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/types.h>
28 #include <linux/skbuff.h>
30 #include <net/inet_sock.h>
36 struct inet_skb_parm
{
37 struct ip_options opt
; /* Compiled IP options */
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
47 static inline unsigned int ip_hdrlen(const struct sk_buff
*skb
)
49 return ip_hdr(skb
)->ihl
* 4;
55 struct ip_options_rcu
*opt
;
59 #define IPCB(skb) ((struct inet_skb_parm*)((skb)->cb))
62 struct ip_ra_chain __rcu
*next
;
65 void (*destructor
)(struct sock
*);
66 struct sock
*saved_sk
;
71 extern struct ip_ra_chain __rcu
*ip_ra_chain
;
74 #define IP_CE 0x8000 /* Flag: "Congestion" */
75 #define IP_DF 0x4000 /* Flag: "Don't Fragment" */
76 #define IP_MF 0x2000 /* Flag: "More Fragments" */
77 #define IP_OFFSET 0x1FFF /* "Fragment Offset" part */
79 #define IP_FRAG_TIME (30 * HZ) /* fragment lifetime */
87 extern int igmp_mc_proc_init(void);
90 * Functions provided by ip.c
93 extern int ip_build_and_send_pkt(struct sk_buff
*skb
, struct sock
*sk
,
94 __be32 saddr
, __be32 daddr
,
95 struct ip_options_rcu
*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_local_out(struct sk_buff
*skb
);
106 extern int ip_local_out(struct sk_buff
*skb
);
107 extern int ip_queue_xmit(struct sk_buff
*skb
, struct flowi
*fl
);
108 extern void ip_init(void);
109 extern int ip_append_data(struct sock
*sk
, struct flowi4
*fl4
,
110 int getfrag(void *from
, char *to
, int offset
, int len
,
111 int odd
, struct sk_buff
*skb
),
112 void *from
, int len
, int protolen
,
113 struct ipcm_cookie
*ipc
,
116 extern int ip_generic_getfrag(void *from
, char *to
, int offset
, int len
, int odd
, struct sk_buff
*skb
);
117 extern ssize_t
ip_append_page(struct sock
*sk
, struct flowi4
*fl4
, struct page
*page
,
118 int offset
, size_t size
, int flags
);
119 extern struct sk_buff
*__ip_make_skb(struct sock
*sk
,
121 struct sk_buff_head
*queue
,
122 struct inet_cork
*cork
);
123 extern int ip_send_skb(struct sk_buff
*skb
);
124 extern int ip_push_pending_frames(struct sock
*sk
, struct flowi4
*fl4
);
125 extern void ip_flush_pending_frames(struct sock
*sk
);
126 extern struct sk_buff
*ip_make_skb(struct sock
*sk
,
128 int getfrag(void *from
, char *to
, int offset
, int len
,
129 int odd
, struct sk_buff
*skb
),
130 void *from
, int length
, int transhdrlen
,
131 struct ipcm_cookie
*ipc
,
135 static inline struct sk_buff
*ip_finish_skb(struct sock
*sk
, struct flowi4
*fl4
)
137 return __ip_make_skb(sk
, fl4
, &sk
->sk_write_queue
, &inet_sk(sk
)->cork
.base
);
141 extern int ip4_datagram_connect(struct sock
*sk
,
142 struct sockaddr
*uaddr
, int addr_len
);
144 struct ip_reply_arg
{
148 int csumoffset
; /* u16 offset of csum in iov[0].iov_base */
149 /* -1 if not needed */
154 #define IP_REPLY_ARG_NOSRCCHECK 1
156 static inline __u8
ip_reply_arg_flowi_flags(const struct ip_reply_arg
*arg
)
158 return (arg
->flags
& IP_REPLY_ARG_NOSRCCHECK
) ? FLOWI_FLAG_ANYSRC
: 0;
161 void ip_send_unicast_reply(struct net
*net
, struct sk_buff
*skb
, __be32 daddr
,
162 __be32 saddr
, const struct ip_reply_arg
*arg
,
170 extern struct ipv4_config ipv4_config
;
171 #define IP_INC_STATS(net, field) SNMP_INC_STATS64((net)->mib.ip_statistics, field)
172 #define IP_INC_STATS_BH(net, field) SNMP_INC_STATS64_BH((net)->mib.ip_statistics, field)
173 #define IP_ADD_STATS(net, field, val) SNMP_ADD_STATS64((net)->mib.ip_statistics, field, val)
174 #define IP_ADD_STATS_BH(net, field, val) SNMP_ADD_STATS64_BH((net)->mib.ip_statistics, field, val)
175 #define IP_UPD_PO_STATS(net, field, val) SNMP_UPD_PO_STATS64((net)->mib.ip_statistics, field, val)
176 #define IP_UPD_PO_STATS_BH(net, field, val) SNMP_UPD_PO_STATS64_BH((net)->mib.ip_statistics, field, val)
177 #define NET_INC_STATS(net, field) SNMP_INC_STATS((net)->mib.net_statistics, field)
178 #define NET_INC_STATS_BH(net, field) SNMP_INC_STATS_BH((net)->mib.net_statistics, field)
179 #define NET_INC_STATS_USER(net, field) SNMP_INC_STATS_USER((net)->mib.net_statistics, field)
180 #define NET_ADD_STATS_BH(net, field, adnd) SNMP_ADD_STATS_BH((net)->mib.net_statistics, field, adnd)
181 #define NET_ADD_STATS_USER(net, field, adnd) SNMP_ADD_STATS_USER((net)->mib.net_statistics, field, adnd)
183 extern unsigned long snmp_fold_field(void __percpu
*mib
[], int offt
);
184 #if BITS_PER_LONG==32
185 extern u64
snmp_fold_field64(void __percpu
*mib
[], int offt
, size_t sync_off
);
187 static inline u64
snmp_fold_field64(void __percpu
*mib
[], int offt
, size_t syncp_off
)
189 return snmp_fold_field(mib
, offt
);
192 extern int snmp_mib_init(void __percpu
*ptr
[2], size_t mibsize
, size_t align
);
193 extern void snmp_mib_free(void __percpu
*ptr
[2]);
195 extern struct local_ports
{
198 } sysctl_local_ports
;
199 extern void inet_get_local_port_range(int *low
, int *high
);
201 extern unsigned long *sysctl_local_reserved_ports
;
202 static inline int inet_is_reserved_local_port(int port
)
204 return test_bit(port
, sysctl_local_reserved_ports
);
207 extern int sysctl_ip_nonlocal_bind
;
209 /* From inetpeer.c */
210 extern int inet_peer_threshold
;
211 extern int inet_peer_minttl
;
212 extern int inet_peer_maxttl
;
214 /* From ip_input.c */
215 extern int sysctl_ip_early_demux
;
217 /* From ip_output.c */
218 extern int sysctl_ip_dynaddr
;
220 extern void ipfrag_init(void);
222 extern void ip_static_sysctl_init(void);
224 static inline bool ip_is_fragment(const struct iphdr
*iph
)
226 return (iph
->frag_off
& htons(IP_MF
| IP_OFFSET
)) != 0;
232 /* The function in 2.2 was invalid, producing wrong result for
233 * check=0xFEFF. It was noticed by Arthur Skawina _year_ ago. --ANK(000625) */
235 int ip_decrease_ttl(struct iphdr
*iph
)
237 u32 check
= (__force u32
)iph
->check
;
238 check
+= (__force u32
)htons(0x0100);
239 iph
->check
= (__force __sum16
)(check
+ (check
>=0xFFFF));
244 int ip_dont_fragment(struct sock
*sk
, struct dst_entry
*dst
)
246 return inet_sk(sk
)->pmtudisc
== IP_PMTUDISC_DO
||
247 (inet_sk(sk
)->pmtudisc
== IP_PMTUDISC_WANT
&&
248 !(dst_metric_locked(dst
, RTAX_MTU
)));
251 extern void __ip_select_ident(struct iphdr
*iph
, struct dst_entry
*dst
, int more
);
253 static inline void ip_select_ident(struct iphdr
*iph
, struct dst_entry
*dst
, struct sock
*sk
)
255 if (iph
->frag_off
& htons(IP_DF
)) {
256 /* This is only to work around buggy Windows95/2000
257 * VJ compression implementations. If the ID field
258 * does not change, they drop every other packet in
259 * a TCP stream using header compression.
261 iph
->id
= (sk
&& inet_sk(sk
)->inet_daddr
) ?
262 htons(inet_sk(sk
)->inet_id
++) : 0;
264 __ip_select_ident(iph
, dst
, 0);
267 static inline void ip_select_ident_more(struct iphdr
*iph
, struct dst_entry
*dst
, struct sock
*sk
, int more
)
269 if (iph
->frag_off
& htons(IP_DF
)) {
270 if (sk
&& inet_sk(sk
)->inet_daddr
) {
271 iph
->id
= htons(inet_sk(sk
)->inet_id
);
272 inet_sk(sk
)->inet_id
+= 1 + more
;
276 __ip_select_ident(iph
, dst
, more
);
280 * Map a multicast IP onto multicast MAC for type ethernet.
283 static inline void ip_eth_mc_map(__be32 naddr
, char *buf
)
285 __u32 addr
=ntohl(naddr
);
297 * Map a multicast IP onto multicast MAC for type IP-over-InfiniBand.
298 * Leave P_Key as 0 to be filled in by driver.
301 static inline void ip_ib_mc_map(__be32 naddr
, const unsigned char *broadcast
, char *buf
)
304 unsigned char scope
= broadcast
[5] & 0xF;
306 buf
[0] = 0; /* Reserved */
307 buf
[1] = 0xff; /* Multicast QPN */
312 buf
[5] = 0x10 | scope
; /* scope from broadcast address */
313 buf
[6] = 0x40; /* IPv4 signature */
315 buf
[8] = broadcast
[8]; /* P_Key */
316 buf
[9] = broadcast
[9];
323 buf
[19] = addr
& 0xff;
325 buf
[18] = addr
& 0xff;
327 buf
[17] = addr
& 0xff;
329 buf
[16] = addr
& 0x0f;
332 static inline void ip_ipgre_mc_map(__be32 naddr
, const unsigned char *broadcast
, char *buf
)
334 if ((broadcast
[0] | broadcast
[1] | broadcast
[2] | broadcast
[3]) != 0)
335 memcpy(buf
, broadcast
, 4);
337 memcpy(buf
, &naddr
, sizeof(naddr
));
340 #if IS_ENABLED(CONFIG_IPV6)
341 #include <linux/ipv6.h>
344 static __inline__
void inet_reset_saddr(struct sock
*sk
)
346 inet_sk(sk
)->inet_rcv_saddr
= inet_sk(sk
)->inet_saddr
= 0;
347 #if IS_ENABLED(CONFIG_IPV6)
348 if (sk
->sk_family
== PF_INET6
) {
349 struct ipv6_pinfo
*np
= inet6_sk(sk
);
351 memset(&np
->saddr
, 0, sizeof(np
->saddr
));
352 memset(&np
->rcv_saddr
, 0, sizeof(np
->rcv_saddr
));
359 static inline int sk_mc_loop(struct sock
*sk
)
363 switch (sk
->sk_family
) {
365 return inet_sk(sk
)->mc_loop
;
366 #if IS_ENABLED(CONFIG_IPV6)
368 return inet6_sk(sk
)->mc_loop
;
375 extern bool ip_call_ra_chain(struct sk_buff
*skb
);
378 * Functions provided by ip_fragment.c
381 enum ip_defrag_users
{
382 IP_DEFRAG_LOCAL_DELIVER
,
383 IP_DEFRAG_CALL_RA_CHAIN
,
384 IP_DEFRAG_CONNTRACK_IN
,
385 __IP_DEFRAG_CONNTRACK_IN_END
= IP_DEFRAG_CONNTRACK_IN
+ USHRT_MAX
,
386 IP_DEFRAG_CONNTRACK_OUT
,
387 __IP_DEFRAG_CONNTRACK_OUT_END
= IP_DEFRAG_CONNTRACK_OUT
+ USHRT_MAX
,
388 IP_DEFRAG_CONNTRACK_BRIDGE_IN
,
389 __IP_DEFRAG_CONNTRACK_BRIDGE_IN
= IP_DEFRAG_CONNTRACK_BRIDGE_IN
+ USHRT_MAX
,
397 int ip_defrag(struct sk_buff
*skb
, u32 user
);
399 struct sk_buff
*ip_check_defrag(struct sk_buff
*skb
, u32 user
);
401 static inline struct sk_buff
*ip_check_defrag(struct sk_buff
*skb
, u32 user
)
406 int ip_frag_mem(struct net
*net
);
407 int ip_frag_nqueues(struct net
*net
);
410 * Functions provided by ip_forward.c
413 extern int ip_forward(struct sk_buff
*skb
);
416 * Functions provided by ip_options.c
419 extern void ip_options_build(struct sk_buff
*skb
, struct ip_options
*opt
,
420 __be32 daddr
, struct rtable
*rt
, int is_frag
);
421 extern int ip_options_echo(struct ip_options
*dopt
, struct sk_buff
*skb
);
422 extern void ip_options_fragment(struct sk_buff
*skb
);
423 extern int ip_options_compile(struct net
*net
,
424 struct ip_options
*opt
, struct sk_buff
*skb
);
425 extern int ip_options_get(struct net
*net
, struct ip_options_rcu
**optp
,
426 unsigned char *data
, int optlen
);
427 extern int ip_options_get_from_user(struct net
*net
, struct ip_options_rcu
**optp
,
428 unsigned char __user
*data
, int optlen
);
429 extern void ip_options_undo(struct ip_options
* opt
);
430 extern void ip_forward_options(struct sk_buff
*skb
);
431 extern int ip_options_rcv_srr(struct sk_buff
*skb
);
434 * Functions provided by ip_sockglue.c
437 extern void ipv4_pktinfo_prepare(struct sk_buff
*skb
);
438 extern void ip_cmsg_recv(struct msghdr
*msg
, struct sk_buff
*skb
);
439 extern int ip_cmsg_send(struct net
*net
,
440 struct msghdr
*msg
, struct ipcm_cookie
*ipc
);
441 extern int ip_setsockopt(struct sock
*sk
, int level
, int optname
, char __user
*optval
, unsigned int optlen
);
442 extern int ip_getsockopt(struct sock
*sk
, int level
, int optname
, char __user
*optval
, int __user
*optlen
);
443 extern int compat_ip_setsockopt(struct sock
*sk
, int level
,
444 int optname
, char __user
*optval
, unsigned int optlen
);
445 extern int compat_ip_getsockopt(struct sock
*sk
, int level
,
446 int optname
, char __user
*optval
, int __user
*optlen
);
447 extern int ip_ra_control(struct sock
*sk
, unsigned char on
, void (*destructor
)(struct sock
*));
449 extern int ip_recv_error(struct sock
*sk
, struct msghdr
*msg
, int len
);
450 extern void ip_icmp_error(struct sock
*sk
, struct sk_buff
*skb
, int err
,
451 __be16 port
, u32 info
, u8
*payload
);
452 extern void ip_local_error(struct sock
*sk
, int err
, __be32 daddr
, __be16 dport
,
455 #ifdef CONFIG_PROC_FS
456 extern int ip_misc_proc_init(void);