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 #define IPSKB_MCROUTE BIT(10)
63
64 u16 frag_max_size;
65 };
66
ipv4_l3mdev_skb(u16 flags)67 static inline bool ipv4_l3mdev_skb(u16 flags)
68 {
69 return !!(flags & IPSKB_L3SLAVE);
70 }
71
ip_hdrlen(const struct sk_buff * skb)72 static inline unsigned int ip_hdrlen(const struct sk_buff *skb)
73 {
74 return ip_hdr(skb)->ihl * 4;
75 }
76
77 struct ipcm_cookie {
78 struct sockcm_cookie sockc;
79 __be32 addr;
80 int oif;
81 struct ip_options_rcu *opt;
82 __u8 protocol;
83 __u8 ttl;
84 __s16 tos;
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 = (struct ipcm_cookie) {
97 .tos = READ_ONCE(inet->tos),
98 };
99
100 sockcm_init(&ipcm->sockc, &inet->sk);
101
102 ipcm->oif = READ_ONCE(inet->sk.sk_bound_dev_if);
103 ipcm->addr = inet->inet_saddr;
104 ipcm->protocol = inet->inet_num;
105 }
106
107 #define IPCB(skb) ((struct inet_skb_parm*)((skb)->cb))
108 #define PKTINFO_SKB_CB(skb) ((struct in_pktinfo *)((skb)->cb))
109
110 /* return enslaved device index if relevant */
inet_sdif(const struct sk_buff * skb)111 static inline int inet_sdif(const struct sk_buff *skb)
112 {
113 #if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV)
114 if (skb && ipv4_l3mdev_skb(IPCB(skb)->flags))
115 return IPCB(skb)->iif;
116 #endif
117 return 0;
118 }
119
120 /* Special input handler for packets caught by router alert option.
121 They are selected only by protocol field, and then processed likely
122 local ones; but only if someone wants them! Otherwise, router
123 not running rsvpd will kill RSVP.
124
125 It is user level problem, what it will make with them.
126 I have no idea, how it will masquearde or NAT them (it is joke, joke :-)),
127 but receiver should be enough clever f.e. to forward mtrace requests,
128 sent to multicast group to reach destination designated router.
129 */
130
131 struct ip_ra_chain {
132 struct ip_ra_chain __rcu *next;
133 struct sock *sk;
134 union {
135 void (*destructor)(struct sock *);
136 struct sock *saved_sk;
137 };
138 struct rcu_head rcu;
139 };
140
141 /* IP flags. */
142 #define IP_CE 0x8000 /* Flag: "Congestion" */
143 #define IP_DF 0x4000 /* Flag: "Don't Fragment" */
144 #define IP_MF 0x2000 /* Flag: "More Fragments" */
145 #define IP_OFFSET 0x1FFF /* "Fragment Offset" part */
146
147 #define IP_FRAG_TIME (30 * HZ) /* fragment lifetime */
148
149 struct msghdr;
150 struct net_device;
151 struct packet_type;
152 struct rtable;
153 struct sockaddr;
154
155 int igmp_mc_init(void);
156
157 /*
158 * Functions provided by ip.c
159 */
160
161 int ip_build_and_send_pkt(struct sk_buff *skb, const struct sock *sk,
162 __be32 saddr, __be32 daddr,
163 struct ip_options_rcu *opt, u8 tos);
164 int ip_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt,
165 struct net_device *orig_dev);
166 void ip_list_rcv(struct list_head *head, struct packet_type *pt,
167 struct net_device *orig_dev);
168 int ip_local_deliver(struct sk_buff *skb);
169 void ip_protocol_deliver_rcu(struct net *net, struct sk_buff *skb, int proto);
170 int ip_mr_input(struct sk_buff *skb);
171 int ip_mr_output(struct net *net, struct sock *sk, struct sk_buff *skb);
172 int ip_output(struct net *net, struct sock *sk, struct sk_buff *skb);
173 int ip_mc_output(struct net *net, struct sock *sk, struct sk_buff *skb);
174 int ip_do_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
175 int (*output)(struct net *, struct sock *, struct sk_buff *));
176
177 struct ip_fraglist_iter {
178 struct sk_buff *frag;
179 struct iphdr *iph;
180 int offset;
181 unsigned int hlen;
182 };
183
184 void ip_fraglist_init(struct sk_buff *skb, struct iphdr *iph,
185 unsigned int hlen, struct ip_fraglist_iter *iter);
186 void ip_fraglist_prepare(struct sk_buff *skb, struct ip_fraglist_iter *iter);
187
ip_fraglist_next(struct ip_fraglist_iter * iter)188 static inline struct sk_buff *ip_fraglist_next(struct ip_fraglist_iter *iter)
189 {
190 struct sk_buff *skb = iter->frag;
191
192 iter->frag = skb->next;
193 skb_mark_not_on_list(skb);
194
195 return skb;
196 }
197
198 struct ip_frag_state {
199 bool DF;
200 unsigned int hlen;
201 unsigned int ll_rs;
202 unsigned int mtu;
203 unsigned int left;
204 int offset;
205 int ptr;
206 __be16 not_last_frag;
207 };
208
209 void ip_frag_init(struct sk_buff *skb, unsigned int hlen, unsigned int ll_rs,
210 unsigned int mtu, bool DF, struct ip_frag_state *state);
211 struct sk_buff *ip_frag_next(struct sk_buff *skb,
212 struct ip_frag_state *state);
213
214 void ip_send_check(struct iphdr *ip);
215 int __ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb);
216 int ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb);
217
218 int __ip_queue_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl,
219 __u8 tos);
220 void ip_init(void);
221 int ip_append_data(struct sock *sk, struct flowi4 *fl4,
222 int getfrag(void *from, char *to, int offset, int len,
223 int odd, struct sk_buff *skb),
224 void *from, int len, int protolen,
225 struct ipcm_cookie *ipc,
226 struct rtable **rt,
227 unsigned int flags);
228 int ip_generic_getfrag(void *from, char *to, int offset, int len, int odd,
229 struct sk_buff *skb);
230 struct sk_buff *__ip_make_skb(struct sock *sk, struct flowi4 *fl4,
231 struct sk_buff_head *queue,
232 struct inet_cork *cork);
233 int ip_send_skb(struct net *net, struct sk_buff *skb);
234 int ip_push_pending_frames(struct sock *sk, struct flowi4 *fl4);
235 void ip_flush_pending_frames(struct sock *sk);
236 struct sk_buff *ip_make_skb(struct sock *sk, struct flowi4 *fl4,
237 int getfrag(void *from, char *to, int offset,
238 int len, int odd, struct sk_buff *skb),
239 void *from, int length, int transhdrlen,
240 struct ipcm_cookie *ipc, struct rtable **rtp,
241 struct inet_cork *cork, unsigned int flags);
242
243 int ip_queue_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl);
244
ip_finish_skb(struct sock * sk,struct flowi4 * fl4)245 static inline struct sk_buff *ip_finish_skb(struct sock *sk, struct flowi4 *fl4)
246 {
247 return __ip_make_skb(sk, fl4, &sk->sk_write_queue, &inet_sk(sk)->cork.base);
248 }
249
250 /* 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)251 static inline u8 ip_sendmsg_scope(const struct inet_sock *inet,
252 const struct ipcm_cookie *ipc,
253 const struct msghdr *msg)
254 {
255 if (sock_flag(&inet->sk, SOCK_LOCALROUTE) ||
256 msg->msg_flags & MSG_DONTROUTE ||
257 (ipc->opt && ipc->opt->opt.is_strictroute))
258 return RT_SCOPE_LINK;
259
260 return RT_SCOPE_UNIVERSE;
261 }
262
263 /* datagram.c */
264 int __ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len);
265 int ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len);
266
267 void ip4_datagram_release_cb(struct sock *sk);
268
269 struct ip_reply_arg {
270 struct kvec iov[1];
271 int flags;
272 __wsum csum;
273 int csumoffset; /* u16 offset of csum in iov[0].iov_base */
274 /* -1 if not needed */
275 int bound_dev_if;
276 u8 tos;
277 kuid_t uid;
278 };
279
280 #define IP_REPLY_ARG_NOSRCCHECK 1
281
ip_reply_arg_flowi_flags(const struct ip_reply_arg * arg)282 static inline __u8 ip_reply_arg_flowi_flags(const struct ip_reply_arg *arg)
283 {
284 return (arg->flags & IP_REPLY_ARG_NOSRCCHECK) ? FLOWI_FLAG_ANYSRC : 0;
285 }
286
287 void ip_send_unicast_reply(struct sock *sk, const struct sock *orig_sk,
288 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
inet_get_local_port_range(const struct net * net,int * low,int * high)352 static inline void inet_get_local_port_range(const struct net *net, int *low, int *high)
353 {
354 u32 range = READ_ONCE(net->ipv4.ip_local_ports.range);
355
356 *low = range & 0xffff;
357 *high = range >> 16;
358 }
359 bool inet_sk_get_local_port_range(const struct sock *sk, int *low, int *high);
360
361 #ifdef CONFIG_SYSCTL
inet_is_local_reserved_port(const struct net * net,unsigned short port)362 static inline bool inet_is_local_reserved_port(const struct net *net, unsigned short port)
363 {
364 if (!net->ipv4.sysctl_local_reserved_ports)
365 return false;
366 return test_bit(port, net->ipv4.sysctl_local_reserved_ports);
367 }
368
sysctl_dev_name_is_allowed(const char * name)369 static inline bool sysctl_dev_name_is_allowed(const char *name)
370 {
371 return strcmp(name, "default") != 0 && strcmp(name, "all") != 0;
372 }
373
inet_port_requires_bind_service(struct net * net,unsigned short port)374 static inline bool inet_port_requires_bind_service(struct net *net, unsigned short port)
375 {
376 return port < READ_ONCE(net->ipv4.sysctl_ip_prot_sock);
377 }
378
379 #else
inet_is_local_reserved_port(struct net * net,unsigned short port)380 static inline bool inet_is_local_reserved_port(struct net *net, unsigned short port)
381 {
382 return false;
383 }
384
inet_port_requires_bind_service(struct net * net,unsigned short port)385 static inline bool inet_port_requires_bind_service(struct net *net, unsigned short port)
386 {
387 return port < PROT_SOCK;
388 }
389 #endif
390
391 __be32 inet_current_timestamp(void);
392
393 /* From inetpeer.c */
394 extern int inet_peer_threshold;
395 extern int inet_peer_minttl;
396 extern int inet_peer_maxttl;
397
398 void ipfrag_init(void);
399
400 void ip_static_sysctl_init(void);
401
402 #define IP4_REPLY_MARK(net, mark) \
403 (READ_ONCE((net)->ipv4.sysctl_fwmark_reflect) ? (mark) : 0)
404
ip_is_fragment(const struct iphdr * iph)405 static inline bool ip_is_fragment(const struct iphdr *iph)
406 {
407 return (iph->frag_off & htons(IP_MF | IP_OFFSET)) != 0;
408 }
409
410 #ifdef CONFIG_INET
411 #include <net/dst.h>
412
413 /* The function in 2.2 was invalid, producing wrong result for
414 * check=0xFEFF. It was noticed by Arthur Skawina _year_ ago. --ANK(000625) */
415 static inline
ip_decrease_ttl(struct iphdr * iph)416 int ip_decrease_ttl(struct iphdr *iph)
417 {
418 u32 check = (__force u32)iph->check;
419 check += (__force u32)htons(0x0100);
420 iph->check = (__force __sum16)(check + (check>=0xFFFF));
421 return --iph->ttl;
422 }
423
ip4h_dscp(const struct iphdr * ip4h)424 static inline dscp_t ip4h_dscp(const struct iphdr *ip4h)
425 {
426 return inet_dsfield_to_dscp(ip4h->tos);
427 }
428
ip_mtu_locked(const struct dst_entry * dst)429 static inline int ip_mtu_locked(const struct dst_entry *dst)
430 {
431 const struct rtable *rt = dst_rtable(dst);
432
433 return rt->rt_mtu_locked || dst_metric_locked(dst, RTAX_MTU);
434 }
435
436 static inline
ip_dont_fragment(const struct sock * sk,const struct dst_entry * dst)437 int ip_dont_fragment(const struct sock *sk, const struct dst_entry *dst)
438 {
439 u8 pmtudisc = READ_ONCE(inet_sk(sk)->pmtudisc);
440
441 return pmtudisc == IP_PMTUDISC_DO ||
442 (pmtudisc == IP_PMTUDISC_WANT &&
443 !ip_mtu_locked(dst));
444 }
445
ip_sk_accept_pmtu(const struct sock * sk)446 static inline bool ip_sk_accept_pmtu(const struct sock *sk)
447 {
448 u8 pmtudisc = READ_ONCE(inet_sk(sk)->pmtudisc);
449
450 return pmtudisc != IP_PMTUDISC_INTERFACE &&
451 pmtudisc != IP_PMTUDISC_OMIT;
452 }
453
ip_sk_use_pmtu(const struct sock * sk)454 static inline bool ip_sk_use_pmtu(const struct sock *sk)
455 {
456 return READ_ONCE(inet_sk(sk)->pmtudisc) < IP_PMTUDISC_PROBE;
457 }
458
ip_sk_ignore_df(const struct sock * sk)459 static inline bool ip_sk_ignore_df(const struct sock *sk)
460 {
461 u8 pmtudisc = READ_ONCE(inet_sk(sk)->pmtudisc);
462
463 return pmtudisc < IP_PMTUDISC_DO || pmtudisc == IP_PMTUDISC_OMIT;
464 }
465
ip_dst_mtu_maybe_forward(const struct dst_entry * dst,bool forwarding)466 static inline unsigned int ip_dst_mtu_maybe_forward(const struct dst_entry *dst,
467 bool forwarding)
468 {
469 const struct rtable *rt = dst_rtable(dst);
470 unsigned int mtu, res;
471 struct net *net;
472
473 rcu_read_lock();
474
475 net = dev_net_rcu(dst_dev(dst));
476 if (READ_ONCE(net->ipv4.sysctl_ip_fwd_use_pmtu) ||
477 ip_mtu_locked(dst) ||
478 !forwarding) {
479 mtu = rt->rt_pmtu;
480 if (mtu && time_before(jiffies, READ_ONCE(rt->dst.expires)))
481 goto out;
482 }
483
484 /* 'forwarding = true' case should always honour route mtu */
485 mtu = dst_metric_raw(dst, RTAX_MTU);
486 if (mtu)
487 goto out;
488
489 mtu = READ_ONCE(dst_dev(dst)->mtu);
490
491 if (unlikely(ip_mtu_locked(dst))) {
492 if (rt->rt_uses_gateway && mtu > 576)
493 mtu = 576;
494 }
495
496 out:
497 mtu = min_t(unsigned int, mtu, IP_MAX_MTU);
498
499 res = mtu - lwtunnel_headroom(dst->lwtstate, mtu);
500
501 rcu_read_unlock();
502
503 return res;
504 }
505
ip_skb_dst_mtu(struct sock * sk,const struct sk_buff * skb)506 static inline unsigned int ip_skb_dst_mtu(struct sock *sk,
507 const struct sk_buff *skb)
508 {
509 const struct dst_entry *dst = skb_dst(skb);
510 unsigned int mtu;
511
512 if (!sk || !sk_fullsock(sk) || ip_sk_use_pmtu(sk)) {
513 bool forwarding = IPCB(skb)->flags & IPSKB_FORWARDED;
514
515 return ip_dst_mtu_maybe_forward(dst, forwarding);
516 }
517
518 mtu = min(READ_ONCE(dst_dev(dst)->mtu), IP_MAX_MTU);
519 return mtu - lwtunnel_headroom(dst->lwtstate, mtu);
520 }
521
522 struct dst_metrics *ip_fib_metrics_init(struct nlattr *fc_mx, int fc_mx_len,
523 struct netlink_ext_ack *extack);
ip_fib_metrics_put(struct dst_metrics * fib_metrics)524 static inline void ip_fib_metrics_put(struct dst_metrics *fib_metrics)
525 {
526 if (fib_metrics != &dst_default_metrics &&
527 refcount_dec_and_test(&fib_metrics->refcnt))
528 kfree(fib_metrics);
529 }
530
531 /* ipv4 and ipv6 both use refcounted metrics if it is not the default */
532 static inline
ip_dst_init_metrics(struct dst_entry * dst,struct dst_metrics * fib_metrics)533 void ip_dst_init_metrics(struct dst_entry *dst, struct dst_metrics *fib_metrics)
534 {
535 dst_init_metrics(dst, fib_metrics->metrics, true);
536
537 if (fib_metrics != &dst_default_metrics) {
538 dst->_metrics |= DST_METRICS_REFCOUNTED;
539 refcount_inc(&fib_metrics->refcnt);
540 }
541 }
542
543 static inline
ip_dst_metrics_put(struct dst_entry * dst)544 void ip_dst_metrics_put(struct dst_entry *dst)
545 {
546 struct dst_metrics *p = (struct dst_metrics *)DST_METRICS_PTR(dst);
547
548 if (p != &dst_default_metrics && refcount_dec_and_test(&p->refcnt))
549 kfree(p);
550 }
551
552 void __ip_select_ident(struct net *net, struct iphdr *iph, int segs);
553
ip_select_ident_segs(struct net * net,struct sk_buff * skb,struct sock * sk,int segs)554 static inline void ip_select_ident_segs(struct net *net, struct sk_buff *skb,
555 struct sock *sk, int segs)
556 {
557 struct iphdr *iph = ip_hdr(skb);
558
559 /* We had many attacks based on IPID, use the private
560 * generator as much as we can.
561 */
562 if (sk && inet_sk(sk)->inet_daddr) {
563 int val;
564
565 /* avoid atomic operations for TCP,
566 * as we hold socket lock at this point.
567 */
568 if (sk_is_tcp(sk)) {
569 sock_owned_by_me(sk);
570 val = atomic_read(&inet_sk(sk)->inet_id);
571 atomic_set(&inet_sk(sk)->inet_id, val + segs);
572 } else {
573 val = atomic_add_return(segs, &inet_sk(sk)->inet_id);
574 }
575 iph->id = htons(val);
576 return;
577 }
578 if ((iph->frag_off & htons(IP_DF)) && !skb->ignore_df) {
579 iph->id = 0;
580 } else {
581 /* Unfortunately we need the big hammer to get a suitable IPID */
582 __ip_select_ident(net, iph, segs);
583 }
584 }
585
ip_select_ident(struct net * net,struct sk_buff * skb,struct sock * sk)586 static inline void ip_select_ident(struct net *net, struct sk_buff *skb,
587 struct sock *sk)
588 {
589 ip_select_ident_segs(net, skb, sk, 1);
590 }
591
inet_compute_pseudo(struct sk_buff * skb,int proto)592 static inline __wsum inet_compute_pseudo(struct sk_buff *skb, int proto)
593 {
594 return csum_tcpudp_nofold(ip_hdr(skb)->saddr, ip_hdr(skb)->daddr,
595 skb->len, proto, 0);
596 }
597
598 /* copy IPv4 saddr & daddr to flow_keys, possibly using 64bit load/store
599 * Equivalent to : flow->v4addrs.src = iph->saddr;
600 * flow->v4addrs.dst = iph->daddr;
601 */
iph_to_flow_copy_v4addrs(struct flow_keys * flow,const struct iphdr * iph)602 static inline void iph_to_flow_copy_v4addrs(struct flow_keys *flow,
603 const struct iphdr *iph)
604 {
605 BUILD_BUG_ON(offsetof(typeof(flow->addrs), v4addrs.dst) !=
606 offsetof(typeof(flow->addrs), v4addrs.src) +
607 sizeof(flow->addrs.v4addrs.src));
608 memcpy(&flow->addrs.v4addrs, &iph->addrs, sizeof(flow->addrs.v4addrs));
609 flow->control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
610 }
611
612 /*
613 * Map a multicast IP onto multicast MAC for type ethernet.
614 */
615
ip_eth_mc_map(__be32 naddr,char * buf)616 static inline void ip_eth_mc_map(__be32 naddr, char *buf)
617 {
618 __u32 addr=ntohl(naddr);
619 buf[0]=0x01;
620 buf[1]=0x00;
621 buf[2]=0x5e;
622 buf[5]=addr&0xFF;
623 addr>>=8;
624 buf[4]=addr&0xFF;
625 addr>>=8;
626 buf[3]=addr&0x7F;
627 }
628
629 /*
630 * Map a multicast IP onto multicast MAC for type IP-over-InfiniBand.
631 * Leave P_Key as 0 to be filled in by driver.
632 */
633
ip_ib_mc_map(__be32 naddr,const unsigned char * broadcast,char * buf)634 static inline void ip_ib_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf)
635 {
636 __u32 addr;
637 unsigned char scope = broadcast[5] & 0xF;
638
639 buf[0] = 0; /* Reserved */
640 buf[1] = 0xff; /* Multicast QPN */
641 buf[2] = 0xff;
642 buf[3] = 0xff;
643 addr = ntohl(naddr);
644 buf[4] = 0xff;
645 buf[5] = 0x10 | scope; /* scope from broadcast address */
646 buf[6] = 0x40; /* IPv4 signature */
647 buf[7] = 0x1b;
648 buf[8] = broadcast[8]; /* P_Key */
649 buf[9] = broadcast[9];
650 buf[10] = 0;
651 buf[11] = 0;
652 buf[12] = 0;
653 buf[13] = 0;
654 buf[14] = 0;
655 buf[15] = 0;
656 buf[19] = addr & 0xff;
657 addr >>= 8;
658 buf[18] = addr & 0xff;
659 addr >>= 8;
660 buf[17] = addr & 0xff;
661 addr >>= 8;
662 buf[16] = addr & 0x0f;
663 }
664
ip_ipgre_mc_map(__be32 naddr,const unsigned char * broadcast,char * buf)665 static inline void ip_ipgre_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf)
666 {
667 if ((broadcast[0] | broadcast[1] | broadcast[2] | broadcast[3]) != 0)
668 memcpy(buf, broadcast, 4);
669 else
670 memcpy(buf, &naddr, sizeof(naddr));
671 }
672
673 #if IS_ENABLED(CONFIG_IPV6)
674 #include <linux/ipv6.h>
675 #endif
676
inet_reset_saddr(struct sock * sk)677 static __inline__ void inet_reset_saddr(struct sock *sk)
678 {
679 inet_sk(sk)->inet_rcv_saddr = inet_sk(sk)->inet_saddr = 0;
680 #if IS_ENABLED(CONFIG_IPV6)
681 if (sk->sk_family == PF_INET6) {
682 struct ipv6_pinfo *np = inet6_sk(sk);
683
684 memset(&np->saddr, 0, sizeof(np->saddr));
685 memset(&sk->sk_v6_rcv_saddr, 0, sizeof(sk->sk_v6_rcv_saddr));
686 }
687 #endif
688 }
689
690 #endif
691
692 #if IS_MODULE(CONFIG_IPV6)
693 #define EXPORT_IPV6_MOD(X) EXPORT_SYMBOL(X)
694 #define EXPORT_IPV6_MOD_GPL(X) EXPORT_SYMBOL_GPL(X)
695 #else
696 #define EXPORT_IPV6_MOD(X)
697 #define EXPORT_IPV6_MOD_GPL(X)
698 #endif
699
ipv4_addr_hash(__be32 ip)700 static inline unsigned int ipv4_addr_hash(__be32 ip)
701 {
702 return (__force unsigned int) ip;
703 }
704
__ipv4_addr_hash(const __be32 ip,const u32 initval)705 static inline u32 __ipv4_addr_hash(const __be32 ip, const u32 initval)
706 {
707 return jhash_1word((__force u32)ip, initval);
708 }
709
ipv4_portaddr_hash(const struct net * net,__be32 saddr,unsigned int port)710 static inline u32 ipv4_portaddr_hash(const struct net *net,
711 __be32 saddr,
712 unsigned int port)
713 {
714 return jhash_1word((__force u32)saddr, net_hash_mix(net)) ^ port;
715 }
716
717 bool ip_call_ra_chain(struct sk_buff *skb);
718
719 /*
720 * Functions provided by ip_fragment.c
721 */
722
723 enum ip_defrag_users {
724 IP_DEFRAG_LOCAL_DELIVER,
725 IP_DEFRAG_CALL_RA_CHAIN,
726 IP_DEFRAG_CONNTRACK_IN,
727 __IP_DEFRAG_CONNTRACK_IN_END = IP_DEFRAG_CONNTRACK_IN + USHRT_MAX,
728 IP_DEFRAG_CONNTRACK_OUT,
729 __IP_DEFRAG_CONNTRACK_OUT_END = IP_DEFRAG_CONNTRACK_OUT + USHRT_MAX,
730 IP_DEFRAG_CONNTRACK_BRIDGE_IN,
731 __IP_DEFRAG_CONNTRACK_BRIDGE_IN = IP_DEFRAG_CONNTRACK_BRIDGE_IN + USHRT_MAX,
732 IP_DEFRAG_VS_IN,
733 IP_DEFRAG_VS_OUT,
734 IP_DEFRAG_VS_FWD,
735 IP_DEFRAG_AF_PACKET,
736 IP_DEFRAG_MACVLAN,
737 };
738
739 /* Return true if the value of 'user' is between 'lower_bond'
740 * and 'upper_bond' inclusively.
741 */
ip_defrag_user_in_between(u32 user,enum ip_defrag_users lower_bond,enum ip_defrag_users upper_bond)742 static inline bool ip_defrag_user_in_between(u32 user,
743 enum ip_defrag_users lower_bond,
744 enum ip_defrag_users upper_bond)
745 {
746 return user >= lower_bond && user <= upper_bond;
747 }
748
749 int ip_defrag(struct net *net, struct sk_buff *skb, u32 user);
750 #ifdef CONFIG_INET
751 struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user);
752 #else
ip_check_defrag(struct net * net,struct sk_buff * skb,u32 user)753 static inline struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user)
754 {
755 return skb;
756 }
757 #endif
758
759 /*
760 * Functions provided by ip_forward.c
761 */
762
763 int ip_forward(struct sk_buff *skb);
764
765 /*
766 * Functions provided by ip_options.c
767 */
768
769 void ip_options_build(struct sk_buff *skb, struct ip_options *opt,
770 __be32 daddr, struct rtable *rt);
771
772 int __ip_options_echo(struct net *net, struct ip_options *dopt,
773 struct sk_buff *skb, const struct ip_options *sopt);
ip_options_echo(struct net * net,struct ip_options * dopt,struct sk_buff * skb)774 static inline int ip_options_echo(struct net *net, struct ip_options *dopt,
775 struct sk_buff *skb)
776 {
777 return __ip_options_echo(net, dopt, skb, &IPCB(skb)->opt);
778 }
779
780 void ip_options_fragment(struct sk_buff *skb);
781 int __ip_options_compile(struct net *net, struct ip_options *opt,
782 struct sk_buff *skb, __be32 *info);
783 int ip_options_compile(struct net *net, struct ip_options *opt,
784 struct sk_buff *skb);
785 int ip_options_get(struct net *net, struct ip_options_rcu **optp,
786 sockptr_t data, int optlen);
787 void ip_options_undo(struct ip_options *opt);
788 void ip_forward_options(struct sk_buff *skb);
789 int ip_options_rcv_srr(struct sk_buff *skb, struct net_device *dev);
790
791 /*
792 * Functions provided by ip_sockglue.c
793 */
794
795 void ipv4_pktinfo_prepare(const struct sock *sk, struct sk_buff *skb, bool drop_dst);
796 void ip_cmsg_recv_offset(struct msghdr *msg, struct sock *sk,
797 struct sk_buff *skb, int tlen, int offset);
798 int ip_cmsg_send(struct sock *sk, struct msghdr *msg,
799 struct ipcm_cookie *ipc, bool allow_ipv6);
800 DECLARE_STATIC_KEY_FALSE(ip4_min_ttl);
801 int do_ip_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval,
802 unsigned int optlen);
803 int ip_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval,
804 unsigned int optlen);
805 int do_ip_getsockopt(struct sock *sk, int level, int optname,
806 sockptr_t optval, sockptr_t optlen);
807 int ip_getsockopt(struct sock *sk, int level, int optname, char __user *optval,
808 int __user *optlen);
809 int ip_ra_control(struct sock *sk, unsigned char on,
810 void (*destructor)(struct sock *));
811
812 int ip_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len);
813 void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err, __be16 port,
814 u32 info, u8 *payload);
815 void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 dport,
816 u32 info);
817
ip_cmsg_recv(struct msghdr * msg,struct sk_buff * skb)818 static inline void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb)
819 {
820 ip_cmsg_recv_offset(msg, skb->sk, skb, 0, 0);
821 }
822
823 bool icmp_global_allow(struct net *net);
824 void icmp_global_consume(struct net *net);
825
826 #ifdef CONFIG_PROC_FS
827 int ip_misc_proc_init(void);
828 #endif
829
830 int rtm_getroute_parse_ip_proto(struct nlattr *attr, u8 *ip_proto, u8 family,
831 struct netlink_ext_ack *extack);
832
inetdev_valid_mtu(unsigned int mtu)833 static inline bool inetdev_valid_mtu(unsigned int mtu)
834 {
835 return likely(mtu >= IPV4_MIN_MTU);
836 }
837
838 void ip_sock_set_freebind(struct sock *sk);
839 int ip_sock_set_mtu_discover(struct sock *sk, int val);
840 void ip_sock_set_pktinfo(struct sock *sk);
841 void ip_sock_set_recverr(struct sock *sk);
842 void ip_sock_set_tos(struct sock *sk, int val);
843 void __ip_sock_set_tos(struct sock *sk, int val);
844
845 #endif /* _IP_H */
846