source3/modules/vfs_dirsort.c

   1 /*
   2  * VFS module to provide a sorted directory list.
   3  *
   4  * Copyright (C) Andy Kelk (andy@mopoke.co.uk), 2009
   5  *
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 3 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  19  */
  20
  21 #include "includes.h"
  22 #include "smbd/smbd.h"
  23 #include "system/filesys.h"
  24
  25 static int compare_dirent (const SMB_STRUCT_DIRENT *da, const SMB_STRUCT_DIRENT *db)
  26 {
  27         return StrCaseCmp(da->d_name, db->d_name);
  28 }
  29
  30 struct dirsort_privates {
  31         long pos;
  32         SMB_STRUCT_DIRENT *directory_list;
  33         unsigned int number_of_entries;
  34         struct timespec mtime;
  35         SMB_STRUCT_DIR *source_directory;
  36         files_struct *fsp; /* If open via FDOPENDIR. */
  37         struct smb_filename *smb_fname; /* If open via OPENDIR */
  38 };
  39
  40 static void free_dirsort_privates(void **datap) {
  41         TALLOC_FREE(*datap);
  42 }
  43
  44 static bool get_sorted_dir_mtime(vfs_handle_struct *handle,
  45                                 struct dirsort_privates *data,
  46                                 struct timespec *ret_mtime)
  47 {
  48         int ret;
  49         struct timespec mtime;
  50
  51         if (data->fsp) {
  52                 ret = fsp_stat(data->fsp);
  53                 mtime = data->fsp->fsp_name->st.st_ex_mtime;
  54         } else {
  55                 ret = SMB_VFS_STAT(handle->conn, data->smb_fname);
  56                 mtime = data->smb_fname->st.st_ex_mtime;
  57         }
  58
  59         if (ret == -1) {
  60                 return false;
  61         }
  62
  63         *ret_mtime = mtime;
  64
  65         return true;
  66 }
  67
  68 static bool open_and_sort_dir(vfs_handle_struct *handle,
  69                                 struct dirsort_privates *data)
  70 {
  71         unsigned int i = 0;
  72         unsigned int total_count = 0;
  73
  74         data->number_of_entries = 0;
  75
  76         if (get_sorted_dir_mtime(handle, data, &data->mtime) == false) {
  77                 return false;
  78         }
  79
  80         while (SMB_VFS_NEXT_READDIR(handle, data->source_directory, NULL)
  81                != NULL) {
  82                 total_count++;
  83         }
  84
  85         if (total_count == 0) {
  86                 return false;
  87         }
  88
  89         /* Open the underlying directory and count the number of entries
  90            Skip back to the beginning as we'll read it again */
  91         SMB_VFS_NEXT_REWINDDIR(handle, data->source_directory);
  92
  93         /* Set up an array and read the directory entries into it */
  94         TALLOC_FREE(data->directory_list); /* destroy previous cache if needed */
  95         data->directory_list = talloc_zero_array(data,
  96                                                  SMB_STRUCT_DIRENT,
  97                                                  total_count);
  98         if (!data->directory_list) {
  99                 return false;
 100         }
 101         for (i = 0; i < total_count; i++) {
 102                 SMB_STRUCT_DIRENT *dp = SMB_VFS_NEXT_READDIR(handle,
 103                                                 data->source_directory,
 104                                                 NULL);
 105                 if (dp == NULL) {
 106                         break;
 107                 }
 108                 data->directory_list[i] = *dp;
 109         }
 110
 111         data->number_of_entries = i;
 112
 113         /* Sort the directory entries by name */
 114         TYPESAFE_QSORT(data->directory_list, data->number_of_entries, compare_dirent);
 115         return true;
 116 }
 117
 118 static SMB_STRUCT_DIR *dirsort_opendir(vfs_handle_struct *handle,
 119                                        const char *fname, const char *mask,
 120                                        uint32 attr)
 121 {
 122         NTSTATUS status;
 123         struct dirsort_privates *data = NULL;
 124
 125         /* set up our private data about this directory */
 126         data = talloc_zero(handle->conn, struct dirsort_privates);
 127         if (!data) {
 128                 return NULL;
 129         }
 130
 131         status = create_synthetic_smb_fname(data,
 132                                         fname,
 133                                         NULL,
 134                                         NULL,
 135                                         &data->smb_fname);
 136         if (!NT_STATUS_IS_OK(status)) {
 137                 TALLOC_FREE(data);
 138                 return NULL;
 139         }
 140
 141         /* Open the underlying directory and count the number of entries */
 142         data->source_directory = SMB_VFS_NEXT_OPENDIR(handle, fname, mask,
 143                                                       attr);
 144
 145         if (data->source_directory == NULL) {
 146                 TALLOC_FREE(data);
 147                 return NULL;
 148         }
 149
 150         if (!open_and_sort_dir(handle, data)) {
 151                 SMB_VFS_NEXT_CLOSEDIR(handle,data->source_directory);
 152                 TALLOC_FREE(data);
 153                 return NULL;
 154         }
 155
 156         SMB_VFS_HANDLE_SET_DATA(handle, data, free_dirsort_privates,
 157                                 struct dirsort_privates, return NULL);
 158
 159         return data->source_directory;
 160 }
 161
 162 static SMB_STRUCT_DIR *dirsort_fdopendir(vfs_handle_struct *handle,
 163                                         files_struct *fsp,
 164                                         const char *mask,
 165                                         uint32 attr)
 166 {
 167         struct dirsort_privates *data = NULL;
 168
 169         /* set up our private data about this directory */
 170         data = talloc_zero(handle->conn, struct dirsort_privates);
 171         if (!data) {
 172                 return NULL;
 173         }
 174
 175         data->fsp = fsp;
 176
 177         /* Open the underlying directory and count the number of entries */
 178         data->source_directory = SMB_VFS_NEXT_FDOPENDIR(handle, fsp, mask,
 179                                                       attr);
 180
 181         if (data->source_directory == NULL) {
 182                 TALLOC_FREE(data);
 183                 return NULL;
 184         }
 185
 186         if (!open_and_sort_dir(handle, data)) {
 187                 SMB_VFS_NEXT_CLOSEDIR(handle,data->source_directory);
 188                 TALLOC_FREE(data);
 189                 /* fd is now closed. */
 190                 fsp->fh->fd = -1;
 191                 return NULL;
 192         }
 193
 194         SMB_VFS_HANDLE_SET_DATA(handle, data, free_dirsort_privates,
 195                                 struct dirsort_privates, return NULL);
 196
 197         return data->source_directory;
 198 }
 199
 200 static SMB_STRUCT_DIRENT *dirsort_readdir(vfs_handle_struct *handle,
 201                                           SMB_STRUCT_DIR *dirp,
 202                                           SMB_STRUCT_STAT *sbuf)
 203 {
 204         struct dirsort_privates *data = NULL;
 205         struct timespec current_mtime;
 206
 207         SMB_VFS_HANDLE_GET_DATA(handle, data, struct dirsort_privates,
 208                                 return NULL);
 209
 210         if (get_sorted_dir_mtime(handle, data, &current_mtime) == false) {
 211                 return NULL;
 212         }
 213
 214         /* throw away cache and re-read the directory if we've changed */
 215         if (timespec_compare(&current_mtime, &data->mtime) > 1) {
 216                 open_and_sort_dir(handle, data);
 217         }
 218
 219         if (data->pos >= data->number_of_entries) {
 220                 return NULL;
 221         }
 222
 223         return &data->directory_list[data->pos++];
 224 }
 225
 226 static void dirsort_seekdir(vfs_handle_struct *handle, SMB_STRUCT_DIR *dirp,
 227                             long offset)
 228 {
 229         struct dirsort_privates *data = NULL;
 230         SMB_VFS_HANDLE_GET_DATA(handle, data, struct dirsort_privates, return);
 231
 232         data->pos = offset;
 233 }
 234
 235 static long dirsort_telldir(vfs_handle_struct *handle, SMB_STRUCT_DIR *dirp)
 236 {
 237         struct dirsort_privates *data = NULL;
 238         SMB_VFS_HANDLE_GET_DATA(handle, data, struct dirsort_privates,
 239                                 return -1);
 240
 241         return data->pos;
 242 }
 243
 244 static void dirsort_rewinddir(vfs_handle_struct *handle, SMB_STRUCT_DIR *dirp)
 245 {
 246         struct dirsort_privates *data = NULL;
 247         SMB_VFS_HANDLE_GET_DATA(handle, data, struct dirsort_privates, return);
 248
 249         data->pos = 0;
 250 }
 251
 252 static struct vfs_fn_pointers vfs_dirsort_fns = {
 253         .opendir = dirsort_opendir,
 254         .fdopendir = dirsort_fdopendir,
 255         .readdir = dirsort_readdir,
 256         .seekdir = dirsort_seekdir,
 257         .telldir = dirsort_telldir,
 258         .rewind_dir = dirsort_rewinddir,
 259 };
 260
 261 NTSTATUS vfs_dirsort_init(void)
 262 {
 263         return smb_register_vfs(SMB_VFS_INTERFACE_VERSION, "dirsort",
 264                                 &vfs_dirsort_fns);
 265 }