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 #include <net/inet_dscp.h>
37
38 #define IPV4_MAX_PMTU 65535U /* RFC 2675, Section 5.1 */
39 #define IPV4_MIN_MTU 68 /* RFC 791 */
40
41 extern unsigned int sysctl_fib_sync_mem;
42 extern unsigned int sysctl_fib_sync_mem_min;
43 extern unsigned int sysctl_fib_sync_mem_max;
44
45 struct sock;
46
47 struct inet_skb_parm {
48 int iif;
49 struct ip_options opt; /* Compiled IP options */
50 u16 flags;
51
52 #define IPSKB_FORWARDED BIT(0)
53 #define IPSKB_XFRM_TUNNEL_SIZE BIT(1)
54 #define IPSKB_XFRM_TRANSFORMED BIT(2)
55 #define IPSKB_FRAG_COMPLETE BIT(3)
56 #define IPSKB_REROUTED BIT(4)
57 #define IPSKB_DOREDIRECT BIT(5)
58 #define IPSKB_FRAG_PMTU BIT(6)
59 #define IPSKB_L3SLAVE BIT(7)
60 #define IPSKB_NOPOLICY BIT(8)
61 #define IPSKB_MULTIPATH BIT(9)
62
63 u16 frag_max_size;
64 };
65
ipv4_l3mdev_skb(u16 flags)66 static inline bool ipv4_l3mdev_skb(u16 flags)
67 {
68 return !!(flags & IPSKB_L3SLAVE);
69 }
70
ip_hdrlen(const struct sk_buff * skb)71 static inline unsigned int ip_hdrlen(const struct sk_buff *skb)
72 {
73 return ip_hdr(skb)->ihl * 4;
74 }
75
76 struct ipcm_cookie {
77 struct sockcm_cookie sockc;
78 __be32 addr;
79 int oif;
80 struct ip_options_rcu *opt;
81 __u8 protocol;
82 __u8 ttl;
83 __s16 tos;
84 char priority;
85 __u16 gso_size;
86 };
87
ipcm_init(struct ipcm_cookie * ipcm)88 static inline void ipcm_init(struct ipcm_cookie *ipcm)
89 {
90 *ipcm = (struct ipcm_cookie) { .tos = -1 };
91 }
92
ipcm_init_sk(struct ipcm_cookie * ipcm,const struct inet_sock * inet)93 static inline void ipcm_init_sk(struct ipcm_cookie *ipcm,
94 const struct inet_sock *inet)
95 {
96 ipcm_init(ipcm);
97
98 ipcm->sockc.mark = READ_ONCE(inet->sk.sk_mark);
99 ipcm->sockc.tsflags = READ_ONCE(inet->sk.sk_tsflags);
100 ipcm->oif = READ_ONCE(inet->sk.sk_bound_dev_if);
101 ipcm->addr = inet->inet_saddr;
102 ipcm->protocol = inet->inet_num;
103 }
104
105 #define IPCB(skb) ((struct inet_skb_parm*)((skb)->cb))
106 #define PKTINFO_SKB_CB(skb) ((struct in_pktinfo *)((skb)->cb))
107
108 /* return enslaved device index if relevant */
inet_sdif(const struct sk_buff * skb)109 static inline int inet_sdif(const struct sk_buff *skb)
110 {
111 #if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV)
112 if (skb && ipv4_l3mdev_skb(IPCB(skb)->flags))
113 return IPCB(skb)->iif;
114 #endif
115 return 0;
116 }
117
118 /* Special input handler for packets caught by router alert option.
119 They are selected only by protocol field, and then processed likely
120 local ones; but only if someone wants them! Otherwise, router
121 not running rsvpd will kill RSVP.
122
123 It is user level problem, what it will make with them.
124 I have no idea, how it will masquearde or NAT them (it is joke, joke :-)),
125 but receiver should be enough clever f.e. to forward mtrace requests,
126 sent to multicast group to reach destination designated router.
127 */
128
129 struct ip_ra_chain {
130 struct ip_ra_chain __rcu *next;
131 struct sock *sk;
132 union {
133 void (*destructor)(struct sock *);
134 struct sock *saved_sk;
135 };
136 struct rcu_head rcu;
137 };
138
139 /* IP flags. */
140 #define IP_CE 0x8000 /* Flag: "Congestion" */
141 #define IP_DF 0x4000 /* Flag: "Don't Fragment" */
142 #define IP_MF 0x2000 /* Flag: "More Fragments" */
143 #define IP_OFFSET 0x1FFF /* "Fragment Offset" part */
144
145 #define IP_FRAG_TIME (30 * HZ) /* fragment lifetime */
146
147 struct msghdr;
148 struct net_device;
149 struct packet_type;
150 struct rtable;
151 struct sockaddr;
152
153 int igmp_mc_init(void);
154
155 /*
156 * Functions provided by ip.c
157 */
158
159 int ip_build_and_send_pkt(struct sk_buff *skb, const struct sock *sk,
160 __be32 saddr, __be32 daddr,
161 struct ip_options_rcu *opt, u8 tos);
162 int ip_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt,
163 struct net_device *orig_dev);
164 void ip_list_rcv(struct list_head *head, struct packet_type *pt,
165 struct net_device *orig_dev);
166 int ip_local_deliver(struct sk_buff *skb);
167 void ip_protocol_deliver_rcu(struct net *net, struct sk_buff *skb, int proto);
168 int ip_mr_input(struct sk_buff *skb);
169 int ip_output(struct net *net, struct sock *sk, struct sk_buff *skb);
170 int ip_mc_output(struct net *net, struct sock *sk, struct sk_buff *skb);
171 int ip_do_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
172 int (*output)(struct net *, struct sock *, struct sk_buff *));
173
174 struct ip_fraglist_iter {
175 struct sk_buff *frag;
176 struct iphdr *iph;
177 int offset;
178 unsigned int hlen;
179 };
180
181 void ip_fraglist_init(struct sk_buff *skb, struct iphdr *iph,
182 unsigned int hlen, struct ip_fraglist_iter *iter);
183 void ip_fraglist_prepare(struct sk_buff *skb, struct ip_fraglist_iter *iter);
184
ip_fraglist_next(struct ip_fraglist_iter * iter)185 static inline struct sk_buff *ip_fraglist_next(struct ip_fraglist_iter *iter)
186 {
187 struct sk_buff *skb = iter->frag;
188
189 iter->frag = skb->next;
190 skb_mark_not_on_list(skb);
191
192 return skb;
193 }
194
195 struct ip_frag_state {
196 bool DF;
197 unsigned int hlen;
198 unsigned int ll_rs;
199 unsigned int mtu;
200 unsigned int left;
201 int offset;
202 int ptr;
203 __be16 not_last_frag;
204 };
205
206 void ip_frag_init(struct sk_buff *skb, unsigned int hlen, unsigned int ll_rs,
207 unsigned int mtu, bool DF, struct ip_frag_state *state);
208 struct sk_buff *ip_frag_next(struct sk_buff *skb,
209 struct ip_frag_state *state);
210
211 void ip_send_check(struct iphdr *ip);
212 int __ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb);
213 int ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb);
214
215 int __ip_queue_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl,
216 __u8 tos);
217 void ip_init(void);
218 int ip_append_data(struct sock *sk, struct flowi4 *fl4,
219 int getfrag(void *from, char *to, int offset, int len,
220 int odd, struct sk_buff *skb),
221 void *from, int len, int protolen,
222 struct ipcm_cookie *ipc,
223 struct rtable **rt,
224 unsigned int flags);
225 int ip_generic_getfrag(void *from, char *to, int offset, int len, int odd,
226 struct sk_buff *skb);
227 struct sk_buff *__ip_make_skb(struct sock *sk, struct flowi4 *fl4,
228 struct sk_buff_head *queue,
229 struct inet_cork *cork);
230 int ip_send_skb(struct net *net, struct sk_buff *skb);
231 int ip_push_pending_frames(struct sock *sk, struct flowi4 *fl4);
232 void ip_flush_pending_frames(struct sock *sk);
233 struct sk_buff *ip_make_skb(struct sock *sk, struct flowi4 *fl4,
234 int getfrag(void *from, char *to, int offset,
235 int len, int odd, struct sk_buff *skb),
236 void *from, int length, int transhdrlen,
237 struct ipcm_cookie *ipc, struct rtable **rtp,
238 struct inet_cork *cork, unsigned int flags);
239
240 int ip_queue_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl);
241
ip_finish_skb(struct sock * sk,struct flowi4 * fl4)242 static inline struct sk_buff *ip_finish_skb(struct sock *sk, struct flowi4 *fl4)
243 {
244 return __ip_make_skb(sk, fl4, &sk->sk_write_queue, &inet_sk(sk)->cork.base);
245 }
246
247 /* Get the route scope that should be used when sending a packet. */
ip_sendmsg_scope(const struct inet_sock * inet,const struct ipcm_cookie * ipc,const struct msghdr * msg)248 static inline u8 ip_sendmsg_scope(const struct inet_sock *inet,
249 const struct ipcm_cookie *ipc,
250 const struct msghdr *msg)
251 {
252 if (sock_flag(&inet->sk, SOCK_LOCALROUTE) ||
253 msg->msg_flags & MSG_DONTROUTE ||
254 (ipc->opt && ipc->opt->opt.is_strictroute))
255 return RT_SCOPE_LINK;
256
257 return RT_SCOPE_UNIVERSE;
258 }
259
get_rttos(struct ipcm_cookie * ipc,struct inet_sock * inet)260 static inline __u8 get_rttos(struct ipcm_cookie* ipc, struct inet_sock *inet)
261 {
262 u8 dsfield = ipc->tos != -1 ? ipc->tos : READ_ONCE(inet->tos);
263
264 return dsfield & INET_DSCP_MASK;
265 }
266
267 /* datagram.c */
268 int __ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len);
269 int ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len);
270
271 void ip4_datagram_release_cb(struct sock *sk);
272
273 struct ip_reply_arg {
274 struct kvec iov[1];
275 int flags;
276 __wsum csum;
277 int csumoffset; /* u16 offset of csum in iov[0].iov_base */
278 /* -1 if not needed */
279 int bound_dev_if;
280 u8 tos;
281 kuid_t uid;
282 };
283
284 #define IP_REPLY_ARG_NOSRCCHECK 1
285
ip_reply_arg_flowi_flags(const struct ip_reply_arg * arg)286 static inline __u8 ip_reply_arg_flowi_flags(const struct ip_reply_arg *arg)
287 {
288 return (arg->flags & IP_REPLY_ARG_NOSRCCHECK) ? FLOWI_FLAG_ANYSRC : 0;
289 }
290
291 void ip_send_unicast_reply(struct sock *sk, struct sk_buff *skb,
292 const struct ip_options *sopt,
293 __be32 daddr, __be32 saddr,
294 const struct ip_reply_arg *arg,
295 unsigned int len, u64 transmit_time, u32 txhash);
296
297 #define IP_INC_STATS(net, field) SNMP_INC_STATS64((net)->mib.ip_statistics, field)
298 #define __IP_INC_STATS(net, field) __SNMP_INC_STATS64((net)->mib.ip_statistics, field)
299 #define IP_ADD_STATS(net, field, val) SNMP_ADD_STATS64((net)->mib.ip_statistics, field, val)
300 #define __IP_ADD_STATS(net, field, val) __SNMP_ADD_STATS64((net)->mib.ip_statistics, field, val)
301 #define IP_UPD_PO_STATS(net, field, val) SNMP_UPD_PO_STATS64((net)->mib.ip_statistics, field, val)
302 #define __IP_UPD_PO_STATS(net, field, val) __SNMP_UPD_PO_STATS64((net)->mib.ip_statistics, field, val)
303 #define NET_INC_STATS(net, field) SNMP_INC_STATS((net)->mib.net_statistics, field)
304 #define __NET_INC_STATS(net, field) __SNMP_INC_STATS((net)->mib.net_statistics, field)
305 #define NET_ADD_STATS(net, field, adnd) SNMP_ADD_STATS((net)->mib.net_statistics, field, adnd)
306 #define __NET_ADD_STATS(net, field, adnd) __SNMP_ADD_STATS((net)->mib.net_statistics, field, adnd)
307
snmp_get_cpu_field(void __percpu * mib,int cpu,int offt)308 static inline u64 snmp_get_cpu_field(void __percpu *mib, int cpu, int offt)
309 {
310 return *(((unsigned long *)per_cpu_ptr(mib, cpu)) + offt);
311 }
312
313 unsigned long snmp_fold_field(void __percpu *mib, int offt);
314 #if BITS_PER_LONG==32
315 u64 snmp_get_cpu_field64(void __percpu *mib, int cpu, int offct,
316 size_t syncp_offset);
317 u64 snmp_fold_field64(void __percpu *mib, int offt, size_t sync_off);
318 #else
snmp_get_cpu_field64(void __percpu * mib,int cpu,int offct,size_t syncp_offset)319 static inline u64 snmp_get_cpu_field64(void __percpu *mib, int cpu, int offct,
320 size_t syncp_offset)
321 {
322 return snmp_get_cpu_field(mib, cpu, offct);
323
324 }
325
snmp_fold_field64(void __percpu * mib,int offt,size_t syncp_off)326 static inline u64 snmp_fold_field64(void __percpu *mib, int offt, size_t syncp_off)
327 {
328 return snmp_fold_field(mib, offt);
329 }
330 #endif
331
332 #define snmp_get_cpu_field64_batch(buff64, stats_list, mib_statistic, offset) \
333 { \
334 int i, c; \
335 for_each_possible_cpu(c) { \
336 for (i = 0; stats_list[i].name; i++) \
337 buff64[i] += snmp_get_cpu_field64( \
338 mib_statistic, \
339 c, stats_list[i].entry, \
340 offset); \
341 } \
342 }
343
344 #define snmp_get_cpu_field_batch(buff, stats_list, mib_statistic) \
345 { \
346 int i, c; \
347 for_each_possible_cpu(c) { \
348 for (i = 0; stats_list[i].name; i++) \
349 buff[i] += snmp_get_cpu_field( \
350 mib_statistic, \
351 c, stats_list[i].entry); \
352 } \
353 }
354
inet_get_local_port_range(const struct net * net,int * low,int * high)355 static inline void inet_get_local_port_range(const struct net *net, int *low, int *high)
356 {
357 u32 range = READ_ONCE(net->ipv4.ip_local_ports.range);
358
359 *low = range & 0xffff;
360 *high = range >> 16;
361 }
362 bool inet_sk_get_local_port_range(const struct sock *sk, int *low, int *high);
363
364 #ifdef CONFIG_SYSCTL
inet_is_local_reserved_port(struct net * net,unsigned short port)365 static inline bool inet_is_local_reserved_port(struct net *net, unsigned short port)
366 {
367 if (!net->ipv4.sysctl_local_reserved_ports)
368 return false;
369 return test_bit(port, net->ipv4.sysctl_local_reserved_ports);
370 }
371
sysctl_dev_name_is_allowed(const char * name)372 static inline bool sysctl_dev_name_is_allowed(const char *name)
373 {
374 return strcmp(name, "default") != 0 && strcmp(name, "all") != 0;
375 }
376
inet_port_requires_bind_service(struct net * net,unsigned short port)377 static inline bool inet_port_requires_bind_service(struct net *net, unsigned short port)
378 {
379 return port < READ_ONCE(net->ipv4.sysctl_ip_prot_sock);
380 }
381
382 #else
inet_is_local_reserved_port(struct net * net,unsigned short port)383 static inline bool inet_is_local_reserved_port(struct net *net, unsigned short port)
384 {
385 return false;
386 }
387
inet_port_requires_bind_service(struct net * net,unsigned short port)388 static inline bool inet_port_requires_bind_service(struct net *net, unsigned short port)
389 {
390 return port < PROT_SOCK;
391 }
392 #endif
393
394 __be32 inet_current_timestamp(void);
395
396 /* From inetpeer.c */
397 extern int inet_peer_threshold;
398 extern int inet_peer_minttl;
399 extern int inet_peer_maxttl;
400
401 void ipfrag_init(void);
402
403 void ip_static_sysctl_init(void);
404
405 #define IP4_REPLY_MARK(net, mark) \
406 (READ_ONCE((net)->ipv4.sysctl_fwmark_reflect) ? (mark) : 0)
407
ip_is_fragment(const struct iphdr * iph)408 static inline bool ip_is_fragment(const struct iphdr *iph)
409 {
410 return (iph->frag_off & htons(IP_MF | IP_OFFSET)) != 0;
411 }
412
413 #ifdef CONFIG_INET
414 #include <net/dst.h>
415
416 /* The function in 2.2 was invalid, producing wrong result for
417 * check=0xFEFF. It was noticed by Arthur Skawina _year_ ago. --ANK(000625) */
418 static inline
ip_decrease_ttl(struct iphdr * iph)419 int ip_decrease_ttl(struct iphdr *iph)
420 {
421 u32 check = (__force u32)iph->check;
422 check += (__force u32)htons(0x0100);
423 iph->check = (__force __sum16)(check + (check>=0xFFFF));
424 return --iph->ttl;
425 }
426
ip_mtu_locked(const struct dst_entry * dst)427 static inline int ip_mtu_locked(const struct dst_entry *dst)
428 {
429 const struct rtable *rt = dst_rtable(dst);
430
431 return rt->rt_mtu_locked || dst_metric_locked(dst, RTAX_MTU);
432 }
433
434 static inline
ip_dont_fragment(const struct sock * sk,const struct dst_entry * dst)435 int ip_dont_fragment(const struct sock *sk, const struct dst_entry *dst)
436 {
437 u8 pmtudisc = READ_ONCE(inet_sk(sk)->pmtudisc);
438
439 return pmtudisc == IP_PMTUDISC_DO ||
440 (pmtudisc == IP_PMTUDISC_WANT &&
441 !ip_mtu_locked(dst));
442 }
443
ip_sk_accept_pmtu(const struct sock * sk)444 static inline bool ip_sk_accept_pmtu(const struct sock *sk)
445 {
446 u8 pmtudisc = READ_ONCE(inet_sk(sk)->pmtudisc);
447
448 return pmtudisc != IP_PMTUDISC_INTERFACE &&
449 pmtudisc != IP_PMTUDISC_OMIT;
450 }
451
ip_sk_use_pmtu(const struct sock * sk)452 static inline bool ip_sk_use_pmtu(const struct sock *sk)
453 {
454 return READ_ONCE(inet_sk(sk)->pmtudisc) < IP_PMTUDISC_PROBE;
455 }
456
ip_sk_ignore_df(const struct sock * sk)457 static inline bool ip_sk_ignore_df(const struct sock *sk)
458 {
459 u8 pmtudisc = READ_ONCE(inet_sk(sk)->pmtudisc);
460
461 return pmtudisc < IP_PMTUDISC_DO || pmtudisc == IP_PMTUDISC_OMIT;
462 }
463
ip_dst_mtu_maybe_forward(const struct dst_entry * dst,bool forwarding)464 static inline unsigned int ip_dst_mtu_maybe_forward(const struct dst_entry *dst,
465 bool forwarding)
466 {
467 const struct rtable *rt = dst_rtable(dst);
468 struct net *net = dev_net(dst->dev);
469 unsigned int mtu;
470
471 if (READ_ONCE(net->ipv4.sysctl_ip_fwd_use_pmtu) ||
472 ip_mtu_locked(dst) ||
473 !forwarding) {
474 mtu = rt->rt_pmtu;
475 if (mtu && time_before(jiffies, rt->dst.expires))
476 goto out;
477 }
478
479 /* 'forwarding = true' case should always honour route mtu */
480 mtu = dst_metric_raw(dst, RTAX_MTU);
481 if (mtu)
482 goto out;
483
484 mtu = READ_ONCE(dst->dev->mtu);
485
486 if (unlikely(ip_mtu_locked(dst))) {
487 if (rt->rt_uses_gateway && mtu > 576)
488 mtu = 576;
489 }
490
491 out:
492 mtu = min_t(unsigned int, mtu, IP_MAX_MTU);
493
494 return mtu - lwtunnel_headroom(dst->lwtstate, mtu);
495 }
496
ip_skb_dst_mtu(struct sock * sk,const struct sk_buff * skb)497 static inline unsigned int ip_skb_dst_mtu(struct sock *sk,
498 const struct sk_buff *skb)
499 {
500 unsigned int mtu;
501
502 if (!sk || !sk_fullsock(sk) || ip_sk_use_pmtu(sk)) {
503 bool forwarding = IPCB(skb)->flags & IPSKB_FORWARDED;
504
505 return ip_dst_mtu_maybe_forward(skb_dst(skb), forwarding);
506 }
507
508 mtu = min(READ_ONCE(skb_dst(skb)->dev->mtu), IP_MAX_MTU);
509 return mtu - lwtunnel_headroom(skb_dst(skb)->lwtstate, mtu);
510 }
511
512 struct dst_metrics *ip_fib_metrics_init(struct nlattr *fc_mx, int fc_mx_len,
513 struct netlink_ext_ack *extack);
ip_fib_metrics_put(struct dst_metrics * fib_metrics)514 static inline void ip_fib_metrics_put(struct dst_metrics *fib_metrics)
515 {
516 if (fib_metrics != &dst_default_metrics &&
517 refcount_dec_and_test(&fib_metrics->refcnt))
518 kfree(fib_metrics);
519 }
520
521 /* ipv4 and ipv6 both use refcounted metrics if it is not the default */
522 static inline
ip_dst_init_metrics(struct dst_entry * dst,struct dst_metrics * fib_metrics)523 void ip_dst_init_metrics(struct dst_entry *dst, struct dst_metrics *fib_metrics)
524 {
525 dst_init_metrics(dst, fib_metrics->metrics, true);
526
527 if (fib_metrics != &dst_default_metrics) {
528 dst->_metrics |= DST_METRICS_REFCOUNTED;
529 refcount_inc(&fib_metrics->refcnt);
530 }
531 }
532
533 static inline
ip_dst_metrics_put(struct dst_entry * dst)534 void ip_dst_metrics_put(struct dst_entry *dst)
535 {
536 struct dst_metrics *p = (struct dst_metrics *)DST_METRICS_PTR(dst);
537
538 if (p != &dst_default_metrics && refcount_dec_and_test(&p->refcnt))
539 kfree(p);
540 }
541
542 void __ip_select_ident(struct net *net, struct iphdr *iph, int segs);
543
ip_select_ident_segs(struct net * net,struct sk_buff * skb,struct sock * sk,int segs)544 static inline void ip_select_ident_segs(struct net *net, struct sk_buff *skb,
545 struct sock *sk, int segs)
546 {
547 struct iphdr *iph = ip_hdr(skb);
548
549 /* We had many attacks based on IPID, use the private
550 * generator as much as we can.
551 */
552 if (sk && inet_sk(sk)->inet_daddr) {
553 int val;
554
555 /* avoid atomic operations for TCP,
556 * as we hold socket lock at this point.
557 */
558 if (sk_is_tcp(sk)) {
559 sock_owned_by_me(sk);
560 val = atomic_read(&inet_sk(sk)->inet_id);
561 atomic_set(&inet_sk(sk)->inet_id, val + segs);
562 } else {
563 val = atomic_add_return(segs, &inet_sk(sk)->inet_id);
564 }
565 iph->id = htons(val);
566 return;
567 }
568 if ((iph->frag_off & htons(IP_DF)) && !skb->ignore_df) {
569 iph->id = 0;
570 } else {
571 /* Unfortunately we need the big hammer to get a suitable IPID */
572 __ip_select_ident(net, iph, segs);
573 }
574 }
575
ip_select_ident(struct net * net,struct sk_buff * skb,struct sock * sk)576 static inline void ip_select_ident(struct net *net, struct sk_buff *skb,
577 struct sock *sk)
578 {
579 ip_select_ident_segs(net, skb, sk, 1);
580 }
581
inet_compute_pseudo(struct sk_buff * skb,int proto)582 static inline __wsum inet_compute_pseudo(struct sk_buff *skb, int proto)
583 {
584 return csum_tcpudp_nofold(ip_hdr(skb)->saddr, ip_hdr(skb)->daddr,
585 skb->len, proto, 0);
586 }
587
588 /* copy IPv4 saddr & daddr to flow_keys, possibly using 64bit load/store
589 * Equivalent to : flow->v4addrs.src = iph->saddr;
590 * flow->v4addrs.dst = iph->daddr;
591 */
iph_to_flow_copy_v4addrs(struct flow_keys * flow,const struct iphdr * iph)592 static inline void iph_to_flow_copy_v4addrs(struct flow_keys *flow,
593 const struct iphdr *iph)
594 {
595 BUILD_BUG_ON(offsetof(typeof(flow->addrs), v4addrs.dst) !=
596 offsetof(typeof(flow->addrs), v4addrs.src) +
597 sizeof(flow->addrs.v4addrs.src));
598 memcpy(&flow->addrs.v4addrs, &iph->addrs, sizeof(flow->addrs.v4addrs));
599 flow->control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
600 }
601
602 /*
603 * Map a multicast IP onto multicast MAC for type ethernet.
604 */
605
ip_eth_mc_map(__be32 naddr,char * buf)606 static inline void ip_eth_mc_map(__be32 naddr, char *buf)
607 {
608 __u32 addr=ntohl(naddr);
609 buf[0]=0x01;
610 buf[1]=0x00;
611 buf[2]=0x5e;
612 buf[5]=addr&0xFF;
613 addr>>=8;
614 buf[4]=addr&0xFF;
615 addr>>=8;
616 buf[3]=addr&0x7F;
617 }
618
619 /*
620 * Map a multicast IP onto multicast MAC for type IP-over-InfiniBand.
621 * Leave P_Key as 0 to be filled in by driver.
622 */
623
ip_ib_mc_map(__be32 naddr,const unsigned char * broadcast,char * buf)624 static inline void ip_ib_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf)
625 {
626 __u32 addr;
627 unsigned char scope = broadcast[5] & 0xF;
628
629 buf[0] = 0; /* Reserved */
630 buf[1] = 0xff; /* Multicast QPN */
631 buf[2] = 0xff;
632 buf[3] = 0xff;
633 addr = ntohl(naddr);
634 buf[4] = 0xff;
635 buf[5] = 0x10 | scope; /* scope from broadcast address */
636 buf[6] = 0x40; /* IPv4 signature */
637 buf[7] = 0x1b;
638 buf[8] = broadcast[8]; /* P_Key */
639 buf[9] = broadcast[9];
640 buf[10] = 0;
641 buf[11] = 0;
642 buf[12] = 0;
643 buf[13] = 0;
644 buf[14] = 0;
645 buf[15] = 0;
646 buf[19] = addr & 0xff;
647 addr >>= 8;
648 buf[18] = addr & 0xff;
649 addr >>= 8;
650 buf[17] = addr & 0xff;
651 addr >>= 8;
652 buf[16] = addr & 0x0f;
653 }
654
ip_ipgre_mc_map(__be32 naddr,const unsigned char * broadcast,char * buf)655 static inline void ip_ipgre_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf)
656 {
657 if ((broadcast[0] | broadcast[1] | broadcast[2] | broadcast[3]) != 0)
658 memcpy(buf, broadcast, 4);
659 else
660 memcpy(buf, &naddr, sizeof(naddr));
661 }
662
663 #if IS_ENABLED(CONFIG_IPV6)
664 #include <linux/ipv6.h>
665 #endif
666
inet_reset_saddr(struct sock * sk)667 static __inline__ void inet_reset_saddr(struct sock *sk)
668 {
669 inet_sk(sk)->inet_rcv_saddr = inet_sk(sk)->inet_saddr = 0;
670 #if IS_ENABLED(CONFIG_IPV6)
671 if (sk->sk_family == PF_INET6) {
672 struct ipv6_pinfo *np = inet6_sk(sk);
673
674 memset(&np->saddr, 0, sizeof(np->saddr));
675 memset(&sk->sk_v6_rcv_saddr, 0, sizeof(sk->sk_v6_rcv_saddr));
676 }
677 #endif
678 }
679
680 #endif
681
ipv4_addr_hash(__be32 ip)682 static inline unsigned int ipv4_addr_hash(__be32 ip)
683 {
684 return (__force unsigned int) ip;
685 }
686
ipv4_portaddr_hash(const struct net * net,__be32 saddr,unsigned int port)687 static inline u32 ipv4_portaddr_hash(const struct net *net,
688 __be32 saddr,
689 unsigned int port)
690 {
691 return jhash_1word((__force u32)saddr, net_hash_mix(net)) ^ port;
692 }
693
694 bool ip_call_ra_chain(struct sk_buff *skb);
695
696 /*
697 * Functions provided by ip_fragment.c
698 */
699
700 enum ip_defrag_users {
701 IP_DEFRAG_LOCAL_DELIVER,
702 IP_DEFRAG_CALL_RA_CHAIN,
703 IP_DEFRAG_CONNTRACK_IN,
704 __IP_DEFRAG_CONNTRACK_IN_END = IP_DEFRAG_CONNTRACK_IN + USHRT_MAX,
705 IP_DEFRAG_CONNTRACK_OUT,
706 __IP_DEFRAG_CONNTRACK_OUT_END = IP_DEFRAG_CONNTRACK_OUT + USHRT_MAX,
707 IP_DEFRAG_CONNTRACK_BRIDGE_IN,
708 __IP_DEFRAG_CONNTRACK_BRIDGE_IN = IP_DEFRAG_CONNTRACK_BRIDGE_IN + USHRT_MAX,
709 IP_DEFRAG_VS_IN,
710 IP_DEFRAG_VS_OUT,
711 IP_DEFRAG_VS_FWD,
712 IP_DEFRAG_AF_PACKET,
713 IP_DEFRAG_MACVLAN,
714 };
715
716 /* Return true if the value of 'user' is between 'lower_bond'
717 * and 'upper_bond' inclusively.
718 */
ip_defrag_user_in_between(u32 user,enum ip_defrag_users lower_bond,enum ip_defrag_users upper_bond)719 static inline bool ip_defrag_user_in_between(u32 user,
720 enum ip_defrag_users lower_bond,
721 enum ip_defrag_users upper_bond)
722 {
723 return user >= lower_bond && user <= upper_bond;
724 }
725
726 int ip_defrag(struct net *net, struct sk_buff *skb, u32 user);
727 #ifdef CONFIG_INET
728 struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user);
729 #else
ip_check_defrag(struct net * net,struct sk_buff * skb,u32 user)730 static inline struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user)
731 {
732 return skb;
733 }
734 #endif
735
736 /*
737 * Functions provided by ip_forward.c
738 */
739
740 int ip_forward(struct sk_buff *skb);
741
742 /*
743 * Functions provided by ip_options.c
744 */
745
746 void ip_options_build(struct sk_buff *skb, struct ip_options *opt,
747 __be32 daddr, struct rtable *rt);
748
749 int __ip_options_echo(struct net *net, struct ip_options *dopt,
750 struct sk_buff *skb, const struct ip_options *sopt);
ip_options_echo(struct net * net,struct ip_options * dopt,struct sk_buff * skb)751 static inline int ip_options_echo(struct net *net, struct ip_options *dopt,
752 struct sk_buff *skb)
753 {
754 return __ip_options_echo(net, dopt, skb, &IPCB(skb)->opt);
755 }
756
757 void ip_options_fragment(struct sk_buff *skb);
758 int __ip_options_compile(struct net *net, struct ip_options *opt,
759 struct sk_buff *skb, __be32 *info);
760 int ip_options_compile(struct net *net, struct ip_options *opt,
761 struct sk_buff *skb);
762 int ip_options_get(struct net *net, struct ip_options_rcu **optp,
763 sockptr_t data, int optlen);
764 void ip_options_undo(struct ip_options *opt);
765 void ip_forward_options(struct sk_buff *skb);
766 int ip_options_rcv_srr(struct sk_buff *skb, struct net_device *dev);
767
768 /*
769 * Functions provided by ip_sockglue.c
770 */
771
772 void ipv4_pktinfo_prepare(const struct sock *sk, struct sk_buff *skb, bool drop_dst);
773 void ip_cmsg_recv_offset(struct msghdr *msg, struct sock *sk,
774 struct sk_buff *skb, int tlen, int offset);
775 int ip_cmsg_send(struct sock *sk, struct msghdr *msg,
776 struct ipcm_cookie *ipc, bool allow_ipv6);
777 DECLARE_STATIC_KEY_FALSE(ip4_min_ttl);
778 int do_ip_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval,
779 unsigned int optlen);
780 int ip_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval,
781 unsigned int optlen);
782 int do_ip_getsockopt(struct sock *sk, int level, int optname,
783 sockptr_t optval, sockptr_t optlen);
784 int ip_getsockopt(struct sock *sk, int level, int optname, char __user *optval,
785 int __user *optlen);
786 int ip_ra_control(struct sock *sk, unsigned char on,
787 void (*destructor)(struct sock *));
788
789 int ip_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len);
790 void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err, __be16 port,
791 u32 info, u8 *payload);
792 void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 dport,
793 u32 info);
794
ip_cmsg_recv(struct msghdr * msg,struct sk_buff * skb)795 static inline void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb)
796 {
797 ip_cmsg_recv_offset(msg, skb->sk, skb, 0, 0);
798 }
799
800 bool icmp_global_allow(struct net *net);
801 void icmp_global_consume(struct net *net);
802
803 #ifdef CONFIG_PROC_FS
804 int ip_misc_proc_init(void);
805 #endif
806
807 int rtm_getroute_parse_ip_proto(struct nlattr *attr, u8 *ip_proto, u8 family,
808 struct netlink_ext_ack *extack);
809
inetdev_valid_mtu(unsigned int mtu)810 static inline bool inetdev_valid_mtu(unsigned int mtu)
811 {
812 return likely(mtu >= IPV4_MIN_MTU);
813 }
814
815 void ip_sock_set_freebind(struct sock *sk);
816 int ip_sock_set_mtu_discover(struct sock *sk, int val);
817 void ip_sock_set_pktinfo(struct sock *sk);
818 void ip_sock_set_recverr(struct sock *sk);
819 void ip_sock_set_tos(struct sock *sk, int val);
820 void __ip_sock_set_tos(struct sock *sk, int val);
821
822 #endif /* _IP_H */
823