int util_open_scoreboard(int flags) {
int res;
struct stat st;
/* Prevent writing to a symlink while avoiding a race condition: open
* the file name O_RDWR|O_CREAT first, then check to see if it's a symlink.
* If so, close the file and error out. If not, truncate as necessary,
* and continue.
*/
util_scoreboard_fd = open(util_scoreboard_file, flags);
if (util_scoreboard_fd < 0)
return -1;
if (fstat(util_scoreboard_fd, &st) < 0) {
close(util_scoreboard_fd);
util_scoreboard_fd = -1;
return -1;
}
if (S_ISLNK(st.st_mode)) {
close(util_scoreboard_fd);
util_scoreboard_fd = -1;
errno = EPERM;
return -1;
}
/* Check the header of this scoreboard file. */
res = read_scoreboard_header(&util_header);
if (res < 0)
return res;
return 0;
}
int pr_open_scoreboard(int flags) {
int res;
struct stat st;
/* Try to prevent a file descriptor leak by only opening the scoreboard
* file if the scoreboard file descriptor is not already positive, i.e.
* if the scoreboard has not already been opened.
*/
if (scoreboard_fd >= 0 && scoreboard_opener == getpid()) {
pr_log_debug(DEBUG7, "scoreboard already opened");
return 0;
}
pr_log_debug(DEBUG7, "opening scoreboard '%s'", scoreboard_file);
/* Prevent writing to a symlink while avoiding a race condition: open
* the file name O_RDWR|O_CREAT first, then check to see if it's a symlink.
* If so, close the file and error out. If not, truncate as necessary,
* and continue.
*/
while ((scoreboard_fd = open(scoreboard_file, flags|O_CREAT,
PR_SCOREBOARD_MODE)) < 0) {
if (errno == EINTR) {
pr_signals_handle();
continue;
} else
return -1;
}
/* Make certain that the scoreboard mode will be read-only for everyone
* except the user owner (this allows for non-root-running daemons to
* still modify the scoreboard).
*/
while (fchmod(scoreboard_fd, 0644) < 0) {
if (errno == EINTR) {
pr_signals_handle();
continue;
} else
break;
}
while (fstat(scoreboard_fd, &st) < 0) {
int st_errno = errno;
if (errno == EINTR) {
pr_signals_handle();
continue;
}
while (close(scoreboard_fd) < 0) {
if (errno == EINTR) {
pr_signals_handle();
continue;
} else
break;
}
/* Either way, the scoreboard fd should be marked as closed. */
scoreboard_fd = -1;
errno = st_errno;
return -1;
}
if (S_ISLNK(st.st_mode)) {
while (close(scoreboard_fd) < 0) {
if (errno == EINTR) {
pr_signals_handle();
continue;
} else
break;
}
errno = EPERM;
scoreboard_fd = -1;
return -1;
}
scoreboard_opener = getpid();
/* Check the header of this scoreboard file. */
if ((res = read_scoreboard_header(&header)) == -1) {
/* If this file is newly created, it needs to have the header
* written.
*/
header.sch_magic = PR_SCOREBOARD_MAGIC;
header.sch_version = PR_SCOREBOARD_VERSION;
if (ServerType == SERVER_STANDALONE) {
header.sch_pid = getpid();
header.sch_uptime = time(NULL);
} else {
header.sch_pid = 0;
header.sch_uptime = 0;
}
/* Write-lock the scoreboard file. */
if (wlock_scoreboard() < 0)
return -1;
while (write(scoreboard_fd, &header, sizeof(header)) != sizeof(header)) {
int wr_errno = errno;
if (errno == EINTR) {
pr_signals_handle();
continue;
}
unlock_scoreboard();
errno = wr_errno;
return -1;
}
unlock_scoreboard();
return 0;
} else
return res;
return 0;
}
