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/opt.h"
  26 #include "libavutil/attributes.h"
  27 #include "libavformat/avio.h"
  28 #include "avformat.h"
  29 #include "internal.h"
  30 #include "url.h"
  31
  32 typedef struct {
  33     const AVClass *class;
  34     ssh_session session;
  35     sftp_session sftp;
  36     sftp_file file;
  37     sftp_dir dir;
  38     int64_t filesize;
  39     int rw_timeout;
  40     int trunc;
  41     char *priv_key;
  42 } LIBSSHContext;
  43
  44 static av_cold int libssh_create_ssh_session(LIBSSHContext *libssh, const char* hostname, unsigned int port)
  45 {
  46     static const int verbosity = SSH_LOG_NOLOG;
  47
  48     if (!(libssh->session = ssh_new())) {
  49         av_log(libssh, AV_LOG_ERROR, "SSH session creation failed: %s\n", ssh_get_error(libssh->session));
  50         return AVERROR(ENOMEM);
  51     }
  52     ssh_options_set(libssh->session, SSH_OPTIONS_HOST, hostname);
  53     ssh_options_set(libssh->session, SSH_OPTIONS_PORT, &port);
  54     ssh_options_set(libssh->session, SSH_OPTIONS_LOG_VERBOSITY, &verbosity);
  55     if (libssh->rw_timeout > 0) {
  56         long timeout = libssh->rw_timeout * 1000;
  57         ssh_options_set(libssh->session, SSH_OPTIONS_TIMEOUT_USEC, &timeout);
  58     }
  59
  60     if (ssh_options_parse_config(libssh->session, NULL) < 0) {
  61         av_log(libssh, AV_LOG_WARNING, "Could not parse the config file.\n");
  62     }
  63
  64     if (ssh_connect(libssh->session) != SSH_OK) {
  65         av_log(libssh, AV_LOG_ERROR, "Connection failed: %s\n", ssh_get_error(libssh->session));
  66         return AVERROR(EIO);
  67     }
  68
  69     return 0;
  70 }
  71
  72 static av_cold int libssh_authentication(LIBSSHContext *libssh, const char *user, const char *password)
  73 {
  74     int authorized = 0;
  75     int auth_methods;
  76
  77     if (user)
  78         ssh_options_set(libssh->session, SSH_OPTIONS_USER, user);
  79
  80     if (ssh_userauth_none(libssh->session, NULL) == SSH_AUTH_SUCCESS)
  81         return 0;
  82
  83     auth_methods = ssh_userauth_list(libssh->session, NULL);
  84
  85     if (auth_methods & SSH_AUTH_METHOD_PUBLICKEY) {
  86         if (libssh->priv_key) {
  87             ssh_string pub_key;
  88             ssh_private_key priv_key;
  89             int type;
  90             if (!ssh_try_publickey_from_file(libssh->session, libssh->priv_key, &pub_key, &type)) {
  91                 priv_key = privatekey_from_file(libssh->session, libssh->priv_key, type, password);
  92                 if (ssh_userauth_pubkey(libssh->session, NULL, pub_key, priv_key) == SSH_AUTH_SUCCESS) {
  93                     av_log(libssh, AV_LOG_DEBUG, "Authentication successful with selected private key.\n");
  94                     authorized = 1;
  95                 }
  96             } else {
  97                 av_log(libssh, AV_LOG_DEBUG, "Invalid key is provided.\n");
  98                 return AVERROR(EACCES);
  99             }
 100         } else if (ssh_userauth_autopubkey(libssh->session, password) == SSH_AUTH_SUCCESS) {
 101             av_log(libssh, AV_LOG_DEBUG, "Authentication successful with auto selected key.\n");
 102             authorized = 1;
 103         }
 104     }
 105
 106     if (!authorized && password && (auth_methods & SSH_AUTH_METHOD_PASSWORD)) {
 107         if (ssh_userauth_password(libssh->session, NULL, password) == SSH_AUTH_SUCCESS) {
 108             av_log(libssh, AV_LOG_DEBUG, "Authentication successful with password.\n");
 109             authorized = 1;
 110         }
 111     }
 112
 113     if (!authorized) {
 114         av_log(libssh, AV_LOG_ERROR, "Authentication failed.\n");
 115         return AVERROR(EACCES);
 116     }
 117
 118     return 0;
 119 }
 120
 121 static av_cold int libssh_create_sftp_session(LIBSSHContext *libssh)
 122 {
 123     if (!(libssh->sftp = sftp_new(libssh->session))) {
 124         av_log(libssh, AV_LOG_ERROR, "SFTP session creation failed: %s\n", ssh_get_error(libssh->session));
 125         return AVERROR(ENOMEM);
 126     }
 127
 128     if (sftp_init(libssh->sftp) != SSH_OK) {
 129         av_log(libssh, AV_LOG_ERROR, "Error initializing sftp session: %s\n", ssh_get_error(libssh->session));
 130         return AVERROR(EIO);
 131     }
 132
 133     return 0;
 134 }
 135
 136 static av_cold int libssh_open_file(LIBSSHContext *libssh, int flags, const char *file)
 137 {
 138     int access;
 139
 140     if ((flags & AVIO_FLAG_WRITE) && (flags & AVIO_FLAG_READ)) {
 141         access = O_CREAT | O_RDWR;
 142         if (libssh->trunc)
 143             access |= O_TRUNC;
 144     } else if (flags & AVIO_FLAG_WRITE) {
 145         access = O_CREAT | O_WRONLY;
 146         if (libssh->trunc)
 147             access |= O_TRUNC;
 148     } else
 149         access = O_RDONLY;
 150
 151     /* 0666 = -rw-rw-rw- = read+write for everyone, minus umask */
 152     if (!(libssh->file = sftp_open(libssh->sftp, file, access, 0666))) {
 153         av_log(libssh, AV_LOG_ERROR, "Error opening sftp file: %s\n", ssh_get_error(libssh->session));
 154         return AVERROR(EIO);
 155     }
 156
 157     return 0;
 158 }
 159
 160 static av_cold void libssh_stat_file(LIBSSHContext *libssh)
 161 {
 162     sftp_attributes stat;
 163
 164     if (!(stat = sftp_fstat(libssh->file))) {
 165         av_log(libssh, AV_LOG_WARNING, "Cannot stat remote file.\n");
 166         libssh->filesize = -1;
 167     } else {
 168         libssh->filesize = stat->size;
 169         sftp_attributes_free(stat);
 170     }
 171 }
 172
 173 static av_cold int libssh_close(URLContext *h)
 174 {
 175     LIBSSHContext *libssh = h->priv_data;
 176     if (libssh->file) {
 177         sftp_close(libssh->file);
 178         libssh->file = NULL;
 179     }
 180     if (libssh->sftp) {
 181         sftp_free(libssh->sftp);
 182         libssh->sftp = NULL;
 183     }
 184     if (libssh->session) {
 185         ssh_disconnect(libssh->session);
 186         ssh_free(libssh->session);
 187         libssh->session = NULL;
 188     }
 189     return 0;
 190 }
 191
 192 static av_cold int libssh_connect(URLContext *h, const char *url, char *path, size_t path_size)
 193 {
 194     LIBSSHContext *libssh = h->priv_data;
 195     char proto[10], hostname[1024], credencials[1024];
 196     int port = 22, ret;
 197     const char *user = NULL, *pass = NULL;
 198     char *end = NULL;
 199
 200     av_url_split(proto, sizeof(proto),
 201                  credencials, sizeof(credencials),
 202                  hostname, sizeof(hostname),
 203                  &port,
 204                  path, path_size,
 205                  url);
 206
 207     if (!(*path))
 208         av_strlcpy(path, "/", path_size);
 209
 210     // a port of 0 will use a port from ~/.ssh/config or the default value 22
 211     if (port < 0 || port > 65535)
 212         port = 0;
 213
 214     if ((ret = libssh_create_ssh_session(libssh, hostname, port)) < 0)
 215         return ret;
 216
 217     user = av_strtok(credencials, ":", &end);
 218     pass = av_strtok(end, ":", &end);
 219
 220     if ((ret = libssh_authentication(libssh, user, pass)) < 0)
 221         return ret;
 222
 223     if ((ret = libssh_create_sftp_session(libssh)) < 0)
 224         return ret;
 225
 226     return 0;
 227 }
 228
 229 static av_cold int libssh_open(URLContext *h, const char *url, int flags)
 230 {
 231     int ret;
 232     LIBSSHContext *libssh = h->priv_data;
 233     char path[MAX_URL_SIZE];
 234
 235     if ((ret = libssh_connect(h, url, path, sizeof(path))) < 0)
 236         goto fail;
 237
 238     if ((ret = libssh_open_file(libssh, flags, path)) < 0)
 239         goto fail;
 240
 241     libssh_stat_file(libssh);
 242
 243     return 0;
 244
 245   fail:
 246     libssh_close(h);
 247     return ret;
 248 }
 249
 250 static int64_t libssh_seek(URLContext *h, int64_t pos, int whence)
 251 {
 252     LIBSSHContext *libssh = h->priv_data;
 253     int64_t newpos;
 254
 255     if (libssh->filesize == -1 && (whence == AVSEEK_SIZE || whence == SEEK_END)) {
 256         av_log(h, AV_LOG_ERROR, "Error during seeking.\n");
 257         return AVERROR(EIO);
 258     }
 259
 260     switch(whence) {
 261     case AVSEEK_SIZE:
 262         return libssh->filesize;
 263     case SEEK_SET:
 264         newpos = pos;
 265         break;
 266     case SEEK_CUR:
 267         newpos = sftp_tell64(libssh->file) + pos;
 268         break;
 269     case SEEK_END:
 270         newpos = libssh->filesize + pos;
 271         break;
 272     default:
 273         return AVERROR(EINVAL);
 274     }
 275
 276     if (newpos < 0) {
 277         av_log(h, AV_LOG_ERROR, "Seeking to nagative position.\n");
 278         return AVERROR(EINVAL);
 279     }
 280
 281     if (sftp_seek64(libssh->file, newpos)) {
 282         av_log(h, AV_LOG_ERROR, "Error during seeking.\n");
 283         return AVERROR(EIO);
 284     }
 285
 286     return newpos;
 287 }
 288
 289 static int libssh_read(URLContext *h, unsigned char *buf, int size)
 290 {
 291     LIBSSHContext *libssh = h->priv_data;
 292     int bytes_read;
 293
 294     if ((bytes_read = sftp_read(libssh->file, buf, size)) < 0) {
 295         av_log(libssh, AV_LOG_ERROR, "Read error.\n");
 296         return AVERROR(EIO);
 297     }
 298     return bytes_read;
 299 }
 300
 301 static int libssh_write(URLContext *h, const unsigned char *buf, int size)
 302 {
 303     LIBSSHContext *libssh = h->priv_data;
 304     int bytes_written;
 305
 306     if ((bytes_written = sftp_write(libssh->file, buf, size)) < 0) {
 307         av_log(libssh, AV_LOG_ERROR, "Write error.\n");
 308         return AVERROR(EIO);
 309     }
 310     return bytes_written;
 311 }
 312
 313 static int libssh_open_dir(URLContext *h)
 314 {
 315     LIBSSHContext *libssh = h->priv_data;
 316     int ret;
 317     char path[MAX_URL_SIZE];
 318
 319     if ((ret = libssh_connect(h, h->filename, path, sizeof(path))) < 0)
 320         goto fail;
 321
 322     if (!(libssh->dir = sftp_opendir(libssh->sftp, path))) {
 323         av_log(libssh, AV_LOG_ERROR, "Error opening sftp dir: %s\n", ssh_get_error(libssh->session));
 324         ret = AVERROR(EIO);
 325         goto fail;
 326     }
 327
 328     return 0;
 329
 330   fail:
 331     libssh_close(h);
 332     return ret;
 333 }
 334
 335 static int libssh_read_dir(URLContext *h, AVIODirEntry **next)
 336 {
 337     LIBSSHContext *libssh = h->priv_data;
 338     sftp_attributes attr = NULL;
 339     AVIODirEntry *entry;
 340
 341     *next = entry = ff_alloc_dir_entry();
 342     if (!entry)
 343         return AVERROR(ENOMEM);
 344
 345     do {
 346         if (attr)
 347             sftp_attributes_free(attr);
 348         attr = sftp_readdir(libssh->sftp, libssh->dir);
 349         if (!attr) {
 350             av_freep(next);
 351             if (sftp_dir_eof(libssh->dir))
 352                 return 0;
 353             return AVERROR(EIO);
 354         }
 355     } while (!strcmp(attr->name, ".") || !strcmp(attr->name, ".."));
 356
 357     entry->name = av_strdup(attr->name);
 358     entry->group_id = attr->gid;
 359     entry->user_id = attr->uid;
 360     entry->size = attr->size;
 361     entry->access_timestamp = INT64_C(1000000) * attr->atime;
 362     entry->modification_timestamp = INT64_C(1000000) * attr->mtime;
 363     entry->filemode = attr->permissions & 0777;
 364     switch(attr->type) {
 365     case SSH_FILEXFER_TYPE_REGULAR:
 366         entry->type = AVIO_ENTRY_FILE;
 367         break;
 368     case SSH_FILEXFER_TYPE_DIRECTORY:
 369         entry->type = AVIO_ENTRY_DIRECTORY;
 370         break;
 371     case SSH_FILEXFER_TYPE_SYMLINK:
 372         entry->type = AVIO_ENTRY_SYMBOLIC_LINK;
 373         break;
 374     case SSH_FILEXFER_TYPE_SPECIAL:
 375         /* Special type includes: sockets, char devices, block devices and pipes.
 376            It is probably better to return unknown type, to not confuse anybody. */
 377     case SSH_FILEXFER_TYPE_UNKNOWN:
 378     default:
 379         entry->type = AVIO_ENTRY_UNKNOWN;
 380     }
 381     sftp_attributes_free(attr);
 382     return 0;
 383 }
 384
 385 static int libssh_close_dir(URLContext *h)
 386 {
 387     LIBSSHContext *libssh = h->priv_data;
 388     if (libssh->dir)
 389         sftp_closedir(libssh->dir);
 390     libssh->dir = NULL;
 391     libssh_close(h);
 392     return 0;
 393 }
 394
 395 static int libssh_delete(URLContext *h)
 396 {
 397     int ret;
 398     LIBSSHContext *libssh = h->priv_data;
 399     sftp_attributes attr = NULL;
 400     char path[MAX_URL_SIZE];
 401
 402     if ((ret = libssh_connect(h, h->filename, path, sizeof(path))) < 0)
 403         goto cleanup;
 404
 405     if (!(attr = sftp_stat(libssh->sftp, path))) {
 406         ret = AVERROR(sftp_get_error(libssh->sftp));
 407         goto cleanup;
 408     }
 409
 410     if (attr->type == SSH_FILEXFER_TYPE_DIRECTORY) {
 411         if (sftp_rmdir(libssh->sftp, path) < 0) {
 412             ret = AVERROR(sftp_get_error(libssh->sftp));
 413             goto cleanup;
 414         }
 415     } else {
 416         if (sftp_unlink(libssh->sftp, path) < 0) {
 417             ret = AVERROR(sftp_get_error(libssh->sftp));
 418             goto cleanup;
 419         }
 420     }
 421
 422     ret = 0;
 423
 424 cleanup:
 425     if (attr)
 426         sftp_attributes_free(attr);
 427     libssh_close(h);
 428     return ret;
 429 }
 430
 431 static int libssh_move(URLContext *h_src, URLContext *h_dst)
 432 {
 433     int ret;
 434     LIBSSHContext *libssh = h_src->priv_data;
 435     char path_src[MAX_URL_SIZE], path_dst[MAX_URL_SIZE];
 436     char hostname_src[1024], hostname_dst[1024];
 437     char credentials_src[1024], credentials_dst[1024];
 438     int port_src = 22, port_dst = 22;
 439
 440     av_url_split(NULL, 0,
 441                  credentials_src, sizeof(credentials_src),
 442                  hostname_src, sizeof(hostname_src),
 443                  &port_src,
 444                  path_src, sizeof(path_src),
 445                  h_src->filename);
 446
 447     av_url_split(NULL, 0,
 448                  credentials_dst, sizeof(credentials_dst),
 449                  hostname_dst, sizeof(hostname_dst),
 450                  &port_dst,
 451                  path_dst, sizeof(path_dst),
 452                  h_dst->filename);
 453
 454     if (strcmp(credentials_src, credentials_dst) ||
 455             strcmp(hostname_src, hostname_dst) ||
 456             port_src != port_dst) {
 457         return AVERROR(EINVAL);
 458     }
 459
 460     if ((ret = libssh_connect(h_src, h_src->filename, path_src, sizeof(path_src))) < 0)
 461         goto cleanup;
 462
 463     if (sftp_rename(libssh->sftp, path_src, path_dst) < 0) {
 464         ret = AVERROR(sftp_get_error(libssh->sftp));
 465         goto cleanup;
 466     }
 467
 468     ret = 0;
 469
 470 cleanup:
 471     libssh_close(h_src);
 472     return ret;
 473 }
 474
 475 #define OFFSET(x) offsetof(LIBSSHContext, x)
 476 #define D AV_OPT_FLAG_DECODING_PARAM
 477 #define E AV_OPT_FLAG_ENCODING_PARAM
 478 static const AVOption options[] = {
 479     {"timeout", "set timeout of socket I/O operations", OFFSET(rw_timeout), AV_OPT_TYPE_INT, {.i64 = -1}, -1, INT_MAX, D|E },
 480     {"truncate", "Truncate existing files on write", OFFSET(trunc), AV_OPT_TYPE_INT, { .i64 = 1 }, 0, 1, E },
 481     {"private_key", "set path to private key", OFFSET(priv_key), AV_OPT_TYPE_STRING, { .str = NULL }, 0, 0, D|E },
 482     {NULL}
 483 };
 484
 485 static const AVClass libssh_context_class = {
 486     .class_name     = "libssh",
 487     .item_name      = av_default_item_name,
 488     .option         = options,
 489     .version        = LIBAVUTIL_VERSION_INT,
 490 };
 491
 492 const URLProtocol ff_libssh_protocol = {
 493     .name                = "sftp",
 494     .url_open            = libssh_open,
 495     .url_read            = libssh_read,
 496     .url_write           = libssh_write,
 497     .url_seek            = libssh_seek,
 498     .url_close           = libssh_close,
 499     .url_delete          = libssh_delete,
 500     .url_move            = libssh_move,
 501     .url_open_dir        = libssh_open_dir,
 502     .url_read_dir        = libssh_read_dir,
 503     .url_close_dir       = libssh_close_dir,
 504     .priv_data_size      = sizeof(LIBSSHContext),
 505     .priv_data_class     = &libssh_context_class,
 506     .flags               = URL_PROTOCOL_FLAG_NETWORK,
 507 };