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
40 extern unsigned int sysctl_fib_sync_mem;
41 extern unsigned int sysctl_fib_sync_mem_min;
42 extern unsigned int sysctl_fib_sync_mem_max;
43
44 struct sock;
45
46 struct 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
ipv4_l3mdev_skb(u16 flags)65 static inline bool ipv4_l3mdev_skb(u16 flags)
66 {
67 return !!(flags & IPSKB_L3SLAVE);
68 }
69
ip_hdrlen(const struct sk_buff * skb)70 static inline unsigned int ip_hdrlen(const struct sk_buff *skb)
71 {
72 return ip_hdr(skb)->ihl * 4;
73 }
74
75 struct 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
ipcm_init(struct ipcm_cookie * ipcm)87 static inline void ipcm_init(struct ipcm_cookie *ipcm)
88 {
89 *ipcm = (struct ipcm_cookie) { .tos = -1 };
90 }
91
ipcm_init_sk(struct ipcm_cookie * ipcm,const struct inet_sock * inet)92 static 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 */
inet_sdif(const struct sk_buff * skb)108 static 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
128 struct 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
146 struct msghdr;
147 struct net_device;
148 struct packet_type;
149 struct rtable;
150 struct sockaddr;
151
152 int igmp_mc_init(void);
153
154 /*
155 * Functions provided by ip.c
156 */
157
158 int 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);
161 int ip_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt,
162 struct net_device *orig_dev);
163 void ip_list_rcv(struct list_head *head, struct packet_type *pt,
164 struct net_device *orig_dev);
165 int ip_local_deliver(struct sk_buff *skb);
166 void ip_protocol_deliver_rcu(struct net *net, struct sk_buff *skb, int proto);
167 int ip_mr_input(struct sk_buff *skb);
168 int ip_output(struct net *net, struct sock *sk, struct sk_buff *skb);
169 int ip_mc_output(struct net *net, struct sock *sk, struct sk_buff *skb);
170 int ip_do_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
171 int (*output)(struct net *, struct sock *, struct sk_buff *));
172
173 struct ip_fraglist_iter {
174 struct sk_buff *frag;
175 struct iphdr *iph;
176 int offset;
177 unsigned int hlen;
178 };
179
180 void ip_fraglist_init(struct sk_buff *skb, struct iphdr *iph,
181 unsigned int hlen, struct ip_fraglist_iter *iter);
182 void ip_fraglist_prepare(struct sk_buff *skb, struct ip_fraglist_iter *iter);
183
ip_fraglist_next(struct ip_fraglist_iter * iter)184 static 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
194 struct 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
205 void 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);
207 struct sk_buff *ip_frag_next(struct sk_buff *skb,
208 struct ip_frag_state *state);
209
210 void ip_send_check(struct iphdr *ip);
211 int __ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb);
212 int ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb);
213
214 int __ip_queue_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl,
215 __u8 tos);
216 void ip_init(void);
217 int 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);
224 int ip_generic_getfrag(void *from, char *to, int offset, int len, int odd,
225 struct sk_buff *skb);
226 struct sk_buff *__ip_make_skb(struct sock *sk, struct flowi4 *fl4,
227 struct sk_buff_head *queue,
228 struct inet_cork *cork);
229 int ip_send_skb(struct net *net, struct sk_buff *skb);
230 int ip_push_pending_frames(struct sock *sk, struct flowi4 *fl4);
231 void ip_flush_pending_frames(struct sock *sk);
232 struct 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
239 int ip_queue_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl);
240
ip_finish_skb(struct sock * sk,struct flowi4 * fl4)241 static 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. */
ip_sendmsg_scope(const struct inet_sock * inet,const struct ipcm_cookie * ipc,const struct msghdr * msg)247 static 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
get_rttos(struct ipcm_cookie * ipc,struct inet_sock * inet)259 static 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 */
265 int __ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len);
266 int ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len);
267
268 void ip4_datagram_release_cb(struct sock *sk);
269
270 struct 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
ip_reply_arg_flowi_flags(const struct ip_reply_arg * arg)283 static 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
288 void 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
snmp_get_cpu_field(void __percpu * mib,int cpu,int offt)305 static 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
310 unsigned long snmp_fold_field(void __percpu *mib, int offt);
311 #if BITS_PER_LONG==32
312 u64 snmp_get_cpu_field64(void __percpu *mib, int cpu, int offct,
313 size_t syncp_offset);
314 u64 snmp_fold_field64(void __percpu *mib, int offt, size_t sync_off);
315 #else
snmp_get_cpu_field64(void __percpu * mib,int cpu,int offct,size_t syncp_offset)316 static 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
snmp_fold_field64(void __percpu * mib,int offt,size_t syncp_off)323 static 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
352 void inet_get_local_port_range(const struct net *net, int *low, int *high);
353 void inet_sk_get_local_port_range(const struct sock *sk, int *low, int *high);
354
355 #ifdef CONFIG_SYSCTL
inet_is_local_reserved_port(struct net * net,unsigned short port)356 static 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
sysctl_dev_name_is_allowed(const char * name)363 static inline bool sysctl_dev_name_is_allowed(const char *name)
364 {
365 return strcmp(name, "default") != 0 && strcmp(name, "all") != 0;
366 }
367
inet_port_requires_bind_service(struct net * net,unsigned short port)368 static 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
inet_is_local_reserved_port(struct net * net,unsigned short port)374 static inline bool inet_is_local_reserved_port(struct net *net, unsigned short port)
375 {
376 return false;
377 }
378
inet_port_requires_bind_service(struct net * net,unsigned short port)379 static 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 */
388 extern int inet_peer_threshold;
389 extern int inet_peer_minttl;
390 extern int inet_peer_maxttl;
391
392 void ipfrag_init(void);
393
394 void ip_static_sysctl_init(void);
395
396 #define IP4_REPLY_MARK(net, mark) \
397 (READ_ONCE((net)->ipv4.sysctl_fwmark_reflect) ? (mark) : 0)
398
ip_is_fragment(const struct iphdr * iph)399 static 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) */
409 static inline
ip_decrease_ttl(struct iphdr * iph)410 int 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
ip4h_dscp(const struct iphdr * ip4h)418 static inline dscp_t ip4h_dscp(const struct iphdr *ip4h)
419 {
420 return inet_dsfield_to_dscp(ip4h->tos);
421 }
422
ip_mtu_locked(const struct dst_entry * dst)423 static inline int ip_mtu_locked(const struct dst_entry *dst)
424 {
425 const struct rtable *rt = (const struct rtable *)dst;
426
427 return rt->rt_mtu_locked || dst_metric_locked(dst, RTAX_MTU);
428 }
429
430 static inline
ip_dont_fragment(const struct sock * sk,const struct dst_entry * dst)431 int ip_dont_fragment(const struct sock *sk, const struct dst_entry *dst)
432 {
433 u8 pmtudisc = READ_ONCE(inet_sk(sk)->pmtudisc);
434
435 return pmtudisc == IP_PMTUDISC_DO ||
436 (pmtudisc == IP_PMTUDISC_WANT &&
437 !ip_mtu_locked(dst));
438 }
439
ip_sk_accept_pmtu(const struct sock * sk)440 static inline bool ip_sk_accept_pmtu(const struct sock *sk)
441 {
442 return inet_sk(sk)->pmtudisc != IP_PMTUDISC_INTERFACE &&
443 inet_sk(sk)->pmtudisc != IP_PMTUDISC_OMIT;
444 }
445
ip_sk_use_pmtu(const struct sock * sk)446 static inline bool ip_sk_use_pmtu(const struct sock *sk)
447 {
448 return inet_sk(sk)->pmtudisc < IP_PMTUDISC_PROBE;
449 }
450
ip_sk_ignore_df(const struct sock * sk)451 static inline bool ip_sk_ignore_df(const struct sock *sk)
452 {
453 return inet_sk(sk)->pmtudisc < IP_PMTUDISC_DO ||
454 inet_sk(sk)->pmtudisc == IP_PMTUDISC_OMIT;
455 }
456
ip_dst_mtu_maybe_forward(const struct dst_entry * dst,bool forwarding)457 static inline unsigned int ip_dst_mtu_maybe_forward(const struct dst_entry *dst,
458 bool forwarding)
459 {
460 const struct rtable *rt = container_of(dst, struct rtable, dst);
461 struct net *net = dev_net(dst->dev);
462 unsigned int mtu;
463
464 if (READ_ONCE(net->ipv4.sysctl_ip_fwd_use_pmtu) ||
465 ip_mtu_locked(dst) ||
466 !forwarding) {
467 mtu = rt->rt_pmtu;
468 if (mtu && time_before(jiffies, rt->dst.expires))
469 goto out;
470 }
471
472 /* 'forwarding = true' case should always honour route mtu */
473 mtu = dst_metric_raw(dst, RTAX_MTU);
474 if (mtu)
475 goto out;
476
477 mtu = READ_ONCE(dst->dev->mtu);
478
479 if (unlikely(ip_mtu_locked(dst))) {
480 if (rt->rt_uses_gateway && mtu > 576)
481 mtu = 576;
482 }
483
484 out:
485 mtu = min_t(unsigned int, mtu, IP_MAX_MTU);
486
487 return mtu - lwtunnel_headroom(dst->lwtstate, mtu);
488 }
489
ip_skb_dst_mtu(struct sock * sk,const struct sk_buff * skb)490 static inline unsigned int ip_skb_dst_mtu(struct sock *sk,
491 const struct sk_buff *skb)
492 {
493 unsigned int mtu;
494
495 if (!sk || !sk_fullsock(sk) || ip_sk_use_pmtu(sk)) {
496 bool forwarding = IPCB(skb)->flags & IPSKB_FORWARDED;
497
498 return ip_dst_mtu_maybe_forward(skb_dst(skb), forwarding);
499 }
500
501 mtu = min(READ_ONCE(skb_dst(skb)->dev->mtu), IP_MAX_MTU);
502 return mtu - lwtunnel_headroom(skb_dst(skb)->lwtstate, mtu);
503 }
504
505 struct dst_metrics *ip_fib_metrics_init(struct nlattr *fc_mx, int fc_mx_len,
506 struct netlink_ext_ack *extack);
ip_fib_metrics_put(struct dst_metrics * fib_metrics)507 static inline void ip_fib_metrics_put(struct dst_metrics *fib_metrics)
508 {
509 if (fib_metrics != &dst_default_metrics &&
510 refcount_dec_and_test(&fib_metrics->refcnt))
511 kfree(fib_metrics);
512 }
513
514 /* ipv4 and ipv6 both use refcounted metrics if it is not the default */
515 static inline
ip_dst_init_metrics(struct dst_entry * dst,struct dst_metrics * fib_metrics)516 void ip_dst_init_metrics(struct dst_entry *dst, struct dst_metrics *fib_metrics)
517 {
518 dst_init_metrics(dst, fib_metrics->metrics, true);
519
520 if (fib_metrics != &dst_default_metrics) {
521 dst->_metrics |= DST_METRICS_REFCOUNTED;
522 refcount_inc(&fib_metrics->refcnt);
523 }
524 }
525
526 static inline
ip_dst_metrics_put(struct dst_entry * dst)527 void ip_dst_metrics_put(struct dst_entry *dst)
528 {
529 struct dst_metrics *p = (struct dst_metrics *)DST_METRICS_PTR(dst);
530
531 if (p != &dst_default_metrics && refcount_dec_and_test(&p->refcnt))
532 kfree(p);
533 }
534
535 void __ip_select_ident(struct net *net, struct iphdr *iph, int segs);
536
ip_select_ident_segs(struct net * net,struct sk_buff * skb,struct sock * sk,int segs)537 static inline void ip_select_ident_segs(struct net *net, struct sk_buff *skb,
538 struct sock *sk, int segs)
539 {
540 struct iphdr *iph = ip_hdr(skb);
541
542 /* We had many attacks based on IPID, use the private
543 * generator as much as we can.
544 */
545 if (sk && inet_sk(sk)->inet_daddr) {
546 int val;
547
548 /* avoid atomic operations for TCP,
549 * as we hold socket lock at this point.
550 */
551 if (sk_is_tcp(sk)) {
552 sock_owned_by_me(sk);
553 val = atomic_read(&inet_sk(sk)->inet_id);
554 atomic_set(&inet_sk(sk)->inet_id, val + segs);
555 } else {
556 val = atomic_add_return(segs, &inet_sk(sk)->inet_id);
557 }
558 iph->id = htons(val);
559 return;
560 }
561 if ((iph->frag_off & htons(IP_DF)) && !skb->ignore_df) {
562 iph->id = 0;
563 } else {
564 /* Unfortunately we need the big hammer to get a suitable IPID */
565 __ip_select_ident(net, iph, segs);
566 }
567 }
568
ip_select_ident(struct net * net,struct sk_buff * skb,struct sock * sk)569 static inline void ip_select_ident(struct net *net, struct sk_buff *skb,
570 struct sock *sk)
571 {
572 ip_select_ident_segs(net, skb, sk, 1);
573 }
574
inet_compute_pseudo(struct sk_buff * skb,int proto)575 static inline __wsum inet_compute_pseudo(struct sk_buff *skb, int proto)
576 {
577 return csum_tcpudp_nofold(ip_hdr(skb)->saddr, ip_hdr(skb)->daddr,
578 skb->len, proto, 0);
579 }
580
581 /* copy IPv4 saddr & daddr to flow_keys, possibly using 64bit load/store
582 * Equivalent to : flow->v4addrs.src = iph->saddr;
583 * flow->v4addrs.dst = iph->daddr;
584 */
iph_to_flow_copy_v4addrs(struct flow_keys * flow,const struct iphdr * iph)585 static inline void iph_to_flow_copy_v4addrs(struct flow_keys *flow,
586 const struct iphdr *iph)
587 {
588 BUILD_BUG_ON(offsetof(typeof(flow->addrs), v4addrs.dst) !=
589 offsetof(typeof(flow->addrs), v4addrs.src) +
590 sizeof(flow->addrs.v4addrs.src));
591 memcpy(&flow->addrs.v4addrs, &iph->addrs, sizeof(flow->addrs.v4addrs));
592 flow->control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
593 }
594
595 /*
596 * Map a multicast IP onto multicast MAC for type ethernet.
597 */
598
ip_eth_mc_map(__be32 naddr,char * buf)599 static inline void ip_eth_mc_map(__be32 naddr, char *buf)
600 {
601 __u32 addr=ntohl(naddr);
602 buf[0]=0x01;
603 buf[1]=0x00;
604 buf[2]=0x5e;
605 buf[5]=addr&0xFF;
606 addr>>=8;
607 buf[4]=addr&0xFF;
608 addr>>=8;
609 buf[3]=addr&0x7F;
610 }
611
612 /*
613 * Map a multicast IP onto multicast MAC for type IP-over-InfiniBand.
614 * Leave P_Key as 0 to be filled in by driver.
615 */
616
ip_ib_mc_map(__be32 naddr,const unsigned char * broadcast,char * buf)617 static inline void ip_ib_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf)
618 {
619 __u32 addr;
620 unsigned char scope = broadcast[5] & 0xF;
621
622 buf[0] = 0; /* Reserved */
623 buf[1] = 0xff; /* Multicast QPN */
624 buf[2] = 0xff;
625 buf[3] = 0xff;
626 addr = ntohl(naddr);
627 buf[4] = 0xff;
628 buf[5] = 0x10 | scope; /* scope from broadcast address */
629 buf[6] = 0x40; /* IPv4 signature */
630 buf[7] = 0x1b;
631 buf[8] = broadcast[8]; /* P_Key */
632 buf[9] = broadcast[9];
633 buf[10] = 0;
634 buf[11] = 0;
635 buf[12] = 0;
636 buf[13] = 0;
637 buf[14] = 0;
638 buf[15] = 0;
639 buf[19] = addr & 0xff;
640 addr >>= 8;
641 buf[18] = addr & 0xff;
642 addr >>= 8;
643 buf[17] = addr & 0xff;
644 addr >>= 8;
645 buf[16] = addr & 0x0f;
646 }
647
ip_ipgre_mc_map(__be32 naddr,const unsigned char * broadcast,char * buf)648 static inline void ip_ipgre_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf)
649 {
650 if ((broadcast[0] | broadcast[1] | broadcast[2] | broadcast[3]) != 0)
651 memcpy(buf, broadcast, 4);
652 else
653 memcpy(buf, &naddr, sizeof(naddr));
654 }
655
656 #if IS_ENABLED(CONFIG_IPV6)
657 #include <linux/ipv6.h>
658 #endif
659
inet_reset_saddr(struct sock * sk)660 static __inline__ void inet_reset_saddr(struct sock *sk)
661 {
662 inet_sk(sk)->inet_rcv_saddr = inet_sk(sk)->inet_saddr = 0;
663 #if IS_ENABLED(CONFIG_IPV6)
664 if (sk->sk_family == PF_INET6) {
665 struct ipv6_pinfo *np = inet6_sk(sk);
666
667 memset(&np->saddr, 0, sizeof(np->saddr));
668 memset(&sk->sk_v6_rcv_saddr, 0, sizeof(sk->sk_v6_rcv_saddr));
669 }
670 #endif
671 }
672
673 #endif
674
ipv4_addr_hash(__be32 ip)675 static inline unsigned int ipv4_addr_hash(__be32 ip)
676 {
677 return (__force unsigned int) ip;
678 }
679
ipv4_portaddr_hash(const struct net * net,__be32 saddr,unsigned int port)680 static inline u32 ipv4_portaddr_hash(const struct net *net,
681 __be32 saddr,
682 unsigned int port)
683 {
684 return jhash_1word((__force u32)saddr, net_hash_mix(net)) ^ port;
685 }
686
687 bool ip_call_ra_chain(struct sk_buff *skb);
688
689 /*
690 * Functions provided by ip_fragment.c
691 */
692
693 enum ip_defrag_users {
694 IP_DEFRAG_LOCAL_DELIVER,
695 IP_DEFRAG_CALL_RA_CHAIN,
696 IP_DEFRAG_CONNTRACK_IN,
697 __IP_DEFRAG_CONNTRACK_IN_END = IP_DEFRAG_CONNTRACK_IN + USHRT_MAX,
698 IP_DEFRAG_CONNTRACK_OUT,
699 __IP_DEFRAG_CONNTRACK_OUT_END = IP_DEFRAG_CONNTRACK_OUT + USHRT_MAX,
700 IP_DEFRAG_CONNTRACK_BRIDGE_IN,
701 __IP_DEFRAG_CONNTRACK_BRIDGE_IN = IP_DEFRAG_CONNTRACK_BRIDGE_IN + USHRT_MAX,
702 IP_DEFRAG_VS_IN,
703 IP_DEFRAG_VS_OUT,
704 IP_DEFRAG_VS_FWD,
705 IP_DEFRAG_AF_PACKET,
706 IP_DEFRAG_MACVLAN,
707 };
708
709 /* Return true if the value of 'user' is between 'lower_bond'
710 * and 'upper_bond' inclusively.
711 */
ip_defrag_user_in_between(u32 user,enum ip_defrag_users lower_bond,enum ip_defrag_users upper_bond)712 static inline bool ip_defrag_user_in_between(u32 user,
713 enum ip_defrag_users lower_bond,
714 enum ip_defrag_users upper_bond)
715 {
716 return user >= lower_bond && user <= upper_bond;
717 }
718
719 int ip_defrag(struct net *net, struct sk_buff *skb, u32 user);
720 #ifdef CONFIG_INET
721 struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user);
722 #else
ip_check_defrag(struct net * net,struct sk_buff * skb,u32 user)723 static inline struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user)
724 {
725 return skb;
726 }
727 #endif
728
729 /*
730 * Functions provided by ip_forward.c
731 */
732
733 int ip_forward(struct sk_buff *skb);
734
735 /*
736 * Functions provided by ip_options.c
737 */
738
739 void ip_options_build(struct sk_buff *skb, struct ip_options *opt,
740 __be32 daddr, struct rtable *rt);
741
742 int __ip_options_echo(struct net *net, struct ip_options *dopt,
743 struct sk_buff *skb, const struct ip_options *sopt);
ip_options_echo(struct net * net,struct ip_options * dopt,struct sk_buff * skb)744 static inline int ip_options_echo(struct net *net, struct ip_options *dopt,
745 struct sk_buff *skb)
746 {
747 return __ip_options_echo(net, dopt, skb, &IPCB(skb)->opt);
748 }
749
750 void ip_options_fragment(struct sk_buff *skb);
751 int __ip_options_compile(struct net *net, struct ip_options *opt,
752 struct sk_buff *skb, __be32 *info);
753 int ip_options_compile(struct net *net, struct ip_options *opt,
754 struct sk_buff *skb);
755 int ip_options_get(struct net *net, struct ip_options_rcu **optp,
756 sockptr_t data, int optlen);
757 void ip_options_undo(struct ip_options *opt);
758 void ip_forward_options(struct sk_buff *skb);
759 int ip_options_rcv_srr(struct sk_buff *skb, struct net_device *dev);
760
761 /*
762 * Functions provided by ip_sockglue.c
763 */
764
765 void ipv4_pktinfo_prepare(const struct sock *sk, struct sk_buff *skb, bool drop_dst);
766 void ip_cmsg_recv_offset(struct msghdr *msg, struct sock *sk,
767 struct sk_buff *skb, int tlen, int offset);
768 int ip_cmsg_send(struct sock *sk, struct msghdr *msg,
769 struct ipcm_cookie *ipc, bool allow_ipv6);
770 DECLARE_STATIC_KEY_FALSE(ip4_min_ttl);
771 int do_ip_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval,
772 unsigned int optlen);
773 int ip_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval,
774 unsigned int optlen);
775 int do_ip_getsockopt(struct sock *sk, int level, int optname,
776 sockptr_t optval, sockptr_t optlen);
777 int ip_getsockopt(struct sock *sk, int level, int optname, char __user *optval,
778 int __user *optlen);
779 int ip_ra_control(struct sock *sk, unsigned char on,
780 void (*destructor)(struct sock *));
781
782 int ip_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len);
783 void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err, __be16 port,
784 u32 info, u8 *payload);
785 void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 dport,
786 u32 info);
787
ip_cmsg_recv(struct msghdr * msg,struct sk_buff * skb)788 static inline void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb)
789 {
790 ip_cmsg_recv_offset(msg, skb->sk, skb, 0, 0);
791 }
792
793 bool icmp_global_allow(void);
794 void icmp_global_consume(void);
795
796 extern int sysctl_icmp_msgs_per_sec;
797 extern int sysctl_icmp_msgs_burst;
798
799 #ifdef CONFIG_PROC_FS
800 int ip_misc_proc_init(void);
801 #endif
802
803 int rtm_getroute_parse_ip_proto(struct nlattr *attr, u8 *ip_proto, u8 family,
804 struct netlink_ext_ack *extack);
805
inetdev_valid_mtu(unsigned int mtu)806 static inline bool inetdev_valid_mtu(unsigned int mtu)
807 {
808 return likely(mtu >= IPV4_MIN_MTU);
809 }
810
811 void ip_sock_set_freebind(struct sock *sk);
812 int ip_sock_set_mtu_discover(struct sock *sk, int val);
813 void ip_sock_set_pktinfo(struct sock *sk);
814 void ip_sock_set_recverr(struct sock *sk);
815 void ip_sock_set_tos(struct sock *sk, int val);
816 void __ip_sock_set_tos(struct sock *sk, int val);
817
818 #endif /* _IP_H */
819