xref: /freebsd/contrib/libfido2/src/hid_netbsd.c (revision 5ca8e32633c4ffbbcd6762e5888b6a4ba0708c6c)
1 /*
2  * Copyright (c) 2020 Yubico AB. All rights reserved.
3  * Use of this source code is governed by a BSD-style
4  * license that can be found in the LICENSE file.
5  * SPDX-License-Identifier: BSD-2-Clause
6  */
7 
8 #include <sys/types.h>
9 #include <sys/ioctl.h>
10 
11 #include <dev/usb/usb.h>
12 #include <dev/usb/usbhid.h>
13 
14 #include <errno.h>
15 #include <poll.h>
16 #include <signal.h>
17 #include <stdbool.h>
18 #include <stdio.h>
19 #include <stdlib.h>
20 #include <string.h>
21 #include <unistd.h>
22 
23 #include "fido.h"
24 
25 #define MAX_UHID	64
26 
27 struct hid_netbsd {
28 	int             fd;
29 	size_t          report_in_len;
30 	size_t          report_out_len;
31 	sigset_t        sigmask;
32 	const sigset_t *sigmaskp;
33 };
34 
35 /* Hack to make this work with newer kernels even if /usr/include is old.  */
36 #if __NetBSD_Version__ < 901000000	/* 9.1 */
37 #define	USB_HID_GET_RAW	_IOR('h', 1, int)
38 #define	USB_HID_SET_RAW	_IOW('h', 2, int)
39 #endif
40 
41 static bool
42 is_fido(int fd)
43 {
44 	struct usb_ctl_report_desc	ucrd;
45 	uint32_t			usage_page = 0;
46 	int				raw = 1;
47 
48 	memset(&ucrd, 0, sizeof(ucrd));
49 
50 	if (ioctl(fd, IOCTL_REQ(USB_GET_REPORT_DESC), &ucrd) == -1) {
51 		fido_log_error(errno, "%s: ioctl", __func__);
52 		return (false);
53 	}
54 
55 	if (ucrd.ucrd_size < 0 ||
56 	    (size_t)ucrd.ucrd_size > sizeof(ucrd.ucrd_data) ||
57 	    fido_hid_get_usage(ucrd.ucrd_data, (size_t)ucrd.ucrd_size,
58 		&usage_page) < 0) {
59 		fido_log_debug("%s: fido_hid_get_usage", __func__);
60 		return (false);
61 	}
62 
63 	if (usage_page != 0xf1d0)
64 		return (false);
65 
66 	/*
67 	 * This step is not strictly necessary -- NetBSD puts fido
68 	 * devices into raw mode automatically by default, but in
69 	 * principle that might change, and this serves as a test to
70 	 * verify that we're running on a kernel with support for raw
71 	 * mode at all so we don't get confused issuing writes that try
72 	 * to set the report descriptor rather than transfer data on
73 	 * the output interrupt pipe as we need.
74 	 */
75 	if (ioctl(fd, IOCTL_REQ(USB_HID_SET_RAW), &raw) == -1) {
76 		fido_log_error(errno, "%s: unable to set raw", __func__);
77 		return (false);
78 	}
79 
80 	return (true);
81 }
82 
83 static int
84 copy_info(fido_dev_info_t *di, const char *path)
85 {
86 	int			fd = -1;
87 	int			ok = -1;
88 	struct usb_device_info	udi;
89 
90 	memset(di, 0, sizeof(*di));
91 	memset(&udi, 0, sizeof(udi));
92 
93 	if ((fd = fido_hid_unix_open(path)) == -1 || is_fido(fd) == 0)
94 		goto fail;
95 
96 	if (ioctl(fd, IOCTL_REQ(USB_GET_DEVICEINFO), &udi) == -1) {
97 		fido_log_error(errno, "%s: ioctl", __func__);
98 		goto fail;
99 	}
100 
101 	if ((di->path = strdup(path)) == NULL ||
102 	    (di->manufacturer = strdup(udi.udi_vendor)) == NULL ||
103 	    (di->product = strdup(udi.udi_product)) == NULL)
104 		goto fail;
105 
106 	di->vendor_id = (int16_t)udi.udi_vendorNo;
107 	di->product_id = (int16_t)udi.udi_productNo;
108 
109 	ok = 0;
110 fail:
111 	if (fd != -1 && close(fd) == -1)
112 		fido_log_error(errno, "%s: close", __func__);
113 
114 	if (ok < 0) {
115 		free(di->path);
116 		free(di->manufacturer);
117 		free(di->product);
118 		explicit_bzero(di, sizeof(*di));
119 	}
120 
121 	return (ok);
122 }
123 
124 int
125 fido_hid_manifest(fido_dev_info_t *devlist, size_t ilen, size_t *olen)
126 {
127 	char	path[64];
128 	size_t	i;
129 
130 	*olen = 0;
131 
132 	if (ilen == 0)
133 		return (FIDO_OK); /* nothing to do */
134 
135 	if (devlist == NULL || olen == NULL)
136 		return (FIDO_ERR_INVALID_ARGUMENT);
137 
138 	for (i = *olen = 0; i < MAX_UHID && *olen < ilen; i++) {
139 		snprintf(path, sizeof(path), "/dev/uhid%zu", i);
140 		if (copy_info(&devlist[*olen], path) == 0) {
141 			devlist[*olen].io = (fido_dev_io_t) {
142 				fido_hid_open,
143 				fido_hid_close,
144 				fido_hid_read,
145 				fido_hid_write,
146 			};
147 			++(*olen);
148 		}
149 	}
150 
151 	return (FIDO_OK);
152 }
153 
154 /*
155  * Workaround for NetBSD (as of 201910) bug that loses
156  * sync of DATA0/DATA1 sequence bit across uhid open/close.
157  * Send pings until we get a response - early pings with incorrect
158  * sequence bits will be ignored as duplicate packets by the device.
159  */
160 static int
161 terrible_ping_kludge(struct hid_netbsd *ctx)
162 {
163 	u_char data[256];
164 	int i, n;
165 	struct pollfd pfd;
166 
167 	if (sizeof(data) < ctx->report_out_len + 1)
168 		return -1;
169 	for (i = 0; i < 4; i++) {
170 		memset(data, 0, sizeof(data));
171 		/* broadcast channel ID */
172 		data[1] = 0xff;
173 		data[2] = 0xff;
174 		data[3] = 0xff;
175 		data[4] = 0xff;
176 		/* Ping command */
177 		data[5] = 0x81;
178 		/* One byte ping only, Vasili */
179 		data[6] = 0;
180 		data[7] = 1;
181 		fido_log_debug("%s: send ping %d", __func__, i);
182 		if (fido_hid_write(ctx, data, ctx->report_out_len + 1) == -1)
183 			return -1;
184 		fido_log_debug("%s: wait reply", __func__);
185 		memset(&pfd, 0, sizeof(pfd));
186 		pfd.fd = ctx->fd;
187 		pfd.events = POLLIN;
188 		if ((n = poll(&pfd, 1, 100)) == -1) {
189 			fido_log_error(errno, "%s: poll", __func__);
190 			return -1;
191 		} else if (n == 0) {
192 			fido_log_debug("%s: timed out", __func__);
193 			continue;
194 		}
195 		if (fido_hid_read(ctx, data, ctx->report_out_len, 250) == -1)
196 			return -1;
197 		/*
198 		 * Ping isn't always supported on the broadcast channel,
199 		 * so we might get an error, but we don't care - we're
200 		 * synched now.
201 		 */
202 		fido_log_xxd(data, ctx->report_out_len, "%s: got reply",
203 		    __func__);
204 		return 0;
205 	}
206 	fido_log_debug("%s: no response", __func__);
207 	return -1;
208 }
209 
210 void *
211 fido_hid_open(const char *path)
212 {
213 	struct hid_netbsd		*ctx;
214 	struct usb_ctl_report_desc	 ucrd;
215 	int				 r;
216 
217 	memset(&ucrd, 0, sizeof(ucrd));
218 
219 	if ((ctx = calloc(1, sizeof(*ctx))) == NULL ||
220 	    (ctx->fd = fido_hid_unix_open(path)) == -1) {
221 		free(ctx);
222 		return (NULL);
223 	}
224 
225 	if ((r = ioctl(ctx->fd, IOCTL_REQ(USB_GET_REPORT_DESC), &ucrd)) == -1 ||
226 	    ucrd.ucrd_size < 0 ||
227 	    (size_t)ucrd.ucrd_size > sizeof(ucrd.ucrd_data) ||
228 	    fido_hid_get_report_len(ucrd.ucrd_data, (size_t)ucrd.ucrd_size,
229 		&ctx->report_in_len, &ctx->report_out_len) < 0) {
230 		if (r == -1)
231 			fido_log_error(errno, "%s: ioctl", __func__);
232 		fido_log_debug("%s: using default report sizes", __func__);
233 		ctx->report_in_len = CTAP_MAX_REPORT_LEN;
234 		ctx->report_out_len = CTAP_MAX_REPORT_LEN;
235 	}
236 
237 	/*
238 	 * NetBSD has a bug that causes it to lose
239 	 * track of the DATA0/DATA1 sequence toggle across uhid device
240 	 * open and close. This is a terrible hack to work around it.
241 	 */
242 	if (!is_fido(ctx->fd) || terrible_ping_kludge(ctx) != 0) {
243 		fido_hid_close(ctx);
244 		return NULL;
245 	}
246 
247 	return (ctx);
248 }
249 
250 void
251 fido_hid_close(void *handle)
252 {
253 	struct hid_netbsd *ctx = handle;
254 
255 	if (close(ctx->fd) == -1)
256 		fido_log_error(errno, "%s: close", __func__);
257 
258 	free(ctx);
259 }
260 
261 int
262 fido_hid_set_sigmask(void *handle, const fido_sigset_t *sigmask)
263 {
264 	struct hid_netbsd *ctx = handle;
265 
266 	ctx->sigmask = *sigmask;
267 	ctx->sigmaskp = &ctx->sigmask;
268 
269 	return (FIDO_OK);
270 }
271 
272 int
273 fido_hid_read(void *handle, unsigned char *buf, size_t len, int ms)
274 {
275 	struct hid_netbsd	*ctx = handle;
276 	ssize_t			 r;
277 
278 	if (len != ctx->report_in_len) {
279 		fido_log_debug("%s: len %zu", __func__, len);
280 		return (-1);
281 	}
282 
283 	if (fido_hid_unix_wait(ctx->fd, ms, ctx->sigmaskp) < 0) {
284 		fido_log_debug("%s: fd not ready", __func__);
285 		return (-1);
286 	}
287 
288 	if ((r = read(ctx->fd, buf, len)) == -1) {
289 		fido_log_error(errno, "%s: read", __func__);
290 		return (-1);
291 	}
292 
293 	if (r < 0 || (size_t)r != len) {
294 		fido_log_error(errno, "%s: %zd != %zu", __func__, r, len);
295 		return (-1);
296 	}
297 
298 	return ((int)r);
299 }
300 
301 int
302 fido_hid_write(void *handle, const unsigned char *buf, size_t len)
303 {
304 	struct hid_netbsd	*ctx = handle;
305 	ssize_t			 r;
306 
307 	if (len != ctx->report_out_len + 1) {
308 		fido_log_debug("%s: len %zu", __func__, len);
309 		return (-1);
310 	}
311 
312 	if ((r = write(ctx->fd, buf + 1, len - 1)) == -1) {
313 		fido_log_error(errno, "%s: write", __func__);
314 		return (-1);
315 	}
316 
317 	if (r < 0 || (size_t)r != len - 1) {
318 		fido_log_error(errno, "%s: %zd != %zu", __func__, r, len - 1);
319 		return (-1);
320 	}
321 
322 	return ((int)len);
323 }
324 
325 size_t
326 fido_hid_report_in_len(void *handle)
327 {
328 	struct hid_netbsd *ctx = handle;
329 
330 	return (ctx->report_in_len);
331 }
332 
333 size_t
334 fido_hid_report_out_len(void *handle)
335 {
336 	struct hid_netbsd *ctx = handle;
337 
338 	return (ctx->report_out_len);
339 }
340