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.
6 * Definitions for the IP module.
8 * Version: @(#)ip.h 1.0.2 05/07/93
11 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
12 * Alan Cox, <gw4pts@gw4pts.ampr.org>
15 * Mike McLagan : Routing by source
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.
25 #include <linux/config.h>
26 #include <linux/types.h>
27 #include <linux/socket.h>
30 #include <linux/netdevice.h>
31 #include <linux/inetdevice.h>
32 #include <linux/in_route.h>
33 #include <net/route.h>
41 struct ip_options opt; /* Compiled IP options */
44 #define IPSKB_MASQUERADED 1
45 #define IPSKB_TRANSLATED 2
46 #define IPSKB_FORWARDED 4
47 #define IPSKB_XFRM_TUNNEL_SIZE 8
54 struct ip_options *opt;
57 #define IPCB(skb) ((struct inet_skb_parm*)((skb)->cb))
61 struct ip_ra_chain *next;
63 void (*destructor)(struct sock *);
66 extern struct ip_ra_chain *ip_ra_chain;
67 extern rwlock_t ip_ra_lock;
70 #define IP_CE 0x8000 /* Flag: "Congestion" */
71 #define IP_DF 0x4000 /* Flag: "Don't Fragment" */
72 #define IP_MF 0x2000 /* Flag: "More Fragments" */
73 #define IP_OFFSET 0x1FFF /* "Fragment Offset" part */
75 #define IP_FRAG_TIME (30 * HZ) /* fragment lifetime */
77 extern void ip_mc_dropsocket(struct sock *);
78 extern void ip_mc_dropdevice(struct net_device *dev);
79 extern int igmp_mc_proc_init(void);
82 * Functions provided by ip.c
85 extern int ip_build_and_send_pkt(struct sk_buff *skb, struct sock *sk,
87 struct ip_options *opt);
88 extern int ip_rcv(struct sk_buff *skb, struct net_device *dev,
89 struct packet_type *pt);
90 extern int ip_local_deliver(struct sk_buff *skb);
91 extern int ip_mr_input(struct sk_buff *skb);
92 extern int ip_output(struct sk_buff *skb);
93 extern int ip_mc_output(struct sk_buff *skb);
94 extern int ip_fragment(struct sk_buff *skb, int (*out)(struct sk_buff*));
95 extern int ip_do_nat(struct sk_buff *skb);
96 extern void ip_send_check(struct iphdr *ip);
97 extern int ip_queue_xmit(struct sk_buff *skb, int ipfragok);
98 extern void ip_init(void);
99 extern int ip_append_data(struct sock *sk,
100 int getfrag(void *from, char *to, int offset, int len,
101 int odd, struct sk_buff *skb),
102 void *from, int len, int protolen,
103 struct ipcm_cookie *ipc,
106 extern int ip_generic_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb);
107 extern ssize_t ip_append_page(struct sock *sk, struct page *page,
108 int offset, size_t size, int flags);
109 extern int ip_push_pending_frames(struct sock *sk);
110 extern void ip_flush_pending_frames(struct sock *sk);
113 extern int ip4_datagram_connect(struct sock *sk,
114 struct sockaddr *uaddr, int addr_len);
117 * Map a multicast IP onto multicast MAC for type Token Ring.
118 * This conforms to RFC1469 Option 2 Multicasting i.e.
119 * using a functional address to transmit / receive
123 static inline void ip_tr_mc_map(u32 addr, char *buf)
133 struct ip_reply_arg {
136 int csumoffset; /* u16 offset of csum in iov[0].iov_base */
137 /* -1 if not needed */
140 void ip_send_reply(struct sock *sk, struct sk_buff *skb, struct ip_reply_arg *arg,
143 extern int ip_finish_output(struct sk_buff *skb);
152 extern struct ipv4_config ipv4_config;
153 DECLARE_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)
157 DECLARE_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)
164 extern int sysctl_local_port_range[2];
165 extern int sysctl_ip_default_ttl;
166 extern int sysctl_ip_nonlocal_bind;
169 /* The function in 2.2 was invalid, producing wrong result for
170 * check=0xFEFF. It was noticed by Arthur Skawina _year_ ago. --ANK(000625) */
172 int ip_decrease_ttl(struct iphdr *iph)
174 u32 check = iph->check;
175 check += htons(0x0100);
176 iph->check = check + (check>=0xFFFF);
181 int ip_dont_fragment(struct sock *sk, struct dst_entry *dst)
183 return (inet_sk(sk)->pmtudisc == IP_PMTUDISC_DO ||
184 (inet_sk(sk)->pmtudisc == IP_PMTUDISC_WANT &&
185 !(dst_metric(dst, RTAX_LOCK)&(1<<RTAX_MTU))));
188 extern void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more);
190 static inline void ip_select_ident(struct iphdr *iph, struct dst_entry *dst, struct sock *sk)
192 if (iph->frag_off & htons(IP_DF)) {
193 /* This is only to work around buggy Windows95/2000
194 * VJ compression implementations. If the ID field
195 * does not change, they drop every other packet in
196 * a TCP stream using header compression.
198 iph->id = (sk && inet_sk(sk)->daddr) ?
199 htons(inet_sk(sk)->id++) : 0;
201 __ip_select_ident(iph, dst, 0);
204 static inline void ip_select_ident_more(struct iphdr *iph, struct dst_entry *dst, struct sock *sk, int more)
206 if (iph->frag_off & htons(IP_DF)) {
207 if (sk && inet_sk(sk)->daddr) {
208 iph->id = htons(inet_sk(sk)->id);
209 inet_sk(sk)->id += 1 + more;
213 __ip_select_ident(iph, dst, more);
217 * Map a multicast IP onto multicast MAC for type ethernet.
220 static inline void ip_eth_mc_map(u32 addr, char *buf)
234 * Map a multicast IP onto multicast MAC for type IP-over-InfiniBand.
235 * Leave P_Key as 0 to be filled in by driver.
238 static inline void ip_ib_mc_map(u32 addr, char *buf)
240 buf[0] = 0; /* Reserved */
241 buf[1] = 0xff; /* Multicast QPN */
246 buf[5] = 0x12; /* link local scope */
247 buf[6] = 0x40; /* IPv4 signature */
249 buf[8] = 0; /* P_Key */
257 buf[19] = addr & 0xff;
259 buf[18] = addr & 0xff;
261 buf[17] = addr & 0xff;
263 buf[16] = addr & 0x0f;
266 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
267 #include <linux/ipv6.h>
270 static __inline__ void inet_reset_saddr(struct sock *sk)
272 inet_sk(sk)->rcv_saddr = inet_sk(sk)->saddr = 0;
273 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
274 if (sk->sk_family == PF_INET6) {
275 struct ipv6_pinfo *np = inet6_sk(sk);
277 memset(&np->saddr, 0, sizeof(np->saddr));
278 memset(&np->rcv_saddr, 0, sizeof(np->rcv_saddr));
285 extern int ip_call_ra_chain(struct sk_buff *skb);
288 * Functions provided by ip_fragment.o
293 IP_DEFRAG_LOCAL_DELIVER,
294 IP_DEFRAG_CALL_RA_CHAIN,
295 IP_DEFRAG_CONNTRACK_IN,
296 IP_DEFRAG_CONNTRACK_OUT,
303 struct sk_buff *ip_defrag(struct sk_buff *skb, u32 user);
304 extern int ip_frag_nqueues;
305 extern atomic_t ip_frag_mem;
308 * Functions provided by ip_forward.c
311 extern int ip_forward(struct sk_buff *skb);
312 extern int ip_net_unreachable(struct sk_buff *skb);
315 * Functions provided by ip_options.c
318 extern void ip_options_build(struct sk_buff *skb, struct ip_options *opt, u32 daddr, struct rtable *rt, int is_frag);
319 extern int ip_options_echo(struct ip_options *dopt, struct sk_buff *skb);
320 extern void ip_options_fragment(struct sk_buff *skb);
321 extern int ip_options_compile(struct ip_options *opt, struct sk_buff *skb);
322 extern int ip_options_get(struct ip_options **optp, unsigned char *data, int optlen, int user);
323 extern void ip_options_undo(struct ip_options * opt);
324 extern void ip_forward_options(struct sk_buff *skb);
325 extern int ip_options_rcv_srr(struct sk_buff *skb);
328 * Functions provided by ip_sockglue.c
331 extern void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb);
332 extern int ip_cmsg_send(struct msghdr *msg, struct ipcm_cookie *ipc);
333 extern int ip_setsockopt(struct sock *sk, int level, int optname, char __user *optval, int optlen);
334 extern int ip_getsockopt(struct sock *sk, int level, int optname, char __user *optval, int __user *optlen);
335 extern int ip_ra_control(struct sock *sk, unsigned char on, void (*destructor)(struct sock *));
337 extern int ip_recv_error(struct sock *sk, struct msghdr *msg, int len);
338 extern void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
339 u16 port, u32 info, u8 *payload);
340 extern void ip_local_error(struct sock *sk, int err, u32 daddr, u16 dport,
343 /* sysctl helpers - any sysctl which holds a value that ends up being
344 * fed into the routing cache should use these handlers.
346 int ipv4_doint_and_flush(ctl_table *ctl, int write,
347 struct file* filp, void __user *buffer,
348 size_t *lenp, loff_t *ppos);
349 int ipv4_doint_and_flush_strategy(ctl_table *table, int __user *name, int nlen,
350 void __user *oldval, size_t __user *oldlenp,
351 void __user *newval, size_t newlen,