF)) { 247 if (sk && inet_sk(sk)->daddr) { 248 iph->id = htons(inet_sk(sk)->id); 249 inet_sk(sk)->id += 1 + more; 250 } else 251 iph->id = 0; 252 } else 253 __ip_select_ident(iph, dst, more); 254 } 255 256 /* 257 * Map a multicast IP onto multicast MAC for type ethernet. 258 */ 259 260 static inline void ip_eth_mc_map(__be32 naddr, char *buf) 261 { 262 __u32 addr=ntohl(naddr); 263 buf[0]=0x01; 264 buf[1]=0x00; 265 buf[2]=0x5e; 266 buf[5]=addr&0xFF; 267 addr>>=8; 268 buf[4]=addr&0xFF; 269 addr>>=8; 270 buf[3]=addr&0x7F; 271 } 272 273 /* 274 * Map a multicast IP onto multicast MAC for type IP-over-InfiniBand. 275 * Leave P_Key as 0 to be filled in by driver. 276 */ 277 278 static inline void ip_ib_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf) 279 { 280 __u32 addr; 281 unsigned char scope = broadcast[5] & 0xF; 282 283 buf[0] = 0; /* Reserved */ 284 buf[1] = 0xff; /* Multicast QPN */ 285 buf[2] = 0xff; 286 buf[3] = 0xff; 287 addr = ntohl(naddr); 288 buf[4] = 0xff; 289 buf[5] = 0x10 | scope; /* scope from broadcast address */ 290 buf[6] = 0x40; /* IPv4 signature */ 291 buf[7] = 0x1b; 292 buf[8] = broadcast[8]; /* P_Key */ 293 buf[9] = broadcast[9]; 294 buf[10] = 0; 295 buf[11] = 0; 296 buf[12] = 0; 297 buf[13] = 0; 298 buf[14] = 0; 299 buf[15] = 0; 300 buf[19] = addr & 0xff; 301 addr >>= 8; 302 buf[18] = addr & 0xff; 303 addr >>= 8; 304 buf[17] = addr & 0xff; 305 addr >>= 8; 306 buf[16] = addr & 0x0f; 307 } 308 309 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 310 #include <linux/ipv6.h> 311 #endif 312 313 static __inline__ void inet_reset_saddr(struct sock *sk) 314 { 315 inet_sk(sk)->rcv_saddr = inet_sk(sk)->saddr = 0; 316 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 317 if (sk->sk_family == PF_INET6) { 318 struct ipv6_pinfo *np = inet6_sk(sk); 319 320 memset(&np->saddr, 0, sizeof(np->saddr)); 321 memset(&np->rcv_saddr, 0, sizeof(np->rcv_saddr)); 322 } 323 #endif 324 } 325 326 #endif 327 328 extern int ip_call_ra_chain(struct sk_buff *skb); 329 330 /* 331 * Functions provided by ip_fragment.c 332 */ 333 334 enum ip_defrag_users 335 { 336 IP_DEFRAG_LOCAL_DELIVER, 337 IP_DEFRAG_CALL_RA_CHAIN, 338 IP_DEFRAG_CONNTRACK_IN, 339 IP_DEFRAG_CONNTRACK_OUT, 340 IP_DEFRAG_VS_IN, 341 IP_DEFRAG_VS_OUT, 342 IP_DEFRAG_VS_FWD 343 }; 344 345 int ip_defrag(struct sk_buff *skb, u32 user); 346 int ip_frag_mem(struct net *net); 347 int ip_frag_nqueues(struct net *net); 348 349 /* 350 * Functions provided by ip_forward.c 351 */ 352 353 extern int ip_forward(struct sk_buff *skb); 354 355 /* 356 * Functions provided by ip_options.c 357 */ 358 359 extern void ip_options_build(struct sk_buff *skb, struct ip_options *opt, __be32 daddr, struct rtable *rt, int is_frag); 360 extern int ip_options_echo(struct ip_options *dopt, struct sk_buff *skb); 361 extern void ip_options_fragment(struct sk_buff *skb); 362 extern int ip_options_compile(struct net *net, 363 struct ip_options *opt, struct sk_buff *skb); 364 extern int ip_options_get(struct net *net, struct ip_options **optp, 365 unsigned char *data, int optlen); 366 extern int ip_options_get_from_user(struct net *net, struct ip_options **optp, 367 unsigned char __user *data, int optlen); 368 extern void ip_options_undo(struct ip_options * opt); 369 extern void ip_forward_options(struct sk_buff *skb); 370 extern int ip_options_rcv_srr(struct sk_buff *skb); 371 372 /* 373 * Functions provided by ip_sockglue.c 374 */ 375 376 extern void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb); 377 extern int ip_cmsg_send(struct net *net, 378 struct msghdr *msg, struct ipcm_cookie *ipc); 379 extern int ip_setsockopt(struct sock *sk, int level, int optname, char __user *optval, int optlen); 380 extern int ip_getsockopt(struct sock *sk, int level, int optname, char __user *optval, int __user *optlen); 381 extern int compat_ip_setsockopt(struct sock *sk, int level, 382 int optname, char __user *optval, int optlen); 383 extern int compat_ip_getsockopt(struct sock *sk, int level, 384 int optname, char __user *optval, int __user *optlen); 385 extern int ip_ra_control(struct sock *sk, unsigned char on, void (*destructor)(struct sock *)); 386 387 extern int ip_recv_error(struct sock *sk, struct msghdr *msg, int len); 388 extern void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err, 389 __be16 port, u32 info, u8 *payload); 390 extern void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 dport, 391 u32 info); 392 393 /* sysctl helpers - any sysctl which holds a value that ends up being 394 * fed into the routing cache should use these handlers. 395 */ 396 int ipv4_doint_and_flush(ctl_table *ctl, int write, 397 struct file* filp, void __user *buffer, 398 size_t *lenp, loff_t *ppos); 399 int ipv4_doint_and_flush_strategy(ctl_table *table, 400 void __user *oldval, size_t __user *oldlenp, 401 void __user *newval, size_t newlen); 402 #ifdef CONFIG_PROC_FS 403 extern int ip_misc_proc_init(void); 404 #endif 405 406 #endif /* _IP_H */ 407