aboutsummaryrefslogtreecommitdiffstats
path: root/libavformat/libssh.c
blob: 21474f0f0a59ab95f0f494a50eb28908af67d56b (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
/*
 * Copyright (c) 2013 Lukasz Marek <lukasz.m.luki@gmail.com>
 *
 * This file is part of FFmpeg.
 *
 * FFmpeg is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * FFmpeg is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with FFmpeg; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

#include <fcntl.h>
#define LIBSSH_STATIC
#include <libssh/sftp.h>
#include "libavutil/avstring.h"
#include "libavutil/opt.h"
#include "libavutil/attributes.h"
#include "libavformat/avio.h"
#include "avformat.h"
#include "internal.h"
#include "url.h"

typedef struct {
    const AVClass *class;
    ssh_session session;
    sftp_session sftp;
    sftp_file file;
    sftp_dir dir;
    int64_t filesize;
    int rw_timeout;
    int trunc;
    char *priv_key;
} LIBSSHContext;

static av_cold int libssh_create_ssh_session(LIBSSHContext *libssh, const char* hostname, unsigned int port)
{
    static const int verbosity = SSH_LOG_NOLOG;

    if (!(libssh->session = ssh_new())) {
        av_log(libssh, AV_LOG_ERROR, "SSH session creation failed: %s\n", ssh_get_error(libssh->session));
        return AVERROR(ENOMEM);
    }
    ssh_options_set(libssh->session, SSH_OPTIONS_HOST, hostname);
    ssh_options_set(libssh->session, SSH_OPTIONS_PORT, &port);
    ssh_options_set(libssh->session, SSH_OPTIONS_LOG_VERBOSITY, &verbosity);
    if (libssh->rw_timeout > 0) {
        long timeout = libssh->rw_timeout * 1000;
        ssh_options_set(libssh->session, SSH_OPTIONS_TIMEOUT_USEC, &timeout);
    }

    if (ssh_options_parse_config(libssh->session, NULL) < 0) {
        av_log(libssh, AV_LOG_WARNING, "Could not parse the config file.\n");
    }

    if (ssh_connect(libssh->session) != SSH_OK) {
        av_log(libssh, AV_LOG_ERROR, "Connection failed: %s\n", ssh_get_error(libssh->session));
        return AVERROR(EIO);
    }

    return 0;
}

static av_cold int libssh_authentication(LIBSSHContext *libssh, const char *user, const char *password)
{
    int authorized = 0;
    int auth_methods;

    if (user)
        ssh_options_set(libssh->session, SSH_OPTIONS_USER, user);

    if (ssh_userauth_none(libssh->session, NULL) == SSH_AUTH_SUCCESS)
        return 0;

    auth_methods = ssh_userauth_list(libssh->session, NULL);

    if (auth_methods & SSH_AUTH_METHOD_PUBLICKEY) {
        if (libssh->priv_key) {
            ssh_string pub_key;
            ssh_private_key priv_key;
            int type;
            if (!ssh_try_publickey_from_file(libssh->session, libssh->priv_key, &pub_key, &type)) {
                priv_key = privatekey_from_file(libssh->session, libssh->priv_key, type, password);
                if (ssh_userauth_pubkey(libssh->session, NULL, pub_key, priv_key) == SSH_AUTH_SUCCESS) {
                    av_log(libssh, AV_LOG_DEBUG, "Authentication successful with selected private key.\n");
                    authorized = 1;
                }
            } else {
                av_log(libssh, AV_LOG_DEBUG, "Invalid key is provided.\n");
                return AVERROR(EACCES);
            }
        } else if (ssh_userauth_autopubkey(libssh->session, password) == SSH_AUTH_SUCCESS) {
            av_log(libssh, AV_LOG_DEBUG, "Authentication successful with auto selected key.\n");
            authorized = 1;
        }
    }

    if (!authorized && password && (auth_methods & SSH_AUTH_METHOD_PASSWORD)) {
        if (ssh_userauth_password(libssh->session, NULL, password) == SSH_AUTH_SUCCESS) {
            av_log(libssh, AV_LOG_DEBUG, "Authentication successful with password.\n");
            authorized = 1;
        }
    }

    if (!authorized) {
        av_log(libssh, AV_LOG_ERROR, "Authentication failed.\n");
        return AVERROR(EACCES);
    }

    return 0;
}

static av_cold int libssh_create_sftp_session(LIBSSHContext *libssh)
{
    if (!(libssh->sftp = sftp_new(libssh->session))) {
        av_log(libssh, AV_LOG_ERROR, "SFTP session creation failed: %s\n", ssh_get_error(libssh->session));
        return AVERROR(ENOMEM);
    }

    if (sftp_init(libssh->sftp) != SSH_OK) {
        av_log(libssh, AV_LOG_ERROR, "Error initializing sftp session: %s\n", ssh_get_error(libssh->session));
        return AVERROR(EIO);
    }

    return 0;
}

static av_cold int libssh_open_file(LIBSSHContext *libssh, int flags, const char *file)
{
    int access;

    if ((flags & AVIO_FLAG_WRITE) && (flags & AVIO_FLAG_READ)) {
        access = O_CREAT | O_RDWR;
        if (libssh->trunc)
            access |= O_TRUNC;
    } else if (flags & AVIO_FLAG_WRITE) {
        access = O_CREAT | O_WRONLY;
        if (libssh->trunc)
            access |= O_TRUNC;
    } else
        access = O_RDONLY;

    /* 0666 = -rw-rw-rw- = read+write for everyone, minus umask */
    if (!(libssh->file = sftp_open(libssh->sftp, file, access, 0666))) {
        av_log(libssh, AV_LOG_ERROR, "Error opening sftp file: %s\n", ssh_get_error(libssh->session));
        return AVERROR(EIO);
    }

    return 0;
}

static av_cold void libssh_stat_file(LIBSSHContext *libssh)
{
    sftp_attributes stat;

    if (!(stat = sftp_fstat(libssh->file))) {
        av_log(libssh, AV_LOG_WARNING, "Cannot stat remote file.\n");
        libssh->filesize = -1;
    } else {
        libssh->filesize = stat->size;
        sftp_attributes_free(stat);
    }
}

static av_cold int libssh_close(URLContext *h)
{
    LIBSSHContext *libssh = h->priv_data;
    if (libssh->file) {
        sftp_close(libssh->file);
        libssh->file = NULL;
    }
    if (libssh->sftp) {
        sftp_free(libssh->sftp);
        libssh->sftp = NULL;
    }
    if (libssh->session) {
        ssh_disconnect(libssh->session);
        ssh_free(libssh->session);
        libssh->session = NULL;
    }
    return 0;
}

static av_cold int libssh_connect(URLContext *h, const char *url, char *path, size_t path_size)
{
    LIBSSHContext *libssh = h->priv_data;
    char proto[10], hostname[1024], credencials[1024];
    int port = 22, ret;
    const char *user = NULL, *pass = NULL;
    char *end = NULL;

    av_url_split(proto, sizeof(proto),
                 credencials, sizeof(credencials),
                 hostname, sizeof(hostname),
                 &port,
                 path, path_size,
                 url);

    if (!(*path))
        av_strlcpy(path, "/", path_size);

    // a port of 0 will use a port from ~/.ssh/config or the default value 22
    if (port < 0 || port > 65535)
        port = 0;

    if ((ret = libssh_create_ssh_session(libssh, hostname, port)) < 0)
        return ret;

    user = av_strtok(credencials, ":", &end);
    pass = av_strtok(end, ":", &end);

    if ((ret = libssh_authentication(libssh, user, pass)) < 0)
        return ret;

    if ((ret = libssh_create_sftp_session(libssh)) < 0)
        return ret;

    return 0;
}

static av_cold int libssh_open(URLContext *h, const char *url, int flags)
{
    int ret;
    LIBSSHContext *libssh = h->priv_data;
    char path[MAX_URL_SIZE];

    if ((ret = libssh_connect(h, url, path, sizeof(path))) < 0)
        goto fail;

    if ((ret = libssh_open_file(libssh, flags, path)) < 0)
        goto fail;

    libssh_stat_file(libssh);

    return 0;

  fail:
    libssh_close(h);
    return ret;
}

static int64_t libssh_seek(URLContext *h, int64_t pos, int whence)
{
    LIBSSHContext *libssh = h->priv_data;
    int64_t newpos;

    if (libssh->filesize == -1 && (whence == AVSEEK_SIZE || whence == SEEK_END)) {
        av_log(h, AV_LOG_ERROR, "Error during seeking.\n");
        return AVERROR(EIO);
    }

    switch(whence) {
    case AVSEEK_SIZE:
        return libssh->filesize;
    case SEEK_SET:
        newpos = pos;
        break;
    case SEEK_CUR:
        newpos = sftp_tell64(libssh->file) + pos;
        break;
    case SEEK_END:
        newpos = libssh->filesize + pos;
        break;
    default:
        return AVERROR(EINVAL);
    }

    if (newpos < 0) {
        av_log(h, AV_LOG_ERROR, "Seeking to nagative position.\n");
        return AVERROR(EINVAL);
    }

    if (sftp_seek64(libssh->file, newpos)) {
        av_log(h, AV_LOG_ERROR, "Error during seeking.\n");
        return AVERROR(EIO);
    }

    return newpos;
}

static int libssh_read(URLContext *h, unsigned char *buf, int size)
{
    LIBSSHContext *libssh = h->priv_data;
    int bytes_read;

    if ((bytes_read = sftp_read(libssh->file, buf, size)) < 0) {
        av_log(libssh, AV_LOG_ERROR, "Read error.\n");
        return AVERROR(EIO);
    }
    return bytes_read ? bytes_read : AVERROR_EOF;
}

static int libssh_write(URLContext *h, const unsigned char *buf, int size)
{
    LIBSSHContext *libssh = h->priv_data;
    int bytes_written;

    if ((bytes_written = sftp_write(libssh->file, buf, size)) < 0) {
        av_log(libssh, AV_LOG_ERROR, "Write error.\n");
        return AVERROR(EIO);
    }
    return bytes_written;
}

static int libssh_open_dir(URLContext *h)
{
    LIBSSHContext *libssh = h->priv_data;
    int ret;
    char path[MAX_URL_SIZE];

    if ((ret = libssh_connect(h, h->filename, path, sizeof(path))) < 0)
        goto fail;

    if (!(libssh->dir = sftp_opendir(libssh->sftp, path))) {
        av_log(libssh, AV_LOG_ERROR, "Error opening sftp dir: %s\n", ssh_get_error(libssh->session));
        ret = AVERROR(EIO);
        goto fail;
    }

    return 0;

  fail:
    libssh_close(h);
    return ret;
}

static int libssh_read_dir(URLContext *h, AVIODirEntry **next)
{
    LIBSSHContext *libssh = h->priv_data;
    sftp_attributes attr = NULL;
    AVIODirEntry *entry;

    *next = entry = ff_alloc_dir_entry();
    if (!entry)
        return AVERROR(ENOMEM);

    do {
        if (attr)
            sftp_attributes_free(attr);
        attr = sftp_readdir(libssh->sftp, libssh->dir);
        if (!attr) {
            av_freep(next);
            if (sftp_dir_eof(libssh->dir))
                return 0;
            return AVERROR(EIO);
        }
    } while (!strcmp(attr->name, ".") || !strcmp(attr->name, ".."));

    entry->name = av_strdup(attr->name);
    entry->group_id = attr->gid;
    entry->user_id = attr->uid;
    entry->size = attr->size;
    entry->access_timestamp = INT64_C(1000000) * attr->atime;
    entry->modification_timestamp = INT64_C(1000000) * attr->mtime;
    entry->filemode = attr->permissions & 0777;
    switch(attr->type) {
    case SSH_FILEXFER_TYPE_REGULAR:
        entry->type = AVIO_ENTRY_FILE;
        break;
    case SSH_FILEXFER_TYPE_DIRECTORY:
        entry->type = AVIO_ENTRY_DIRECTORY;
        break;
    case SSH_FILEXFER_TYPE_SYMLINK:
        entry->type = AVIO_ENTRY_SYMBOLIC_LINK;
        break;
    case SSH_FILEXFER_TYPE_SPECIAL:
        /* Special type includes: sockets, char devices, block devices and pipes.
           It is probably better to return unknown type, to not confuse anybody. */
    case SSH_FILEXFER_TYPE_UNKNOWN:
    default:
        entry->type = AVIO_ENTRY_UNKNOWN;
    }
    sftp_attributes_free(attr);
    return 0;
}

static int libssh_close_dir(URLContext *h)
{
    LIBSSHContext *libssh = h->priv_data;
    if (libssh->dir)
        sftp_closedir(libssh->dir);
    libssh->dir = NULL;
    libssh_close(h);
    return 0;
}

static int libssh_delete(URLContext *h)
{
    int ret;
    LIBSSHContext *libssh = h->priv_data;
    sftp_attributes attr = NULL;
    char path[MAX_URL_SIZE];

    if ((ret = libssh_connect(h, h->filename, path, sizeof(path))) < 0)
        goto cleanup;

    if (!(attr = sftp_stat(libssh->sftp, path))) {
        ret = AVERROR(sftp_get_error(libssh->sftp));
        goto cleanup;
    }

    if (attr->type == SSH_FILEXFER_TYPE_DIRECTORY) {
        if (sftp_rmdir(libssh->sftp, path) < 0) {
            ret = AVERROR(sftp_get_error(libssh->sftp));
            goto cleanup;
        }
    } else {
        if (sftp_unlink(libssh->sftp, path) < 0) {
            ret = AVERROR(sftp_get_error(libssh->sftp));
            goto cleanup;
        }
    }

    ret = 0;

cleanup:
    if (attr)
        sftp_attributes_free(attr);
    libssh_close(h);
    return ret;
}

static int libssh_move(URLContext *h_src, URLContext *h_dst)
{
    int ret;
    LIBSSHContext *libssh = h_src->priv_data;
    char path_src[MAX_URL_SIZE], path_dst[MAX_URL_SIZE];
    char hostname_src[1024], hostname_dst[1024];
    char credentials_src[1024], credentials_dst[1024];
    int port_src = 22, port_dst = 22;

    av_url_split(NULL, 0,
                 credentials_src, sizeof(credentials_src),
                 hostname_src, sizeof(hostname_src),
                 &port_src,
                 path_src, sizeof(path_src),
                 h_src->filename);

    av_url_split(NULL, 0,
                 credentials_dst, sizeof(credentials_dst),
                 hostname_dst, sizeof(hostname_dst),
                 &port_dst,
                 path_dst, sizeof(path_dst),
                 h_dst->filename);

    if (strcmp(credentials_src, credentials_dst) ||
            strcmp(hostname_src, hostname_dst) ||
            port_src != port_dst) {
        return AVERROR(EINVAL);
    }

    if ((ret = libssh_connect(h_src, h_src->filename, path_src, sizeof(path_src))) < 0)
        goto cleanup;

    if (sftp_rename(libssh->sftp, path_src, path_dst) < 0) {
        ret = AVERROR(sftp_get_error(libssh->sftp));
        goto cleanup;
    }

    ret = 0;

cleanup:
    libssh_close(h_src);
    return ret;
}

#define OFFSET(x) offsetof(LIBSSHContext, x)
#define D AV_OPT_FLAG_DECODING_PARAM
#define E AV_OPT_FLAG_ENCODING_PARAM
static const AVOption options[] = {
    {"timeout", "set timeout of socket I/O operations", OFFSET(rw_timeout), AV_OPT_TYPE_INT, {.i64 = -1}, -1, INT_MAX, D|E },
    {"truncate", "Truncate existing files on write", OFFSET(trunc), AV_OPT_TYPE_INT, { .i64 = 1 }, 0, 1, E },
    {"private_key", "set path to private key", OFFSET(priv_key), AV_OPT_TYPE_STRING, { .str = NULL }, 0, 0, D|E },
    {NULL}
};

static const AVClass libssh_context_class = {
    .class_name     = "libssh",
    .item_name      = av_default_item_name,
    .option         = options,
    .version        = LIBAVUTIL_VERSION_INT,
};

const URLProtocol ff_libssh_protocol = {
    .name                = "sftp",
    .url_open            = libssh_open,
    .url_read            = libssh_read,
    .url_write           = libssh_write,
    .url_seek            = libssh_seek,
    .url_close           = libssh_close,
    .url_delete          = libssh_delete,
    .url_move            = libssh_move,
    .url_open_dir        = libssh_open_dir,
    .url_read_dir        = libssh_read_dir,
    .url_close_dir       = libssh_close_dir,
    .priv_data_size      = sizeof(LIBSSHContext),
    .priv_data_class     = &libssh_context_class,
    .flags               = URL_PROTOCOL_FLAG_NETWORK,
};