forked from torvalds/linux
-
Notifications
You must be signed in to change notification settings - Fork 4
/
ping.c
1211 lines (1023 loc) · 28.8 KB
/
ping.c
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* INET An implementation of the TCP/IP protocol suite for the LINUX
* operating system. INET is implemented using the BSD Socket
* interface as the means of communication with the user level.
*
* "Ping" sockets
*
* Based on ipv4/udp.c code.
*
* Authors: Vasiliy Kulikov / Openwall (for Linux 2.6),
* Pavel Kankovsky (for Linux 2.4.32)
*
* Pavel gave all rights to bugs to Vasiliy,
* none of the bugs are Pavel's now.
*/
#include <linux/uaccess.h>
#include <linux/types.h>
#include <linux/fcntl.h>
#include <linux/socket.h>
#include <linux/sockios.h>
#include <linux/in.h>
#include <linux/errno.h>
#include <linux/timer.h>
#include <linux/mm.h>
#include <linux/inet.h>
#include <linux/netdevice.h>
#include <net/snmp.h>
#include <net/ip.h>
#include <net/icmp.h>
#include <net/protocol.h>
#include <linux/skbuff.h>
#include <linux/proc_fs.h>
#include <linux/export.h>
#include <linux/bpf-cgroup.h>
#include <net/sock.h>
#include <net/ping.h>
#include <net/udp.h>
#include <net/route.h>
#include <net/inet_common.h>
#include <net/checksum.h>
#if IS_ENABLED(CONFIG_IPV6)
#include <linux/in6.h>
#include <linux/icmpv6.h>
#include <net/addrconf.h>
#include <net/ipv6.h>
#include <net/transp_v6.h>
#endif
#define ping_portaddr_for_each_entry(__sk, node, list) \
hlist_nulls_for_each_entry(__sk, node, list, sk_nulls_node)
#define ping_portaddr_for_each_entry_rcu(__sk, node, list) \
hlist_nulls_for_each_entry_rcu(__sk, node, list, sk_nulls_node)
struct ping_table {
struct hlist_nulls_head hash[PING_HTABLE_SIZE];
spinlock_t lock;
};
static struct ping_table ping_table;
struct pingv6_ops pingv6_ops;
EXPORT_SYMBOL_GPL(pingv6_ops);
static u16 ping_port_rover;
static inline u32 ping_hashfn(const struct net *net, u32 num, u32 mask)
{
u32 res = (num + net_hash_mix(net)) & mask;
pr_debug("hash(%u) = %u\n", num, res);
return res;
}
EXPORT_SYMBOL_GPL(ping_hash);
static inline struct hlist_nulls_head *ping_hashslot(struct ping_table *table,
struct net *net, unsigned int num)
{
return &table->hash[ping_hashfn(net, num, PING_HTABLE_MASK)];
}
int ping_get_port(struct sock *sk, unsigned short ident)
{
struct hlist_nulls_node *node;
struct hlist_nulls_head *hlist;
struct inet_sock *isk, *isk2;
struct sock *sk2 = NULL;
isk = inet_sk(sk);
spin_lock(&ping_table.lock);
if (ident == 0) {
u32 i;
u16 result = ping_port_rover + 1;
for (i = 0; i < (1L << 16); i++, result++) {
if (!result)
result++; /* avoid zero */
hlist = ping_hashslot(&ping_table, sock_net(sk),
result);
ping_portaddr_for_each_entry(sk2, node, hlist) {
isk2 = inet_sk(sk2);
if (isk2->inet_num == result)
goto next_port;
}
/* found */
ping_port_rover = ident = result;
break;
next_port:
;
}
if (i >= (1L << 16))
goto fail;
} else {
hlist = ping_hashslot(&ping_table, sock_net(sk), ident);
ping_portaddr_for_each_entry(sk2, node, hlist) {
isk2 = inet_sk(sk2);
/* BUG? Why is this reuse and not reuseaddr? ping.c
* doesn't turn off SO_REUSEADDR, and it doesn't expect
* that other ping processes can steal its packets.
*/
if ((isk2->inet_num == ident) &&
(sk2 != sk) &&
(!sk2->sk_reuse || !sk->sk_reuse))
goto fail;
}
}
pr_debug("found port/ident = %d\n", ident);
isk->inet_num = ident;
if (sk_unhashed(sk)) {
pr_debug("was not hashed\n");
sock_hold(sk);
sock_set_flag(sk, SOCK_RCU_FREE);
hlist_nulls_add_head_rcu(&sk->sk_nulls_node, hlist);
sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
}
spin_unlock(&ping_table.lock);
return 0;
fail:
spin_unlock(&ping_table.lock);
return -EADDRINUSE;
}
EXPORT_SYMBOL_GPL(ping_get_port);
int ping_hash(struct sock *sk)
{
pr_debug("ping_hash(sk->port=%u)\n", inet_sk(sk)->inet_num);
BUG(); /* "Please do not press this button again." */
return 0;
}
void ping_unhash(struct sock *sk)
{
struct inet_sock *isk = inet_sk(sk);
pr_debug("ping_unhash(isk=%p,isk->num=%u)\n", isk, isk->inet_num);
spin_lock(&ping_table.lock);
if (sk_hashed(sk)) {
hlist_nulls_del_init_rcu(&sk->sk_nulls_node);
sock_put(sk);
isk->inet_num = 0;
isk->inet_sport = 0;
sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
}
spin_unlock(&ping_table.lock);
}
EXPORT_SYMBOL_GPL(ping_unhash);
/* Called under rcu_read_lock() */
static struct sock *ping_lookup(struct net *net, struct sk_buff *skb, u16 ident)
{
struct hlist_nulls_head *hslot = ping_hashslot(&ping_table, net, ident);
struct sock *sk = NULL;
struct inet_sock *isk;
struct hlist_nulls_node *hnode;
int dif, sdif;
if (skb->protocol == htons(ETH_P_IP)) {
dif = inet_iif(skb);
sdif = inet_sdif(skb);
pr_debug("try to find: num = %d, daddr = %pI4, dif = %d\n",
(int)ident, &ip_hdr(skb)->daddr, dif);
#if IS_ENABLED(CONFIG_IPV6)
} else if (skb->protocol == htons(ETH_P_IPV6)) {
dif = inet6_iif(skb);
sdif = inet6_sdif(skb);
pr_debug("try to find: num = %d, daddr = %pI6c, dif = %d\n",
(int)ident, &ipv6_hdr(skb)->daddr, dif);
#endif
} else {
return NULL;
}
ping_portaddr_for_each_entry_rcu(sk, hnode, hslot) {
isk = inet_sk(sk);
pr_debug("iterate\n");
if (isk->inet_num != ident)
continue;
if (skb->protocol == htons(ETH_P_IP) &&
sk->sk_family == AF_INET) {
pr_debug("found: %p: num=%d, daddr=%pI4, dif=%d\n", sk,
(int) isk->inet_num, &isk->inet_rcv_saddr,
sk->sk_bound_dev_if);
if (isk->inet_rcv_saddr &&
isk->inet_rcv_saddr != ip_hdr(skb)->daddr)
continue;
#if IS_ENABLED(CONFIG_IPV6)
} else if (skb->protocol == htons(ETH_P_IPV6) &&
sk->sk_family == AF_INET6) {
pr_debug("found: %p: num=%d, daddr=%pI6c, dif=%d\n", sk,
(int) isk->inet_num,
&sk->sk_v6_rcv_saddr,
sk->sk_bound_dev_if);
if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr) &&
!ipv6_addr_equal(&sk->sk_v6_rcv_saddr,
&ipv6_hdr(skb)->daddr))
continue;
#endif
} else {
continue;
}
if (sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif &&
sk->sk_bound_dev_if != sdif)
continue;
goto exit;
}
sk = NULL;
exit:
return sk;
}
static void inet_get_ping_group_range_net(struct net *net, kgid_t *low,
kgid_t *high)
{
kgid_t *data = net->ipv4.ping_group_range.range;
unsigned int seq;
do {
seq = read_seqbegin(&net->ipv4.ping_group_range.lock);
*low = data[0];
*high = data[1];
} while (read_seqretry(&net->ipv4.ping_group_range.lock, seq));
}
int ping_init_sock(struct sock *sk)
{
struct net *net = sock_net(sk);
kgid_t group = current_egid();
struct group_info *group_info;
int i;
kgid_t low, high;
int ret = 0;
if (sk->sk_family == AF_INET6)
sk->sk_ipv6only = 1;
inet_get_ping_group_range_net(net, &low, &high);
if (gid_lte(low, group) && gid_lte(group, high))
return 0;
group_info = get_current_groups();
for (i = 0; i < group_info->ngroups; i++) {
kgid_t gid = group_info->gid[i];
if (gid_lte(low, gid) && gid_lte(gid, high))
goto out_release_group;
}
ret = -EACCES;
out_release_group:
put_group_info(group_info);
return ret;
}
EXPORT_SYMBOL_GPL(ping_init_sock);
void ping_close(struct sock *sk, long timeout)
{
pr_debug("ping_close(sk=%p,sk->num=%u)\n",
inet_sk(sk), inet_sk(sk)->inet_num);
pr_debug("isk->refcnt = %d\n", refcount_read(&sk->sk_refcnt));
sk_common_release(sk);
}
EXPORT_SYMBOL_GPL(ping_close);
static int ping_pre_connect(struct sock *sk, struct sockaddr *uaddr,
int addr_len)
{
/* This check is replicated from __ip4_datagram_connect() and
* intended to prevent BPF program called below from accessing bytes
* that are out of the bound specified by user in addr_len.
*/
if (addr_len < sizeof(struct sockaddr_in))
return -EINVAL;
return BPF_CGROUP_RUN_PROG_INET4_CONNECT_LOCK(sk, uaddr);
}
/* Checks the bind address and possibly modifies sk->sk_bound_dev_if. */
static int ping_check_bind_addr(struct sock *sk, struct inet_sock *isk,
struct sockaddr *uaddr, int addr_len)
{
struct net *net = sock_net(sk);
if (sk->sk_family == AF_INET) {
struct sockaddr_in *addr = (struct sockaddr_in *) uaddr;
u32 tb_id = RT_TABLE_LOCAL;
int chk_addr_ret;
if (addr_len < sizeof(*addr))
return -EINVAL;
if (addr->sin_family != AF_INET &&
!(addr->sin_family == AF_UNSPEC &&
addr->sin_addr.s_addr == htonl(INADDR_ANY)))
return -EAFNOSUPPORT;
pr_debug("ping_check_bind_addr(sk=%p,addr=%pI4,port=%d)\n",
sk, &addr->sin_addr.s_addr, ntohs(addr->sin_port));
if (addr->sin_addr.s_addr == htonl(INADDR_ANY))
return 0;
tb_id = l3mdev_fib_table_by_index(net, sk->sk_bound_dev_if) ? : tb_id;
chk_addr_ret = inet_addr_type_table(net, addr->sin_addr.s_addr, tb_id);
if (chk_addr_ret == RTN_MULTICAST ||
chk_addr_ret == RTN_BROADCAST ||
(chk_addr_ret != RTN_LOCAL &&
!inet_can_nonlocal_bind(net, isk)))
return -EADDRNOTAVAIL;
#if IS_ENABLED(CONFIG_IPV6)
} else if (sk->sk_family == AF_INET6) {
struct sockaddr_in6 *addr = (struct sockaddr_in6 *) uaddr;
int addr_type, scoped, has_addr;
struct net_device *dev = NULL;
if (addr_len < sizeof(*addr))
return -EINVAL;
if (addr->sin6_family != AF_INET6)
return -EAFNOSUPPORT;
pr_debug("ping_check_bind_addr(sk=%p,addr=%pI6c,port=%d)\n",
sk, addr->sin6_addr.s6_addr, ntohs(addr->sin6_port));
addr_type = ipv6_addr_type(&addr->sin6_addr);
scoped = __ipv6_addr_needs_scope_id(addr_type);
if ((addr_type != IPV6_ADDR_ANY &&
!(addr_type & IPV6_ADDR_UNICAST)) ||
(scoped && !addr->sin6_scope_id))
return -EINVAL;
rcu_read_lock();
if (addr->sin6_scope_id) {
dev = dev_get_by_index_rcu(net, addr->sin6_scope_id);
if (!dev) {
rcu_read_unlock();
return -ENODEV;
}
}
if (!dev && sk->sk_bound_dev_if) {
dev = dev_get_by_index_rcu(net, sk->sk_bound_dev_if);
if (!dev) {
rcu_read_unlock();
return -ENODEV;
}
}
has_addr = pingv6_ops.ipv6_chk_addr(net, &addr->sin6_addr, dev,
scoped);
rcu_read_unlock();
if (!(ipv6_can_nonlocal_bind(net, isk) || has_addr ||
addr_type == IPV6_ADDR_ANY))
return -EADDRNOTAVAIL;
if (scoped)
sk->sk_bound_dev_if = addr->sin6_scope_id;
#endif
} else {
return -EAFNOSUPPORT;
}
return 0;
}
static void ping_set_saddr(struct sock *sk, struct sockaddr *saddr)
{
if (saddr->sa_family == AF_INET) {
struct inet_sock *isk = inet_sk(sk);
struct sockaddr_in *addr = (struct sockaddr_in *) saddr;
isk->inet_rcv_saddr = isk->inet_saddr = addr->sin_addr.s_addr;
#if IS_ENABLED(CONFIG_IPV6)
} else if (saddr->sa_family == AF_INET6) {
struct sockaddr_in6 *addr = (struct sockaddr_in6 *) saddr;
struct ipv6_pinfo *np = inet6_sk(sk);
sk->sk_v6_rcv_saddr = np->saddr = addr->sin6_addr;
#endif
}
}
/*
* We need our own bind because there are no privileged id's == local ports.
* Moreover, we don't allow binding to multi- and broadcast addresses.
*/
int ping_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len)
{
struct inet_sock *isk = inet_sk(sk);
unsigned short snum;
int err;
int dif = sk->sk_bound_dev_if;
err = ping_check_bind_addr(sk, isk, uaddr, addr_len);
if (err)
return err;
lock_sock(sk);
err = -EINVAL;
if (isk->inet_num != 0)
goto out;
err = -EADDRINUSE;
snum = ntohs(((struct sockaddr_in *)uaddr)->sin_port);
if (ping_get_port(sk, snum) != 0) {
/* Restore possibly modified sk->sk_bound_dev_if by ping_check_bind_addr(). */
sk->sk_bound_dev_if = dif;
goto out;
}
ping_set_saddr(sk, uaddr);
pr_debug("after bind(): num = %hu, dif = %d\n",
isk->inet_num,
sk->sk_bound_dev_if);
err = 0;
if (sk->sk_family == AF_INET && isk->inet_rcv_saddr)
sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
#if IS_ENABLED(CONFIG_IPV6)
if (sk->sk_family == AF_INET6 && !ipv6_addr_any(&sk->sk_v6_rcv_saddr))
sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
#endif
if (snum)
sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
isk->inet_sport = htons(isk->inet_num);
isk->inet_daddr = 0;
isk->inet_dport = 0;
#if IS_ENABLED(CONFIG_IPV6)
if (sk->sk_family == AF_INET6)
memset(&sk->sk_v6_daddr, 0, sizeof(sk->sk_v6_daddr));
#endif
sk_dst_reset(sk);
out:
release_sock(sk);
pr_debug("ping_v4_bind -> %d\n", err);
return err;
}
EXPORT_SYMBOL_GPL(ping_bind);
/*
* Is this a supported type of ICMP message?
*/
static inline int ping_supported(int family, int type, int code)
{
return (family == AF_INET && type == ICMP_ECHO && code == 0) ||
(family == AF_INET && type == ICMP_EXT_ECHO && code == 0) ||
(family == AF_INET6 && type == ICMPV6_ECHO_REQUEST && code == 0) ||
(family == AF_INET6 && type == ICMPV6_EXT_ECHO_REQUEST && code == 0);
}
/*
* This routine is called by the ICMP module when it gets some
* sort of error condition.
*/
void ping_err(struct sk_buff *skb, int offset, u32 info)
{
int family;
struct icmphdr *icmph;
struct inet_sock *inet_sock;
int type;
int code;
struct net *net = dev_net(skb->dev);
struct sock *sk;
int harderr;
int err;
if (skb->protocol == htons(ETH_P_IP)) {
family = AF_INET;
type = icmp_hdr(skb)->type;
code = icmp_hdr(skb)->code;
icmph = (struct icmphdr *)(skb->data + offset);
} else if (skb->protocol == htons(ETH_P_IPV6)) {
family = AF_INET6;
type = icmp6_hdr(skb)->icmp6_type;
code = icmp6_hdr(skb)->icmp6_code;
icmph = (struct icmphdr *) (skb->data + offset);
} else {
BUG();
}
/* We assume the packet has already been checked by icmp_unreach */
if (!ping_supported(family, icmph->type, icmph->code))
return;
pr_debug("ping_err(proto=0x%x,type=%d,code=%d,id=%04x,seq=%04x)\n",
skb->protocol, type, code, ntohs(icmph->un.echo.id),
ntohs(icmph->un.echo.sequence));
sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id));
if (!sk) {
pr_debug("no socket, dropping\n");
return; /* No socket for error */
}
pr_debug("err on socket %p\n", sk);
err = 0;
harderr = 0;
inet_sock = inet_sk(sk);
if (skb->protocol == htons(ETH_P_IP)) {
switch (type) {
default:
case ICMP_TIME_EXCEEDED:
err = EHOSTUNREACH;
break;
case ICMP_SOURCE_QUENCH:
/* This is not a real error but ping wants to see it.
* Report it with some fake errno.
*/
err = EREMOTEIO;
break;
case ICMP_PARAMETERPROB:
err = EPROTO;
harderr = 1;
break;
case ICMP_DEST_UNREACH:
if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */
ipv4_sk_update_pmtu(skb, sk, info);
if (inet_sock->pmtudisc != IP_PMTUDISC_DONT) {
err = EMSGSIZE;
harderr = 1;
break;
}
goto out;
}
err = EHOSTUNREACH;
if (code <= NR_ICMP_UNREACH) {
harderr = icmp_err_convert[code].fatal;
err = icmp_err_convert[code].errno;
}
break;
case ICMP_REDIRECT:
/* See ICMP_SOURCE_QUENCH */
ipv4_sk_redirect(skb, sk);
err = EREMOTEIO;
break;
}
#if IS_ENABLED(CONFIG_IPV6)
} else if (skb->protocol == htons(ETH_P_IPV6)) {
harderr = pingv6_ops.icmpv6_err_convert(type, code, &err);
#endif
}
/*
* RFC1122: OK. Passes ICMP errors back to application, as per
* 4.1.3.3.
*/
if ((family == AF_INET && !inet_sock->recverr) ||
(family == AF_INET6 && !inet6_sk(sk)->recverr)) {
if (!harderr || sk->sk_state != TCP_ESTABLISHED)
goto out;
} else {
if (family == AF_INET) {
ip_icmp_error(sk, skb, err, 0 /* no remote port */,
info, (u8 *)icmph);
#if IS_ENABLED(CONFIG_IPV6)
} else if (family == AF_INET6) {
pingv6_ops.ipv6_icmp_error(sk, skb, err, 0,
info, (u8 *)icmph);
#endif
}
}
sk->sk_err = err;
sk_error_report(sk);
out:
return;
}
EXPORT_SYMBOL_GPL(ping_err);
/*
* Copy and checksum an ICMP Echo packet from user space into a buffer
* starting from the payload.
*/
int ping_getfrag(void *from, char *to,
int offset, int fraglen, int odd, struct sk_buff *skb)
{
struct pingfakehdr *pfh = from;
if (!csum_and_copy_from_iter_full(to, fraglen, &pfh->wcheck,
&pfh->msg->msg_iter))
return -EFAULT;
#if IS_ENABLED(CONFIG_IPV6)
/* For IPv6, checksum each skb as we go along, as expected by
* icmpv6_push_pending_frames. For IPv4, accumulate the checksum in
* wcheck, it will be finalized in ping_v4_push_pending_frames.
*/
if (pfh->family == AF_INET6) {
skb->csum = csum_block_add(skb->csum, pfh->wcheck, odd);
skb->ip_summed = CHECKSUM_NONE;
pfh->wcheck = 0;
}
#endif
return 0;
}
EXPORT_SYMBOL_GPL(ping_getfrag);
static int ping_v4_push_pending_frames(struct sock *sk, struct pingfakehdr *pfh,
struct flowi4 *fl4)
{
struct sk_buff *skb = skb_peek(&sk->sk_write_queue);
if (!skb)
return 0;
pfh->wcheck = csum_partial((char *)&pfh->icmph,
sizeof(struct icmphdr), pfh->wcheck);
pfh->icmph.checksum = csum_fold(pfh->wcheck);
memcpy(icmp_hdr(skb), &pfh->icmph, sizeof(struct icmphdr));
skb->ip_summed = CHECKSUM_NONE;
return ip_push_pending_frames(sk, fl4);
}
int ping_common_sendmsg(int family, struct msghdr *msg, size_t len,
void *user_icmph, size_t icmph_len)
{
u8 type, code;
if (len > 0xFFFF)
return -EMSGSIZE;
/* Must have at least a full ICMP header. */
if (len < icmph_len)
return -EINVAL;
/*
* Check the flags.
*/
/* Mirror BSD error message compatibility */
if (msg->msg_flags & MSG_OOB)
return -EOPNOTSUPP;
/*
* Fetch the ICMP header provided by the userland.
* iovec is modified! The ICMP header is consumed.
*/
if (memcpy_from_msg(user_icmph, msg, icmph_len))
return -EFAULT;
if (family == AF_INET) {
type = ((struct icmphdr *) user_icmph)->type;
code = ((struct icmphdr *) user_icmph)->code;
#if IS_ENABLED(CONFIG_IPV6)
} else if (family == AF_INET6) {
type = ((struct icmp6hdr *) user_icmph)->icmp6_type;
code = ((struct icmp6hdr *) user_icmph)->icmp6_code;
#endif
} else {
BUG();
}
if (!ping_supported(family, type, code))
return -EINVAL;
return 0;
}
EXPORT_SYMBOL_GPL(ping_common_sendmsg);
static int ping_v4_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
{
struct net *net = sock_net(sk);
struct flowi4 fl4;
struct inet_sock *inet = inet_sk(sk);
struct ipcm_cookie ipc;
struct icmphdr user_icmph;
struct pingfakehdr pfh;
struct rtable *rt = NULL;
struct ip_options_data opt_copy;
int free = 0;
__be32 saddr, daddr, faddr;
u8 tos;
int err;
pr_debug("ping_v4_sendmsg(sk=%p,sk->num=%u)\n", inet, inet->inet_num);
err = ping_common_sendmsg(AF_INET, msg, len, &user_icmph,
sizeof(user_icmph));
if (err)
return err;
/*
* Get and verify the address.
*/
if (msg->msg_name) {
DECLARE_SOCKADDR(struct sockaddr_in *, usin, msg->msg_name);
if (msg->msg_namelen < sizeof(*usin))
return -EINVAL;
if (usin->sin_family != AF_INET)
return -EAFNOSUPPORT;
daddr = usin->sin_addr.s_addr;
/* no remote port */
} else {
if (sk->sk_state != TCP_ESTABLISHED)
return -EDESTADDRREQ;
daddr = inet->inet_daddr;
/* no remote port */
}
ipcm_init_sk(&ipc, inet);
if (msg->msg_controllen) {
err = ip_cmsg_send(sk, msg, &ipc, false);
if (unlikely(err)) {
kfree(ipc.opt);
return err;
}
if (ipc.opt)
free = 1;
}
if (!ipc.opt) {
struct ip_options_rcu *inet_opt;
rcu_read_lock();
inet_opt = rcu_dereference(inet->inet_opt);
if (inet_opt) {
memcpy(&opt_copy, inet_opt,
sizeof(*inet_opt) + inet_opt->opt.optlen);
ipc.opt = &opt_copy.opt;
}
rcu_read_unlock();
}
saddr = ipc.addr;
ipc.addr = faddr = daddr;
if (ipc.opt && ipc.opt->opt.srr) {
if (!daddr) {
err = -EINVAL;
goto out_free;
}
faddr = ipc.opt->opt.faddr;
}
tos = get_rttos(&ipc, inet);
if (sock_flag(sk, SOCK_LOCALROUTE) ||
(msg->msg_flags & MSG_DONTROUTE) ||
(ipc.opt && ipc.opt->opt.is_strictroute)) {
tos |= RTO_ONLINK;
}
if (ipv4_is_multicast(daddr)) {
if (!ipc.oif || netif_index_is_l3_master(sock_net(sk), ipc.oif))
ipc.oif = inet->mc_index;
if (!saddr)
saddr = inet->mc_addr;
} else if (!ipc.oif)
ipc.oif = inet->uc_index;
flowi4_init_output(&fl4, ipc.oif, ipc.sockc.mark, tos,
RT_SCOPE_UNIVERSE, sk->sk_protocol,
inet_sk_flowi_flags(sk), faddr, saddr, 0, 0,
sk->sk_uid);
fl4.fl4_icmp_type = user_icmph.type;
fl4.fl4_icmp_code = user_icmph.code;
security_sk_classify_flow(sk, flowi4_to_flowi_common(&fl4));
rt = ip_route_output_flow(net, &fl4, sk);
if (IS_ERR(rt)) {
err = PTR_ERR(rt);
rt = NULL;
if (err == -ENETUNREACH)
IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES);
goto out;
}
err = -EACCES;
if ((rt->rt_flags & RTCF_BROADCAST) &&
!sock_flag(sk, SOCK_BROADCAST))
goto out;
if (msg->msg_flags & MSG_CONFIRM)
goto do_confirm;
back_from_confirm:
if (!ipc.addr)
ipc.addr = fl4.daddr;
lock_sock(sk);
pfh.icmph.type = user_icmph.type; /* already checked */
pfh.icmph.code = user_icmph.code; /* ditto */
pfh.icmph.checksum = 0;
pfh.icmph.un.echo.id = inet->inet_sport;
pfh.icmph.un.echo.sequence = user_icmph.un.echo.sequence;
pfh.msg = msg;
pfh.wcheck = 0;
pfh.family = AF_INET;
err = ip_append_data(sk, &fl4, ping_getfrag, &pfh, len,
sizeof(struct icmphdr), &ipc, &rt,
msg->msg_flags);
if (err)
ip_flush_pending_frames(sk);
else
err = ping_v4_push_pending_frames(sk, &pfh, &fl4);
release_sock(sk);
out:
ip_rt_put(rt);
out_free:
if (free)
kfree(ipc.opt);
if (!err) {
icmp_out_count(sock_net(sk), user_icmph.type);
return len;
}
return err;
do_confirm:
if (msg->msg_flags & MSG_PROBE)
dst_confirm_neigh(&rt->dst, &fl4.daddr);
if (!(msg->msg_flags & MSG_PROBE) || len)
goto back_from_confirm;
err = 0;
goto out;
}
int ping_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int flags,
int *addr_len)
{
struct inet_sock *isk = inet_sk(sk);
int family = sk->sk_family;
struct sk_buff *skb;
int copied, err;
pr_debug("ping_recvmsg(sk=%p,sk->num=%u)\n", isk, isk->inet_num);
err = -EOPNOTSUPP;
if (flags & MSG_OOB)
goto out;
if (flags & MSG_ERRQUEUE)
return inet_recv_error(sk, msg, len, addr_len);
skb = skb_recv_datagram(sk, flags, &err);
if (!skb)
goto out;
copied = skb->len;
if (copied > len) {
msg->msg_flags |= MSG_TRUNC;
copied = len;
}
/* Don't bother checking the checksum */
err = skb_copy_datagram_msg(skb, 0, msg, copied);
if (err)
goto done;
sock_recv_timestamp(msg, sk, skb);
/* Copy the address and add cmsg data. */
if (family == AF_INET) {
DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name);
if (sin) {
sin->sin_family = AF_INET;
sin->sin_port = 0 /* skb->h.uh->source */;
sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
*addr_len = sizeof(*sin);
}
if (isk->cmsg_flags)
ip_cmsg_recv(msg, skb);
#if IS_ENABLED(CONFIG_IPV6)
} else if (family == AF_INET6) {
struct ipv6_pinfo *np = inet6_sk(sk);
struct ipv6hdr *ip6 = ipv6_hdr(skb);
DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name);
if (sin6) {
sin6->sin6_family = AF_INET6;
sin6->sin6_port = 0;
sin6->sin6_addr = ip6->saddr;
sin6->sin6_flowinfo = 0;
if (np->sndflow)
sin6->sin6_flowinfo = ip6_flowinfo(ip6);
sin6->sin6_scope_id =
ipv6_iface_scope_id(&sin6->sin6_addr,
inet6_iif(skb));
*addr_len = sizeof(*sin6);
}
if (inet6_sk(sk)->rxopt.all)
pingv6_ops.ip6_datagram_recv_common_ctl(sk, msg, skb);
if (skb->protocol == htons(ETH_P_IPV6) &&
inet6_sk(sk)->rxopt.all)
pingv6_ops.ip6_datagram_recv_specific_ctl(sk, msg, skb);
else if (skb->protocol == htons(ETH_P_IP) && isk->cmsg_flags)
ip_cmsg_recv(msg, skb);
#endif
} else {
BUG();
}
err = copied;
done:
skb_free_datagram(sk, skb);
out:
pr_debug("ping_recvmsg -> %d\n", err);
return err;
}
EXPORT_SYMBOL_GPL(ping_recvmsg);
static enum skb_drop_reason __ping_queue_rcv_skb(struct sock *sk,
struct sk_buff *skb)
{
enum skb_drop_reason reason;
pr_debug("ping_queue_rcv_skb(sk=%p,sk->num=%d,skb=%p)\n",
inet_sk(sk), inet_sk(sk)->inet_num, skb);
if (sock_queue_rcv_skb_reason(sk, skb, &reason) < 0) {
kfree_skb_reason(skb, reason);
pr_debug("ping_queue_rcv_skb -> failed\n");
return reason;
}
return SKB_NOT_DROPPED_YET;
}
int ping_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
{
return __ping_queue_rcv_skb(sk, skb) ? -1 : 0;
}
EXPORT_SYMBOL_GPL(ping_queue_rcv_skb);
/*
* All we need to do is get the socket.
*/
enum skb_drop_reason ping_rcv(struct sk_buff *skb)
{
enum skb_drop_reason reason = SKB_DROP_REASON_NO_SOCKET;
struct sock *sk;
struct net *net = dev_net(skb->dev);
struct icmphdr *icmph = icmp_hdr(skb);
/* We assume the packet has already been checked by icmp_rcv */
pr_debug("ping_rcv(skb=%p,id=%04x,seq=%04x)\n",
skb, ntohs(icmph->un.echo.id), ntohs(icmph->un.echo.sequence));
/* Push ICMP header back */
skb_push(skb, skb->data - (u8 *)icmph);
sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id));
if (sk) {
struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);