xref: /openbmc/linux/include/net/ip.h (revision e868d61272caa648214046a096e5a6bfc068dc8c)
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 
33 struct sock;
34 
35 struct 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 
47 static inline unsigned int ip_hdrlen(const struct sk_buff *skb)
48 {
49 	return ip_hdr(skb)->ihl * 4;
50 }
51 
52 struct 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 
61 struct ip_ra_chain
62 {
63 	struct ip_ra_chain	*next;
64 	struct sock		*sk;
65 	void			(*destructor)(struct sock *);
66 };
67 
68 extern struct ip_ra_chain *ip_ra_chain;
69 extern 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 
79 struct msghdr;
80 struct net_device;
81 struct packet_type;
82 struct rtable;
83 struct sockaddr;
84 
85 extern void		ip_mc_dropsocket(struct sock *);
86 extern void		ip_mc_dropdevice(struct net_device *dev);
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_queue_xmit(struct sk_buff *skb, int ipfragok);
106 extern void		ip_init(void);
107 extern 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);
114 extern int		ip_generic_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb);
115 extern ssize_t		ip_append_page(struct sock *sk, struct page *page,
116 				int offset, size_t size, int flags);
117 extern int		ip_push_pending_frames(struct sock *sk);
118 extern void		ip_flush_pending_frames(struct sock *sk);
119 
120 /* datagram.c */
121 extern 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 
131 static 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 
141 struct 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 };
147 
148 void ip_send_reply(struct sock *sk, struct sk_buff *skb, struct ip_reply_arg *arg,
149 		   unsigned int len);
150 
151 struct ipv4_config
152 {
153 	int	log_martians;
154 	int	no_pmtu_disc;
155 };
156 
157 extern struct ipv4_config ipv4_config;
158 DECLARE_SNMP_STAT(struct ipstats_mib, ip_statistics);
159 #define IP_INC_STATS(field)		SNMP_INC_STATS(ip_statistics, field)
160 #define IP_INC_STATS_BH(field)		SNMP_INC_STATS_BH(ip_statistics, field)
161 #define IP_INC_STATS_USER(field) 	SNMP_INC_STATS_USER(ip_statistics, field)
162 DECLARE_SNMP_STAT(struct linux_mib, net_statistics);
163 #define NET_INC_STATS(field)		SNMP_INC_STATS(net_statistics, field)
164 #define NET_INC_STATS_BH(field)		SNMP_INC_STATS_BH(net_statistics, field)
165 #define NET_INC_STATS_USER(field) 	SNMP_INC_STATS_USER(net_statistics, field)
166 #define NET_ADD_STATS_BH(field, adnd)	SNMP_ADD_STATS_BH(net_statistics, field, adnd)
167 #define NET_ADD_STATS_USER(field, adnd)	SNMP_ADD_STATS_USER(net_statistics, field, adnd)
168 
169 extern unsigned long snmp_fold_field(void *mib[], int offt);
170 extern int snmp_mib_init(void *ptr[2], size_t mibsize, size_t mibalign);
171 extern void snmp_mib_free(void *ptr[2]);
172 
173 extern int sysctl_local_port_range[2];
174 extern int sysctl_ip_default_ttl;
175 extern int sysctl_ip_nonlocal_bind;
176 
177 /* From ip_fragment.c */
178 extern int sysctl_ipfrag_high_thresh;
179 extern int sysctl_ipfrag_low_thresh;
180 extern int sysctl_ipfrag_time;
181 extern int sysctl_ipfrag_secret_interval;
182 extern int sysctl_ipfrag_max_dist;
183 
184 /* From inetpeer.c */
185 extern int inet_peer_threshold;
186 extern int inet_peer_minttl;
187 extern int inet_peer_maxttl;
188 extern int inet_peer_gc_mintime;
189 extern int inet_peer_gc_maxtime;
190 
191 /* From ip_output.c */
192 extern int sysctl_ip_dynaddr;
193 
194 extern void ipfrag_init(void);
195 
196 #ifdef CONFIG_INET
197 #include <net/dst.h>
198 
199 /* The function in 2.2 was invalid, producing wrong result for
200  * check=0xFEFF. It was noticed by Arthur Skawina _year_ ago. --ANK(000625) */
201 static inline
202 int ip_decrease_ttl(struct iphdr *iph)
203 {
204 	u32 check = (__force u32)iph->check;
205 	check += (__force u32)htons(0x0100);
206 	iph->check = (__force __sum16)(check + (check>=0xFFFF));
207 	return --iph->ttl;
208 }
209 
210 static inline
211 int ip_dont_fragment(struct sock *sk, struct dst_entry *dst)
212 {
213 	return (inet_sk(sk)->pmtudisc == IP_PMTUDISC_DO ||
214 		(inet_sk(sk)->pmtudisc == IP_PMTUDISC_WANT &&
215 		 !(dst_metric(dst, RTAX_LOCK)&(1<<RTAX_MTU))));
216 }
217 
218 extern void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more);
219 
220 static inline void ip_select_ident(struct iphdr *iph, struct dst_entry *dst, struct sock *sk)
221 {
222 	if (iph->frag_off & htons(IP_DF)) {
223 		/* This is only to work around buggy Windows95/2000
224 		 * VJ compression implementations.  If the ID field
225 		 * does not change, they drop every other packet in
226 		 * a TCP stream using header compression.
227 		 */
228 		iph->id = (sk && inet_sk(sk)->daddr) ?
229 					htons(inet_sk(sk)->id++) : 0;
230 	} else
231 		__ip_select_ident(iph, dst, 0);
232 }
233 
234 static inline void ip_select_ident_more(struct iphdr *iph, struct dst_entry *dst, struct sock *sk, int more)
235 {
236 	if (iph->frag_off & htons(IP_DF)) {
237 		if (sk && inet_sk(sk)->daddr) {
238 			iph->id = htons(inet_sk(sk)->id);
239 			inet_sk(sk)->id += 1 + more;
240 		} else
241 			iph->id = 0;
242 	} else
243 		__ip_select_ident(iph, dst, more);
244 }
245 
246 /*
247  *	Map a multicast IP onto multicast MAC for type ethernet.
248  */
249 
250 static inline void ip_eth_mc_map(__be32 naddr, char *buf)
251 {
252 	__u32 addr=ntohl(naddr);
253 	buf[0]=0x01;
254 	buf[1]=0x00;
255 	buf[2]=0x5e;
256 	buf[5]=addr&0xFF;
257 	addr>>=8;
258 	buf[4]=addr&0xFF;
259 	addr>>=8;
260 	buf[3]=addr&0x7F;
261 }
262 
263 /*
264  *	Map a multicast IP onto multicast MAC for type IP-over-InfiniBand.
265  *	Leave P_Key as 0 to be filled in by driver.
266  */
267 
268 static inline void ip_ib_mc_map(__be32 naddr, char *buf)
269 {
270 	__u32 addr;
271 	buf[0]  = 0;		/* Reserved */
272 	buf[1]  = 0xff;		/* Multicast QPN */
273 	buf[2]  = 0xff;
274 	buf[3]  = 0xff;
275 	addr    = ntohl(naddr);
276 	buf[4]  = 0xff;
277 	buf[5]  = 0x12;		/* link local scope */
278 	buf[6]  = 0x40;		/* IPv4 signature */
279 	buf[7]  = 0x1b;
280 	buf[8]  = 0;		/* P_Key */
281 	buf[9]  = 0;
282 	buf[10] = 0;
283 	buf[11] = 0;
284 	buf[12] = 0;
285 	buf[13] = 0;
286 	buf[14] = 0;
287 	buf[15] = 0;
288 	buf[19] = addr & 0xff;
289 	addr  >>= 8;
290 	buf[18] = addr & 0xff;
291 	addr  >>= 8;
292 	buf[17] = addr & 0xff;
293 	addr  >>= 8;
294 	buf[16] = addr & 0x0f;
295 }
296 
297 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
298 #include <linux/ipv6.h>
299 #endif
300 
301 static __inline__ void inet_reset_saddr(struct sock *sk)
302 {
303 	inet_sk(sk)->rcv_saddr = inet_sk(sk)->saddr = 0;
304 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
305 	if (sk->sk_family == PF_INET6) {
306 		struct ipv6_pinfo *np = inet6_sk(sk);
307 
308 		memset(&np->saddr, 0, sizeof(np->saddr));
309 		memset(&np->rcv_saddr, 0, sizeof(np->rcv_saddr));
310 	}
311 #endif
312 }
313 
314 #endif
315 
316 extern int	ip_call_ra_chain(struct sk_buff *skb);
317 
318 /*
319  *	Functions provided by ip_fragment.o
320  */
321 
322 enum ip_defrag_users
323 {
324 	IP_DEFRAG_LOCAL_DELIVER,
325 	IP_DEFRAG_CALL_RA_CHAIN,
326 	IP_DEFRAG_CONNTRACK_IN,
327 	IP_DEFRAG_CONNTRACK_OUT,
328 	IP_DEFRAG_VS_IN,
329 	IP_DEFRAG_VS_OUT,
330 	IP_DEFRAG_VS_FWD
331 };
332 
333 struct sk_buff *ip_defrag(struct sk_buff *skb, u32 user);
334 extern int ip_frag_nqueues;
335 extern atomic_t ip_frag_mem;
336 
337 /*
338  *	Functions provided by ip_forward.c
339  */
340 
341 extern int ip_forward(struct sk_buff *skb);
342 extern int ip_net_unreachable(struct sk_buff *skb);
343 
344 /*
345  *	Functions provided by ip_options.c
346  */
347 
348 extern void ip_options_build(struct sk_buff *skb, struct ip_options *opt, __be32 daddr, struct rtable *rt, int is_frag);
349 extern int ip_options_echo(struct ip_options *dopt, struct sk_buff *skb);
350 extern void ip_options_fragment(struct sk_buff *skb);
351 extern int ip_options_compile(struct ip_options *opt, struct sk_buff *skb);
352 extern int ip_options_get(struct ip_options **optp,
353 			  unsigned char *data, int optlen);
354 extern int ip_options_get_from_user(struct ip_options **optp,
355 				    unsigned char __user *data, int optlen);
356 extern void ip_options_undo(struct ip_options * opt);
357 extern void ip_forward_options(struct sk_buff *skb);
358 extern int ip_options_rcv_srr(struct sk_buff *skb);
359 
360 /*
361  *	Functions provided by ip_sockglue.c
362  */
363 
364 extern void	ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb);
365 extern int	ip_cmsg_send(struct msghdr *msg, struct ipcm_cookie *ipc);
366 extern int	ip_setsockopt(struct sock *sk, int level, int optname, char __user *optval, int optlen);
367 extern int	ip_getsockopt(struct sock *sk, int level, int optname, char __user *optval, int __user *optlen);
368 extern int	compat_ip_setsockopt(struct sock *sk, int level,
369 			int optname, char __user *optval, int optlen);
370 extern int	compat_ip_getsockopt(struct sock *sk, int level,
371 			int optname, char __user *optval, int __user *optlen);
372 extern int	ip_ra_control(struct sock *sk, unsigned char on, void (*destructor)(struct sock *));
373 
374 extern int 	ip_recv_error(struct sock *sk, struct msghdr *msg, int len);
375 extern void	ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
376 			      __be16 port, u32 info, u8 *payload);
377 extern 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  */
383 int ipv4_doint_and_flush(ctl_table *ctl, int write,
384 			 struct file* filp, void __user *buffer,
385 			 size_t *lenp, loff_t *ppos);
386 int 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
390 extern int ip_misc_proc_init(void);
391 #endif
392 
393 extern struct ctl_table ipv4_table[];
394 
395 #endif	/* _IP_H */
396