xref: /freebsd/contrib/libfido2/src/hid_openbsd.c (revision 18054d0220cfc8df9c9568c437bd6fbb59d53c3c)
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 };
27 
28 int
29 fido_hid_manifest(fido_dev_info_t *devlist, size_t ilen, size_t *olen)
30 {
31 	size_t i;
32 	char path[64];
33 	int fd;
34 	struct usb_device_info udi;
35 	fido_dev_info_t *di;
36 
37 	if (ilen == 0)
38 		return (FIDO_OK); /* nothing to do */
39 
40 	if (devlist == NULL || olen == NULL)
41 		return (FIDO_ERR_INVALID_ARGUMENT);
42 
43 	for (i = *olen = 0; i < MAX_UHID && *olen < ilen; i++) {
44 		snprintf(path, sizeof(path), "/dev/fido/%zu", i);
45 		if ((fd = fido_hid_unix_open(path)) == -1)
46 			continue;
47 		memset(&udi, 0, sizeof(udi));
48 		if (ioctl(fd, IOCTL_REQ(USB_GET_DEVICEINFO), &udi) == -1) {
49 			fido_log_error(errno, "%s: get device info %s",
50 			    __func__, path);
51 			if (close(fd) == -1)
52 				fido_log_error(errno, "%s: close", __func__);
53 			continue;
54 		}
55 		if (close(fd) == -1)
56 			fido_log_error(errno, "%s: close", __func__);
57 
58 		fido_log_debug("%s: %s: bus = 0x%02x, addr = 0x%02x",
59 		    __func__, path, udi.udi_bus, udi.udi_addr);
60 		fido_log_debug("%s: %s: vendor = \"%s\", product = \"%s\"",
61 		    __func__, path, udi.udi_vendor, udi.udi_product);
62 		fido_log_debug("%s: %s: productNo = 0x%04x, vendorNo = 0x%04x, "
63 		    "releaseNo = 0x%04x", __func__, path, udi.udi_productNo,
64 		    udi.udi_vendorNo, udi.udi_releaseNo);
65 
66 		di = &devlist[*olen];
67 		memset(di, 0, sizeof(*di));
68 		di->io = (fido_dev_io_t) {
69 			fido_hid_open,
70 			fido_hid_close,
71 			fido_hid_read,
72 			fido_hid_write,
73 		};
74 		if ((di->path = strdup(path)) == NULL ||
75 		    (di->manufacturer = strdup(udi.udi_vendor)) == NULL ||
76 		    (di->product = strdup(udi.udi_product)) == NULL) {
77 			free(di->path);
78 			free(di->manufacturer);
79 			free(di->product);
80 			explicit_bzero(di, sizeof(*di));
81 			return FIDO_ERR_INTERNAL;
82 		}
83 		di->vendor_id = (int16_t)udi.udi_vendorNo;
84 		di->product_id = (int16_t)udi.udi_productNo;
85 		(*olen)++;
86 	}
87 
88 	return FIDO_OK;
89 }
90 
91 /*
92  * Workaround for OpenBSD <=6.6-current (as of 201910) bug that loses
93  * sync of DATA0/DATA1 sequence bit across uhid open/close.
94  * Send pings until we get a response - early pings with incorrect
95  * sequence bits will be ignored as duplicate packets by the device.
96  */
97 static int
98 terrible_ping_kludge(struct hid_openbsd *ctx)
99 {
100 	u_char data[256];
101 	int i, n;
102 	struct pollfd pfd;
103 
104 	if (sizeof(data) < ctx->report_out_len + 1)
105 		return -1;
106 	for (i = 0; i < 4; i++) {
107 		memset(data, 0, sizeof(data));
108 		/* broadcast channel ID */
109 		data[1] = 0xff;
110 		data[2] = 0xff;
111 		data[3] = 0xff;
112 		data[4] = 0xff;
113 		/* Ping command */
114 		data[5] = 0x81;
115 		/* One byte ping only, Vasili */
116 		data[6] = 0;
117 		data[7] = 1;
118 		fido_log_debug("%s: send ping %d", __func__, i);
119 		if (fido_hid_write(ctx, data, ctx->report_out_len + 1) == -1)
120 			return -1;
121 		fido_log_debug("%s: wait reply", __func__);
122 		memset(&pfd, 0, sizeof(pfd));
123 		pfd.fd = ctx->fd;
124 		pfd.events = POLLIN;
125 		if ((n = poll(&pfd, 1, 100)) == -1) {
126 			fido_log_error(errno, "%s: poll", __func__);
127 			return -1;
128 		} else if (n == 0) {
129 			fido_log_debug("%s: timed out", __func__);
130 			continue;
131 		}
132 		if (fido_hid_read(ctx, data, ctx->report_out_len, 250) == -1)
133 			return -1;
134 		/*
135 		 * Ping isn't always supported on the broadcast channel,
136 		 * so we might get an error, but we don't care - we're
137 		 * synched now.
138 		 */
139 		fido_log_xxd(data, ctx->report_out_len, "%s: got reply",
140 		    __func__);
141 		return 0;
142 	}
143 	fido_log_debug("%s: no response", __func__);
144 	return -1;
145 }
146 
147 void *
148 fido_hid_open(const char *path)
149 {
150 	struct hid_openbsd *ret = NULL;
151 
152 	if ((ret = calloc(1, sizeof(*ret))) == NULL ||
153 	    (ret->fd = fido_hid_unix_open(path)) == -1) {
154 		free(ret);
155 		return (NULL);
156 	}
157 	ret->report_in_len = ret->report_out_len = CTAP_MAX_REPORT_LEN;
158 	fido_log_debug("%s: inlen = %zu outlen = %zu", __func__,
159 	    ret->report_in_len, ret->report_out_len);
160 
161 	/*
162 	 * OpenBSD (as of 201910) has a bug that causes it to lose
163 	 * track of the DATA0/DATA1 sequence toggle across uhid device
164 	 * open and close. This is a terrible hack to work around it.
165 	 */
166 	if (terrible_ping_kludge(ret) != 0) {
167 		fido_hid_close(ret);
168 		return NULL;
169 	}
170 
171 	return (ret);
172 }
173 
174 void
175 fido_hid_close(void *handle)
176 {
177 	struct hid_openbsd *ctx = (struct hid_openbsd *)handle;
178 
179 	if (close(ctx->fd) == -1)
180 		fido_log_error(errno, "%s: close", __func__);
181 
182 	free(ctx);
183 }
184 
185 int
186 fido_hid_set_sigmask(void *handle, const fido_sigset_t *sigmask)
187 {
188 	(void)handle;
189 	(void)sigmask;
190 
191 	return (FIDO_ERR_INTERNAL);
192 }
193 
194 int
195 fido_hid_read(void *handle, unsigned char *buf, size_t len, int ms)
196 {
197 	struct hid_openbsd *ctx = (struct hid_openbsd *)handle;
198 	ssize_t r;
199 
200 	(void)ms; /* XXX */
201 
202 	if (len != ctx->report_in_len) {
203 		fido_log_debug("%s: invalid len: got %zu, want %zu", __func__,
204 		    len, ctx->report_in_len);
205 		return (-1);
206 	}
207 
208 	if ((r = read(ctx->fd, buf, len)) == -1) {
209 		fido_log_error(errno, "%s: read", __func__);
210 		return (-1);
211 	}
212 
213 	if (r < 0 || (size_t)r != len) {
214 		fido_log_debug("%s: %zd != %zu", __func__, r, len);
215 		return (-1);
216 	}
217 
218 	return ((int)len);
219 }
220 
221 int
222 fido_hid_write(void *handle, const unsigned char *buf, size_t len)
223 {
224 	struct hid_openbsd *ctx = (struct hid_openbsd *)handle;
225 	ssize_t r;
226 
227 	if (len != ctx->report_out_len + 1) {
228 		fido_log_debug("%s: invalid len: got %zu, want %zu", __func__,
229 		    len, ctx->report_out_len);
230 		return (-1);
231 	}
232 
233 	if ((r = write(ctx->fd, buf + 1, len - 1)) == -1) {
234 		fido_log_error(errno, "%s: write", __func__);
235 		return (-1);
236 	}
237 
238 	if (r < 0 || (size_t)r != len - 1) {
239 		fido_log_debug("%s: %zd != %zu", __func__, r, len - 1);
240 		return (-1);
241 	}
242 
243 	return ((int)len);
244 }
245 
246 size_t
247 fido_hid_report_in_len(void *handle)
248 {
249 	struct hid_openbsd *ctx = handle;
250 
251 	return (ctx->report_in_len);
252 }
253 
254 size_t
255 fido_hid_report_out_len(void *handle)
256 {
257 	struct hid_openbsd *ctx = handle;
258 
259 	return (ctx->report_out_len);
260 }
261