src/vfs/sftpfs/internal.c

   1 /* Virtual File System: SFTP file system.
   2    The internal functions
   3
   4    Copyright (C) 2011-2017
   5    Free Software Foundation, Inc.
   6
   7    Written by:
   8    Ilia Maslakov <il.smind@gmail.com>, 2011
   9    Slava Zanko <slavazanko@gmail.com>, 2011, 2012
  10
  11    This file is part of the Midnight Commander.
  12
  13    The Midnight Commander is free software: you can redistribute it
  14    and/or modify it under the terms of the GNU General Public License as
  15    published by the Free Software Foundation, either version 3 of the License,
  16    or (at your option) any later version.
  17
  18    The Midnight Commander is distributed in the hope that it will be useful,
  19    but WITHOUT ANY WARRANTY; without even the implied warranty of
  20    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  21    GNU General Public License for more details.
  22
  23    You should have received a copy of the GNU General Public License
  24    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  25  */
  26
  27 #include <config.h>
  28 #include <errno.h>
  29
  30 #include "lib/global.h"
  31 #include "lib/util.h"
  32
  33 #include "internal.h"
  34
  35 /*** global variables ****************************************************************************/
  36
  37 GString *sftpfs_filename_buffer = NULL;
  38
  39 /*** file scope macro definitions ****************************************************************/
  40
  41 /*** file scope type declarations ****************************************************************/
  42
  43 /*** file scope variables ************************************************************************/
  44
  45 /* --------------------------------------------------------------------------------------------- */
  46 /*** file scope functions ************************************************************************/
  47 /* --------------------------------------------------------------------------------------------- */
  48
  49 static gboolean
  50 sftpfs_is_sftp_error (LIBSSH2_SFTP * sftp_session, int sftp_res, int sftp_error)
  51 {
  52     return (sftp_res == LIBSSH2_ERROR_SFTP_PROTOCOL &&
  53             libssh2_sftp_last_error (sftp_session) == (unsigned long) sftp_error);
  54 }
  55
  56 /* --------------------------------------------------------------------------------------------- */
  57
  58 /* Adjust block size and number of blocks */
  59
  60 static void
  61 sftpfs_blksize (struct stat *s)
  62 {
  63 #ifdef HAVE_STRUCT_STAT_ST_BLKSIZE
  64     s->st_blksize = LIBSSH2_CHANNEL_WINDOW_DEFAULT;     /* FIXME */
  65 #endif /* HAVE_STRUCT_STAT_ST_BLKSIZE */
  66     vfs_adjust_stat (s);
  67 }
  68
  69 /* --------------------------------------------------------------------------------------------- */
  70
  71 static gboolean
  72 sftpfs_waitsocket_or_error (sftpfs_super_data_t * super_data, int res, GError ** mcerror,
  73                             void *to_free)
  74 {
  75     if (res != LIBSSH2_ERROR_EAGAIN)
  76     {
  77         sftpfs_ssherror_to_gliberror (super_data, res, mcerror);
  78         g_free (to_free);
  79         return FALSE;
  80     }
  81
  82     sftpfs_waitsocket (super_data, mcerror);
  83
  84     if (mcerror != NULL && *mcerror != NULL)
  85     {
  86         g_free (to_free);
  87         return FALSE;
  88     }
  89
  90     return TRUE;
  91 }
  92
  93 /* --------------------------------------------------------------------------------------------- */
  94 /*** public functions ****************************************************************************/
  95 /* --------------------------------------------------------------------------------------------- */
  96 /**
  97  * Convert libssh error to GError object.
  98  *
  99  * @param super_data   extra data for SFTP connection
 100  * @param libssh_errno errno from libssh
 101  * @param mcerror      pointer to the error object
 102  */
 103
 104 void
 105 sftpfs_ssherror_to_gliberror (sftpfs_super_data_t * super_data, int libssh_errno, GError ** mcerror)
 106 {
 107     char *err = NULL;
 108     int err_len;
 109
 110     mc_return_if_error (mcerror);
 111
 112     libssh2_session_last_error (super_data->session, &err, &err_len, 1);
 113     if (libssh_errno == LIBSSH2_ERROR_SFTP_PROTOCOL && super_data->sftp_session != NULL)
 114         mc_propagate_error (mcerror, libssh_errno, "%s %lu", err,
 115                             libssh2_sftp_last_error (super_data->sftp_session));
 116     else
 117         mc_propagate_error (mcerror, libssh_errno, "%s", err);
 118     g_free (err);
 119 }
 120
 121 /* --------------------------------------------------------------------------------------------- */
 122 /**
 123  * Fix filename for SFTP operations: add leading slash to file name.
 124  *
 125  * @param file_name file name
 126  * @param length length of returned string
 127  *
 128  * @return pointer to string that contains the file name with leading slash
 129  */
 130
 131 const char *
 132 sftpfs_fix_filename (const char *file_name, unsigned int *length)
 133 {
 134     g_string_printf (sftpfs_filename_buffer, "%c%s", PATH_SEP, file_name);
 135     *length = sftpfs_filename_buffer->len;
 136     return sftpfs_filename_buffer->str;
 137 }
 138
 139 /* --------------------------------------------------------------------------------------------- */
 140 /**
 141  * Awaiting for any activity on socket.
 142  *
 143  * @param super_data extra data for SFTP connection
 144  * @param mcerror    pointer to the error object
 145  * @return 0 if success, negative value otherwise
 146  */
 147
 148 int
 149 sftpfs_waitsocket (sftpfs_super_data_t * super_data, GError ** mcerror)
 150 {
 151     struct timeval timeout = { 10, 0 };
 152     fd_set fd;
 153     fd_set *writefd = NULL;
 154     fd_set *readfd = NULL;
 155     int dir, ret;
 156
 157     mc_return_val_if_error (mcerror, -1);
 158
 159     FD_ZERO (&fd);
 160     FD_SET (super_data->socket_handle, &fd);
 161
 162     /* now make sure we wait in the correct direction */
 163     dir = libssh2_session_block_directions (super_data->session);
 164
 165     if ((dir & LIBSSH2_SESSION_BLOCK_INBOUND) != 0)
 166         readfd = &fd;
 167
 168     if ((dir & LIBSSH2_SESSION_BLOCK_OUTBOUND) != 0)
 169         writefd = &fd;
 170
 171     ret = select (super_data->socket_handle + 1, readfd, writefd, NULL, &timeout);
 172
 173     if (ret < 0)
 174         mc_propagate_error (mcerror, 0, _("sftp: socket error: %s"), unix_error_string (errno));
 175
 176     return ret;
 177 }
 178
 179 /* --------------------------------------------------------------------------------------------- */
 180
 181 void
 182 sftpfs_attr_to_stat (const LIBSSH2_SFTP_ATTRIBUTES * attrs, struct stat *s)
 183 {
 184     if ((attrs->flags & LIBSSH2_SFTP_ATTR_UIDGID) != 0)
 185     {
 186         s->st_uid = attrs->uid;
 187         s->st_gid = attrs->gid;
 188     }
 189
 190     if ((attrs->flags & LIBSSH2_SFTP_ATTR_ACMODTIME) != 0)
 191     {
 192         s->st_atime = attrs->atime;
 193         s->st_mtime = attrs->mtime;
 194         s->st_ctime = attrs->mtime;
 195 #ifdef HAVE_STRUCT_STAT_ST_MTIM
 196         s->st_atim.tv_nsec = s->st_mtim.tv_nsec = s->st_ctim.tv_nsec = 0;
 197 #endif
 198     }
 199
 200     if ((attrs->flags & LIBSSH2_SFTP_ATTR_SIZE) != 0)
 201     {
 202         s->st_size = attrs->filesize;
 203         sftpfs_blksize (s);
 204     }
 205
 206     if ((attrs->flags & LIBSSH2_SFTP_ATTR_PERMISSIONS) != 0)
 207         s->st_mode = attrs->permissions;
 208 }
 209
 210 /* --------------------------------------------------------------------------------------------- */
 211 /**
 212  * Getting information about a symbolic link.
 213  *
 214  * @param vpath   path to file, directory or symbolic link
 215  * @param buf     buffer for store stat-info
 216  * @param mcerror pointer to error object
 217  * @return 0 if success, negative value otherwise
 218  */
 219
 220 int
 221 sftpfs_lstat (const vfs_path_t * vpath, struct stat *buf, GError ** mcerror)
 222 {
 223     struct vfs_s_super *super;
 224     sftpfs_super_data_t *super_data;
 225     LIBSSH2_SFTP_ATTRIBUTES attrs;
 226     int res;
 227     const vfs_path_element_t *path_element;
 228
 229     mc_return_val_if_error (mcerror, -1);
 230
 231     path_element = vfs_path_get_by_index (vpath, -1);
 232
 233     if (vfs_s_get_path (vpath, &super, 0) == NULL)
 234         return -1;
 235
 236     if (super == NULL)
 237         return -1;
 238
 239     super_data = (sftpfs_super_data_t *) super->data;
 240     if (super_data->sftp_session == NULL)
 241         return -1;
 242
 243     do
 244     {
 245         const char *fixfname;
 246         unsigned int fixfname_len = 0;
 247
 248         fixfname = sftpfs_fix_filename (path_element->path, &fixfname_len);
 249
 250         res =
 251             libssh2_sftp_stat_ex (super_data->sftp_session, fixfname, fixfname_len,
 252                                   LIBSSH2_SFTP_LSTAT, &attrs);
 253         if (res >= 0)
 254             break;
 255
 256         if (sftpfs_is_sftp_error (super_data->sftp_session, res, LIBSSH2_FX_PERMISSION_DENIED))
 257             return -EACCES;
 258
 259         /* perhaps the copy function tries to stat destination file
 260            to make sure it's not overwriting anything */
 261         if (sftpfs_is_sftp_error (super_data->sftp_session, res, LIBSSH2_FX_NO_SUCH_FILE))
 262             return -ENOENT;
 263
 264         if (!sftpfs_waitsocket_or_error (super_data, res, mcerror, NULL))
 265             return -1;
 266     }
 267     while (res == LIBSSH2_ERROR_EAGAIN);
 268
 269     sftpfs_attr_to_stat (&attrs, buf);
 270
 271     return 0;
 272 }
 273
 274 /* --------------------------------------------------------------------------------------------- */
 275 /**
 276  * Getting information about a file or directory.
 277  *
 278  * @param vpath   path to file or directory
 279  * @param buf     buffer for store stat-info
 280  * @param mcerror pointer to error object
 281  * @return 0 if success, negative value otherwise
 282  */
 283
 284 int
 285 sftpfs_stat (const vfs_path_t * vpath, struct stat *buf, GError ** mcerror)
 286 {
 287     struct vfs_s_super *super;
 288     sftpfs_super_data_t *super_data;
 289     LIBSSH2_SFTP_ATTRIBUTES attrs;
 290     int res;
 291     const vfs_path_element_t *path_element;
 292
 293     mc_return_val_if_error (mcerror, -1);
 294
 295     path_element = vfs_path_get_by_index (vpath, -1);
 296
 297     if (vfs_s_get_path (vpath, &super, 0) == NULL)
 298         return -1;
 299
 300     if (super == NULL)
 301         return -1;
 302
 303     super_data = (sftpfs_super_data_t *) super->data;
 304     if (super_data->sftp_session == NULL)
 305         return -1;
 306
 307     do
 308     {
 309         const char *fixfname;
 310         unsigned int fixfname_len = 0;
 311
 312         fixfname = sftpfs_fix_filename (path_element->path, &fixfname_len);
 313
 314         res =
 315             libssh2_sftp_stat_ex (super_data->sftp_session, fixfname, fixfname_len,
 316                                   LIBSSH2_SFTP_STAT, &attrs);
 317         if (res >= 0)
 318             break;
 319
 320         if (sftpfs_is_sftp_error (super_data->sftp_session, res, LIBSSH2_FX_PERMISSION_DENIED))
 321             return -EACCES;
 322
 323         /* perhaps the copy function tries to stat destination file
 324            to make sure it's not overwriting anything */
 325         if (sftpfs_is_sftp_error (super_data->sftp_session, res, LIBSSH2_FX_NO_SUCH_FILE))
 326             return -ENOENT;
 327
 328         if (!sftpfs_waitsocket_or_error (super_data, res, mcerror, NULL))
 329             return -1;
 330     }
 331     while (res == LIBSSH2_ERROR_EAGAIN);
 332
 333     buf->st_nlink = 1;
 334
 335     sftpfs_attr_to_stat (&attrs, buf);
 336
 337     return 0;
 338 }
 339
 340 /* --------------------------------------------------------------------------------------------- */
 341 /**
 342  * Read value of a symbolic link.
 343  *
 344  * @param vpath   path to file or directory
 345  * @param buf     buffer for store stat-info
 346  * @param size    buffer size
 347  * @param mcerror pointer to error object
 348  * @return 0 if success, negative value otherwise
 349  */
 350
 351 int
 352 sftpfs_readlink (const vfs_path_t * vpath, char *buf, size_t size, GError ** mcerror)
 353 {
 354     struct vfs_s_super *super;
 355     sftpfs_super_data_t *super_data;
 356     int res;
 357     const vfs_path_element_t *path_element;
 358
 359     mc_return_val_if_error (mcerror, -1);
 360
 361     path_element = vfs_path_get_by_index (vpath, -1);
 362
 363     if (vfs_s_get_path (vpath, &super, 0) == NULL)
 364         return -1;
 365
 366     if (super == NULL)
 367         return -1;
 368
 369     super_data = (sftpfs_super_data_t *) super->data;
 370     if (super_data->sftp_session == NULL)
 371         return -1;
 372
 373     do
 374     {
 375         const char *fixfname;
 376         unsigned int fixfname_len = 0;
 377
 378         fixfname = sftpfs_fix_filename (path_element->path, &fixfname_len);
 379
 380         res =
 381             libssh2_sftp_symlink_ex (super_data->sftp_session, fixfname, fixfname_len, buf, size,
 382                                      LIBSSH2_SFTP_READLINK);
 383         if (res >= 0)
 384             break;
 385
 386         if (!sftpfs_waitsocket_or_error (super_data, res, mcerror, NULL))
 387             return -1;
 388     }
 389     while (res == LIBSSH2_ERROR_EAGAIN);
 390
 391     return res;
 392 }
 393
 394 /* --------------------------------------------------------------------------------------------- */
 395 /**
 396  * Create symlink to file or directory
 397  *
 398  * @param vpath1  path to file or directory
 399  * @param vpath2  path to symlink
 400  * @param mcerror pointer to error object
 401  * @return 0 if success, negative value otherwise
 402  */
 403
 404 int
 405 sftpfs_symlink (const vfs_path_t * vpath1, const vfs_path_t * vpath2, GError ** mcerror)
 406 {
 407     struct vfs_s_super *super;
 408     sftpfs_super_data_t *super_data;
 409     const vfs_path_element_t *path_element1;
 410     const vfs_path_element_t *path_element2;
 411     char *tmp_path;
 412     unsigned int tmp_path_len;
 413     int res;
 414
 415     mc_return_val_if_error (mcerror, -1);
 416
 417     path_element2 = vfs_path_get_by_index (vpath2, -1);
 418
 419     if (vfs_s_get_path (vpath2, &super, 0) == NULL)
 420         return -1;
 421
 422     if (super == NULL)
 423         return -1;
 424
 425     super_data = (sftpfs_super_data_t *) super->data;
 426     if (super_data->sftp_session == NULL)
 427         return -1;
 428
 429     tmp_path = (char *) sftpfs_fix_filename (path_element2->path, &tmp_path_len);
 430     tmp_path = g_strndup (tmp_path, tmp_path_len);
 431
 432     path_element1 = vfs_path_get_by_index (vpath1, -1);
 433
 434     do
 435     {
 436         const char *fixfname;
 437         unsigned int fixfname_len = 0;
 438
 439         fixfname = sftpfs_fix_filename (path_element1->path, &fixfname_len);
 440
 441         res =
 442             libssh2_sftp_symlink_ex (super_data->sftp_session, fixfname, fixfname_len, tmp_path,
 443                                      tmp_path_len, LIBSSH2_SFTP_SYMLINK);
 444         if (res >= 0)
 445             break;
 446
 447         if (!sftpfs_waitsocket_or_error (super_data, res, mcerror, tmp_path))
 448             return -1;
 449     }
 450     while (res == LIBSSH2_ERROR_EAGAIN);
 451     g_free (tmp_path);
 452
 453     return 0;
 454 }
 455
 456 /* --------------------------------------------------------------------------------------------- */
 457 /**
 458  * Changes the permissions of the file.
 459  *
 460  * @param vpath   path to file or directory
 461  * @param mode    mode (see man 2 open)
 462  * @param mcerror pointer to error object
 463  * @return 0 if success, negative value otherwise
 464  */
 465
 466 int
 467 sftpfs_chmod (const vfs_path_t * vpath, mode_t mode, GError ** mcerror)
 468 {
 469     struct vfs_s_super *super;
 470     sftpfs_super_data_t *super_data;
 471     LIBSSH2_SFTP_ATTRIBUTES attrs;
 472     int res;
 473     const vfs_path_element_t *path_element;
 474
 475     mc_return_val_if_error (mcerror, -1);
 476
 477     path_element = vfs_path_get_by_index (vpath, -1);
 478
 479     if (vfs_s_get_path (vpath, &super, 0) == NULL)
 480         return -1;
 481
 482     if (super == NULL)
 483         return -1;
 484
 485     super_data = (sftpfs_super_data_t *) super->data;
 486     if (super_data->sftp_session == NULL)
 487         return -1;
 488
 489     do
 490     {
 491         const char *fixfname;
 492         unsigned int fixfname_len = 0;
 493
 494         fixfname = sftpfs_fix_filename (path_element->path, &fixfname_len);
 495
 496         res =
 497             libssh2_sftp_stat_ex (super_data->sftp_session, fixfname, fixfname_len,
 498                                   LIBSSH2_SFTP_LSTAT, &attrs);
 499         if (res >= 0)
 500             break;
 501
 502         if (sftpfs_is_sftp_error (super_data->sftp_session, res, LIBSSH2_FX_PERMISSION_DENIED))
 503             return -EACCES;
 504
 505         if (sftpfs_is_sftp_error (super_data->sftp_session, res, LIBSSH2_FX_FAILURE))
 506         {
 507             res = 0;            /* need something like ftpfs_ignore_chattr_errors */
 508             break;
 509         }
 510
 511         if (!sftpfs_waitsocket_or_error (super_data, res, mcerror, NULL))
 512             return -1;
 513     }
 514     while (res == LIBSSH2_ERROR_EAGAIN);
 515
 516     attrs.permissions = mode;
 517
 518     do
 519     {
 520         const char *fixfname;
 521         unsigned int fixfname_len = 0;
 522
 523         fixfname = sftpfs_fix_filename (path_element->path, &fixfname_len);
 524
 525         res =
 526             libssh2_sftp_stat_ex (super_data->sftp_session, fixfname, fixfname_len,
 527                                   LIBSSH2_SFTP_SETSTAT, &attrs);
 528         if (res >= 0)
 529             break;
 530
 531         if (sftpfs_is_sftp_error (super_data->sftp_session, res, LIBSSH2_FX_NO_SUCH_FILE))
 532             return -ENOENT;
 533
 534         if (sftpfs_is_sftp_error (super_data->sftp_session, res, LIBSSH2_FX_FAILURE))
 535         {
 536             res = 0;            /* need something like ftpfs_ignore_chattr_errors */
 537             break;
 538         }
 539
 540         if (!sftpfs_waitsocket_or_error (super_data, res, mcerror, NULL))
 541             return -1;
 542     }
 543     while (res == LIBSSH2_ERROR_EAGAIN);
 544
 545     return res;
 546 }
 547
 548 /* --------------------------------------------------------------------------------------------- */
 549 /**
 550  * Delete a name from the file system.
 551  *
 552  * @param vpath   path to file or directory
 553  * @param mcerror pointer to error object
 554  * @return 0 if success, negative value otherwise
 555  */
 556
 557 int
 558 sftpfs_unlink (const vfs_path_t * vpath, GError ** mcerror)
 559 {
 560     struct vfs_s_super *super;
 561     sftpfs_super_data_t *super_data;
 562     int res;
 563     const vfs_path_element_t *path_element;
 564
 565     mc_return_val_if_error (mcerror, -1);
 566
 567     path_element = vfs_path_get_by_index (vpath, -1);
 568
 569     if (vfs_s_get_path (vpath, &super, 0) == NULL)
 570         return -1;
 571
 572     if (super == NULL)
 573         return -1;
 574
 575     super_data = (sftpfs_super_data_t *) super->data;
 576     if (super_data->sftp_session == NULL)
 577         return -1;
 578
 579     do
 580     {
 581         const char *fixfname;
 582         unsigned int fixfname_len = 0;
 583
 584         fixfname = sftpfs_fix_filename (path_element->path, &fixfname_len);
 585
 586         res = libssh2_sftp_unlink_ex (super_data->sftp_session, fixfname, fixfname_len);
 587         if (res >= 0)
 588             break;
 589
 590         if (!sftpfs_waitsocket_or_error (super_data, res, mcerror, NULL))
 591             return -1;
 592     }
 593     while (res == LIBSSH2_ERROR_EAGAIN);
 594
 595     return res;
 596 }
 597
 598 /* --------------------------------------------------------------------------------------------- */
 599 /**
 600  * Rename a file, moving it between directories if required.
 601  *
 602  * @param vpath1   path to source file or directory
 603  * @param vpath2   path to destination file or directory
 604  * @param mcerror  pointer to error object
 605  * @return 0 if success, negative value otherwise
 606  */
 607
 608 int
 609 sftpfs_rename (const vfs_path_t * vpath1, const vfs_path_t * vpath2, GError ** mcerror)
 610 {
 611     struct vfs_s_super *super;
 612     sftpfs_super_data_t *super_data;
 613     const vfs_path_element_t *path_element1;
 614     const vfs_path_element_t *path_element2;
 615     char *tmp_path;
 616     unsigned int tmp_path_len;
 617     int res;
 618
 619     mc_return_val_if_error (mcerror, -1);
 620     path_element2 = vfs_path_get_by_index (vpath2, -1);
 621
 622     if (vfs_s_get_path (vpath2, &super, 0) == NULL)
 623         return -1;
 624
 625     if (super == NULL)
 626         return -1;
 627
 628     super_data = (sftpfs_super_data_t *) super->data;
 629     if (super_data->sftp_session == NULL)
 630         return -1;
 631
 632     tmp_path = (char *) sftpfs_fix_filename (path_element2->path, &tmp_path_len);
 633     tmp_path = g_strndup (tmp_path, tmp_path_len);
 634
 635     path_element1 = vfs_path_get_by_index (vpath1, -1);
 636
 637     do
 638     {
 639         const char *fixfname;
 640         unsigned int fixfname_len = 0;
 641
 642         fixfname = sftpfs_fix_filename (path_element1->path, &fixfname_len);
 643
 644         res =
 645             libssh2_sftp_rename_ex (super_data->sftp_session, fixfname, fixfname_len, tmp_path,
 646                                     tmp_path_len, LIBSSH2_SFTP_SYMLINK);
 647         if (res >= 0)
 648             break;
 649
 650         if (!sftpfs_waitsocket_or_error (super_data, res, mcerror, tmp_path))
 651             return -1;
 652     }
 653     while (res == LIBSSH2_ERROR_EAGAIN);
 654     g_free (tmp_path);
 655
 656     return 0;
 657 }
 658
 659 /* --------------------------------------------------------------------------------------------- */