audit: refactor audit_receive_msg() to clarify AUDIT_*_RULE* cases

audit_receive_msg() needlessly contained a fallthrough case that called
audit_receive_filter(), containing no common code between the cases.  Separate
them to make the logic clearer.  Refactor AUDIT_LIST_RULES, AUDIT_ADD_RULE,
AUDIT_DEL_RULE cases to create audit_rule_change(), audit_list_rules_send()
functions.  This should not functionally change the logic.

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
This commit is contained in:
Richard Guy Briggs 2013-11-20 14:01:53 -05:00 committed by Eric Paris
parent a06e56b2a1
commit ce0d9f0469
3 changed files with 48 additions and 34 deletions

View file

@ -461,8 +461,10 @@ extern int audit_update_lsm_rules(void);
/* Private API (for audit.c only) */
extern int audit_filter_user(int type);
extern int audit_filter_type(int type);
extern int audit_receive_filter(int type, __u32 portid, int seq,
extern int audit_rule_change(int type, __u32 portid, int seq,
void *data, size_t datasz);
extern int audit_list_rules_send(__u32 portid, int seq);
extern int audit_enabled;
#else /* CONFIG_AUDIT */
static inline __printf(4, 5)

View file

@ -903,11 +903,12 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
audit_log_end(ab);
return -EPERM;
}
/* fallthrough */
case AUDIT_LIST_RULES:
err = audit_receive_filter(msg_type, NETLINK_CB(skb).portid,
err = audit_rule_change(msg_type, NETLINK_CB(skb).portid,
seq, data, nlmsg_len(nlh));
break;
case AUDIT_LIST_RULES:
err = audit_list_rules_send(NETLINK_CB(skb).portid, seq);
break;
case AUDIT_TRIM:
audit_trim_trees();
audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE);

View file

@ -1023,47 +1023,20 @@ static void audit_log_rule_change(char *action, struct audit_krule *rule, int re
}
/**
* audit_receive_filter - apply all rules to the specified message type
* audit_rule_change - apply all rules to the specified message type
* @type: audit message type
* @portid: target port id for netlink audit messages
* @seq: netlink audit message sequence (serial) number
* @data: payload data
* @datasz: size of payload data
*/
int audit_receive_filter(int type, __u32 portid, int seq, void *data,
size_t datasz)
int audit_rule_change(int type, __u32 portid, int seq, void *data,
size_t datasz)
{
struct task_struct *tsk;
struct audit_netlink_list *dest;
int err = 0;
struct audit_entry *entry;
switch (type) {
case AUDIT_LIST_RULES:
/* We can't just spew out the rules here because we might fill
* the available socket buffer space and deadlock waiting for
* auditctl to read from it... which isn't ever going to
* happen if we're actually running in the context of auditctl
* trying to _send_ the stuff */
dest = kmalloc(sizeof(struct audit_netlink_list), GFP_KERNEL);
if (!dest)
return -ENOMEM;
dest->portid = portid;
dest->pid = task_pid_vnr(current);
skb_queue_head_init(&dest->q);
mutex_lock(&audit_filter_mutex);
audit_list_rules(portid, seq, &dest->q);
mutex_unlock(&audit_filter_mutex);
tsk = kthread_run(audit_send_list, dest, "audit_send_list");
if (IS_ERR(tsk)) {
skb_queue_purge(&dest->q);
kfree(dest);
err = PTR_ERR(tsk);
}
break;
case AUDIT_ADD_RULE:
entry = audit_data_to_entry(data, datasz);
if (IS_ERR(entry))
@ -1090,6 +1063,44 @@ int audit_receive_filter(int type, __u32 portid, int seq, void *data,
return err;
}
/**
* audit_list_rules_send - list the audit rules
* @portid: target portid for netlink audit messages
* @seq: netlink audit message sequence (serial) number
*/
int audit_list_rules_send(__u32 portid, int seq)
{
struct task_struct *tsk;
struct audit_netlink_list *dest;
int err = 0;
/* We can't just spew out the rules here because we might fill
* the available socket buffer space and deadlock waiting for
* auditctl to read from it... which isn't ever going to
* happen if we're actually running in the context of auditctl
* trying to _send_ the stuff */
dest = kmalloc(sizeof(struct audit_netlink_list), GFP_KERNEL);
if (!dest)
return -ENOMEM;
dest->portid = portid;
dest->pid = task_pid_vnr(current);
skb_queue_head_init(&dest->q);
mutex_lock(&audit_filter_mutex);
audit_list_rules(portid, seq, &dest->q);
mutex_unlock(&audit_filter_mutex);
tsk = kthread_run(audit_send_list, dest, "audit_send_list");
if (IS_ERR(tsk)) {
skb_queue_purge(&dest->q);
kfree(dest);
err = PTR_ERR(tsk);
}
return err;
}
int audit_comparator(u32 left, u32 op, u32 right)
{
switch (op) {