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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/ip.h>
28#include <linux/in.h>
29
30#include <net/inet_sock.h>
31#include <net/snmp.h>
32
33struct sock;
34
35struct 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
47struct ipcm_cookie
48{
49 u32 addr;
50 int oif;
51 struct ip_options *opt;
52};
53
54#define IPCB(skb) ((struct inet_skb_parm*)((skb)->cb))
55
56struct ip_ra_chain
57{
58 struct ip_ra_chain *next;
59 struct sock *sk;
60 void (*destructor)(struct sock *);
61};
62
63extern struct ip_ra_chain *ip_ra_chain;
64extern rwlock_t ip_ra_lock;
65
66/* IP flags. */
67#define IP_CE 0x8000 /* Flag: "Congestion" */
68#define IP_DF 0x4000 /* Flag: "Don't Fragment" */
69#define IP_MF 0x2000 /* Flag: "More Fragments" */
70#define IP_OFFSET 0x1FFF /* "Fragment Offset" part */
71
72#define IP_FRAG_TIME (30 * HZ) /* fragment lifetime */
73
74struct msghdr;
75struct net_device;
76struct packet_type;
77struct rtable;
78struct sk_buff;
79struct sockaddr;
80
81extern void ip_mc_dropsocket(struct sock *);
82extern void ip_mc_dropdevice(struct net_device *dev);
83extern int igmp_mc_proc_init(void);
84
85/*
86 * Functions provided by ip.c
87 */
88
89extern int ip_build_and_send_pkt(struct sk_buff *skb, struct sock *sk,
90 u32 saddr, u32 daddr,
91 struct ip_options *opt);
92extern int ip_rcv(struct sk_buff *skb, struct net_device *dev,
93 struct packet_type *pt, struct net_device *orig_dev);
94extern int ip_local_deliver(struct sk_buff *skb);
95extern int ip_mr_input(struct sk_buff *skb);
96extern int ip_output(struct sk_buff *skb);
97extern int ip_mc_output(struct sk_buff *skb);
98extern int ip_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *));
99extern int ip_do_nat(struct sk_buff *skb);
100extern void ip_send_check(struct iphdr *ip);
101extern int ip_queue_xmit(struct sk_buff *skb, int ipfragok);
102extern void ip_init(void);
103extern int ip_append_data(struct sock *sk,
104 int getfrag(void *from, char *to, int offset, int len,
105 int odd, struct sk_buff *skb),
106 void *from, int len, int protolen,
107 struct ipcm_cookie *ipc,
108 struct rtable *rt,
109 unsigned int flags);
110extern int ip_generic_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb);
111extern ssize_t ip_append_page(struct sock *sk, struct page *page,
112 int offset, size_t size, int flags);
113extern int ip_push_pending_frames(struct sock *sk);
114extern void ip_flush_pending_frames(struct sock *sk);
115
116/* datagram.c */
117extern int ip4_datagram_connect(struct sock *sk,
118 struct sockaddr *uaddr, int addr_len);
119
120/*
121 * Map a multicast IP onto multicast MAC for type Token Ring.
122 * This conforms to RFC1469 Option 2 Multicasting i.e.
123 * using a functional address to transmit / receive
124 * multicast packets.
125 */
126
127static inline void ip_tr_mc_map(u32 addr, char *buf)
128{
129 buf[0]=0xC0;
130 buf[1]=0x00;
131 buf[2]=0x00;
132 buf[3]=0x04;
133 buf[4]=0x00;
134 buf[5]=0x00;
135}
136
137struct ip_reply_arg {
138 struct kvec iov[1];
139 u32 csum;
140 int csumoffset; /* u16 offset of csum in iov[0].iov_base */
141 /* -1 if not needed */
142};
143
144void ip_send_reply(struct sock *sk, struct sk_buff *skb, struct ip_reply_arg *arg,
145 unsigned int len);
146
147struct ipv4_config
148{
149 int log_martians;
150 int autoconfig;
151 int no_pmtu_disc;
152};
153
154extern struct ipv4_config ipv4_config;
155DECLARE_SNMP_STAT(struct ipstats_mib, ip_statistics);
156#define IP_INC_STATS(field) SNMP_INC_STATS(ip_statistics, field)
157#define IP_INC_STATS_BH(field) SNMP_INC_STATS_BH(ip_statistics, field)
158#define IP_INC_STATS_USER(field) SNMP_INC_STATS_USER(ip_statistics, field)
159DECLARE_SNMP_STAT(struct linux_mib, net_statistics);
160#define NET_INC_STATS(field) SNMP_INC_STATS(net_statistics, field)
161#define NET_INC_STATS_BH(field) SNMP_INC_STATS_BH(net_statistics, field)
162#define NET_INC_STATS_USER(field) SNMP_INC_STATS_USER(net_statistics, field)
163#define NET_ADD_STATS_BH(field, adnd) SNMP_ADD_STATS_BH(net_statistics, field, adnd)
164#define NET_ADD_STATS_USER(field, adnd) SNMP_ADD_STATS_USER(net_statistics, field, adnd)
165
166extern int sysctl_local_port_range[2];
167extern int sysctl_ip_default_ttl;
168extern int sysctl_ip_nonlocal_bind;
169
170/* From ip_fragment.c */
171extern int sysctl_ipfrag_high_thresh;
172extern int sysctl_ipfrag_low_thresh;
173extern int sysctl_ipfrag_time;
174extern int sysctl_ipfrag_secret_interval;
175extern int sysctl_ipfrag_max_dist;
176
177/* From inetpeer.c */
178extern int inet_peer_threshold;
179extern int inet_peer_minttl;
180extern int inet_peer_maxttl;
181extern int inet_peer_gc_mintime;
182extern int inet_peer_gc_maxtime;
183
184/* From ip_output.c */
185extern int sysctl_ip_dynaddr;
186
187extern void ipfrag_init(void);
188
189#ifdef CONFIG_INET
190#include <net/dst.h>
191
192/* The function in 2.2 was invalid, producing wrong result for
193 * check=0xFEFF. It was noticed by Arthur Skawina _year_ ago. --ANK(000625) */
194static inline
195int ip_decrease_ttl(struct iphdr *iph)
196{
197 u32 check = iph->check;
198 check += htons(0x0100);
199 iph->check = check + (check>=0xFFFF);
200 return --iph->ttl;
201}
202
203static inline
204int ip_dont_fragment(struct sock *sk, struct dst_entry *dst)
205{
206 return (inet_sk(sk)->pmtudisc == IP_PMTUDISC_DO ||
207 (inet_sk(sk)->pmtudisc == IP_PMTUDISC_WANT &&
208 !(dst_metric(dst, RTAX_LOCK)&(1<<RTAX_MTU))));
209}
210
211extern void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more);
212
213static inline void ip_select_ident(struct iphdr *iph, struct dst_entry *dst, struct sock *sk)
214{
215 if (iph->frag_off & htons(IP_DF)) {
216 /* This is only to work around buggy Windows95/2000
217 * VJ compression implementations. If the ID field
218 * does not change, they drop every other packet in
219 * a TCP stream using header compression.
220 */
221 iph->id = (sk && inet_sk(sk)->daddr) ?
222 htons(inet_sk(sk)->id++) : 0;
223 } else
224 __ip_select_ident(iph, dst, 0);
225}
226
227static inline void ip_select_ident_more(struct iphdr *iph, struct dst_entry *dst, struct sock *sk, int more)
228{
229 if (iph->frag_off & htons(IP_DF)) {
230 if (sk && inet_sk(sk)->daddr) {
231 iph->id = htons(inet_sk(sk)->id);
232 inet_sk(sk)->id += 1 + more;
233 } else
234 iph->id = 0;
235 } else
236 __ip_select_ident(iph, dst, more);
237}
238
239/*
240 * Map a multicast IP onto multicast MAC for type ethernet.
241 */
242
243static inline void ip_eth_mc_map(u32 addr, char *buf)
244{
245 addr=ntohl(addr);
246 buf[0]=0x01;
247 buf[1]=0x00;
248 buf[2]=0x5e;
249 buf[5]=addr&0xFF;
250 addr>>=8;
251 buf[4]=addr&0xFF;
252 addr>>=8;
253 buf[3]=addr&0x7F;
254}
255
256/*
257 * Map a multicast IP onto multicast MAC for type IP-over-InfiniBand.
258 * Leave P_Key as 0 to be filled in by driver.
259 */
260
261static inline void ip_ib_mc_map(u32 addr, char *buf)
262{
263 buf[0] = 0; /* Reserved */
264 buf[1] = 0xff; /* Multicast QPN */
265 buf[2] = 0xff;
266 buf[3] = 0xff;
267 addr = ntohl(addr);
268 buf[4] = 0xff;
269 buf[5] = 0x12; /* link local scope */
270 buf[6] = 0x40; /* IPv4 signature */
271 buf[7] = 0x1b;
272 buf[8] = 0; /* P_Key */
273 buf[9] = 0;
274 buf[10] = 0;
275 buf[11] = 0;
276 buf[12] = 0;
277 buf[13] = 0;
278 buf[14] = 0;
279 buf[15] = 0;
280 buf[19] = addr & 0xff;
281 addr >>= 8;
282 buf[18] = addr & 0xff;
283 addr >>= 8;
284 buf[17] = addr & 0xff;
285 addr >>= 8;
286 buf[16] = addr & 0x0f;
287}
288
289#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
290#include <linux/ipv6.h>
291#endif
292
293static __inline__ void inet_reset_saddr(struct sock *sk)
294{
295 inet_sk(sk)->rcv_saddr = inet_sk(sk)->saddr = 0;
296#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
297 if (sk->sk_family == PF_INET6) {
298 struct ipv6_pinfo *np = inet6_sk(sk);
299
300 memset(&np->saddr, 0, sizeof(np->saddr));
301 memset(&np->rcv_saddr, 0, sizeof(np->rcv_saddr));
302 }
303#endif
304}
305
306#endif
307
308extern int ip_call_ra_chain(struct sk_buff *skb);
309
310/*
311 * Functions provided by ip_fragment.o
312 */
313
314enum ip_defrag_users
315{
316 IP_DEFRAG_LOCAL_DELIVER,
317 IP_DEFRAG_CALL_RA_CHAIN,
318 IP_DEFRAG_CONNTRACK_IN,
319 IP_DEFRAG_CONNTRACK_OUT,
320 IP_DEFRAG_VS_IN,
321 IP_DEFRAG_VS_OUT,
322 IP_DEFRAG_VS_FWD
323};
324
325struct sk_buff *ip_defrag(struct sk_buff *skb, u32 user);
326extern int ip_frag_nqueues;
327extern atomic_t ip_frag_mem;
328
329/*
330 * Functions provided by ip_forward.c
331 */
332
333extern int ip_forward(struct sk_buff *skb);
334extern int ip_net_unreachable(struct sk_buff *skb);
335
336/*
337 * Functions provided by ip_options.c
338 */
339
340extern void ip_options_build(struct sk_buff *skb, struct ip_options *opt, u32 daddr, struct rtable *rt, int is_frag);
341extern int ip_options_echo(struct ip_options *dopt, struct sk_buff *skb);
342extern void ip_options_fragment(struct sk_buff *skb);
343extern int ip_options_compile(struct ip_options *opt, struct sk_buff *skb);
344extern int ip_options_get(struct ip_options **optp,
345 unsigned char *data, int optlen);
346extern int ip_options_get_from_user(struct ip_options **optp,
347 unsigned char __user *data, int optlen);
348extern void ip_options_undo(struct ip_options * opt);
349extern void ip_forward_options(struct sk_buff *skb);
350extern int ip_options_rcv_srr(struct sk_buff *skb);
351
352/*
353 * Functions provided by ip_sockglue.c
354 */
355
356extern void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb);
357extern int ip_cmsg_send(struct msghdr *msg, struct ipcm_cookie *ipc);
358extern int ip_setsockopt(struct sock *sk, int level, int optname, char __user *optval, int optlen);
359extern int ip_getsockopt(struct sock *sk, int level, int optname, char __user *optval, int __user *optlen);
360extern int compat_ip_setsockopt(struct sock *sk, int level,
361 int optname, char __user *optval, int optlen);
362extern int compat_ip_getsockopt(struct sock *sk, int level,
363 int optname, char __user *optval, int __user *optlen);
364extern int ip_ra_control(struct sock *sk, unsigned char on, void (*destructor)(struct sock *));
365
366extern int ip_recv_error(struct sock *sk, struct msghdr *msg, int len);
367extern void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
368 u16 port, u32 info, u8 *payload);
369extern void ip_local_error(struct sock *sk, int err, u32 daddr, u16 dport,
370 u32 info);
371
372/* sysctl helpers - any sysctl which holds a value that ends up being
373 * fed into the routing cache should use these handlers.
374 */
375int ipv4_doint_and_flush(ctl_table *ctl, int write,
376 struct file* filp, void __user *buffer,
377 size_t *lenp, loff_t *ppos);
378int ipv4_doint_and_flush_strategy(ctl_table *table, int __user *name, int nlen,
379 void __user *oldval, size_t __user *oldlenp,
380 void __user *newval, size_t newlen,
381 void **context);
382#ifdef CONFIG_PROC_FS
383extern int ip_misc_proc_init(void);
384#endif
385
386extern struct ctl_table ipv4_table[];
387
388#endif /* _IP_H */