forked from iputils/iputils
-
Notifications
You must be signed in to change notification settings - Fork 0
/
Copy pathrdisc.c
1521 lines (1363 loc) · 34.6 KB
/
rdisc.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
/*
* Rdisc (this program) was developed by Sun Microsystems, Inc. and is
* provided for unrestricted use provided that this legend is included on
* all tape media and as a part of the software program in whole or part.
* Users may copy or modify Rdisc without charge, and they may freely
* distribute it.
*
* RDISC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
* WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
* PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
*
* Rdisc is provided with no support and without any obligation on the
* part of Sun Microsystems, Inc. to assist in its use, correction,
* modification or enhancement.
*
* SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
* INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY RDISC
* OR ANY PART THEREOF.
*
* In no event will Sun Microsystems, Inc. be liable for any lost revenue
* or profits or other special, indirect and consequential damages, even if
* Sun has been advised of the possibility of such damages.
*
* Sun Microsystems, Inc.
* 2550 Garcia Avenue
* Mountain View, California 94043
*/
#include <stdio.h>
#include <stdarg.h>
#include <errno.h>
#include <signal.h>
#include <unistd.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/time.h>
/* Do not use "improved" glibc version! */
#include <linux/limits.h>
#include <sys/param.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <sys/file.h>
#include <malloc.h>
#include <sys/ioctl.h>
#include <linux/if.h>
#include <linux/route.h>
#include <netinet/in.h>
#include <netinet/ip.h>
#include <netinet/ip_icmp.h>
/*
* The next include contains all defs and structures for multicast
* that are not in SunOS 4.1.x. On a SunOS 4.1.x system none of this code
* is ever used because it does not support multicast
* Fraser Gardiner - Sun Microsystems Australia
*/
#include <netdb.h>
#include <arpa/inet.h>
#include <string.h>
#include <syslog.h>
#include "iputils_common.h"
struct interface
{
struct in_addr address; /* Used to identify the interface */
struct in_addr localaddr; /* Actual address if the interface */
int preference;
int flags;
struct in_addr bcastaddr;
struct in_addr remoteaddr;
struct in_addr netmask;
int ifindex;
char name[IFNAMSIZ];
};
/*
* TBD
* Use 255.255.255.255 for broadcasts - not the interface broadcast
* address.
*/
#define ALLIGN(ptr) (ptr)
static int join(int sock, struct sockaddr_in *sin);
static void solicitor(struct sockaddr_in *);
#ifdef RDISC_SERVER
static void advertise(struct sockaddr_in *, int lft);
#endif
static char *pr_name(struct in_addr addr);
static void pr_pack(char *buf, int cc, struct sockaddr_in *from);
static void age_table(int time);
static void record_router(struct in_addr router, int preference, int ttl);
static void add_route(struct in_addr addr);
static void del_route(struct in_addr addr);
static void rtioctl(struct in_addr addr, int op);
static int support_multicast(void);
static int sendbcast(int s, char *packet, int packetlen);
static int sendmcast(int s, char *packet, int packetlen, struct sockaddr_in *);
static int sendbcastif(int s, char *packet, int packetlen, struct interface *ifp);
static int sendmcastif(int s, char *packet, int packetlen, struct sockaddr_in *sin, struct interface *ifp);
static int is_directly_connected(struct in_addr in);
static void initlog(void);
static void discard_table(void);
static void init(void);
#define ICMP_ROUTER_ADVERTISEMENT 9
#define ICMP_ROUTER_SOLICITATION 10
#define ALL_HOSTS_ADDRESS "224.0.0.1"
#define ALL_ROUTERS_ADDRESS "224.0.0.2"
#define MAXIFS 32
#if defined(__GLIBC__) && __GLIBC__ < 2
/* For router advertisement */
struct icmp_ra
{
unsigned char icmp_type; /* type of message, see below */
unsigned char icmp_code; /* type sub code */
unsigned short icmp_cksum; /* ones complement cksum of struct */
unsigned char icmp_num_addrs;
unsigned char icmp_wpa; /* Words per address */
short icmp_lifetime;
};
struct icmp_ra_addr
{
uint32_t ira_addr;
uint32_t ira_preference;
};
#else
#define icmp_ra icmp
#endif
/* Router constants */
#define MAX_INITIAL_ADVERT_INTERVAL 16
#define MAX_INITIAL_ADVERTISEMENTS 3
#define MAX_RESPONSE_DELAY 2 /* Not used */
/* Host constants */
#define MAX_SOLICITATIONS 3
#define SOLICITATION_INTERVAL 3
#define MAX_SOLICITATION_DELAY 1 /* Not used */
#define INELIGIBLE_PREF 0x80000000 /* Maximum negative */
#define MAX_ADV_INT 600
/* Statics */
static int num_interfaces;
static struct interface *interfaces;
static int interfaces_size; /* Number of elements in interfaces */
#define MAXPACKET 4096 /* max packet size */
/* fraser */
int debugfile;
int s; /* Socket file descriptor */
struct sockaddr_in whereto;/* Address to send to */
/* Common variables */
int verbose = 0;
int debug = 0;
int trace = 0;
int solicit = 0;
int ntransmitted = 0;
int nreceived = 0;
int forever = 0; /* Never give up on host. If 0 defer fork until
* first response.
*/
#ifdef RDISC_SERVER
/* Router variables */
int responder;
int max_adv_int = MAX_ADV_INT;
int min_adv_int;
int lifetime;
int initial_advert_interval = MAX_INITIAL_ADVERT_INTERVAL;
int initial_advertisements = MAX_INITIAL_ADVERTISEMENTS;
int preference = 0; /* Setable with -p option */
#endif
/* Host variables */
int max_solicitations = MAX_SOLICITATIONS;
unsigned int solicitation_interval = SOLICITATION_INTERVAL;
int best_preference = 1; /* Set to record only the router(s) with the
best preference in the kernel. Not set
puts all routes in the kernel. */
static void graceful_finish(void);
static void finish(void);
static void timer(void);
static void initifs(void);
static unsigned short in_cksum(unsigned short *addr, int len);
static int logging = 0;
static void logmsg(int prio, char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
if (logging)
vsyslog(prio, fmt, ap);
else
vfprintf(stderr, fmt, ap);
va_end(ap);
}
static void logperror(char *str);
static __inline__ int isbroadcast(struct sockaddr_in *sin)
{
return (sin->sin_addr.s_addr == INADDR_BROADCAST);
}
static __inline__ int ismulticast(struct sockaddr_in *sin)
{
return IN_CLASSD(ntohl(sin->sin_addr.s_addr));
}
static void prusage(void)
{
fprintf(stderr,
"\nUsage\n"
" rdisc [options] <send address> <receive address>\n"
"\nOptions:\n"
" -a accept all routers\n"
" -b accept best only (default)\n"
" -d enable debug syslog messages\n"
" -f run forever\n"
#ifdef RDISC_SERVER
" -r responder mode\n"
#endif
" -s send solicitation messages at startup\n"
#ifdef RDISC_SERVER
" -p <preference> set <preference> in advertisement\n"
" -T <seconds> set max advertisement interval in <seconds>\n"
#endif
" -t test mode, do not go background\n"
" -v verbose mode\n"
" -V print version and exit\n"
"\nFor more details see rdisc(8).\n"
);
exit(1);
}
void do_fork(void)
{
if (trace)
return;
if (daemon(0, 0) < 0)
error(1, errno, "failed to daemon()");
initlog();
}
void signal_setup(int signo, void (*handler)(void))
{
struct sigaction sa;
memset(&sa, 0, sizeof(sa));
sa.sa_handler = (void (*)(int))handler;
sigaction(signo, &sa, NULL);
}
/*
* M A I N
*/
char *sendaddress, *recvaddress;
int main(int argc, char **argv)
{
struct sockaddr_in from = { 0 };
char **av = argv;
struct sockaddr_in *to = &whereto;
struct sockaddr_in joinaddr;
sigset_t sset, sset_empty;
#ifdef RDISC_SERVER
int val;
atexit(close_stdout);
min_adv_int =( max_adv_int * 3 / 4);
lifetime = (3*max_adv_int);
#endif
argc--, av++;
while (argc > 0 && *av[0] == '-') {
while (*++av[0]) {
switch (*av[0]) {
case 'd':
debug = 1;
break;
case 't':
trace = 1;
break;
case 'v':
verbose++;
break;
case 's':
solicit = 1;
break;
#ifdef RDISC_SERVER
case 'r':
responder = 1;
break;
#endif
case 'a':
best_preference = 0;
break;
case 'b':
best_preference = 1;
break;
case 'f':
forever = 1;
break;
case 'V':
printf(IPUTILS_VERSION("rdisc"));
exit(0);
#ifdef RDISC_SERVER
case 'T':
argc--, av++;
if (argc != 0) {
val = strtol(av[0], (char **)NULL, 0);
if (val < 4 || val > 1800)
error(1, 0, "Bad Max Advertizement Interval: %d",
val);
max_adv_int = val;
min_adv_int =( max_adv_int * 3 / 4);
lifetime = (3*max_adv_int);
} else {
prusage();
/* NOTREACHED*/
}
goto next;
case 'p':
argc--, av++;
if (argc != 0) {
val = strtol(av[0], (char **)NULL, 0);
preference = val;
} else {
prusage();
/* NOTREACHED*/
}
goto next;
#endif
default:
prusage();
/* NOTREACHED*/
}
}
#ifdef RDISC_SERVER
next:
#endif
argc--, av++;
}
if( argc < 1) {
if (support_multicast()) {
sendaddress = ALL_ROUTERS_ADDRESS;
#ifdef RDISC_SERVER
if (responder)
sendaddress = ALL_HOSTS_ADDRESS;
#endif
} else
sendaddress = "255.255.255.255";
} else {
sendaddress = av[0];
argc--;
}
if (argc < 1) {
if (support_multicast()) {
recvaddress = ALL_HOSTS_ADDRESS;
#ifdef RDISC_SERVER
if (responder)
recvaddress = ALL_ROUTERS_ADDRESS;
#endif
} else
recvaddress = "255.255.255.255";
} else {
recvaddress = av[0];
argc--;
}
if (argc != 0) {
error(0, 0, "Extra parameters");
prusage();
/* NOTREACHED */
}
#ifdef RDISC_SERVER
if (solicit && responder) {
prusage();
/* NOTREACHED */
}
#endif
if (!(solicit && !forever)) {
do_fork();
/*
* Added the next line to stop forking a second time
* Fraser Gardiner - Sun Microsystems Australia
*/
forever = 1;
}
memset( (char *)&whereto, 0, sizeof(struct sockaddr_in) );
to->sin_family = AF_INET;
to->sin_addr.s_addr = inet_addr(sendaddress);
memset( (char *)&joinaddr, 0, sizeof(struct sockaddr_in) );
joinaddr.sin_family = AF_INET;
joinaddr.sin_addr.s_addr = inet_addr(recvaddress);
#ifdef RDISC_SERVER
if (responder)
srandom((int)gethostid());
#endif
if ((s = socket(AF_INET, SOCK_RAW, IPPROTO_ICMP)) < 0) {
logperror("socket");
exit(5);
}
setlinebuf( stdout );
signal_setup(SIGINT, finish );
signal_setup(SIGTERM, graceful_finish );
signal_setup(SIGHUP, initifs );
signal_setup(SIGALRM, timer );
sigemptyset(&sset);
sigemptyset(&sset_empty);
sigaddset(&sset, SIGALRM);
sigaddset(&sset, SIGHUP);
sigaddset(&sset, SIGTERM);
sigaddset(&sset, SIGINT);
init();
if (join(s, &joinaddr) < 0) {
logmsg(LOG_ERR, "Failed joining addresses\n");
exit (2);
}
timer(); /* start things going */
for (;;) {
unsigned char packet[MAXPACKET];
int len = sizeof (packet);
socklen_t fromlen = sizeof (from);
int cc;
cc=recvfrom(s, (char *)packet, len, 0,
(struct sockaddr *)&from, &fromlen);
if (cc<0) {
if (errno == EINTR)
continue;
logperror("recvfrom");
continue;
}
sigprocmask(SIG_SETMASK, &sset, NULL);
pr_pack( (char *)packet, cc, &from );
sigprocmask(SIG_SETMASK, &sset_empty, NULL);
}
/*NOTREACHED*/
}
#define TIMER_INTERVAL 3
#define GETIFCONF_TIMER 30
static int left_until_advertise;
/* Called every TIMER_INTERVAL */
void timer()
{
static int time;
static int left_until_getifconf;
static int left_until_solicit;
time += TIMER_INTERVAL;
left_until_getifconf -= TIMER_INTERVAL;
left_until_advertise -= TIMER_INTERVAL;
left_until_solicit -= TIMER_INTERVAL;
if (left_until_getifconf < 0) {
initifs();
left_until_getifconf = GETIFCONF_TIMER;
}
#ifdef RDISC_SERVER
if (responder && left_until_advertise <= 0) {
ntransmitted++;
advertise(&whereto, lifetime);
if (ntransmitted < initial_advertisements)
left_until_advertise = initial_advert_interval;
else
left_until_advertise = min_adv_int +
((max_adv_int - min_adv_int) *
(random() % 1000)/1000);
} else
#endif
if (solicit && left_until_solicit <= 0) {
ntransmitted++;
solicitor(&whereto);
if (ntransmitted < max_solicitations)
left_until_solicit = solicitation_interval;
else {
solicit = 0;
if (!forever && nreceived == 0)
exit(5);
}
}
age_table(TIMER_INTERVAL);
alarm(TIMER_INTERVAL);
}
/*
* S O L I C I T O R
*
* Compose and transmit an ICMP ROUTER SOLICITATION REQUEST packet.
* The IP packet will be added on by the kernel.
*/
void
solicitor(struct sockaddr_in *sin)
{
static unsigned char outpack[MAXPACKET];
struct icmphdr *icp = (struct icmphdr *) ALLIGN(outpack);
int packetlen, i;
if (verbose) {
logmsg(LOG_INFO, "Sending solicitation to %s\n",
pr_name(sin->sin_addr));
}
icp->type = ICMP_ROUTER_SOLICITATION;
icp->code = 0;
icp->checksum = 0;
icp->un.gateway = 0; /* Reserved */
packetlen = 8;
/* Compute ICMP checksum here */
icp->checksum = in_cksum( (unsigned short *)icp, packetlen );
if (isbroadcast(sin))
i = sendbcast(s, (char *)outpack, packetlen);
else if (ismulticast(sin))
i = sendmcast(s, (char *)outpack, packetlen, sin);
else
i = sendto( s, (char *)outpack, packetlen, 0,
(struct sockaddr *)sin, sizeof(struct sockaddr));
if( i < 0 || i != packetlen ) {
if( i<0 ) {
logperror("solicitor:sendto");
}
logmsg(LOG_ERR, "wrote %s %d chars, ret=%d\n",
sendaddress, packetlen, i );
}
}
#ifdef RDISC_SERVER
/*
* A V E R T I S E
*
* Compose and transmit an ICMP ROUTER ADVERTISEMENT packet.
* The IP packet will be added on by the kernel.
*/
void
advertise(struct sockaddr_in *sin, int lft)
{
static unsigned char outpack[MAXPACKET];
struct icmp_ra *rap = (struct icmp_ra *) ALLIGN(outpack);
struct icmp_ra_addr *ap;
int packetlen, i, cc;
if (verbose) {
logmsg(LOG_INFO, "Sending advertisement to %s\n",
pr_name(sin->sin_addr));
}
for (i = 0; i < num_interfaces; i++) {
rap->icmp_type = ICMP_ROUTER_ADVERTISEMENT;
rap->icmp_code = 0;
rap->icmp_cksum = 0;
rap->icmp_num_addrs = 0;
rap->icmp_wpa = 2;
rap->icmp_lifetime = htons(lft);
packetlen = 8;
/*
* TODO handle multiple logical interfaces per
* physical interface. (increment with rap->icmp_wpa * 4 for
* each address.)
*/
ap = (struct icmp_ra_addr *)ALLIGN(outpack + ICMP_MINLEN);
ap->ira_addr = interfaces[i].localaddr.s_addr;
ap->ira_preference = htonl(interfaces[i].preference);
packetlen += rap->icmp_wpa * 4;
rap->icmp_num_addrs++;
/* Compute ICMP checksum here */
rap->icmp_cksum = in_cksum( (unsigned short *)rap, packetlen );
if (isbroadcast(sin))
cc = sendbcastif(s, (char *)outpack, packetlen,
&interfaces[i]);
else if (ismulticast(sin))
cc = sendmcastif( s, (char *)outpack, packetlen, sin,
&interfaces[i]);
else {
struct interface *ifp = &interfaces[i];
/*
* Verify that the interface matches the destination
* address.
*/
if ((sin->sin_addr.s_addr & ifp->netmask.s_addr) ==
(ifp->address.s_addr & ifp->netmask.s_addr)) {
if (debug) {
logmsg(LOG_DEBUG, "Unicast to %s ",
pr_name(sin->sin_addr));
logmsg(LOG_DEBUG, "on interface %s, %s\n",
ifp->name,
pr_name(ifp->address));
}
cc = sendto( s, (char *)outpack, packetlen, 0,
(struct sockaddr *)sin,
sizeof(struct sockaddr));
} else
cc = packetlen;
}
if( cc < 0 || cc != packetlen ) {
if (cc < 0) {
logperror("sendto");
} else {
logmsg(LOG_ERR, "wrote %s %d chars, ret=%d\n",
sendaddress, packetlen, cc );
}
}
}
}
#endif
/*
* P R _ T Y P E
*
* Convert an ICMP "type" field to a printable string.
*/
char *
pr_type(int t)
{
static char *ttab[] = {
"Echo Reply",
"ICMP 1",
"ICMP 2",
"Dest Unreachable",
"Source Quench",
"Redirect",
"ICMP 6",
"ICMP 7",
"Echo",
"Router Advertise",
"Router Solicitation",
"Time Exceeded",
"Parameter Problem",
"Timestamp",
"Timestamp Reply",
"Info Request",
"Info Reply",
"Netmask Request",
"Netmask Reply"
};
if ( t < 0 || t > 16 )
return("OUT-OF-RANGE");
return(ttab[t]);
}
/*
* P R _ N A M E
*
* Return a string name for the given IP address.
*/
char *pr_name(struct in_addr addr)
{
struct sockaddr_in sin = { .sin_family = AF_INET, .sin_addr = addr };
char hnamebuf[NI_MAXHOST] = "";
static char buf[sizeof(hnamebuf) + INET6_ADDRSTRLEN + sizeof(" ()")];
getnameinfo((struct sockaddr *) &sin, sizeof sin, hnamebuf, sizeof hnamebuf, NULL, 0, 0);
snprintf(buf, sizeof buf, "%s (%s)", hnamebuf, inet_ntoa(addr));
return(buf);
}
/*
* P R _ P A C K
*
* Print out the packet, if it came from us. This logic is necessary
* because ALL readers of the ICMP socket get a copy of ALL ICMP packets
* which arrive ('tis only fair). This permits multiple copies of this
* program to be run without having intermingled output (or statistics!).
*/
void
pr_pack(char *buf, int cc, struct sockaddr_in *from)
{
struct iphdr *ip;
struct icmphdr *icp;
int i;
int hlen;
ip = (struct iphdr *) ALLIGN(buf);
hlen = ip->ihl << 2;
if (cc < hlen + 8) {
if (verbose)
logmsg(LOG_INFO, "packet too short (%d bytes) from %s\n", cc,
pr_name(from->sin_addr));
return;
}
cc -= hlen;
icp = (struct icmphdr *)ALLIGN(buf + hlen);
switch (icp->type) {
case ICMP_ROUTER_ADVERTISEMENT:
{
struct icmp_ra *rap = (struct icmp_ra *)ALLIGN(icp);
struct icmp_ra_addr *ap;
#ifdef RDISC_SERVER
if (responder)
break;
#endif
/* TBD verify that the link is multicast or broadcast */
/* XXX Find out the link it came in over? */
if (in_cksum((unsigned short *)ALLIGN(buf+hlen), cc)) {
if (verbose)
logmsg(LOG_INFO, "ICMP %s from %s: Bad checksum\n",
pr_type((int)rap->icmp_type),
pr_name(from->sin_addr));
return;
}
if (rap->icmp_code != 0) {
if (verbose)
logmsg(LOG_INFO, "ICMP %s from %s: Code = %d\n",
pr_type((int)rap->icmp_type),
pr_name(from->sin_addr),
rap->icmp_code);
return;
}
if (rap->icmp_num_addrs < 1) {
if (verbose)
logmsg(LOG_INFO, "ICMP %s from %s: No addresses\n",
pr_type((int)rap->icmp_type),
pr_name(from->sin_addr));
return;
}
if (rap->icmp_wpa < 2) {
if (verbose)
logmsg(LOG_INFO, "ICMP %s from %s: Words/addr = %d\n",
pr_type((int)rap->icmp_type),
pr_name(from->sin_addr),
rap->icmp_wpa);
return;
}
if (cc <
8 + rap->icmp_num_addrs * rap->icmp_wpa * 4) {
if (verbose)
logmsg(LOG_INFO, "ICMP %s from %s: Too short %d, %d\n",
pr_type((int)rap->icmp_type),
pr_name(from->sin_addr),
cc,
8 + rap->icmp_num_addrs * rap->icmp_wpa * 4);
return;
}
if (verbose)
logmsg(LOG_INFO, "ICMP %s from %s, lifetime %d\n",
pr_type((int)rap->icmp_type),
pr_name(from->sin_addr),
ntohs(rap->icmp_lifetime));
/* Check that at least one router address is a neighbour
* on the arriving link.
*/
for (i = 0; (unsigned)i < rap->icmp_num_addrs; i++) {
struct in_addr ina;
ap = (struct icmp_ra_addr *)
ALLIGN(buf + hlen + 8 +
i * rap->icmp_wpa * 4);
ina.s_addr = ap->ira_addr;
if (verbose)
logmsg(LOG_INFO, "\taddress %s, preference 0x%x\n",
pr_name(ina),
(unsigned int)ntohl(ap->ira_preference));
if (is_directly_connected(ina))
record_router(ina,
ntohl(ap->ira_preference),
ntohs(rap->icmp_lifetime));
}
nreceived++;
if (!forever) {
do_fork();
forever = 1;
/*
* The next line was added so that the alarm is set for the new procces
* Fraser Gardiner Sun Microsystems Australia
*/
(void) alarm(TIMER_INTERVAL);
}
break;
}
#ifdef RDISC_SERVER
case ICMP_ROUTER_SOLICITATION:
{
struct sockaddr_in sin;
if (!responder)
break;
/* TBD verify that the link is multicast or broadcast */
/* XXX Find out the link it came in over? */
if (in_cksum((unsigned short *)ALLIGN(buf+hlen), cc)) {
if (verbose)
logmsg(LOG_INFO, "ICMP %s from %s: Bad checksum\n",
pr_type((int)icp->type),
pr_name(from->sin_addr));
return;
}
if (icp->code != 0) {
if (verbose)
logmsg(LOG_INFO, "ICMP %s from %s: Code = %d\n",
pr_type((int)icp->type),
pr_name(from->sin_addr),
icp->code);
return;
}
if (cc < ICMP_MINLEN) {
if (verbose)
logmsg(LOG_INFO, "ICMP %s from %s: Too short %d, %d\n",
pr_type((int)icp->type),
pr_name(from->sin_addr),
cc,
ICMP_MINLEN);
return;
}
if (verbose)
logmsg(LOG_INFO, "ICMP %s from %s\n",
pr_type((int)icp->type),
pr_name(from->sin_addr));
/* Check that ip_src is either a neighbour
* on the arriving link or 0.
*/
sin.sin_family = AF_INET;
if (ip->saddr == 0) {
/* If it was sent to the broadcast address we respond
* to the broadcast address.
*/
if (IN_CLASSD(ntohl(ip->daddr)))
sin.sin_addr.s_addr = htonl(0xe0000001);
else
sin.sin_addr.s_addr = INADDR_BROADCAST;
/* Restart the timer when we broadcast */
left_until_advertise = min_adv_int +
((max_adv_int - min_adv_int)
* (random() % 1000)/1000);
} else {
sin.sin_addr.s_addr = ip->saddr;
if (!is_directly_connected(sin.sin_addr)) {
if (verbose)
logmsg(LOG_INFO, "ICMP %s from %s: source not directly connected\n",
pr_type((int)icp->type),
pr_name(from->sin_addr));
break;
}
}
nreceived++;
ntransmitted++;
advertise(&sin, lifetime);
break;
}
#endif
}
}
/*
* I N _ C K S U M
*
* Checksum routine for Internet Protocol family headers (C Version)
*
*/
#if BYTE_ORDER == LITTLE_ENDIAN
# define ODDBYTE(v) (v)
#elif BYTE_ORDER == BIG_ENDIAN
# define ODDBYTE(v) ((unsigned short)(v) << 8)
#else
# define ODDBYTE(v) htons((unsigned short)(v) << 8)
#endif
unsigned short in_cksum(unsigned short *addr, int len)
{
int nleft = len;
unsigned short *w = addr;
unsigned short answer;
int sum = 0;
/*
* Our algorithm is simple, using a 32 bit accumulator (sum),
* we add sequential 16 bit words to it, and at the end, fold
* back all the carry bits from the top 16 bits into the lower
* 16 bits.
*/
while( nleft > 1 ) {
sum += *w++;
nleft -= 2;
}
/* mop up an odd byte, if necessary */
if( nleft == 1 )
sum += ODDBYTE(*(unsigned char *)w); /* le16toh() may be unavailable on old systems */
/*
* add back carry outs from top 16 bits to low 16 bits
*/
sum = (sum >> 16) + (sum & 0xffff); /* add hi 16 to low 16 */
sum += (sum >> 16); /* add carry */
answer = ~sum; /* truncate to 16 bits */
return (answer);
}
/*
* F I N I S H
*
* Print out statistics, and give up.
* Heavily buffered STDIO is used here, so that all the statistics
* will be written with 1 sys-write call. This is nice when more
* than one copy of the program is running on a terminal; it prevents
* the statistics output from becoming intermingled.
*/
void
finish()
{
#ifdef RDISC_SERVER
if (responder) {
/* Send out a packet with a preference so that all
* hosts will know that we are dead.
*
* Wrong comment, wrong code.
* ttl must be set to 0 instead. --ANK
*/
logmsg(LOG_ERR, "terminated\n");
ntransmitted++;
advertise(&whereto, 0);
}
#endif
logmsg(LOG_INFO, "\n----%s rdisc Statistics----\n"
"%d packets transmitted, "
"%d packets received, \n",
sendaddress, ntransmitted, nreceived);
(void) fflush(stdout);
exit(0);
}
void
graceful_finish()
{
discard_table();
finish();
exit(0);
}
/* From libc/rpc/pmap_rmt.c */
int
sendbcast(int socket, char *packet, int packetlen)
{
int i, cc;
for (i = 0; i < num_interfaces; i++) {
if ((interfaces[i].flags & (IFF_BROADCAST|IFF_POINTOPOINT)) == 0)
continue;
cc = sendbcastif(socket, packet, packetlen, &interfaces[i]);
if (cc!= packetlen) {
return (cc);
}