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
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
|
/* $OpenBSD: ip_input.c,v 1.38 1999/04/11 19:41:38 niklas Exp $ */
/* $NetBSD: ip_input.c,v 1.30 1996/03/16 23:53:58 christos Exp $ */
/*
* Copyright (c) 1982, 1986, 1988, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)ip_input.c 8.2 (Berkeley) 1/4/94
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/domain.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#include <sys/errno.h>
#include <sys/time.h>
#include <sys/kernel.h>
#include <sys/syslog.h>
#include <sys/proc.h>
#include <vm/vm.h>
#include <sys/sysctl.h>
#include <net/if.h>
#include <net/if_dl.h>
#include <net/route.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/if_ether.h>
#include <netinet/ip.h>
#include <netinet/in_pcb.h>
#include <netinet/in_var.h>
#include <netinet/ip_var.h>
#include <netinet/ip_icmp.h>
#include <netinet/ip_ipsp.h>
#ifndef IPFORWARDING
#ifdef GATEWAY
#define IPFORWARDING 1 /* forward IP packets not for us */
#else /* GATEWAY */
#define IPFORWARDING 0 /* don't forward IP packets not for us */
#endif /* GATEWAY */
#endif /* IPFORWARDING */
#ifndef IPSENDREDIRECTS
#define IPSENDREDIRECTS 1
#endif
/*
* Note: DIRECTED_BROADCAST is handled this way so that previous
* configuration using this option will Just Work.
*/
#ifndef IPDIRECTEDBCAST
#ifdef DIRECTED_BROADCAST
#define IPDIRECTEDBCAST 1
#else
#define IPDIRECTEDBCAST 0
#endif /* DIRECTED_BROADCAST */
#endif /* IPDIRECTEDBCAST */
int ipforwarding = IPFORWARDING;
int ipsendredirects = IPSENDREDIRECTS;
int ip_dosourceroute = 0; /* no src-routing unless sysctl'd to enable */
int ip_defttl = IPDEFTTL;
int ip_directedbcast = IPDIRECTEDBCAST;
#ifdef DIAGNOSTIC
int ipprintfs = 0;
#endif
int ipsec_auth_default_level = IPSEC_AUTH_LEVEL_DEFAULT;
int ipsec_esp_trans_default_level = IPSEC_ESP_TRANS_LEVEL_DEFAULT;
int ipsec_esp_network_default_level = IPSEC_ESP_NETWORK_LEVEL_DEFAULT;
/* Keep track of memory used for reassembly */
int ip_maxqueue = 300;
int ip_frags = 0;
/* from in_pcb.c */
extern int ipport_firstauto;
extern int ipport_lastauto;
extern int ipport_hifirstauto;
extern int ipport_hilastauto;
extern struct baddynamicports baddynamicports;
extern struct domain inetdomain;
extern struct protosw inetsw[];
u_char ip_protox[IPPROTO_MAX];
int ipqmaxlen = IFQ_MAXLEN;
struct in_ifaddrhead in_ifaddr;
struct ifqueue ipintrq;
#if defined(IPFILTER) || defined(IPFILTER_LKM)
int (*fr_checkp) __P((struct ip *, int, struct ifnet *, int,
struct mbuf **));
#endif
int ipq_locked;
static __inline int ipq_lock_try __P((void));
static __inline void ipq_unlock __P((void));
static __inline int
ipq_lock_try()
{
int s;
s = splimp();
if (ipq_locked) {
splx(s);
return (0);
}
ipq_locked = 1;
splx(s);
return (1);
}
#define ipq_lock() ipq_lock_try()
static __inline void
ipq_unlock()
{
int s;
s = splimp();
ipq_locked = 0;
splx(s);
}
char *
inet_ntoa(ina)
struct in_addr ina;
{
static char buf[4*sizeof "123"];
unsigned char *ucp = (unsigned char *)&ina;
sprintf(buf, "%d.%d.%d.%d", ucp[0] & 0xff, ucp[1] & 0xff,
ucp[2] & 0xff, ucp[3] & 0xff);
return (buf);
}
/*
* We need to save the IP options in case a protocol wants to respond
* to an incoming packet over the same route if the packet got here
* using IP source routing. This allows connection establishment and
* maintenance when the remote end is on a network that is not known
* to us.
*/
int ip_nhops = 0;
static struct ip_srcrt {
struct in_addr dst; /* final destination */
char nop; /* one NOP to align */
char srcopt[IPOPT_OFFSET + 1]; /* OPTVAL, OLEN and OFFSET */
struct in_addr route[MAX_IPOPTLEN/sizeof(struct in_addr)];
} ip_srcrt;
static void save_rte __P((u_char *, struct in_addr));
static int ip_weadvertise(u_int32_t);
/*
* IP initialization: fill in IP protocol switch table.
* All protocols not implemented in kernel go to raw IP protocol handler.
*/
void
ip_init()
{
register struct protosw *pr;
register int i;
const u_int16_t defbaddynamicports_tcp[] = DEFBADDYNAMICPORTS_TCP;
const u_int16_t defbaddynamicports_udp[] = DEFBADDYNAMICPORTS_UDP;
pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
if (pr == 0)
panic("ip_init");
for (i = 0; i < IPPROTO_MAX; i++)
ip_protox[i] = pr - inetsw;
for (pr = inetdomain.dom_protosw;
pr < inetdomain.dom_protoswNPROTOSW; pr++)
if (pr->pr_domain->dom_family == PF_INET &&
pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW)
ip_protox[pr->pr_protocol] = pr - inetsw;
LIST_INIT(&ipq);
ipintrq.ifq_maxlen = ipqmaxlen;
TAILQ_INIT(&in_ifaddr);
/* Fill in list of ports not to allocate dynamically. */
bzero((void *)&baddynamicports, sizeof(baddynamicports));
for (i = 0; defbaddynamicports_tcp[i] != 0; i++)
DP_SET(baddynamicports.tcp, defbaddynamicports_tcp[i]);
for (i = 0; defbaddynamicports_udp[i] != 0; i++)
DP_SET(baddynamicports.udp, defbaddynamicports_tcp[i]);
}
struct sockaddr_in ipaddr = { sizeof(ipaddr), AF_INET };
struct route ipforward_rt;
void
ipintr()
{
register struct mbuf *m;
int s;
if (needqueuedrain)
m_reclaim();
while (1) {
/*
* Get next datagram off input queue and get IP header
* in first mbuf.
*/
s = splimp();
IF_DEQUEUE(&ipintrq, m);
splx(s);
if (m == 0)
return;
#ifdef DIAGNOSTIC
if ((m->m_flags & M_PKTHDR) == 0)
panic("ipintr no HDR");
#endif
ipv4_input(m, 0, NULL, 0);
}
}
/*
* Ip input routine. Checksum and byte swap header. If fragmented
* try to reassemble. Process options. Pass to next level.
*/
void
ipv4_input(struct mbuf *m, ...)
{
register struct ip *ip;
register struct ipq *fp;
struct ipqent *ipqe;
int hlen, mff;
va_list ap;
int extra;
va_start(ap, m);
extra = va_arg(ap, int);
va_end(ap);
if (extra) {
struct mbuf *newpacket;
if (!(newpacket = m_split(m, extra, M_NOWAIT))) {
m_freem(m);
return;
}
newpacket->m_flags |= m->m_flags;
m_freem(m);
m = newpacket;
extra = 0;
}
/*
* If no IP addresses have been set yet but the interfaces
* are receiving, can't do anything with incoming packets yet.
*/
if (in_ifaddr.tqh_first == 0)
goto bad;
ipstat.ips_total++;
if (m->m_len < sizeof (struct ip) &&
(m = m_pullup(m, sizeof (struct ip))) == 0) {
ipstat.ips_toosmall++;
return;
}
ip = mtod(m, struct ip *);
if (ip->ip_v != IPVERSION) {
ipstat.ips_badvers++;
goto bad;
}
hlen = ip->ip_hl << 2;
if (hlen < sizeof(struct ip)) { /* minimum header length */
ipstat.ips_badhlen++;
goto bad;
}
if (hlen > m->m_len) {
if ((m = m_pullup(m, hlen)) == 0) {
ipstat.ips_badhlen++;
return;
}
ip = mtod(m, struct ip *);
}
if ((ip->ip_sum = in_cksum(m, hlen)) != 0) {
ipstat.ips_badsum++;
goto bad;
}
/*
* Convert fields to host representation.
*/
NTOHS(ip->ip_len);
if (ip->ip_len < hlen) {
ipstat.ips_badlen++;
goto bad;
}
NTOHS(ip->ip_id);
NTOHS(ip->ip_off);
/*
* Check that the amount of data in the buffers
* is as at least much as the IP header would have us expect.
* Trim mbufs if longer than we expect.
* Drop packet if shorter than we expect.
*/
if (m->m_pkthdr.len < ip->ip_len) {
ipstat.ips_tooshort++;
goto bad;
}
if (m->m_pkthdr.len > ip->ip_len) {
if (m->m_len == m->m_pkthdr.len) {
m->m_len = ip->ip_len;
m->m_pkthdr.len = ip->ip_len;
} else
m_adj(m, ip->ip_len - m->m_pkthdr.len);
}
#if defined(IPFILTER) || defined(IPFILTER_LKM)
/*
* Check if we want to allow this packet to be processed.
* Consider it to be bad if not.
*/
{
struct mbuf *m0 = m;
if (fr_checkp && (*fr_checkp)(ip, hlen, m->m_pkthdr.rcvif, 0, &m0))
return;
ip = mtod(m = m0, struct ip *);
}
#endif
/*
* Process options and, if not destined for us,
* ship it on. ip_dooptions returns 1 when an
* error was detected (causing an icmp message
* to be sent and the original packet to be freed).
*/
ip_nhops = 0; /* for source routed packets */
if (hlen > sizeof (struct ip) && ip_dooptions(m))
return;
/*
* Check our list of addresses, to see if the packet is for us.
*/
if (in_iawithaddr(ip->ip_dst, m))
goto ours;
if (IN_MULTICAST(ip->ip_dst.s_addr)) {
struct in_multi *inm;
#ifdef MROUTING
extern struct socket *ip_mrouter;
if (m->m_flags & M_EXT) {
if ((m = m_pullup(m, hlen)) == 0) {
ipstat.ips_toosmall++;
return;
}
ip = mtod(m, struct ip *);
}
if (ip_mrouter) {
/*
* If we are acting as a multicast router, all
* incoming multicast packets are passed to the
* kernel-level multicast forwarding function.
* The packet is returned (relatively) intact; if
* ip_mforward() returns a non-zero value, the packet
* must be discarded, else it may be accepted below.
*
* (The IP ident field is put in the same byte order
* as expected when ip_mforward() is called from
* ip_output().)
*/
ip->ip_id = htons(ip->ip_id);
if (ip_mforward(m, m->m_pkthdr.rcvif) != 0) {
ipstat.ips_cantforward++;
m_freem(m);
return;
}
ip->ip_id = ntohs(ip->ip_id);
/*
* The process-level routing demon needs to receive
* all multicast IGMP packets, whether or not this
* host belongs to their destination groups.
*/
if (ip->ip_p == IPPROTO_IGMP)
goto ours;
ipstat.ips_forward++;
}
#endif
/*
* See if we belong to the destination multicast group on the
* arrival interface.
*/
IN_LOOKUP_MULTI(ip->ip_dst, m->m_pkthdr.rcvif, inm);
if (inm == NULL) {
ipstat.ips_cantforward++;
m_freem(m);
return;
}
goto ours;
}
if (ip->ip_dst.s_addr == INADDR_BROADCAST ||
ip->ip_dst.s_addr == INADDR_ANY)
goto ours;
/*
* Not for us; forward if possible and desirable.
*/
if (ipforwarding == 0) {
ipstat.ips_cantforward++;
m_freem(m);
} else
ip_forward(m, 0);
return;
ours:
/*
* If offset or IP_MF are set, must reassemble.
* Otherwise, nothing need be done.
* (We could look in the reassembly queue to see
* if the packet was previously fragmented,
* but it's not worth the time; just let them time out.)
*/
if (ip->ip_off &~ (IP_DF | IP_RF)) {
if (m->m_flags & M_EXT) { /* XXX */
if ((m = m_pullup(m, hlen)) == 0) {
ipstat.ips_toosmall++;
return;
}
ip = mtod(m, struct ip *);
}
/*
* Look for queue of fragments
* of this datagram.
*/
ipq_lock();
for (fp = ipq.lh_first; fp != NULL; fp = fp->ipq_q.le_next)
if (ip->ip_id == fp->ipq_id &&
ip->ip_src.s_addr == fp->ipq_src.s_addr &&
ip->ip_dst.s_addr == fp->ipq_dst.s_addr &&
ip->ip_p == fp->ipq_p)
goto found;
fp = 0;
found:
/*
* Adjust ip_len to not reflect header,
* set ipqe_mff if more fragments are expected,
* convert offset of this to bytes.
*/
ip->ip_len -= hlen;
mff = (ip->ip_off & IP_MF) != 0;
if (mff) {
/*
* Make sure that fragments have a data length
* that's a non-zero multiple of 8 bytes.
*/
if (ip->ip_len == 0 || (ip->ip_len & 0x7) != 0) {
ipstat.ips_badfrags++;
ipq_unlock();
goto bad;
}
}
ip->ip_off <<= 3;
/*
* If datagram marked as having more fragments
* or if this is not the first fragment,
* attempt reassembly; if it succeeds, proceed.
*/
if (mff || ip->ip_off) {
ipstat.ips_fragments++;
if (ip_frags + 1 > ip_maxqueue) {
ip_flush();
ipstat.ips_rcvmemdrop++;
ipq_unlock();
goto bad;
}
MALLOC(ipqe, struct ipqent *, sizeof (struct ipqent),
M_IPQ, M_NOWAIT);
if (ipqe == NULL) {
ipstat.ips_rcvmemdrop++;
ipq_unlock();
goto bad;
}
ip_frags++;
ipqe->ipqe_mff = mff;
ipqe->ipqe_ip = ip;
ip = ip_reass(ipqe, fp);
if (ip == 0) {
ipq_unlock();
return;
}
ipstat.ips_reassembled++;
m = dtom(ip);
hlen = ip->ip_hl << 2;
} else
if (fp)
ip_freef(fp);
ipq_unlock();
} else
ip->ip_len -= hlen;
/*
* Switch out to protocol's input routine.
*/
ipstat.ips_delivered++;
(*inetsw[ip_protox[ip->ip_p]].pr_input)(m, hlen, NULL, 0);
return;
bad:
m_freem(m);
}
struct in_ifaddr *
in_iawithaddr(ina, m)
struct in_addr ina;
register struct mbuf *m;
{
register struct in_ifaddr *ia;
for (ia = in_ifaddr.tqh_first; ia; ia = ia->ia_list.tqe_next) {
if ((ina.s_addr == ia->ia_addr.sin_addr.s_addr) ||
((ia->ia_ifp->if_flags & (IFF_LOOPBACK|IFF_LINK1)) ==
(IFF_LOOPBACK|IFF_LINK1) &&
ia->ia_subnet == (ina.s_addr & ia->ia_subnetmask)))
return ia;
if (m && ((ip_directedbcast == 0) || (ip_directedbcast &&
ia->ia_ifp == m->m_pkthdr.rcvif)) &&
(ia->ia_ifp->if_flags & IFF_BROADCAST)) {
if (ina.s_addr == ia->ia_broadaddr.sin_addr.s_addr ||
ina.s_addr == ia->ia_netbroadcast.s_addr ||
/*
* Look for all-0's host part (old broadcast addr),
* either for subnet or net.
*/
ina.s_addr == ia->ia_subnet ||
ina.s_addr == ia->ia_net)
return ia;
}
}
return NULL;
}
/*
* Take incoming datagram fragment and try to
* reassemble it into whole datagram. If a chain for
* reassembly of this datagram already exists, then it
* is given as fp; otherwise have to make a chain.
*/
struct ip *
ip_reass(ipqe, fp)
register struct ipqent *ipqe;
register struct ipq *fp;
{
register struct mbuf *m = dtom(ipqe->ipqe_ip);
register struct ipqent *nq, *p, *q;
struct ip *ip;
struct mbuf *t;
int hlen = ipqe->ipqe_ip->ip_hl << 2;
int i, next;
/*
* Presence of header sizes in mbufs
* would confuse code below.
*/
m->m_data += hlen;
m->m_len -= hlen;
/*
* If first fragment to arrive, create a reassembly queue.
*/
if (fp == 0) {
if ((t = m_get(M_DONTWAIT, MT_FTABLE)) == NULL)
goto dropfrag;
fp = mtod(t, struct ipq *);
LIST_INSERT_HEAD(&ipq, fp, ipq_q);
fp->ipq_ttl = IPFRAGTTL;
fp->ipq_p = ipqe->ipqe_ip->ip_p;
fp->ipq_id = ipqe->ipqe_ip->ip_id;
LIST_INIT(&fp->ipq_fragq);
fp->ipq_src = ipqe->ipqe_ip->ip_src;
fp->ipq_dst = ipqe->ipqe_ip->ip_dst;
p = NULL;
goto insert;
}
/*
* Find a segment which begins after this one does.
*/
for (p = NULL, q = fp->ipq_fragq.lh_first; q != NULL;
p = q, q = q->ipqe_q.le_next)
if (q->ipqe_ip->ip_off > ipqe->ipqe_ip->ip_off)
break;
/*
* If there is a preceding segment, it may provide some of
* our data already. If so, drop the data from the incoming
* segment. If it provides all of our data, drop us.
*/
if (p != NULL) {
i = p->ipqe_ip->ip_off + p->ipqe_ip->ip_len -
ipqe->ipqe_ip->ip_off;
if (i > 0) {
if (i >= ipqe->ipqe_ip->ip_len)
goto dropfrag;
m_adj(dtom(ipqe->ipqe_ip), i);
ipqe->ipqe_ip->ip_off += i;
ipqe->ipqe_ip->ip_len -= i;
}
}
/*
* While we overlap succeeding segments trim them or,
* if they are completely covered, dequeue them.
*/
for (; q != NULL && ipqe->ipqe_ip->ip_off + ipqe->ipqe_ip->ip_len >
q->ipqe_ip->ip_off; q = nq) {
i = (ipqe->ipqe_ip->ip_off + ipqe->ipqe_ip->ip_len) -
q->ipqe_ip->ip_off;
if (i < q->ipqe_ip->ip_len) {
q->ipqe_ip->ip_len -= i;
q->ipqe_ip->ip_off += i;
m_adj(dtom(q->ipqe_ip), i);
break;
}
nq = q->ipqe_q.le_next;
m_freem(dtom(q->ipqe_ip));
LIST_REMOVE(q, ipqe_q);
FREE(q, M_IPQ);
ip_frags--;
}
insert:
/*
* Stick new segment in its place;
* check for complete reassembly.
*/
if (p == NULL) {
LIST_INSERT_HEAD(&fp->ipq_fragq, ipqe, ipqe_q);
} else {
LIST_INSERT_AFTER(p, ipqe, ipqe_q);
}
next = 0;
for (p = NULL, q = fp->ipq_fragq.lh_first; q != NULL;
p = q, q = q->ipqe_q.le_next) {
if (q->ipqe_ip->ip_off != next)
return (0);
next += q->ipqe_ip->ip_len;
}
if (p->ipqe_mff)
return (0);
/*
* Reassembly is complete. Check for a bogus message size and
* concatenate fragments.
*/
q = fp->ipq_fragq.lh_first;
ip = q->ipqe_ip;
if ((next + (ip->ip_hl << 2)) > IP_MAXPACKET) {
ipstat.ips_toolong++;
ip_freef(fp);
return (0);
}
m = dtom(q->ipqe_ip);
t = m->m_next;
m->m_next = 0;
m_cat(m, t);
nq = q->ipqe_q.le_next;
FREE(q, M_IPQ);
ip_frags--;
for (q = nq; q != NULL; q = nq) {
t = dtom(q->ipqe_ip);
nq = q->ipqe_q.le_next;
FREE(q, M_IPQ);
ip_frags--;
m_cat(m, t);
}
/*
* Create header for new ip packet by
* modifying header of first packet;
* dequeue and discard fragment reassembly header.
* Make header visible.
*/
ip->ip_len = next;
ip->ip_src = fp->ipq_src;
ip->ip_dst = fp->ipq_dst;
LIST_REMOVE(fp, ipq_q);
(void) m_free(dtom(fp));
m->m_len += (ip->ip_hl << 2);
m->m_data -= (ip->ip_hl << 2);
/* some debugging cruft by sklower, below, will go away soon */
if (m->m_flags & M_PKTHDR) { /* XXX this should be done elsewhere */
register int plen = 0;
for (t = m; m; m = m->m_next)
plen += m->m_len;
t->m_pkthdr.len = plen;
}
return (ip);
dropfrag:
ipstat.ips_fragdropped++;
m_freem(m);
FREE(ipqe, M_IPQ);
ip_frags--;
return (0);
}
/*
* Free a fragment reassembly header and all
* associated datagrams.
*/
void
ip_freef(fp)
struct ipq *fp;
{
register struct ipqent *q, *p;
for (q = fp->ipq_fragq.lh_first; q != NULL; q = p) {
p = q->ipqe_q.le_next;
m_freem(dtom(q->ipqe_ip));
LIST_REMOVE(q, ipqe_q);
FREE(q, M_IPQ);
ip_frags--;
}
LIST_REMOVE(fp, ipq_q);
(void) m_free(dtom(fp));
}
/*
* IP timer processing;
* if a timer expires on a reassembly
* queue, discard it.
*/
void
ip_slowtimo()
{
register struct ipq *fp, *nfp;
int s = splsoftnet();
ipq_lock();
for (fp = ipq.lh_first; fp != NULL; fp = nfp) {
nfp = fp->ipq_q.le_next;
if (--fp->ipq_ttl == 0) {
ipstat.ips_fragtimeout++;
ip_freef(fp);
}
}
ipq_unlock();
splx(s);
}
/*
* Drain off all datagram fragments.
*/
void
ip_drain()
{
if (ipq_lock_try() == 0)
return;
while (ipq.lh_first != NULL) {
ipstat.ips_fragdropped++;
ip_freef(ipq.lh_first);
}
ipq_unlock();
}
/*
* Flush a bunch of datagram fragments, till we are down to 75%.
*/
void
ip_flush()
{
int max = 50;
/* ipq already locked */
while (ipq.lh_first != NULL && ip_frags > ip_maxqueue * 3 / 4 && --max) {
ipstat.ips_fragdropped++;
ip_freef(ipq.lh_first);
}
}
/*
* Do option processing on a datagram,
* possibly discarding it if bad options are encountered,
* or forwarding it if source-routed.
* Returns 1 if packet has been forwarded/freed,
* 0 if the packet should be processed further.
*/
int
ip_dooptions(m)
struct mbuf *m;
{
register struct ip *ip = mtod(m, struct ip *);
register u_char *cp;
register struct ip_timestamp *ipt;
register struct in_ifaddr *ia;
int opt, optlen, cnt, off, code, type = ICMP_PARAMPROB, forward = 0;
struct in_addr *sin, dst;
n_time ntime;
dst = ip->ip_dst;
cp = (u_char *)(ip + 1);
cnt = (ip->ip_hl << 2) - sizeof (struct ip);
for (; cnt > 0; cnt -= optlen, cp += optlen) {
opt = cp[IPOPT_OPTVAL];
if (opt == IPOPT_EOL)
break;
if (opt == IPOPT_NOP)
optlen = 1;
else {
optlen = cp[IPOPT_OLEN];
if (optlen <= 0 || optlen > cnt) {
code = &cp[IPOPT_OLEN] - (u_char *)ip;
goto bad;
}
}
switch (opt) {
default:
break;
/*
* Source routing with record.
* Find interface with current destination address.
* If none on this machine then drop if strictly routed,
* or do nothing if loosely routed.
* Record interface address and bring up next address
* component. If strictly routed make sure next
* address is on directly accessible net.
*/
case IPOPT_LSRR:
case IPOPT_SSRR:
if (!ip_dosourceroute) {
char buf[4*sizeof "123"];
strcpy(buf, inet_ntoa(ip->ip_dst));
log(LOG_WARNING,
"attempted source route from %s to %s\n",
inet_ntoa(ip->ip_src), buf);
type = ICMP_UNREACH;
code = ICMP_UNREACH_SRCFAIL;
goto bad;
}
if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
code = &cp[IPOPT_OFFSET] - (u_char *)ip;
goto bad;
}
ipaddr.sin_addr = ip->ip_dst;
ia = ifatoia(ifa_ifwithaddr(sintosa(&ipaddr)));
if (ia == 0) {
if (opt == IPOPT_SSRR) {
type = ICMP_UNREACH;
code = ICMP_UNREACH_SRCFAIL;
goto bad;
}
/*
* Loose routing, and not at next destination
* yet; nothing to do except forward.
*/
break;
}
off--; /* 0 origin */
if (off > optlen - sizeof(struct in_addr)) {
/*
* End of source route. Should be for us.
*/
save_rte(cp, ip->ip_src);
break;
}
/*
* locate outgoing interface
*/
bcopy((caddr_t)(cp + off), (caddr_t)&ipaddr.sin_addr,
sizeof(ipaddr.sin_addr));
if (opt == IPOPT_SSRR) {
#define INA struct in_ifaddr *
#define SA struct sockaddr *
if ((ia = (INA)ifa_ifwithdstaddr((SA)&ipaddr)) == 0)
ia = (INA)ifa_ifwithnet((SA)&ipaddr);
} else
ia = ip_rtaddr(ipaddr.sin_addr);
if (ia == 0) {
type = ICMP_UNREACH;
code = ICMP_UNREACH_SRCFAIL;
goto bad;
}
ip->ip_dst = ipaddr.sin_addr;
bcopy((caddr_t)&ia->ia_addr.sin_addr,
(caddr_t)(cp + off), sizeof(struct in_addr));
cp[IPOPT_OFFSET] += sizeof(struct in_addr);
/*
* Let ip_intr's mcast routing check handle mcast pkts
*/
forward = !IN_MULTICAST(ip->ip_dst.s_addr);
break;
case IPOPT_RR:
if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
code = &cp[IPOPT_OFFSET] - (u_char *)ip;
goto bad;
}
/*
* If no space remains, ignore.
*/
off--; /* 0 origin */
if (off > optlen - sizeof(struct in_addr))
break;
bcopy((caddr_t)(&ip->ip_dst), (caddr_t)&ipaddr.sin_addr,
sizeof(ipaddr.sin_addr));
/*
* locate outgoing interface; if we're the destination,
* use the incoming interface (should be same).
*/
if ((ia = (INA)ifa_ifwithaddr((SA)&ipaddr)) == 0 &&
(ia = ip_rtaddr(ipaddr.sin_addr)) == 0) {
type = ICMP_UNREACH;
code = ICMP_UNREACH_HOST;
goto bad;
}
bcopy((caddr_t)&ia->ia_addr.sin_addr,
(caddr_t)(cp + off), sizeof(struct in_addr));
cp[IPOPT_OFFSET] += sizeof(struct in_addr);
break;
case IPOPT_TS:
code = cp - (u_char *)ip;
ipt = (struct ip_timestamp *)cp;
if (ipt->ipt_ptr < 5 || ipt->ipt_len < 5)
goto bad;
if (ipt->ipt_ptr - 1 + sizeof(n_time) > ipt->ipt_len) {
if (++ipt->ipt_oflw == 0)
goto bad;
break;
}
sin = (struct in_addr *)(cp + ipt->ipt_ptr - 1);
switch (ipt->ipt_flg) {
case IPOPT_TS_TSONLY:
break;
case IPOPT_TS_TSANDADDR:
if (ipt->ipt_ptr - 1 + sizeof(n_time) +
sizeof(struct in_addr) > ipt->ipt_len)
goto bad;
ipaddr.sin_addr = dst;
ia = (INA)ifaof_ifpforaddr((SA)&ipaddr,
m->m_pkthdr.rcvif);
if (ia == 0)
continue;
bcopy((caddr_t)&ia->ia_addr.sin_addr,
(caddr_t)sin, sizeof(struct in_addr));
ipt->ipt_ptr += sizeof(struct in_addr);
break;
case IPOPT_TS_PRESPEC:
if (ipt->ipt_ptr - 1 + sizeof(n_time) +
sizeof(struct in_addr) > ipt->ipt_len)
goto bad;
bcopy((caddr_t)sin, (caddr_t)&ipaddr.sin_addr,
sizeof(struct in_addr));
if (ifa_ifwithaddr((SA)&ipaddr) == 0)
continue;
ipt->ipt_ptr += sizeof(struct in_addr);
break;
default:
goto bad;
}
ntime = iptime();
bcopy((caddr_t)&ntime, (caddr_t)cp + ipt->ipt_ptr - 1,
sizeof(n_time));
ipt->ipt_ptr += sizeof(n_time);
}
}
if (forward && ipforwarding) {
ip_forward(m, 1);
return (1);
}
return (0);
bad:
ip->ip_len -= ip->ip_hl << 2; /* XXX icmp_error adds in hdr length */
HTONS(ip->ip_len); /* XXX because ip_input changed these three */
HTONS(ip->ip_id);
HTONS(ip->ip_off);
icmp_error(m, type, code, 0, 0);
ipstat.ips_badoptions++;
return (1);
}
/*
* Given address of next destination (final or next hop),
* return internet address info of interface to be used to get there.
*/
struct in_ifaddr *
ip_rtaddr(dst)
struct in_addr dst;
{
register struct sockaddr_in *sin;
sin = satosin(&ipforward_rt.ro_dst);
if (ipforward_rt.ro_rt == 0 || dst.s_addr != sin->sin_addr.s_addr) {
if (ipforward_rt.ro_rt) {
RTFREE(ipforward_rt.ro_rt);
ipforward_rt.ro_rt = 0;
}
sin->sin_family = AF_INET;
sin->sin_len = sizeof(*sin);
sin->sin_addr = dst;
rtalloc(&ipforward_rt);
}
if (ipforward_rt.ro_rt == 0)
return ((struct in_ifaddr *)0);
return (ifatoia(ipforward_rt.ro_rt->rt_ifa));
}
/*
* Save incoming source route for use in replies,
* to be picked up later by ip_srcroute if the receiver is interested.
*/
void
save_rte(option, dst)
u_char *option;
struct in_addr dst;
{
unsigned olen;
olen = option[IPOPT_OLEN];
#ifdef DIAGNOSTIC
if (ipprintfs)
printf("save_rte: olen %d\n", olen);
#endif
if (olen > sizeof(ip_srcrt) - (1 + sizeof(dst)))
return;
bcopy((caddr_t)option, (caddr_t)ip_srcrt.srcopt, olen);
ip_nhops = (olen - IPOPT_OFFSET - 1) / sizeof(struct in_addr);
ip_srcrt.dst = dst;
}
/*
* Check whether we do proxy ARP for this address and we point to ourselves.
* Code shamelessly copied from arplookup().
*/
static int
ip_weadvertise(addr)
u_int32_t addr;
{
register struct rtentry *rt;
register struct ifnet *ifp;
register struct ifaddr *ifa;
struct sockaddr_inarp sin;
sin.sin_len = sizeof(sin);
sin.sin_family = AF_INET;
sin.sin_addr.s_addr = addr;
sin.sin_other = SIN_PROXY;
rt = rtalloc1(sintosa(&sin), 0);
if (rt == 0)
return 0;
RTFREE(rt);
if ((rt->rt_flags & RTF_GATEWAY) || (rt->rt_flags & RTF_LLINFO) == 0 ||
rt->rt_gateway->sa_family != AF_LINK)
return 0;
for (ifp = ifnet.tqh_first; ifp != 0; ifp = ifp->if_list.tqe_next)
for (ifa = ifp->if_addrlist.tqh_first; ifa != 0;
ifa = ifa->ifa_list.tqe_next) {
if (ifa->ifa_addr->sa_family != rt->rt_gateway->sa_family)
continue;
if (!bcmp(LLADDR((struct sockaddr_dl *)ifa->ifa_addr),
LLADDR((struct sockaddr_dl *)rt->rt_gateway),
ETHER_ADDR_LEN))
return 1;
}
return 0;
}
/*
* Retrieve incoming source route for use in replies,
* in the same form used by setsockopt.
* The first hop is placed before the options, will be removed later.
*/
struct mbuf *
ip_srcroute()
{
register struct in_addr *p, *q;
register struct mbuf *m;
if (ip_nhops == 0)
return ((struct mbuf *)0);
m = m_get(M_DONTWAIT, MT_SOOPTS);
if (m == 0)
return ((struct mbuf *)0);
#define OPTSIZ (sizeof(ip_srcrt.nop) + sizeof(ip_srcrt.srcopt))
/* length is (nhops+1)*sizeof(addr) + sizeof(nop + srcrt header) */
m->m_len = ip_nhops * sizeof(struct in_addr) + sizeof(struct in_addr) +
OPTSIZ;
#ifdef DIAGNOSTIC
if (ipprintfs)
printf("ip_srcroute: nhops %d mlen %d", ip_nhops, m->m_len);
#endif
/*
* First save first hop for return route
*/
p = &ip_srcrt.route[ip_nhops - 1];
*(mtod(m, struct in_addr *)) = *p--;
#ifdef DIAGNOSTIC
if (ipprintfs)
printf(" hops %x", ntohl(mtod(m, struct in_addr *)->s_addr));
#endif
/*
* Copy option fields and padding (nop) to mbuf.
*/
ip_srcrt.nop = IPOPT_NOP;
ip_srcrt.srcopt[IPOPT_OFFSET] = IPOPT_MINOFF;
bcopy((caddr_t)&ip_srcrt.nop,
mtod(m, caddr_t) + sizeof(struct in_addr), OPTSIZ);
q = (struct in_addr *)(mtod(m, caddr_t) +
sizeof(struct in_addr) + OPTSIZ);
#undef OPTSIZ
/*
* Record return path as an IP source route,
* reversing the path (pointers are now aligned).
*/
while (p >= ip_srcrt.route) {
#ifdef DIAGNOSTIC
if (ipprintfs)
printf(" %x", ntohl(q->s_addr));
#endif
*q++ = *p--;
}
/*
* Last hop goes to final destination.
*/
*q = ip_srcrt.dst;
#ifdef DIAGNOSTIC
if (ipprintfs)
printf(" %x\n", ntohl(q->s_addr));
#endif
return (m);
}
/*
* Strip out IP options, at higher
* level protocol in the kernel.
* Second argument is buffer to which options
* will be moved, and return value is their length.
* XXX should be deleted; last arg currently ignored.
*/
void
ip_stripoptions(m, mopt)
register struct mbuf *m;
struct mbuf *mopt;
{
register int i;
struct ip *ip = mtod(m, struct ip *);
register caddr_t opts;
int olen;
olen = (ip->ip_hl<<2) - sizeof (struct ip);
opts = (caddr_t)(ip + 1);
i = m->m_len - (sizeof (struct ip) + olen);
bcopy(opts + olen, opts, (unsigned)i);
m->m_len -= olen;
if (m->m_flags & M_PKTHDR)
m->m_pkthdr.len -= olen;
ip->ip_hl = sizeof(struct ip) >> 2;
}
int inetctlerrmap[PRC_NCMDS] = {
0, 0, 0, 0,
0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH,
EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED,
EMSGSIZE, EHOSTUNREACH, 0, 0,
0, 0, 0, 0,
ENOPROTOOPT
};
/*
* Forward a packet. If some error occurs return the sender
* an icmp packet. Note we can't always generate a meaningful
* icmp message because icmp doesn't have a large enough repertoire
* of codes and types.
*
* If not forwarding, just drop the packet. This could be confusing
* if ipforwarding was zero but some routing protocol was advancing
* us as a gateway to somewhere. However, we must let the routing
* protocol deal with that.
*
* The srcrt parameter indicates whether the packet is being forwarded
* via a source route.
*/
void
ip_forward(m, srcrt)
struct mbuf *m;
int srcrt;
{
register struct ip *ip = mtod(m, struct ip *);
register struct sockaddr_in *sin;
register struct rtentry *rt;
int error, type = 0, code = 0;
struct mbuf *mcopy;
n_long dest;
struct ifnet *destifp;
dest = 0;
#ifdef DIAGNOSTIC
if (ipprintfs)
printf("forward: src %x dst %x ttl %x\n", ip->ip_src.s_addr,
ip->ip_dst.s_addr, ip->ip_ttl);
#endif
if (m->m_flags & M_BCAST || in_canforward(ip->ip_dst) == 0) {
ipstat.ips_cantforward++;
m_freem(m);
return;
}
HTONS(ip->ip_id);
if (ip->ip_ttl <= IPTTLDEC) {
HTONS(ip->ip_off);
HTONS(ip->ip_len);
icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, dest, 0);
return;
}
ip->ip_ttl -= IPTTLDEC;
sin = satosin(&ipforward_rt.ro_dst);
if ((rt = ipforward_rt.ro_rt) == 0 ||
ip->ip_dst.s_addr != sin->sin_addr.s_addr) {
if (ipforward_rt.ro_rt) {
RTFREE(ipforward_rt.ro_rt);
ipforward_rt.ro_rt = 0;
}
sin->sin_family = AF_INET;
sin->sin_len = sizeof(*sin);
sin->sin_addr = ip->ip_dst;
rtalloc(&ipforward_rt);
if (ipforward_rt.ro_rt == 0) {
HTONS(ip->ip_off);
HTONS(ip->ip_len);
icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, dest, 0);
return;
}
rt = ipforward_rt.ro_rt;
}
/*
* Save at most 68 bytes of the packet in case
* we need to generate an ICMP message to the src.
*/
mcopy = m_copy(m, 0, imin((int)ip->ip_len, 68));
/*
* If forwarding packet using same interface that it came in on,
* perhaps should send a redirect to sender to shortcut a hop.
* Only send redirect if source is sending directly to us,
* and if packet was not source routed (or has any options).
* Also, don't send redirect if forwarding using a default route
* or a route modified by a redirect.
* Don't send redirect if we advertise destination's arp address
* as ours (proxy arp).
*/
if (rt->rt_ifp == m->m_pkthdr.rcvif &&
(rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0 &&
satosin(rt_key(rt))->sin_addr.s_addr != 0 &&
ipsendredirects && !srcrt &&
!ip_weadvertise(satosin(rt_key(rt))->sin_addr.s_addr)) {
if (rt->rt_ifa &&
(ip->ip_src.s_addr & ifatoia(rt->rt_ifa)->ia_subnetmask) ==
ifatoia(rt->rt_ifa)->ia_subnet) {
if (rt->rt_flags & RTF_GATEWAY)
dest = satosin(rt->rt_gateway)->sin_addr.s_addr;
else
dest = ip->ip_dst.s_addr;
/* Router requirements says to only send host redirects */
type = ICMP_REDIRECT;
code = ICMP_REDIRECT_HOST;
#ifdef DIAGNOSTIC
if (ipprintfs)
printf("redirect (%d) to %x\n", code, (u_int32_t)dest);
#endif
}
}
error = ip_output(m, (struct mbuf *)0, &ipforward_rt,
(IP_FORWARDING | (ip_directedbcast ? IP_ALLOWBROADCAST : 0)),
0, NULL, NULL);
if (error)
ipstat.ips_cantforward++;
else {
ipstat.ips_forward++;
if (type)
ipstat.ips_redirectsent++;
else {
if (mcopy)
m_freem(mcopy);
return;
}
}
if (mcopy == NULL)
return;
destifp = NULL;
switch (error) {
case 0: /* forwarded, but need redirect */
/* type, code set above */
break;
case ENETUNREACH: /* shouldn't happen, checked above */
case EHOSTUNREACH:
case ENETDOWN:
case EHOSTDOWN:
default:
type = ICMP_UNREACH;
code = ICMP_UNREACH_HOST;
break;
case EMSGSIZE:
type = ICMP_UNREACH;
code = ICMP_UNREACH_NEEDFRAG;
if (ipforward_rt.ro_rt)
destifp = ipforward_rt.ro_rt->rt_ifp;
ipstat.ips_cantfrag++;
break;
case ENOBUFS:
type = ICMP_SOURCEQUENCH;
code = 0;
break;
}
ip = mtod(mcopy, struct ip *);
HTONS(ip->ip_off);
HTONS(ip->ip_len);
icmp_error(mcopy, type, code, dest, destifp);
}
int
ip_sysctl(name, namelen, oldp, oldlenp, newp, newlen)
int *name;
u_int namelen;
void *oldp;
size_t *oldlenp;
void *newp;
size_t newlen;
{
/* All sysctl names at this level are terminal. */
if (namelen != 1)
return (ENOTDIR);
switch (name[0]) {
case IPCTL_FORWARDING:
return (sysctl_int(oldp, oldlenp, newp, newlen, &ipforwarding));
case IPCTL_SENDREDIRECTS:
return (sysctl_int(oldp, oldlenp, newp, newlen,
&ipsendredirects));
case IPCTL_DEFTTL:
return (sysctl_int(oldp, oldlenp, newp, newlen, &ip_defttl));
#ifdef notyet
case IPCTL_DEFMTU:
return (sysctl_int(oldp, oldlenp, newp, newlen, &ip_mtu));
#endif
case IPCTL_SOURCEROUTE:
/*
* Don't allow this to change in a secure environment.
*/
if (newp && securelevel > 0)
return (EPERM);
return (sysctl_int(oldp, oldlenp, newp, newlen,
&ip_dosourceroute));
case IPCTL_DIRECTEDBCAST:
return (sysctl_int(oldp, oldlenp, newp, newlen,
&ip_directedbcast));
case IPCTL_IPPORT_FIRSTAUTO:
return (sysctl_int(oldp, oldlenp, newp, newlen,
&ipport_firstauto));
case IPCTL_IPPORT_LASTAUTO:
return (sysctl_int(oldp, oldlenp, newp, newlen,
&ipport_lastauto));
case IPCTL_IPPORT_HIFIRSTAUTO:
return (sysctl_int(oldp, oldlenp, newp, newlen,
&ipport_hifirstauto));
case IPCTL_IPPORT_HILASTAUTO:
return (sysctl_int(oldp, oldlenp, newp, newlen,
&ipport_hilastauto));
case IPCTL_IPPORT_MAXQUEUE:
return (sysctl_int(oldp, oldlenp, newp, newlen,
&ip_maxqueue));
case IPCTL_ENCDEBUG:
return (sysctl_int(oldp, oldlenp, newp, newlen, &encdebug));
default:
return (EOPNOTSUPP);
}
/* NOTREACHED */
}
|