s3:libsmb/ntlmssp: an empty string should mean no password
[Samba/gebeck_regimport.git] / lib / replace / repdir_getdirentries.c
blob197e5931fc7e48e2540c6f9dade2fced3848b449
1 /*
2 Unix SMB/CIFS implementation.
4 Copyright (C) Andrew Tridgell 2005
6 ** NOTE! The following LGPL license applies to the replace
7 ** library. This does NOT imply that all of Samba is released
8 ** under the LGPL
10 This library is free software; you can redistribute it and/or
11 modify it under the terms of the GNU Lesser General Public
12 License as published by the Free Software Foundation; either
13 version 3 of the License, or (at your option) any later version.
15 This library is distributed in the hope that it will be useful,
16 but WITHOUT ANY WARRANTY; without even the implied warranty of
17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 Lesser General Public License for more details.
20 You should have received a copy of the GNU Lesser General Public
21 License along with this library; if not, see <http://www.gnu.org/licenses/>.
24 a replacement for opendir/readdir/telldir/seekdir/closedir for BSD
25 systems using getdirentries
27 This is needed because the existing directory handling in FreeBSD
28 and OpenBSD (and possibly NetBSD) doesn't correctly handle unlink()
29 on files in a directory where telldir() has been used. On a block
30 boundary it will occasionally miss a file when seekdir() is used to
31 return to a position previously recorded with telldir().
33 This also fixes a severe performance and memory usage problem with
34 telldir() on BSD systems. Each call to telldir() in BSD adds an
35 entry to a linked list, and those entries are cleaned up on
36 closedir(). This means with a large directory closedir() can take an
37 arbitrary amount of time, causing network timeouts as millions of
38 telldir() entries are freed
40 Note! This replacement code is not portable. It relies on
41 getdirentries() always leaving the file descriptor at a seek offset
42 that is a multiple of DIR_BUF_SIZE. If the code detects that this
43 doesn't happen then it will abort(). It also does not handle
44 directories with offsets larger than can be stored in a long,
46 This code is available under other free software licenses as
47 well. Contact the author.
50 #include "replace.h"
51 #include <stdlib.h>
52 #include <sys/stat.h>
53 #include <unistd.h>
54 #include <sys/types.h>
55 #include <errno.h>
56 #include <fcntl.h>
57 #include <dirent.h>
59 #define DIR_BUF_BITS 9
60 #define DIR_BUF_SIZE (1<<DIR_BUF_BITS)
62 struct dir_buf {
63 int fd;
64 int nbytes, ofs;
65 off_t seekpos;
66 char buf[DIR_BUF_SIZE];
69 DIR *opendir(const char *dname)
71 struct dir_buf *d;
72 struct stat sb;
73 d = malloc(sizeof(*d));
74 if (d == NULL) {
75 errno = ENOMEM;
76 return NULL;
78 d->fd = open(dname, O_RDONLY);
79 if (d->fd == -1) {
80 free(d);
81 return NULL;
83 if (fstat(d->fd, &sb) < 0) {
84 close(d->fd);
85 free(d);
86 return NULL;
88 if (!S_ISDIR(sb.st_mode)) {
89 close(d->fd);
90 free(d);
91 errno = ENOTDIR;
92 return NULL;
94 d->ofs = 0;
95 d->seekpos = 0;
96 d->nbytes = 0;
97 return (DIR *)d;
100 struct dirent *readdir(DIR *dir)
102 struct dir_buf *d = (struct dir_buf *)dir;
103 struct dirent *de;
105 if (d->ofs >= d->nbytes) {
106 long pos;
107 d->nbytes = getdirentries(d->fd, d->buf, DIR_BUF_SIZE, &pos);
108 d->seekpos = pos;
109 d->ofs = 0;
111 if (d->ofs >= d->nbytes) {
112 return NULL;
114 de = (struct dirent *)&d->buf[d->ofs];
115 d->ofs += de->d_reclen;
116 return de;
119 #ifdef TELLDIR_TAKES_CONST_DIR
120 long telldir(const DIR *dir)
121 #else
122 long telldir(DIR *dir)
123 #endif
125 struct dir_buf *d = (struct dir_buf *)dir;
126 if (d->ofs >= d->nbytes) {
127 d->seekpos = lseek(d->fd, 0, SEEK_CUR);
128 d->ofs = 0;
129 d->nbytes = 0;
131 /* this relies on seekpos always being a multiple of
132 DIR_BUF_SIZE. Is that always true on BSD systems? */
133 if (d->seekpos & (DIR_BUF_SIZE-1)) {
134 abort();
136 return d->seekpos + d->ofs;
139 #ifdef SEEKDIR_RETURNS_INT
140 int seekdir(DIR *dir, long ofs)
141 #else
142 void seekdir(DIR *dir, long ofs)
143 #endif
145 struct dir_buf *d = (struct dir_buf *)dir;
146 long pos;
147 d->seekpos = lseek(d->fd, ofs & ~(DIR_BUF_SIZE-1), SEEK_SET);
148 d->nbytes = getdirentries(d->fd, d->buf, DIR_BUF_SIZE, &pos);
149 d->ofs = 0;
150 while (d->ofs < (ofs & (DIR_BUF_SIZE-1))) {
151 if (readdir(dir) == NULL) break;
153 #ifdef SEEKDIR_RETURNS_INT
154 return -1;
155 #endif
158 void rewinddir(DIR *dir)
160 seekdir(dir, 0);
163 int closedir(DIR *dir)
165 struct dir_buf *d = (struct dir_buf *)dir;
166 int r = close(d->fd);
167 if (r != 0) {
168 return r;
170 free(d);
171 return 0;
174 #ifndef dirfd
175 /* darn, this is a macro on some systems. */
176 int dirfd(DIR *dir)
178 struct dir_buf *d = (struct dir_buf *)dir;
179 return d->fd;
181 #endif