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>
31 #include <net/route.h>
37 struct inet_skb_parm
{
38 struct ip_options opt
; /* Compiled IP options */
41 #define IPSKB_FORWARDED 1
42 #define IPSKB_XFRM_TUNNEL_SIZE 2
43 #define IPSKB_XFRM_TRANSFORMED 4
44 #define IPSKB_FRAG_COMPLETE 8
45 #define IPSKB_REROUTED 16
50 static inline unsigned int ip_hdrlen(const struct sk_buff
*skb
)
52 return ip_hdr(skb
)->ihl
* 4;
58 struct ip_options_rcu
*opt
;
65 #define IPCB(skb) ((struct inet_skb_parm*)((skb)->cb))
68 struct ip_ra_chain __rcu
*next
;
71 void (*destructor
)(struct sock
*);
72 struct sock
*saved_sk
;
77 extern struct ip_ra_chain __rcu
*ip_ra_chain
;
80 #define IP_CE 0x8000 /* Flag: "Congestion" */
81 #define IP_DF 0x4000 /* Flag: "Don't Fragment" */
82 #define IP_MF 0x2000 /* Flag: "More Fragments" */
83 #define IP_OFFSET 0x1FFF /* "Fragment Offset" part */
85 #define IP_FRAG_TIME (30 * HZ) /* fragment lifetime */
93 int igmp_mc_proc_init(void);
96 * Functions provided by ip.c
99 int ip_build_and_send_pkt(struct sk_buff
*skb
, struct sock
*sk
,
100 __be32 saddr
, __be32 daddr
,
101 struct ip_options_rcu
*opt
);
102 int ip_rcv(struct sk_buff
*skb
, struct net_device
*dev
, struct packet_type
*pt
,
103 struct net_device
*orig_dev
);
104 int ip_local_deliver(struct sk_buff
*skb
);
105 int ip_mr_input(struct sk_buff
*skb
);
106 int ip_output(struct sk_buff
*skb
);
107 int ip_mc_output(struct sk_buff
*skb
);
108 int ip_fragment(struct sk_buff
*skb
, int (*output
)(struct sk_buff
*));
109 int ip_do_nat(struct sk_buff
*skb
);
110 void ip_send_check(struct iphdr
*ip
);
111 int __ip_local_out(struct sk_buff
*skb
);
112 int ip_local_out(struct sk_buff
*skb
);
113 int ip_queue_xmit(struct sk_buff
*skb
, struct flowi
*fl
);
115 int ip_append_data(struct sock
*sk
, struct flowi4
*fl4
,
116 int getfrag(void *from
, char *to
, int offset
, int len
,
117 int odd
, struct sk_buff
*skb
),
118 void *from
, int len
, int protolen
,
119 struct ipcm_cookie
*ipc
,
122 int ip_generic_getfrag(void *from
, char *to
, int offset
, int len
, int odd
,
123 struct sk_buff
*skb
);
124 ssize_t
ip_append_page(struct sock
*sk
, struct flowi4
*fl4
, struct page
*page
,
125 int offset
, size_t size
, int flags
);
126 struct sk_buff
*__ip_make_skb(struct sock
*sk
, struct flowi4
*fl4
,
127 struct sk_buff_head
*queue
,
128 struct inet_cork
*cork
);
129 int ip_send_skb(struct net
*net
, struct sk_buff
*skb
);
130 int ip_push_pending_frames(struct sock
*sk
, struct flowi4
*fl4
);
131 void ip_flush_pending_frames(struct sock
*sk
);
132 struct sk_buff
*ip_make_skb(struct sock
*sk
, struct flowi4
*fl4
,
133 int getfrag(void *from
, char *to
, int offset
,
134 int len
, int odd
, struct sk_buff
*skb
),
135 void *from
, int length
, int transhdrlen
,
136 struct ipcm_cookie
*ipc
, struct rtable
**rtp
,
139 static inline struct sk_buff
*ip_finish_skb(struct sock
*sk
, struct flowi4
*fl4
)
141 return __ip_make_skb(sk
, fl4
, &sk
->sk_write_queue
, &inet_sk(sk
)->cork
.base
);
144 static inline __u8
get_rttos(struct ipcm_cookie
* ipc
, struct inet_sock
*inet
)
146 return (ipc
->tos
!= -1) ? RT_TOS(ipc
->tos
) : RT_TOS(inet
->tos
);
149 static inline __u8
get_rtconn_flags(struct ipcm_cookie
* ipc
, struct sock
* sk
)
151 return (ipc
->tos
!= -1) ? RT_CONN_FLAGS_TOS(sk
, ipc
->tos
) : RT_CONN_FLAGS(sk
);
155 int ip4_datagram_connect(struct sock
*sk
, struct sockaddr
*uaddr
, int addr_len
);
157 void ip4_datagram_release_cb(struct sock
*sk
);
159 struct ip_reply_arg
{
163 int csumoffset
; /* u16 offset of csum in iov[0].iov_base */
164 /* -1 if not needed */
169 #define IP_REPLY_ARG_NOSRCCHECK 1
171 static inline __u8
ip_reply_arg_flowi_flags(const struct ip_reply_arg
*arg
)
173 return (arg
->flags
& IP_REPLY_ARG_NOSRCCHECK
) ? FLOWI_FLAG_ANYSRC
: 0;
176 void ip_send_unicast_reply(struct net
*net
, struct sk_buff
*skb
, __be32 daddr
,
177 __be32 saddr
, const struct ip_reply_arg
*arg
,
185 extern struct ipv4_config ipv4_config
;
186 #define IP_INC_STATS(net, field) SNMP_INC_STATS64((net)->mib.ip_statistics, field)
187 #define IP_INC_STATS_BH(net, field) SNMP_INC_STATS64_BH((net)->mib.ip_statistics, field)
188 #define IP_ADD_STATS(net, field, val) SNMP_ADD_STATS64((net)->mib.ip_statistics, field, val)
189 #define IP_ADD_STATS_BH(net, field, val) SNMP_ADD_STATS64_BH((net)->mib.ip_statistics, field, val)
190 #define IP_UPD_PO_STATS(net, field, val) SNMP_UPD_PO_STATS64((net)->mib.ip_statistics, field, val)
191 #define IP_UPD_PO_STATS_BH(net, field, val) SNMP_UPD_PO_STATS64_BH((net)->mib.ip_statistics, field, val)
192 #define NET_INC_STATS(net, field) SNMP_INC_STATS((net)->mib.net_statistics, field)
193 #define NET_INC_STATS_BH(net, field) SNMP_INC_STATS_BH((net)->mib.net_statistics, field)
194 #define NET_INC_STATS_USER(net, field) SNMP_INC_STATS_USER((net)->mib.net_statistics, field)
195 #define NET_ADD_STATS_BH(net, field, adnd) SNMP_ADD_STATS_BH((net)->mib.net_statistics, field, adnd)
196 #define NET_ADD_STATS_USER(net, field, adnd) SNMP_ADD_STATS_USER((net)->mib.net_statistics, field, adnd)
198 unsigned long snmp_fold_field(void __percpu
*mib
[], int offt
);
199 #if BITS_PER_LONG==32
200 u64
snmp_fold_field64(void __percpu
*mib
[], int offt
, size_t sync_off
);
202 static inline u64
snmp_fold_field64(void __percpu
*mib
[], int offt
, size_t syncp_off
)
204 return snmp_fold_field(mib
, offt
);
207 int snmp_mib_init(void __percpu
*ptr
[2], size_t mibsize
, size_t align
);
209 static inline void snmp_mib_free(void __percpu
*ptr
[SNMP_ARRAY_SZ
])
214 for (i
= 0; i
< SNMP_ARRAY_SZ
; i
++) {
220 void inet_get_local_port_range(struct net
*net
, int *low
, int *high
);
222 extern unsigned long *sysctl_local_reserved_ports
;
223 static inline int inet_is_reserved_local_port(int port
)
225 return test_bit(port
, sysctl_local_reserved_ports
);
228 extern int sysctl_ip_nonlocal_bind
;
230 /* From inetpeer.c */
231 extern int inet_peer_threshold
;
232 extern int inet_peer_minttl
;
233 extern int inet_peer_maxttl
;
235 /* From ip_input.c */
236 extern int sysctl_ip_early_demux
;
238 /* From ip_output.c */
239 extern int sysctl_ip_dynaddr
;
241 void ipfrag_init(void);
243 void ip_static_sysctl_init(void);
245 static inline bool ip_is_fragment(const struct iphdr
*iph
)
247 return (iph
->frag_off
& htons(IP_MF
| IP_OFFSET
)) != 0;
253 /* The function in 2.2 was invalid, producing wrong result for
254 * check=0xFEFF. It was noticed by Arthur Skawina _year_ ago. --ANK(000625) */
256 int ip_decrease_ttl(struct iphdr
*iph
)
258 u32 check
= (__force u32
)iph
->check
;
259 check
+= (__force u32
)htons(0x0100);
260 iph
->check
= (__force __sum16
)(check
+ (check
>=0xFFFF));
265 int ip_dont_fragment(struct sock
*sk
, struct dst_entry
*dst
)
267 return inet_sk(sk
)->pmtudisc
== IP_PMTUDISC_DO
||
268 (inet_sk(sk
)->pmtudisc
== IP_PMTUDISC_WANT
&&
269 !(dst_metric_locked(dst
, RTAX_MTU
)));
272 void __ip_select_ident(struct iphdr
*iph
, struct dst_entry
*dst
, int more
);
274 static inline void ip_select_ident(struct sk_buff
*skb
, struct dst_entry
*dst
, struct sock
*sk
)
276 struct iphdr
*iph
= ip_hdr(skb
);
278 if ((iph
->frag_off
& htons(IP_DF
)) && !skb
->local_df
) {
279 /* This is only to work around buggy Windows95/2000
280 * VJ compression implementations. If the ID field
281 * does not change, they drop every other packet in
282 * a TCP stream using header compression.
284 iph
->id
= (sk
&& inet_sk(sk
)->inet_daddr
) ?
285 htons(inet_sk(sk
)->inet_id
++) : 0;
287 __ip_select_ident(iph
, dst
, 0);
290 static inline void ip_select_ident_more(struct sk_buff
*skb
, struct dst_entry
*dst
, struct sock
*sk
, int more
)
292 struct iphdr
*iph
= ip_hdr(skb
);
294 if ((iph
->frag_off
& htons(IP_DF
)) && !skb
->local_df
) {
295 if (sk
&& inet_sk(sk
)->inet_daddr
) {
296 iph
->id
= htons(inet_sk(sk
)->inet_id
);
297 inet_sk(sk
)->inet_id
+= 1 + more
;
301 __ip_select_ident(iph
, dst
, more
);
305 * Map a multicast IP onto multicast MAC for type ethernet.
308 static inline void ip_eth_mc_map(__be32 naddr
, char *buf
)
310 __u32 addr
=ntohl(naddr
);
322 * Map a multicast IP onto multicast MAC for type IP-over-InfiniBand.
323 * Leave P_Key as 0 to be filled in by driver.
326 static inline void ip_ib_mc_map(__be32 naddr
, const unsigned char *broadcast
, char *buf
)
329 unsigned char scope
= broadcast
[5] & 0xF;
331 buf
[0] = 0; /* Reserved */
332 buf
[1] = 0xff; /* Multicast QPN */
337 buf
[5] = 0x10 | scope
; /* scope from broadcast address */
338 buf
[6] = 0x40; /* IPv4 signature */
340 buf
[8] = broadcast
[8]; /* P_Key */
341 buf
[9] = broadcast
[9];
348 buf
[19] = addr
& 0xff;
350 buf
[18] = addr
& 0xff;
352 buf
[17] = addr
& 0xff;
354 buf
[16] = addr
& 0x0f;
357 static inline void ip_ipgre_mc_map(__be32 naddr
, const unsigned char *broadcast
, char *buf
)
359 if ((broadcast
[0] | broadcast
[1] | broadcast
[2] | broadcast
[3]) != 0)
360 memcpy(buf
, broadcast
, 4);
362 memcpy(buf
, &naddr
, sizeof(naddr
));
365 #if IS_ENABLED(CONFIG_IPV6)
366 #include <linux/ipv6.h>
369 static __inline__
void inet_reset_saddr(struct sock
*sk
)
371 inet_sk(sk
)->inet_rcv_saddr
= inet_sk(sk
)->inet_saddr
= 0;
372 #if IS_ENABLED(CONFIG_IPV6)
373 if (sk
->sk_family
== PF_INET6
) {
374 struct ipv6_pinfo
*np
= inet6_sk(sk
);
376 memset(&np
->saddr
, 0, sizeof(np
->saddr
));
377 memset(&sk
->sk_v6_rcv_saddr
, 0, sizeof(sk
->sk_v6_rcv_saddr
));
384 static inline int sk_mc_loop(struct sock
*sk
)
388 switch (sk
->sk_family
) {
390 return inet_sk(sk
)->mc_loop
;
391 #if IS_ENABLED(CONFIG_IPV6)
393 return inet6_sk(sk
)->mc_loop
;
400 bool ip_call_ra_chain(struct sk_buff
*skb
);
403 * Functions provided by ip_fragment.c
406 enum ip_defrag_users
{
407 IP_DEFRAG_LOCAL_DELIVER
,
408 IP_DEFRAG_CALL_RA_CHAIN
,
409 IP_DEFRAG_CONNTRACK_IN
,
410 __IP_DEFRAG_CONNTRACK_IN_END
= IP_DEFRAG_CONNTRACK_IN
+ USHRT_MAX
,
411 IP_DEFRAG_CONNTRACK_OUT
,
412 __IP_DEFRAG_CONNTRACK_OUT_END
= IP_DEFRAG_CONNTRACK_OUT
+ USHRT_MAX
,
413 IP_DEFRAG_CONNTRACK_BRIDGE_IN
,
414 __IP_DEFRAG_CONNTRACK_BRIDGE_IN
= IP_DEFRAG_CONNTRACK_BRIDGE_IN
+ USHRT_MAX
,
422 int ip_defrag(struct sk_buff
*skb
, u32 user
);
424 struct sk_buff
*ip_check_defrag(struct sk_buff
*skb
, u32 user
);
426 static inline struct sk_buff
*ip_check_defrag(struct sk_buff
*skb
, u32 user
)
431 int ip_frag_mem(struct net
*net
);
432 int ip_frag_nqueues(struct net
*net
);
435 * Functions provided by ip_forward.c
438 int ip_forward(struct sk_buff
*skb
);
441 * Functions provided by ip_options.c
444 void ip_options_build(struct sk_buff
*skb
, struct ip_options
*opt
,
445 __be32 daddr
, struct rtable
*rt
, int is_frag
);
446 int ip_options_echo(struct ip_options
*dopt
, struct sk_buff
*skb
);
447 void ip_options_fragment(struct sk_buff
*skb
);
448 int ip_options_compile(struct net
*net
, struct ip_options
*opt
,
449 struct sk_buff
*skb
);
450 int ip_options_get(struct net
*net
, struct ip_options_rcu
**optp
,
451 unsigned char *data
, int optlen
);
452 int ip_options_get_from_user(struct net
*net
, struct ip_options_rcu
**optp
,
453 unsigned char __user
*data
, int optlen
);
454 void ip_options_undo(struct ip_options
*opt
);
455 void ip_forward_options(struct sk_buff
*skb
);
456 int ip_options_rcv_srr(struct sk_buff
*skb
);
459 * Functions provided by ip_sockglue.c
462 void ipv4_pktinfo_prepare(const struct sock
*sk
, struct sk_buff
*skb
);
463 void ip_cmsg_recv(struct msghdr
*msg
, struct sk_buff
*skb
);
464 int ip_cmsg_send(struct net
*net
, struct msghdr
*msg
, struct ipcm_cookie
*ipc
);
465 int ip_setsockopt(struct sock
*sk
, int level
, int optname
, char __user
*optval
,
466 unsigned int optlen
);
467 int ip_getsockopt(struct sock
*sk
, int level
, int optname
, char __user
*optval
,
469 int compat_ip_setsockopt(struct sock
*sk
, int level
, int optname
,
470 char __user
*optval
, unsigned int optlen
);
471 int compat_ip_getsockopt(struct sock
*sk
, int level
, int optname
,
472 char __user
*optval
, int __user
*optlen
);
473 int ip_ra_control(struct sock
*sk
, unsigned char on
,
474 void (*destructor
)(struct sock
*));
476 int ip_recv_error(struct sock
*sk
, struct msghdr
*msg
, int len
, int *addr_len
);
477 void ip_icmp_error(struct sock
*sk
, struct sk_buff
*skb
, int err
, __be16 port
,
478 u32 info
, u8
*payload
);
479 void ip_local_error(struct sock
*sk
, int err
, __be32 daddr
, __be16 dport
,
482 #ifdef CONFIG_PROC_FS
483 int ip_misc_proc_init(void);