xref: /freebsd/contrib/libfido2/src/hid_openbsd.c (revision f5463265955b829775bbb32e1fd0bc11dafc36ce)
1 /*
2  * Copyright (c) 2019 Google LLC. 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 
10 #include <sys/ioctl.h>
11 #include <dev/usb/usb.h>
12 
13 #include <errno.h>
14 #include <fcntl.h>
15 #include <poll.h>
16 #include <signal.h>
17 #include <unistd.h>
18 
19 #include "fido.h"
20 
21 #define MAX_UHID	64
22 
23 struct hid_openbsd {
24 	int fd;
25 	size_t report_in_len;
26 	size_t report_out_len;
27 	sigset_t sigmask;
28 	const sigset_t *sigmaskp;
29 };
30 
31 static int
32 copy_info(fido_dev_info_t *di, const char *path)
33 {
34 	int fd = -1, ok = -1;
35 	struct usb_device_info udi;
36 
37 	memset(di, 0, sizeof(*di));
38 	memset(&udi, 0, sizeof(udi));
39 
40 	if ((fd = fido_hid_unix_open(path)) == -1)
41 		goto fail;
42 	if (ioctl(fd, IOCTL_REQ(USB_GET_DEVICEINFO), &udi) == -1) {
43 		fido_log_error(errno, "%s: ioctl %s", __func__, path);
44 		goto fail;
45 	}
46 
47 	fido_log_debug("%s: %s: bus = 0x%02x, addr = 0x%02x", __func__, path,
48 	    udi.udi_bus, udi.udi_addr);
49 	fido_log_debug("%s: %s: vendor = \"%s\", product = \"%s\"", __func__,
50 	    path, udi.udi_vendor, udi.udi_product);
51 	fido_log_debug("%s: %s: productNo = 0x%04x, vendorNo = 0x%04x, "
52 	    "releaseNo = 0x%04x", __func__, path, udi.udi_productNo,
53 	    udi.udi_vendorNo, udi.udi_releaseNo);
54 
55 	if ((di->path = strdup(path)) == NULL ||
56 	    (di->manufacturer = strdup(udi.udi_vendor)) == NULL ||
57 	    (di->product = strdup(udi.udi_product)) == NULL)
58 		goto fail;
59 
60 	di->vendor_id = (int16_t)udi.udi_vendorNo;
61 	di->product_id = (int16_t)udi.udi_productNo;
62 
63 	ok = 0;
64 fail:
65 	if (fd != -1 && close(fd) == -1)
66 		fido_log_error(errno, "%s: close %s", __func__, path);
67 
68 	if (ok < 0) {
69 		free(di->path);
70 		free(di->manufacturer);
71 		free(di->product);
72 		explicit_bzero(di, sizeof(*di));
73 	}
74 
75 	return (ok);
76 }
77 
78 int
79 fido_hid_manifest(fido_dev_info_t *devlist, size_t ilen, size_t *olen)
80 {
81 	size_t i;
82 	char path[64];
83 
84 	if (ilen == 0)
85 		return (FIDO_OK); /* nothing to do */
86 
87 	if (devlist == NULL || olen == NULL)
88 		return (FIDO_ERR_INVALID_ARGUMENT);
89 
90 	for (i = *olen = 0; i < MAX_UHID && *olen < ilen; i++) {
91 		snprintf(path, sizeof(path), "/dev/fido/%zu", i);
92 		if (copy_info(&devlist[*olen], path) == 0) {
93 			devlist[*olen].io = (fido_dev_io_t) {
94 				fido_hid_open,
95 				fido_hid_close,
96 				fido_hid_read,
97 				fido_hid_write,
98 			};
99 			++(*olen);
100 		}
101 	}
102 
103 	return (FIDO_OK);
104 }
105 
106 /*
107  * Workaround for OpenBSD <=6.6-current (as of 201910) bug that loses
108  * sync of DATA0/DATA1 sequence bit across uhid open/close.
109  * Send pings until we get a response - early pings with incorrect
110  * sequence bits will be ignored as duplicate packets by the device.
111  */
112 static int
113 terrible_ping_kludge(struct hid_openbsd *ctx)
114 {
115 	u_char data[256];
116 	int i, n;
117 	struct pollfd pfd;
118 
119 	if (sizeof(data) < ctx->report_out_len + 1)
120 		return -1;
121 	for (i = 0; i < 4; i++) {
122 		memset(data, 0, sizeof(data));
123 		/* broadcast channel ID */
124 		data[1] = 0xff;
125 		data[2] = 0xff;
126 		data[3] = 0xff;
127 		data[4] = 0xff;
128 		/* Ping command */
129 		data[5] = 0x81;
130 		/* One byte ping only, Vasili */
131 		data[6] = 0;
132 		data[7] = 1;
133 		fido_log_debug("%s: send ping %d", __func__, i);
134 		if (fido_hid_write(ctx, data, ctx->report_out_len + 1) == -1)
135 			return -1;
136 		fido_log_debug("%s: wait reply", __func__);
137 		memset(&pfd, 0, sizeof(pfd));
138 		pfd.fd = ctx->fd;
139 		pfd.events = POLLIN;
140 		if ((n = poll(&pfd, 1, 100)) == -1) {
141 			fido_log_error(errno, "%s: poll", __func__);
142 			return -1;
143 		} else if (n == 0) {
144 			fido_log_debug("%s: timed out", __func__);
145 			continue;
146 		}
147 		if (fido_hid_read(ctx, data, ctx->report_out_len, 250) == -1)
148 			return -1;
149 		/*
150 		 * Ping isn't always supported on the broadcast channel,
151 		 * so we might get an error, but we don't care - we're
152 		 * synched now.
153 		 */
154 		fido_log_xxd(data, ctx->report_out_len, "%s: got reply",
155 		    __func__);
156 		return 0;
157 	}
158 	fido_log_debug("%s: no response", __func__);
159 	return -1;
160 }
161 
162 void *
163 fido_hid_open(const char *path)
164 {
165 	struct hid_openbsd *ret = NULL;
166 
167 	if ((ret = calloc(1, sizeof(*ret))) == NULL ||
168 	    (ret->fd = fido_hid_unix_open(path)) == -1) {
169 		free(ret);
170 		return (NULL);
171 	}
172 	ret->report_in_len = ret->report_out_len = CTAP_MAX_REPORT_LEN;
173 	fido_log_debug("%s: inlen = %zu outlen = %zu", __func__,
174 	    ret->report_in_len, ret->report_out_len);
175 
176 	/*
177 	 * OpenBSD (as of 201910) has a bug that causes it to lose
178 	 * track of the DATA0/DATA1 sequence toggle across uhid device
179 	 * open and close. This is a terrible hack to work around it.
180 	 */
181 	if (terrible_ping_kludge(ret) != 0) {
182 		fido_hid_close(ret);
183 		return NULL;
184 	}
185 
186 	return (ret);
187 }
188 
189 void
190 fido_hid_close(void *handle)
191 {
192 	struct hid_openbsd *ctx = (struct hid_openbsd *)handle;
193 
194 	if (close(ctx->fd) == -1)
195 		fido_log_error(errno, "%s: close", __func__);
196 
197 	free(ctx);
198 }
199 
200 int
201 fido_hid_set_sigmask(void *handle, const fido_sigset_t *sigmask)
202 {
203 	struct hid_openbsd *ctx = handle;
204 
205 	ctx->sigmask = *sigmask;
206 	ctx->sigmaskp = &ctx->sigmask;
207 
208 	return (FIDO_OK);
209 }
210 
211 int
212 fido_hid_read(void *handle, unsigned char *buf, size_t len, int ms)
213 {
214 	struct hid_openbsd *ctx = (struct hid_openbsd *)handle;
215 	ssize_t r;
216 
217 	if (len != ctx->report_in_len) {
218 		fido_log_debug("%s: invalid len: got %zu, want %zu", __func__,
219 		    len, ctx->report_in_len);
220 		return (-1);
221 	}
222 
223 	if (fido_hid_unix_wait(ctx->fd, ms, ctx->sigmaskp) < 0) {
224 		fido_log_debug("%s: fd not ready", __func__);
225 		return (-1);
226 	}
227 
228 	if ((r = read(ctx->fd, buf, len)) == -1) {
229 		fido_log_error(errno, "%s: read", __func__);
230 		return (-1);
231 	}
232 
233 	if (r < 0 || (size_t)r != len) {
234 		fido_log_debug("%s: %zd != %zu", __func__, r, len);
235 		return (-1);
236 	}
237 
238 	return ((int)len);
239 }
240 
241 int
242 fido_hid_write(void *handle, const unsigned char *buf, size_t len)
243 {
244 	struct hid_openbsd *ctx = (struct hid_openbsd *)handle;
245 	ssize_t r;
246 
247 	if (len != ctx->report_out_len + 1) {
248 		fido_log_debug("%s: invalid len: got %zu, want %zu", __func__,
249 		    len, ctx->report_out_len);
250 		return (-1);
251 	}
252 
253 	if ((r = write(ctx->fd, buf + 1, len - 1)) == -1) {
254 		fido_log_error(errno, "%s: write", __func__);
255 		return (-1);
256 	}
257 
258 	if (r < 0 || (size_t)r != len - 1) {
259 		fido_log_debug("%s: %zd != %zu", __func__, r, len - 1);
260 		return (-1);
261 	}
262 
263 	return ((int)len);
264 }
265 
266 size_t
267 fido_hid_report_in_len(void *handle)
268 {
269 	struct hid_openbsd *ctx = handle;
270 
271 	return (ctx->report_in_len);
272 }
273 
274 size_t
275 fido_hid_report_out_len(void *handle)
276 {
277 	struct hid_openbsd *ctx = handle;
278 
279 	return (ctx->report_out_len);
280 }
281