1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3 * INET An implementation of the TCP/IP protocol suite for the LINUX
4 * operating system. INET is implemented using the BSD Socket
5 * interface as the means of communication with the user level.
6 *
7 * Definitions for the IP module.
8 *
9 * Version: @(#)ip.h 1.0.2 05/07/93
10 *
11 * Authors: Ross Biro
12 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
13 * Alan Cox, <gw4pts@gw4pts.ampr.org>
14 *
15 * Changes:
16 * Mike McLagan : Routing by source
17 */
18 #ifndef _IP_H
19 #define _IP_H
20
21 #include <linux/types.h>
22 #include <linux/ip.h>
23 #include <linux/in.h>
24 #include <linux/skbuff.h>
25 #include <linux/jhash.h>
26
27 #include <net/inet_sock.h>
28 #include <net/route.h>
29 #include <net/snmp.h>
30 #include <net/flow.h>
31 #include <net/flow_dissector.h>
32 #include <net/netns/hash.h>
33
34 #define IPV4_MAX_PMTU 65535U /* RFC 2675, Section 5.1 */
35 #define IPV4_MIN_MTU 68 /* RFC 791 */
36
37 extern unsigned int sysctl_fib_sync_mem;
38 extern unsigned int sysctl_fib_sync_mem_min;
39 extern unsigned int sysctl_fib_sync_mem_max;
40
41 struct sock;
42
43 struct inet_skb_parm {
44 int iif;
45 struct ip_options opt; /* Compiled IP options */
46 u16 flags;
47
48 #define IPSKB_FORWARDED BIT(0)
49 #define IPSKB_XFRM_TUNNEL_SIZE BIT(1)
50 #define IPSKB_XFRM_TRANSFORMED BIT(2)
51 #define IPSKB_FRAG_COMPLETE BIT(3)
52 #define IPSKB_REROUTED BIT(4)
53 #define IPSKB_DOREDIRECT BIT(5)
54 #define IPSKB_FRAG_PMTU BIT(6)
55 #define IPSKB_L3SLAVE BIT(7)
56
57 u16 frag_max_size;
58 };
59
ipv4_l3mdev_skb(u16 flags)60 static inline bool ipv4_l3mdev_skb(u16 flags)
61 {
62 return !!(flags & IPSKB_L3SLAVE);
63 }
64
ip_hdrlen(const struct sk_buff * skb)65 static inline unsigned int ip_hdrlen(const struct sk_buff *skb)
66 {
67 return ip_hdr(skb)->ihl * 4;
68 }
69
70 struct ipcm_cookie {
71 struct sockcm_cookie sockc;
72 __be32 addr;
73 int oif;
74 struct ip_options_rcu *opt;
75 __u8 ttl;
76 __s16 tos;
77 char priority;
78 __u16 gso_size;
79 };
80
ipcm_init(struct ipcm_cookie * ipcm)81 static inline void ipcm_init(struct ipcm_cookie *ipcm)
82 {
83 *ipcm = (struct ipcm_cookie) { .tos = -1 };
84 }
85
ipcm_init_sk(struct ipcm_cookie * ipcm,const struct inet_sock * inet)86 static inline void ipcm_init_sk(struct ipcm_cookie *ipcm,
87 const struct inet_sock *inet)
88 {
89 ipcm_init(ipcm);
90
91 ipcm->sockc.mark = inet->sk.sk_mark;
92 ipcm->sockc.tsflags = inet->sk.sk_tsflags;
93 ipcm->oif = inet->sk.sk_bound_dev_if;
94 ipcm->addr = inet->inet_saddr;
95 }
96
97 #define IPCB(skb) ((struct inet_skb_parm*)((skb)->cb))
98 #define PKTINFO_SKB_CB(skb) ((struct in_pktinfo *)((skb)->cb))
99
100 /* return enslaved device index if relevant */
inet_sdif(struct sk_buff * skb)101 static inline int inet_sdif(struct sk_buff *skb)
102 {
103 #if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV)
104 if (skb && ipv4_l3mdev_skb(IPCB(skb)->flags))
105 return IPCB(skb)->iif;
106 #endif
107 return 0;
108 }
109
110 /* Special input handler for packets caught by router alert option.
111 They are selected only by protocol field, and then processed likely
112 local ones; but only if someone wants them! Otherwise, router
113 not running rsvpd will kill RSVP.
114
115 It is user level problem, what it will make with them.
116 I have no idea, how it will masquearde or NAT them (it is joke, joke :-)),
117 but receiver should be enough clever f.e. to forward mtrace requests,
118 sent to multicast group to reach destination designated router.
119 */
120
121 struct ip_ra_chain {
122 struct ip_ra_chain __rcu *next;
123 struct sock *sk;
124 union {
125 void (*destructor)(struct sock *);
126 struct sock *saved_sk;
127 };
128 struct rcu_head rcu;
129 };
130
131 /* IP flags. */
132 #define IP_CE 0x8000 /* Flag: "Congestion" */
133 #define IP_DF 0x4000 /* Flag: "Don't Fragment" */
134 #define IP_MF 0x2000 /* Flag: "More Fragments" */
135 #define IP_OFFSET 0x1FFF /* "Fragment Offset" part */
136
137 #define IP_FRAG_TIME (30 * HZ) /* fragment lifetime */
138
139 struct msghdr;
140 struct net_device;
141 struct packet_type;
142 struct rtable;
143 struct sockaddr;
144
145 int igmp_mc_init(void);
146
147 /*
148 * Functions provided by ip.c
149 */
150
151 int ip_build_and_send_pkt(struct sk_buff *skb, const struct sock *sk,
152 __be32 saddr, __be32 daddr,
153 struct ip_options_rcu *opt);
154 int ip_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt,
155 struct net_device *orig_dev);
156 void ip_list_rcv(struct list_head *head, struct packet_type *pt,
157 struct net_device *orig_dev);
158 int ip_local_deliver(struct sk_buff *skb);
159 void ip_protocol_deliver_rcu(struct net *net, struct sk_buff *skb, int proto);
160 int ip_mr_input(struct sk_buff *skb);
161 int ip_output(struct net *net, struct sock *sk, struct sk_buff *skb);
162 int ip_mc_output(struct net *net, struct sock *sk, struct sk_buff *skb);
163 int ip_do_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
164 int (*output)(struct net *, struct sock *, struct sk_buff *));
165
166 struct ip_fraglist_iter {
167 struct sk_buff *frag;
168 struct iphdr *iph;
169 int offset;
170 unsigned int hlen;
171 };
172
173 void ip_fraglist_init(struct sk_buff *skb, struct iphdr *iph,
174 unsigned int hlen, struct ip_fraglist_iter *iter);
175 void ip_fraglist_prepare(struct sk_buff *skb, struct ip_fraglist_iter *iter);
176
ip_fraglist_next(struct ip_fraglist_iter * iter)177 static inline struct sk_buff *ip_fraglist_next(struct ip_fraglist_iter *iter)
178 {
179 struct sk_buff *skb = iter->frag;
180
181 iter->frag = skb->next;
182 skb_mark_not_on_list(skb);
183
184 return skb;
185 }
186
187 struct ip_frag_state {
188 bool DF;
189 unsigned int hlen;
190 unsigned int ll_rs;
191 unsigned int mtu;
192 unsigned int left;
193 int offset;
194 int ptr;
195 __be16 not_last_frag;
196 };
197
198 void ip_frag_init(struct sk_buff *skb, unsigned int hlen, unsigned int ll_rs,
199 unsigned int mtu, bool DF, struct ip_frag_state *state);
200 struct sk_buff *ip_frag_next(struct sk_buff *skb,
201 struct ip_frag_state *state);
202
203 void ip_send_check(struct iphdr *ip);
204 int __ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb);
205 int ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb);
206
207 int __ip_queue_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl,
208 __u8 tos);
209 void ip_init(void);
210 int ip_append_data(struct sock *sk, struct flowi4 *fl4,
211 int getfrag(void *from, char *to, int offset, int len,
212 int odd, struct sk_buff *skb),
213 void *from, int len, int protolen,
214 struct ipcm_cookie *ipc,
215 struct rtable **rt,
216 unsigned int flags);
217 int ip_generic_getfrag(void *from, char *to, int offset, int len, int odd,
218 struct sk_buff *skb);
219 ssize_t ip_append_page(struct sock *sk, struct flowi4 *fl4, struct page *page,
220 int offset, size_t size, int flags);
221 struct sk_buff *__ip_make_skb(struct sock *sk, struct flowi4 *fl4,
222 struct sk_buff_head *queue,
223 struct inet_cork *cork);
224 int ip_send_skb(struct net *net, struct sk_buff *skb);
225 int ip_push_pending_frames(struct sock *sk, struct flowi4 *fl4);
226 void ip_flush_pending_frames(struct sock *sk);
227 struct sk_buff *ip_make_skb(struct sock *sk, struct flowi4 *fl4,
228 int getfrag(void *from, char *to, int offset,
229 int len, int odd, struct sk_buff *skb),
230 void *from, int length, int transhdrlen,
231 struct ipcm_cookie *ipc, struct rtable **rtp,
232 struct inet_cork *cork, unsigned int flags);
233
ip_queue_xmit(struct sock * sk,struct sk_buff * skb,struct flowi * fl)234 static inline int ip_queue_xmit(struct sock *sk, struct sk_buff *skb,
235 struct flowi *fl)
236 {
237 return __ip_queue_xmit(sk, skb, fl, inet_sk(sk)->tos);
238 }
239
ip_finish_skb(struct sock * sk,struct flowi4 * fl4)240 static inline struct sk_buff *ip_finish_skb(struct sock *sk, struct flowi4 *fl4)
241 {
242 return __ip_make_skb(sk, fl4, &sk->sk_write_queue, &inet_sk(sk)->cork.base);
243 }
244
get_rttos(struct ipcm_cookie * ipc,struct inet_sock * inet)245 static inline __u8 get_rttos(struct ipcm_cookie* ipc, struct inet_sock *inet)
246 {
247 return (ipc->tos != -1) ? RT_TOS(ipc->tos) : RT_TOS(inet->tos);
248 }
249
get_rtconn_flags(struct ipcm_cookie * ipc,struct sock * sk)250 static inline __u8 get_rtconn_flags(struct ipcm_cookie* ipc, struct sock* sk)
251 {
252 return (ipc->tos != -1) ? RT_CONN_FLAGS_TOS(sk, ipc->tos) : RT_CONN_FLAGS(sk);
253 }
254
255 /* datagram.c */
256 int __ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len);
257 int ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len);
258
259 void ip4_datagram_release_cb(struct sock *sk);
260
261 struct ip_reply_arg {
262 struct kvec iov[1];
263 int flags;
264 __wsum csum;
265 int csumoffset; /* u16 offset of csum in iov[0].iov_base */
266 /* -1 if not needed */
267 int bound_dev_if;
268 u8 tos;
269 kuid_t uid;
270 };
271
272 #define IP_REPLY_ARG_NOSRCCHECK 1
273
ip_reply_arg_flowi_flags(const struct ip_reply_arg * arg)274 static inline __u8 ip_reply_arg_flowi_flags(const struct ip_reply_arg *arg)
275 {
276 return (arg->flags & IP_REPLY_ARG_NOSRCCHECK) ? FLOWI_FLAG_ANYSRC : 0;
277 }
278
279 void ip_send_unicast_reply(struct sock *sk, struct sk_buff *skb,
280 const struct ip_options *sopt,
281 __be32 daddr, __be32 saddr,
282 const struct ip_reply_arg *arg,
283 unsigned int len, u64 transmit_time);
284
285 #define IP_INC_STATS(net, field) SNMP_INC_STATS64((net)->mib.ip_statistics, field)
286 #define __IP_INC_STATS(net, field) __SNMP_INC_STATS64((net)->mib.ip_statistics, field)
287 #define IP_ADD_STATS(net, field, val) SNMP_ADD_STATS64((net)->mib.ip_statistics, field, val)
288 #define __IP_ADD_STATS(net, field, val) __SNMP_ADD_STATS64((net)->mib.ip_statistics, field, val)
289 #define IP_UPD_PO_STATS(net, field, val) SNMP_UPD_PO_STATS64((net)->mib.ip_statistics, field, val)
290 #define __IP_UPD_PO_STATS(net, field, val) __SNMP_UPD_PO_STATS64((net)->mib.ip_statistics, field, val)
291 #define NET_INC_STATS(net, field) SNMP_INC_STATS((net)->mib.net_statistics, field)
292 #define __NET_INC_STATS(net, field) __SNMP_INC_STATS((net)->mib.net_statistics, field)
293 #define NET_ADD_STATS(net, field, adnd) SNMP_ADD_STATS((net)->mib.net_statistics, field, adnd)
294 #define __NET_ADD_STATS(net, field, adnd) __SNMP_ADD_STATS((net)->mib.net_statistics, field, adnd)
295
296 u64 snmp_get_cpu_field(void __percpu *mib, int cpu, int offct);
297 unsigned long snmp_fold_field(void __percpu *mib, int offt);
298 #if BITS_PER_LONG==32
299 u64 snmp_get_cpu_field64(void __percpu *mib, int cpu, int offct,
300 size_t syncp_offset);
301 u64 snmp_fold_field64(void __percpu *mib, int offt, size_t sync_off);
302 #else
snmp_get_cpu_field64(void __percpu * mib,int cpu,int offct,size_t syncp_offset)303 static inline u64 snmp_get_cpu_field64(void __percpu *mib, int cpu, int offct,
304 size_t syncp_offset)
305 {
306 return snmp_get_cpu_field(mib, cpu, offct);
307
308 }
309
snmp_fold_field64(void __percpu * mib,int offt,size_t syncp_off)310 static inline u64 snmp_fold_field64(void __percpu *mib, int offt, size_t syncp_off)
311 {
312 return snmp_fold_field(mib, offt);
313 }
314 #endif
315
316 #define snmp_get_cpu_field64_batch(buff64, stats_list, mib_statistic, offset) \
317 { \
318 int i, c; \
319 for_each_possible_cpu(c) { \
320 for (i = 0; stats_list[i].name; i++) \
321 buff64[i] += snmp_get_cpu_field64( \
322 mib_statistic, \
323 c, stats_list[i].entry, \
324 offset); \
325 } \
326 }
327
328 #define snmp_get_cpu_field_batch(buff, stats_list, mib_statistic) \
329 { \
330 int i, c; \
331 for_each_possible_cpu(c) { \
332 for (i = 0; stats_list[i].name; i++) \
333 buff[i] += snmp_get_cpu_field( \
334 mib_statistic, \
335 c, stats_list[i].entry); \
336 } \
337 }
338
339 void inet_get_local_port_range(struct net *net, int *low, int *high);
340
341 #ifdef CONFIG_SYSCTL
inet_is_local_reserved_port(struct net * net,int port)342 static inline int inet_is_local_reserved_port(struct net *net, int port)
343 {
344 if (!net->ipv4.sysctl_local_reserved_ports)
345 return 0;
346 return test_bit(port, net->ipv4.sysctl_local_reserved_ports);
347 }
348
sysctl_dev_name_is_allowed(const char * name)349 static inline bool sysctl_dev_name_is_allowed(const char *name)
350 {
351 return strcmp(name, "default") != 0 && strcmp(name, "all") != 0;
352 }
353
inet_prot_sock(struct net * net)354 static inline int inet_prot_sock(struct net *net)
355 {
356 return net->ipv4.sysctl_ip_prot_sock;
357 }
358
359 #else
inet_is_local_reserved_port(struct net * net,int port)360 static inline int inet_is_local_reserved_port(struct net *net, int port)
361 {
362 return 0;
363 }
364
inet_prot_sock(struct net * net)365 static inline int inet_prot_sock(struct net *net)
366 {
367 return PROT_SOCK;
368 }
369 #endif
370
371 __be32 inet_current_timestamp(void);
372
373 /* From inetpeer.c */
374 extern int inet_peer_threshold;
375 extern int inet_peer_minttl;
376 extern int inet_peer_maxttl;
377
378 void ipfrag_init(void);
379
380 void ip_static_sysctl_init(void);
381
382 #define IP4_REPLY_MARK(net, mark) \
383 ((net)->ipv4.sysctl_fwmark_reflect ? (mark) : 0)
384
ip_is_fragment(const struct iphdr * iph)385 static inline bool ip_is_fragment(const struct iphdr *iph)
386 {
387 return (iph->frag_off & htons(IP_MF | IP_OFFSET)) != 0;
388 }
389
390 #ifdef CONFIG_INET
391 #include <net/dst.h>
392
393 /* The function in 2.2 was invalid, producing wrong result for
394 * check=0xFEFF. It was noticed by Arthur Skawina _year_ ago. --ANK(000625) */
395 static inline
ip_decrease_ttl(struct iphdr * iph)396 int ip_decrease_ttl(struct iphdr *iph)
397 {
398 u32 check = (__force u32)iph->check;
399 check += (__force u32)htons(0x0100);
400 iph->check = (__force __sum16)(check + (check>=0xFFFF));
401 return --iph->ttl;
402 }
403
ip_mtu_locked(const struct dst_entry * dst)404 static inline int ip_mtu_locked(const struct dst_entry *dst)
405 {
406 const struct rtable *rt = (const struct rtable *)dst;
407
408 return rt->rt_mtu_locked || dst_metric_locked(dst, RTAX_MTU);
409 }
410
411 static inline
ip_dont_fragment(const struct sock * sk,const struct dst_entry * dst)412 int ip_dont_fragment(const struct sock *sk, const struct dst_entry *dst)
413 {
414 u8 pmtudisc = READ_ONCE(inet_sk(sk)->pmtudisc);
415
416 return pmtudisc == IP_PMTUDISC_DO ||
417 (pmtudisc == IP_PMTUDISC_WANT &&
418 !ip_mtu_locked(dst));
419 }
420
ip_sk_accept_pmtu(const struct sock * sk)421 static inline bool ip_sk_accept_pmtu(const struct sock *sk)
422 {
423 return inet_sk(sk)->pmtudisc != IP_PMTUDISC_INTERFACE &&
424 inet_sk(sk)->pmtudisc != IP_PMTUDISC_OMIT;
425 }
426
ip_sk_use_pmtu(const struct sock * sk)427 static inline bool ip_sk_use_pmtu(const struct sock *sk)
428 {
429 return inet_sk(sk)->pmtudisc < IP_PMTUDISC_PROBE;
430 }
431
ip_sk_ignore_df(const struct sock * sk)432 static inline bool ip_sk_ignore_df(const struct sock *sk)
433 {
434 return inet_sk(sk)->pmtudisc < IP_PMTUDISC_DO ||
435 inet_sk(sk)->pmtudisc == IP_PMTUDISC_OMIT;
436 }
437
ip_dst_mtu_maybe_forward(const struct dst_entry * dst,bool forwarding)438 static inline unsigned int ip_dst_mtu_maybe_forward(const struct dst_entry *dst,
439 bool forwarding)
440 {
441 struct net *net = dev_net(dst->dev);
442
443 if (net->ipv4.sysctl_ip_fwd_use_pmtu ||
444 ip_mtu_locked(dst) ||
445 !forwarding)
446 return dst_mtu(dst);
447
448 return min(READ_ONCE(dst->dev->mtu), IP_MAX_MTU);
449 }
450
ip_skb_dst_mtu(struct sock * sk,const struct sk_buff * skb)451 static inline unsigned int ip_skb_dst_mtu(struct sock *sk,
452 const struct sk_buff *skb)
453 {
454 if (!sk || !sk_fullsock(sk) || ip_sk_use_pmtu(sk)) {
455 bool forwarding = IPCB(skb)->flags & IPSKB_FORWARDED;
456
457 return ip_dst_mtu_maybe_forward(skb_dst(skb), forwarding);
458 }
459
460 return min(READ_ONCE(skb_dst(skb)->dev->mtu), IP_MAX_MTU);
461 }
462
463 struct dst_metrics *ip_fib_metrics_init(struct net *net, struct nlattr *fc_mx,
464 int fc_mx_len,
465 struct netlink_ext_ack *extack);
ip_fib_metrics_put(struct dst_metrics * fib_metrics)466 static inline void ip_fib_metrics_put(struct dst_metrics *fib_metrics)
467 {
468 if (fib_metrics != &dst_default_metrics &&
469 refcount_dec_and_test(&fib_metrics->refcnt))
470 kfree(fib_metrics);
471 }
472
473 /* ipv4 and ipv6 both use refcounted metrics if it is not the default */
474 static inline
ip_dst_init_metrics(struct dst_entry * dst,struct dst_metrics * fib_metrics)475 void ip_dst_init_metrics(struct dst_entry *dst, struct dst_metrics *fib_metrics)
476 {
477 dst_init_metrics(dst, fib_metrics->metrics, true);
478
479 if (fib_metrics != &dst_default_metrics) {
480 dst->_metrics |= DST_METRICS_REFCOUNTED;
481 refcount_inc(&fib_metrics->refcnt);
482 }
483 }
484
485 static inline
ip_dst_metrics_put(struct dst_entry * dst)486 void ip_dst_metrics_put(struct dst_entry *dst)
487 {
488 struct dst_metrics *p = (struct dst_metrics *)DST_METRICS_PTR(dst);
489
490 if (p != &dst_default_metrics && refcount_dec_and_test(&p->refcnt))
491 kfree(p);
492 }
493
494 u32 ip_idents_reserve(u32 hash, int segs);
495 void __ip_select_ident(struct net *net, struct iphdr *iph, int segs);
496
ip_select_ident_segs(struct net * net,struct sk_buff * skb,struct sock * sk,int segs)497 static inline void ip_select_ident_segs(struct net *net, struct sk_buff *skb,
498 struct sock *sk, int segs)
499 {
500 struct iphdr *iph = ip_hdr(skb);
501
502 if ((iph->frag_off & htons(IP_DF)) && !skb->ignore_df) {
503 /* This is only to work around buggy Windows95/2000
504 * VJ compression implementations. If the ID field
505 * does not change, they drop every other packet in
506 * a TCP stream using header compression.
507 */
508 if (sk && inet_sk(sk)->inet_daddr) {
509 iph->id = htons(inet_sk(sk)->inet_id);
510 inet_sk(sk)->inet_id += segs;
511 } else {
512 iph->id = 0;
513 }
514 } else {
515 __ip_select_ident(net, iph, segs);
516 }
517 }
518
ip_select_ident(struct net * net,struct sk_buff * skb,struct sock * sk)519 static inline void ip_select_ident(struct net *net, struct sk_buff *skb,
520 struct sock *sk)
521 {
522 ip_select_ident_segs(net, skb, sk, 1);
523 }
524
inet_compute_pseudo(struct sk_buff * skb,int proto)525 static inline __wsum inet_compute_pseudo(struct sk_buff *skb, int proto)
526 {
527 return csum_tcpudp_nofold(ip_hdr(skb)->saddr, ip_hdr(skb)->daddr,
528 skb->len, proto, 0);
529 }
530
531 /* copy IPv4 saddr & daddr to flow_keys, possibly using 64bit load/store
532 * Equivalent to : flow->v4addrs.src = iph->saddr;
533 * flow->v4addrs.dst = iph->daddr;
534 */
iph_to_flow_copy_v4addrs(struct flow_keys * flow,const struct iphdr * iph)535 static inline void iph_to_flow_copy_v4addrs(struct flow_keys *flow,
536 const struct iphdr *iph)
537 {
538 BUILD_BUG_ON(offsetof(typeof(flow->addrs), v4addrs.dst) !=
539 offsetof(typeof(flow->addrs), v4addrs.src) +
540 sizeof(flow->addrs.v4addrs.src));
541 memcpy(&flow->addrs.v4addrs, &iph->saddr, sizeof(flow->addrs.v4addrs));
542 flow->control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
543 }
544
inet_gro_compute_pseudo(struct sk_buff * skb,int proto)545 static inline __wsum inet_gro_compute_pseudo(struct sk_buff *skb, int proto)
546 {
547 const struct iphdr *iph = skb_gro_network_header(skb);
548
549 return csum_tcpudp_nofold(iph->saddr, iph->daddr,
550 skb_gro_len(skb), proto, 0);
551 }
552
553 /*
554 * Map a multicast IP onto multicast MAC for type ethernet.
555 */
556
ip_eth_mc_map(__be32 naddr,char * buf)557 static inline void ip_eth_mc_map(__be32 naddr, char *buf)
558 {
559 __u32 addr=ntohl(naddr);
560 buf[0]=0x01;
561 buf[1]=0x00;
562 buf[2]=0x5e;
563 buf[5]=addr&0xFF;
564 addr>>=8;
565 buf[4]=addr&0xFF;
566 addr>>=8;
567 buf[3]=addr&0x7F;
568 }
569
570 /*
571 * Map a multicast IP onto multicast MAC for type IP-over-InfiniBand.
572 * Leave P_Key as 0 to be filled in by driver.
573 */
574
ip_ib_mc_map(__be32 naddr,const unsigned char * broadcast,char * buf)575 static inline void ip_ib_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf)
576 {
577 __u32 addr;
578 unsigned char scope = broadcast[5] & 0xF;
579
580 buf[0] = 0; /* Reserved */
581 buf[1] = 0xff; /* Multicast QPN */
582 buf[2] = 0xff;
583 buf[3] = 0xff;
584 addr = ntohl(naddr);
585 buf[4] = 0xff;
586 buf[5] = 0x10 | scope; /* scope from broadcast address */
587 buf[6] = 0x40; /* IPv4 signature */
588 buf[7] = 0x1b;
589 buf[8] = broadcast[8]; /* P_Key */
590 buf[9] = broadcast[9];
591 buf[10] = 0;
592 buf[11] = 0;
593 buf[12] = 0;
594 buf[13] = 0;
595 buf[14] = 0;
596 buf[15] = 0;
597 buf[19] = addr & 0xff;
598 addr >>= 8;
599 buf[18] = addr & 0xff;
600 addr >>= 8;
601 buf[17] = addr & 0xff;
602 addr >>= 8;
603 buf[16] = addr & 0x0f;
604 }
605
ip_ipgre_mc_map(__be32 naddr,const unsigned char * broadcast,char * buf)606 static inline void ip_ipgre_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf)
607 {
608 if ((broadcast[0] | broadcast[1] | broadcast[2] | broadcast[3]) != 0)
609 memcpy(buf, broadcast, 4);
610 else
611 memcpy(buf, &naddr, sizeof(naddr));
612 }
613
614 #if IS_ENABLED(CONFIG_IPV6)
615 #include <linux/ipv6.h>
616 #endif
617
inet_reset_saddr(struct sock * sk)618 static __inline__ void inet_reset_saddr(struct sock *sk)
619 {
620 inet_sk(sk)->inet_rcv_saddr = inet_sk(sk)->inet_saddr = 0;
621 #if IS_ENABLED(CONFIG_IPV6)
622 if (sk->sk_family == PF_INET6) {
623 struct ipv6_pinfo *np = inet6_sk(sk);
624
625 memset(&np->saddr, 0, sizeof(np->saddr));
626 memset(&sk->sk_v6_rcv_saddr, 0, sizeof(sk->sk_v6_rcv_saddr));
627 }
628 #endif
629 }
630
631 #endif
632
ipv4_addr_hash(__be32 ip)633 static inline unsigned int ipv4_addr_hash(__be32 ip)
634 {
635 return (__force unsigned int) ip;
636 }
637
ipv4_portaddr_hash(const struct net * net,__be32 saddr,unsigned int port)638 static inline u32 ipv4_portaddr_hash(const struct net *net,
639 __be32 saddr,
640 unsigned int port)
641 {
642 return jhash_1word((__force u32)saddr, net_hash_mix(net)) ^ port;
643 }
644
645 bool ip_call_ra_chain(struct sk_buff *skb);
646
647 /*
648 * Functions provided by ip_fragment.c
649 */
650
651 enum ip_defrag_users {
652 IP_DEFRAG_LOCAL_DELIVER,
653 IP_DEFRAG_CALL_RA_CHAIN,
654 IP_DEFRAG_CONNTRACK_IN,
655 __IP_DEFRAG_CONNTRACK_IN_END = IP_DEFRAG_CONNTRACK_IN + USHRT_MAX,
656 IP_DEFRAG_CONNTRACK_OUT,
657 __IP_DEFRAG_CONNTRACK_OUT_END = IP_DEFRAG_CONNTRACK_OUT + USHRT_MAX,
658 IP_DEFRAG_CONNTRACK_BRIDGE_IN,
659 __IP_DEFRAG_CONNTRACK_BRIDGE_IN = IP_DEFRAG_CONNTRACK_BRIDGE_IN + USHRT_MAX,
660 IP_DEFRAG_VS_IN,
661 IP_DEFRAG_VS_OUT,
662 IP_DEFRAG_VS_FWD,
663 IP_DEFRAG_AF_PACKET,
664 IP_DEFRAG_MACVLAN,
665 };
666
667 /* Return true if the value of 'user' is between 'lower_bond'
668 * and 'upper_bond' inclusively.
669 */
ip_defrag_user_in_between(u32 user,enum ip_defrag_users lower_bond,enum ip_defrag_users upper_bond)670 static inline bool ip_defrag_user_in_between(u32 user,
671 enum ip_defrag_users lower_bond,
672 enum ip_defrag_users upper_bond)
673 {
674 return user >= lower_bond && user <= upper_bond;
675 }
676
677 int ip_defrag(struct net *net, struct sk_buff *skb, u32 user);
678 #ifdef CONFIG_INET
679 struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user);
680 #else
ip_check_defrag(struct net * net,struct sk_buff * skb,u32 user)681 static inline struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user)
682 {
683 return skb;
684 }
685 #endif
686
687 /*
688 * Functions provided by ip_forward.c
689 */
690
691 int ip_forward(struct sk_buff *skb);
692
693 /*
694 * Functions provided by ip_options.c
695 */
696
697 void ip_options_build(struct sk_buff *skb, struct ip_options *opt,
698 __be32 daddr, struct rtable *rt, int is_frag);
699
700 int __ip_options_echo(struct net *net, struct ip_options *dopt,
701 struct sk_buff *skb, const struct ip_options *sopt);
ip_options_echo(struct net * net,struct ip_options * dopt,struct sk_buff * skb)702 static inline int ip_options_echo(struct net *net, struct ip_options *dopt,
703 struct sk_buff *skb)
704 {
705 return __ip_options_echo(net, dopt, skb, &IPCB(skb)->opt);
706 }
707
708 void ip_options_fragment(struct sk_buff *skb);
709 int __ip_options_compile(struct net *net, struct ip_options *opt,
710 struct sk_buff *skb, __be32 *info);
711 int ip_options_compile(struct net *net, struct ip_options *opt,
712 struct sk_buff *skb);
713 int ip_options_get(struct net *net, struct ip_options_rcu **optp,
714 unsigned char *data, int optlen);
715 int ip_options_get_from_user(struct net *net, struct ip_options_rcu **optp,
716 unsigned char __user *data, int optlen);
717 void ip_options_undo(struct ip_options *opt);
718 void ip_forward_options(struct sk_buff *skb);
719 int ip_options_rcv_srr(struct sk_buff *skb, struct net_device *dev);
720
721 /*
722 * Functions provided by ip_sockglue.c
723 */
724
725 void ipv4_pktinfo_prepare(const struct sock *sk, struct sk_buff *skb);
726 void ip_cmsg_recv_offset(struct msghdr *msg, struct sock *sk,
727 struct sk_buff *skb, int tlen, int offset);
728 int ip_cmsg_send(struct sock *sk, struct msghdr *msg,
729 struct ipcm_cookie *ipc, bool allow_ipv6);
730 int ip_setsockopt(struct sock *sk, int level, int optname, char __user *optval,
731 unsigned int optlen);
732 int ip_getsockopt(struct sock *sk, int level, int optname, char __user *optval,
733 int __user *optlen);
734 int compat_ip_setsockopt(struct sock *sk, int level, int optname,
735 char __user *optval, unsigned int optlen);
736 int compat_ip_getsockopt(struct sock *sk, int level, int optname,
737 char __user *optval, int __user *optlen);
738 int ip_ra_control(struct sock *sk, unsigned char on,
739 void (*destructor)(struct sock *));
740
741 int ip_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len);
742 void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err, __be16 port,
743 u32 info, u8 *payload);
744 void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 dport,
745 u32 info);
746
ip_cmsg_recv(struct msghdr * msg,struct sk_buff * skb)747 static inline void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb)
748 {
749 ip_cmsg_recv_offset(msg, skb->sk, skb, 0, 0);
750 }
751
752 bool icmp_global_allow(void);
753 extern int sysctl_icmp_msgs_per_sec;
754 extern int sysctl_icmp_msgs_burst;
755
756 #ifdef CONFIG_PROC_FS
757 int ip_misc_proc_init(void);
758 #endif
759
760 int rtm_getroute_parse_ip_proto(struct nlattr *attr, u8 *ip_proto, u8 family,
761 struct netlink_ext_ack *extack);
762
763 #endif /* _IP_H */
764
