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 #include "smbd/smbd.h"
  20 #include "system/filesys.h"
  21 #include "transfer_file.h"
  22 #include "smbprofile.h"
  23
  24 #define MODULE "crossrename"
  25 static off_t module_sizelimit;
  26
  27 static int crossrename_connect(
  28                 struct vfs_handle_struct *  handle,
  29                 const char *                service,
  30                 const char *                user)
  31 {
  32         int ret = SMB_VFS_NEXT_CONNECT(handle, service, user);
  33
  34         if (ret < 0) {
  35                 return ret;
  36         }
  37
  38         module_sizelimit = (off_t) lp_parm_int(SNUM(handle->conn),
  39                                         MODULE, "sizelimit", 20);
  40         /* convert from MiB to byte: */
  41         module_sizelimit *= 1048576;
  42
  43         return 0;
  44 }
  45
  46 /*********************************************************
  47  For rename across filesystems initial Patch from Warren Birnbaum
  48  <warrenb@hpcvscdp.cv.hp.com>
  49 **********************************************************/
  50
  51 static int copy_reg(const char *source, const char *dest)
  52 {
  53         SMB_STRUCT_STAT source_stats;
  54         int saved_errno;
  55         int ifd = -1;
  56         int ofd = -1;
  57
  58         if (sys_lstat(source, &source_stats, false) == -1)
  59                 return -1;
  60
  61         if (!S_ISREG (source_stats.st_ex_mode))
  62                 return -1;
  63
  64         if (source_stats.st_ex_size > module_sizelimit) {
  65                 DEBUG(5,
  66                         ("%s: size of %s larger than sizelimit (%lld > %lld), rename prohititted\n",
  67                         MODULE, source,
  68                         (long long)source_stats.st_ex_size,
  69                         (long long)module_sizelimit));
  70                 return -1;
  71         }
  72
  73         if((ifd = open (source, O_RDONLY, 0)) < 0)
  74                 return -1;
  75
  76         if (unlink (dest) && errno != ENOENT) {
  77                 close(ifd);
  78                 return -1;
  79         }
  80
  81 #ifdef O_NOFOLLOW
  82         if((ofd = open (dest, O_WRONLY | O_CREAT | O_TRUNC | O_NOFOLLOW, 0600)) < 0 )
  83 #else
  84         if((ofd = open (dest, O_WRONLY | O_CREAT | O_TRUNC , 0600)) < 0 )
  85 #endif
  86                 goto err;
  87
  88         if (transfer_file(ifd, ofd, source_stats.st_ex_size) == -1)
  89                 goto err;
  90
  91         /*
  92          * Try to preserve ownership.  For non-root it might fail, but that's ok.
  93          * But root probably wants to know, e.g. if NFS disallows it.
  94          */
  95
  96 #ifdef HAVE_FCHOWN
  97         if ((fchown(ofd, source_stats.st_ex_uid, source_stats.st_ex_gid) == -1) && (errno != EPERM))
  98 #else
  99         if ((chown(dest, source_stats.st_ex_uid, source_stats.st_ex_gid) == -1) && (errno != EPERM))
 100 #endif
 101                 goto err;
 102
 103         /*
 104          * fchown turns off set[ug]id bits for non-root,
 105          * so do the chmod last.
 106          */
 107
 108 #if defined(HAVE_FCHMOD)
 109         if (fchmod (ofd, source_stats.st_ex_mode & 07777))
 110 #else
 111         if (chmod (dest, source_stats.st_ex_mode & 07777))
 112 #endif
 113                 goto err;
 114
 115         if (close (ifd) == -1)
 116                 goto err;
 117
 118         if (close (ofd) == -1)
 119                 return -1;
 120
 121         /* Try to copy the old file's modtime and access time.  */
 122 #if defined(HAVE_UTIMENSAT)
 123         {
 124                 struct timespec ts[2];
 125
 126                 ts[0] = source_stats.st_ex_atime;
 127                 ts[1] = source_stats.st_ex_mtime;
 128                 utimensat(AT_FDCWD, dest, ts, AT_SYMLINK_NOFOLLOW);
 129         }
 130 #elif defined(HAVE_UTIMES)
 131         {
 132                 struct timeval tv[2];
 133
 134                 tv[0] = convert_timespec_to_timeval(source_stats.st_ex_atime);
 135                 tv[1] = convert_timespec_to_timeval(source_stats.st_ex_mtime);
 136 #ifdef HAVE_LUTIMES
 137                 lutimes(dest, tv);
 138 #else
 139                 utimes(dest, tv);
 140 #endif
 141         }
 142 #elif defined(HAVE_UTIME)
 143         {
 144                 struct utimbuf tv;
 145
 146                 tv.actime = convert_timespec_to_time_t(source_stats.st_ex_atime);
 147                 tv.modtime = convert_timespec_to_time_t(source_stats.st_ex_mtime);
 148                 utime(dest, &tv);
 149         }
 150 #endif
 151
 152         if (unlink (source) == -1)
 153                 return -1;
 154
 155         return 0;
 156
 157   err:
 158
 159         saved_errno = errno;
 160         if (ifd != -1)
 161                 close(ifd);
 162         if (ofd != -1)
 163                 close(ofd);
 164         errno = saved_errno;
 165         return -1;
 166 }
 167
 168
 169 static int crossrename_rename(vfs_handle_struct *handle,
 170                           const struct smb_filename *smb_fname_src,
 171                           const struct smb_filename *smb_fname_dst)
 172 {
 173         int result = -1;
 174
 175         START_PROFILE(syscall_rename);
 176
 177         if (smb_fname_src->stream_name || smb_fname_dst->stream_name) {
 178                 errno = ENOENT;
 179                 goto out;
 180         }
 181
 182         result = rename(smb_fname_src->base_name, smb_fname_dst->base_name);
 183         if ((result == -1) && (errno == EXDEV)) {
 184                 /* Rename across filesystems needed. */
 185                 result = copy_reg(smb_fname_src->base_name,
 186                                   smb_fname_dst->base_name);
 187         }
 188
 189  out:
 190         END_PROFILE(syscall_rename);
 191         return result;
 192 }
 193
 194 static struct vfs_fn_pointers vfs_crossrename_fns = {
 195         .connect_fn = crossrename_connect,
 196         .rename_fn = crossrename_rename
 197 };
 198
 199 NTSTATUS vfs_crossrename_init(void);
 200 NTSTATUS vfs_crossrename_init(void)
 201 {
 202         return smb_register_vfs(SMB_VFS_INTERFACE_VERSION, MODULE,
 203                                 &vfs_crossrename_fns);
 204 }
 205