mkpath.c

/*
   BAREOS® - Backup Archiving REcovery Open Sourced

   Copyright (C) 2007-2011 Free Software Foundation Europe e.V.

   This program is Free Software; you can redistribute it and/or
   modify it under the terms of version three of the GNU Affero General Public
   License as published by the Free Software Foundation and included
   in the file LICENSE.

   This program 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
   Affero General Public License for more details.

   You should have received a copy of the GNU Affero General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
   02110-1301, USA.
*/

/*
 * Kern Sibbald, September MMVII
 *
 * This is tricky code, especially when writing from scratch. Fortunately,
 * a non-copyrighted version of mkdir was available to consult.
 *
 * ***FIXME*** the mkpath code could be significantly optimized by
 * walking up the path chain from the bottom until it either gets
 * to the top or finds an existing directory then walk back down
 * creating the path components.  Currently, it always starts at
 * the top, which can be rather inefficient for long path names.
 */
#include "bareos.h"
#include "jcr.h"

#define dbglvl 50

/*
 *  * For old systems that don't have lchown() use chown()
 *   */
#ifndef HAVE_LCHOWN
#define lchown chown
#endif

/*
 *  * For old systems that don't have lchmod() use chmod()
 *   */
#ifndef HAVE_LCHMOD
#define lchmod chmod
#endif

typedef struct PrivateCurDir {
   hlink link;
   char fname[1];
} CurDir;

/* Initialize the path hash table */
static bool path_list_init(JCR *jcr)
{
   CurDir *elt = NULL;
   jcr->path_list = (htable *)malloc(sizeof(htable));

   /* Hard to know in advance how many directories will
    * be stored in this hash
    */
   jcr->path_list->init(elt, &elt->link, 10000);
   return true;
}

/* Add a path to the hash when we create a directory
 * with the replace=NEVER option
 */
bool path_list_add(JCR *jcr, uint32_t len, char *fname)
{
   bool ret = true;
   CurDir *item;

   if (!jcr->path_list) {
      path_list_init(jcr);
   }

   /* we store CurDir, fname in the same chunk */
   item = (CurDir *)jcr->path_list->hash_malloc(sizeof(CurDir)+len+1);

   memset(item, 0, sizeof(CurDir));
   memcpy(item->fname, fname, len+1);

   jcr->path_list->insert(item->fname, item);

   Dmsg1(dbglvl, "add fname=<%s>\n", fname);
   return ret;
}

void free_path_list(JCR *jcr)
{
   if (jcr->path_list) {
      jcr->path_list->destroy();
      free(jcr->path_list);
      jcr->path_list = NULL;
   }
}

bool path_list_lookup(JCR *jcr, char *fname)
{
   bool found=false;
   char bkp;

   if (!jcr->path_list) {
      return false;
   }

   /* Strip trailing / */
   int len = strlen(fname);
   if (len == 0) {
      return false;
   }
   len--;
   bkp = fname[len];
   if (fname[len] == '/') {       /* strip any trailing slash */
      fname[len] = 0;
   }

   CurDir *temp = (CurDir *)jcr->path_list->lookup(fname);
   if (temp) {
      found=true;
   }

   Dmsg2(dbglvl, "lookup <%s> %s\n", fname, found?"ok":"not ok");

   fname[len] = bkp;            /* restore last / */
   return found;
}

static bool makedir(JCR *jcr, char *path, mode_t mode, int *created)
{
   struct stat statp;

   if (mkdir(path, mode) != 0) {
      berrno be;
      *created = false;
      if (stat(path, &statp) != 0) {
         Jmsg2(jcr, M_ERROR, 0, _("Cannot create directory %s: ERR=%s\n"),
              path, be.bstrerror());
         return false;
      } else if (!S_ISDIR(statp.st_mode)) {
         Jmsg1(jcr, M_ERROR, 0, _("%s exists but is not a directory.\n"), path);
         return false;
      }
      return true;                 /* directory exists */
   }

   if (jcr->keep_path_list) {
      /* When replace=NEVER, we keep track of all directories newly created */
      path_list_add(jcr, strlen(path), path);
   }

   *created = true;
   return true;
}

static void set_own_mod(ATTR *attr, char *path, uid_t owner, gid_t group, mode_t mode)
{
   if (lchown(path, owner, group) != 0 && attr->uid == 0
#ifdef AFS
        && errno != EPERM
#endif
   ) {
      berrno be;
      Jmsg2(attr->jcr, M_WARNING, 0, _("Cannot change owner and/or group of %s: ERR=%s\n"),
           path, be.bstrerror());
   }
#if defined(HAVE_WIN32)
   if (win32_chmod(path, mode, 0) != 0 && attr->uid == 0) {
#else
   if (lchmod(path, mode) != 0 && attr->uid == 0) {
#endif
      berrno be;
      Jmsg2(attr->jcr, M_WARNING, 0, _("Cannot change permissions of %s: ERR=%s\n"),
           path, be.bstrerror());
   }
}

/*
 * mode is the mode bits to use in creating a new directory
 * parent_mode are the parent's modes if we need to create parent directories.
 * owner and group are to set on any created dirs
 * keep_dir_modes if set means don't change mode bits if dir exists
 */
bool makepath(ATTR *attr, const char *apath, mode_t mode, mode_t parent_mode,
              uid_t owner, gid_t group, bool keep_dir_modes)
{
   struct stat statp;
   mode_t omask, tmode;
   char *path = (char *)apath;
   char *p;
   int len;
   bool ok = false;
   int created;
   char new_dir[5000];
   int ndir = 0;
   int i = 0;
   int max_dirs = (int)sizeof(new_dir);
   JCR *jcr = attr->jcr;

   if (stat(path, &statp) == 0) {     /* Does dir exist? */
      if (!S_ISDIR(statp.st_mode)) {
         Jmsg1(jcr, M_ERROR, 0, _("%s exists but is not a directory.\n"), path);
         return false;
      }
      /* Full path exists */
      if (keep_dir_modes) {
         return true;
      }
      set_own_mod(attr, path, owner, group, mode);
      return true;
   }
   omask = umask(0);
   umask(omask);
   len = strlen(apath);
   path = (char *)alloca(len+1);
   bstrncpy(path, apath, len+1);
   strip_trailing_slashes(path);
   /*
    * Now for one of the complexities. If we are not running as root,
    * then if the parent_mode does not have wx user perms, or we are
    * setting the userid or group, and the parent_mode has setuid, setgid,
    * or sticky bits, we must create the dir with open permissions, then
    * go back and patch all the dirs up with the correct perms.
    * Solution, set everything to 0777, then go back and reset them at the
    * end.
    */
   tmode = 0777;

#if defined(HAVE_WIN32)
   /*
    * Validate drive letter
    */
   if (path[1] == ':') {
      char drive[4] = "X:\\";

      drive[0] = path[0];

      UINT drive_type = GetDriveType(drive);

      if (drive_type == DRIVE_UNKNOWN || drive_type == DRIVE_NO_ROOT_DIR) {
         Jmsg1(jcr, M_ERROR, 0, _("%c: is not a valid drive.\n"), path[0]);
         goto bail_out;
      }

      if (path[2] == '\0') {          /* attempt to create a drive */
         ok = true;
         goto bail_out;               /* OK, it is already there */
      }

      p = &path[3];
   } else {
      p = path;
   }
#else
   p = path;
#endif

   /*
    * Skip leading slash(es)
    */
   while (IsPathSeparator(*p)) {
      p++;
   }
   while ((p = first_path_separator(p))) {
      char save_p;
      save_p = *p;
      *p = 0;
      if (!makedir(jcr, path, tmode, &created)) {
         goto bail_out;
      }
      if (ndir < max_dirs) {
         new_dir[ndir++] = created;
      }
      *p = save_p;
      while (IsPathSeparator(*p)) {
         p++;
      }
   }
   /*
    * Create final component if not a junction/symlink
    */
   if(attr->type != FT_JUNCTION ){
      if (!makedir(jcr, path, tmode, &created)) {
         goto bail_out;
      }
   }

   if (ndir < max_dirs) {
      new_dir[ndir++] = created;
   }
   if (ndir >= max_dirs) {
      Jmsg0(jcr, M_WARNING, 0, _("Too many subdirectories. Some permissions not reset.\n"));
   }

   /*
    * Now set the proper owner and modes
    */
#if defined(HAVE_WIN32)

   /*
    * Don't propagate the hidden attribute to parent directories
    */
   parent_mode &= ~S_ISVTX;

   if (path[1] == ':') {
      p = &path[3];
   } else {
      p = path;
   }
#else
   p = path;
#endif
   /*
    * Skip leading slash(es)
    */
   while (IsPathSeparator(*p)) {
      p++;
   }
   while ((p = first_path_separator(p))) {
      char save_p;
      save_p = *p;
      *p = 0;
      if (i < ndir && new_dir[i++] && !keep_dir_modes) {
         set_own_mod(attr, path, owner, group, parent_mode);
      }
      *p = save_p;
      while (IsPathSeparator(*p)) {
         p++;
      }
   }

   /*
    * Set for final component
    */
   if (i < ndir && new_dir[i++]) {
      set_own_mod(attr, path, owner, group, mode);
   }

   ok = true;
bail_out:
   umask(omask);
   return ok;
}