source3/modules/vfs_crossrename.c

   1 /*
   2  * Copyright (c) Björn Jacke 2010
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 3 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 #include "includes.h"
  19
  20
  21 #define MODULE "crossrename"
  22 static SMB_OFF_T module_sizelimit;
  23
  24 static int crossrename_connect(
  25                 struct vfs_handle_struct *  handle,
  26                 const char *                service,
  27                 const char *                user)
  28 {
  29         int ret = SMB_VFS_NEXT_CONNECT(handle, service, user);
  30
  31         if (ret < 0) {
  32                 return ret;
  33         }
  34
  35         module_sizelimit = (SMB_OFF_T) lp_parm_int(SNUM(handle->conn),
  36                                         MODULE, "sizelimit", 20);
  37         /* convert from MiB to byte: */
  38         module_sizelimit *= 1048576;
  39
  40         return 0;
  41 }
  42
  43 /*********************************************************
  44  For rename across filesystems initial Patch from Warren Birnbaum
  45  <warrenb@hpcvscdp.cv.hp.com>
  46 **********************************************************/
  47
  48 static int copy_reg(const char *source, const char *dest)
  49 {
  50         SMB_STRUCT_STAT source_stats;
  51         int saved_errno;
  52         int ifd = -1;
  53         int ofd = -1;
  54
  55         if (sys_lstat(source, &source_stats, false) == -1)
  56                 return -1;
  57
  58         if (!S_ISREG (source_stats.st_ex_mode))
  59                 return -1;
  60
  61         if (source_stats.st_ex_size > module_sizelimit) {
  62                 DEBUG(5,
  63                         ("%s: size of %s larger than sizelimit (%lld > %lld), rename prohititted\n",
  64                         MODULE, source,
  65                         (long long)source_stats.st_ex_size,
  66                         (long long)module_sizelimit));
  67                 return -1;
  68         }
  69
  70         if((ifd = sys_open (source, O_RDONLY, 0)) < 0)
  71                 return -1;
  72
  73         if (unlink (dest) && errno != ENOENT)
  74                 return -1;
  75
  76 #ifdef O_NOFOLLOW
  77         if((ofd = sys_open (dest, O_WRONLY | O_CREAT | O_TRUNC | O_NOFOLLOW, 0600)) < 0 )
  78 #else
  79         if((ofd = sys_open (dest, O_WRONLY | O_CREAT | O_TRUNC , 0600)) < 0 )
  80 #endif
  81                 goto err;
  82
  83         if (transfer_file(ifd, ofd, (size_t)-1) == -1)
  84                 goto err;
  85
  86         /*
  87          * Try to preserve ownership.  For non-root it might fail, but that's ok.
  88          * But root probably wants to know, e.g. if NFS disallows it.
  89          */
  90
  91 #ifdef HAVE_FCHOWN
  92         if ((fchown(ofd, source_stats.st_ex_uid, source_stats.st_ex_gid) == -1) && (errno != EPERM))
  93 #else
  94         if ((chown(dest, source_stats.st_ex_uid, source_stats.st_ex_gid) == -1) && (errno != EPERM))
  95 #endif
  96                 goto err;
  97
  98         /*
  99          * fchown turns off set[ug]id bits for non-root,
 100          * so do the chmod last.
 101          */
 102
 103 #if defined(HAVE_FCHMOD)
 104         if (fchmod (ofd, source_stats.st_ex_mode & 07777))
 105 #else
 106         if (chmod (dest, source_stats.st_ex_mode & 07777))
 107 #endif
 108                 goto err;
 109
 110         if (close (ifd) == -1)
 111                 goto err;
 112
 113         if (close (ofd) == -1)
 114                 return -1;
 115
 116         /* Try to copy the old file's modtime and access time.  */
 117 #if defined(HAVE_UTIMENSAT)
 118         {
 119                 struct timespec ts[2];
 120
 121                 ts[0] = source_stats.st_ex_atime;
 122                 ts[1] = source_stats.st_ex_mtime;
 123                 utimensat(AT_FDCWD, dest, ts, AT_SYMLINK_NOFOLLOW);
 124         }
 125 #elif defined(HAVE_UTIMES)
 126         {
 127                 struct timeval tv[2];
 128
 129                 tv[0] = convert_timespec_to_timeval(source_stats.st_ex_atime);
 130                 tv[1] = convert_timespec_to_timeval(source_stats.st_ex_mtime);
 131 #ifdef HAVE_LUTIMES
 132                 lutimes(dest, tv);
 133 #else
 134                 utimes(dest, tv);
 135 #endif
 136         }
 137 #elif defined(HAVE_UTIME)
 138         {
 139                 struct utimbuf tv;
 140
 141                 tv.actime = convert_timespec_to_time_t(source_stats.st_ex_atime);
 142                 tv.modtime = convert_timespec_to_time_t(source_stats.st_ex_mtime);
 143                 utime(dest, &tv);
 144         }
 145 #endif
 146
 147         if (unlink (source) == -1)
 148                 return -1;
 149
 150         return 0;
 151
 152   err:
 153
 154         saved_errno = errno;
 155         if (ifd != -1)
 156                 close(ifd);
 157         if (ofd != -1)
 158                 close(ofd);
 159         errno = saved_errno;
 160         return -1;
 161 }
 162
 163
 164 static int crossrename_rename(vfs_handle_struct *handle,
 165                           const struct smb_filename *smb_fname_src,
 166                           const struct smb_filename *smb_fname_dst)
 167 {
 168         int result = -1;
 169
 170         START_PROFILE(syscall_rename);
 171
 172         if (smb_fname_src->stream_name || smb_fname_dst->stream_name) {
 173                 errno = ENOENT;
 174                 goto out;
 175         }
 176
 177         result = rename(smb_fname_src->base_name, smb_fname_dst->base_name);
 178         if ((result == -1) && (errno == EXDEV)) {
 179                 /* Rename across filesystems needed. */
 180                 result = copy_reg(smb_fname_src->base_name,
 181                                   smb_fname_dst->base_name);
 182         }
 183
 184  out:
 185         END_PROFILE(syscall_rename);
 186         return result;
 187 }
 188
 189 static struct vfs_fn_pointers vfs_crossrename_fns = {
 190         .connect_fn = crossrename_connect,
 191         .rename = crossrename_rename
 192 };
 193
 194 NTSTATUS vfs_crossrename_init(void);
 195 NTSTATUS vfs_crossrename_init(void)
 196 {
 197         return smb_register_vfs(SMB_VFS_INTERFACE_VERSION, MODULE,
 198                                 &vfs_crossrename_fns);
 199 }
 200