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>
34 #include <net/flow_dissector.h>
38 struct inet_skb_parm
{
40 struct ip_options opt
; /* Compiled IP options */
43 #define IPSKB_FORWARDED BIT(0)
44 #define IPSKB_XFRM_TUNNEL_SIZE BIT(1)
45 #define IPSKB_XFRM_TRANSFORMED BIT(2)
46 #define IPSKB_FRAG_COMPLETE BIT(3)
47 #define IPSKB_REROUTED BIT(4)
48 #define IPSKB_DOREDIRECT BIT(5)
49 #define IPSKB_FRAG_PMTU BIT(6)
50 #define IPSKB_L3SLAVE BIT(7)
55 static inline bool ipv4_l3mdev_skb(u16 flags
)
57 return !!(flags
& IPSKB_L3SLAVE
);
60 static inline unsigned int ip_hdrlen(const struct sk_buff
*skb
)
62 return ip_hdr(skb
)->ihl
* 4;
66 struct sockcm_cookie sockc
;
69 struct ip_options_rcu
*opt
;
76 #define IPCB(skb) ((struct inet_skb_parm*)((skb)->cb))
77 #define PKTINFO_SKB_CB(skb) ((struct in_pktinfo *)((skb)->cb))
80 struct ip_ra_chain __rcu
*next
;
83 void (*destructor
)(struct sock
*);
84 struct sock
*saved_sk
;
89 extern struct ip_ra_chain __rcu
*ip_ra_chain
;
92 #define IP_CE 0x8000 /* Flag: "Congestion" */
93 #define IP_DF 0x4000 /* Flag: "Don't Fragment" */
94 #define IP_MF 0x2000 /* Flag: "More Fragments" */
95 #define IP_OFFSET 0x1FFF /* "Fragment Offset" part */
97 #define IP_FRAG_TIME (30 * HZ) /* fragment lifetime */
105 int igmp_mc_init(void);
108 * Functions provided by ip.c
111 int ip_build_and_send_pkt(struct sk_buff
*skb
, const struct sock
*sk
,
112 __be32 saddr
, __be32 daddr
,
113 struct ip_options_rcu
*opt
);
114 int ip_rcv(struct sk_buff
*skb
, struct net_device
*dev
, struct packet_type
*pt
,
115 struct net_device
*orig_dev
);
116 int ip_local_deliver(struct sk_buff
*skb
);
117 int ip_mr_input(struct sk_buff
*skb
);
118 int ip_output(struct net
*net
, struct sock
*sk
, struct sk_buff
*skb
);
119 int ip_mc_output(struct net
*net
, struct sock
*sk
, struct sk_buff
*skb
);
120 int ip_do_fragment(struct net
*net
, struct sock
*sk
, struct sk_buff
*skb
,
121 int (*output
)(struct net
*, struct sock
*, struct sk_buff
*));
122 void ip_send_check(struct iphdr
*ip
);
123 int __ip_local_out(struct net
*net
, struct sock
*sk
, struct sk_buff
*skb
);
124 int ip_local_out(struct net
*net
, struct sock
*sk
, struct sk_buff
*skb
);
126 int ip_queue_xmit(struct sock
*sk
, struct sk_buff
*skb
, struct flowi
*fl
);
128 int ip_append_data(struct sock
*sk
, struct flowi4
*fl4
,
129 int getfrag(void *from
, char *to
, int offset
, int len
,
130 int odd
, struct sk_buff
*skb
),
131 void *from
, int len
, int protolen
,
132 struct ipcm_cookie
*ipc
,
135 int ip_generic_getfrag(void *from
, char *to
, int offset
, int len
, int odd
,
136 struct sk_buff
*skb
);
137 ssize_t
ip_append_page(struct sock
*sk
, struct flowi4
*fl4
, struct page
*page
,
138 int offset
, size_t size
, int flags
);
139 struct sk_buff
*__ip_make_skb(struct sock
*sk
, struct flowi4
*fl4
,
140 struct sk_buff_head
*queue
,
141 struct inet_cork
*cork
);
142 int ip_send_skb(struct net
*net
, struct sk_buff
*skb
);
143 int ip_push_pending_frames(struct sock
*sk
, struct flowi4
*fl4
);
144 void ip_flush_pending_frames(struct sock
*sk
);
145 struct sk_buff
*ip_make_skb(struct sock
*sk
, struct flowi4
*fl4
,
146 int getfrag(void *from
, char *to
, int offset
,
147 int len
, int odd
, struct sk_buff
*skb
),
148 void *from
, int length
, int transhdrlen
,
149 struct ipcm_cookie
*ipc
, struct rtable
**rtp
,
152 static inline struct sk_buff
*ip_finish_skb(struct sock
*sk
, struct flowi4
*fl4
)
154 return __ip_make_skb(sk
, fl4
, &sk
->sk_write_queue
, &inet_sk(sk
)->cork
.base
);
157 static inline __u8
get_rttos(struct ipcm_cookie
* ipc
, struct inet_sock
*inet
)
159 return (ipc
->tos
!= -1) ? RT_TOS(ipc
->tos
) : RT_TOS(inet
->tos
);
162 static inline __u8
get_rtconn_flags(struct ipcm_cookie
* ipc
, struct sock
* sk
)
164 return (ipc
->tos
!= -1) ? RT_CONN_FLAGS_TOS(sk
, ipc
->tos
) : RT_CONN_FLAGS(sk
);
168 int __ip4_datagram_connect(struct sock
*sk
, struct sockaddr
*uaddr
, int addr_len
);
169 int ip4_datagram_connect(struct sock
*sk
, struct sockaddr
*uaddr
, int addr_len
);
171 void ip4_datagram_release_cb(struct sock
*sk
);
173 struct ip_reply_arg
{
177 int csumoffset
; /* u16 offset of csum in iov[0].iov_base */
178 /* -1 if not needed */
184 #define IP_REPLY_ARG_NOSRCCHECK 1
186 static inline __u8
ip_reply_arg_flowi_flags(const struct ip_reply_arg
*arg
)
188 return (arg
->flags
& IP_REPLY_ARG_NOSRCCHECK
) ? FLOWI_FLAG_ANYSRC
: 0;
191 void ip_send_unicast_reply(struct sock
*sk
, struct sk_buff
*skb
,
192 const struct ip_options
*sopt
,
193 __be32 daddr
, __be32 saddr
,
194 const struct ip_reply_arg
*arg
,
197 #define IP_INC_STATS(net, field) SNMP_INC_STATS64((net)->mib.ip_statistics, field)
198 #define __IP_INC_STATS(net, field) __SNMP_INC_STATS64((net)->mib.ip_statistics, field)
199 #define IP_ADD_STATS(net, field, val) SNMP_ADD_STATS64((net)->mib.ip_statistics, field, val)
200 #define __IP_ADD_STATS(net, field, val) __SNMP_ADD_STATS64((net)->mib.ip_statistics, field, val)
201 #define IP_UPD_PO_STATS(net, field, val) SNMP_UPD_PO_STATS64((net)->mib.ip_statistics, field, val)
202 #define __IP_UPD_PO_STATS(net, field, val) __SNMP_UPD_PO_STATS64((net)->mib.ip_statistics, field, val)
203 #define NET_INC_STATS(net, field) SNMP_INC_STATS((net)->mib.net_statistics, field)
204 #define __NET_INC_STATS(net, field) __SNMP_INC_STATS((net)->mib.net_statistics, field)
205 #define NET_ADD_STATS(net, field, adnd) SNMP_ADD_STATS((net)->mib.net_statistics, field, adnd)
206 #define __NET_ADD_STATS(net, field, adnd) __SNMP_ADD_STATS((net)->mib.net_statistics, field, adnd)
208 u64
snmp_get_cpu_field(void __percpu
*mib
, int cpu
, int offct
);
209 unsigned long snmp_fold_field(void __percpu
*mib
, int offt
);
210 #if BITS_PER_LONG==32
211 u64
snmp_get_cpu_field64(void __percpu
*mib
, int cpu
, int offct
,
212 size_t syncp_offset
);
213 u64
snmp_fold_field64(void __percpu
*mib
, int offt
, size_t sync_off
);
215 static inline u64
snmp_get_cpu_field64(void __percpu
*mib
, int cpu
, int offct
,
218 return snmp_get_cpu_field(mib
, cpu
, offct
);
222 static inline u64
snmp_fold_field64(void __percpu
*mib
, int offt
, size_t syncp_off
)
224 return snmp_fold_field(mib
, offt
);
228 #define snmp_get_cpu_field64_batch(buff64, stats_list, mib_statistic, offset) \
231 for_each_possible_cpu(c) { \
232 for (i = 0; stats_list[i].name; i++) \
233 buff64[i] += snmp_get_cpu_field64( \
235 c, stats_list[i].entry, \
240 #define snmp_get_cpu_field_batch(buff, stats_list, mib_statistic) \
243 for_each_possible_cpu(c) { \
244 for (i = 0; stats_list[i].name; i++) \
245 buff[i] += snmp_get_cpu_field( \
247 c, stats_list[i].entry); \
251 void inet_get_local_port_range(struct net
*net
, int *low
, int *high
);
254 static inline int inet_is_local_reserved_port(struct net
*net
, int port
)
256 if (!net
->ipv4
.sysctl_local_reserved_ports
)
258 return test_bit(port
, net
->ipv4
.sysctl_local_reserved_ports
);
261 static inline bool sysctl_dev_name_is_allowed(const char *name
)
263 return strcmp(name
, "default") != 0 && strcmp(name
, "all") != 0;
267 static inline int inet_is_local_reserved_port(struct net
*net
, int port
)
273 __be32
inet_current_timestamp(void);
275 /* From inetpeer.c */
276 extern int inet_peer_threshold
;
277 extern int inet_peer_minttl
;
278 extern int inet_peer_maxttl
;
280 void ipfrag_init(void);
282 void ip_static_sysctl_init(void);
284 #define IP4_REPLY_MARK(net, mark) \
285 ((net)->ipv4.sysctl_fwmark_reflect ? (mark) : 0)
287 static inline bool ip_is_fragment(const struct iphdr
*iph
)
289 return (iph
->frag_off
& htons(IP_MF
| IP_OFFSET
)) != 0;
295 /* The function in 2.2 was invalid, producing wrong result for
296 * check=0xFEFF. It was noticed by Arthur Skawina _year_ ago. --ANK(000625) */
298 int ip_decrease_ttl(struct iphdr
*iph
)
300 u32 check
= (__force u32
)iph
->check
;
301 check
+= (__force u32
)htons(0x0100);
302 iph
->check
= (__force __sum16
)(check
+ (check
>=0xFFFF));
307 int ip_dont_fragment(const struct sock
*sk
, const struct dst_entry
*dst
)
309 u8 pmtudisc
= READ_ONCE(inet_sk(sk
)->pmtudisc
);
311 return pmtudisc
== IP_PMTUDISC_DO
||
312 (pmtudisc
== IP_PMTUDISC_WANT
&&
313 !(dst_metric_locked(dst
, RTAX_MTU
)));
316 static inline bool ip_sk_accept_pmtu(const struct sock
*sk
)
318 return inet_sk(sk
)->pmtudisc
!= IP_PMTUDISC_INTERFACE
&&
319 inet_sk(sk
)->pmtudisc
!= IP_PMTUDISC_OMIT
;
322 static inline bool ip_sk_use_pmtu(const struct sock
*sk
)
324 return inet_sk(sk
)->pmtudisc
< IP_PMTUDISC_PROBE
;
327 static inline bool ip_sk_ignore_df(const struct sock
*sk
)
329 return inet_sk(sk
)->pmtudisc
< IP_PMTUDISC_DO
||
330 inet_sk(sk
)->pmtudisc
== IP_PMTUDISC_OMIT
;
333 static inline unsigned int ip_dst_mtu_maybe_forward(const struct dst_entry
*dst
,
336 struct net
*net
= dev_net(dst
->dev
);
338 if (net
->ipv4
.sysctl_ip_fwd_use_pmtu
||
339 dst_metric_locked(dst
, RTAX_MTU
) ||
343 return min(dst
->dev
->mtu
, IP_MAX_MTU
);
346 static inline unsigned int ip_skb_dst_mtu(struct sock
*sk
,
347 const struct sk_buff
*skb
)
349 if (!sk
|| !sk_fullsock(sk
) || ip_sk_use_pmtu(sk
)) {
350 bool forwarding
= IPCB(skb
)->flags
& IPSKB_FORWARDED
;
352 return ip_dst_mtu_maybe_forward(skb_dst(skb
), forwarding
);
355 return min(skb_dst(skb
)->dev
->mtu
, IP_MAX_MTU
);
358 u32
ip_idents_reserve(u32 hash
, int segs
);
359 void __ip_select_ident(struct net
*net
, struct iphdr
*iph
, int segs
);
361 static inline void ip_select_ident_segs(struct net
*net
, struct sk_buff
*skb
,
362 struct sock
*sk
, int segs
)
364 struct iphdr
*iph
= ip_hdr(skb
);
366 if ((iph
->frag_off
& htons(IP_DF
)) && !skb
->ignore_df
) {
367 /* This is only to work around buggy Windows95/2000
368 * VJ compression implementations. If the ID field
369 * does not change, they drop every other packet in
370 * a TCP stream using header compression.
372 if (sk
&& inet_sk(sk
)->inet_daddr
) {
373 iph
->id
= htons(inet_sk(sk
)->inet_id
);
374 inet_sk(sk
)->inet_id
+= segs
;
379 __ip_select_ident(net
, iph
, segs
);
383 static inline void ip_select_ident(struct net
*net
, struct sk_buff
*skb
,
386 ip_select_ident_segs(net
, skb
, sk
, 1);
389 static inline __wsum
inet_compute_pseudo(struct sk_buff
*skb
, int proto
)
391 return csum_tcpudp_nofold(ip_hdr(skb
)->saddr
, ip_hdr(skb
)->daddr
,
395 /* copy IPv4 saddr & daddr to flow_keys, possibly using 64bit load/store
396 * Equivalent to : flow->v4addrs.src = iph->saddr;
397 * flow->v4addrs.dst = iph->daddr;
399 static inline void iph_to_flow_copy_v4addrs(struct flow_keys
*flow
,
400 const struct iphdr
*iph
)
402 BUILD_BUG_ON(offsetof(typeof(flow
->addrs
), v4addrs
.dst
) !=
403 offsetof(typeof(flow
->addrs
), v4addrs
.src
) +
404 sizeof(flow
->addrs
.v4addrs
.src
));
405 memcpy(&flow
->addrs
.v4addrs
, &iph
->saddr
, sizeof(flow
->addrs
.v4addrs
));
406 flow
->control
.addr_type
= FLOW_DISSECTOR_KEY_IPV4_ADDRS
;
409 static inline __wsum
inet_gro_compute_pseudo(struct sk_buff
*skb
, int proto
)
411 const struct iphdr
*iph
= skb_gro_network_header(skb
);
413 return csum_tcpudp_nofold(iph
->saddr
, iph
->daddr
,
414 skb_gro_len(skb
), proto
, 0);
418 * Map a multicast IP onto multicast MAC for type ethernet.
421 static inline void ip_eth_mc_map(__be32 naddr
, char *buf
)
423 __u32 addr
=ntohl(naddr
);
435 * Map a multicast IP onto multicast MAC for type IP-over-InfiniBand.
436 * Leave P_Key as 0 to be filled in by driver.
439 static inline void ip_ib_mc_map(__be32 naddr
, const unsigned char *broadcast
, char *buf
)
442 unsigned char scope
= broadcast
[5] & 0xF;
444 buf
[0] = 0; /* Reserved */
445 buf
[1] = 0xff; /* Multicast QPN */
450 buf
[5] = 0x10 | scope
; /* scope from broadcast address */
451 buf
[6] = 0x40; /* IPv4 signature */
453 buf
[8] = broadcast
[8]; /* P_Key */
454 buf
[9] = broadcast
[9];
461 buf
[19] = addr
& 0xff;
463 buf
[18] = addr
& 0xff;
465 buf
[17] = addr
& 0xff;
467 buf
[16] = addr
& 0x0f;
470 static inline void ip_ipgre_mc_map(__be32 naddr
, const unsigned char *broadcast
, char *buf
)
472 if ((broadcast
[0] | broadcast
[1] | broadcast
[2] | broadcast
[3]) != 0)
473 memcpy(buf
, broadcast
, 4);
475 memcpy(buf
, &naddr
, sizeof(naddr
));
478 #if IS_ENABLED(CONFIG_IPV6)
479 #include <linux/ipv6.h>
482 static __inline__
void inet_reset_saddr(struct sock
*sk
)
484 inet_sk(sk
)->inet_rcv_saddr
= inet_sk(sk
)->inet_saddr
= 0;
485 #if IS_ENABLED(CONFIG_IPV6)
486 if (sk
->sk_family
== PF_INET6
) {
487 struct ipv6_pinfo
*np
= inet6_sk(sk
);
489 memset(&np
->saddr
, 0, sizeof(np
->saddr
));
490 memset(&sk
->sk_v6_rcv_saddr
, 0, sizeof(sk
->sk_v6_rcv_saddr
));
497 static inline unsigned int ipv4_addr_hash(__be32 ip
)
499 return (__force
unsigned int) ip
;
502 bool ip_call_ra_chain(struct sk_buff
*skb
);
505 * Functions provided by ip_fragment.c
508 enum ip_defrag_users
{
509 IP_DEFRAG_LOCAL_DELIVER
,
510 IP_DEFRAG_CALL_RA_CHAIN
,
511 IP_DEFRAG_CONNTRACK_IN
,
512 __IP_DEFRAG_CONNTRACK_IN_END
= IP_DEFRAG_CONNTRACK_IN
+ USHRT_MAX
,
513 IP_DEFRAG_CONNTRACK_OUT
,
514 __IP_DEFRAG_CONNTRACK_OUT_END
= IP_DEFRAG_CONNTRACK_OUT
+ USHRT_MAX
,
515 IP_DEFRAG_CONNTRACK_BRIDGE_IN
,
516 __IP_DEFRAG_CONNTRACK_BRIDGE_IN
= IP_DEFRAG_CONNTRACK_BRIDGE_IN
+ USHRT_MAX
,
524 /* Return true if the value of 'user' is between 'lower_bond'
525 * and 'upper_bond' inclusively.
527 static inline bool ip_defrag_user_in_between(u32 user
,
528 enum ip_defrag_users lower_bond
,
529 enum ip_defrag_users upper_bond
)
531 return user
>= lower_bond
&& user
<= upper_bond
;
534 int ip_defrag(struct net
*net
, struct sk_buff
*skb
, u32 user
);
536 struct sk_buff
*ip_check_defrag(struct net
*net
, struct sk_buff
*skb
, u32 user
);
538 static inline struct sk_buff
*ip_check_defrag(struct net
*net
, struct sk_buff
*skb
, u32 user
)
543 int ip_frag_mem(struct net
*net
);
546 * Functions provided by ip_forward.c
549 int ip_forward(struct sk_buff
*skb
);
552 * Functions provided by ip_options.c
555 void ip_options_build(struct sk_buff
*skb
, struct ip_options
*opt
,
556 __be32 daddr
, struct rtable
*rt
, int is_frag
);
558 int __ip_options_echo(struct ip_options
*dopt
, struct sk_buff
*skb
,
559 const struct ip_options
*sopt
);
560 static inline int ip_options_echo(struct ip_options
*dopt
, struct sk_buff
*skb
)
562 return __ip_options_echo(dopt
, skb
, &IPCB(skb
)->opt
);
565 void ip_options_fragment(struct sk_buff
*skb
);
566 int ip_options_compile(struct net
*net
, struct ip_options
*opt
,
567 struct sk_buff
*skb
);
568 int ip_options_get(struct net
*net
, struct ip_options_rcu
**optp
,
569 unsigned char *data
, int optlen
);
570 int ip_options_get_from_user(struct net
*net
, struct ip_options_rcu
**optp
,
571 unsigned char __user
*data
, int optlen
);
572 void ip_options_undo(struct ip_options
*opt
);
573 void ip_forward_options(struct sk_buff
*skb
);
574 int ip_options_rcv_srr(struct sk_buff
*skb
);
577 * Functions provided by ip_sockglue.c
580 void ipv4_pktinfo_prepare(const struct sock
*sk
, struct sk_buff
*skb
);
581 void ip_cmsg_recv_offset(struct msghdr
*msg
, struct sock
*sk
,
582 struct sk_buff
*skb
, int tlen
, int offset
);
583 int ip_cmsg_send(struct sock
*sk
, struct msghdr
*msg
,
584 struct ipcm_cookie
*ipc
, bool allow_ipv6
);
585 int ip_setsockopt(struct sock
*sk
, int level
, int optname
, char __user
*optval
,
586 unsigned int optlen
);
587 int ip_getsockopt(struct sock
*sk
, int level
, int optname
, char __user
*optval
,
589 int compat_ip_setsockopt(struct sock
*sk
, int level
, int optname
,
590 char __user
*optval
, unsigned int optlen
);
591 int compat_ip_getsockopt(struct sock
*sk
, int level
, int optname
,
592 char __user
*optval
, int __user
*optlen
);
593 int ip_ra_control(struct sock
*sk
, unsigned char on
,
594 void (*destructor
)(struct sock
*));
596 int ip_recv_error(struct sock
*sk
, struct msghdr
*msg
, int len
, int *addr_len
);
597 void ip_icmp_error(struct sock
*sk
, struct sk_buff
*skb
, int err
, __be16 port
,
598 u32 info
, u8
*payload
);
599 void ip_local_error(struct sock
*sk
, int err
, __be32 daddr
, __be16 dport
,
602 static inline void ip_cmsg_recv(struct msghdr
*msg
, struct sk_buff
*skb
)
604 ip_cmsg_recv_offset(msg
, skb
->sk
, skb
, 0, 0);
607 bool icmp_global_allow(void);
608 extern int sysctl_icmp_msgs_per_sec
;
609 extern int sysctl_icmp_msgs_burst
;
611 #ifdef CONFIG_PROC_FS
612 int ip_misc_proc_init(void);