summaryrefslogtreecommitdiffstats
path: root/src/plugins/http_static/static_server.c
blob: 40de6cb578de90dbaf74c99f3265a8c786a76356 (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
/*
 * Copyright (c) 2017-2022 Cisco and/or its affiliates.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at:
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include <http_static/http_static.h>

#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>

#include <http/http_header_names.h>
#include <http/http_content_types.h>

/** @file static_server.c
 *  Static http server, sufficient to serve .html / .css / .js content.
 */
/*? %%clicmd:group_label Static HTTP Server %% ?*/

#define HSS_FIFO_THRESH (16 << 10)

hss_main_t hss_main;

static hss_session_t *
hss_session_alloc (u32 thread_index)
{
  hss_main_t *hsm = &hss_main;
  hss_session_t *hs;

  pool_get_zero (hsm->sessions[thread_index], hs);
  hs->session_index = hs - hsm->sessions[thread_index];
  hs->thread_index = thread_index;
  hs->cache_pool_index = ~0;
  return hs;
}

__clib_export hss_session_t *
hss_session_get (u32 thread_index, u32 hs_index)
{
  hss_main_t *hsm = &hss_main;
  if (pool_is_free_index (hsm->sessions[thread_index], hs_index))
    return 0;
  return pool_elt_at_index (hsm->sessions[thread_index], hs_index);
}

static void
hss_session_free (hss_session_t *hs)
{
  hss_main_t *hsm = &hss_main;

  pool_put (hsm->sessions[hs->thread_index], hs);

  if (CLIB_DEBUG)
    {
      u32 save_thread_index;
      save_thread_index = hs->thread_index;
      /* Poison the entry, preserve timer state and thread index */
      memset (hs, 0xfa, sizeof (*hs));
      hs->thread_index = save_thread_index;
    }
}

/** \brief Disconnect a session
 */
static void
hss_session_disconnect_transport (hss_session_t *hs)
{
  vnet_disconnect_args_t _a = { 0 }, *a = &_a;
  a->handle = hs->vpp_session_handle;
  a->app_index = hss_main.app_index;
  vnet_disconnect_session (a);
}

static void
start_send_data (hss_session_t *hs, http_status_code_t status)
{
  http_msg_t msg;
  session_t *ts;
  u8 *headers_buf = 0;
  int rv;

  ts = session_get (hs->vpp_session_index, hs->thread_index);

  if (vec_len (hs->resp_headers))
    {
      headers_buf = http_serialize_headers (hs->resp_headers);
      vec_free (hs->resp_headers);
      msg.data.headers_offset = 0;
      msg.data.headers_len = vec_len (headers_buf);
    }
  else
    {
      msg.data.headers_offset = 0;
      msg.data.headers_len = 0;
    }

  msg.type = HTTP_MSG_REPLY;
  msg.code = status;
  msg.data.body_len = hs->data_len;
  msg.data.len = msg.data.body_len + msg.data.headers_len;

  if (msg.data.len > hss_main.use_ptr_thresh)
    {
      msg.data.type = HTTP_MSG_DATA_PTR;
      rv = svm_fifo_enqueue (ts->tx_fifo, sizeof (msg), (u8 *) &msg);
      ASSERT (rv == sizeof (msg));

      if (msg.data.headers_len)
	{
	  hs->headers_buf = headers_buf;
	  uword headers = pointer_to_uword (hs->headers_buf);
	  rv =
	    svm_fifo_enqueue (ts->tx_fifo, sizeof (headers), (u8 *) &headers);
	  ASSERT (rv == sizeof (headers));
	}

      uword data = pointer_to_uword (hs->data);
      rv = svm_fifo_enqueue (ts->tx_fifo, sizeof (data), (u8 *) &data);
      ASSERT (rv == sizeof (data));

      goto done;
    }

  msg.data.type = HTTP_MSG_DATA_INLINE;
  msg.data.body_offset = msg.data.headers_len;

  rv = svm_fifo_enqueue (ts->tx_fifo, sizeof (msg), (u8 *) &msg);
  ASSERT (rv == sizeof (msg));

  if (msg.data.headers_len)
    {
      rv = svm_fifo_enqueue (ts->tx_fifo, vec_len (headers_buf), headers_buf);
      ASSERT (rv == msg.data.headers_len);
      vec_free (headers_buf);
    }

  if (!msg.data.body_len)
    goto done;

  rv = svm_fifo_enqueue (ts->tx_fifo, hs->data_len, hs->data);

  if (rv != hs->data_len)
    {
      hs->data_offset = (rv > 0) ? rv : 0;
      svm_fifo_add_want_deq_ntf (ts->tx_fifo, SVM_FIFO_WANT_DEQ_NOTIF);
    }

done:

  if (svm_fifo_set_event (ts->tx_fifo))
    session_program_tx_io_evt (ts->handle, SESSION_IO_EVT_TX);
}

__clib_export void
hss_session_send_data (hss_url_handler_args_t *args)
{
  hss_session_t *hs;

  hs = hss_session_get (args->sh.thread_index, args->sh.session_index);
  if (!hs)
    return;

  if (hs->data && hs->free_data)
    vec_free (hs->data);

  hs->data = args->data;
  hs->data_len = args->data_len;
  hs->free_data = args->free_vec_data;

  /* Set content type only if we have some response data */
  if (hs->data_len)
    {
      http_add_header (&hs->resp_headers,
		       http_header_name_token (HTTP_HEADER_CONTENT_TYPE),
		       http_content_type_token (args->ct));
    }

  start_send_data (hs, args->sc);
}

/*
 * path_has_known_suffix()
 * Returns 1 if the request ends with a known suffix, like .htm or .ico
 * Used to avoid looking for "/favicon.ico/index.html" or similar.
 */

static int
path_has_known_suffix (u8 *request)
{
  u8 *ext;
  uword *p;

  if (vec_len (request) == 0)
    {
      return 0;
    }

  ext = request + vec_len (request) - 1;

  while (ext > request && ext[0] != '.')
    ext--;

  if (ext == request)
    return 0;

  p = hash_get_mem (hss_main.mime_type_indices_by_file_extensions, ext);
  if (p)
    return 1;

  return 0;
}

/*
 * content_type_from_request
 * Returns the index of the request's suffix in the
 * http-layer http_content_type_str[] array.
 */

static http_content_type_t
content_type_from_request (u8 *request)
{
  u8 *ext;
  uword *p;
  /* default to text/html */
  http_content_type_t rv = HTTP_CONTENT_TEXT_HTML;

  ASSERT (vec_len (request) > 0);

  ext = request + vec_len (request) - 1;

  while (ext > request && ext[0] != '.')
    ext--;

  if (ext == request)
    return rv;

  p = hash_get_mem (hss_main.mime_type_indices_by_file_extensions, ext);

  if (p == 0)
    return rv;

  rv = p[0];
  return rv;
}

static int
try_url_handler (hss_main_t *hsm, hss_session_t *hs, http_req_method_t rt,
		 u8 *target_path, u8 *target_query, u8 *data)
{
  http_status_code_t sc = HTTP_STATUS_OK;
  hss_url_handler_args_t args = {};
  uword *p, *url_table;
  int rv;

  if (!hsm->enable_url_handlers || !target_path)
    return -1;

  /* zero-length? try "index.html" */
  if (vec_len (target_path) == 0)
    {
      target_path = format (target_path, "index.html");
    }

  /* Look for built-in GET / POST handlers */
  url_table =
    (rt == HTTP_REQ_GET) ? hsm->get_url_handlers : hsm->post_url_handlers;

  p = hash_get_mem (url_table, target_path);
  if (!p)
    return -1;

  hs->path = 0;
  hs->data_offset = 0;
  hs->cache_pool_index = ~0;

  if (hsm->debug_level > 0)
    clib_warning ("%s '%s'", (rt == HTTP_REQ_GET) ? "GET" : "POST",
		  target_path);

  args.req_type = rt;
  args.query = target_query;
  args.req_data = data;
  args.sh.thread_index = hs->thread_index;
  args.sh.session_index = hs->session_index;

  rv = ((hss_url_handler_fn) p[0]) (&args);

  /* Wait for data from handler */
  if (rv == HSS_URL_HANDLER_ASYNC)
    return 0;

  if (rv == HSS_URL_HANDLER_ERROR)
    {
      clib_warning ("builtin handler %llx hit on %s '%s' but failed!", p[0],
		    (rt == HTTP_REQ_GET) ? "GET" : "POST", target_path);
      sc = HTTP_STATUS_BAD_GATEWAY;
    }

  hs->data = args.data;
  hs->data_len = args.data_len;
  hs->free_data = args.free_vec_data;

  /* Set content type only if we have some response data */
  if (hs->data_len)
    {
      http_add_header (&hs->resp_headers,
		       http_header_name_token (HTTP_HEADER_CONTENT_TYPE),
		       http_content_type_token (args.ct));
    }

  start_send_data (hs, sc);

  if (!hs->data_len)
    hss_session_disconnect_transport (hs);

  return 0;
}

static u8
file_path_is_valid (u8 *path)
{
  struct stat _sb, *sb = &_sb;

  if (stat ((char *) path, sb) < 0 /* can't stat the file */
      || (sb->st_mode & S_IFMT) != S_IFREG /* not a regular file */)
    return 0;

  return 1;
}

static u32
try_index_file (hss_main_t *hsm, hss_session_t *hs, u8 *path)
{
  u8 *port_str = 0, *redirect;
  transport_endpoint_t endpt;
  transport_proto_t proto;
  int print_port = 0;
  u16 local_port;
  session_t *ts;
  u32 plen;

  /* Remove the trailing space */
  vec_dec_len (path, 1);
  plen = vec_len (path);

  /* Append "index.html" */
  if (path[plen - 1] != '/')
    path = format (path, "/index.html%c", 0);
  else
    path = format (path, "index.html%c", 0);

  if (hsm->debug_level > 0)
    clib_warning ("trying to find index: %s", path);

  if (!file_path_is_valid (path))
    return HTTP_STATUS_NOT_FOUND;

  /*
   * We found an index.html file, build a redirect
   */
  vec_delete (path, vec_len (hsm->www_root) - 1, 0);

  ts = session_get (hs->vpp_session_index, hs->thread_index);
  session_get_endpoint (ts, &endpt, 1 /* is_local */);

  local_port = clib_net_to_host_u16 (endpt.port);
  proto = session_type_transport_proto (ts->session_type);

  if ((proto == TRANSPORT_PROTO_TCP && local_port != 80) ||
      (proto == TRANSPORT_PROTO_TLS && local_port != 443))
    {
      print_port = 1;
      port_str = format (0, ":%u", (u32) local_port);
    }

  redirect =
    format (0, "http%s://%U%s%s", proto == TRANSPORT_PROTO_TLS ? "s" : "",
	    format_ip46_address, &endpt.ip, endpt.is_ip4,
	    print_port ? port_str : (u8 *) "", path);

  if (hsm->debug_level > 0)
    clib_warning ("redirect: %s", redirect);

  vec_free (port_str);

  http_add_header (&hs->resp_headers,
		   http_header_name_token (HTTP_HEADER_LOCATION),
		   (const char *) redirect, vec_len (redirect));
  hs->data = redirect; /* TODO: find better way  */
  hs->data_len = 0;
  hs->free_data = 1;

  return HTTP_STATUS_MOVED;
}

static int
try_file_handler (hss_main_t *hsm, hss_session_t *hs, http_req_method_t rt,
		  u8 *target)
{
  http_status_code_t sc = HTTP_STATUS_OK;
  u8 *path, *sanitized_path;
  u32 ce_index;
  http_content_type_t type;

  /* Feature not enabled */
  if (!hsm->www_root)
    return -1;

  /* Remove dot segments to prevent path traversal */
  sanitized_path = http_path_remove_dot_segments (target);

  /*
   * Construct the file to open
   */
  if (!target)
    path = format (0, "%s%c", hsm->www_root, 0);
  else
    path = format (0, "%s/%s%c", hsm->www_root, sanitized_path, 0);

  if (hsm->debug_level > 0)
    clib_warning ("%s '%s'", (rt == HTTP_REQ_GET) ? "GET" : "POST", path);

  if (hs->data && hs->free_data)
    vec_free (hs->data);

  hs->data_offset = 0;

  ce_index =
    hss_cache_lookup_and_attach (&hsm->cache, path, &hs->data, &hs->data_len);
  if (ce_index == ~0)
    {
      if (!file_path_is_valid (path))
	{
	  /*
	   * Generate error 404 right now if we can't find a path with
	   * a known file extension. It's silly to look for
	   * "favicon.ico/index.html" if you can't find
	   * "favicon.ico"; realistic example which used to happen.
	   */
	  if (path_has_known_suffix (path))
	    {
	      sc = HTTP_STATUS_NOT_FOUND;
	      goto done;
	    }
	  sc = try_index_file (hsm, hs, path);
	  goto done;
	}
      ce_index =
	hss_cache_add_and_attach (&hsm->cache, path, &hs->data, &hs->data_len);
      if (ce_index == ~0)
	{
	  sc = HTTP_STATUS_INTERNAL_ERROR;
	  goto done;
	}
    }

  hs->path = path;
  hs->cache_pool_index = ce_index;

  /* Set following headers only for happy path:
   * Content-Type
   * Cache-Control max-age
   */
  type = content_type_from_request (target);
  http_add_header (&hs->resp_headers,
		   http_header_name_token (HTTP_HEADER_CONTENT_TYPE),
		   http_content_type_token (type));
  http_add_header (
    &hs->resp_headers, http_header_name_token (HTTP_HEADER_CACHE_CONTROL),
    (const char *) hsm->max_age_formatted, vec_len (hsm->max_age_formatted));

done:
  vec_free (sanitized_path);
  start_send_data (hs, sc);
  if (!hs->data_len)
    hss_session_disconnect_transport (hs);

  return 0;
}

static void
handle_request (hss_session_t *hs, http_req_method_t rt, u8 *target_path,
		u8 *target_query, u8 *data)
{
  hss_main_t *hsm = &hss_main;

  if (!try_url_handler (hsm, hs, rt, target_path, target_query, data))
    return;

  if (!try_file_handler (hsm, hs, rt, target_path))
    return;

  /* Handler did not find anything return 404 */
  start_send_data (hs, HTTP_STATUS_NOT_FOUND);
  hss_session_disconnect_transport (hs);
}

static int
hss_ts_rx_callback (session_t *ts)
{
  hss_session_t *hs;
  u8 *target_path = 0, *target_query = 0, *data = 0;
  http_msg_t msg;
  int rv;

  hs = hss_session_get (ts->thread_index, ts->opaque);
  if (hs->free_data)
    vec_free (hs->data);
  hs->data = 0;
  hs->resp_headers = 0;
  vec_free (hs->headers_buf);

  /* Read the http message header */
  rv = svm_fifo_dequeue (ts->rx_fifo, sizeof (msg), (u8 *) &msg);
  ASSERT (rv == sizeof (msg));

  if (msg.type != HTTP_MSG_REQUEST ||
      (msg.method_type != HTTP_REQ_GET && msg.method_type != HTTP_REQ_POST))
    {
      http_add_header (&hs->resp_headers,
		       http_header_name_token (HTTP_HEADER_ALLOW),
		       http_token_lit ("GET, POST"));
      start_send_data (hs, HTTP_STATUS_METHOD_NOT_ALLOWED);
      goto done;
    }

  if (msg.data.target_form != HTTP_TARGET_ORIGIN_FORM)
    {
      start_send_data (hs, HTTP_STATUS_BAD_REQUEST);
      goto done;
    }

  /* Read target path */
  if (msg.data.target_path_len)
    {
      vec_validate (target_path, msg.data.target_path_len - 1);
      rv = svm_fifo_peek (ts->rx_fifo, msg.data.target_path_offset,
			  msg.data.target_path_len, target_path);
      ASSERT (rv == msg.data.target_path_len);
      if (http_validate_abs_path_syntax (target_path, 0))
	{
	  start_send_data (hs, HTTP_STATUS_BAD_REQUEST);
	  goto done;
	}
      /* Target path must be a proper C-string in addition to a vector */
      vec_add1 (target_path, 0);
    }

  /* Read target query */
  if (msg.data.target_query_len)
    {
      vec_validate (target_query, msg.data.target_query_len - 1);
      rv = svm_fifo_peek (ts->rx_fifo, msg.data.target_query_offset,
			  msg.data.target_query_len, target_query);
      ASSERT (rv == msg.data.target_query_len);
      if (http_validate_query_syntax (target_query, 0))
	{
	  start_send_data (hs, HTTP_STATUS_BAD_REQUEST);
	  goto done;
	}
    }

  /* Read body */
  if (msg.data.body_len)
    {
      vec_validate (data, msg.data.body_len - 1);
      rv = svm_fifo_peek (ts->rx_fifo, msg.data.body_offset, msg.data.body_len,
			  data);
      ASSERT (rv == msg.data.body_len);
    }

  /* Find and send data */
  handle_request (hs, msg.method_type, target_path, target_query, data);

done:
  vec_free (target_path);
  vec_free (target_query);
  vec_free (data);
  svm_fifo_dequeue_drop (ts->rx_fifo, msg.data.len);
  return 0;
}

static int
hss_ts_tx_callback (session_t *ts)
{
  hss_session_t *hs;
  u32 to_send;
  int rv;

  hs = hss_session_get (ts->thread_index, ts->opaque);
  if (!hs || !hs->data)
    return 0;

  to_send = hs->data_len - hs->data_offset;
  rv = svm_fifo_enqueue (ts->tx_fifo, to_send, hs->data + hs->data_offset);

  if (rv <= 0)
    {
      svm_fifo_add_want_deq_ntf (ts->tx_fifo, SVM_FIFO_WANT_DEQ_NOTIF);
      return 0;
    }

  if (rv < to_send)
    {
      hs->data_offset += rv;
      svm_fifo_add_want_deq_ntf (ts->tx_fifo, SVM_FIFO_WANT_DEQ_NOTIF);
    }

  if (svm_fifo_set_event (ts->tx_fifo))
    session_program_tx_io_evt (ts->handle, SESSION_IO_EVT_TX);

  return 0;
}

/** \brief Session accept callback
 */
static int
hss_ts_accept_callback (session_t *ts)
{
  hss_session_t *hs;
  u32 thresh;

  hs = hss_session_alloc (ts->thread_index);

  hs->vpp_session_index = ts->session_index;
  hs->vpp_session_handle = session_handle (ts);

  /* The application sets a threshold for it's fifo to get notified when
   * additional data can be enqueued. We want to keep the TX fifo reasonably
   * full, however avoid entering a state where the
   * fifo is full all the time and small chunks of data are being enqueued
   * each time. If the fifo is small (under 16K) we set
   * the threshold to it's size, meaning a notification will be given when the
   * fifo empties.
   */
  thresh = clib_min (svm_fifo_size (ts->tx_fifo), HSS_FIFO_THRESH);
  svm_fifo_set_deq_thresh (ts->tx_fifo, thresh);

  ts->opaque = hs->session_index;
  ts->session_state = SESSION_STATE_READY;
  return 0;
}

static void
hss_ts_disconnect_callback (session_t *ts)
{
  hss_main_t *hsm = &hss_main;
  vnet_disconnect_args_t _a = { 0 }, *a = &_a;

  a->handle = session_handle (ts);
  a->app_index = hsm->app_index;
  vnet_disconnect_session (a);
}

static void
hss_ts_reset_callback (session_t *ts)
{
  hss_main_t *hsm = &hss_main;
  vnet_disconnect_args_t _a = { 0 }, *a = &_a;

  a->handle = session_handle (ts);
  a->app_index = hsm->app_index;
  vnet_disconnect_session (a);
}

static int
hss_ts_connected_callback (u32 app_index, u32 api_context, session_t *ts,
			   session_error_t err)
{
  clib_warning ("called...");
  return -1;
}

static int
hss_add_segment_callback (u32 client_index, u64 segment_handle)
{
  return 0;
}

static void
hss_ts_cleanup (session_t *s, session_cleanup_ntf_t ntf)
{
  hss_main_t *hsm = &hss_main;
  hss_session_t *hs;

  if (ntf == SESSION_CLEANUP_TRANSPORT)
    return;

  hs = hss_session_get (s->thread_index, s->opaque);
  if (!hs)
    return;

  if (hs->cache_pool_index != ~0)
    {
      hss_cache_detach_entry (&hsm->cache, hs->cache_pool_index);
      hs->cache_pool_index = ~0;
    }

  if (hs->free_data)
    vec_free (hs->data);
  hs->data = 0;
  hs->data_offset = 0;
  hs->free_data = 0;
  vec_free (hs->headers_buf);
  vec_free (hs->path);

  hss_session_free (hs);
}

static session_cb_vft_t hss_cb_vft = {
  .session_accept_callback = hss_ts_accept_callback,
  .session_disconnect_callback = hss_ts_disconnect_callback,
  .session_connected_callback = hss_ts_connected_callback,
  .add_segment_callback = hss_add_segment_callback,
  .builtin_app_rx_callback = hss_ts_rx_callback,
  .builtin_app_tx_callback = hss_ts_tx_callback,
  .session_reset_callback = hss_ts_reset_callback,
  .session_cleanup_callback = hss_ts_cleanup,
};

static int
hss_attach ()
{
  vnet_app_add_cert_key_pair_args_t _ck_pair, *ck_pair = &_ck_pair;
  hss_main_t *hsm = &hss_main;
  u64 options[APP_OPTIONS_N_OPTIONS];
  vnet_app_attach_args_t _a, *a = &_a;
  u32 segment_size = 128 << 20;

  clib_memset (a, 0, sizeof (*a));
  clib_memset (options, 0, sizeof (options));

  if (hsm->private_segment_size)
    segment_size = hsm->private_segment_size;

  a->api_client_index = ~0;
  a->name = format (0, "http_static_server");
  a->session_cb_vft = &hss_cb_vft;
  a->options = options;
  a->options[APP_OPTIONS_SEGMENT_SIZE] = segment_size;
  a->options[APP_OPTIONS_ADD_SEGMENT_SIZE] = segment_size;
  a->options[APP_OPTIONS_RX_FIFO_SIZE] =
    hsm->fifo_size ? hsm->fifo_size : 8 << 10;
  a->options[APP_OPTIONS_TX_FIFO_SIZE] =
    hsm->fifo_size ? hsm->fifo_size : 32 << 10;
  a->options[APP_OPTIONS_FLAGS] = APP_OPTIONS_FLAGS_IS_BUILTIN;
  a->options[APP_OPTIONS_PREALLOC_FIFO_PAIRS] = hsm->prealloc_fifos;
  a->options[APP_OPTIONS_TLS_ENGINE] = CRYPTO_ENGINE_OPENSSL;

  if (vnet_application_attach (a))
    {
      vec_free (a->name);
      clib_warning ("failed to attach server");
      return -1;
    }
  vec_free (a->name);
  hsm->app_index = a->app_index;

  clib_memset (ck_pair, 0, sizeof (*ck_pair));
  ck_pair->cert = (u8 *) test_srv_crt_rsa;
  ck_pair->key = (u8 *) test_srv_key_rsa;
  ck_pair->cert_len = test_srv_crt_rsa_len;
  ck_pair->key_len = test_srv_key_rsa_len;
  vnet_app_add_cert_key_pair (ck_pair);
  hsm->ckpair_index = ck_pair->index;

  return 0;
}

static int
hss_transport_needs_crypto (transport_proto_t proto)
{
  return proto == TRANSPORT_PROTO_TLS || proto == TRANSPORT_PROTO_DTLS ||
	 proto == TRANSPORT_PROTO_QUIC;
}

static int
hss_listen (void)
{
  hss_main_t *hsm = &hss_main;
  session_endpoint_cfg_t sep = SESSION_ENDPOINT_CFG_NULL;
  vnet_listen_args_t _a, *a = &_a;
  char *uri = "tcp://0.0.0.0/80";
  u8 need_crypto;
  int rv;

  clib_memset (a, 0, sizeof (*a));
  a->app_index = hsm->app_index;

  if (hsm->uri)
    uri = (char *) hsm->uri;

  if (parse_uri (uri, &sep))
    return -1;

  need_crypto = hss_transport_needs_crypto (sep.transport_proto);

  sep.transport_proto = TRANSPORT_PROTO_HTTP;
  clib_memcpy (&a->sep_ext, &sep, sizeof (sep));

  if (need_crypto)
    {
      session_endpoint_alloc_ext_cfg (&a->sep_ext,
				      TRANSPORT_ENDPT_EXT_CFG_CRYPTO);
      a->sep_ext.ext_cfg->crypto.ckpair_index = hsm->ckpair_index;
    }

  rv = vnet_listen (a);

  if (need_crypto)
    clib_mem_free (a->sep_ext.ext_cfg);

  return rv;
}

static void
hss_url_handlers_init (hss_main_t *hsm)
{
  if (!hsm->get_url_handlers)
    {
      hsm->get_url_handlers = hash_create_string (0, sizeof (uword));
      hsm->post_url_handlers = hash_create_string (0, sizeof (uword));
    }

  hss_builtinurl_json_handlers_init ();
}

int
hss_create (vlib_main_t *vm)
{
  vlib_thread_main_t *vtm = vlib_get_thread_main ();
  hss_main_t *hsm = &hss_main;
  u32 num_threads;

  num_threads = 1 /* main thread */  + vtm->n_threads;
  vec_validate (hsm->sessions, num_threads - 1);

  if (hss_attach ())
    {
      clib_warning ("failed to attach server");
      return -1;
    }
  if (hss_listen ())
    {
      clib_warning ("failed to start listening");
      return -1;
    }

  if (hsm->www_root)
    hss_cache_init (&hsm->cache, hsm->cache_size, hsm->debug_level);

  if (hsm->enable_url_handlers)
    hss_url_handlers_init (hsm);

  hsm->max_age_formatted = format (0, "max-age=%d", hsm->max_age);

  return 0;
}

static clib_error_t *
hss_create_command_fn (vlib_main_t *vm, unformat_input_t *input,
		       vlib_cli_command_t *cmd)
{
  unformat_input_t _line_input, *line_input = &_line_input;
  hss_main_t *hsm = &hss_main;
  clib_error_t *error = 0;
  u64 seg_size;
  int rv;

  if (hsm->app_index != (u32) ~0)
    return clib_error_return (0, "http server already running...");

  hsm->prealloc_fifos = 0;
  hsm->private_segment_size = 0;
  hsm->fifo_size = 0;
  hsm->cache_size = 10 << 20;
  hsm->max_age = HSS_DEFAULT_MAX_AGE;

  /* Get a line of input. */
  if (!unformat_user (input, unformat_line_input, line_input))
    goto no_input;

  while (unformat_check_input (line_input) != UNFORMAT_END_OF_INPUT)
    {
      if (unformat (line_input, "www-root %s", &hsm->www_root))
	;
      else
	if (unformat (line_input, "prealloc-fifos %d", &hsm->prealloc_fifos))
	;
      else if (unformat (line_input, "private-segment-size %U",
			 unformat_memory_size, &seg_size))
	hsm->private_segment_size = seg_size;
      else if (unformat (line_input, "fifo-size %d", &hsm->fifo_size))
	hsm->fifo_size <<= 10;
      else if (unformat (line_input, "cache-size %U", unformat_memory_size,
			 &hsm->cache_size))
	;
      else if (unformat (line_input, "uri %s", &hsm->uri))
	;
      else if (unformat (line_input, "debug %d", &hsm->debug_level))
	;
      else if (unformat (line_input, "debug"))
	hsm->debug_level = 1;
      else if (unformat (line_input, "ptr-thresh %U", unformat_memory_size,
			 &hsm->use_ptr_thresh))
	;
      else if (unformat (line_input, "url-handlers"))
	hsm->enable_url_handlers = 1;
      else if (unformat (line_input, "max-age %d", &hsm->max_age))
	;
      else
	{
	  error = clib_error_return (0, "unknown input `%U'",
				     format_unformat_error, line_input);
	  break;
	}
    }

  unformat_free (line_input);

no_input:

  if (error)
    goto done;

  if (hsm->www_root == 0 && !hsm->enable_url_handlers)
    {
      error = clib_error_return (0, "Must set www-root or url-handlers");
      goto done;
    }

  if (hsm->cache_size < (128 << 10))
    {
      error = clib_error_return (0, "cache-size must be at least 128kb");
      vec_free (hsm->www_root);
      goto done;
    }

  vnet_session_enable_disable (vm, 1 /* turn on TCP, etc. */ );

  if ((rv = hss_create (vm)))
    {
      error = clib_error_return (0, "server_create returned %d", rv);
      vec_free (hsm->www_root);
    }

done:

  return error;
}

/*?
 * Enable the static http server
 *
 * @cliexpar
 * This command enables the static http server. Only the www-root
 * parameter is required
 * @clistart
 * http static server www-root /tmp/www uri tcp://0.0.0.0/80 cache-size 2m
 * @cliend
 * @cliexcmd{http static server www-root <path> [prealloc-fios <nn>]
 *   [private-segment-size <nnMG>] [fifo-size <nbytes>] [uri <uri>]}
?*/
VLIB_CLI_COMMAND (hss_create_command, static) = {
  .path = "http static server",
  .short_help =
    "http static server www-root <path> [prealloc-fifos <nn>]\n"
    "[private-segment-size <nnMG>] [fifo-size <nbytes>] [max-age <nseconds>]\n"
    "[uri <uri>] [ptr-thresh <nn>] [url-handlers] [debug [nn]]\n",
  .function = hss_create_command_fn,
};

static u8 *
format_hss_session (u8 *s, va_list *args)
{
  hss_session_t *hs = va_arg (*args, hss_session_t *);
  int __clib_unused verbose = va_arg (*args, int);

  s = format (s, "\n path %s, data length %u, data_offset %u",
	      hs->path ? hs->path : (u8 *) "[none]", hs->data_len,
	      hs->data_offset);
  return s;
}

static clib_error_t *
hss_show_command_fn (vlib_main_t *vm, unformat_input_t *input,
		     vlib_cli_command_t *cmd)
{
  int verbose = 0, show_cache = 0, show_sessions = 0;
  hss_main_t *hsm = &hss_main;

  if (hsm->www_root == 0)
    return clib_error_return (0, "Static server disabled");

  while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
    {
      if (unformat (input, "verbose %d", &verbose))
	;
      else if (unformat (input, "verbose"))
	verbose = 1;
      else if (unformat (input, "cache"))
	show_cache = 1;
      else if (unformat (input, "sessions"))
	show_sessions = 1;
      else
	break;
    }

  if ((show_cache + show_sessions) == 0)
    return clib_error_return (0, "specify one or more of cache, sessions");

  if (show_cache)
    vlib_cli_output (vm, "%U", format_hss_cache, &hsm->cache, verbose);

  if (show_sessions)
    {
      u32 *session_indices = 0;
      hss_session_t *hs;
      int i, j;


      for (i = 0; i < vec_len (hsm->sessions); i++)
	{
	  pool_foreach (hs, hsm->sessions[i])
            vec_add1 (session_indices, hs - hsm->sessions[i]);

	  for (j = 0; j < vec_len (session_indices); j++)
	    {
	      vlib_cli_output (
		vm, "%U", format_hss_session,
		pool_elt_at_index (hsm->sessions[i], session_indices[j]),
		verbose);
	    }
	  vec_reset_length (session_indices);
	}
      vec_free (session_indices);
    }
  return 0;
}

/*?
 * Display static http server cache statistics
 *
 * @cliexpar
 * This command shows the contents of the static http server cache
 * @clistart
 * show http static server
 * @cliend
 * @cliexcmd{show http static server sessions cache [verbose [nn]]}
?*/
VLIB_CLI_COMMAND (hss_show_command, static) = {
  .path = "show http static server",
  .short_help = "show http static server sessions cache [verbose [<nn>]]",
  .function = hss_show_command_fn,
};

static clib_error_t *
hss_clear_cache_command_fn (vlib_main_t *vm, unformat_input_t *input,
			    vlib_cli_command_t *cmd)
{
  hss_main_t *hsm = &hss_main;
  u32 busy_items = 0;

  if (hsm->www_root == 0)
    return clib_error_return (0, "Static server disabled");

  busy_items = hss_cache_clear (&hsm->cache);

  if (busy_items > 0)
    vlib_cli_output (vm, "Note: %d busy items still in cache...", busy_items);
  else
    vlib_cli_output (vm, "Cache cleared...");
  return 0;
}

/*?
 * Clear the static http server cache, to force the server to
 * reload content from backing files
 *
 * @cliexpar
 * This command clear the static http server cache
 * @clistart
 * clear http static cache
 * @cliend
 * @cliexcmd{clear http static cache}
?*/
VLIB_CLI_COMMAND (clear_hss_cache_command, static) = {
  .path = "clear http static cache",
  .short_help = "clear http static cache",
  .function = hss_clear_cache_command_fn,
};

static clib_error_t *
hss_main_init (vlib_main_t *vm)
{
  hss_main_t *hsm = &hss_main;

  hsm->app_index = ~0;
  hsm->vlib_main = vm;

  /* Set up file extension to mime type index map */
  hsm->mime_type_indices_by_file_extensions =
    hash_create_string (0, sizeof (uword));

#define _(def, ext, str)                                                      \
  hash_set_mem (hsm->mime_type_indices_by_file_extensions, ext,               \
		HTTP_CONTENT_##def);
  foreach_http_content_type;
#undef _

  return 0;
}

VLIB_INIT_FUNCTION (hss_main_init);

/*
 * fd.io coding-style-patch-verification: ON
 *
 * Local Variables:
 * eval: (c-set-style "gnu")
 * End:
 */