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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#include <linux/sockptr.h>
27#include <linux/static_key.h>
28
29#include <net/inet_sock.h>
30#include <net/route.h>
31#include <net/snmp.h>
32#include <net/flow.h>
33#include <net/flow_dissector.h>
34#include <net/netns/hash.h>
35#include <net/lwtunnel.h>
36
37#define IPV4_MAX_PMTU 65535U /* RFC 2675, Section 5.1 */
38#define IPV4_MIN_MTU 68 /* RFC 791 */
39
40extern unsigned int sysctl_fib_sync_mem;
41extern unsigned int sysctl_fib_sync_mem_min;
42extern unsigned int sysctl_fib_sync_mem_max;
43
44struct sock;
45
46struct inet_skb_parm {
47 int iif;
48 struct ip_options opt; /* Compiled IP options */
49 u16 flags;
50
51#define IPSKB_FORWARDED BIT(0)
52#define IPSKB_XFRM_TUNNEL_SIZE BIT(1)
53#define IPSKB_XFRM_TRANSFORMED BIT(2)
54#define IPSKB_FRAG_COMPLETE BIT(3)
55#define IPSKB_REROUTED BIT(4)
56#define IPSKB_DOREDIRECT BIT(5)
57#define IPSKB_FRAG_PMTU BIT(6)
58#define IPSKB_L3SLAVE BIT(7)
59#define IPSKB_NOPOLICY BIT(8)
60#define IPSKB_MULTIPATH BIT(9)
61
62 u16 frag_max_size;
63};
64
65static inline bool ipv4_l3mdev_skb(u16 flags)
66{
67 return !!(flags & IPSKB_L3SLAVE);
68}
69
70static inline unsigned int ip_hdrlen(const struct sk_buff *skb)
71{
72 return ip_hdr(skb)->ihl * 4;
73}
74
75struct ipcm_cookie {
76 struct sockcm_cookie sockc;
77 __be32 addr;
78 int oif;
79 struct ip_options_rcu *opt;
80 __u8 protocol;
81 __u8 ttl;
82 __s16 tos;
83 char priority;
84 __u16 gso_size;
85};
86
87static inline void ipcm_init(struct ipcm_cookie *ipcm)
88{
89 *ipcm = (struct ipcm_cookie) { .tos = -1 };
90}
91
92static inline void ipcm_init_sk(struct ipcm_cookie *ipcm,
93 const struct inet_sock *inet)
94{
95 ipcm_init(ipcm);
96
97 ipcm->sockc.mark = READ_ONCE(inet->sk.sk_mark);
98 ipcm->sockc.tsflags = READ_ONCE(inet->sk.sk_tsflags);
99 ipcm->oif = READ_ONCE(inet->sk.sk_bound_dev_if);
100 ipcm->addr = inet->inet_saddr;
101 ipcm->protocol = inet->inet_num;
102}
103
104#define IPCB(skb) ((struct inet_skb_parm*)((skb)->cb))
105#define PKTINFO_SKB_CB(skb) ((struct in_pktinfo *)((skb)->cb))
106
107/* return enslaved device index if relevant */
108static inline int inet_sdif(const struct sk_buff *skb)
109{
110#if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV)
111 if (skb && ipv4_l3mdev_skb(IPCB(skb)->flags))
112 return IPCB(skb)->iif;
113#endif
114 return 0;
115}
116
117/* Special input handler for packets caught by router alert option.
118 They are selected only by protocol field, and then processed likely
119 local ones; but only if someone wants them! Otherwise, router
120 not running rsvpd will kill RSVP.
121
122 It is user level problem, what it will make with them.
123 I have no idea, how it will masquearde or NAT them (it is joke, joke :-)),
124 but receiver should be enough clever f.e. to forward mtrace requests,
125 sent to multicast group to reach destination designated router.
126 */
127
128struct ip_ra_chain {
129 struct ip_ra_chain __rcu *next;
130 struct sock *sk;
131 union {
132 void (*destructor)(struct sock *);
133 struct sock *saved_sk;
134 };
135 struct rcu_head rcu;
136};
137
138/* IP flags. */
139#define IP_CE 0x8000 /* Flag: "Congestion" */
140#define IP_DF 0x4000 /* Flag: "Don't Fragment" */
141#define IP_MF 0x2000 /* Flag: "More Fragments" */
142#define IP_OFFSET 0x1FFF /* "Fragment Offset" part */
143
144#define IP_FRAG_TIME (30 * HZ) /* fragment lifetime */
145
146struct msghdr;
147struct net_device;
148struct packet_type;
149struct rtable;
150struct sockaddr;
151
152int igmp_mc_init(void);
153
154/*
155 * Functions provided by ip.c
156 */
157
158int ip_build_and_send_pkt(struct sk_buff *skb, const struct sock *sk,
159 __be32 saddr, __be32 daddr,
160 struct ip_options_rcu *opt, u8 tos);
161int ip_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt,
162 struct net_device *orig_dev);
163void ip_list_rcv(struct list_head *head, struct packet_type *pt,
164 struct net_device *orig_dev);
165int ip_local_deliver(struct sk_buff *skb);
166void ip_protocol_deliver_rcu(struct net *net, struct sk_buff *skb, int proto);
167int ip_mr_input(struct sk_buff *skb);
168int ip_output(struct net *net, struct sock *sk, struct sk_buff *skb);
169int ip_mc_output(struct net *net, struct sock *sk, struct sk_buff *skb);
170int ip_do_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
171 int (*output)(struct net *, struct sock *, struct sk_buff *));
172
173struct ip_fraglist_iter {
174 struct sk_buff *frag;
175 struct iphdr *iph;
176 int offset;
177 unsigned int hlen;
178};
179
180void ip_fraglist_init(struct sk_buff *skb, struct iphdr *iph,
181 unsigned int hlen, struct ip_fraglist_iter *iter);
182void ip_fraglist_prepare(struct sk_buff *skb, struct ip_fraglist_iter *iter);
183
184static inline struct sk_buff *ip_fraglist_next(struct ip_fraglist_iter *iter)
185{
186 struct sk_buff *skb = iter->frag;
187
188 iter->frag = skb->next;
189 skb_mark_not_on_list(skb);
190
191 return skb;
192}
193
194struct ip_frag_state {
195 bool DF;
196 unsigned int hlen;
197 unsigned int ll_rs;
198 unsigned int mtu;
199 unsigned int left;
200 int offset;
201 int ptr;
202 __be16 not_last_frag;
203};
204
205void ip_frag_init(struct sk_buff *skb, unsigned int hlen, unsigned int ll_rs,
206 unsigned int mtu, bool DF, struct ip_frag_state *state);
207struct sk_buff *ip_frag_next(struct sk_buff *skb,
208 struct ip_frag_state *state);
209
210void ip_send_check(struct iphdr *ip);
211int __ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb);
212int ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb);
213
214int __ip_queue_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl,
215 __u8 tos);
216void ip_init(void);
217int ip_append_data(struct sock *sk, struct flowi4 *fl4,
218 int getfrag(void *from, char *to, int offset, int len,
219 int odd, struct sk_buff *skb),
220 void *from, int len, int protolen,
221 struct ipcm_cookie *ipc,
222 struct rtable **rt,
223 unsigned int flags);
224int ip_generic_getfrag(void *from, char *to, int offset, int len, int odd,
225 struct sk_buff *skb);
226struct sk_buff *__ip_make_skb(struct sock *sk, struct flowi4 *fl4,
227 struct sk_buff_head *queue,
228 struct inet_cork *cork);
229int ip_send_skb(struct net *net, struct sk_buff *skb);
230int ip_push_pending_frames(struct sock *sk, struct flowi4 *fl4);
231void ip_flush_pending_frames(struct sock *sk);
232struct sk_buff *ip_make_skb(struct sock *sk, struct flowi4 *fl4,
233 int getfrag(void *from, char *to, int offset,
234 int len, int odd, struct sk_buff *skb),
235 void *from, int length, int transhdrlen,
236 struct ipcm_cookie *ipc, struct rtable **rtp,
237 struct inet_cork *cork, unsigned int flags);
238
239int ip_queue_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl);
240
241static inline struct sk_buff *ip_finish_skb(struct sock *sk, struct flowi4 *fl4)
242{
243 return __ip_make_skb(sk, fl4, &sk->sk_write_queue, &inet_sk(sk)->cork.base);
244}
245
246/* Get the route scope that should be used when sending a packet. */
247static inline u8 ip_sendmsg_scope(const struct inet_sock *inet,
248 const struct ipcm_cookie *ipc,
249 const struct msghdr *msg)
250{
251 if (sock_flag(&inet->sk, SOCK_LOCALROUTE) ||
252 msg->msg_flags & MSG_DONTROUTE ||
253 (ipc->opt && ipc->opt->opt.is_strictroute))
254 return RT_SCOPE_LINK;
255
256 return RT_SCOPE_UNIVERSE;
257}
258
259static inline __u8 get_rttos(struct ipcm_cookie* ipc, struct inet_sock *inet)
260{
261 return (ipc->tos != -1) ? RT_TOS(ipc->tos) : RT_TOS(inet->tos);
262}
263
264/* datagram.c */
265int __ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len);
266int ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len);
267
268void ip4_datagram_release_cb(struct sock *sk);
269
270struct ip_reply_arg {
271 struct kvec iov[1];
272 int flags;
273 __wsum csum;
274 int csumoffset; /* u16 offset of csum in iov[0].iov_base */
275 /* -1 if not needed */
276 int bound_dev_if;
277 u8 tos;
278 kuid_t uid;
279};
280
281#define IP_REPLY_ARG_NOSRCCHECK 1
282
283static inline __u8 ip_reply_arg_flowi_flags(const struct ip_reply_arg *arg)
284{
285 return (arg->flags & IP_REPLY_ARG_NOSRCCHECK) ? FLOWI_FLAG_ANYSRC : 0;
286}
287
288void ip_send_unicast_reply(struct sock *sk, struct sk_buff *skb,
289 const struct ip_options *sopt,
290 __be32 daddr, __be32 saddr,
291 const struct ip_reply_arg *arg,
292 unsigned int len, u64 transmit_time, u32 txhash);
293
294#define IP_INC_STATS(net, field) SNMP_INC_STATS64((net)->mib.ip_statistics, field)
295#define __IP_INC_STATS(net, field) __SNMP_INC_STATS64((net)->mib.ip_statistics, field)
296#define IP_ADD_STATS(net, field, val) SNMP_ADD_STATS64((net)->mib.ip_statistics, field, val)
297#define __IP_ADD_STATS(net, field, val) __SNMP_ADD_STATS64((net)->mib.ip_statistics, field, val)
298#define IP_UPD_PO_STATS(net, field, val) SNMP_UPD_PO_STATS64((net)->mib.ip_statistics, field, val)
299#define __IP_UPD_PO_STATS(net, field, val) __SNMP_UPD_PO_STATS64((net)->mib.ip_statistics, field, val)
300#define NET_INC_STATS(net, field) SNMP_INC_STATS((net)->mib.net_statistics, field)
301#define __NET_INC_STATS(net, field) __SNMP_INC_STATS((net)->mib.net_statistics, field)
302#define NET_ADD_STATS(net, field, adnd) SNMP_ADD_STATS((net)->mib.net_statistics, field, adnd)
303#define __NET_ADD_STATS(net, field, adnd) __SNMP_ADD_STATS((net)->mib.net_statistics, field, adnd)
304
305static inline u64 snmp_get_cpu_field(void __percpu *mib, int cpu, int offt)
306{
307 return *(((unsigned long *)per_cpu_ptr(mib, cpu)) + offt);
308}
309
310unsigned long snmp_fold_field(void __percpu *mib, int offt);
311#if BITS_PER_LONG==32
312u64 snmp_get_cpu_field64(void __percpu *mib, int cpu, int offct,
313 size_t syncp_offset);
314u64 snmp_fold_field64(void __percpu *mib, int offt, size_t sync_off);
315#else
316static inline u64 snmp_get_cpu_field64(void __percpu *mib, int cpu, int offct,
317 size_t syncp_offset)
318{
319 return snmp_get_cpu_field(mib, cpu, offct);
320
321}
322
323static inline u64 snmp_fold_field64(void __percpu *mib, int offt, size_t syncp_off)
324{
325 return snmp_fold_field(mib, offt);
326}
327#endif
328
329#define snmp_get_cpu_field64_batch(buff64, stats_list, mib_statistic, offset) \
330{ \
331 int i, c; \
332 for_each_possible_cpu(c) { \
333 for (i = 0; stats_list[i].name; i++) \
334 buff64[i] += snmp_get_cpu_field64( \
335 mib_statistic, \
336 c, stats_list[i].entry, \
337 offset); \
338 } \
339}
340
341#define snmp_get_cpu_field_batch(buff, stats_list, mib_statistic) \
342{ \
343 int i, c; \
344 for_each_possible_cpu(c) { \
345 for (i = 0; stats_list[i].name; i++) \
346 buff[i] += snmp_get_cpu_field( \
347 mib_statistic, \
348 c, stats_list[i].entry); \
349 } \
350}
351
352void inet_get_local_port_range(const struct net *net, int *low, int *high);
353void inet_sk_get_local_port_range(const struct sock *sk, int *low, int *high);
354
355#ifdef CONFIG_SYSCTL
356static inline bool inet_is_local_reserved_port(struct net *net, unsigned short port)
357{
358 if (!net->ipv4.sysctl_local_reserved_ports)
359 return false;
360 return test_bit(port, net->ipv4.sysctl_local_reserved_ports);
361}
362
363static inline bool sysctl_dev_name_is_allowed(const char *name)
364{
365 return strcmp(name, "default") != 0 && strcmp(name, "all") != 0;
366}
367
368static inline bool inet_port_requires_bind_service(struct net *net, unsigned short port)
369{
370 return port < READ_ONCE(net->ipv4.sysctl_ip_prot_sock);
371}
372
373#else
374static inline bool inet_is_local_reserved_port(struct net *net, unsigned short port)
375{
376 return false;
377}
378
379static inline bool inet_port_requires_bind_service(struct net *net, unsigned short port)
380{
381 return port < PROT_SOCK;
382}
383#endif
384
385__be32 inet_current_timestamp(void);
386
387/* From inetpeer.c */
388extern int inet_peer_threshold;
389extern int inet_peer_minttl;
390extern int inet_peer_maxttl;
391
392void ipfrag_init(void);
393
394void ip_static_sysctl_init(void);
395
396#define IP4_REPLY_MARK(net, mark) \
397 (READ_ONCE((net)->ipv4.sysctl_fwmark_reflect) ? (mark) : 0)
398
399static inline bool ip_is_fragment(const struct iphdr *iph)
400{
401 return (iph->frag_off & htons(IP_MF | IP_OFFSET)) != 0;
402}
403
404#ifdef CONFIG_INET
405#include <net/dst.h>
406
407/* The function in 2.2 was invalid, producing wrong result for
408 * check=0xFEFF. It was noticed by Arthur Skawina _year_ ago. --ANK(000625) */
409static inline
410int ip_decrease_ttl(struct iphdr *iph)
411{
412 u32 check = (__force u32)iph->check;
413 check += (__force u32)htons(0x0100);
414 iph->check = (__force __sum16)(check + (check>=0xFFFF));
415 return --iph->ttl;
416}
417
418static inline int ip_mtu_locked(const struct dst_entry *dst)
419{
420 const struct rtable *rt = (const struct rtable *)dst;
421
422 return rt->rt_mtu_locked || dst_metric_locked(dst, RTAX_MTU);
423}
424
425static inline
426int ip_dont_fragment(const struct sock *sk, const struct dst_entry *dst)
427{
428 u8 pmtudisc = READ_ONCE(inet_sk(sk)->pmtudisc);
429
430 return pmtudisc == IP_PMTUDISC_DO ||
431 (pmtudisc == IP_PMTUDISC_WANT &&
432 !ip_mtu_locked(dst));
433}
434
435static inline bool ip_sk_accept_pmtu(const struct sock *sk)
436{
437 return inet_sk(sk)->pmtudisc != IP_PMTUDISC_INTERFACE &&
438 inet_sk(sk)->pmtudisc != IP_PMTUDISC_OMIT;
439}
440
441static inline bool ip_sk_use_pmtu(const struct sock *sk)
442{
443 return inet_sk(sk)->pmtudisc < IP_PMTUDISC_PROBE;
444}
445
446static inline bool ip_sk_ignore_df(const struct sock *sk)
447{
448 return inet_sk(sk)->pmtudisc < IP_PMTUDISC_DO ||
449 inet_sk(sk)->pmtudisc == IP_PMTUDISC_OMIT;
450}
451
452static inline unsigned int ip_dst_mtu_maybe_forward(const struct dst_entry *dst,
453 bool forwarding)
454{
455 const struct rtable *rt = container_of(dst, struct rtable, dst);
456 struct net *net = dev_net(dst->dev);
457 unsigned int mtu;
458
459 if (READ_ONCE(net->ipv4.sysctl_ip_fwd_use_pmtu) ||
460 ip_mtu_locked(dst) ||
461 !forwarding) {
462 mtu = rt->rt_pmtu;
463 if (mtu && time_before(jiffies, rt->dst.expires))
464 goto out;
465 }
466
467 /* 'forwarding = true' case should always honour route mtu */
468 mtu = dst_metric_raw(dst, RTAX_MTU);
469 if (mtu)
470 goto out;
471
472 mtu = READ_ONCE(dst->dev->mtu);
473
474 if (unlikely(ip_mtu_locked(dst))) {
475 if (rt->rt_uses_gateway && mtu > 576)
476 mtu = 576;
477 }
478
479out:
480 mtu = min_t(unsigned int, mtu, IP_MAX_MTU);
481
482 return mtu - lwtunnel_headroom(dst->lwtstate, mtu);
483}
484
485static inline unsigned int ip_skb_dst_mtu(struct sock *sk,
486 const struct sk_buff *skb)
487{
488 unsigned int mtu;
489
490 if (!sk || !sk_fullsock(sk) || ip_sk_use_pmtu(sk)) {
491 bool forwarding = IPCB(skb)->flags & IPSKB_FORWARDED;
492
493 return ip_dst_mtu_maybe_forward(skb_dst(skb), forwarding);
494 }
495
496 mtu = min(READ_ONCE(skb_dst(skb)->dev->mtu), IP_MAX_MTU);
497 return mtu - lwtunnel_headroom(skb_dst(skb)->lwtstate, mtu);
498}
499
500struct dst_metrics *ip_fib_metrics_init(struct net *net, struct nlattr *fc_mx,
501 int fc_mx_len,
502 struct netlink_ext_ack *extack);
503static inline void ip_fib_metrics_put(struct dst_metrics *fib_metrics)
504{
505 if (fib_metrics != &dst_default_metrics &&
506 refcount_dec_and_test(&fib_metrics->refcnt))
507 kfree(fib_metrics);
508}
509
510/* ipv4 and ipv6 both use refcounted metrics if it is not the default */
511static inline
512void ip_dst_init_metrics(struct dst_entry *dst, struct dst_metrics *fib_metrics)
513{
514 dst_init_metrics(dst, fib_metrics->metrics, true);
515
516 if (fib_metrics != &dst_default_metrics) {
517 dst->_metrics |= DST_METRICS_REFCOUNTED;
518 refcount_inc(&fib_metrics->refcnt);
519 }
520}
521
522static inline
523void ip_dst_metrics_put(struct dst_entry *dst)
524{
525 struct dst_metrics *p = (struct dst_metrics *)DST_METRICS_PTR(dst);
526
527 if (p != &dst_default_metrics && refcount_dec_and_test(&p->refcnt))
528 kfree(p);
529}
530
531void __ip_select_ident(struct net *net, struct iphdr *iph, int segs);
532
533static inline void ip_select_ident_segs(struct net *net, struct sk_buff *skb,
534 struct sock *sk, int segs)
535{
536 struct iphdr *iph = ip_hdr(skb);
537
538 /* We had many attacks based on IPID, use the private
539 * generator as much as we can.
540 */
541 if (sk && inet_sk(sk)->inet_daddr) {
542 int val;
543
544 /* avoid atomic operations for TCP,
545 * as we hold socket lock at this point.
546 */
547 if (sk_is_tcp(sk)) {
548 sock_owned_by_me(sk);
549 val = atomic_read(&inet_sk(sk)->inet_id);
550 atomic_set(&inet_sk(sk)->inet_id, val + segs);
551 } else {
552 val = atomic_add_return(segs, &inet_sk(sk)->inet_id);
553 }
554 iph->id = htons(val);
555 return;
556 }
557 if ((iph->frag_off & htons(IP_DF)) && !skb->ignore_df) {
558 iph->id = 0;
559 } else {
560 /* Unfortunately we need the big hammer to get a suitable IPID */
561 __ip_select_ident(net, iph, segs);
562 }
563}
564
565static inline void ip_select_ident(struct net *net, struct sk_buff *skb,
566 struct sock *sk)
567{
568 ip_select_ident_segs(net, skb, sk, 1);
569}
570
571static inline __wsum inet_compute_pseudo(struct sk_buff *skb, int proto)
572{
573 return csum_tcpudp_nofold(ip_hdr(skb)->saddr, ip_hdr(skb)->daddr,
574 skb->len, proto, 0);
575}
576
577/* copy IPv4 saddr & daddr to flow_keys, possibly using 64bit load/store
578 * Equivalent to : flow->v4addrs.src = iph->saddr;
579 * flow->v4addrs.dst = iph->daddr;
580 */
581static inline void iph_to_flow_copy_v4addrs(struct flow_keys *flow,
582 const struct iphdr *iph)
583{
584 BUILD_BUG_ON(offsetof(typeof(flow->addrs), v4addrs.dst) !=
585 offsetof(typeof(flow->addrs), v4addrs.src) +
586 sizeof(flow->addrs.v4addrs.src));
587 memcpy(&flow->addrs.v4addrs, &iph->addrs, sizeof(flow->addrs.v4addrs));
588 flow->control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
589}
590
591/*
592 * Map a multicast IP onto multicast MAC for type ethernet.
593 */
594
595static inline void ip_eth_mc_map(__be32 naddr, char *buf)
596{
597 __u32 addr=ntohl(naddr);
598 buf[0]=0x01;
599 buf[1]=0x00;
600 buf[2]=0x5e;
601 buf[5]=addr&0xFF;
602 addr>>=8;
603 buf[4]=addr&0xFF;
604 addr>>=8;
605 buf[3]=addr&0x7F;
606}
607
608/*
609 * Map a multicast IP onto multicast MAC for type IP-over-InfiniBand.
610 * Leave P_Key as 0 to be filled in by driver.
611 */
612
613static inline void ip_ib_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf)
614{
615 __u32 addr;
616 unsigned char scope = broadcast[5] & 0xF;
617
618 buf[0] = 0; /* Reserved */
619 buf[1] = 0xff; /* Multicast QPN */
620 buf[2] = 0xff;
621 buf[3] = 0xff;
622 addr = ntohl(naddr);
623 buf[4] = 0xff;
624 buf[5] = 0x10 | scope; /* scope from broadcast address */
625 buf[6] = 0x40; /* IPv4 signature */
626 buf[7] = 0x1b;
627 buf[8] = broadcast[8]; /* P_Key */
628 buf[9] = broadcast[9];
629 buf[10] = 0;
630 buf[11] = 0;
631 buf[12] = 0;
632 buf[13] = 0;
633 buf[14] = 0;
634 buf[15] = 0;
635 buf[19] = addr & 0xff;
636 addr >>= 8;
637 buf[18] = addr & 0xff;
638 addr >>= 8;
639 buf[17] = addr & 0xff;
640 addr >>= 8;
641 buf[16] = addr & 0x0f;
642}
643
644static inline void ip_ipgre_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf)
645{
646 if ((broadcast[0] | broadcast[1] | broadcast[2] | broadcast[3]) != 0)
647 memcpy(buf, broadcast, 4);
648 else
649 memcpy(buf, &naddr, sizeof(naddr));
650}
651
652#if IS_ENABLED(CONFIG_IPV6)
653#include <linux/ipv6.h>
654#endif
655
656static __inline__ void inet_reset_saddr(struct sock *sk)
657{
658 inet_sk(sk)->inet_rcv_saddr = inet_sk(sk)->inet_saddr = 0;
659#if IS_ENABLED(CONFIG_IPV6)
660 if (sk->sk_family == PF_INET6) {
661 struct ipv6_pinfo *np = inet6_sk(sk);
662
663 memset(&np->saddr, 0, sizeof(np->saddr));
664 memset(&sk->sk_v6_rcv_saddr, 0, sizeof(sk->sk_v6_rcv_saddr));
665 }
666#endif
667}
668
669#endif
670
671static inline unsigned int ipv4_addr_hash(__be32 ip)
672{
673 return (__force unsigned int) ip;
674}
675
676static inline u32 ipv4_portaddr_hash(const struct net *net,
677 __be32 saddr,
678 unsigned int port)
679{
680 return jhash_1word((__force u32)saddr, net_hash_mix(net)) ^ port;
681}
682
683bool ip_call_ra_chain(struct sk_buff *skb);
684
685/*
686 * Functions provided by ip_fragment.c
687 */
688
689enum ip_defrag_users {
690 IP_DEFRAG_LOCAL_DELIVER,
691 IP_DEFRAG_CALL_RA_CHAIN,
692 IP_DEFRAG_CONNTRACK_IN,
693 __IP_DEFRAG_CONNTRACK_IN_END = IP_DEFRAG_CONNTRACK_IN + USHRT_MAX,
694 IP_DEFRAG_CONNTRACK_OUT,
695 __IP_DEFRAG_CONNTRACK_OUT_END = IP_DEFRAG_CONNTRACK_OUT + USHRT_MAX,
696 IP_DEFRAG_CONNTRACK_BRIDGE_IN,
697 __IP_DEFRAG_CONNTRACK_BRIDGE_IN = IP_DEFRAG_CONNTRACK_BRIDGE_IN + USHRT_MAX,
698 IP_DEFRAG_VS_IN,
699 IP_DEFRAG_VS_OUT,
700 IP_DEFRAG_VS_FWD,
701 IP_DEFRAG_AF_PACKET,
702 IP_DEFRAG_MACVLAN,
703};
704
705/* Return true if the value of 'user' is between 'lower_bond'
706 * and 'upper_bond' inclusively.
707 */
708static inline bool ip_defrag_user_in_between(u32 user,
709 enum ip_defrag_users lower_bond,
710 enum ip_defrag_users upper_bond)
711{
712 return user >= lower_bond && user <= upper_bond;
713}
714
715int ip_defrag(struct net *net, struct sk_buff *skb, u32 user);
716#ifdef CONFIG_INET
717struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user);
718#else
719static inline struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user)
720{
721 return skb;
722}
723#endif
724
725/*
726 * Functions provided by ip_forward.c
727 */
728
729int ip_forward(struct sk_buff *skb);
730
731/*
732 * Functions provided by ip_options.c
733 */
734
735void ip_options_build(struct sk_buff *skb, struct ip_options *opt,
736 __be32 daddr, struct rtable *rt);
737
738int __ip_options_echo(struct net *net, struct ip_options *dopt,
739 struct sk_buff *skb, const struct ip_options *sopt);
740static inline int ip_options_echo(struct net *net, struct ip_options *dopt,
741 struct sk_buff *skb)
742{
743 return __ip_options_echo(net, dopt, skb, &IPCB(skb)->opt);
744}
745
746void ip_options_fragment(struct sk_buff *skb);
747int __ip_options_compile(struct net *net, struct ip_options *opt,
748 struct sk_buff *skb, __be32 *info);
749int ip_options_compile(struct net *net, struct ip_options *opt,
750 struct sk_buff *skb);
751int ip_options_get(struct net *net, struct ip_options_rcu **optp,
752 sockptr_t data, int optlen);
753void ip_options_undo(struct ip_options *opt);
754void ip_forward_options(struct sk_buff *skb);
755int ip_options_rcv_srr(struct sk_buff *skb, struct net_device *dev);
756
757/*
758 * Functions provided by ip_sockglue.c
759 */
760
761void ipv4_pktinfo_prepare(const struct sock *sk, struct sk_buff *skb);
762void ip_cmsg_recv_offset(struct msghdr *msg, struct sock *sk,
763 struct sk_buff *skb, int tlen, int offset);
764int ip_cmsg_send(struct sock *sk, struct msghdr *msg,
765 struct ipcm_cookie *ipc, bool allow_ipv6);
766DECLARE_STATIC_KEY_FALSE(ip4_min_ttl);
767int do_ip_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval,
768 unsigned int optlen);
769int ip_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval,
770 unsigned int optlen);
771int do_ip_getsockopt(struct sock *sk, int level, int optname,
772 sockptr_t optval, sockptr_t optlen);
773int ip_getsockopt(struct sock *sk, int level, int optname, char __user *optval,
774 int __user *optlen);
775int ip_ra_control(struct sock *sk, unsigned char on,
776 void (*destructor)(struct sock *));
777
778int ip_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len);
779void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err, __be16 port,
780 u32 info, u8 *payload);
781void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 dport,
782 u32 info);
783
784static inline void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb)
785{
786 ip_cmsg_recv_offset(msg, skb->sk, skb, 0, 0);
787}
788
789bool icmp_global_allow(void);
790extern int sysctl_icmp_msgs_per_sec;
791extern int sysctl_icmp_msgs_burst;
792
793#ifdef CONFIG_PROC_FS
794int ip_misc_proc_init(void);
795#endif
796
797int rtm_getroute_parse_ip_proto(struct nlattr *attr, u8 *ip_proto, u8 family,
798 struct netlink_ext_ack *extack);
799
800static inline bool inetdev_valid_mtu(unsigned int mtu)
801{
802 return likely(mtu >= IPV4_MIN_MTU);
803}
804
805void ip_sock_set_freebind(struct sock *sk);
806int ip_sock_set_mtu_discover(struct sock *sk, int val);
807void ip_sock_set_pktinfo(struct sock *sk);
808void ip_sock_set_recverr(struct sock *sk);
809void ip_sock_set_tos(struct sock *sk, int val);
810void __ip_sock_set_tos(struct sock *sk, int val);
811
812#endif /* _IP_H */