int LogAudit::getLogSocket() {
int fd = audit_open();
if (fd < 0) {
return fd;
}
if (audit_set_pid(fd, getpid(), WAIT_YES) < 0) {
audit_close(fd);
fd = -1;
}
return fd;
}
/*
* A clean exit means :
* 1) we log that we are going down
* 2) deregister with kernel
* 3) close the netlink socket
*/
static void clean_exit(void)
{
audit_msg(LOG_INFO, "The audit daemon is exiting.");
if (fd >= 0) {
audit_set_pid(fd, 0, WAIT_NO);
audit_close(fd);
}
if (pidfile)
unlink(pidfile);
closelog();
}
static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
{
u32 uid, pid, seq;
void *data;
struct audit_status *status_get, status_set;
int err;
struct audit_buffer *ab;
u16 msg_type = nlh->nlmsg_type;
uid_t loginuid; /* loginuid of sender */
struct audit_sig_info sig_data;
err = audit_netlink_ok(NETLINK_CB(skb).eff_cap, msg_type);
if (err)
return err;
/* As soon as there's any sign of userspace auditd, start kauditd to talk to it */
if (!kauditd_task)
kauditd_task = kthread_run(kauditd_thread, NULL, "kauditd");
if (IS_ERR(kauditd_task)) {
err = PTR_ERR(kauditd_task);
kauditd_task = NULL;
return err;
}
pid = NETLINK_CREDS(skb)->pid;
uid = NETLINK_CREDS(skb)->uid;
loginuid = NETLINK_CB(skb).loginuid;
seq = nlh->nlmsg_seq;
data = NLMSG_DATA(nlh);
switch (msg_type) {
case AUDIT_GET:
status_set.enabled = audit_enabled;
status_set.failure = audit_failure;
status_set.pid = audit_pid;
status_set.rate_limit = audit_rate_limit;
status_set.backlog_limit = audit_backlog_limit;
status_set.lost = atomic_read(&audit_lost);
status_set.backlog = skb_queue_len(&audit_skb_queue);
audit_send_reply(NETLINK_CB(skb).pid, seq, AUDIT_GET, 0, 0,
&status_set, sizeof(status_set));
break;
case AUDIT_SET:
if (nlh->nlmsg_len < sizeof(struct audit_status))
return -EINVAL;
status_get = (struct audit_status *)data;
if (status_get->mask & AUDIT_STATUS_ENABLED) {
err = audit_set_enabled(status_get->enabled, loginuid);
if (err < 0) return err;
}
if (status_get->mask & AUDIT_STATUS_FAILURE) {
err = audit_set_failure(status_get->failure, loginuid);
if (err < 0) return err;
}
if (status_get->mask & AUDIT_STATUS_PID) {
int old = audit_pid;
audit_pid = status_get->pid;
audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE,
"audit_pid=%d old=%d by auid=%u",
audit_pid, old, loginuid);
}
if (status_get->mask & AUDIT_STATUS_RATE_LIMIT)
audit_set_rate_limit(status_get->rate_limit, loginuid);
if (status_get->mask & AUDIT_STATUS_BACKLOG_LIMIT)
audit_set_backlog_limit(status_get->backlog_limit,
loginuid);
break;
case AUDIT_USER:
case AUDIT_FIRST_USER_MSG...AUDIT_LAST_USER_MSG:
if (!audit_enabled && msg_type != AUDIT_USER_AVC)
return 0;
err = audit_filter_user(&NETLINK_CB(skb), msg_type);
if (err == 1) {
err = 0;
ab = audit_log_start(NULL, GFP_KERNEL, msg_type);
if (ab) {
audit_log_format(ab,
"user pid=%d uid=%u auid=%u msg='%.1024s'",
pid, uid, loginuid, (char *)data);
audit_set_pid(ab, pid);
audit_log_end(ab);
}
}
break;
case AUDIT_ADD:
case AUDIT_DEL:
if (nlh->nlmsg_len < sizeof(struct audit_rule))
return -EINVAL;
/* fallthrough */
case AUDIT_LIST:
err = audit_receive_filter(nlh->nlmsg_type, NETLINK_CB(skb).pid,
uid, seq, data, loginuid);
break;
case AUDIT_SIGNAL_INFO:
sig_data.uid = audit_sig_uid;
sig_data.pid = audit_sig_pid;
audit_send_reply(NETLINK_CB(skb).pid, seq, AUDIT_SIGNAL_INFO,
0, 0, &sig_data, sizeof(sig_data));
break;
default:
err = -EINVAL;
break;
}
return err < 0 ? err : 0;
}
static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
{
u32 uid, pid, seq, sid;
void *data;
struct audit_status *status_get, status_set;
int err;
struct audit_buffer *ab;
u16 msg_type = nlh->nlmsg_type;
uid_t loginuid; /* loginuid of sender */
struct audit_sig_info *sig_data;
char *ctx;
u32 len;
err = audit_netlink_ok(skb, msg_type);
if (err)
return err;
/* As soon as there's any sign of userspace auditd,
* start kauditd to talk to it */
if (!kauditd_task)
kauditd_task = kthread_run(kauditd_thread, NULL, "kauditd");
if (IS_ERR(kauditd_task)) {
err = PTR_ERR(kauditd_task);
kauditd_task = NULL;
return err;
}
pid = NETLINK_CREDS(skb)->pid;
uid = NETLINK_CREDS(skb)->uid;
loginuid = NETLINK_CB(skb).loginuid;
sid = NETLINK_CB(skb).sid;
seq = nlh->nlmsg_seq;
data = NLMSG_DATA(nlh);
switch (msg_type) {
case AUDIT_GET:
status_set.enabled = audit_enabled;
status_set.failure = audit_failure;
status_set.pid = audit_pid;
status_set.rate_limit = audit_rate_limit;
status_set.backlog_limit = audit_backlog_limit;
status_set.lost = atomic_read(&audit_lost);
status_set.backlog = skb_queue_len(&audit_skb_queue);
audit_send_reply(NETLINK_CB(skb).pid, seq, AUDIT_GET, 0, 0,
&status_set, sizeof(status_set));
break;
case AUDIT_SET:
if (nlh->nlmsg_len < sizeof(struct audit_status))
return -EINVAL;
status_get = (struct audit_status *)data;
if (status_get->mask & AUDIT_STATUS_ENABLED) {
err = audit_set_enabled(status_get->enabled,
loginuid, sid);
if (err < 0) return err;
}
if (status_get->mask & AUDIT_STATUS_FAILURE) {
err = audit_set_failure(status_get->failure,
loginuid, sid);
if (err < 0) return err;
}
if (status_get->mask & AUDIT_STATUS_PID) {
int old = audit_pid;
if (sid) {
if ((err = selinux_sid_to_string(
sid, &ctx, &len)))
return err;
else
audit_log(NULL, GFP_KERNEL,
AUDIT_CONFIG_CHANGE,
"audit_pid=%d old=%d by auid=%u subj=%s",
status_get->pid, old,
loginuid, ctx);
kfree(ctx);
} else
audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE,
"audit_pid=%d old=%d by auid=%u",
status_get->pid, old, loginuid);
audit_pid = status_get->pid;
}
if (status_get->mask & AUDIT_STATUS_RATE_LIMIT)
err = audit_set_rate_limit(status_get->rate_limit,
loginuid, sid);
if (status_get->mask & AUDIT_STATUS_BACKLOG_LIMIT)
err = audit_set_backlog_limit(status_get->backlog_limit,
loginuid, sid);
break;
case AUDIT_USER:
case AUDIT_FIRST_USER_MSG...AUDIT_LAST_USER_MSG:
case AUDIT_FIRST_USER_MSG2...AUDIT_LAST_USER_MSG2:
if (!audit_enabled && msg_type != AUDIT_USER_AVC)
return 0;
err = audit_filter_user(&NETLINK_CB(skb), msg_type);
if (err == 1) {
err = 0;
ab = audit_log_start(NULL, GFP_KERNEL, msg_type);
if (ab) {
audit_log_format(ab,
"user pid=%d uid=%u auid=%u",
pid, uid, loginuid);
if (sid) {
if (selinux_sid_to_string(
sid, &ctx, &len)) {
audit_log_format(ab,
" ssid=%u", sid);
/* Maybe call audit_panic? */
} else
audit_log_format(ab,
" subj=%s", ctx);
kfree(ctx);
}
audit_log_format(ab, " msg='%.1024s'",
(char *)data);
audit_set_pid(ab, pid);
audit_log_end(ab);
}
}
break;
case AUDIT_ADD:
case AUDIT_DEL:
if (nlmsg_len(nlh) < sizeof(struct audit_rule))
return -EINVAL;
if (audit_enabled == 2) {
ab = audit_log_start(NULL, GFP_KERNEL,
AUDIT_CONFIG_CHANGE);
if (ab) {
audit_log_format(ab,
"pid=%d uid=%u auid=%u",
pid, uid, loginuid);
if (sid) {
if (selinux_sid_to_string(
sid, &ctx, &len)) {
audit_log_format(ab,
" ssid=%u", sid);
/* Maybe call audit_panic? */
} else
audit_log_format(ab,
" subj=%s", ctx);
kfree(ctx);
}
audit_log_format(ab, " audit_enabled=%d res=0",
audit_enabled);
audit_log_end(ab);
}
return -EPERM;
}
/* fallthrough */
case AUDIT_LIST:
err = audit_receive_filter(nlh->nlmsg_type, NETLINK_CB(skb).pid,
uid, seq, data, nlmsg_len(nlh),
loginuid, sid);
break;
case AUDIT_ADD_RULE:
case AUDIT_DEL_RULE:
if (nlmsg_len(nlh) < sizeof(struct audit_rule_data))
return -EINVAL;
if (audit_enabled == 2) {
ab = audit_log_start(NULL, GFP_KERNEL,
AUDIT_CONFIG_CHANGE);
if (ab) {
audit_log_format(ab,
"pid=%d uid=%u auid=%u",
pid, uid, loginuid);
if (sid) {
if (selinux_sid_to_string(
sid, &ctx, &len)) {
audit_log_format(ab,
" ssid=%u", sid);
/* Maybe call audit_panic? */
} else
audit_log_format(ab,
" subj=%s", ctx);
kfree(ctx);
}
audit_log_format(ab, " audit_enabled=%d res=0",
audit_enabled);
audit_log_end(ab);
}
return -EPERM;
}
/* fallthrough */
case AUDIT_LIST_RULES:
err = audit_receive_filter(nlh->nlmsg_type, NETLINK_CB(skb).pid,
uid, seq, data, nlmsg_len(nlh),
loginuid, sid);
break;
case AUDIT_SIGNAL_INFO:
err = selinux_sid_to_string(audit_sig_sid, &ctx, &len);
if (err)
return err;
sig_data = kmalloc(sizeof(*sig_data) + len, GFP_KERNEL);
if (!sig_data) {
kfree(ctx);
return -ENOMEM;
}
sig_data->uid = audit_sig_uid;
sig_data->pid = audit_sig_pid;
memcpy(sig_data->ctx, ctx, len);
kfree(ctx);
audit_send_reply(NETLINK_CB(skb).pid, seq, AUDIT_SIGNAL_INFO,
0, 0, sig_data, sizeof(*sig_data) + len);
kfree(sig_data);
break;
default:
err = -EINVAL;
break;
}
return err < 0 ? err : 0;
}
int main(int argc, char *argv[])
{
struct sigaction sa;
struct rlimit limit;
int i, c, rc;
int opt_foreground = 0, opt_allow_links = 0;
enum startup_state opt_startup = startup_enable;
extern char *optarg;
extern int optind;
struct ev_loop *loop;
struct ev_io netlink_watcher;
struct ev_signal sigterm_watcher;
struct ev_signal sighup_watcher;
struct ev_signal sigusr1_watcher;
struct ev_signal sigusr2_watcher;
struct ev_signal sigchld_watcher;
/* Get params && set mode */
while ((c = getopt(argc, argv, "flns:")) != -1) {
switch (c) {
case 'f':
opt_foreground = 1;
break;
case 'l':
opt_allow_links=1;
break;
case 'n':
do_fork = 0;
break;
case 's':
for (i=0; i<startup_INVALID; i++) {
if (strncmp(optarg, startup_states[i],
strlen(optarg)) == 0) {
opt_startup = i;
break;
}
}
if (i == startup_INVALID) {
fprintf(stderr, "unknown startup mode '%s'\n",
optarg);
usage();
}
break;
default:
usage();
}
}
/* check for trailing command line following options */
if (optind < argc) {
usage();
}
if (opt_allow_links)
set_allow_links(1);
if (opt_foreground) {
config.daemonize = D_FOREGROUND;
set_aumessage_mode(MSG_STDERR, DBG_YES);
} else {
config.daemonize = D_BACKGROUND;
set_aumessage_mode(MSG_SYSLOG, DBG_NO);
(void) umask( umask( 077 ) | 022 );
}
#ifndef DEBUG
/* Make sure we are root */
if (getuid() != 0) {
fprintf(stderr, "You must be root to run this program.\n");
return 4;
}
#endif
/* Register sighandlers */
sa.sa_flags = 0 ;
sigemptyset( &sa.sa_mask ) ;
/* Ignore all signals by default */
sa.sa_handler = SIG_IGN;
for (i=1; i<NSIG; i++)
sigaction( i, &sa, NULL );
atexit(clean_exit);
/* Raise the rlimits in case we're being started from a shell
* with restrictions. Not a fatal error. */
limit.rlim_cur = RLIM_INFINITY;
limit.rlim_max = RLIM_INFINITY;
setrlimit(RLIMIT_FSIZE, &limit);
setrlimit(RLIMIT_CPU, &limit);
/* Load the Configuration File */
if (load_config(&config, TEST_AUDITD))
return 6;
if (config.priority_boost != 0) {
errno = 0;
rc = nice((int)-config.priority_boost);
if (rc == -1 && errno) {
audit_msg(LOG_ERR, "Cannot change priority (%s)",
strerror(errno));
return 1;
}
}
/* Daemonize or stay in foreground for debugging */
if (config.daemonize == D_BACKGROUND) {
if (become_daemon() != 0) {
audit_msg(LOG_ERR, "Cannot daemonize (%s)",
strerror(errno));
tell_parent(FAILURE);
return 1;
}
openlog("auditd", LOG_PID, LOG_DAEMON);
}
/* Init netlink */
if ((fd = audit_open()) < 0) {
audit_msg(LOG_ERR, "Cannot open netlink audit socket");
tell_parent(FAILURE);
return 1;
}
/* Init the event handler thread */
write_pid_file();
if (init_event(&config)) {
if (pidfile)
unlink(pidfile);
tell_parent(FAILURE);
return 1;
}
if (init_dispatcher(&config)) {
if (pidfile)
unlink(pidfile);
tell_parent(FAILURE);
return 1;
}
/* Get machine name ready for use */
if (resolve_node(&config)) {
if (pidfile)
unlink(pidfile);
tell_parent(FAILURE);
return 1;
}
/* Write message to log that we are alive */
{
struct utsname ubuf;
char start[DEFAULT_BUF_SZ];
const char *fmt = audit_lookup_format((int)config.log_format);
if (fmt == NULL)
fmt = "UNKNOWN";
if (uname(&ubuf) != 0) {
if (pidfile)
unlink(pidfile);
tell_parent(FAILURE);
return 1;
}
if (getsubj(subj))
snprintf(start, sizeof(start),
"auditd start, ver=%s format=%s "
"kernel=%.56s auid=%u pid=%d subj=%s res=success",
VERSION, fmt, ubuf.release,
audit_getloginuid(), getpid(), subj);
else
snprintf(start, sizeof(start),
"auditd start, ver=%s format=%s "
"kernel=%.56s auid=%u pid=%d res=success",
VERSION, fmt, ubuf.release,
audit_getloginuid(), getpid());
if (send_audit_event(AUDIT_DAEMON_START, start)) {
audit_msg(LOG_ERR, "Cannot send start message");
if (pidfile)
unlink(pidfile);
shutdown_dispatcher();
tell_parent(FAILURE);
return 1;
}
}
/* Tell kernel not to kill us */
avoid_oom_killer();
/* let config manager init */
init_config_manager();
if (opt_startup != startup_nochange && (audit_is_enabled(fd) < 2) &&
audit_set_enabled(fd, (int)opt_startup) < 0) {
char emsg[DEFAULT_BUF_SZ];
if (*subj)
snprintf(emsg, sizeof(emsg),
"auditd error halt, auid=%u pid=%d subj=%s res=failed",
audit_getloginuid(), getpid(), subj);
else
snprintf(emsg, sizeof(emsg),
"auditd error halt, auid=%u pid=%d res=failed",
audit_getloginuid(), getpid());
stop = 1;
send_audit_event(AUDIT_DAEMON_ABORT, emsg);
audit_msg(LOG_ERR,
"Unable to set initial audit startup state to '%s', exiting",
startup_states[opt_startup]);
close_down();
if (pidfile)
unlink(pidfile);
shutdown_dispatcher();
tell_parent(FAILURE);
return 1;
}
/* Tell the kernel we are alive */
if (audit_set_pid(fd, getpid(), WAIT_YES) < 0) {
char emsg[DEFAULT_BUF_SZ];
if (*subj)
snprintf(emsg, sizeof(emsg),
"auditd error halt, auid=%u pid=%d subj=%s res=failed",
audit_getloginuid(), getpid(), subj);
else
snprintf(emsg, sizeof(emsg),
"auditd error halt, auid=%u pid=%d res=failed",
audit_getloginuid(), getpid());
stop = 1;
send_audit_event(AUDIT_DAEMON_ABORT, emsg);
audit_msg(LOG_ERR, "Unable to set audit pid, exiting");
close_down();
if (pidfile)
unlink(pidfile);
shutdown_dispatcher();
tell_parent(FAILURE);
return 1;
}
/* Depending on value of opt_startup (-s) set initial audit state */
loop = ev_default_loop (EVFLAG_NOENV);
ev_io_init (&netlink_watcher, netlink_handler, fd, EV_READ);
ev_io_start (loop, &netlink_watcher);
ev_signal_init (&sigterm_watcher, term_handler, SIGTERM);
ev_signal_start (loop, &sigterm_watcher);
ev_signal_init (&sighup_watcher, hup_handler, SIGHUP);
ev_signal_start (loop, &sighup_watcher);
ev_signal_init (&sigusr1_watcher, user1_handler, SIGUSR1);
ev_signal_start (loop, &sigusr1_watcher);
ev_signal_init (&sigusr2_watcher, user2_handler, SIGUSR2);
ev_signal_start (loop, &sigusr2_watcher);
ev_signal_init (&sigchld_watcher, child_handler, SIGCHLD);
ev_signal_start (loop, &sigchld_watcher);
if (auditd_tcp_listen_init (loop, &config)) {
char emsg[DEFAULT_BUF_SZ];
if (*subj)
snprintf(emsg, sizeof(emsg),
"auditd error halt, auid=%u pid=%d subj=%s res=failed",
audit_getloginuid(), getpid(), subj);
else
snprintf(emsg, sizeof(emsg),
"auditd error halt, auid=%u pid=%d res=failed",
audit_getloginuid(), getpid());
stop = 1;
send_audit_event(AUDIT_DAEMON_ABORT, emsg);
tell_parent(FAILURE);
} else {
/* Now tell parent that everything went OK */
tell_parent(SUCCESS);
audit_msg(LOG_NOTICE,
"Init complete, auditd %s listening for events (startup state %s)",
VERSION,
startup_states[opt_startup]);
}
/* Parent should be gone by now... */
if (do_fork)
close(init_pipe[1]);
// Init complete, start event loop
if (!stop)
ev_loop (loop, 0);
auditd_tcp_listen_uninit (loop, &config);
// Tear down IO watchers Part 1
ev_signal_stop (loop, &sighup_watcher);
ev_signal_stop (loop, &sigusr1_watcher);
ev_signal_stop (loop, &sigusr2_watcher);
ev_signal_stop (loop, &sigterm_watcher);
/* Write message to log that we are going down */
rc = audit_request_signal_info(fd);
if (rc > 0) {
struct audit_reply trep;
rc = get_reply(fd, &trep, rc);
if (rc > 0) {
char txt[MAX_AUDIT_MESSAGE_LENGTH];
snprintf(txt, sizeof(txt),
"auditd normal halt, sending auid=%u "
"pid=%d subj=%s res=success",
trep.signal_info->uid,
trep.signal_info->pid,
trep.signal_info->ctx);
send_audit_event(AUDIT_DAEMON_END, txt);
}
}
if (rc <= 0)
send_audit_event(AUDIT_DAEMON_END,
"auditd normal halt, sending auid=? "
"pid=? subj=? res=success");
free(rep);
// Tear down IO watchers Part 2
ev_io_stop (loop, &netlink_watcher);
// Give DAEMON_END event a little time to be sent in case
// of remote logging
usleep(10000); // 10 milliseconds
shutdown_dispatcher();
// Tear down IO watchers Part 3
ev_signal_stop (loop, &sigchld_watcher);
close_down();
free_config(&config);
ev_default_destroy();
return 0;
}
static void do_auditd(int fd) {
struct audit_reply rep;
sigset_t sigs;
struct sigaction sa;
struct pollfd pds = {
.events = POLLIN | POLLPRI | POLLERR | POLLHUP | POLLMSG,
.revents = 0,
.fd = fd,
};
if (audit_set_pid(fd, getpid(), WAIT_YES) < 0)
return;
if (audit_set_enabled(fd, 1) < 0)
return;
memset(&sa, '\0', sizeof (sa));
sa.sa_handler = sig_done;
sigaction(SIGTERM, &sa, NULL);
sigaction(SIGINT, &sa, NULL);
sigaction(SIGHUP, &sa, NULL);
sigfillset(&sigs);
sigdelset(&sigs, SIGTERM);
sigdelset(&sigs, SIGINT);
sigdelset(&sigs, SIGHUP);
while (1) {
struct timespec timeout = { -1, -1 };
int retval;
memset(&rep, 0, sizeof(rep));
do {
retval = ppoll(&pds, 1, &timeout, &sigs);
} while (retval == -1 && errno == EINTR && !done);
if (done)
break;
if (audit_get_reply(fd, &rep, GET_REPLY_NONBLOCKING, 0) > 0) {
/* we don't actually want to do anything here. */
;
}
}
return;
}
#endif /* USESELINUX */
int audit_daemonize(void) {
#ifdef USESELINUX
int fd;
#ifndef STANDALONE
int i;
pid_t child;
if ((child = fork()) > 0)
return 0;
for (i = 0; i < getdtablesize(); i++)
close(i);
signal(SIGTTOU, SIG_IGN);
signal(SIGTTIN, SIG_IGN);
signal(SIGTSTP, SIG_IGN);
if ((fd = open("/proc/self/oom_adj", O_RDWR)) >= 0) {
i = write(fd, "-17", 3);
close(fd);
}
#endif /* !defined(STANDALONE) */
fd = audit_open();
do_auditd(fd);
audit_close(fd);
#endif /* USESELINUX */
exit(0);
}
