xref: /openbmc/linux/include/net/ip.h (revision 545e4006)
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 int		igmp_mc_proc_init(void);
86 
87 /*
88  *	Functions provided by ip.c
89  */
90 
91 extern int		ip_build_and_send_pkt(struct sk_buff *skb, struct sock *sk,
92 					      __be32 saddr, __be32 daddr,
93 					      struct ip_options *opt);
94 extern int		ip_rcv(struct sk_buff *skb, struct net_device *dev,
95 			       struct packet_type *pt, struct net_device *orig_dev);
96 extern int		ip_local_deliver(struct sk_buff *skb);
97 extern int		ip_mr_input(struct sk_buff *skb);
98 extern int		ip_output(struct sk_buff *skb);
99 extern int		ip_mc_output(struct sk_buff *skb);
100 extern int		ip_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *));
101 extern int		ip_do_nat(struct sk_buff *skb);
102 extern void		ip_send_check(struct iphdr *ip);
103 extern int		__ip_local_out(struct sk_buff *skb);
104 extern int		ip_local_out(struct sk_buff *skb);
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 	int	    bound_dev_if;
147 };
148 
149 void ip_send_reply(struct sock *sk, struct sk_buff *skb, struct ip_reply_arg *arg,
150 		   unsigned int len);
151 
152 struct ipv4_config
153 {
154 	int	log_martians;
155 	int	no_pmtu_disc;
156 };
157 
158 extern 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 
168 extern unsigned long snmp_fold_field(void *mib[], int offt);
169 extern int snmp_mib_init(void *ptr[2], size_t mibsize);
170 extern void snmp_mib_free(void *ptr[2]);
171 
172 extern void inet_get_local_port_range(int *low, int *high);
173 
174 extern int sysctl_ip_default_ttl;
175 extern int sysctl_ip_nonlocal_bind;
176 
177 extern struct ctl_path net_ipv4_ctl_path[];
178 
179 /* From inetpeer.c */
180 extern int inet_peer_threshold;
181 extern int inet_peer_minttl;
182 extern int inet_peer_maxttl;
183 extern int inet_peer_gc_mintime;
184 extern int inet_peer_gc_maxtime;
185 
186 /* From ip_output.c */
187 extern int sysctl_ip_dynaddr;
188 
189 extern void ipfrag_init(void);
190 
191 #ifdef CONFIG_INET
192 #include <net/dst.h>
193 
194 /* The function in 2.2 was invalid, producing wrong result for
195  * check=0xFEFF. It was noticed by Arthur Skawina _year_ ago. --ANK(000625) */
196 static inline
197 int ip_decrease_ttl(struct iphdr *iph)
198 {
199 	u32 check = (__force u32)iph->check;
200 	check += (__force u32)htons(0x0100);
201 	iph->check = (__force __sum16)(check + (check>=0xFFFF));
202 	return --iph->ttl;
203 }
204 
205 static inline
206 int ip_dont_fragment(struct sock *sk, struct dst_entry *dst)
207 {
208 	return (inet_sk(sk)->pmtudisc == IP_PMTUDISC_DO ||
209 		(inet_sk(sk)->pmtudisc == IP_PMTUDISC_WANT &&
210 		 !(dst_metric_locked(dst, RTAX_MTU))));
211 }
212 
213 extern void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more);
214 
215 static inline void ip_select_ident(struct iphdr *iph, struct dst_entry *dst, struct sock *sk)
216 {
217 	if (iph->frag_off & htons(IP_DF)) {
218 		/* This is only to work around buggy Windows95/2000
219 		 * VJ compression implementations.  If the ID field
220 		 * does not change, they drop every other packet in
221 		 * a TCP stream using header compression.
222 		 */
223 		iph->id = (sk && inet_sk(sk)->daddr) ?
224 					htons(inet_sk(sk)->id++) : 0;
225 	} else
226 		__ip_select_ident(iph, dst, 0);
227 }
228 
229 static inline void ip_select_ident_more(struct iphdr *iph, struct dst_entry *dst, struct sock *sk, int more)
230 {
231 	if (iph->frag_off & htons(IP_DF)) {
232 		if (sk && inet_sk(sk)->daddr) {
233 			iph->id = htons(inet_sk(sk)->id);
234 			inet_sk(sk)->id += 1 + more;
235 		} else
236 			iph->id = 0;
237 	} else
238 		__ip_select_ident(iph, dst, more);
239 }
240 
241 /*
242  *	Map a multicast IP onto multicast MAC for type ethernet.
243  */
244 
245 static inline void ip_eth_mc_map(__be32 naddr, char *buf)
246 {
247 	__u32 addr=ntohl(naddr);
248 	buf[0]=0x01;
249 	buf[1]=0x00;
250 	buf[2]=0x5e;
251 	buf[5]=addr&0xFF;
252 	addr>>=8;
253 	buf[4]=addr&0xFF;
254 	addr>>=8;
255 	buf[3]=addr&0x7F;
256 }
257 
258 /*
259  *	Map a multicast IP onto multicast MAC for type IP-over-InfiniBand.
260  *	Leave P_Key as 0 to be filled in by driver.
261  */
262 
263 static inline void ip_ib_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf)
264 {
265 	__u32 addr;
266 	unsigned char scope = broadcast[5] & 0xF;
267 
268 	buf[0]  = 0;		/* Reserved */
269 	buf[1]  = 0xff;		/* Multicast QPN */
270 	buf[2]  = 0xff;
271 	buf[3]  = 0xff;
272 	addr    = ntohl(naddr);
273 	buf[4]  = 0xff;
274 	buf[5]  = 0x10 | scope;	/* scope from broadcast address */
275 	buf[6]  = 0x40;		/* IPv4 signature */
276 	buf[7]  = 0x1b;
277 	buf[8]  = broadcast[8];		/* P_Key */
278 	buf[9]  = broadcast[9];
279 	buf[10] = 0;
280 	buf[11] = 0;
281 	buf[12] = 0;
282 	buf[13] = 0;
283 	buf[14] = 0;
284 	buf[15] = 0;
285 	buf[19] = addr & 0xff;
286 	addr  >>= 8;
287 	buf[18] = addr & 0xff;
288 	addr  >>= 8;
289 	buf[17] = addr & 0xff;
290 	addr  >>= 8;
291 	buf[16] = addr & 0x0f;
292 }
293 
294 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
295 #include <linux/ipv6.h>
296 #endif
297 
298 static __inline__ void inet_reset_saddr(struct sock *sk)
299 {
300 	inet_sk(sk)->rcv_saddr = inet_sk(sk)->saddr = 0;
301 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
302 	if (sk->sk_family == PF_INET6) {
303 		struct ipv6_pinfo *np = inet6_sk(sk);
304 
305 		memset(&np->saddr, 0, sizeof(np->saddr));
306 		memset(&np->rcv_saddr, 0, sizeof(np->rcv_saddr));
307 	}
308 #endif
309 }
310 
311 #endif
312 
313 extern int	ip_call_ra_chain(struct sk_buff *skb);
314 
315 /*
316  *	Functions provided by ip_fragment.c
317  */
318 
319 enum ip_defrag_users
320 {
321 	IP_DEFRAG_LOCAL_DELIVER,
322 	IP_DEFRAG_CALL_RA_CHAIN,
323 	IP_DEFRAG_CONNTRACK_IN,
324 	IP_DEFRAG_CONNTRACK_OUT,
325 	IP_DEFRAG_VS_IN,
326 	IP_DEFRAG_VS_OUT,
327 	IP_DEFRAG_VS_FWD
328 };
329 
330 int ip_defrag(struct sk_buff *skb, u32 user);
331 int ip_frag_mem(struct net *net);
332 int ip_frag_nqueues(struct net *net);
333 
334 /*
335  *	Functions provided by ip_forward.c
336  */
337 
338 extern int ip_forward(struct sk_buff *skb);
339 
340 /*
341  *	Functions provided by ip_options.c
342  */
343 
344 extern void ip_options_build(struct sk_buff *skb, struct ip_options *opt, __be32 daddr, struct rtable *rt, int is_frag);
345 extern int ip_options_echo(struct ip_options *dopt, struct sk_buff *skb);
346 extern void ip_options_fragment(struct sk_buff *skb);
347 extern int ip_options_compile(struct net *net,
348 			      struct ip_options *opt, struct sk_buff *skb);
349 extern int ip_options_get(struct net *net, struct ip_options **optp,
350 			  unsigned char *data, int optlen);
351 extern int ip_options_get_from_user(struct net *net, struct ip_options **optp,
352 				    unsigned char __user *data, int optlen);
353 extern void ip_options_undo(struct ip_options * opt);
354 extern void ip_forward_options(struct sk_buff *skb);
355 extern int ip_options_rcv_srr(struct sk_buff *skb);
356 
357 /*
358  *	Functions provided by ip_sockglue.c
359  */
360 
361 extern void	ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb);
362 extern int	ip_cmsg_send(struct net *net,
363 			     struct msghdr *msg, struct ipcm_cookie *ipc);
364 extern int	ip_setsockopt(struct sock *sk, int level, int optname, char __user *optval, int optlen);
365 extern int	ip_getsockopt(struct sock *sk, int level, int optname, char __user *optval, int __user *optlen);
366 extern int	compat_ip_setsockopt(struct sock *sk, int level,
367 			int optname, char __user *optval, int optlen);
368 extern int	compat_ip_getsockopt(struct sock *sk, int level,
369 			int optname, char __user *optval, int __user *optlen);
370 extern int	ip_ra_control(struct sock *sk, unsigned char on, void (*destructor)(struct sock *));
371 
372 extern int 	ip_recv_error(struct sock *sk, struct msghdr *msg, int len);
373 extern void	ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
374 			      __be16 port, u32 info, u8 *payload);
375 extern void	ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 dport,
376 			       u32 info);
377 
378 /* sysctl helpers - any sysctl which holds a value that ends up being
379  * fed into the routing cache should use these handlers.
380  */
381 int ipv4_doint_and_flush(ctl_table *ctl, int write,
382 			 struct file* filp, void __user *buffer,
383 			 size_t *lenp, loff_t *ppos);
384 int ipv4_doint_and_flush_strategy(ctl_table *table, int __user *name, int nlen,
385 				  void __user *oldval, size_t __user *oldlenp,
386 				  void __user *newval, size_t newlen);
387 #ifdef CONFIG_PROC_FS
388 extern int ip_misc_proc_init(void);
389 #endif
390 
391 #endif	/* _IP_H */
392