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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/types.h>
26#include <linux/ip.h>
27#include <linux/in.h>
28
29#include <net/inet_sock.h>
30#include <net/snmp.h>
31
32struct sock;
33
34struct inet_skb_parm
35{
36 struct ip_options opt; /* Compiled IP options */
37 unsigned char flags;
38
39#define IPSKB_FORWARDED 1
40#define IPSKB_XFRM_TUNNEL_SIZE 2
41#define IPSKB_XFRM_TRANSFORMED 4
42#define IPSKB_FRAG_COMPLETE 8
43#define IPSKB_REROUTED 16
44};
45
46struct ipcm_cookie
47{
48 __be32 addr;
49 int oif;
50 struct ip_options *opt;
51};
52
53#define IPCB(skb) ((struct inet_skb_parm*)((skb)->cb))
54
55struct ip_ra_chain
56{
57 struct ip_ra_chain *next;
58 struct sock *sk;
59 void (*destructor)(struct sock *);
60};
61
62extern struct ip_ra_chain *ip_ra_chain;
63extern rwlock_t ip_ra_lock;
64
65/* IP flags. */
66#define IP_CE 0x8000 /* Flag: "Congestion" */
67#define IP_DF 0x4000 /* Flag: "Don't Fragment" */
68#define IP_MF 0x2000 /* Flag: "More Fragments" */
69#define IP_OFFSET 0x1FFF /* "Fragment Offset" part */
70
71#define IP_FRAG_TIME (30 * HZ) /* fragment lifetime */
72
73struct msghdr;
74struct net_device;
75struct packet_type;
76struct rtable;
77struct sk_buff;
78struct sockaddr;
79
80extern void ip_mc_dropsocket(struct sock *);
81extern void ip_mc_dropdevice(struct net_device *dev);
82extern int igmp_mc_proc_init(void);
83
84/*
85 * Functions provided by ip.c
86 */
87
88extern int ip_build_and_send_pkt(struct sk_buff *skb, struct sock *sk,
89 __be32 saddr, __be32 daddr,
90 struct ip_options *opt);
91extern int ip_rcv(struct sk_buff *skb, struct net_device *dev,
92 struct packet_type *pt, struct net_device *orig_dev);
93extern int ip_local_deliver(struct sk_buff *skb);
94extern int ip_mr_input(struct sk_buff *skb);
95extern int ip_output(struct sk_buff *skb);
96extern int ip_mc_output(struct sk_buff *skb);
97extern int ip_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *));
98extern int ip_do_nat(struct sk_buff *skb);
99extern void ip_send_check(struct iphdr *ip);
100extern int ip_queue_xmit(struct sk_buff *skb, int ipfragok);
101extern void ip_init(void);
102extern int ip_append_data(struct sock *sk,
103 int getfrag(void *from, char *to, int offset, int len,
104 int odd, struct sk_buff *skb),
105 void *from, int len, int protolen,
106 struct ipcm_cookie *ipc,
107 struct rtable *rt,
108 unsigned int flags);
109extern int ip_generic_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb);
110extern ssize_t ip_append_page(struct sock *sk, struct page *page,
111 int offset, size_t size, int flags);
112extern int ip_push_pending_frames(struct sock *sk);
113extern void ip_flush_pending_frames(struct sock *sk);
114
115/* datagram.c */
116extern int ip4_datagram_connect(struct sock *sk,
117 struct sockaddr *uaddr, int addr_len);
118
119/*
120 * Map a multicast IP onto multicast MAC for type Token Ring.
121 * This conforms to RFC1469 Option 2 Multicasting i.e.
122 * using a functional address to transmit / receive
123 * multicast packets.
124 */
125
126static inline void ip_tr_mc_map(__be32 addr, char *buf)
127{
128 buf[0]=0xC0;
129 buf[1]=0x00;
130 buf[2]=0x00;
131 buf[3]=0x04;
132 buf[4]=0x00;
133 buf[5]=0x00;
134}
135
136struct ip_reply_arg {
137 struct kvec iov[1];
138 __wsum csum;
139 int csumoffset; /* u16 offset of csum in iov[0].iov_base */
140 /* -1 if not needed */
141};
142
143void ip_send_reply(struct sock *sk, struct sk_buff *skb, struct ip_reply_arg *arg,
144 unsigned int len);
145
146struct ipv4_config
147{
148 int log_martians;
149 int no_pmtu_disc;
150};
151
152extern struct ipv4_config ipv4_config;
153DECLARE_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)
157DECLARE_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
164extern int sysctl_local_port_range[2];
165extern int sysctl_ip_default_ttl;
166extern int sysctl_ip_nonlocal_bind;
167
168/* From ip_fragment.c */
169extern int sysctl_ipfrag_high_thresh;
170extern int sysctl_ipfrag_low_thresh;
171extern int sysctl_ipfrag_time;
172extern int sysctl_ipfrag_secret_interval;
173extern int sysctl_ipfrag_max_dist;
174
175/* From inetpeer.c */
176extern int inet_peer_threshold;
177extern int inet_peer_minttl;
178extern int inet_peer_maxttl;
179extern int inet_peer_gc_mintime;
180extern int inet_peer_gc_maxtime;
181
182/* From ip_output.c */
183extern int sysctl_ip_dynaddr;
184
185extern void ipfrag_init(void);
186
187#ifdef CONFIG_INET
188#include <net/dst.h>
189
190/* The function in 2.2 was invalid, producing wrong result for
191 * check=0xFEFF. It was noticed by Arthur Skawina _year_ ago. --ANK(000625) */
192static inline
193int ip_decrease_ttl(struct iphdr *iph)
194{
195 u32 check = (__force u32)iph->check;
196 check += (__force u32)htons(0x0100);
197 iph->check = (__force __sum16)(check + (check>=0xFFFF));
198 return --iph->ttl;
199}
200
201static inline
202int ip_dont_fragment(struct sock *sk, struct dst_entry *dst)
203{
204 return (inet_sk(sk)->pmtudisc == IP_PMTUDISC_DO ||
205 (inet_sk(sk)->pmtudisc == IP_PMTUDISC_WANT &&
206 !(dst_metric(dst, RTAX_LOCK)&(1<<RTAX_MTU))));
207}
208
209extern void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more);
210
211static inline void ip_select_ident(struct iphdr *iph, struct dst_entry *dst, struct sock *sk)
212{
213 if (iph->frag_off & htons(IP_DF)) {
214 /* This is only to work around buggy Windows95/2000
215 * VJ compression implementations. If the ID field
216 * does not change, they drop every other packet in
217 * a TCP stream using header compression.
218 */
219 iph->id = (sk && inet_sk(sk)->daddr) ?
220 htons(inet_sk(sk)->id++) : 0;
221 } else
222 __ip_select_ident(iph, dst, 0);
223}
224
225static inline void ip_select_ident_more(struct iphdr *iph, struct dst_entry *dst, struct sock *sk, int more)
226{
227 if (iph->frag_off & htons(IP_DF)) {
228 if (sk && inet_sk(sk)->daddr) {
229 iph->id = htons(inet_sk(sk)->id);
230 inet_sk(sk)->id += 1 + more;
231 } else
232 iph->id = 0;
233 } else
234 __ip_select_ident(iph, dst, more);
235}
236
237/*
238 * Map a multicast IP onto multicast MAC for type ethernet.
239 */
240
241static inline void ip_eth_mc_map(__be32 naddr, char *buf)
242{
243 __u32 addr=ntohl(naddr);
244 buf[0]=0x01;
245 buf[1]=0x00;
246 buf[2]=0x5e;
247 buf[5]=addr&0xFF;
248 addr>>=8;
249 buf[4]=addr&0xFF;
250 addr>>=8;
251 buf[3]=addr&0x7F;
252}
253
254/*
255 * Map a multicast IP onto multicast MAC for type IP-over-InfiniBand.
256 * Leave P_Key as 0 to be filled in by driver.
257 */
258
259static inline void ip_ib_mc_map(__be32 naddr, char *buf)
260{
261 __u32 addr;
262 buf[0] = 0; /* Reserved */
263 buf[1] = 0xff; /* Multicast QPN */
264 buf[2] = 0xff;
265 buf[3] = 0xff;
266 addr = ntohl(naddr);
267 buf[4] = 0xff;
268 buf[5] = 0x12; /* link local scope */
269 buf[6] = 0x40; /* IPv4 signature */
270 buf[7] = 0x1b;
271 buf[8] = 0; /* P_Key */
272 buf[9] = 0;
273 buf[10] = 0;
274 buf[11] = 0;
275 buf[12] = 0;
276 buf[13] = 0;
277 buf[14] = 0;
278 buf[15] = 0;
279 buf[19] = addr & 0xff;
280 addr >>= 8;
281 buf[18] = addr & 0xff;
282 addr >>= 8;
283 buf[17] = addr & 0xff;
284 addr >>= 8;
285 buf[16] = addr & 0x0f;
286}
287
288#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
289#include <linux/ipv6.h>
290#endif
291
292static __inline__ void inet_reset_saddr(struct sock *sk)
293{
294 inet_sk(sk)->rcv_saddr = inet_sk(sk)->saddr = 0;
295#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
296 if (sk->sk_family == PF_INET6) {
297 struct ipv6_pinfo *np = inet6_sk(sk);
298
299 memset(&np->saddr, 0, sizeof(np->saddr));
300 memset(&np->rcv_saddr, 0, sizeof(np->rcv_saddr));
301 }
302#endif
303}
304
305#endif
306
307extern int ip_call_ra_chain(struct sk_buff *skb);
308
309/*
310 * Functions provided by ip_fragment.o
311 */
312
313enum ip_defrag_users
314{
315 IP_DEFRAG_LOCAL_DELIVER,
316 IP_DEFRAG_CALL_RA_CHAIN,
317 IP_DEFRAG_CONNTRACK_IN,
318 IP_DEFRAG_CONNTRACK_OUT,
319 IP_DEFRAG_VS_IN,
320 IP_DEFRAG_VS_OUT,
321 IP_DEFRAG_VS_FWD
322};
323
324struct sk_buff *ip_defrag(struct sk_buff *skb, u32 user);
325extern int ip_frag_nqueues;
326extern atomic_t ip_frag_mem;
327
328/*
329 * Functions provided by ip_forward.c
330 */
331
332extern int ip_forward(struct sk_buff *skb);
333extern int ip_net_unreachable(struct sk_buff *skb);
334
335/*
336 * Functions provided by ip_options.c
337 */
338
339extern void ip_options_build(struct sk_buff *skb, struct ip_options *opt, __be32 daddr, struct rtable *rt, int is_frag);
340extern int ip_options_echo(struct ip_options *dopt, struct sk_buff *skb);
341extern void ip_options_fragment(struct sk_buff *skb);
342extern int ip_options_compile(struct ip_options *opt, struct sk_buff *skb);
343extern int ip_options_get(struct ip_options **optp,
344 unsigned char *data, int optlen);
345extern int ip_options_get_from_user(struct ip_options **optp,
346 unsigned char __user *data, int optlen);
347extern void ip_options_undo(struct ip_options * opt);
348extern void ip_forward_options(struct sk_buff *skb);
349extern int ip_options_rcv_srr(struct sk_buff *skb);
350
351/*
352 * Functions provided by ip_sockglue.c
353 */
354
355extern void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb);
356extern int ip_cmsg_send(struct msghdr *msg, struct ipcm_cookie *ipc);
357extern int ip_setsockopt(struct sock *sk, int level, int optname, char __user *optval, int optlen);
358extern int ip_getsockopt(struct sock *sk, int level, int optname, char __user *optval, int __user *optlen);
359extern int compat_ip_setsockopt(struct sock *sk, int level,
360 int optname, char __user *optval, int optlen);
361extern int compat_ip_getsockopt(struct sock *sk, int level,
362 int optname, char __user *optval, int __user *optlen);
363extern int ip_ra_control(struct sock *sk, unsigned char on, void (*destructor)(struct sock *));
364
365extern int ip_recv_error(struct sock *sk, struct msghdr *msg, int len);
366extern void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
367 __be16 port, u32 info, u8 *payload);
368extern void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 dport,
369 u32 info);
370
371/* sysctl helpers - any sysctl which holds a value that ends up being
372 * fed into the routing cache should use these handlers.
373 */
374int ipv4_doint_and_flush(ctl_table *ctl, int write,
375 struct file* filp, void __user *buffer,
376 size_t *lenp, loff_t *ppos);
377int ipv4_doint_and_flush_strategy(ctl_table *table, int __user *name, int nlen,
378 void __user *oldval, size_t __user *oldlenp,
379 void __user *newval, size_t newlen);
380#ifdef CONFIG_PROC_FS
381extern int ip_misc_proc_init(void);
382#endif
383
384extern struct ctl_table ipv4_table[];
385
386#endif /* _IP_H */