usb: fix use after free
[qemu/kevin.git] / hw / usb.c
bloba091e4eafc0b9b698b21fafd0fc44e5692920e0d
1 /*
2 * QEMU USB emulation
4 * Copyright (c) 2005 Fabrice Bellard
6 * 2008 Generic packet handler rewrite by Max Krasnyansky
8 * Permission is hereby granted, free of charge, to any person obtaining a copy
9 * of this software and associated documentation files (the "Software"), to deal
10 * in the Software without restriction, including without limitation the rights
11 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
12 * copies of the Software, and to permit persons to whom the Software is
13 * furnished to do so, subject to the following conditions:
15 * The above copyright notice and this permission notice shall be included in
16 * all copies or substantial portions of the Software.
18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
19 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
20 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
21 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
22 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
23 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
24 * THE SOFTWARE.
26 #include "qemu-common.h"
27 #include "usb.h"
28 #include "iov.h"
30 void usb_attach(USBPort *port, USBDevice *dev)
32 if (dev != NULL) {
33 /* attach */
34 if (port->dev) {
35 usb_attach(port, NULL);
37 dev->port = port;
38 port->dev = dev;
39 port->ops->attach(port);
40 usb_send_msg(dev, USB_MSG_ATTACH);
41 } else {
42 /* detach */
43 dev = port->dev;
44 assert(dev);
45 port->ops->detach(port);
46 usb_send_msg(dev, USB_MSG_DETACH);
47 dev->port = NULL;
48 port->dev = NULL;
52 void usb_wakeup(USBDevice *dev)
54 if (dev->remote_wakeup && dev->port && dev->port->ops->wakeup) {
55 dev->port->ops->wakeup(dev->port);
59 /**********************/
61 /* generic USB device helpers (you are not forced to use them when
62 writing your USB device driver, but they help handling the
63 protocol)
66 #define SETUP_STATE_IDLE 0
67 #define SETUP_STATE_SETUP 1
68 #define SETUP_STATE_DATA 2
69 #define SETUP_STATE_ACK 3
71 static int do_token_setup(USBDevice *s, USBPacket *p)
73 int request, value, index;
74 int ret = 0;
76 if (p->iov.size != 8) {
77 return USB_RET_STALL;
80 usb_packet_copy(p, s->setup_buf, p->iov.size);
81 s->setup_len = (s->setup_buf[7] << 8) | s->setup_buf[6];
82 s->setup_index = 0;
84 request = (s->setup_buf[0] << 8) | s->setup_buf[1];
85 value = (s->setup_buf[3] << 8) | s->setup_buf[2];
86 index = (s->setup_buf[5] << 8) | s->setup_buf[4];
88 if (s->setup_buf[0] & USB_DIR_IN) {
89 ret = s->info->handle_control(s, p, request, value, index,
90 s->setup_len, s->data_buf);
91 if (ret == USB_RET_ASYNC) {
92 s->setup_state = SETUP_STATE_SETUP;
93 return USB_RET_ASYNC;
95 if (ret < 0)
96 return ret;
98 if (ret < s->setup_len)
99 s->setup_len = ret;
100 s->setup_state = SETUP_STATE_DATA;
101 } else {
102 if (s->setup_len > sizeof(s->data_buf)) {
103 fprintf(stderr,
104 "usb_generic_handle_packet: ctrl buffer too small (%d > %zu)\n",
105 s->setup_len, sizeof(s->data_buf));
106 return USB_RET_STALL;
108 if (s->setup_len == 0)
109 s->setup_state = SETUP_STATE_ACK;
110 else
111 s->setup_state = SETUP_STATE_DATA;
114 return ret;
117 static int do_token_in(USBDevice *s, USBPacket *p)
119 int request, value, index;
120 int ret = 0;
122 if (p->devep != 0)
123 return s->info->handle_data(s, p);
125 request = (s->setup_buf[0] << 8) | s->setup_buf[1];
126 value = (s->setup_buf[3] << 8) | s->setup_buf[2];
127 index = (s->setup_buf[5] << 8) | s->setup_buf[4];
129 switch(s->setup_state) {
130 case SETUP_STATE_ACK:
131 if (!(s->setup_buf[0] & USB_DIR_IN)) {
132 ret = s->info->handle_control(s, p, request, value, index,
133 s->setup_len, s->data_buf);
134 if (ret == USB_RET_ASYNC) {
135 return USB_RET_ASYNC;
137 s->setup_state = SETUP_STATE_IDLE;
138 if (ret > 0)
139 return 0;
140 return ret;
143 /* return 0 byte */
144 return 0;
146 case SETUP_STATE_DATA:
147 if (s->setup_buf[0] & USB_DIR_IN) {
148 int len = s->setup_len - s->setup_index;
149 if (len > p->iov.size) {
150 len = p->iov.size;
152 usb_packet_copy(p, s->data_buf + s->setup_index, len);
153 s->setup_index += len;
154 if (s->setup_index >= s->setup_len)
155 s->setup_state = SETUP_STATE_ACK;
156 return len;
159 s->setup_state = SETUP_STATE_IDLE;
160 return USB_RET_STALL;
162 default:
163 return USB_RET_STALL;
167 static int do_token_out(USBDevice *s, USBPacket *p)
169 if (p->devep != 0)
170 return s->info->handle_data(s, p);
172 switch(s->setup_state) {
173 case SETUP_STATE_ACK:
174 if (s->setup_buf[0] & USB_DIR_IN) {
175 s->setup_state = SETUP_STATE_IDLE;
176 /* transfer OK */
177 } else {
178 /* ignore additional output */
180 return 0;
182 case SETUP_STATE_DATA:
183 if (!(s->setup_buf[0] & USB_DIR_IN)) {
184 int len = s->setup_len - s->setup_index;
185 if (len > p->iov.size) {
186 len = p->iov.size;
188 usb_packet_copy(p, s->data_buf + s->setup_index, len);
189 s->setup_index += len;
190 if (s->setup_index >= s->setup_len)
191 s->setup_state = SETUP_STATE_ACK;
192 return len;
195 s->setup_state = SETUP_STATE_IDLE;
196 return USB_RET_STALL;
198 default:
199 return USB_RET_STALL;
204 * Generic packet handler.
205 * Called by the HC (host controller).
207 * Returns length of the transaction or one of the USB_RET_XXX codes.
209 int usb_generic_handle_packet(USBDevice *s, USBPacket *p)
211 switch(p->pid) {
212 case USB_MSG_ATTACH:
213 s->state = USB_STATE_ATTACHED;
214 if (s->info->handle_attach) {
215 s->info->handle_attach(s);
217 return 0;
219 case USB_MSG_DETACH:
220 s->state = USB_STATE_NOTATTACHED;
221 return 0;
223 case USB_MSG_RESET:
224 s->remote_wakeup = 0;
225 s->addr = 0;
226 s->state = USB_STATE_DEFAULT;
227 if (s->info->handle_reset) {
228 s->info->handle_reset(s);
230 return 0;
233 /* Rest of the PIDs must match our address */
234 if (s->state < USB_STATE_DEFAULT || p->devaddr != s->addr)
235 return USB_RET_NODEV;
237 switch (p->pid) {
238 case USB_TOKEN_SETUP:
239 return do_token_setup(s, p);
241 case USB_TOKEN_IN:
242 return do_token_in(s, p);
244 case USB_TOKEN_OUT:
245 return do_token_out(s, p);
247 default:
248 return USB_RET_STALL;
252 /* ctrl complete function for devices which use usb_generic_handle_packet and
253 may return USB_RET_ASYNC from their handle_control callback. Device code
254 which does this *must* call this function instead of the normal
255 usb_packet_complete to complete their async control packets. */
256 void usb_generic_async_ctrl_complete(USBDevice *s, USBPacket *p)
258 if (p->result < 0) {
259 s->setup_state = SETUP_STATE_IDLE;
262 switch (s->setup_state) {
263 case SETUP_STATE_SETUP:
264 if (p->result < s->setup_len) {
265 s->setup_len = p->result;
267 s->setup_state = SETUP_STATE_DATA;
268 p->result = 8;
269 break;
271 case SETUP_STATE_ACK:
272 s->setup_state = SETUP_STATE_IDLE;
273 p->result = 0;
274 break;
276 default:
277 break;
279 usb_packet_complete(s, p);
282 /* XXX: fix overflow */
283 int set_usb_string(uint8_t *buf, const char *str)
285 int len, i;
286 uint8_t *q;
288 q = buf;
289 len = strlen(str);
290 *q++ = 2 * len + 2;
291 *q++ = 3;
292 for(i = 0; i < len; i++) {
293 *q++ = str[i];
294 *q++ = 0;
296 return q - buf;
299 /* Send an internal message to a USB device. */
300 void usb_send_msg(USBDevice *dev, int msg)
302 USBPacket p;
303 int ret;
305 memset(&p, 0, sizeof(p));
306 p.pid = msg;
307 ret = usb_handle_packet(dev, &p);
308 /* This _must_ be synchronous */
309 assert(ret != USB_RET_ASYNC);
312 /* Hand over a packet to a device for processing. Return value
313 USB_RET_ASYNC indicates the processing isn't finished yet, the
314 driver will call usb_packet_complete() when done processing it. */
315 int usb_handle_packet(USBDevice *dev, USBPacket *p)
317 int ret;
319 assert(p->owner == NULL);
320 ret = dev->info->handle_packet(dev, p);
321 if (ret == USB_RET_ASYNC) {
322 if (p->owner == NULL) {
323 p->owner = dev;
324 } else {
325 /* We'll end up here when usb_handle_packet is called
326 * recursively due to a hub being in the chain. Nothing
327 * to do. Leave p->owner pointing to the device, not the
328 * hub. */;
331 return ret;
334 /* Notify the controller that an async packet is complete. This should only
335 be called for packets previously deferred by returning USB_RET_ASYNC from
336 handle_packet. */
337 void usb_packet_complete(USBDevice *dev, USBPacket *p)
339 /* Note: p->owner != dev is possible in case dev is a hub */
340 assert(p->owner != NULL);
341 p->owner = NULL;
342 dev->port->ops->complete(dev->port, p);
345 /* Cancel an active packet. The packed must have been deferred by
346 returning USB_RET_ASYNC from handle_packet, and not yet
347 completed. */
348 void usb_cancel_packet(USBPacket * p)
350 assert(p->owner != NULL);
351 p->owner->info->cancel_packet(p->owner, p);
352 p->owner = NULL;
356 void usb_packet_init(USBPacket *p)
358 qemu_iovec_init(&p->iov, 1);
361 void usb_packet_setup(USBPacket *p, int pid, uint8_t addr, uint8_t ep)
363 p->pid = pid;
364 p->devaddr = addr;
365 p->devep = ep;
366 p->result = 0;
367 qemu_iovec_reset(&p->iov);
370 void usb_packet_addbuf(USBPacket *p, void *ptr, size_t len)
372 qemu_iovec_add(&p->iov, ptr, len);
375 void usb_packet_copy(USBPacket *p, void *ptr, size_t bytes)
377 assert(p->result >= 0);
378 assert(p->result + bytes <= p->iov.size);
379 switch (p->pid) {
380 case USB_TOKEN_SETUP:
381 case USB_TOKEN_OUT:
382 iov_to_buf(p->iov.iov, p->iov.niov, ptr, p->result, bytes);
383 break;
384 case USB_TOKEN_IN:
385 iov_from_buf(p->iov.iov, p->iov.niov, ptr, p->result, bytes);
386 break;
387 default:
388 fprintf(stderr, "%s: invalid pid: %x\n", __func__, p->pid);
389 abort();
391 p->result += bytes;
394 void usb_packet_skip(USBPacket *p, size_t bytes)
396 assert(p->result >= 0);
397 assert(p->result + bytes <= p->iov.size);
398 if (p->pid == USB_TOKEN_IN) {
399 iov_clear(p->iov.iov, p->iov.niov, p->result, bytes);
401 p->result += bytes;
404 void usb_packet_cleanup(USBPacket *p)
406 qemu_iovec_destroy(&p->iov);