blob: d793b65d7b93ae17e9babdc06d9041b73cb9f6df [file] [log] [blame]
Daniel Thompson1d507a02018-07-12 11:02:28 +01001/*
2 * This file is part of the flashrom project.
3 *
4 * Copyright (C) 2016 secunet Security Networks AG
5 * Copyright (C) 2018 Linaro Limited
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 */
17
Daniel Thompsonaf499192018-07-12 12:03:51 +010018#include <stdbool.h>
Daniel Thompson1d507a02018-07-12 11:02:28 +010019#include <string.h>
20#include <libusb.h>
21#include "programmer.h"
22
Daniel Thompsonaf499192018-07-12 12:03:51 +010023/*
24 * Check whether we should filter the current device.
25 *
26 * The main code filters by VID/PID then calls out to the filter function for extra filtering.
27 * The filter function is called twice for each device. Once with handle == NULL to allow the
28 * filter to cull devices without opening them and, assuming the first filter does not trigger,
29 * also with a real handle to allow the filter to query the device further.
30 *
31 * Returns true if the device should be skipped.
32 */
33typedef bool (*filter_func)(struct libusb_device_descriptor *desc, struct libusb_device_handle *handle, void*ctx);
34
35static struct libusb_device_handle *get_by_vid_pid_filter(struct libusb_context *usb_ctx,
36 uint16_t vid, uint16_t pid, filter_func filter_fn, void *filter_ctx)
Daniel Thompson1d507a02018-07-12 11:02:28 +010037{
38 struct libusb_device **list;
39 ssize_t count = libusb_get_device_list(usb_ctx, &list);
40 if (count < 0) {
41 msg_perr("Getting the USB device list failed (%s)!\n", libusb_error_name(count));
42 return NULL;
43 }
44
45 ssize_t i = 0;
46 for (i = 0; i < count; i++) {
47 struct libusb_device *dev = list[i];
48 struct libusb_device_descriptor desc;
49 struct libusb_device_handle *handle;
50
51 int res = libusb_get_device_descriptor(dev, &desc);
52 if (res != 0) {
53 msg_perr("Reading the USB device descriptor failed (%s)!\n", libusb_error_name(res));
54 continue;
55 }
56
57 if ((desc.idVendor != vid) && (desc.idProduct != pid))
58 continue;
59
60 msg_pdbg("Found USB device %04"PRIx16":%04"PRIx16" at address %d-%d.\n",
61 desc.idVendor, desc.idProduct,
62 libusb_get_bus_number(dev), libusb_get_device_address(dev));
63
Daniel Thompsonaf499192018-07-12 12:03:51 +010064 /* allow filters to trigger before the device is opened */
65 if (filter_fn(&desc, NULL, filter_ctx))
66 continue;
67
Daniel Thompson1d507a02018-07-12 11:02:28 +010068 res = libusb_open(dev, &handle);
69 if (res != 0) {
Daniel Thompsonaf499192018-07-12 12:03:51 +010070 msg_perr("Opening the USB device at address %d-%d failed (%s)!\n",
71 libusb_get_bus_number(dev), libusb_get_device_address(dev),
72 libusb_error_name(res));
73 break;
Daniel Thompson1d507a02018-07-12 11:02:28 +010074 }
75
Daniel Thompsonaf499192018-07-12 12:03:51 +010076 /* filter can also trigger after a device is opened */
77 if (filter_fn(&desc, handle, filter_ctx)) {
78 libusb_close(handle);
79 continue;
Daniel Thompson1d507a02018-07-12 11:02:28 +010080 }
81
82 libusb_free_device_list(list, 1);
83 return handle;
84 }
85
86 libusb_free_device_list(list, 1);
87 return NULL;
Daniel Thompsonaf499192018-07-12 12:03:51 +010088
89}
90
91static bool filter_by_serial(struct libusb_device_descriptor *desc, struct libusb_device_handle *handle,
92 void *serialno)
93{
94 /* Never filter if device is not yet open or when user did not provide a serial number */
95 if (!handle || !serialno)
96 return false;
97
98 unsigned char myserial[64];
99 int res = libusb_get_string_descriptor_ascii(handle, desc->iSerialNumber, myserial, sizeof(myserial));
100 if (res < 0) {
101 msg_perr("Reading the USB serialno failed (%s)!\n", libusb_error_name(res));
102 return true;
103 }
104 msg_pdbg("Serial number is %s\n", myserial);
105
106 /* Filter out any serial number that does not commence with serialno */
107 return 0 != strncmp(serialno, (char *)myserial, strlen(serialno));
108}
109
110struct libusb_device_handle *usb_dev_get_by_vid_pid_serial(
111 struct libusb_context *usb_ctx, uint16_t vid, uint16_t pid, const char *serialno)
112{
113 return get_by_vid_pid_filter(usb_ctx, vid, pid, filter_by_serial, (void *)serialno);
114}
115
116static bool filter_by_number(struct libusb_device_descriptor *desc, struct libusb_device_handle *handle,
117 void *ctx)
118{
119 /* This filter never triggers once it has allowed the device to be opened */
120 if (handle != NULL)
121 return false;
122
123 unsigned int *nump = ctx;
124 if (*nump) {
125 (*nump)--;
126 return true;
127 }
128
129 return false;
Daniel Thompson1d507a02018-07-12 11:02:28 +0100130}
131
132/*
133 * This function allows different devices to be targeted based on enumeration order. Different
134 * hotplug sequencing (or simply a reboot) may change the enumeration order. This function should
135 * only be used if a programmers does not provide an alternative way to identify itself uniquely
136 * (such as a unique serial number).
137 */
138struct libusb_device_handle *usb_dev_get_by_vid_pid_number(
139 struct libusb_context *usb_ctx, uint16_t vid, uint16_t pid, unsigned int num)
140{
Daniel Thompsonaf499192018-07-12 12:03:51 +0100141 return get_by_vid_pid_filter(usb_ctx, vid, pid, filter_by_number, &num);
Daniel Thompson1d507a02018-07-12 11:02:28 +0100142}