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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-10 20:34:10 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-10 20:34:10 +0000
commite4ba6dbc3f1e76890b22773807ea37fe8fa2b1bc (patch)
tree68cb5ef9081156392f1dd62a00c6ccc1451b93df /epan/dissectors/packet-epon.c
parentInitial commit. (diff)
downloadwireshark-e4ba6dbc3f1e76890b22773807ea37fe8fa2b1bc.tar.xz
wireshark-e4ba6dbc3f1e76890b22773807ea37fe8fa2b1bc.zip
Adding upstream version 4.2.2.upstream/4.2.2
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'epan/dissectors/packet-epon.c')
-rw-r--r--epan/dissectors/packet-epon.c299
1 files changed, 299 insertions, 0 deletions
diff --git a/epan/dissectors/packet-epon.c b/epan/dissectors/packet-epon.c
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+/* packet-epon.c
+ * Routines for Ethernet Passive Optical Network dissection
+ * Copyright 2014, Philip Rosenberg-Watt <p.rosenberg-watt[at]cablelabs.com>
+ *
+ * Wireshark - Network traffic analyzer
+ * By Gerald Combs <gerald@wireshark.org>
+ * Copyright 1998 Gerald Combs
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+/* 2014-04 Philip Rosenberg-Watt <p.rosenberg-watt[at]cablelabs.com>
+ * + EPON preamble with CableLabs DPoE securty byte.
+ * See IEEE 802.3-2012 Section 5, Clause 65 and
+ * CableLabs DPoE SEC 1.0 specification.
+ */
+
+#include "config.h"
+
+#include <epan/packet.h>
+#include <epan/expert.h>
+
+#include <epan/addr_resolv.h>
+#include <epan/crc8-tvb.h>
+
+void proto_register_epon(void);
+void proto_reg_handoff_epon(void);
+
+static dissector_handle_t epon_handle;
+
+static int proto_epon = -1;
+static int hf_epon_dpoe_security = -1;
+static int hf_epon_dpoe_encrypted = -1;
+static int hf_epon_dpoe_reserved = -1;
+static int hf_epon_dpoe_encrypted_data = -1;
+static int hf_epon_dpoe_keyid = -1;
+static int hf_epon_mode = -1;
+static int hf_epon_llid = -1;
+static int hf_epon_checksum = -1;
+static int hf_epon_checksum_status = -1;
+
+static expert_field ei_epon_sld_bad = EI_INIT;
+static expert_field ei_epon_dpoe_reserved_bad = EI_INIT;
+static expert_field ei_epon_dpoe_bad = EI_INIT;
+static expert_field ei_epon_dpoe_encrypted_data = EI_INIT;
+static expert_field ei_epon_checksum_bad = EI_INIT;
+
+static dissector_handle_t eth_maybefcs_handle;
+
+static gint ett_epon = -1;
+static gint ett_epon_sec = -1;
+static gint ett_epon_checksum = -1;
+
+static const true_false_string epon_mode_tfs = {
+ "Broadcast/Multicast",
+ "Unicast"
+};
+
+static int
+dissect_epon(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
+ void *data _U_)
+{
+ proto_tree *epon_tree;
+ proto_item *ti;
+ proto_item *item;
+ proto_tree *sec_tree;
+ tvbuff_t *next_tvb;
+ guint checksum;
+ guint sent_checksum;
+ guint offset = 0;
+ guint dpoe_sec_byte;
+ gboolean dpoe_encrypted = FALSE;
+
+ /* Start_of_Packet delimiter (/S/) can happen in byte 1, 2 or 3,
+ * making the captured preamble 8, 7 or 6 bytes in length. If the
+ * preamble starts with 0x55, then /S/ happened in byte 1, making the
+ * captured preamble 7 bytes in length.
+ */
+ if (tvb_get_ntohl(tvb, 0) == 0x5555D555) {
+ offset += 2;
+ } else if (tvb_get_ntoh24(tvb, 0) == 0x55D555) {
+ offset += 1;
+ } else if (tvb_get_ntohs(tvb, 0) == 0xD555) {
+ offset += 0;
+ } else {
+ item = proto_tree_add_item(tree, proto_epon, tvb, offset, 0, ENC_NA);
+ expert_add_info(pinfo, item, &ei_epon_sld_bad);
+ return 0;
+ }
+
+ /* Set the columns */
+ col_set_str(pinfo->cinfo, COL_PROTOCOL, "EPON");
+ col_set_str(pinfo->cinfo, COL_INFO, "EPON Preamble");
+
+ /* Create display subtree for the protocol */
+ ti = proto_tree_add_item(tree, proto_epon, tvb, 0+offset, 6, ENC_NA);
+ epon_tree = proto_item_add_subtree(ti, ett_epon);
+
+ /* Decode byte 5 of the preamble according to CableLabs DPoE specification.
+ * If security is disabled, the DPoE byte will remain 0x55 and no decoding
+ * is necessary.
+ */
+ dpoe_sec_byte = tvb_get_guint8(tvb, 2+offset);
+ if (dpoe_sec_byte != 0x55) {
+ guint dpoe_keyid;
+ guint dpoe_reserved;
+
+ item = proto_tree_add_item(epon_tree, hf_epon_dpoe_security,
+ tvb, 2+offset, 1, ENC_BIG_ENDIAN);
+ sec_tree = proto_item_add_subtree(item, ett_epon_sec);
+
+ /* The DPoE security byte is split into three fields:
+ * bits 7-2 are reserved in 1G mode
+ * bit 1 is the encryption mode
+ * bit 0 is the key ID
+ */
+ dpoe_reserved = dpoe_sec_byte & 0xFC;
+ dpoe_encrypted = dpoe_sec_byte & 0x02;
+ dpoe_keyid = dpoe_sec_byte & 0x01;
+
+ /* Add encryption status text to sec_tree subtree
+ */
+ proto_item_append_text(item, " (Encrypted: ");
+ if (dpoe_encrypted) {
+ proto_item_append_text(item, "True, Key ID: %x", dpoe_keyid);
+ } else {
+ proto_item_append_text(item, "False");
+ }
+ proto_item_append_text(item, ")");
+
+ /* We don't need to see the reserved bits of the DPoE security byte unless
+ * there's something wrong with them.
+ */
+ if (dpoe_reserved != 0x54) {
+ proto_tree_add_item(sec_tree, hf_epon_dpoe_reserved, tvb, 2+offset, 1,
+ ENC_BIG_ENDIAN);
+ expert_add_info(pinfo, sec_tree, &ei_epon_dpoe_reserved_bad);
+ }
+
+ /* Add encryption and key ID bits
+ * Error if encryption is disabled but key bit is not 1
+ */
+ proto_tree_add_item(sec_tree, hf_epon_dpoe_encrypted, tvb, 2+offset, 1,
+ ENC_BIG_ENDIAN);
+ proto_tree_add_item(sec_tree, hf_epon_dpoe_keyid, tvb, 2+offset, 1,
+ ENC_BIG_ENDIAN);
+ if (!dpoe_encrypted && (dpoe_keyid == 0)) {
+ expert_add_info(pinfo, sec_tree, &ei_epon_dpoe_bad);
+ }
+
+ }
+
+ /* Mode bit
+ */
+ proto_tree_add_item(epon_tree, hf_epon_mode, tvb, 3+offset, 2,
+ ENC_BIG_ENDIAN);
+
+ /* LLID
+ */
+ proto_tree_add_item(epon_tree, hf_epon_llid, tvb, 3+offset, 2,
+ ENC_BIG_ENDIAN);
+
+ /* Verify the CRC-8 checksum
+ */
+ sent_checksum = tvb_get_guint8(tvb, 5+offset);
+ checksum = get_crc8_ieee8023_epon(tvb, 5, 0+offset);
+
+ proto_tree_add_checksum(epon_tree, tvb, 5+offset, hf_epon_checksum, hf_epon_checksum_status, &ei_epon_checksum_bad, pinfo, checksum, ENC_NA, PROTO_CHECKSUM_VERIFY);
+ if (sent_checksum != checksum) {
+ col_append_str(pinfo->cinfo, COL_INFO, " [EPON PREAMBLE CHECKSUM INCORRECT]");
+ }
+
+ /* Do not bother parsing encrypted data, otherwise send the rest on to the
+ * eth dissector.
+ */
+ if (dpoe_encrypted) {
+ item = proto_tree_add_item(tree, hf_epon_dpoe_encrypted_data, tvb,
+ 6+offset, -1, ENC_NA);
+ expert_add_info(pinfo, item, &ei_epon_dpoe_encrypted_data);
+ col_append_str(pinfo->cinfo, COL_INFO, " [ENCRYPTED]");
+ } else {
+ next_tvb = tvb_new_subset_remaining(tvb, 6+offset);
+ /*
+ * XXX - is it guaranteed whether the capture will, or won't, have
+ * an FCS?
+ */
+ call_dissector(eth_maybefcs_handle, next_tvb, pinfo, tree);
+ }
+
+ return tvb_captured_length(tvb);
+}
+
+void
+proto_register_epon(void)
+{
+ expert_module_t *expert_epon;
+
+ static hf_register_info hf[] = {
+ { &hf_epon_dpoe_security,
+ { "DPoE security", "epon.dpoe.sec", FT_UINT8, BASE_HEX, NULL, 0x0,
+ "DPoE security octet", HFILL }
+ },
+ { &hf_epon_dpoe_reserved,
+ { "Reserved", "epon.dpoe.reserved", FT_UINT8, BASE_DEC, NULL, 0xFC,
+ "Reserved in 1G mode", HFILL }
+ },
+ { &hf_epon_dpoe_encrypted,
+ { "Encryption enabled", "epon.dpoe.encrypted", FT_BOOLEAN, 8, NULL, 0x02,
+ "Specifies if this is an encrypted frame", HFILL }
+ },
+ { &hf_epon_dpoe_keyid,
+ { "Key ID", "epon.dpoe.keyid", FT_UINT8, BASE_HEX, NULL, 0x01,
+ "Identification number of the key used to encrypt this frame",
+ HFILL }
+ },
+ { &hf_epon_dpoe_encrypted_data,
+ { "Encrypted data", "epon.dpoe.encrypted.data", FT_BYTES, BASE_NONE,
+ NULL, 0x0, "DPoE encrypted data", HFILL }
+ },
+ { &hf_epon_mode,
+ { "Mode", "epon.mode", FT_BOOLEAN, 16, TFS(&epon_mode_tfs), 0x8000,
+ "Broadcast/multicast if true, unicast if false", HFILL }
+ },
+ { &hf_epon_llid,
+ { "LLID", "epon.llid", FT_UINT16, BASE_DEC_HEX, NULL, 0x7FFF,
+ "Logical Link ID", HFILL }
+ },
+ { &hf_epon_checksum,
+ { "Frame check sequence", "epon.checksum", FT_UINT8, BASE_HEX, NULL,
+ 0x0, "EPON preamble checksum", HFILL }
+ },
+ { &hf_epon_checksum_status,
+ { "Frame check sequence Status", "epon.checksum.status", FT_UINT8, BASE_NONE, VALS(proto_checksum_vals),
+ 0x0, NULL, HFILL }
+ },
+ };
+
+ static gint *ett[] = {
+ &ett_epon,
+ &ett_epon_sec,
+ &ett_epon_checksum
+ };
+
+ /* Setup protocol expert items */
+ static ei_register_info ei[] = {
+ { &ei_epon_checksum_bad,
+ { "epon.checksum_bad.expert", PI_CHECKSUM, PI_ERROR,
+ "Bad checksum", EXPFILL }
+ },
+ { &ei_epon_sld_bad,
+ { "epon.sld_bad.expert", PI_MALFORMED, PI_ERROR,
+ "Unable to locate SLD or invalid byte sequence: preamble must start with 0xD555", EXPFILL }
+ },
+ { &ei_epon_dpoe_reserved_bad,
+ { "epon.dpoe.encrypted.expert", PI_MALFORMED, PI_ERROR,
+ "Bits 7-2 of DPoE security byte must be 010101 in 1G mode.", EXPFILL }
+ },
+ { &ei_epon_dpoe_bad,
+ { "epon.dpoe.expert", PI_MALFORMED, PI_ERROR,
+ "DPoE security byte must be 0x55 if encryption is disabled.", EXPFILL }
+ },
+ { &ei_epon_dpoe_encrypted_data,
+ { "epon.dpoe.encrypted.expert", PI_UNDECODED, PI_NOTE,
+ "Remaining data is encrypted and will not decode.", EXPFILL }
+ }
+ };
+
+ proto_epon = proto_register_protocol("IEEE 802.3 EPON Preamble",
+ "EPON", "epon");
+
+ proto_register_field_array(proto_epon, hf, array_length(hf));
+ proto_register_subtree_array(ett, array_length(ett));
+
+ expert_epon = expert_register_protocol(proto_epon);
+ expert_register_field_array(expert_epon, ei, array_length(ei));
+
+ epon_handle = register_dissector("epon", dissect_epon, proto_epon);
+}
+
+void
+proto_reg_handoff_epon(void)
+{
+ dissector_add_uint("wtap_encap", WTAP_ENCAP_EPON, epon_handle);
+
+ eth_maybefcs_handle = find_dissector_add_dependency("eth_maybefcs", proto_epon);
+}
+
+/*
+ * Editor modelines - https://www.wireshark.org/tools/modelines.html
+ *
+ * Local Variables:
+ * c-basic-offset: 2
+ * tab-width: 8
+ * indent-tabs-mode: nil
+ * End:
+ *
+ * ex: set shiftwidth=2 tabstop=8 expandtab:
+ * :indentSize=2:tabSize=8:noTabs=true:
+ */