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#include <sys/types.h>
#include <linux/types.h>
#include <paths.h>
#include <limits.h>
#include <time.h>
#include <stdio.h>
#include <signal.h>
#include <stdlib.h>
#include <fcntl.h>
#include <errno.h>
#include <string.h>
#include <syslog.h>
#include <unistd.h>
#include <sys/ioctl.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <poll.h>
#include <linux/auto_fs4.h>
#include "include/log.h"
#include "include/sys.h"
#include "include/timer.h"
#include "include/mount.h"
#include "include/signal.h"
#include "include/ucix.h"
#include "include/autofs.h"
static int fdin = 0; /* data coming out of the kernel */
static int fdout = 0;/* data going into the kernel */
static bool term = false;
static dev_t dev;
static time_t uci_timeout;
char uci_path[32];
static void umount_autofs(void)
{
system_printf("umount %s 2> /dev/null", "/tmp/run/mountd/");
}
static int mount_autofs(void)
{
int pipefd[2];
struct stat st;
log_printf("trying to mount %s as the autofs root\n", "/tmp/run/mountd/");
if(is_mounted(0, "/tmp/run/mountd/"))
{
log_printf("%s is already mounted\n", "/tmp/run/mountd/");
return -1;
}
fdout = fdin = -1;
mkdir("/tmp/run/mountd/", 0555);
if(pipe(pipefd) < 0)
{
log_printf("failed to get kernel pipe\n");
return -1;
}
if(system_printf("/bin/mount -t autofs -o fd=%d,pgrp=%u,minproto=5,maxproto=5 \"mountd(pid%u)\" %s",
pipefd[1], (unsigned) getpgrp(), getpid(), "/tmp/run/mountd/") != 0)
{
log_printf("unable to mount autofs on %s\n", "/tmp/run/mountd/");
close(pipefd[0]);
close(pipefd[1]);
return -1;
}
close(pipefd[1]);
fdout = pipefd[0];
fdin = open("/tmp/run/mountd/", O_RDONLY);
if(fdin < 0)
{
umount_autofs();
return -1;
}
stat("/tmp/run/mountd/", &st);
return 0;
}
static void send_ready(unsigned int wait_queue_token)
{
if(ioctl(fdin, AUTOFS_IOC_READY, wait_queue_token) < 0)
log_printf("failed to report ready to kernel\n");
}
static void send_fail(unsigned int wait_queue_token)
{
if(ioctl(fdin, AUTOFS_IOC_FAIL, wait_queue_token) < 0)
log_printf("failed to report fail to kernel\n");
}
static int autofs_process_request(const struct autofs_v5_packet *pkt)
{
struct stat st;
log_printf("kernel is requesting a mount -> %s\n", pkt->name);
chdir("/tmp/run/mountd/");
if (lstat(pkt->name, &st) == -1 || (S_ISDIR(st.st_mode) && st.st_dev == dev)) {
if(!mount_new("/tmp/run/mountd/", (char*)pkt->name))
{
send_ready(pkt->wait_queue_token);
} else {
send_fail(pkt->wait_queue_token);
log_printf("failed to mount %s\n", pkt->name);
}
} else {
send_ready(pkt->wait_queue_token);
}
chdir("/");
return 0;
}
static void expire_proc(void)
{
struct autofs_packet_expire pkt;
while(ioctl(fdin, AUTOFS_IOC_EXPIRE, &pkt) == 0)
mount_remove("/tmp/run/mountd/", pkt.name);
}
static int fullread(void *ptr, size_t len)
{
char *buf = (char *) ptr;
while(len > 0)
{
ssize_t r = read(fdout, buf, len);
if(r == -1)
{
if (errno == EINTR)
continue;
break;
}
buf += r;
len -= r;
}
return len;
}
static int autofs_in(union autofs_v5_packet_union *pkt)
{
int res;
struct pollfd fds[1];
fds[0].fd = fdout;
fds[0].events = POLLIN;
while(!term)
{
res = poll(fds, 1, -1);
if (res == -1)
{
if (errno == EINTR)
continue;
log_printf("failed while trying to read packet from kernel\n");
return -1;
}
else if ((res > 0) && (fds[0].revents & POLLIN))
{
return fullread(pkt, sizeof(*pkt));
}
}
return 1;
}
pid_t autofs_safe_fork(void)
{
pid_t pid = fork();
if(!pid)
{
close(fdin);
close(fdout);
}
return pid;
}
static void autofs_cleanup(void)
{
close(fdin);
close(fdout);
umount_autofs();
}
static void autofs_end_handler(int sig)
{
term = true;
}
static void autofs_init(void)
{
int kproto_version;
char *p;
struct uci_context *ctx;
signal_init(autofs_end_handler);
ctx = ucix_init("mountd");
uci_timeout = ucix_get_option_int(ctx, "mountd", "mountd", "timeout", 60);
p = ucix_get_option(ctx, "mountd", "mountd", "path");
ucix_cleanup(ctx);
if(p)
snprintf(uci_path, 31, "%s", p);
else
snprintf(uci_path, 31, "/tmp/mounts/");
uci_path[31] = '\0';
mkdir("/tmp/run/", 0555);
mkdir("/tmp/mounts", 0555);
system_printf("rm -rf %s*", uci_path);
if(uci_timeout < 16)
uci_timeout = 16;
umount_autofs();
mount_init();
if(mount_autofs() < 0)
{
closelog();
exit(1);
}
ioctl(fdin, AUTOFS_IOC_PROTOVER, &kproto_version);
if(kproto_version != 5)
{
log_printf("only kernel protocol version 5 is tested. You have %d.\n",
kproto_version);
closelog();
exit(1);
}
ioctl(fdin, AUTOFS_IOC_SETTIMEOUT, &uci_timeout);
timer_add(expire_proc, 15);
}
int autofs_loop(void)
{
chdir("/");
autofs_init();
while(!term)
{
union autofs_v5_packet_union pkt;
if(autofs_in(&pkt))
{
continue;
}
log_printf("Got a autofs packet\n");
if(pkt.hdr.type == autofs_ptype_missing_indirect)
autofs_process_request(&pkt.missing_indirect);
else
log_printf("unknown packet type %d\n", pkt.hdr.type);
poll(0, 0, 200);
}
autofs_cleanup();
log_printf("... quitting\n");
closelog();
return 0;
}
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