Adding upstream version 4.2.2.upstream/4.2.2

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 234 insertions, 0 deletions

diff --git a/epan/dissectors/packet-lapb.c b/epan/dissectors/packet-lapb.c
new file mode 100644
index 00000000..c1ea6838
--- /dev/null
+++ b/epan/dissectors/packet-lapb.c
@@ -0,0 +1,234 @@
+/* packet-lapb.c
+ * Routines for lapb frame disassembly
+ * Olivier Abad <oabad@noos.fr>
+ *
+ * Wireshark - Network traffic analyzer
+ * By Gerald Combs <gerald@wireshark.org>
+ * Copyright 1998
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include "config.h"
+
+#include <epan/packet.h>
+#include <wiretap/wtap.h>
+#include <epan/xdlc.h>
+
+void proto_register_lapb(void);
+void proto_reg_handoff_lapb(void);
+
+static int proto_lapb = -1;
+static int hf_lapb_address = -1;
+static int hf_lapb_control = -1;
+static int hf_lapb_n_r = -1;
+static int hf_lapb_n_s = -1;
+static int hf_lapb_p = -1;
+static int hf_lapb_f = -1;
+static int hf_lapb_s_ftype = -1;
+static int hf_lapb_u_modifier_cmd = -1;
+static int hf_lapb_u_modifier_resp = -1;
+static int hf_lapb_ftype_i = -1;
+static int hf_lapb_ftype_s_u = -1;
+
+static gint ett_lapb = -1;
+static gint ett_lapb_control = -1;
+
+static dissector_handle_t x25_dir_handle;
+static dissector_handle_t x25_handle;
+static dissector_handle_t lapb_handle;
+
+static const xdlc_cf_items lapb_cf_items = {
+    &hf_lapb_n_r,
+    &hf_lapb_n_s,
+    &hf_lapb_p,
+    &hf_lapb_f,
+    &hf_lapb_s_ftype,
+    &hf_lapb_u_modifier_cmd,
+    &hf_lapb_u_modifier_resp,
+    &hf_lapb_ftype_i,
+    &hf_lapb_ftype_s_u
+};
+
+static int
+dissect_lapb(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
+{
+    proto_tree          *lapb_tree, *ti;
+    guint16             control;
+    int                 is_response;
+    guint8              byte0;
+    tvbuff_t            *next_tvb;
+
+    col_set_str(pinfo->cinfo, COL_PROTOCOL, "LAPB");
+    col_clear(pinfo->cinfo, COL_INFO);
+
+    switch (pinfo->p2p_dir) {
+
+    case P2P_DIR_SENT:
+        col_set_str(pinfo->cinfo, COL_RES_DL_SRC, "DTE");
+        col_set_str(pinfo->cinfo, COL_RES_DL_DST, "DCE");
+        break;
+
+    case P2P_DIR_RECV:
+        col_set_str(pinfo->cinfo, COL_RES_DL_SRC, "DCE");
+        col_set_str(pinfo->cinfo, COL_RES_DL_DST, "DTE");
+        break;
+
+    default:
+        col_set_str(pinfo->cinfo, COL_RES_DL_SRC, "N/A");
+        col_set_str(pinfo->cinfo, COL_RES_DL_DST, "N/A");
+        break;
+    }
+
+    byte0 = tvb_get_guint8(tvb, 0);
+
+    if (byte0 != 0x01 && byte0 != 0x03 && byte0 != 0x07 && byte0 != 0x0f) /* invalid LAPB frame */
+    {
+        col_set_str(pinfo->cinfo, COL_INFO, "Invalid LAPB frame");
+        if (tree)
+            proto_tree_add_protocol_format(tree, proto_lapb, tvb, 0, -1,
+                            "Invalid LAPB frame");
+        return 1;
+    }
+
+    switch (pinfo->p2p_dir) {
+
+    case P2P_DIR_SENT:
+        if (byte0 == 0x03)
+            is_response = TRUE;
+        else
+            is_response = FALSE;
+        break;
+
+    case P2P_DIR_RECV:
+        if (byte0 == 0x01)
+            is_response = TRUE;
+        else
+            is_response = FALSE;
+        break;
+
+    default:
+        /*
+         * XXX - should we base this on the source and destination
+         * addresses?  The problem is that we can tell one direction
+         * from another with that, but we can't say which is DTE->DCE
+         * and which is DCE->DTE.
+         */
+        is_response = FALSE;
+        break;
+    }
+
+    ti = proto_tree_add_protocol_format(tree, proto_lapb, tvb, 0, 2,
+                                        "LAPB");
+    lapb_tree = proto_item_add_subtree(ti, ett_lapb);
+    proto_tree_add_uint(lapb_tree, hf_lapb_address, tvb, 0, 1, byte0);
+
+    control = dissect_xdlc_control(tvb, 1, pinfo, lapb_tree, hf_lapb_control,
+            ett_lapb_control, &lapb_cf_items, NULL, NULL, NULL,
+            is_response, FALSE, FALSE);
+
+    /* information frame ==> X.25 */
+    if (XDLC_IS_INFORMATION(control)) {
+        next_tvb = tvb_new_subset_remaining(tvb, 2);
+        switch (pinfo->p2p_dir) {
+
+        case P2P_DIR_SENT:
+        case P2P_DIR_RECV:
+            call_dissector(x25_dir_handle, next_tvb, pinfo, tree);
+            break;
+
+        default:
+            call_dissector(x25_handle, next_tvb, pinfo, tree);
+            break;
+        }
+    }
+    return tvb_captured_length(tvb);
+}
+
+void
+proto_register_lapb(void)
+{
+    static hf_register_info hf[] = {
+        { &hf_lapb_address,
+          { "Address", "lapb.address", FT_UINT8, BASE_HEX, NULL, 0x0,
+            NULL, HFILL }},
+
+        { &hf_lapb_control,
+          { "Control Field", "lapb.control", FT_UINT8, BASE_HEX, NULL, 0x0,
+            NULL, HFILL }},
+
+        { &hf_lapb_n_r,
+          { "N(R)", "lapb.control.n_r", FT_UINT8, BASE_DEC,
+            NULL, XDLC_N_R_MASK, NULL, HFILL }},
+
+        { &hf_lapb_n_s,
+          { "N(S)", "lapb.control.n_s", FT_UINT8, BASE_DEC,
+            NULL, XDLC_N_S_MASK, NULL, HFILL }},
+
+        { &hf_lapb_p,
+          { "Poll", "lapb.control.p", FT_BOOLEAN, 8,
+            TFS(&tfs_set_notset), XDLC_P_F, NULL, HFILL }},
+
+        { &hf_lapb_f,
+          { "Final", "lapb.control.f", FT_BOOLEAN, 8,
+            TFS(&tfs_set_notset), XDLC_P_F, NULL, HFILL }},
+
+        { &hf_lapb_s_ftype,
+          { "Supervisory frame type", "lapb.control.s_ftype", FT_UINT8, BASE_HEX,
+            VALS(stype_vals), XDLC_S_FTYPE_MASK, NULL, HFILL }},
+
+        { &hf_lapb_u_modifier_cmd,
+          { "Command", "lapb.control.u_modifier_cmd", FT_UINT8, BASE_HEX,
+            VALS(modifier_vals_cmd), XDLC_U_MODIFIER_MASK, NULL, HFILL }},
+
+        { &hf_lapb_u_modifier_resp,
+          { "Response", "lapb.control.u_modifier_resp", FT_UINT8, BASE_HEX,
+            VALS(modifier_vals_resp), XDLC_U_MODIFIER_MASK, NULL, HFILL }},
+
+        { &hf_lapb_ftype_i,
+          { "Frame type", "lapb.control.ftype", FT_UINT8, BASE_HEX,
+            VALS(ftype_vals), XDLC_I_MASK, NULL, HFILL }},
+
+        { &hf_lapb_ftype_s_u,
+          { "Frame type", "lapb.control.ftype", FT_UINT8, BASE_HEX,
+            VALS(ftype_vals), XDLC_S_U_MASK, NULL, HFILL }},
+    };
+    static gint *ett[] = {
+        &ett_lapb,
+        &ett_lapb_control,
+    };
+
+    proto_lapb = proto_register_protocol("Link Access Procedure Balanced (LAPB)",
+                                         "LAPB", "lapb");
+    proto_register_field_array (proto_lapb, hf, array_length(hf));
+    proto_register_subtree_array(ett, array_length(ett));
+
+    lapb_handle = register_dissector("lapb", dissect_lapb, proto_lapb);
+}
+
+void
+proto_reg_handoff_lapb(void)
+{
+    /*
+     * Get handles for the X.25 dissectors; we don't get an X.25
+     * pseudo-header for LAPB-over-Ethernet, but we do get it
+     * for raw LAPB.
+     */
+    x25_dir_handle = find_dissector_add_dependency("x.25_dir", proto_lapb);
+    x25_handle = find_dissector_add_dependency("x.25", proto_lapb);
+
+    dissector_add_uint("wtap_encap", WTAP_ENCAP_LAPB, lapb_handle);
+}
+
+/*
+ * 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:
+ */