summaryrefslogtreecommitdiffstats
path: root/epan/dissectors/packet-usb-printer.c
blob: dda82ea748442db1e6d1eaa7917daea080d17bf2 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
/* packet-usb-printer.c
 *
 * Copyright 2020, Martin Kaiser <martin@kaiser.cx>
 *
 * Wireshark - Network traffic analyzer
 * By Gerald Combs <gerald@wireshark.org>
 * Copyright 1998 Gerald Combs
 *
 * SPDX-License-Identifier: GPL-2.0-or-later
 */

/*
 * References:
 *
 * USB printer class specification
 * https://www.usb.org/sites/default/files/usbprint11a021811.pdf
 *
 * IEEE 1284 (parallel peripheral interface for personal computers)
 * http://kazus.ru/nuke/modules/Downloads/pub/148/0/IEEE%201284-2000.pdf
 */

#include "config.h"
#include <epan/packet.h>
#include <epan/proto.h>
#include "packet-usb.h"
#include <epan/value_string.h>

static dissector_handle_t usb_printer_ctl_handle;

static int proto_usb_printer;

static int hf_usb_printer_req;
static int hf_usb_printer_cfg_idx;
static int hf_usb_printer_intf;
static int hf_usb_printer_alt_set;
static int hf_usb_printer_max_len;
static int hf_usb_printer_dev_id_len;
static int hf_usb_printer_dev_id;

static int ett_usb_printer;

void proto_register_usb_printer(void);
void proto_reg_handoff_usb_printer(void);

#define REQ_GET_DEV_ID    0
#define REQ_GET_PORT_STAT 1
#define REQ_GET_SOFT_RST  2

static const value_string usb_printer_req[] = {
    { REQ_GET_DEV_ID,    "GET_DEVICE_ID" },
    { REQ_GET_PORT_STAT, "GET_PORT_STATUS" },
    { REQ_GET_SOFT_RST,  "SOFT_RESET" },
    { 0, NULL }
};

static int dissect_usb_printer_ctl(
        tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data)
{
    bool is_request = (pinfo->srcport == NO_ENDPOINT);
    urb_info_t *urb = (urb_info_t *)data;
    usb_trans_info_t *usb_trans_info;
    int offset = 0;
    uint8_t bReq;
    uint32_t dev_id_len;

    if (!urb)
        return 0;

    usb_trans_info = urb->usb_trans_info;
    if (!usb_trans_info)
        return 0;

    col_set_str(pinfo->cinfo, COL_PROTOCOL, "USBPRINTER");
    col_set_str(pinfo->cinfo, COL_INFO,
            val_to_str_const(usb_trans_info->setup.request,
                usb_printer_req, "Invalid"));

    if (is_request) {
        col_append_str(pinfo->cinfo, COL_INFO, " request");

        bReq = tvb_get_uint8(tvb, offset);
        proto_tree_add_item(tree, hf_usb_printer_req,
                tvb, offset, 1, ENC_LITTLE_ENDIAN);
        offset++;

        if (bReq == REQ_GET_DEV_ID) {
            /* Generally, fields in USB messages are little endian. */
            proto_tree_add_item(tree, hf_usb_printer_cfg_idx,
                    tvb, offset, 2, ENC_LITTLE_ENDIAN);
            offset += 2;
            proto_tree_add_item(tree, hf_usb_printer_intf,
                    tvb, offset, 2, ENC_LITTLE_ENDIAN);
            proto_tree_add_item(tree, hf_usb_printer_alt_set,
                    tvb, offset, 2, ENC_LITTLE_ENDIAN);
            offset += 2;
            proto_tree_add_item(tree, hf_usb_printer_max_len,
                    tvb, offset, 2, ENC_LITTLE_ENDIAN);
            offset += 2;
        }
    }
    else {
        col_append_str(pinfo->cinfo, COL_INFO, " response");

        if (usb_trans_info->setup.request == REQ_GET_DEV_ID) {
            /*
             * A printer's Device ID is defined in IEEE 1284, section 7.6.
             * It starts with a 16-bit length field in big endian encoding.
             * The length field includes the two bytes for itself. Therefore,
             * we can't use an FT_UINT_STRING for the entire Device ID.
             * The actual Device ID string consists of ASCII characters.
             */
            proto_tree_add_item_ret_uint(tree, hf_usb_printer_dev_id_len,
                    tvb, offset, 2, ENC_BIG_ENDIAN, &dev_id_len);
            offset += 2;
            if (dev_id_len > 2) {
                proto_tree_add_item(tree, hf_usb_printer_dev_id,
                        tvb, offset, dev_id_len-2, ENC_ASCII);
                offset += dev_id_len-2;
            }
            /* XXX - expert info for invalid dev_id_len */
        }
    }

    return offset;
}

void proto_register_usb_printer(void)
{
    static hf_register_info hf[] = {
        { &hf_usb_printer_req,
            { "bRequest", "usbprinter.bRequest", FT_UINT8, BASE_HEX,
                VALS(usb_printer_req), 0x0, NULL, HFILL }
        },
        { &hf_usb_printer_cfg_idx,
            { "Config index", "usbprinter.config_index", FT_UINT16, BASE_HEX,
                NULL, 0x0, NULL, HFILL }
        },
        { &hf_usb_printer_intf,
            { "Interface", "usbprinter.interface", FT_UINT16, BASE_HEX,
                NULL, 0xFF00, NULL, HFILL }
        },
        { &hf_usb_printer_alt_set,
            { "Alternate setting", "usbprinter.alt_set", FT_UINT16, BASE_HEX,
                NULL, 0x00FF, NULL, HFILL }
        },
        { &hf_usb_printer_max_len,
            { "Maximum length", "usbprinter.max_len", FT_UINT16, BASE_HEX,
                NULL, 0, NULL, HFILL }
        },
        { &hf_usb_printer_dev_id_len,
            { "Device ID length", "usbprinter.device_id_len", FT_UINT16,
                BASE_HEX, NULL, 0, NULL, HFILL }
        },
        { &hf_usb_printer_dev_id,
            { "Device ID", "usbprinter.device_id", FT_STRING, BASE_NONE,
                NULL, 0, NULL, HFILL }
        }
    };

    static int *ett[] = {
        &ett_usb_printer
    };

    proto_usb_printer = proto_register_protocol("USB Printer", "USBPRINTER", "usbprinter");
    proto_register_field_array(proto_usb_printer, hf, array_length(hf));
    proto_register_subtree_array(ett, array_length(ett));
    usb_printer_ctl_handle = register_dissector("usbprinter",  dissect_usb_printer_ctl, proto_usb_printer);
}

void
proto_reg_handoff_usb_printer(void)
{
    dissector_add_uint("usb.control", IF_CLASS_PRINTER, usb_printer_ctl_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:
*/