libavformat/libssh.c

   1 /*
   2  * Copyright (c) 2013 Lukasz Marek <lukasz.m.luki@gmail.com>
   3  *
   4  * This file is part of FFmpeg.
   5  *
   6  * FFmpeg is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * FFmpeg is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with FFmpeg; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  19  */
  20
  21 #include <fcntl.h>
  22 #define LIBSSH_STATIC
  23 #include <libssh/sftp.h>
  24 #include "libavutil/avstring.h"
  25 #include "libavutil/mem.h"
  26 #include "libavutil/opt.h"
  27 #include "libavutil/attributes.h"
  28 #include "libavformat/avio.h"
  29 #include "avformat.h"
  30 #include "internal.h"
  31 #include "url.h"
  32
  33 typedef struct {
  34     const AVClass *class;
  35     ssh_session session;
  36     sftp_session sftp;
  37     sftp_file file;
  38     sftp_dir dir;
  39     int64_t filesize;
  40     int rw_timeout;
  41     int trunc;
  42     char *priv_key;
  43 } LIBSSHContext;
  44
  45 static av_cold int libssh_create_ssh_session(LIBSSHContext *libssh, const char* hostname, unsigned int port)
  46 {
  47     static const int verbosity = SSH_LOG_NOLOG;
  48
  49     if (!(libssh->session = ssh_new())) {
  50         av_log(libssh, AV_LOG_ERROR, "SSH session creation failed: %s\n", ssh_get_error(libssh->session));
  51         return AVERROR(ENOMEM);
  52     }
  53     ssh_options_set(libssh->session, SSH_OPTIONS_HOST, hostname);
  54     ssh_options_set(libssh->session, SSH_OPTIONS_PORT, &port);
  55     ssh_options_set(libssh->session, SSH_OPTIONS_LOG_VERBOSITY, &verbosity);
  56     if (libssh->rw_timeout > 0) {
  57         long timeout = libssh->rw_timeout * 1000;
  58         ssh_options_set(libssh->session, SSH_OPTIONS_TIMEOUT_USEC, &timeout);
  59     }
  60
  61     if (ssh_options_parse_config(libssh->session, NULL) < 0) {
  62         av_log(libssh, AV_LOG_WARNING, "Could not parse the config file.\n");
  63     }
  64
  65     if (ssh_connect(libssh->session) != SSH_OK) {
  66         av_log(libssh, AV_LOG_ERROR, "Connection failed: %s\n", ssh_get_error(libssh->session));
  67         return AVERROR(EIO);
  68     }
  69
  70     return 0;
  71 }
  72
  73 static av_cold int libssh_authentication(LIBSSHContext *libssh, const char *user, const char *password)
  74 {
  75     int authorized = 0;
  76     int auth_methods;
  77
  78     if (user)
  79         ssh_options_set(libssh->session, SSH_OPTIONS_USER, user);
  80
  81     if (ssh_userauth_none(libssh->session, NULL) == SSH_AUTH_SUCCESS)
  82         return 0;
  83
  84     auth_methods = ssh_userauth_list(libssh->session, NULL);
  85
  86     if (auth_methods & SSH_AUTH_METHOD_PUBLICKEY) {
  87         if (libssh->priv_key) {
  88             ssh_key priv_key;
  89             if (ssh_pki_import_privkey_file(libssh->priv_key, password, NULL, NULL, &priv_key) == SSH_OK) {
  90                 if (ssh_userauth_publickey(libssh->session, NULL, priv_key) == SSH_AUTH_SUCCESS) {
  91                     av_log(libssh, AV_LOG_DEBUG, "Authentication successful with selected private key.\n");
  92                     authorized = 1;
  93                 }
  94             } else {
  95                 av_log(libssh, AV_LOG_DEBUG, "Invalid key is provided.\n");
  96                 return AVERROR(EACCES);
  97             }
  98         } else if (ssh_userauth_publickey_auto(libssh->session, NULL, password) == SSH_AUTH_SUCCESS) {
  99             av_log(libssh, AV_LOG_DEBUG, "Authentication successful with auto selected key.\n");
 100             authorized = 1;
 101         }
 102     }
 103
 104     if (!authorized && password && (auth_methods & SSH_AUTH_METHOD_PASSWORD)) {
 105         if (ssh_userauth_password(libssh->session, NULL, password) == SSH_AUTH_SUCCESS) {
 106             av_log(libssh, AV_LOG_DEBUG, "Authentication successful with password.\n");
 107             authorized = 1;
 108         }
 109     }
 110
 111     if (!authorized) {
 112         av_log(libssh, AV_LOG_ERROR, "Authentication failed.\n");
 113         return AVERROR(EACCES);
 114     }
 115
 116     return 0;
 117 }
 118
 119 static av_cold int libssh_create_sftp_session(LIBSSHContext *libssh)
 120 {
 121     if (!(libssh->sftp = sftp_new(libssh->session))) {
 122         av_log(libssh, AV_LOG_ERROR, "SFTP session creation failed: %s\n", ssh_get_error(libssh->session));
 123         return AVERROR(ENOMEM);
 124     }
 125
 126     if (sftp_init(libssh->sftp) != SSH_OK) {
 127         av_log(libssh, AV_LOG_ERROR, "Error initializing sftp session: %s\n", ssh_get_error(libssh->session));
 128         return AVERROR(EIO);
 129     }
 130
 131     return 0;
 132 }
 133
 134 static av_cold int libssh_open_file(LIBSSHContext *libssh, int flags, const char *file)
 135 {
 136     int access;
 137
 138     if ((flags & AVIO_FLAG_WRITE) && (flags & AVIO_FLAG_READ)) {
 139         access = O_CREAT | O_RDWR;
 140         if (libssh->trunc)
 141             access |= O_TRUNC;
 142     } else if (flags & AVIO_FLAG_WRITE) {
 143         access = O_CREAT | O_WRONLY;
 144         if (libssh->trunc)
 145             access |= O_TRUNC;
 146     } else
 147         access = O_RDONLY;
 148
 149     /* 0666 = -rw-rw-rw- = read+write for everyone, minus umask */
 150     if (!(libssh->file = sftp_open(libssh->sftp, file, access, 0666))) {
 151         av_log(libssh, AV_LOG_ERROR, "Error opening sftp file: %s\n", ssh_get_error(libssh->session));
 152         return AVERROR(EIO);
 153     }
 154
 155     return 0;
 156 }
 157
 158 static av_cold void libssh_stat_file(LIBSSHContext *libssh)
 159 {
 160     sftp_attributes stat;
 161
 162     if (!(stat = sftp_fstat(libssh->file))) {
 163         av_log(libssh, AV_LOG_WARNING, "Cannot stat remote file.\n");
 164         libssh->filesize = -1;
 165     } else {
 166         libssh->filesize = stat->size;
 167         sftp_attributes_free(stat);
 168     }
 169 }
 170
 171 static av_cold int libssh_close(URLContext *h)
 172 {
 173     LIBSSHContext *libssh = h->priv_data;
 174     if (libssh->file) {
 175         sftp_close(libssh->file);
 176         libssh->file = NULL;
 177     }
 178     if (libssh->sftp) {
 179         sftp_free(libssh->sftp);
 180         libssh->sftp = NULL;
 181     }
 182     if (libssh->session) {
 183         ssh_disconnect(libssh->session);
 184         ssh_free(libssh->session);
 185         libssh->session = NULL;
 186     }
 187     return 0;
 188 }
 189
 190 static av_cold int libssh_connect(URLContext *h, const char *url, char *path, size_t path_size)
 191 {
 192     LIBSSHContext *libssh = h->priv_data;
 193     char proto[10], hostname[1024], credentials[1024];
 194     int port = 22, ret;
 195     const char *user = NULL, *pass = NULL;
 196     char *end = NULL;
 197
 198     av_url_split(proto, sizeof(proto),
 199                  credentials, sizeof(credentials),
 200                  hostname, sizeof(hostname),
 201                  &port,
 202                  path, path_size,
 203                  url);
 204
 205     if (!(*path))
 206         av_strlcpy(path, "/", path_size);
 207
 208     // a port of 0 will use a port from ~/.ssh/config or the default value 22
 209     if (port < 0 || port > 65535)
 210         port = 0;
 211
 212     if ((ret = libssh_create_ssh_session(libssh, hostname, port)) < 0)
 213         return ret;
 214
 215     user = av_strtok(credentials, ":", &end);
 216     pass = av_strtok(end, ":", &end);
 217
 218     if ((ret = libssh_authentication(libssh, user, pass)) < 0)
 219         return ret;
 220
 221     if ((ret = libssh_create_sftp_session(libssh)) < 0)
 222         return ret;
 223
 224     return 0;
 225 }
 226
 227 static av_cold int libssh_open(URLContext *h, const char *url, int flags)
 228 {
 229     int ret;
 230     LIBSSHContext *libssh = h->priv_data;
 231     char path[MAX_URL_SIZE];
 232
 233     if ((ret = libssh_connect(h, url, path, sizeof(path))) < 0)
 234         goto fail;
 235
 236     if ((ret = libssh_open_file(libssh, flags, path)) < 0)
 237         goto fail;
 238
 239     libssh_stat_file(libssh);
 240
 241     return 0;
 242
 243   fail:
 244     libssh_close(h);
 245     return ret;
 246 }
 247
 248 static int64_t libssh_seek(URLContext *h, int64_t pos, int whence)
 249 {
 250     LIBSSHContext *libssh = h->priv_data;
 251     int64_t newpos;
 252
 253     if (libssh->filesize == -1 && (whence == AVSEEK_SIZE || whence == SEEK_END)) {
 254         av_log(h, AV_LOG_ERROR, "Error during seeking.\n");
 255         return AVERROR(EIO);
 256     }
 257
 258     switch(whence) {
 259     case AVSEEK_SIZE:
 260         return libssh->filesize;
 261     case SEEK_SET:
 262         newpos = pos;
 263         break;
 264     case SEEK_CUR:
 265         newpos = sftp_tell64(libssh->file) + pos;
 266         break;
 267     case SEEK_END:
 268         newpos = libssh->filesize + pos;
 269         break;
 270     default:
 271         return AVERROR(EINVAL);
 272     }
 273
 274     if (newpos < 0) {
 275         av_log(h, AV_LOG_ERROR, "Seeking to negative position.\n");
 276         return AVERROR(EINVAL);
 277     }
 278
 279     if (sftp_seek64(libssh->file, newpos)) {
 280         av_log(h, AV_LOG_ERROR, "Error during seeking.\n");
 281         return AVERROR(EIO);
 282     }
 283
 284     return newpos;
 285 }
 286
 287 static int libssh_read(URLContext *h, unsigned char *buf, int size)
 288 {
 289     LIBSSHContext *libssh = h->priv_data;
 290     int bytes_read;
 291
 292     if ((bytes_read = sftp_read(libssh->file, buf, size)) < 0) {
 293         av_log(libssh, AV_LOG_ERROR, "Read error.\n");
 294         return AVERROR(EIO);
 295     }
 296     return bytes_read ? bytes_read : AVERROR_EOF;
 297 }
 298
 299 static int libssh_write(URLContext *h, const unsigned char *buf, int size)
 300 {
 301     LIBSSHContext *libssh = h->priv_data;
 302     int bytes_written;
 303
 304     if ((bytes_written = sftp_write(libssh->file, buf, size)) < 0) {
 305         av_log(libssh, AV_LOG_ERROR, "Write error.\n");
 306         return AVERROR(EIO);
 307     }
 308     return bytes_written;
 309 }
 310
 311 static int libssh_open_dir(URLContext *h)
 312 {
 313     LIBSSHContext *libssh = h->priv_data;
 314     int ret;
 315     char path[MAX_URL_SIZE];
 316
 317     if ((ret = libssh_connect(h, h->filename, path, sizeof(path))) < 0)
 318         goto fail;
 319
 320     if (!(libssh->dir = sftp_opendir(libssh->sftp, path))) {
 321         av_log(libssh, AV_LOG_ERROR, "Error opening sftp dir: %s\n", ssh_get_error(libssh->session));
 322         ret = AVERROR(EIO);
 323         goto fail;
 324     }
 325
 326     return 0;
 327
 328   fail:
 329     libssh_close(h);
 330     return ret;
 331 }
 332
 333 static int libssh_read_dir(URLContext *h, AVIODirEntry **next)
 334 {
 335     LIBSSHContext *libssh = h->priv_data;
 336     sftp_attributes attr = NULL;
 337     AVIODirEntry *entry;
 338
 339     *next = entry = ff_alloc_dir_entry();
 340     if (!entry)
 341         return AVERROR(ENOMEM);
 342
 343     do {
 344         if (attr)
 345             sftp_attributes_free(attr);
 346         attr = sftp_readdir(libssh->sftp, libssh->dir);
 347         if (!attr) {
 348             av_freep(next);
 349             if (sftp_dir_eof(libssh->dir))
 350                 return 0;
 351             return AVERROR(EIO);
 352         }
 353     } while (!strcmp(attr->name, ".") || !strcmp(attr->name, ".."));
 354
 355     entry->name = av_strdup(attr->name);
 356     entry->group_id = attr->gid;
 357     entry->user_id = attr->uid;
 358     entry->size = attr->size;
 359     entry->access_timestamp = INT64_C(1000000) * attr->atime;
 360     entry->modification_timestamp = INT64_C(1000000) * attr->mtime;
 361     entry->filemode = attr->permissions & 0777;
 362     switch(attr->type) {
 363     case SSH_FILEXFER_TYPE_REGULAR:
 364         entry->type = AVIO_ENTRY_FILE;
 365         break;
 366     case SSH_FILEXFER_TYPE_DIRECTORY:
 367         entry->type = AVIO_ENTRY_DIRECTORY;
 368         break;
 369     case SSH_FILEXFER_TYPE_SYMLINK:
 370         entry->type = AVIO_ENTRY_SYMBOLIC_LINK;
 371         break;
 372     case SSH_FILEXFER_TYPE_SPECIAL:
 373         /* Special type includes: sockets, char devices, block devices and pipes.
 374            It is probably better to return unknown type, to not confuse anybody. */
 375     case SSH_FILEXFER_TYPE_UNKNOWN:
 376     default:
 377         entry->type = AVIO_ENTRY_UNKNOWN;
 378     }
 379     sftp_attributes_free(attr);
 380     return 0;
 381 }
 382
 383 static int libssh_close_dir(URLContext *h)
 384 {
 385     LIBSSHContext *libssh = h->priv_data;
 386     if (libssh->dir)
 387         sftp_closedir(libssh->dir);
 388     libssh->dir = NULL;
 389     libssh_close(h);
 390     return 0;
 391 }
 392
 393 static int libssh_delete(URLContext *h)
 394 {
 395     int ret;
 396     LIBSSHContext *libssh = h->priv_data;
 397     sftp_attributes attr = NULL;
 398     char path[MAX_URL_SIZE];
 399
 400     if ((ret = libssh_connect(h, h->filename, path, sizeof(path))) < 0)
 401         goto cleanup;
 402
 403     if (!(attr = sftp_stat(libssh->sftp, path))) {
 404         ret = AVERROR(sftp_get_error(libssh->sftp));
 405         goto cleanup;
 406     }
 407
 408     if (attr->type == SSH_FILEXFER_TYPE_DIRECTORY) {
 409         if (sftp_rmdir(libssh->sftp, path) < 0) {
 410             ret = AVERROR(sftp_get_error(libssh->sftp));
 411             goto cleanup;
 412         }
 413     } else {
 414         if (sftp_unlink(libssh->sftp, path) < 0) {
 415             ret = AVERROR(sftp_get_error(libssh->sftp));
 416             goto cleanup;
 417         }
 418     }
 419
 420     ret = 0;
 421
 422 cleanup:
 423     if (attr)
 424         sftp_attributes_free(attr);
 425     libssh_close(h);
 426     return ret;
 427 }
 428
 429 static int libssh_move(URLContext *h_src, URLContext *h_dst)
 430 {
 431     int ret;
 432     LIBSSHContext *libssh = h_src->priv_data;
 433     char path_src[MAX_URL_SIZE], path_dst[MAX_URL_SIZE];
 434     char hostname_src[1024], hostname_dst[1024];
 435     char credentials_src[1024], credentials_dst[1024];
 436     int port_src = 22, port_dst = 22;
 437
 438     av_url_split(NULL, 0,
 439                  credentials_src, sizeof(credentials_src),
 440                  hostname_src, sizeof(hostname_src),
 441                  &port_src,
 442                  path_src, sizeof(path_src),
 443                  h_src->filename);
 444
 445     av_url_split(NULL, 0,
 446                  credentials_dst, sizeof(credentials_dst),
 447                  hostname_dst, sizeof(hostname_dst),
 448                  &port_dst,
 449                  path_dst, sizeof(path_dst),
 450                  h_dst->filename);
 451
 452     if (strcmp(credentials_src, credentials_dst) ||
 453             strcmp(hostname_src, hostname_dst) ||
 454             port_src != port_dst) {
 455         return AVERROR(EINVAL);
 456     }
 457
 458     if ((ret = libssh_connect(h_src, h_src->filename, path_src, sizeof(path_src))) < 0)
 459         goto cleanup;
 460
 461     if (sftp_rename(libssh->sftp, path_src, path_dst) < 0) {
 462         ret = AVERROR(sftp_get_error(libssh->sftp));
 463         goto cleanup;
 464     }
 465
 466     ret = 0;
 467
 468 cleanup:
 469     libssh_close(h_src);
 470     return ret;
 471 }
 472
 473 #define OFFSET(x) offsetof(LIBSSHContext, x)
 474 #define D AV_OPT_FLAG_DECODING_PARAM
 475 #define E AV_OPT_FLAG_ENCODING_PARAM
 476 static const AVOption options[] = {
 477     {"timeout", "set timeout of socket I/O operations", OFFSET(rw_timeout), AV_OPT_TYPE_INT, {.i64 = -1}, -1, INT_MAX, D|E },
 478     {"truncate", "Truncate existing files on write", OFFSET(trunc), AV_OPT_TYPE_INT, { .i64 = 1 }, 0, 1, E },
 479     {"private_key", "set path to private key", OFFSET(priv_key), AV_OPT_TYPE_STRING, { .str = NULL }, 0, 0, D|E },
 480     {NULL}
 481 };
 482
 483 static const AVClass libssh_context_class = {
 484     .class_name     = "libssh",
 485     .item_name      = av_default_item_name,
 486     .option         = options,
 487     .version        = LIBAVUTIL_VERSION_INT,
 488 };
 489
 490 const URLProtocol ff_libssh_protocol = {
 491     .name                = "sftp",
 492     .url_open            = libssh_open,
 493     .url_read            = libssh_read,
 494     .url_write           = libssh_write,
 495     .url_seek            = libssh_seek,
 496     .url_close           = libssh_close,
 497     .url_delete          = libssh_delete,
 498     .url_move            = libssh_move,
 499     .url_open_dir        = libssh_open_dir,
 500     .url_read_dir        = libssh_read_dir,
 501     .url_close_dir       = libssh_close_dir,
 502     .priv_data_size      = sizeof(LIBSSHContext),
 503     .priv_data_class     = &libssh_context_class,
 504     .flags               = URL_PROTOCOL_FLAG_NETWORK,
 505 };