summaryrefslogtreecommitdiffstats
path: root/sbin/dhclient/dhclient.c
blob: 4f2405a3409e2c54f7ea0f8de88bf73d6f7176e5 (plain)
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
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273
2274
2275
2276
2277
2278
2279
2280
2281
2282
2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
2298
2299
2300
2301
2302
2303
2304
2305
2306
2307
2308
2309
2310
2311
2312
2313
2314
2315
2316
2317
2318
2319
2320
2321
2322
2323
2324
2325
2326
2327
2328
2329
2330
2331
2332
2333
2334
2335
2336
2337
2338
2339
2340
2341
2342
2343
2344
2345
2346
2347
2348
2349
2350
2351
2352
2353
2354
2355
2356
2357
2358
2359
2360
2361
2362
2363
2364
2365
2366
2367
2368
2369
2370
2371
2372
2373
2374
2375
2376
2377
2378
2379
2380
2381
2382
2383
2384
2385
2386
2387
2388
2389
2390
2391
2392
2393
2394
2395
2396
2397
2398
2399
2400
2401
2402
2403
2404
2405
2406
2407
2408
2409
2410
2411
2412
2413
2414
2415
2416
2417
2418
2419
2420
2421
2422
2423
2424
2425
2426
2427
2428
2429
2430
2431
2432
2433
2434
2435
2436
2437
2438
2439
2440
2441
2442
2443
2444
2445
2446
2447
2448
2449
2450
2451
2452
2453
2454
2455
2456
2457
2458
2459
2460
2461
2462
2463
2464
2465
2466
2467
2468
2469
2470
2471
2472
2473
2474
2475
2476
2477
2478
2479
2480
2481
2482
2483
2484
2485
2486
2487
2488
2489
2490
2491
2492
2493
2494
2495
2496
2497
2498
2499
2500
2501
2502
2503
2504
2505
2506
2507
2508
2509
2510
2511
2512
2513
2514
2515
2516
2517
2518
2519
2520
2521
2522
2523
2524
2525
2526
2527
2528
2529
2530
2531
2532
2533
2534
2535
2536
2537
2538
2539
2540
2541
2542
2543
2544
2545
2546
2547
2548
2549
2550
2551
2552
2553
2554
2555
2556
2557
2558
2559
2560
2561
2562
2563
2564
2565
2566
2567
2568
2569
2570
2571
2572
2573
2574
2575
2576
2577
2578
2579
2580
2581
2582
2583
2584
2585
2586
2587
2588
2589
2590
2591
2592
2593
2594
2595
2596
2597
2598
2599
2600
2601
2602
2603
2604
2605
2606
2607
2608
2609
2610
2611
2612
2613
2614
2615
2616
2617
2618
2619
2620
2621
2622
2623
2624
2625
2626
2627
2628
2629
2630
2631
2632
2633
2634
2635
2636
2637
2638
2639
2640
2641
2642
2643
2644
2645
2646
2647
2648
2649
2650
2651
2652
2653
2654
2655
2656
2657
2658
2659
2660
2661
2662
2663
2664
2665
2666
2667
2668
2669
2670
2671
2672
2673
2674
2675
2676
2677
2678
2679
2680
2681
2682
2683
2684
2685
2686
2687
2688
2689
2690
2691
2692
2693
2694
2695
2696
2697
2698
2699
/*	$OpenBSD: dhclient.c,v 1.63 2005/02/06 17:10:13 krw Exp $	*/

/*
 * Copyright 2004 Henning Brauer <henning@openbsd.org>
 * Copyright (c) 1995, 1996, 1997, 1998, 1999
 * The Internet Software Consortium.    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. Neither the name of The Internet Software Consortium 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 INTERNET SOFTWARE CONSORTIUM 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 INTERNET SOFTWARE CONSORTIUM 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.
 *
 * This software has been written for the Internet Software Consortium
 * by Ted Lemon <mellon@fugue.com> in cooperation with Vixie
 * Enterprises.  To learn more about the Internet Software Consortium,
 * see ``http://www.vix.com/isc''.  To learn more about Vixie
 * Enterprises, see ``http://www.vix.com''.
 *
 * This client was substantially modified and enhanced by Elliot Poger
 * for use on Linux while he was working on the MosquitoNet project at
 * Stanford.
 *
 * The current version owes much to Elliot's Linux enhancements, but
 * was substantially reorganized and partially rewritten by Ted Lemon
 * so as to use the same networking framework that the Internet Software
 * Consortium DHCP server uses.   Much system-specific configuration code
 * was moved into a shell script so that as support for more operating
 * systems is added, it will not be necessary to port and maintain
 * system-specific configuration code to these operating systems - instead,
 * the shell script can invoke the native tools to accomplish the same
 * purpose.
 */

#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");

#include "dhcpd.h"
#include "privsep.h"

#include <net80211/ieee80211_freebsd.h>

#ifndef _PATH_VAREMPTY
#define	_PATH_VAREMPTY	"/var/empty"
#endif

#define	PERIOD 0x2e
#define	hyphenchar(c) ((c) == 0x2d)
#define	bslashchar(c) ((c) == 0x5c)
#define	periodchar(c) ((c) == PERIOD)
#define	asterchar(c) ((c) == 0x2a)
#define	alphachar(c) (((c) >= 0x41 && (c) <= 0x5a) || \
	    ((c) >= 0x61 && (c) <= 0x7a))
#define	digitchar(c) ((c) >= 0x30 && (c) <= 0x39)
#define	whitechar(c) ((c) == ' ' || (c) == '\t')

#define	borderchar(c) (alphachar(c) || digitchar(c))
#define	middlechar(c) (borderchar(c) || hyphenchar(c))
#define	domainchar(c) ((c) > 0x20 && (c) < 0x7f)

#define	CLIENT_PATH "PATH=/usr/bin:/usr/sbin:/bin:/sbin"

time_t cur_time;
time_t default_lease_time = 43200; /* 12 hours... */

char *path_dhclient_conf = _PATH_DHCLIENT_CONF;
char *path_dhclient_db = NULL;

int log_perror = 1;
int privfd;
int nullfd = -1;

struct iaddr iaddr_broadcast = { 4, { 255, 255, 255, 255 } };
struct in_addr inaddr_any;
struct sockaddr_in sockaddr_broadcast;

char *path_dhclient_pidfile;
struct pidfh *pidfile;

/*
 * ASSERT_STATE() does nothing now; it used to be
 * assert (state_is == state_shouldbe).
 */
#define ASSERT_STATE(state_is, state_shouldbe) {}

#define TIME_MAX 2147483647

int		log_priority;
int		no_daemon;
int		unknown_ok = 1;
int		routefd;

struct interface_info	*ifi;

int		 findproto(char *, int);
struct sockaddr	*get_ifa(char *, int);
void		 routehandler(struct protocol *);
void		 usage(void);
int		 check_option(struct client_lease *l, int option);
int		 check_classless_option(unsigned char *data, int len);
int		 ipv4addrs(char * buf);
int		 res_hnok(const char *dn);
int		 check_search(const char *srch);
char		*option_as_string(unsigned int code, unsigned char *data, int len);
int		 fork_privchld(int, int);

#define	ROUNDUP(a) \
	    ((a) > 0 ? (1 + (((a) - 1) | (sizeof(long) - 1))) : sizeof(long))
#define	ADVANCE(x, n) (x += ROUNDUP((n)->sa_len))

static time_t	scripttime;

int
findproto(char *cp, int n)
{
	struct sockaddr *sa;
	int i;

	if (n == 0)
		return -1;
	for (i = 1; i; i <<= 1) {
		if (i & n) {
			sa = (struct sockaddr *)cp;
			switch (i) {
			case RTA_IFA:
			case RTA_DST:
			case RTA_GATEWAY:
			case RTA_NETMASK:
				if (sa->sa_family == AF_INET)
					return AF_INET;
				if (sa->sa_family == AF_INET6)
					return AF_INET6;
				break;
			case RTA_IFP:
				break;
			}
			ADVANCE(cp, sa);
		}
	}
	return (-1);
}

struct sockaddr *
get_ifa(char *cp, int n)
{
	struct sockaddr *sa;
	int i;

	if (n == 0)
		return (NULL);
	for (i = 1; i; i <<= 1)
		if (i & n) {
			sa = (struct sockaddr *)cp;
			if (i == RTA_IFA)
				return (sa);
			ADVANCE(cp, sa);
		}

	return (NULL);
}

struct iaddr defaddr = { 4 };
uint8_t curbssid[6];

static void
disassoc(void *arg)
{
	struct interface_info *ifi = arg;

	/*
	 * Clear existing state.
	 */
	if (ifi->client->active != NULL) {
		script_init("EXPIRE", NULL);
		script_write_params("old_",
		    ifi->client->active);
		if (ifi->client->alias)
			script_write_params("alias_",
				ifi->client->alias);
		script_go();
	}
	ifi->client->state = S_INIT;
}

/* ARGSUSED */
void
routehandler(struct protocol *p)
{
	char msg[2048], *addr;
	struct rt_msghdr *rtm;
	struct if_msghdr *ifm;
	struct ifa_msghdr *ifam;
	struct if_announcemsghdr *ifan;
	struct ieee80211_join_event *jev;
	struct client_lease *l;
	time_t t = time(NULL);
	struct sockaddr *sa;
	struct iaddr a;
	ssize_t n;

	n = read(routefd, &msg, sizeof(msg));
	rtm = (struct rt_msghdr *)msg;
	if (n < sizeof(rtm->rtm_msglen) || n < rtm->rtm_msglen ||
	    rtm->rtm_version != RTM_VERSION)
		return;

	switch (rtm->rtm_type) {
	case RTM_NEWADDR:
	case RTM_DELADDR:
		ifam = (struct ifa_msghdr *)rtm;

		if (ifam->ifam_index != ifi->index)
			break;
		if (findproto((char *)(ifam + 1), ifam->ifam_addrs) != AF_INET)
			break;
		if (scripttime == 0 || t < scripttime + 10)
			break;

		sa = get_ifa((char *)(ifam + 1), ifam->ifam_addrs);
		if (sa == NULL)
			break;

		if ((a.len = sizeof(struct in_addr)) > sizeof(a.iabuf))
			error("king bula sez: len mismatch");
		memcpy(a.iabuf, &((struct sockaddr_in *)sa)->sin_addr, a.len);
		if (addr_eq(a, defaddr))
			break;

		for (l = ifi->client->active; l != NULL; l = l->next)
			if (addr_eq(a, l->address))
				break;

		if (l == NULL)	/* added/deleted addr is not the one we set */
			break;

		addr = inet_ntoa(((struct sockaddr_in *)sa)->sin_addr);
		if (rtm->rtm_type == RTM_NEWADDR)  {
			/*
			 * XXX: If someone other than us adds our address,
			 * should we assume they are taking over from us,
			 * delete the lease record, and exit without modifying
			 * the interface?
			 */
			warning("My address (%s) was re-added", addr);
		} else {
			warning("My address (%s) was deleted, dhclient exiting",
			    addr);
			goto die;
		}
		break;
	case RTM_IFINFO:
		ifm = (struct if_msghdr *)rtm;
		if (ifm->ifm_index != ifi->index)
			break;
		if ((rtm->rtm_flags & RTF_UP) == 0) {
			warning("Interface %s is down, dhclient exiting",
			    ifi->name);
			goto die;
		}
		break;
	case RTM_IFANNOUNCE:
		ifan = (struct if_announcemsghdr *)rtm;
		if (ifan->ifan_what == IFAN_DEPARTURE &&
		    ifan->ifan_index == ifi->index) {
			warning("Interface %s is gone, dhclient exiting",
			    ifi->name);
			goto die;
		}
		break;
	case RTM_IEEE80211:
		ifan = (struct if_announcemsghdr *)rtm;
		if (ifan->ifan_index != ifi->index)
			break;
		switch (ifan->ifan_what) {
		case RTM_IEEE80211_ASSOC:
		case RTM_IEEE80211_REASSOC:
			/*
			 * Use assoc/reassoc event to kick state machine
			 * in case we roam.  Otherwise fall back to the
			 * normal state machine just like a wired network.
			 */
			jev = (struct ieee80211_join_event *) &ifan[1];
			if (memcmp(curbssid, jev->iev_addr, 6)) {
				disassoc(ifi);
				state_reboot(ifi);
			}
			memcpy(curbssid, jev->iev_addr, 6);
			break;
		}
		break;
	default:
		break;
	}
	return;

die:
	script_init("FAIL", NULL);
	if (ifi->client->alias)
		script_write_params("alias_", ifi->client->alias);
	script_go();
	if (pidfile != NULL)
		pidfile_remove(pidfile);
	exit(1);
}

int
main(int argc, char *argv[])
{
	extern char		*__progname;
	int			 ch, fd, quiet = 0, i = 0;
	int			 pipe_fd[2];
	int			 immediate_daemon = 0;
	struct passwd		*pw;
	pid_t			 otherpid;

	/* Initially, log errors to stderr as well as to syslogd. */
	openlog(__progname, LOG_PID | LOG_NDELAY, DHCPD_LOG_FACILITY);
	setlogmask(LOG_UPTO(LOG_DEBUG));

	while ((ch = getopt(argc, argv, "bc:dl:p:qu")) != -1)
		switch (ch) {
		case 'b':
			immediate_daemon = 1;
			break;
		case 'c':
			path_dhclient_conf = optarg;
			break;
		case 'd':
			no_daemon = 1;
			break;
		case 'l':
			path_dhclient_db = optarg;
			break;
		case 'p':
			path_dhclient_pidfile = optarg;
			break;
		case 'q':
			quiet = 1;
			break;
		case 'u':
			unknown_ok = 0;
			break;
		default:
			usage();
		}

	argc -= optind;
	argv += optind;

	if (argc != 1)
		usage();

	if (path_dhclient_pidfile == NULL) {
		asprintf(&path_dhclient_pidfile,
		    "%sdhclient.%s.pid", _PATH_VARRUN, *argv);
		if (path_dhclient_pidfile == NULL)
			error("asprintf");
	}
	pidfile = pidfile_open(path_dhclient_pidfile, 0600, &otherpid);
	if (pidfile == NULL) {
		if (errno == EEXIST)
			error("dhclient already running, pid: %d.", otherpid);
		if (errno == EAGAIN)
			error("dhclient already running.");
		warning("Cannot open or create pidfile: %m");
	}

	if ((ifi = calloc(1, sizeof(struct interface_info))) == NULL)
		error("calloc");
	if (strlcpy(ifi->name, argv[0], IFNAMSIZ) >= IFNAMSIZ)
		error("Interface name too long");
	if (path_dhclient_db == NULL && asprintf(&path_dhclient_db, "%s.%s",
	    _PATH_DHCLIENT_DB, ifi->name) == -1)
		error("asprintf");

	if (quiet)
		log_perror = 0;

	tzset();
	time(&cur_time);

	memset(&sockaddr_broadcast, 0, sizeof(sockaddr_broadcast));
	sockaddr_broadcast.sin_family = AF_INET;
	sockaddr_broadcast.sin_port = htons(REMOTE_PORT);
	sockaddr_broadcast.sin_addr.s_addr = INADDR_BROADCAST;
	sockaddr_broadcast.sin_len = sizeof(sockaddr_broadcast);
	inaddr_any.s_addr = INADDR_ANY;

	read_client_conf();

	/* The next bit is potentially very time-consuming, so write out
	   the pidfile right away.  We will write it out again with the
	   correct pid after daemonizing. */
	if (pidfile != NULL)
		pidfile_write(pidfile);

	if (!interface_link_status(ifi->name)) {
		fprintf(stderr, "%s: no link ...", ifi->name);
		fflush(stderr);
		sleep(1);
		while (!interface_link_status(ifi->name)) {
			fprintf(stderr, ".");
			fflush(stderr);
			if (++i > 10) {
				fprintf(stderr, " giving up\n");
				exit(1);
			}
			sleep(1);
		}
		fprintf(stderr, " got link\n");
	}

	if ((nullfd = open(_PATH_DEVNULL, O_RDWR, 0)) == -1)
		error("cannot open %s: %m", _PATH_DEVNULL);

	if ((pw = getpwnam("_dhcp")) == NULL) {
		warning("no such user: _dhcp, falling back to \"nobody\"");
		if ((pw = getpwnam("nobody")) == NULL)
			error("no such user: nobody");
	}

	if (pipe(pipe_fd) == -1)
		error("pipe");

	fork_privchld(pipe_fd[0], pipe_fd[1]);

	close(pipe_fd[0]);
	privfd = pipe_fd[1];

	if ((fd = open(path_dhclient_db, O_RDONLY|O_EXLOCK|O_CREAT, 0)) == -1)
		error("can't open and lock %s: %m", path_dhclient_db);
	read_client_leases();
	rewrite_client_leases();
	close(fd);

	priv_script_init("PREINIT", NULL);
	if (ifi->client->alias)
		priv_script_write_params("alias_", ifi->client->alias);
	priv_script_go();

	if ((routefd = socket(PF_ROUTE, SOCK_RAW, 0)) != -1)
		add_protocol("AF_ROUTE", routefd, routehandler, ifi);

	/* set up the interface */
	discover_interfaces(ifi);

	if (chroot(_PATH_VAREMPTY) == -1)
		error("chroot");
	if (chdir("/") == -1)
		error("chdir(\"/\")");

	if (setgroups(1, &pw->pw_gid) ||
	    setegid(pw->pw_gid) || setgid(pw->pw_gid) ||
	    seteuid(pw->pw_uid) || setuid(pw->pw_uid))
		error("can't drop privileges: %m");

	endpwent();

	setproctitle("%s", ifi->name);

	if (immediate_daemon)
		go_daemon();

	ifi->client->state = S_INIT;
	state_reboot(ifi);

	bootp_packet_handler = do_packet;

	dispatch();

	/* not reached */
	return (0);
}

void
usage(void)
{
	extern char	*__progname;

	fprintf(stderr, "usage: %s [-bdqu] ", __progname);
	fprintf(stderr, "[-c conffile] [-l leasefile] interface\n");
	exit(1);
}

/*
 * Individual States:
 *
 * Each routine is called from the dhclient_state_machine() in one of
 * these conditions:
 * -> entering INIT state
 * -> recvpacket_flag == 0: timeout in this state
 * -> otherwise: received a packet in this state
 *
 * Return conditions as handled by dhclient_state_machine():
 * Returns 1, sendpacket_flag = 1: send packet, reset timer.
 * Returns 1, sendpacket_flag = 0: just reset the timer (wait for a milestone).
 * Returns 0: finish the nap which was interrupted for no good reason.
 *
 * Several per-interface variables are used to keep track of the process:
 *   active_lease: the lease that is being used on the interface
 *                 (null pointer if not configured yet).
 *   offered_leases: leases corresponding to DHCPOFFER messages that have
 *                   been sent to us by DHCP servers.
 *   acked_leases: leases corresponding to DHCPACK messages that have been
 *                 sent to us by DHCP servers.
 *   sendpacket: DHCP packet we're trying to send.
 *   destination: IP address to send sendpacket to
 * In addition, there are several relevant per-lease variables.
 *   T1_expiry, T2_expiry, lease_expiry: lease milestones
 * In the active lease, these control the process of renewing the lease;
 * In leases on the acked_leases list, this simply determines when we
 * can no longer legitimately use the lease.
 */

void
state_reboot(void *ipp)
{
	struct interface_info *ip = ipp;

	/* If we don't remember an active lease, go straight to INIT. */
	if (!ip->client->active || ip->client->active->is_bootp) {
		state_init(ip);
		return;
	}

	/* We are in the rebooting state. */
	ip->client->state = S_REBOOTING;

	/* make_request doesn't initialize xid because it normally comes
	   from the DHCPDISCOVER, but we haven't sent a DHCPDISCOVER,
	   so pick an xid now. */
	ip->client->xid = arc4random();

	/* Make a DHCPREQUEST packet, and set appropriate per-interface
	   flags. */
	make_request(ip, ip->client->active);
	ip->client->destination = iaddr_broadcast;
	ip->client->first_sending = cur_time;
	ip->client->interval = ip->client->config->initial_interval;

	/* Zap the medium list... */
	ip->client->medium = NULL;

	/* Send out the first DHCPREQUEST packet. */
	send_request(ip);
}

/*
 * Called when a lease has completely expired and we've
 * been unable to renew it.
 */
void
state_init(void *ipp)
{
	struct interface_info *ip = ipp;

	ASSERT_STATE(state, S_INIT);

	/* Make a DHCPDISCOVER packet, and set appropriate per-interface
	   flags. */
	make_discover(ip, ip->client->active);
	ip->client->xid = ip->client->packet.xid;
	ip->client->destination = iaddr_broadcast;
	ip->client->state = S_SELECTING;
	ip->client->first_sending = cur_time;
	ip->client->interval = ip->client->config->initial_interval;

	/* Add an immediate timeout to cause the first DHCPDISCOVER packet
	   to go out. */
	send_discover(ip);
}

/*
 * state_selecting is called when one or more DHCPOFFER packets
 * have been received and a configurable period of time has passed.
 */
void
state_selecting(void *ipp)
{
	struct interface_info *ip = ipp;
	struct client_lease *lp, *next, *picked;

	ASSERT_STATE(state, S_SELECTING);

	/* Cancel state_selecting and send_discover timeouts, since either
	   one could have got us here. */
	cancel_timeout(state_selecting, ip);
	cancel_timeout(send_discover, ip);

	/* We have received one or more DHCPOFFER packets.   Currently,
	   the only criterion by which we judge leases is whether or
	   not we get a response when we arp for them. */
	picked = NULL;
	for (lp = ip->client->offered_leases; lp; lp = next) {
		next = lp->next;

		/* Check to see if we got an ARPREPLY for the address
		   in this particular lease. */
		if (!picked) {
			script_init("ARPCHECK", lp->medium);
			script_write_params("check_", lp);

			/* If the ARPCHECK code detects another
			   machine using the offered address, it exits
			   nonzero.  We need to send a DHCPDECLINE and
			   toss the lease. */
			if (script_go()) {
				make_decline(ip, lp);
				send_decline(ip);
				goto freeit;
			}
			picked = lp;
			picked->next = NULL;
		} else {
freeit:
			free_client_lease(lp);
		}
	}
	ip->client->offered_leases = NULL;

	/* If we just tossed all the leases we were offered, go back
	   to square one. */
	if (!picked) {
		ip->client->state = S_INIT;
		state_init(ip);
		return;
	}

	/* If it was a BOOTREPLY, we can just take the address right now. */
	if (!picked->options[DHO_DHCP_MESSAGE_TYPE].len) {
		ip->client->new = picked;

		/* Make up some lease expiry times
		   XXX these should be configurable. */
		ip->client->new->expiry = cur_time + 12000;
		ip->client->new->renewal += cur_time + 8000;
		ip->client->new->rebind += cur_time + 10000;

		ip->client->state = S_REQUESTING;

		/* Bind to the address we received. */
		bind_lease(ip);
		return;
	}

	/* Go to the REQUESTING state. */
	ip->client->destination = iaddr_broadcast;
	ip->client->state = S_REQUESTING;
	ip->client->first_sending = cur_time;
	ip->client->interval = ip->client->config->initial_interval;

	/* Make a DHCPREQUEST packet from the lease we picked. */
	make_request(ip, picked);
	ip->client->xid = ip->client->packet.xid;

	/* Toss the lease we picked - we'll get it back in a DHCPACK. */
	free_client_lease(picked);

	/* Add an immediate timeout to send the first DHCPREQUEST packet. */
	send_request(ip);
}

/* state_requesting is called when we receive a DHCPACK message after
   having sent out one or more DHCPREQUEST packets. */

void
dhcpack(struct packet *packet)
{
	struct interface_info *ip = packet->interface;
	struct client_lease *lease;

	/* If we're not receptive to an offer right now, or if the offer
	   has an unrecognizable transaction id, then just drop it. */
	if (packet->interface->client->xid != packet->raw->xid ||
	    (packet->interface->hw_address.hlen != packet->raw->hlen) ||
	    (memcmp(packet->interface->hw_address.haddr,
	    packet->raw->chaddr, packet->raw->hlen)))
		return;

	if (ip->client->state != S_REBOOTING &&
	    ip->client->state != S_REQUESTING &&
	    ip->client->state != S_RENEWING &&
	    ip->client->state != S_REBINDING)
		return;

	note("DHCPACK from %s", piaddr(packet->client_addr));

	lease = packet_to_lease(packet);
	if (!lease) {
		note("packet_to_lease failed.");
		return;
	}

	ip->client->new = lease;

	/* Stop resending DHCPREQUEST. */
	cancel_timeout(send_request, ip);

	/* Figure out the lease time. */
	if (ip->client->new->options[DHO_DHCP_LEASE_TIME].data)
		ip->client->new->expiry = getULong(
		    ip->client->new->options[DHO_DHCP_LEASE_TIME].data);
	else
		ip->client->new->expiry = default_lease_time;
	/* A number that looks negative here is really just very large,
	   because the lease expiry offset is unsigned. */
	if (ip->client->new->expiry < 0)
		ip->client->new->expiry = TIME_MAX;
	/* XXX should be fixed by resetting the client state */
	if (ip->client->new->expiry < 60)
		ip->client->new->expiry = 60;

	/* Take the server-provided renewal time if there is one;
	   otherwise figure it out according to the spec. */
	if (ip->client->new->options[DHO_DHCP_RENEWAL_TIME].len)
		ip->client->new->renewal = getULong(
		    ip->client->new->options[DHO_DHCP_RENEWAL_TIME].data);
	else
		ip->client->new->renewal = ip->client->new->expiry / 2;

	/* Same deal with the rebind time. */
	if (ip->client->new->options[DHO_DHCP_REBINDING_TIME].len)
		ip->client->new->rebind = getULong(
		    ip->client->new->options[DHO_DHCP_REBINDING_TIME].data);
	else
		ip->client->new->rebind = ip->client->new->renewal +
		    ip->client->new->renewal / 2 + ip->client->new->renewal / 4;

	ip->client->new->expiry += cur_time;
	/* Lease lengths can never be negative. */
	if (ip->client->new->expiry < cur_time)
		ip->client->new->expiry = TIME_MAX;
	ip->client->new->renewal += cur_time;
	if (ip->client->new->renewal < cur_time)
		ip->client->new->renewal = TIME_MAX;
	ip->client->new->rebind += cur_time;
	if (ip->client->new->rebind < cur_time)
		ip->client->new->rebind = TIME_MAX;

	bind_lease(ip);
}

void
bind_lease(struct interface_info *ip)
{
	/* Remember the medium. */
	ip->client->new->medium = ip->client->medium;

	/* Write out the new lease. */
	write_client_lease(ip, ip->client->new, 0);

	/* Run the client script with the new parameters. */
	script_init((ip->client->state == S_REQUESTING ? "BOUND" :
	    (ip->client->state == S_RENEWING ? "RENEW" :
	    (ip->client->state == S_REBOOTING ? "REBOOT" : "REBIND"))),
	    ip->client->new->medium);
	if (ip->client->active && ip->client->state != S_REBOOTING)
		script_write_params("old_", ip->client->active);
	script_write_params("new_", ip->client->new);
	if (ip->client->alias)
		script_write_params("alias_", ip->client->alias);
	script_go();

	/* Replace the old active lease with the new one. */
	if (ip->client->active)
		free_client_lease(ip->client->active);
	ip->client->active = ip->client->new;
	ip->client->new = NULL;

	/* Set up a timeout to start the renewal process. */
	add_timeout(ip->client->active->renewal, state_bound, ip);

	note("bound to %s -- renewal in %d seconds.",
	    piaddr(ip->client->active->address),
	    (int)(ip->client->active->renewal - cur_time));
	ip->client->state = S_BOUND;
	reinitialize_interfaces();
	go_daemon();
}

/*
 * state_bound is called when we've successfully bound to a particular
 * lease, but the renewal time on that lease has expired.   We are
 * expected to unicast a DHCPREQUEST to the server that gave us our
 * original lease.
 */
void
state_bound(void *ipp)
{
	struct interface_info *ip = ipp;

	ASSERT_STATE(state, S_BOUND);

	/* T1 has expired. */
	make_request(ip, ip->client->active);
	ip->client->xid = ip->client->packet.xid;

	if (ip->client->active->options[DHO_DHCP_SERVER_IDENTIFIER].len == 4) {
		memcpy(ip->client->destination.iabuf, ip->client->active->
		    options[DHO_DHCP_SERVER_IDENTIFIER].data, 4);
		ip->client->destination.len = 4;
	} else
		ip->client->destination = iaddr_broadcast;

	ip->client->first_sending = cur_time;
	ip->client->interval = ip->client->config->initial_interval;
	ip->client->state = S_RENEWING;

	/* Send the first packet immediately. */
	send_request(ip);
}

void
bootp(struct packet *packet)
{
	struct iaddrlist *ap;

	if (packet->raw->op != BOOTREPLY)
		return;

	/* If there's a reject list, make sure this packet's sender isn't
	   on it. */
	for (ap = packet->interface->client->config->reject_list;
	    ap; ap = ap->next) {
		if (addr_eq(packet->client_addr, ap->addr)) {
			note("BOOTREPLY from %s rejected.", piaddr(ap->addr));
			return;
		}
	}
	dhcpoffer(packet);
}

void
dhcp(struct packet *packet)
{
	struct iaddrlist *ap;
	void (*handler)(struct packet *);
	char *type;

	switch (packet->packet_type) {
	case DHCPOFFER:
		handler = dhcpoffer;
		type = "DHCPOFFER";
		break;
	case DHCPNAK:
		handler = dhcpnak;
		type = "DHCPNACK";
		break;
	case DHCPACK:
		handler = dhcpack;
		type = "DHCPACK";
		break;
	default:
		return;
	}

	/* If there's a reject list, make sure this packet's sender isn't
	   on it. */
	for (ap = packet->interface->client->config->reject_list;
	    ap; ap = ap->next) {
		if (addr_eq(packet->client_addr, ap->addr)) {
			note("%s from %s rejected.", type, piaddr(ap->addr));
			return;
		}
	}
	(*handler)(packet);
}

void
dhcpoffer(struct packet *packet)
{
	struct interface_info *ip = packet->interface;
	struct client_lease *lease, *lp;
	int i;
	int arp_timeout_needed, stop_selecting;
	char *name = packet->options[DHO_DHCP_MESSAGE_TYPE].len ?
	    "DHCPOFFER" : "BOOTREPLY";

	/* If we're not receptive to an offer right now, or if the offer
	   has an unrecognizable transaction id, then just drop it. */
	if (ip->client->state != S_SELECTING ||
	    packet->interface->client->xid != packet->raw->xid ||
	    (packet->interface->hw_address.hlen != packet->raw->hlen) ||
	    (memcmp(packet->interface->hw_address.haddr,
	    packet->raw->chaddr, packet->raw->hlen)))
		return;

	note("%s from %s", name, piaddr(packet->client_addr));


	/* If this lease doesn't supply the minimum required parameters,
	   blow it off. */
	for (i = 0; ip->client->config->required_options[i]; i++) {
		if (!packet->options[ip->client->config->
		    required_options[i]].len) {
			note("%s isn't satisfactory.", name);
			return;
		}
	}

	/* If we've already seen this lease, don't record it again. */
	for (lease = ip->client->offered_leases;
	    lease; lease = lease->next) {
		if (lease->address.len == sizeof(packet->raw->yiaddr) &&
		    !memcmp(lease->address.iabuf,
		    &packet->raw->yiaddr, lease->address.len)) {
			debug("%s already seen.", name);
			return;
		}
	}

	lease = packet_to_lease(packet);
	if (!lease) {
		note("packet_to_lease failed.");
		return;
	}

	/* If this lease was acquired through a BOOTREPLY, record that
	   fact. */
	if (!packet->options[DHO_DHCP_MESSAGE_TYPE].len)
		lease->is_bootp = 1;

	/* Record the medium under which this lease was offered. */
	lease->medium = ip->client->medium;

	/* Send out an ARP Request for the offered IP address. */
	script_init("ARPSEND", lease->medium);
	script_write_params("check_", lease);
	/* If the script can't send an ARP request without waiting,
	   we'll be waiting when we do the ARPCHECK, so don't wait now. */
	if (script_go())
		arp_timeout_needed = 0;
	else
		arp_timeout_needed = 2;

	/* Figure out when we're supposed to stop selecting. */
	stop_selecting =
	    ip->client->first_sending + ip->client->config->select_interval;

	/* If this is the lease we asked for, put it at the head of the
	   list, and don't mess with the arp request timeout. */
	if (lease->address.len == ip->client->requested_address.len &&
	    !memcmp(lease->address.iabuf,
	    ip->client->requested_address.iabuf,
	    ip->client->requested_address.len)) {
		lease->next = ip->client->offered_leases;
		ip->client->offered_leases = lease;
	} else {
		/* If we already have an offer, and arping for this
		   offer would take us past the selection timeout,
		   then don't extend the timeout - just hope for the
		   best. */
		if (ip->client->offered_leases &&
		    (cur_time + arp_timeout_needed) > stop_selecting)
			arp_timeout_needed = 0;

		/* Put the lease at the end of the list. */
		lease->next = NULL;
		if (!ip->client->offered_leases)
			ip->client->offered_leases = lease;
		else {
			for (lp = ip->client->offered_leases; lp->next;
			    lp = lp->next)
				;	/* nothing */
			lp->next = lease;
		}
	}

	/* If we're supposed to stop selecting before we've had time
	   to wait for the ARPREPLY, add some delay to wait for
	   the ARPREPLY. */
	if (stop_selecting - cur_time < arp_timeout_needed)
		stop_selecting = cur_time + arp_timeout_needed;

	/* If the selecting interval has expired, go immediately to
	   state_selecting().  Otherwise, time out into
	   state_selecting at the select interval. */
	if (stop_selecting <= 0)
		state_selecting(ip);
	else {
		add_timeout(stop_selecting, state_selecting, ip);
		cancel_timeout(send_discover, ip);
	}
}

/* Allocate a client_lease structure and initialize it from the parameters
   in the specified packet. */

struct client_lease *
packet_to_lease(struct packet *packet)
{
	struct client_lease *lease;
	int i;

	lease = malloc(sizeof(struct client_lease));

	if (!lease) {
		warning("dhcpoffer: no memory to record lease.");
		return (NULL);
	}

	memset(lease, 0, sizeof(*lease));

	/* Copy the lease options. */
	for (i = 0; i < 256; i++) {
		if (packet->options[i].len) {
			lease->options[i].data =
			    malloc(packet->options[i].len + 1);
			if (!lease->options[i].data) {
				warning("dhcpoffer: no memory for option %d", i);
				free_client_lease(lease);
				return (NULL);
			} else {
				memcpy(lease->options[i].data,
				    packet->options[i].data,
				    packet->options[i].len);
				lease->options[i].len =
				    packet->options[i].len;
				lease->options[i].data[lease->options[i].len] =
				    0;
			}
			if (!check_option(lease,i)) {
				/* ignore a bogus lease offer */
				warning("Invalid lease option - ignoring offer");
				free_client_lease(lease);
				return (NULL);
			}
		}
	}

	lease->address.len = sizeof(packet->raw->yiaddr);
	memcpy(lease->address.iabuf, &packet->raw->yiaddr, lease->address.len);

	/* If the server name was filled out, copy it.
	   Do not attempt to validate the server name as a host name.
	   RFC 2131 merely states that sname is NUL-terminated (which do
	   do not assume) and that it is the server's host name.  Since
	   the ISC client and server allow arbitrary characters, we do
	   as well. */
	if ((!packet->options[DHO_DHCP_OPTION_OVERLOAD].len ||
	    !(packet->options[DHO_DHCP_OPTION_OVERLOAD].data[0] & 2)) &&
	    packet->raw->sname[0]) {
		lease->server_name = malloc(DHCP_SNAME_LEN + 1);
		if (!lease->server_name) {
			warning("dhcpoffer: no memory for server name.");
			free_client_lease(lease);
			return (NULL);
		}
		memcpy(lease->server_name, packet->raw->sname, DHCP_SNAME_LEN);
		lease->server_name[DHCP_SNAME_LEN]='\0';
	}

	/* Ditto for the filename. */
	if ((!packet->options[DHO_DHCP_OPTION_OVERLOAD].len ||
	    !(packet->options[DHO_DHCP_OPTION_OVERLOAD].data[0] & 1)) &&
	    packet->raw->file[0]) {
		/* Don't count on the NUL terminator. */
		lease->filename = malloc(DHCP_FILE_LEN + 1);
		if (!lease->filename) {
			warning("dhcpoffer: no memory for filename.");
			free_client_lease(lease);
			return (NULL);
		}
		memcpy(lease->filename, packet->raw->file, DHCP_FILE_LEN);
		lease->filename[DHCP_FILE_LEN]='\0';
	}
	return lease;
}

void
dhcpnak(struct packet *packet)
{
	struct interface_info *ip = packet->interface;

	/* If we're not receptive to an offer right now, or if the offer
	   has an unrecognizable transaction id, then just drop it. */
	if (packet->interface->client->xid != packet->raw->xid ||
	    (packet->interface->hw_address.hlen != packet->raw->hlen) ||
	    (memcmp(packet->interface->hw_address.haddr,
	    packet->raw->chaddr, packet->raw->hlen)))
		return;

	if (ip->client->state != S_REBOOTING &&
	    ip->client->state != S_REQUESTING &&
	    ip->client->state != S_RENEWING &&
	    ip->client->state != S_REBINDING)
		return;

	note("DHCPNAK from %s", piaddr(packet->client_addr));

	if (!ip->client->active) {
		note("DHCPNAK with no active lease.\n");
		return;
	}

	free_client_lease(ip->client->active);
	ip->client->active = NULL;

	/* Stop sending DHCPREQUEST packets... */
	cancel_timeout(send_request, ip);

	ip->client->state = S_INIT;
	state_init(ip);
}

/* Send out a DHCPDISCOVER packet, and set a timeout to send out another
   one after the right interval has expired.  If we don't get an offer by
   the time we reach the panic interval, call the panic function. */

void
send_discover(void *ipp)
{
	struct interface_info *ip = ipp;
	int interval, increase = 1;

	/* Figure out how long it's been since we started transmitting. */
	interval = cur_time - ip->client->first_sending;

	/* If we're past the panic timeout, call the script and tell it
	   we haven't found anything for this interface yet. */
	if (interval > ip->client->config->timeout) {
		state_panic(ip);
		return;
	}

	/* If we're selecting media, try the whole list before doing
	   the exponential backoff, but if we've already received an
	   offer, stop looping, because we obviously have it right. */
	if (!ip->client->offered_leases &&
	    ip->client->config->media) {
		int fail = 0;
again:
		if (ip->client->medium) {
			ip->client->medium = ip->client->medium->next;
			increase = 0;
		}
		if (!ip->client->medium) {
			if (fail)
				error("No valid media types for %s!", ip->name);
			ip->client->medium = ip->client->config->media;
			increase = 1;
		}

		note("Trying medium \"%s\" %d", ip->client->medium->string,
		    increase);
		script_init("MEDIUM", ip->client->medium);
		if (script_go())
			goto again;
	}

	/*
	 * If we're supposed to increase the interval, do so.  If it's
	 * currently zero (i.e., we haven't sent any packets yet), set
	 * it to one; otherwise, add to it a random number between zero
	 * and two times itself.  On average, this means that it will
	 * double with every transmission.
	 */
	if (increase) {
		if (!ip->client->interval)
			ip->client->interval =
			    ip->client->config->initial_interval;
		else {
			ip->client->interval += (arc4random() >> 2) %
			    (2 * ip->client->interval);
		}

		/* Don't backoff past cutoff. */
		if (ip->client->interval >
		    ip->client->config->backoff_cutoff)
			ip->client->interval =
				((ip->client->config->backoff_cutoff / 2)
				 + ((arc4random() >> 2) %
				    ip->client->config->backoff_cutoff));
	} else if (!ip->client->interval)
		ip->client->interval =
			ip->client->config->initial_interval;

	/* If the backoff would take us to the panic timeout, just use that
	   as the interval. */
	if (cur_time + ip->client->interval >
	    ip->client->first_sending + ip->client->config->timeout)
		ip->client->interval =
			(ip->client->first_sending +
			 ip->client->config->timeout) - cur_time + 1;

	/* Record the number of seconds since we started sending. */
	if (interval < 65536)
		ip->client->packet.secs = htons(interval);
	else
		ip->client->packet.secs = htons(65535);
	ip->client->secs = ip->client->packet.secs;

	note("DHCPDISCOVER on %s to %s port %d interval %d",
	    ip->name, inet_ntoa(sockaddr_broadcast.sin_addr),
	    ntohs(sockaddr_broadcast.sin_port),
	    (int)ip->client->interval);

	/* Send out a packet. */
	(void)send_packet(ip, &ip->client->packet, ip->client->packet_length,
	    inaddr_any, &sockaddr_broadcast, NULL);

	add_timeout(cur_time + ip->client->interval, send_discover, ip);
}

/*
 * state_panic gets called if we haven't received any offers in a preset
 * amount of time.   When this happens, we try to use existing leases
 * that haven't yet expired, and failing that, we call the client script
 * and hope it can do something.
 */
void
state_panic(void *ipp)
{
	struct interface_info *ip = ipp;
	struct client_lease *loop = ip->client->active;
	struct client_lease *lp;

	note("No DHCPOFFERS received.");

	/* We may not have an active lease, but we may have some
	   predefined leases that we can try. */
	if (!ip->client->active && ip->client->leases)
		goto activate_next;

	/* Run through the list of leases and see if one can be used. */
	while (ip->client->active) {
		if (ip->client->active->expiry > cur_time) {
			note("Trying recorded lease %s",
			    piaddr(ip->client->active->address));
			/* Run the client script with the existing
			   parameters. */
			script_init("TIMEOUT",
			    ip->client->active->medium);
			script_write_params("new_", ip->client->active);
			if (ip->client->alias)
				script_write_params("alias_",
				    ip->client->alias);

			/* If the old lease is still good and doesn't
			   yet need renewal, go into BOUND state and
			   timeout at the renewal time. */
			if (!script_go()) {
				if (cur_time <
				    ip->client->active->renewal) {
					ip->client->state = S_BOUND;
					note("bound: renewal in %d seconds.",
					    (int)(ip->client->active->renewal -
					    cur_time));
					add_timeout(
					    ip->client->active->renewal,
					    state_bound, ip);
				} else {
					ip->client->state = S_BOUND;
					note("bound: immediate renewal.");
					state_bound(ip);
				}
				reinitialize_interfaces();
				go_daemon();
				return;
			}
		}

		/* If there are no other leases, give up. */
		if (!ip->client->leases) {
			ip->client->leases = ip->client->active;
			ip->client->active = NULL;
			break;
		}

activate_next:
		/* Otherwise, put the active lease at the end of the
		   lease list, and try another lease.. */
		for (lp = ip->client->leases; lp->next; lp = lp->next)
			;
		lp->next = ip->client->active;
		if (lp->next)
			lp->next->next = NULL;
		ip->client->active = ip->client->leases;
		ip->client->leases = ip->client->leases->next;

		/* If we already tried this lease, we've exhausted the
		   set of leases, so we might as well give up for
		   now. */
		if (ip->client->active == loop)
			break;
		else if (!loop)
			loop = ip->client->active;
	}

	/* No leases were available, or what was available didn't work, so
	   tell the shell script that we failed to allocate an address,
	   and try again later. */
	note("No working leases in persistent database - sleeping.\n");
	script_init("FAIL", NULL);
	if (ip->client->alias)
		script_write_params("alias_", ip->client->alias);
	script_go();
	ip->client->state = S_INIT;
	add_timeout(cur_time + ip->client->config->retry_interval, state_init,
	    ip);
	go_daemon();
}

void
send_request(void *ipp)
{
	struct interface_info *ip = ipp;
	struct sockaddr_in destination;
	struct in_addr from;
	int interval;

	/* Figure out how long it's been since we started transmitting. */
	interval = cur_time - ip->client->first_sending;

	/* If we're in the INIT-REBOOT or REQUESTING state and we're
	   past the reboot timeout, go to INIT and see if we can
	   DISCOVER an address... */
	/* XXX In the INIT-REBOOT state, if we don't get an ACK, it
	   means either that we're on a network with no DHCP server,
	   or that our server is down.  In the latter case, assuming
	   that there is a backup DHCP server, DHCPDISCOVER will get
	   us a new address, but we could also have successfully
	   reused our old address.  In the former case, we're hosed
	   anyway.  This is not a win-prone situation. */
	if ((ip->client->state == S_REBOOTING ||
	    ip->client->state == S_REQUESTING) &&
	    interval > ip->client->config->reboot_timeout) {
cancel:
		ip->client->state = S_INIT;
		cancel_timeout(send_request, ip);
		state_init(ip);
		return;
	}

	/* If we're in the reboot state, make sure the media is set up
	   correctly. */
	if (ip->client->state == S_REBOOTING &&
	    !ip->client->medium &&
	    ip->client->active->medium ) {
		script_init("MEDIUM", ip->client->active->medium);

		/* If the medium we chose won't fly, go to INIT state. */
		if (script_go())
			goto cancel;

		/* Record the medium. */
		ip->client->medium = ip->client->active->medium;
	}

	/* If the lease has expired, relinquish the address and go back
	   to the INIT state. */
	if (ip->client->state != S_REQUESTING &&
	    cur_time > ip->client->active->expiry) {
		/* Run the client script with the new parameters. */
		script_init("EXPIRE", NULL);
		script_write_params("old_", ip->client->active);
		if (ip->client->alias)
			script_write_params("alias_", ip->client->alias);
		script_go();

		/* Now do a preinit on the interface so that we can
		   discover a new address. */
		script_init("PREINIT", NULL);
		if (ip->client->alias)
			script_write_params("alias_", ip->client->alias);
		script_go();

		ip->client->state = S_INIT;
		state_init(ip);
		return;
	}

	/* Do the exponential backoff... */
	if (!ip->client->interval)
		ip->client->interval = ip->client->config->initial_interval;
	else
		ip->client->interval += ((arc4random() >> 2) %
		    (2 * ip->client->interval));

	/* Don't backoff past cutoff. */
	if (ip->client->interval >
	    ip->client->config->backoff_cutoff)
		ip->client->interval =
		    ((ip->client->config->backoff_cutoff / 2) +
		    ((arc4random() >> 2) % ip->client->interval));

	/* If the backoff would take us to the expiry time, just set the
	   timeout to the expiry time. */
	if (ip->client->state != S_REQUESTING &&
	    cur_time + ip->client->interval >
	    ip->client->active->expiry)
		ip->client->interval =
		    ip->client->active->expiry - cur_time + 1;

	/* If the lease T2 time has elapsed, or if we're not yet bound,
	   broadcast the DHCPREQUEST rather than unicasting. */
	memset(&destination, 0, sizeof(destination));
	if (ip->client->state == S_REQUESTING ||
	    ip->client->state == S_REBOOTING ||
	    cur_time > ip->client->active->rebind)
		destination.sin_addr.s_addr = INADDR_BROADCAST;
	else
		memcpy(&destination.sin_addr.s_addr,
		    ip->client->destination.iabuf,
		    sizeof(destination.sin_addr.s_addr));
	destination.sin_port = htons(REMOTE_PORT);
	destination.sin_family = AF_INET;
	destination.sin_len = sizeof(destination);

	if (ip->client->state != S_REQUESTING)
		memcpy(&from, ip->client->active->address.iabuf,
		    sizeof(from));
	else
		from.s_addr = INADDR_ANY;

	/* Record the number of seconds since we started sending. */
	if (ip->client->state == S_REQUESTING)
		ip->client->packet.secs = ip->client->secs;
	else {
		if (interval < 65536)
			ip->client->packet.secs = htons(interval);
		else
			ip->client->packet.secs = htons(65535);
	}

	note("DHCPREQUEST on %s to %s port %d", ip->name,
	    inet_ntoa(destination.sin_addr), ntohs(destination.sin_port));

	/* Send out a packet. */
	(void) send_packet(ip, &ip->client->packet, ip->client->packet_length,
	    from, &destination, NULL);

	add_timeout(cur_time + ip->client->interval, send_request, ip);
}

void
send_decline(void *ipp)
{
	struct interface_info *ip = ipp;

	note("DHCPDECLINE on %s to %s port %d", ip->name,
	    inet_ntoa(sockaddr_broadcast.sin_addr),
	    ntohs(sockaddr_broadcast.sin_port));

	/* Send out a packet. */
	(void) send_packet(ip, &ip->client->packet, ip->client->packet_length,
	    inaddr_any, &sockaddr_broadcast, NULL);
}

void
make_discover(struct interface_info *ip, struct client_lease *lease)
{
	unsigned char discover = DHCPDISCOVER;
	struct tree_cache *options[256];
	struct tree_cache option_elements[256];
	int i;

	memset(option_elements, 0, sizeof(option_elements));
	memset(options, 0, sizeof(options));
	memset(&ip->client->packet, 0, sizeof(ip->client->packet));

	/* Set DHCP_MESSAGE_TYPE to DHCPDISCOVER */
	i = DHO_DHCP_MESSAGE_TYPE;
	options[i] = &option_elements[i];
	options[i]->value = &discover;
	options[i]->len = sizeof(discover);
	options[i]->buf_size = sizeof(discover);
	options[i]->timeout = 0xFFFFFFFF;

	/* Request the options we want */
	i  = DHO_DHCP_PARAMETER_REQUEST_LIST;
	options[i] = &option_elements[i];
	options[i]->value = ip->client->config->requested_options;
	options[i]->len = ip->client->config->requested_option_count;
	options[i]->buf_size =
		ip->client->config->requested_option_count;
	options[i]->timeout = 0xFFFFFFFF;

	/* If we had an address, try to get it again. */
	if (lease) {
		ip->client->requested_address = lease->address;
		i = DHO_DHCP_REQUESTED_ADDRESS;
		options[i] = &option_elements[i];
		options[i]->value = lease->address.iabuf;
		options[i]->len = lease->address.len;
		options[i]->buf_size = lease->address.len;
		options[i]->timeout = 0xFFFFFFFF;
	} else
		ip->client->requested_address.len = 0;

	/* Send any options requested in the config file. */
	for (i = 0; i < 256; i++)
		if (!options[i] &&
		    ip->client->config->send_options[i].data) {
			options[i] = &option_elements[i];
			options[i]->value =
			    ip->client->config->send_options[i].data;
			options[i]->len =
			    ip->client->config->send_options[i].len;
			options[i]->buf_size =
			    ip->client->config->send_options[i].len;
			options[i]->timeout = 0xFFFFFFFF;
		}
		
	/* send host name if not set via config file. */
	char hostname[_POSIX_HOST_NAME_MAX+1];
	if (!options[DHO_HOST_NAME]) {
		if (gethostname(hostname, sizeof(hostname)) == 0) {
			size_t len;
			char* posDot = strchr(hostname, '.');
			if (posDot != NULL)
				len = posDot - hostname;
			else
				len = strlen(hostname);
			options[DHO_HOST_NAME] = &option_elements[DHO_HOST_NAME];
			options[DHO_HOST_NAME]->value = hostname;
			options[DHO_HOST_NAME]->len = len;
			options[DHO_HOST_NAME]->buf_size = len;
			options[DHO_HOST_NAME]->timeout = 0xFFFFFFFF;
		}
	}

	/* set unique client identifier */
	char client_ident[sizeof(struct hardware)];
	if (!options[DHO_DHCP_CLIENT_IDENTIFIER]) {
		int hwlen = (ip->hw_address.hlen < sizeof(client_ident)-1) ?
				ip->hw_address.hlen : sizeof(client_ident)-1;
		client_ident[0] = ip->hw_address.htype;
		memcpy(&client_ident[1], ip->hw_address.haddr, hwlen); 
		options[DHO_DHCP_CLIENT_IDENTIFIER] = &option_elements[DHO_DHCP_CLIENT_IDENTIFIER];
		options[DHO_DHCP_CLIENT_IDENTIFIER]->value = client_ident;
		options[DHO_DHCP_CLIENT_IDENTIFIER]->len = hwlen+1;
		options[DHO_DHCP_CLIENT_IDENTIFIER]->buf_size = hwlen+1;
		options[DHO_DHCP_CLIENT_IDENTIFIER]->timeout = 0xFFFFFFFF;
	}

	/* Set up the option buffer... */
	ip->client->packet_length = cons_options(NULL, &ip->client->packet, 0,
	    options, 0, 0, 0, NULL, 0);
	if (ip->client->packet_length < BOOTP_MIN_LEN)
		ip->client->packet_length = BOOTP_MIN_LEN;

	ip->client->packet.op = BOOTREQUEST;
	ip->client->packet.htype = ip->hw_address.htype;
	ip->client->packet.hlen = ip->hw_address.hlen;
	ip->client->packet.hops = 0;
	ip->client->packet.xid = arc4random();
	ip->client->packet.secs = 0; /* filled in by send_discover. */
	ip->client->packet.flags = 0;

	memset(&(ip->client->packet.ciaddr),
	    0, sizeof(ip->client->packet.ciaddr));
	memset(&(ip->client->packet.yiaddr),
	    0, sizeof(ip->client->packet.yiaddr));
	memset(&(ip->client->packet.siaddr),
	    0, sizeof(ip->client->packet.siaddr));
	memset(&(ip->client->packet.giaddr),
	    0, sizeof(ip->client->packet.giaddr));
	memcpy(ip->client->packet.chaddr,
	    ip->hw_address.haddr, ip->hw_address.hlen);
}


void
make_request(struct interface_info *ip, struct client_lease * lease)
{
	unsigned char request = DHCPREQUEST;
	struct tree_cache *options[256];
	struct tree_cache option_elements[256];
	int i;

	memset(options, 0, sizeof(options));
	memset(&ip->client->packet, 0, sizeof(ip->client->packet));

	/* Set DHCP_MESSAGE_TYPE to DHCPREQUEST */
	i = DHO_DHCP_MESSAGE_TYPE;
	options[i] = &option_elements[i];
	options[i]->value = &request;
	options[i]->len = sizeof(request);
	options[i]->buf_size = sizeof(request);
	options[i]->timeout = 0xFFFFFFFF;

	/* Request the options we want */
	i = DHO_DHCP_PARAMETER_REQUEST_LIST;
	options[i] = &option_elements[i];
	options[i]->value = ip->client->config->requested_options;
	options[i]->len = ip->client->config->requested_option_count;
	options[i]->buf_size =
		ip->client->config->requested_option_count;
	options[i]->timeout = 0xFFFFFFFF;

	/* If we are requesting an address that hasn't yet been assigned
	   to us, use the DHCP Requested Address option. */
	if (ip->client->state == S_REQUESTING) {
		/* Send back the server identifier... */
		i = DHO_DHCP_SERVER_IDENTIFIER;
		options[i] = &option_elements[i];
		options[i]->value = lease->options[i].data;
		options[i]->len = lease->options[i].len;
		options[i]->buf_size = lease->options[i].len;
		options[i]->timeout = 0xFFFFFFFF;
	}
	if (ip->client->state == S_REQUESTING ||
	    ip->client->state == S_REBOOTING) {
		ip->client->requested_address = lease->address;
		i = DHO_DHCP_REQUESTED_ADDRESS;
		options[i] = &option_elements[i];
		options[i]->value = lease->address.iabuf;
		options[i]->len = lease->address.len;
		options[i]->buf_size = lease->address.len;
		options[i]->timeout = 0xFFFFFFFF;
	} else
		ip->client->requested_address.len = 0;

	/* Send any options requested in the config file. */
	for (i = 0; i < 256; i++)
		if (!options[i] &&
		    ip->client->config->send_options[i].data) {
			options[i] = &option_elements[i];
			options[i]->value =
			    ip->client->config->send_options[i].data;
			options[i]->len =
			    ip->client->config->send_options[i].len;
			options[i]->buf_size =
			    ip->client->config->send_options[i].len;
			options[i]->timeout = 0xFFFFFFFF;
		}
		
	/* send host name if not set via config file. */
	char hostname[_POSIX_HOST_NAME_MAX+1];
	if (!options[DHO_HOST_NAME]) {
		if (gethostname(hostname, sizeof(hostname)) == 0) {
			size_t len;
			char* posDot = strchr(hostname, '.');
			if (posDot != NULL)
				len = posDot - hostname;
			else
				len = strlen(hostname);
			options[DHO_HOST_NAME] = &option_elements[DHO_HOST_NAME];
			options[DHO_HOST_NAME]->value = hostname;
			options[DHO_HOST_NAME]->len = len;
			options[DHO_HOST_NAME]->buf_size = len;
			options[DHO_HOST_NAME]->timeout = 0xFFFFFFFF;
		}
	}

	/* set unique client identifier */
	char client_ident[sizeof(struct hardware)];
	if (!options[DHO_DHCP_CLIENT_IDENTIFIER]) {
		int hwlen = (ip->hw_address.hlen < sizeof(client_ident)-1) ?
				ip->hw_address.hlen : sizeof(client_ident)-1;
		client_ident[0] = ip->hw_address.htype;
		memcpy(&client_ident[1], ip->hw_address.haddr, hwlen); 
		options[DHO_DHCP_CLIENT_IDENTIFIER] = &option_elements[DHO_DHCP_CLIENT_IDENTIFIER];
		options[DHO_DHCP_CLIENT_IDENTIFIER]->value = client_ident;
		options[DHO_DHCP_CLIENT_IDENTIFIER]->len = hwlen+1;
		options[DHO_DHCP_CLIENT_IDENTIFIER]->buf_size = hwlen+1;
		options[DHO_DHCP_CLIENT_IDENTIFIER]->timeout = 0xFFFFFFFF;
	}

	/* Set up the option buffer... */
	ip->client->packet_length = cons_options(NULL, &ip->client->packet, 0,
	    options, 0, 0, 0, NULL, 0);
	if (ip->client->packet_length < BOOTP_MIN_LEN)
		ip->client->packet_length = BOOTP_MIN_LEN;

	ip->client->packet.op = BOOTREQUEST;
	ip->client->packet.htype = ip->hw_address.htype;
	ip->client->packet.hlen = ip->hw_address.hlen;
	ip->client->packet.hops = 0;
	ip->client->packet.xid = ip->client->xid;
	ip->client->packet.secs = 0; /* Filled in by send_request. */

	/* If we own the address we're requesting, put it in ciaddr;
	   otherwise set ciaddr to zero. */
	if (ip->client->state == S_BOUND ||
	    ip->client->state == S_RENEWING ||
	    ip->client->state == S_REBINDING) {
		memcpy(&ip->client->packet.ciaddr,
		    lease->address.iabuf, lease->address.len);
		ip->client->packet.flags = 0;
	} else {
		memset(&ip->client->packet.ciaddr, 0,
		    sizeof(ip->client->packet.ciaddr));
		ip->client->packet.flags = 0;
	}

	memset(&ip->client->packet.yiaddr, 0,
	    sizeof(ip->client->packet.yiaddr));
	memset(&ip->client->packet.siaddr, 0,
	    sizeof(ip->client->packet.siaddr));
	memset(&ip->client->packet.giaddr, 0,
	    sizeof(ip->client->packet.giaddr));
	memcpy(ip->client->packet.chaddr,
	    ip->hw_address.haddr, ip->hw_address.hlen);
}

void
make_decline(struct interface_info *ip, struct client_lease *lease)
{
	struct tree_cache *options[256], message_type_tree;
	struct tree_cache requested_address_tree;
	struct tree_cache server_id_tree, client_id_tree;
	unsigned char decline = DHCPDECLINE;
	int i;

	memset(options, 0, sizeof(options));
	memset(&ip->client->packet, 0, sizeof(ip->client->packet));

	/* Set DHCP_MESSAGE_TYPE to DHCPDECLINE */
	i = DHO_DHCP_MESSAGE_TYPE;
	options[i] = &message_type_tree;
	options[i]->value = &decline;
	options[i]->len = sizeof(decline);
	options[i]->buf_size = sizeof(decline);
	options[i]->timeout = 0xFFFFFFFF;

	/* Send back the server identifier... */
	i = DHO_DHCP_SERVER_IDENTIFIER;
	options[i] = &server_id_tree;
	options[i]->value = lease->options[i].data;
	options[i]->len = lease->options[i].len;
	options[i]->buf_size = lease->options[i].len;
	options[i]->timeout = 0xFFFFFFFF;

	/* Send back the address we're declining. */
	i = DHO_DHCP_REQUESTED_ADDRESS;
	options[i] = &requested_address_tree;
	options[i]->value = lease->address.iabuf;
	options[i]->len = lease->address.len;
	options[i]->buf_size = lease->address.len;
	options[i]->timeout = 0xFFFFFFFF;

	/* Send the uid if the user supplied one. */
	i = DHO_DHCP_CLIENT_IDENTIFIER;
	if (ip->client->config->send_options[i].len) {
		options[i] = &client_id_tree;
		options[i]->value = ip->client->config->send_options[i].data;
		options[i]->len = ip->client->config->send_options[i].len;
		options[i]->buf_size = ip->client->config->send_options[i].len;
		options[i]->timeout = 0xFFFFFFFF;
	}


	/* Set up the option buffer... */
	ip->client->packet_length = cons_options(NULL, &ip->client->packet, 0,
	    options, 0, 0, 0, NULL, 0);
	if (ip->client->packet_length < BOOTP_MIN_LEN)
		ip->client->packet_length = BOOTP_MIN_LEN;

	ip->client->packet.op = BOOTREQUEST;
	ip->client->packet.htype = ip->hw_address.htype;
	ip->client->packet.hlen = ip->hw_address.hlen;
	ip->client->packet.hops = 0;
	ip->client->packet.xid = ip->client->xid;
	ip->client->packet.secs = 0; /* Filled in by send_request. */
	ip->client->packet.flags = 0;

	/* ciaddr must always be zero. */
	memset(&ip->client->packet.ciaddr, 0,
	    sizeof(ip->client->packet.ciaddr));
	memset(&ip->client->packet.yiaddr, 0,
	    sizeof(ip->client->packet.yiaddr));
	memset(&ip->client->packet.siaddr, 0,
	    sizeof(ip->client->packet.siaddr));
	memset(&ip->client->packet.giaddr, 0,
	    sizeof(ip->client->packet.giaddr));
	memcpy(ip->client->packet.chaddr,
	    ip->hw_address.haddr, ip->hw_address.hlen);
}

void
free_client_lease(struct client_lease *lease)
{
	int i;

	if (lease->server_name)
		free(lease->server_name);
	if (lease->filename)
		free(lease->filename);
	for (i = 0; i < 256; i++) {
		if (lease->options[i].len)
			free(lease->options[i].data);
	}
	free(lease);
}

FILE *leaseFile;

void
rewrite_client_leases(void)
{
	struct client_lease *lp;

	if (!leaseFile) {
		leaseFile = fopen(path_dhclient_db, "w");
		if (!leaseFile)
			error("can't create %s: %m", path_dhclient_db);
	} else {
		fflush(leaseFile);
		rewind(leaseFile);
	}

	for (lp = ifi->client->leases; lp; lp = lp->next)
		write_client_lease(ifi, lp, 1);
	if (ifi->client->active)
		write_client_lease(ifi, ifi->client->active, 1);

	fflush(leaseFile);
	ftruncate(fileno(leaseFile), ftello(leaseFile));
	fsync(fileno(leaseFile));
}

void
write_client_lease(struct interface_info *ip, struct client_lease *lease,
    int rewrite)
{
	static int leases_written;
	struct tm *t;
	int i;

	if (!rewrite) {
		if (leases_written++ > 20) {
			rewrite_client_leases();
			leases_written = 0;
		}
	}

	/* If the lease came from the config file, we don't need to stash
	   a copy in the lease database. */
	if (lease->is_static)
		return;

	if (!leaseFile) {	/* XXX */
		leaseFile = fopen(path_dhclient_db, "w");
		if (!leaseFile)
			error("can't create %s: %m", path_dhclient_db);
	}

	fprintf(leaseFile, "lease {\n");
	if (lease->is_bootp)
		fprintf(leaseFile, "  bootp;\n");
	fprintf(leaseFile, "  interface \"%s\";\n", ip->name);
	fprintf(leaseFile, "  fixed-address %s;\n", piaddr(lease->address));
	if (lease->filename)
		fprintf(leaseFile, "  filename \"%s\";\n", lease->filename);
	if (lease->server_name)
		fprintf(leaseFile, "  server-name \"%s\";\n",
		    lease->server_name);
	if (lease->medium)
		fprintf(leaseFile, "  medium \"%s\";\n", lease->medium->string);
	for (i = 0; i < 256; i++)
		if (lease->options[i].len)
			fprintf(leaseFile, "  option %s %s;\n",
			    dhcp_options[i].name,
			    pretty_print_option(i, lease->options[i].data,
			    lease->options[i].len, 1, 1));

	t = gmtime(&lease->renewal);
	fprintf(leaseFile, "  renew %d %d/%d/%d %02d:%02d:%02d;\n",
	    t->tm_wday, t->tm_year + 1900, t->tm_mon + 1, t->tm_mday,
	    t->tm_hour, t->tm_min, t->tm_sec);
	t = gmtime(&lease->rebind);
	fprintf(leaseFile, "  rebind %d %d/%d/%d %02d:%02d:%02d;\n",
	    t->tm_wday, t->tm_year + 1900, t->tm_mon + 1, t->tm_mday,
	    t->tm_hour, t->tm_min, t->tm_sec);
	t = gmtime(&lease->expiry);
	fprintf(leaseFile, "  expire %d %d/%d/%d %02d:%02d:%02d;\n",
	    t->tm_wday, t->tm_year + 1900, t->tm_mon + 1, t->tm_mday,
	    t->tm_hour, t->tm_min, t->tm_sec);
	fprintf(leaseFile, "}\n");
	fflush(leaseFile);
}

void
script_init(char *reason, struct string_list *medium)
{
	size_t		 len, mediumlen = 0;
	struct imsg_hdr	 hdr;
	struct buf	*buf;
	int		 errs;

	if (medium != NULL && medium->string != NULL)
		mediumlen = strlen(medium->string);

	hdr.code = IMSG_SCRIPT_INIT;
	hdr.len = sizeof(struct imsg_hdr) +
	    sizeof(size_t) + mediumlen +
	    sizeof(size_t) + strlen(reason);

	if ((buf = buf_open(hdr.len)) == NULL)
		error("buf_open: %m");

	errs = 0;
	errs += buf_add(buf, &hdr, sizeof(hdr));
	errs += buf_add(buf, &mediumlen, sizeof(mediumlen));
	if (mediumlen > 0)
		errs += buf_add(buf, medium->string, mediumlen);
	len = strlen(reason);
	errs += buf_add(buf, &len, sizeof(len));
	errs += buf_add(buf, reason, len);

	if (errs)
		error("buf_add: %m");

	if (buf_close(privfd, buf) == -1)
		error("buf_close: %m");
}

void
priv_script_init(char *reason, char *medium)
{
	struct interface_info *ip = ifi;

	if (ip) {
		ip->client->scriptEnvsize = 100;
		if (ip->client->scriptEnv == NULL)
			ip->client->scriptEnv =
			    malloc(ip->client->scriptEnvsize * sizeof(char *));
		if (ip->client->scriptEnv == NULL)
			error("script_init: no memory for environment");

		ip->client->scriptEnv[0] = strdup(CLIENT_PATH);
		if (ip->client->scriptEnv[0] == NULL)
			error("script_init: no memory for environment");

		ip->client->scriptEnv[1] = NULL;

		script_set_env(ip->client, "", "interface", ip->name);

		if (medium)
			script_set_env(ip->client, "", "medium", medium);

		script_set_env(ip->client, "", "reason", reason);
	}
}

void
priv_script_write_params(char *prefix, struct client_lease *lease)
{
	struct interface_info *ip = ifi;
	u_int8_t dbuf[1500], *dp = NULL;
	int i, len;
	char tbuf[128];

	script_set_env(ip->client, prefix, "ip_address",
	    piaddr(lease->address));

	if (ip->client->config->default_actions[DHO_SUBNET_MASK] ==
	    ACTION_SUPERSEDE) {
		dp = ip->client->config->defaults[DHO_SUBNET_MASK].data;
		len = ip->client->config->defaults[DHO_SUBNET_MASK].len;
	} else {
		dp = lease->options[DHO_SUBNET_MASK].data;
		len = lease->options[DHO_SUBNET_MASK].len;
	}
	if (len && (len < sizeof(lease->address.iabuf))) {
		struct iaddr netmask, subnet, broadcast;

		memcpy(netmask.iabuf, dp, len);
		netmask.len = len;
		subnet = subnet_number(lease->address, netmask);
		if (subnet.len) {
			script_set_env(ip->client, prefix, "network_number",
			    piaddr(subnet));
			if (!lease->options[DHO_BROADCAST_ADDRESS].len) {
				broadcast = broadcast_addr(subnet, netmask);
				if (broadcast.len)
					script_set_env(ip->client, prefix,
					    "broadcast_address",
					    piaddr(broadcast));
			}
		}
	}

	if (lease->filename)
		script_set_env(ip->client, prefix, "filename", lease->filename);
	if (lease->server_name)
		script_set_env(ip->client, prefix, "server_name",
		    lease->server_name);
	for (i = 0; i < 256; i++) {
		len = 0;

		if (ip->client->config->defaults[i].len) {
			if (lease->options[i].len) {
				switch (
				    ip->client->config->default_actions[i]) {
				case ACTION_DEFAULT:
					dp = lease->options[i].data;
					len = lease->options[i].len;
					break;
				case ACTION_SUPERSEDE:
supersede:
					dp = ip->client->
						config->defaults[i].data;
					len = ip->client->
						config->defaults[i].len;
					break;
				case ACTION_PREPEND:
					len = ip->client->
					    config->defaults[i].len +
					    lease->options[i].len;
					if (len >= sizeof(dbuf)) {
						warning("no space to %s %s",
						    "prepend option",
						    dhcp_options[i].name);
						goto supersede;
					}
					dp = dbuf;
					memcpy(dp,
						ip->client->
						config->defaults[i].data,
						ip->client->
						config->defaults[i].len);
					memcpy(dp + ip->client->
						config->defaults[i].len,
						lease->options[i].data,
						lease->options[i].len);
					dp[len] = '\0';
					break;
				case ACTION_APPEND:
					/*
					 * When we append, we assume that we're
					 * appending to text.  Some MS servers
					 * include a NUL byte at the end of
					 * the search string provided.
					 */
					len = ip->client->
					    config->defaults[i].len +
					    lease->options[i].len;
					if (len >= sizeof(dbuf)) {
						warning("no space to %s %s",
						    "append option",
						    dhcp_options[i].name);
						goto supersede;
					}
					memcpy(dbuf,
						lease->options[i].data,
						lease->options[i].len);
					for (dp = dbuf + lease->options[i].len;
					    dp > dbuf; dp--, len--)
						if (dp[-1] != '\0')
							break;
					memcpy(dp,
						ip->client->
						config->defaults[i].data,
						ip->client->
						config->defaults[i].len);
					dp = dbuf;
					dp[len] = '\0';
				}
			} else {
				dp = ip->client->
					config->defaults[i].data;
				len = ip->client->
					config->defaults[i].len;
			}
		} else if (lease->options[i].len) {
			len = lease->options[i].len;
			dp = lease->options[i].data;
		} else {
			len = 0;
		}
		if (len) {
			char name[256];

			if (dhcp_option_ev_name(name, sizeof(name),
			    &dhcp_options[i]))
				script_set_env(ip->client, prefix, name,
				    pretty_print_option(i, dp, len, 0, 0));
		}
	}
	snprintf(tbuf, sizeof(tbuf), "%d", (int)lease->expiry);
	script_set_env(ip->client, prefix, "expiry", tbuf);
}

void
script_write_params(char *prefix, struct client_lease *lease)
{
	size_t		 fn_len = 0, sn_len = 0, pr_len = 0;
	struct imsg_hdr	 hdr;
	struct buf	*buf;
	int		 errs, i;

	if (lease->filename != NULL)
		fn_len = strlen(lease->filename);
	if (lease->server_name != NULL)
		sn_len = strlen(lease->server_name);
	if (prefix != NULL)
		pr_len = strlen(prefix);

	hdr.code = IMSG_SCRIPT_WRITE_PARAMS;
	hdr.len = sizeof(hdr) + sizeof(struct client_lease) +
	    sizeof(size_t) + fn_len + sizeof(size_t) + sn_len +
	    sizeof(size_t) + pr_len;

	for (i = 0; i < 256; i++)
		hdr.len += sizeof(int) + lease->options[i].len;

	scripttime = time(NULL);

	if ((buf = buf_open(hdr.len)) == NULL)
		error("buf_open: %m");

	errs = 0;
	errs += buf_add(buf, &hdr, sizeof(hdr));
	errs += buf_add(buf, lease, sizeof(struct client_lease));
	errs += buf_add(buf, &fn_len, sizeof(fn_len));
	errs += buf_add(buf, lease->filename, fn_len);
	errs += buf_add(buf, &sn_len, sizeof(sn_len));
	errs += buf_add(buf, lease->server_name, sn_len);
	errs += buf_add(buf, &pr_len, sizeof(pr_len));
	errs += buf_add(buf, prefix, pr_len);

	for (i = 0; i < 256; i++) {
		errs += buf_add(buf, &lease->options[i].len,
		    sizeof(lease->options[i].len));
		errs += buf_add(buf, lease->options[i].data,
		    lease->options[i].len);
	}

	if (errs)
		error("buf_add: %m");

	if (buf_close(privfd, buf) == -1)
		error("buf_close: %m");
}

int
script_go(void)
{
	struct imsg_hdr	 hdr;
	struct buf	*buf;
	int		 ret;

	hdr.code = IMSG_SCRIPT_GO;
	hdr.len = sizeof(struct imsg_hdr);

	if ((buf = buf_open(hdr.len)) == NULL)
		error("buf_open: %m");

	if (buf_add(buf, &hdr, sizeof(hdr)))
		error("buf_add: %m");

	if (buf_close(privfd, buf) == -1)
		error("buf_close: %m");

	bzero(&hdr, sizeof(hdr));
	buf_read(privfd, &hdr, sizeof(hdr));
	if (hdr.code != IMSG_SCRIPT_GO_RET)
		error("unexpected msg type %u", hdr.code);
	if (hdr.len != sizeof(hdr) + sizeof(int))
		error("received corrupted message");
	buf_read(privfd, &ret, sizeof(ret));

	scripttime = time(NULL);

	return (ret);
}

int
priv_script_go(void)
{
	char *scriptName, *argv[2], **envp, *epp[3], reason[] = "REASON=NBI";
	static char client_path[] = CLIENT_PATH;
	struct interface_info *ip = ifi;
	int pid, wpid, wstatus;

	scripttime = time(NULL);

	if (ip) {
		scriptName = ip->client->config->script_name;
		envp = ip->client->scriptEnv;
	} else {
		scriptName = top_level_config.script_name;
		epp[0] = reason;
		epp[1] = client_path;
		epp[2] = NULL;
		envp = epp;
	}

	argv[0] = scriptName;
	argv[1] = NULL;

	pid = fork();
	if (pid < 0) {
		error("fork: %m");
		wstatus = 0;
	} else if (pid) {
		do {
			wpid = wait(&wstatus);
		} while (wpid != pid && wpid > 0);
		if (wpid < 0) {
			error("wait: %m");
			wstatus = 0;
		}
	} else {
		execve(scriptName, argv, envp);
		error("execve (%s, ...): %m", scriptName);
	}

	if (ip)
		script_flush_env(ip->client);

	return (wstatus & 0xff);
}

void
script_set_env(struct client_state *client, const char *prefix,
    const char *name, const char *value)
{
	int i, j, namelen;

	namelen = strlen(name);

	for (i = 0; client->scriptEnv[i]; i++)
		if (strncmp(client->scriptEnv[i], name, namelen) == 0 &&
		    client->scriptEnv[i][namelen] == '=')
			break;

	if (client->scriptEnv[i])
		/* Reuse the slot. */
		free(client->scriptEnv[i]);
	else {
		/* New variable.  Expand if necessary. */
		if (i >= client->scriptEnvsize - 1) {
			char **newscriptEnv;
			int newscriptEnvsize = client->scriptEnvsize + 50;

			newscriptEnv = realloc(client->scriptEnv,
			    newscriptEnvsize);
			if (newscriptEnv == NULL) {
				free(client->scriptEnv);
				client->scriptEnv = NULL;
				client->scriptEnvsize = 0;
				error("script_set_env: no memory for variable");
			}
			client->scriptEnv = newscriptEnv;
			client->scriptEnvsize = newscriptEnvsize;
		}
		/* need to set the NULL pointer at end of array beyond
		   the new slot. */
		client->scriptEnv[i + 1] = NULL;
	}
	/* Allocate space and format the variable in the appropriate slot. */
	client->scriptEnv[i] = malloc(strlen(prefix) + strlen(name) + 1 +
	    strlen(value) + 1);
	if (client->scriptEnv[i] == NULL)
		error("script_set_env: no memory for variable assignment");

	/* No `` or $() command substitution allowed in environment values! */
	for (j=0; j < strlen(value); j++)
		switch (value[j]) {
		case '`':
		case '$':
			error("illegal character (%c) in value '%s'", value[j],
			    value);
			/* not reached */
		}
	snprintf(client->scriptEnv[i], strlen(prefix) + strlen(name) +
	    1 + strlen(value) + 1, "%s%s=%s", prefix, name, value);
}

void
script_flush_env(struct client_state *client)
{
	int i;

	for (i = 0; client->scriptEnv[i]; i++) {
		free(client->scriptEnv[i]);
		client->scriptEnv[i] = NULL;
	}
	client->scriptEnvsize = 0;
}

int
dhcp_option_ev_name(char *buf, size_t buflen, struct option *option)
{
	int i;

	for (i = 0; option->name[i]; i++) {
		if (i + 1 == buflen)
			return 0;
		if (option->name[i] == '-')
			buf[i] = '_';
		else
			buf[i] = option->name[i];
	}

	buf[i] = 0;
	return 1;
}

void
go_daemon(void)
{
	static int state = 0;

	if (no_daemon || state)
		return;

	state = 1;

	/* Stop logging to stderr... */
	log_perror = 0;

	if (daemon(1, 0) == -1)
		error("daemon");

	if (pidfile != NULL)
		pidfile_write(pidfile);

	/* we are chrooted, daemon(3) fails to open /dev/null */
	if (nullfd != -1) {
		dup2(nullfd, STDIN_FILENO);
		dup2(nullfd, STDOUT_FILENO);
		dup2(nullfd, STDERR_FILENO);
		close(nullfd);
		nullfd = -1;
	}
}

int
check_option(struct client_lease *l, int option)
{
	char *opbuf;
	char *sbuf;

	/* we use this, since this is what gets passed to dhclient-script */

	opbuf = pretty_print_option(option, l->options[option].data,
	    l->options[option].len, 0, 0);

	sbuf = option_as_string(option, l->options[option].data,
	    l->options[option].len);

	switch (option) {
	case DHO_SUBNET_MASK:
	case DHO_TIME_SERVERS:
	case DHO_NAME_SERVERS:
	case DHO_ROUTERS:
	case DHO_DOMAIN_NAME_SERVERS:
	case DHO_LOG_SERVERS:
	case DHO_COOKIE_SERVERS:
	case DHO_LPR_SERVERS:
	case DHO_IMPRESS_SERVERS:
	case DHO_RESOURCE_LOCATION_SERVERS:
	case DHO_SWAP_SERVER:
	case DHO_BROADCAST_ADDRESS:
	case DHO_NIS_SERVERS:
	case DHO_NTP_SERVERS:
	case DHO_NETBIOS_NAME_SERVERS:
	case DHO_NETBIOS_DD_SERVER:
	case DHO_FONT_SERVERS:
	case DHO_DHCP_SERVER_IDENTIFIER:
	case DHO_NISPLUS_SERVERS:
	case DHO_MOBILE_IP_HOME_AGENT:
	case DHO_SMTP_SERVER:
	case DHO_POP_SERVER:
	case DHO_NNTP_SERVER:
	case DHO_WWW_SERVER:
	case DHO_FINGER_SERVER:
	case DHO_IRC_SERVER:
	case DHO_STREETTALK_SERVER:
	case DHO_STREETTALK_DA_SERVER:
		if (!ipv4addrs(opbuf)) {
			warning("Invalid IP address in option: %s", opbuf);
			return (0);
		}
		return (1)  ;
	case DHO_HOST_NAME:
	case DHO_NIS_DOMAIN:
	case DHO_NISPLUS_DOMAIN:
	case DHO_TFTP_SERVER_NAME:
		if (!res_hnok(sbuf)) {
			warning("Bogus Host Name option %d: %s (%s)", option,
			    sbuf, opbuf);
			l->options[option].len = 0;
			free(l->options[option].data);
		}
		return (1);
	case DHO_DOMAIN_NAME:
	case DHO_DOMAIN_SEARCH:
		if (!res_hnok(sbuf)) {
			if (!check_search(sbuf)) {
				warning("Bogus domain search list %d: %s (%s)",
				    option, sbuf, opbuf);
				l->options[option].len = 0;
				free(l->options[option].data);
			}
		}
		return (1);
	case DHO_PAD:
	case DHO_TIME_OFFSET:
	case DHO_BOOT_SIZE:
	case DHO_MERIT_DUMP:
	case DHO_ROOT_PATH:
	case DHO_EXTENSIONS_PATH:
	case DHO_IP_FORWARDING:
	case DHO_NON_LOCAL_SOURCE_ROUTING:
	case DHO_POLICY_FILTER:
	case DHO_MAX_DGRAM_REASSEMBLY:
	case DHO_DEFAULT_IP_TTL:
	case DHO_PATH_MTU_AGING_TIMEOUT:
	case DHO_PATH_MTU_PLATEAU_TABLE:
	case DHO_INTERFACE_MTU:
	case DHO_ALL_SUBNETS_LOCAL:
	case DHO_PERFORM_MASK_DISCOVERY:
	case DHO_MASK_SUPPLIER:
	case DHO_ROUTER_DISCOVERY:
	case DHO_ROUTER_SOLICITATION_ADDRESS:
	case DHO_STATIC_ROUTES:
	case DHO_TRAILER_ENCAPSULATION:
	case DHO_ARP_CACHE_TIMEOUT:
	case DHO_IEEE802_3_ENCAPSULATION:
	case DHO_DEFAULT_TCP_TTL:
	case DHO_TCP_KEEPALIVE_INTERVAL:
	case DHO_TCP_KEEPALIVE_GARBAGE:
	case DHO_VENDOR_ENCAPSULATED_OPTIONS:
	case DHO_NETBIOS_NODE_TYPE:
	case DHO_NETBIOS_SCOPE:
	case DHO_X_DISPLAY_MANAGER:
	case DHO_DHCP_REQUESTED_ADDRESS:
	case DHO_DHCP_LEASE_TIME:
	case DHO_DHCP_OPTION_OVERLOAD:
	case DHO_DHCP_MESSAGE_TYPE:
	case DHO_DHCP_PARAMETER_REQUEST_LIST:
	case DHO_DHCP_MESSAGE:
	case DHO_DHCP_MAX_MESSAGE_SIZE:
	case DHO_DHCP_RENEWAL_TIME:
	case DHO_DHCP_REBINDING_TIME:
	case DHO_DHCP_CLASS_IDENTIFIER:
	case DHO_DHCP_CLIENT_IDENTIFIER:
	case DHO_BOOTFILE_NAME:
	case DHO_DHCP_USER_CLASS_ID:
	case DHO_END:
		return (1);
	case DHO_CLASSLESS_ROUTES:
		return (check_classless_option(l->options[option].data,
		    l->options[option].len));
	default:
		warning("unknown dhcp option value 0x%x", option);
		return (unknown_ok);
	}
}

/* RFC 3442 The Classless Static Routes option checks */
int
check_classless_option(unsigned char *data, int len)
{
	int i = 0;
	unsigned char width;
	in_addr_t addr, mask;

	if (len < 5) {
		warning("Too small length: %d", len);
		return (0);
	}
	while(i < len) {
		width = data[i++];
		if (width == 0) {
			i += 4;
			continue;
		} else if (width < 9) {
			addr =  (in_addr_t)(data[i] 	<< 24);
			i += 1;
		} else if (width < 17) {
			addr =  (in_addr_t)(data[i] 	<< 24) +
				(in_addr_t)(data[i + 1]	<< 16);
			i += 2;
		} else if (width < 25) {
			addr =  (in_addr_t)(data[i] 	<< 24) +
				(in_addr_t)(data[i + 1]	<< 16) +
				(in_addr_t)(data[i + 2]	<< 8);
			i += 3;
		} else if (width < 33) {
			addr =  (in_addr_t)(data[i] 	<< 24) +
				(in_addr_t)(data[i + 1]	<< 16) +
				(in_addr_t)(data[i + 2]	<< 8)  +
				data[i + 3];
			i += 4;
		} else {
			warning("Incorrect subnet width: %d", width);
			return (0);
		}
		mask = (in_addr_t)(~0) << (32 - width);
		addr = ntohl(addr);
		mask = ntohl(mask);

		/*
		 * From RFC 3442:
		 * ... After deriving a subnet number and subnet mask
		 * from each destination descriptor, the DHCP client
		 * MUST zero any bits in the subnet number where the
		 * corresponding bit in the mask is zero...
		 */
		if ((addr & mask) != addr) {
			addr &= mask;
			data[i - 1] = (unsigned char)(
				(addr >> (((32 - width)/8)*8)) & 0xFF);
		} 
		i += 4;
	}
	if (i > len) {
		warning("Incorrect data length: %d (must be %d)", len, i);
		return (0);
	}
	return (1);
}

int
res_hnok(const char *dn)
{
	int pch = PERIOD, ch = *dn++;

	while (ch != '\0') {
		int nch = *dn++;

		if (periodchar(ch)) {
			;
		} else if (periodchar(pch)) {
			if (!borderchar(ch))
				return (0);
		} else if (periodchar(nch) || nch == '\0') {
			if (!borderchar(ch))
				return (0);
		} else {
			if (!middlechar(ch))
				return (0);
		}
		pch = ch, ch = nch;
	}
	return (1);
}

int
check_search(const char *srch)
{
        int pch = PERIOD, ch = *srch++;
	int domains = 1;

	/* 256 char limit re resolv.conf(5) */
	if (strlen(srch) > 256)
		return (0);

	while (whitechar(ch))
		ch = *srch++;

        while (ch != '\0') {
                int nch = *srch++;

                if (periodchar(ch) || whitechar(ch)) {
                        ;
                } else if (periodchar(pch)) {
                        if (!borderchar(ch))
                                return (0);
                } else if (periodchar(nch) || nch == '\0') {
                        if (!borderchar(ch))
                                return (0);
                } else {
                        if (!middlechar(ch))
                                return (0);
                }
		if (!whitechar(ch)) {
			pch = ch;
		} else {
			while (whitechar(nch)) {
				nch = *srch++;
			}
			if (nch != '\0')
				domains++;
			pch = PERIOD;
		}
		ch = nch;
        }
	/* 6 domain limit re resolv.conf(5) */
	if (domains > 6)
		return (0);
        return (1);
}

/* Does buf consist only of dotted decimal ipv4 addrs?
 * return how many if so,
 * otherwise, return 0
 */
int
ipv4addrs(char * buf)
{
	struct in_addr jnk;
	int count = 0;

	while (inet_aton(buf, &jnk) == 1){
		count++;
		while (periodchar(*buf) || digitchar(*buf))
			buf++;
		if (*buf == '\0')
			return (count);
		while (*buf ==  ' ')
			buf++;
	}
	return (0);
}


char *
option_as_string(unsigned int code, unsigned char *data, int len)
{
	static char optbuf[32768]; /* XXX */
	char *op = optbuf;
	int opleft = sizeof(optbuf);
	unsigned char *dp = data;

	if (code > 255)
		error("option_as_string: bad code %d", code);

	for (; dp < data + len; dp++) {
		if (!isascii(*dp) || !isprint(*dp)) {
			if (dp + 1 != data + len || *dp != 0) {
				snprintf(op, opleft, "\\%03o", *dp);
				op += 4;
				opleft -= 4;
			}
		} else if (*dp == '"' || *dp == '\'' || *dp == '$' ||
		    *dp == '`' || *dp == '\\') {
			*op++ = '\\';
			*op++ = *dp;
			opleft -= 2;
		} else {
			*op++ = *dp;
			opleft--;
		}
	}
	if (opleft < 1)
		goto toobig;
	*op = 0;
	return optbuf;
toobig:
	warning("dhcp option too large");
	return "<error>";
}

int
fork_privchld(int fd, int fd2)
{
	struct pollfd pfd[1];
	int nfds;

	switch (fork()) {
	case -1:
		error("cannot fork");
	case 0:
		break;
	default:
		return (0);
	}

	setproctitle("%s [priv]", ifi->name);

	setsid();
	dup2(nullfd, STDIN_FILENO);
	dup2(nullfd, STDOUT_FILENO);
	dup2(nullfd, STDERR_FILENO);
	close(nullfd);
	close(fd2);

	for (;;) {
		pfd[0].fd = fd;
		pfd[0].events = POLLIN;
		if ((nfds = poll(pfd, 1, INFTIM)) == -1)
			if (errno != EINTR)
				error("poll error");

		if (nfds == 0 || !(pfd[0].revents & POLLIN))
			continue;

		dispatch_imsg(fd);
	}
}
OpenPOWER on IntegriCloud