xref: /qemu/hw/usb/canokey.c (revision 8607b5149e556db1e5c6d722867330f88a5b8d1a)
1 /*
2  * CanoKey QEMU device implementation.
3  *
4  * Copyright (c) 2021-2022 Canokeys.org <contact@canokeys.org>
5  * Written by Hongren (Zenithal) Zheng <i@zenithal.me>
6  *
7  * This code is licensed under the Apache-2.0.
8  */
9 
10 #include "qemu/osdep.h"
11 #include <canokey-qemu.h>
12 
13 #include "qemu/module.h"
14 #include "qapi/error.h"
15 #include "hw/usb.h"
16 #include "hw/qdev-properties.h"
17 #include "trace.h"
18 #include "desc.h"
19 #include "canokey.h"
20 
21 #define CANOKEY_EP_IN(ep) ((ep) & 0x7F)
22 
23 #define CANOKEY_VENDOR_NUM     0x20a0
24 #define CANOKEY_PRODUCT_NUM    0x42d2
25 
26 /*
27  * placeholder, canokey-qemu implements its own usb desc
28  * Namely we do not use usb_desc_handle_contorl
29  */
30 enum {
31     STR_MANUFACTURER = 1,
32     STR_PRODUCT,
33     STR_SERIALNUMBER
34 };
35 
36 static const USBDescStrings desc_strings = {
37     [STR_MANUFACTURER]     = "canokeys.org",
38     [STR_PRODUCT]          = "CanoKey QEMU",
39     [STR_SERIALNUMBER]     = "0"
40 };
41 
42 static const USBDescDevice desc_device_canokey = {
43     .bcdUSB                        = 0x0,
44     .bMaxPacketSize0               = 16,
45     .bNumConfigurations            = 0,
46     .confs = NULL,
47 };
48 
49 static const USBDesc desc_canokey = {
50     .id = {
51         .idVendor          = CANOKEY_VENDOR_NUM,
52         .idProduct         = CANOKEY_PRODUCT_NUM,
53         .bcdDevice         = 0x0100,
54         .iManufacturer     = STR_MANUFACTURER,
55         .iProduct          = STR_PRODUCT,
56         .iSerialNumber     = STR_SERIALNUMBER,
57     },
58     .full = &desc_device_canokey,
59     .high = &desc_device_canokey,
60     .str  = desc_strings,
61 };
62 
63 
64 /*
65  * libcanokey-qemu.so side functions
66  * All functions are called from canokey_emu_device_loop
67  */
68 int canokey_emu_stall_ep(void *base, uint8_t ep)
69 {
70     trace_canokey_emu_stall_ep(ep);
71     CanoKeyState *key = base;
72     uint8_t ep_in = CANOKEY_EP_IN(ep); /* INTR IN has ep 129 */
73     key->ep_in_size[ep_in] = 0;
74     key->ep_in_state[ep_in] = CANOKEY_EP_IN_STALL;
75     return 0;
76 }
77 
78 int canokey_emu_set_address(void *base, uint8_t addr)
79 {
80     trace_canokey_emu_set_address(addr);
81     CanoKeyState *key = base;
82     key->dev.addr = addr;
83     return 0;
84 }
85 
86 int canokey_emu_prepare_receive(
87         void *base, uint8_t ep, uint8_t *pbuf, uint16_t size)
88 {
89     trace_canokey_emu_prepare_receive(ep, size);
90     CanoKeyState *key = base;
91     key->ep_out[ep] = pbuf;
92     key->ep_out_size[ep] = size;
93     return 0;
94 }
95 
96 int canokey_emu_transmit(
97         void *base, uint8_t ep, const uint8_t *pbuf, uint16_t size)
98 {
99     trace_canokey_emu_transmit(ep, size);
100     CanoKeyState *key = base;
101     uint8_t ep_in = CANOKEY_EP_IN(ep); /* INTR IN has ep 129 */
102     memcpy(key->ep_in[ep_in] + key->ep_in_size[ep_in],
103             pbuf, size);
104     key->ep_in_size[ep_in] += size;
105     key->ep_in_state[ep_in] = CANOKEY_EP_IN_READY;
106     /*
107      * wake up controller if we NAKed IN token before
108      * Note: this is a quirk for CanoKey CTAPHID
109      */
110     if (ep_in == CANOKEY_EMU_EP_CTAPHID) {
111         usb_wakeup(usb_ep_get(&key->dev, USB_TOKEN_IN, ep_in), 0);
112     }
113     /*
114      * ready for more data in device loop
115      *
116      * Note: this is a quirk for CanoKey CTAPHID
117      * because it calls multiple emu_transmit in one device_loop
118      * but w/o data_in it would stuck in device_loop
119      * This has side effect for CCID since CCID can send ZLP
120      * This also has side effect for Control transfer
121      */
122     if (ep_in == CANOKEY_EMU_EP_CTAPHID) {
123         canokey_emu_data_in(ep_in);
124     }
125     return 0;
126 }
127 
128 uint32_t canokey_emu_get_rx_data_size(void *base, uint8_t ep)
129 {
130     CanoKeyState *key = base;
131     return key->ep_out_size[ep];
132 }
133 
134 /*
135  * QEMU side functions
136  */
137 static void canokey_handle_reset(USBDevice *dev)
138 {
139     trace_canokey_handle_reset();
140     CanoKeyState *key = CANOKEY(dev);
141     for (int i = 0; i != CANOKEY_EP_NUM; ++i) {
142         key->ep_in_state[i] = CANOKEY_EP_IN_WAIT;
143         key->ep_in_pos[i] = 0;
144         key->ep_in_size[i] = 0;
145     }
146     canokey_emu_reset();
147 }
148 
149 static void canokey_handle_control(USBDevice *dev, USBPacket *p,
150                int request, int value, int index, int length, uint8_t *data)
151 {
152     trace_canokey_handle_control_setup(request, value, index, length);
153     CanoKeyState *key = CANOKEY(dev);
154 
155     canokey_emu_setup(request, value, index, length);
156 
157     uint32_t dir_in = request & DeviceRequest;
158     if (!dir_in) {
159         /* OUT */
160         trace_canokey_handle_control_out();
161         if (key->ep_out[0] != NULL) {
162             memcpy(key->ep_out[0], data, length);
163         }
164         canokey_emu_data_out(p->ep->nr, data);
165     }
166 
167     canokey_emu_device_loop();
168 
169     /* IN */
170     switch (key->ep_in_state[0]) {
171     case CANOKEY_EP_IN_WAIT:
172         p->status = USB_RET_NAK;
173         break;
174     case CANOKEY_EP_IN_STALL:
175         p->status = USB_RET_STALL;
176         break;
177     case CANOKEY_EP_IN_READY:
178         memcpy(data, key->ep_in[0], key->ep_in_size[0]);
179         p->actual_length = key->ep_in_size[0];
180         trace_canokey_handle_control_in(p->actual_length);
181         /* reset state */
182         key->ep_in_state[0] = CANOKEY_EP_IN_WAIT;
183         key->ep_in_size[0] = 0;
184         key->ep_in_pos[0] = 0;
185         break;
186     }
187 }
188 
189 static void canokey_handle_data(USBDevice *dev, USBPacket *p)
190 {
191     CanoKeyState *key = CANOKEY(dev);
192 
193     uint8_t ep_in = CANOKEY_EP_IN(p->ep->nr);
194     uint8_t ep_out = p->ep->nr;
195     uint32_t in_len;
196     uint32_t out_pos;
197     uint32_t out_len;
198     switch (p->pid) {
199     case USB_TOKEN_OUT:
200         trace_canokey_handle_data_out(ep_out, p->iov.size);
201         usb_packet_copy(p, key->ep_out_buffer[ep_out], p->iov.size);
202         out_pos = 0;
203         while (out_pos != p->iov.size) {
204             /*
205              * key->ep_out[ep_out] set by prepare_receive
206              * to be a buffer inside libcanokey-qemu.so
207              * key->ep_out_size[ep_out] set by prepare_receive
208              * to be the buffer length
209              */
210             out_len = MIN(p->iov.size - out_pos, key->ep_out_size[ep_out]);
211             memcpy(key->ep_out[ep_out],
212                     key->ep_out_buffer[ep_out] + out_pos, out_len);
213             out_pos += out_len;
214             /* update ep_out_size to actual len */
215             key->ep_out_size[ep_out] = out_len;
216             canokey_emu_data_out(ep_out, NULL);
217         }
218         /*
219          * Note: this is a quirk for CanoKey CTAPHID
220          *
221          * There is one code path that uses this device loop
222          * INTR IN -> useful data_in and useless device_loop -> NAKed
223          * INTR OUT -> useful device loop -> transmit -> wakeup
224          *   (useful thanks to both data_in and data_out having been called)
225          * the next INTR IN -> actual data to guest
226          *
227          * if there is no such device loop, there would be no further
228          * INTR IN, no device loop, no transmit hence no usb_wakeup
229          * then qemu would hang
230          */
231         if (ep_in == CANOKEY_EMU_EP_CTAPHID) {
232             canokey_emu_device_loop(); /* may call transmit multiple times */
233         }
234         break;
235     case USB_TOKEN_IN:
236         if (key->ep_in_pos[ep_in] == 0) { /* first time IN */
237             canokey_emu_data_in(ep_in);
238             canokey_emu_device_loop(); /* may call transmit multiple times */
239         }
240         switch (key->ep_in_state[ep_in]) {
241         case CANOKEY_EP_IN_WAIT:
242             /* NAK for early INTR IN */
243             p->status = USB_RET_NAK;
244             break;
245         case CANOKEY_EP_IN_STALL:
246             p->status = USB_RET_STALL;
247             break;
248         case CANOKEY_EP_IN_READY:
249             /* submit part of ep_in buffer to USBPacket */
250             in_len = MIN(key->ep_in_size[ep_in] - key->ep_in_pos[ep_in],
251                     p->iov.size);
252             usb_packet_copy(p,
253                     key->ep_in[ep_in] + key->ep_in_pos[ep_in], in_len);
254             key->ep_in_pos[ep_in] += in_len;
255             /* reset state if all data submitted */
256             if (key->ep_in_pos[ep_in] == key->ep_in_size[ep_in]) {
257                 key->ep_in_state[ep_in] = CANOKEY_EP_IN_WAIT;
258                 key->ep_in_size[ep_in] = 0;
259                 key->ep_in_pos[ep_in] = 0;
260             }
261             trace_canokey_handle_data_in(ep_in, in_len);
262             break;
263         }
264         break;
265     default:
266         p->status = USB_RET_STALL;
267         break;
268     }
269 }
270 
271 static void canokey_realize(USBDevice *base, Error **errp)
272 {
273     trace_canokey_realize();
274     CanoKeyState *key = CANOKEY(base);
275 
276     if (key->file == NULL) {
277         error_setg(errp, "You must provide file=/path/to/canokey-file");
278         return;
279     }
280 
281     usb_desc_init(base);
282 
283     for (int i = 0; i != CANOKEY_EP_NUM; ++i) {
284         key->ep_in_state[i] = CANOKEY_EP_IN_WAIT;
285         key->ep_in_size[i] = 0;
286         key->ep_in_pos[i] = 0;
287     }
288 
289     if (canokey_emu_init(key, key->file)) {
290         error_setg(errp, "canokey can not create or read %s", key->file);
291         return;
292     }
293 }
294 
295 static void canokey_unrealize(USBDevice *base)
296 {
297     trace_canokey_unrealize();
298 }
299 
300 static Property canokey_properties[] = {
301     DEFINE_PROP_STRING("file", CanoKeyState, file),
302     DEFINE_PROP_END_OF_LIST(),
303 };
304 
305 static void canokey_class_init(ObjectClass *klass, void *data)
306 {
307     DeviceClass *dc = DEVICE_CLASS(klass);
308     USBDeviceClass *uc = USB_DEVICE_CLASS(klass);
309 
310     uc->product_desc   = "CanoKey QEMU";
311     uc->usb_desc       = &desc_canokey;
312     uc->handle_reset   = canokey_handle_reset;
313     uc->handle_control = canokey_handle_control;
314     uc->handle_data    = canokey_handle_data;
315     uc->handle_attach  = usb_desc_attach;
316     uc->realize        = canokey_realize;
317     uc->unrealize      = canokey_unrealize;
318     dc->desc           = "CanoKey QEMU";
319     device_class_set_props(dc, canokey_properties);
320     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
321 }
322 
323 static const TypeInfo canokey_info = {
324     .name = TYPE_CANOKEY,
325     .parent = TYPE_USB_DEVICE,
326     .instance_size = sizeof(CanoKeyState),
327     .class_init = canokey_class_init
328 };
329 
330 static void canokey_register_types(void)
331 {
332     type_register_static(&canokey_info);
333 }
334 
335 type_init(canokey_register_types)
336