Coverage Report

Created: 2024-06-03 09:43

/libfido2/src/nfc_linux.c
Line
Count
Source (jump to first uncovered line)
1
/*
2
 * Copyright (c) 2020-2022 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/uio.h>
10
#include <sys/socket.h>
11
12
#include <linux/nfc.h>
13
14
#include <errno.h>
15
#include <libudev.h>
16
#include <signal.h>
17
#include <stdio.h>
18
#include <string.h>
19
#include <unistd.h>
20
21
#include "fido.h"
22
#include "fido/param.h"
23
#include "netlink.h"
24
#include "iso7816.h"
25
26
struct nfc_linux {
27
        int             fd;
28
        uint32_t        dev;
29
        uint32_t        target;
30
        sigset_t        sigmask;
31
        const sigset_t *sigmaskp;
32
        struct fido_nl *nl;
33
};
34
35
static char *
36
get_parent_attr(struct udev_device *dev, const char *subsystem,
37
    const char *devtype, const char *attr)
38
0
{
39
0
        struct udev_device *parent;
40
0
        const char *value;
41
42
0
        if ((parent = udev_device_get_parent_with_subsystem_devtype(dev,
43
0
            subsystem, devtype)) == NULL || (value =
44
0
            udev_device_get_sysattr_value(parent, attr)) == NULL)
45
0
                return NULL;
46
47
0
        return strdup(value);
48
0
}
49
50
static char *
51
get_usb_attr(struct udev_device *dev, const char *attr)
52
0
{
53
0
        return get_parent_attr(dev, "usb", "usb_device", attr);
54
0
}
55
56
static int
57
copy_info(fido_dev_info_t *di, struct udev *udev,
58
    struct udev_list_entry *udev_entry)
59
740k
{
60
740k
        const char *name;
61
740k
        char *str;
62
740k
        struct udev_device *dev = NULL;
63
740k
        uint64_t id;
64
740k
        int ok = -1;
65
66
740k
        memset(di, 0, sizeof(*di));
67
68
740k
        if ((name = udev_list_entry_get_name(udev_entry)) == NULL ||
69
740k
            (dev = udev_device_new_from_syspath(udev, name)) == NULL)
70
3.71k
                goto fail;
71
737k
        if (asprintf(&di->path, "%s/%s", FIDO_NFC_PREFIX, name) == -1) {
72
1.88k
                di->path = NULL;
73
1.88k
                goto fail;
74
1.88k
        }
75
735k
        if (nfc_is_fido(di->path) == false) {
76
735k
                fido_log_debug("%s: nfc_is_fido: %s", __func__, di->path);
77
735k
                goto fail;
78
735k
        }
79
0
        if ((di->manufacturer = get_usb_attr(dev, "manufacturer")) == NULL)
80
0
                di->manufacturer = strdup("");
81
0
        if ((di->product = get_usb_attr(dev, "product")) == NULL)
82
0
                di->product = strdup("");
83
0
        if (di->manufacturer == NULL || di->product == NULL)
84
0
                goto fail;
85
        /* XXX assumes USB for vendor/product info */
86
0
        if ((str = get_usb_attr(dev, "idVendor")) != NULL &&
87
0
            fido_to_uint64(str, 16, &id) == 0 && id <= UINT16_MAX)
88
0
                di->vendor_id = (int16_t)id;
89
0
        free(str);
90
0
        if ((str = get_usb_attr(dev, "idProduct")) != NULL &&
91
0
            fido_to_uint64(str, 16, &id) == 0 && id <= UINT16_MAX)
92
0
                di->product_id = (int16_t)id;
93
0
        free(str);
94
95
0
        ok = 0;
96
740k
fail:
97
740k
        if (dev != NULL)
98
737k
                udev_device_unref(dev);
99
100
740k
        if (ok < 0) {
101
740k
                free(di->path);
102
740k
                free(di->manufacturer);
103
740k
                free(di->product);
104
740k
                explicit_bzero(di, sizeof(*di));
105
740k
        }
106
107
740k
        return ok;
108
0
}
109
110
static int
111
sysnum_from_syspath(const char *path)
112
731k
{
113
731k
        struct udev *udev = NULL;
114
731k
        struct udev_device *dev = NULL;
115
731k
        const char *str;
116
731k
        uint64_t idx64;
117
731k
        int idx = -1;
118
119
731k
        if ((udev = udev_new()) != NULL &&
120
731k
            (dev = udev_device_new_from_syspath(udev, path)) != NULL &&
121
731k
            (str = udev_device_get_sysnum(dev)) != NULL &&
122
731k
            fido_to_uint64(str, 10, &idx64) == 0 && idx64 < INT_MAX)
123
726k
                idx = (int)idx64;
124
125
731k
        if (dev != NULL)
126
727k
                udev_device_unref(dev);
127
731k
        if (udev != NULL)
128
729k
                udev_unref(udev);
129
130
731k
        return idx;
131
731k
}
132
133
int
134
fido_nfc_manifest(fido_dev_info_t *devlist, size_t ilen, size_t *olen)
135
1.60k
{
136
1.60k
        struct udev *udev = NULL;
137
1.60k
        struct udev_enumerate *udev_enum = NULL;
138
1.60k
        struct udev_list_entry *udev_list;
139
1.60k
        struct udev_list_entry *udev_entry;
140
1.60k
        int r = FIDO_ERR_INTERNAL;
141
142
1.60k
        *olen = 0;
143
144
1.60k
        if (ilen == 0)
145
0
                return FIDO_OK;
146
147
1.60k
        if (devlist == NULL)
148
0
                return FIDO_ERR_INVALID_ARGUMENT;
149
150
1.60k
        if ((udev = udev_new()) == NULL ||
151
1.60k
            (udev_enum = udev_enumerate_new(udev)) == NULL)
152
9
                goto fail;
153
154
1.59k
        if (udev_enumerate_add_match_subsystem(udev_enum, "nfc") < 0 ||
155
1.59k
            udev_enumerate_scan_devices(udev_enum) < 0)
156
6
                goto fail;
157
158
1.59k
        if ((udev_list = udev_enumerate_get_list_entry(udev_enum)) == NULL) {
159
2
                r = FIDO_OK; /* zero nfc devices */
160
2
                goto fail;
161
2
        }
162
163
740k
        udev_list_entry_foreach(udev_entry, udev_list) {
164
740k
                if (copy_info(&devlist[*olen], udev, udev_entry) == 0) {
165
0
                        devlist[*olen].io = (fido_dev_io_t) {
166
0
                                fido_nfc_open,
167
0
                                fido_nfc_close,
168
0
                                fido_nfc_read,
169
0
                                fido_nfc_write,
170
0
                        };
171
0
                        devlist[*olen].transport = (fido_dev_transport_t) {
172
0
                                fido_nfc_rx,
173
0
                                fido_nfc_tx,
174
0
                        };
175
0
                        if (++(*olen) == ilen)
176
0
                                break;
177
0
                }
178
740k
        }
179
180
1.58k
        r = FIDO_OK;
181
1.60k
fail:
182
1.60k
        if (udev_enum != NULL)
183
1.59k
                udev_enumerate_unref(udev_enum);
184
1.60k
        if (udev != NULL)
185
1.60k
                udev_unref(udev);
186
187
1.60k
        return r;
188
1.58k
}
189
190
static int
191
nfc_target_connect(struct nfc_linux *ctx)
192
2
{
193
2
        struct sockaddr_nfc sa;
194
195
2
        memset(&sa, 0, sizeof(sa));
196
2
        sa.sa_family = AF_NFC;
197
2
        sa.dev_idx = ctx->dev;
198
2
        sa.target_idx = ctx->target;
199
2
        sa.nfc_protocol = NFC_PROTO_ISO14443;
200
201
2
        if ((ctx->fd = socket(AF_NFC, SOCK_SEQPACKET | SOCK_CLOEXEC,
202
2
            NFC_SOCKPROTO_RAW)) == -1) {
203
2
                fido_log_error(errno, "%s: socket", __func__);
204
2
                return -1;
205
2
        }
206
0
        if (connect(ctx->fd, (struct sockaddr *)&sa, sizeof(sa)) == -1) {
207
0
                fido_log_error(errno, "%s: connect", __func__);
208
0
                if (close(ctx->fd) == -1)
209
0
                        fido_log_error(errno, "%s: close", __func__);
210
0
                ctx->fd = -1;
211
0
                return -1;
212
0
        }
213
214
0
        return 0;
215
0
}
216
217
static void
218
nfc_free(struct nfc_linux **ctx_p)
219
1.45M
{
220
1.45M
        struct nfc_linux *ctx;
221
222
1.45M
        if (ctx_p == NULL || (ctx = *ctx_p) == NULL)
223
732k
                return;
224
724k
        if (ctx->fd != -1 && close(ctx->fd) == -1)
225
723k
                fido_log_error(errno, "%s: close", __func__);
226
724k
        if (ctx->nl != NULL)
227
441
                fido_nl_free(&ctx->nl);
228
229
724k
        free(ctx);
230
724k
        *ctx_p = NULL;
231
724k
}
232
233
static struct nfc_linux *
234
nfc_new(uint32_t dev)
235
726k
{
236
726k
        struct nfc_linux *ctx;
237
238
726k
        if ((ctx = calloc(1, sizeof(*ctx))) == NULL ||
239
726k
            (ctx->nl = fido_nl_new()) == NULL) {
240
725k
                nfc_free(&ctx);
241
725k
                return NULL;
242
725k
        }
243
244
441
        ctx->fd = -1;
245
441
        ctx->dev = dev;
246
247
441
        return ctx;
248
726k
}
249
250
void *
251
fido_nfc_open(const char *path)
252
731k
{
253
731k
        struct nfc_linux *ctx = NULL;
254
731k
        int idx;
255
256
731k
        if (strncmp(path, FIDO_NFC_PREFIX, strlen(FIDO_NFC_PREFIX)) != 0) {
257
0
                fido_log_debug("%s: bad prefix", __func__);
258
0
                goto fail;
259
0
        }
260
731k
        if ((idx = sysnum_from_syspath(path + strlen(FIDO_NFC_PREFIX))) < 0 ||
261
731k
            (ctx = nfc_new((uint32_t)idx)) == NULL) {
262
731k
                fido_log_debug("%s: nfc_new", __func__);
263
731k
                goto fail;
264
731k
        }
265
441
        if (fido_nl_power_nfc(ctx->nl, ctx->dev) < 0 ||
266
441
            fido_nl_get_nfc_target(ctx->nl, ctx->dev, &ctx->target) < 0 ||
267
441
            nfc_target_connect(ctx) < 0) {
268
441
                fido_log_debug("%s: netlink", __func__);
269
441
                goto fail;
270
441
        }
271
272
0
        return ctx;
273
731k
fail:
274
731k
        nfc_free(&ctx);
275
731k
        return NULL;
276
441
}
277
278
void
279
fido_nfc_close(void *handle)
280
0
{
281
0
        struct nfc_linux *ctx = handle;
282
283
0
        nfc_free(&ctx);
284
0
}
285
286
int
287
fido_nfc_set_sigmask(void *handle, const fido_sigset_t *sigmask)
288
0
{
289
0
        struct nfc_linux *ctx = handle;
290
291
0
        ctx->sigmask = *sigmask;
292
0
        ctx->sigmaskp = &ctx->sigmask;
293
294
0
        return FIDO_OK;
295
0
}
296
297
int
298
fido_nfc_read(void *handle, unsigned char *buf, size_t len, int ms)
299
0
{
300
0
        struct nfc_linux *ctx = handle;
301
0
        struct iovec iov[2];
302
0
        uint8_t preamble;
303
0
        ssize_t r;
304
305
0
        memset(&iov, 0, sizeof(iov));
306
0
        iov[0].iov_base = &preamble;
307
0
        iov[0].iov_len = sizeof(preamble);
308
0
        iov[1].iov_base = buf;
309
0
        iov[1].iov_len = len;
310
311
0
        if (fido_hid_unix_wait(ctx->fd, ms, ctx->sigmaskp) < 0) {
312
0
                fido_log_debug("%s: fido_hid_unix_wait", __func__);
313
0
                return -1;
314
0
        }
315
0
        if ((r = readv(ctx->fd, iov, nitems(iov))) == -1) {
316
0
                fido_log_error(errno, "%s: read", __func__);
317
0
                return -1;
318
0
        }
319
0
        if (r < 1) {
320
0
                fido_log_debug("%s: %zd < 1", __func__, r);
321
0
                return -1;
322
0
        }
323
0
        if (preamble != 0x00) {
324
0
                fido_log_debug("%s: preamble", __func__);
325
0
                return -1;
326
0
        }
327
328
0
        r--;
329
0
        fido_log_xxd(buf, (size_t)r, "%s", __func__);
330
331
0
        return (int)r;
332
0
}
333
334
int
335
fido_nfc_write(void *handle, const unsigned char *buf, size_t len)
336
0
{
337
0
        struct nfc_linux *ctx = handle;
338
0
        ssize_t r;
339
340
0
        fido_log_xxd(buf, len, "%s", __func__);
341
342
0
        if (len > INT_MAX) {
343
0
                fido_log_debug("%s: len", __func__);
344
0
                return -1;
345
0
        }
346
0
        if ((r = write(ctx->fd, buf, len)) == -1) {
347
0
                fido_log_error(errno, "%s: write", __func__);
348
0
                return -1;
349
0
        }
350
0
        if (r < 0 || (size_t)r != len) {
351
0
                fido_log_debug("%s: %zd != %zu", __func__, r, len);
352
0
                return -1;
353
0
        }
354
355
0
        return (int)r;
356
0
}