aboutsummaryrefslogtreecommitdiffstats
path: root/net/wanrouter/af_wanpipe.c
blob: 8b9bf4a763b55408e3449aa6a0aa4c2a6d80be4d (plain) (blame)
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
/*****************************************************************************
* af_wanpipe.c	WANPIPE(tm) Secure Socket Layer.
*
* Author:	Nenad Corbic	<ncorbic@sangoma.com>
*
* Copyright:	(c) 2000 Sangoma Technologies Inc.
*
*		This program is free software; you can redistribute it and/or
*		modify it under the terms of the GNU General Public License
*		as published by the Free Software Foundation; either version
*		2 of the License, or (at your option) any later version.
* ============================================================================
* Due Credit:
*               Wanpipe socket layer is based on Packet and 
*               the X25 socket layers. The above sockets were 
*               used for the specific use of Sangoma Technoloiges 
*               API programs. 
*               Packet socket Authors: Ross Biro, Fred N. van Kempen and 
*                                      Alan Cox.
*               X25 socket Author: Jonathan Naylor.
* ============================================================================
* Mar 15, 2002  Arnaldo C. Melo  o Use wp_sk()->num, as it isnt anymore in sock
* Apr 25, 2000  Nenad Corbic     o Added the ability to send zero length packets.
* Mar 13, 2000  Nenad Corbic	 o Added a tx buffer check via ioctl call.
* Mar 06, 2000  Nenad Corbic     o Fixed the corrupt sock lcn problem.
*                                  Server and client applicaton can run
*                                  simultaneously without conflicts.
* Feb 29, 2000  Nenad Corbic     o Added support for PVC protocols, such as
*                                  CHDLC, Frame Relay and HDLC API.
* Jan 17, 2000 	Nenad Corbic	 o Initial version, based on AF_PACKET socket.
*			           X25API support only. 
*
******************************************************************************/

#include <linux/config.h>
#include <linux/types.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/capability.h>
#include <linux/fcntl.h>
#include <linux/socket.h>
#include <linux/in.h>
#include <linux/inet.h>
#include <linux/netdevice.h>
#include <linux/poll.h>
#include <linux/wireless.h>
#include <linux/kmod.h>
#include <net/ip.h>
#include <net/protocol.h>
#include <linux/skbuff.h>
#include <net/sock.h>
#include <linux/errno.h>
#include <linux/timer.h>
#include <asm/system.h>
#include <asm/uaccess.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/wanpipe.h>
#include <linux/if_wanpipe.h>
#include <linux/pkt_sched.h>
#include <linux/tcp_states.h>
#include <linux/if_wanpipe_common.h>
#include <linux/sdla_x25.h>

#ifdef CONFIG_INET
#include <net/inet_common.h>
#endif

#define SLOW_BACKOFF 0.1*HZ
#define FAST_BACKOFF 0.01*HZ

//#define PRINT_DEBUG
#ifdef PRINT_DEBUG
	#define DBG_PRINTK(format, a...) printk(format, ## a)
#else
	#define DBG_PRINTK(format, a...)
#endif      


/* SECURE SOCKET IMPLEMENTATION 
 * 
 *   TRANSMIT:
 *
 *      When the user sends a packet via send() system call
 *      the wanpipe_sendmsg() function is executed.  
 *      
 *      Each packet is enqueud into sk->sk_write_queue transmit
 *      queue. When the packet is enqueued, a delayed transmit
 *      timer is triggerd which acts as a Bottom Half hander. 
 *
 *      wanpipe_delay_transmit() function (BH), dequeues packets
 *      from the sk->sk_write_queue transmit queue and sends it 
 *      to the deriver via dev->hard_start_xmit(skb, dev) function.  
 *      Note, this function is actual a function pointer of if_send()
 *      routine in the wanpipe driver.
 *
 *      X25API GUARANTEED DELIVERY:
 *
 *         In order to provide 100% guaranteed packet delivery, 
 *         an atomic 'packet_sent' counter is implemented.  Counter 
 *         is incremented for each packet enqueued 
 *         into sk->sk_write_queue.  Counter is decremented each
 *         time wanpipe_delayed_transmit() function successfuly 
 *         passes the packet to the driver. Before each send(), a poll
 *         routine checks the sock resources The maximum value of
 *         packet sent counter is 1, thus if one packet is queued, the
 *         application will block until that packet is passed to the
 *         driver.
 *
 *   RECEIVE:
 *
 *      Wanpipe device drivers call the socket bottom half
 *      function, wanpipe_rcv() to queue the incoming packets
 *      into an AF_WANPIPE socket queue.  Based on wanpipe_rcv()
 *      return code, the driver knows whether the packet was
 *      successfully queued.  If the socket queue is full, 
 *      protocol flow control is used by the driver, if any, 
 *      to slow down the traffic until the sock queue is free.
 *
 *      Every time a packet arrives into a socket queue the 
 *      socket wakes up processes which are waiting to receive
 *      data.
 *
 *      If the socket queue is full, the driver sets a block
 *      bit which signals the socket to kick the wanpipe driver
 *      bottom half hander when the socket queue is partialy
 *      empty. wanpipe_recvmsg() function performs this action.
 * 
 *      In case of x25api, packets will never be dropped, since
 *      flow control is available. 
 *      
 *      In case of streaming protocols like CHDLC, packets will 
 *      be dropped but the statistics will be generated. 
 */


/* The code below is used to test memory leaks. It prints out
 * a message every time kmalloc and kfree system calls get executed.
 * If the calls match there is no leak :)
 */

/***********FOR DEBUGGING PURPOSES*********************************************
#define KMEM_SAFETYZONE 8

static void * dbg_kmalloc(unsigned int size, int prio, int line) {
	void * v = kmalloc(size,prio);
	printk(KERN_INFO "line %d  kmalloc(%d,%d) = %p\n",line,size,prio,v);
	return v;
}
static void dbg_kfree(void * v, int line) {
	printk(KERN_INFO "line %d  kfree(%p)\n",line,v);
	kfree(v);
}

#define kmalloc(x,y) dbg_kmalloc(x,y,__LINE__)
#define kfree(x) dbg_kfree(x,__LINE__)
******************************************************************************/


/* List of all wanpipe sockets. */
HLIST_HEAD(wanpipe_sklist);
static DEFINE_RWLOCK(wanpipe_sklist_lock);

atomic_t wanpipe_socks_nr;
static unsigned long wanpipe_tx_critical;

#if 0
/* Private wanpipe socket structures. */
struct wanpipe_opt
{
	void   *mbox;		/* Mail box  */
	void   *card; 		/* Card bouded to */
	struct net_device *dev;	/* Bounded device */
	unsigned short lcn;	/* Binded LCN */
	unsigned char  svc;	/* 0=pvc, 1=svc */
	unsigned char  timer;   /* flag for delayed transmit*/	
	struct timer_list tx_timer;
	unsigned poll_cnt;
	unsigned char force;	/* Used to force sock release */
	atomic_t packet_sent;   
};
#endif

static int sk_count;
extern const struct proto_ops wanpipe_ops;
static unsigned long find_free_critical;

static void wanpipe_unlink_driver(struct sock *sk);
static void wanpipe_link_driver(struct net_device *dev, struct sock *sk);
static void wanpipe_wakeup_driver(struct sock *sk);
static int execute_command(struct sock *, unsigned char, unsigned int);
static int check_dev(struct net_device *dev, sdla_t *card);
struct net_device *wanpipe_find_free_dev(sdla_t *card);
static void wanpipe_unlink_card (struct sock *);
static int wanpipe_link_card (struct sock *);
static struct sock *wanpipe_make_new(struct sock *);
static struct sock *wanpipe_alloc_socket(void);
static inline int get_atomic_device(struct net_device *dev);
static int wanpipe_exec_cmd(struct sock *, int, unsigned int);
static int get_ioctl_cmd (struct sock *, void *);
static int set_ioctl_cmd (struct sock *, void *);
static void release_device(struct net_device *dev);
static void wanpipe_kill_sock_timer (unsigned long data);
static void wanpipe_kill_sock_irq (struct sock *);
static void wanpipe_kill_sock_accept (struct sock *);
static int wanpipe_do_bind(struct sock *sk, struct net_device *dev,
			   int protocol);
struct sock * get_newsk_from_skb (struct sk_buff *);
static int wanpipe_debug (struct sock *, void *);
static void wanpipe_delayed_transmit (unsigned long data);
static void release_driver(struct sock *);
static void start_cleanup_timer (struct sock *);
static void check_write_queue(struct sock *);
static int check_driver_busy (struct sock *);

/*============================================================
 * wanpipe_rcv
 *
 *	Wanpipe socket bottom half handler.  This function
 *      is called by the WANPIPE device drivers to queue a
 *      incoming packet into the socket receive queue. 
 *      Once the packet is queued, all processes waiting to 
 *      read are woken up.
 *
 *      During socket bind, this function is bounded into
 *      WANPIPE driver private.
 *===========================================================*/

static int wanpipe_rcv(struct sk_buff *skb, struct net_device *dev,
		       struct sock *sk)
{
	struct wan_sockaddr_ll *sll = (struct wan_sockaddr_ll*)skb->cb;
	wanpipe_common_t *chan = dev->priv;
	/*
	 *	When we registered the protocol we saved the socket in the data
	 *	field for just this event.
	 */

	skb->dev = dev;

	sll->sll_family = AF_WANPIPE;
	sll->sll_hatype = dev->type;
	sll->sll_protocol = skb->protocol;
	sll->sll_pkttype = skb->pkt_type;
	sll->sll_ifindex = dev->ifindex;
	sll->sll_halen = 0;

	if (dev->hard_header_parse)
		sll->sll_halen = dev->hard_header_parse(skb, sll->sll_addr);

	/* 
	 * WAN_PACKET_DATA : Data which should be passed up the receive queue.
         * WAN_PACKET_ASYC : Asynchronous data like place call, which should
         *                   be passed up the listening sock.
         * WAN_PACKET_ERR  : Asynchronous data like clear call or restart 
         *                   which should go into an error queue.
         */
	switch (skb->pkt_type){

		case WAN_PACKET_DATA:
			if (sock_queue_rcv_skb(sk,skb)<0){
				return -ENOMEM;
			}
			break;
		case WAN_PACKET_CMD:
			sk->sk_state = chan->state;
			/* Bug fix: update Mar6. 
                         * Do not set the sock lcn number here, since
         		 * cmd is not guaranteed to be executed on the
                         * board, thus Lcn could be wrong */
			sk->sk_data_ready(sk, skb->len);
			kfree_skb(skb);
			break;
		case WAN_PACKET_ERR:
			sk->sk_state = chan->state;
			if (sock_queue_err_skb(sk,skb)<0){
				return -ENOMEM;
			}
			break;
		default:
			printk(KERN_INFO "wansock: BH Illegal Packet Type Dropping\n");
			kfree_skb(skb); 
			break;
	}

//??????????????????????
//	if (sk->sk_state == WANSOCK_DISCONNECTED){
//		if (sk->sk_zapped) {
//			//printk(KERN_INFO "wansock: Disconnected, killing early\n");
//			wanpipe_unlink_driver(sk);
//			sk->sk_bound_dev_if = 0;
//		}
//	}

	return 0;
}

/*============================================================
 * wanpipe_listen_rcv
 *
 *	Wanpipe LISTEN socket bottom half handler.  This function
 *      is called by the WANPIPE device drivers to queue an
 *      incoming call into the socket listening queue. 
 *      Once the packet is queued, the waiting accept() process 
 *      is woken up.
 *
 *      During socket bind, this function is bounded into
 *      WANPIPE driver private. 
 * 
 *      IMPORTANT NOTE:
 *          The accept call() is waiting for an skb packet
 *          which contains a pointer to a device structure.
 *
 *          When we do a bind to a device structre, we 
 *          bind a newly created socket into "chan->sk".  Thus, 
 *          when accept receives the skb packet, it will know 
 *          from which dev it came form, and in turn it will know
 *          the address of the new sock.
 *
 *  	NOTE: This function gets called from driver ISR.
 *===========================================================*/

static int wanpipe_listen_rcv (struct sk_buff *skb,  struct sock *sk)
{
	wanpipe_opt *wp = wp_sk(sk), *newwp;
	struct wan_sockaddr_ll *sll = (struct wan_sockaddr_ll*)skb->cb;
	struct sock *newsk;
	struct net_device *dev; 
	sdla_t *card;
	mbox_cmd_t *mbox_ptr;
	wanpipe_common_t *chan;

	/* Find a free device, if none found, all svc's are busy 
         */

	card = (sdla_t*)wp->card;
	if (!card){
		printk(KERN_INFO "wansock: LISTEN ERROR, No Card\n");
		return -ENODEV;
	}
	
	dev = wanpipe_find_free_dev(card);
	if (!dev){
		printk(KERN_INFO "wansock: LISTEN ERROR, No Free Device\n");
		return -ENODEV;
	}

	chan=dev->priv;	
	chan->state = WANSOCK_CONNECTING;

	/* Allocate a new sock, which accept will bind
         * and pass up to the user 
	 */
	if ((newsk = wanpipe_make_new(sk)) == NULL){
		release_device(dev);
		return -ENOMEM;
	}


	/* Initialize the new sock structure 
	 */
	newsk->sk_bound_dev_if = dev->ifindex;
	newwp = wp_sk(newsk);
	newwp->card = wp->card;

	/* Insert the sock into the main wanpipe
         * sock list.
         */
	atomic_inc(&wanpipe_socks_nr);

	/* Allocate and fill in the new Mail Box. Then
         * bind the mail box to the sock. It will be 
         * used by the ioctl call to read call information
         * and to execute commands. 
         */	
	if ((mbox_ptr = kmalloc(sizeof(mbox_cmd_t), GFP_ATOMIC)) == NULL) {
		wanpipe_kill_sock_irq (newsk);
		release_device(dev);		
		return -ENOMEM;
	}
	memset(mbox_ptr, 0, sizeof(mbox_cmd_t));
	memcpy(mbox_ptr,skb->data,skb->len);

	/* Register the lcn on which incoming call came
         * from. Thus, if we have to clear it, we know
         * which lcn to clear
	 */ 

	newwp->lcn = mbox_ptr->cmd.lcn;
	newwp->mbox = (void *)mbox_ptr;

	DBG_PRINTK(KERN_INFO "NEWSOCK : Device %s, bind to lcn %i\n",
			dev->name,mbox_ptr->cmd.lcn);

	chan->lcn = mbox_ptr->cmd.lcn;
	card->u.x.svc_to_dev_map[(chan->lcn%MAX_X25_LCN)] = dev;

	sock_reset_flag(newsk, SOCK_ZAPPED);
	newwp->num = htons(X25_PROT);

	if (wanpipe_do_bind(newsk, dev, newwp->num)) {
		wanpipe_kill_sock_irq (newsk);
		release_device(dev);
		return -EINVAL;
	}
	newsk->sk_state = WANSOCK_CONNECTING;


	/* Fill in the standard sock address info */

	sll->sll_family = AF_WANPIPE;
	sll->sll_hatype = dev->type;
	sll->sll_protocol = skb->protocol;
	sll->sll_pkttype = skb->pkt_type;
	sll->sll_ifindex = dev->ifindex;
	sll->sll_halen = 0;

	skb->dev = dev;
	sk->sk_ack_backlog++;

	/* We must do this manually, since the sock_queue_rcv_skb()
	 * function sets the skb->dev to NULL.  However, we use
	 * the dev field in the accept function.*/ 
	if (atomic_read(&sk->sk_rmem_alloc) + skb->truesize >= 
	    (unsigned)sk->sk_rcvbuf) {

         	wanpipe_unlink_driver(newsk);
		wanpipe_kill_sock_irq (newsk);
		--sk->sk_ack_backlog;
		return -ENOMEM;
	}	

	skb_set_owner_r(skb, sk);
	skb_queue_tail(&sk->sk_receive_queue, skb);
	sk->sk_data_ready(sk, skb->len);
	
	return 0;
}



/*============================================================
 * wanpipe_make_new
 *
 *	Create a new sock, and allocate a wanpipe private
 *      structure to it. Also, copy the important data
 *      from the original sock to the new sock.
 *
 *      This function is used by wanpipe_listen_rcv() listen
 *      bottom half handler.  A copy of the listening sock
 *      is created using this function.
 *
 *===========================================================*/

static struct sock *wanpipe_make_new(struct sock *osk)
{
	struct sock *sk;

	if (osk->sk_type != SOCK_RAW)
		return NULL;

	if ((sk = wanpipe_alloc_socket()) == NULL)
		return NULL;

	sk->sk_type	= osk->sk_type;
	sk->sk_socket	= osk->sk_socket;
	sk->sk_priority	= osk->sk_priority;
	sk->sk_protocol	= osk->sk_protocol;
	wp_sk(sk)->num	= wp_sk(osk)->num;
	sk->sk_rcvbuf	= osk->sk_rcvbuf;
	sk->sk_sndbuf	= osk->sk_sndbuf;
	sk->sk_state	= WANSOCK_CONNECTING;
	sk->sk_sleep	= osk->sk_sleep;

	if (sock_flag(osk, SOCK_DBG))
		sock_set_flag(sk, SOCK_DBG);

	return sk;
}

/* 
 * FIXME: wanpipe_opt has to include a sock in its definition and stop using
 * sk_protinfo, but this code is not even compilable now, so lets leave it for
 * later.
 */
static struct proto wanpipe_proto = {
	.name	  = "WANPIPE",
	.owner	  = THIS_MODULE,
	.obj_size = sizeof(struct sock),
};

/*============================================================
 * wanpipe_make_new
 *
 *	Allocate memory for the a new sock, and sock
 *      private data.  
 *	
 *	Increment the module use count.
 *       	
 *      This function is used by wanpipe_create() and 
 *      wanpipe_make_new() functions. 
 *
 *===========================================================*/

static struct sock *wanpipe_alloc_socket(void)
{
	struct sock *sk;
	struct wanpipe_opt *wan_opt;

	if ((sk = sk_alloc(PF_WANPIPE, GFP_ATOMIC, &wanpipe_proto, 1)) == NULL)
		return NULL;

	if ((wan_opt = kmalloc(sizeof(struct wanpipe_opt), GFP_ATOMIC)) == NULL) {
		sk_free(sk);
		return NULL;
	}
	memset(wan_opt, 0x00, sizeof(struct wanpipe_opt));

	wp_sk(sk) = wan_opt;

	/* Use timer to send data to the driver. This will act
         * as a BH handler for sendmsg functions */
	init_timer(&wan_opt->tx_timer);
	wan_opt->tx_timer.data	   = (unsigned long)sk;
	wan_opt->tx_timer.function = wanpipe_delayed_transmit;

	sock_init_data(NULL, sk);
	return sk;
}


/*============================================================
 * wanpipe_sendmsg
 *
 *	This function implements a sendto() system call,
 *      for AF_WANPIPE socket family. 
 *      During socket bind() sk->sk_bound_dev_if is initialized
 *      to a correct network device. This number is used
 *      to find a network device to which the packet should
 *      be passed to.
 *
 *      Each packet is queued into sk->sk_write_queue and 
 *      delayed transmit bottom half handler is marked for 
 *      execution.
 *
 *      A socket must be in WANSOCK_CONNECTED state before
 *      a packet is queued into sk->sk_write_queue.
 *===========================================================*/

static int wanpipe_sendmsg(struct kiocb *iocb, struct socket *sock,
			   struct msghdr *msg, int len)
{
	wanpipe_opt *wp;
	struct sock *sk = sock->sk;
	struct wan_sockaddr_ll *saddr=(struct wan_sockaddr_ll *)msg->msg_name;
	struct sk_buff *skb;
	struct net_device *dev;
	unsigned short proto;
	unsigned char *addr;
	int ifindex, err, reserve = 0;

	
	if (!sock_flag(sk, SOCK_ZAPPED))
		return -ENETDOWN;

	if (sk->sk_state != WANSOCK_CONNECTED)
		return -ENOTCONN;	

	if (msg->msg_flags & ~(MSG_DONTWAIT|MSG_CMSG_COMPAT)) 
		return(-EINVAL);

	/* it was <=, now one can send
         * zero length packets */
	if (len < sizeof(x25api_hdr_t))
		return -EINVAL;

	wp = wp_sk(sk);

	if (saddr == NULL) {
		ifindex	= sk->sk_bound_dev_if;
		proto	= wp->num;
		addr	= NULL;

	}else{
		if (msg->msg_namelen < sizeof(struct wan_sockaddr_ll)){ 
			return -EINVAL;
		}

		ifindex = sk->sk_bound_dev_if;
		proto	= saddr->sll_protocol;
		addr	= saddr->sll_addr;
	}

	dev = dev_get_by_index(ifindex);
	if (dev == NULL){
		printk(KERN_INFO "wansock: Send failed, dev index: %i\n",ifindex);
		return -ENXIO;
	}
	dev_put(dev);
	
	if (sock->type == SOCK_RAW)
		reserve = dev->hard_header_len;

	if (len > dev->mtu+reserve){
  		return -EMSGSIZE;
	}

	skb = sock_alloc_send_skb(sk, len + LL_RESERVED_SPACE(dev),
				msg->msg_flags & MSG_DONTWAIT, &err);

	if (skb==NULL){
		goto out_unlock;
	}
		
	skb_reserve(skb, LL_RESERVED_SPACE(dev));
	skb->nh.raw = skb->data;

	/* Returns -EFAULT on error */
	err = memcpy_fromiovec(skb_put(skb,len), msg->msg_iov, len);
	if (err){
		goto out_free;
	}

	if (dev->hard_header) {
		int res;
		err = -EINVAL;
		res = dev->hard_header(skb, dev, ntohs(proto), addr, NULL, len);
		if (res<0){
			goto out_free;
		}
	}

	skb->protocol = proto;
	skb->dev = dev;
	skb->priority = sk->sk_priority;
	skb->pkt_type = WAN_PACKET_DATA;

	err = -ENETDOWN;
	if (!(dev->flags & IFF_UP))
		goto out_free;

	if (atomic_read(&sk->sk_wmem_alloc) + skb->truesize >
	    (unsigned int)sk->sk_sndbuf){
		kfree_skb(skb);
		return -ENOBUFS;
	}

	skb_queue_tail(&sk->sk_write_queue,skb);
	atomic_inc(&wp->packet_sent);

	if (!(test_and_set_bit(0, &wp->timer)))
		mod_timer(&wp->tx_timer, jiffies + 1);
	
	return(len);

out_free:
	kfree_skb(skb);
out_unlock:
	return err;
}

/*============================================================
 * wanpipe_delayed_tarnsmit
 *
 *	Transmit bottom half handler. It dequeues packets
 *      from sk->sk_write_queue and passes them to the 
 *      driver.  If the driver is busy, the packet is 
 *      re-enqueued.  
 *
 *      Packet Sent counter is decremented on successful
 *      transmission. 
 *===========================================================*/


static void wanpipe_delayed_transmit (unsigned long data)
{
	struct sock *sk=(struct sock *)data;
	struct sk_buff *skb;
	wanpipe_opt *wp = wp_sk(sk);
	struct net_device *dev = wp->dev;
	sdla_t *card = (sdla_t*)wp->card;

	if (!card || !dev){
		clear_bit(0, &wp->timer);
		DBG_PRINTK(KERN_INFO "wansock: Transmit delay, no dev or card\n");
		return;
	}
	
	if (sk->sk_state != WANSOCK_CONNECTED || !sock_flag(sk, SOCK_ZAPPED)) {
		clear_bit(0, &wp->timer);
		DBG_PRINTK(KERN_INFO "wansock: Tx Timer, State not CONNECTED\n");
		return;
	}
	
	/* If driver is executing command, we must offload
         * the board by not sending data. Otherwise a 
         * pending command will never get a free buffer
         * to execute */ 	
	if (atomic_read(&card->u.x.command_busy)){
		wp->tx_timer.expires = jiffies + SLOW_BACKOFF;
		add_timer(&wp->tx_timer);
		DBG_PRINTK(KERN_INFO "wansock: Tx Timer, command bys BACKOFF\n");
		return;
	}

	
	if (test_and_set_bit(0,&wanpipe_tx_critical)){
		printk(KERN_INFO "WanSock: Tx timer critical %s\n",dev->name);
		wp->tx_timer.expires = jiffies + SLOW_BACKOFF;
		add_timer(&wp->tx_timer);
		return;
	}	
	
	/* Check for a packet in the fifo and send */
	if ((skb = skb_dequeue(&sk->sk_write_queue)) != NULL){

		if (dev->hard_start_xmit(skb, dev) != 0){			

			/* Driver failed to transmit, re-enqueue
                         * the packet and retry again later */
			skb_queue_head(&sk->sk_write_queue,skb);
			clear_bit(0,&wanpipe_tx_critical);
			return;
		}else{

			/* Packet Sent successful. Check for more packets
                         * if more packets, re-trigger the transmit routine 
                         * other wise exit
                         */
			atomic_dec(&wp->packet_sent);

			if (skb_peek(&sk->sk_write_queue) == NULL) {
				/* If there is nothing to send, kick
				 * the poll routine, which will trigger
				 * the application to send more data */
				sk->sk_data_ready(sk, 0);
				clear_bit(0, &wp->timer);
			}else{
				/* Reschedule as fast as possible */
				wp->tx_timer.expires = jiffies + 1;
				add_timer(&wp->tx_timer);
			}
		}
	}
	clear_bit(0,&wanpipe_tx_critical);
}

/*============================================================
 * execute_command 
 *
 *	Execute x25api commands.  The atomic variable
 *      chan->command is used to indicate to the driver that
 *      command is pending for execution.  The acutal command
 *      structure is placed into a sock mbox structure 
 *      (wp_sk(sk)->mbox).
 *
 *      The sock private structure, mbox is
 *      used as shared memory between sock and the driver.
 *      Driver uses the sock mbox to execute the command
 *      and return the result.  
 *
 *      For all command except PLACE CALL, the function
 *      waits for the result.  PLACE CALL can be ether
 *      blocking or nonblocking. The user sets this option
 *      via ioctl call.
 *===========================================================*/


static int execute_command(struct sock *sk,  unsigned char cmd, unsigned int flags)
{
	wanpipe_opt *wp = wp_sk(sk);
	struct net_device *dev;
	wanpipe_common_t *chan=NULL;
	int err=0;
	DECLARE_WAITQUEUE(wait, current);
	
	dev = dev_get_by_index(sk->sk_bound_dev_if);
	if (dev == NULL){
		printk(KERN_INFO "wansock: Exec failed no dev %i\n",
			sk->sk_bound_dev_if);
		return -ENODEV;
	}
	dev_put(dev);

	if ((chan=dev->priv) == NULL){
		printk(KERN_INFO "wansock: Exec cmd failed no priv area\n");
		return -ENODEV;
	}

	if (atomic_read(&chan->command)){
		printk(KERN_INFO "wansock: ERROR: Command already running %x, %s\n",
			atomic_read(&chan->command),dev->name);
		return -EINVAL;
	}

	if (!wp->mbox) {
		printk(KERN_INFO "wansock: In execute without MBOX\n");
		return -EINVAL;
	}

	((mbox_cmd_t*)wp->mbox)->cmd.command = cmd;	
	((mbox_cmd_t*)wp->mbox)->cmd.lcn     = wp->lcn;
	((mbox_cmd_t*)wp->mbox)->cmd.result  = 0x7F;


	if (flags & O_NONBLOCK){
		cmd |= 0x80;
		atomic_set(&chan->command, cmd);
	}else{
		atomic_set(&chan->command, cmd);
	}

	add_wait_queue(sk->sk_sleep,&wait);
	current->state = TASK_INTERRUPTIBLE;
	for (;;){
		if (((mbox_cmd_t*)wp->mbox)->cmd.result != 0x7F) {
			err = 0;
			break;
		}
		if (signal_pending(current)) {
			err = -ERESTARTSYS;
			break;
		}
		schedule();
	}
	current->state = TASK_RUNNING;
	remove_wait_queue(sk->sk_sleep,&wait);
	
	return err;
}

/*============================================================
 * wanpipe_destroy_timer 
 *
 *	Used by wanpipe_release, to delay release of
 *      the socket.
 *===========================================================*/

static void wanpipe_destroy_timer(unsigned long data)
{
	struct sock *sk=(struct sock *)data;
	wanpipe_opt *wp = wp_sk(sk);

	if ((!atomic_read(&sk->sk_wmem_alloc) &&
	     !atomic_read(&sk->sk_rmem_alloc)) ||
	    (++wp->force == 5)) {

		if (atomic_read(&sk->sk_wmem_alloc) ||
		    atomic_read(&sk->sk_rmem_alloc))
			printk(KERN_INFO "wansock: Warning, Packet Discarded due to sock shutdown!\n");

		kfree(wp);
		wp_sk(sk) = NULL;
		
		if (atomic_read(&sk->sk_refcnt) != 1) {
			atomic_set(&sk->sk_refcnt, 1);
			DBG_PRINTK(KERN_INFO "wansock: Error, wrong reference count: %i ! :delay.\n",
					atomic_read(&sk->sk_refcnt));
		}
		sock_put(sk);
		atomic_dec(&wanpipe_socks_nr);
		return;
	}

	sk->sk_timer.expires = jiffies + 5 * HZ;
	add_timer(&sk->sk_timer);
	printk(KERN_INFO "wansock: packet sk destroy delayed\n");
}

/*============================================================
 * wanpipe_unlink_driver
 *
 * 	When the socket is released, this function is 
 *      used to remove links that bind the sock and the
 *      driver together.  
 *===========================================================*/
static void wanpipe_unlink_driver (struct sock *sk)
{
	struct net_device *dev;
	wanpipe_common_t *chan=NULL;

	sock_reset_flag(sk, SOCK_ZAPPED);
	sk->sk_state = WANSOCK_DISCONNECTED;
	wp_sk(sk)->dev = NULL;

	dev = dev_get_by_index(sk->sk_bound_dev_if);
	if (!dev){
		printk(KERN_INFO "wansock: No dev on release\n");
		return;
	}			
	dev_put(dev);

	if ((chan = dev->priv) == NULL){
		printk(KERN_INFO "wansock: No Priv Area on release\n");
		return;
	}

	set_bit(0,&chan->common_critical);
	chan->sk=NULL;
	chan->func=NULL;
	chan->mbox=NULL;
	chan->tx_timer=NULL;
	clear_bit(0,&chan->common_critical);
	release_device(dev);
	
	return;
}

/*============================================================
 * wanpipe_link_driver
 *
 * 	Upon successful bind(), sock is linked to a driver
 *      by binding in the wanpipe_rcv() bottom half handler
 *      to the driver function pointer, as well as sock and
 *      sock mailbox addresses.  This way driver can pass
 *      data up the socket.
 *===========================================================*/

static void wanpipe_link_driver(struct net_device *dev, struct sock *sk)
{
	wanpipe_opt *wp = wp_sk(sk);
	wanpipe_common_t *chan = dev->priv;
	if (!chan)
		return;
	set_bit(0,&chan->common_critical);
	chan->sk=sk;
	chan->func=wanpipe_rcv;
	chan->mbox = wp->mbox;
	chan->tx_timer = &wp->tx_timer;
	wp->dev = dev;
	sock_set_flag(sk, SOCK_ZAPPED);
	clear_bit(0,&chan->common_critical);
}


/*============================================================
 * release_device
 *
 *   	During sock release, clear a critical bit, which 
 *      marks the device a being taken.
 *===========================================================*/


static void release_device(struct net_device *dev)
{
	wanpipe_common_t *chan=dev->priv;
	clear_bit(0,(void*)&chan->rw_bind);
}

/*============================================================
 * wanpipe_release
 *
 *	Close a PACKET socket. This is fairly simple. We 
 *      immediately go to 'closed' state and remove our 
 *      protocol entry in the device list.
 *===========================================================*/

static int wanpipe_release(struct socket *sock)
{
	wanpipe_opt *wp;
	struct sock *sk = sock->sk;
	
	if (!sk)
		return 0;

	wp = wp_sk(sk);
	check_write_queue(sk);

	/* Kill the tx timer, if we don't kill it now, the timer
         * will run after we kill the sock.  Timer code will 
         * try to access the sock which has been killed and cause
         * kernel panic */

	del_timer(&wp->tx_timer);

	/*
	 *	Unhook packet receive handler.
	 */

	if (wp->num == htons(X25_PROT) &&
	    sk->sk_state != WANSOCK_DISCONNECTED && sock_flag(sk, SOCK_ZAPPED)) {
		struct net_device *dev = dev_get_by_index(sk->sk_bound_dev_if);
		wanpipe_common_t *chan;
		if (dev){
			chan=dev->priv;
			atomic_set(&chan->disconnect,1);
			DBG_PRINTK(KERN_INFO "wansock: Sending Clear Indication %i\n",
					sk->sk_state);
			dev_put(dev);
		}	
	}

	set_bit(1,&wanpipe_tx_critical);
	write_lock(&wanpipe_sklist_lock);
	sk_del_node_init(sk);
	write_unlock(&wanpipe_sklist_lock);
	clear_bit(1,&wanpipe_tx_critical);


	
	release_driver(sk);

	
	/*
	 *	Now the socket is dead. No more input will appear.
	 */

	sk->sk_state_change(sk);	/* It is useless. Just for sanity. */

	sock->sk = NULL;
	sk->sk_socket = NULL;
	sock_set_flag(sk, SOCK_DEAD);

	/* Purge queues */
	skb_queue_purge(&sk->sk_receive_queue);
	skb_queue_purge(&sk->sk_write_queue);
	skb_queue_purge(&sk->sk_error_queue);

	if (atomic_read(&sk->sk_rmem_alloc) ||
	    atomic_read(&sk->sk_wmem_alloc)) {
		del_timer(&sk->sk_timer);
		printk(KERN_INFO "wansock: Killing in Timer R %i , W %i\n",
			atomic_read(&sk->sk_rmem_alloc),
			atomic_read(&sk->sk_wmem_alloc));
		sk->sk_timer.data	= (unsigned long)sk;
		sk->sk_timer.expires	= jiffies + HZ;
		sk->sk_timer.function	= wanpipe_destroy_timer;
		add_timer(&sk->sk_timer);
		return 0;
	}

	kfree(wp);
	wp_sk(sk) = NULL;

	if (atomic_read(&sk->sk_refcnt) != 1) {
		DBG_PRINTK(KERN_INFO "wansock: Error, wrong reference count: %i !:release.\n",
					atomic_read(&sk->sk_refcnt));
		atomic_set(&sk->sk_refcnt, 1);
	}
	sock_put(sk);
	atomic_dec(&wanpipe_socks_nr);
	return 0;
}

/*============================================================
 * check_write_queue
 *
 *  	During sock shutdown, if the sock state is 
 *      WANSOCK_CONNECTED and there is transmit data 
 *      pending. Wait until data is released 
 *      before proceeding.
 *===========================================================*/

static void check_write_queue(struct sock *sk)
{

	if (sk->sk_state != WANSOCK_CONNECTED)
		return;

	if (!atomic_read(&sk->sk_wmem_alloc))
		return;

	printk(KERN_INFO "wansock: MAJOR ERROR, Data lost on sock release !!!\n");

}

/*============================================================
 * release_driver
 *
 *	This function is called during sock shutdown, to 
 *      release any resources and links that bind the sock
 *      to the driver.  It also changes the state of the
 *      sock to WANSOCK_DISCONNECTED
 *===========================================================*/

static void release_driver(struct sock *sk)
{
	wanpipe_opt *wp;
	struct sk_buff *skb=NULL;
	struct sock *deadsk=NULL;

	if (sk->sk_state == WANSOCK_LISTEN ||
	    sk->sk_state == WANSOCK_BIND_LISTEN) {
		while ((skb = skb_dequeue(&sk->sk_receive_queue)) != NULL) {
			if ((deadsk = get_newsk_from_skb(skb))){
				DBG_PRINTK (KERN_INFO "wansock: RELEASE: FOUND DEAD SOCK\n");
				sock_set_flag(deadsk, SOCK_DEAD);
				start_cleanup_timer(deadsk);
			}
			kfree_skb(skb);
		}
		if (sock_flag(sk, SOCK_ZAPPED))
			wanpipe_unlink_card(sk);
	}else{
		if (sock_flag(sk, SOCK_ZAPPED))
			wanpipe_unlink_driver(sk);
	}
	sk->sk_state	    = WANSOCK_DISCONNECTED;
	sk->sk_bound_dev_if = 0;
	sock_reset_flag(sk, SOCK_ZAPPED);
	wp = wp_sk(sk);

	if (wp) {
		kfree(wp->mbox);
		wp->mbox = NULL;
	}
}

/*============================================================
 *  start_cleanup_timer
 *
 *  	If new incoming call's are pending but the socket
 *      is being released, start the timer which will 
 *      envoke the kill routines for pending socks.
 *===========================================================*/


static void start_cleanup_timer (struct sock *sk)
{
	del_timer(&sk->sk_timer);
	sk->sk_timer.data	= (unsigned long)sk;
	sk->sk_timer.expires	= jiffies + HZ;
	sk->sk_timer.function	= wanpipe_kill_sock_timer;
	add_timer(&sk->sk_timer);
}


/*============================================================
 *  wanpipe_kill_sock
 *
 *	This is a function which performs actual killing
 *      of the sock.  It releases socket resources,
 *      and unlinks the sock from the driver. 
 *===========================================================*/

static void wanpipe_kill_sock_timer (unsigned long data)
{

	struct sock *sk = (struct sock *)data;
	struct sock **skp;

	if (!sk)
		return;

	/* This function can be called from interrupt. We must use
	 * appropriate locks */
	
	if (test_bit(1,&wanpipe_tx_critical)){
		sk->sk_timer.expires = jiffies + 10;
		add_timer(&sk->sk_timer);
		return;
	}
	
	write_lock(&wanpipe_sklist_lock);
	sk_del_node_init(sk);
	write_unlock(&wanpipe_sklist_lock);


	if (wp_sk(sk)->num == htons(X25_PROT) &&
	    sk->sk_state != WANSOCK_DISCONNECTED) {
		struct net_device *dev = dev_get_by_index(sk->sk_bound_dev_if);
		wanpipe_common_t *chan;
		if (dev){
			chan=dev->priv;
			atomic_set(&chan->disconnect,1);
			dev_put(dev);
		}	
	}

	release_driver(sk);

	sk->sk_socket = NULL;

	/* Purge queues */
	skb_queue_purge(&sk->sk_receive_queue);
	skb_queue_purge(&sk->sk_write_queue);
	skb_queue_purge(&sk->sk_error_queue);
	
	if (atomic_read(&sk->sk_rmem_alloc) ||
	    atomic_read(&sk->sk_wmem_alloc)) {
		del_timer(&sk->sk_timer);
		printk(KERN_INFO "wansock: Killing SOCK in Timer\n");
		sk->sk_timer.data	= (unsigned long)sk;
		sk->sk_timer.expires	= jiffies + HZ;
		sk->sk_timer.function	= wanpipe_destroy_timer;
		add_timer(&sk->sk_timer);
		return;
	}

	kfree(wp_sk(sk));
	wp_sk(sk) = NULL;

	if (atomic_read(&sk->sk_refcnt) != 1) {
		atomic_set(&sk->sk_refcnt, 1);
		DBG_PRINTK(KERN_INFO "wansock: Error, wrong reference count: %i ! :timer.\n",
					atomic_read(&sk->sk_refcnt));
	}
	sock_put(sk);
	atomic_dec(&wanpipe_socks_nr);
	return;
}

static void wanpipe_kill_sock_accept (struct sock *sk)
{

	struct sock **skp;

	if (!sk)
		return;

	/* This function can be called from interrupt. We must use
	 * appropriate locks */
	
	write_lock(&wanpipe_sklist_lock);
	sk_del_node_init(sk);
	write_unlock(&wanpipe_sklist_lock);

	sk->sk_socket = NULL;


	kfree(wp_sk(sk));
	wp_sk(sk) = NULL;

	if (atomic_read(&sk->sk_refcnt) != 1) {
		atomic_set(&sk->sk_refcnt, 1);
		DBG_PRINTK(KERN_INFO "wansock: Error, wrong reference count: %i ! :timer.\n",
					atomic_read(&sk->sk_refcnt));
	}
	sock_put(sk);
	atomic_dec(&wanpipe_socks_nr);
	return;
}


static void wanpipe_kill_sock_irq (struct sock *sk)
{

	if (!sk)
		return;

	sk->sk_socket = NULL;

	kfree(wp_sk(sk));
	wp_sk(sk) = NULL;

	if (atomic_read(&sk->sk_refcnt) != 1) {
		atomic_set(&sk->sk_refcnt, 1);
		DBG_PRINTK(KERN_INFO "wansock: Error, wrong reference count: %i !:listen.\n",
					atomic_read(&sk->sk_refcnt));
	}
	sock_put(sk);
	atomic_dec(&wanpipe_socks_nr);
}


/*============================================================
 *  wanpipe_do_bind
 *
 * 	Bottom half of the binding system call.
 *      Once the wanpipe_bind() function checks  the
 *      legality of the call, this function binds the
 *      sock to the driver.
 *===========================================================*/

static int wanpipe_do_bind(struct sock *sk, struct net_device *dev,
			   int protocol)
{
	wanpipe_opt *wp = wp_sk(sk);
	wanpipe_common_t *chan=NULL;
	int err=0;

	if (sock_flag(sk, SOCK_ZAPPED)) {
		err = -EALREADY;
		goto bind_unlock_exit;
	}

	wp->num = protocol;

	if (protocol == 0){
		release_device(dev);
		err = -EINVAL;
		goto bind_unlock_exit;
	}

	if (dev) {
		if (dev->flags&IFF_UP) {
			chan=dev->priv;
			sk->sk_state = chan->state;

			if (wp->num == htons(X25_PROT) && 
			    sk->sk_state != WANSOCK_DISCONNECTED && 
			    sk->sk_state != WANSOCK_CONNECTING) {
				DBG_PRINTK(KERN_INFO 
					"wansock: Binding to Device not DISCONNECTED %i\n",
						sk->sk_state);
				release_device(dev);
				err = -EAGAIN;
				goto bind_unlock_exit;
			}

			wanpipe_link_driver(dev,sk);
			sk->sk_bound_dev_if = dev->ifindex;

			/* X25 Specific option */
			if (wp->num == htons(X25_PROT))
				wp_sk(sk)->svc = chan->svc;

		} else {
			sk->sk_err = ENETDOWN;
			sk->sk_error_report(sk);
			release_device(dev);
			err = -EINVAL;
		}
	} else {
		err = -ENODEV;
	}
bind_unlock_exit:
	/* FIXME where is this lock */

	return err;
}

/*============================================================
 *  wanpipe_bind
 *
 *      BIND() System call, which is bound to the AF_WANPIPE
 *      operations structure.  It checks for correct wanpipe
 *      card name, and cross references interface names with
 *      the card names.  Thus, interface name must belong to
 *      the actual card.
 *===========================================================*/


static int wanpipe_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
{
	struct wan_sockaddr_ll *sll = (struct wan_sockaddr_ll*)uaddr;
	struct sock *sk=sock->sk;
	wanpipe_opt *wp = wp_sk(sk);
	struct net_device *dev = NULL;
	sdla_t *card=NULL;
	char name[15];

	/*
	 *	Check legality
	 */
	 
	if (addr_len < sizeof(struct wan_sockaddr_ll)){
		printk(KERN_INFO "wansock: Address length error\n");
		return -EINVAL;
	}
	if (sll->sll_family != AF_WANPIPE){
		printk(KERN_INFO "wansock: Illegal family name specified.\n");
		return -EINVAL;
	}

	card = wanpipe_find_card (sll->sll_card);
	if (!card){
		printk(KERN_INFO "wansock: Wanpipe card not found: %s\n",sll->sll_card);
		return -ENODEV;
	}else{
		wp_sk(sk)->card = (void *)card;
	}

	if (!strcmp(sll->sll_device,"svc_listen")){

		/* Bind a sock to a card structure for listening 
		 */		
		int err=0; 

		/* This is x25 specific area if protocol doesn't
                 * match, return error */
		if (sll->sll_protocol != htons(X25_PROT))
			return -EINVAL;

		err= wanpipe_link_card (sk);
		if (err < 0)
			return err;

		if (sll->sll_protocol)
			wp->num = sll->sll_protocol;
		sk->sk_state = WANSOCK_BIND_LISTEN;
		return 0;

	}else if (!strcmp(sll->sll_device,"svc_connect")){ 

		/* This is x25 specific area if protocol doesn't
                 * match, return error */
		if (sll->sll_protocol != htons(X25_PROT))
			return -EINVAL;

		/* Find a free device 
		 */
		dev = wanpipe_find_free_dev(card);
		if (dev == NULL){
			DBG_PRINTK(KERN_INFO "wansock: No free network devices for card %s\n",
				card->devname);
			return -EINVAL;
		}
	}else{
		/* Bind a socket to a interface name 
                 * This is used by PVC mostly
                 */
		strlcpy(name,sll->sll_device,sizeof(name));
		dev = dev_get_by_name(name);
		if (dev == NULL){
			printk(KERN_INFO "wansock: Failed to get Dev from name: %s,\n",
					name);
			return -ENODEV;
		}

		dev_put(dev);

		if (check_dev(dev, card)){
			printk(KERN_INFO "wansock: Device %s, doesn't belong to card %s\n",
				dev->name, card->devname);
			return -EINVAL;
		}
		if (get_atomic_device (dev))
			return -EINVAL;
	}

	return wanpipe_do_bind(sk, dev, sll->sll_protocol ? : wp->num);
}

/*============================================================
 * get_atomic_device
 *	
 *	Sets a bit atomically which indicates that 
 *      the interface is taken. This avoids race conditions.
 *===========================================================*/


static inline int get_atomic_device(struct net_device *dev)
{
	wanpipe_common_t *chan = dev->priv;
	if (!test_and_set_bit(0,(void *)&chan->rw_bind)){
		return 0;
	}
	return 1;
}

/*============================================================
 * check_dev
 *	
 *  	Check that device name belongs to a particular card.
 *===========================================================*/

static int check_dev(struct net_device *dev, sdla_t *card)
{
	struct net_device* tmp_dev;

	for (tmp_dev = card->wandev.dev; tmp_dev;
	     tmp_dev = *((struct net_device **)tmp_dev->priv)) {
		if (tmp_dev->ifindex == dev->ifindex){ 
			return 0;	
		}
	}
	return 1;
}

/*============================================================
 *  wanpipe_find_free_dev
 *	
 *	Find a free network interface. If found set atomic
 *      bit indicating that the interface is taken.
 *      X25API Specific.
 *===========================================================*/

struct net_device *wanpipe_find_free_dev(sdla_t *card)
{
	struct net_device* dev;
	volatile wanpipe_common_t *chan;

	if (test_and_set_bit(0,&find_free_critical)){
		printk(KERN_INFO "CRITICAL in Find Free\n");
	}	

	for (dev = card->wandev.dev; dev;
	     dev = *((struct net_device **)dev->priv)) {
		chan = dev->priv;
		if (!chan) 
			continue;
		if (chan->usedby == API && chan->svc){
			if (!get_atomic_device (dev)){
				if (chan->state != WANSOCK_DISCONNECTED){
					release_device(dev);
				}else{
					clear_bit(0,&find_free_critical);
					return dev;
				}
			}
		}
	}
	clear_bit(0,&find_free_critical);
	return NULL;
}

/*============================================================
 *  wanpipe_create
 *	
 * 	SOCKET() System call.  It allocates a sock structure
 *      and adds the socket to the wanpipe_sk_list. 
 *      Crates AF_WANPIPE socket.
 *===========================================================*/

static int wanpipe_create(struct socket *sock, int protocol)
{
	struct sock *sk;
	
	//FIXME: This checks for root user, SECURITY ?
	//if (!capable(CAP_NET_RAW))
	//	return -EPERM;

	if (sock->type != SOCK_DGRAM && sock->type != SOCK_RAW)
		return -ESOCKTNOSUPPORT;

	sock->state = SS_UNCONNECTED;

	if ((sk = wanpipe_alloc_socket()) == NULL)
		return -ENOBUFS;

	sk->sk_reuse = 1;
	sock->ops = &wanpipe_ops;
	sock_init_data(sock,sk);

	sock_reset_flag(sk, SOCK_ZAPPED);
	sk->sk_family	    = PF_WANPIPE;
	wp_sk(sk)->num	    = protocol;
	sk->sk_state	    = WANSOCK_DISCONNECTED;
	sk->sk_ack_backlog  = 0;
	sk->sk_bound_dev_if = 0;

	atomic_inc(&wanpipe_socks_nr);
	
	/* We must disable interrupts because the ISR
	 * can also change the list */
	set_bit(1,&wanpipe_tx_critical);
	write_lock(&wanpipe_sklist_lock);
	sk_add_node(sk, &wanpipe_sklist);
	write_unlock(&wanpipe_sklist_lock);
	clear_bit(1,&wanpipe_tx_critical);

	return(0);
}


/*============================================================
 *  wanpipe_recvmsg
 *	
 *	Pull a packet from our receive queue and hand it 
 *      to the user. If necessary we block.
 *===========================================================*/

static int wanpipe_recvmsg(struct kiocb *iocb, struct socket *sock,
			   struct msghdr *msg, int len, int flags)
{
	struct sock *sk = sock->sk;
	struct sk_buff *skb;
	int copied, err=-ENOBUFS;


	/*
	 *	If the address length field is there to be filled in, we fill
	 *	it in now.
	 */

	msg->msg_namelen = sizeof(struct wan_sockaddr_ll);

	/*
	 *	Call the generic datagram receiver. This handles all sorts
	 *	of horrible races and re-entrancy so we can forget about it
	 *	in the protocol layers.
	 *
	 *	Now it will return ENETDOWN, if device have just gone down,
	 *	but then it will block.
	 */

	if (flags & MSG_OOB){	
		skb = skb_dequeue(&sk->sk_error_queue);
	}else{
		skb=skb_recv_datagram(sk,flags,1,&err);
	}
	/*
	 *	An error occurred so return it. Because skb_recv_datagram() 
	 *	handles the blocking we don't see and worry about blocking
	 *	retries.
	 */

	if(skb==NULL)
		goto out;

	/*
	 *	You lose any data beyond the buffer you gave. If it worries a
	 *	user program they can ask the device for its MTU anyway.
	 */

	copied = skb->len;
	if (copied > len)
	{
		copied=len;
		msg->msg_flags|=MSG_TRUNC;
	}

	wanpipe_wakeup_driver(sk);

	/* We can't use skb_copy_datagram here */
	err = memcpy_toiovec(msg->msg_iov, skb->data, copied);
	if (err)
		goto out_free;
	
	sock_recv_timestamp(msg, sk, skb);
	
	if (msg->msg_name)
		memcpy(msg->msg_name, skb->cb, msg->msg_namelen);

	/*
	 *	Free or return the buffer as appropriate. Again this
	 *	hides all the races and re-entrancy issues from us.
	 */
	err = (flags&MSG_TRUNC) ? skb->len : copied;

out_free:
	skb_free_datagram(sk, skb);
out:
	return err;
}


/*============================================================
 *  wanpipe_wakeup_driver
 *	
 * 	If socket receive buffer is full and driver cannot
 *      pass data up the sock, it sets a packet_block flag.
 *      This function check that flag and if sock receive 
 *      queue has room it kicks the driver BH handler. 
 *
 * 	This way, driver doesn't have to poll the sock 
 *      receive queue.
 *===========================================================*/

static void wanpipe_wakeup_driver(struct sock *sk)
{
	struct net_device *dev = NULL;
	wanpipe_common_t *chan=NULL;

	dev = dev_get_by_index(sk->sk_bound_dev_if);
	if (!dev)
		return;

	dev_put(dev);

	if ((chan = dev->priv) == NULL)
		return;
	
	if (atomic_read(&chan->receive_block)){  
		if (atomic_read(&sk->sk_rmem_alloc) <
		    ((unsigned)sk->sk_rcvbuf * 0.9)) {
			printk(KERN_INFO "wansock: Queuing task for wanpipe\n");
			atomic_set(&chan->receive_block,0);
			wanpipe_queue_tq(&chan->wanpipe_task);
			wanpipe_mark_bh();
		}
	}	
}	

/*============================================================
 *  wanpipe_getname
 *	
 * 	I don't know what to do with this yet. 
 *      User can use this function to get sock address
 *      information. Not very useful for Sangoma's purposes.
 *===========================================================*/


static int wanpipe_getname(struct socket *sock, struct sockaddr *uaddr,
			  int *uaddr_len, int peer)
{
	struct net_device *dev;
	struct sock *sk = sock->sk;
	struct wan_sockaddr_ll *sll = (struct wan_sockaddr_ll*)uaddr;

	sll->sll_family = AF_WANPIPE;
	sll->sll_ifindex = sk->sk_bound_dev_if;
	sll->sll_protocol = wp_sk(sk)->num;
	dev = dev_get_by_index(sk->sk_bound_dev_if);
	if (dev) {
		sll->sll_hatype = dev->type;
		sll->sll_halen = dev->addr_len;
		memcpy(sll->sll_addr, dev->dev_addr, dev->addr_len);
	} else {
		sll->sll_hatype = 0;	/* Bad: we have no ARPHRD_UNSPEC */
		sll->sll_halen = 0;
	}
	*uaddr_len = sizeof(*sll);
	
	dev_put(dev);
	
	return 0;
}

/*============================================================
 *  wanpipe_notifier
 *	
 *	If driver turns off network interface, this function
 *      will be envoked. Currently I treate it as a 
 *      call disconnect. More thought should go into this
 *      function.
 *
 * FIXME: More thought should go into this function.
 *
 *===========================================================*/

static int wanpipe_notifier(struct notifier_block *this, unsigned long msg, void *data)
{
	struct sock *sk;
	hlist_node *node;
	struct net_device *dev = (struct net_device *)data;

	sk_for_each(sk, node, &wanpipe_sklist) {
		struct wanpipe_opt *po = wp_sk(sk);

		if (!po)
			continue;
		if (dev == NULL)
			continue;
		
		switch (msg) {
		case NETDEV_DOWN:
		case NETDEV_UNREGISTER:
			if (dev->ifindex == sk->sk_bound_dev_if) {
				printk(KERN_INFO "wansock: Device down %s\n",dev->name);
				if (sock_flag(sk, SOCK_ZAPPED)) {
					wanpipe_unlink_driver(sk);
					sk->sk_err = ENETDOWN;
					sk->sk_error_report(sk);
				}

				if (msg == NETDEV_UNREGISTER) {
					printk(KERN_INFO "wansock: Unregistering Device: %s\n",
						 	  dev->name);
					wanpipe_unlink_driver(sk);
					sk->sk_bound_dev_if = 0;
				}
			}
			break;
		case NETDEV_UP:
			if (dev->ifindex == sk->sk_bound_dev_if &&
			    po->num && !sock_flag(sk, SOCK_ZAPPED)) {
				printk(KERN_INFO "wansock: Registering Device: %s\n",
						dev->name);
				wanpipe_link_driver(dev,sk);
			}
			break;
		}
	}
	return NOTIFY_DONE;
}

/*============================================================
 *  wanpipe_ioctl
 *	
 * 	Execute a user commands, and set socket options.
 *
 * FIXME: More thought should go into this function.
 *
 *===========================================================*/

static int wanpipe_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
{
	struct sock *sk = sock->sk;
	int err;

	switch(cmd) 
	{
		case SIOCGSTAMP:
			return sock_get_timestamp(sk, (struct timeval __user *)arg);

		case SIOC_WANPIPE_CHECK_TX:

			return atomic_read(&sk->sk_wmem_alloc);

		case SIOC_WANPIPE_SOCK_STATE:

			if (sk->sk_state == WANSOCK_CONNECTED)
				return 0;
			
			return 1;


		case SIOC_WANPIPE_GET_CALL_DATA:

			return get_ioctl_cmd (sk,(void*)arg);

		case SIOC_WANPIPE_SET_CALL_DATA:

			return set_ioctl_cmd (sk,(void*)arg);

		case SIOC_WANPIPE_ACCEPT_CALL:
		case SIOC_WANPIPE_CLEAR_CALL:
		case SIOC_WANPIPE_RESET_CALL:

			if ((err=set_ioctl_cmd(sk,(void*)arg)) < 0)
				return err;

			err=wanpipe_exec_cmd(sk,cmd,0);
			get_ioctl_cmd(sk,(void*)arg);
			return err;

		case SIOC_WANPIPE_DEBUG:

			return wanpipe_debug(sk,(void*)arg);
	
		case SIOC_WANPIPE_SET_NONBLOCK:

			if (sk->sk_state != WANSOCK_DISCONNECTED)
				return -EINVAL;

			sock->file->f_flags |= O_NONBLOCK;
			return 0;
	
#ifdef CONFIG_INET
		case SIOCADDRT:
		case SIOCDELRT:
		case SIOCDARP:
		case SIOCGARP:
		case SIOCSARP:
		case SIOCDRARP:
		case SIOCGRARP:
		case SIOCSRARP:
		case SIOCGIFADDR:
		case SIOCSIFADDR:
		case SIOCGIFBRDADDR:
		case SIOCSIFBRDADDR:
		case SIOCGIFNETMASK:
		case SIOCSIFNETMASK:
		case SIOCGIFDSTADDR:
		case SIOCSIFDSTADDR:
		case SIOCSIFFLAGS:
			return inet_dgram_ops.ioctl(sock, cmd, arg);
#endif

		default:
			return -ENOIOCTLCMD;
	}
	/*NOTREACHED*/
}

/*============================================================
 *  wanpipe_debug
 *	
 *	This function will pass up information about all
 *      active sockets.
 *
 * FIXME: More thought should go into this function.
 *
 *===========================================================*/

static int wanpipe_debug (struct sock *origsk, void *arg)
{
	struct sock *sk;
	struct hlist_node *node;
	struct net_device *dev = NULL;
	wanpipe_common_t *chan=NULL;
	int cnt=0, err=0;
	wan_debug_t *dbg_data = (wan_debug_t *)arg;

	sk_for_each(sk, node, &wanpipe_sklist) {
		wanpipe_opt *wp = wp_sk(sk);

		if (sk == origsk){
			continue;
		}

		if ((err=put_user(1, &dbg_data->debug[cnt].free)))
			return err;
		if ((err = put_user(sk->sk_state,
				    &dbg_data->debug[cnt].state_sk)))
			return err;
		if ((err = put_user(sk->sk_rcvbuf,
				    &dbg_data->debug[cnt].rcvbuf)))
			return err;
		if ((err = put_user(atomic_read(&sk->sk_rmem_alloc),
				    &dbg_data->debug[cnt].rmem)))
			return err;
		if ((err = put_user(atomic_read(&sk->sk_wmem_alloc),
				    &dbg_data->debug[cnt].wmem)))
			return err;
		if ((err = put_user(sk->sk_sndbuf,
				    &dbg_data->debug[cnt].sndbuf)))
			return err;
		if ((err=put_user(sk_count, &dbg_data->debug[cnt].sk_count)))
			return err;
		if ((err=put_user(wp->poll_cnt, &dbg_data->debug[cnt].poll_cnt)))
			return err;
		if ((err = put_user(sk->sk_bound_dev_if,
				    &dbg_data->debug[cnt].bound)))
			return err;

		if (sk->sk_bound_dev_if) {
			dev = dev_get_by_index(sk->sk_bound_dev_if);
			if (!dev)	
				continue;

			chan=dev->priv;
			dev_put(dev);
	
			if ((err=put_user(chan->state, &dbg_data->debug[cnt].d_state)))
				return err;
			if ((err=put_user(chan->svc, &dbg_data->debug[cnt].svc)))
				return err;

			if ((err=put_user(atomic_read(&chan->command), 
						&dbg_data->debug[cnt].command)))
				return err;


			if (wp){
				sdla_t *card = (sdla_t*)wp->card;			
	
				if (card){
					if ((err=put_user(atomic_read(&card->u.x.command_busy), 
								&dbg_data->debug[cnt].cmd_busy)))
						return err;
				}

				if ((err=put_user(wp->lcn, 
						  &dbg_data->debug[cnt].lcn)))
					return err;
				
				if (wp->mbox) {
					if ((err=put_user(1, &dbg_data->debug[cnt].mbox)))
						return err;
				}
			}

			if ((err=put_user(atomic_read(&chan->receive_block), 
								&dbg_data->debug[cnt].rblock)))
				return err;

			if (copy_to_user(dbg_data->debug[cnt].name, dev->name, strlen(dev->name)))
				return -EFAULT;
		}
	
		if (++cnt == MAX_NUM_DEBUG)
			break;
	}
	return 0;
}

/*============================================================
 *  get_ioctl_cmd
 *	
 *	Pass up the contents of socket MBOX to the user.
 *===========================================================*/

static int get_ioctl_cmd (struct sock *sk, void *arg)
{
	x25api_t *usr_data = (x25api_t *)arg;
	mbox_cmd_t *mbox_ptr;
	int err;

	if (usr_data == NULL)
		return -EINVAL;

	if (!wp_sk(sk)->mbox) {
		return -EINVAL;
	}

	mbox_ptr = (mbox_cmd_t *)wp_sk(sk)->mbox;

	if ((err=put_user(mbox_ptr->cmd.qdm, &usr_data->hdr.qdm)))
		return err;
	if ((err=put_user(mbox_ptr->cmd.cause, &usr_data->hdr.cause)))
		return err;
	if ((err=put_user(mbox_ptr->cmd.diagn, &usr_data->hdr.diagn)))
		return err;
	if ((err=put_user(mbox_ptr->cmd.length, &usr_data->hdr.length)))
		return err;
	if ((err=put_user(mbox_ptr->cmd.result, &usr_data->hdr.result)))
		return err;
	if ((err=put_user(mbox_ptr->cmd.lcn, &usr_data->hdr.lcn)))
		return err;	

	if (mbox_ptr->cmd.length > 0){
		if (mbox_ptr->cmd.length > X25_MAX_DATA)
			return -EINVAL;

		if (copy_to_user(usr_data->data, mbox_ptr->data, mbox_ptr->cmd.length)){
			printk(KERN_INFO "wansock: Copy failed !!!\n");
			return -EFAULT;
		}
	}
	return 0;
} 

/*============================================================
 *  set_ioctl_cmd
 *	
 *	Before command can be execute, socket MBOX must
 *      be created, and initialized with user data.	
 *===========================================================*/

static int set_ioctl_cmd (struct sock *sk, void *arg)
{
	x25api_t *usr_data = (x25api_t *)arg;
	mbox_cmd_t *mbox_ptr;
	int err;

	if (!wp_sk(sk)->mbox) {
		void *mbox_ptr;
		struct net_device *dev = dev_get_by_index(sk->sk_bound_dev_if);
		if (!dev)
			return -ENODEV;

		dev_put(dev);
		
		if ((mbox_ptr = kmalloc(sizeof(mbox_cmd_t), GFP_ATOMIC)) == NULL)
			return -ENOMEM;

		memset(mbox_ptr, 0, sizeof(mbox_cmd_t));
		wp_sk(sk)->mbox = mbox_ptr;

		wanpipe_link_driver(dev,sk);
	}

	mbox_ptr = (mbox_cmd_t*)wp_sk(sk)->mbox;
	memset(mbox_ptr, 0, sizeof(mbox_cmd_t));

	if (usr_data == NULL){
		return 0;
	}
	if ((err=get_user(mbox_ptr->cmd.qdm, &usr_data->hdr.qdm)))
		return err;
	if ((err=get_user(mbox_ptr->cmd.cause, &usr_data->hdr.cause)))
		return err;
	if ((err=get_user(mbox_ptr->cmd.diagn, &usr_data->hdr.diagn)))
		return err;
	if ((err=get_user(mbox_ptr->cmd.length, &usr_data->hdr.length)))
		return err;
	if ((err=get_user(mbox_ptr->cmd.result, &usr_data->hdr.result)))
		return err;

	if (mbox_ptr->cmd.length > 0){
		if (mbox_ptr->cmd.length > X25_MAX_DATA)
			return -EINVAL;

		if (copy_from_user(mbox_ptr->data, usr_data->data, mbox_ptr->cmd.length)){
			printk(KERN_INFO "Copy failed\n");
			return -EFAULT;
		}
	}
	return 0;
}


/*======================================================================
 * wanpipe_poll
 *
 *	Datagram poll: Again totally generic. This also handles
 *	sequenced packet sockets providing the socket receive queue
 *	is only ever holding data ready to receive.
 *
 *	Note: when you _don't_ use this routine for this protocol,
 *	and you use a different write policy from sock_writeable()
 *	then please supply your own write_space callback.
 *=====================================================================*/

unsigned int wanpipe_poll(struct file * file, struct socket *sock, poll_table *wait)
{
	struct sock *sk = sock->sk;
	unsigned int mask;

	++wp_sk(sk)->poll_cnt;

	poll_wait(file, sk->sk_sleep, wait);
	mask = 0;

	/* exceptional events? */
	if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue)) {
		mask |= POLLPRI;
		return mask;
	}
	if (sk->sk_shutdown & RCV_SHUTDOWN)
		mask |= POLLHUP;

	/* readable? */
	if (!skb_queue_empty(&sk->sk_receive_queue)) {
		mask |= POLLIN | POLLRDNORM;
	}

	/* connection hasn't started yet */
	if (sk->sk_state == WANSOCK_CONNECTING) {
		return mask;
	}

	if (sk->sk_state == WANSOCK_DISCONNECTED) {
		mask = POLLPRI;
		return mask;
	}

	/* This check blocks the user process if there is   
	 * a packet already queued in the socket write queue.
         * This option is only for X25API protocol, for other
         * protocol like chdlc enable streaming mode, 
         * where multiple packets can be pending in the socket 
         * transmit queue */

	if (wp_sk(sk)->num == htons(X25_PROT)) {
		if (atomic_read(&wp_sk(sk)->packet_sent))
			return mask;
	}

	/* writable? */
	if (sock_writeable(sk)){
		mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
	}else{
		set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
	}
		
	return mask;
}

/*======================================================================
 * wanpipe_listen
 *
 *	X25API Specific function. Set a socket into LISTENING  MODE.
 *=====================================================================*/


static int wanpipe_listen(struct socket *sock, int backlog)
{
	struct sock *sk = sock->sk;

 	/* This is x25 specific area if protocol doesn't
         * match, return error */
	if (wp_sk(sk)->num != htons(X25_PROT))
		return -EINVAL;

	if (sk->sk_state == WANSOCK_BIND_LISTEN) {

		sk->sk_max_ack_backlog = backlog;
		sk->sk_state           = WANSOCK_LISTEN;
		return 0;
	}else{
		printk(KERN_INFO "wansock: Listening sock was not binded\n");
	}

	return -EINVAL;
}

/*======================================================================
 * wanpipe_link_card
 *
 *	Connects the listening socket to the driver
 *=====================================================================*/

static int wanpipe_link_card (struct sock *sk)
{
	sdla_t *card = (sdla_t*)wp_sk(sk)->card;

	if (!card)
		return -ENOMEM;

	if ((card->sk != NULL) || (card->func != NULL)){
		printk(KERN_INFO "wansock: Listening queue is already established\n");
		return -EINVAL;
	}

	card->sk=sk;
	card->func=wanpipe_listen_rcv;
	sock_set_flag(sk, SOCK_ZAPPED);
 
	return 0;
}

/*======================================================================
 * wanpipe_listen
 *
 *	X25API Specific function. Disconnect listening socket from
 *      the driver.
 *=====================================================================*/

static void wanpipe_unlink_card (struct sock *sk)
{
	sdla_t *card = (sdla_t*)wp_sk(sk)->card; 

	if (card){
		card->sk=NULL;
		card->func=NULL;
	}
}

/*======================================================================
 * wanpipe_exec_cmd
 *
 *	Ioctl function calls this function to execute user command.
 *      Connect() sytem call also calls this function to execute
 *      place call.  This function blocks until command is executed.
 *=====================================================================*/

static int wanpipe_exec_cmd(struct sock *sk, int cmd, unsigned int flags)
{
	int err = -EINVAL;
	wanpipe_opt *wp = wp_sk(sk);
	mbox_cmd_t *mbox_ptr = (mbox_cmd_t*)wp->mbox;

	if (!mbox_ptr){
		printk(KERN_INFO "NO MBOX PTR !!!!!\n");
		return -EINVAL;
	}
	
	/* This is x25 specific area if protocol doesn't
         * match, return error */
	if (wp->num != htons(X25_PROT))
		return -EINVAL;


	switch (cmd){

		case SIOC_WANPIPE_ACCEPT_CALL:

			if (sk->sk_state != WANSOCK_CONNECTING) {
				err = -EHOSTDOWN;
				break;
			}
			
			err = execute_command(sk,X25_ACCEPT_CALL,0);
			if (err < 0)
				break;

			/* Update. Mar6 2000. 
                         * Do not set the sock lcn number here, since
                         * it is done in wanpipe_listen_rcv(). 
                         */ 
		 	if (sk->sk_state == WANSOCK_CONNECTED) {
				wp->lcn = ((mbox_cmd_t*)wp->mbox)->cmd.lcn;	
				DBG_PRINTK(KERN_INFO "\nwansock: Accept OK %i\n",
					wp->lcn);
				err = 0;

			}else{
				DBG_PRINTK (KERN_INFO "\nwansock: Accept Failed %i\n",
					wp->lcn);
				wp->lcn = 0;
				err = -ECONNREFUSED;
			}
			break;

		case SIOC_WANPIPE_CLEAR_CALL:

			if (sk->sk_state == WANSOCK_DISCONNECTED) {
				err = -EINVAL;
				break;
			}


			/* Check if data buffers are pending for transmission,
                         * if so, check whether user wants to wait until data
                         * is transmitted, or clear a call and drop packets */
                          
			if (atomic_read(&sk->sk_wmem_alloc) ||
			    check_driver_busy(sk)) {
			  	mbox_cmd_t *mbox = wp->mbox;
				if (mbox->cmd.qdm & 0x80){
					mbox->cmd.result = 0x35;
					err = -EAGAIN;	
					break;
				}
			}

			sk->sk_state = WANSOCK_DISCONNECTING;

			err = execute_command(sk,X25_CLEAR_CALL,0);
			if (err < 0)
				break;

			err = -ECONNREFUSED;
			if (sk->sk_state == WANSOCK_DISCONNECTED) {
				DBG_PRINTK(KERN_INFO "\nwansock: CLEAR OK %i\n",
					   wp->lcn);
				wp->lcn = 0;
				err = 0;
			}
			break;

		case SIOC_WANPIPE_RESET_CALL:

			if (sk->sk_state != WANSOCK_CONNECTED) {
				err = -EINVAL;
				break;
			}


			/* Check if data buffers are pending for transmission,
                         * if so, check whether user wants to wait until data
                         * is transmitted, or reset a call and drop packets */
                          
			if (atomic_read(&sk->sk_wmem_alloc) ||
			    check_driver_busy(sk)) {
			  	mbox_cmd_t *mbox = wp->mbox;
				if (mbox->cmd.qdm & 0x80){
					mbox->cmd.result = 0x35;
					err = -EAGAIN;	
					break;
				}
			}


			err = execute_command(sk, X25_RESET,0);
			if (err < 0)
				break;

			err = mbox_ptr->cmd.result;
			break;


		case X25_PLACE_CALL:

			err=execute_command(sk,X25_PLACE_CALL,flags);
			if (err < 0)
				break;

			if (sk->sk_state == WANSOCK_CONNECTED) {

				wp->lcn = ((mbox_cmd_t*)wp->mbox)->cmd.lcn;	

				DBG_PRINTK(KERN_INFO "\nwansock: PLACE CALL OK %i\n",
					wp->lcn);
				err = 0;

			} else if (sk->sk_state == WANSOCK_CONNECTING &&
				   (flags & O_NONBLOCK)) {
				wp->lcn = ((mbox_cmd_t*)wp->mbox)->cmd.lcn;
				DBG_PRINTK(KERN_INFO "\nwansock: Place Call OK: Waiting %i\n",
					wp->lcn);

				err = 0;

			}else{
				DBG_PRINTK(KERN_INFO "\nwansock: Place call Failed\n");
				err = -ECONNREFUSED;
			}

			break;

		default: 
			return -EINVAL;
	}

	return err;
}

static int check_driver_busy (struct sock *sk)
{
	struct net_device *dev = dev_get_by_index(sk->sk_bound_dev_if);
	wanpipe_common_t *chan;

	if (!dev)
		return 0;

	dev_put(dev);

	if ((chan=dev->priv) == NULL)
		return 0;

	return atomic_read(&chan->driver_busy);
}


/*======================================================================
 * wanpipe_accept
 *
 *	ACCEPT() System call.	X25API Specific function. 
 *	For each incoming call, create a new socket and 
 *      return it to the user.	
 *=====================================================================*/

static int wanpipe_accept(struct socket *sock, struct socket *newsock, int flags)
{
	struct sock *sk;
	struct sock *newsk;
	struct sk_buff *skb;
	DECLARE_WAITQUEUE(wait, current);
	int err=0;

	if (newsock->sk != NULL){
		wanpipe_kill_sock_accept(newsock->sk);	
		newsock->sk=NULL;
	}
	
	if ((sk = sock->sk) == NULL)
		return -EINVAL;

	if (sk->sk_type != SOCK_RAW)
		return -EOPNOTSUPP;

	if (sk->sk_state != WANSOCK_LISTEN)
		return -EINVAL;

	if (wp_sk(sk)->num != htons(X25_PROT))
		return -EINVAL;

	add_wait_queue(sk->sk_sleep,&wait);
	current->state = TASK_INTERRUPTIBLE;
	for (;;){
		skb = skb_dequeue(&sk->sk_receive_queue);
		if (skb){
			err=0;
			break;
		}
		if (signal_pending(current)) {
			err = -ERESTARTSYS;
			break;
		}
		schedule();
	}
	current->state = TASK_RUNNING;
	remove_wait_queue(sk->sk_sleep,&wait);
	
	if (err != 0)
		return err;
	
	newsk = get_newsk_from_skb(skb);
	if (!newsk){
		return -EINVAL;
	}

	set_bit(1,&wanpipe_tx_critical);
	write_lock(&wanpipe_sklist_lock);
	sk_add_node(newsk, &wanpipe_sklist);
	write_unlock(&wanpipe_sklist_lock);
	clear_bit(1,&wanpipe_tx_critical);

	newsk->sk_socket = newsock;
	newsk->sk_sleep = &newsock->wait;

	/* Now attach up the new socket */
	sk->sk_ack_backlog--;
	newsock->sk = newsk;
	
	kfree_skb(skb);

	DBG_PRINTK(KERN_INFO "\nwansock: ACCEPT Got LCN %i\n",
		   wp_sk(newsk)->lcn);
	return 0;
}

/*======================================================================
 *  get_newsk_from_skb
 *
 *	Accept() uses this function to get the address of the new
 *      socket structure.
 *=====================================================================*/

struct sock * get_newsk_from_skb (struct sk_buff *skb)
{
	struct net_device *dev = skb->dev;
	wanpipe_common_t *chan;	

	if (!dev){
		return NULL;
	}
		
	if ((chan = dev->priv) == NULL){
		return NULL;
	}
		
	if (!chan->sk){
		return NULL;
	}
	return (struct sock *)chan->sk;
}

/*======================================================================
 *  wanpipe_connect
 *
 *  	CONNECT() System Call. X25API specific function
 * 	Check the state of the sock, and execute PLACE_CALL command.
 *      Connect can ether block or return without waiting for connection, 
 *      if specified by user.
 *=====================================================================*/

static int wanpipe_connect(struct socket *sock, struct sockaddr *uaddr, int addr_len, int flags)
{
	struct sock *sk = sock->sk;
	struct wan_sockaddr_ll *addr = (struct wan_sockaddr_ll*)uaddr;
	struct net_device *dev;
	int err;

	if (wp_sk(sk)->num != htons(X25_PROT))
		return -EINVAL;

	if (sk->sk_state == WANSOCK_CONNECTED)
		return -EISCONN;	/* No reconnect on a seqpacket socket */

	if (sk->sk_state != WAN_DISCONNECTED) {
		printk(KERN_INFO "wansock: Trying to connect on channel NON DISCONNECT\n");
		return -ECONNREFUSED;
	}

	sk->sk_state = WANSOCK_DISCONNECTED;	
	sock->state  = SS_UNCONNECTED;

	if (addr_len != sizeof(struct wan_sockaddr_ll))
		return -EINVAL;

	if (addr->sll_family != AF_WANPIPE)
		return -EINVAL;

	if ((dev = dev_get_by_index(sk->sk_bound_dev_if)) == NULL)
		return -ENETUNREACH;

	dev_put(dev);
	
	if (!sock_flag(sk, SOCK_ZAPPED)) /* Must bind first - autobinding does not work */
		return -EINVAL;

	sock->state   = SS_CONNECTING;
	sk->sk_state  = WANSOCK_CONNECTING;

	if (!wp_sk(sk)->mbox) {
		if (wp_sk (sk)->svc)
			return -EINVAL;
		else {
			int err;
			if ((err=set_ioctl_cmd(sk,NULL)) < 0)
				return err;
		}
	}

	if ((err=wanpipe_exec_cmd(sk, X25_PLACE_CALL,flags)) != 0){
		sock->state = SS_UNCONNECTED;
		sk->sk_state = WANSOCK_CONNECTED;
		return err;
	}

	if (sk->sk_state != WANSOCK_CONNECTED && (flags & O_NONBLOCK)) {
		return 0;
	}

	if (sk->sk_state != WANSOCK_CONNECTED) {
		sock->state = SS_UNCONNECTED;
		return -ECONNREFUSED; 
	}

	sock->state = SS_CONNECTED;
	return 0;
}

const struct proto_ops wanpipe_ops = {
	.family = 	PF_WANPIPE,
	.owner =	THIS_MODULE,
	.release = 	wanpipe_release,
	.bind = 	wanpipe_bind,
	.connect = 	wanpipe_connect,
	.socketpair = 	sock_no_socketpair,
	.accept = 	wanpipe_accept,
	.getname = 	wanpipe_getname, 
	.poll = 	wanpipe_poll,
	.ioctl = 	wanpipe_ioctl,
	.listen = 	wanpipe_listen, 
	.shutdown = 	sock_no_shutdown,
	.setsockopt = 	sock_no_setsockopt,
	.getsockopt = 	sock_no_getsockopt,
	.sendmsg = 	wanpipe_sendmsg,
	.recvmsg = 	wanpipe_recvmsg
};

static struct net_proto_family wanpipe_family_ops = {
	.family = PF_WANPIPE,
	.create = wanpipe_create,
	.owner	= THIS_MODULE,
};

struct notifier_block wanpipe_netdev_notifier = {
	.notifier_call = wanpipe_notifier,
};


#ifdef MODULE
void cleanup_module(void)
{
	printk(KERN_INFO "wansock: Cleaning up \n");
	unregister_netdevice_notifier(&wanpipe_netdev_notifier);
	sock_unregister(PF_WANPIPE);
	proto_unregister(&wanpipe_proto);
}

int init_module(void)
{
	int rc;

	printk(KERN_INFO "wansock: Registering Socket \n");

	rc = proto_register(&wanpipe_proto, 0);
	if (rc != 0)
		goto out;

	sock_register(&wanpipe_family_ops);
	register_netdevice_notifier(&wanpipe_netdev_notifier);
out:
	return rc;
}
#endif
MODULE_LICENSE("GPL");
MODULE_ALIAS_NETPROTO(PF_WANPIPE);