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wireshark/epan/dissectors/packet-mrp-mvrp.c
Guy Harris e1d9a226a2 Fix the type of arrays of pointers to hf_ values for bitfield routines. 
The static arrays are supposed to be arrays of const pointers to int,
not arrays of non-const pointers to const int.

Fixing that means some bugs (scribbling on what's *supposed* to be a
const array) will be caught (see packet-ieee80211-radiotap.c for
examples, the first of which inspired this change and the second of
which was discovered while testing compiles with this change), and
removes the need for some annoying casts.

Also make some of those arrays static while we're at it.

Update documentation and dissector-generator tools.

Change-Id: I789da5fc60aadc15797cefecfd9a9fbe9a130ccc
Reviewed-on: https://code.wireshark.org/review/37517
Petri-Dish: Guy Harris <gharris@sonic.net>
Tested-by: Petri Dish Buildbot
Reviewed-by: Anders Broman <a.broman58@gmail.com>
2020-06-19 11:32:26 +00:00

438 lines
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/* packet-mrp_mvrp.c
* Routines for MVRP (MRP Multiple VLAN Registration Protocol) dissection
* Copyright 2011, Pascal Levesque <plevesque[AT]orthogone.ca>
*
*
* Based on the code from packet-mrp-mmrp.c (MMRP) from
* Johannes Jochen <johannes.jochen[AT]belden.com>
* Copyright 2011
*
* Wireshark - Network traffic analyzer
* By Gerald Combs <gerald[AT]wireshark.org>
* Copyright 1998 Gerald Combs
*
* SPDX-License-Identifier: GPL-2.0-or-later
*
* The MVRP Protocol specification can be found at the following:
* http://standards.ieee.org/about/get/802/802.1.html
*
*/
#include "config.h"
#include <epan/packet.h>
#include <epan/etypes.h>
void proto_register_mrp_mvrp(void);
void proto_reg_handoff_mrp_mvrp(void);
/* MVRP End Mark Sequence */
#define MVRP_END_MARK 0x0000
/**********************************************************/
/* Offsets of fields within an MVRP packet */
/**********************************************************/
#define MVRP_PROTOCOL_VERSION_OFFSET 0
/* Next comes the MVRP Message group */
#define MVRP_MESSAGE_GROUP_OFFSET (MVRP_PROTOCOL_VERSION_OFFSET + 1) /* Message is a group of fields */
#define MVRP_ATTRIBUTE_TYPE_OFFSET (MVRP_MESSAGE_GROUP_OFFSET)
#define MVRP_ATTRIBUTE_LENGTH_OFFSET (MVRP_ATTRIBUTE_TYPE_OFFSET + 1)
/* Next comes the MVRP AttributeList group */
#define MVRP_ATTRIBUTE_LIST_GROUP_OFFSET (MVRP_ATTRIBUTE_LENGTH_OFFSET + 1) /* AttributeList is a group of fields */
/* Next comes the MVRP VectorAttribute group */
#define MVRP_VECTOR_ATTRIBUTE_GROUP_OFFSET (MVRP_ATTRIBUTE_LIST_GROUP_OFFSET) /* VectorAttribute is a group of fields */
#define MVRP_VECTOR_HEADER_OFFSET (MVRP_VECTOR_ATTRIBUTE_GROUP_OFFSET) /* contains the following two fields */
#define MVRP_LEAVE_ALL_EVENT_OFFSET (MVRP_VECTOR_HEADER_OFFSET)
#define MVRP_LEAVE_ALL_EVENT_MASK 0xE000
#define MVRP_NUMBER_OF_VALUES_OFFSET (MVRP_VECTOR_HEADER_OFFSET)
#define MVRP_NUMBER_OF_VALUES_MASK 0x1fff
/* Next comes the MVRP FirstValue group */
#define MVRP_FIRST_VALUE_GROUP_OFFSET (MVRP_VECTOR_HEADER_OFFSET + 2) /* FirstValue is a group of fields */
#define MVRP_VID_THREE_PACKED_OFFSET (MVRP_FIRST_VALUE_GROUP_OFFSET + 2)
/**********************************************************/
/* Valid field contents */
/**********************************************************/
/* Attribute Type definitions */
#define MVRP_ATTRIBUTE_TYPE_VID 0x01
static const value_string attribute_type_vals[] = {
{ MVRP_ATTRIBUTE_TYPE_VID, "VLAN Identifier" },
{ 0, NULL }
};
/* Leave All Event definitions */
#define MVRP_NULLLEAVEALL 0
#define MVRP_LEAVEALL 1
static const value_string leave_all_vals[] = {
{ MVRP_NULLLEAVEALL, "Null" },
{ MVRP_LEAVEALL, "Leave All" },
{ 0, NULL }
};
/* Three Packed Event definitions */
static const value_string three_packed_vals[] = {
{ 0, "New" },
{ 1, "JoinIn" },
{ 2, "In" },
{ 3, "JoinMt" },
{ 4, "Mt" },
{ 5, "Lv" },
{ 0, NULL }
};
/**********************************************************/
/* Initialize the protocol and registered fields */
/**********************************************************/
static int proto_mvrp = -1;
static int hf_mvrp_proto_id = -1;
static int hf_mvrp_message = -1; /* Message is a group of fields */
static int hf_mvrp_attribute_type = -1;
static int hf_mvrp_attribute_length = -1;
static int hf_mvrp_attribute_list = -1; /* AttributeList is a group of fields */
static int hf_mvrp_vector_attribute = -1; /* VectorAttribute is a group of fields */
/* The following VectorHeader contains the LeaveAllEvent and NumberOfValues */
static int hf_mvrp_vector_header = -1;
static int hf_mvrp_leave_all_event = -1;
static int hf_mvrp_number_of_values = -1;
static gint ett_vector_header = -1;
static int * const vector_header_fields[] = {
&hf_mvrp_leave_all_event,
&hf_mvrp_number_of_values,
NULL
};
static int hf_mvrp_first_value = -1; /* FirstValue is a group of fields */
static int hf_mvrp_vid = -1;
static int hf_mvrp_three_packed_event = -1;
static int hf_mvrp_end_mark = -1;
/* Initialize the subtree pointers */
static gint ett_mvrp = -1;
static gint ett_msg = -1;
static gint ett_attr_list = -1;
static gint ett_vect_attr = -1;
static gint ett_first_value = -1;
/**********************************************************/
/* Dissector starts here */
/**********************************************************/
/* dissect_mvrp_common1 (called from dissect_mvrp)
*
* dissect the following fields which are common to all MVRP attributes:
* Attribute Type
* Attribute Length
* Attribute List Length
*/
static void
dissect_mvrp_common1(proto_tree *msg_tree, tvbuff_t *tvb, int msg_offset)
{
proto_tree_add_item(msg_tree, hf_mvrp_attribute_type, tvb,
MVRP_ATTRIBUTE_TYPE_OFFSET + msg_offset, 1, ENC_BIG_ENDIAN);
proto_tree_add_item(msg_tree, hf_mvrp_attribute_length, tvb,
MVRP_ATTRIBUTE_LENGTH_OFFSET + msg_offset, 1, ENC_BIG_ENDIAN);
}
/* dissect_mvrp_common2 (called from dissect_mvrp)
*
* dissect the following fields which are common to all MVRP attributes:
* Leave All Event
* Number of Values fields
*/
static void
dissect_mvrp_common2(proto_tree *vect_attr_tree, tvbuff_t *tvb, int msg_offset)
{
proto_tree_add_bitmask(vect_attr_tree, tvb, MVRP_VECTOR_HEADER_OFFSET + msg_offset,
hf_mvrp_vector_header, ett_vector_header, vector_header_fields, ENC_BIG_ENDIAN);
}
/* dissect_mvrp_three_packed_event (called from dissect_mvrp)
*
* dissect one or more ThreePackedEvents
*/
static guint
dissect_mvrp_three_packed_event(proto_tree *vect_attr_tree, tvbuff_t *tvb, guint offset, guint16 number_of_values)
{
guint counter;
for ( counter = 0; counter < number_of_values; ) {
guint8 value;
guint8 three_packed_event[3];
value = tvb_get_guint8(tvb, offset);
three_packed_event[0] = value / 36;
value -= 36 * three_packed_event[0];
three_packed_event[1] = value / 6;
value -= 6 * three_packed_event[1];
three_packed_event[2] = value;
proto_tree_add_uint(vect_attr_tree, hf_mvrp_three_packed_event, tvb, offset, sizeof(guint8),
three_packed_event[0]);
counter++;
if ( counter < number_of_values ) {
proto_tree_add_uint(vect_attr_tree, hf_mvrp_three_packed_event, tvb, offset, sizeof(guint8),
three_packed_event[1]);
counter++;
}
if ( counter < number_of_values ) {
proto_tree_add_uint(vect_attr_tree, hf_mvrp_three_packed_event, tvb, offset, sizeof(guint8),
three_packed_event[2]);
counter++;
}
offset++;
}
return( offset );
}
/* dissect_main
*
* main dissect function that calls the other functions listed above as necessary
*/
static int
dissect_mvrp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
{
/* Set up structures needed to add the protocol subtrees and manage them */
proto_item *ti, *msg_ti, *attr_list_ti, *vect_attr_ti, *first_value_ti;
proto_tree *mvrp_tree, *msg_tree, *attr_list_tree, *vect_attr_tree, *first_value_tree;
/* Make entries in Protocol column and Info column on summary display */
col_set_str(pinfo->cinfo, COL_PROTOCOL, "MRP-MVRP");
col_set_str(pinfo->cinfo, COL_INFO, "Multiple VLAN Registration Protocol");
if (tree) {
guint8 attribute_type;
guint8 attribute_length;
guint16 number_of_values;
guint offset = 0;
unsigned int vect_attr_len;
unsigned int msg_offset; /* Use when handling multiple messages. This points to current msg being decoded. */
unsigned int vect_offset; /* Use when handling multiple vector attributes. This points to the current vector attribute being decoded. */
ti = proto_tree_add_item(tree, proto_mvrp, tvb, 0, -1, ENC_NA);
mvrp_tree = proto_item_add_subtree(ti, ett_mvrp);
proto_tree_add_item(mvrp_tree, hf_mvrp_proto_id, tvb, MVRP_PROTOCOL_VERSION_OFFSET, 1, ENC_BIG_ENDIAN);
/* MVRP supports multiple MRP Messages per frame. Handle those Messages in
* the following while() loop. You will know you are at the end of the list
* of messages when the EndMark (0x0000) is encountered instead of an
* Attribute Type and Attribute Length (guaranteed to not be 0x0000).
*/
msg_offset = 0;
while (MVRP_ATTRIBUTE_TYPE_OFFSET + msg_offset < tvb_reported_length(tvb) && tvb_get_ntohs(tvb, MVRP_ATTRIBUTE_TYPE_OFFSET + msg_offset) != MVRP_END_MARK) {
attribute_type = tvb_get_guint8(tvb, MVRP_ATTRIBUTE_TYPE_OFFSET + msg_offset);
attribute_length = tvb_get_guint8(tvb, MVRP_ATTRIBUTE_LENGTH_OFFSET + msg_offset);
/* MVRP Message is a group of fields
*
* Contains AttributeType (1 byte)
* + AttributeLength (1 byte)
* + AttributeList (AttributeListLength bytes)
* bytes of data
*/
msg_ti = proto_tree_add_item(mvrp_tree, hf_mvrp_message, tvb,
MVRP_MESSAGE_GROUP_OFFSET + msg_offset,
-1, ENC_NA);
msg_tree = proto_item_add_subtree(msg_ti, ett_msg);
/* Append AttributeType description to the end of the "Message" heading */
proto_item_append_text(msg_tree, ": %s (%d)",
val_to_str_const(attribute_type, attribute_type_vals, "<Unknown>"),
attribute_type);
dissect_mvrp_common1(msg_tree, tvb, msg_offset);
/* MVRP AttributeList is a group of fields
*
* Contains AttributeListLength bytes of data NOT
*/
attr_list_ti = proto_tree_add_item(msg_tree, hf_mvrp_attribute_list, tvb,
MVRP_ATTRIBUTE_LIST_GROUP_OFFSET + msg_offset,
-1, ENC_NA);
attr_list_tree = proto_item_add_subtree(attr_list_ti, ett_attr_list);
/* MVRP supports multiple MRP Vector Attributes per Attribute List. Handle those
* Vector Attributes in the following while() loop. You will know you are at the
* end of the list of Vector Attributes when the EndMark (0x0000) is encountered
* instead of a Vector Header (guaranteed to not be 0x0000).
*/
vect_offset = 0;
while (MVRP_VECTOR_HEADER_OFFSET + msg_offset + vect_offset < tvb_reported_length(tvb) && tvb_get_ntohs(tvb, MVRP_VECTOR_HEADER_OFFSET + msg_offset + vect_offset) != MVRP_END_MARK) {
/* MVRP VectorAttribute is a group of fields
*
* Contains VectorHeader (2 bytes)
* + FirstValue (AttributeLength bytes)
* + VectorThreePacked (NumberOfValues @ 3/vector bytes)
* + VectorFourPacked (NumberOfValues @ 4/vector bytes only for Listener attributes)
* bytes of data
*/
number_of_values = tvb_get_ntohs(tvb, MVRP_NUMBER_OF_VALUES_OFFSET + msg_offset + vect_offset)
& MVRP_NUMBER_OF_VALUES_MASK;
vect_attr_len = 2 + attribute_length + (number_of_values + 2)/3; /* stores 3 values per byte */
vect_attr_ti = proto_tree_add_item(attr_list_tree, hf_mvrp_vector_attribute, tvb,
MVRP_VECTOR_ATTRIBUTE_GROUP_OFFSET + msg_offset + vect_offset,
vect_attr_len, ENC_NA);
vect_attr_tree = proto_item_add_subtree(vect_attr_ti, ett_vect_attr);
dissect_mvrp_common2(vect_attr_tree, tvb, msg_offset + vect_offset);
if (attribute_type == MVRP_ATTRIBUTE_TYPE_VID) {
/* MVRP VLAN ID FirstValue is a group of fields
*
* Contains VID (2 bytes)
* bytes of data
*/
first_value_ti = proto_tree_add_item(vect_attr_tree, hf_mvrp_first_value, tvb,
MVRP_FIRST_VALUE_GROUP_OFFSET + msg_offset + vect_offset,
attribute_length, ENC_NA);
first_value_tree = proto_item_add_subtree(first_value_ti, ett_first_value);
/* Add VLAN components to First Value tree */
proto_tree_add_item(first_value_tree, hf_mvrp_vid, tvb,
MVRP_FIRST_VALUE_GROUP_OFFSET + msg_offset + vect_offset, 2, ENC_BIG_ENDIAN);
/* Decode three packed events. */
offset = dissect_mvrp_three_packed_event(vect_attr_tree, tvb,
MVRP_VID_THREE_PACKED_OFFSET + msg_offset + vect_offset,
number_of_values);
}
vect_offset += vect_attr_len; /* Move to next Vector Attribute, if there is one */
} /* Multiple VectorAttribute while() */
if (MVRP_VECTOR_HEADER_OFFSET + msg_offset + vect_offset < tvb_reported_length(tvb)) {
proto_tree_add_item(attr_list_tree, hf_mvrp_end_mark, tvb, offset, 2, ENC_BIG_ENDIAN); /* VectorAttribute EndMark */
}
proto_item_set_len(attr_list_ti, vect_offset); /*without an endmark*/
msg_offset += vect_offset + 4; /* + endmark; Move to next Message, if there is one */
proto_item_set_len(msg_ti, vect_offset + 2); /*length of message*/
} /* Multiple Message while() */
if (MVRP_ATTRIBUTE_TYPE_OFFSET + msg_offset < tvb_reported_length(tvb)) {
proto_tree_add_item(mvrp_tree, hf_mvrp_end_mark, tvb, offset+2, 2, ENC_BIG_ENDIAN); /* Message EndMark */
}
}
return tvb_captured_length(tvb);
}
/* Register the protocol with Wireshark */
void
proto_register_mrp_mvrp(void)
{
static hf_register_info hf[] = {
{ &hf_mvrp_proto_id,
{ "Protocol Version", "mrp-mvrp.protocol_version",
FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL }
},
{ &hf_mvrp_message, /* Message is a group of fields */
{ "Message", "mrp-mvrp.message",
FT_NONE, BASE_NONE, NULL, 0x0, NULL, HFILL }
},
{ &hf_mvrp_attribute_type,
{ "Attribute Type", "mrp-mvrp.attribute_type",
FT_UINT8, BASE_DEC, VALS(attribute_type_vals), 0x0, NULL, HFILL }
},
{ &hf_mvrp_attribute_length,
{ "Attribute Length", "mrp-mvrp.attribute_length",
FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL }
},
{ &hf_mvrp_attribute_list, /* AttributeList is a group of fields */
{ "Attribute List", "mrp-mvrp.attribute_list",
FT_NONE, BASE_NONE, NULL, 0x0, NULL, HFILL }
},
{ &hf_mvrp_vector_attribute, /* VectorAttribute is a group of fields */
{ "Vector Attribute", "mrp-mvrp.vector_attribute",
FT_NONE, BASE_NONE, NULL, 0x0, NULL, HFILL }
},
{ &hf_mvrp_vector_header,
{ "Vector Header", "mrp-mvrp.vector_header",
FT_UINT16, BASE_HEX, NULL, 0x0, NULL, HFILL }
},
{ &hf_mvrp_leave_all_event,
{ "Leave All Event", "mrp-mvrp.leave_all_event",
FT_UINT16, BASE_DEC, VALS(leave_all_vals), MVRP_LEAVE_ALL_EVENT_MASK, NULL, HFILL }
},
{ &hf_mvrp_number_of_values,
{ "Number of Values", "mrp-mvrp.number_of_values",
FT_UINT16, BASE_DEC, NULL, MVRP_NUMBER_OF_VALUES_MASK, NULL, HFILL }
},
{ &hf_mvrp_first_value, /* FirstValue is a group of fields */
{ "First Value", "mrp-mvrp.first_value",
FT_NONE, BASE_NONE, NULL, 0x0, NULL, HFILL }
},
{ &hf_mvrp_vid,
{ "VLAN ID", "mrp-mvrp.vid",
FT_UINT16, BASE_DEC, NULL, 0x0, NULL, HFILL }
},
{ &hf_mvrp_three_packed_event,
{ "Attribute Event", "mrp-mvrp.three_packed_event",
FT_UINT8, BASE_DEC, VALS(three_packed_vals), 0x0, NULL, HFILL }
},
{ &hf_mvrp_end_mark,
{ "End Mark", "mrp-mvrp.end_mark",
FT_UINT16, BASE_HEX, NULL, 0x0, NULL, HFILL }
},
};
/* Setup protocol subtree array */
static gint *ett[] = {
&ett_mvrp,
&ett_msg,
&ett_attr_list,
&ett_vect_attr,
&ett_vector_header,
&ett_first_value
};
/* Register the protocol name and description */
proto_mvrp = proto_register_protocol("Multiple VLAN Registration Protocol",
"MRP-MVRP", "mrp-mvrp");
/* Required function calls to register the header fields and subtrees used */
proto_register_field_array(proto_mvrp, hf, array_length(hf));
proto_register_subtree_array(ett, array_length(ett));
}
void
proto_reg_handoff_mrp_mvrp(void)
{
dissector_handle_t mvrp_handle;
mvrp_handle = create_dissector_handle(dissect_mvrp, proto_mvrp);
dissector_add_uint("ethertype", ETHERTYPE_MVRP, mvrp_handle);
}
/*
* Editor modelines - https://www.wireshark.org/tools/modelines.html
*
* Local variables:
* c-basic-offset: 4
* tab-width: 8
* indent-tabs-mode: nil
* End:
*
* ex: set shiftwidth=4 tabstop=8 expandtab:
* :indentSize=4:tabSize=8:noTabs=true:
*/
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