aboutsummaryrefslogtreecommitdiffstats
path: root/nest/proto.c
blob: 6051ba9db0e11655887c41273cc7b69895ed8174 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
/*
 *	BIRD -- Protocols
 *
 *	(c) 1998--2000 Martin Mares <mj@ucw.cz>
 *
 *	Can be freely distributed and used under the terms of the GNU GPL.
 */

#undef LOCAL_DEBUG

#include "nest/bird.h"
#include "nest/protocol.h"
#include "lib/resource.h"
#include "lib/lists.h"
#include "lib/event.h"
#include "lib/timer.h"
#include "lib/string.h"
#include "conf/conf.h"
#include "nest/route.h"
#include "nest/iface.h"
#include "nest/cli.h"
#include "filter/filter.h"

pool *proto_pool;
list  proto_list;

static list protocol_list;
struct protocol *class_to_protocol[PROTOCOL__MAX];

#define PD(pr, msg, args...) do { if (pr->debug & D_STATES) { log(L_TRACE "%s: " msg, pr->name , ## args); } } while(0)

static timer *proto_shutdown_timer;
static timer *gr_wait_timer;

#define GRS_NONE	0
#define GRS_INIT	1
#define GRS_ACTIVE	2
#define GRS_DONE	3

static int graceful_restart_state;
static u32 graceful_restart_locks;

static char *p_states[] = { "DOWN", "START", "UP", "STOP" };
static char *c_states[] = { "DOWN", "START", "UP", "FLUSHING" };

extern struct protocol proto_unix_iface;

static void proto_shutdown_loop(timer *);
static void proto_rethink_goal(struct proto *p);
static char *proto_state_name(struct proto *p);
static void channel_verify_limits(struct channel *c);
static inline void channel_reset_limit(struct channel_limit *l);


static inline int proto_is_done(struct proto *p)
{ return (p->proto_state == PS_DOWN) && (p->active_channels == 0); }

static inline int channel_is_active(struct channel *c)
{ return (c->channel_state == CS_START) || (c->channel_state == CS_UP); }

static void
proto_log_state_change(struct proto *p)
{
  if (p->debug & D_STATES)
  {
    char *name = proto_state_name(p);
    if (name != p->last_state_name_announced)
    {
      p->last_state_name_announced = name;
      PD(p, "State changed to %s", proto_state_name(p));
    }
  }
  else
    p->last_state_name_announced = NULL;
}


struct channel_config *
proto_cf_find_channel(struct proto_config *pc, uint net_type)
{
  struct channel_config *cc;

  WALK_LIST(cc, pc->channels)
    if (cc->net_type == net_type)
      return cc;

  return NULL;
}

/**
 * proto_find_channel_by_table - find channel connected to a routing table
 * @p: protocol instance
 * @t: routing table
 *
 * Returns pointer to channel or NULL
 */
struct channel *
proto_find_channel_by_table(struct proto *p, struct rtable *t)
{
  struct channel *c;

  WALK_LIST(c, p->channels)
    if (c->table == t)
      return c;

  return NULL;
}

/**
 * proto_find_channel_by_name - find channel by its name
 * @p: protocol instance
 * @n: channel name
 *
 * Returns pointer to channel or NULL
 */
struct channel *
proto_find_channel_by_name(struct proto *p, const char *n)
{
  struct channel *c;

  WALK_LIST(c, p->channels)
    if (!strcmp(c->name, n))
      return c;

  return NULL;
}

/**
 * proto_add_channel - connect protocol to a routing table
 * @p: protocol instance
 * @cf: channel configuration
 *
 * This function creates a channel between the protocol instance @p and the
 * routing table specified in the configuration @cf, making the protocol hear
 * all changes in the table and allowing the protocol to update routes in the
 * table.
 *
 * The channel is linked in the protocol channel list and when active also in
 * the table channel list. Channels are allocated from the global resource pool
 * (@proto_pool) and they are automatically freed when the protocol is removed.
 */

struct channel *
proto_add_channel(struct proto *p, struct channel_config *cf)
{
  struct channel *c = mb_allocz(proto_pool, cf->channel->channel_size);

  c->name = cf->name;
  c->channel = cf->channel;
  c->proto = p;
  c->table = cf->table->table;

  c->in_filter = cf->in_filter;
  c->out_filter = cf->out_filter;
  c->rx_limit = cf->rx_limit;
  c->in_limit = cf->in_limit;
  c->out_limit = cf->out_limit;

  c->net_type = cf->net_type;
  c->ra_mode = cf->ra_mode;
  c->preference = cf->preference;
  c->merge_limit = cf->merge_limit;
  c->in_keep_filtered = cf->in_keep_filtered;

  c->channel_state = CS_DOWN;
  c->export_state = ES_DOWN;
  c->last_state_change = current_time();
  c->last_tx_filter_change = current_time();
  c->reloadable = 1;

  CALL(c->channel->init, c, cf);

  add_tail(&p->channels, &c->n);

  PD(p, "Channel %s connected to table %s", c->name, c->table->name);

  return c;
}

void
proto_remove_channel(struct proto *p, struct channel *c)
{
  ASSERT(c->channel_state == CS_DOWN);

  PD(p, "Channel %s removed", c->name);

  rem_node(&c->n);
  mb_free(c);
}


static void
proto_start_channels(struct proto *p)
{
  struct channel *c;
  WALK_LIST(c, p->channels)
    if (!c->disabled)
      channel_set_state(c, CS_UP);
}

static void
proto_pause_channels(struct proto *p)
{
  struct channel *c;
  WALK_LIST(c, p->channels)
    if (!c->disabled && channel_is_active(c))
      channel_set_state(c, CS_START);
}

static void
proto_stop_channels(struct proto *p)
{
  struct channel *c;
  WALK_LIST(c, p->channels)
    if (!c->disabled && channel_is_active(c))
      channel_set_state(c, CS_FLUSHING);
}

static void
proto_remove_channels(struct proto *p)
{
  struct channel *c;
  WALK_LIST_FIRST(c, p->channels)
    proto_remove_channel(p, c);
}

static void
channel_schedule_feed(struct channel *c, int initial)
{
  // DBG("%s: Scheduling meal\n", p->name);
  ASSERT(c->channel_state == CS_UP);

  c->export_state = ES_FEEDING;
  c->refeeding = !initial;

  ev_schedule(c->feed_event);
}

static void
channel_feed_loop(void *ptr)
{
  struct channel *c = ptr;

  if (c->export_state != ES_FEEDING)
    return;

  if (!c->feed_active)
    if (c->proto->feed_begin)
      c->proto->feed_begin(c, !c->refeeding);

  // DBG("Feeding protocol %s continued\n", p->name);
  if (!rt_feed_channel(c))
  {
    ev_schedule(c->feed_event);
    return;
  }

  /* Reset export limit if the feed ended with acceptable number of exported routes */
  struct channel_limit *l = &c->out_limit;
  if (c->refeeding &&
      (l->state == PLS_BLOCKED) &&
      (c->refeed_count <= l->limit) &&
      (c->stats.exp_routes <= l->limit))
  {
    log(L_INFO "Protocol %s resets route export limit (%u)", c->proto->name, l->limit);
    channel_reset_limit(&c->out_limit);

    /* Continue in feed - it will process routing table again from beginning */
    c->refeed_count = 0;
    ev_schedule(c->feed_event);
    return;
  }

  // DBG("Feeding protocol %s finished\n", p->name);
  c->export_state = ES_READY;
  // proto_log_state_change(p);

  if (c->proto->feed_end)
    c->proto->feed_end(c);
}


static void
channel_start_export(struct channel *c)
{
  ASSERT(c->channel_state == CS_UP);
  ASSERT(c->export_state == ES_DOWN);

  channel_schedule_feed(c, 1);	/* Sets ES_FEEDING */
}

static void
channel_stop_export(struct channel *c)
{
  /* Need to abort feeding */
  if (c->export_state == ES_FEEDING)
    rt_feed_channel_abort(c);

  c->export_state = ES_DOWN;
  c->stats.exp_routes = 0;
  bmap_reset(&c->export_map, 1024);
}


/* Called by protocol for reload from in_table */
void
channel_schedule_reload(struct channel *c)
{
  ASSERT(c->channel_state == CS_UP);

  rt_reload_channel_abort(c);
  ev_schedule(c->reload_event);
}

static void
channel_reload_loop(void *ptr)
{
  struct channel *c = ptr;

  if (!rt_reload_channel(c))
  {
    ev_schedule(c->reload_event);
    return;
  }
}

static void
channel_reset_import(struct channel *c)
{
  /* Need to abort feeding */
  ev_postpone(c->reload_event);
  rt_reload_channel_abort(c);

  rt_prune_sync(c->in_table, 1);
}

static void
channel_reset_export(struct channel *c)
{
  /* Just free the routes */
  rt_prune_sync(c->out_table, 1);
}

/* Called by protocol to activate in_table */
void
channel_setup_in_table(struct channel *c)
{
  struct rtable_config *cf = mb_allocz(c->proto->pool, sizeof(struct rtable_config));
  cf->name = "import";
  cf->addr_type = c->net_type;

  c->in_table = mb_allocz(c->proto->pool, sizeof(struct rtable));
  rt_setup(c->proto->pool, c->in_table, cf);

  c->reload_event = ev_new_init(c->proto->pool, channel_reload_loop, c);
}

/* Called by protocol to activate out_table */
void
channel_setup_out_table(struct channel *c)
{
  struct rtable_config *cf = mb_allocz(c->proto->pool, sizeof(struct rtable_config));
  cf->name = "export";
  cf->addr_type = c->net_type;

  c->out_table = mb_allocz(c->proto->pool, sizeof(struct rtable));
  rt_setup(c->proto->pool, c->out_table, cf);
}


static void
channel_do_start(struct channel *c)
{
  rt_lock_table(c->table);
  add_tail(&c->table->channels, &c->table_node);
  c->proto->active_channels++;

  c->feed_event = ev_new_init(c->proto->pool, channel_feed_loop, c);

  bmap_init(&c->export_map, c->proto->pool, 1024);
  memset(&c->stats, 0, sizeof(struct proto_stats));

  channel_reset_limit(&c->rx_limit);
  channel_reset_limit(&c->in_limit);
  channel_reset_limit(&c->out_limit);

  CALL(c->channel->start, c);
}

static void
channel_do_flush(struct channel *c)
{
  rt_schedule_prune(c->table);

  c->gr_wait = 0;
  if (c->gr_lock)
    channel_graceful_restart_unlock(c);

  CALL(c->channel->shutdown, c);

  /* This have to be done in here, as channel pool is freed before channel_do_down() */
  bmap_free(&c->export_map);
  c->in_table = NULL;
  c->reload_event = NULL;
  c->out_table = NULL;
}

static void
channel_do_down(struct channel *c)
{
  ASSERT(!c->feed_active && !c->reload_active);

  rem_node(&c->table_node);
  rt_unlock_table(c->table);
  c->proto->active_channels--;

  if ((c->stats.imp_routes + c->stats.filt_routes) != 0)
    log(L_ERR "%s: Channel %s is down but still has some routes", c->proto->name, c->name);

  // bmap_free(&c->export_map);
  memset(&c->stats, 0, sizeof(struct proto_stats));

  c->in_table = NULL;
  c->reload_event = NULL;
  c->out_table = NULL;

  CALL(c->channel->cleanup, c);

  /* Schedule protocol shutddown */
  if (proto_is_done(c->proto))
    ev_schedule(c->proto->event);
}

void
channel_set_state(struct channel *c, uint state)
{
  uint cs = c->channel_state;
  uint es = c->export_state;

  DBG("%s reporting channel %s state transition %s -> %s\n", c->proto->name, c->name, c_states[cs], c_states[state]);
  if (state == cs)
    return;

  c->channel_state = state;
  c->last_state_change = current_time();

  switch (state)
  {
  case CS_START:
    ASSERT(cs == CS_DOWN || cs == CS_UP);

    if (cs == CS_DOWN)
      channel_do_start(c);

    if (es != ES_DOWN)
      channel_stop_export(c);

    if (c->in_table && (cs == CS_UP))
      channel_reset_import(c);

    if (c->out_table && (cs == CS_UP))
      channel_reset_export(c);

    break;

  case CS_UP:
    ASSERT(cs == CS_DOWN || cs == CS_START);

    if (cs == CS_DOWN)
      channel_do_start(c);

    if (!c->gr_wait && c->proto->rt_notify)
      channel_start_export(c);

    break;

  case CS_FLUSHING:
    ASSERT(cs == CS_START || cs == CS_UP);

    if (es != ES_DOWN)
      channel_stop_export(c);

    if (c->in_table && (cs == CS_UP))
      channel_reset_import(c);

    if (c->out_table && (cs == CS_UP))
      channel_reset_export(c);

    channel_do_flush(c);
    break;

  case CS_DOWN:
    ASSERT(cs == CS_FLUSHING);

    channel_do_down(c);
    break;

  default:
    ASSERT(0);
  }
  // XXXX proto_log_state_change(c);
}

/**
 * channel_request_feeding - request feeding routes to the channel
 * @c: given channel
 *
 * Sometimes it is needed to send again all routes to the channel. This is
 * called feeding and can be requested by this function. This would cause
 * channel export state transition to ES_FEEDING (during feeding) and when
 * completed, it will switch back to ES_READY. This function can be called
 * even when feeding is already running, in that case it is restarted.
 */
void
channel_request_feeding(struct channel *c)
{
  ASSERT(c->channel_state == CS_UP);

  /* Do nothing if we are still waiting for feeding */
  if (c->export_state == ES_DOWN)
    return;

  /* If we are already feeding, we want to restart it */
  if (c->export_state == ES_FEEDING)
  {
    /* Unless feeding is in initial state */
    if (!c->feed_active)
	return;

    rt_feed_channel_abort(c);
  }

  /* Track number of exported routes during refeed */
  c->refeed_count = 0;

  channel_schedule_feed(c, 0);	/* Sets ES_FEEDING */
  // proto_log_state_change(c);
}

static inline int
channel_reloadable(struct channel *c)
{
  return c->proto->reload_routes && c->reloadable;
}

static void
channel_request_reload(struct channel *c)
{
  ASSERT(c->channel_state == CS_UP);
  ASSERT(channel_reloadable(c));

  c->proto->reload_routes(c);

  /*
   * Should this be done before reload_routes() hook?
   * Perhaps, but routes are updated asynchronously.
   */
  channel_reset_limit(&c->rx_limit);
  channel_reset_limit(&c->in_limit);
}

const struct channel_class channel_basic = {
  .channel_size = sizeof(struct channel),
  .config_size = sizeof(struct channel_config)
};

void *
channel_config_new(const struct channel_class *cc, const char *name, uint net_type, struct proto_config *proto)
{
  struct channel_config *cf = NULL;
  struct rtable_config *tab = NULL;

  if (net_type)
  {
    if (!net_val_match(net_type, proto->protocol->channel_mask))
      cf_error("Unsupported channel type");

    if (proto->net_type && (net_type != proto->net_type))
      cf_error("Different channel type");

    tab = new_config->def_tables[net_type];
  }

  if (!cc)
    cc = &channel_basic;

  cf = cfg_allocz(cc->config_size);
  cf->name = name;
  cf->channel = cc;
  cf->parent = proto;
  cf->table = tab;
  cf->out_filter = FILTER_REJECT;

  cf->net_type = net_type;
  cf->ra_mode = RA_OPTIMAL;
  cf->preference = proto->protocol->preference;

  add_tail(&proto->channels, &cf->n);

  return cf;
}

void *
channel_config_get(const struct channel_class *cc, const char *name, uint net_type, struct proto_config *proto)
{
  struct channel_config *cf;

  /* We are using name as token, so no strcmp() */
  WALK_LIST(cf, proto->channels)
    if (cf->name == name)
    {
      /* Allow to redefine channel only if inherited from template */
      if (cf->parent == proto)
	cf_error("Multiple %s channels", name);

      cf->parent = proto;
      return cf;
    }

  return channel_config_new(cc, name, net_type, proto);
}

struct channel_config *
channel_copy_config(struct channel_config *src, struct proto_config *proto)
{
  struct channel_config *dst = cfg_alloc(src->channel->config_size);

  memcpy(dst, src, src->channel->config_size);
  add_tail(&proto->channels, &dst->n);
  CALL(src->channel->copy_config, dst, src);

  return dst;
}


static int reconfigure_type;  /* Hack to propagate type info to channel_reconfigure() */

int
channel_reconfigure(struct channel *c, struct channel_config *cf)
{
  /* FIXME: better handle these changes, also handle in_keep_filtered */
  if ((c->table != cf->table->table) || (cf->ra_mode && (c->ra_mode != cf->ra_mode)))
    return 0;

  /* Note that filter_same() requires arguments in (new, old) order */
  int import_changed = !filter_same(cf->in_filter, c->in_filter);
  int export_changed = !filter_same(cf->out_filter, c->out_filter);

  if (c->preference != cf->preference)
    import_changed = 1;

  if (c->merge_limit != cf->merge_limit)
    export_changed = 1;

  /* Reconfigure channel fields */
  c->in_filter = cf->in_filter;
  c->out_filter = cf->out_filter;
  c->rx_limit = cf->rx_limit;
  c->in_limit = cf->in_limit;
  c->out_limit = cf->out_limit;

  // c->ra_mode = cf->ra_mode;
  c->merge_limit = cf->merge_limit;
  c->preference = cf->preference;
  c->in_keep_filtered = cf->in_keep_filtered;

  channel_verify_limits(c);

  if (export_changed)
    c->last_tx_filter_change = current_time();

  /* Execute channel-specific reconfigure hook */
  if (c->channel->reconfigure && !c->channel->reconfigure(c, cf, &import_changed, &export_changed))
    return 0;

  /* If the channel is not open, it has no routes and we cannot reload it anyways */
  if (c->channel_state != CS_UP)
    return 1;

  if (reconfigure_type == RECONFIG_SOFT)
  {
    if (import_changed)
      log(L_INFO "Channel %s.%s changed import", c->proto->name, c->name);

    if (export_changed)
      log(L_INFO "Channel %s.%s changed export", c->proto->name, c->name);

    return 1;
  }

  /* Route reload may be not supported */
  if (import_changed && !channel_reloadable(c))
    return 0;

  if (import_changed || export_changed)
    log(L_INFO "Reloading channel %s.%s", c->proto->name, c->name);

  if (import_changed)
    channel_request_reload(c);

  if (export_changed)
    channel_request_feeding(c);

  return 1;
}


int
proto_configure_channel(struct proto *p, struct channel **pc, struct channel_config *cf)
{
  struct channel *c = *pc;

  if (!c && cf)
  {
    /* We could add the channel, but currently it would just stay in down state
       until protocol is restarted, so it is better to force restart anyways. */
    if (p->proto_state != PS_DOWN)
    {
      log(L_INFO "Cannot add channel %s.%s", p->name, cf->name);
      return 0;
    }

    *pc = proto_add_channel(p, cf);
  }
  else if (c && !cf)
  {
    if (c->channel_state != CS_DOWN)
    {
      log(L_INFO "Cannot remove channel %s.%s", c->proto->name, c->name);
      return 0;
    }

    proto_remove_channel(p, c);
    *pc = NULL;
  }
  else if (c && cf)
  {
    if (!channel_reconfigure(c, cf))
    {
      log(L_INFO "Cannot reconfigure channel %s.%s", c->proto->name, c->name);
      return 0;
    }
  }

  return 1;
}


static void
proto_event(void *ptr)
{
  struct proto *p = ptr;

  if (p->do_start)
  {
    if_feed_baby(p);
    p->do_start = 0;
  }

  if (p->do_stop)
  {
    if (p->proto == &proto_unix_iface)
      if_flush_ifaces(p);
    p->do_stop = 0;
  }

  if (proto_is_done(p))
  {
    if (p->proto->cleanup)
      p->proto->cleanup(p);

    p->active = 0;
    proto_log_state_change(p);
    proto_rethink_goal(p);
  }
}


/**
 * proto_new - create a new protocol instance
 * @c: protocol configuration
 *
 * When a new configuration has been read in, the core code starts
 * initializing all the protocol instances configured by calling their
 * init() hooks with the corresponding instance configuration. The initialization
 * code of the protocol is expected to create a new instance according to the
 * configuration by calling this function and then modifying the default settings
 * to values wanted by the protocol.
 */
void *
proto_new(struct proto_config *cf)
{
  struct proto *p = mb_allocz(proto_pool, cf->protocol->proto_size);

  p->cf = cf;
  p->debug = cf->debug;
  p->mrtdump = cf->mrtdump;
  p->name = cf->name;
  p->proto = cf->protocol;
  p->net_type = cf->net_type;
  p->disabled = cf->disabled;
  p->hash_key = random_u32();
  cf->proto = p;

  init_list(&p->channels);

  return p;
}

static struct proto *
proto_init(struct proto_config *c, node *n)
{
  struct protocol *pr = c->protocol;
  struct proto *p = pr->init(c);

  p->proto_state = PS_DOWN;
  p->last_state_change = current_time();
  p->vrf = c->vrf;
  p->vrf_set = c->vrf_set;
  insert_node(&p->n, n);

  p->event = ev_new_init(proto_pool, proto_event, p);

  PD(p, "Initializing%s", p->disabled ? " [disabled]" : "");

  return p;
}

static void
proto_start(struct proto *p)
{
  /* Here we cannot use p->cf->name since it won't survive reconfiguration */
  p->pool = rp_new(proto_pool, p->proto->name);

  if (graceful_restart_state == GRS_INIT)
    p->gr_recovery = 1;
}


/**
 * proto_config_new - create a new protocol configuration
 * @pr: protocol the configuration will belong to
 * @class: SYM_PROTO or SYM_TEMPLATE
 *
 * Whenever the configuration file says that a new instance
 * of a routing protocol should be created, the parser calls
 * proto_config_new() to create a configuration entry for this
 * instance (a structure staring with the &proto_config header
 * containing all the generic items followed by protocol-specific
 * ones). Also, the configuration entry gets added to the list
 * of protocol instances kept in the configuration.
 *
 * The function is also used to create protocol templates (when class
 * SYM_TEMPLATE is specified), the only difference is that templates
 * are not added to the list of protocol instances and therefore not
 * initialized during protos_commit()).
 */
void *
proto_config_new(struct protocol *pr, int class)
{
  struct proto_config *cf = cfg_allocz(pr->config_size);

  if (class == SYM_PROTO)
    add_tail(&new_config->protos, &cf->n);

  cf->global = new_config;
  cf->protocol = pr;
  cf->name = pr->name;
  cf->class = class;
  cf->debug = new_config->proto_default_debug;
  cf->mrtdump = new_config->proto_default_mrtdump;

  init_list(&cf->channels);

  return cf;
}


/**
 * proto_copy_config - copy a protocol configuration
 * @dest: destination protocol configuration
 * @src: source protocol configuration
 *
 * Whenever a new instance of a routing protocol is created from the
 * template, proto_copy_config() is called to copy a content of
 * the source protocol configuration to the new protocol configuration.
 * Name, class and a node in protos list of @dest are kept intact.
 * copy_config() protocol hook is used to copy protocol-specific data.
 */
void
proto_copy_config(struct proto_config *dest, struct proto_config *src)
{
  struct channel_config *cc;
  node old_node;
  int old_class;
  char *old_name;

  if (dest->protocol != src->protocol)
    cf_error("Can't copy configuration from a different protocol type");

  if (dest->protocol->copy_config == NULL)
    cf_error("Inheriting configuration for %s is not supported", src->protocol->name);

  DBG("Copying configuration from %s to %s\n", src->name, dest->name);

  /*
   * Copy struct proto_config here. Keep original node, class and name.
   * protocol-specific config copy is handled by protocol copy_config() hook
   */

  old_node = dest->n;
  old_class = dest->class;
  old_name = dest->name;

  memcpy(dest, src, src->protocol->config_size);

  dest->n = old_node;
  dest->class = old_class;
  dest->name = old_name;
  init_list(&dest->channels);

  WALK_LIST(cc, src->channels)
    channel_copy_config(cc, dest);

  /* FIXME: allow for undefined copy_config */
  dest->protocol->copy_config(dest, src);
}

void
proto_clone_config(struct symbol *sym, struct proto_config *parent)
{
  struct proto_config *cf = proto_config_new(parent->protocol, SYM_PROTO);
  proto_copy_config(cf, parent);
  cf->name = sym->name;
  cf->proto = NULL;
  cf->parent = parent;

  sym->class = cf->class;
  sym->proto = cf;
}

static void
proto_undef_clone(struct symbol *sym, struct proto_config *cf)
{
  rem_node(&cf->n);

  sym->class = SYM_VOID;
  sym->proto = NULL;
}

/**
 * protos_preconfig - pre-configuration processing
 * @c: new configuration
 *
 * This function calls the preconfig() hooks of all routing
 * protocols available to prepare them for reading of the new
 * configuration.
 */
void
protos_preconfig(struct config *c)
{
  struct protocol *p;

  init_list(&c->protos);
  DBG("Protocol preconfig:");
  WALK_LIST(p, protocol_list)
  {
    DBG(" %s", p->name);
    p->name_counter = 0;
    if (p->preconfig)
      p->preconfig(p, c);
  }
  DBG("\n");
}

static int
proto_reconfigure(struct proto *p, struct proto_config *oc, struct proto_config *nc, int type)
{
  /* If the protocol is DOWN, we just restart it */
  if (p->proto_state == PS_DOWN)
    return 0;

  /* If there is a too big change in core attributes, ... */
  if ((nc->protocol != oc->protocol) ||
      (nc->net_type != oc->net_type) ||
      (nc->disabled != p->disabled) ||
      (nc->vrf != oc->vrf) ||
      (nc->vrf_set != oc->vrf_set))
    return 0;

  p->name = nc->name;
  p->debug = nc->debug;
  p->mrtdump = nc->mrtdump;
  reconfigure_type = type;

  /* Execute protocol specific reconfigure hook */
  if (!p->proto->reconfigure || !p->proto->reconfigure(p, nc))
    return 0;

  DBG("\t%s: same\n", oc->name);
  PD(p, "Reconfigured");
  p->cf = nc;

  return 1;
}

/**
 * protos_commit - commit new protocol configuration
 * @new: new configuration
 * @old: old configuration or %NULL if it's boot time config
 * @force_reconfig: force restart of all protocols (used for example
 * when the router ID changes)
 * @type: type of reconfiguration (RECONFIG_SOFT or RECONFIG_HARD)
 *
 * Scan differences between @old and @new configuration and adjust all
 * protocol instances to conform to the new configuration.
 *
 * When a protocol exists in the new configuration, but it doesn't in the
 * original one, it's immediately started. When a collision with the other
 * running protocol would arise, the new protocol will be temporarily stopped
 * by the locking mechanism.
 *
 * When a protocol exists in the old configuration, but it doesn't in the
 * new one, it's shut down and deleted after the shutdown completes.
 *
 * When a protocol exists in both configurations, the core decides
 * whether it's possible to reconfigure it dynamically - it checks all
 * the core properties of the protocol (changes in filters are ignored
 * if type is RECONFIG_SOFT) and if they match, it asks the
 * reconfigure() hook of the protocol to see if the protocol is able
 * to switch to the new configuration.  If it isn't possible, the
 * protocol is shut down and a new instance is started with the new
 * configuration after the shutdown is completed.
 */
void
protos_commit(struct config *new, struct config *old, int force_reconfig, int type)
{
  struct proto_config *oc, *nc;
  struct symbol *sym;
  struct proto *p;
  node *n;


  DBG("protos_commit:\n");
  if (old)
  {
    WALK_LIST(oc, old->protos)
    {
      p = oc->proto;
      sym = cf_find_symbol(new, oc->name);

      /* Handle dynamic protocols */
      if (!sym && oc->parent && !new->shutdown)
      {
	struct symbol *parsym = cf_find_symbol(new, oc->parent->name);
	if (parsym && parsym->class == SYM_PROTO)
	{
	  /* This is hack, we would like to share config, but we need to copy it now */
	  new_config = new;
	  cfg_mem = new->mem;
	  conf_this_scope = new->root_scope;
	  sym = cf_get_symbol(oc->name);
	  proto_clone_config(sym, parsym->proto);
	  new_config = NULL;
	  cfg_mem = NULL;
	}
      }

      if (sym && sym->class == SYM_PROTO && !new->shutdown)
      {
	/* Found match, let's check if we can smoothly switch to new configuration */
	/* No need to check description */
	nc = sym->proto;
	nc->proto = p;

	/* We will try to reconfigure protocol p */
	if (! force_reconfig && proto_reconfigure(p, oc, nc, type))
	  continue;

	if (nc->parent)
	{
	  proto_undef_clone(sym, nc);
	  goto remove;
	}

	/* Unsuccessful, we will restart it */
	if (!p->disabled && !nc->disabled)
	  log(L_INFO "Restarting protocol %s", p->name);
	else if (p->disabled && !nc->disabled)
	  log(L_INFO "Enabling protocol %s", p->name);
	else if (!p->disabled && nc->disabled)
	  log(L_INFO "Disabling protocol %s", p->name);

	p->down_code = nc->disabled ? PDC_CF_DISABLE : PDC_CF_RESTART;
	p->cf_new = nc;
      }
      else if (!new->shutdown)
      {
      remove:
	log(L_INFO "Removing protocol %s", p->name);
	p->down_code = PDC_CF_REMOVE;
	p->cf_new = NULL;
      }
      else if (new->gr_down)
      {
	p->down_code = PDC_CMD_GR_DOWN;
	p->cf_new = NULL;
      }
      else /* global shutdown */
      {
	p->down_code = PDC_CMD_SHUTDOWN;
	p->cf_new = NULL;
      }

      p->reconfiguring = 1;
      config_add_obstacle(old);
      proto_rethink_goal(p);
    }
  }

  struct proto *first_dev_proto = NULL;

  n = NODE &(proto_list.head);
  WALK_LIST(nc, new->protos)
    if (!nc->proto)
    {
      /* Not a first-time configuration */
      if (old)
	log(L_INFO "Adding protocol %s", nc->name);

      p = proto_init(nc, n);
      n = NODE p;

      if (p->proto == &proto_unix_iface)
	first_dev_proto = p;
    }
    else
      n = NODE nc->proto;

  DBG("Protocol start\n");

  /* Start device protocol first */
  if (first_dev_proto)
    proto_rethink_goal(first_dev_proto);

  /* Determine router ID for the first time - it has to be here and not in
     global_commit() because it is postponed after start of device protocol */
  if (!config->router_id)
  {
    config->router_id = if_choose_router_id(config->router_id_from, 0);
    if (!config->router_id)
      die("Cannot determine router ID, please configure it manually");
  }

  /* Start all new protocols */
  WALK_LIST_DELSAFE(p, n, proto_list)
    proto_rethink_goal(p);
}

static void
proto_rethink_goal(struct proto *p)
{
  struct protocol *q;
  byte goal;

  if (p->reconfiguring && !p->active)
  {
    struct proto_config *nc = p->cf_new;
    node *n = p->n.prev;
    DBG("%s has shut down for reconfiguration\n", p->name);
    p->cf->proto = NULL;
    config_del_obstacle(p->cf->global);
    proto_remove_channels(p);
    rem_node(&p->n);
    rfree(p->event);
    mb_free(p->message);
    mb_free(p);
    if (!nc)
      return;
    p = proto_init(nc, n);
  }

  /* Determine what state we want to reach */
  if (p->disabled || p->reconfiguring)
    goal = PS_DOWN;
  else
    goal = PS_UP;

  q = p->proto;
  if (goal == PS_UP)
  {
    if (!p->active)
    {
      /* Going up */
      DBG("Kicking %s up\n", p->name);
      PD(p, "Starting");
      proto_start(p);
      proto_notify_state(p, (q->start ? q->start(p) : PS_UP));
    }
  }
  else
  {
    if (p->proto_state == PS_START || p->proto_state == PS_UP)
    {
      /* Going down */
      DBG("Kicking %s down\n", p->name);
      PD(p, "Shutting down");
      proto_notify_state(p, (q->shutdown ? q->shutdown(p) : PS_DOWN));
    }
  }
}

struct proto *
proto_spawn(struct proto_config *cf, uint disabled)
{
  struct proto *p = proto_init(cf, TAIL(proto_list));
  p->disabled = disabled;
  proto_rethink_goal(p);
  return p;
}


/**
 * DOC: Graceful restart recovery
 *
 * Graceful restart of a router is a process when the routing plane (e.g. BIRD)
 * restarts but both the forwarding plane (e.g kernel routing table) and routing
 * neighbors keep proper routes, and therefore uninterrupted packet forwarding
 * is maintained.
 *
 * BIRD implements graceful restart recovery by deferring export of routes to
 * protocols until routing tables are refilled with the expected content. After
 * start, protocols generate routes as usual, but routes are not propagated to
 * them, until protocols report that they generated all routes. After that,
 * graceful restart recovery is finished and the export (and the initial feed)
 * to protocols is enabled.
 *
 * When graceful restart recovery need is detected during initialization, then
 * enabled protocols are marked with @gr_recovery flag before start. Such
 * protocols then decide how to proceed with graceful restart, participation is
 * voluntary. Protocols could lock the recovery for each channel by function
 * channel_graceful_restart_lock() (state stored in @gr_lock flag), which means
 * that they want to postpone the end of the recovery until they converge and
 * then unlock it. They also could set @gr_wait before advancing to %PS_UP,
 * which means that the core should defer route export to that channel until
 * the end of the recovery. This should be done by protocols that expect their
 * neigbors to keep the proper routes (kernel table, BGP sessions with BGP
 * graceful restart capability).
 *
 * The graceful restart recovery is finished when either all graceful restart
 * locks are unlocked or when graceful restart wait timer fires.
 *
 */

static void graceful_restart_done(timer *t);

/**
 * graceful_restart_recovery - request initial graceful restart recovery
 *
 * Called by the platform initialization code if the need for recovery
 * after graceful restart is detected during boot. Have to be called
 * before protos_commit().
 */
void
graceful_restart_recovery(void)
{
  graceful_restart_state = GRS_INIT;
}

/**
 * graceful_restart_init - initialize graceful restart
 *
 * When graceful restart recovery was requested, the function starts an active
 * phase of the recovery and initializes graceful restart wait timer. The
 * function have to be called after protos_commit().
 */
void
graceful_restart_init(void)
{
  if (!graceful_restart_state)
    return;

  log(L_INFO "Graceful restart started");

  if (!graceful_restart_locks)
  {
    graceful_restart_done(NULL);
    return;
  }

  graceful_restart_state = GRS_ACTIVE;
  gr_wait_timer = tm_new_init(proto_pool, graceful_restart_done, NULL, 0, 0);
  tm_start(gr_wait_timer, config->gr_wait S);
}

/**
 * graceful_restart_done - finalize graceful restart
 * @t: unused
 *
 * When there are no locks on graceful restart, the functions finalizes the
 * graceful restart recovery. Protocols postponing route export until the end of
 * the recovery are awakened and the export to them is enabled. All other
 * related state is cleared. The function is also called when the graceful
 * restart wait timer fires (but there are still some locks).
 */
static void
graceful_restart_done(timer *t UNUSED)
{
  log(L_INFO "Graceful restart done");
  graceful_restart_state = GRS_DONE;

  struct proto *p;
  WALK_LIST(p, proto_list)
  {
    if (!p->gr_recovery)
      continue;

    struct channel *c;
    WALK_LIST(c, p->channels)
    {
      /* Resume postponed export of routes */
      if ((c->channel_state == CS_UP) && c->gr_wait && c->proto->rt_notify)
	channel_start_export(c);

      /* Cleanup */
      c->gr_wait = 0;
      c->gr_lock = 0;
    }

    p->gr_recovery = 0;
  }

  graceful_restart_locks = 0;
}

void
graceful_restart_show_status(void)
{
  if (graceful_restart_state != GRS_ACTIVE)
    return;

  cli_msg(-24, "Graceful restart recovery in progress");
  cli_msg(-24, "  Waiting for %d channels to recover", graceful_restart_locks);
  cli_msg(-24, "  Wait timer is %t/%u", tm_remains(gr_wait_timer), config->gr_wait);
}

/**
 * channel_graceful_restart_lock - lock graceful restart by channel
 * @p: channel instance
 *
 * This function allows a protocol to postpone the end of graceful restart
 * recovery until it converges. The lock is removed when the protocol calls
 * channel_graceful_restart_unlock() or when the channel is closed.
 *
 * The function have to be called during the initial phase of graceful restart
 * recovery and only for protocols that are part of graceful restart (i.e. their
 * @gr_recovery is set), which means it should be called from protocol start
 * hooks.
 */
void
channel_graceful_restart_lock(struct channel *c)
{
  ASSERT(graceful_restart_state == GRS_INIT);
  ASSERT(c->proto->gr_recovery);

  if (c->gr_lock)
    return;

  c->gr_lock = 1;
  graceful_restart_locks++;
}

/**
 * channel_graceful_restart_unlock - unlock graceful restart by channel
 * @p: channel instance
 *
 * This function unlocks a lock from channel_graceful_restart_lock(). It is also
 * automatically called when the lock holding protocol went down.
 */
void
channel_graceful_restart_unlock(struct channel *c)
{
  if (!c->gr_lock)
    return;

  c->gr_lock = 0;
  graceful_restart_locks--;

  if ((graceful_restart_state == GRS_ACTIVE) && !graceful_restart_locks)
    tm_start(gr_wait_timer, 0);
}



/**
 * protos_dump_all - dump status of all protocols
 *
 * This function dumps status of all existing protocol instances to the
 * debug output. It involves printing of general status information
 * such as protocol states, its position on the protocol lists
 * and also calling of a dump() hook of the protocol to print
 * the internals.
 */
void
protos_dump_all(void)
{
  debug("Protocols:\n");

  struct proto *p;
  WALK_LIST(p, proto_list)
  {
    debug("  protocol %s state %s\n", p->name, p_states[p->proto_state]);

    struct channel *c;
    WALK_LIST(c, p->channels)
    {
      debug("\tTABLE %s\n", c->table->name);
      if (c->in_filter)
	debug("\tInput filter: %s\n", filter_name(c->in_filter));
      if (c->out_filter)
	debug("\tOutput filter: %s\n", filter_name(c->out_filter));
    }

    if (p->proto->dump && (p->proto_state != PS_DOWN))
      p->proto->dump(p);
  }
}

/**
 * proto_build - make a single protocol available
 * @p: the protocol
 *
 * After the platform specific initialization code uses protos_build()
 * to add all the standard protocols, it should call proto_build() for
 * all platform specific protocols to inform the core that they exist.
 */
void
proto_build(struct protocol *p)
{
  add_tail(&protocol_list, &p->n);
  ASSERT(p->class);
  ASSERT(!class_to_protocol[p->class]);
  class_to_protocol[p->class] = p;
}

/* FIXME: convert this call to some protocol hook */
extern void bfd_init_all(void);

/**
 * protos_build - build a protocol list
 *
 * This function is called during BIRD startup to insert
 * all standard protocols to the global protocol list. Insertion
 * of platform specific protocols (such as the kernel syncer)
 * is in the domain of competence of the platform dependent
 * startup code.
 */
void
protos_build(void)
{
  init_list(&proto_list);
  init_list(&protocol_list);

  proto_build(&proto_device);
#ifdef CONFIG_RADV
  proto_build(&proto_radv);
#endif
#ifdef CONFIG_RIP
  proto_build(&proto_rip);
#endif
#ifdef CONFIG_STATIC
  proto_build(&proto_static);
#endif
#ifdef CONFIG_MRT
  proto_build(&proto_mrt);
#endif
#ifdef CONFIG_OSPF
  proto_build(&proto_ospf);
#endif
#ifdef CONFIG_PIPE
  proto_build(&proto_pipe);
#endif
#ifdef CONFIG_BGP
  proto_build(&proto_bgp);
#endif
#ifdef CONFIG_BFD
  proto_build(&proto_bfd);
  bfd_init_all();
#endif
#ifdef CONFIG_BABEL
  proto_build(&proto_babel);
#endif
#ifdef CONFIG_RPKI
  proto_build(&proto_rpki);
#endif
#ifdef CONFIG_PERF
  proto_build(&proto_perf);
#endif

  proto_pool = rp_new(&root_pool, "Protocols");
  proto_shutdown_timer = tm_new(proto_pool);
  proto_shutdown_timer->hook = proto_shutdown_loop;
}


/* Temporary hack to propagate restart to BGP */
int proto_restart;

static void
proto_shutdown_loop(timer *t UNUSED)
{
  struct proto *p, *p_next;

  WALK_LIST_DELSAFE(p, p_next, proto_list)
    if (p->down_sched)
    {
      proto_restart = (p->down_sched == PDS_RESTART);

      p->disabled = 1;
      proto_rethink_goal(p);
      if (proto_restart)
      {
	p->disabled = 0;
	proto_rethink_goal(p);
      }
    }
}

static inline void
proto_schedule_down(struct proto *p, byte restart, byte code)
{
  /* Does not work for other states (even PS_START) */
  ASSERT(p->proto_state == PS_UP);

  /* Scheduled restart may change to shutdown, but not otherwise */
  if (p->down_sched == PDS_DISABLE)
    return;

  p->down_sched = restart ? PDS_RESTART : PDS_DISABLE;
  p->down_code = code;
  tm_start_max(proto_shutdown_timer, restart ? 250 MS : 0);
}

/**
 * proto_set_message - set administrative message to protocol
 * @p: protocol
 * @msg: message
 * @len: message length (-1 for NULL-terminated string)
 *
 * The function sets administrative message (string) related to protocol state
 * change. It is called by the nest code for manual enable/disable/restart
 * commands all routes to the protocol, and by protocol-specific code when the
 * protocol state change is initiated by the protocol. Using NULL message clears
 * the last message. The message string may be either NULL-terminated or with an
 * explicit length.
 */
void
proto_set_message(struct proto *p, char *msg, int len)
{
  mb_free(p->message);
  p->message = NULL;

  if (!msg || !len)
    return;

  if (len < 0)
    len = strlen(msg);

  if (!len)
    return;

  p->message = mb_alloc(proto_pool, len + 1);
  memcpy(p->message, msg, len);
  p->message[len] = 0;
}


static const char *
channel_limit_name(struct channel_limit *l)
{
  const char *actions[] = {
    [PLA_WARN] = "warn",
    [PLA_BLOCK] = "block",
    [PLA_RESTART] = "restart",
    [PLA_DISABLE] = "disable",
  };

  return actions[l->action];
}

/**
 * channel_notify_limit: notify about limit hit and take appropriate action
 * @c: channel
 * @l: limit being hit
 * @dir: limit direction (PLD_*)
 * @rt_count: the number of routes
 *
 * The function is called by the route processing core when limit @l
 * is breached. It activates the limit and tooks appropriate action
 * according to @l->action.
 */
void
channel_notify_limit(struct channel *c, struct channel_limit *l, int dir, u32 rt_count)
{
  const char *dir_name[PLD_MAX] = { "receive", "import" , "export" };
  const byte dir_down[PLD_MAX] = { PDC_RX_LIMIT_HIT, PDC_IN_LIMIT_HIT, PDC_OUT_LIMIT_HIT };
  struct proto *p = c->proto;

  if (l->state == PLS_BLOCKED)
    return;

  /* For warning action, we want the log message every time we hit the limit */
  if (!l->state || ((l->action == PLA_WARN) && (rt_count == l->limit)))
    log(L_WARN "Protocol %s hits route %s limit (%d), action: %s",
	p->name, dir_name[dir], l->limit, channel_limit_name(l));

  switch (l->action)
  {
  case PLA_WARN:
    l->state = PLS_ACTIVE;
    break;

  case PLA_BLOCK:
    l->state = PLS_BLOCKED;
    break;

  case PLA_RESTART:
  case PLA_DISABLE:
    l->state = PLS_BLOCKED;
    if (p->proto_state == PS_UP)
      proto_schedule_down(p, l->action == PLA_RESTART, dir_down[dir]);
    break;
  }
}

static void
channel_verify_limits(struct channel *c)
{
  struct channel_limit *l;
  u32 all_routes = c->stats.imp_routes + c->stats.filt_routes;

  l = &c->rx_limit;
  if (l->action && (all_routes > l->limit))
    channel_notify_limit(c, l, PLD_RX, all_routes);

  l = &c->in_limit;
  if (l->action && (c->stats.imp_routes > l->limit))
    channel_notify_limit(c, l, PLD_IN, c->stats.imp_routes);

  l = &c->out_limit;
  if (l->action && (c->stats.exp_routes > l->limit))
    channel_notify_limit(c, l, PLD_OUT, c->stats.exp_routes);
}

static inline void
channel_reset_limit(struct channel_limit *l)
{
  if (l->action)
    l->state = PLS_INITIAL;
}

static inline void
proto_do_start(struct proto *p)
{
  p->active = 1;
  p->do_start = 1;
  ev_schedule(p->event);
}

static void
proto_do_up(struct proto *p)
{
  if (!p->main_source)
  {
    p->main_source = rt_get_source(p, 0);
    rt_lock_source(p->main_source);
  }

  proto_start_channels(p);
}

static inline void
proto_do_pause(struct proto *p)
{
  proto_pause_channels(p);
}

static void
proto_do_stop(struct proto *p)
{
  p->down_sched = 0;
  p->gr_recovery = 0;

  p->do_stop = 1;
  ev_schedule(p->event);

  if (p->main_source)
  {
    rt_unlock_source(p->main_source);
    p->main_source = NULL;
  }

  proto_stop_channels(p);
}

static void
proto_do_down(struct proto *p)
{
  p->down_code = 0;
  neigh_prune();
  rfree(p->pool);
  p->pool = NULL;

  /* Shutdown is finished in the protocol event */
  if (proto_is_done(p))
    ev_schedule(p->event);
}



/**
 * proto_notify_state - notify core about protocol state change
 * @p: protocol the state of which has changed
 * @ps: the new status
 *
 * Whenever a state of a protocol changes due to some event internal
 * to the protocol (i.e., not inside a start() or shutdown() hook),
 * it should immediately notify the core about the change by calling
 * proto_notify_state() which will write the new state to the &proto
 * structure and take all the actions necessary to adapt to the new
 * state. State change to PS_DOWN immediately frees resources of protocol
 * and might execute start callback of protocol; therefore,
 * it should be used at tail positions of protocol callbacks.
 */
void
proto_notify_state(struct proto *p, uint state)
{
  uint ps = p->proto_state;

  DBG("%s reporting state transition %s -> %s\n", p->name, p_states[ps], p_states[state]);
  if (state == ps)
    return;

  p->proto_state = state;
  p->last_state_change = current_time();

  switch (state)
  {
  case PS_START:
    ASSERT(ps == PS_DOWN || ps == PS_UP);

    if (ps == PS_DOWN)
      proto_do_start(p);
    else
      proto_do_pause(p);
    break;

  case PS_UP:
    ASSERT(ps == PS_DOWN || ps == PS_START);

    if (ps == PS_DOWN)
      proto_do_start(p);

    proto_do_up(p);
    break;

  case PS_STOP:
    ASSERT(ps == PS_START || ps == PS_UP);

    proto_do_stop(p);
    break;

  case PS_DOWN:
    if (ps != PS_STOP)
      proto_do_stop(p);

    proto_do_down(p);
    break;

  default:
    bug("%s: Invalid state %d", p->name, ps);
  }

  proto_log_state_change(p);
}

/*
 *  CLI Commands
 */

static char *
proto_state_name(struct proto *p)
{
  switch (p->proto_state)
  {
  case PS_DOWN:		return p->active ? "flush" : "down";
  case PS_START:	return "start";
  case PS_UP:		return "up";
  case PS_STOP:		return "stop";
  default:		return "???";
  }
}

static void
channel_show_stats(struct channel *c)
{
  struct proto_stats *s = &c->stats;

  if (c->in_keep_filtered)
    cli_msg(-1006, "    Routes:         %u imported, %u filtered, %u exported, %u preferred",
	    s->imp_routes, s->filt_routes, s->exp_routes, s->pref_routes);
  else
    cli_msg(-1006, "    Routes:         %u imported, %u exported, %u preferred",
	    s->imp_routes, s->exp_routes, s->pref_routes);

  cli_msg(-1006, "    Route change stats:     received   rejected   filtered    ignored   accepted");
  cli_msg(-1006, "      Import updates:     %10u %10u %10u %10u %10u",
	  s->imp_updates_received, s->imp_updates_invalid,
	  s->imp_updates_filtered, s->imp_updates_ignored,
	  s->imp_updates_accepted);
  cli_msg(-1006, "      Import withdraws:   %10u %10u        --- %10u %10u",
	  s->imp_withdraws_received, s->imp_withdraws_invalid,
	  s->imp_withdraws_ignored, s->imp_withdraws_accepted);
  cli_msg(-1006, "      Export updates:     %10u %10u %10u        --- %10u",
	  s->exp_updates_received, s->exp_updates_rejected,
	  s->exp_updates_filtered, s->exp_updates_accepted);
  cli_msg(-1006, "      Export withdraws:   %10u        ---        ---        --- %10u",
	  s->exp_withdraws_received, s->exp_withdraws_accepted);
}

void
channel_show_limit(struct channel_limit *l, const char *dsc)
{
  if (!l->action)
    return;

  cli_msg(-1006, "    %-16s%d%s", dsc, l->limit, l->state ? " [HIT]" : "");
  cli_msg(-1006, "      Action:       %s", channel_limit_name(l));
}

void
channel_show_info(struct channel *c)
{
  cli_msg(-1006, "  Channel %s", c->name);
  cli_msg(-1006, "    State:          %s", c_states[c->channel_state]);
  cli_msg(-1006, "    Table:          %s", c->table->name);
  cli_msg(-1006, "    Preference:     %d", c->preference);
  cli_msg(-1006, "    Input filter:   %s", filter_name(c->in_filter));
  cli_msg(-1006, "    Output filter:  %s", filter_name(c->out_filter));

  if (graceful_restart_state == GRS_ACTIVE)
    cli_msg(-1006, "    GR recovery:   %s%s",
	    c->gr_lock ? " pending" : "",
	    c->gr_wait ? " waiting" : "");

  channel_show_limit(&c->rx_limit, "Receive limit:");
  channel_show_limit(&c->in_limit, "Import limit:");
  channel_show_limit(&c->out_limit, "Export limit:");

  if (c->channel_state != CS_DOWN)
    channel_show_stats(c);
}

void
proto_cmd_show(struct proto *p, uintptr_t verbose, int cnt)
{
  byte buf[256], tbuf[TM_DATETIME_BUFFER_SIZE];

  /* First protocol - show header */
  if (!cnt)
    cli_msg(-2002, "%-10s %-10s %-10s %-6s %-12s  %s",
	    "Name", "Proto", "Table", "State", "Since", "Info");

  buf[0] = 0;
  if (p->proto->get_status)
    p->proto->get_status(p, buf);
  tm_format_time(tbuf, &config->tf_proto, p->last_state_change);
  cli_msg(-1002, "%-10s %-10s %-10s %-6s %-12s  %s",
	  p->name,
	  p->proto->name,
	  p->main_channel ? p->main_channel->table->name : "---",
	  proto_state_name(p),
	  tbuf,
	  buf);

  if (verbose)
  {
    if (p->cf->dsc)
      cli_msg(-1006, "  Description:    %s", p->cf->dsc);
    if (p->message)
      cli_msg(-1006, "  Message:        %s", p->message);
    if (p->cf->router_id)
      cli_msg(-1006, "  Router ID:      %R", p->cf->router_id);
    if (p->vrf_set)
      cli_msg(-1006, "  VRF:            %s", p->vrf ? p->vrf->name : "default");

    if (p->proto->show_proto_info)
      p->proto->show_proto_info(p);
    else
    {
      struct channel *c;
      WALK_LIST(c, p->channels)
	channel_show_info(c);
    }

    cli_msg(-1006, "");
  }
}

void
proto_cmd_disable(struct proto *p, uintptr_t arg, int cnt UNUSED)
{
  if (p->disabled)
  {
    cli_msg(-8, "%s: already disabled", p->name);
    return;
  }

  log(L_INFO "Disabling protocol %s", p->name);
  p->disabled = 1;
  p->down_code = PDC_CMD_DISABLE;
  proto_set_message(p, (char *) arg, -1);
  proto_rethink_goal(p);
  cli_msg(-9, "%s: disabled", p->name);
}

void
proto_cmd_enable(struct proto *p, uintptr_t arg, int cnt UNUSED)
{
  if (!p->disabled)
  {
    cli_msg(-10, "%s: already enabled", p->name);
    return;
  }

  log(L_INFO "Enabling protocol %s", p->name);
  p->disabled = 0;
  proto_set_message(p, (char *) arg, -1);
  proto_rethink_goal(p);
  cli_msg(-11, "%s: enabled", p->name);
}

void
proto_cmd_restart(struct proto *p, uintptr_t arg, int cnt UNUSED)
{
  if (p->disabled)
  {
    cli_msg(-8, "%s: already disabled", p->name);
    return;
  }

  log(L_INFO "Restarting protocol %s", p->name);
  p->disabled = 1;
  p->down_code = PDC_CMD_RESTART;
  proto_set_message(p, (char *) arg, -1);
  proto_rethink_goal(p);
  p->disabled = 0;
  proto_rethink_goal(p);
  cli_msg(-12, "%s: restarted", p->name);
}

void
proto_cmd_reload(struct proto *p, uintptr_t dir, int cnt UNUSED)
{
  struct channel *c;

  if (p->disabled)
  {
    cli_msg(-8, "%s: already disabled", p->name);
    return;
  }

  /* If the protocol in not UP, it has no routes */
  if (p->proto_state != PS_UP)
    return;

  /* All channels must support reload */
  if (dir != CMD_RELOAD_OUT)
    WALK_LIST(c, p->channels)
      if ((c->channel_state == CS_UP) && !channel_reloadable(c))
      {
	cli_msg(-8006, "%s: reload failed", p->name);
	return;
      }

  log(L_INFO "Reloading protocol %s", p->name);

  /* re-importing routes */
  if (dir != CMD_RELOAD_OUT)
    WALK_LIST(c, p->channels)
      if (c->channel_state == CS_UP)
	channel_request_reload(c);

  /* re-exporting routes */
  if (dir != CMD_RELOAD_IN)
    WALK_LIST(c, p->channels)
      if (c->channel_state == CS_UP)
	channel_request_feeding(c);

  cli_msg(-15, "%s: reloading", p->name);
}

void
proto_cmd_debug(struct proto *p, uintptr_t mask, int cnt UNUSED)
{
  p->debug = mask;
}

void
proto_cmd_mrtdump(struct proto *p, uintptr_t mask, int cnt UNUSED)
{
  p->mrtdump = mask;
}

static void
proto_apply_cmd_symbol(struct symbol *s, void (* cmd)(struct proto *, uintptr_t, int), uintptr_t arg)
{
  if (s->class != SYM_PROTO)
  {
    cli_msg(9002, "%s is not a protocol", s->name);
    return;
  }

  cmd(s->proto->proto, arg, 0);
  cli_msg(0, "");
}

static void
proto_apply_cmd_patt(char *patt, void (* cmd)(struct proto *, uintptr_t, int), uintptr_t arg)
{
  struct proto *p;
  int cnt = 0;

  WALK_LIST(p, proto_list)
    if (!patt || patmatch(patt, p->name))
      cmd(p, arg, cnt++);

  if (!cnt)
    cli_msg(8003, "No protocols match");
  else
    cli_msg(0, "");
}

void
proto_apply_cmd(struct proto_spec ps, void (* cmd)(struct proto *, uintptr_t, int),
		int restricted, uintptr_t arg)
{
  if (restricted && cli_access_restricted())
    return;

  if (ps.patt)
    proto_apply_cmd_patt(ps.ptr, cmd, arg);
  else
    proto_apply_cmd_symbol(ps.ptr, cmd, arg);
}

struct proto *
proto_get_named(struct symbol *sym, struct protocol *pr)
{
  struct proto *p, *q;

  if (sym)
  {
    if (sym->class != SYM_PROTO)
      cf_error("%s: Not a protocol", sym->name);

    p = sym->proto->proto;
    if (!p || p->proto != pr)
      cf_error("%s: Not a %s protocol", sym->name, pr->name);
  }
  else
  {
    p = NULL;
    WALK_LIST(q, proto_list)
      if ((q->proto == pr) && (q->proto_state != PS_DOWN))
      {
	if (p)
	  cf_error("There are multiple %s protocols running", pr->name);
	p = q;
      }
    if (!p)
      cf_error("There is no %s protocol running", pr->name);
  }

  return p;
}