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
|
/*
Simple prototype Xen Store Daemon providing simple tree-like database.
Copyright (C) 2005 Rusty Russell IBM Corporation
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
*/
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <fcntl.h>
#include <stdlib.h>
#include <sys/mman.h>
#include "utils.h"
#include "xenstored_core.h"
void write_pidfile(const char *pidfile)
{
char buf[100];
int len;
int fd;
fd = open(pidfile, O_RDWR | O_CREAT, 0600);
if (fd == -1)
barf_perror("Opening pid file %s", pidfile);
/* We exit silently if daemon already running. */
if (lockf(fd, F_TLOCK, 0) == -1)
exit(0);
len = snprintf(buf, sizeof(buf), "%ld\n", (long)getpid());
if (write(fd, buf, len) != len)
barf_perror("Writing pid file %s", pidfile);
}
/* Stevens. */
void daemonize(void)
{
pid_t pid;
/* Separate from our parent via fork, so init inherits us. */
if ((pid = fork()) < 0)
barf_perror("Failed to fork daemon");
if (pid != 0)
exit(0);
/* Session leader so ^C doesn't whack us. */
setsid();
/* Let session leader exit so child cannot regain CTTY */
if ((pid = fork()) < 0)
barf_perror("Failed to fork daemon");
if (pid != 0)
exit(0);
/* Move off any mount points we might be in. */
if (chdir("/") == -1)
barf_perror("Failed to chdir");
/* Discard our parent's old-fashioned umask prejudices. */
umask(0);
}
void finish_daemonize(void)
{
int devnull = open("/dev/null", O_RDWR);
if (devnull == -1)
barf_perror("Could not open /dev/null\n");
dup2(devnull, STDIN_FILENO);
dup2(devnull, STDOUT_FILENO);
dup2(devnull, STDERR_FILENO);
close(devnull);
xprintf = trace;
}
void init_pipe(int reopen_log_pipe[2])
{
if (pipe(reopen_log_pipe)) {
barf_perror("pipe");
}
}
void unmap_xenbus(void *interface)
{
munmap(interface, getpagesize());
}
|
