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
|
/*
Anacron - run commands periodically
Copyright (C) 1998 Itai Tzur <itzur@actcom.co.il>
Copyright (C) 1999 Sean 'Shaleh' Perry <shaleh@debian.org>
Copyirght (C) 2004 Pascal Hakim <pasc@redellipse.net>
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 2 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, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
The GNU General Public License can also be found in the file
`COPYING' that comes with the Anacron source distribution.
*/
/* Lock and timestamp management
*/
#include <stdio.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
#include <errno.h>
#include <signal.h>
#include "global.h"
#include "gregor.h"
static void
open_tsfile(job_rec *jr)
/* Open the timestamp file for job jr */
{
jr->timestamp_fd = open(jr->ident, O_RDWR | O_CREAT, S_IRUSR | S_IWUSR);
if (jr->timestamp_fd == -1)
die_e("Can't open timestamp file for job %s", jr->ident);
fcntl(jr->timestamp_fd, F_SETFD, 1); /* set close-on-exec flag */
/* We want to own this file, and set its mode to 0600. This is necessary
* in order to prevent other users from putting locks on it. */
if (fchown(jr->timestamp_fd, getuid(), getgid()))
die_e("Can't chown timestamp file %s", jr->ident);
if (fchmod(jr->timestamp_fd, S_IRUSR | S_IWUSR))
die_e("Can't chmod timestamp file %s", jr->ident);
}
static int
lock_file(int fd)
/* Attempt to put an exclusive fcntl() lock on file "fd"
* Return 1 on success, 0 on failure.
*/
{
int r;
struct flock sfl;
sfl.l_type = F_WRLCK;
sfl.l_start = 0;
sfl.l_whence = SEEK_SET;
sfl.l_len = 0; /* we lock all the file */
errno = 0;
r = fcntl(fd, F_SETLK, &sfl);
if (r != -1) return 1;
if (errno != EACCES && errno != EAGAIN)
die_e("fcntl() error");
return 0;
}
int
consider_job(job_rec *jr)
/* Check the timestamp of the job. If "its time has come", lock the job
* and return 1, if it's too early, or we can't get the lock, return 0.
*/
{
char timestamp[9];
int ts_year, ts_month, ts_day, dn;
ssize_t b;
open_tsfile(jr);
/* read timestamp */
b = read(jr->timestamp_fd, timestamp, 8);
if (b == -1) die_e("Error reading timestamp file %s", jr->ident);
timestamp[8] = 0;
/* is it too early? */
if (!force && b == 8)
{
int day_delta;
if (sscanf(timestamp, "%4d%2d%2d", &ts_year, &ts_month, &ts_day) == 3)
dn = day_num(ts_year, ts_month, ts_day);
else
dn = 0;
day_delta = day_now - dn;
/*
* if day_delta is negative, we assume there was a clock skew
* and re-run any affected jobs
* otherwise we check if the job's time has come
*/
if (day_delta >= 0 && day_delta < jr->period)
{
/* yes, skip job */
xclose(jr->timestamp_fd);
return 0;
}
/*
* Check to see if it's a named period, in which case we need
* to figure it out.
*/
if (jr->named_period)
{
int period = 0, bypass = 0;
switch (jr->named_period)
{
case 1:
period = days_last_month ();
bypass = days_this_month ();
break;
case 2:
period = days_last_year ();
bypass = days_this_year ();
break;
default:
die ("Unknown named period for %s (%d)", jr->ident, jr->named_period);
}
printf ("Checking against %d with %d\n", day_delta, period);
if (day_delta < period && day_delta != bypass)
{
/* Job is still too young */
xclose (jr->timestamp_fd);
return 0;
}
}
}
/* no! try to grab the lock */
if (lock_file(jr->timestamp_fd)) return 1; /* success */
/* didn't get lock */
xclose(jr->timestamp_fd);
explain("Job `%s' locked by another anacron - skipping", jr->ident);
return 0;
}
void
unlock(job_rec *jr)
{
xclose(jr->timestamp_fd);
}
void
update_timestamp(job_rec *jr)
/* We write the date "now". "Now" can be either the time when anacron
* started, or the time when the job finished.
* I'm not quite sure which is more "right", but I've decided on the first
* option.
* Note that this is not the way it was with anacron 1.0.3 to 1.0.7.
*/
{
char stamp[10];
snprintf(stamp, 10, "%04d%02d%02d\n", year, month, day_of_month);
if (lseek(jr->timestamp_fd, 0, SEEK_SET))
die_e("Can't lseek timestamp file for job %s", jr->ident);
if (write(jr->timestamp_fd, stamp, 9) != 9)
die_e("Can't write timestamp file for job %s", jr->ident);
if (ftruncate(jr->timestamp_fd, 9))
die_e("ftruncate error");
}
void
fake_job(job_rec *jr)
/* We don't bother with any locking here. There's no point. */
{
open_tsfile(jr);
update_timestamp(jr);
xclose(jr->timestamp_fd);
}
|