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
|
/*
Unix SMB/CIFS implementation.
pidfile handling
Copyright (C) Andrew Tridgell 1998
Copyright (C) Amitay Isaccs 2016
This program 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.
This program 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 this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "replace.h"
#include "system/filesys.h"
#include "lib/util/blocking.h"
#include "lib/util/debug.h"
#include "lib/util/samba_util.h" /* For process_exists_by_pid() */
#include "lib/util/pidfile.h"
int pidfile_path_create(const char *path, int *outfd)
{
struct flock lck;
char tmp[64] = { 0 };
pid_t pid;
int fd, ret = 0;
int len;
ssize_t nwritten;
pid = getpid();
fd = open(path, O_CREAT|O_WRONLY|O_NONBLOCK, 0644);
if (fd == -1) {
return errno;
}
if (! set_close_on_exec(fd)) {
close(fd);
return EIO;
}
lck = (struct flock) {
.l_type = F_WRLCK,
.l_whence = SEEK_SET,
};
do {
ret = fcntl(fd, F_SETLK, &lck);
} while ((ret == -1) && (errno == EINTR));
if (ret != 0) {
ret = errno;
close(fd);
return ret;
}
/*
* PID file is locked by us so from here on we should unlink
* on failure
*/
do {
ret = ftruncate(fd, 0);
} while ((ret == -1) && (errno == EINTR));
if (ret == -1) {
ret = EIO;
goto fail_unlink;
}
len = snprintf(tmp, sizeof(tmp), "%u\n", pid);
if (len < 0) {
ret = errno;
goto fail_unlink;
}
if (len >= sizeof(tmp)) {
ret = ENOSPC;
goto fail_unlink;
}
do {
nwritten = write(fd, tmp, len);
} while ((nwritten == -1) && (errno == EINTR));
if ((nwritten == -1) || (nwritten != len)) {
ret = EIO;
goto fail_unlink;
}
if (outfd != NULL) {
*outfd = fd;
}
return 0;
fail_unlink:
unlink(path);
close(fd);
return ret;
}
void pidfile_fd_close(int fd)
{
struct flock lck = {
.l_type = F_UNLCK,
.l_whence = SEEK_SET,
};
int ret;
do {
ret = fcntl(fd, F_SETLK, &lck);
} while ((ret == -1) && (errno == EINTR));
do {
ret = close(fd);
} while ((ret == -1) && (errno == EINTR));
}
/**
* return the pid in a pidfile. return 0 if the process (or pidfile)
* does not exist
*/
pid_t pidfile_pid(const char *piddir, const char *name)
{
size_t len = strlen(piddir) + strlen(name) + 6;
char pidFile[len];
int fd;
char pidstr[20];
pid_t ret = -1;
snprintf(pidFile, sizeof(pidFile), "%s/%s.pid", piddir, name);
fd = open(pidFile, O_NONBLOCK | O_RDONLY, 0644);
if (fd == -1) {
return 0;
}
ZERO_STRUCT(pidstr);
if (read(fd, pidstr, sizeof(pidstr)-1) <= 0) {
goto noproc;
}
ret = (pid_t)atoi(pidstr);
if (ret <= 0) {
DEBUG(1, ("Could not parse contents of pidfile %s\n",
pidFile));
goto noproc;
}
if (!process_exists_by_pid(ret)) {
DEBUG(10, ("Process with PID=%d does not exist.\n", (int)ret));
goto noproc;
}
if (fcntl_lock(fd,F_SETLK,0,1,F_RDLCK)) {
/* we could get the lock - it can't be a Samba process */
DEBUG(10, ("Process with PID=%d is not a Samba process.\n",
(int)ret));
goto noproc;
}
close(fd);
DEBUG(10, ("Process with PID=%d is running.\n", (int)ret));
return ret;
noproc:
close(fd);
return 0;
}
/**
* create a pid file in the pid directory. open it and leave it locked
*/
void pidfile_create(const char *piddir, const char *name)
{
size_t len = strlen(piddir) + strlen(name) + 6;
char pidFile[len];
pid_t pid;
int ret;
snprintf(pidFile, sizeof(pidFile), "%s/%s.pid", piddir, name);
pid = pidfile_pid(piddir, name);
if (pid != 0) {
DEBUG(0,("ERROR: %s is already running. File %s exists and process id %d is running.\n",
name, pidFile, (int)pid));
exit(1);
}
ret = pidfile_path_create(pidFile, NULL);
if (ret != 0) {
DBG_ERR("ERROR: Failed to create PID file %s (%s)\n",
pidFile, strerror(ret));
exit(1);
}
/* Leave pid file open & locked for the duration... */
}
void pidfile_unlink(const char *piddir, const char *name)
{
int ret;
char *pidFile = NULL;
if (asprintf(&pidFile, "%s/%s.pid", piddir, name) < 0) {
DEBUG(0,("ERROR: Out of memory\n"));
exit(1);
}
ret = unlink(pidFile);
if (ret == -1) {
DEBUG(0,("Failed to delete pidfile %s. Error was %s\n",
pidFile, strerror(errno)));
}
}
|
