Free Electrons

Embedded Linux Experts

   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
/*
 *   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.
 *
 *   Robert Olsson <robert.olsson@its.uu.se> Uppsala Universitet
 *     & Swedish University of Agricultural Sciences.
 *
 *   Jens Laas <jens.laas@data.slu.se> Swedish University of
 *     Agricultural Sciences.
 *
 *   Hans Liss <hans.liss@its.uu.se>  Uppsala Universitet
 *
 * This work is based on the LPC-trie which is originally described in:
 *
 * An experimental study of compression methods for dynamic tries
 * Stefan Nilsson and Matti Tikkanen. Algorithmica, 33(1):19-33, 2002.
 * http://www.csc.kth.se/~snilsson/software/dyntrie2/
 *
 *
 * IP-address lookup using LC-tries. Stefan Nilsson and Gunnar Karlsson
 * IEEE Journal on Selected Areas in Communications, 17(6):1083-1092, June 1999
 *
 *
 * Code from fib_hash has been reused which includes the following header:
 *
 *
 * INET		An implementation of the TCP/IP protocol suite for the LINUX
 *		operating system.  INET is implemented using the  BSD Socket
 *		interface as the means of communication with the user level.
 *
 *		IPv4 FIB: lookup engine and maintenance routines.
 *
 *
 * Authors:	Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
 *
 *		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.
 *
 * Substantial contributions to this work comes from:
 *
 *		David S. Miller, <davem@davemloft.net>
 *		Stephen Hemminger <shemminger@osdl.org>
 *		Paul E. McKenney <paulmck@us.ibm.com>
 *		Patrick McHardy <kaber@trash.net>
 */

#define VERSION "0.409"

#include <linux/uaccess.h>
#include <linux/bitops.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/string.h>
#include <linux/socket.h>
#include <linux/sockios.h>
#include <linux/errno.h>
#include <linux/in.h>
#include <linux/inet.h>
#include <linux/inetdevice.h>
#include <linux/netdevice.h>
#include <linux/if_arp.h>
#include <linux/proc_fs.h>
#include <linux/rcupdate.h>
#include <linux/skbuff.h>
#include <linux/netlink.h>
#include <linux/init.h>
#include <linux/list.h>
#include <linux/slab.h>
#include <linux/export.h>
#include <linux/vmalloc.h>
#include <linux/notifier.h>
#include <net/net_namespace.h>
#include <net/ip.h>
#include <net/protocol.h>
#include <net/route.h>
#include <net/tcp.h>
#include <net/sock.h>
#include <net/ip_fib.h>
#include <net/fib_notifier.h>
#include <trace/events/fib.h>
#include "fib_lookup.h"

static int call_fib_entry_notifier(struct notifier_block *nb, struct net *net,
				   enum fib_event_type event_type, u32 dst,
				   int dst_len, struct fib_info *fi,
				   u8 tos, u8 type, u32 tb_id)
{
	struct fib_entry_notifier_info info = {
		.dst = dst,
		.dst_len = dst_len,
		.fi = fi,
		.tos = tos,
		.type = type,
		.tb_id = tb_id,
	};
	return call_fib4_notifier(nb, net, event_type, &info.info);
}

static int call_fib_entry_notifiers(struct net *net,
				    enum fib_event_type event_type, u32 dst,
				    int dst_len, struct fib_info *fi,
				    u8 tos, u8 type, u32 tb_id)
{
	struct fib_entry_notifier_info info = {
		.dst = dst,
		.dst_len = dst_len,
		.fi = fi,
		.tos = tos,
		.type = type,
		.tb_id = tb_id,
	};
	return call_fib4_notifiers(net, event_type, &info.info);
}

#define MAX_STAT_DEPTH 32

#define KEYLENGTH	(8*sizeof(t_key))
#define KEY_MAX		((t_key)~0)

typedef unsigned int t_key;

#define IS_TRIE(n)	((n)->pos >= KEYLENGTH)
#define IS_TNODE(n)	((n)->bits)
#define IS_LEAF(n)	(!(n)->bits)

struct key_vector {
	t_key key;
	unsigned char pos;		/* 2log(KEYLENGTH) bits needed */
	unsigned char bits;		/* 2log(KEYLENGTH) bits needed */
	unsigned char slen;
	union {
		/* This list pointer if valid if (pos | bits) == 0 (LEAF) */
		struct hlist_head leaf;
		/* This array is valid if (pos | bits) > 0 (TNODE) */
		struct key_vector __rcu *tnode[0];
	};
};

struct tnode {
	struct rcu_head rcu;
	t_key empty_children;		/* KEYLENGTH bits needed */
	t_key full_children;		/* KEYLENGTH bits needed */
	struct key_vector __rcu *parent;
	struct key_vector kv[1];
#define tn_bits kv[0].bits
};

#define TNODE_SIZE(n)	offsetof(struct tnode, kv[0].tnode[n])
#define LEAF_SIZE	TNODE_SIZE(1)

#ifdef CONFIG_IP_FIB_TRIE_STATS
struct trie_use_stats {
	unsigned int gets;
	unsigned int backtrack;
	unsigned int semantic_match_passed;
	unsigned int semantic_match_miss;
	unsigned int null_node_hit;
	unsigned int resize_node_skipped;
};
#endif

struct trie_stat {
	unsigned int totdepth;
	unsigned int maxdepth;
	unsigned int tnodes;
	unsigned int leaves;
	unsigned int nullpointers;
	unsigned int prefixes;
	unsigned int nodesizes[MAX_STAT_DEPTH];
};

struct trie {
	struct key_vector kv[1];
#ifdef CONFIG_IP_FIB_TRIE_STATS
	struct trie_use_stats __percpu *stats;
#endif
};

static struct key_vector *resize(struct trie *t, struct key_vector *tn);
static size_t tnode_free_size;

/*
 * synchronize_rcu after call_rcu for that many pages; it should be especially
 * useful before resizing the root node with PREEMPT_NONE configs; the value was
 * obtained experimentally, aiming to avoid visible slowdown.
 */
static const int sync_pages = 128;

static struct kmem_cache *fn_alias_kmem __read_mostly;
static struct kmem_cache *trie_leaf_kmem __read_mostly;

static inline struct tnode *tn_info(struct key_vector *kv)
{
	return container_of(kv, struct tnode, kv[0]);
}

/* caller must hold RTNL */
#define node_parent(tn) rtnl_dereference(tn_info(tn)->parent)
#define get_child(tn, i) rtnl_dereference((tn)->tnode[i])

/* caller must hold RCU read lock or RTNL */
#define node_parent_rcu(tn) rcu_dereference_rtnl(tn_info(tn)->parent)
#define get_child_rcu(tn, i) rcu_dereference_rtnl((tn)->tnode[i])

/* wrapper for rcu_assign_pointer */
static inline void node_set_parent(struct key_vector *n, struct key_vector *tp)
{
	if (n)
		rcu_assign_pointer(tn_info(n)->parent, tp);
}

#define NODE_INIT_PARENT(n, p) RCU_INIT_POINTER(tn_info(n)->parent, p)

/* This provides us with the number of children in this node, in the case of a
 * leaf this will return 0 meaning none of the children are accessible.
 */
static inline unsigned long child_length(const struct key_vector *tn)
{
	return (1ul << tn->bits) & ~(1ul);
}

#define get_cindex(key, kv) (((key) ^ (kv)->key) >> (kv)->pos)

static inline unsigned long get_index(t_key key, struct key_vector *kv)
{
	unsigned long index = key ^ kv->key;

	if ((BITS_PER_LONG <= KEYLENGTH) && (KEYLENGTH == kv->pos))
		return 0;

	return index >> kv->pos;
}

/* To understand this stuff, an understanding of keys and all their bits is
 * necessary. Every node in the trie has a key associated with it, but not
 * all of the bits in that key are significant.
 *
 * Consider a node 'n' and its parent 'tp'.
 *
 * If n is a leaf, every bit in its key is significant. Its presence is
 * necessitated by path compression, since during a tree traversal (when
 * searching for a leaf - unless we are doing an insertion) we will completely
 * ignore all skipped bits we encounter. Thus we need to verify, at the end of
 * a potentially successful search, that we have indeed been walking the
 * correct key path.
 *
 * Note that we can never "miss" the correct key in the tree if present by
 * following the wrong path. Path compression ensures that segments of the key
 * that are the same for all keys with a given prefix are skipped, but the
 * skipped part *is* identical for each node in the subtrie below the skipped
 * bit! trie_insert() in this implementation takes care of that.
 *
 * if n is an internal node - a 'tnode' here, the various parts of its key
 * have many different meanings.
 *
 * Example:
 * _________________________________________________________________
 * | i | i | i | i | i | i | i | N | N | N | S | S | S | S | S | C |
 * -----------------------------------------------------------------
 *  31  30  29  28  27  26  25  24  23  22  21  20  19  18  17  16
 *
 * _________________________________________________________________
 * | C | C | C | u | u | u | u | u | u | u | u | u | u | u | u | u |
 * -----------------------------------------------------------------
 *  15  14  13  12  11  10   9   8   7   6   5   4   3   2   1   0
 *
 * tp->pos = 22
 * tp->bits = 3
 * n->pos = 13
 * n->bits = 4
 *
 * First, let's just ignore the bits that come before the parent tp, that is
 * the bits from (tp->pos + tp->bits) to 31. They are *known* but at this
 * point we do not use them for anything.
 *
 * The bits from (tp->pos) to (tp->pos + tp->bits - 1) - "N", above - are the
 * index into the parent's child array. That is, they will be used to find
 * 'n' among tp's children.
 *
 * The bits from (n->pos + n->bits) to (tp->pos - 1) - "S" - are skipped bits
 * for the node n.
 *
 * All the bits we have seen so far are significant to the node n. The rest
 * of the bits are really not needed or indeed known in n->key.
 *
 * The bits from (n->pos) to (n->pos + n->bits - 1) - "C" - are the index into
 * n's child array, and will of course be different for each child.
 *
 * The rest of the bits, from 0 to (n->pos -1) - "u" - are completely unknown
 * at this point.
 */

static const int halve_threshold = 25;
static const int inflate_threshold = 50;
static const int halve_threshold_root = 15;
static const int inflate_threshold_root = 30;

static void __alias_free_mem(struct rcu_head *head)
{
	struct fib_alias *fa = container_of(head, struct fib_alias, rcu);
	kmem_cache_free(fn_alias_kmem, fa);
}

static inline void alias_free_mem_rcu(struct fib_alias *fa)
{
	call_rcu(&fa->rcu, __alias_free_mem);
}

#define TNODE_KMALLOC_MAX \
	ilog2((PAGE_SIZE - TNODE_SIZE(0)) / sizeof(struct key_vector *))
#define TNODE_VMALLOC_MAX \
	ilog2((SIZE_MAX - TNODE_SIZE(0)) / sizeof(struct key_vector *))

static void __node_free_rcu(struct rcu_head *head)
{
	struct tnode *n = container_of(head, struct tnode, rcu);

	if (!n->tn_bits)
		kmem_cache_free(trie_leaf_kmem, n);
	else
		kvfree(n);
}

#define node_free(n) call_rcu(&tn_info(n)->rcu, __node_free_rcu)

static struct tnode *tnode_alloc(int bits)
{
	size_t size;

	/* verify bits is within bounds */
	if (bits > TNODE_VMALLOC_MAX)
		return NULL;

	/* determine size and verify it is non-zero and didn't overflow */
	size = TNODE_SIZE(1ul << bits);

	if (size <= PAGE_SIZE)
		return kzalloc(size, GFP_KERNEL);
	else
		return vzalloc(size);
}

static inline void empty_child_inc(struct key_vector *n)
{
	++tn_info(n)->empty_children ? : ++tn_info(n)->full_children;
}

static inline void empty_child_dec(struct key_vector *n)
{
	tn_info(n)->empty_children-- ? : tn_info(n)->full_children--;
}

static struct key_vector *leaf_new(t_key key, struct fib_alias *fa)
{
	struct key_vector *l;
	struct tnode *kv;

	kv = kmem_cache_alloc(trie_leaf_kmem, GFP_KERNEL);
	if (!kv)
		return NULL;

	/* initialize key vector */
	l = kv->kv;
	l->key = key;
	l->pos = 0;
	l->bits = 0;
	l->slen = fa->fa_slen;

	/* link leaf to fib alias */
	INIT_HLIST_HEAD(&l->leaf);
	hlist_add_head(&fa->fa_list, &l->leaf);

	return l;
}

static struct key_vector *tnode_new(t_key key, int pos, int bits)
{
	unsigned int shift = pos + bits;
	struct key_vector *tn;
	struct tnode *tnode;

	/* verify bits and pos their msb bits clear and values are valid */
	BUG_ON(!bits || (shift > KEYLENGTH));

	tnode = tnode_alloc(bits);
	if (!tnode)
		return NULL;

	pr_debug("AT %p s=%zu %zu\n", tnode, TNODE_SIZE(0),
		 sizeof(struct key_vector *) << bits);

	if (bits == KEYLENGTH)
		tnode->full_children = 1;
	else
		tnode->empty_children = 1ul << bits;

	tn = tnode->kv;
	tn->key = (shift < KEYLENGTH) ? (key >> shift) << shift : 0;
	tn->pos = pos;
	tn->bits = bits;
	tn->slen = pos;

	return tn;
}

/* Check whether a tnode 'n' is "full", i.e. it is an internal node
 * and no bits are skipped. See discussion in dyntree paper p. 6
 */
static inline int tnode_full(struct key_vector *tn, struct key_vector *n)
{
	return n && ((n->pos + n->bits) == tn->pos) && IS_TNODE(n);
}

/* Add a child at position i overwriting the old value.
 * Update the value of full_children and empty_children.
 */
static void put_child(struct key_vector *tn, unsigned long i,
		      struct key_vector *n)
{
	struct key_vector *chi = get_child(tn, i);
	int isfull, wasfull;

	BUG_ON(i >= child_length(tn));

	/* update emptyChildren, overflow into fullChildren */
	if (!n && chi)
		empty_child_inc(tn);
	if (n && !chi)
		empty_child_dec(tn);

	/* update fullChildren */
	wasfull = tnode_full(tn, chi);
	isfull = tnode_full(tn, n);

	if (wasfull && !isfull)
		tn_info(tn)->full_children--;
	else if (!wasfull && isfull)
		tn_info(tn)->full_children++;

	if (n && (tn->slen < n->slen))
		tn->slen = n->slen;

	rcu_assign_pointer(tn->tnode[i], n);
}

static void update_children(struct key_vector *tn)
{
	unsigned long i;

	/* update all of the child parent pointers */
	for (i = child_length(tn); i;) {
		struct key_vector *inode = get_child(tn, --i);

		if (!inode)
			continue;

		/* Either update the children of a tnode that
		 * already belongs to us or update the child
		 * to point to ourselves.
		 */
		if (node_parent(inode) == tn)
			update_children(inode);
		else
			node_set_parent(inode, tn);
	}
}

static inline void put_child_root(struct key_vector *tp, t_key key,
				  struct key_vector *n)
{
	if (IS_TRIE(tp))
		rcu_assign_pointer(tp->tnode[0], n);
	else
		put_child(tp, get_index(key, tp), n);
}

static inline void tnode_free_init(struct key_vector *tn)
{
	tn_info(tn)->rcu.next = NULL;
}

static inline void tnode_free_append(struct key_vector *tn,
				     struct key_vector *n)
{
	tn_info(n)->rcu.next = tn_info(tn)->rcu.next;
	tn_info(tn)->rcu.next = &tn_info(n)->rcu;
}

static void tnode_free(struct key_vector *tn)
{
	struct callback_head *head = &tn_info(tn)->rcu;

	while (head) {
		head = head->next;
		tnode_free_size += TNODE_SIZE(1ul << tn->bits);
		node_free(tn);

		tn = container_of(head, struct tnode, rcu)->kv;
	}

	if (tnode_free_size >= PAGE_SIZE * sync_pages) {
		tnode_free_size = 0;
		synchronize_rcu();
	}
}

static struct key_vector *replace(struct trie *t,
				  struct key_vector *oldtnode,
				  struct key_vector *tn)
{
	struct key_vector *tp = node_parent(oldtnode);
	unsigned long i;

	/* setup the parent pointer out of and back into this node */
	NODE_INIT_PARENT(tn, tp);
	put_child_root(tp, tn->key, tn);

	/* update all of the child parent pointers */
	update_children(tn);

	/* all pointers should be clean so we are done */
	tnode_free(oldtnode);

	/* resize children now that oldtnode is freed */
	for (i = child_length(tn); i;) {
		struct key_vector *inode = get_child(tn, --i);

		/* resize child node */
		if (tnode_full(tn, inode))
			tn = resize(t, inode);
	}

	return tp;
}

static struct key_vector *inflate(struct trie *t,
				  struct key_vector *oldtnode)
{
	struct key_vector *tn;
	unsigned long i;
	t_key m;

	pr_debug("In inflate\n");

	tn = tnode_new(oldtnode->key, oldtnode->pos - 1, oldtnode->bits + 1);
	if (!tn)
		goto notnode;

	/* prepare oldtnode to be freed */
	tnode_free_init(oldtnode);

	/* Assemble all of the pointers in our cluster, in this case that
	 * represents all of the pointers out of our allocated nodes that
	 * point to existing tnodes and the links between our allocated
	 * nodes.
	 */
	for (i = child_length(oldtnode), m = 1u << tn->pos; i;) {
		struct key_vector *inode = get_child(oldtnode, --i);
		struct key_vector *node0, *node1;
		unsigned long j, k;

		/* An empty child */
		if (!inode)
			continue;

		/* A leaf or an internal node with skipped bits */
		if (!tnode_full(oldtnode, inode)) {
			put_child(tn, get_index(inode->key, tn), inode);
			continue;
		}

		/* drop the node in the old tnode free list */
		tnode_free_append(oldtnode, inode);

		/* An internal node with two children */
		if (inode->bits == 1) {
			put_child(tn, 2 * i + 1, get_child(inode, 1));
			put_child(tn, 2 * i, get_child(inode, 0));
			continue;
		}

		/* We will replace this node 'inode' with two new
		 * ones, 'node0' and 'node1', each with half of the
		 * original children. The two new nodes will have
		 * a position one bit further down the key and this
		 * means that the "significant" part of their keys
		 * (see the discussion near the top of this file)
		 * will differ by one bit, which will be "0" in
		 * node0's key and "1" in node1's key. Since we are
		 * moving the key position by one step, the bit that
		 * we are moving away from - the bit at position
		 * (tn->pos) - is the one that will differ between
		 * node0 and node1. So... we synthesize that bit in the
		 * two new keys.
		 */
		node1 = tnode_new(inode->key | m, inode->pos, inode->bits - 1);
		if (!node1)
			goto nomem;
		node0 = tnode_new(inode->key, inode->pos, inode->bits - 1);

		tnode_free_append(tn, node1);
		if (!node0)
			goto nomem;
		tnode_free_append(tn, node0);

		/* populate child pointers in new nodes */
		for (k = child_length(inode), j = k / 2; j;) {
			put_child(node1, --j, get_child(inode, --k));
			put_child(node0, j, get_child(inode, j));
			put_child(node1, --j, get_child(inode, --k));
			put_child(node0, j, get_child(inode, j));
		}

		/* link new nodes to parent */
		NODE_INIT_PARENT(node1, tn);
		NODE_INIT_PARENT(node0, tn);

		/* link parent to nodes */
		put_child(tn, 2 * i + 1, node1);
		put_child(tn, 2 * i, node0);
	}

	/* setup the parent pointers into and out of this node */
	return replace(t, oldtnode, tn);
nomem:
	/* all pointers should be clean so we are done */
	tnode_free(tn);
notnode:
	return NULL;
}

static struct key_vector *halve(struct trie *t,
				struct key_vector *oldtnode)
{
	struct key_vector *tn;
	unsigned long i;

	pr_debug("In halve\n");

	tn = tnode_new(oldtnode->key, oldtnode->pos + 1, oldtnode->bits - 1);
	if (!tn)
		goto notnode;

	/* prepare oldtnode to be freed */
	tnode_free_init(oldtnode);

	/* Assemble all of the pointers in our cluster, in this case that
	 * represents all of the pointers out of our allocated nodes that
	 * point to existing tnodes and the links between our allocated
	 * nodes.
	 */
	for (i = child_length(oldtnode); i;) {
		struct key_vector *node1 = get_child(oldtnode, --i);
		struct key_vector *node0 = get_child(oldtnode, --i);
		struct key_vector *inode;

		/* At least one of the children is empty */
		if (!node1 || !node0) {
			put_child(tn, i / 2, node1 ? : node0);
			continue;
		}

		/* Two nonempty children */
		inode = tnode_new(node0->key, oldtnode->pos, 1);
		if (!inode)
			goto nomem;
		tnode_free_append(tn, inode);

		/* initialize pointers out of node */
		put_child(inode, 1, node1);
		put_child(inode, 0, node0);
		NODE_INIT_PARENT(inode, tn);

		/* link parent to node */
		put_child(tn, i / 2, inode);
	}

	/* setup the parent pointers into and out of this node */
	return replace(t, oldtnode, tn);
nomem:
	/* all pointers should be clean so we are done */
	tnode_free(tn);
notnode:
	return NULL;
}

static struct key_vector *collapse(struct trie *t,
				   struct key_vector *oldtnode)
{
	struct key_vector *n, *tp;
	unsigned long i;

	/* scan the tnode looking for that one child that might still exist */
	for (n = NULL, i = child_length(oldtnode); !n && i;)
		n = get_child(oldtnode, --i);

	/* compress one level */
	tp = node_parent(oldtnode);
	put_child_root(tp, oldtnode->key, n);
	node_set_parent(n, tp);

	/* drop dead node */
	node_free(oldtnode);

	return tp;
}

static unsigned char update_suffix(struct key_vector *tn)
{
	unsigned char slen = tn->pos;
	unsigned long stride, i;
	unsigned char slen_max;

	/* only vector 0 can have a suffix length greater than or equal to
	 * tn->pos + tn->bits, the second highest node will have a suffix
	 * length at most of tn->pos + tn->bits - 1
	 */
	slen_max = min_t(unsigned char, tn->pos + tn->bits - 1, tn->slen);

	/* search though the list of children looking for nodes that might
	 * have a suffix greater than the one we currently have.  This is
	 * why we start with a stride of 2 since a stride of 1 would
	 * represent the nodes with suffix length equal to tn->pos
	 */
	for (i = 0, stride = 0x2ul ; i < child_length(tn); i += stride) {
		struct key_vector *n = get_child(tn, i);

		if (!n || (n->slen <= slen))
			continue;

		/* update stride and slen based on new value */
		stride <<= (n->slen - slen);
		slen = n->slen;
		i &= ~(stride - 1);

		/* stop searching if we have hit the maximum possible value */
		if (slen >= slen_max)
			break;
	}

	tn->slen = slen;

	return slen;
}

/* From "Implementing a dynamic compressed trie" by Stefan Nilsson of
 * the Helsinki University of Technology and Matti Tikkanen of Nokia
 * Telecommunications, page 6:
 * "A node is doubled if the ratio of non-empty children to all
 * children in the *doubled* node is at least 'high'."
 *
 * 'high' in this instance is the variable 'inflate_threshold'. It
 * is expressed as a percentage, so we multiply it with
 * child_length() and instead of multiplying by 2 (since the
 * child array will be doubled by inflate()) and multiplying
 * the left-hand side by 100 (to handle the percentage thing) we
 * multiply the left-hand side by 50.
 *
 * The left-hand side may look a bit weird: child_length(tn)
 * - tn->empty_children is of course the number of non-null children
 * in the current node. tn->full_children is the number of "full"
 * children, that is non-null tnodes with a skip value of 0.
 * All of those will be doubled in the resulting inflated tnode, so
 * we just count them one extra time here.
 *
 * A clearer way to write this would be:
 *
 * to_be_doubled = tn->full_children;
 * not_to_be_doubled = child_length(tn) - tn->empty_children -
 *     tn->full_children;
 *
 * new_child_length = child_length(tn) * 2;
 *
 * new_fill_factor = 100 * (not_to_be_doubled + 2*to_be_doubled) /
 *      new_child_length;
 * if (new_fill_factor >= inflate_threshold)
 *
 * ...and so on, tho it would mess up the while () loop.
 *
 * anyway,
 * 100 * (not_to_be_doubled + 2*to_be_doubled) / new_child_length >=
 *      inflate_threshold
 *
 * avoid a division:
 * 100 * (not_to_be_doubled + 2*to_be_doubled) >=
 *      inflate_threshold * new_child_length
 *
 * expand not_to_be_doubled and to_be_doubled, and shorten:
 * 100 * (child_length(tn) - tn->empty_children +
 *    tn->full_children) >= inflate_threshold * new_child_length
 *
 * expand new_child_length:
 * 100 * (child_length(tn) - tn->empty_children +
 *    tn->full_children) >=
 *      inflate_threshold * child_length(tn) * 2
 *
 * shorten again:
 * 50 * (tn->full_children + child_length(tn) -
 *    tn->empty_children) >= inflate_threshold *
 *    child_length(tn)
 *
 */
static inline bool should_inflate(struct key_vector *tp, struct key_vector *tn)
{
	unsigned long used = child_length(tn);
	unsigned long threshold = used;

	/* Keep root node larger */
	threshold *= IS_TRIE(tp) ? inflate_threshold_root : inflate_threshold;
	used -= tn_info(tn)->empty_children;
	used += tn_info(tn)->full_children;

	/* if bits == KEYLENGTH then pos = 0, and will fail below */

	return (used > 1) && tn->pos && ((50 * used) >= threshold);
}

static inline bool should_halve(struct key_vector *tp, struct key_vector *tn)
{
	unsigned long used = child_length(tn);
	unsigned long threshold = used;

	/* Keep root node larger */
	threshold *= IS_TRIE(tp) ? halve_threshold_root : halve_threshold;
	used -= tn_info(tn)->empty_children;

	/* if bits == KEYLENGTH then used = 100% on wrap, and will fail below */

	return (used > 1) && (tn->bits > 1) && ((100 * used) < threshold);
}

static inline bool should_collapse(struct key_vector *tn)
{
	unsigned long used = child_length(tn);

	used -= tn_info(tn)->empty_children;

	/* account for bits == KEYLENGTH case */
	if ((tn->bits == KEYLENGTH) && tn_info(tn)->full_children)
		used -= KEY_MAX;

	/* One child or none, time to drop us from the trie */
	return used < 2;
}

#define MAX_WORK 10
static struct key_vector *resize(struct trie *t, struct key_vector *tn)
{
#ifdef CONFIG_IP_FIB_TRIE_STATS
	struct trie_use_stats __percpu *stats = t->stats;
#endif
	struct key_vector *tp = node_parent(tn);
	unsigned long cindex = get_index(tn->key, tp);
	int max_work = MAX_WORK;

	pr_debug("In tnode_resize %p inflate_threshold=%d threshold=%d\n",
		 tn, inflate_threshold, halve_threshold);

	/* track the tnode via the pointer from the parent instead of
	 * doing it ourselves.  This way we can let RCU fully do its
	 * thing without us interfering
	 */
	BUG_ON(tn != get_child(tp, cindex));

	/* Double as long as the resulting node has a number of
	 * nonempty nodes that are above the threshold.
	 */
	while (should_inflate(tp, tn) && max_work) {
		tp = inflate(t, tn);
		if (!tp) {
#ifdef CONFIG_IP_FIB_TRIE_STATS
			this_cpu_inc(stats->resize_node_skipped);
#endif
			break;
		}

		max_work--;
		tn = get_child(tp, cindex);
	}

	/* update parent in case inflate failed */
	tp = node_parent(tn);

	/* Return if at least one inflate is run */
	if (max_work != MAX_WORK)
		return tp;

	/* Halve as long as the number of empty children in this
	 * node is above threshold.
	 */
	while (should_halve(tp, tn) && max_work) {
		tp = halve(t, tn);
		if (!tp) {
#ifdef CONFIG_IP_FIB_TRIE_STATS
			this_cpu_inc(stats->resize_node_skipped);
#endif
			break;
		}

		max_work--;
		tn = get_child(tp, cindex);
	}

	/* Only one child remains */
	if (should_collapse(tn))
		return collapse(t, tn);

	/* update parent in case halve failed */
	return node_parent(tn);
}

static void node_pull_suffix(struct key_vector *tn, unsigned char slen)
{
	unsigned char node_slen = tn->slen;

	while ((node_slen > tn->pos) && (node_slen > slen)) {
		slen = update_suffix(tn);
		if (node_slen == slen)
			break;

		tn = node_parent(tn);
		node_slen = tn->slen;
	}
}

static void node_push_suffix(struct key_vector *tn, unsigned char slen)
{
	while (tn->slen < slen) {
		tn->slen = slen;
		tn = node_parent(tn);
	}
}

/* rcu_read_lock needs to be hold by caller from readside */
static struct key_vector *fib_find_node(struct trie *t,
					struct key_vector **tp, u32 key)
{
	struct key_vector *pn, *n = t->kv;
	unsigned long index = 0;

	do {
		pn = n;
		n = get_child_rcu(n, index);

		if (!n)
			break;

		index = get_cindex(key, n);

		/* This bit of code is a bit tricky but it combines multiple
		 * checks into a single check.  The prefix consists of the
		 * prefix plus zeros for the bits in the cindex. The index
		 * is the difference between the key and this value.  From
		 * this we can actually derive several pieces of data.
		 *   if (index >= (1ul << bits))
		 *     we have a mismatch in skip bits and failed
		 *   else
		 *     we know the value is cindex
		 *
		 * This check is safe even if bits == KEYLENGTH due to the
		 * fact that we can only allocate a node with 32 bits if a
		 * long is greater than 32 bits.
		 */
		if (index >= (1ul << n->bits)) {
			n = NULL;
			break;
		}

		/* keep searching until we find a perfect match leaf or NULL */
	} while (IS_TNODE(n));

	*tp = pn;

	return n;
}

/* Return the first fib alias matching TOS with
 * priority less than or equal to PRIO.
 */
static struct fib_alias *fib_find_alias(struct hlist_head *fah, u8 slen,
					u8 tos, u32 prio, u32 tb_id)
{
	struct fib_alias *fa;

	if (!fah)
		return NULL;

	hlist_for_each_entry(fa, fah, fa_list) {
		if (fa->fa_slen < slen)
			continue;
		if (fa->fa_slen != slen)
			break;
		if (fa->tb_id > tb_id)
			continue;
		if (fa->tb_id != tb_id)
			break;
		if (fa->fa_tos > tos)
			continue;
		if (fa->fa_info->fib_priority >= prio || fa->fa_tos < tos)
			return fa;
	}

	return NULL;
}

static void trie_rebalance(struct trie *t, struct key_vector *tn)
{
	while (!IS_TRIE(tn))
		tn = resize(t, tn);
}

static int fib_insert_node(struct trie *t, struct key_vector *tp,
			   struct fib_alias *new, t_key key)
{
	struct key_vector *n, *l;

	l = leaf_new(key, new);
	if (!l)
		goto noleaf;

	/* retrieve child from parent node */
	n = get_child(tp, get_index(key, tp));

	/* Case 2: n is a LEAF or a TNODE and the key doesn't match.
	 *
	 *  Add a new tnode here
	 *  first tnode need some special handling
	 *  leaves us in position for handling as case 3
	 */
	if (n) {
		struct key_vector *tn;

		tn = tnode_new(key, __fls(key ^ n->key), 1);
		if (!tn)
			goto notnode;

		/* initialize routes out of node */
		NODE_INIT_PARENT(tn, tp);
		put_child(tn, get_index(key, tn) ^ 1, n);

		/* start adding routes into the node */
		put_child_root(tp, key, tn);
		node_set_parent(n, tn);

		/* parent now has a NULL spot where the leaf can go */
		tp = tn;
	}

	/* Case 3: n is NULL, and will just insert a new leaf */
	node_push_suffix(tp, new->fa_slen);
	NODE_INIT_PARENT(l, tp);
	put_child_root(tp, key, l);
	trie_rebalance(t, tp);

	return 0;
notnode:
	node_free(l);
noleaf:
	return -ENOMEM;
}

static int fib_insert_alias(struct trie *t, struct key_vector *tp,
			    struct key_vector *l, struct fib_alias *new,
			    struct fib_alias *fa, t_key key)
{
	if (!l)
		return fib_insert_node(t, tp, new, key);

	if (fa) {
		hlist_add_before_rcu(&new->fa_list, &fa->fa_list);
	} else {
		struct fib_alias *last;

		hlist_for_each_entry(last, &l->leaf, fa_list) {
			if (new->fa_slen < last->fa_slen)
				break;
			if ((new->fa_slen == last->fa_slen) &&
			    (new->tb_id > last->tb_id))
				break;
			fa = last;
		}

		if (fa)
			hlist_add_behind_rcu(&new->fa_list, &fa->fa_list);
		else
			hlist_add_head_rcu(&new->fa_list, &l->leaf);
	}

	/* if we added to the tail node then we need to update slen */
	if (l->slen < new->fa_slen) {
		l->slen = new->fa_slen;
		node_push_suffix(tp, new->fa_slen);
	}

	return 0;
}

static bool fib_valid_key_len(u32 key, u8 plen, struct netlink_ext_ack *extack)
{
	if (plen > KEYLENGTH) {
		NL_SET_ERR_MSG(extack, "Invalid prefix length");
		return false;
	}

	if ((plen < KEYLENGTH) && (key << plen)) {
		NL_SET_ERR_MSG(extack,
			       "Invalid prefix for given prefix length");
		return false;
	}

	return true;
}

/* Caller must hold RTNL. */
int fib_table_insert(struct net *net, struct fib_table *tb,
		     struct fib_config *cfg, struct netlink_ext_ack *extack)
{
	enum fib_event_type event = FIB_EVENT_ENTRY_ADD;
	struct trie *t = (struct trie *)tb->tb_data;
	struct fib_alias *fa, *new_fa;
	struct key_vector *l, *tp;
	u16 nlflags = NLM_F_EXCL;
	struct fib_info *fi;
	u8 plen = cfg->fc_dst_len;
	u8 slen = KEYLENGTH - plen;
	u8 tos = cfg->fc_tos;
	u32 key;
	int err;

	key = ntohl(cfg->fc_dst);

	if (!fib_valid_key_len(key, plen, extack))
		return -EINVAL;

	pr_debug("Insert table=%u %08x/%d\n", tb->tb_id, key, plen);

	fi = fib_create_info(cfg, extack);
	if (IS_ERR(fi)) {
		err = PTR_ERR(fi);
		goto err;
	}

	l = fib_find_node(t, &tp, key);
	fa = l ? fib_find_alias(&l->leaf, slen, tos, fi->fib_priority,
				tb->tb_id) : NULL;

	/* Now fa, if non-NULL, points to the first fib alias
	 * with the same keys [prefix,tos,priority], if such key already
	 * exists or to the node before which we will insert new one.
	 *
	 * If fa is NULL, we will need to allocate a new one and
	 * insert to the tail of the section matching the suffix length
	 * of the new alias.
	 */

	if (fa && fa->fa_tos == tos &&
	    fa->fa_info->fib_priority == fi->fib_priority) {
		struct fib_alias *fa_first, *fa_match;

		err = -EEXIST;
		if (cfg->fc_nlflags & NLM_F_EXCL)
			goto out;

		nlflags &= ~NLM_F_EXCL;

		/* We have 2 goals:
		 * 1. Find exact match for type, scope, fib_info to avoid
		 * duplicate routes
		 * 2. Find next 'fa' (or head), NLM_F_APPEND inserts before it
		 */
		fa_match = NULL;
		fa_first = fa;
		hlist_for_each_entry_from(fa, fa_list) {
			if ((fa->fa_slen != slen) ||
			    (fa->tb_id != tb->tb_id) ||
			    (fa->fa_tos != tos))
				break;
			if (fa->fa_info->fib_priority != fi->fib_priority)
				break;
			if (fa->fa_type == cfg->fc_type &&
			    fa->fa_info == fi) {
				fa_match = fa;
				break;
			}
		}

		if (cfg->fc_nlflags & NLM_F_REPLACE) {
			struct fib_info *fi_drop;
			u8 state;

			nlflags |= NLM_F_REPLACE;
			fa = fa_first;
			if (fa_match) {
				if (fa == fa_match)
					err = 0;
				goto out;
			}
			err = -ENOBUFS;
			new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL);
			if (!new_fa)
				goto out;

			fi_drop = fa->fa_info;
			new_fa->fa_tos = fa->fa_tos;
			new_fa->fa_info = fi;
			new_fa->fa_type = cfg->fc_type;
			state = fa->fa_state;
			new_fa->fa_state = state & ~FA_S_ACCESSED;
			new_fa->fa_slen = fa->fa_slen;
			new_fa->tb_id = tb->tb_id;
			new_fa->fa_default = -1;

			call_fib_entry_notifiers(net, FIB_EVENT_ENTRY_REPLACE,
						 key, plen, fi,
						 new_fa->fa_tos, cfg->fc_type,
						 tb->tb_id);
			rtmsg_fib(RTM_NEWROUTE, htonl(key), new_fa, plen,
				  tb->tb_id, &cfg->fc_nlinfo, nlflags);

			hlist_replace_rcu(&fa->fa_list, &new_fa->fa_list);

			alias_free_mem_rcu(fa);

			fib_release_info(fi_drop);
			if (state & FA_S_ACCESSED)
				rt_cache_flush(cfg->fc_nlinfo.nl_net);

			goto succeeded;
		}
		/* Error if we find a perfect match which
		 * uses the same scope, type, and nexthop
		 * information.
		 */
		if (fa_match)
			goto out;

		if (cfg->fc_nlflags & NLM_F_APPEND) {
			event = FIB_EVENT_ENTRY_APPEND;
			nlflags |= NLM_F_APPEND;
		} else {
			fa = fa_first;
		}
	}
	err = -ENOENT;
	if (!(cfg->fc_nlflags & NLM_F_CREATE))
		goto out;

	nlflags |= NLM_F_CREATE;
	err = -ENOBUFS;
	new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL);
	if (!new_fa)
		goto out;

	new_fa->fa_info = fi;
	new_fa->fa_tos = tos;
	new_fa->fa_type = cfg->fc_type;
	new_fa->fa_state = 0;
	new_fa->fa_slen = slen;
	new_fa->tb_id = tb->tb_id;
	new_fa->fa_default = -1;

	/* Insert new entry to the list. */
	err = fib_insert_alias(t, tp, l, new_fa, fa, key);
	if (err)
		goto out_free_new_fa;

	if (!plen)
		tb->tb_num_default++;

	rt_cache_flush(cfg->fc_nlinfo.nl_net);
	call_fib_entry_notifiers(net, event, key, plen, fi, tos, cfg->fc_type,
				 tb->tb_id);
	rtmsg_fib(RTM_NEWROUTE, htonl(key), new_fa, plen, new_fa->tb_id,
		  &cfg->fc_nlinfo, nlflags);
succeeded:
	return 0;

out_free_new_fa:
	kmem_cache_free(fn_alias_kmem, new_fa);
out:
	fib_release_info(fi);
err:
	return err;
}

static inline t_key prefix_mismatch(t_key key, struct key_vector *n)
{
	t_key prefix = n->key;

	return (key ^ prefix) & (prefix | -prefix);
}

/* should be called with rcu_read_lock */
int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp,
		     struct fib_result *res, int fib_flags)
{
	struct trie *t = (struct trie *) tb->tb_data;
#ifdef CONFIG_IP_FIB_TRIE_STATS
	struct trie_use_stats __percpu *stats = t->stats;
#endif
	const t_key key = ntohl(flp->daddr);
	struct key_vector *n, *pn;
	struct fib_alias *fa;
	unsigned long index;
	t_key cindex;

	trace_fib_table_lookup(tb->tb_id, flp);

	pn = t->kv;
	cindex = 0;

	n = get_child_rcu(pn, cindex);
	if (!n)
		return -EAGAIN;

#ifdef CONFIG_IP_FIB_TRIE_STATS
	this_cpu_inc(stats->gets);
#endif

	/* Step 1: Travel to the longest prefix match in the trie */
	for (;;) {
		index = get_cindex(key, n);

		/* This bit of code is a bit tricky but it combines multiple
		 * checks into a single check.  The prefix consists of the
		 * prefix plus zeros for the "bits" in the prefix. The index
		 * is the difference between the key and this value.  From
		 * this we can actually derive several pieces of data.
		 *   if (index >= (1ul << bits))
		 *     we have a mismatch in skip bits and failed
		 *   else
		 *     we know the value is cindex
		 *
		 * This check is safe even if bits == KEYLENGTH due to the
		 * fact that we can only allocate a node with 32 bits if a
		 * long is greater than 32 bits.
		 */
		if (index >= (1ul << n->bits))
			break;

		/* we have found a leaf. Prefixes have already been compared */
		if (IS_LEAF(n))
			goto found;

		/* only record pn and cindex if we are going to be chopping
		 * bits later.  Otherwise we are just wasting cycles.
		 */
		if (n->slen > n->pos) {
			pn = n;
			cindex = index;
		}

		n = get_child_rcu(n, index);
		if (unlikely(!n))
			goto backtrace;
	}

	/* Step 2: Sort out leaves and begin backtracing for longest prefix */
	for (;;) {
		/* record the pointer where our next node pointer is stored */
		struct key_vector __rcu **cptr = n->tnode;

		/* This test verifies that none of the bits that differ
		 * between the key and the prefix exist in the region of
		 * the lsb and higher in the prefix.
		 */
		if (unlikely(prefix_mismatch(key, n)) || (n->slen == n->pos))
			goto backtrace;

		/* exit out and process leaf */
		if (unlikely(IS_LEAF(n)))
			break;

		/* Don't bother recording parent info.  Since we are in
		 * prefix match mode we will have to come back to wherever
		 * we started this traversal anyway
		 */

		while ((n = rcu_dereference(*cptr)) == NULL) {
backtrace:
#ifdef CONFIG_IP_FIB_TRIE_STATS
			if (!n)
				this_cpu_inc(stats->null_node_hit);
#endif
			/* If we are at cindex 0 there are no more bits for
			 * us to strip at this level so we must ascend back
			 * up one level to see if there are any more bits to
			 * be stripped there.
			 */
			while (!cindex) {
				t_key pkey = pn->key;

				/* If we don't have a parent then there is
				 * nothing for us to do as we do not have any
				 * further nodes to parse.
				 */
				if (IS_TRIE(pn))
					return -EAGAIN;
#ifdef CONFIG_IP_FIB_TRIE_STATS
				this_cpu_inc(stats->backtrack);
#endif
				/* Get Child's index */
				pn = node_parent_rcu(pn);
				cindex = get_index(pkey, pn);
			}

			/* strip the least significant bit from the cindex */
			cindex &= cindex - 1;

			/* grab pointer for next child node */
			cptr = &pn->tnode[cindex];
		}
	}

found:
	/* this line carries forward the xor from earlier in the function */
	index = key ^ n->key;

	/* Step 3: Process the leaf, if that fails fall back to backtracing */
	hlist_for_each_entry_rcu(fa, &n->leaf, fa_list) {
		struct fib_info *fi = fa->fa_info;
		int nhsel, err;

		if ((BITS_PER_LONG > KEYLENGTH) || (fa->fa_slen < KEYLENGTH)) {
			if (index >= (1ul << fa->fa_slen))
				continue;
		}
		if (fa->fa_tos && fa->fa_tos != flp->flowi4_tos)
			continue;
		if (fi->fib_dead)
			continue;
		if (fa->fa_info->fib_scope < flp->flowi4_scope)
			continue;
		fib_alias_accessed(fa);
		err = fib_props[fa->fa_type].error;
		if (unlikely(err < 0)) {
#ifdef CONFIG_IP_FIB_TRIE_STATS
			this_cpu_inc(stats->semantic_match_passed);
#endif
			return err;
		}
		if (fi->fib_flags & RTNH_F_DEAD)
			continue;
		for (nhsel = 0; nhsel < fi->fib_nhs; nhsel++) {
			const struct fib_nh *nh = &fi->fib_nh[nhsel];
			struct in_device *in_dev = __in_dev_get_rcu(nh->nh_dev);

			if (nh->nh_flags & RTNH_F_DEAD)
				continue;
			if (in_dev &&
			    IN_DEV_IGNORE_ROUTES_WITH_LINKDOWN(in_dev) &&
			    nh->nh_flags & RTNH_F_LINKDOWN &&
			    !(fib_flags & FIB_LOOKUP_IGNORE_LINKSTATE))
				continue;
			if (!(flp->flowi4_flags & FLOWI_FLAG_SKIP_NH_OIF)) {
				if (flp->flowi4_oif &&
				    flp->flowi4_oif != nh->nh_oif)
					continue;
			}

			if (!(fib_flags & FIB_LOOKUP_NOREF))
				refcount_inc(&fi->fib_clntref);

			res->prefix = htonl(n->key);
			res->prefixlen = KEYLENGTH - fa->fa_slen;
			res->nh_sel = nhsel;
			res->type = fa->fa_type;
			res->scope = fi->fib_scope;
			res->fi = fi;
			res->table = tb;
			res->fa_head = &n->leaf;
#ifdef CONFIG_IP_FIB_TRIE_STATS
			this_cpu_inc(stats->semantic_match_passed);
#endif
			trace_fib_table_lookup_nh(nh);

			return err;
		}
	}
#ifdef CONFIG_IP_FIB_TRIE_STATS
	this_cpu_inc(stats->semantic_match_miss);
#endif
	goto backtrace;
}
EXPORT_SYMBOL_GPL(fib_table_lookup);

static void fib_remove_alias(struct trie *t, struct key_vector *tp,
			     struct key_vector *l, struct fib_alias *old)
{
	/* record the location of the previous list_info entry */
	struct hlist_node **pprev = old->fa_list.pprev;
	struct fib_alias *fa = hlist_entry(pprev, typeof(*fa), fa_list.next);

	/* remove the fib_alias from the list */
	hlist_del_rcu(&old->fa_list);

	/* if we emptied the list this leaf will be freed and we can sort
	 * out parent suffix lengths as a part of trie_rebalance
	 */
	if (hlist_empty(&l->leaf)) {
		if (tp->slen == l->slen)
			node_pull_suffix(tp, tp->pos);
		put_child_root(tp, l->key, NULL);
		node_free(l);
		trie_rebalance(t, tp);
		return;
	}

	/* only access fa if it is pointing at the last valid hlist_node */
	if (*pprev)
		return;

	/* update the trie with the latest suffix length */
	l->slen = fa->fa_slen;
	node_pull_suffix(tp, fa->fa_slen);
}

/* Caller must hold RTNL. */
int fib_table_delete(struct net *net, struct fib_table *tb,
		     struct fib_config *cfg, struct netlink_ext_ack *extack)
{
	struct trie *t = (struct trie *) tb->tb_data;
	struct fib_alias *fa, *fa_to_delete;
	struct key_vector *l, *tp;
	u8 plen = cfg->fc_dst_len;
	u8 slen = KEYLENGTH - plen;
	u8 tos = cfg->fc_tos;
	u32 key;

	key = ntohl(cfg->fc_dst);

	if (!fib_valid_key_len(key, plen, extack))
		return -EINVAL;

	l = fib_find_node(t, &tp, key);
	if (!l)
		return -ESRCH;

	fa = fib_find_alias(&l->leaf, slen, tos, 0, tb->tb_id);
	if (!fa)
		return -ESRCH;

	pr_debug("Deleting %08x/%d tos=%d t=%p\n", key, plen, tos, t);

	fa_to_delete = NULL;
	hlist_for_each_entry_from(fa, fa_list) {
		struct fib_info *fi = fa->fa_info;

		if ((fa->fa_slen != slen) ||
		    (fa->tb_id != tb->tb_id) ||
		    (fa->fa_tos != tos))
			break;

		if ((!cfg->fc_type || fa->fa_type == cfg->fc_type) &&
		    (cfg->fc_scope == RT_SCOPE_NOWHERE ||
		     fa->fa_info->fib_scope == cfg->fc_scope) &&
		    (!cfg->fc_prefsrc ||
		     fi->fib_prefsrc == cfg->fc_prefsrc) &&
		    (!cfg->fc_protocol ||
		     fi->fib_protocol == cfg->fc_protocol) &&
		    fib_nh_match(cfg, fi, extack) == 0 &&
		    fib_metrics_match(cfg, fi)) {
			fa_to_delete = fa;
			break;
		}
	}

	if (!fa_to_delete)
		return -ESRCH;

	call_fib_entry_notifiers(net, FIB_EVENT_ENTRY_DEL, key, plen,
				 fa_to_delete->fa_info, tos,
				 fa_to_delete->fa_type, tb->tb_id);
	rtmsg_fib(RTM_DELROUTE, htonl(key), fa_to_delete, plen, tb->tb_id,
		  &cfg->fc_nlinfo, 0);

	if (!plen)
		tb->tb_num_default--;

	fib_remove_alias(t, tp, l, fa_to_delete);

	if (fa_to_delete->fa_state & FA_S_ACCESSED)
		rt_cache_flush(cfg->fc_nlinfo.nl_net);

	fib_release_info(fa_to_delete->fa_info);
	alias_free_mem_rcu(fa_to_delete);
	return 0;
}

/* Scan for the next leaf starting at the provided key value */
static struct key_vector *leaf_walk_rcu(struct key_vector **tn, t_key key)
{
	struct key_vector *pn, *n = *tn;
	unsigned long cindex;

	/* this loop is meant to try and find the key in the trie */
	do {
		/* record parent and next child index */
		pn = n;
		cindex = (key > pn->key) ? get_index(key, pn) : 0;

		if (cindex >> pn->bits)
			break;

		/* descend into the next child */
		n = get_child_rcu(pn, cindex++);
		if (!n)
			break;

		/* guarantee forward progress on the keys */
		if (IS_LEAF(n) && (n->key >= key))
			goto found;
	} while (IS_TNODE(n));

	/* this loop will search for the next leaf with a greater key */
	while (!IS_TRIE(pn)) {
		/* if we exhausted the parent node we will need to climb */
		if (cindex >= (1ul << pn->bits)) {
			t_key pkey = pn->key;

			pn = node_parent_rcu(pn);
			cindex = get_index(pkey, pn) + 1;
			continue;
		}

		/* grab the next available node */
		n = get_child_rcu(pn, cindex++);
		if (!n)
			continue;

		/* no need to compare keys since we bumped the index */
		if (IS_LEAF(n))
			goto found;

		/* Rescan start scanning in new node */
		pn = n;
		cindex = 0;
	}

	*tn = pn;
	return NULL; /* Root of trie */
found:
	/* if we are at the limit for keys just return NULL for the tnode */
	*tn = pn;
	return n;
}

static void fib_trie_free(struct fib_table *tb)
{
	struct trie *t = (struct trie *)tb->tb_data;
	struct key_vector *pn = t->kv;
	unsigned long cindex = 1;
	struct hlist_node *tmp;
	struct fib_alias *fa;

	/* walk trie in reverse order and free everything */
	for (;;) {
		struct key_vector *n;

		if (!(cindex--)) {
			t_key pkey = pn->key;

			if (IS_TRIE(pn))
				break;

			n = pn;
			pn = node_parent(pn);

			/* drop emptied tnode */
			put_child_root(pn, n->key, NULL);
			node_free(n);

			cindex = get_index(pkey, pn);

			continue;
		}

		/* grab the next available node */
		n = get_child(pn, cindex);
		if (!n)
			continue;

		if (IS_TNODE(n)) {
			/* record pn and cindex for leaf walking */
			pn = n;
			cindex = 1ul << n->bits;

			continue;
		}

		hlist_for_each_entry_safe(fa, tmp, &n->leaf, fa_list) {
			hlist_del_rcu(&fa->fa_list);
			alias_free_mem_rcu(fa);
		}

		put_child_root(pn, n->key, NULL);
		node_free(n);
	}

#ifdef CONFIG_IP_FIB_TRIE_STATS
	free_percpu(t->stats);
#endif
	kfree(tb);
}

struct fib_table *fib_trie_unmerge(struct fib_table *oldtb)
{
	struct trie *ot = (struct trie *)oldtb->tb_data;
	struct key_vector *l, *tp = ot->kv;
	struct fib_table *local_tb;
	struct fib_alias *fa;
	struct trie *lt;
	t_key key = 0;

	if (oldtb->tb_data == oldtb->__data)
		return oldtb;

	local_tb = fib_trie_table(RT_TABLE_LOCAL, NULL);
	if (!local_tb)
		return NULL;

	lt = (struct trie *)local_tb->tb_data;

	while ((l = leaf_walk_rcu(&tp, key)) != NULL) {
		struct key_vector *local_l = NULL, *local_tp;

		hlist_for_each_entry_rcu(fa, &l->leaf, fa_list) {
			struct fib_alias *new_fa;

			if (local_tb->tb_id != fa->tb_id)
				continue;

			/* clone fa for new local table */
			new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL);
			if (!new_fa)
				goto out;

			memcpy(new_fa, fa, sizeof(*fa));

			/* insert clone into table */
			if (!local_l)
				local_l = fib_find_node(lt, &local_tp, l->key);

			if (fib_insert_alias(lt, local_tp, local_l, new_fa,
					     NULL, l->key)) {
				kmem_cache_free(fn_alias_kmem, new_fa);
				goto out;
			}
		}

		/* stop loop if key wrapped back to 0 */
		key = l->key + 1;
		if (key < l->key)
			break;
	}

	return local_tb;
out:
	fib_trie_free(local_tb);

	return NULL;
}

/* Caller must hold RTNL */
void fib_table_flush_external(struct fib_table *tb)
{
	struct trie *t = (struct trie *)tb->tb_data;
	struct key_vector *pn = t->kv;
	unsigned long cindex = 1;
	struct hlist_node *tmp;
	struct fib_alias *fa;

	/* walk trie in reverse order */
	for (;;) {
		unsigned char slen = 0;
		struct key_vector *n;

		if (!(cindex--)) {
			t_key pkey = pn->key;

			/* cannot resize the trie vector */
			if (IS_TRIE(pn))
				break;

			/* update the suffix to address pulled leaves */
			if (pn->slen > pn->pos)
				update_suffix(pn);

			/* resize completed node */
			pn = resize(t, pn);
			cindex = get_index(pkey, pn);

			continue;
		}

		/* grab the next available node */
		n = get_child(pn, cindex);
		if (!n)
			continue;

		if (IS_TNODE(n)) {
			/* record pn and cindex for leaf walking */
			pn = n;
			cindex = 1ul << n->bits;

			continue;
		}

		hlist_for_each_entry_safe(fa, tmp, &n->leaf, fa_list) {
			/* if alias was cloned to local then we just
			 * need to remove the local copy from main
			 */
			if (tb->tb_id != fa->tb_id) {
				hlist_del_rcu(&fa->fa_list);
				alias_free_mem_rcu(fa);
				continue;
			}

			/* record local slen */
			slen = fa->fa_slen;
		}

		/* update leaf slen */
		n->slen = slen;

		if (hlist_empty(&n->leaf)) {
			put_child_root(pn, n->key, NULL);
			node_free(n);
		}
	}
}

/* Caller must hold RTNL. */
int fib_table_flush(struct net *net, struct fib_table *tb)
{
	struct trie *t = (struct trie *)tb->tb_data;
	struct key_vector *pn = t->kv;
	unsigned long cindex = 1;
	struct hlist_node *tmp;
	struct fib_alias *fa;
	int found = 0;

	/* walk trie in reverse order */
	for (;;) {
		unsigned char slen = 0;
		struct key_vector *n;

		if (!(cindex--)) {
			t_key pkey = pn->key;

			/* cannot resize the trie vector */
			if (IS_TRIE(pn))
				break;

			/* update the suffix to address pulled leaves */
			if (pn->slen > pn->pos)
				update_suffix(pn);

			/* resize completed node */
			pn = resize(t, pn);
			cindex = get_index(pkey, pn);

			continue;
		}

		/* grab the next available node */
		n = get_child(pn, cindex);
		if (!n)
			continue;

		if (IS_TNODE(n)) {
			/* record pn and cindex for leaf walking */
			pn = n;
			cindex = 1ul << n->bits;

			continue;
		}

		hlist_for_each_entry_safe(fa, tmp, &n->leaf, fa_list) {
			struct fib_info *fi = fa->fa_info;

			if (!fi || !(fi->fib_flags & RTNH_F_DEAD) ||
			    tb->tb_id != fa->tb_id) {
				slen = fa->fa_slen;
				continue;
			}

			call_fib_entry_notifiers(net, FIB_EVENT_ENTRY_DEL,
						 n->key,
						 KEYLENGTH - fa->fa_slen,
						 fi, fa->fa_tos, fa->fa_type,
						 tb->tb_id);
			hlist_del_rcu(&fa->fa_list);
			fib_release_info(fa->fa_info);
			alias_free_mem_rcu(fa);
			found++;
		}

		/* update leaf slen */
		n->slen = slen;

		if (hlist_empty(&n->leaf)) {
			put_child_root(pn, n->key, NULL);
			node_free(n);
		}
	}

	pr_debug("trie_flush found=%d\n", found);
	return found;
}

static void fib_leaf_notify(struct net *net, struct key_vector *l,
			    struct fib_table *tb, struct notifier_block *nb)
{
	struct fib_alias *fa;

	hlist_for_each_entry_rcu(fa, &l->leaf, fa_list) {
		struct fib_info *fi = fa->fa_info;

		if (!fi)
			continue;

		/* local and main table can share the same trie,
		 * so don't notify twice for the same entry.
		 */
		if (tb->tb_id != fa->tb_id)
			continue;

		call_fib_entry_notifier(nb, net, FIB_EVENT_ENTRY_ADD, l->key,
					KEYLENGTH - fa->fa_slen, fi, fa->fa_tos,
					fa->fa_type, fa->tb_id);
	}
}

static void fib_table_notify(struct net *net, struct fib_table *tb,
			     struct notifier_block *nb)
{
	struct trie *t = (struct trie *)tb->tb_data;
	struct key_vector *l, *tp = t->kv;
	t_key key = 0;

	while ((l = leaf_walk_rcu(&tp, key)) != NULL) {
		fib_leaf_notify(net, l, tb, nb);

		key = l->key + 1;
		/* stop in case of wrap around */
		if (key < l->key)
			break;
	}
}

void fib_notify(struct net *net, struct notifier_block *nb)
{
	unsigned int h;

	for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
		struct hlist_head *head = &net->ipv4.fib_table_hash[h];
		struct fib_table *tb;

		hlist_for_each_entry_rcu(tb, head, tb_hlist)
			fib_table_notify(net, tb, nb);
	}
}

static void __trie_free_rcu(struct rcu_head *head)
{
	struct fib_table *tb = container_of(head, struct fib_table, rcu);
#ifdef CONFIG_IP_FIB_TRIE_STATS
	struct trie *t = (struct trie *)tb->tb_data;

	if (tb->tb_data == tb->__data)
		free_percpu(t->stats);
#endif /* CONFIG_IP_FIB_TRIE_STATS */
	kfree(tb);
}

void fib_free_table(struct fib_table *tb)
{
	call_rcu(&tb->rcu, __trie_free_rcu);
}

static int fn_trie_dump_leaf(struct key_vector *l, struct fib_table *tb,
			     struct sk_buff *skb, struct netlink_callback *cb)
{
	__be32 xkey = htonl(l->key);
	struct fib_alias *fa;
	int i, s_i;

	s_i = cb->args[4];
	i = 0;

	/* rcu_read_lock is hold by caller */
	hlist_for_each_entry_rcu(fa, &l->leaf, fa_list) {
		int err;

		if (i < s_i) {
			i++;
			continue;
		}

		if (tb->tb_id != fa->tb_id) {
			i++;
			continue;
		}

		err = fib_dump_info(skb, NETLINK_CB(cb->skb).portid,
				    cb->nlh->nlmsg_seq, RTM_NEWROUTE,
				    tb->tb_id, fa->fa_type,
				    xkey, KEYLENGTH - fa->fa_slen,
				    fa->fa_tos, fa->fa_info, NLM_F_MULTI);
		if (err < 0) {
			cb->args[4] = i;
			return err;
		}
		i++;
	}

	cb->args[4] = i;
	return skb->len;
}

/* rcu_read_lock needs to be hold by caller from readside */
int fib_table_dump(struct fib_table *tb, struct sk_buff *skb,
		   struct netlink_callback *cb)
{
	struct trie *t = (struct trie *)tb->tb_data;
	struct key_vector *l, *tp = t->kv;
	/* Dump starting at last key.
	 * Note: 0.0.0.0/0 (ie default) is first key.
	 */
	int count = cb->args[2];
	t_key key = cb->args[3];

	while ((l = leaf_walk_rcu(&tp, key)) != NULL) {
		int err;

		err = fn_trie_dump_leaf(l, tb, skb, cb);
		if (err < 0) {
			cb->args[3] = key;
			cb->args[2] = count;
			return err;
		}

		++count;
		key = l->key + 1;

		memset(&cb->args[4], 0,
		       sizeof(cb->args) - 4*sizeof(cb->args[0]));

		/* stop loop if key wrapped back to 0 */
		if (key < l->key)
			break;
	}

	cb->args[3] = key;
	cb->args[2] = count;

	return skb->len;
}

void __init fib_trie_init(void)
{
	fn_alias_kmem = kmem_cache_create("ip_fib_alias",
					  sizeof(struct fib_alias),
					  0, SLAB_PANIC, NULL);

	trie_leaf_kmem = kmem_cache_create("ip_fib_trie",
					   LEAF_SIZE,
					   0, SLAB_PANIC, NULL);
}

struct fib_table *fib_trie_table(u32 id, struct fib_table *alias)
{
	struct fib_table *tb;
	struct trie *t;
	size_t sz = sizeof(*tb);

	if (!alias)
		sz += sizeof(struct trie);

	tb = kzalloc(sz, GFP_KERNEL);
	if (!tb)
		return NULL;

	tb->tb_id = id;
	tb->tb_num_default = 0;
	tb->tb_data = (alias ? alias->__data : tb->__data);

	if (alias)
		return tb;

	t = (struct trie *) tb->tb_data;
	t->kv[0].pos = KEYLENGTH;
	t->kv[0].slen = KEYLENGTH;
#ifdef CONFIG_IP_FIB_TRIE_STATS
	t->stats = alloc_percpu(struct trie_use_stats);
	if (!t->stats) {
		kfree(tb);
		tb = NULL;
	}
#endif

	return tb;
}

#ifdef CONFIG_PROC_FS
/* Depth first Trie walk iterator */
struct fib_trie_iter {
	struct seq_net_private p;
	struct fib_table *tb;
	struct key_vector *tnode;
	unsigned int index;
	unsigned int depth;
};

static struct key_vector *fib_trie_get_next(struct fib_trie_iter *iter)
{
	unsigned long cindex = iter->index;
	struct key_vector *pn = iter->tnode;
	t_key pkey;

	pr_debug("get_next iter={node=%p index=%d depth=%d}\n",
		 iter->tnode, iter->index, iter->depth);

	while (!IS_TRIE(pn)) {
		while (cindex < child_length(pn)) {
			struct key_vector *n = get_child_rcu(pn, cindex++);

			if (!n)
				continue;

			if (IS_LEAF(n)) {
				iter->tnode = pn;
				iter->index = cindex;
			} else {
				/* push down one level */
				iter->tnode = n;
				iter->index = 0;
				++iter->depth;
			}

			return n;
		}

		/* Current node exhausted, pop back up */
		pkey = pn->key;
		pn = node_parent_rcu(pn);
		cindex = get_index(pkey, pn) + 1;
		--iter->depth;
	}

	/* record root node so further searches know we are done */
	iter->tnode = pn;
	iter->index = 0;

	return NULL;
}

static struct key_vector *fib_trie_get_first(struct fib_trie_iter *iter,
					     struct trie *t)
{
	struct key_vector *n, *pn;

	if (!t)
		return NULL;

	pn = t->kv;
	n = rcu_dereference(pn->tnode[0]);
	if (!n)
		return NULL;

	if (IS_TNODE(n)) {
		iter->tnode = n;
		iter->index = 0;
		iter->depth = 1;
	} else {
		iter->tnode = pn;
		iter->index = 0;
		iter->depth = 0;
	}

	return n;
}

static void trie_collect_stats(struct trie *t, struct trie_stat *s)
{
	struct key_vector *n;
	struct fib_trie_iter iter;

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

	rcu_read_lock();
	for (n = fib_trie_get_first(&iter, t); n; n = fib_trie_get_next(&iter)) {
		if (IS_LEAF(n)) {
			struct fib_alias *fa;

			s->leaves++;
			s->totdepth += iter.depth;
			if (iter.depth > s->maxdepth)
				s->maxdepth = iter.depth;

			hlist_for_each_entry_rcu(fa, &n->leaf, fa_list)
				++s->prefixes;
		} else {
			s->tnodes++;
			if (n->bits < MAX_STAT_DEPTH)
				s->nodesizes[n->bits]++;
			s->nullpointers += tn_info(n)->empty_children;
		}
	}
	rcu_read_unlock();
}

/*
 *	This outputs /proc/net/fib_triestats
 */
static void trie_show_stats(struct seq_file *seq, struct trie_stat *stat)
{
	unsigned int i, max, pointers, bytes, avdepth;

	if (stat->leaves)
		avdepth = stat->totdepth*100 / stat->leaves;
	else
		avdepth = 0;

	seq_printf(seq, "\tAver depth:     %u.%02d\n",
		   avdepth / 100, avdepth % 100);
	seq_printf(seq, "\tMax depth:      %u\n", stat->maxdepth);

	seq_printf(seq, "\tLeaves:         %u\n", stat->leaves);
	bytes = LEAF_SIZE * stat->leaves;

	seq_printf(seq, "\tPrefixes:       %u\n", stat->prefixes);
	bytes += sizeof(struct fib_alias) * stat->prefixes;

	seq_printf(seq, "\tInternal nodes: %u\n\t", stat->tnodes);
	bytes += TNODE_SIZE(0) * stat->tnodes;

	max = MAX_STAT_DEPTH;
	while (max > 0 && stat->nodesizes[max-1] == 0)
		max--;

	pointers = 0;
	for (i = 1; i < max; i++)
		if (stat->nodesizes[i] != 0) {
			seq_printf(seq, "  %u: %u",  i, stat->nodesizes[i]);
			pointers += (1<<i) * stat->nodesizes[i];
		}
	seq_putc(seq, '\n');
	seq_printf(seq, "\tPointers: %u\n", pointers);

	bytes += sizeof(struct key_vector *) * pointers;
	seq_printf(seq, "Null ptrs: %u\n", stat->nullpointers);
	seq_printf(seq, "Total size: %u  kB\n", (bytes + 1023) / 1024);
}

#ifdef CONFIG_IP_FIB_TRIE_STATS
static void trie_show_usage(struct seq_file *seq,
			    const struct trie_use_stats __percpu *stats)
{
	struct trie_use_stats s = { 0 };
	int cpu;

	/* loop through all of the CPUs and gather up the stats */
	for_each_possible_cpu(cpu) {
		const struct trie_use_stats *pcpu = per_cpu_ptr(stats, cpu);

		s.gets += pcpu->gets;
		s.backtrack += pcpu->backtrack;
		s.semantic_match_passed += pcpu->semantic_match_passed;
		s.semantic_match_miss += pcpu->semantic_match_miss;
		s.null_node_hit += pcpu->null_node_hit;
		s.resize_node_skipped += pcpu->resize_node_skipped;
	}

	seq_printf(seq, "\nCounters:\n---------\n");
	seq_printf(seq, "gets = %u\n", s.gets);
	seq_printf(seq, "backtracks = %u\n", s.backtrack);
	seq_printf(seq, "semantic match passed = %u\n",
		   s.semantic_match_passed);
	seq_printf(seq, "semantic match miss = %u\n", s.semantic_match_miss);
	seq_printf(seq, "null node hit= %u\n", s.null_node_hit);
	seq_printf(seq, "skipped node resize = %u\n\n", s.resize_node_skipped);
}
#endif /*  CONFIG_IP_FIB_TRIE_STATS */

static void fib_table_print(struct seq_file *seq, struct fib_table *tb)
{
	if (tb->tb_id == RT_TABLE_LOCAL)
		seq_puts(seq, "Local:\n");
	else if (tb->tb_id == RT_TABLE_MAIN)
		seq_puts(seq, "Main:\n");
	else
		seq_printf(seq, "Id %d:\n", tb->tb_id);
}


static int fib_triestat_seq_show(struct seq_file *seq, void *v)
{
	struct net *net = (struct net *)seq->private;
	unsigned int h;

	seq_printf(seq,
		   "Basic info: size of leaf:"
		   " %zd bytes, size of tnode: %zd bytes.\n",
		   LEAF_SIZE, TNODE_SIZE(0));

	for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
		struct hlist_head *head = &net->ipv4.fib_table_hash[h];
		struct fib_table *tb;

		hlist_for_each_entry_rcu(tb, head, tb_hlist) {
			struct trie *t = (struct trie *) tb->tb_data;
			struct trie_stat stat;

			if (!t)
				continue;

			fib_table_print(seq, tb);

			trie_collect_stats(t, &stat);
			trie_show_stats(seq, &stat);
#ifdef CONFIG_IP_FIB_TRIE_STATS
			trie_show_usage(seq, t->stats);
#endif
		}
	}

	return 0;
}

static int fib_triestat_seq_open(struct inode *inode, struct file *file)
{
	return single_open_net(inode, file, fib_triestat_seq_show);
}

static const struct file_operations fib_triestat_fops = {
	.owner	= THIS_MODULE,
	.open	= fib_triestat_seq_open,
	.read	= seq_read,
	.llseek	= seq_lseek,
	.release = single_release_net,
};

static struct key_vector *fib_trie_get_idx(struct seq_file *seq, loff_t pos)
{
	struct fib_trie_iter *iter = seq->private;
	struct net *net = seq_file_net(seq);
	loff_t idx = 0;
	unsigned int h;

	for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
		struct hlist_head *head = &net->ipv4.fib_table_hash[h];
		struct fib_table *tb;

		hlist_for_each_entry_rcu(tb, head, tb_hlist) {
			struct key_vector *n;

			for (n = fib_trie_get_first(iter,
						    (struct trie *) tb->tb_data);
			     n; n = fib_trie_get_next(iter))
				if (pos == idx++) {
					iter->tb = tb;
					return n;
				}
		}
	}

	return NULL;
}

static void *fib_trie_seq_start(struct seq_file *seq, loff_t *pos)
	__acquires(RCU)
{
	rcu_read_lock();
	return fib_trie_get_idx(seq, *pos);
}

static void *fib_trie_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
	struct fib_trie_iter *iter = seq->private;
	struct net *net = seq_file_net(seq);
	struct fib_table *tb = iter->tb;
	struct hlist_node *tb_node;
	unsigned int h;
	struct key_vector *n;

	++*pos;
	/* next node in same table */
	n = fib_trie_get_next(iter);
	if (n)
		return n;

	/* walk rest of this hash chain */
	h = tb->tb_id & (FIB_TABLE_HASHSZ - 1);
	while ((tb_node = rcu_dereference(hlist_next_rcu(&tb->tb_hlist)))) {
		tb = hlist_entry(tb_node, struct fib_table, tb_hlist);
		n = fib_trie_get_first(iter, (struct trie *) tb->tb_data);
		if (n)
			goto found;
	}

	/* new hash chain */
	while (++h < FIB_TABLE_HASHSZ) {
		struct hlist_head *head = &net->ipv4.fib_table_hash[h];
		hlist_for_each_entry_rcu(tb, head, tb_hlist) {
			n = fib_trie_get_first(iter, (struct trie *) tb->tb_data);
			if (n)
				goto found;
		}
	}
	return NULL;

found:
	iter->tb = tb;
	return n;
}

static void fib_trie_seq_stop(struct seq_file *seq, void *v)
	__releases(RCU)
{
	rcu_read_unlock();
}

static void seq_indent(struct seq_file *seq, int n)
{
	while (n-- > 0)
		seq_puts(seq, "   ");
}

static inline const char *rtn_scope(char *buf, size_t len, enum rt_scope_t s)
{
	switch (s) {
	case RT_SCOPE_UNIVERSE: return "universe";
	case RT_SCOPE_SITE:	return "site";
	case RT_SCOPE_LINK:	return "link";
	case RT_SCOPE_HOST:	return "host";
	case RT_SCOPE_NOWHERE:	return "nowhere";
	default:
		snprintf(buf, len, "scope=%d", s);
		return buf;
	}
}

static const char *const rtn_type_names[__RTN_MAX] = {
	[RTN_UNSPEC] = "UNSPEC",
	[RTN_UNICAST] = "UNICAST",
	[RTN_LOCAL] = "LOCAL",
	[RTN_BROADCAST] = "BROADCAST",
	[RTN_ANYCAST] = "ANYCAST",
	[RTN_MULTICAST] = "MULTICAST",
	[RTN_BLACKHOLE] = "BLACKHOLE",
	[RTN_UNREACHABLE] = "UNREACHABLE",
	[RTN_PROHIBIT] = "PROHIBIT",
	[RTN_THROW] = "THROW",
	[RTN_NAT] = "NAT",
	[RTN_XRESOLVE] = "XRESOLVE",
};

static inline const char *rtn_type(char *buf, size_t len, unsigned int t)
{
	if (t < __RTN_MAX && rtn_type_names[t])
		return rtn_type_names[t];
	snprintf(buf, len, "type %u", t);
	return buf;
}

/* Pretty print the trie */
static int fib_trie_seq_show(struct seq_file *seq, void *v)
{
	const struct fib_trie_iter *iter = seq->private;
	struct key_vector *n = v;

	if (IS_TRIE(node_parent_rcu(n)))
		fib_table_print(seq, iter->tb);

	if (IS_TNODE(n)) {
		__be32 prf = htonl(n->key);

		seq_indent(seq, iter->depth-1);
		seq_printf(seq, "  +-- %pI4/%zu %u %u %u\n",
			   &prf, KEYLENGTH - n->pos - n->bits, n->bits,
			   tn_info(n)->full_children,
			   tn_info(n)->empty_children);
	} else {
		__be32 val = htonl(n->key);
		struct fib_alias *fa;

		seq_indent(seq, iter->depth);
		seq_printf(seq, "  |-- %pI4\n", &val);

		hlist_for_each_entry_rcu(fa, &n->leaf, fa_list) {
			char buf1[32], buf2[32];

			seq_indent(seq, iter->depth + 1);
			seq_printf(seq, "  /%zu %s %s",
				   KEYLENGTH - fa->fa_slen,
				   rtn_scope(buf1, sizeof(buf1),
					     fa->fa_info->fib_scope),
				   rtn_type(buf2, sizeof(buf2),
					    fa->fa_type));
			if (fa->fa_tos)
				seq_printf(seq, " tos=%d", fa->fa_tos);
			seq_putc(seq, '\n');
		}
	}

	return 0;
}

static const struct seq_operations fib_trie_seq_ops = {
	.start  = fib_trie_seq_start,
	.next   = fib_trie_seq_next,
	.stop   = fib_trie_seq_stop,
	.show   = fib_trie_seq_show,
};

static int fib_trie_seq_open(struct inode *inode, struct file *file)
{
	return seq_open_net(inode, file, &fib_trie_seq_ops,
			    sizeof(struct fib_trie_iter));
}

static const struct file_operations fib_trie_fops = {
	.owner  = THIS_MODULE,
	.open   = fib_trie_seq_open,
	.read   = seq_read,
	.llseek = seq_lseek,
	.release = seq_release_net,
};

struct fib_route_iter {
	struct seq_net_private p;
	struct fib_table *main_tb;
	struct key_vector *tnode;
	loff_t	pos;
	t_key	key;
};

static struct key_vector *fib_route_get_idx(struct fib_route_iter *iter,
					    loff_t pos)
{
	struct key_vector *l, **tp = &iter->tnode;
	t_key key;

	/* use cached location of previously found key */
	if (iter->pos > 0 && pos >= iter->pos) {
		key = iter->key;
	} else {
		iter->pos = 1;
		key = 0;
	}

	pos -= iter->pos;

	while ((l = leaf_walk_rcu(tp, key)) && (pos-- > 0)) {
		key = l->key + 1;
		iter->pos++;
		l = NULL;

		/* handle unlikely case of a key wrap */
		if (!key)
			break;
	}

	if (l)
		iter->key = l->key;	/* remember it */
	else
		iter->pos = 0;		/* forget it */

	return l;
}

static void *fib_route_seq_start(struct seq_file *seq, loff_t *pos)
	__acquires(RCU)
{
	struct fib_route_iter *iter = seq->private;
	struct fib_table *tb;
	struct trie *t;

	rcu_read_lock();

	tb = fib_get_table(seq_file_net(seq), RT_TABLE_MAIN);
	if (!tb)
		return NULL;

	iter->main_tb = tb;
	t = (struct trie *)tb->tb_data;
	iter->tnode = t->kv;

	if (*pos != 0)
		return fib_route_get_idx(iter, *pos);

	iter->pos = 0;
	iter->key = KEY_MAX;

	return SEQ_START_TOKEN;
}

static void *fib_route_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
	struct fib_route_iter *iter = seq->private;
	struct key_vector *l = NULL;
	t_key key = iter->key + 1;

	++*pos;

	/* only allow key of 0 for start of sequence */
	if ((v == SEQ_START_TOKEN) || key)
		l = leaf_walk_rcu(&iter->tnode, key);

	if (l) {
		iter->key = l->key;
		iter->pos++;
	} else {
		iter->pos = 0;
	}

	return l;
}

static void fib_route_seq_stop(struct seq_file *seq, void *v)
	__releases(RCU)
{
	rcu_read_unlock();
}

static unsigned int fib_flag_trans(int type, __be32 mask, const struct fib_info *fi)
{
	unsigned int flags = 0;

	if (type == RTN_UNREACHABLE || type == RTN_PROHIBIT)
		flags = RTF_REJECT;
	if (fi && fi->fib_nh->nh_gw)
		flags |= RTF_GATEWAY;
	if (mask == htonl(0xFFFFFFFF))
		flags |= RTF_HOST;
	flags |= RTF_UP;
	return flags;
}

/*
 *	This outputs /proc/net/route.
 *	The format of the file is not supposed to be changed
 *	and needs to be same as fib_hash output to avoid breaking
 *	legacy utilities
 */
static int fib_route_seq_show(struct seq_file *seq, void *v)
{
	struct fib_route_iter *iter = seq->private;
	struct fib_table *tb = iter->main_tb;
	struct fib_alias *fa;
	struct key_vector *l = v;
	__be32 prefix;

	if (v == SEQ_START_TOKEN) {
		seq_printf(seq, "%-127s\n", "Iface\tDestination\tGateway "
			   "\tFlags\tRefCnt\tUse\tMetric\tMask\t\tMTU"
			   "\tWindow\tIRTT");
		return 0;
	}

	prefix = htonl(l->key);

	hlist_for_each_entry_rcu(fa, &l->leaf, fa_list) {
		const struct fib_info *fi = fa->fa_info;
		__be32 mask = inet_make_mask(KEYLENGTH - fa->fa_slen);
		unsigned int flags = fib_flag_trans(fa->fa_type, mask, fi);

		if ((fa->fa_type == RTN_BROADCAST) ||
		    (fa->fa_type == RTN_MULTICAST))
			continue;

		if (fa->tb_id != tb->tb_id)
			continue;

		seq_setwidth(seq, 127);

		if (fi)
			seq_printf(seq,
				   "%s\t%08X\t%08X\t%04X\t%d\t%u\t"
				   "%d\t%08X\t%d\t%u\t%u",
				   fi->fib_dev ? fi->fib_dev->name : "*",
				   prefix,
				   fi->fib_nh->nh_gw, flags, 0, 0,
				   fi->fib_priority,
				   mask,
				   (fi->fib_advmss ?
				    fi->fib_advmss + 40 : 0),
				   fi->fib_window,
				   fi->fib_rtt >> 3);
		else
			seq_printf(seq,
				   "*\t%08X\t%08X\t%04X\t%d\t%u\t"
				   "%d\t%08X\t%d\t%u\t%u",
				   prefix, 0, flags, 0, 0, 0,
				   mask, 0, 0, 0);

		seq_pad(seq, '\n');
	}

	return 0;
}

static const struct seq_operations fib_route_seq_ops = {
	.start  = fib_route_seq_start,
	.next   = fib_route_seq_next,
	.stop   = fib_route_seq_stop,
	.show   = fib_route_seq_show,
};

static int fib_route_seq_open(struct inode *inode, struct file *file)
{
	return seq_open_net(inode, file, &fib_route_seq_ops,
			    sizeof(struct fib_route_iter));
}

static const struct file_operations fib_route_fops = {
	.owner  = THIS_MODULE,
	.open   = fib_route_seq_open,
	.read   = seq_read,
	.llseek = seq_lseek,
	.release = seq_release_net,
};

int __net_init fib_proc_init(struct net *net)
{
	if (!proc_create("fib_trie", S_IRUGO, net->proc_net, &fib_trie_fops))
		goto out1;

	if (!proc_create("fib_triestat", S_IRUGO, net->proc_net,
			 &fib_triestat_fops))
		goto out2;

	if (!proc_create("route", S_IRUGO, net->proc_net, &fib_route_fops))
		goto out3;

	return 0;

out3:
	remove_proc_entry("fib_triestat", net->proc_net);
out2:
	remove_proc_entry("fib_trie", net->proc_net);
out1:
	return -ENOMEM;
}

void __net_exit fib_proc_exit(struct net *net)
{
	remove_proc_entry("fib_trie", net->proc_net);
	remove_proc_entry("fib_triestat", net->proc_net);
	remove_proc_entry("route", net->proc_net);
}

#endif /* CONFIG_PROC_FS */