/* Main loop, run as root */
static void
priv_loop(int privileged, int once)
{
enum priv_cmd cmd;
struct dispatch_actions *a;
#ifdef ENABLE_PRIVSEP
setproctitle("monitor");
#ifdef USE_SECCOMP
if (priv_seccomp_init(privileged, monitored) != 0)
fatal("privsep", "cannot continue without seccomp setup");
#endif
#endif
while (!may_read(PRIV_PRIVILEGED, &cmd, sizeof(enum priv_cmd))) {
log_debug("privsep", "received command %d", cmd);
for (a = actions; a->function != NULL; a++) {
if (cmd == a->msg) {
a->function();
break;
}
}
if (a->function == NULL)
fatalx("privsep", "bogus message received");
if (once) break;
}
}
int
isc_priv_init(int lstderr)
{
int i, socks[2], cmd;
logmsg(LOG_NOTICE, "Starting privilege separation");
log_stderr = lstderr;
/* Create sockets */
if (socketpair(AF_LOCAL, SOCK_STREAM, PF_UNSPEC, socks) == -1)
fatal("socketpair() failed");
switch (child_pid = fork()) {
case -1:
fatal("failed to fork() for privsep");
case 0:
close(socks[0]);
priv_fd = socks[1];
return (0);
default:
break;
}
for (i = 1; i < _NSIG; i++)
signal(i, SIG_DFL);
signal(SIGALRM, sig_pass_to_chld);
signal(SIGTERM, sig_pass_to_chld);
signal(SIGHUP, sig_pass_to_chld);
signal(SIGINT, sig_pass_to_chld);
signal(SIGCHLD, sig_got_chld);
/* Father - close unneeded sockets */
for (i = STDERR_FILENO + 1; i < socks[0]; i++)
close(i);
closefrom(socks[0] + 1);
setproctitle("[priv]");
while (cur_state != STATE_QUIT) {
if (may_read(socks[0], &cmd, sizeof(int)))
break;
switch (cmd) {
case PRIV_BIND:
parent_bind(socks[0]);
break;
default:
logmsg(LOG_ERR, "[priv]: unknown command %d", cmd);
_exit(1);
/* NOTREACHED */
}
}
_exit(0);
}
/* Main loop, run as root */
static void
priv_loop()
{
enum priv_cmd cmd;
struct dispatch_actions *a;
setproctitle("monitor");
while (!may_read(&cmd, sizeof(enum priv_cmd))) {
for (a = actions; a->function != NULL; a++) {
if (cmd == a->msg) {
a->function();
break;
}
}
if (a->function == NULL)
fatal("privsep", "bogus message received");
}
/* Should never be there */
}
/* based on syslogd privsep */
int
priv_init(void)
{
int i, fd, socks[2], cmd;
int snaplen, ret, olderrno;
struct passwd *pw;
#ifdef __FreeBSD__
for (i = 1; i < NSIG; i++)
#else
for (i = 1; i < _NSIG; i++)
#endif
signal(i, SIG_DFL);
/* Create sockets */
if (socketpair(AF_LOCAL, SOCK_STREAM, PF_UNSPEC, socks) == -1)
err(1, "socketpair() failed");
pw = getpwnam("_pflogd");
if (pw == NULL)
errx(1, "unknown user _pflogd");
endpwent();
child_pid = fork();
if (child_pid < 0)
err(1, "fork() failed");
if (!child_pid) {
gid_t gidset[1];
/* Child - drop privileges and return */
if (chroot(pw->pw_dir) != 0)
err(1, "unable to chroot");
if (chdir("/") != 0)
err(1, "unable to chdir");
gidset[0] = pw->pw_gid;
if (setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) == -1)
err(1, "setresgid() failed");
if (setgroups(1, gidset) == -1)
err(1, "setgroups() failed");
if (setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid) == -1)
err(1, "setresuid() failed");
close(socks[0]);
priv_fd = socks[1];
return 0;
}
/* Father */
/* Pass ALRM/TERM/HUP/INT/QUIT through to child, and accept CHLD */
signal(SIGALRM, sig_pass_to_chld);
signal(SIGTERM, sig_pass_to_chld);
signal(SIGHUP, sig_pass_to_chld);
signal(SIGINT, sig_pass_to_chld);
signal(SIGQUIT, sig_pass_to_chld);
signal(SIGCHLD, sig_chld);
setproctitle("[priv]");
close(socks[1]);
while (!gotsig_chld) {
if (may_read(socks[0], &cmd, sizeof(int)))
break;
switch (cmd) {
case PRIV_SET_SNAPLEN:
logmsg(LOG_DEBUG,
"[priv]: msg PRIV_SET_SNAPLENGTH received");
must_read(socks[0], &snaplen, sizeof(int));
ret = set_snaplen(snaplen);
if (ret) {
logmsg(LOG_NOTICE,
"[priv]: set_snaplen failed for snaplen %d",
snaplen);
}
must_write(socks[0], &ret, sizeof(int));
break;
case PRIV_OPEN_LOG:
logmsg(LOG_DEBUG,
"[priv]: msg PRIV_OPEN_LOG received");
/* create or append logs but do not follow symlinks */
fd = open(filename,
O_RDWR|O_CREAT|O_APPEND|O_NONBLOCK|O_NOFOLLOW,
0600);
olderrno = errno;
send_fd(socks[0], fd);
if (fd < 0)
logmsg(LOG_NOTICE,
"[priv]: failed to open %s: %s",
filename, strerror(olderrno));
else
close(fd);
break;
case PRIV_MOVE_LOG:
logmsg(LOG_DEBUG,
"[priv]: msg PRIV_MOVE_LOG received");
ret = move_log(filename);
must_write(socks[0], &ret, sizeof(int));
break;
default:
logmsg(LOG_ERR, "[priv]: unknown command %d", cmd);
_exit(1);
/* NOTREACHED */
}
}
_exit(1);
}
