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 union skb_shared_tx shtx; 59 }; 60 61 #define IPCB(skb) ((struct inet_skb_parm*)((skb)->cb)) 62 63 struct ip_ra_chain 64 { 65 struct ip_ra_chain *next; 66 struct sock *sk; 67 void (*destructor)(struct sock *); 68 }; 69 70 extern struct ip_ra_chain *ip_ra_chain; 71 extern rwlock_t ip_ra_lock; 72 73 /* IP flags. */ 74 #define IP_CE 0x8000 /* Flag: "Congestion" */ 75 #define IP_DF 0x4000 /* Flag: "Don't Fragment" */ 76 #define IP_MF 0x2000 /* Flag: "More Fragments" */ 77 #define IP_OFFSET 0x1FFF /* "Fragment Offset" part */ 78 79 #define IP_FRAG_TIME (30 * HZ) /* fragment lifetime */ 80 81 struct msghdr; 82 struct net_device; 83 struct packet_type; 84 struct rtable; 85 struct sockaddr; 86 87 extern int igmp_mc_proc_init(void); 88 89 /* 90 * Functions provided by ip.c 91 */ 92 93 extern int ip_build_and_send_pkt(struct sk_buff *skb, struct sock *sk, 94 __be32 saddr, __be32 daddr, 95 struct ip_options *opt); 96 extern int ip_rcv(struct sk_buff *skb, struct net_device *dev, 97 struct packet_type *pt, struct net_device *orig_dev); 98 extern int ip_local_deliver(struct sk_buff *skb); 99 extern int ip_mr_input(struct sk_buff *skb); 100 extern int ip_output(struct sk_buff *skb); 101 extern int ip_mc_output(struct sk_buff *skb); 102 extern int ip_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *)); 103 extern int ip_do_nat(struct sk_buff *skb); 104 extern void ip_send_check(struct iphdr *ip); 105 extern int __ip_local_out(struct sk_buff *skb); 106 extern int ip_local_out(struct sk_buff *skb); 107 extern int ip_queue_xmit(struct sk_buff *skb, int ipfragok); 108 extern void ip_init(void); 109 extern int ip_append_data(struct sock *sk, 110 int getfrag(void *from, char *to, int offset, int len, 111 int odd, struct sk_buff *skb), 112 void *from, int len, int protolen, 113 struct ipcm_cookie *ipc, 114 struct rtable **rt, 115 unsigned int flags); 116 extern int ip_generic_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb); 117 extern ssize_t ip_append_page(struct sock *sk, struct page *page, 118 int offset, size_t size, int flags); 119 extern int ip_push_pending_frames(struct sock *sk); 120 extern void ip_flush_pending_frames(struct sock *sk); 121 122 /* datagram.c */ 123 extern int ip4_datagram_connect(struct sock *sk, 124 struct sockaddr *uaddr, int addr_len); 125 126 /* 127 * Map a multicast IP onto multicast MAC for type Token Ring. 128 * This conforms to RFC1469 Option 2 Multicasting i.e. 129 * using a functional address to transmit / receive 130 * multicast packets. 131 */ 132 133 static inline void ip_tr_mc_map(__be32 addr, char *buf) 134 { 135 buf[0]=0xC0; 136 buf[1]=0x00; 137 buf[2]=0x00; 138 buf[3]=0x04; 139 buf[4]=0x00; 140 buf[5]=0x00; 141 } 142 143 struct ip_reply_arg { 144 struct kvec iov[1]; 145 int flags; 146 __wsum csum; 147 int csumoffset; /* u16 offset of csum in iov[0].iov_base */ 148 /* -1 if not needed */ 149 int bound_dev_if; 150 }; 151 152 #define IP_REPLY_ARG_NOSRCCHECK 1 153 154 static inline __u8 ip_reply_arg_flowi_flags(const struct ip_reply_arg *arg) 155 { 156 return (arg->flags & IP_REPLY_ARG_NOSRCCHECK) ? FLOWI_FLAG_ANYSRC : 0; 157 } 158 159 void ip_send_reply(struct sock *sk, struct sk_buff *skb, struct ip_reply_arg *arg, 160 unsigned int len); 161 162 struct ipv4_config 163 { 164 int log_martians; 165 int no_pmtu_disc; 166 }; 167 168 extern struct ipv4_config ipv4_config; 169 #define IP_INC_STATS(net, field) SNMP_INC_STATS((net)->mib.ip_statistics, field) 170 #define IP_INC_STATS_BH(net, field) SNMP_INC_STATS_BH((net)->mib.ip_statistics, field) 171 #define IP_ADD_STATS_BH(net, field, val) SNMP_ADD_STATS_BH((net)->mib.ip_statistics, field, val) 172 #define NET_INC_STATS(net, field) SNMP_INC_STATS((net)->mib.net_statistics, field) 173 #define NET_INC_STATS_BH(net, field) SNMP_INC_STATS_BH((net)->mib.net_statistics, field) 174 #define NET_INC_STATS_USER(net, field) SNMP_INC_STATS_USER((net)->mib.net_statistics, field) 175 #define NET_ADD_STATS_BH(net, field, adnd) SNMP_ADD_STATS_BH((net)->mib.net_statistics, field, adnd) 176 #define NET_ADD_STATS_USER(net, field, adnd) SNMP_ADD_STATS_USER((net)->mib.net_statistics, field, adnd) 177 178 extern unsigned long snmp_fold_field(void *mib[], int offt); 179 extern int snmp_mib_init(void *ptr[2], size_t mibsize); 180 extern void snmp_mib_free(void *ptr[2]); 181 182 extern struct local_ports { 183 seqlock_t lock; 184 int range[2]; 185 } sysctl_local_ports; 186 extern void inet_get_local_port_range(int *low, int *high); 187 188 extern int sysctl_ip_default_ttl; 189 extern int sysctl_ip_nonlocal_bind; 190 191 extern struct ctl_path net_core_path[]; 192 extern struct ctl_path net_ipv4_ctl_path[]; 193 194 /* From inetpeer.c */ 195 extern int inet_peer_threshold; 196 extern int inet_peer_minttl; 197 extern int inet_peer_maxttl; 198 extern int inet_peer_gc_mintime; 199 extern int inet_peer_gc_maxtime; 200 201 /* From ip_output.c */ 202 extern int sysctl_ip_dynaddr; 203 204 extern void ipfrag_init(void); 205 206 extern void ip_static_sysctl_init(void); 207 208 #ifdef CONFIG_INET 209 #include <net/dst.h> 210 211 /* The function in 2.2 was invalid, producing wrong result for 212 * check=0xFEFF. It was noticed by Arthur Skawina _year_ ago. --ANK(000625) */ 213 static inline 214 int ip_decrease_ttl(struct iphdr *iph) 215 { 216 u32 check = (__force u32)iph->check; 217 check += (__force u32)htons(0x0100); 218 iph->check = (__force __sum16)(check + (check>=0xFFFF)); 219 return --iph->ttl; 220 } 221 222 static inline 223 int ip_dont_fragment(struct sock *sk, struct dst_entry *dst) 224 { 225 return (inet_sk(sk)->pmtudisc == IP_PMTUDISC_DO || 226 (inet_sk(sk)->pmtudisc == IP_PMTUDISC_WANT && 227 !(dst_metric_locked(dst, RTAX_MTU)))); 228 } 229 230 extern void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more); 231 232 static inline void ip_select_ident(struct iphdr *iph, struct dst_entry *dst, struct sock *sk) 233 { 234 if (iph->frag_off & htons(IP_DF)) { 235 /* This is only to work around buggy Windows95/2000 236 * VJ compression implementations. If the ID field 237 * does not change, they drop every other packet in 238 * a TCP stream using header compression. 239 */ 240 iph->id = (sk && inet_sk(sk)->daddr) ? 241 htons(inet_sk(sk)->id++) : 0; 242 } else 243 __ip_select_ident(iph, dst, 0); 244 } 245 246 static inline void ip_select_ident_more(struct iphdr *iph, struct dst_entry *dst, struct sock *sk, int more) 247 { 248 if (iph->frag_off & htons(IP_DF)) { 249 if (sk && inet_sk(sk)->daddr) { 250 iph->id = htons(inet_sk(sk)->id); 251 inet_sk(sk)->id += 1 + more; 252 } else 253 iph->id = 0; 254 } else 255 __ip_select_ident(iph, dst, more); 256 } 257 258 /* 259 * Map a multicast IP onto multicast MAC for type ethernet. 260 */ 261 262 static inline void ip_eth_mc_map(__be32 naddr, char *buf) 263 { 264 __u32 addr=ntohl(naddr); 265 buf[0]=0x01; 266 buf[1]=0x00; 267 buf[2]=0x5e; 268 buf[5]=addr&0xFF; 269 addr>>=8; 270 buf[4]=addr&0xFF; 271 addr>>=8; 272 buf[3]=addr&0x7F; 273 } 274 275 /* 276 * Map a multicast IP onto multicast MAC for type IP-over-InfiniBand. 277 * Leave P_Key as 0 to be filled in by driver. 278 */ 279 280 static inline void ip_ib_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf) 281 { 282 __u32 addr; 283 unsigned char scope = broadcast[5] & 0xF; 284 285 buf[0] = 0; /* Reserved */ 286 buf[1] = 0xff; /* Multicast QPN */ 287 buf[2] = 0xff; 288 buf[3] = 0xff; 289 addr = ntohl(naddr); 290 buf[4] = 0xff; 291 buf[5] = 0x10 | scope; /* scope from broadcast address */ 292 buf[6] = 0x40; /* IPv4 signature */ 293 buf[7] = 0x1b; 294 buf[8] = broadcast[8]; /* P_Key */ 295 buf[9] = broadcast[9]; 296 buf[10] = 0; 297 buf[11] = 0; 298 buf[12] = 0; 299 buf[13] = 0; 300 buf[14] = 0; 301 buf[15] = 0; 302 buf[19] = addr & 0xff; 303 addr >>= 8; 304 buf[18] = addr & 0xff; 305 addr >>= 8; 306 buf[17] = addr & 0xff; 307 addr >>= 8; 308 buf[16] = addr & 0x0f; 309 } 310 311 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 312 #include <linux/ipv6.h> 313 #endif 314 315 static __inline__ void inet_reset_saddr(struct sock *sk) 316 { 317 inet_sk(sk)->rcv_saddr = inet_sk(sk)->saddr = 0; 318 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 319 if (sk->sk_family == PF_INET6) { 320 struct ipv6_pinfo *np = inet6_sk(sk); 321 322 memset(&np->saddr, 0, sizeof(np->saddr)); 323 memset(&np->rcv_saddr, 0, sizeof(np->rcv_saddr)); 324 } 325 #endif 326 } 327 328 #endif 329 330 extern int ip_call_ra_chain(struct sk_buff *skb); 331 332 /* 333 * Functions provided by ip_fragment.c 334 */ 335 336 enum ip_defrag_users 337 { 338 IP_DEFRAG_LOCAL_DELIVER, 339 IP_DEFRAG_CALL_RA_CHAIN, 340 IP_DEFRAG_CONNTRACK_IN, 341 IP_DEFRAG_CONNTRACK_OUT, 342 IP_DEFRAG_VS_IN, 343 IP_DEFRAG_VS_OUT, 344 IP_DEFRAG_VS_FWD 345 }; 346 347 int ip_defrag(struct sk_buff *skb, u32 user); 348 int ip_frag_mem(struct net *net); 349 int ip_frag_nqueues(struct net *net); 350 351 /* 352 * Functions provided by ip_forward.c 353 */ 354 355 extern int ip_forward(struct sk_buff *skb); 356 357 /* 358 * Functions provided by ip_options.c 359 */ 360 361 extern void ip_options_build(struct sk_buff *skb, struct ip_options *opt, __be32 daddr, struct rtable *rt, int is_frag); 362 extern int ip_options_echo(struct ip_options *dopt, struct sk_buff *skb); 363 extern void ip_options_fragment(struct sk_buff *skb); 364 extern int ip_options_compile(struct net *net, 365 struct ip_options *opt, struct sk_buff *skb); 366 extern int ip_options_get(struct net *net, struct ip_options **optp, 367 unsigned char *data, int optlen); 368 extern int ip_options_get_from_user(struct net *net, struct ip_options **optp, 369 unsigned char __user *data, int optlen); 370 extern void ip_options_undo(struct ip_options * opt); 371 extern void ip_forward_options(struct sk_buff *skb); 372 extern int ip_options_rcv_srr(struct sk_buff *skb); 373 374 /* 375 * Functions provided by ip_sockglue.c 376 */ 377 378 extern void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb); 379 extern int ip_cmsg_send(struct net *net, 380 struct msghdr *msg, struct ipcm_cookie *ipc); 381 extern int ip_setsockopt(struct sock *sk, int level, int optname, char __user *optval, int optlen); 382 extern int ip_getsockopt(struct sock *sk, int level, int optname, char __user *optval, int __user *optlen); 383 extern int compat_ip_setsockopt(struct sock *sk, int level, 384 int optname, char __user *optval, int optlen); 385 extern int compat_ip_getsockopt(struct sock *sk, int level, 386 int optname, char __user *optval, int __user *optlen); 387 extern int ip_ra_control(struct sock *sk, unsigned char on, void (*destructor)(struct sock *)); 388 389 extern int ip_recv_error(struct sock *sk, struct msghdr *msg, int len); 390 extern void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err, 391 __be16 port, u32 info, u8 *payload); 392 extern void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 dport, 393 u32 info); 394 395 /* sysctl helpers - any sysctl which holds a value that ends up being 396 * fed into the routing cache should use these handlers. 397 */ 398 int ipv4_doint_and_flush(ctl_table *ctl, int write, 399 struct file* filp, void __user *buffer, 400 size_t *lenp, loff_t *ppos); 401 int ipv4_doint_and_flush_strategy(ctl_table *table, 402 void __user *oldval, size_t __user *oldlenp, 403 void __user *newval, size_t newlen); 404 #ifdef CONFIG_PROC_FS 405 extern int ip_misc_proc_init(void); 406 #endif 407 408 #endif /* _IP_H */ 409