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/*
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, see <http://www.gnu.org/licenses/>.
*/
#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"
#include "xenstored_osdep.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);
close(fd);
}
/* 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);
}
void init_pipe(int reopen_log_pipe[2])
{
int flags;
unsigned int i;
if (pipe(reopen_log_pipe)) {
barf_perror("pipe");
}
for (i = 0; i < 2; i++) {
flags = fcntl(reopen_log_pipe[i], F_GETFD);
if (flags < 0)
barf_perror("pipe get flags");
flags |= FD_CLOEXEC;
if (fcntl(reopen_log_pipe[i], F_SETFD, flags) < 0)
barf_perror("pipe set flags");
}
}
void unmap_xenbus(void *interface)
{
munmap(interface, getpagesize());
}
evtchn_port_t xenbus_evtchn(void)
{
int fd;
int rc;
evtchn_port_t port;
char str[20];
fd = open(XENSTORED_PORT_DEV, O_RDONLY);
if (fd == -1)
return -1;
rc = read(fd, str, sizeof(str) - 1);
if (rc == -1)
{
int err = errno;
close(fd);
errno = err;
return -1;
}
str[rc] = '\0';
port = strtoul(str, NULL, 0);
close(fd);
return port;
}
void *xenbus_map(void)
{
int fd;
void *addr;
fd = open(XENSTORED_KVA_DEV, O_RDWR);
if (fd == -1)
return NULL;
addr = mmap(NULL, getpagesize(), PROT_READ|PROT_WRITE,
MAP_SHARED, fd, 0);
if (addr == MAP_FAILED)
addr = NULL;
close(fd);
return addr;
}
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