Keep the sample command line in the usage message within 80 characters.

[obnox/wireshark/wip.git] / packet-lapd.c

diff --git a/packet-lapd.c b/packet-lapd.c
index a0b98e9fe1acf7d9d0590df565a15e9c1d607fc3..d0de40bb7e1bdb4740c4d2a7dc2ed6ce9e2d3335 100644 (file)
--- 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 1.4 2000/01/24 02:05:38 guy Exp $
  *
  * Ethereal - Network traffic analyzer
  * By Gerald Combs <gerald@zing.org>
@@ -45,21 +45,40 @@
  * http://www.acacia-net.com/Clarinet/Protocol/q9213o84.htm
  */
 
-int proto_lapd = -1;
-int hf_lapd_address = -1;
-int hf_lapd_sapi = -1;
-int hf_lapd_cr = -1;
-int hf_lapd_ea1 = -1;
-int hf_lapd_tei = -1;
-int hf_lapd_ea2 = -1;
-int hf_lapd_control = -1;
+static int proto_lapd = -1;
+static int hf_lapd_address = -1;
+static int hf_lapd_sapi = -1;
+static int hf_lapd_cr = -1;
+static int hf_lapd_ea1 = -1;
+static int hf_lapd_tei = -1;
+static int hf_lapd_ea2 = -1;
+static int hf_lapd_control = -1;
+
+static gint ett_lapd = -1;
+static gint ett_lapd_address = -1;
+static gint ett_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 +86,20 @@ 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;
@@ -96,10 +119,10 @@ dissect_lapd(const u_char *pd, frame_data *fd, proto_tree *tree)
 
        if (tree) {
                ti = proto_tree_add_item(tree, proto_lapd, 0, 3, NULL);
-               lapd_tree = proto_item_add_subtree(ti, ETT_LAPD);
+               lapd_tree = proto_item_add_subtree(ti, ett_lapd);
 
                ti = proto_tree_add_item(lapd_tree, hf_lapd_address, 0, 2, address);
-               addr_tree = proto_item_add_subtree(ti, ETT_LAPD_ADDRESS);
+               addr_tree = proto_item_add_subtree(ti, ett_lapd_address);
 
                proto_tree_add_item(addr_tree, hf_lapd_sapi,    0, 1, address);
                proto_tree_add_item(addr_tree, hf_lapd_cr,      0, 1, address);
@@ -111,9 +134,24 @@ 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,
+           ett_lapd_control, is_response, TRUE);
+       lapd_header_len += XDLC_CONTROL_LEN(control, TRUE);
+
+       if (XDLC_IS_INFORMATION(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;
+               }
+       } else
+               dissect_data(pd, lapd_header_len, fd, tree);
 }
 
 void
@@ -125,30 +163,36 @@ 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,
          { "Control Field", "lapd.control", FT_UINT16, BASE_HEX, NULL, 0x0,
                "" }},
     };
+    static gint *ett[] = {
+        &ett_lapd,
+        &ett_lapd_address,
+        &ett_lapd_control,
+    };
 
     proto_lapd = proto_register_protocol ("Link Access Procedure, Channel D (LAPD)", "lapd");
     proto_register_field_array (proto_lapd, hf, array_length(hf));
+    proto_register_subtree_array(ett, array_length(ett));
 }