1 /*
2  * Copyright (C) 2011 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #include <unistd.h>
18 #include <stdio.h>
19 #include <string.h>
20 #include <stdlib.h>
21 
22 #include <sys/types.h>
23 #include <sys/stat.h>
24 #include <fcntl.h>
25 #include <errno.h>
26 #include <pthread.h>
27 #include <time.h>
28 
29 #include <usbhost/usbhost.h>
30 #include <linux/usb/f_accessory.h>
31 
32 struct usb_device *sDevice = NULL;
33 
read_thread(void * arg)34 static void* read_thread(void* arg) {
35     int endpoint = (int)(uintptr_t)arg;
36     int ret = 0;
37 
38     while (sDevice && ret >= 0) {
39         char    buffer[16384];
40 
41         ret = usb_device_bulk_transfer(sDevice, endpoint, buffer, sizeof(buffer), 1000);
42         if (ret < 0 && errno == ETIMEDOUT)
43             ret = 0;
44         if (ret > 0) {
45             fwrite(buffer, 1, ret, stdout);
46             printf("\n");
47             fflush(stdout);
48         }
49     }
50 
51     return NULL;
52 }
53 
write_thread(void * arg)54 static void* write_thread(void* arg) {
55     int endpoint = (int)(uintptr_t)arg;
56     int ret = 0;
57 
58     while (ret >= 0) {
59         char    buffer[16384];
60         char *line = fgets(buffer, sizeof(buffer), stdin);
61         if (!line || !sDevice)
62             break;
63         ret = usb_device_bulk_transfer(sDevice, endpoint, line, strlen(line), 1000);
64     }
65 
66     return NULL;
67 }
68 
milli_sleep(int millis)69 static void milli_sleep(int millis) {
70     struct timespec tm;
71 
72     tm.tv_sec = 0;
73     tm.tv_nsec = millis * 1000000;
74     nanosleep(&tm, NULL);
75 }
76 
send_string(struct usb_device * device,int index,const char * string)77 static void send_string(struct usb_device *device, int index, const char* string) {
78     int ret = usb_device_control_transfer(device, USB_DIR_OUT | USB_TYPE_VENDOR,
79             ACCESSORY_SEND_STRING, 0, index, (void *)string, strlen(string) + 1, 0);
80 
81     // some devices can't handle back-to-back requests, so delay a bit
82     milli_sleep(10);
83 }
84 
usb_device_added(const char * devname,void * client_data)85 static int usb_device_added(const char *devname, void* client_data) {
86     struct usb_descriptor_header* desc;
87     struct usb_descriptor_iter iter;
88     uint16_t vendorId, productId;
89     int ret;
90     pthread_t th;
91 
92     struct usb_device *device = usb_device_open(devname);
93     if (!device) {
94         fprintf(stderr, "usb_device_open failed\n");
95         return 0;
96     }
97 
98     vendorId = usb_device_get_vendor_id(device);
99     productId = usb_device_get_product_id(device);
100 
101     if (vendorId == 0x18D1 || vendorId == 0x22B8 || vendorId == 0x04e8) {
102         if (!sDevice && (productId == 0x2D00 || productId == 0x2D01)) {
103             struct usb_descriptor_header* desc;
104             struct usb_descriptor_iter iter;
105             struct usb_interface_descriptor *intf = NULL;
106             struct usb_endpoint_descriptor *ep1 = NULL;
107             struct usb_endpoint_descriptor *ep2 = NULL;
108 
109             printf("Found android device in accessory mode\n");
110             sDevice = device;
111 
112             usb_descriptor_iter_init(device, &iter);
113             while ((desc = usb_descriptor_iter_next(&iter)) != NULL && (!intf || !ep1 || !ep2)) {
114                 if (desc->bDescriptorType == USB_DT_INTERFACE) {
115                     intf = (struct usb_interface_descriptor *)desc;
116                 } else if (desc->bDescriptorType == USB_DT_ENDPOINT) {
117                     if (ep1)
118                         ep2 = (struct usb_endpoint_descriptor *)desc;
119                     else
120                         ep1 = (struct usb_endpoint_descriptor *)desc;
121                 }
122             }
123 
124             if (!intf) {
125                 fprintf(stderr, "interface not found\n");
126                 exit(1);
127             }
128             if (!ep1 || !ep2) {
129                 fprintf(stderr, "endpoints not found\n");
130                 exit(1);
131             }
132 
133             if (usb_device_claim_interface(device, intf->bInterfaceNumber)) {
134                 fprintf(stderr, "usb_device_claim_interface failed errno: %d\n", errno);
135                 exit(1);
136             }
137 
138             if ((ep1->bEndpointAddress & USB_ENDPOINT_DIR_MASK) == USB_DIR_IN) {
139                 pthread_create(&th, NULL, read_thread, (void *)(uintptr_t)ep1->bEndpointAddress);
140                 pthread_create(&th, NULL, write_thread, (void *)(uintptr_t)ep2->bEndpointAddress);
141             } else {
142                 pthread_create(&th, NULL, read_thread, (void *)(uintptr_t)ep2->bEndpointAddress);
143                 pthread_create(&th, NULL, write_thread, (void *)(uintptr_t)ep1->bEndpointAddress);
144             }
145         } else {
146             printf("Found possible android device - attempting to switch to accessory mode\n");
147 
148             uint16_t protocol;
149             ret = usb_device_control_transfer(device, USB_DIR_IN | USB_TYPE_VENDOR,
150                     ACCESSORY_GET_PROTOCOL, 0, 0, &protocol, sizeof(protocol), 0);
151             if (ret == 2)
152                 printf("device supports protocol version %d\n", protocol);
153             else
154                 fprintf(stderr, "failed to read protocol version\n");
155 
156             send_string(device, ACCESSORY_STRING_MANUFACTURER, "Google, Inc.");
157             send_string(device, ACCESSORY_STRING_MODEL, "AccessoryChat");
158             send_string(device, ACCESSORY_STRING_DESCRIPTION, "Accessory Chat");
159             send_string(device, ACCESSORY_STRING_VERSION, "1.0");
160             send_string(device, ACCESSORY_STRING_URI, "http://www.android.com");
161             send_string(device, ACCESSORY_STRING_SERIAL, "1234567890");
162 
163             ret = usb_device_control_transfer(device, USB_DIR_OUT | USB_TYPE_VENDOR,
164                     ACCESSORY_START, 0, 0, 0, 0, 0);
165             return 0;
166         }
167     }
168 
169     if (device != sDevice)
170         usb_device_close(device);
171 
172     return 0;
173 }
174 
usb_device_removed(const char * devname,void * client_data)175 static int usb_device_removed(const char *devname, void* client_data) {
176     if (sDevice && !strcmp(usb_device_get_name(sDevice), devname)) {
177         usb_device_close(sDevice);
178         sDevice = NULL;
179         // exit when we are disconnected
180         return 1;
181     }
182     return 0;
183 }
184 
185 
main(int argc,char * argv[])186 int main(int argc, char* argv[]) {
187     struct usb_host_context* context = usb_host_init();
188     if (!context) {
189         fprintf(stderr, "usb_host_init failed");
190         return 1;
191     }
192 
193     // this will never return so it is safe to pass thiz directly
194     usb_host_run(context, usb_device_added, usb_device_removed, NULL, NULL);
195     return 0;
196 }
197