forked from FRRouting/frr
-
Notifications
You must be signed in to change notification settings - Fork 0
/
Copy patheigrp_packet.c
1361 lines (1131 loc) · 35.3 KB
/
eigrp_packet.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
/*
* EIGRP General Sending and Receiving of EIGRP Packets.
* Copyright (C) 2013-2014
* Authors:
* Donnie Savage
* Jan Janovic
* Matej Perina
* Peter Orsag
* Peter Paluch
*
* This file is part of GNU Zebra.
*
* GNU Zebra is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2, or (at your option) any
* later version.
*
* GNU Zebra is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; see the file COPYING; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <zebra.h>
#include "thread.h"
#include "memory.h"
#include "linklist.h"
#include "vty.h"
#include "keychain.h"
#include "prefix.h"
#include "if.h"
#include "table.h"
#include "sockunion.h"
#include "stream.h"
#include "log.h"
#include "sockopt.h"
#include "checksum.h"
#include "md5.h"
#include "sha256.h"
#include "lib_errors.h"
#include "eigrpd/eigrp_structs.h"
#include "eigrpd/eigrpd.h"
#include "eigrpd/eigrp_interface.h"
#include "eigrpd/eigrp_neighbor.h"
#include "eigrpd/eigrp_packet.h"
#include "eigrpd/eigrp_zebra.h"
#include "eigrpd/eigrp_vty.h"
#include "eigrpd/eigrp_dump.h"
#include "eigrpd/eigrp_macros.h"
#include "eigrpd/eigrp_network.h"
#include "eigrpd/eigrp_topology.h"
#include "eigrpd/eigrp_fsm.h"
#include "eigrpd/eigrp_memory.h"
#include "eigrpd/eigrp_errors.h"
/* Packet Type String. */
const struct message eigrp_packet_type_str[] = {
{EIGRP_OPC_UPDATE, "Update"},
{EIGRP_OPC_REQUEST, "Request"},
{EIGRP_OPC_QUERY, "Query"},
{EIGRP_OPC_REPLY, "Reply"},
{EIGRP_OPC_HELLO, "Hello"},
{EIGRP_OPC_IPXSAP, "IPX-SAP"},
{EIGRP_OPC_PROBE, "Probe"},
{EIGRP_OPC_ACK, "Ack"},
{EIGRP_OPC_SIAQUERY, "SIAQuery"},
{EIGRP_OPC_SIAREPLY, "SIAReply"},
{0}};
static unsigned char zeropad[16] = {0};
/* Forward function reference*/
static struct stream *eigrp_recv_packet(struct eigrp *eigrp, int fd,
struct interface **ifp,
struct stream *s);
static int eigrp_verify_header(struct stream *s, struct eigrp_interface *ei,
struct ip *addr, struct eigrp_header *header);
static int eigrp_check_network_mask(struct eigrp_interface *ei,
struct in_addr mask);
static int eigrp_retrans_count_exceeded(struct eigrp_packet *ep,
struct eigrp_neighbor *nbr)
{
return 1;
}
int eigrp_make_md5_digest(struct eigrp_interface *ei, struct stream *s,
uint8_t flags)
{
struct key *key = NULL;
struct keychain *keychain;
unsigned char digest[EIGRP_AUTH_TYPE_MD5_LEN];
MD5_CTX ctx;
uint8_t *ibuf;
size_t backup_get, backup_end;
struct TLV_MD5_Authentication_Type *auth_TLV;
ibuf = s->data;
backup_end = s->endp;
backup_get = s->getp;
auth_TLV = eigrp_authTLV_MD5_new();
stream_set_getp(s, EIGRP_HEADER_LEN);
stream_get(auth_TLV, s, EIGRP_AUTH_MD5_TLV_SIZE);
stream_set_getp(s, backup_get);
keychain = keychain_lookup(ei->params.auth_keychain);
if (keychain)
key = key_lookup_for_send(keychain);
else {
eigrp_authTLV_MD5_free(auth_TLV);
return EIGRP_AUTH_TYPE_NONE;
}
memset(&ctx, 0, sizeof(ctx));
MD5Init(&ctx);
/* Generate a digest. Each situation needs different handling */
if (flags & EIGRP_AUTH_BASIC_HELLO_FLAG) {
MD5Update(&ctx, ibuf, EIGRP_MD5_BASIC_COMPUTE);
MD5Update(&ctx, key->string, strlen(key->string));
if (strlen(key->string) < 16)
MD5Update(&ctx, zeropad, 16 - strlen(key->string));
} else if (flags & EIGRP_AUTH_UPDATE_INIT_FLAG) {
MD5Update(&ctx, ibuf, EIGRP_MD5_UPDATE_INIT_COMPUTE);
} else if (flags & EIGRP_AUTH_UPDATE_FLAG) {
MD5Update(&ctx, ibuf, EIGRP_MD5_BASIC_COMPUTE);
MD5Update(&ctx, key->string, strlen(key->string));
if (strlen(key->string) < 16)
MD5Update(&ctx, zeropad, 16 - strlen(key->string));
if (backup_end > (EIGRP_HEADER_LEN + EIGRP_AUTH_MD5_TLV_SIZE)) {
MD5Update(&ctx,
ibuf + (EIGRP_HEADER_LEN
+ EIGRP_AUTH_MD5_TLV_SIZE),
backup_end - 20
- (EIGRP_HEADER_LEN
+ EIGRP_AUTH_MD5_TLV_SIZE));
}
}
MD5Final(digest, &ctx);
/* Append md5 digest to the end of the stream. */
memcpy(auth_TLV->digest, digest, EIGRP_AUTH_TYPE_MD5_LEN);
stream_set_endp(s, EIGRP_HEADER_LEN);
stream_put(s, auth_TLV, EIGRP_AUTH_MD5_TLV_SIZE);
stream_set_endp(s, backup_end);
eigrp_authTLV_MD5_free(auth_TLV);
return EIGRP_AUTH_TYPE_MD5_LEN;
}
int eigrp_check_md5_digest(struct stream *s,
struct TLV_MD5_Authentication_Type *authTLV,
struct eigrp_neighbor *nbr, uint8_t flags)
{
MD5_CTX ctx;
unsigned char digest[EIGRP_AUTH_TYPE_MD5_LEN];
unsigned char orig[EIGRP_AUTH_TYPE_MD5_LEN];
struct key *key = NULL;
struct keychain *keychain;
uint8_t *ibuf;
size_t backup_end;
struct TLV_MD5_Authentication_Type *auth_TLV;
struct eigrp_header *eigrph;
if (ntohl(nbr->crypt_seqnum) > ntohl(authTLV->key_sequence)) {
zlog_warn(
"interface %s: eigrp_check_md5 bad sequence %d (expect %d)",
IF_NAME(nbr->ei), ntohl(authTLV->key_sequence),
ntohl(nbr->crypt_seqnum));
return 0;
}
eigrph = (struct eigrp_header *)s->data;
eigrph->checksum = 0;
auth_TLV = (struct TLV_MD5_Authentication_Type *)(s->data
+ EIGRP_HEADER_LEN);
memcpy(orig, auth_TLV->digest, EIGRP_AUTH_TYPE_MD5_LEN);
memset(digest, 0, EIGRP_AUTH_TYPE_MD5_LEN);
memset(auth_TLV->digest, 0, EIGRP_AUTH_TYPE_MD5_LEN);
ibuf = s->data;
backup_end = s->endp;
keychain = keychain_lookup(nbr->ei->params.auth_keychain);
if (keychain)
key = key_lookup_for_send(keychain);
if (!key) {
zlog_warn(
"Interface %s: Expected key value not found in config",
nbr->ei->ifp->name);
return 0;
}
memset(&ctx, 0, sizeof(ctx));
MD5Init(&ctx);
/* Generate a digest. Each situation needs different handling */
if (flags & EIGRP_AUTH_BASIC_HELLO_FLAG) {
MD5Update(&ctx, ibuf, EIGRP_MD5_BASIC_COMPUTE);
MD5Update(&ctx, key->string, strlen(key->string));
if (strlen(key->string) < 16)
MD5Update(&ctx, zeropad, 16 - strlen(key->string));
} else if (flags & EIGRP_AUTH_UPDATE_INIT_FLAG) {
MD5Update(&ctx, ibuf, EIGRP_MD5_UPDATE_INIT_COMPUTE);
} else if (flags & EIGRP_AUTH_UPDATE_FLAG) {
MD5Update(&ctx, ibuf, EIGRP_MD5_BASIC_COMPUTE);
MD5Update(&ctx, key->string, strlen(key->string));
if (strlen(key->string) < 16)
MD5Update(&ctx, zeropad, 16 - strlen(key->string));
if (backup_end > (EIGRP_HEADER_LEN + EIGRP_AUTH_MD5_TLV_SIZE)) {
MD5Update(&ctx,
ibuf + (EIGRP_HEADER_LEN
+ EIGRP_AUTH_MD5_TLV_SIZE),
backup_end - 20
- (EIGRP_HEADER_LEN
+ EIGRP_AUTH_MD5_TLV_SIZE));
}
}
MD5Final(digest, &ctx);
/* compare the two */
if (memcmp(orig, digest, EIGRP_AUTH_TYPE_MD5_LEN) != 0) {
zlog_warn("interface %s: eigrp_check_md5 checksum mismatch",
IF_NAME(nbr->ei));
return 0;
}
/* save neighbor's crypt_seqnum */
nbr->crypt_seqnum = authTLV->key_sequence;
return 1;
}
int eigrp_make_sha256_digest(struct eigrp_interface *ei, struct stream *s,
uint8_t flags)
{
struct key *key = NULL;
struct keychain *keychain;
char source_ip[PREFIX_STRLEN];
unsigned char digest[EIGRP_AUTH_TYPE_SHA256_LEN];
unsigned char buffer[1 + PLAINTEXT_LENGTH + 45 + 1] = {0};
HMAC_SHA256_CTX ctx;
void *ibuf;
size_t backup_get, backup_end;
struct TLV_SHA256_Authentication_Type *auth_TLV;
ibuf = s->data;
backup_end = s->endp;
backup_get = s->getp;
auth_TLV = eigrp_authTLV_SHA256_new();
stream_set_getp(s, EIGRP_HEADER_LEN);
stream_get(auth_TLV, s, EIGRP_AUTH_SHA256_TLV_SIZE);
stream_set_getp(s, backup_get);
keychain = keychain_lookup(ei->params.auth_keychain);
if (keychain)
key = key_lookup_for_send(keychain);
if (!key) {
zlog_warn(
"Interface %s: Expected key value not found in config",
ei->ifp->name);
eigrp_authTLV_SHA256_free(auth_TLV);
return 0;
}
inet_ntop(AF_INET, &ei->address.u.prefix4, source_ip, PREFIX_STRLEN);
memset(&ctx, 0, sizeof(ctx));
buffer[0] = '\n';
memcpy(buffer + 1, key, strlen(key->string));
memcpy(buffer + 1 + strlen(key->string), source_ip, strlen(source_ip));
HMAC__SHA256_Init(&ctx, buffer,
1 + strlen(key->string) + strlen(source_ip));
HMAC__SHA256_Update(&ctx, ibuf, strlen(ibuf));
HMAC__SHA256_Final(digest, &ctx);
/* Put hmac-sha256 digest to it's place */
memcpy(auth_TLV->digest, digest, EIGRP_AUTH_TYPE_SHA256_LEN);
stream_set_endp(s, EIGRP_HEADER_LEN);
stream_put(s, auth_TLV, EIGRP_AUTH_SHA256_TLV_SIZE);
stream_set_endp(s, backup_end);
eigrp_authTLV_SHA256_free(auth_TLV);
return EIGRP_AUTH_TYPE_SHA256_LEN;
}
int eigrp_check_sha256_digest(struct stream *s,
struct TLV_SHA256_Authentication_Type *authTLV,
struct eigrp_neighbor *nbr, uint8_t flags)
{
return 1;
}
int eigrp_write(struct thread *thread)
{
struct eigrp *eigrp = THREAD_ARG(thread);
struct eigrp_header *eigrph;
struct eigrp_interface *ei;
struct eigrp_packet *ep;
struct sockaddr_in sa_dst;
struct ip iph;
struct msghdr msg;
struct iovec iov[2];
uint32_t seqno, ack;
int ret;
int flags = 0;
struct listnode *node;
#ifdef WANT_EIGRP_WRITE_FRAGMENT
static uint16_t ipid = 0;
#endif /* WANT_EIGRP_WRITE_FRAGMENT */
#define EIGRP_WRITE_IPHL_SHIFT 2
eigrp->t_write = NULL;
node = listhead(eigrp->oi_write_q);
assert(node);
ei = listgetdata(node);
assert(ei);
#ifdef WANT_EIGRP_WRITE_FRAGMENT
/* seed ipid static with low order bits of time */
if (ipid == 0)
ipid = (time(NULL) & 0xffff);
#endif /* WANT_EIGRP_WRITE_FRAGMENT */
/* Get one packet from queue. */
ep = eigrp_fifo_next(ei->obuf);
if (!ep) {
flog_err(EC_LIB_DEVELOPMENT,
"%s: Interface %s no packet on queue?", __func__,
ei->ifp->name);
goto out;
}
if (ep->length < EIGRP_HEADER_LEN) {
flog_err(EC_EIGRP_PACKET, "%s: Packet just has a header?",
__func__);
eigrp_header_dump((struct eigrp_header *)ep->s->data);
eigrp_packet_delete(ei);
goto out;
}
if (ep->dst.s_addr == htonl(EIGRP_MULTICAST_ADDRESS))
eigrp_if_ipmulticast(eigrp, &ei->address, ei->ifp->ifindex);
memset(&iph, 0, sizeof(struct ip));
memset(&sa_dst, 0, sizeof(sa_dst));
/*
* We build and schedule packets to go out
* in the future. In the mean time we may
* process some update packets from the
* neighbor, thus making it necessary
* to update the ack we are using for
* this outgoing packet.
*/
eigrph = (struct eigrp_header *)STREAM_DATA(ep->s);
seqno = ntohl(eigrph->sequence);
ack = ntohl(eigrph->ack);
if (ep->nbr && (ack != ep->nbr->recv_sequence_number)) {
eigrph->ack = htonl(ep->nbr->recv_sequence_number);
ack = ep->nbr->recv_sequence_number;
eigrph->checksum = 0;
eigrp_packet_checksum(ei, ep->s, ep->length);
}
sa_dst.sin_family = AF_INET;
#ifdef HAVE_STRUCT_SOCKADDR_IN_SIN_LEN
sa_dst.sin_len = sizeof(sa_dst);
#endif /* HAVE_STRUCT_SOCKADDR_IN_SIN_LEN */
sa_dst.sin_addr = ep->dst;
sa_dst.sin_port = htons(0);
/* Set DONTROUTE flag if dst is unicast. */
if (!IN_MULTICAST(htonl(ep->dst.s_addr)))
flags = MSG_DONTROUTE;
iph.ip_hl = sizeof(struct ip) >> EIGRP_WRITE_IPHL_SHIFT;
/* it'd be very strange for header to not be 4byte-word aligned but.. */
if (sizeof(struct ip)
> (unsigned int)(iph.ip_hl << EIGRP_WRITE_IPHL_SHIFT))
iph.ip_hl++; /* we presume sizeof struct ip cant overflow
ip_hl.. */
iph.ip_v = IPVERSION;
iph.ip_tos = IPTOS_PREC_INTERNETCONTROL;
iph.ip_len = (iph.ip_hl << EIGRP_WRITE_IPHL_SHIFT) + ep->length;
#if defined(__DragonFly__)
/*
* DragonFly's raw socket expects ip_len/ip_off in network byte order.
*/
iph.ip_len = htons(iph.ip_len);
#endif
iph.ip_off = 0;
iph.ip_ttl = EIGRP_IP_TTL;
iph.ip_p = IPPROTO_EIGRPIGP;
iph.ip_sum = 0;
iph.ip_src.s_addr = ei->address.u.prefix4.s_addr;
iph.ip_dst.s_addr = ep->dst.s_addr;
memset(&msg, 0, sizeof(msg));
msg.msg_name = (caddr_t)&sa_dst;
msg.msg_namelen = sizeof(sa_dst);
msg.msg_iov = iov;
msg.msg_iovlen = 2;
iov[0].iov_base = (char *)&iph;
iov[0].iov_len = iph.ip_hl << EIGRP_WRITE_IPHL_SHIFT;
iov[1].iov_base = stream_pnt(ep->s);
iov[1].iov_len = ep->length;
/* send final fragment (could be first) */
sockopt_iphdrincl_swab_htosys(&iph);
ret = sendmsg(eigrp->fd, &msg, flags);
sockopt_iphdrincl_swab_systoh(&iph);
if (IS_DEBUG_EIGRP_TRANSMIT(0, SEND)) {
eigrph = (struct eigrp_header *)STREAM_DATA(ep->s);
zlog_debug(
"Sending [%s][%d/%d] to [%s] via [%s] ret [%d].",
lookup_msg(eigrp_packet_type_str, eigrph->opcode, NULL),
seqno, ack, inet_ntoa(ep->dst), IF_NAME(ei), ret);
}
if (ret < 0)
zlog_warn(
"*** sendmsg in eigrp_write failed to %s, "
"id %d, off %d, len %d, interface %s, mtu %u: %s",
inet_ntoa(iph.ip_dst), iph.ip_id, iph.ip_off,
iph.ip_len, ei->ifp->name, ei->ifp->mtu,
safe_strerror(errno));
/* Now delete packet from queue. */
eigrp_packet_delete(ei);
out:
if (eigrp_fifo_next(ei->obuf) == NULL) {
ei->on_write_q = 0;
list_delete_node(eigrp->oi_write_q, node);
}
/* If packets still remain in queue, call write thread. */
if (!list_isempty(eigrp->oi_write_q)) {
eigrp->t_write = NULL;
thread_add_write(master, eigrp_write, eigrp, eigrp->fd,
&eigrp->t_write);
}
return 0;
}
/* Starting point of packet process function. */
int eigrp_read(struct thread *thread)
{
int ret;
struct stream *ibuf;
struct eigrp *eigrp;
struct eigrp_interface *ei;
struct ip *iph;
struct eigrp_header *eigrph;
struct interface *ifp;
struct eigrp_neighbor *nbr;
struct in_addr srcaddr;
uint16_t opcode = 0;
uint16_t length = 0;
/* first of all get interface pointer. */
eigrp = THREAD_ARG(thread);
/* prepare for next packet. */
eigrp->t_read = NULL;
thread_add_read(master, eigrp_read, eigrp, eigrp->fd, &eigrp->t_read);
stream_reset(eigrp->ibuf);
if (!(ibuf = eigrp_recv_packet(eigrp, eigrp->fd, &ifp, eigrp->ibuf))) {
/* This raw packet is known to be at least as big as its IP
* header. */
return -1;
}
/* Note that there should not be alignment problems with this assignment
because this is at the beginning of the stream data buffer. */
iph = (struct ip *)STREAM_DATA(ibuf);
// Substract IPv4 header size from EIGRP Packet itself
if (iph->ip_v == 4)
length = (iph->ip_len) - 20U;
srcaddr = iph->ip_src;
/* IP Header dump. */
if (IS_DEBUG_EIGRP_TRANSMIT(0, RECV)
&& IS_DEBUG_EIGRP_TRANSMIT(0, PACKET_DETAIL))
eigrp_ip_header_dump(iph);
/* Note that sockopt_iphdrincl_swab_systoh was called in
* eigrp_recv_packet. */
if (ifp == NULL) {
struct connected *c;
/* Handle cases where the platform does not support retrieving
the ifindex,
and also platforms (such as Solaris 8) that claim to support
ifindex
retrieval but do not. */
c = if_lookup_address((void *)&srcaddr, AF_INET,
eigrp->vrf_id);
if (c == NULL)
return 0;
ifp = c->ifp;
}
/* associate packet with eigrp interface */
ei = ifp->info;
/* eigrp_verify_header() relies on a valid "ei" and thus can be called
only
after the checks below are passed. These checks in turn access the
fields of unverified "eigrph" structure for their own purposes and
must remain very accurate in doing this.
*/
if (!ei)
return 0;
/* Self-originated packet should be discarded silently. */
if (eigrp_if_lookup_by_local_addr(eigrp, NULL, iph->ip_src)
|| (IPV4_ADDR_SAME(&srcaddr, &ei->address.u.prefix4))) {
if (IS_DEBUG_EIGRP_TRANSMIT(0, RECV))
zlog_debug(
"eigrp_read[%s]: Dropping self-originated packet",
inet_ntoa(srcaddr));
return 0;
}
/* Advance from IP header to EIGRP header (iph->ip_hl has been verified
by eigrp_recv_packet() to be correct). */
stream_forward_getp(ibuf, (iph->ip_hl * 4));
eigrph = (struct eigrp_header *)stream_pnt(ibuf);
if (IS_DEBUG_EIGRP_TRANSMIT(0, RECV)
&& IS_DEBUG_EIGRP_TRANSMIT(0, PACKET_DETAIL))
eigrp_header_dump(eigrph);
// if (MSG_OK != eigrp_packet_examin(eigrph, stream_get_endp(ibuf) -
// stream_get_getp(ibuf)))
// return -1;
/* If incoming interface is passive one, ignore it. */
if (eigrp_if_is_passive(ei)) {
char buf[3][INET_ADDRSTRLEN];
if (IS_DEBUG_EIGRP_TRANSMIT(0, RECV))
zlog_debug(
"ignoring packet from router %s sent to %s, "
"received on a passive interface, %s",
inet_ntop(AF_INET, &eigrph->vrid, buf[0],
sizeof(buf[0])),
inet_ntop(AF_INET, &iph->ip_dst, buf[1],
sizeof(buf[1])),
inet_ntop(AF_INET, &ei->address.u.prefix4,
buf[2], sizeof(buf[2])));
if (iph->ip_dst.s_addr == htonl(EIGRP_MULTICAST_ADDRESS)) {
eigrp_if_set_multicast(ei);
}
return 0;
}
/* else it must be a local eigrp interface, check it was received on
* correct link
*/
else if (ei->ifp != ifp) {
if (IS_DEBUG_EIGRP_TRANSMIT(0, RECV))
zlog_warn("Packet from [%s] received on wrong link %s",
inet_ntoa(iph->ip_src), ifp->name);
return 0;
}
/* Verify more EIGRP header fields. */
ret = eigrp_verify_header(ibuf, ei, iph, eigrph);
if (ret < 0) {
if (IS_DEBUG_EIGRP_TRANSMIT(0, RECV))
zlog_debug(
"eigrp_read[%s]: Header check failed, dropping.",
inet_ntoa(iph->ip_src));
return ret;
}
/* calcualte the eigrp packet length, and move the pounter to the
start of the eigrp TLVs */
opcode = eigrph->opcode;
if (IS_DEBUG_EIGRP_TRANSMIT(0, RECV)) {
char src[PREFIX_STRLEN], dst[PREFIX_STRLEN];
strlcpy(src, inet_ntoa(iph->ip_src), sizeof(src));
strlcpy(dst, inet_ntoa(iph->ip_dst), sizeof(dst));
zlog_debug(
"Received [%s][%d/%d] length [%u] via [%s] src [%s] dst [%s]",
lookup_msg(eigrp_packet_type_str, opcode, NULL),
ntohl(eigrph->sequence), ntohl(eigrph->ack), length,
IF_NAME(ei), src, dst);
}
/* Read rest of the packet and call each sort of packet routine. */
stream_forward_getp(ibuf, EIGRP_HEADER_LEN);
/* New testing block of code for handling Acks */
if (ntohl(eigrph->ack) != 0) {
struct eigrp_packet *ep = NULL;
nbr = eigrp_nbr_get(ei, eigrph, iph);
// neighbor must be valid, eigrp_nbr_get creates if none existed
assert(nbr);
ep = eigrp_fifo_next(nbr->retrans_queue);
if ((ep) && (ntohl(eigrph->ack) == ep->sequence_number)) {
ep = eigrp_fifo_pop(nbr->retrans_queue);
eigrp_packet_free(ep);
if ((nbr->state == EIGRP_NEIGHBOR_PENDING)
&& (ntohl(eigrph->ack)
== nbr->init_sequence_number)) {
eigrp_nbr_state_set(nbr, EIGRP_NEIGHBOR_UP);
zlog_info("Neighbor(%s) adjacency became full",
inet_ntoa(nbr->src));
nbr->init_sequence_number = 0;
nbr->recv_sequence_number =
ntohl(eigrph->sequence);
eigrp_update_send_EOT(nbr);
} else
eigrp_send_packet_reliably(nbr);
}
ep = eigrp_fifo_next(nbr->multicast_queue);
if (ep) {
if (ntohl(eigrph->ack) == ep->sequence_number) {
ep = eigrp_fifo_pop(nbr->multicast_queue);
eigrp_packet_free(ep);
if (nbr->multicast_queue->count > 0) {
eigrp_send_packet_reliably(nbr);
}
}
}
}
switch (opcode) {
case EIGRP_OPC_HELLO:
eigrp_hello_receive(eigrp, iph, eigrph, ibuf, ei, length);
break;
case EIGRP_OPC_PROBE:
// eigrp_probe_receive(eigrp, iph, eigrph, ibuf, ei,
// length);
break;
case EIGRP_OPC_QUERY:
eigrp_query_receive(eigrp, iph, eigrph, ibuf, ei, length);
break;
case EIGRP_OPC_REPLY:
eigrp_reply_receive(eigrp, iph, eigrph, ibuf, ei, length);
break;
case EIGRP_OPC_REQUEST:
// eigrp_request_receive(eigrp, iph, eigrph, ibuf, ei,
// length);
break;
case EIGRP_OPC_SIAQUERY:
eigrp_query_receive(eigrp, iph, eigrph, ibuf, ei, length);
break;
case EIGRP_OPC_SIAREPLY:
eigrp_reply_receive(eigrp, iph, eigrph, ibuf, ei, length);
break;
case EIGRP_OPC_UPDATE:
eigrp_update_receive(eigrp, iph, eigrph, ibuf, ei, length);
break;
default:
zlog_warn(
"interface %s: EIGRP packet header type %d unsupported",
IF_NAME(ei), opcode);
break;
}
return 0;
}
static struct stream *eigrp_recv_packet(struct eigrp *eigrp,
int fd, struct interface **ifp,
struct stream *ibuf)
{
int ret;
struct ip *iph;
uint16_t ip_len;
unsigned int ifindex = 0;
struct iovec iov;
/* Header and data both require alignment. */
char buff[CMSG_SPACE(SOPT_SIZE_CMSG_IFINDEX_IPV4())];
struct msghdr msgh;
memset(&msgh, 0, sizeof(struct msghdr));
msgh.msg_iov = &iov;
msgh.msg_iovlen = 1;
msgh.msg_control = (caddr_t)buff;
msgh.msg_controllen = sizeof(buff);
ret = stream_recvmsg(ibuf, fd, &msgh, 0, (EIGRP_PACKET_MAX_LEN + 1));
if (ret < 0) {
zlog_warn("stream_recvmsg failed: %s", safe_strerror(errno));
return NULL;
}
if ((unsigned int)ret < sizeof(*iph)) /* ret must be > 0 now */
{
zlog_warn(
"eigrp_recv_packet: discarding runt packet of length %d "
"(ip header size is %u)",
ret, (unsigned int)sizeof(*iph));
return NULL;
}
/* Note that there should not be alignment problems with this assignment
because this is at the beginning of the stream data buffer. */
iph = (struct ip *)STREAM_DATA(ibuf);
sockopt_iphdrincl_swab_systoh(iph);
ip_len = iph->ip_len;
#if defined(__FreeBSD__) && (__FreeBSD_version < 1000000)
/*
* Kernel network code touches incoming IP header parameters,
* before protocol specific processing.
*
* 1) Convert byteorder to host representation.
* --> ip_len, ip_id, ip_off
*
* 2) Adjust ip_len to strip IP header size!
* --> If user process receives entire IP packet via RAW
* socket, it must consider adding IP header size to
* the "ip_len" field of "ip" structure.
*
* For more details, see <netinet/ip_input.c>.
*/
ip_len = ip_len + (iph->ip_hl << 2);
#endif
#if defined(__DragonFly__)
/*
* in DragonFly's raw socket, ip_len/ip_off are read
* in network byte order.
* As OpenBSD < 200311 adjust ip_len to strip IP header size!
*/
ip_len = ntohs(iph->ip_len) + (iph->ip_hl << 2);
#endif
ifindex = getsockopt_ifindex(AF_INET, &msgh);
*ifp = if_lookup_by_index(ifindex, eigrp->vrf_id);
if (ret != ip_len) {
zlog_warn(
"eigrp_recv_packet read length mismatch: ip_len is %d, "
"but recvmsg returned %d",
ip_len, ret);
return NULL;
}
return ibuf;
}
struct eigrp_fifo *eigrp_fifo_new(void)
{
struct eigrp_fifo *new;
new = XCALLOC(MTYPE_EIGRP_FIFO, sizeof(struct eigrp_fifo));
return new;
}
/* Free eigrp packet fifo. */
void eigrp_fifo_free(struct eigrp_fifo *fifo)
{
struct eigrp_packet *ep;
struct eigrp_packet *next;
for (ep = fifo->head; ep; ep = next) {
next = ep->next;
eigrp_packet_free(ep);
}
fifo->head = fifo->tail = NULL;
fifo->count = 0;
XFREE(MTYPE_EIGRP_FIFO, fifo);
}
/* Free eigrp fifo entries without destroying fifo itself*/
void eigrp_fifo_reset(struct eigrp_fifo *fifo)
{
struct eigrp_packet *ep;
struct eigrp_packet *next;
for (ep = fifo->head; ep; ep = next) {
next = ep->next;
eigrp_packet_free(ep);
}
fifo->head = fifo->tail = NULL;
fifo->count = 0;
}
struct eigrp_packet *eigrp_packet_new(size_t size, struct eigrp_neighbor *nbr)
{
struct eigrp_packet *new;
new = XCALLOC(MTYPE_EIGRP_PACKET, sizeof(struct eigrp_packet));
new->s = stream_new(size);
new->retrans_counter = 0;
new->nbr = nbr;
return new;
}
void eigrp_send_packet_reliably(struct eigrp_neighbor *nbr)
{
struct eigrp_packet *ep;
ep = eigrp_fifo_next(nbr->retrans_queue);
if (ep) {
struct eigrp_packet *duplicate;
duplicate = eigrp_packet_duplicate(ep, nbr);
/* Add packet to the top of the interface output queue*/
eigrp_fifo_push(nbr->ei->obuf, duplicate);
/*Start retransmission timer*/
thread_add_timer(master, eigrp_unack_packet_retrans, nbr,
EIGRP_PACKET_RETRANS_TIME,
&ep->t_retrans_timer);
/*Increment sequence number counter*/
nbr->ei->eigrp->sequence_number++;
/* Hook thread to write packet. */
if (nbr->ei->on_write_q == 0) {
listnode_add(nbr->ei->eigrp->oi_write_q, nbr->ei);
nbr->ei->on_write_q = 1;
}
thread_add_write(master, eigrp_write, nbr->ei->eigrp,
nbr->ei->eigrp->fd, &nbr->ei->eigrp->t_write);
}
}
/* Calculate EIGRP checksum */
void eigrp_packet_checksum(struct eigrp_interface *ei, struct stream *s,
uint16_t length)
{
struct eigrp_header *eigrph;
eigrph = (struct eigrp_header *)STREAM_DATA(s);
/* Calculate checksum. */
eigrph->checksum = in_cksum(eigrph, length);
}
/* Make EIGRP header. */
void eigrp_packet_header_init(int type, struct eigrp *eigrp, struct stream *s,
uint32_t flags, uint32_t sequence, uint32_t ack)
{
struct eigrp_header *eigrph;
stream_reset(s);
eigrph = (struct eigrp_header *)STREAM_DATA(s);
eigrph->version = (uint8_t)EIGRP_HEADER_VERSION;
eigrph->opcode = (uint8_t)type;
eigrph->checksum = 0;
eigrph->vrid = htons(eigrp->vrid);
eigrph->ASNumber = htons(eigrp->AS);
eigrph->ack = htonl(ack);
eigrph->sequence = htonl(sequence);
// if(flags == EIGRP_INIT_FLAG)
// eigrph->sequence = htonl(3);
eigrph->flags = htonl(flags);
if (IS_DEBUG_EIGRP_TRANSMIT(0, PACKET_DETAIL))
zlog_debug("Packet Header Init Seq [%u] Ack [%u]",
htonl(eigrph->sequence), htonl(eigrph->ack));
stream_forward_endp(s, EIGRP_HEADER_LEN);
}
/* Add new packet to head of fifo. */
void eigrp_fifo_push(struct eigrp_fifo *fifo, struct eigrp_packet *ep)
{
ep->next = fifo->head;
ep->previous = NULL;
if (fifo->tail == NULL)
fifo->tail = ep;
if (fifo->count != 0)
fifo->head->previous = ep;
fifo->head = ep;
fifo->count++;
}
/* Return last fifo entry. */
struct eigrp_packet *eigrp_fifo_next(struct eigrp_fifo *fifo)
{
return fifo->tail;
}
void eigrp_packet_delete(struct eigrp_interface *ei)
{
struct eigrp_packet *ep;
ep = eigrp_fifo_pop(ei->obuf);
if (ep)
eigrp_packet_free(ep);
}
void eigrp_packet_free(struct eigrp_packet *ep)
{
if (ep->s)
stream_free(ep->s);
THREAD_OFF(ep->t_retrans_timer);
XFREE(MTYPE_EIGRP_PACKET, ep);
}
/* EIGRP Header verification. */
static int eigrp_verify_header(struct stream *ibuf, struct eigrp_interface *ei,
struct ip *iph, struct eigrp_header *eigrph)
{
/* Check network mask, Silently discarded. */
if (!eigrp_check_network_mask(ei, iph->ip_src)) {
zlog_warn(
"interface %s: eigrp_read network address is not same [%s]",
IF_NAME(ei), inet_ntoa(iph->ip_src));
return -1;
}
//
// /* Check authentication. The function handles logging actions, where
// required. */
// if (! eigrp_check_auth(ei, eigrph))
// return -1;
return 0;
}
/* Unbound socket will accept any Raw IP packets if proto is matched.
To prevent it, compare src IP address and i/f address with masking
i/f network mask. */
static int eigrp_check_network_mask(struct eigrp_interface *ei,
struct in_addr ip_src)
{
struct in_addr mask, me, him;
if (ei->type == EIGRP_IFTYPE_POINTOPOINT)
return 1;
masklen2ip(ei->address.prefixlen, &mask);
me.s_addr = ei->address.u.prefix4.s_addr & mask.s_addr;
him.s_addr = ip_src.s_addr & mask.s_addr;
if (IPV4_ADDR_SAME(&me, &him))
return 1;
return 0;
}
int eigrp_unack_packet_retrans(struct thread *thread)
{