-
Notifications
You must be signed in to change notification settings - Fork 0
/
util-file.c
377 lines (314 loc) · 8.89 KB
/
util-file.c
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
/*****************************************************************************
* $Id: util-file.c 1033 2011-04-06 21:53:48Z chris.m.dunlap $
*****************************************************************************
* Written by Chris Dunlap <cdunlap@llnl.gov>.
* Copyright (C) 2007-2011 Lawrence Livermore National Security, LLC.
* Copyright (C) 2001-2007 The Regents of the University of California.
* UCRL-CODE-2002-009.
*
* This file is part of ConMan: The Console Manager.
* For details, see <http://conman.googlecode.com/>.
*
* ConMan is free software: you can redistribute it and/or modify it under
* the terms of the GNU General Public License as published by the Free
* Software Foundation, either version 3 of the License, or (at your option)
* any later version.
*
* ConMan is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* for more details.
*
* You should have received a copy of the GNU General Public License along
* with ConMan. If not, see <http://www.gnu.org/licenses/>.
*****************************************************************************
* Refer to "util-file.h" for documentation on public functions.
*****************************************************************************/
#if HAVE_CONFIG_H
# include <config.h>
#endif /* HAVE_CONFIG_H */
#include <assert.h>
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <string.h>
#include <sys/stat.h>
#include <unistd.h>
#include "log.h"
#include "util-file.h"
#include "util-str.h"
static int get_file_lock(int fd, int cmd, int type);
static pid_t test_file_lock(int fd, int type);
void set_fd_closed_on_exec(int fd)
{
assert(fd >= 0);
if (fcntl(fd, F_SETFD, FD_CLOEXEC) < 0)
log_err(errno, "fcntl(F_SETFD) failed");
return;
}
void set_fd_blocking(int fd)
{
int fval;
assert(fd >= 0);
if ((fval = fcntl(fd, F_GETFL, 0)) < 0)
log_err(errno, "fcntl(F_GETFL) failed");
if (fcntl(fd, F_SETFL, fval & (~O_NONBLOCK)) < 0)
log_err(errno, "fcntl(F_SETFL) failed");
return;
}
void set_fd_nonblocking(int fd)
{
int fval;
assert(fd >= 0);
if ((fval = fcntl(fd, F_GETFL, 0)) < 0)
log_err(errno, "fcntl(F_GETFL) failed");
if (fcntl(fd, F_SETFL, fval | O_NONBLOCK) < 0)
log_err(errno, "fcntl(F_SETFL) failed");
return;
}
int get_read_lock(int fd)
{
return(get_file_lock(fd, F_SETLK, F_RDLCK));
}
int get_readw_lock(int fd)
{
return(get_file_lock(fd, F_SETLKW, F_RDLCK));
}
int get_write_lock(int fd)
{
return(get_file_lock(fd, F_SETLK, F_WRLCK));
}
int get_writew_lock(int fd)
{
return(get_file_lock(fd, F_SETLKW, F_WRLCK));
}
int release_lock(int fd)
{
return(get_file_lock(fd, F_SETLK, F_UNLCK));
}
pid_t is_read_lock_blocked(int fd)
{
return(test_file_lock(fd, F_RDLCK));
}
pid_t is_write_lock_blocked(int fd)
{
return(test_file_lock(fd, F_WRLCK));
}
static int get_file_lock(int fd, int cmd, int type)
{
struct flock lock;
assert(fd >= 0);
lock.l_type = type;
lock.l_start = 0;
lock.l_whence = SEEK_SET;
lock.l_len = 0;
return(fcntl(fd, cmd, &lock));
}
static pid_t test_file_lock(int fd, int type)
{
struct flock lock;
assert(fd >= 0);
lock.l_type = type;
lock.l_start = 0;
lock.l_whence = SEEK_SET;
lock.l_len = 0;
if (fcntl(fd, F_GETLK, &lock) < 0)
log_err(errno, "Unable to test for file lock");
if (lock.l_type == F_UNLCK)
return(0);
return(lock.l_pid);
}
ssize_t read_n(int fd, void *buf, size_t n)
{
size_t nleft;
ssize_t nread;
unsigned char *p;
p = buf;
nleft = n;
while (nleft > 0) {
if ((nread = read(fd, p, nleft)) < 0) {
if (errno == EINTR)
continue;
else
return(-1);
}
else if (nread == 0) { /* EOF */
break;
}
nleft -= nread;
p += nread;
}
return(n - nleft);
}
ssize_t write_n(int fd, void *buf, size_t n)
{
size_t nleft;
ssize_t nwritten;
unsigned char *p;
p = buf;
nleft = n;
while (nleft > 0) {
if ((nwritten = write(fd, p, nleft)) < 0) {
if (errno == EINTR)
continue;
else
return(-1);
}
nleft -= nwritten;
p += nwritten;
}
return(n);
}
ssize_t read_line(int fd, void *buf, size_t maxlen)
{
ssize_t n, rc;
unsigned char c, *p;
n = 0;
p = buf;
while (n < maxlen - 1) { /* reserve space for NUL-termination */
if ((rc = read(fd, &c, 1)) == 1) {
n++;
*p++ = c;
if (c == '\n')
break; /* store newline, like fgets() */
}
else if (rc == 0) {
if (n == 0) /* EOF, no data read */
return(0);
else /* EOF, some data read */
break;
}
else {
if (errno == EINTR)
continue;
return(-1);
}
}
*p = '\0'; /* NUL-terminate, like fgets() */
return(n);
}
char *
get_dir_name (const char *srcpath, char *dstdir, size_t dstdirlen)
{
const char *p;
int len;
if ((srcpath == NULL) || (dstdir == NULL)) {
errno = EINVAL;
return (NULL);
}
p = srcpath + strlen (srcpath) - 1;
/* Ignore trailing slashes except for the root slash.
*/
while ((p > srcpath) && (*p == '/')) {
p--;
}
/* Skip over last path component.
*/
while ((p >= srcpath) && (*p != '/')) {
p--;
}
/* Skip over adjacent slashes except for the root slash.
*/
while ((p > srcpath) && (*p == '/')) {
p--;
}
/* A path not containing a slash shall return the dot directory.
*/
if (p < srcpath) {
if (dstdirlen < 2) {
errno = ENAMETOOLONG;
return (NULL);
}
dstdir [0] = '.';
dstdir [1] = '\0';
}
/* Otherwise, copy the directory string into dstdir.
*/
else {
len = p - srcpath + 1;
/* Protect against integer overflows and buffer overruns.
*/
if ((len <= 0) || (len >= dstdirlen)) {
errno = ENAMETOOLONG;
return (NULL);
}
(void) strncpy (dstdir, srcpath, len);
dstdir [len] = '\0';
}
return (dstdir);
}
int
create_dirs (const char *dir_name)
{
struct stat st_buf;
char dir_buf [PATH_MAX];
char *p;
char *slash_ptr;
mode_t dir_mode = S_IRWXU | S_IRGRP | S_IXGRP | S_IROTH | S_IXOTH;
if ((dir_name == NULL) || (*dir_name == '\0')) {
errno = EINVAL;
log_msg (LOG_WARNING, "No directory specified for creation");
return (-1);
}
/* Check if the directory already exists.
*/
if (stat (dir_name, &st_buf) == 0) {
if (S_ISDIR (st_buf.st_mode)) {
return (0);
}
errno = EEXIST;
log_msg (LOG_WARNING, "Cannot create directory \"%s\": %s",
dir_name, strerror (errno));
return (-1);
}
/* Create copy of [dir_name] for modification.
*/
if (strlcpy (dir_buf, dir_name, sizeof (dir_buf)) >= sizeof (dir_buf)) {
errno = ENAMETOOLONG;
log_msg (LOG_WARNING, "Exceeded maximum directory length of %d bytes",
sizeof (dir_buf) - 1);
return (-1);
}
/* Remove trailing slashes from the directory name
* (while ensuring the root slash is not removed in the process).
*/
p = dir_buf + strlen (dir_buf) - 1;
while ((p > dir_buf) && (*p == '/')) {
*p-- = '\0';
}
/* The slash_ptr points to the leftmost unprocessed directory component.
*/
slash_ptr = dir_buf;
/* Process directory components.
*/
while (1) {
/* Skip over adjacent slashes (omitting unnecessary calls to mkdir).
*/
while (*slash_ptr == '/') {
slash_ptr++;
}
/* Advance slash_ptr to the next directory component.
*/
slash_ptr = strchr (slash_ptr, '/');
if (slash_ptr != NULL) {
*slash_ptr = '\0';
}
/* Create directory.
*/
if (mkdir (dir_buf, dir_mode) < 0) {
int mkdir_errno = errno;
if ((mkdir_errno != EEXIST)
|| (stat (dir_buf, &st_buf) < 0)
|| (! S_ISDIR (st_buf.st_mode))) {
log_msg (LOG_WARNING, "Cannot create directory \"%s\": %s",
dir_buf, strerror (mkdir_errno));
return (-1);
}
}
if (slash_ptr == NULL) {
break;
}
*slash_ptr++ = '/';
}
return (0);
}