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1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/*
3 * INET An implementation of the TCP/IP protocol suite for the LINUX
4 * operating system. INET is implemented using the BSD Socket
5 * interface as the means of communication with the user level.
6 *
7 * Definitions for the IP module.
8 *
9 * Version: @(#)ip.h 1.0.2 05/07/93
10 *
11 * Authors: Ross Biro
12 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
13 * Alan Cox, <gw4pts@gw4pts.ampr.org>
14 *
15 * Changes:
16 * Mike McLagan : Routing by source
17 */
18#ifndef _IP_H
19#define _IP_H
20
21#include <linux/types.h>
22#include <linux/ip.h>
23#include <linux/in.h>
24#include <linux/skbuff.h>
25#include <linux/jhash.h>
26
27#include <net/inet_sock.h>
28#include <net/route.h>
29#include <net/snmp.h>
30#include <net/flow.h>
31#include <net/flow_dissector.h>
32#include <net/netns/hash.h>
33
34#define IPV4_MAX_PMTU 65535U /* RFC 2675, Section 5.1 */
35#define IPV4_MIN_MTU 68 /* RFC 791 */
36
37extern unsigned int sysctl_fib_sync_mem;
38extern unsigned int sysctl_fib_sync_mem_min;
39extern unsigned int sysctl_fib_sync_mem_max;
40
41struct sock;
42
43struct inet_skb_parm {
44 int iif;
45 struct ip_options opt; /* Compiled IP options */
46 u16 flags;
47
48#define IPSKB_FORWARDED BIT(0)
49#define IPSKB_XFRM_TUNNEL_SIZE BIT(1)
50#define IPSKB_XFRM_TRANSFORMED BIT(2)
51#define IPSKB_FRAG_COMPLETE BIT(3)
52#define IPSKB_REROUTED BIT(4)
53#define IPSKB_DOREDIRECT BIT(5)
54#define IPSKB_FRAG_PMTU BIT(6)
55#define IPSKB_L3SLAVE BIT(7)
56
57 u16 frag_max_size;
58};
59
60static inline bool ipv4_l3mdev_skb(u16 flags)
61{
62 return !!(flags & IPSKB_L3SLAVE);
63}
64
65static inline unsigned int ip_hdrlen(const struct sk_buff *skb)
66{
67 return ip_hdr(skb)->ihl * 4;
68}
69
70struct ipcm_cookie {
71 struct sockcm_cookie sockc;
72 __be32 addr;
73 int oif;
74 struct ip_options_rcu *opt;
75 __u8 ttl;
76 __s16 tos;
77 char priority;
78 __u16 gso_size;
79};
80
81static inline void ipcm_init(struct ipcm_cookie *ipcm)
82{
83 *ipcm = (struct ipcm_cookie) { .tos = -1 };
84}
85
86static inline void ipcm_init_sk(struct ipcm_cookie *ipcm,
87 const struct inet_sock *inet)
88{
89 ipcm_init(ipcm);
90
91 ipcm->sockc.mark = inet->sk.sk_mark;
92 ipcm->sockc.tsflags = inet->sk.sk_tsflags;
93 ipcm->oif = inet->sk.sk_bound_dev_if;
94 ipcm->addr = inet->inet_saddr;
95}
96
97#define IPCB(skb) ((struct inet_skb_parm*)((skb)->cb))
98#define PKTINFO_SKB_CB(skb) ((struct in_pktinfo *)((skb)->cb))
99
100/* return enslaved device index if relevant */
101static inline int inet_sdif(struct sk_buff *skb)
102{
103#if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV)
104 if (skb && ipv4_l3mdev_skb(IPCB(skb)->flags))
105 return IPCB(skb)->iif;
106#endif
107 return 0;
108}
109
110/* Special input handler for packets caught by router alert option.
111 They are selected only by protocol field, and then processed likely
112 local ones; but only if someone wants them! Otherwise, router
113 not running rsvpd will kill RSVP.
114
115 It is user level problem, what it will make with them.
116 I have no idea, how it will masquearde or NAT them (it is joke, joke :-)),
117 but receiver should be enough clever f.e. to forward mtrace requests,
118 sent to multicast group to reach destination designated router.
119 */
120
121struct ip_ra_chain {
122 struct ip_ra_chain __rcu *next;
123 struct sock *sk;
124 union {
125 void (*destructor)(struct sock *);
126 struct sock *saved_sk;
127 };
128 struct rcu_head rcu;
129};
130
131/* IP flags. */
132#define IP_CE 0x8000 /* Flag: "Congestion" */
133#define IP_DF 0x4000 /* Flag: "Don't Fragment" */
134#define IP_MF 0x2000 /* Flag: "More Fragments" */
135#define IP_OFFSET 0x1FFF /* "Fragment Offset" part */
136
137#define IP_FRAG_TIME (30 * HZ) /* fragment lifetime */
138
139struct msghdr;
140struct net_device;
141struct packet_type;
142struct rtable;
143struct sockaddr;
144
145int igmp_mc_init(void);
146
147/*
148 * Functions provided by ip.c
149 */
150
151int ip_build_and_send_pkt(struct sk_buff *skb, const struct sock *sk,
152 __be32 saddr, __be32 daddr,
153 struct ip_options_rcu *opt);
154int ip_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt,
155 struct net_device *orig_dev);
156void ip_list_rcv(struct list_head *head, struct packet_type *pt,
157 struct net_device *orig_dev);
158int ip_local_deliver(struct sk_buff *skb);
159void ip_protocol_deliver_rcu(struct net *net, struct sk_buff *skb, int proto);
160int ip_mr_input(struct sk_buff *skb);
161int ip_output(struct net *net, struct sock *sk, struct sk_buff *skb);
162int ip_mc_output(struct net *net, struct sock *sk, struct sk_buff *skb);
163int ip_do_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
164 int (*output)(struct net *, struct sock *, struct sk_buff *));
165
166struct ip_fraglist_iter {
167 struct sk_buff *frag;
168 struct iphdr *iph;
169 int offset;
170 unsigned int hlen;
171};
172
173void ip_fraglist_init(struct sk_buff *skb, struct iphdr *iph,
174 unsigned int hlen, struct ip_fraglist_iter *iter);
175void ip_fraglist_prepare(struct sk_buff *skb, struct ip_fraglist_iter *iter);
176
177static inline struct sk_buff *ip_fraglist_next(struct ip_fraglist_iter *iter)
178{
179 struct sk_buff *skb = iter->frag;
180
181 iter->frag = skb->next;
182 skb_mark_not_on_list(skb);
183
184 return skb;
185}
186
187struct ip_frag_state {
188 bool DF;
189 unsigned int hlen;
190 unsigned int ll_rs;
191 unsigned int mtu;
192 unsigned int left;
193 int offset;
194 int ptr;
195 __be16 not_last_frag;
196};
197
198void ip_frag_init(struct sk_buff *skb, unsigned int hlen, unsigned int ll_rs,
199 unsigned int mtu, bool DF, struct ip_frag_state *state);
200struct sk_buff *ip_frag_next(struct sk_buff *skb,
201 struct ip_frag_state *state);
202
203void ip_send_check(struct iphdr *ip);
204int __ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb);
205int ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb);
206
207int __ip_queue_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl,
208 __u8 tos);
209void ip_init(void);
210int ip_append_data(struct sock *sk, struct flowi4 *fl4,
211 int getfrag(void *from, char *to, int offset, int len,
212 int odd, struct sk_buff *skb),
213 void *from, int len, int protolen,
214 struct ipcm_cookie *ipc,
215 struct rtable **rt,
216 unsigned int flags);
217int ip_generic_getfrag(void *from, char *to, int offset, int len, int odd,
218 struct sk_buff *skb);
219ssize_t ip_append_page(struct sock *sk, struct flowi4 *fl4, struct page *page,
220 int offset, size_t size, int flags);
221struct sk_buff *__ip_make_skb(struct sock *sk, struct flowi4 *fl4,
222 struct sk_buff_head *queue,
223 struct inet_cork *cork);
224int ip_send_skb(struct net *net, struct sk_buff *skb);
225int ip_push_pending_frames(struct sock *sk, struct flowi4 *fl4);
226void ip_flush_pending_frames(struct sock *sk);
227struct sk_buff *ip_make_skb(struct sock *sk, struct flowi4 *fl4,
228 int getfrag(void *from, char *to, int offset,
229 int len, int odd, struct sk_buff *skb),
230 void *from, int length, int transhdrlen,
231 struct ipcm_cookie *ipc, struct rtable **rtp,
232 struct inet_cork *cork, unsigned int flags);
233
234static inline int ip_queue_xmit(struct sock *sk, struct sk_buff *skb,
235 struct flowi *fl)
236{
237 return __ip_queue_xmit(sk, skb, fl, inet_sk(sk)->tos);
238}
239
240static inline struct sk_buff *ip_finish_skb(struct sock *sk, struct flowi4 *fl4)
241{
242 return __ip_make_skb(sk, fl4, &sk->sk_write_queue, &inet_sk(sk)->cork.base);
243}
244
245static inline __u8 get_rttos(struct ipcm_cookie* ipc, struct inet_sock *inet)
246{
247 return (ipc->tos != -1) ? RT_TOS(ipc->tos) : RT_TOS(inet->tos);
248}
249
250static inline __u8 get_rtconn_flags(struct ipcm_cookie* ipc, struct sock* sk)
251{
252 return (ipc->tos != -1) ? RT_CONN_FLAGS_TOS(sk, ipc->tos) : RT_CONN_FLAGS(sk);
253}
254
255/* datagram.c */
256int __ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len);
257int ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len);
258
259void ip4_datagram_release_cb(struct sock *sk);
260
261struct ip_reply_arg {
262 struct kvec iov[1];
263 int flags;
264 __wsum csum;
265 int csumoffset; /* u16 offset of csum in iov[0].iov_base */
266 /* -1 if not needed */
267 int bound_dev_if;
268 u8 tos;
269 kuid_t uid;
270};
271
272#define IP_REPLY_ARG_NOSRCCHECK 1
273
274static inline __u8 ip_reply_arg_flowi_flags(const struct ip_reply_arg *arg)
275{
276 return (arg->flags & IP_REPLY_ARG_NOSRCCHECK) ? FLOWI_FLAG_ANYSRC : 0;
277}
278
279void ip_send_unicast_reply(struct sock *sk, struct sk_buff *skb,
280 const struct ip_options *sopt,
281 __be32 daddr, __be32 saddr,
282 const struct ip_reply_arg *arg,
283 unsigned int len, u64 transmit_time);
284
285#define IP_INC_STATS(net, field) SNMP_INC_STATS64((net)->mib.ip_statistics, field)
286#define __IP_INC_STATS(net, field) __SNMP_INC_STATS64((net)->mib.ip_statistics, field)
287#define IP_ADD_STATS(net, field, val) SNMP_ADD_STATS64((net)->mib.ip_statistics, field, val)
288#define __IP_ADD_STATS(net, field, val) __SNMP_ADD_STATS64((net)->mib.ip_statistics, field, val)
289#define IP_UPD_PO_STATS(net, field, val) SNMP_UPD_PO_STATS64((net)->mib.ip_statistics, field, val)
290#define __IP_UPD_PO_STATS(net, field, val) __SNMP_UPD_PO_STATS64((net)->mib.ip_statistics, field, val)
291#define NET_INC_STATS(net, field) SNMP_INC_STATS((net)->mib.net_statistics, field)
292#define __NET_INC_STATS(net, field) __SNMP_INC_STATS((net)->mib.net_statistics, field)
293#define NET_ADD_STATS(net, field, adnd) SNMP_ADD_STATS((net)->mib.net_statistics, field, adnd)
294#define __NET_ADD_STATS(net, field, adnd) __SNMP_ADD_STATS((net)->mib.net_statistics, field, adnd)
295
296u64 snmp_get_cpu_field(void __percpu *mib, int cpu, int offct);
297unsigned long snmp_fold_field(void __percpu *mib, int offt);
298#if BITS_PER_LONG==32
299u64 snmp_get_cpu_field64(void __percpu *mib, int cpu, int offct,
300 size_t syncp_offset);
301u64 snmp_fold_field64(void __percpu *mib, int offt, size_t sync_off);
302#else
303static inline u64 snmp_get_cpu_field64(void __percpu *mib, int cpu, int offct,
304 size_t syncp_offset)
305{
306 return snmp_get_cpu_field(mib, cpu, offct);
307
308}
309
310static inline u64 snmp_fold_field64(void __percpu *mib, int offt, size_t syncp_off)
311{
312 return snmp_fold_field(mib, offt);
313}
314#endif
315
316#define snmp_get_cpu_field64_batch(buff64, stats_list, mib_statistic, offset) \
317{ \
318 int i, c; \
319 for_each_possible_cpu(c) { \
320 for (i = 0; stats_list[i].name; i++) \
321 buff64[i] += snmp_get_cpu_field64( \
322 mib_statistic, \
323 c, stats_list[i].entry, \
324 offset); \
325 } \
326}
327
328#define snmp_get_cpu_field_batch(buff, stats_list, mib_statistic) \
329{ \
330 int i, c; \
331 for_each_possible_cpu(c) { \
332 for (i = 0; stats_list[i].name; i++) \
333 buff[i] += snmp_get_cpu_field( \
334 mib_statistic, \
335 c, stats_list[i].entry); \
336 } \
337}
338
339void inet_get_local_port_range(struct net *net, int *low, int *high);
340
341#ifdef CONFIG_SYSCTL
342static inline int inet_is_local_reserved_port(struct net *net, int port)
343{
344 if (!net->ipv4.sysctl_local_reserved_ports)
345 return 0;
346 return test_bit(port, net->ipv4.sysctl_local_reserved_ports);
347}
348
349static inline bool sysctl_dev_name_is_allowed(const char *name)
350{
351 return strcmp(name, "default") != 0 && strcmp(name, "all") != 0;
352}
353
354static inline int inet_prot_sock(struct net *net)
355{
356 return net->ipv4.sysctl_ip_prot_sock;
357}
358
359#else
360static inline int inet_is_local_reserved_port(struct net *net, int port)
361{
362 return 0;
363}
364
365static inline int inet_prot_sock(struct net *net)
366{
367 return PROT_SOCK;
368}
369#endif
370
371__be32 inet_current_timestamp(void);
372
373/* From inetpeer.c */
374extern int inet_peer_threshold;
375extern int inet_peer_minttl;
376extern int inet_peer_maxttl;
377
378void ipfrag_init(void);
379
380void ip_static_sysctl_init(void);
381
382#define IP4_REPLY_MARK(net, mark) \
383 ((net)->ipv4.sysctl_fwmark_reflect ? (mark) : 0)
384
385static inline bool ip_is_fragment(const struct iphdr *iph)
386{
387 return (iph->frag_off & htons(IP_MF | IP_OFFSET)) != 0;
388}
389
390#ifdef CONFIG_INET
391#include <net/dst.h>
392
393/* The function in 2.2 was invalid, producing wrong result for
394 * check=0xFEFF. It was noticed by Arthur Skawina _year_ ago. --ANK(000625) */
395static inline
396int ip_decrease_ttl(struct iphdr *iph)
397{
398 u32 check = (__force u32)iph->check;
399 check += (__force u32)htons(0x0100);
400 iph->check = (__force __sum16)(check + (check>=0xFFFF));
401 return --iph->ttl;
402}
403
404static inline int ip_mtu_locked(const struct dst_entry *dst)
405{
406 const struct rtable *rt = (const struct rtable *)dst;
407
408 return rt->rt_mtu_locked || dst_metric_locked(dst, RTAX_MTU);
409}
410
411static inline
412int ip_dont_fragment(const struct sock *sk, const struct dst_entry *dst)
413{
414 u8 pmtudisc = READ_ONCE(inet_sk(sk)->pmtudisc);
415
416 return pmtudisc == IP_PMTUDISC_DO ||
417 (pmtudisc == IP_PMTUDISC_WANT &&
418 !ip_mtu_locked(dst));
419}
420
421static inline bool ip_sk_accept_pmtu(const struct sock *sk)
422{
423 return inet_sk(sk)->pmtudisc != IP_PMTUDISC_INTERFACE &&
424 inet_sk(sk)->pmtudisc != IP_PMTUDISC_OMIT;
425}
426
427static inline bool ip_sk_use_pmtu(const struct sock *sk)
428{
429 return inet_sk(sk)->pmtudisc < IP_PMTUDISC_PROBE;
430}
431
432static inline bool ip_sk_ignore_df(const struct sock *sk)
433{
434 return inet_sk(sk)->pmtudisc < IP_PMTUDISC_DO ||
435 inet_sk(sk)->pmtudisc == IP_PMTUDISC_OMIT;
436}
437
438static inline unsigned int ip_dst_mtu_maybe_forward(const struct dst_entry *dst,
439 bool forwarding)
440{
441 struct net *net = dev_net(dst->dev);
442
443 if (net->ipv4.sysctl_ip_fwd_use_pmtu ||
444 ip_mtu_locked(dst) ||
445 !forwarding)
446 return dst_mtu(dst);
447
448 return min(READ_ONCE(dst->dev->mtu), IP_MAX_MTU);
449}
450
451static inline unsigned int ip_skb_dst_mtu(struct sock *sk,
452 const struct sk_buff *skb)
453{
454 if (!sk || !sk_fullsock(sk) || ip_sk_use_pmtu(sk)) {
455 bool forwarding = IPCB(skb)->flags & IPSKB_FORWARDED;
456
457 return ip_dst_mtu_maybe_forward(skb_dst(skb), forwarding);
458 }
459
460 return min(READ_ONCE(skb_dst(skb)->dev->mtu), IP_MAX_MTU);
461}
462
463struct dst_metrics *ip_fib_metrics_init(struct net *net, struct nlattr *fc_mx,
464 int fc_mx_len,
465 struct netlink_ext_ack *extack);
466static inline void ip_fib_metrics_put(struct dst_metrics *fib_metrics)
467{
468 if (fib_metrics != &dst_default_metrics &&
469 refcount_dec_and_test(&fib_metrics->refcnt))
470 kfree(fib_metrics);
471}
472
473/* ipv4 and ipv6 both use refcounted metrics if it is not the default */
474static inline
475void ip_dst_init_metrics(struct dst_entry *dst, struct dst_metrics *fib_metrics)
476{
477 dst_init_metrics(dst, fib_metrics->metrics, true);
478
479 if (fib_metrics != &dst_default_metrics) {
480 dst->_metrics |= DST_METRICS_REFCOUNTED;
481 refcount_inc(&fib_metrics->refcnt);
482 }
483}
484
485static inline
486void ip_dst_metrics_put(struct dst_entry *dst)
487{
488 struct dst_metrics *p = (struct dst_metrics *)DST_METRICS_PTR(dst);
489
490 if (p != &dst_default_metrics && refcount_dec_and_test(&p->refcnt))
491 kfree(p);
492}
493
494u32 ip_idents_reserve(u32 hash, int segs);
495void __ip_select_ident(struct net *net, struct iphdr *iph, int segs);
496
497static inline void ip_select_ident_segs(struct net *net, struct sk_buff *skb,
498 struct sock *sk, int segs)
499{
500 struct iphdr *iph = ip_hdr(skb);
501
502 if ((iph->frag_off & htons(IP_DF)) && !skb->ignore_df) {
503 /* This is only to work around buggy Windows95/2000
504 * VJ compression implementations. If the ID field
505 * does not change, they drop every other packet in
506 * a TCP stream using header compression.
507 */
508 if (sk && inet_sk(sk)->inet_daddr) {
509 iph->id = htons(inet_sk(sk)->inet_id);
510 inet_sk(sk)->inet_id += segs;
511 } else {
512 iph->id = 0;
513 }
514 } else {
515 __ip_select_ident(net, iph, segs);
516 }
517}
518
519static inline void ip_select_ident(struct net *net, struct sk_buff *skb,
520 struct sock *sk)
521{
522 ip_select_ident_segs(net, skb, sk, 1);
523}
524
525static inline __wsum inet_compute_pseudo(struct sk_buff *skb, int proto)
526{
527 return csum_tcpudp_nofold(ip_hdr(skb)->saddr, ip_hdr(skb)->daddr,
528 skb->len, proto, 0);
529}
530
531/* copy IPv4 saddr & daddr to flow_keys, possibly using 64bit load/store
532 * Equivalent to : flow->v4addrs.src = iph->saddr;
533 * flow->v4addrs.dst = iph->daddr;
534 */
535static inline void iph_to_flow_copy_v4addrs(struct flow_keys *flow,
536 const struct iphdr *iph)
537{
538 BUILD_BUG_ON(offsetof(typeof(flow->addrs), v4addrs.dst) !=
539 offsetof(typeof(flow->addrs), v4addrs.src) +
540 sizeof(flow->addrs.v4addrs.src));
541 memcpy(&flow->addrs.v4addrs, &iph->saddr, sizeof(flow->addrs.v4addrs));
542 flow->control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
543}
544
545static inline __wsum inet_gro_compute_pseudo(struct sk_buff *skb, int proto)
546{
547 const struct iphdr *iph = skb_gro_network_header(skb);
548
549 return csum_tcpudp_nofold(iph->saddr, iph->daddr,
550 skb_gro_len(skb), proto, 0);
551}
552
553/*
554 * Map a multicast IP onto multicast MAC for type ethernet.
555 */
556
557static inline void ip_eth_mc_map(__be32 naddr, char *buf)
558{
559 __u32 addr=ntohl(naddr);
560 buf[0]=0x01;
561 buf[1]=0x00;
562 buf[2]=0x5e;
563 buf[5]=addr&0xFF;
564 addr>>=8;
565 buf[4]=addr&0xFF;
566 addr>>=8;
567 buf[3]=addr&0x7F;
568}
569
570/*
571 * Map a multicast IP onto multicast MAC for type IP-over-InfiniBand.
572 * Leave P_Key as 0 to be filled in by driver.
573 */
574
575static inline void ip_ib_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf)
576{
577 __u32 addr;
578 unsigned char scope = broadcast[5] & 0xF;
579
580 buf[0] = 0; /* Reserved */
581 buf[1] = 0xff; /* Multicast QPN */
582 buf[2] = 0xff;
583 buf[3] = 0xff;
584 addr = ntohl(naddr);
585 buf[4] = 0xff;
586 buf[5] = 0x10 | scope; /* scope from broadcast address */
587 buf[6] = 0x40; /* IPv4 signature */
588 buf[7] = 0x1b;
589 buf[8] = broadcast[8]; /* P_Key */
590 buf[9] = broadcast[9];
591 buf[10] = 0;
592 buf[11] = 0;
593 buf[12] = 0;
594 buf[13] = 0;
595 buf[14] = 0;
596 buf[15] = 0;
597 buf[19] = addr & 0xff;
598 addr >>= 8;
599 buf[18] = addr & 0xff;
600 addr >>= 8;
601 buf[17] = addr & 0xff;
602 addr >>= 8;
603 buf[16] = addr & 0x0f;
604}
605
606static inline void ip_ipgre_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf)
607{
608 if ((broadcast[0] | broadcast[1] | broadcast[2] | broadcast[3]) != 0)
609 memcpy(buf, broadcast, 4);
610 else
611 memcpy(buf, &naddr, sizeof(naddr));
612}
613
614#if IS_ENABLED(CONFIG_IPV6)
615#include <linux/ipv6.h>
616#endif
617
618static __inline__ void inet_reset_saddr(struct sock *sk)
619{
620 inet_sk(sk)->inet_rcv_saddr = inet_sk(sk)->inet_saddr = 0;
621#if IS_ENABLED(CONFIG_IPV6)
622 if (sk->sk_family == PF_INET6) {
623 struct ipv6_pinfo *np = inet6_sk(sk);
624
625 memset(&np->saddr, 0, sizeof(np->saddr));
626 memset(&sk->sk_v6_rcv_saddr, 0, sizeof(sk->sk_v6_rcv_saddr));
627 }
628#endif
629}
630
631#endif
632
633static inline unsigned int ipv4_addr_hash(__be32 ip)
634{
635 return (__force unsigned int) ip;
636}
637
638static inline u32 ipv4_portaddr_hash(const struct net *net,
639 __be32 saddr,
640 unsigned int port)
641{
642 return jhash_1word((__force u32)saddr, net_hash_mix(net)) ^ port;
643}
644
645bool ip_call_ra_chain(struct sk_buff *skb);
646
647/*
648 * Functions provided by ip_fragment.c
649 */
650
651enum ip_defrag_users {
652 IP_DEFRAG_LOCAL_DELIVER,
653 IP_DEFRAG_CALL_RA_CHAIN,
654 IP_DEFRAG_CONNTRACK_IN,
655 __IP_DEFRAG_CONNTRACK_IN_END = IP_DEFRAG_CONNTRACK_IN + USHRT_MAX,
656 IP_DEFRAG_CONNTRACK_OUT,
657 __IP_DEFRAG_CONNTRACK_OUT_END = IP_DEFRAG_CONNTRACK_OUT + USHRT_MAX,
658 IP_DEFRAG_CONNTRACK_BRIDGE_IN,
659 __IP_DEFRAG_CONNTRACK_BRIDGE_IN = IP_DEFRAG_CONNTRACK_BRIDGE_IN + USHRT_MAX,
660 IP_DEFRAG_VS_IN,
661 IP_DEFRAG_VS_OUT,
662 IP_DEFRAG_VS_FWD,
663 IP_DEFRAG_AF_PACKET,
664 IP_DEFRAG_MACVLAN,
665};
666
667/* Return true if the value of 'user' is between 'lower_bond'
668 * and 'upper_bond' inclusively.
669 */
670static inline bool ip_defrag_user_in_between(u32 user,
671 enum ip_defrag_users lower_bond,
672 enum ip_defrag_users upper_bond)
673{
674 return user >= lower_bond && user <= upper_bond;
675}
676
677int ip_defrag(struct net *net, struct sk_buff *skb, u32 user);
678#ifdef CONFIG_INET
679struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user);
680#else
681static inline struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user)
682{
683 return skb;
684}
685#endif
686
687/*
688 * Functions provided by ip_forward.c
689 */
690
691int ip_forward(struct sk_buff *skb);
692
693/*
694 * Functions provided by ip_options.c
695 */
696
697void ip_options_build(struct sk_buff *skb, struct ip_options *opt,
698 __be32 daddr, struct rtable *rt, int is_frag);
699
700int __ip_options_echo(struct net *net, struct ip_options *dopt,
701 struct sk_buff *skb, const struct ip_options *sopt);
702static inline int ip_options_echo(struct net *net, struct ip_options *dopt,
703 struct sk_buff *skb)
704{
705 return __ip_options_echo(net, dopt, skb, &IPCB(skb)->opt);
706}
707
708void ip_options_fragment(struct sk_buff *skb);
709int __ip_options_compile(struct net *net, struct ip_options *opt,
710 struct sk_buff *skb, __be32 *info);
711int ip_options_compile(struct net *net, struct ip_options *opt,
712 struct sk_buff *skb);
713int ip_options_get(struct net *net, struct ip_options_rcu **optp,
714 unsigned char *data, int optlen);
715int ip_options_get_from_user(struct net *net, struct ip_options_rcu **optp,
716 unsigned char __user *data, int optlen);
717void ip_options_undo(struct ip_options *opt);
718void ip_forward_options(struct sk_buff *skb);
719int ip_options_rcv_srr(struct sk_buff *skb, struct net_device *dev);
720
721/*
722 * Functions provided by ip_sockglue.c
723 */
724
725void ipv4_pktinfo_prepare(const struct sock *sk, struct sk_buff *skb);
726void ip_cmsg_recv_offset(struct msghdr *msg, struct sock *sk,
727 struct sk_buff *skb, int tlen, int offset);
728int ip_cmsg_send(struct sock *sk, struct msghdr *msg,
729 struct ipcm_cookie *ipc, bool allow_ipv6);
730int ip_setsockopt(struct sock *sk, int level, int optname, char __user *optval,
731 unsigned int optlen);
732int ip_getsockopt(struct sock *sk, int level, int optname, char __user *optval,
733 int __user *optlen);
734int compat_ip_setsockopt(struct sock *sk, int level, int optname,
735 char __user *optval, unsigned int optlen);
736int compat_ip_getsockopt(struct sock *sk, int level, int optname,
737 char __user *optval, int __user *optlen);
738int ip_ra_control(struct sock *sk, unsigned char on,
739 void (*destructor)(struct sock *));
740
741int ip_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len);
742void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err, __be16 port,
743 u32 info, u8 *payload);
744void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 dport,
745 u32 info);
746
747static inline void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb)
748{
749 ip_cmsg_recv_offset(msg, skb->sk, skb, 0, 0);
750}
751
752bool icmp_global_allow(void);
753extern int sysctl_icmp_msgs_per_sec;
754extern int sysctl_icmp_msgs_burst;
755
756#ifdef CONFIG_PROC_FS
757int ip_misc_proc_init(void);
758#endif
759
760int rtm_getroute_parse_ip_proto(struct nlattr *attr, u8 *ip_proto, u8 family,
761 struct netlink_ext_ack *extack);
762
763#endif /* _IP_H */
1/*
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.
5 *
6 * Definitions for the IP module.
7 *
8 * Version: @(#)ip.h 1.0.2 05/07/93
9 *
10 * Authors: Ross Biro
11 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
12 * Alan Cox, <gw4pts@gw4pts.ampr.org>
13 *
14 * Changes:
15 * Mike McLagan : Routing by source
16 *
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.
21 */
22#ifndef _IP_H
23#define _IP_H
24
25#include <linux/types.h>
26#include <linux/ip.h>
27#include <linux/in.h>
28#include <linux/skbuff.h>
29
30#include <net/inet_sock.h>
31#include <net/snmp.h>
32#include <net/flow.h>
33
34struct sock;
35
36struct inet_skb_parm {
37 struct ip_options opt; /* Compiled IP options */
38 unsigned char flags;
39
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
45};
46
47static inline unsigned int ip_hdrlen(const struct sk_buff *skb)
48{
49 return ip_hdr(skb)->ihl * 4;
50}
51
52struct ipcm_cookie {
53 __be32 addr;
54 int oif;
55 struct ip_options_rcu *opt;
56 __u8 tx_flags;
57};
58
59#define IPCB(skb) ((struct inet_skb_parm*)((skb)->cb))
60
61struct ip_ra_chain {
62 struct ip_ra_chain __rcu *next;
63 struct sock *sk;
64 union {
65 void (*destructor)(struct sock *);
66 struct sock *saved_sk;
67 };
68 struct rcu_head rcu;
69};
70
71extern struct ip_ra_chain __rcu *ip_ra_chain;
72
73/* IP flags. */
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 */
78
79#define IP_FRAG_TIME (30 * HZ) /* fragment lifetime */
80
81struct msghdr;
82struct net_device;
83struct packet_type;
84struct rtable;
85struct sockaddr;
86
87extern int igmp_mc_proc_init(void);
88
89/*
90 * Functions provided by ip.c
91 */
92
93extern int ip_build_and_send_pkt(struct sk_buff *skb, struct sock *sk,
94 __be32 saddr, __be32 daddr,
95 struct ip_options_rcu *opt);
96extern int ip_rcv(struct sk_buff *skb, struct net_device *dev,
97 struct packet_type *pt, struct net_device *orig_dev);
98extern int ip_local_deliver(struct sk_buff *skb);
99extern int ip_mr_input(struct sk_buff *skb);
100extern int ip_output(struct sk_buff *skb);
101extern int ip_mc_output(struct sk_buff *skb);
102extern int ip_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *));
103extern int ip_do_nat(struct sk_buff *skb);
104extern void ip_send_check(struct iphdr *ip);
105extern int __ip_local_out(struct sk_buff *skb);
106extern int ip_local_out(struct sk_buff *skb);
107extern int ip_queue_xmit(struct sk_buff *skb, struct flowi *fl);
108extern void ip_init(void);
109extern 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,
114 struct rtable **rt,
115 unsigned int flags);
116extern int ip_generic_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb);
117extern ssize_t ip_append_page(struct sock *sk, struct flowi4 *fl4, struct page *page,
118 int offset, size_t size, int flags);
119extern struct sk_buff *__ip_make_skb(struct sock *sk,
120 struct flowi4 *fl4,
121 struct sk_buff_head *queue,
122 struct inet_cork *cork);
123extern int ip_send_skb(struct sk_buff *skb);
124extern int ip_push_pending_frames(struct sock *sk, struct flowi4 *fl4);
125extern void ip_flush_pending_frames(struct sock *sk);
126extern struct sk_buff *ip_make_skb(struct sock *sk,
127 struct flowi4 *fl4,
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,
132 struct rtable **rtp,
133 unsigned int flags);
134
135static inline struct sk_buff *ip_finish_skb(struct sock *sk, struct flowi4 *fl4)
136{
137 return __ip_make_skb(sk, fl4, &sk->sk_write_queue, &inet_sk(sk)->cork.base);
138}
139
140/* datagram.c */
141extern int ip4_datagram_connect(struct sock *sk,
142 struct sockaddr *uaddr, int addr_len);
143
144/*
145 * Map a multicast IP onto multicast MAC for type Token Ring.
146 * This conforms to RFC1469 Option 2 Multicasting i.e.
147 * using a functional address to transmit / receive
148 * multicast packets.
149 */
150
151static inline void ip_tr_mc_map(__be32 addr, char *buf)
152{
153 buf[0]=0xC0;
154 buf[1]=0x00;
155 buf[2]=0x00;
156 buf[3]=0x04;
157 buf[4]=0x00;
158 buf[5]=0x00;
159}
160
161struct ip_reply_arg {
162 struct kvec iov[1];
163 int flags;
164 __wsum csum;
165 int csumoffset; /* u16 offset of csum in iov[0].iov_base */
166 /* -1 if not needed */
167 int bound_dev_if;
168};
169
170#define IP_REPLY_ARG_NOSRCCHECK 1
171
172static inline __u8 ip_reply_arg_flowi_flags(const struct ip_reply_arg *arg)
173{
174 return (arg->flags & IP_REPLY_ARG_NOSRCCHECK) ? FLOWI_FLAG_ANYSRC : 0;
175}
176
177void ip_send_reply(struct sock *sk, struct sk_buff *skb, __be32 daddr,
178 struct ip_reply_arg *arg, unsigned int len);
179
180struct ipv4_config {
181 int log_martians;
182 int no_pmtu_disc;
183};
184
185extern 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)
197
198extern unsigned long snmp_fold_field(void __percpu *mib[], int offt);
199#if BITS_PER_LONG==32
200extern u64 snmp_fold_field64(void __percpu *mib[], int offt, size_t sync_off);
201#else
202static inline u64 snmp_fold_field64(void __percpu *mib[], int offt, size_t syncp_off)
203{
204 return snmp_fold_field(mib, offt);
205}
206#endif
207extern int snmp_mib_init(void __percpu *ptr[2], size_t mibsize, size_t align);
208extern void snmp_mib_free(void __percpu *ptr[2]);
209
210extern struct local_ports {
211 seqlock_t lock;
212 int range[2];
213} sysctl_local_ports;
214extern void inet_get_local_port_range(int *low, int *high);
215
216extern unsigned long *sysctl_local_reserved_ports;
217static inline int inet_is_reserved_local_port(int port)
218{
219 return test_bit(port, sysctl_local_reserved_ports);
220}
221
222extern int sysctl_ip_nonlocal_bind;
223
224extern struct ctl_path net_core_path[];
225extern struct ctl_path net_ipv4_ctl_path[];
226
227/* From inetpeer.c */
228extern int inet_peer_threshold;
229extern int inet_peer_minttl;
230extern int inet_peer_maxttl;
231
232/* From ip_output.c */
233extern int sysctl_ip_dynaddr;
234
235extern void ipfrag_init(void);
236
237extern void ip_static_sysctl_init(void);
238
239static inline bool ip_is_fragment(const struct iphdr *iph)
240{
241 return (iph->frag_off & htons(IP_MF | IP_OFFSET)) != 0;
242}
243
244#ifdef CONFIG_INET
245#include <net/dst.h>
246
247/* The function in 2.2 was invalid, producing wrong result for
248 * check=0xFEFF. It was noticed by Arthur Skawina _year_ ago. --ANK(000625) */
249static inline
250int ip_decrease_ttl(struct iphdr *iph)
251{
252 u32 check = (__force u32)iph->check;
253 check += (__force u32)htons(0x0100);
254 iph->check = (__force __sum16)(check + (check>=0xFFFF));
255 return --iph->ttl;
256}
257
258static inline
259int ip_dont_fragment(struct sock *sk, struct dst_entry *dst)
260{
261 return inet_sk(sk)->pmtudisc == IP_PMTUDISC_DO ||
262 (inet_sk(sk)->pmtudisc == IP_PMTUDISC_WANT &&
263 !(dst_metric_locked(dst, RTAX_MTU)));
264}
265
266extern void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more);
267
268static inline void ip_select_ident(struct iphdr *iph, struct dst_entry *dst, struct sock *sk)
269{
270 if (iph->frag_off & htons(IP_DF)) {
271 /* This is only to work around buggy Windows95/2000
272 * VJ compression implementations. If the ID field
273 * does not change, they drop every other packet in
274 * a TCP stream using header compression.
275 */
276 iph->id = (sk && inet_sk(sk)->inet_daddr) ?
277 htons(inet_sk(sk)->inet_id++) : 0;
278 } else
279 __ip_select_ident(iph, dst, 0);
280}
281
282static inline void ip_select_ident_more(struct iphdr *iph, struct dst_entry *dst, struct sock *sk, int more)
283{
284 if (iph->frag_off & htons(IP_DF)) {
285 if (sk && inet_sk(sk)->inet_daddr) {
286 iph->id = htons(inet_sk(sk)->inet_id);
287 inet_sk(sk)->inet_id += 1 + more;
288 } else
289 iph->id = 0;
290 } else
291 __ip_select_ident(iph, dst, more);
292}
293
294/*
295 * Map a multicast IP onto multicast MAC for type ethernet.
296 */
297
298static inline void ip_eth_mc_map(__be32 naddr, char *buf)
299{
300 __u32 addr=ntohl(naddr);
301 buf[0]=0x01;
302 buf[1]=0x00;
303 buf[2]=0x5e;
304 buf[5]=addr&0xFF;
305 addr>>=8;
306 buf[4]=addr&0xFF;
307 addr>>=8;
308 buf[3]=addr&0x7F;
309}
310
311/*
312 * Map a multicast IP onto multicast MAC for type IP-over-InfiniBand.
313 * Leave P_Key as 0 to be filled in by driver.
314 */
315
316static inline void ip_ib_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf)
317{
318 __u32 addr;
319 unsigned char scope = broadcast[5] & 0xF;
320
321 buf[0] = 0; /* Reserved */
322 buf[1] = 0xff; /* Multicast QPN */
323 buf[2] = 0xff;
324 buf[3] = 0xff;
325 addr = ntohl(naddr);
326 buf[4] = 0xff;
327 buf[5] = 0x10 | scope; /* scope from broadcast address */
328 buf[6] = 0x40; /* IPv4 signature */
329 buf[7] = 0x1b;
330 buf[8] = broadcast[8]; /* P_Key */
331 buf[9] = broadcast[9];
332 buf[10] = 0;
333 buf[11] = 0;
334 buf[12] = 0;
335 buf[13] = 0;
336 buf[14] = 0;
337 buf[15] = 0;
338 buf[19] = addr & 0xff;
339 addr >>= 8;
340 buf[18] = addr & 0xff;
341 addr >>= 8;
342 buf[17] = addr & 0xff;
343 addr >>= 8;
344 buf[16] = addr & 0x0f;
345}
346
347static inline void ip_ipgre_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf)
348{
349 if ((broadcast[0] | broadcast[1] | broadcast[2] | broadcast[3]) != 0)
350 memcpy(buf, broadcast, 4);
351 else
352 memcpy(buf, &naddr, sizeof(naddr));
353}
354
355#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
356#include <linux/ipv6.h>
357#endif
358
359static __inline__ void inet_reset_saddr(struct sock *sk)
360{
361 inet_sk(sk)->inet_rcv_saddr = inet_sk(sk)->inet_saddr = 0;
362#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
363 if (sk->sk_family == PF_INET6) {
364 struct ipv6_pinfo *np = inet6_sk(sk);
365
366 memset(&np->saddr, 0, sizeof(np->saddr));
367 memset(&np->rcv_saddr, 0, sizeof(np->rcv_saddr));
368 }
369#endif
370}
371
372#endif
373
374static inline int sk_mc_loop(struct sock *sk)
375{
376 if (!sk)
377 return 1;
378 switch (sk->sk_family) {
379 case AF_INET:
380 return inet_sk(sk)->mc_loop;
381#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
382 case AF_INET6:
383 return inet6_sk(sk)->mc_loop;
384#endif
385 }
386 WARN_ON(1);
387 return 1;
388}
389
390extern int ip_call_ra_chain(struct sk_buff *skb);
391
392/*
393 * Functions provided by ip_fragment.c
394 */
395
396enum ip_defrag_users {
397 IP_DEFRAG_LOCAL_DELIVER,
398 IP_DEFRAG_CALL_RA_CHAIN,
399 IP_DEFRAG_CONNTRACK_IN,
400 __IP_DEFRAG_CONNTRACK_IN_END = IP_DEFRAG_CONNTRACK_IN + USHRT_MAX,
401 IP_DEFRAG_CONNTRACK_OUT,
402 __IP_DEFRAG_CONNTRACK_OUT_END = IP_DEFRAG_CONNTRACK_OUT + USHRT_MAX,
403 IP_DEFRAG_CONNTRACK_BRIDGE_IN,
404 __IP_DEFRAG_CONNTRACK_BRIDGE_IN = IP_DEFRAG_CONNTRACK_BRIDGE_IN + USHRT_MAX,
405 IP_DEFRAG_VS_IN,
406 IP_DEFRAG_VS_OUT,
407 IP_DEFRAG_VS_FWD,
408 IP_DEFRAG_AF_PACKET,
409};
410
411int ip_defrag(struct sk_buff *skb, u32 user);
412int ip_frag_mem(struct net *net);
413int ip_frag_nqueues(struct net *net);
414
415/*
416 * Functions provided by ip_forward.c
417 */
418
419extern int ip_forward(struct sk_buff *skb);
420
421/*
422 * Functions provided by ip_options.c
423 */
424
425extern void ip_options_build(struct sk_buff *skb, struct ip_options *opt,
426 __be32 daddr, struct rtable *rt, int is_frag);
427extern int ip_options_echo(struct ip_options *dopt, struct sk_buff *skb);
428extern void ip_options_fragment(struct sk_buff *skb);
429extern int ip_options_compile(struct net *net,
430 struct ip_options *opt, struct sk_buff *skb);
431extern int ip_options_get(struct net *net, struct ip_options_rcu **optp,
432 unsigned char *data, int optlen);
433extern int ip_options_get_from_user(struct net *net, struct ip_options_rcu **optp,
434 unsigned char __user *data, int optlen);
435extern void ip_options_undo(struct ip_options * opt);
436extern void ip_forward_options(struct sk_buff *skb);
437extern int ip_options_rcv_srr(struct sk_buff *skb);
438
439/*
440 * Functions provided by ip_sockglue.c
441 */
442
443extern int ip_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
444extern void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb);
445extern int ip_cmsg_send(struct net *net,
446 struct msghdr *msg, struct ipcm_cookie *ipc);
447extern int ip_setsockopt(struct sock *sk, int level, int optname, char __user *optval, unsigned int optlen);
448extern int ip_getsockopt(struct sock *sk, int level, int optname, char __user *optval, int __user *optlen);
449extern int compat_ip_setsockopt(struct sock *sk, int level,
450 int optname, char __user *optval, unsigned int optlen);
451extern int compat_ip_getsockopt(struct sock *sk, int level,
452 int optname, char __user *optval, int __user *optlen);
453extern int ip_ra_control(struct sock *sk, unsigned char on, void (*destructor)(struct sock *));
454
455extern int ip_recv_error(struct sock *sk, struct msghdr *msg, int len);
456extern void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
457 __be16 port, u32 info, u8 *payload);
458extern void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 dport,
459 u32 info);
460
461#ifdef CONFIG_PROC_FS
462extern int ip_misc_proc_init(void);
463#endif
464
465#endif /* _IP_H */