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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#include <linux/skbuff.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
47static inline unsigned int ip_hdrlen(const struct sk_buff *skb)
48{
49 return ip_hdr(skb)->ihl * 4;
50}
51
52struct 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
61struct ip_ra_chain
62{
63 struct ip_ra_chain *next;
64 struct sock *sk;
65 void (*destructor)(struct sock *);
66};
67
68extern struct ip_ra_chain *ip_ra_chain;
69extern 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
79struct msghdr;
80struct net_device;
81struct packet_type;
82struct rtable;
83struct sockaddr;
84
85extern int igmp_mc_proc_init(void);
86
87/*
88 * Functions provided by ip.c
89 */
90
91extern int ip_build_and_send_pkt(struct sk_buff *skb, struct sock *sk,
92 __be32 saddr, __be32 daddr,
93 struct ip_options *opt);
94extern int ip_rcv(struct sk_buff *skb, struct net_device *dev,
95 struct packet_type *pt, struct net_device *orig_dev);
96extern int ip_local_deliver(struct sk_buff *skb);
97extern int ip_mr_input(struct sk_buff *skb);
98extern int ip_output(struct sk_buff *skb);
99extern int ip_mc_output(struct sk_buff *skb);
100extern int ip_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *));
101extern int ip_do_nat(struct sk_buff *skb);
102extern void ip_send_check(struct iphdr *ip);
103extern int __ip_local_out(struct sk_buff *skb);
104extern int ip_local_out(struct sk_buff *skb);
105extern int ip_queue_xmit(struct sk_buff *skb, int ipfragok);
106extern void ip_init(void);
107extern 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);
114extern int ip_generic_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb);
115extern ssize_t ip_append_page(struct sock *sk, struct page *page,
116 int offset, size_t size, int flags);
117extern int ip_push_pending_frames(struct sock *sk);
118extern void ip_flush_pending_frames(struct sock *sk);
119
120/* datagram.c */
121extern 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
131static 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
141struct 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
149void ip_send_reply(struct sock *sk, struct sk_buff *skb, struct ip_reply_arg *arg,
150 unsigned int len);
151
152struct ipv4_config
153{
154 int log_martians;
155 int no_pmtu_disc;
156};
157
158extern 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
168extern unsigned long snmp_fold_field(void *mib[], int offt);
169extern int snmp_mib_init(void *ptr[2], size_t mibsize);
170extern void snmp_mib_free(void *ptr[2]);
171
172extern void inet_get_local_port_range(int *low, int *high);
173
174extern int sysctl_ip_default_ttl;
175extern int sysctl_ip_nonlocal_bind;
176
177extern struct ctl_path net_ipv4_ctl_path[];
178
179/* From inetpeer.c */
180extern int inet_peer_threshold;
181extern int inet_peer_minttl;
182extern int inet_peer_maxttl;
183extern int inet_peer_gc_mintime;
184extern int inet_peer_gc_maxtime;
185
186/* From ip_output.c */
187extern int sysctl_ip_dynaddr;
188
189extern void ipfrag_init(void);
190
191extern void ip_static_sysctl_init(void);
192
193#ifdef CONFIG_INET
194#include <net/dst.h>
195
196/* The function in 2.2 was invalid, producing wrong result for
197 * check=0xFEFF. It was noticed by Arthur Skawina _year_ ago. --ANK(000625) */
198static inline
199int ip_decrease_ttl(struct iphdr *iph)
200{
201 u32 check = (__force u32)iph->check;
202 check += (__force u32)htons(0x0100);
203 iph->check = (__force __sum16)(check + (check>=0xFFFF));
204 return --iph->ttl;
205}
206
207static inline
208int ip_dont_fragment(struct sock *sk, struct dst_entry *dst)
209{
210 return (inet_sk(sk)->pmtudisc == IP_PMTUDISC_DO ||
211 (inet_sk(sk)->pmtudisc == IP_PMTUDISC_WANT &&
212 !(dst_metric_locked(dst, RTAX_MTU))));
213}
214
215extern void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more);
216
217static inline void ip_select_ident(struct iphdr *iph, struct dst_entry *dst, struct sock *sk)
218{
219 if (iph->frag_off & htons(IP_DF)) {
220 /* This is only to work around buggy Windows95/2000
221 * VJ compression implementations. If the ID field
222 * does not change, they drop every other packet in
223 * a TCP stream using header compression.
224 */
225 iph->id = (sk && inet_sk(sk)->daddr) ?
226 htons(inet_sk(sk)->id++) : 0;
227 } else
228 __ip_select_ident(iph, dst, 0);
229}
230
231static inline void ip_select_ident_more(struct iphdr *iph, struct dst_entry *dst, struct sock *sk, int more)
232{
233 if (iph->frag_off & htons(IP_DF)) {
234 if (sk && inet_sk(sk)->daddr) {
235 iph->id = htons(inet_sk(sk)->id);
236 inet_sk(sk)->id += 1 + more;
237 } else
238 iph->id = 0;
239 } else
240 __ip_select_ident(iph, dst, more);
241}
242
243/*
244 * Map a multicast IP onto multicast MAC for type ethernet.
245 */
246
247static inline void ip_eth_mc_map(__be32 naddr, char *buf)
248{
249 __u32 addr=ntohl(naddr);
250 buf[0]=0x01;
251 buf[1]=0x00;
252 buf[2]=0x5e;
253 buf[5]=addr&0xFF;
254 addr>>=8;
255 buf[4]=addr&0xFF;
256 addr>>=8;
257 buf[3]=addr&0x7F;
258}
259
260/*
261 * Map a multicast IP onto multicast MAC for type IP-over-InfiniBand.
262 * Leave P_Key as 0 to be filled in by driver.
263 */
264
265static inline void ip_ib_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf)
266{
267 __u32 addr;
268 unsigned char scope = broadcast[5] & 0xF;
269
270 buf[0] = 0; /* Reserved */
271 buf[1] = 0xff; /* Multicast QPN */
272 buf[2] = 0xff;
273 buf[3] = 0xff;
274 addr = ntohl(naddr);
275 buf[4] = 0xff;
276 buf[5] = 0x10 | scope; /* scope from broadcast address */
277 buf[6] = 0x40; /* IPv4 signature */
278 buf[7] = 0x1b;
279 buf[8] = broadcast[8]; /* P_Key */
280 buf[9] = broadcast[9];
281 buf[10] = 0;
282 buf[11] = 0;
283 buf[12] = 0;
284 buf[13] = 0;
285 buf[14] = 0;
286 buf[15] = 0;
287 buf[19] = addr & 0xff;
288 addr >>= 8;
289 buf[18] = addr & 0xff;
290 addr >>= 8;
291 buf[17] = addr & 0xff;
292 addr >>= 8;
293 buf[16] = addr & 0x0f;
294}
295
296#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
297#include <linux/ipv6.h>
298#endif
299
300static __inline__ void inet_reset_saddr(struct sock *sk)
301{
302 inet_sk(sk)->rcv_saddr = inet_sk(sk)->saddr = 0;
303#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
304 if (sk->sk_family == PF_INET6) {
305 struct ipv6_pinfo *np = inet6_sk(sk);
306
307 memset(&np->saddr, 0, sizeof(np->saddr));
308 memset(&np->rcv_saddr, 0, sizeof(np->rcv_saddr));
309 }
310#endif
311}
312
313#endif
314
315extern int ip_call_ra_chain(struct sk_buff *skb);
316
317/*
318 * Functions provided by ip_fragment.c
319 */
320
321enum ip_defrag_users
322{
323 IP_DEFRAG_LOCAL_DELIVER,
324 IP_DEFRAG_CALL_RA_CHAIN,
325 IP_DEFRAG_CONNTRACK_IN,
326 IP_DEFRAG_CONNTRACK_OUT,
327 IP_DEFRAG_VS_IN,
328 IP_DEFRAG_VS_OUT,
329 IP_DEFRAG_VS_FWD
330};
331
332int ip_defrag(struct sk_buff *skb, u32 user);
333int ip_frag_mem(struct net *net);
334int ip_frag_nqueues(struct net *net);
335
336/*
337 * Functions provided by ip_forward.c
338 */
339
340extern int ip_forward(struct sk_buff *skb);
341
342/*
343 * Functions provided by ip_options.c
344 */
345
346extern void ip_options_build(struct sk_buff *skb, struct ip_options *opt, __be32 daddr, struct rtable *rt, int is_frag);
347extern int ip_options_echo(struct ip_options *dopt, struct sk_buff *skb);
348extern void ip_options_fragment(struct sk_buff *skb);
349extern int ip_options_compile(struct net *net,
350 struct ip_options *opt, struct sk_buff *skb);
351extern int ip_options_get(struct net *net, struct ip_options **optp,
352 unsigned char *data, int optlen);
353extern int ip_options_get_from_user(struct net *net, struct ip_options **optp,
354 unsigned char __user *data, int optlen);
355extern void ip_options_undo(struct ip_options * opt);
356extern void ip_forward_options(struct sk_buff *skb);
357extern int ip_options_rcv_srr(struct sk_buff *skb);
358
359/*
360 * Functions provided by ip_sockglue.c
361 */
362
363extern void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb);
364extern int ip_cmsg_send(struct net *net,
365 struct msghdr *msg, struct ipcm_cookie *ipc);
366extern int ip_setsockopt(struct sock *sk, int level, int optname, char __user *optval, int optlen);
367extern int ip_getsockopt(struct sock *sk, int level, int optname, char __user *optval, int __user *optlen);
368extern int compat_ip_setsockopt(struct sock *sk, int level,
369 int optname, char __user *optval, int optlen);
370extern int compat_ip_getsockopt(struct sock *sk, int level,
371 int optname, char __user *optval, int __user *optlen);
372extern int ip_ra_control(struct sock *sk, unsigned char on, void (*destructor)(struct sock *));
373
374extern int ip_recv_error(struct sock *sk, struct msghdr *msg, int len);
375extern void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
376 __be16 port, u32 info, u8 *payload);
377extern void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 dport,
378 u32 info);
379
380/* sysctl helpers - any sysctl which holds a value that ends up being
381 * fed into the routing cache should use these handlers.
382 */
383int ipv4_doint_and_flush(ctl_table *ctl, int write,
384 struct file* filp, void __user *buffer,
385 size_t *lenp, loff_t *ppos);
386int ipv4_doint_and_flush_strategy(ctl_table *table, int __user *name, int nlen,
387 void __user *oldval, size_t __user *oldlenp,
388 void __user *newval, size_t newlen);
389#ifdef CONFIG_PROC_FS
390extern int ip_misc_proc_init(void);
391#endif
392
393#endif /* _IP_H */