summaryrefslogtreecommitdiffstats
blob: ffe59da227a9bb8f8d942bfab580b945e8553666 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
/*
 * Copyright (C) 2007 The Android Open Source Project
 *
 * 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 <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>

#include "sysdeps.h"

#define   TRACE_TAG  TRACE_TRANSPORT
#include "adb.h"

static void transport_unref(atransport *t);

static atransport transport_list = {
    .next = &transport_list,
    .prev = &transport_list,
};

static atransport pending_list = {
    .next = &pending_list,
    .prev = &pending_list,
};

ADB_MUTEX_DEFINE( transport_lock );

#if ADB_TRACE
#define MAX_DUMP_HEX_LEN 16
static void  dump_hex( const unsigned char*  ptr, size_t  len )
{
    int  nn, len2 = len;
    // Build a string instead of logging each character.
    // MAX chars in 2 digit hex, one space, MAX chars, one '\0'.
    char buffer[MAX_DUMP_HEX_LEN *2 + 1 + MAX_DUMP_HEX_LEN + 1 ], *pb = buffer;

    if (len2 > MAX_DUMP_HEX_LEN) len2 = MAX_DUMP_HEX_LEN;

    for (nn = 0; nn < len2; nn++) {
        sprintf(pb, "%02x", ptr[nn]);
        pb += 2;
    }
    sprintf(pb++, " ");

    for (nn = 0; nn < len2; nn++) {
        int  c = ptr[nn];
        if (c < 32 || c > 127)
            c = '.';
        *pb++ =  c;
    }
    *pb++ = '\0';
    DR("%s\n", buffer);
}
#endif

void
kick_transport(atransport*  t)
{
    if (t && !t->kicked)
    {
        int  kicked;

        adb_mutex_lock(&transport_lock);
        kicked = t->kicked;
        if (!kicked)
            t->kicked = 1;
        adb_mutex_unlock(&transport_lock);

        if (!kicked)
            t->kick(t);
    }
}

void
run_transport_disconnects(atransport*  t)
{
    adisconnect*  dis = t->disconnects.next;

    D("%s: run_transport_disconnects\n", t->serial);
    while (dis != &t->disconnects) {
        adisconnect*  next = dis->next;
        dis->func( dis->opaque, t );
        dis = next;
    }
}

#if ADB_TRACE
static void
dump_packet(const char* name, const char* func, apacket* p)
{
    unsigned  command = p->msg.command;
    int       len     = p->msg.data_length;
    char      cmd[9];
    char      arg0[12], arg1[12];
    int       n;

    for (n = 0; n < 4; n++) {
        int  b = (command >> (n*8)) & 255;
        if (b < 32 || b >= 127)
            break;
        cmd[n] = (char)b;
    }
    if (n == 4) {
        cmd[4] = 0;
    } else {
        /* There is some non-ASCII name in the command, so dump
            * the hexadecimal value instead */
        snprintf(cmd, sizeof cmd, "%08x", command);
    }

    if (p->msg.arg0 < 256U)
        snprintf(arg0, sizeof arg0, "%d", p->msg.arg0);
    else
        snprintf(arg0, sizeof arg0, "0x%x", p->msg.arg0);

    if (p->msg.arg1 < 256U)
        snprintf(arg1, sizeof arg1, "%d", p->msg.arg1);
    else
        snprintf(arg1, sizeof arg1, "0x%x", p->msg.arg1);

    D("%s: %s: [%s] arg0=%s arg1=%s (len=%d) ",
        name, func, cmd, arg0, arg1, len);
    dump_hex(p->data, len);
}
#endif /* ADB_TRACE */

static int
read_packet(int  fd, const char* name, apacket** ppacket)
{
    char *p = (char*)ppacket;  /* really read a packet address */
    int   r;
    int   len = sizeof(*ppacket);
    char  buff[8];
    if (!name) {
        snprintf(buff, sizeof buff, "fd=%d", fd);
        name = buff;
    }
    while(len > 0) {
        r = adb_read(fd, p, len);
        if(r > 0) {
            len -= r;
            p   += r;
        } else {
            D("%s: read_packet (fd=%d), error ret=%d errno=%d: %s\n", name, fd, r, errno, strerror(errno));
            if((r < 0) && (errno == EINTR)) continue;
            return -1;
        }
    }

#if ADB_TRACE
    if (ADB_TRACING) {
        dump_packet(name, "from remote", *ppacket);
    }
#endif
    return 0;
}

static int
write_packet(int  fd, const char* name, apacket** ppacket)
{
    char *p = (char*) ppacket;  /* we really write the packet address */
    int r, len = sizeof(ppacket);
    char buff[8];
    if (!name) {
        snprintf(buff, sizeof buff, "fd=%d", fd);
        name = buff;
    }

#if ADB_TRACE
    if (ADB_TRACING) {
        dump_packet(name, "to remote", *ppacket);
    }
#endif
    len = sizeof(ppacket);
    while(len > 0) {
        r = adb_write(fd, p, len);
        if(r > 0) {
            len -= r;
            p += r;
        } else {
            D("%s: write_packet (fd=%d) error ret=%d errno=%d: %s\n", name, fd, r, errno, strerror(errno));
            if((r < 0) && (errno == EINTR)) continue;
            return -1;
        }
    }
    return 0;
}

static void transport_socket_events(int fd, unsigned events, void *_t)
{
    atransport *t = _t;
    D("transport_socket_events(fd=%d, events=%04x,...)\n", fd, events);
    if(events & FDE_READ){
        apacket *p = 0;
        if(read_packet(fd, t->serial, &p)){
            D("%s: failed to read packet from transport socket on fd %d\n", t->serial, fd);
        } else {
            handle_packet(p, (atransport *) _t);
        }
    }
}

void send_packet(apacket *p, atransport *t)
{
    unsigned char *x;
    unsigned sum;
    unsigned count;

    p->msg.magic = p->msg.command ^ 0xffffffff;

    count = p->msg.data_length;
    x = (unsigned char *) p->data;
    sum = 0;
    while(count-- > 0){
        sum += *x++;
    }
    p->msg.data_check = sum;

    print_packet("send", p);

    if (t == NULL) {
        D("Transport is null \n");
        // Zap errno because print_packet() and other stuff have errno effect.
        errno = 0;
        fatal_errno("Transport is null");
    }

    if(write_packet(t->transport_socket, t->serial, &p)){
        fatal_errno("cannot enqueue packet on transport socket");
    }
}

/* The transport is opened by transport_register_func before
** the input and output threads are started.
**
** The output thread issues a SYNC(1, token) message to let
** the input thread know to start things up.  In the event
** of transport IO failure, the output thread will post a
** SYNC(0,0) message to ensure shutdown.
**
** The transport will not actually be closed until both
** threads exit, but the input thread will kick the transport
** on its way out to disconnect the underlying device.
*/

static void *output_thread(void *_t)
{
    atransport *t = _t;
    apacket *p;

    D("%s: starting transport output thread on fd %d, SYNC online (%d)\n",
       t->serial, t->fd, t->sync_token + 1);
    p = get_apacket();
    p->msg.command = A_SYNC;
    p->msg.arg0 = 1;
    p->msg.arg1 = ++(t->sync_token);
    p->msg.magic = A_SYNC ^ 0xffffffff;
    if(write_packet(t->fd, t->serial, &p)) {
        put_apacket(p);
        D("%s: failed to write SYNC packet\n", t->serial);
        goto oops;
    }

    D("%s: data pump started\n", t->serial);
    for(;;) {
        p = get_apacket();

        if(t->read_from_remote(p, t) == 0){
            D("%s: received remote packet, sending to transport\n",
              t->serial);
            if(write_packet(t->fd, t->serial, &p)){
                put_apacket(p);
                D("%s: failed to write apacket to transport\n", t->serial);
                goto oops;
            }
        } else {
            D("%s: remote read failed for transport\n", t->serial);
            put_apacket(p);
            break;
        }
    }

    D("%s: SYNC offline for transport\n", t->serial);
    p = get_apacket();
    p->msg.command = A_SYNC;
    p->msg.arg0 = 0;
    p->msg.arg1 = 0;
    p->msg.magic = A_SYNC ^ 0xffffffff;
    if(write_packet(t->fd, t->serial, &p)) {
        put_apacket(p);
        D("%s: failed to write SYNC apacket to transport", t->serial);
    }

oops:
    D("%s: transport output thread is exiting\n", t->serial);
    kick_transport(t);
    transport_unref(t);
    return 0;
}

static void *input_thread(void *_t)
{
    atransport *t = _t;
    apacket *p;
    int active = 0;

    D("%s: starting transport input thread, reading from fd %d\n",
       t->serial, t->fd);

    for(;;){
        if(read_packet(t->fd, t->serial, &p)) {
            D("%s: failed to read apacket from transport on fd %d\n",
               t->serial, t->fd );
            break;
        }
        if(p->msg.command == A_SYNC){
            if(p->msg.arg0 == 0) {
                D("%s: transport SYNC offline\n", t->serial);
                put_apacket(p);
                break;
            } else {
                if(p->msg.arg1 == t->sync_token) {
                    D("%s: transport SYNC online\n", t->serial);
                    active = 1;
                } else {
                    D("%s: transport ignoring SYNC %d != %d\n",
                      t->serial, p->msg.arg1, t->sync_token);
                }
            }
        } else {
            if(active) {
                D("%s: transport got packet, sending to remote\n", t->serial);
                t->write_to_remote(p, t);
            } else {
                D("%s: transport ignoring packet while offline\n", t->serial);
            }
        }

        put_apacket(p);
    }

    // this is necessary to avoid a race condition that occured when a transport closes
    // while a client socket is still active.
    close_all_sockets(t);

    D("%s: transport input thread is exiting, fd %d\n", t->serial, t->fd);
    kick_transport(t);
    transport_unref(t);
    return 0;
}


static int transport_registration_send = -1;
static int transport_registration_recv = -1;
static fdevent transport_registration_fde;


#if ADB_HOST
static int list_transports_msg(char*  buffer, size_t  bufferlen)
{
    char  head[5];
    int   len;

    len = list_transports(buffer+4, bufferlen-4, 0);
    snprintf(head, sizeof(head), "%04x", len);
    memcpy(buffer, head, 4);
    len += 4;
    return len;
}

/* this adds support required by the 'track-devices' service.
 * this is used to send the content of "list_transport" to any
 * number of client connections that want it through a single
 * live TCP connection
 */
typedef struct device_tracker  device_tracker;
struct device_tracker {
    asocket          socket;
    int              update_needed;
    device_tracker*  next;
};

/* linked list of all device trackers */
static device_tracker*   device_tracker_list;

static void
device_tracker_remove( device_tracker*  tracker )
{
    device_tracker**  pnode = &device_tracker_list;
    device_tracker*   node  = *pnode;

    adb_mutex_lock( &transport_lock );
    while (node) {
        if (node == tracker) {
            *pnode = node->next;
            break;
        }
        pnode = &node->next;
        node  = *pnode;
    }
    adb_mutex_unlock( &transport_lock );
}

static void
device_tracker_close( asocket*  socket )
{
    device_tracker*  tracker = (device_tracker*) socket;
    asocket*         peer    = socket->peer;

    D( "device tracker %p removed\n", tracker);
    if (peer) {
        peer->peer = NULL;
        peer->close(peer);
    }
    device_tracker_remove(tracker);
    free(tracker);
}

static int
device_tracker_enqueue( asocket*  socket, apacket*  p )
{
    /* you can't read from a device tracker, close immediately */
    put_apacket(p);
    device_tracker_close(socket);
    return -1;
}

static int
device_tracker_send( device_tracker*  tracker,
                     const char*      buffer,
                     int              len )
{
    apacket*  p = get_apacket();
    asocket*  peer = tracker->socket.peer;

    memcpy(p->data, buffer, len);
    p->len = len;
    return peer->enqueue( peer, p );
}


static void
device_tracker_ready( asocket*  socket )
{
    device_tracker*  tracker = (device_tracker*) socket;

    /* we want to send the device list when the tracker connects
    * for the first time, even if no update occured */
    if (tracker->update_needed > 0) {
        char  buffer[1024];
        int   len;

        tracker->update_needed = 0;

        len = list_transports_msg(buffer, sizeof(buffer));
        device_tracker_send(tracker, buffer, len);
    }
}


asocket*
create_device_tracker(void)
{
    device_tracker*  tracker = calloc(1,sizeof(*tracker));

    if(tracker == 0) fatal("cannot allocate device tracker");

    D( "device tracker %p created\n", tracker);

    tracker->socket.enqueue = device_tracker_enqueue;
    tracker->socket.ready   = device_tracker_ready;
    tracker->socket.close   = device_tracker_close;
    tracker->update_needed  = 1;

    tracker->next       = device_tracker_list;
    device_tracker_list = tracker;

    return &tracker->socket;
}


/* call this function each time the transport list has changed */
void  update_transports(void)
{
    char             buffer[1024];
    int              len;
    device_tracker*  tracker;

    len = list_transports_msg(buffer, sizeof(buffer));

    tracker = device_tracker_list;
    while (tracker != NULL) {
        device_tracker*  next = tracker->next;
        /* note: this may destroy the tracker if the connection is closed */
        device_tracker_send(tracker, buffer, len);
        tracker = next;
    }
}
#else
void  update_transports(void)
{
    // nothing to do on the device side
}
#endif // ADB_HOST

typedef struct tmsg tmsg;
struct tmsg
{
    atransport *transport;
    int         action;
};

static int
transport_read_action(int  fd, struct tmsg*  m)
{
    char *p   = (char*)m;
    int   len = sizeof(*m);
    int   r;

    while(len > 0) {
        r = adb_read(fd, p, len);
        if(r > 0) {
            len -= r;
            p   += r;
        } else {
            if((r < 0) && (errno == EINTR)) continue;
            D("transport_read_action: on fd %d, error %d: %s\n",
              fd, errno, strerror(errno));
            return -1;
        }
    }
    return 0;
}

static int
transport_write_action(int  fd, struct tmsg*  m)
{
    char *p   = (char*)m;
    int   len = sizeof(*m);
    int   r;

    while(len > 0) {
        r = adb_write(fd, p, len);
        if(r > 0) {
            len -= r;
            p   += r;
        } else {
            if((r < 0) && (errno == EINTR)) continue;
            D("transport_write_action: on fd %d, error %d: %s\n",
              fd, errno, strerror(errno));
            return -1;
        }
    }
    return 0;
}

static void transport_registration_func(int _fd, unsigned ev, void *data)
{
    tmsg m;
    adb_thread_t output_thread_ptr;
    adb_thread_t input_thread_ptr;
    int s[2];
    atransport *t;

    if(!(ev & FDE_READ)) {
        return;
    }

    if(transport_read_action(_fd, &m)) {
        fatal_errno("cannot read transport registration socket");
    }

    t = m.transport;

    if(m.action == 0){
        D("transport: %s removing and free'ing %d\n", t->serial, t->transport_socket);

            /* IMPORTANT: the remove closes one half of the
            ** socket pair.  The close closes the other half.
            */
        fdevent_remove(&(t->transport_fde));
        adb_close(t->fd);

        adb_mutex_lock(&transport_lock);
        t->next->prev = t->prev;
        t->prev->next = t->next;
        adb_mutex_unlock(&transport_lock);

        run_transport_disconnects(t);

        if (t->product)
            free(t->product);
        if (t->serial)
            free(t->serial);
        if (t->model)
            free(t->model);
        if (t->device)
            free(t->device);
        if (t->devpath)
            free(t->devpath);

        memset(t,0xee,sizeof(atransport));
        free(t);

        update_transports();
        return;
    }

    /* don't create transport threads for inaccessible devices */
    if (t->connection_state != CS_NOPERM) {
        /* initial references are the two threads */
        t->ref_count = 2;

        if(adb_socketpair(s)) {
            fatal_errno("cannot open transport socketpair");
        }

        D("transport: %s socketpair: (%d,%d) starting", t->serial, s[0], s[1]);

        t->transport_socket = s[0];
        t->fd = s[1];

        fdevent_install(&(t->transport_fde),
                        t->transport_socket,
                        transport_socket_events,
                        t);

        fdevent_set(&(t->transport_fde), FDE_READ);

        if(adb_thread_create(&input_thread_ptr, input_thread, t)){
            fatal_errno("cannot create input thread");
        }

        if(adb_thread_create(&output_thread_ptr, output_thread, t)){
            fatal_errno("cannot create output thread");
        }
    }

    adb_mutex_lock(&transport_lock);
    /* remove from pending list */
    t->next->prev = t->prev;
    t->prev->next = t->next;
    /* put us on the master device list */
    t->next = &transport_list;
    t->prev = transport_list.prev;
    t->next->prev = t;
    t->prev->next = t;
    adb_mutex_unlock(&transport_lock);

    t->disconnects.next = t->disconnects.prev = &t->disconnects;

    update_transports();
}

void init_transport_registration(void)
{
    int s[2];

    if(adb_socketpair(s)){
        fatal_errno("cannot open transport registration socketpair");
    }
    D("socketpair: (%d,%d)", s[0], s[1]);

    transport_registration_send = s[0];
    transport_registration_recv = s[1];

    fdevent_install(&transport_registration_fde,
                    transport_registration_recv,
                    transport_registration_func,
                    0);

    fdevent_set(&transport_registration_fde, FDE_READ);
}

/* the fdevent select pump is single threaded */
static void register_transport(atransport *transport)
{
    tmsg m;
    m.transport = transport;
    m.action = 1;
    D("transport: %s registered\n", transport->serial);
    if(transport_write_action(transport_registration_send, &m)) {
        fatal_errno("cannot write transport registration socket\n");
    }
}

static void remove_transport(atransport *transport)
{
    tmsg m;
    m.transport = transport;
    m.action = 0;
    D("transport: %s removed\n", transport->serial);
    if(transport_write_action(transport_registration_send, &m)) {
        fatal_errno("cannot write transport registration socket\n");
    }
}


static void transport_unref_locked(atransport *t)
{
    t->ref_count--;
    if (t->ref_count == 0) {
        D("transport: %s unref (kicking and closing)\n", t->serial);
        if (!t->kicked) {
            t->kicked = 1;
            t->kick(t);
        }
        t->close(t);
        remove_transport(t);
    } else {
        D("transport: %s unref (count=%d)\n", t->serial, t->ref_count);
    }
}

static void transport_unref(atransport *t)
{
    if (t) {
        adb_mutex_lock(&transport_lock);
        transport_unref_locked(t);
        adb_mutex_unlock(&transport_lock);
    }
}

void add_transport_disconnect(atransport*  t, adisconnect*  dis)
{
    adb_mutex_lock(&transport_lock);
    dis->next       = &t->disconnects;
    dis->prev       = dis->next->prev;
    dis->prev->next = dis;
    dis->next->prev = dis;
    adb_mutex_unlock(&transport_lock);
}

void remove_transport_disconnect(atransport*  t, adisconnect*  dis)
{
    dis->prev->next = dis->next;
    dis->next->prev = dis->prev;
    dis->next = dis->prev = dis;
}

static int qual_char_is_invalid(char ch)
{
    if ('A' <= ch && ch <= 'Z')
        return 0;
    if ('a' <= ch && ch <= 'z')
        return 0;
    if ('0' <= ch && ch <= '9')
        return 0;
    return 1;
}

static int qual_match(const char *to_test,
                      const char *prefix, const char *qual, int sanitize_qual)
{
    if (!to_test || !*to_test)
        /* Return true if both the qual and to_test are null strings. */
        return !qual || !*qual;

    if (!qual)
        return 0;

    if (prefix) {
        while (*prefix) {
            if (*prefix++ != *to_test++)
                return 0;
        }
    }

    while (*qual) {
        char ch = *qual++;
        if (sanitize_qual && qual_char_is_invalid(ch))
            ch = '_';
        if (ch != *to_test++)
            return 0;
    }

    /* Everything matched so far.  Return true if *to_test is a NUL. */
    return !*to_test;
}

atransport *acquire_one_transport(int state, transport_type ttype, const char* serial, char** error_out)
{
    atransport *t;
    atransport *result = NULL;
    int ambiguous = 0;

retry:
    if (error_out)
        *error_out = "device not found";

    adb_mutex_lock(&transport_lock);
    for (t = transport_list.next; t != &transport_list; t = t->next) {
        if (t->connection_state == CS_NOPERM) {
        if (error_out)
            *error_out = "insufficient permissions for device";
            continue;
        }

        /* check for matching serial number */
        if (serial) {
            if ((t->serial && !strcmp(serial, t->serial)) ||
                (t->devpath && !strcmp(serial, t->devpath)) ||
                qual_match(serial, "product:", t->product, 0) ||
                qual_match(serial, "model:", t->model, 1) ||
                qual_match(serial, "device:", t->device, 0)) {
                if (result) {
                    if (error_out)
                        *error_out = "more than one device";
                    ambiguous = 1;
                    result = NULL;
                    break;
                }
                result = t;
            }
        } else {
            if (ttype == kTransportUsb && t->type == kTransportUsb) {
                if (result) {
                    if (error_out)
                        *error_out = "more than one device";
                    ambiguous = 1;
                    result = NULL;
                    break;
                }
                result = t;
            } else if (ttype == kTransportLocal && t->type == kTransportLocal) {
                if (result) {
                    if (error_out)
                        *error_out = "more than one emulator";
                    ambiguous = 1;
                    result = NULL;
                    break;
                }
                result = t;
            } else if (ttype == kTransportAny) {
                if (result) {
                    if (error_out)
                        *error_out = "more than one device and emulator";
                    ambiguous = 1;
                    result = NULL;
                    break;
                }
                result = t;
            }
        }
    }
    adb_mutex_unlock(&transport_lock);

    if (result) {
        if (result->connection_state == CS_UNAUTHORIZED) {
            if (error_out)
                *error_out = "device unauthorized. Please check the confirmation dialog on your device.";
            result = NULL;
        }

         /* offline devices are ignored -- they are either being born or dying */
        if (result && result->connection_state == CS_OFFLINE) {
            if (error_out)
                *error_out = "device offline";
            result = NULL;
        }
         /* check for required connection state */
        if (result && state != CS_ANY && result->connection_state != state) {
            if (error_out)
                *error_out = "invalid device state";
            result = NULL;
        }
    }

    if (result) {
        /* found one that we can take */
        if (error_out)
            *error_out = NULL;
    } else if (state != CS_ANY && (serial || !ambiguous)) {
        adb_sleep_ms(1000);
        goto retry;
    }

    return result;
}

#if ADB_HOST
static const char *statename(atransport *t)
{
    switch(t->connection_state){
    case CS_OFFLINE: return "offline";
    case CS_BOOTLOADER: return "bootloader";
    case CS_DEVICE: return "device";
    case CS_HOST: return "host";
    case CS_RECOVERY: return "recovery";
    case CS_SIDELOAD: return "sideload";
    case CS_NOPERM: return "no permissions";
    case CS_UNAUTHORIZED: return "unauthorized";
    default: return "unknown";
    }
}

static void add_qual(char **buf, size_t *buf_size,
                     const char *prefix, const char *qual, int sanitize_qual)
{
    size_t len;
    int prefix_len;

    if (!buf || !*buf || !buf_size || !*buf_size || !qual || !*qual)
        return;

    len = snprintf(*buf, *buf_size, "%s%n%s", prefix, &prefix_len, qual);

    if (sanitize_qual) {
        char *cp;
        for (cp = *buf + prefix_len; cp < *buf + len; cp++) {
            if (qual_char_is_invalid(*cp))
                *cp = '_';
        }
    }

    *buf_size -= len;
    *buf += len;
}

static size_t format_transport(atransport *t, char *buf, size_t bufsize,
                               int long_listing)
{
    const char* serial = t->serial;
    if (!serial || !serial[0])
        serial = "????????????";

    if (!long_listing) {
        return snprintf(buf, bufsize, "%s\t%s\n", serial, statename(t));
    } else {
        size_t len, remaining = bufsize;

        len = snprintf(buf, remaining, "%-22s %s", serial, statename(t));
        remaining -= len;
        buf += len;

        add_qual(&buf, &remaining, " ", t->devpath, 0);
        add_qual(&buf, &remaining, " product:", t->product, 0);
        add_qual(&buf, &remaining, " model:", t->model, 1);
        add_qual(&buf, &remaining, " device:", t->device, 0);

        len = snprintf(buf, remaining, "\n");
        remaining -= len;

        return bufsize - remaining;
    }
}

int list_transports(char *buf, size_t  bufsize, int long_listing)
{
    char*       p   = buf;
    char*       end = buf + bufsize;
    int         len;
    atransport *t;

        /* XXX OVERRUN PROBLEMS XXX */
    adb_mutex_lock(&transport_lock);
    for(t = transport_list.next; t != &transport_list; t = t->next) {
        len = format_transport(t, p, end - p, long_listing);
        if (p + len >= end) {
            /* discard last line if buffer is too short */
            break;
        }
        p += len;
    }
    p[0] = 0;
    adb_mutex_unlock(&transport_lock);
    return p - buf;
}


/* hack for osx */
void close_usb_devices()
{
    atransport *t;

    adb_mutex_lock(&transport_lock);
    for(t = transport_list.next; t != &transport_list; t = t->next) {
        if ( !t->kicked ) {
            t->kicked = 1;
            t->kick(t);
        }
    }
    adb_mutex_unlock(&transport_lock);
}
#endif // ADB_HOST

int register_socket_transport(int s, const char *serial, int port, int local)
{
    atransport *t = calloc(1, sizeof(atransport));
    atransport *n;
    char buff[32];

    if (!serial) {
        snprintf(buff, sizeof buff, "T-%p", t);
        serial = buff;
    }
    D("transport: %s init'ing for socket %d, on port %d\n", serial, s, port);
    if (init_socket_transport(t, s, port, local) < 0) {
        free(t);
        return -1;
    }

    adb_mutex_lock(&transport_lock);
    for (n = pending_list.next; n != &pending_list; n = n->next) {
        if (n->serial && !strcmp(serial, n->serial)) {
            adb_mutex_unlock(&transport_lock);
            free(t);
            return -1;
        }
    }

    for (n = transport_list.next; n != &transport_list; n = n->next) {
        if (n->serial && !strcmp(serial, n->serial)) {
            adb_mutex_unlock(&transport_lock);
            free(t);
            return -1;
        }
    }

    t->next = &pending_list;
    t->prev = pending_list.prev;
    t->next->prev = t;
    t->prev->next = t;
    t->serial = strdup(serial);
    adb_mutex_unlock(&transport_lock);

    register_transport(t);
    return 0;
}

#if ADB_HOST
atransport *find_transport(const char *serial)
{
    atransport *t;

    adb_mutex_lock(&transport_lock);
    for(t = transport_list.next; t != &transport_list; t = t->next) {
        if (t->serial && !strcmp(serial, t->serial)) {
            break;
        }
     }
    adb_mutex_unlock(&transport_lock);

    if (t != &transport_list)
        return t;
    else
        return 0;
}

void unregister_transport(atransport *t)
{
    adb_mutex_lock(&transport_lock);
    t->next->prev = t->prev;
    t->prev->next = t->next;
    adb_mutex_unlock(&transport_lock);

    kick_transport(t);
    transport_unref(t);
}

// unregisters all non-emulator TCP transports
void unregister_all_tcp_transports()
{
    atransport *t, *next;
    adb_mutex_lock(&transport_lock);
    for (t = transport_list.next; t != &transport_list; t = next) {
        next = t->next;
        if (t->type == kTransportLocal && t->adb_port == 0) {
            t->next->prev = t->prev;
            t->prev->next = next;
            // we cannot call kick_transport when holding transport_lock
            if (!t->kicked)
            {
                t->kicked = 1;
                t->kick(t);
            }
            transport_unref_locked(t);
        }
     }

    adb_mutex_unlock(&transport_lock);
}

#endif

void register_usb_transport(usb_handle *usb, const char *serial, const char *devpath, unsigned writeable)
{
    atransport *t = calloc(1, sizeof(atransport));
    D("transport: %p init'ing for usb_handle %p (sn='%s')\n", t, usb,
      serial ? serial : "");
    init_usb_transport(t, usb, (writeable ? CS_OFFLINE : CS_NOPERM));
    if(serial) {
        t->serial = strdup(serial);
    }
    if(devpath) {
        t->devpath = strdup(devpath);
    }

    adb_mutex_lock(&transport_lock);
    t->next = &pending_list;
    t->prev = pending_list.prev;
    t->next->prev = t;
    t->prev->next = t;
    adb_mutex_unlock(&transport_lock);

    register_transport(t);
}

/* this should only be used for transports with connection_state == CS_NOPERM */
void unregister_usb_transport(usb_handle *usb)
{
    atransport *t;
    adb_mutex_lock(&transport_lock);
    for(t = transport_list.next; t != &transport_list; t = t->next) {
        if (t->usb == usb && t->connection_state == CS_NOPERM) {
            t->next->prev = t->prev;
            t->prev->next = t->next;
            break;
        }
     }
    adb_mutex_unlock(&transport_lock);
}

#undef TRACE_TAG
#define TRACE_TAG  TRACE_RWX

int readx(int fd, void *ptr, size_t len)
{
    char *p = ptr;
    int r;
#if ADB_TRACE
    size_t len0 = len;
#endif
    D("readx: fd=%d wanted=%zu\n", fd, len);
    while(len > 0) {
        r = adb_read(fd, p, len);
        if(r > 0) {
            len -= r;
            p += r;
        } else {
            if (r < 0) {
                D("readx: fd=%d error %d: %s\n", fd, errno, strerror(errno));
                if (errno == EINTR)
                    continue;
            } else {
                D("readx: fd=%d disconnected\n", fd);
            }
            return -1;
        }
    }

#if ADB_TRACE
    D("readx: fd=%d wanted=%zu got=%zu\n", fd, len0, len0 - len);
    if (ADB_TRACING) {
        dump_hex( ptr, len0 );
    }
#endif
    return 0;
}

int writex(int fd, const void *ptr, size_t len)
{
    char *p = (char*) ptr;
    int r;

#if ADB_TRACE
    D("writex: fd=%d len=%d: ", fd, (int)len);
    if (ADB_TRACING) {
        dump_hex( ptr, len );
    }
#endif
    while(len > 0) {
        r = adb_write(fd, p, len);
        if(r > 0) {
            len -= r;
            p += r;
        } else {
            if (r < 0) {
                D("writex: fd=%d error %d: %s\n", fd, errno, strerror(errno));
                if (errno == EINTR)
                    continue;
                if (errno == EAGAIN) {
                    adb_sleep_ms(1); // just yield some cpu time
                    continue;
                }
            } else {
                D("writex: fd=%d disconnected\n", fd);
            }
            return -1;
        }
    }
    return 0;
}

int check_header(apacket *p)
{
    if(p->msg.magic != (p->msg.command ^ 0xffffffff)) {
        D("check_header(): invalid magic\n");
        return -1;
    }

    if(p->msg.data_length > MAX_PAYLOAD) {
        D("check_header(): %d > MAX_PAYLOAD\n", p->msg.data_length);
        return -1;
    }

    return 0;
}

int check_data(apacket *p)
{
    unsigned count, sum;
    unsigned char *x;

    count = p->msg.data_length;
    x = p->data;
    sum = 0;
    while(count-- > 0) {
        sum += *x++;
    }

    if(sum != p->msg.data_check) {
        return -1;
    } else {
        return 0;
    }
}