summaryrefslogtreecommitdiffstats
path: root/epan/dissectors/packet-msrp.c
blob: c1fc9f991e2acb2b9dca5a1cd77f4c83f71f4511 (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
/* packet-msrp.c
 * Routines for Message Session Relay Protocol(MSRP) dissection
 * Copyright 2005, Anders Broman <anders.broman[at]ericsson.com>
 *
 * Wireshark - Network traffic analyzer
 * By Gerald Combs <gerald@wireshark.org>
 * Copyright 1998 Gerald Combs
 *
 * SPDX-License-Identifier: GPL-2.0-or-later
 *
 * References:
 * https://tools.ietf.org/html/rfc4975
 */

#include "config.h"

#include <stdlib.h>

#include <epan/packet.h>
#include <epan/conversation.h>
#include <epan/prefs.h>
#include <epan/proto_data.h>
#include <epan/expert.h>
#include <wsutil/strtoi.h>
#include <wsutil/str_util.h>

#include "packet-msrp.h"
#include "packet-media-type.h"

void proto_register_msrp(void);
void proto_reg_handoff_msrp(void);

#define TCP_PORT_MSRP 2855

#define MSRP_HDR "MSRP"
#define MSRP_HDR_LEN (strlen (MSRP_HDR))

/* Initialize the protocol and registered fields */
static int proto_msrp       = -1;

/* Initialize the subtree pointers */
static int ett_msrp                 = -1;
static int ett_raw_text             = -1;
static int ett_msrp_reqresp         = -1;
static int ett_msrp_hdr             = -1;
static int ett_msrp_data            = -1;
static int ett_msrp_end_line        = -1;
static int ett_msrp_setup           = -1;

static int hf_msrp_response_line    = -1;
static int hf_msrp_request_line     = -1;
static int hf_msrp_transactionID    = -1;
static int hf_msrp_method           = -1;
static int hf_msrp_status_code      = -1;
static int hf_msrp_hdr              = -1;
static int hf_msrp_msg_hdr          = -1;
static int hf_msrp_end_line         = -1;
static int hf_msrp_cnt_flg          = -1;

static int hf_msrp_data             = -1;

static expert_field ei_msrp_status_code_invalid = EI_INIT;

/* MSRP setup fields */
static int hf_msrp_setup        = -1;
static int hf_msrp_setup_frame  = -1;
static int hf_msrp_setup_method = -1;

typedef struct {
        const char *name;
} msrp_header_t;

static const msrp_header_t msrp_headers[] = {
    { "Unknown-header"},
    { "From-Path"},             /*  1 */
    { "To-Path"},               /*  2 */
    { "Message-ID"},            /*  3 */
    { "Success-Report"},        /*  4 */
    { "Failure-Report"},        /*  5 */
    { "Byte-Range"},            /*  6 */
    { "Status"},                /*  7 */
    { "Content-Type"},          /*  8 */
    { "Content-ID"},            /*  9 */
    { "Content-Description"},   /*  10 */
    { "Content-Disposition"},   /*  11 */
    { "Use-Path"},              /*  12 */
    { "WWW-Authenticate"},      /*  13 */
    { "Authorization"},         /*  14 */
    { "Authentication-Info"},   /*  15 */
};

static gint hf_header_array[] = {
    -1, /* 0"Unknown-header" - Pad so that the real headers start at index 1 */
    -1, /* 1"From-Path                                                       */
    -1, /* 2"To-Path                                                         */
    -1, /* 3"Message-ID"                                                     */
    -1, /* 4"Success-Report"                                                 */
    -1, /* 5"Failure-Report"                                                 */
    -1, /* 6"Byte-Range"                                                     */
    -1, /* 7"Status"                                                         */
    -1, /* 8"Content-Type"                                                   */
    -1, /* 9"Content-ID"                                                     */
    -1, /* 10"Content-Description"                                           */
    -1, /* 11"Content-Disposition"                                           */
    -1, /* 12"Use-Path"                                                      */
    -1, /* 13"WWW-Authenticate"                                              */
    -1, /* 14"Authorization"                                                 */
    -1, /* 15"Authentication-Info"                                           */
};

#define MSRP_FROM_PATH                          1
#define MSRP_TO_PATH                            2
#define MSRP_MESSAGE_ID                         3
#define MSRP_SUCCESS_REPORT                     4
#define MSRP_FAILURE_REPORT                     5
#define MSRP_BYTE_RANGE                         6
#define MSRP_STATUS                             7
#define MSRP_CONTENT_TYPE                       8
#define MSRP_CONTENT_ID                         9
#define MSRP_CONTENT_DISCRIPTION                10
#define MSRP_CONTENT_DISPOSITION                11
#define MSRP_USE_PATH                           12
#define MSRP_WWW_AUTHENTICATE                   13
#define MSRP_AUTHORIZATION                      14
#define MSRP_AUTHENTICATION_INFO                15

static dissector_handle_t msrp_handle;
static gboolean global_msrp_raw_text = TRUE;

/* MSRP content type and internet media type used by other dissectors
 * are the same.  List of media types from IANA at:
 * http://www.iana.org/assignments/media-types/index.html */
static dissector_table_t media_type_dissector_table;

static int dissect_msrp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data);


/* Displaying conversation setup info */
static gboolean global_msrp_show_setup_info = TRUE;
static void show_setup_info(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree);

/* Set up an MSRP conversation using the info given */
void
msrp_add_address( packet_info *pinfo,
                       address *addr, int port,
                       const gchar *setup_method, guint32 setup_frame_number)
{
    address null_addr;
    conversation_t* p_conv;
    struct _msrp_conversation_info *p_conv_data = NULL;

    /*
     * If this isn't the first time this packet has been processed,
     * we've already done this work, so we don't need to do it
     * again.
     */
    if (pinfo->fd->visited)
    {
        return;
    }

    clear_address(&null_addr);

    /*
     * Check if the ip address and port combination is not
     * already registered as a conversation.
     */
    p_conv = find_conversation( pinfo->num, addr, &null_addr, CONVERSATION_TCP, port, 0,
                                NO_ADDR_B | NO_PORT_B);

    /*
     * If not, create a new conversation.
     */
    if (!p_conv) {
        p_conv = conversation_new( pinfo->num, addr, &null_addr, CONVERSATION_TCP,
                                   (guint32)port, 0,
                                   NO_ADDR2 | NO_PORT2);
    }

    /* Set dissector */
    conversation_set_dissector(p_conv, msrp_handle);

    /*
     * Check if the conversation has data associated with it.
     */
    p_conv_data = (struct _msrp_conversation_info *)conversation_get_proto_data(p_conv, proto_msrp);

    /*
     * If not, add a new data item.
     */
    if (!p_conv_data) {
        /* Create conversation data */
        p_conv_data = wmem_new0(wmem_file_scope(), struct _msrp_conversation_info);
        conversation_add_proto_data(p_conv, proto_msrp, p_conv_data);
    }

    /*
     * Update the conversation data.
     */
    p_conv_data->setup_method_set = TRUE;
    (void) g_strlcpy(p_conv_data->setup_method, setup_method, MAX_MSRP_SETUP_METHOD_SIZE);
    p_conv_data->setup_frame_number = setup_frame_number;
}



/* Look for conversation info and display any setup info found */
static void
show_setup_info(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
{
    /* Conversation and current data */
    conversation_t *p_conv = NULL;
    struct _msrp_conversation_info *p_conv_data = NULL;

    /* Use existing packet data if available */
    p_conv_data = (struct _msrp_conversation_info *)p_get_proto_data(wmem_file_scope(), pinfo, proto_msrp, 0);

    if (!p_conv_data)
    {
        /* First time, get info from conversation */
        p_conv = find_conversation(pinfo->num, &pinfo->net_dst, &pinfo->net_src,
                                   CONVERSATION_TCP,
                                   pinfo->destport, pinfo->srcport, 0);

        if (p_conv)
        {
            /* Look for data in conversation */
            struct _msrp_conversation_info *p_conv_packet_data;
            p_conv_data = (struct _msrp_conversation_info *)conversation_get_proto_data(p_conv, proto_msrp);

            if (p_conv_data)
            {
                /* Save this conversation info into packet info */
                p_conv_packet_data = (struct _msrp_conversation_info *)wmem_memdup(wmem_file_scope(),
                       p_conv_data, sizeof(struct _msrp_conversation_info));

                p_add_proto_data(wmem_file_scope(), pinfo, proto_msrp, 0, p_conv_packet_data);
            }
        }
    }

    /* Create setup info subtree with summary info. */
    if (p_conv_data && p_conv_data->setup_method_set)
    {
        proto_tree *msrp_setup_tree;
        proto_item *ti =  proto_tree_add_string_format(tree, hf_msrp_setup, tvb, 0, 0,
                                                       "",
                                                       "Stream setup by %s (frame %u)",
                                                       p_conv_data->setup_method,
                                                       p_conv_data->setup_frame_number);
        proto_item_set_generated(ti);
        msrp_setup_tree = proto_item_add_subtree(ti, ett_msrp_setup);
        if (msrp_setup_tree)
        {
            /* Add details into subtree */
            proto_item* item = proto_tree_add_uint(msrp_setup_tree, hf_msrp_setup_frame,
                                                   tvb, 0, 0, p_conv_data->setup_frame_number);
            proto_item_set_generated(item);
            item = proto_tree_add_string(msrp_setup_tree, hf_msrp_setup_method,
                                         tvb, 0, 0, p_conv_data->setup_method);
            proto_item_set_generated(item);
        }
    }
}



/* Returns index of headers */
static gint msrp_is_known_msrp_header(tvbuff_t *tvb, int offset, guint header_len)
{
    guint i;

    for (i = 1; i < array_length(msrp_headers); i++) {
        if (header_len == strlen(msrp_headers[i].name) &&
            tvb_strncaseeql(tvb, offset, msrp_headers[i].name, header_len) == 0)
        {
            return i;
        }
    }

    return -1;
}


/*
 * Display the entire message as raw text.
 */
static void
tvb_raw_text_add(tvbuff_t *tvb, proto_tree *tree)
{
    int offset, next_offset, linelen;
    offset = 0;

    while (tvb_offset_exists(tvb, offset)) {
        /* 'desegment' is FALSE so will set next_offset to beyond the end of
           the buffer if no line ending is found */
        tvb_find_line_end(tvb, offset, -1, &next_offset, FALSE);
        linelen = next_offset - offset;
        proto_tree_add_format_text(tree, tvb, offset, linelen);
        offset = next_offset;
    }
}

/* This code is modeled on the code in packet-sip.c
 *  ABNF code for the MSRP header:
 *  The following syntax specification uses the augmented Backus-Naur
 *  Form (BNF) as described in RFC-2234 [6].
 *
 *
 *  msrp-req-or-resp = msrp-request / msrp-response
 *  msrp-request = req-start headers [content-stuff] end-line
 *  msrp-response = resp-start headers end-line
 *
 *  req-start  = pMSRP SP transact-id SP method CRLF
 *  resp-start = pMSRP SP transact-id SP status-code [SP phrase] CRLF
 *  phrase = utf8text
 *
 *  pMSRP = %x4D.53.52.50 ; MSRP in caps
 *  transact-id = ident
 *  method = mSEND / mREPORT / other-method
 *  mSEND = %x53.45.4e.44 ; SEND in caps
 *  mREPORT = %x52.45.50.4f.52.54; REPORT in caps
 *  other-method = 1*UPALPHA
 *  Examples:
 *  "MSRP 1234 SEND(CRLF)"
 *  "MSRP 1234 200 OK(CRLF)
 */
static gboolean
check_msrp_header(tvbuff_t *tvb)
{
    gint linelen;
    gint space_offset;
    gint next_offset = 0;
    guint token_1_len;
    gint token_2_start;

    /*
     * Note that "tvb_find_line_end()" will return a value that
     * is not longer than what's in the buffer, so the
     * "tvb_get_ptr()" calls below won't throw exceptions.   *
     */
    if(tvb_captured_length(tvb) < 4 ||  tvb_get_ntohl(tvb, 0) != 0x4d535250 /* MSRP */){
        return FALSE;
    }

    linelen = tvb_find_line_end(tvb, 0, -1, &next_offset, FALSE);
    /* Find the first SP */
    space_offset = tvb_find_guint8(tvb, 0, linelen, ' ');

    if (space_offset <= 0) {
        /*
         * Either there's no space in the line (which means
         * the line is empty or doesn't have a token followed
         * by a space; neither is valid for a request or response), or
         * the first character in the line is a space ( which isn't valid
         * for a MSRP header.)
         */
        return FALSE;
    }

    token_1_len = space_offset;
    token_2_start = space_offset + 1;
    space_offset = tvb_find_guint8(tvb, token_2_start, linelen, ' ');
    if (space_offset == -1) {
        /*
         * There's no space after the second token, so we don't
         * have a third token.
         */
        return FALSE;
    }
    /*
     * Is the first token "MSRP"?
     */
    if (token_1_len == MSRP_HDR_LEN) { /*  && tvb_strneql(tvb, 0, MSRP_HDR, MSRP_HDR_LEN) == 0){ */
        /* This check can be made more strict but accept we do have MSRP for now */
        return TRUE;

    }
    return FALSE;
}

/* ABNF of line-end:
 * end-line = "-------" transact-id continuation-flag CRLF
 * This code is modeled on the code in packet-multipart.c
 */
static int
find_end_line(tvbuff_t *tvb, gint start)
{
    gint offset = start, next_offset, linelen;

    while (tvb_offset_exists(tvb, offset)) {
        /* 'desegment' is FALSE so will set next_offset to beyond the end of
           the buffer if no line ending is found */
        linelen =  tvb_find_line_end(tvb, offset, -1, &next_offset, FALSE);
        if (linelen == -1) {
            return -1;
        }
        if (tvb_strneql(tvb, next_offset, (const gchar *)"-------", 7) == 0)
            return next_offset;
        offset = next_offset;
    }

    return -1;
}

static gboolean
dissect_msrp_heur(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_)
{
    conversation_t* conversation;

    if ( check_msrp_header(tvb)){
        /*
         * TODO Set up conversation here
         */
        if (pinfo->fd->visited){
            /* Look for existing conversation */
            conversation = find_or_create_conversation(pinfo);
            /* Set dissector */
            conversation_set_dissector(conversation, msrp_handle);
        }
        dissect_msrp(tvb, pinfo, tree, NULL);
        return TRUE;
    }
    return FALSE;
}

/* Code to actually dissect the packets */
static int
dissect_msrp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_)
{
    gint offset = 0;
    gint next_offset = 0;
    proto_item *ti, *th, *msrp_headers_item;
    proto_tree *msrp_tree, *reqresp_tree, *raw_tree, *msrp_hdr_tree, *msrp_end_tree;
    proto_tree *msrp_data_tree;
    gint linelen;
    gint space_offset;
    gint token_2_start;
    guint token_2_len;
    gint token_3_start;
    guint token_3_len;
    gint token_4_start = 0;
    guint token_4_len = 0;
    gboolean is_msrp_response;
    gint end_line_offset;
    gint end_line_len;
    gint line_end_offset;
    gint message_end_offset;
    gint colon_offset;
    gint header_len;
    gint hf_index;
    gint value_offset;
    guchar c;
    gint value_len;
    char *value;
    gboolean have_body = FALSE;
    int found_match = 0;
    gint content_type_len, content_type_parameter_str_len;
    gchar *media_type_str_lower_case = NULL;
    media_content_info_t content_info = { MEDIA_CONTAINER_OTHER, NULL, NULL, NULL };
    tvbuff_t *next_tvb;
    gint parameter_offset;
    gint semi_colon_offset;
    gchar* hdr_str;

    if ( !check_msrp_header(tvb)){
        return 0;
    }
    /* We have a MSRP header with at least three tokens
     *
     * Note that "tvb_find_line_end()" will return a value that
     * is not longer than what's in the buffer, so the
     * "tvb_get_ptr()" calls below won't throw exceptions.   *
     */
    linelen = tvb_find_line_end(tvb, 0, -1, &next_offset, FALSE);

    /* Find the first SP and skip the first token */
    token_2_start = tvb_find_guint8(tvb, 0, linelen, ' ') + 1;

    /* Work out 2nd token's length by finding next space */
    space_offset = tvb_find_guint8(tvb, token_2_start, linelen-token_2_start, ' ');
    token_2_len = space_offset - token_2_start;

    /* Look for another space in this line to indicate a 4th token */
    token_3_start = space_offset + 1;
    space_offset = tvb_find_guint8(tvb, token_3_start,linelen-token_3_start, ' ');
    if ( space_offset == -1){
        /* 3rd token runs to the end of the line */
        token_3_len = linelen - token_3_start;
    }else{
        /* We have a fourth token */
        token_3_len = space_offset - token_3_start;
        token_4_start = space_offset + 1;
        token_4_len = linelen - token_4_start;
    }

    /*
     * Yes, so this is either a msrp-request or msrp-response.
     * To be a msrp-response, the second token must be
     * a 3-digit number.
     */
    is_msrp_response = FALSE;
    if (token_3_len == 3) {
            if (g_ascii_isdigit(tvb_get_guint8(tvb, token_3_start)) &&
                g_ascii_isdigit(tvb_get_guint8(tvb, token_3_start + 1)) &&
                g_ascii_isdigit(tvb_get_guint8(tvb, token_3_start + 2))) {
                is_msrp_response = TRUE;
            }
    }

    /* Find the end line to be able to process the headers
     * Note that in case of [content-stuff] headers and [content-stuff] is separated by CRLF
     */

    offset = next_offset;
    end_line_offset = find_end_line(tvb,offset);
    if (end_line_offset < 0) {
        pinfo->desegment_offset = 0;
        pinfo->desegment_len = DESEGMENT_ONE_MORE_SEGMENT;
        return tvb_reported_length_remaining(tvb, offset);
    }
    end_line_len =  tvb_find_line_end(tvb, end_line_offset, -1, &next_offset, FALSE);
    message_end_offset = end_line_offset + end_line_len + 2;

    /* Make entries in Protocol column and Info column on summary display */
    col_set_str(pinfo->cinfo, COL_PROTOCOL, "MSRP");
    if (is_msrp_response){
        col_add_fstr(pinfo->cinfo, COL_INFO, "Response: %s ",
                tvb_format_text(pinfo->pool, tvb, token_3_start, token_3_len));

        if (token_4_len )
            col_append_fstr(pinfo->cinfo, COL_INFO, "%s ",
                tvb_format_text(pinfo->pool, tvb, token_4_start, token_4_len));

        col_append_fstr(pinfo->cinfo, COL_INFO, "Transaction ID: %s",
                tvb_format_text(pinfo->pool, tvb, token_2_start, token_2_len));
    }else{
        col_add_fstr(pinfo->cinfo, COL_INFO, "Request: %s ",
                tvb_format_text(pinfo->pool, tvb, token_3_start, token_3_len));

        col_append_fstr(pinfo->cinfo, COL_INFO, "Transaction ID: %s",
                tvb_format_text(pinfo->pool, tvb, token_2_start, token_2_len));
    }

    if (tree) {
        ti = proto_tree_add_item(tree, proto_msrp, tvb, 0, message_end_offset, ENC_NA);
        msrp_tree = proto_item_add_subtree(ti, ett_msrp);

        if (is_msrp_response){
            guint32 msrp_status_code = -1;
            gboolean msrp_status_code_valid;
            proto_item* pi;
            th = proto_tree_add_item(msrp_tree,hf_msrp_response_line,tvb,0,linelen,ENC_UTF_8);
            reqresp_tree = proto_item_add_subtree(th, ett_msrp_reqresp);
            proto_tree_add_item(reqresp_tree,hf_msrp_transactionID,tvb,token_2_start,token_2_len,ENC_UTF_8);
            msrp_status_code_valid = ws_strtou32(
                tvb_get_string_enc(pinfo->pool, tvb, token_3_start, token_3_len, ENC_UTF_8|ENC_NA),
                NULL, & msrp_status_code);
            pi = proto_tree_add_uint(reqresp_tree,hf_msrp_status_code,tvb,token_3_start,token_3_len,msrp_status_code);
            if (!msrp_status_code_valid)
                expert_add_info(pinfo, pi, &ei_msrp_status_code_invalid);
        }else{
            th = proto_tree_add_item(msrp_tree,hf_msrp_request_line,tvb,0,linelen,ENC_UTF_8);
            reqresp_tree = proto_item_add_subtree(th, ett_msrp_reqresp);
            proto_tree_add_item(reqresp_tree,hf_msrp_transactionID,tvb,token_2_start,token_2_len,ENC_UTF_8);
            proto_tree_add_item(reqresp_tree,hf_msrp_method,tvb,token_3_start,token_3_len,ENC_UTF_8);
        }

        /* Conversation setup info */
        if (global_msrp_show_setup_info)
        {
            show_setup_info(tvb, pinfo, msrp_tree);
        }

        /* Headers */
        msrp_headers_item = proto_tree_add_item(msrp_tree, hf_msrp_msg_hdr, tvb, offset,(end_line_offset - offset), ENC_NA);
        msrp_hdr_tree = proto_item_add_subtree(msrp_headers_item, ett_msrp_hdr);

        /*
         * Process the headers
         */
        while (tvb_offset_exists(tvb, offset) && offset < end_line_offset  ) {
            /* 'desegment' is FALSE so will set next_offset to beyond the end of
               the buffer if no line ending is found */
            linelen = tvb_find_line_end(tvb, offset, -1, &next_offset, FALSE);
            if (linelen == 0) {
                /*
                 * This is a blank line separating the
                 * message header from the message body.
                 */
                have_body = TRUE;
                break;
            }
            line_end_offset = offset + linelen;
            colon_offset = tvb_find_guint8(tvb, offset, linelen, ':');
            if (colon_offset == -1) {
                /*
                 * Malformed header - no colon after the name.
                 */
                hdr_str = tvb_format_text(pinfo->pool, tvb, offset, linelen);
                proto_tree_add_string_format(msrp_hdr_tree, hf_msrp_hdr, tvb, offset,
                                    next_offset - offset, hdr_str, "%s", hdr_str);
            } else {
                header_len = colon_offset - offset;
                hf_index = msrp_is_known_msrp_header(tvb, offset, header_len);

                if (hf_index == -1) {
                    hdr_str = tvb_format_text(pinfo->pool, tvb, offset, linelen);
                    proto_tree_add_string_format(msrp_hdr_tree, hf_msrp_hdr, tvb,
                                    offset, next_offset - offset, hdr_str, "%s", hdr_str);
                } else {
                    /*
                     * Skip whitespace after the colon.
                     */
                    value_offset = colon_offset + 1;
                    while (value_offset < line_end_offset &&
                           ((c = tvb_get_guint8(tvb, value_offset)) == ' ' ||
                             c == '\t'))
                        value_offset++;
                    /*
                     * Fetch the value.
                     */
                    value_len = line_end_offset - value_offset;
                    value = tvb_get_string_enc(pinfo->pool, tvb, value_offset,
                                       value_len, ENC_UTF_8|ENC_NA);

                    /*
                     * Add it to the protocol tree,
                     * but display the line as is.
                     */
                    proto_tree_add_string_format(msrp_hdr_tree,
                                   hf_header_array[hf_index], tvb,
                                   offset, next_offset - offset,
                                   value, "%s",
                                   tvb_format_text(pinfo->pool, tvb, offset, linelen));

                    switch ( hf_index ) {

                        case MSRP_CONTENT_TYPE :
                            content_type_len = value_len;
                            semi_colon_offset = tvb_find_guint8(tvb, value_offset,linelen, ';');
                            if ( semi_colon_offset != -1) {
                                parameter_offset = semi_colon_offset +1;
                                /*
                                 * Skip whitespace after the semicolon.
                                 */
                                while (parameter_offset < line_end_offset
                                       && ((c = tvb_get_guint8(tvb, parameter_offset)) == ' '
                                         || c == '\t'))
                                    parameter_offset++;
                                content_type_len = semi_colon_offset - value_offset;
                                content_type_parameter_str_len = line_end_offset - parameter_offset;
                                content_info.media_str = tvb_get_string_enc(pinfo->pool, tvb,
                                             parameter_offset, content_type_parameter_str_len, ENC_UTF_8|ENC_NA);
                            }
                            media_type_str_lower_case = ascii_strdown_inplace(
                                                            (gchar *)tvb_get_string_enc(pinfo->pool, tvb, value_offset, content_type_len, ENC_UTF_8|ENC_NA));
                            break;

                        default:
                            break;
                    }
                }
            }
            offset = next_offset;
        }/* End while */

        if ( have_body ){
            /*
             * There's a message body starting at "next_offset".
             * Set the length of the header item.
             */
            proto_item_set_end(msrp_headers_item, tvb, next_offset);

            /* Create new tree & tvb for data */
            next_tvb = tvb_new_subset_remaining(tvb, next_offset);
            ti = proto_tree_add_item(msrp_tree, hf_msrp_data, tvb,
                                     next_offset, -1, ENC_UTF_8);
            msrp_data_tree = proto_item_add_subtree(ti, ett_msrp_data);

            /* give the content type parameters to sub dissectors */

            if ( media_type_str_lower_case != NULL ) {
                found_match = dissector_try_string(media_type_dissector_table,
                                               media_type_str_lower_case,
                                               next_tvb, pinfo,
                                               msrp_data_tree, &content_info);
                /* If no match dump as text */
            }
            if ( found_match == 0 )
            {
                offset = 0;
                while (tvb_offset_exists(next_tvb, offset)) {
                    tvb_find_line_end(next_tvb, offset, -1, &next_offset, FALSE);
                    linelen = next_offset - offset;
                    proto_tree_add_format_text(msrp_data_tree, next_tvb, offset, linelen);
                    offset = next_offset;
                }/* end while */
            }

        }



        /* End line */
        ti = proto_tree_add_item(msrp_tree,hf_msrp_end_line,tvb,end_line_offset,end_line_len,ENC_UTF_8);
        msrp_end_tree = proto_item_add_subtree(ti, ett_msrp_end_line);

        proto_tree_add_item(msrp_end_tree,hf_msrp_transactionID,tvb,end_line_offset + 7,token_2_len,ENC_UTF_8);
        /* continuation-flag */
        proto_tree_add_item(msrp_end_tree,hf_msrp_cnt_flg,tvb,end_line_offset+end_line_len-1,1,ENC_UTF_8);

        if (global_msrp_raw_text && tree) {
            raw_tree = proto_tree_add_subtree(tree, tvb, 0, -1, ett_msrp, NULL, "Message Session Relay Protocol(as raw text)");
            tvb_raw_text_add(tvb,raw_tree);
        }

    }/* if tree */
    return message_end_offset;
    /*  return tvb_captured_length(tvb); */

/* If this protocol has a sub-dissector call it here, see section 1.8 */
}


void
proto_register_msrp(void)
{
    expert_module_t* expert_msrp;

    /* Setup protocol subtree array */
    static gint *ett[] = {
        &ett_msrp,
        &ett_raw_text,
        &ett_msrp_reqresp,
        &ett_msrp_hdr,
        &ett_msrp_data,
        &ett_msrp_end_line,
        &ett_msrp_setup
    };

    /* Setup list of header fields */
    static hf_register_info hf[] = {
        { &hf_msrp_request_line,
            { "Request Line",       "msrp.request.line",
            FT_STRING, BASE_NONE,NULL,0x0,
            NULL, HFILL }
        },
        { &hf_msrp_response_line,
            { "Response Line",      "msrp.response.line",
            FT_STRING, BASE_NONE,NULL,0x0,
            NULL, HFILL }
        },
        { &hf_msrp_transactionID,
            { "Transaction Id",         "msrp.transaction.id",
            FT_STRING, BASE_NONE,NULL,0x0,
            NULL, HFILL }
        },
        { &hf_msrp_method,
            { "Method",                 "msrp.method",
            FT_STRING, BASE_NONE,NULL,0x0,
            NULL, HFILL }
        },
        { &hf_msrp_status_code,
            { "Status code",        "msrp.status.code",
            FT_UINT16, BASE_DEC,NULL,0x0,
            NULL, HFILL }
        },
        { &hf_msrp_hdr,
            { "Header",         "msrp.hdr",
            FT_STRING, BASE_NONE,NULL,0x0,
            NULL, HFILL }
        },
        { &hf_msrp_msg_hdr,
            { "Message Header",         "msrp.msg.hdr",
            FT_NONE, BASE_NONE,NULL,0x0,
            NULL, HFILL }
        },
        { &hf_msrp_end_line,
            { "End Line",       "msrp.end.line",
            FT_STRING, BASE_NONE,NULL,0x0,
            NULL, HFILL }
        },
        { &hf_msrp_cnt_flg,
            { "Continuation-flag",      "msrp.cnt.flg",
            FT_STRING, BASE_NONE,NULL,0x0,
            NULL, HFILL }
        },
        { &hf_header_array[MSRP_FROM_PATH],
            { "From Path",      "msrp.from.path",
            FT_STRING, BASE_NONE,NULL,0x0,
            NULL, HFILL }
        },
        { &hf_header_array[MSRP_TO_PATH],
            { "To Path",        "msrp.to.path",
            FT_STRING, BASE_NONE,NULL,0x0,
            NULL, HFILL }
        },
        { &hf_header_array[MSRP_MESSAGE_ID],
            { "Message ID",         "msrp.messageid",
            FT_STRING, BASE_NONE,NULL,0x0,
            NULL, HFILL }
        },
        { &hf_header_array[MSRP_SUCCESS_REPORT],
            { "Success Report",         "msrp.success.report",
            FT_STRING, BASE_NONE,NULL,0x0,
            NULL, HFILL }
        },
        { &hf_header_array[MSRP_FAILURE_REPORT],
            { "Failure Report",         "msrp.failure.report",
            FT_STRING, BASE_NONE,NULL,0x0,
            NULL, HFILL }
        },
        { &hf_header_array[MSRP_BYTE_RANGE],
            { "Byte Range",         "msrp.byte.range",
            FT_STRING, BASE_NONE,NULL,0x0,
            NULL, HFILL }
        },
        { &hf_header_array[MSRP_STATUS],
            { "Status",         "msrp.status",
            FT_STRING, BASE_NONE,NULL,0x0,
            NULL, HFILL }
        },
        { &hf_header_array[MSRP_CONTENT_TYPE],
            { "Content-Type",       "msrp.content.type",
            FT_STRING, BASE_NONE,NULL,0x0,
            NULL, HFILL }
        },
        { &hf_header_array[MSRP_CONTENT_ID],
            { "Content-ID",         "msrp.content.id",
            FT_STRING, BASE_NONE,NULL,0x0,
            NULL, HFILL }
        },
        { &hf_header_array[MSRP_CONTENT_DISCRIPTION],
            { "Content-Description",        "msrp.content.description",
            FT_STRING, BASE_NONE,NULL,0x0,
            NULL, HFILL }
        },
        { &hf_header_array[MSRP_CONTENT_DISPOSITION],
            { "Content-Disposition",        "msrp.content.disposition",
            FT_STRING, BASE_NONE,NULL,0x0,
            NULL, HFILL }
        },
        { &hf_header_array[MSRP_USE_PATH],
            { "Use-Path",       "msrp.use.path",
            FT_STRING, BASE_NONE,NULL,0x0,
            NULL, HFILL }
        },
        { &hf_header_array[MSRP_WWW_AUTHENTICATE],
            { "WWW-Authenticate",       "msrp.www.authenticate",
            FT_STRING, BASE_NONE,NULL,0x0,
            NULL, HFILL }
        },
        { &hf_header_array[MSRP_AUTHORIZATION],
            { "Authorization",      "msrp.authorization",
            FT_STRING, BASE_NONE,NULL,0x0,
            NULL, HFILL }
        },
        { &hf_header_array[MSRP_AUTHENTICATION_INFO],
            { "Authentication-Info",        "msrp.authentication.info",
            FT_STRING, BASE_NONE,NULL,0x0,
            NULL, HFILL }
        },
        { &hf_msrp_data,
            { "Data", "msrp.data",
            FT_STRING, BASE_NONE, NULL, 0x0,
            NULL, HFILL}
        },
        { &hf_msrp_setup,
            { "Stream setup", "msrp.setup",
            FT_STRING, BASE_NONE, NULL, 0x0,
            "Stream setup, method and frame number", HFILL}
        },
        { &hf_msrp_setup_frame,
            { "Setup frame", "msrp.setup-frame",
            FT_FRAMENUM, BASE_NONE, NULL, 0x0,
            "Frame that set up this stream", HFILL}
        },
        { &hf_msrp_setup_method,
            { "Setup Method", "msrp.setup-method",
            FT_STRING, BASE_NONE, NULL, 0x0,
            "Method used to set up this stream", HFILL}
        },
    };

    static ei_register_info ei[] = {
        { &ei_msrp_status_code_invalid, { "msrp.status.code.invalid", PI_MALFORMED, PI_ERROR,
            "Invalid status code", EXPFILL }}
    };

    module_t *msrp_module;
    /* Register the protocol name and description */
    proto_msrp = proto_register_protocol("Message Session Relay Protocol","MSRP", "msrp");

    /* Required function calls to register the header fields and subtrees used */
    proto_register_field_array(proto_msrp, hf, array_length(hf));
    proto_register_subtree_array(ett, array_length(ett));

    msrp_module = prefs_register_protocol(proto_msrp, NULL);

    prefs_register_bool_preference(msrp_module, "display_raw_text",
        "Display raw text for MSRP message",
        "Specifies that the raw text of the "
        "MSRP message should be displayed "
        "in addition to the dissection tree",
        &global_msrp_raw_text);

    prefs_register_bool_preference(msrp_module, "show_setup_info",
        "Show stream setup information",
        "Where available, show which protocol and frame caused "
        "this MSRP stream to be created",
        &global_msrp_show_setup_info);


    /*
     * Register the dissector by name, so other dissectors can
     * grab it by name rather than just referring to it directly.
     */
    msrp_handle = register_dissector("msrp", dissect_msrp, proto_msrp);

    expert_msrp = expert_register_protocol(proto_msrp);
    expert_register_field_array(expert_msrp, ei, array_length(ei));
}


/* Register the protocol with Wireshark */
void
proto_reg_handoff_msrp(void)
{
    heur_dissector_add("tcp", dissect_msrp_heur, "MSRP over TCP", "msrp_tcp", proto_msrp, HEURISTIC_ENABLE);
    dissector_add_uint_with_preference("tcp.port", TCP_PORT_MSRP, msrp_handle);
    media_type_dissector_table = find_dissector_table("media_type");
}

/*
 * Editor modelines  -  https://www.wireshark.org/tools/modelines.html
 *
 * Local variables:
 * c-basic-offset: 4
 * tab-width: 8
 * indent-tabs-mode: nil
 * End:
 *
 * vi: set shiftwidth=4 tabstop=8 expandtab:
 * :indentSize=4:tabSize=8:noTabs=true:
 */