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
49 static inline unsigned int ip_hdrlen(const struct sk_buff
*skb
)
51 return ip_hdr(skb
)->ihl
* 4;
57 struct ip_options_rcu
*opt
;
61 #define IPCB(skb) ((struct inet_skb_parm*)((skb)->cb))
64 struct ip_ra_chain __rcu
*next
;
67 void (*destructor
)(struct sock
*);
68 struct sock
*saved_sk
;
73 extern struct ip_ra_chain __rcu
*ip_ra_chain
;
76 #define IP_CE 0x8000 /* Flag: "Congestion" */
77 #define IP_DF 0x4000 /* Flag: "Don't Fragment" */
78 #define IP_MF 0x2000 /* Flag: "More Fragments" */
79 #define IP_OFFSET 0x1FFF /* "Fragment Offset" part */
81 #define IP_FRAG_TIME (30 * HZ) /* fragment lifetime */
89 extern int igmp_mc_proc_init(void);
92 * Functions provided by ip.c
95 extern int ip_build_and_send_pkt(struct sk_buff
*skb
, struct sock
*sk
,
96 __be32 saddr
, __be32 daddr
,
97 struct ip_options_rcu
*opt
);
98 extern int ip_rcv(struct sk_buff
*skb
, struct net_device
*dev
,
99 struct packet_type
*pt
, struct net_device
*orig_dev
);
100 extern int ip_local_deliver(struct sk_buff
*skb
);
101 extern int ip_mr_input(struct sk_buff
*skb
);
102 extern int ip_output(struct sk_buff
*skb
);
103 extern int ip_mc_output(struct sk_buff
*skb
);
104 extern int ip_fragment(struct sk_buff
*skb
, int (*output
)(struct sk_buff
*));
105 extern int ip_do_nat(struct sk_buff
*skb
);
106 extern void ip_send_check(struct iphdr
*ip
);
107 extern int __ip_local_out(struct sk_buff
*skb
);
108 extern int ip_local_out(struct sk_buff
*skb
);
109 extern int ip_queue_xmit(struct sk_buff
*skb
, struct flowi
*fl
);
110 extern void ip_init(void);
111 extern int ip_append_data(struct sock
*sk
, struct flowi4
*fl4
,
112 int getfrag(void *from
, char *to
, int offset
, int len
,
113 int odd
, struct sk_buff
*skb
),
114 void *from
, int len
, int protolen
,
115 struct ipcm_cookie
*ipc
,
118 extern int ip_generic_getfrag(void *from
, char *to
, int offset
, int len
, int odd
, struct sk_buff
*skb
);
119 extern ssize_t
ip_append_page(struct sock
*sk
, struct flowi4
*fl4
, struct page
*page
,
120 int offset
, size_t size
, int flags
);
121 extern struct sk_buff
*__ip_make_skb(struct sock
*sk
,
123 struct sk_buff_head
*queue
,
124 struct inet_cork
*cork
);
125 extern int ip_send_skb(struct net
*net
, struct sk_buff
*skb
);
126 extern int ip_push_pending_frames(struct sock
*sk
, struct flowi4
*fl4
);
127 extern void ip_flush_pending_frames(struct sock
*sk
);
128 extern struct sk_buff
*ip_make_skb(struct sock
*sk
,
130 int getfrag(void *from
, char *to
, int offset
, int len
,
131 int odd
, struct sk_buff
*skb
),
132 void *from
, int length
, int transhdrlen
,
133 struct ipcm_cookie
*ipc
,
137 static inline struct sk_buff
*ip_finish_skb(struct sock
*sk
, struct flowi4
*fl4
)
139 return __ip_make_skb(sk
, fl4
, &sk
->sk_write_queue
, &inet_sk(sk
)->cork
.base
);
143 extern int ip4_datagram_connect(struct sock
*sk
,
144 struct sockaddr
*uaddr
, int addr_len
);
146 extern void ip4_datagram_release_cb(struct sock
*sk
);
148 struct ip_reply_arg
{
152 int csumoffset
; /* u16 offset of csum in iov[0].iov_base */
153 /* -1 if not needed */
158 #define IP_REPLY_ARG_NOSRCCHECK 1
160 static inline __u8
ip_reply_arg_flowi_flags(const struct ip_reply_arg
*arg
)
162 return (arg
->flags
& IP_REPLY_ARG_NOSRCCHECK
) ? FLOWI_FLAG_ANYSRC
: 0;
165 void ip_send_unicast_reply(struct net
*net
, struct sk_buff
*skb
, __be32 daddr
,
166 __be32 saddr
, const struct ip_reply_arg
*arg
,
174 extern struct ipv4_config ipv4_config
;
175 #define IP_INC_STATS(net, field) SNMP_INC_STATS64((net)->mib.ip_statistics, field)
176 #define IP_INC_STATS_BH(net, field) SNMP_INC_STATS64_BH((net)->mib.ip_statistics, field)
177 #define IP_ADD_STATS(net, field, val) SNMP_ADD_STATS64((net)->mib.ip_statistics, field, val)
178 #define IP_ADD_STATS_BH(net, field, val) SNMP_ADD_STATS64_BH((net)->mib.ip_statistics, field, val)
179 #define IP_UPD_PO_STATS(net, field, val) SNMP_UPD_PO_STATS64((net)->mib.ip_statistics, field, val)
180 #define IP_UPD_PO_STATS_BH(net, field, val) SNMP_UPD_PO_STATS64_BH((net)->mib.ip_statistics, field, val)
181 #define NET_INC_STATS(net, field) SNMP_INC_STATS((net)->mib.net_statistics, field)
182 #define NET_INC_STATS_BH(net, field) SNMP_INC_STATS_BH((net)->mib.net_statistics, field)
183 #define NET_INC_STATS_USER(net, field) SNMP_INC_STATS_USER((net)->mib.net_statistics, field)
184 #define NET_ADD_STATS_BH(net, field, adnd) SNMP_ADD_STATS_BH((net)->mib.net_statistics, field, adnd)
185 #define NET_ADD_STATS_USER(net, field, adnd) SNMP_ADD_STATS_USER((net)->mib.net_statistics, field, adnd)
187 extern unsigned long snmp_fold_field(void __percpu
*mib
[], int offt
);
188 #if BITS_PER_LONG==32
189 extern u64
snmp_fold_field64(void __percpu
*mib
[], int offt
, size_t sync_off
);
191 static inline u64
snmp_fold_field64(void __percpu
*mib
[], int offt
, size_t syncp_off
)
193 return snmp_fold_field(mib
, offt
);
196 extern int snmp_mib_init(void __percpu
*ptr
[2], size_t mibsize
, size_t align
);
197 extern void snmp_mib_free(void __percpu
*ptr
[2]);
199 extern struct local_ports
{
202 } sysctl_local_ports
;
203 extern void inet_get_local_port_range(int *low
, int *high
);
205 extern unsigned long *sysctl_local_reserved_ports
;
206 static inline int inet_is_reserved_local_port(int port
)
208 return test_bit(port
, sysctl_local_reserved_ports
);
211 extern int sysctl_ip_nonlocal_bind
;
213 /* From inetpeer.c */
214 extern int inet_peer_threshold
;
215 extern int inet_peer_minttl
;
216 extern int inet_peer_maxttl
;
218 /* From ip_input.c */
219 extern int sysctl_ip_early_demux
;
221 /* From ip_output.c */
222 extern int sysctl_ip_dynaddr
;
224 extern void ipfrag_init(void);
226 extern void ip_static_sysctl_init(void);
228 static inline bool ip_is_fragment(const struct iphdr
*iph
)
230 return (iph
->frag_off
& htons(IP_MF
| IP_OFFSET
)) != 0;
236 /* The function in 2.2 was invalid, producing wrong result for
237 * check=0xFEFF. It was noticed by Arthur Skawina _year_ ago. --ANK(000625) */
239 int ip_decrease_ttl(struct iphdr
*iph
)
241 u32 check
= (__force u32
)iph
->check
;
242 check
+= (__force u32
)htons(0x0100);
243 iph
->check
= (__force __sum16
)(check
+ (check
>=0xFFFF));
248 int ip_dont_fragment(struct sock
*sk
, struct dst_entry
*dst
)
250 return inet_sk(sk
)->pmtudisc
== IP_PMTUDISC_DO
||
251 (inet_sk(sk
)->pmtudisc
== IP_PMTUDISC_WANT
&&
252 !(dst_metric_locked(dst
, RTAX_MTU
)));
255 #define IP_IDENTS_SZ 2048u
256 extern atomic_t
*ip_idents
;
258 static inline u32
ip_idents_reserve(u32 hash
, int segs
)
260 atomic_t
*id_ptr
= ip_idents
+ hash
% IP_IDENTS_SZ
;
262 return atomic_add_return(segs
, id_ptr
) - segs
;
265 void __ip_select_ident(struct iphdr
*iph
, int segs
);
267 static inline void ip_select_ident_segs(struct sk_buff
*skb
, struct sock
*sk
, int segs
)
269 struct iphdr
*iph
= ip_hdr(skb
);
271 if ((iph
->frag_off
& htons(IP_DF
)) && !skb
->local_df
) {
272 /* This is only to work around buggy Windows95/2000
273 * VJ compression implementations. If the ID field
274 * does not change, they drop every other packet in
275 * a TCP stream using header compression.
277 if (sk
&& inet_sk(sk
)->inet_daddr
) {
278 iph
->id
= htons(inet_sk(sk
)->inet_id
);
279 inet_sk(sk
)->inet_id
+= segs
;
284 __ip_select_ident(iph
, segs
);
288 static inline void ip_select_ident(struct sk_buff
*skb
, struct sock
*sk
)
290 ip_select_ident_segs(skb
, sk
, 1);
294 * Map a multicast IP onto multicast MAC for type ethernet.
297 static inline void ip_eth_mc_map(__be32 naddr
, char *buf
)
299 __u32 addr
=ntohl(naddr
);
311 * Map a multicast IP onto multicast MAC for type IP-over-InfiniBand.
312 * Leave P_Key as 0 to be filled in by driver.
315 static inline void ip_ib_mc_map(__be32 naddr
, const unsigned char *broadcast
, char *buf
)
318 unsigned char scope
= broadcast
[5] & 0xF;
320 buf
[0] = 0; /* Reserved */
321 buf
[1] = 0xff; /* Multicast QPN */
326 buf
[5] = 0x10 | scope
; /* scope from broadcast address */
327 buf
[6] = 0x40; /* IPv4 signature */
329 buf
[8] = broadcast
[8]; /* P_Key */
330 buf
[9] = broadcast
[9];
337 buf
[19] = addr
& 0xff;
339 buf
[18] = addr
& 0xff;
341 buf
[17] = addr
& 0xff;
343 buf
[16] = addr
& 0x0f;
346 static inline void ip_ipgre_mc_map(__be32 naddr
, const unsigned char *broadcast
, char *buf
)
348 if ((broadcast
[0] | broadcast
[1] | broadcast
[2] | broadcast
[3]) != 0)
349 memcpy(buf
, broadcast
, 4);
351 memcpy(buf
, &naddr
, sizeof(naddr
));
354 #if IS_ENABLED(CONFIG_IPV6)
355 #include <linux/ipv6.h>
358 static __inline__
void inet_reset_saddr(struct sock
*sk
)
360 inet_sk(sk
)->inet_rcv_saddr
= inet_sk(sk
)->inet_saddr
= 0;
361 #if IS_ENABLED(CONFIG_IPV6)
362 if (sk
->sk_family
== PF_INET6
) {
363 struct ipv6_pinfo
*np
= inet6_sk(sk
);
365 memset(&np
->saddr
, 0, sizeof(np
->saddr
));
366 memset(&np
->rcv_saddr
, 0, sizeof(np
->rcv_saddr
));
373 static inline int sk_mc_loop(struct sock
*sk
)
377 switch (sk
->sk_family
) {
379 return inet_sk(sk
)->mc_loop
;
380 #if IS_ENABLED(CONFIG_IPV6)
382 return inet6_sk(sk
)->mc_loop
;
389 extern bool ip_call_ra_chain(struct sk_buff
*skb
);
392 * Functions provided by ip_fragment.c
395 enum ip_defrag_users
{
396 IP_DEFRAG_LOCAL_DELIVER
,
397 IP_DEFRAG_CALL_RA_CHAIN
,
398 IP_DEFRAG_CONNTRACK_IN
,
399 __IP_DEFRAG_CONNTRACK_IN_END
= IP_DEFRAG_CONNTRACK_IN
+ USHRT_MAX
,
400 IP_DEFRAG_CONNTRACK_OUT
,
401 __IP_DEFRAG_CONNTRACK_OUT_END
= IP_DEFRAG_CONNTRACK_OUT
+ USHRT_MAX
,
402 IP_DEFRAG_CONNTRACK_BRIDGE_IN
,
403 __IP_DEFRAG_CONNTRACK_BRIDGE_IN
= IP_DEFRAG_CONNTRACK_BRIDGE_IN
+ USHRT_MAX
,
411 int ip_defrag(struct sk_buff
*skb
, u32 user
);
413 struct sk_buff
*ip_check_defrag(struct sk_buff
*skb
, u32 user
);
415 static inline struct sk_buff
*ip_check_defrag(struct sk_buff
*skb
, u32 user
)
420 int ip_frag_mem(struct net
*net
);
421 int ip_frag_nqueues(struct net
*net
);
424 * Functions provided by ip_forward.c
427 extern int ip_forward(struct sk_buff
*skb
);
430 * Functions provided by ip_options.c
433 extern void ip_options_build(struct sk_buff
*skb
, struct ip_options
*opt
,
434 __be32 daddr
, struct rtable
*rt
, int is_frag
);
435 extern int ip_options_echo(struct ip_options
*dopt
, struct sk_buff
*skb
);
436 extern void ip_options_fragment(struct sk_buff
*skb
);
437 extern int ip_options_compile(struct net
*net
,
438 struct ip_options
*opt
, struct sk_buff
*skb
);
439 extern int ip_options_get(struct net
*net
, struct ip_options_rcu
**optp
,
440 unsigned char *data
, int optlen
);
441 extern int ip_options_get_from_user(struct net
*net
, struct ip_options_rcu
**optp
,
442 unsigned char __user
*data
, int optlen
);
443 extern void ip_options_undo(struct ip_options
* opt
);
444 extern void ip_forward_options(struct sk_buff
*skb
);
445 extern int ip_options_rcv_srr(struct sk_buff
*skb
);
448 * Functions provided by ip_sockglue.c
451 extern void ipv4_pktinfo_prepare(struct sk_buff
*skb
);
452 extern void ip_cmsg_recv(struct msghdr
*msg
, struct sk_buff
*skb
);
453 extern int ip_cmsg_send(struct net
*net
,
454 struct msghdr
*msg
, struct ipcm_cookie
*ipc
);
455 extern int ip_setsockopt(struct sock
*sk
, int level
, int optname
, char __user
*optval
, unsigned int optlen
);
456 extern int ip_getsockopt(struct sock
*sk
, int level
, int optname
, char __user
*optval
, int __user
*optlen
);
457 extern int compat_ip_setsockopt(struct sock
*sk
, int level
,
458 int optname
, char __user
*optval
, unsigned int optlen
);
459 extern int compat_ip_getsockopt(struct sock
*sk
, int level
,
460 int optname
, char __user
*optval
, int __user
*optlen
);
461 extern int ip_ra_control(struct sock
*sk
, unsigned char on
, void (*destructor
)(struct sock
*));
463 extern int ip_recv_error(struct sock
*sk
, struct msghdr
*msg
, int len
, int *addr_len
);
464 extern void ip_icmp_error(struct sock
*sk
, struct sk_buff
*skb
, int err
,
465 __be16 port
, u32 info
, u8
*payload
);
466 extern void ip_local_error(struct sock
*sk
, int err
, __be32 daddr
, __be16 dport
,
469 #ifdef CONFIG_PROC_FS
470 extern int ip_misc_proc_init(void);