xref: /freebsd/contrib/libfido2/src/hid_openbsd.c (revision e6bfd18d21b225af6a0ed67ceeaf1293b7b9eba5)
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  */
6 
7 #include <sys/types.h>
8 
9 #include <sys/ioctl.h>
10 #include <dev/usb/usb.h>
11 
12 #include <errno.h>
13 #include <fcntl.h>
14 #include <poll.h>
15 #include <signal.h>
16 #include <unistd.h>
17 
18 #include "fido.h"
19 
20 #define MAX_UHID	64
21 
22 struct hid_openbsd {
23 	int fd;
24 	size_t report_in_len;
25 	size_t report_out_len;
26 	sigset_t sigmask;
27 	const sigset_t *sigmaskp;
28 };
29 
30 int
31 fido_hid_manifest(fido_dev_info_t *devlist, size_t ilen, size_t *olen)
32 {
33 	size_t i;
34 	char path[64];
35 	int fd;
36 	struct usb_device_info udi;
37 	fido_dev_info_t *di;
38 
39 	if (ilen == 0)
40 		return (FIDO_OK); /* nothing to do */
41 
42 	if (devlist == NULL || olen == NULL)
43 		return (FIDO_ERR_INVALID_ARGUMENT);
44 
45 	for (i = *olen = 0; i < MAX_UHID && *olen < ilen; i++) {
46 		snprintf(path, sizeof(path), "/dev/fido/%zu", i);
47 		if ((fd = fido_hid_unix_open(path)) == -1)
48 			continue;
49 		memset(&udi, 0, sizeof(udi));
50 		if (ioctl(fd, IOCTL_REQ(USB_GET_DEVICEINFO), &udi) == -1) {
51 			fido_log_error(errno, "%s: get device info %s",
52 			    __func__, path);
53 			if (close(fd) == -1)
54 				fido_log_error(errno, "%s: close", __func__);
55 			continue;
56 		}
57 		if (close(fd) == -1)
58 			fido_log_error(errno, "%s: close", __func__);
59 
60 		fido_log_debug("%s: %s: bus = 0x%02x, addr = 0x%02x",
61 		    __func__, path, udi.udi_bus, udi.udi_addr);
62 		fido_log_debug("%s: %s: vendor = \"%s\", product = \"%s\"",
63 		    __func__, path, udi.udi_vendor, udi.udi_product);
64 		fido_log_debug("%s: %s: productNo = 0x%04x, vendorNo = 0x%04x, "
65 		    "releaseNo = 0x%04x", __func__, path, udi.udi_productNo,
66 		    udi.udi_vendorNo, udi.udi_releaseNo);
67 
68 		di = &devlist[*olen];
69 		memset(di, 0, sizeof(*di));
70 		di->io = (fido_dev_io_t) {
71 			fido_hid_open,
72 			fido_hid_close,
73 			fido_hid_read,
74 			fido_hid_write,
75 		};
76 		if ((di->path = strdup(path)) == NULL ||
77 		    (di->manufacturer = strdup(udi.udi_vendor)) == NULL ||
78 		    (di->product = strdup(udi.udi_product)) == NULL) {
79 			free(di->path);
80 			free(di->manufacturer);
81 			free(di->product);
82 			explicit_bzero(di, sizeof(*di));
83 			return FIDO_ERR_INTERNAL;
84 		}
85 		di->vendor_id = (int16_t)udi.udi_vendorNo;
86 		di->product_id = (int16_t)udi.udi_productNo;
87 		(*olen)++;
88 	}
89 
90 	return FIDO_OK;
91 }
92 
93 /*
94  * Workaround for OpenBSD <=6.6-current (as of 201910) bug that loses
95  * sync of DATA0/DATA1 sequence bit across uhid open/close.
96  * Send pings until we get a response - early pings with incorrect
97  * sequence bits will be ignored as duplicate packets by the device.
98  */
99 static int
100 terrible_ping_kludge(struct hid_openbsd *ctx)
101 {
102 	u_char data[256];
103 	int i, n;
104 	struct pollfd pfd;
105 
106 	if (sizeof(data) < ctx->report_out_len + 1)
107 		return -1;
108 	for (i = 0; i < 4; i++) {
109 		memset(data, 0, sizeof(data));
110 		/* broadcast channel ID */
111 		data[1] = 0xff;
112 		data[2] = 0xff;
113 		data[3] = 0xff;
114 		data[4] = 0xff;
115 		/* Ping command */
116 		data[5] = 0x81;
117 		/* One byte ping only, Vasili */
118 		data[6] = 0;
119 		data[7] = 1;
120 		fido_log_debug("%s: send ping %d", __func__, i);
121 		if (fido_hid_write(ctx, data, ctx->report_out_len + 1) == -1)
122 			return -1;
123 		fido_log_debug("%s: wait reply", __func__);
124 		memset(&pfd, 0, sizeof(pfd));
125 		pfd.fd = ctx->fd;
126 		pfd.events = POLLIN;
127 		if ((n = poll(&pfd, 1, 100)) == -1) {
128 			fido_log_error(errno, "%s: poll", __func__);
129 			return -1;
130 		} else if (n == 0) {
131 			fido_log_debug("%s: timed out", __func__);
132 			continue;
133 		}
134 		if (fido_hid_read(ctx, data, ctx->report_out_len, 250) == -1)
135 			return -1;
136 		/*
137 		 * Ping isn't always supported on the broadcast channel,
138 		 * so we might get an error, but we don't care - we're
139 		 * synched now.
140 		 */
141 		fido_log_xxd(data, ctx->report_out_len, "%s: got reply",
142 		    __func__);
143 		return 0;
144 	}
145 	fido_log_debug("%s: no response", __func__);
146 	return -1;
147 }
148 
149 void *
150 fido_hid_open(const char *path)
151 {
152 	struct hid_openbsd *ret = NULL;
153 
154 	if ((ret = calloc(1, sizeof(*ret))) == NULL ||
155 	    (ret->fd = fido_hid_unix_open(path)) == -1) {
156 		free(ret);
157 		return (NULL);
158 	}
159 	ret->report_in_len = ret->report_out_len = CTAP_MAX_REPORT_LEN;
160 	fido_log_debug("%s: inlen = %zu outlen = %zu", __func__,
161 	    ret->report_in_len, ret->report_out_len);
162 
163 	/*
164 	 * OpenBSD (as of 201910) has a bug that causes it to lose
165 	 * track of the DATA0/DATA1 sequence toggle across uhid device
166 	 * open and close. This is a terrible hack to work around it.
167 	 */
168 	if (terrible_ping_kludge(ret) != 0) {
169 		fido_hid_close(ret);
170 		return NULL;
171 	}
172 
173 	return (ret);
174 }
175 
176 void
177 fido_hid_close(void *handle)
178 {
179 	struct hid_openbsd *ctx = (struct hid_openbsd *)handle;
180 
181 	if (close(ctx->fd) == -1)
182 		fido_log_error(errno, "%s: close", __func__);
183 
184 	free(ctx);
185 }
186 
187 int
188 fido_hid_set_sigmask(void *handle, const fido_sigset_t *sigmask)
189 {
190 	struct hid_openbsd *ctx = handle;
191 
192 	ctx->sigmask = *sigmask;
193 	ctx->sigmaskp = &ctx->sigmask;
194 
195 	return (FIDO_OK);
196 }
197 
198 int
199 fido_hid_read(void *handle, unsigned char *buf, size_t len, int ms)
200 {
201 	struct hid_openbsd *ctx = (struct hid_openbsd *)handle;
202 	ssize_t r;
203 
204 	if (len != ctx->report_in_len) {
205 		fido_log_debug("%s: invalid len: got %zu, want %zu", __func__,
206 		    len, ctx->report_in_len);
207 		return (-1);
208 	}
209 
210 	if (fido_hid_unix_wait(ctx->fd, ms, ctx->sigmaskp) < 0) {
211 		fido_log_debug("%s: fd not ready", __func__);
212 		return (-1);
213 	}
214 
215 	if ((r = read(ctx->fd, buf, len)) == -1) {
216 		fido_log_error(errno, "%s: read", __func__);
217 		return (-1);
218 	}
219 
220 	if (r < 0 || (size_t)r != len) {
221 		fido_log_debug("%s: %zd != %zu", __func__, r, len);
222 		return (-1);
223 	}
224 
225 	return ((int)len);
226 }
227 
228 int
229 fido_hid_write(void *handle, const unsigned char *buf, size_t len)
230 {
231 	struct hid_openbsd *ctx = (struct hid_openbsd *)handle;
232 	ssize_t r;
233 
234 	if (len != ctx->report_out_len + 1) {
235 		fido_log_debug("%s: invalid len: got %zu, want %zu", __func__,
236 		    len, ctx->report_out_len);
237 		return (-1);
238 	}
239 
240 	if ((r = write(ctx->fd, buf + 1, len - 1)) == -1) {
241 		fido_log_error(errno, "%s: write", __func__);
242 		return (-1);
243 	}
244 
245 	if (r < 0 || (size_t)r != len - 1) {
246 		fido_log_debug("%s: %zd != %zu", __func__, r, len - 1);
247 		return (-1);
248 	}
249 
250 	return ((int)len);
251 }
252 
253 size_t
254 fido_hid_report_in_len(void *handle)
255 {
256 	struct hid_openbsd *ctx = handle;
257 
258 	return (ctx->report_in_len);
259 }
260 
261 size_t
262 fido_hid_report_out_len(void *handle)
263 {
264 	struct hid_openbsd *ctx = handle;
265 
266 	return (ctx->report_out_len);
267 }
268