diff options
| author | Guy Harris <guy@alum.mit.edu> | 1999-11-11 08:35:11 +0000 |
|---|---|---|
| committer | Guy Harris <guy@alum.mit.edu> | 1999-11-11 08:35:11 +0000 |
| commit | 6c10717158210677db3da957b690a3bbb05d13e8 (patch) | |
| tree | dafeaa20ed79dc15f27d2836517145db5b7977b6 /packet-lapd.c | |
| parent | 80d5d4bf7ed90d3314ecfcbc2cea7d9f85d820d5 (diff) | |
Add #defines for bits in the LAPD address field and for the LAPD SAPI
values.
Dissect the LAPD payload, if present.
Add the beginnings of a Q.931 dissector.
svn path=/trunk/; revision=1007
Diffstat (limited to 'packet-lapd.c')
| -rw-r--r-- | packet-lapd.c | 64 |
1 files changed, 48 insertions, 16 deletions
diff --git a/packet-lapd.c b/packet-lapd.c index a0b98e9fe1..38db27d384 100644 --- a/packet-lapd.c +++ b/packet-lapd.c @@ -2,7 +2,7 @@ * Routines for LAPD frame disassembly * Gilbert Ramirez <gram@xiexie.org> * - * $Id: packet-lapd.c,v 1.1 1999/11/11 05:36:05 gram Exp $ + * $Id: packet-lapd.c,v 1.2 1999/11/11 08:35:10 guy Exp $ * * Ethereal - Network traffic analyzer * By Gerald Combs <gerald@zing.org> @@ -54,12 +54,27 @@ int hf_lapd_tei = -1; int hf_lapd_ea2 = -1; int hf_lapd_control = -1; +/* + * Bits in the address field. + */ +#define LAPD_SAPI 0xfc00 /* Service Access Point Identifier */ +#define LAPD_SAPI_SHIFT 10 +#define LAPD_CR 0x0200 /* Command/Response bit */ +#define LAPD_EA1 0x0100 /* First Address Extension bit */ +#define LAPD_TEI 0x00fe /* Terminal Endpoint Identifier */ +#define LAPD_EA2 0x0001 /* Second Address Extension bit */ + +#define LAPD_SAPI_Q931 0 /* Q.931 call control procedure */ +#define LAPD_SAPI_PM_Q931 1 /* Packet mode Q.931 call control procedure */ +#define LAPD_SAPI_X25 16 /* X.25 Level 3 procedures */ +#define LAPD_SAPI_L2 63 /* Layer 2 management procedures */ + static const value_string lapd_sapi_vals[] = { - { 0, "Q.931 Call control procedure" }, - { 1, "Packet mode Q.931 Call control procedure" }, - { 16, "X.25 Level 3 procedures" }, - { 63, "Layer 2 management procedures" }, - { 0, NULL } + { LAPD_SAPI_Q931, "Q.931 Call control procedure" }, + { LAPD_SAPI_PM_Q931, "Packet mode Q.931 Call control procedure" }, + { LAPD_SAPI_X25, "X.25 Level 3 procedures" }, + { LAPD_SAPI_L2, "Layer 2 management procedures" }, + { 0, NULL } }; void @@ -67,16 +82,20 @@ dissect_lapd(const u_char *pd, frame_data *fd, proto_tree *tree) { proto_tree *lapd_tree, *addr_tree; proto_item *ti; + guint16 control; + int lapd_header_len; - guint16 address, cr; + guint16 address, cr, sapi; gboolean is_response; if (check_col(fd, COL_PROTOCOL)) - col_add_str(fd, COL_PROTOCOL, "LAPD"); + col_add_str(fd, COL_PROTOCOL, "LAPD"); address = pntohs(&pd[0]); - cr = address & 0x0200; + cr = address & LAPD_CR; + sapi = (address & LAPD_SAPI) >> LAPD_SAPI_SHIFT; + lapd_header_len = 2; /* address */ if (fd->pseudo_header.lapd.from_network_to_user) { is_response = cr ? FALSE : TRUE; @@ -111,9 +130,22 @@ dissect_lapd(const u_char *pd, frame_data *fd, proto_tree *tree) lapd_tree = NULL; } - dissect_xdlc_control(pd, 2, fd, lapd_tree, hf_lapd_control, is_response, TRUE); + control = dissect_xdlc_control(pd, 2, fd, lapd_tree, hf_lapd_control, is_response, TRUE); + lapd_header_len += XDLC_CONTROL_LEN(control, TRUE); + + if (XDLC_HAS_PAYLOAD(control)) { + /* call next protocol */ + switch (sapi) { - /* call next protocol */ + case LAPD_SAPI_Q931: + dissect_q931(pd, lapd_header_len, fd, tree); + break; + + default: + dissect_data(pd, lapd_header_len, fd, tree); + break; + } + } } void @@ -125,23 +157,23 @@ proto_register_lapd(void) "" }}, { &hf_lapd_sapi, - { "SAPI", "lapd.sapi", FT_UINT16, BASE_DEC, VALS(lapd_sapi_vals), 0xfc00, + { "SAPI", "lapd.sapi", FT_UINT16, BASE_DEC, VALS(lapd_sapi_vals), LAPD_SAPI, "Service Access Point Identifier" }}, { &hf_lapd_cr, - { "C/R", "lapd.cr", FT_UINT16, BASE_DEC, NULL, 0x0200, + { "C/R", "lapd.cr", FT_UINT16, BASE_DEC, NULL, LAPD_CR, "Command/Response bit" }}, { &hf_lapd_ea1, - { "EA1", "lapd.ea1", FT_UINT16, BASE_DEC, NULL, 0x0100, + { "EA1", "lapd.ea1", FT_UINT16, BASE_DEC, NULL, LAPD_EA1, "First Address Extension bit" }}, { &hf_lapd_tei, - { "TEI", "lapd.tei", FT_UINT16, BASE_DEC, NULL, 0x00fe, + { "TEI", "lapd.tei", FT_UINT16, BASE_DEC, NULL, LAPD_TEI, "Terminal Endpoint Identifier" }}, { &hf_lapd_ea2, - { "EA2", "lapd.ea2", FT_UINT16, BASE_DEC, NULL, 0x0001, + { "EA2", "lapd.ea2", FT_UINT16, BASE_DEC, NULL, LAPD_EA2, "Second Address Extension bit" }}, { &hf_lapd_control, |