summaryrefslogtreecommitdiff
path: root/src/nm-connectivity.c
blob: 5f0567e9d0d91737d0663267085a6d12c5f895b7 (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
/* -*- Mode: C; tab-width: 4; indent-tabs-mode: t; c-basic-offset: 4 -*- */
/* NetworkManager -- Network link manager
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Copyright (C) 2011 Thomas Bechtold <thomasbechtold@jpberlin.de>
 * Copyright (C) 2011 Dan Williams <dcbw@redhat.com>
 * Copyright (C) 2016 - 2018 Red Hat, Inc.
 */

#include "nm-default.h"

#include "nm-connectivity.h"

#include <string.h>

#if WITH_CONCHECK
#include <curl/curl.h>
#endif

#include "c-list/src/c-list.h"
#include "nm-core-internal.h"
#include "nm-config.h"
#include "NetworkManagerUtils.h"
#include "nm-dbus-manager.h"
#include "dns/nm-dns-manager.h"

#define HEADER_STATUS_ONLINE "X-NetworkManager-Status: online\r\n"

/*****************************************************************************/

NM_UTILS_LOOKUP_STR_DEFINE_STATIC (_state_to_string, int /*NMConnectivityState*/,
	NM_UTILS_LOOKUP_DEFAULT_WARN ("???"),
	NM_UTILS_LOOKUP_STR_ITEM (NM_CONNECTIVITY_UNKNOWN,  "UNKNOWN"),
	NM_UTILS_LOOKUP_STR_ITEM (NM_CONNECTIVITY_NONE,     "NONE"),
	NM_UTILS_LOOKUP_STR_ITEM (NM_CONNECTIVITY_LIMITED,  "LIMITED"),
	NM_UTILS_LOOKUP_STR_ITEM (NM_CONNECTIVITY_PORTAL,   "PORTAL"),
	NM_UTILS_LOOKUP_STR_ITEM (NM_CONNECTIVITY_FULL,     "FULL"),

	NM_UTILS_LOOKUP_STR_ITEM (NM_CONNECTIVITY_ERROR,     "ERROR"),
	NM_UTILS_LOOKUP_STR_ITEM (NM_CONNECTIVITY_FAKE,      "FAKE"),
	NM_UTILS_LOOKUP_STR_ITEM (NM_CONNECTIVITY_CANCELLED, "CANCELLED"),
	NM_UTILS_LOOKUP_STR_ITEM (NM_CONNECTIVITY_DISPOSING, "DISPOSING"),
);

const char *
nm_connectivity_state_to_string (NMConnectivityState state)
{
	return _state_to_string (state);
}

/*****************************************************************************/

typedef struct {
	guint ref_count;
	char *uri;
	char *host;
	char *port;
	char *response;
} ConConfig;

struct _NMConnectivityCheckHandle {
	CList handles_lst;
	NMConnectivity *self;
	NMConnectivityCheckCallback callback;
	gpointer user_data;

	char *ifspec;

	const char *completed_log_message;
	char *completed_log_message_free;

#if WITH_CONCHECK
	struct {
		ConConfig *con_config;

		GCancellable *resolve_cancellable;
		CURLM *curl_mhandle;
		CURL *curl_ehandle;
		struct curl_slist *request_headers;
		struct curl_slist *hosts;

		GString *recv_msg;

		guint curl_timer;
		int ch_ifindex;
	} concheck;
#endif

	guint64 request_counter;

	int addr_family;

	guint timeout_id;

	NMConnectivityState completed_state;

	bool fail_reason_no_dbus_connection:1;
};

enum {
	CONFIG_CHANGED,

	LAST_SIGNAL
};

static guint signals[LAST_SIGNAL] = { 0 };

typedef struct {
	CList handles_lst_head;
	CList completed_handles_lst_head;
	NMConfig *config;
	ConConfig *con_config;
	guint interval;

	bool enabled:1;
	bool uri_valid:1;
} NMConnectivityPrivate;

struct _NMConnectivity {
	GObject parent;
	NMConnectivityPrivate _priv;
};

struct _NMConnectivityClass {
	GObjectClass parent;
};

G_DEFINE_TYPE (NMConnectivity, nm_connectivity, G_TYPE_OBJECT)

#define NM_CONNECTIVITY_GET_PRIVATE(self) _NM_GET_PRIVATE (self, NMConnectivity, NM_IS_CONNECTIVITY)

NM_DEFINE_SINGLETON_GETTER (NMConnectivity, nm_connectivity_get, NM_TYPE_CONNECTIVITY);

/*****************************************************************************/

#define _NMLOG_DOMAIN      LOGD_CONCHECK
#define _NMLOG(level, ...) __NMLOG_DEFAULT (level, _NMLOG_DOMAIN, "connectivity", __VA_ARGS__)

#define _NMLOG2_DOMAIN     LOGD_CONCHECK
#define _NMLOG2(level, ...) \
    G_STMT_START { \
        const NMLogLevel __level = (level); \
        \
        if (nm_logging_enabled (__level, _NMLOG2_DOMAIN)) { \
            _nm_log (__level, _NMLOG2_DOMAIN, 0, \
                     (cb_data->ifspec ? &cb_data->ifspec[3] : NULL), \
                     NULL, \
                     "connectivity: (%s,IPv%c,%"G_GUINT64_FORMAT") " \
                     _NM_UTILS_MACRO_FIRST (__VA_ARGS__), \
                     (cb_data->ifspec ? &cb_data->ifspec[3] : ""), \
                     nm_utils_addr_family_to_char (cb_data->addr_family), \
                     cb_data->request_counter \
                     _NM_UTILS_MACRO_REST (__VA_ARGS__)); \
        } \
    } G_STMT_END

/*****************************************************************************/

static ConConfig *
_con_config_ref (ConConfig *con_config)
{
	if (con_config) {
		nm_assert (con_config->ref_count > 0);
		++con_config->ref_count;
	}
	return con_config;
}

static void
_con_config_unref (ConConfig *con_config)
{
	if (!con_config)
		return;

	nm_assert (con_config->ref_count > 0);

	if (--con_config->ref_count != 0)
		return;

	g_free (con_config->uri);
	g_free (con_config->host);
	g_free (con_config->port);
	g_free (con_config->response);
	g_slice_free (ConConfig, con_config);
}

static const char *
_con_config_get_response (const ConConfig *con_config)
{
	return con_config->response ?: NM_CONFIG_DEFAULT_CONNECTIVITY_RESPONSE;
}

/*****************************************************************************/

static void
cb_data_complete (NMConnectivityCheckHandle *cb_data,
                  NMConnectivityState state,
                  const char *log_message)
{
	NMConnectivity *self;

	nm_assert (cb_data);
	nm_assert (NM_IS_CONNECTIVITY (cb_data->self));
	nm_assert (cb_data->callback);
	nm_assert (state != NM_CONNECTIVITY_UNKNOWN);
	nm_assert (log_message);

	self = cb_data->self;

	/* mark the handle as completing. After this point, nm_connectivity_check_cancel()
	 * is no longer possible. */
	cb_data->self = NULL;

	c_list_unlink_stale (&cb_data->handles_lst);

#if WITH_CONCHECK
	if (cb_data->concheck.curl_ehandle) {
		/* Contrary to what cURL manual claim it is *not* safe to remove
		 * the easy handle "at any moment"; specifically it's not safe to
		 * remove *any* handle from within a libcurl callback. That is
		 * why we queue completed handles in this case.
		 *
		 * cb_data_complete() is however only called *not* from within a
		 * libcurl callback. So, this is fine. */
		curl_easy_setopt (cb_data->concheck.curl_ehandle, CURLOPT_WRITEFUNCTION, NULL);
		curl_easy_setopt (cb_data->concheck.curl_ehandle, CURLOPT_WRITEDATA, NULL);
		curl_easy_setopt (cb_data->concheck.curl_ehandle, CURLOPT_HEADERFUNCTION, NULL);
		curl_easy_setopt (cb_data->concheck.curl_ehandle, CURLOPT_HEADERDATA, NULL);
		curl_easy_setopt (cb_data->concheck.curl_ehandle, CURLOPT_PRIVATE, NULL);
		curl_easy_setopt (cb_data->concheck.curl_ehandle, CURLOPT_HTTPHEADER, NULL);

		curl_multi_remove_handle (cb_data->concheck.curl_mhandle,
		                          cb_data->concheck.curl_ehandle);
		curl_easy_cleanup (cb_data->concheck.curl_ehandle);
		curl_multi_cleanup (cb_data->concheck.curl_mhandle);

		curl_slist_free_all (cb_data->concheck.request_headers);
		curl_slist_free_all (cb_data->concheck.hosts);
	}
	nm_clear_g_source (&cb_data->concheck.curl_timer);
	nm_clear_g_cancellable (&cb_data->concheck.resolve_cancellable);
#endif

	nm_clear_g_source (&cb_data->timeout_id);

	_LOG2D ("check completed: %s; %s",
	        nm_connectivity_state_to_string (state),
	        log_message);

	cb_data->callback (self,
	                   cb_data,
	                   state,
	                   cb_data->user_data);

	/* Note: self might be a danling pointer at this point. It must not be used
	 * after this point, and all callers must either take a reference first, or
	 * not use the self pointer too. */

#if WITH_CONCHECK
	_con_config_unref (cb_data->concheck.con_config);
	if (cb_data->concheck.recv_msg)
		g_string_free (cb_data->concheck.recv_msg, TRUE);
#endif
	g_free (cb_data->ifspec);
	if (cb_data->completed_log_message_free)
		g_free (cb_data->completed_log_message_free);
	g_slice_free (NMConnectivityCheckHandle, cb_data);
}

/*****************************************************************************/

#if WITH_CONCHECK

static void
cb_data_queue_completed (NMConnectivityCheckHandle *cb_data,
                         NMConnectivityState state,
                         const char *log_message_static,
                         char *log_message_take /* take */)
{
	nm_assert (cb_data);
	nm_assert (NM_IS_CONNECTIVITY (cb_data->self));
	nm_assert (state != NM_CONNECTIVITY_UNKNOWN);
	nm_assert (log_message_static || log_message_take);
	nm_assert (cb_data->completed_state == NM_CONNECTIVITY_UNKNOWN);
	nm_assert (!cb_data->completed_log_message);
	nm_assert (c_list_contains (&NM_CONNECTIVITY_GET_PRIVATE (cb_data->self)->handles_lst_head, &cb_data->handles_lst));

	cb_data->completed_state = state;
	cb_data->completed_log_message = log_message_static ?: log_message_take;
	cb_data->completed_log_message_free = log_message_take;

	c_list_unlink_stale (&cb_data->handles_lst);
	c_list_link_tail (&NM_CONNECTIVITY_GET_PRIVATE (cb_data->self)->completed_handles_lst_head, &cb_data->handles_lst);
}

static void
_complete_queued (NMConnectivity *self)
{
	NMConnectivity *self_keep_alive = NULL;
	NMConnectivityPrivate *priv = NM_CONNECTIVITY_GET_PRIVATE (self);
	NMConnectivityCheckHandle *cb_data;

	while ((cb_data = c_list_first_entry (&priv->completed_handles_lst_head, NMConnectivityCheckHandle, handles_lst))) {
		if (!self_keep_alive)
			self_keep_alive = g_object_ref (self);
		cb_data_complete (cb_data,
		                  cb_data->completed_state,
		                  cb_data->completed_log_message);
	}
	nm_g_object_unref (self_keep_alive);
}

static gboolean
_con_curl_check_connectivity (CURLM *mhandle, int sockfd, int ev_bitmask)
{
	NMConnectivityCheckHandle *cb_data;
	CURLMsg *msg;
	CURLcode eret;
	int m_left;
	long response_code;
	CURLMcode ret;
	int running_handles;
	gboolean success = TRUE;

	ret = curl_multi_socket_action (mhandle, sockfd, ev_bitmask, &running_handles);
	if (ret != CURLM_OK) {
		_LOGD ("connectivity check failed: (%d) %s", ret, curl_easy_strerror (ret));
		success = FALSE;
	}

	while ((msg = curl_multi_info_read (mhandle, &m_left))) {

		if (msg->msg != CURLMSG_DONE)
			continue;

		/* Here we have completed a session. Check easy session result. */
		eret = curl_easy_getinfo (msg->easy_handle, CURLINFO_PRIVATE, (char **) &cb_data);
		if (eret != CURLE_OK) {
			_LOGD ("curl cannot extract cb_data for easy handle, skipping msg: (%d) %s",
			       eret, curl_easy_strerror (eret));
			success = FALSE;
			continue;
		}

		nm_assert (cb_data);
		nm_assert (NM_IS_CONNECTIVITY (cb_data->self));

		if (cb_data->completed_state != NM_CONNECTIVITY_UNKNOWN) {
			/* callback was already invoked earlier. Nothing to do. */
			continue;
		}

		if (msg->data.result != CURLE_OK) {
			cb_data_queue_completed (cb_data,
			                         NM_CONNECTIVITY_LIMITED,
			                         NULL,
			                         g_strdup_printf ("check failed: (%d) %s",
			                                          msg->data.result,
			                                          curl_easy_strerror (msg->data.result)));
		} else if (   !((_con_config_get_response (cb_data->concheck.con_config))[0])
		           && (curl_easy_getinfo (msg->easy_handle, CURLINFO_RESPONSE_CODE, &response_code) == CURLE_OK)
		           && response_code == 204) {
			/* If we got a 204 response code (no content) and we actually
			 * requested no content, report full connectivity. */
			cb_data_queue_completed (cb_data,
			                         NM_CONNECTIVITY_FULL,
			                         "no content, as expected",
			                         NULL);
		} else {
			/* If we get here, it means that easy_write_cb() didn't read enough
			 * bytes to be able to do a match, or that we were asking for no content
			 * (204 response code) and we actually got some. Either way, that is
			 * an indication of a captive portal */
			cb_data_queue_completed (cb_data,
			                         NM_CONNECTIVITY_PORTAL,
			                         "unexpected short response",
			                         NULL);
		}
	}

	/* if we return a failure, we don't know what went wrong. It's likely serious, because
	 * a failure here is not expected. Return FALSE, so that we stop polling the file descriptor.
	 * Worst case, this leaves the pending connectivity check unhandled, until our regular
	 * time-out kicks in. */
	return success;
}

static gboolean
_con_curl_timeout_cb (gpointer user_data)
{
	NMConnectivityCheckHandle *cb_data = user_data;

	cb_data->concheck.curl_timer = 0;
	_con_curl_check_connectivity (cb_data->concheck.curl_mhandle, CURL_SOCKET_TIMEOUT, 0);
	_complete_queued (cb_data->self);
	return G_SOURCE_REMOVE;
}

static int
multi_timer_cb (CURLM *multi, long timeout_ms, void *userdata)
{
	NMConnectivityCheckHandle *cb_data = userdata;

	nm_clear_g_source (&cb_data->concheck.curl_timer);
	if (timeout_ms != -1)
		cb_data->concheck.curl_timer = g_timeout_add (timeout_ms, _con_curl_timeout_cb, cb_data);
	return 0;
}

typedef struct {
	NMConnectivityCheckHandle *cb_data;
	GIOChannel *ch;

	/* this is a very simplistic weak-pointer. If ConCurlSockData gets
	 * destroyed, it will set *destroy_notify to TRUE.
	 *
	 * _con_curl_socketevent_cb() uses this to detect whether it can
	 * safely access @fdp after _con_curl_check_connectivity(). */
	gboolean *destroy_notify;

	guint ev;
} ConCurlSockData;

static gboolean
_con_curl_socketevent_cb (GIOChannel *ch, GIOCondition condition, gpointer user_data)
{
	ConCurlSockData *fdp = user_data;
	NMConnectivityCheckHandle *cb_data = fdp->cb_data;
	int fd = g_io_channel_unix_get_fd (ch);
	int action = 0;
	gboolean fdp_destroyed = FALSE;
	gboolean success;

	if (condition & G_IO_IN)
		action |= CURL_CSELECT_IN;
	if (condition & G_IO_OUT)
		action |= CURL_CSELECT_OUT;
	if (condition & G_IO_ERR)
		action |= CURL_CSELECT_ERR;

	nm_assert (!fdp->destroy_notify);
	fdp->destroy_notify = &fdp_destroyed;

	success = _con_curl_check_connectivity (cb_data->concheck.curl_mhandle, fd, action);

	if (fdp_destroyed) {
		/* hups. fdp got invalidated during _con_curl_check_connectivity(). That's fine,
		 * just don't touch it. */
	} else {
		nm_assert (fdp->destroy_notify == &fdp_destroyed);
		fdp->destroy_notify = NULL;
		if (!success)
			fdp->ev = 0;
	}

	_complete_queued (cb_data->self);

	return success ? G_SOURCE_CONTINUE : G_SOURCE_REMOVE;
}

static int
multi_socket_cb (CURL *e_handle, curl_socket_t fd, int what, void *userdata, void *socketp)
{
	NMConnectivityCheckHandle *cb_data = userdata;
	ConCurlSockData *fdp = socketp;
	GIOCondition condition = 0;

	(void) _NM_ENSURE_TYPE (int, fd);

	if (what == CURL_POLL_REMOVE) {
		if (fdp) {
			if (fdp->destroy_notify)
				*fdp->destroy_notify = TRUE;
			curl_multi_assign (cb_data->concheck.curl_mhandle, fd, NULL);
			nm_clear_g_source (&fdp->ev);
			g_io_channel_unref (fdp->ch);
			g_slice_free (ConCurlSockData, fdp);
		}
	} else {
		if (!fdp) {
			fdp = g_slice_new0 (ConCurlSockData);
			fdp->cb_data = cb_data;
			fdp->ch = g_io_channel_unix_new (fd);
			curl_multi_assign (cb_data->concheck.curl_mhandle, fd, fdp);
		} else
			nm_clear_g_source (&fdp->ev);

		if (what == CURL_POLL_IN)
			condition = G_IO_IN;
		else if (what == CURL_POLL_OUT)
			condition = G_IO_OUT;
		else if (what == CURL_POLL_INOUT)
			condition = G_IO_IN | G_IO_OUT;

		if (condition)
			fdp->ev = g_io_add_watch (fdp->ch, condition, _con_curl_socketevent_cb, fdp);
	}

	return CURLM_OK;
}

static size_t
easy_header_cb (char *buffer, size_t size, size_t nitems, void *userdata)
{
	NMConnectivityCheckHandle *cb_data = userdata;
	size_t len = size * nitems;

	if (cb_data->completed_state != NM_CONNECTIVITY_UNKNOWN) {
		/* already completed. */
		return 0;
	}

	if (   len >= sizeof (HEADER_STATUS_ONLINE) - 1
	    && !g_ascii_strncasecmp (buffer, HEADER_STATUS_ONLINE, sizeof (HEADER_STATUS_ONLINE) - 1)) {
		cb_data_queue_completed (cb_data,
		                         NM_CONNECTIVITY_FULL,
		                         "status header found",
		                         NULL);
		return 0;
	}

	return len;
}

static size_t
easy_write_cb (void *buffer, size_t size, size_t nmemb, void *userdata)
{
	NMConnectivityCheckHandle *cb_data = userdata;
	size_t len = size * nmemb;
	const char *response;

	if (cb_data->completed_state != NM_CONNECTIVITY_UNKNOWN) {
		/* already completed. */
		return 0;
	}

	if (!cb_data->concheck.recv_msg)
		cb_data->concheck.recv_msg = g_string_sized_new (len + 10);

	g_string_append_len (cb_data->concheck.recv_msg, buffer, len);

	response = _con_config_get_response (cb_data->concheck.con_config);;
	if (   response
	    && cb_data->concheck.recv_msg->len >= strlen (response)) {
		/* We already have enough data -- check response */
		if (g_str_has_prefix (cb_data->concheck.recv_msg->str, response)) {
			cb_data_queue_completed (cb_data,
			                         NM_CONNECTIVITY_FULL,
			                         "expected response",
			                         NULL);
		} else {
			cb_data_queue_completed (cb_data,
			                         NM_CONNECTIVITY_PORTAL,
			                         "unexpected response",
			                         NULL);
		}
		return 0;
	}

	return len;
}

static gboolean
_timeout_cb (gpointer user_data)
{
	NMConnectivityCheckHandle *cb_data = user_data;

	nm_assert (NM_IS_CONNECTIVITY (cb_data->self));
	nm_assert (c_list_contains (&NM_CONNECTIVITY_GET_PRIVATE (cb_data->self)->handles_lst_head, &cb_data->handles_lst));

	cb_data_complete (cb_data, NM_CONNECTIVITY_LIMITED, "timeout");
	return G_SOURCE_REMOVE;
}
#endif

static gboolean
_idle_cb (gpointer user_data)
{
	NMConnectivityCheckHandle *cb_data = user_data;

	nm_assert (NM_IS_CONNECTIVITY (cb_data->self));
	nm_assert (c_list_contains (&NM_CONNECTIVITY_GET_PRIVATE (cb_data->self)->handles_lst_head, &cb_data->handles_lst));

	cb_data->timeout_id = 0;
	if (!cb_data->ifspec) {
		gs_free_error GError *error = NULL;

		/* the invocation was with an invalid ifname. It is a fail. */
		g_set_error (&error, NM_UTILS_ERROR, NM_UTILS_ERROR_INVALID_ARGUMENT,
		             "no interface specified for connectivity check");
		cb_data_complete (cb_data, NM_CONNECTIVITY_ERROR, "missing interface");
	} else if (cb_data->fail_reason_no_dbus_connection) {
		gs_free_error GError *error = NULL;

		g_set_error (&error, NM_UTILS_ERROR, NM_UTILS_ERROR_INVALID_ARGUMENT,
		             "no D-Bus connection");
		cb_data_complete (cb_data, NM_CONNECTIVITY_ERROR, "no D-Bus connection");
	} else
		cb_data_complete (cb_data, NM_CONNECTIVITY_FAKE, "fake result");
	return G_SOURCE_REMOVE;
}

static void
do_curl_request (NMConnectivityCheckHandle *cb_data)
{
	CURLM *mhandle;
	CURL *ehandle;
	long resolve;

	mhandle = curl_multi_init ();
	if (!mhandle) {
		cb_data_complete (cb_data, NM_CONNECTIVITY_ERROR, "curl error");
		return;
	}

	ehandle = curl_easy_init ();
	if (!ehandle) {
		curl_multi_cleanup (mhandle);
		cb_data_complete (cb_data, NM_CONNECTIVITY_ERROR, "curl error");
		return;
	}

	cb_data->concheck.curl_mhandle = mhandle;
	cb_data->concheck.curl_ehandle = ehandle;
	cb_data->concheck.request_headers = curl_slist_append (NULL, "Connection: close");
	cb_data->timeout_id = g_timeout_add_seconds (20, _timeout_cb, cb_data);

	curl_multi_setopt (mhandle, CURLMOPT_SOCKETFUNCTION, multi_socket_cb);
	curl_multi_setopt (mhandle, CURLMOPT_SOCKETDATA, cb_data);
	curl_multi_setopt (mhandle, CURLMOPT_TIMERFUNCTION, multi_timer_cb);
	curl_multi_setopt (mhandle, CURLMOPT_TIMERDATA, cb_data);
	curl_multi_setopt (mhandle, CURLOPT_VERBOSE, 1);

	switch (cb_data->addr_family) {
	case AF_INET:
		resolve = CURL_IPRESOLVE_V4;
		break;
	case AF_INET6:
		resolve = CURL_IPRESOLVE_V6;
		break;
	case AF_UNSPEC:
		resolve = CURL_IPRESOLVE_WHATEVER;
		break;
	default:
		resolve = CURL_IPRESOLVE_WHATEVER;
		g_warn_if_reached ();
	}

	curl_easy_setopt (ehandle, CURLOPT_URL, cb_data->concheck.con_config->uri);
	curl_easy_setopt (ehandle, CURLOPT_WRITEFUNCTION, easy_write_cb);
	curl_easy_setopt (ehandle, CURLOPT_WRITEDATA, cb_data);
	curl_easy_setopt (ehandle, CURLOPT_HEADERFUNCTION, easy_header_cb);
	curl_easy_setopt (ehandle, CURLOPT_HEADERDATA, cb_data);
	curl_easy_setopt (ehandle, CURLOPT_PRIVATE, cb_data);
	curl_easy_setopt (ehandle, CURLOPT_HTTPHEADER, cb_data->concheck.request_headers);
	curl_easy_setopt (ehandle, CURLOPT_INTERFACE, cb_data->ifspec);
	curl_easy_setopt (ehandle, CURLOPT_RESOLVE, cb_data->concheck.hosts);
	curl_easy_setopt (ehandle, CURLOPT_IPRESOLVE, resolve);

	curl_multi_add_handle (mhandle, ehandle);
}

static void
resolve_cb (GObject *object, GAsyncResult *res, gpointer user_data)
{
	NMConnectivityCheckHandle *cb_data;
	gs_unref_variant GVariant *result = NULL;
	gs_unref_variant GVariant *addresses = NULL;
	gsize no_addresses;
	int ifindex;
	int addr_family;
	gsize len = 0;
	gsize i;
	gs_free_error GError *error = NULL;

	result = g_dbus_connection_call_finish (G_DBUS_CONNECTION (object), res, &error);
	if (g_error_matches (error, G_IO_ERROR, G_IO_ERROR_CANCELLED))
		return;

	cb_data = user_data;

	g_clear_object (&cb_data->concheck.resolve_cancellable);

	if (!result) {
		/* Never mind. Just let do curl do its own resolving. */
		_LOG2D ("can't resolve a name via systemd-resolved: %s", error->message);
		do_curl_request (cb_data);
		return;
	}

	addresses = g_variant_get_child_value (result, 0);
	no_addresses = g_variant_n_children (addresses);

	for (i = 0; i < no_addresses; i++) {
		gs_unref_variant GVariant *address = NULL;
		char str_addr[NM_UTILS_INET_ADDRSTRLEN];
		gs_free char *host_entry = NULL;
		const guchar *address_buf;

		g_variant_get_child (addresses, i, "(ii@ay)", &ifindex, &addr_family, &address);

		if (   cb_data->addr_family != AF_UNSPEC
		    && cb_data->addr_family != addr_family)
			continue;

		address_buf = g_variant_get_fixed_array (address, &len, 1);
		if (   (addr_family == AF_INET  && len != sizeof (struct in_addr))
		    || (addr_family == AF_INET6 && len != sizeof (struct in6_addr)))
			continue;

		host_entry = g_strdup_printf ("%s:%s:%s",
		                              cb_data->concheck.con_config->host,
		                              cb_data->concheck.con_config->port ?: "80",
		                              nm_utils_inet_ntop (addr_family, address_buf, str_addr));
		cb_data->concheck.hosts = curl_slist_append (cb_data->concheck.hosts, host_entry);
		_LOG2T ("adding '%s' to curl resolve list", host_entry);
	}

	do_curl_request (cb_data);
}

#define SD_RESOLVED_DNS ((guint64) (1LL << 0))

NMConnectivityCheckHandle *
nm_connectivity_check_start (NMConnectivity *self,
                             int addr_family,
                             int ifindex,
                             const char *iface,
                             NMConnectivityCheckCallback callback,
                             gpointer user_data)
{
	NMConnectivityPrivate *priv;
	NMConnectivityCheckHandle *cb_data;
	static guint64 request_counter = 0;

	g_return_val_if_fail (NM_IS_CONNECTIVITY (self), NULL);
	g_return_val_if_fail (callback, NULL);

	priv = NM_CONNECTIVITY_GET_PRIVATE (self);

	cb_data = g_slice_new0 (NMConnectivityCheckHandle);
	cb_data->self = self;
	cb_data->request_counter = ++request_counter;
	c_list_link_tail (&priv->handles_lst_head, &cb_data->handles_lst);
	cb_data->callback = callback;
	cb_data->user_data = user_data;
	cb_data->completed_state = NM_CONNECTIVITY_UNKNOWN;
	cb_data->addr_family = addr_family;
	cb_data->concheck.con_config = _con_config_ref (priv->con_config);

	if (iface)
		cb_data->ifspec = g_strdup_printf ("if!%s", iface);

#if WITH_CONCHECK

	if (   iface
	    && ifindex > 0
	    && priv->enabled
	    && priv->uri_valid) {
		gboolean has_systemd_resolved;

		cb_data->concheck.ch_ifindex = ifindex;

		/* note that we pick up support for systemd-resolved right away when we need it.
		 * We don't need to remember the setting, because we can (cheaply) check anew
		 * on each request.
		 *
		 * Yes, this makes NMConnectivity singleton dependent on NMDnsManager singleton.
		 * Well, not really: it makes connectivity-check-start dependent on NMDnsManager
		 * which merely means, not to start a connectivity check, late during shutdown. */
		has_systemd_resolved = nm_dns_manager_has_systemd_resolved (nm_dns_manager_get ());

		if (has_systemd_resolved) {
			GDBusConnection *dbus_connection;

			dbus_connection = nm_dbus_manager_get_dbus_connection (nm_dbus_manager_get ());
			if (!dbus_connection) {
				/* we have no D-Bus connection? That might happen in configure and quit mode.
				 *
				 * Anyway, something is very odd, just fail connectivity check. */
				_LOG2D ("start fake request (fail due to no D-Bus connection)");
				cb_data->fail_reason_no_dbus_connection = TRUE;
				cb_data->timeout_id = g_idle_add (_idle_cb, cb_data);
				return cb_data;
			}

			cb_data->concheck.resolve_cancellable = g_cancellable_new ();

			g_dbus_connection_call (nm_dbus_manager_get_dbus_connection (nm_dbus_manager_get ()),
			                        "org.freedesktop.resolve1",
			                        "/org/freedesktop/resolve1",
			                        "org.freedesktop.resolve1.Manager",
			                        "ResolveHostname",
			                        g_variant_new ("(isit)",
			                                       (gint32) cb_data->concheck.ch_ifindex,
			                                       cb_data->concheck.con_config->host,
			                                       (gint32) cb_data->addr_family,
			                                       SD_RESOLVED_DNS),
			                        G_VARIANT_TYPE ("(a(iiay)st)"),
			                        G_DBUS_CALL_FLAGS_NONE,
			                        -1,
			                        cb_data->concheck.resolve_cancellable,
			                        resolve_cb,
			                        cb_data);
			_LOG2D ("start request to '%s' (try resolving '%s' using systemd-resolved)",
			        cb_data->concheck.con_config->uri,
			        cb_data->concheck.con_config->host);
		} else {
			_LOG2D ("start request to '%s' (systemd-resolved not available)",
			        cb_data->concheck.con_config->uri);
			do_curl_request (cb_data);
		}

		return cb_data;
	}
#endif

	_LOG2D ("start fake request");
	cb_data->timeout_id = g_idle_add (_idle_cb, cb_data);

	return cb_data;
}

void
nm_connectivity_check_cancel (NMConnectivityCheckHandle *cb_data)
{
	g_return_if_fail (cb_data);
	g_return_if_fail (NM_IS_CONNECTIVITY (cb_data->self));

	nm_assert (   c_list_contains (&NM_CONNECTIVITY_GET_PRIVATE (cb_data->self)->handles_lst_head,           &cb_data->handles_lst)
	           || c_list_contains (&NM_CONNECTIVITY_GET_PRIVATE (cb_data->self)->completed_handles_lst_head, &cb_data->handles_lst));

	cb_data_complete (cb_data, NM_CONNECTIVITY_CANCELLED, "cancelled");
}

/*****************************************************************************/

gboolean
nm_connectivity_check_enabled (NMConnectivity *self)
{
	g_return_val_if_fail (NM_IS_CONNECTIVITY (self), FALSE);

	return NM_CONNECTIVITY_GET_PRIVATE (self)->enabled;
}

/*****************************************************************************/

guint
nm_connectivity_get_interval (NMConnectivity *self)
{
	return nm_connectivity_check_enabled (self)
	       ? NM_CONNECTIVITY_GET_PRIVATE (self)->interval
	       : 0;
}

static gboolean
host_and_port_from_uri (const char *uri, char **host, char **port)
{
	const char *p = uri;
	const char *host_begin = NULL;
	size_t host_len = 0;
	const char *port_begin = NULL;
	size_t port_len = 0;

	/* scheme */
	while (*p != ':' && *p != '/') {
		if (!*p++)
			return FALSE;
	}

	/* :// */
	if (*p++ != ':')
		return FALSE;
	if (*p++ != '/')
		return FALSE;
	if (*p++ != '/')
		return FALSE;
	/* host */
	if (*p == '[')
		return FALSE;
	host_begin = p;
	while (*p && *p != ':' && *p != '/') {
		host_len++;
		p++;
	}
	if (host_len == 0)
		return FALSE;
	*host = g_strndup (host_begin, host_len);

	/* port */
	if (*p++ == ':') {
		port_begin = p;
		while (*p && *p != '/') {
			port_len++;
			p++;
		}
		if (port_len)
			*port = g_strndup (port_begin, port_len);
	}

	return TRUE;
}

static void
update_config (NMConnectivity *self, NMConfigData *config_data)
{
	NMConnectivityPrivate *priv = NM_CONNECTIVITY_GET_PRIVATE (self);
	guint interval;
	gboolean enabled;
	gboolean changed = FALSE;
	const char *cur_uri = priv->con_config ? priv->con_config->uri : NULL;
	const char *cur_response = priv->con_config ? priv->con_config->response : NULL;
	const char *new_response;
	const char *new_uri;
	gboolean new_uri_valid = priv->uri_valid;
	gboolean new_host_port = FALSE;
	gs_free char *new_host = NULL;
	gs_free char *new_port = NULL;

	new_uri = nm_config_data_get_connectivity_uri (config_data);
	if (!nm_streq0 (new_uri, cur_uri)) {

		new_uri_valid = (new_uri && *new_uri);
		if (new_uri_valid) {
			gs_free char *scheme = g_uri_parse_scheme (new_uri);
			gboolean is_https = FALSE;

			if (!scheme) {
				_LOGE ("invalid URI '%s' for connectivity check.", new_uri);
				new_uri_valid = FALSE;
			} else if (g_ascii_strcasecmp (scheme, "https") == 0) {
				_LOGW ("use of HTTPS for connectivity checking is not reliable and is discouraged (URI: %s)", new_uri);
				is_https = TRUE;
			} else if (g_ascii_strcasecmp (scheme, "http") != 0) {
				_LOGE ("scheme of '%s' uri doesn't use a scheme that is allowed for connectivity check.", new_uri);
				new_uri_valid = FALSE;
			}
			if (new_uri_valid) {
				new_host_port = TRUE;
				if (!host_and_port_from_uri (new_uri, &new_host, &new_port)) {
					_LOGE ("cannot parse host and port from '%s'", new_uri);
					new_uri_valid = FALSE;
				} else if (!new_port && is_https)
					new_port = g_strdup ("443");
			}
		}

		if (   new_uri_valid
		    || priv->uri_valid != new_uri_valid)
			changed = TRUE;
	}

	new_response = nm_config_data_get_connectivity_response (config_data);
	if (!nm_streq0 (new_response, cur_response))
		changed = TRUE;

	if (   !priv->con_config
	    || !nm_streq0 (new_uri, priv->con_config->uri)
	    || !nm_streq0 (new_response, priv->con_config->response)) {
		if (!new_host_port) {
			new_host = priv->con_config ? g_strdup (priv->con_config->host) : NULL;
			new_port = priv->con_config ? g_strdup (priv->con_config->port) : NULL;
		}
		_con_config_unref (priv->con_config);
		priv->con_config = g_slice_new (ConConfig);
		*priv->con_config = (ConConfig) {
			.ref_count = 1,
			.uri       = g_strdup (new_uri),
			.response  = g_strdup (new_response),
			.host      = g_steal_pointer (&new_host),
			.port      = g_steal_pointer (&new_port),
		};
	}
	priv->uri_valid = new_uri_valid;

	interval = nm_config_data_get_connectivity_interval (config_data);
	interval = MIN (interval, (7 * 24 * 3600));
	if (priv->interval != interval) {
		priv->interval = interval;
		changed = TRUE;
	}

	enabled = FALSE;
#if WITH_CONCHECK
	if (   priv->uri_valid
	    && priv->interval)
		enabled = nm_config_data_get_connectivity_enabled (config_data);
#endif

	if (priv->enabled != enabled) {
		priv->enabled = enabled;
		changed = TRUE;
	}

	if (changed)
		g_signal_emit (self, signals[CONFIG_CHANGED], 0);
}

static void
config_changed_cb (NMConfig *config,
                   NMConfigData *config_data,
                   NMConfigChangeFlags changes,
                   NMConfigData *old_data,
                   NMConnectivity *self)
{
	update_config (self, config_data);
}

/*****************************************************************************/

static void
nm_connectivity_init (NMConnectivity *self)
{
	NMConnectivityPrivate *priv = NM_CONNECTIVITY_GET_PRIVATE (self);
#if WITH_CONCHECK
	CURLcode ret;
#endif

	c_list_init (&priv->handles_lst_head);
	c_list_init (&priv->completed_handles_lst_head);

	priv->config = g_object_ref (nm_config_get ());
	g_signal_connect (G_OBJECT (priv->config),
	                  NM_CONFIG_SIGNAL_CONFIG_CHANGED,
	                  G_CALLBACK (config_changed_cb),
	                  self);

#if WITH_CONCHECK
	ret = curl_global_init (CURL_GLOBAL_ALL);
	if (ret != CURLE_OK) {
		 _LOGE ("unable to init cURL, connectivity check will not work: (%d) %s",
		        ret, curl_easy_strerror (ret));
	}
#endif

	update_config (self, nm_config_get_data (priv->config));
}

static void
dispose (GObject *object)
{
	NMConnectivity *self = NM_CONNECTIVITY (object);
	NMConnectivityPrivate *priv = NM_CONNECTIVITY_GET_PRIVATE (self);
	NMConnectivityCheckHandle *cb_data;

	nm_assert (c_list_is_empty (&priv->completed_handles_lst_head));

	while ((cb_data = c_list_first_entry (&priv->handles_lst_head,
	                                      NMConnectivityCheckHandle,
	                                      handles_lst)))
		cb_data_complete (cb_data, NM_CONNECTIVITY_DISPOSING, "shutting down");

	nm_clear_pointer (&priv->con_config, _con_config_unref);

#if WITH_CONCHECK
	curl_global_cleanup ();
#endif

	if (priv->config) {
		g_signal_handlers_disconnect_by_func (priv->config, config_changed_cb, self);
		g_clear_object (&priv->config);
	}

	G_OBJECT_CLASS (nm_connectivity_parent_class)->dispose (object);
}

static void
nm_connectivity_class_init (NMConnectivityClass *klass)
{
	GObjectClass *object_class = G_OBJECT_CLASS (klass);

	signals[CONFIG_CHANGED] =
	    g_signal_new (NM_CONNECTIVITY_CONFIG_CHANGED,
	                  G_OBJECT_CLASS_TYPE (object_class),
	                  G_SIGNAL_RUN_FIRST,
	                  0, NULL, NULL, NULL,
	                  G_TYPE_NONE, 0);

	object_class->dispose = dispose;
}