summaryrefslogtreecommitdiffstats
path: root/drivers/isdn/i4l/isdn_ppp.c
blob: b9fed8a3bcc650036e170719ac9d0320a602e4ac (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
2700
2701
2702
2703
2704
2705
2706
2707
2708
2709
2710
2711
2712
2713
2714
2715
2716
2717
2718
2719
2720
2721
2722
2723
2724
2725
2726
2727
2728
2729
2730
2731
2732
2733
2734
2735
2736
2737
2738
2739
2740
2741
2742
2743
2744
2745
2746
2747
2748
2749
2750
2751
2752
2753
2754
2755
2756
2757
2758
2759
2760
2761
2762
2763
2764
2765
2766
2767
2768
2769
2770
2771
2772
2773
2774
2775
2776
2777
2778
2779
2780
2781
2782
2783
2784
2785
2786
2787
2788
2789
2790
2791
2792
2793
2794
2795
2796
2797
2798
2799
2800
2801
2802
2803
2804
2805
2806
2807
2808
2809
2810
2811
2812
2813
2814
2815
2816
2817
2818
2819
2820
2821
2822
2823
2824
2825
2826
2827
2828
2829
2830
2831
2832
2833
2834
2835
2836
2837
2838
2839
2840
2841
2842
2843
2844
2845
2846
2847
2848
2849
2850
2851
2852
2853
2854
2855
2856
2857
2858
2859
2860
2861
2862
2863
2864
2865
2866
2867
2868
2869
2870
2871
2872
2873
2874
2875
2876
2877
2878
2879
2880
2881
2882
2883
2884
2885
2886
2887
2888
2889
2890
2891
2892
2893
2894
2895
2896
2897
2898
2899
2900
2901
2902
2903
2904
2905
2906
2907
2908
2909
2910
2911
2912
2913
2914
2915
2916
2917
2918
2919
2920
2921
2922
2923
2924
2925
2926
2927
2928
2929
2930
2931
2932
2933
2934
2935
2936
2937
2938
2939
2940
2941
2942
2943
2944
2945
2946
2947
2948
2949
2950
2951
2952
2953
2954
2955
2956
2957
2958
2959
2960
2961
2962
2963
2964
2965
2966
2967
2968
2969
2970
2971
2972
2973
2974
2975
2976
2977
2978
2979
2980
2981
2982
2983
2984
2985
2986
2987
2988
2989
2990
2991
2992
2993
2994
2995
2996
2997
2998
2999
3000
3001
3002
3003
3004
3005
3006
3007
3008
3009
3010
3011
3012
3013
/* $Id: isdn_ppp.c,v 1.1.2.3 2004/02/10 01:07:13 keil Exp $
 *
 * Linux ISDN subsystem, functions for synchronous PPP (linklevel).
 *
 * Copyright 1995,96 by Michael Hipp (Michael.Hipp@student.uni-tuebingen.de)
 *
 * This software may be used and distributed according to the terms
 * of the GNU General Public License, incorporated herein by reference.
 *
 */

#include <linux/config.h>
#include <linux/isdn.h>
#include <linux/poll.h>
#include <linux/ppp-comp.h>
#ifdef CONFIG_IPPP_FILTER
#include <linux/filter.h>
#endif

#include "isdn_common.h"
#include "isdn_ppp.h"
#include "isdn_net.h"

#ifndef PPP_IPX
#define PPP_IPX 0x002b
#endif

/* Prototypes */
static int isdn_ppp_fill_rq(unsigned char *buf, int len, int proto, int slot);
static int isdn_ppp_closewait(int slot);
static void isdn_ppp_push_higher(isdn_net_dev * net_dev, isdn_net_local * lp,
				 struct sk_buff *skb, int proto);
static int isdn_ppp_if_get_unit(char *namebuf);
static int isdn_ppp_set_compressor(struct ippp_struct *is,struct isdn_ppp_comp_data *);
static struct sk_buff *isdn_ppp_decompress(struct sk_buff *,
				struct ippp_struct *,struct ippp_struct *,int *proto);
static void isdn_ppp_receive_ccp(isdn_net_dev * net_dev, isdn_net_local * lp,
				struct sk_buff *skb,int proto);
static struct sk_buff *isdn_ppp_compress(struct sk_buff *skb_in,int *proto,
	struct ippp_struct *is,struct ippp_struct *master,int type);
static void isdn_ppp_send_ccp(isdn_net_dev *net_dev, isdn_net_local *lp,
	 struct sk_buff *skb);

/* New CCP stuff */
static void isdn_ppp_ccp_kickup(struct ippp_struct *is);
static void isdn_ppp_ccp_xmit_reset(struct ippp_struct *is, int proto,
				    unsigned char code, unsigned char id,
				    unsigned char *data, int len);
static struct ippp_ccp_reset *isdn_ppp_ccp_reset_alloc(struct ippp_struct *is);
static void isdn_ppp_ccp_reset_free(struct ippp_struct *is);
static void isdn_ppp_ccp_reset_free_state(struct ippp_struct *is,
					  unsigned char id);
static void isdn_ppp_ccp_timer_callback(unsigned long closure);
static struct ippp_ccp_reset_state *isdn_ppp_ccp_reset_alloc_state(struct ippp_struct *is,
						      unsigned char id);
static void isdn_ppp_ccp_reset_trans(struct ippp_struct *is,
				     struct isdn_ppp_resetparams *rp);
static void isdn_ppp_ccp_reset_ack_rcvd(struct ippp_struct *is,
					unsigned char id);



#ifdef CONFIG_ISDN_MPP
static ippp_bundle * isdn_ppp_bundle_arr = NULL;
 
static int isdn_ppp_mp_bundle_array_init(void);
static int isdn_ppp_mp_init( isdn_net_local * lp, ippp_bundle * add_to );
static void isdn_ppp_mp_receive(isdn_net_dev * net_dev, isdn_net_local * lp, 
							struct sk_buff *skb);
static void isdn_ppp_mp_cleanup( isdn_net_local * lp );

static int isdn_ppp_bundle(struct ippp_struct *, int unit);
#endif	/* CONFIG_ISDN_MPP */
  
char *isdn_ppp_revision = "$Revision: 1.1.2.3 $";

static struct ippp_struct *ippp_table[ISDN_MAX_CHANNELS];

static struct isdn_ppp_compressor *ipc_head = NULL;

/*
 * frame log (debug)
 */
static void
isdn_ppp_frame_log(char *info, char *data, int len, int maxlen,int unit,int slot)
{
	int cnt,
	 j,
	 i;
	char buf[80];

	if (len < maxlen)
		maxlen = len;

	for (i = 0, cnt = 0; cnt < maxlen; i++) {
		for (j = 0; j < 16 && cnt < maxlen; j++, cnt++)
			sprintf(buf + j * 3, "%02x ", (unsigned char) data[cnt]);
		printk(KERN_DEBUG "[%d/%d].%s[%d]: %s\n",unit,slot, info, i, buf);
	}
}

/*
 * unbind isdn_net_local <=> ippp-device
 * note: it can happen, that we hangup/free the master before the slaves
 *       in this case we bind another lp to the master device
 */
int
isdn_ppp_free(isdn_net_local * lp)
{
	struct ippp_struct *is;

	if (lp->ppp_slot < 0 || lp->ppp_slot > ISDN_MAX_CHANNELS) {
		printk(KERN_ERR "%s: ppp_slot(%d) out of range\n",
			__FUNCTION__, lp->ppp_slot);
		return 0;
	}

#ifdef CONFIG_ISDN_MPP
	spin_lock(&lp->netdev->pb->lock);
#endif
	isdn_net_rm_from_bundle(lp);
#ifdef CONFIG_ISDN_MPP
	if (lp->netdev->pb->ref_ct == 1)	/* last link in queue? */
		isdn_ppp_mp_cleanup(lp);

	lp->netdev->pb->ref_ct--;
	spin_unlock(&lp->netdev->pb->lock);
#endif /* CONFIG_ISDN_MPP */
	if (lp->ppp_slot < 0 || lp->ppp_slot > ISDN_MAX_CHANNELS) {
		printk(KERN_ERR "%s: ppp_slot(%d) now invalid\n",
			__FUNCTION__, lp->ppp_slot);
		return 0;
	}
	is = ippp_table[lp->ppp_slot];
	if ((is->state & IPPP_CONNECT))
		isdn_ppp_closewait(lp->ppp_slot);	/* force wakeup on ippp device */
	else if (is->state & IPPP_ASSIGNED)
		is->state = IPPP_OPEN;	/* fallback to 'OPEN but not ASSIGNED' state */

	if (is->debug & 0x1)
		printk(KERN_DEBUG "isdn_ppp_free %d %lx %lx\n", lp->ppp_slot, (long) lp, (long) is->lp);

	is->lp = NULL;          /* link is down .. set lp to NULL */
	lp->ppp_slot = -1;      /* is this OK ?? */

	return 0;
}

/*
 * bind isdn_net_local <=> ippp-device
 *
 * This function is allways called with holding dev->lock so
 * no additional lock is needed
 */
int
isdn_ppp_bind(isdn_net_local * lp)
{
	int i;
	int unit = 0;
	struct ippp_struct *is;
	int retval;

	if (lp->pppbind < 0) {  /* device bounded to ippp device ? */
		isdn_net_dev *net_dev = dev->netdev;
		char exclusive[ISDN_MAX_CHANNELS];	/* exclusive flags */
		memset(exclusive, 0, ISDN_MAX_CHANNELS);
		while (net_dev) {	/* step through net devices to find exclusive minors */
			isdn_net_local *lp = net_dev->local;
			if (lp->pppbind >= 0)
				exclusive[lp->pppbind] = 1;
			net_dev = net_dev->next;
		}
		/*
		 * search a free device / slot
		 */
		for (i = 0; i < ISDN_MAX_CHANNELS; i++) {
			if (ippp_table[i]->state == IPPP_OPEN && !exclusive[ippp_table[i]->minor]) {	/* OPEN, but not connected! */
				break;
			}
		}
	} else {
		for (i = 0; i < ISDN_MAX_CHANNELS; i++) {
			if (ippp_table[i]->minor == lp->pppbind &&
			    (ippp_table[i]->state & IPPP_OPEN) == IPPP_OPEN)
				break;
		}
	}

	if (i >= ISDN_MAX_CHANNELS) {
		printk(KERN_WARNING "isdn_ppp_bind: Can't find a (free) connection to the ipppd daemon.\n");
		retval = -1;
		goto out;
	}
	unit = isdn_ppp_if_get_unit(lp->name);	/* get unit number from interface name .. ugly! */
	if (unit < 0) {
		printk(KERN_ERR "isdn_ppp_bind: illegal interface name %s.\n", lp->name);
		retval = -1;
		goto out;
	}
	
	lp->ppp_slot = i;
	is = ippp_table[i];
	is->lp = lp;
	is->unit = unit;
	is->state = IPPP_OPEN | IPPP_ASSIGNED;	/* assigned to a netdevice but not connected */
#ifdef CONFIG_ISDN_MPP
	retval = isdn_ppp_mp_init(lp, NULL);
	if (retval < 0)
		goto out;
#endif /* CONFIG_ISDN_MPP */

	retval = lp->ppp_slot;

 out:
	return retval;
}

/*
 * kick the ipppd on the device
 * (wakes up daemon after B-channel connect)
 */

void
isdn_ppp_wakeup_daemon(isdn_net_local * lp)
{
	if (lp->ppp_slot < 0 || lp->ppp_slot >= ISDN_MAX_CHANNELS) {
		printk(KERN_ERR "%s: ppp_slot(%d) out of range\n",
			__FUNCTION__, lp->ppp_slot);
		return;
	}
	ippp_table[lp->ppp_slot]->state = IPPP_OPEN | IPPP_CONNECT | IPPP_NOBLOCK;
	wake_up_interruptible(&ippp_table[lp->ppp_slot]->wq);
}

/*
 * there was a hangup on the netdevice
 * force wakeup of the ippp device
 * go into 'device waits for release' state
 */
static int
isdn_ppp_closewait(int slot)
{
	struct ippp_struct *is;

	if (slot < 0 || slot >= ISDN_MAX_CHANNELS) {
		printk(KERN_ERR "%s: slot(%d) out of range\n",
			__FUNCTION__, slot);
		return 0;
	}
	is = ippp_table[slot];
	if (is->state)
		wake_up_interruptible(&is->wq);
	is->state = IPPP_CLOSEWAIT;
	return 1;
}

/*
 * isdn_ppp_find_slot / isdn_ppp_free_slot
 */

static int
isdn_ppp_get_slot(void)
{
	int i;
	for (i = 0; i < ISDN_MAX_CHANNELS; i++) {
		if (!ippp_table[i]->state)
			return i;
	}
	return -1;
}

/*
 * isdn_ppp_open
 */

int
isdn_ppp_open(int min, struct file *file)
{
	int slot;
	struct ippp_struct *is;

	if (min < 0 || min > ISDN_MAX_CHANNELS)
		return -ENODEV;

	slot = isdn_ppp_get_slot();
	if (slot < 0) {
		return -EBUSY;
	}
	is = file->private_data = ippp_table[slot];
	
	printk(KERN_DEBUG "ippp, open, slot: %d, minor: %d, state: %04x\n",
	       slot, min, is->state);

	/* compression stuff */
	is->link_compressor   = is->compressor = NULL;
	is->link_decompressor = is->decompressor = NULL;
	is->link_comp_stat    = is->comp_stat = NULL;
	is->link_decomp_stat  = is->decomp_stat = NULL;
	is->compflags = 0;

	is->reset = isdn_ppp_ccp_reset_alloc(is);

	is->lp = NULL;
	is->mp_seqno = 0;       /* MP sequence number */
	is->pppcfg = 0;         /* ppp configuration */
	is->mpppcfg = 0;        /* mppp configuration */
	is->last_link_seqno = -1;	/* MP: maybe set to Bundle-MIN, when joining a bundle ?? */
	is->unit = -1;          /* set, when we have our interface */
	is->mru = 1524;         /* MRU, default 1524 */
	is->maxcid = 16;        /* VJ: maxcid */
	is->tk = current;
	init_waitqueue_head(&is->wq);
	is->first = is->rq + NUM_RCV_BUFFS - 1;	/* receive queue */
	is->last = is->rq;
	is->minor = min;
#ifdef CONFIG_ISDN_PPP_VJ
	/*
	 * VJ header compression init
	 */
	is->slcomp = slhc_init(16, 16);	/* not necessary for 2. link in bundle */
#endif
#ifdef CONFIG_IPPP_FILTER
	is->pass_filter = NULL;
	is->active_filter = NULL;
#endif
	is->state = IPPP_OPEN;

	return 0;
}

/*
 * release ippp device
 */
void
isdn_ppp_release(int min, struct file *file)
{
	int i;
	struct ippp_struct *is;

	if (min < 0 || min >= ISDN_MAX_CHANNELS)
		return;
	is = file->private_data;

	if (!is) {
		printk(KERN_ERR "%s: no file->private_data\n", __FUNCTION__);
		return;
	}
	if (is->debug & 0x1)
		printk(KERN_DEBUG "ippp: release, minor: %d %lx\n", min, (long) is->lp);

	if (is->lp) {           /* a lp address says: this link is still up */
		isdn_net_dev *p = is->lp->netdev;

		if (!p) {
			printk(KERN_ERR "%s: no lp->netdev\n", __FUNCTION__);
			return;
		}
		is->state &= ~IPPP_CONNECT;	/* -> effect: no call of wakeup */
		/*
		 * isdn_net_hangup() calls isdn_ppp_free()
		 * isdn_ppp_free() sets is->lp to NULL and lp->ppp_slot to -1
		 * removing the IPPP_CONNECT flag omits calling of isdn_ppp_wakeup_daemon()
		 */
		isdn_net_hangup(&p->dev);
	}
	for (i = 0; i < NUM_RCV_BUFFS; i++) {
		kfree(is->rq[i].buf);
		is->rq[i].buf = NULL;
	}
	is->first = is->rq + NUM_RCV_BUFFS - 1;	/* receive queue */
	is->last = is->rq;

#ifdef CONFIG_ISDN_PPP_VJ
/* TODO: if this was the previous master: link the slcomp to the new master */
	slhc_free(is->slcomp);
	is->slcomp = NULL;
#endif
#ifdef CONFIG_IPPP_FILTER
	kfree(is->pass_filter);
	is->pass_filter = NULL;
	kfree(is->active_filter);
	is->active_filter = NULL;
#endif

/* TODO: if this was the previous master: link the stuff to the new master */
	if(is->comp_stat)
		is->compressor->free(is->comp_stat);
	if(is->link_comp_stat)
		is->link_compressor->free(is->link_comp_stat);
	if(is->link_decomp_stat)
		is->link_decompressor->free(is->link_decomp_stat);
	if(is->decomp_stat)
		is->decompressor->free(is->decomp_stat);
        is->compressor   = is->link_compressor   = NULL;
        is->decompressor = is->link_decompressor = NULL;
	is->comp_stat    = is->link_comp_stat    = NULL;
        is->decomp_stat  = is->link_decomp_stat  = NULL;

	/* Clean up if necessary */
	if(is->reset)
		isdn_ppp_ccp_reset_free(is);

	/* this slot is ready for new connections */
	is->state = 0;
}

/*
 * get_arg .. ioctl helper
 */
static int
get_arg(void __user *b, void *val, int len)
{
	if (len <= 0)
		len = sizeof(void *);
	if (copy_from_user(val, b, len))
		return -EFAULT;
	return 0;
}

/*
 * set arg .. ioctl helper
 */
static int
set_arg(void __user *b, void *val,int len)
{
	if(len <= 0)
		len = sizeof(void *);
	if (copy_to_user(b, val, len))
		return -EFAULT;
	return 0;
}

static int get_filter(void __user *arg, struct sock_filter **p)
{
	struct sock_fprog uprog;
	struct sock_filter *code = NULL;
	int len, err;

	if (copy_from_user(&uprog, arg, sizeof(uprog)))
		return -EFAULT;

	if (!uprog.len) {
		*p = NULL;
		return 0;
	}

	/* uprog.len is unsigned short, so no overflow here */
	len = uprog.len * sizeof(struct sock_filter);
	code = kmalloc(len, GFP_KERNEL);
	if (code == NULL)
		return -ENOMEM;

	if (copy_from_user(code, uprog.filter, len)) {
		kfree(code);
		return -EFAULT;
	}

	err = sk_chk_filter(code, uprog.len);
	if (err) {
		kfree(code);
		return err;
	}

	*p = code;
	return uprog.len;
}

/*
 * ippp device ioctl
 */
int
isdn_ppp_ioctl(int min, struct file *file, unsigned int cmd, unsigned long arg)
{
	unsigned long val;
	int r,i,j;
	struct ippp_struct *is;
	isdn_net_local *lp;
	struct isdn_ppp_comp_data data;
	void __user *argp = (void __user *)arg;

	is = (struct ippp_struct *) file->private_data;
	lp = is->lp;

	if (is->debug & 0x1)
		printk(KERN_DEBUG "isdn_ppp_ioctl: minor: %d cmd: %x state: %x\n", min, cmd, is->state);

	if (!(is->state & IPPP_OPEN))
		return -EINVAL;

	switch (cmd) {
		case PPPIOCBUNDLE:
#ifdef CONFIG_ISDN_MPP
			if (!(is->state & IPPP_CONNECT))
				return -EINVAL;
			if ((r = get_arg(argp, &val, sizeof(val) )))
				return r;
			printk(KERN_DEBUG "iPPP-bundle: minor: %d, slave unit: %d, master unit: %d\n",
			       (int) min, (int) is->unit, (int) val);
			return isdn_ppp_bundle(is, val);
#else
			return -1;
#endif
			break;
		case PPPIOCGUNIT:	/* get ppp/isdn unit number */
			if ((r = set_arg(argp, &is->unit, sizeof(is->unit) )))
				return r;
			break;
		case PPPIOCGIFNAME:
			if(!lp)
				return -EINVAL;
			if ((r = set_arg(argp, lp->name, strlen(lp->name))))
				return r;
			break;
		case PPPIOCGMPFLAGS:	/* get configuration flags */
			if ((r = set_arg(argp, &is->mpppcfg, sizeof(is->mpppcfg) )))
				return r;
			break;
		case PPPIOCSMPFLAGS:	/* set configuration flags */
			if ((r = get_arg(argp, &val, sizeof(val) )))
				return r;
			is->mpppcfg = val;
			break;
		case PPPIOCGFLAGS:	/* get configuration flags */
			if ((r = set_arg(argp, &is->pppcfg,sizeof(is->pppcfg) )))
				return r;
			break;
		case PPPIOCSFLAGS:	/* set configuration flags */
			if ((r = get_arg(argp, &val, sizeof(val) ))) {
				return r;
			}
			if (val & SC_ENABLE_IP && !(is->pppcfg & SC_ENABLE_IP) && (is->state & IPPP_CONNECT)) {
				if (lp) {
					/* OK .. we are ready to send buffers */
					is->pppcfg = val; /* isdn_ppp_xmit test for SC_ENABLE_IP !!! */
					netif_wake_queue(&lp->netdev->dev);
					break;
				}
			}
			is->pppcfg = val;
			break;
		case PPPIOCGIDLE:	/* get idle time information */
			if (lp) {
				struct ppp_idle pidle;
				pidle.xmit_idle = pidle.recv_idle = lp->huptimer;
				if ((r = set_arg(argp, &pidle,sizeof(struct ppp_idle))))
					 return r;
			}
			break;
		case PPPIOCSMRU:	/* set receive unit size for PPP */
			if ((r = get_arg(argp, &val, sizeof(val) )))
				return r;
			is->mru = val;
			break;
		case PPPIOCSMPMRU:
			break;
		case PPPIOCSMPMTU:
			break;
		case PPPIOCSMAXCID:	/* set the maximum compression slot id */
			if ((r = get_arg(argp, &val, sizeof(val) )))
				return r;
			val++;
			if (is->maxcid != val) {
#ifdef CONFIG_ISDN_PPP_VJ
				struct slcompress *sltmp;
#endif
				if (is->debug & 0x1)
					printk(KERN_DEBUG "ippp, ioctl: changed MAXCID to %ld\n", val);
				is->maxcid = val;
#ifdef CONFIG_ISDN_PPP_VJ
				sltmp = slhc_init(16, val);
				if (!sltmp) {
					printk(KERN_ERR "ippp, can't realloc slhc struct\n");
					return -ENOMEM;
				}
				if (is->slcomp)
					slhc_free(is->slcomp);
				is->slcomp = sltmp;
#endif
			}
			break;
		case PPPIOCGDEBUG:
			if ((r = set_arg(argp, &is->debug, sizeof(is->debug) )))
				return r;
			break;
		case PPPIOCSDEBUG:
			if ((r = get_arg(argp, &val, sizeof(val) )))
				return r;
			is->debug = val;
			break;
		case PPPIOCGCOMPRESSORS:
			{
				unsigned long protos[8] = {0,};
				struct isdn_ppp_compressor *ipc = ipc_head;
				while(ipc) {
					j = ipc->num / (sizeof(long)*8);
					i = ipc->num % (sizeof(long)*8);
					if(j < 8)
						protos[j] |= (0x1<<i);
					ipc = ipc->next;
				}
				if ((r = set_arg(argp,protos,8*sizeof(long) )))
					return r;
			}
			break;
		case PPPIOCSCOMPRESSOR:
			if ((r = get_arg(argp, &data, sizeof(struct isdn_ppp_comp_data))))
				return r;
			return isdn_ppp_set_compressor(is, &data);
		case PPPIOCGCALLINFO:
			{
				struct pppcallinfo pci;
				memset((char *) &pci,0,sizeof(struct pppcallinfo));
				if(lp)
				{
					strncpy(pci.local_num,lp->msn,63);
					if(lp->dial) {
						strncpy(pci.remote_num,lp->dial->num,63);
					}
					pci.charge_units = lp->charge;
					if(lp->outgoing)
						pci.calltype = CALLTYPE_OUTGOING;
					else
						pci.calltype = CALLTYPE_INCOMING;
					if(lp->flags & ISDN_NET_CALLBACK)
						pci.calltype |= CALLTYPE_CALLBACK;
				}
				return set_arg(argp,&pci,sizeof(struct pppcallinfo));
			}
#ifdef CONFIG_IPPP_FILTER
		case PPPIOCSPASS:
			{
				struct sock_filter *code;
				int len = get_filter(argp, &code);
				if (len < 0)
					return len;
				kfree(is->pass_filter);
				is->pass_filter = code;
				is->pass_len = len;
				break;
			}
		case PPPIOCSACTIVE:
			{
				struct sock_filter *code;
				int len = get_filter(argp, &code);
				if (len < 0)
					return len;
				kfree(is->active_filter);
				is->active_filter = code;
				is->active_len = len;
				break;
			}
#endif /* CONFIG_IPPP_FILTER */
		default:
			break;
	}
	return 0;
}

unsigned int
isdn_ppp_poll(struct file *file, poll_table * wait)
{
	u_int mask;
	struct ippp_buf_queue *bf, *bl;
	u_long flags;
	struct ippp_struct *is;

	is = file->private_data;

	if (is->debug & 0x2)
		printk(KERN_DEBUG "isdn_ppp_poll: minor: %d\n",
				MINOR(file->f_dentry->d_inode->i_rdev));

	/* just registers wait_queue hook. This doesn't really wait. */
	poll_wait(file, &is->wq, wait);

	if (!(is->state & IPPP_OPEN)) {
		if(is->state == IPPP_CLOSEWAIT)
			return POLLHUP;
		printk(KERN_DEBUG "isdn_ppp: device not open\n");
		return POLLERR;
	}
	/* we're always ready to send .. */
	mask = POLLOUT | POLLWRNORM;

	spin_lock_irqsave(&is->buflock, flags);
	bl = is->last;
	bf = is->first;
	/*
	 * if IPPP_NOBLOCK is set we return even if we have nothing to read
	 */
	if (bf->next != bl || (is->state & IPPP_NOBLOCK)) {
		is->state &= ~IPPP_NOBLOCK;
		mask |= POLLIN | POLLRDNORM;
	}
	spin_unlock_irqrestore(&is->buflock, flags);
	return mask;
}

/*
 *  fill up isdn_ppp_read() queue ..
 */

static int
isdn_ppp_fill_rq(unsigned char *buf, int len, int proto, int slot)
{
	struct ippp_buf_queue *bf, *bl;
	u_long flags;
	u_char *nbuf;
	struct ippp_struct *is;

	if (slot < 0 || slot >= ISDN_MAX_CHANNELS) {
		printk(KERN_WARNING "ippp: illegal slot(%d).\n", slot);
		return 0;
	}
	is = ippp_table[slot];

	if (!(is->state & IPPP_CONNECT)) {
		printk(KERN_DEBUG "ippp: device not activated.\n");
		return 0;
	}
	nbuf = (unsigned char *) kmalloc(len + 4, GFP_ATOMIC);
	if (!nbuf) {
		printk(KERN_WARNING "ippp: Can't alloc buf\n");
		return 0;
	}
	nbuf[0] = PPP_ALLSTATIONS;
	nbuf[1] = PPP_UI;
	nbuf[2] = proto >> 8;
	nbuf[3] = proto & 0xff;
	memcpy(nbuf + 4, buf, len);

	spin_lock_irqsave(&is->buflock, flags);
	bf = is->first;
	bl = is->last;

	if (bf == bl) {
		printk(KERN_WARNING "ippp: Queue is full; discarding first buffer\n");
		bf = bf->next;
		kfree(bf->buf);
		is->first = bf;
	}
	bl->buf = (char *) nbuf;
	bl->len = len + 4;

	is->last = bl->next;
	spin_unlock_irqrestore(&is->buflock, flags);
	wake_up_interruptible(&is->wq);
	return len;
}

/*
 * read() .. non-blocking: ipppd calls it only after select()
 *           reports, that there is data
 */

int
isdn_ppp_read(int min, struct file *file, char __user *buf, int count)
{
	struct ippp_struct *is;
	struct ippp_buf_queue *b;
	u_long flags;
	u_char *save_buf;

	is = file->private_data;

	if (!(is->state & IPPP_OPEN))
		return 0;

	if (!access_ok(VERIFY_WRITE, buf, count))
		return -EFAULT;

	spin_lock_irqsave(&is->buflock, flags);
	b = is->first->next;
	save_buf = b->buf;
	if (!save_buf) {
		spin_unlock_irqrestore(&is->buflock, flags);
		return -EAGAIN;
	}
	if (b->len < count)
		count = b->len;
	b->buf = NULL;
	is->first = b;

	spin_unlock_irqrestore(&is->buflock, flags);
	if (copy_to_user(buf, save_buf, count))
		count = -EFAULT;
	kfree(save_buf);

	return count;
}

/*
 * ipppd wanna write a packet to the card .. non-blocking
 */

int
isdn_ppp_write(int min, struct file *file, const char __user *buf, int count)
{
	isdn_net_local *lp;
	struct ippp_struct *is;
	int proto;
	unsigned char protobuf[4];

	is = file->private_data;

	if (!(is->state & IPPP_CONNECT))
		return 0;

	lp = is->lp;

	/* -> push it directly to the lowlevel interface */

	if (!lp)
		printk(KERN_DEBUG "isdn_ppp_write: lp == NULL\n");
	else {
		/*
		 * Don't reset huptimer for
		 * LCP packets. (Echo requests).
		 */
		if (copy_from_user(protobuf, buf, 4))
			return -EFAULT;
		proto = PPP_PROTOCOL(protobuf);
		if (proto != PPP_LCP)
			lp->huptimer = 0;

		if (lp->isdn_device < 0 || lp->isdn_channel < 0)
			return 0;

		if ((dev->drv[lp->isdn_device]->flags & DRV_FLAG_RUNNING) &&
			lp->dialstate == 0 &&
		    (lp->flags & ISDN_NET_CONNECTED)) {
			unsigned short hl;
			struct sk_buff *skb;
			/*
			 * we need to reserve enought space in front of
			 * sk_buff. old call to dev_alloc_skb only reserved
			 * 16 bytes, now we are looking what the driver want
			 */
			hl = dev->drv[lp->isdn_device]->interface->hl_hdrlen;
			skb = alloc_skb(hl+count, GFP_ATOMIC);
			if (!skb) {
				printk(KERN_WARNING "isdn_ppp_write: out of memory!\n");
				return count;
			}
			skb_reserve(skb, hl);
			if (copy_from_user(skb_put(skb, count), buf, count))
			{
				kfree_skb(skb);
				return -EFAULT;
			}
			if (is->debug & 0x40) {
				printk(KERN_DEBUG "ppp xmit: len %d\n", (int) skb->len);
				isdn_ppp_frame_log("xmit", skb->data, skb->len, 32,is->unit,lp->ppp_slot);
			}

			isdn_ppp_send_ccp(lp->netdev,lp,skb); /* keeps CCP/compression states in sync */

			isdn_net_write_super(lp, skb);
		}
	}
	return count;
}

/*
 * init memory, structures etc.
 */

int
isdn_ppp_init(void)
{
	int i,
	 j;
	 
#ifdef CONFIG_ISDN_MPP
	if( isdn_ppp_mp_bundle_array_init() < 0 )
		return -ENOMEM;
#endif /* CONFIG_ISDN_MPP */

	for (i = 0; i < ISDN_MAX_CHANNELS; i++) {
		if (!(ippp_table[i] = (struct ippp_struct *)
		      kmalloc(sizeof(struct ippp_struct), GFP_KERNEL))) {
			printk(KERN_WARNING "isdn_ppp_init: Could not alloc ippp_table\n");
			for (j = 0; j < i; j++)
				kfree(ippp_table[j]);
			return -1;
		}
		memset((char *) ippp_table[i], 0, sizeof(struct ippp_struct));
		spin_lock_init(&ippp_table[i]->buflock);
		ippp_table[i]->state = 0;
		ippp_table[i]->first = ippp_table[i]->rq + NUM_RCV_BUFFS - 1;
		ippp_table[i]->last = ippp_table[i]->rq;

		for (j = 0; j < NUM_RCV_BUFFS; j++) {
			ippp_table[i]->rq[j].buf = NULL;
			ippp_table[i]->rq[j].last = ippp_table[i]->rq +
			    (NUM_RCV_BUFFS + j - 1) % NUM_RCV_BUFFS;
			ippp_table[i]->rq[j].next = ippp_table[i]->rq + (j + 1) % NUM_RCV_BUFFS;
		}
	}
	return 0;
}

void
isdn_ppp_cleanup(void)
{
	int i;

	for (i = 0; i < ISDN_MAX_CHANNELS; i++)
		kfree(ippp_table[i]);

#ifdef CONFIG_ISDN_MPP
	kfree(isdn_ppp_bundle_arr);
#endif /* CONFIG_ISDN_MPP */

}

/*
 * check for address/control field and skip if allowed
 * retval != 0 -> discard packet silently
 */
static int isdn_ppp_skip_ac(struct ippp_struct *is, struct sk_buff *skb) 
{
	if (skb->len < 1)
		return -1;

	if (skb->data[0] == 0xff) {
		if (skb->len < 2)
			return -1;

		if (skb->data[1] != 0x03)
			return -1;

		// skip address/control (AC) field
		skb_pull(skb, 2);
	} else { 
		if (is->pppcfg & SC_REJ_COMP_AC)
			// if AC compression was not negotiated, but used, discard packet
			return -1;
	}
	return 0;
}

/*
 * get the PPP protocol header and pull skb
 * retval < 0 -> discard packet silently
 */
static int isdn_ppp_strip_proto(struct sk_buff *skb) 
{
	int proto;
	
	if (skb->len < 1)
		return -1;

	if (skb->data[0] & 0x1) {
		// protocol field is compressed
		proto = skb->data[0];
		skb_pull(skb, 1);
	} else {
		if (skb->len < 2)
			return -1;
		proto = ((int) skb->data[0] << 8) + skb->data[1];
		skb_pull(skb, 2);
	}
	return proto;
}


/*
 * handler for incoming packets on a syncPPP interface
 */
void isdn_ppp_receive(isdn_net_dev * net_dev, isdn_net_local * lp, struct sk_buff *skb)
{
	struct ippp_struct *is;
	int slot;
	int proto;

	if (net_dev->local->master)
		BUG(); // we're called with the master device always

	slot = lp->ppp_slot;
	if (slot < 0 || slot >= ISDN_MAX_CHANNELS) {
		printk(KERN_ERR "isdn_ppp_receive: lp->ppp_slot(%d)\n",
			lp->ppp_slot);
		kfree_skb(skb);
		return;
	}
	is = ippp_table[slot];

	if (is->debug & 0x4) {
		printk(KERN_DEBUG "ippp_receive: is:%08lx lp:%08lx slot:%d unit:%d len:%d\n",
		       (long)is,(long)lp,lp->ppp_slot,is->unit,(int) skb->len);
		isdn_ppp_frame_log("receive", skb->data, skb->len, 32,is->unit,lp->ppp_slot);
	}

 	if (isdn_ppp_skip_ac(is, skb) < 0) {
 		kfree_skb(skb);
 		return;
 	}
  	proto = isdn_ppp_strip_proto(skb);
 	if (proto < 0) {
 		kfree_skb(skb);
 		return;
 	}
  
#ifdef CONFIG_ISDN_MPP
 	if (is->compflags & SC_LINK_DECOMP_ON) {
 		skb = isdn_ppp_decompress(skb, is, NULL, &proto);
 		if (!skb) // decompression error
 			return;
 	}
	
 	if (!(is->mpppcfg & SC_REJ_MP_PROT)) { // we agreed to receive MPPP
  		if (proto == PPP_MP) {
  			isdn_ppp_mp_receive(net_dev, lp, skb);
 			return;
 		}
 	} 
#endif
 	isdn_ppp_push_higher(net_dev, lp, skb, proto);
}

/*
 * we receive a reassembled frame, MPPP has been taken care of before.
 * address/control and protocol have been stripped from the skb
 * note: net_dev has to be master net_dev
 */
static void
isdn_ppp_push_higher(isdn_net_dev * net_dev, isdn_net_local * lp, struct sk_buff *skb, int proto)
{
	struct net_device *dev = &net_dev->dev;
 	struct ippp_struct *is, *mis;
	isdn_net_local *mlp = NULL;
	int slot;

	slot = lp->ppp_slot;
	if (slot < 0 || slot >= ISDN_MAX_CHANNELS) {
		printk(KERN_ERR "isdn_ppp_push_higher: lp->ppp_slot(%d)\n",
			lp->ppp_slot);
		goto drop_packet;
	}
	is = ippp_table[slot];
 	
 	if (lp->master) { // FIXME?
		mlp = (isdn_net_local *) lp->master->priv;
 		slot = mlp->ppp_slot;
 		if (slot < 0 || slot > ISDN_MAX_CHANNELS) {
 			printk(KERN_ERR "isdn_ppp_push_higher: master->ppp_slot(%d)\n",
 				lp->ppp_slot);
			goto drop_packet;
 		}
 	}
 	mis = ippp_table[slot];

	if (is->debug & 0x10) {
		printk(KERN_DEBUG "push, skb %d %04x\n", (int) skb->len, proto);
		isdn_ppp_frame_log("rpush", skb->data, skb->len, 32,is->unit,lp->ppp_slot);
	}
	if (mis->compflags & SC_DECOMP_ON) {
		skb = isdn_ppp_decompress(skb, is, mis, &proto);
		if (!skb) // decompression error
  			return;
  	}
	switch (proto) {
		case PPP_IPX:  /* untested */
			if (is->debug & 0x20)
				printk(KERN_DEBUG "isdn_ppp: IPX\n");
			skb->protocol = htons(ETH_P_IPX);
			break;
		case PPP_IP:
			if (is->debug & 0x20)
				printk(KERN_DEBUG "isdn_ppp: IP\n");
			skb->protocol = htons(ETH_P_IP);
			break;
		case PPP_COMP:
		case PPP_COMPFRAG:
			printk(KERN_INFO "isdn_ppp: unexpected compressed frame dropped\n");
			goto drop_packet;
#ifdef CONFIG_ISDN_PPP_VJ
		case PPP_VJC_UNCOMP:
			if (is->debug & 0x20)
				printk(KERN_DEBUG "isdn_ppp: VJC_UNCOMP\n");
			if (net_dev->local->ppp_slot < 0) {
				printk(KERN_ERR "%s: net_dev->local->ppp_slot(%d) out of range\n",
					__FUNCTION__, net_dev->local->ppp_slot);
				goto drop_packet;
			}
			if (slhc_remember(ippp_table[net_dev->local->ppp_slot]->slcomp, skb->data, skb->len) <= 0) {
				printk(KERN_WARNING "isdn_ppp: received illegal VJC_UNCOMP frame!\n");
				goto drop_packet;
			}
			skb->protocol = htons(ETH_P_IP);
			break;
		case PPP_VJC_COMP:
			if (is->debug & 0x20)
				printk(KERN_DEBUG "isdn_ppp: VJC_COMP\n");
			{
				struct sk_buff *skb_old = skb;
				int pkt_len;
				skb = dev_alloc_skb(skb_old->len + 128);

				if (!skb) {
					printk(KERN_WARNING "%s: Memory squeeze, dropping packet.\n", dev->name);
					skb = skb_old;
					goto drop_packet;
				}
				skb_put(skb, skb_old->len + 128);
				memcpy(skb->data, skb_old->data, skb_old->len);
				if (net_dev->local->ppp_slot < 0) {
					printk(KERN_ERR "%s: net_dev->local->ppp_slot(%d) out of range\n",
						__FUNCTION__, net_dev->local->ppp_slot);
					goto drop_packet;
				}
				pkt_len = slhc_uncompress(ippp_table[net_dev->local->ppp_slot]->slcomp,
						skb->data, skb_old->len);
				kfree_skb(skb_old);
				if (pkt_len < 0)
					goto drop_packet;

				skb_trim(skb, pkt_len);
				skb->protocol = htons(ETH_P_IP);
			}
			break;
#endif
		case PPP_CCP:
		case PPP_CCPFRAG:
			isdn_ppp_receive_ccp(net_dev,lp,skb,proto);
			/* Dont pop up ResetReq/Ack stuff to the daemon any
			   longer - the job is done already */
			if(skb->data[0] == CCP_RESETREQ ||
			   skb->data[0] == CCP_RESETACK)
				break;
			/* fall through */
		default:
			isdn_ppp_fill_rq(skb->data, skb->len, proto, lp->ppp_slot);	/* push data to pppd device */
			kfree_skb(skb);
			return;
	}

#ifdef CONFIG_IPPP_FILTER
	/* check if the packet passes the pass and active filters
	 * the filter instructions are constructed assuming
	 * a four-byte PPP header on each packet (which is still present) */
	skb_push(skb, 4);

	{
		u_int16_t *p = (u_int16_t *) skb->data;

		*p = 0;	/* indicate inbound */
	}

	if (is->pass_filter
	    && sk_run_filter(skb, is->pass_filter, is->pass_len) == 0) {
		if (is->debug & 0x2)
			printk(KERN_DEBUG "IPPP: inbound frame filtered.\n");
		kfree_skb(skb);
		return;
	}
	if (!(is->active_filter
	      && sk_run_filter(skb, is->active_filter,
	                       is->active_len) == 0)) {
		if (is->debug & 0x2)
			printk(KERN_DEBUG "IPPP: link-active filter: reseting huptimer.\n");
		lp->huptimer = 0;
		if (mlp)
			mlp->huptimer = 0;
	}
	skb_pull(skb, 4);
#else /* CONFIG_IPPP_FILTER */
	lp->huptimer = 0;
	if (mlp)
		mlp->huptimer = 0;
#endif /* CONFIG_IPPP_FILTER */
	skb->dev = dev;
	skb->mac.raw = skb->data;
	netif_rx(skb);
	/* net_dev->local->stats.rx_packets++; done in isdn_net.c */
	return;

 drop_packet:
	net_dev->local->stats.rx_dropped++;
	kfree_skb(skb);
}

/*
 * isdn_ppp_skb_push ..
 * checks whether we have enough space at the beginning of the skb
 * and allocs a new SKB if necessary
 */
static unsigned char *isdn_ppp_skb_push(struct sk_buff **skb_p,int len)
{
	struct sk_buff *skb = *skb_p;

	if(skb_headroom(skb) < len) {
		struct sk_buff *nskb = skb_realloc_headroom(skb, len);

		if (!nskb) {
			printk(KERN_ERR "isdn_ppp_skb_push: can't realloc headroom!\n");
			dev_kfree_skb(skb);
			return NULL;
		}
		printk(KERN_DEBUG "isdn_ppp_skb_push:under %d %d\n",skb_headroom(skb),len);
		dev_kfree_skb(skb);
		*skb_p = nskb;
		return skb_push(nskb, len);
	}
	return skb_push(skb,len);
}

/*
 * send ppp frame .. we expect a PIDCOMPressable proto --
 *  (here: currently always PPP_IP,PPP_VJC_COMP,PPP_VJC_UNCOMP)
 *
 * VJ compression may change skb pointer!!! .. requeue with old
 * skb isn't allowed!!
 */

int
isdn_ppp_xmit(struct sk_buff *skb, struct net_device *netdev)
{
	isdn_net_local *lp,*mlp;
	isdn_net_dev *nd;
	unsigned int proto = PPP_IP;     /* 0x21 */
	struct ippp_struct *ipt,*ipts;
	int slot, retval = 0;

	mlp = (isdn_net_local *) (netdev->priv);
	nd = mlp->netdev;       /* get master lp */

	slot = mlp->ppp_slot;
	if (slot < 0 || slot >= ISDN_MAX_CHANNELS) {
		printk(KERN_ERR "isdn_ppp_xmit: lp->ppp_slot(%d)\n",
			mlp->ppp_slot);
		kfree_skb(skb);
		goto out;
	}
	ipts = ippp_table[slot];

	if (!(ipts->pppcfg & SC_ENABLE_IP)) {	/* PPP connected ? */
		if (ipts->debug & 0x1)
			printk(KERN_INFO "%s: IP frame delayed.\n", netdev->name);
		retval = 1;
		goto out;
	}

	switch (ntohs(skb->protocol)) {
		case ETH_P_IP:
			proto = PPP_IP;
			break;
		case ETH_P_IPX:
			proto = PPP_IPX;	/* untested */
			break;
		default:
			printk(KERN_ERR "isdn_ppp: skipped unsupported protocol: %#x.\n", 
			       skb->protocol);
			dev_kfree_skb(skb);
			goto out;
	}

	lp = isdn_net_get_locked_lp(nd);
	if (!lp) {
		printk(KERN_WARNING "%s: all channels busy - requeuing!\n", netdev->name);
		retval = 1;
		goto out;
	}
	/* we have our lp locked from now on */

	slot = lp->ppp_slot;
	if (slot < 0 || slot > ISDN_MAX_CHANNELS) {
		printk(KERN_ERR "isdn_ppp_xmit: lp->ppp_slot(%d)\n",
			lp->ppp_slot);
		kfree_skb(skb);
		goto unlock;
	}
	ipt = ippp_table[slot];

	/*
	 * after this line .. requeueing in the device queue is no longer allowed!!!
	 */

	/* Pull off the fake header we stuck on earlier to keep
	 * the fragmentation code happy.
	 */
	skb_pull(skb,IPPP_MAX_HEADER);

#ifdef CONFIG_IPPP_FILTER
	/* check if we should pass this packet
	 * the filter instructions are constructed assuming
	 * a four-byte PPP header on each packet */
	*skb_push(skb, 4) = 1; /* indicate outbound */

	{
		u_int16_t *p = (u_int16_t *) skb->data;

		p++;
		*p   = htons(proto);
	}

	if (ipt->pass_filter
	    && sk_run_filter(skb, ipt->pass_filter, ipt->pass_len) == 0) {
		if (ipt->debug & 0x4)
			printk(KERN_DEBUG "IPPP: outbound frame filtered.\n");
		kfree_skb(skb);
		goto unlock;
	}
	if (!(ipt->active_filter
	      && sk_run_filter(skb, ipt->active_filter,
		               ipt->active_len) == 0)) {
		if (ipt->debug & 0x4)
			printk(KERN_DEBUG "IPPP: link-active filter: reseting huptimer.\n");
		lp->huptimer = 0;
	}
	skb_pull(skb, 4);
#else /* CONFIG_IPPP_FILTER */
	lp->huptimer = 0;
#endif /* CONFIG_IPPP_FILTER */

	if (ipt->debug & 0x4)
		printk(KERN_DEBUG "xmit skb, len %d\n", (int) skb->len);
        if (ipts->debug & 0x40)
                isdn_ppp_frame_log("xmit0", skb->data, skb->len, 32,ipts->unit,lp->ppp_slot);

#ifdef CONFIG_ISDN_PPP_VJ
	if (proto == PPP_IP && ipts->pppcfg & SC_COMP_TCP) {	/* ipts here? probably yes, but check this again */
		struct sk_buff *new_skb;
	        unsigned short hl;
		/*
		 * we need to reserve enought space in front of
		 * sk_buff. old call to dev_alloc_skb only reserved
		 * 16 bytes, now we are looking what the driver want.
		 */
		hl = dev->drv[lp->isdn_device]->interface->hl_hdrlen + IPPP_MAX_HEADER;
		/* 
		 * Note: hl might still be insufficient because the method
		 * above does not account for a possibible MPPP slave channel
		 * which had larger HL header space requirements than the
		 * master.
		 */
		new_skb = alloc_skb(hl+skb->len, GFP_ATOMIC);
		if (new_skb) {
			u_char *buf;
			int pktlen;

			skb_reserve(new_skb, hl);
			new_skb->dev = skb->dev;
			skb_put(new_skb, skb->len);
			buf = skb->data;

			pktlen = slhc_compress(ipts->slcomp, skb->data, skb->len, new_skb->data,
				 &buf, !(ipts->pppcfg & SC_NO_TCP_CCID));

			if (buf != skb->data) {	
				if (new_skb->data != buf)
					printk(KERN_ERR "isdn_ppp: FATAL error after slhc_compress!!\n");
				dev_kfree_skb(skb);
				skb = new_skb;
			} else {
				dev_kfree_skb(new_skb);
			}

			skb_trim(skb, pktlen);
			if (skb->data[0] & SL_TYPE_COMPRESSED_TCP) {	/* cslip? style -> PPP */
				proto = PPP_VJC_COMP;
				skb->data[0] ^= SL_TYPE_COMPRESSED_TCP;
			} else {
				if (skb->data[0] >= SL_TYPE_UNCOMPRESSED_TCP)
					proto = PPP_VJC_UNCOMP;
				skb->data[0] = (skb->data[0] & 0x0f) | 0x40;
			}
		}
	}
#endif

	/*
	 * normal (single link) or bundle compression
	 */
	if(ipts->compflags & SC_COMP_ON) {
		/* We send compressed only if both down- und upstream
		   compression is negotiated, that means, CCP is up */
		if(ipts->compflags & SC_DECOMP_ON) {
			skb = isdn_ppp_compress(skb,&proto,ipt,ipts,0);
		} else {
			printk(KERN_DEBUG "isdn_ppp: CCP not yet up - sending as-is\n");
		}
	}

	if (ipt->debug & 0x24)
		printk(KERN_DEBUG "xmit2 skb, len %d, proto %04x\n", (int) skb->len, proto);

#ifdef CONFIG_ISDN_MPP
	if (ipt->mpppcfg & SC_MP_PROT) {
		/* we get mp_seqno from static isdn_net_local */
		long mp_seqno = ipts->mp_seqno;
		ipts->mp_seqno++;
		if (ipt->mpppcfg & SC_OUT_SHORT_SEQ) {
			unsigned char *data = isdn_ppp_skb_push(&skb, 3);
			if(!data)
				goto unlock;
			mp_seqno &= 0xfff;
			data[0] = MP_BEGIN_FRAG | MP_END_FRAG | ((mp_seqno >> 8) & 0xf);	/* (B)egin & (E)ndbit .. */
			data[1] = mp_seqno & 0xff;
			data[2] = proto;	/* PID compression */
		} else {
			unsigned char *data = isdn_ppp_skb_push(&skb, 5);
			if(!data)
				goto unlock;
			data[0] = MP_BEGIN_FRAG | MP_END_FRAG;	/* (B)egin & (E)ndbit .. */
			data[1] = (mp_seqno >> 16) & 0xff;	/* sequence number: 24bit */
			data[2] = (mp_seqno >> 8) & 0xff;
			data[3] = (mp_seqno >> 0) & 0xff;
			data[4] = proto;	/* PID compression */
		}
		proto = PPP_MP; /* MP Protocol, 0x003d */
	}
#endif

	/*
	 * 'link in bundle' compression  ...
	 */
	if(ipt->compflags & SC_LINK_COMP_ON)
		skb = isdn_ppp_compress(skb,&proto,ipt,ipts,1);

	if( (ipt->pppcfg & SC_COMP_PROT) && (proto <= 0xff) ) {
		unsigned char *data = isdn_ppp_skb_push(&skb,1);
		if(!data)
			goto unlock;
		data[0] = proto & 0xff;
	}
	else {
		unsigned char *data = isdn_ppp_skb_push(&skb,2);
		if(!data)
			goto unlock;
		data[0] = (proto >> 8) & 0xff;
		data[1] = proto & 0xff;
	}
	if(!(ipt->pppcfg & SC_COMP_AC)) {
		unsigned char *data = isdn_ppp_skb_push(&skb,2);
		if(!data)
			goto unlock;
		data[0] = 0xff;    /* All Stations */
		data[1] = 0x03;    /* Unnumbered information */
	}

	/* tx-stats are now updated via BSENT-callback */

	if (ipts->debug & 0x40) {
		printk(KERN_DEBUG "skb xmit: len: %d\n", (int) skb->len);
		isdn_ppp_frame_log("xmit", skb->data, skb->len, 32,ipt->unit,lp->ppp_slot);
	}
	
	isdn_net_writebuf_skb(lp, skb);

 unlock:
	spin_unlock_bh(&lp->xmit_lock);
 out:
	return retval;
}

#ifdef CONFIG_IPPP_FILTER
/*
 * check if this packet may trigger auto-dial.
 */

int isdn_ppp_autodial_filter(struct sk_buff *skb, isdn_net_local *lp)
{
	struct ippp_struct *is = ippp_table[lp->ppp_slot];
	u_int16_t proto;
	int drop = 0;

	switch (ntohs(skb->protocol)) {
	case ETH_P_IP:
		proto = PPP_IP;
		break;
	case ETH_P_IPX:
		proto = PPP_IPX;
		break;
	default:
		printk(KERN_ERR "isdn_ppp_autodial_filter: unsupported protocol 0x%x.\n",
		       skb->protocol);
		return 1;
	}

	/* the filter instructions are constructed assuming
	 * a four-byte PPP header on each packet. we have to
	 * temporarily remove part of the fake header stuck on
	 * earlier.
	 */
	*skb_pull(skb, IPPP_MAX_HEADER - 4) = 1; /* indicate outbound */

	{
		u_int16_t *p = (u_int16_t *) skb->data;

		p++;
		*p   = htons(proto);
	}
	
	drop |= is->pass_filter
	        && sk_run_filter(skb, is->pass_filter, is->pass_len) == 0;
	drop |= is->active_filter
	        && sk_run_filter(skb, is->active_filter, is->active_len) == 0;
	
	skb_push(skb, IPPP_MAX_HEADER - 4);
	return drop;
}
#endif
#ifdef CONFIG_ISDN_MPP

/* this is _not_ rfc1990 header, but something we convert both short and long
 * headers to for convinience's sake:
 * 	byte 0 is flags as in rfc1990
 *	bytes 1...4 is 24-bit seqence number converted to host byte order 
 */
#define MP_HEADER_LEN	5

#define MP_LONGSEQ_MASK		0x00ffffff
#define MP_SHORTSEQ_MASK	0x00000fff
#define MP_LONGSEQ_MAX		MP_LONGSEQ_MASK
#define MP_SHORTSEQ_MAX		MP_SHORTSEQ_MASK
#define MP_LONGSEQ_MAXBIT	((MP_LONGSEQ_MASK+1)>>1)
#define MP_SHORTSEQ_MAXBIT	((MP_SHORTSEQ_MASK+1)>>1)

/* sequence-wrap safe comparisions (for long sequence)*/ 
#define MP_LT(a,b)	((a-b)&MP_LONGSEQ_MAXBIT)
#define MP_LE(a,b) 	!((b-a)&MP_LONGSEQ_MAXBIT)
#define MP_GT(a,b) 	((b-a)&MP_LONGSEQ_MAXBIT)
#define MP_GE(a,b)	!((a-b)&MP_LONGSEQ_MAXBIT)

#define MP_SEQ(f)	((*(u32*)(f->data+1)))
#define MP_FLAGS(f)	(f->data[0])

static int isdn_ppp_mp_bundle_array_init(void)
{
	int i;
	int sz = ISDN_MAX_CHANNELS*sizeof(ippp_bundle);
	if( (isdn_ppp_bundle_arr = (ippp_bundle*)kmalloc(sz, 
							GFP_KERNEL)) == NULL )
		return -ENOMEM;
	memset(isdn_ppp_bundle_arr, 0, sz);
	for( i = 0; i < ISDN_MAX_CHANNELS; i++ )
		spin_lock_init(&isdn_ppp_bundle_arr[i].lock);
	return 0;
}

static ippp_bundle * isdn_ppp_mp_bundle_alloc(void)
{
	int i;
	for( i = 0; i < ISDN_MAX_CHANNELS; i++ )
		if (isdn_ppp_bundle_arr[i].ref_ct <= 0)
			return (isdn_ppp_bundle_arr + i);
	return NULL;
}

static int isdn_ppp_mp_init( isdn_net_local * lp, ippp_bundle * add_to )
{
	struct ippp_struct * is;

	if (lp->ppp_slot < 0) {
		printk(KERN_ERR "%s: lp->ppp_slot(%d) out of range\n",
			__FUNCTION__, lp->ppp_slot);
		return(-EINVAL);
	}

	is = ippp_table[lp->ppp_slot];
	if (add_to) {
		if( lp->netdev->pb )
			lp->netdev->pb->ref_ct--;
		lp->netdev->pb = add_to;
	} else {		/* first link in a bundle */
		is->mp_seqno = 0;
		if ((lp->netdev->pb = isdn_ppp_mp_bundle_alloc()) == NULL)
			return -ENOMEM;
		lp->next = lp->last = lp;	/* nobody else in a queue */
		lp->netdev->pb->frags = NULL;
		lp->netdev->pb->frames = 0;
		lp->netdev->pb->seq = UINT_MAX;
	}
	lp->netdev->pb->ref_ct++;
	
	is->last_link_seqno = 0;
	return 0;
}

static u32 isdn_ppp_mp_get_seq( int short_seq, 
					struct sk_buff * skb, u32 last_seq );
static struct sk_buff * isdn_ppp_mp_discard( ippp_bundle * mp,
			struct sk_buff * from, struct sk_buff * to );
static void isdn_ppp_mp_reassembly( isdn_net_dev * net_dev, isdn_net_local * lp,
				struct sk_buff * from, struct sk_buff * to );
static void isdn_ppp_mp_free_skb( ippp_bundle * mp, struct sk_buff * skb );
static void isdn_ppp_mp_print_recv_pkt( int slot, struct sk_buff * skb );

static void isdn_ppp_mp_receive(isdn_net_dev * net_dev, isdn_net_local * lp, 
							struct sk_buff *skb)
{
	struct ippp_struct *is;
	isdn_net_local * lpq;
	ippp_bundle * mp;
	isdn_mppp_stats * stats;
	struct sk_buff * newfrag, * frag, * start, *nextf;
	u32 newseq, minseq, thisseq;
	unsigned long flags;
	int slot;

	spin_lock_irqsave(&net_dev->pb->lock, flags);
    	mp = net_dev->pb;
        stats = &mp->stats;
	slot = lp->ppp_slot;
	if (slot < 0 || slot > ISDN_MAX_CHANNELS) {
		printk(KERN_ERR "%s: lp->ppp_slot(%d)\n",
			__FUNCTION__, lp->ppp_slot);
		stats->frame_drops++;
		dev_kfree_skb(skb);
		spin_unlock_irqrestore(&mp->lock, flags);
		return;
	}
	is = ippp_table[slot];
    	if( ++mp->frames > stats->max_queue_len )
		stats->max_queue_len = mp->frames;
	
	if (is->debug & 0x8)
		isdn_ppp_mp_print_recv_pkt(lp->ppp_slot, skb);

	newseq = isdn_ppp_mp_get_seq(is->mpppcfg & SC_IN_SHORT_SEQ, 
						skb, is->last_link_seqno);


	/* if this packet seq # is less than last already processed one,
	 * toss it right away, but check for sequence start case first 
	 */
	if( mp->seq > MP_LONGSEQ_MAX && (newseq & MP_LONGSEQ_MAXBIT) ) {
		mp->seq = newseq;	/* the first packet: required for
					 * rfc1990 non-compliant clients --
					 * prevents constant packet toss */
	} else if( MP_LT(newseq, mp->seq) ) {
		stats->frame_drops++;
		isdn_ppp_mp_free_skb(mp, skb);
		spin_unlock_irqrestore(&mp->lock, flags);
		return;
	}
	
	/* find the minimum received sequence number over all links */
	is->last_link_seqno = minseq = newseq;
	for (lpq = net_dev->queue;;) {
		slot = lpq->ppp_slot;
		if (slot < 0 || slot > ISDN_MAX_CHANNELS) {
			printk(KERN_ERR "%s: lpq->ppp_slot(%d)\n",
				__FUNCTION__, lpq->ppp_slot);
		} else {
			u32 lls = ippp_table[slot]->last_link_seqno;
			if (MP_LT(lls, minseq))
				minseq = lls;
		}
		if ((lpq = lpq->next) == net_dev->queue)
			break;
	}
	if (MP_LT(minseq, mp->seq))
		minseq = mp->seq;	/* can't go beyond already processed
					 * packets */
	newfrag = skb;

  	/* if this new fragment is before the first one, then enqueue it now. */
  	if ((frag = mp->frags) == NULL || MP_LT(newseq, MP_SEQ(frag))) {
		newfrag->next = frag;
    		mp->frags = frag = newfrag;
    		newfrag = NULL;
  	}

  	start = MP_FLAGS(frag) & MP_BEGIN_FRAG &&
				MP_SEQ(frag) == mp->seq ? frag : NULL;

	/* 
	 * main fragment traversing loop
	 *
	 * try to accomplish several tasks:
	 * - insert new fragment into the proper sequence slot (once that's done
	 *   newfrag will be set to NULL)
	 * - reassemble any complete fragment sequence (non-null 'start'
	 *   indicates there is a continguous sequence present)
	 * - discard any incomplete sequences that are below minseq -- due
	 *   to the fact that sender always increment sequence number, if there
	 *   is an incomplete sequence below minseq, no new fragments would
	 *   come to complete such sequence and it should be discarded
	 *
	 * loop completes when we accomplished the following tasks:
	 * - new fragment is inserted in the proper sequence ('newfrag' is 
	 *   set to NULL)
	 * - we hit a gap in the sequence, so no reassembly/processing is 
	 *   possible ('start' would be set to NULL)
	 *
	 * algorightm for this code is derived from code in the book
	 * 'PPP Design And Debugging' by James Carlson (Addison-Wesley)
	 */
  	while (start != NULL || newfrag != NULL) {

    		thisseq = MP_SEQ(frag);
    		nextf = frag->next;

    		/* drop any duplicate fragments */
    		if (newfrag != NULL && thisseq == newseq) {
      			isdn_ppp_mp_free_skb(mp, newfrag);
      			newfrag = NULL;
    		}

    		/* insert new fragment before next element if possible. */
    		if (newfrag != NULL && (nextf == NULL || 
						MP_LT(newseq, MP_SEQ(nextf)))) {
      			newfrag->next = nextf;
      			frag->next = nextf = newfrag;
      			newfrag = NULL;
    		}

    		if (start != NULL) {
	    		/* check for misplaced start */
      			if (start != frag && (MP_FLAGS(frag) & MP_BEGIN_FRAG)) {
				printk(KERN_WARNING"isdn_mppp(seq %d): new "
				      "BEGIN flag with no prior END", thisseq);
				stats->seqerrs++;
				stats->frame_drops++;
				start = isdn_ppp_mp_discard(mp, start,frag);
				nextf = frag->next;
      			}
    		} else if (MP_LE(thisseq, minseq)) {		
      			if (MP_FLAGS(frag) & MP_BEGIN_FRAG)
				start = frag;
      			else {
				if (MP_FLAGS(frag) & MP_END_FRAG)
	  				stats->frame_drops++;
				if( mp->frags == frag )
					mp->frags = nextf;	
				isdn_ppp_mp_free_skb(mp, frag);
				frag = nextf;
				continue;
      			}
		}
		
		/* if start is non-null and we have end fragment, then
		 * we have full reassembly sequence -- reassemble 
		 * and process packet now
		 */
    		if (start != NULL && (MP_FLAGS(frag) & MP_END_FRAG)) {
      			minseq = mp->seq = (thisseq+1) & MP_LONGSEQ_MASK;
      			/* Reassemble the packet then dispatch it */
			isdn_ppp_mp_reassembly(net_dev, lp, start, nextf);
      
      			start = NULL;
      			frag = NULL;

      			mp->frags = nextf;
    		}

		/* check if need to update start pointer: if we just
		 * reassembled the packet and sequence is contiguous
		 * then next fragment should be the start of new reassembly
		 * if sequence is contiguous, but we haven't reassembled yet,
		 * keep going.
		 * if sequence is not contiguous, either clear everyting
		 * below low watermark and set start to the next frag or
		 * clear start ptr.
		 */ 
    		if (nextf != NULL && 
		    ((thisseq+1) & MP_LONGSEQ_MASK) == MP_SEQ(nextf)) {
      			/* if we just reassembled and the next one is here, 
			 * then start another reassembly. */

      			if (frag == NULL) {
				if (MP_FLAGS(nextf) & MP_BEGIN_FRAG)
	  				start = nextf;
				else
				{
	  				printk(KERN_WARNING"isdn_mppp(seq %d):"
						" END flag with no following "
						"BEGIN", thisseq);
					stats->seqerrs++;
				}
			}

    		} else {
			if ( nextf != NULL && frag != NULL &&
						MP_LT(thisseq, minseq)) {
				/* we've got a break in the sequence
				 * and we not at the end yet
				 * and we did not just reassembled
				 *(if we did, there wouldn't be anything before)
				 * and we below the low watermark 
			 	 * discard all the frames below low watermark 
				 * and start over */
				stats->frame_drops++;
				mp->frags = isdn_ppp_mp_discard(mp,start,nextf);
			}
			/* break in the sequence, no reassembly */
      			start = NULL;
    		}
	  			
    		frag = nextf;
  	}	/* while -- main loop */
	
  	if (mp->frags == NULL)
    		mp->frags = frag;
		
	/* rather straighforward way to deal with (not very) possible 
	 * queue overflow */
	if (mp->frames > MP_MAX_QUEUE_LEN) {
		stats->overflows++;
		while (mp->frames > MP_MAX_QUEUE_LEN) {
			frag = mp->frags->next;
			isdn_ppp_mp_free_skb(mp, mp->frags);
			mp->frags = frag;
		}
	}
	spin_unlock_irqrestore(&mp->lock, flags);
}

static void isdn_ppp_mp_cleanup( isdn_net_local * lp )
{
	struct sk_buff * frag = lp->netdev->pb->frags;
	struct sk_buff * nextfrag;
    	while( frag ) {
		nextfrag = frag->next;
		isdn_ppp_mp_free_skb(lp->netdev->pb, frag);
		frag = nextfrag;
	}
	lp->netdev->pb->frags = NULL;
}

static u32 isdn_ppp_mp_get_seq( int short_seq, 
					struct sk_buff * skb, u32 last_seq )
{
	u32 seq;
	int flags = skb->data[0] & (MP_BEGIN_FRAG | MP_END_FRAG);
   
   	if( !short_seq )
	{
		seq = ntohl(*(u32*)skb->data) & MP_LONGSEQ_MASK;
		skb_push(skb,1);
	}
	else
	{
		/* convert 12-bit short seq number to 24-bit long one 
	 	*/
		seq = ntohs(*(u16*)skb->data) & MP_SHORTSEQ_MASK;
	
		/* check for seqence wrap */
		if( !(seq &  MP_SHORTSEQ_MAXBIT) && 
		     (last_seq &  MP_SHORTSEQ_MAXBIT) && 
		     (unsigned long)last_seq <= MP_LONGSEQ_MAX )
			seq |= (last_seq + MP_SHORTSEQ_MAX+1) & 
					(~MP_SHORTSEQ_MASK & MP_LONGSEQ_MASK);
		else
			seq |= last_seq & (~MP_SHORTSEQ_MASK & MP_LONGSEQ_MASK);
		
		skb_push(skb, 3);	/* put converted seqence back in skb */
	}
	*(u32*)(skb->data+1) = seq; 	/* put seqence back in _host_ byte
					 * order */
	skb->data[0] = flags;	        /* restore flags */
	return seq;
}

struct sk_buff * isdn_ppp_mp_discard( ippp_bundle * mp,
			struct sk_buff * from, struct sk_buff * to )
{
	if( from )
		while (from != to) {
	  		struct sk_buff * next = from->next;
			isdn_ppp_mp_free_skb(mp, from);
	  		from = next;
		}
	return from;
}

void isdn_ppp_mp_reassembly( isdn_net_dev * net_dev, isdn_net_local * lp,
				struct sk_buff * from, struct sk_buff * to )
{
	ippp_bundle * mp = net_dev->pb;
	int proto;
	struct sk_buff * skb;
	unsigned int tot_len;

	if (lp->ppp_slot < 0 || lp->ppp_slot >= ISDN_MAX_CHANNELS) {
		printk(KERN_ERR "%s: lp->ppp_slot(%d) out of range\n",
			__FUNCTION__, lp->ppp_slot);
		return;
	}
	if( MP_FLAGS(from) == (MP_BEGIN_FRAG | MP_END_FRAG) ) {
		if( ippp_table[lp->ppp_slot]->debug & 0x40 )
			printk(KERN_DEBUG "isdn_mppp: reassembly: frame %d, "
					"len %d\n", MP_SEQ(from), from->len );
		skb = from;
		skb_pull(skb, MP_HEADER_LEN);
		mp->frames--;	
	} else {
		struct sk_buff * frag;
		int n;

		for(tot_len=n=0, frag=from; frag != to; frag=frag->next, n++)
			tot_len += frag->len - MP_HEADER_LEN;

		if( ippp_table[lp->ppp_slot]->debug & 0x40 )
			printk(KERN_DEBUG"isdn_mppp: reassembling frames %d "
				"to %d, len %d\n", MP_SEQ(from), 
				(MP_SEQ(from)+n-1) & MP_LONGSEQ_MASK, tot_len );
		if( (skb = dev_alloc_skb(tot_len)) == NULL ) {
			printk(KERN_ERR "isdn_mppp: cannot allocate sk buff "
					"of size %d\n", tot_len);
			isdn_ppp_mp_discard(mp, from, to);
			return;
		}

		while( from != to ) {
			unsigned int len = from->len - MP_HEADER_LEN;

			memcpy(skb_put(skb,len), from->data+MP_HEADER_LEN, len);
			frag = from->next;
			isdn_ppp_mp_free_skb(mp, from);
			from = frag; 
		}
	}
   	proto = isdn_ppp_strip_proto(skb);
	isdn_ppp_push_higher(net_dev, lp, skb, proto);
}

static void isdn_ppp_mp_free_skb(ippp_bundle * mp, struct sk_buff * skb)
{
	dev_kfree_skb(skb);
	mp->frames--;
}

static void isdn_ppp_mp_print_recv_pkt( int slot, struct sk_buff * skb )
{
	printk(KERN_DEBUG "mp_recv: %d/%d -> %02x %02x %02x %02x %02x %02x\n", 
		slot, (int) skb->len, 
		(int) skb->data[0], (int) skb->data[1], (int) skb->data[2],
		(int) skb->data[3], (int) skb->data[4], (int) skb->data[5]);
}

static int
isdn_ppp_bundle(struct ippp_struct *is, int unit)
{
	char ifn[IFNAMSIZ + 1];
	isdn_net_dev *p;
	isdn_net_local *lp, *nlp;
	int rc;
	unsigned long flags;

	sprintf(ifn, "ippp%d", unit);
	p = isdn_net_findif(ifn);
	if (!p) {
		printk(KERN_ERR "ippp_bundle: cannot find %s\n", ifn);
		return -EINVAL;
	}

    	spin_lock_irqsave(&p->pb->lock, flags);

	nlp = is->lp;
	lp = p->queue;
	if( nlp->ppp_slot < 0 || nlp->ppp_slot >= ISDN_MAX_CHANNELS ||
		lp->ppp_slot < 0 || lp->ppp_slot >= ISDN_MAX_CHANNELS ) {
		printk(KERN_ERR "ippp_bundle: binding to invalid slot %d\n",
			nlp->ppp_slot < 0 || nlp->ppp_slot >= ISDN_MAX_CHANNELS ? 
			nlp->ppp_slot : lp->ppp_slot );
		rc = -EINVAL;
		goto out;
 	}

	isdn_net_add_to_bundle(p, nlp);

	ippp_table[nlp->ppp_slot]->unit = ippp_table[lp->ppp_slot]->unit;

	/* maybe also SC_CCP stuff */
	ippp_table[nlp->ppp_slot]->pppcfg |= ippp_table[lp->ppp_slot]->pppcfg &
		(SC_ENABLE_IP | SC_NO_TCP_CCID | SC_REJ_COMP_TCP);
	ippp_table[nlp->ppp_slot]->mpppcfg |= ippp_table[lp->ppp_slot]->mpppcfg &
		(SC_MP_PROT | SC_REJ_MP_PROT | SC_OUT_SHORT_SEQ | SC_IN_SHORT_SEQ);
	rc = isdn_ppp_mp_init(nlp, p->pb);
out:
	spin_unlock_irqrestore(&p->pb->lock, flags);
	return rc;
}
  
#endif /* CONFIG_ISDN_MPP */
  
/*
 * network device ioctl handlers
 */

static int
isdn_ppp_dev_ioctl_stats(int slot, struct ifreq *ifr, struct net_device *dev)
{
	struct ppp_stats __user *res = ifr->ifr_data;
	struct ppp_stats t;
	isdn_net_local *lp = (isdn_net_local *) dev->priv;

	if (!access_ok(VERIFY_WRITE, res, sizeof(struct ppp_stats)))
		return -EFAULT;

	/* build a temporary stat struct and copy it to user space */

	memset(&t, 0, sizeof(struct ppp_stats));
	if (dev->flags & IFF_UP) {
		t.p.ppp_ipackets = lp->stats.rx_packets;
		t.p.ppp_ibytes = lp->stats.rx_bytes;
		t.p.ppp_ierrors = lp->stats.rx_errors;
		t.p.ppp_opackets = lp->stats.tx_packets;
		t.p.ppp_obytes = lp->stats.tx_bytes;
		t.p.ppp_oerrors = lp->stats.tx_errors;
#ifdef CONFIG_ISDN_PPP_VJ
		if (slot >= 0 && ippp_table[slot]->slcomp) {
			struct slcompress *slcomp = ippp_table[slot]->slcomp;
			t.vj.vjs_packets = slcomp->sls_o_compressed + slcomp->sls_o_uncompressed;
			t.vj.vjs_compressed = slcomp->sls_o_compressed;
			t.vj.vjs_searches = slcomp->sls_o_searches;
			t.vj.vjs_misses = slcomp->sls_o_misses;
			t.vj.vjs_errorin = slcomp->sls_i_error;
			t.vj.vjs_tossed = slcomp->sls_i_tossed;
			t.vj.vjs_uncompressedin = slcomp->sls_i_uncompressed;
			t.vj.vjs_compressedin = slcomp->sls_i_compressed;
		}
#endif
	}
	if (copy_to_user(res, &t, sizeof(struct ppp_stats)))
		return -EFAULT;
	return 0;
}

int
isdn_ppp_dev_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
{
	int error=0;
	int len;
	isdn_net_local *lp = (isdn_net_local *) dev->priv;


	if (lp->p_encap != ISDN_NET_ENCAP_SYNCPPP)
		return -EINVAL;

	switch (cmd) {
#define PPP_VERSION "2.3.7"
		case SIOCGPPPVER:
			len = strlen(PPP_VERSION) + 1;
			if (copy_to_user(ifr->ifr_data, PPP_VERSION, len))
				error = -EFAULT;
			break;

		case SIOCGPPPSTATS:
			error = isdn_ppp_dev_ioctl_stats(lp->ppp_slot, ifr, dev);
			break;
		default:
			error = -EINVAL;
			break;
	}
	return error;
}

static int
isdn_ppp_if_get_unit(char *name)
{
	int len,
	 i,
	 unit = 0,
	 deci;

	len = strlen(name);

	if (strncmp("ippp", name, 4) || len > 8)
		return -1;

	for (i = 0, deci = 1; i < len; i++, deci *= 10) {
		char a = name[len - i - 1];
		if (a >= '0' && a <= '9')
			unit += (a - '0') * deci;
		else
			break;
	}
	if (!i || len - i != 4)
		unit = -1;

	return unit;
}


int
isdn_ppp_dial_slave(char *name)
{
#ifdef CONFIG_ISDN_MPP
	isdn_net_dev *ndev;
	isdn_net_local *lp;
	struct net_device *sdev;

	if (!(ndev = isdn_net_findif(name)))
		return 1;
	lp = ndev->local;
	if (!(lp->flags & ISDN_NET_CONNECTED))
		return 5;

	sdev = lp->slave;
	while (sdev) {
		isdn_net_local *mlp = (isdn_net_local *) sdev->priv;
		if (!(mlp->flags & ISDN_NET_CONNECTED))
			break;
		sdev = mlp->slave;
	}
	if (!sdev)
		return 2;

	isdn_net_dial_req((isdn_net_local *) sdev->priv);
	return 0;
#else
	return -1;
#endif
}

int
isdn_ppp_hangup_slave(char *name)
{
#ifdef CONFIG_ISDN_MPP
	isdn_net_dev *ndev;
	isdn_net_local *lp;
	struct net_device *sdev;

	if (!(ndev = isdn_net_findif(name)))
		return 1;
	lp = ndev->local;
	if (!(lp->flags & ISDN_NET_CONNECTED))
		return 5;

	sdev = lp->slave;
	while (sdev) {
		isdn_net_local *mlp = (isdn_net_local *) sdev->priv;

		if (mlp->slave) { /* find last connected link in chain */
			isdn_net_local *nlp = (isdn_net_local *) mlp->slave->priv;

			if (!(nlp->flags & ISDN_NET_CONNECTED))
				break;
		} else if (mlp->flags & ISDN_NET_CONNECTED)
			break;
		
		sdev = mlp->slave;
	}
	if (!sdev)
		return 2;

	isdn_net_hangup(sdev);
	return 0;
#else
	return -1;
#endif
}

/*
 * PPP compression stuff
 */


/* Push an empty CCP Data Frame up to the daemon to wake it up and let it
   generate a CCP Reset-Request or tear down CCP altogether */

static void isdn_ppp_ccp_kickup(struct ippp_struct *is)
{
	isdn_ppp_fill_rq(NULL, 0, PPP_COMP, is->lp->ppp_slot);
}

/* In-kernel handling of CCP Reset-Request and Reset-Ack is necessary,
   but absolutely nontrivial. The most abstruse problem we are facing is
   that the generation, reception and all the handling of timeouts and
   resends including proper request id management should be entirely left
   to the (de)compressor, but indeed is not covered by the current API to
   the (de)compressor. The API is a prototype version from PPP where only
   some (de)compressors have yet been implemented and all of them are
   rather simple in their reset handling. Especially, their is only one
   outstanding ResetAck at a time with all of them and ResetReq/-Acks do
   not have parameters. For this very special case it was sufficient to
   just return an error code from the decompressor and have a single
   reset() entry to communicate all the necessary information between
   the framework and the (de)compressor. Bad enough, LZS is different
   (and any other compressor may be different, too). It has multiple
   histories (eventually) and needs to Reset each of them independently
   and thus uses multiple outstanding Acks and history numbers as an
   additional parameter to Reqs/Acks.
   All that makes it harder to port the reset state engine into the
   kernel because it is not just the same simple one as in (i)pppd but
   it must be able to pass additional parameters and have multiple out-
   standing Acks. We are trying to achieve the impossible by handling
   reset transactions independent by their id. The id MUST change when
   the data portion changes, thus any (de)compressor who uses more than
   one resettable state must provide and recognize individual ids for
   each individual reset transaction. The framework itself does _only_
   differentiate them by id, because it has no other semantics like the
   (de)compressor might.
   This looks like a major redesign of the interface would be nice,
   but I don't have an idea how to do it better. */

/* Send a CCP Reset-Request or Reset-Ack directly from the kernel. This is
   getting that lengthy because there is no simple "send-this-frame-out"
   function above but every wrapper does a bit different. Hope I guess
   correct in this hack... */

static void isdn_ppp_ccp_xmit_reset(struct ippp_struct *is, int proto,
				    unsigned char code, unsigned char id,
				    unsigned char *data, int len)
{
	struct sk_buff *skb;
	unsigned char *p;
	int hl;
	int cnt = 0;
	isdn_net_local *lp = is->lp;

	/* Alloc large enough skb */
	hl = dev->drv[lp->isdn_device]->interface->hl_hdrlen;
	skb = alloc_skb(len + hl + 16,GFP_ATOMIC);
	if(!skb) {
		printk(KERN_WARNING
		       "ippp: CCP cannot send reset - out of memory\n");
		return;
	}
	skb_reserve(skb, hl);

	/* We may need to stuff an address and control field first */
	if(!(is->pppcfg & SC_COMP_AC)) {
		p = skb_put(skb, 2);
		*p++ = 0xff;
		*p++ = 0x03;
	}

	/* Stuff proto, code, id and length */
	p = skb_put(skb, 6);
	*p++ = (proto >> 8);
	*p++ = (proto & 0xff);
	*p++ = code;
	*p++ = id;
	cnt = 4 + len;
	*p++ = (cnt >> 8);
	*p++ = (cnt & 0xff);

	/* Now stuff remaining bytes */
	if(len) {
		p = skb_put(skb, len);
		memcpy(p, data, len);
	}

	/* skb is now ready for xmit */
	printk(KERN_DEBUG "Sending CCP Frame:\n");
	isdn_ppp_frame_log("ccp-xmit", skb->data, skb->len, 32, is->unit,lp->ppp_slot);

	isdn_net_write_super(lp, skb);
}

/* Allocate the reset state vector */
static struct ippp_ccp_reset *isdn_ppp_ccp_reset_alloc(struct ippp_struct *is)
{
	struct ippp_ccp_reset *r;
	r = kmalloc(sizeof(struct ippp_ccp_reset), GFP_KERNEL);
	if(!r) {
		printk(KERN_ERR "ippp_ccp: failed to allocate reset data"
		       " structure - no mem\n");
		return NULL;
	}
	memset(r, 0, sizeof(struct ippp_ccp_reset));
	printk(KERN_DEBUG "ippp_ccp: allocated reset data structure %p\n", r);
	is->reset = r;
	return r;
}

/* Destroy the reset state vector. Kill all pending timers first. */
static void isdn_ppp_ccp_reset_free(struct ippp_struct *is)
{
	unsigned int id;

	printk(KERN_DEBUG "ippp_ccp: freeing reset data structure %p\n",
	       is->reset);
	for(id = 0; id < 256; id++) {
		if(is->reset->rs[id]) {
			isdn_ppp_ccp_reset_free_state(is, (unsigned char)id);
		}
	}
	kfree(is->reset);
	is->reset = NULL;
}

/* Free a given state and clear everything up for later reallocation */
static void isdn_ppp_ccp_reset_free_state(struct ippp_struct *is,
					  unsigned char id)
{
	struct ippp_ccp_reset_state *rs;

	if(is->reset->rs[id]) {
		printk(KERN_DEBUG "ippp_ccp: freeing state for id %d\n", id);
		rs = is->reset->rs[id];
		/* Make sure the kernel will not call back later */
		if(rs->ta)
			del_timer(&rs->timer);
		is->reset->rs[id] = NULL;
		kfree(rs);
	} else {
		printk(KERN_WARNING "ippp_ccp: id %d is not allocated\n", id);
	}
}

/* The timer callback function which is called when a ResetReq has timed out,
   aka has never been answered by a ResetAck */
static void isdn_ppp_ccp_timer_callback(unsigned long closure)
{
	struct ippp_ccp_reset_state *rs =
		(struct ippp_ccp_reset_state *)closure;

	if(!rs) {
		printk(KERN_ERR "ippp_ccp: timer cb with zero closure.\n");
		return;
	}
	if(rs->ta && rs->state == CCPResetSentReq) {
		/* We are correct here */
		if(!rs->expra) {
			/* Hmm, there is no Ack really expected. We can clean
			   up the state now, it will be reallocated if the
			   decompressor insists on another reset */
			rs->ta = 0;
			isdn_ppp_ccp_reset_free_state(rs->is, rs->id);
			return;
		}
		printk(KERN_DEBUG "ippp_ccp: CCP Reset timed out for id %d\n",
		       rs->id);
		/* Push it again */
		isdn_ppp_ccp_xmit_reset(rs->is, PPP_CCP, CCP_RESETREQ, rs->id,
					rs->data, rs->dlen);
		/* Restart timer */
		rs->timer.expires = jiffies + HZ*5;
		add_timer(&rs->timer);
	} else {
		printk(KERN_WARNING "ippp_ccp: timer cb in wrong state %d\n",
		       rs->state);
	}
}

/* Allocate a new reset transaction state */
static struct ippp_ccp_reset_state *isdn_ppp_ccp_reset_alloc_state(struct ippp_struct *is,
						      unsigned char id)
{
	struct ippp_ccp_reset_state *rs;
	if(is->reset->rs[id]) {
		printk(KERN_WARNING "ippp_ccp: old state exists for id %d\n",
		       id);
		return NULL;
	} else {
		rs = kmalloc(sizeof(struct ippp_ccp_reset_state), GFP_KERNEL);
		if(!rs)
			return NULL;
		memset(rs, 0, sizeof(struct ippp_ccp_reset_state));
		rs->state = CCPResetIdle;
		rs->is = is;
		rs->id = id;
		rs->timer.data = (unsigned long)rs;
		rs->timer.function = isdn_ppp_ccp_timer_callback;
		is->reset->rs[id] = rs;
	}
	return rs;
}


/* A decompressor wants a reset with a set of parameters - do what is
   necessary to fulfill it */
static void isdn_ppp_ccp_reset_trans(struct ippp_struct *is,
				     struct isdn_ppp_resetparams *rp)
{
	struct ippp_ccp_reset_state *rs;

	if(rp->valid) {
		/* The decompressor defines parameters by itself */
		if(rp->rsend) {
			/* And he wants us to send a request */
			if(!(rp->idval)) {
				printk(KERN_ERR "ippp_ccp: decompressor must"
				       " specify reset id\n");
				return;
			}
			if(is->reset->rs[rp->id]) {
				/* There is already a transaction in existence
				   for this id. May be still waiting for a
				   Ack or may be wrong. */
				rs = is->reset->rs[rp->id];
				if(rs->state == CCPResetSentReq && rs->ta) {
					printk(KERN_DEBUG "ippp_ccp: reset"
					       " trans still in progress"
					       " for id %d\n", rp->id);
				} else {
					printk(KERN_WARNING "ippp_ccp: reset"
					       " trans in wrong state %d for"
					       " id %d\n", rs->state, rp->id);
				}
			} else {
				/* Ok, this is a new transaction */
				printk(KERN_DEBUG "ippp_ccp: new trans for id"
				       " %d to be started\n", rp->id);
				rs = isdn_ppp_ccp_reset_alloc_state(is, rp->id);
				if(!rs) {
					printk(KERN_ERR "ippp_ccp: out of mem"
					       " allocing ccp trans\n");
					return;
				}
				rs->state = CCPResetSentReq;
				rs->expra = rp->expra;
				if(rp->dtval) {
					rs->dlen = rp->dlen;
					memcpy(rs->data, rp->data, rp->dlen);
				}
				/* HACK TODO - add link comp here */
				isdn_ppp_ccp_xmit_reset(is, PPP_CCP,
							CCP_RESETREQ, rs->id,
							rs->data, rs->dlen);
				/* Start the timer */
				rs->timer.expires = jiffies + 5*HZ;
				add_timer(&rs->timer);
				rs->ta = 1;
			}
		} else {
			printk(KERN_DEBUG "ippp_ccp: no reset sent\n");
		}
	} else {
		/* The reset params are invalid. The decompressor does not
		   care about them, so we just send the minimal requests
		   and increase ids only when an Ack is received for a
		   given id */
		if(is->reset->rs[is->reset->lastid]) {
			/* There is already a transaction in existence
			   for this id. May be still waiting for a
			   Ack or may be wrong. */
			rs = is->reset->rs[is->reset->lastid];
			if(rs->state == CCPResetSentReq && rs->ta) {
				printk(KERN_DEBUG "ippp_ccp: reset"
				       " trans still in progress"
				       " for id %d\n", rp->id);
			} else {
				printk(KERN_WARNING "ippp_ccp: reset"
				       " trans in wrong state %d for"
				       " id %d\n", rs->state, rp->id);
			}
		} else {
			printk(KERN_DEBUG "ippp_ccp: new trans for id"
			       " %d to be started\n", is->reset->lastid);
			rs = isdn_ppp_ccp_reset_alloc_state(is,
							    is->reset->lastid);
			if(!rs) {
				printk(KERN_ERR "ippp_ccp: out of mem"
				       " allocing ccp trans\n");
				return;
			}
			rs->state = CCPResetSentReq;
			/* We always expect an Ack if the decompressor doesn't
			   know	better */
			rs->expra = 1;
			rs->dlen = 0;
			/* HACK TODO - add link comp here */
			isdn_ppp_ccp_xmit_reset(is, PPP_CCP, CCP_RESETREQ,
						rs->id, NULL, 0);
			/* Start the timer */
			rs->timer.expires = jiffies + 5*HZ;
			add_timer(&rs->timer);
			rs->ta = 1;
		}
	}
}

/* An Ack was received for this id. This means we stop the timer and clean
   up the state prior to calling the decompressors reset routine. */
static void isdn_ppp_ccp_reset_ack_rcvd(struct ippp_struct *is,
					unsigned char id)
{
	struct ippp_ccp_reset_state *rs = is->reset->rs[id];

	if(rs) {
		if(rs->ta && rs->state == CCPResetSentReq) {
			/* Great, we are correct */
			if(!rs->expra)
				printk(KERN_DEBUG "ippp_ccp: ResetAck received"
				       " for id %d but not expected\n", id);
		} else {
			printk(KERN_INFO "ippp_ccp: ResetAck received out of"
			       "sync for id %d\n", id);
		}
		if(rs->ta) {
			rs->ta = 0;
			del_timer(&rs->timer);
		}
		isdn_ppp_ccp_reset_free_state(is, id);
	} else {
		printk(KERN_INFO "ippp_ccp: ResetAck received for unknown id"
		       " %d\n", id);
	}
	/* Make sure the simple reset stuff uses a new id next time */
	is->reset->lastid++;
}

/* 
 * decompress packet
 *
 * if master = 0, we're trying to uncompress an per-link compressed packet,
 * as opposed to an compressed reconstructed-from-MPPP packet.
 * proto is updated to protocol field of uncompressed packet.
 *
 * retval: decompressed packet,
 *         same packet if uncompressed,
 *	   NULL if decompression error
 */

static struct sk_buff *isdn_ppp_decompress(struct sk_buff *skb,struct ippp_struct *is,struct ippp_struct *master,
	int *proto)
{
	void *stat = NULL;
	struct isdn_ppp_compressor *ipc = NULL;
	struct sk_buff *skb_out;
	int len;
	struct ippp_struct *ri;
	struct isdn_ppp_resetparams rsparm;
	unsigned char rsdata[IPPP_RESET_MAXDATABYTES];

	if(!master) {
		// per-link decompression 
		stat = is->link_decomp_stat;
		ipc = is->link_decompressor;
		ri = is;
	} else {
		stat = master->decomp_stat;
		ipc = master->decompressor;
		ri = master;
	}

	if (!ipc) {
		// no decompressor -> we can't decompress.
		printk(KERN_DEBUG "ippp: no decompressor defined!\n");
		return skb;
	}
	if (!stat) // if we have a compressor, stat has been set as well
		BUG();

	if((master && *proto == PPP_COMP) || (!master && *proto == PPP_COMPFRAG) ) {
		// compressed packets are compressed by their protocol type

		// Set up reset params for the decompressor
  		memset(&rsparm, 0, sizeof(rsparm));
  		rsparm.data = rsdata;
  		rsparm.maxdlen = IPPP_RESET_MAXDATABYTES;
  
  		skb_out = dev_alloc_skb(is->mru + PPP_HDRLEN);
		len = ipc->decompress(stat, skb, skb_out, &rsparm);
		kfree_skb(skb);
		if (len <= 0) {
			switch(len) {
			case DECOMP_ERROR:
				printk(KERN_INFO "ippp: decomp wants reset %s params\n",
				       rsparm.valid ? "with" : "without");
				
				isdn_ppp_ccp_reset_trans(ri, &rsparm);
				break;
			case DECOMP_FATALERROR:
				ri->pppcfg |= SC_DC_FERROR;
				/* Kick ipppd to recognize the error */
				isdn_ppp_ccp_kickup(ri);
				break;
			}
			kfree_skb(skb_out);
			return NULL;
		}
		*proto = isdn_ppp_strip_proto(skb_out);
		if (*proto < 0) {
			kfree_skb(skb_out);
			return NULL;
		}
		return skb_out;
	} else { 
		// uncompressed packets are fed through the decompressor to
		// update the decompressor state
		ipc->incomp(stat, skb, *proto);
		return skb;
	}
}

/*
 * compress a frame 
 *   type=0: normal/bundle compression
 *       =1: link compression
 * returns original skb if we haven't compressed the frame
 * and a new skb pointer if we've done it
 */
static struct sk_buff *isdn_ppp_compress(struct sk_buff *skb_in,int *proto,
	struct ippp_struct *is,struct ippp_struct *master,int type)
{
    int ret;
    int new_proto;
    struct isdn_ppp_compressor *compressor;
    void *stat;
    struct sk_buff *skb_out;

	/* we do not compress control protocols */
    if(*proto < 0 || *proto > 0x3fff) {
	    return skb_in;
    }

	if(type) { /* type=1 => Link compression */
		return skb_in;
	}
	else {
		if(!master) {
			compressor = is->compressor;
			stat = is->comp_stat;
		}
		else {
			compressor = master->compressor;
			stat = master->comp_stat;
		}
		new_proto = PPP_COMP;
	}

	if(!compressor) {
		printk(KERN_ERR "isdn_ppp: No compressor set!\n");
		return skb_in;
	}
	if(!stat) {
		printk(KERN_ERR "isdn_ppp: Compressor not initialized?\n");
		return skb_in;
	}

	/* Allow for at least 150 % expansion (for now) */
	skb_out = alloc_skb(skb_in->len + skb_in->len/2 + 32 +
		skb_headroom(skb_in), GFP_ATOMIC);
	if(!skb_out)
		return skb_in;
	skb_reserve(skb_out, skb_headroom(skb_in));

	ret = (compressor->compress)(stat,skb_in,skb_out,*proto);
	if(!ret) {
		dev_kfree_skb(skb_out);
		return skb_in;
	}
	
	dev_kfree_skb(skb_in);
	*proto = new_proto;
	return skb_out;
}

/*
 * we received a CCP frame .. 
 * not a clean solution, but we MUST handle a few cases in the kernel
 */
static void isdn_ppp_receive_ccp(isdn_net_dev *net_dev, isdn_net_local *lp,
	 struct sk_buff *skb,int proto)
{
	struct ippp_struct *is;
	struct ippp_struct *mis;
	int len;
	struct isdn_ppp_resetparams rsparm;
	unsigned char rsdata[IPPP_RESET_MAXDATABYTES];	

	printk(KERN_DEBUG "Received CCP frame from peer slot(%d)\n",
		lp->ppp_slot);
	if (lp->ppp_slot < 0 || lp->ppp_slot > ISDN_MAX_CHANNELS) {
		printk(KERN_ERR "%s: lp->ppp_slot(%d) out of range\n",
			__FUNCTION__, lp->ppp_slot);
		return;
	}
	is = ippp_table[lp->ppp_slot];
	isdn_ppp_frame_log("ccp-rcv", skb->data, skb->len, 32, is->unit,lp->ppp_slot);

	if(lp->master) {
		int slot = ((isdn_net_local *) (lp->master->priv))->ppp_slot;
		if (slot < 0 || slot > ISDN_MAX_CHANNELS) {
			printk(KERN_ERR "%s: slot(%d) out of range\n",
				__FUNCTION__, slot);
			return;
		}	
		mis = ippp_table[slot];
	} else
		mis = is;

	switch(skb->data[0]) {
	case CCP_CONFREQ:
		if(is->debug & 0x10)
			printk(KERN_DEBUG "Disable compression here!\n");
		if(proto == PPP_CCP)
			mis->compflags &= ~SC_COMP_ON;		
		else
			is->compflags &= ~SC_LINK_COMP_ON;		
		break;
	case CCP_TERMREQ:
	case CCP_TERMACK:
		if(is->debug & 0x10)
			printk(KERN_DEBUG "Disable (de)compression here!\n");
		if(proto == PPP_CCP)
			mis->compflags &= ~(SC_DECOMP_ON|SC_COMP_ON);		
		else
			is->compflags &= ~(SC_LINK_DECOMP_ON|SC_LINK_COMP_ON);		
		break;
	case CCP_CONFACK:
		/* if we RECEIVE an ackowledge we enable the decompressor */
		if(is->debug & 0x10)
			printk(KERN_DEBUG "Enable decompression here!\n");
		if(proto == PPP_CCP) {
			if (!mis->decompressor)
				break;
			mis->compflags |= SC_DECOMP_ON;
		} else {
			if (!is->decompressor)
				break;
			is->compflags |= SC_LINK_DECOMP_ON;
		}
		break;

	case CCP_RESETACK:
		printk(KERN_DEBUG "Received ResetAck from peer\n");
		len = (skb->data[2] << 8) | skb->data[3];
		len -= 4;

		if(proto == PPP_CCP) {
			/* If a reset Ack was outstanding for this id, then
			   clean up the state engine */
			isdn_ppp_ccp_reset_ack_rcvd(mis, skb->data[1]);
			if(mis->decompressor && mis->decomp_stat)
				mis->decompressor->
					reset(mis->decomp_stat,
					      skb->data[0],
					      skb->data[1],
					      len ? &skb->data[4] : NULL,
					      len, NULL);
			/* TODO: This is not easy to decide here */
			mis->compflags &= ~SC_DECOMP_DISCARD;
		}
		else {
			isdn_ppp_ccp_reset_ack_rcvd(is, skb->data[1]);
			if(is->link_decompressor && is->link_decomp_stat)
				is->link_decompressor->
					reset(is->link_decomp_stat,
					      skb->data[0],
					      skb->data[1],
					      len ? &skb->data[4] : NULL,
					      len, NULL);
			/* TODO: neither here */
			is->compflags &= ~SC_LINK_DECOMP_DISCARD;
		}
		break;

	case CCP_RESETREQ:
		printk(KERN_DEBUG "Received ResetReq from peer\n");
		/* Receiving a ResetReq means we must reset our compressor */
		/* Set up reset params for the reset entry */
		memset(&rsparm, 0, sizeof(rsparm));
		rsparm.data = rsdata;
		rsparm.maxdlen = IPPP_RESET_MAXDATABYTES; 
		/* Isolate data length */
		len = (skb->data[2] << 8) | skb->data[3];
		len -= 4;
		if(proto == PPP_CCP) {
			if(mis->compressor && mis->comp_stat)
				mis->compressor->
					reset(mis->comp_stat,
					      skb->data[0],
					      skb->data[1],
					      len ? &skb->data[4] : NULL,
					      len, &rsparm);
		}
		else {
			if(is->link_compressor && is->link_comp_stat)
				is->link_compressor->
					reset(is->link_comp_stat,
					      skb->data[0],
					      skb->data[1],
					      len ? &skb->data[4] : NULL,
					      len, &rsparm);
		}
		/* Ack the Req as specified by rsparm */
		if(rsparm.valid) {
			/* Compressor reset handler decided how to answer */
			if(rsparm.rsend) {
				/* We should send a Frame */
				isdn_ppp_ccp_xmit_reset(is, proto, CCP_RESETACK,
							rsparm.idval ? rsparm.id
							: skb->data[1],
							rsparm.dtval ?
							rsparm.data : NULL,
							rsparm.dtval ?
							rsparm.dlen : 0);
			} else {
				printk(KERN_DEBUG "ResetAck suppressed\n");
			}
		} else {
			/* We answer with a straight reflected Ack */
			isdn_ppp_ccp_xmit_reset(is, proto, CCP_RESETACK,
						skb->data[1],
						len ? &skb->data[4] : NULL,
						len);
		}
		break;
	}
}


/*
 * Daemon sends a CCP frame ...
 */

/* TODO: Clean this up with new Reset semantics */

/* I believe the CCP handling as-is is done wrong. Compressed frames
 * should only be sent/received after CCP reaches UP state, which means
 * both sides have sent CONF_ACK. Currently, we handle both directions
 * independently, which means we may accept compressed frames too early
 * (supposedly not a problem), but may also mean we send compressed frames
 * too early, which may turn out to be a problem.
 * This part of state machine should actually be handled by (i)pppd, but
 * that's too big of a change now. --kai
 */

/* Actually, we might turn this into an advantage: deal with the RFC in
 * the old tradition of beeing generous on what we accept, but beeing
 * strict on what we send. Thus we should just
 * - accept compressed frames as soon as decompression is negotiated
 * - send compressed frames only when decomp *and* comp are negotiated
 * - drop rx compressed frames if we cannot decomp (instead of pushing them
 *   up to ipppd)
 * and I tried to modify this file according to that. --abp
 */

static void isdn_ppp_send_ccp(isdn_net_dev *net_dev, isdn_net_local *lp, struct sk_buff *skb)
{
	struct ippp_struct *mis,*is;
	int proto, slot = lp->ppp_slot;
	unsigned char *data;

	if(!skb || skb->len < 3)
		return;
	if (slot < 0 || slot >= ISDN_MAX_CHANNELS) {
		printk(KERN_ERR "%s: lp->ppp_slot(%d) out of range\n",
			__FUNCTION__, slot);
		return;
	}	
	is = ippp_table[slot];
	/* Daemon may send with or without address and control field comp */
	data = skb->data;
	if(!(is->pppcfg & SC_COMP_AC) && data[0] == 0xff && data[1] == 0x03) {
		data += 2;
		if(skb->len < 5)
			return;
	}

	proto = ((int)data[0]<<8)+data[1];
	if(proto != PPP_CCP && proto != PPP_CCPFRAG)
		return;

	printk(KERN_DEBUG "Received CCP frame from daemon:\n");
	isdn_ppp_frame_log("ccp-xmit", skb->data, skb->len, 32, is->unit,lp->ppp_slot);

	if (lp->master) {
		slot = ((isdn_net_local *) (lp->master->priv))->ppp_slot;
		if (slot < 0 || slot > ISDN_MAX_CHANNELS) {
			printk(KERN_ERR "%s: slot(%d) out of range\n",
				__FUNCTION__, slot);
			return;
		}	
		mis = ippp_table[slot];
	} else
		mis = is;
	if (mis != is)
		printk(KERN_DEBUG "isdn_ppp: Ouch! Master CCP sends on slave slot!\n");
	
        switch(data[2]) {
	case CCP_CONFREQ:
		if(is->debug & 0x10)
			printk(KERN_DEBUG "Disable decompression here!\n");
		if(proto == PPP_CCP)
			is->compflags &= ~SC_DECOMP_ON;
		else
			is->compflags &= ~SC_LINK_DECOMP_ON;
		break;
	case CCP_TERMREQ:
	case CCP_TERMACK:
		if(is->debug & 0x10)
			printk(KERN_DEBUG "Disable (de)compression here!\n");
		if(proto == PPP_CCP)
			is->compflags &= ~(SC_DECOMP_ON|SC_COMP_ON);
		else
			is->compflags &= ~(SC_LINK_DECOMP_ON|SC_LINK_COMP_ON);
		break;
	case CCP_CONFACK:
		/* if we SEND an ackowledge we can/must enable the compressor */
		if(is->debug & 0x10)
			printk(KERN_DEBUG "Enable compression here!\n");
		if(proto == PPP_CCP) {
			if (!is->compressor)
				break;
			is->compflags |= SC_COMP_ON;
		} else {
			if (!is->compressor)
				break;
			is->compflags |= SC_LINK_COMP_ON;
		}
		break;
	case CCP_RESETACK:
		/* If we send a ACK we should reset our compressor */
		if(is->debug & 0x10)
			printk(KERN_DEBUG "Reset decompression state here!\n");
		printk(KERN_DEBUG "ResetAck from daemon passed by\n");
		if(proto == PPP_CCP) {
			/* link to master? */
			if(is->compressor && is->comp_stat)
				is->compressor->reset(is->comp_stat, 0, 0,
						      NULL, 0, NULL);
			is->compflags &= ~SC_COMP_DISCARD;	
		}
		else {
			if(is->link_compressor && is->link_comp_stat)
				is->link_compressor->reset(is->link_comp_stat,
							   0, 0, NULL, 0, NULL);
			is->compflags &= ~SC_LINK_COMP_DISCARD;	
		}
		break;
	case CCP_RESETREQ:
		/* Just let it pass by */
		printk(KERN_DEBUG "ResetReq from daemon passed by\n");
		break;
	}
}

int isdn_ppp_register_compressor(struct isdn_ppp_compressor *ipc)
{
	ipc->next = ipc_head;
	ipc->prev = NULL;
	if(ipc_head) {
		ipc_head->prev = ipc;
	}
	ipc_head = ipc;
	return 0;
}

int isdn_ppp_unregister_compressor(struct isdn_ppp_compressor *ipc)
{
	if(ipc->prev)
		ipc->prev->next = ipc->next;
	else
		ipc_head = ipc->next;
	if(ipc->next)
		ipc->next->prev = ipc->prev;
	ipc->prev = ipc->next = NULL;
	return 0;
}

static int isdn_ppp_set_compressor(struct ippp_struct *is, struct isdn_ppp_comp_data *data)
{
	struct isdn_ppp_compressor *ipc = ipc_head;
	int ret;
	void *stat;
	int num = data->num;

	if(is->debug & 0x10)
		printk(KERN_DEBUG "[%d] Set %s type %d\n",is->unit,
			(data->flags&IPPP_COMP_FLAG_XMIT)?"compressor":"decompressor",num);

	/* If is has no valid reset state vector, we cannot allocate a
	   decompressor. The decompressor would cause reset transactions
	   sooner or later, and they need that vector. */

	if(!(data->flags & IPPP_COMP_FLAG_XMIT) && !is->reset) {
		printk(KERN_ERR "ippp_ccp: no reset data structure - can't"
		       " allow decompression.\n");
		return -ENOMEM;
	}

	while(ipc) {
		if(ipc->num == num) {
			stat = ipc->alloc(data);
			if(stat) {
				ret = ipc->init(stat,data,is->unit,0);
				if(!ret) {
					printk(KERN_ERR "Can't init (de)compression!\n");
					ipc->free(stat);
					stat = NULL;
					break;
				}
			}
			else {
				printk(KERN_ERR "Can't alloc (de)compression!\n");
				break;
			}

                        if(data->flags & IPPP_COMP_FLAG_XMIT) {
				if(data->flags & IPPP_COMP_FLAG_LINK) {
					if(is->link_comp_stat)
						is->link_compressor->free(is->link_comp_stat);
					is->link_comp_stat = stat;
                                	is->link_compressor = ipc;
				}
				else {
					if(is->comp_stat)
						is->compressor->free(is->comp_stat);
					is->comp_stat = stat;
                                	is->compressor = ipc;
				}
			}
                        else {
				if(data->flags & IPPP_COMP_FLAG_LINK) {
					if(is->link_decomp_stat)
						is->link_decompressor->free(is->link_decomp_stat);
					is->link_decomp_stat = stat;
        	                        is->link_decompressor = ipc;
				}
				else {
					if(is->decomp_stat)
						is->decompressor->free(is->decomp_stat);
					is->decomp_stat = stat;
        	                        is->decompressor = ipc;
				}
			}
			return 0;
		}
		ipc = ipc->next;
	}
	return -EINVAL;
}