s3-vfs: Use the system. namespace for fake ACLs
[kai/samba.git] / 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 struct dirent *da, const struct dirent *db)
26 {
27         return strcasecmp_m(da->d_name, db->d_name);
28 }
29
30 struct dirsort_privates {
31         long pos;
32         struct dirent *directory_list;
33         long number_of_entries;
34         time_t mtime;
35         DIR *source_directory;
36         int fd;
37 };
38
39 static void free_dirsort_privates(void **datap) {
40         struct dirsort_privates *data = (struct dirsort_privates *) *datap;
41         SAFE_FREE(data->directory_list);
42         SAFE_FREE(data);
43         *datap = NULL;
44 }
45
46 static bool open_and_sort_dir (vfs_handle_struct *handle)
47 {
48         struct dirent *dp;
49         struct stat dir_stat;
50         long current_pos;
51         struct dirsort_privates *data = NULL;
52
53         SMB_VFS_HANDLE_GET_DATA(handle, data, struct dirsort_privates,
54                                 return false);
55
56         data->number_of_entries = 0;
57
58         if (fstat(data->fd, &dir_stat) == 0) {
59                 data->mtime = dir_stat.st_mtime;
60         }
61
62         while (SMB_VFS_NEXT_READDIR(handle, data->source_directory, NULL)
63                != NULL) {
64                 data->number_of_entries++;
65         }
66
67         /* Open the underlying directory and count the number of entries
68            Skip back to the beginning as we'll read it again */
69         SMB_VFS_NEXT_REWINDDIR(handle, data->source_directory);
70
71         /* Set up an array and read the directory entries into it */
72         SAFE_FREE(data->directory_list); /* destroy previous cache if needed */
73         data->directory_list = (struct dirent *)SMB_MALLOC(
74                 data->number_of_entries * sizeof(struct dirent));
75         if (!data->directory_list) {
76                 return false;
77         }
78         current_pos = data->pos;
79         data->pos = 0;
80         while ((dp = SMB_VFS_NEXT_READDIR(handle, data->source_directory,
81                                           NULL)) != NULL) {
82                 data->directory_list[data->pos++] = *dp;
83         }
84
85         /* Sort the directory entries by name */
86         data->pos = current_pos;
87         TYPESAFE_QSORT(data->directory_list, data->number_of_entries, compare_dirent);
88         return true;
89 }
90
91 static DIR *dirsort_opendir(vfs_handle_struct *handle,
92                                        const char *fname, const char *mask,
93                                        uint32 attr)
94 {
95         struct dirsort_privates *data = NULL;
96
97         /* set up our private data about this directory */
98         data = (struct dirsort_privates *)SMB_MALLOC(
99                 sizeof(struct dirsort_privates));
100
101         if (!data) {
102                 return NULL;
103         }
104
105         data->directory_list = NULL;
106         data->pos = 0;
107
108         /* Open the underlying directory and count the number of entries */
109         data->source_directory = SMB_VFS_NEXT_OPENDIR(handle, fname, mask,
110                                                       attr);
111
112         data->fd = dirfd(data->source_directory);
113
114         SMB_VFS_HANDLE_SET_DATA(handle, data, free_dirsort_privates,
115                                 struct dirsort_privates, return NULL);
116
117         if (!open_and_sort_dir(handle)) {
118                 SMB_VFS_NEXT_CLOSEDIR(handle,data->source_directory);
119                 return NULL;
120         }
121
122         return data->source_directory;
123 }
124
125 static DIR *dirsort_fdopendir(vfs_handle_struct *handle,
126                                         files_struct *fsp,
127                                         const char *mask,
128                                         uint32 attr)
129 {
130         struct dirsort_privates *data = NULL;
131
132         /* set up our private data about this directory */
133         data = (struct dirsort_privates *)SMB_MALLOC(
134                 sizeof(struct dirsort_privates));
135
136         if (!data) {
137                 return NULL;
138         }
139
140         data->directory_list = NULL;
141         data->pos = 0;
142
143         /* Open the underlying directory and count the number of entries */
144         data->source_directory = SMB_VFS_NEXT_FDOPENDIR(handle, fsp, mask,
145                                                       attr);
146
147         if (data->source_directory == NULL) {
148                 SAFE_FREE(data);
149                 return NULL;
150         }
151
152         data->fd = dirfd(data->source_directory);
153
154         SMB_VFS_HANDLE_SET_DATA(handle, data, free_dirsort_privates,
155                                 struct dirsort_privates, return NULL);
156
157         if (!open_and_sort_dir(handle)) {
158                 SMB_VFS_NEXT_CLOSEDIR(handle,data->source_directory);
159                 /* fd is now closed. */
160                 fsp->fh->fd = -1;
161                 return NULL;
162         }
163
164         return data->source_directory;
165 }
166
167 static struct dirent *dirsort_readdir(vfs_handle_struct *handle,
168                                           DIR *dirp,
169                                           SMB_STRUCT_STAT *sbuf)
170 {
171         struct dirsort_privates *data = NULL;
172         time_t current_mtime;
173         struct stat dir_stat;
174
175         SMB_VFS_HANDLE_GET_DATA(handle, data, struct dirsort_privates,
176                                 return NULL);
177
178         if (fstat(data->fd, &dir_stat) == -1) {
179                 return NULL;
180         }
181
182         current_mtime = dir_stat.st_mtime;
183
184         /* throw away cache and re-read the directory if we've changed */
185         if (current_mtime > data->mtime) {
186                 open_and_sort_dir(handle);
187         }
188
189         if (data->pos >= data->number_of_entries) {
190                 return NULL;
191         }
192
193         return &data->directory_list[data->pos++];
194 }
195
196 static void dirsort_seekdir(vfs_handle_struct *handle, DIR *dirp,
197                             long offset)
198 {
199         struct dirsort_privates *data = NULL;
200         SMB_VFS_HANDLE_GET_DATA(handle, data, struct dirsort_privates, return);
201
202         data->pos = offset;
203 }
204
205 static long dirsort_telldir(vfs_handle_struct *handle, DIR *dirp)
206 {
207         struct dirsort_privates *data = NULL;
208         SMB_VFS_HANDLE_GET_DATA(handle, data, struct dirsort_privates,
209                                 return -1);
210
211         return data->pos;
212 }
213
214 static void dirsort_rewinddir(vfs_handle_struct *handle, DIR *dirp)
215 {
216         struct dirsort_privates *data = NULL;
217         SMB_VFS_HANDLE_GET_DATA(handle, data, struct dirsort_privates, return);
218
219         data->pos = 0;
220 }
221
222 static struct vfs_fn_pointers vfs_dirsort_fns = {
223         .opendir_fn = dirsort_opendir,
224         .fdopendir_fn = dirsort_fdopendir,
225         .readdir_fn = dirsort_readdir,
226         .seekdir_fn = dirsort_seekdir,
227         .telldir_fn = dirsort_telldir,
228         .rewind_dir_fn = dirsort_rewinddir,
229 };
230
231 NTSTATUS vfs_dirsort_init(void)
232 {
233         return smb_register_vfs(SMB_VFS_INTERFACE_VERSION, "dirsort",
234                                 &vfs_dirsort_fns);
235 }