/**
* kauditd_rehold_skb - Handle a audit record send failure in the hold queue
* @skb: audit record
+ * @error: error code (unused)
*
* Description:
* This should only be used by the kauditd_thread when it fails to flush the
* hold queue.
*/
-static void kauditd_rehold_skb(struct sk_buff *skb)
+static void kauditd_rehold_skb(struct sk_buff *skb, __always_unused int error)
{
- /* put the record back in the queue at the same place */
- skb_queue_head(&audit_hold_queue, skb);
+ /* put the record back in the queue */
+ skb_queue_tail(&audit_hold_queue, skb);
}
/**
* kauditd_hold_skb - Queue an audit record, waiting for auditd
* @skb: audit record
+ * @error: error code
*
* Description:
* Queue the audit record, waiting for an instance of auditd. When this
* and queue it, if we have room. If we want to hold on to the record, but we
* don't have room, record a record lost message.
*/
-static void kauditd_hold_skb(struct sk_buff *skb)
+static void kauditd_hold_skb(struct sk_buff *skb, int error)
{
/* at this point it is uncertain if we will ever send this to auditd so
* try to send the message via printk before we go any further */
kauditd_printk_skb(skb);
/* can we just silently drop the message? */
- if (!audit_default) {
- kfree_skb(skb);
- return;
+ if (!audit_default)
+ goto drop;
+
+ /* the hold queue is only for when the daemon goes away completely,
+ * not -EAGAIN failures; if we are in a -EAGAIN state requeue the
+ * record on the retry queue unless it's full, in which case drop it
+ */
+ if (error == -EAGAIN) {
+ if (!audit_backlog_limit ||
+ skb_queue_len(&audit_retry_queue) < audit_backlog_limit) {
+ skb_queue_tail(&audit_retry_queue, skb);
+ return;
+ }
+ audit_log_lost("kauditd retry queue overflow");
+ goto drop;
}
- /* if we have room, queue the message */
+ /* if we have room in the hold queue, queue the message */
if (!audit_backlog_limit ||
skb_queue_len(&audit_hold_queue) < audit_backlog_limit) {
skb_queue_tail(&audit_hold_queue, skb);
/* we have no other options - drop the message */
audit_log_lost("kauditd hold queue overflow");
+drop:
kfree_skb(skb);
}
/**
* kauditd_retry_skb - Queue an audit record, attempt to send again to auditd
* @skb: audit record
+ * @error: error code (unused)
*
* Description:
* Not as serious as kauditd_hold_skb() as we still have a connected auditd,
* but for some reason we are having problems sending it audit records so
* queue the given record and attempt to resend.
*/
-static void kauditd_retry_skb(struct sk_buff *skb)
+static void kauditd_retry_skb(struct sk_buff *skb, __always_unused int error)
{
- /* NOTE: because records should only live in the retry queue for a
- * short period of time, before either being sent or moved to the hold
- * queue, we don't currently enforce a limit on this queue */
- skb_queue_tail(&audit_retry_queue, skb);
+ if (!audit_backlog_limit ||
+ skb_queue_len(&audit_retry_queue) < audit_backlog_limit) {
+ skb_queue_tail(&audit_retry_queue, skb);
+ return;
+ }
+
+ /* we have to drop the record, send it via printk as a last effort */
+ kauditd_printk_skb(skb);
+ audit_log_lost("kauditd retry queue overflow");
+ kfree_skb(skb);
}
/**
/* flush the retry queue to the hold queue, but don't touch the main
* queue since we need to process that normally for multicast */
while ((skb = skb_dequeue(&audit_retry_queue)))
- kauditd_hold_skb(skb);
+ kauditd_hold_skb(skb, -ECONNREFUSED);
}
/**
struct sk_buff_head *queue,
unsigned int retry_limit,
void (*skb_hook)(struct sk_buff *skb),
- void (*err_hook)(struct sk_buff *skb))
+ void (*err_hook)(struct sk_buff *skb, int error))
{
int rc = 0;
- struct sk_buff *skb;
- static unsigned int failed = 0;
+ struct sk_buff *skb = NULL;
+ struct sk_buff *skb_tail;
+ unsigned int failed = 0;
/* NOTE: kauditd_thread takes care of all our locking, we just use
* the netlink info passed to us (e.g. sk and portid) */
- while ((skb = skb_dequeue(queue))) {
+ skb_tail = skb_peek_tail(queue);
+ while ((skb != skb_tail) && (skb = skb_dequeue(queue))) {
/* call the skb_hook for each skb we touch */
if (skb_hook)
(*skb_hook)(skb);
/* can we send to anyone via unicast? */
if (!sk) {
if (err_hook)
- (*err_hook)(skb);
+ (*err_hook)(skb, -ECONNREFUSED);
continue;
}
+retry:
/* grab an extra skb reference in case of error */
skb_get(skb);
rc = netlink_unicast(sk, skb, portid, 0);
if (rc < 0) {
- /* fatal failure for our queue flush attempt? */
+ /* send failed - try a few times unless fatal error */
if (++failed >= retry_limit ||
rc == -ECONNREFUSED || rc == -EPERM) {
- /* yes - error processing for the queue */
sk = NULL;
if (err_hook)
- (*err_hook)(skb);
- if (!skb_hook)
- goto out;
- /* keep processing with the skb_hook */
+ (*err_hook)(skb, rc);
+ if (rc == -EAGAIN)
+ rc = 0;
+ /* continue to drain the queue */
continue;
} else
- /* no - requeue to preserve ordering */
- skb_queue_head(queue, skb);
+ goto retry;
} else {
- /* it worked - drop the extra reference and continue */
+ /* skb sent - drop the extra reference and continue */
consume_skb(skb);
failed = 0;
}
}
-out:
return (rc >= 0 ? 0 : rc);
}
nlh = nlmsg_next(nlh, &len);
}
audit_ctl_unlock();
+
+ /* can't block with the ctrl lock, so penalize the sender now */
+ if (audit_backlog_limit &&
+ (skb_queue_len(&audit_queue) > audit_backlog_limit)) {
+ DECLARE_WAITQUEUE(wait, current);
+
+ /* wake kauditd to try and flush the queue */
+ wake_up_interruptible(&kauditd_wait);
+
+ add_wait_queue_exclusive(&audit_backlog_wait, &wait);
+ set_current_state(TASK_UNINTERRUPTIBLE);
+ schedule_timeout(audit_backlog_wait_time);
+ remove_wait_queue(&audit_backlog_wait, &wait);
+ }
}
/* Log information about who is connecting to the audit multicast socket */
audit_panic("cannot initialize netlink socket in namespace");
return -ENOMEM;
}
- aunet->sk->sk_sndtimeo = MAX_SCHEDULE_TIMEOUT;
+ /* limit the timeout in case auditd is blocked/stopped */
+ aunet->sk->sk_sndtimeo = HZ / 10;
return 0;
}
* task_tgid_vnr() since auditd_pid is set in audit_receive_msg()
* using a PID anchored in the caller's namespace
* 2. generator holding the audit_cmd_mutex - we don't want to block
- * while holding the mutex */
+ * while holding the mutex, although we do penalize the sender
+ * later in audit_receive() when it is safe to block
+ */
if (!(auditd_test_task(current) || audit_ctl_owner_current())) {
long stime = audit_backlog_wait_time;
projects / platform / kernel / linux-rpi.git / blobdiff