#include <ipc/ipc_port.h>
#include <kern/ipc_kobject.h>
#include <kern/audit_sessionport.h>
+#include <libkern/OSAtomic.h>
#if CONFIG_AUDIT
/*
* audit_session_mksend
*
- * Description: Obtain a send right for given audit session information.
+ * Description: Obtain a send right for given audit session.
*
* Parameters: *aia_p Audit session information to assosiate with
- * the new port.
- * *sessionport Pointer to the current session port. This may
- * actually be set to IPC_PORT_NULL.
- *
- * Returns: !NULL Resulting send right.
- * NULL Failed to allocate port (due to lack of memory
- * resources).
- *
- * *sessionport The session port that may have been allocated.
- *
- * Notes: On return, sendport will be set to the new send right on success,
- * or null/dead on error.
+ * the new port.
+ * *sessionport Pointer to the current session port. This may
+ * actually be set to IPC_PORT_NULL.
+ *
+ * Returns: !NULL Resulting send right.
+ * NULL Failed to allocate port (due to lack of memory
+ * resources).
+ *
+ * Assumptions: Caller holds a reference on the session during the call.
+ * If there were no outstanding send rights against the port,
+ * hold a reference on the session and arm a new no-senders
+ * notification to determine when to release that reference.
+ * Otherwise, by creating an additional send right, we share
+ * the port's reference until all send rights go away.
*/
ipc_port_t
audit_session_mksend(struct auditinfo_addr *aia_p, ipc_port_t *sessionport)
{
- ipc_port_t notifyport;
- ipc_port_t sendport = IPC_PORT_NULL;
-
- /*
- * If we have an existing, active session port then use it.
- */
- sendport = ipc_port_make_send(*sessionport);
- if (IP_VALID(sendport)) {
- ip_lock(sendport);
- if (ip_active(sendport) &&
- IKOT_AU_SESSIONPORT == ip_kotype(sendport)) {
- ip_unlock(sendport);
- return (sendport);
- }
- ip_unlock(sendport);
- ipc_port_release_send(sendport);
+ audit_session_aiaref(aia_p);
+ if (!ipc_kobject_make_send_lazy_alloc_port(sessionport,
+ (ipc_kobject_t)aia_p, IKOT_AU_SESSIONPORT)) {
+ audit_session_aiaunref(aia_p);
}
- /*
- * Otherwise, create a new one for this session.
- */
- *sessionport = ipc_port_alloc_kernel();
- if (IP_VALID(*sessionport)) {
- ipc_kobject_set(*sessionport, (ipc_kobject_t)aia_p,
- IKOT_AU_SESSIONPORT);
-
- /* Request a no-senders notification. */
- notifyport = ipc_port_make_sonce(*sessionport);
- ip_lock(*sessionport);
- /* unlocked by ipc_port_nsrequest */
- ipc_port_nsrequest(*sessionport, 1, notifyport, ¬ifyport);
- }
- sendport = ipc_port_make_send(*sessionport);
-
- return (sendport);
+ return *sessionport;
}
* audit_session_porttoaia
*
* Description: Obtain the audit session info associated with the given port.
-
+ *
* Parameters: port A Mach port.
*
* Returns: NULL The given Mach port did not reference audit
- * session info.
+ * session info.
* !NULL The audit session info that is associated with
* the Mach port.
*
if (IP_VALID(port)) {
ip_lock(port);
- if (ip_active(port) && IKOT_AU_SESSIONPORT == ip_kotype(port))
- aia_p = (struct auditinfo_addr *)port->ip_kobject;
+ if (IKOT_AU_SESSIONPORT == ip_kotype(port)) {
+ require_ip_active(port);
+ aia_p = (struct auditinfo_addr *)ip_get_kobject(port);
+ }
ip_unlock(port);
- }
+ }
- return (aia_p);
+ return aia_p;
}
* Parameters: msg A Mach no-senders notification message.
*
* Notes: It is possible that new send rights are created after a
- * no-senders notification has been sent (i.e. via audit_session_mksend).
- * We check the port's mscount against the notification's not_count
- * to detect when this happens, and re-arm the notification in that
- * case.
- *
- * In the normal case (no new senders), we first mark the port
- * as dying by setting its object type to IKOT_NONE so that
- * audit_session_mksend will no longer use it to create
- * additional send rights. We can then safely call
- * audit_session_port_destroy with no locks.
+ * no-senders notification has been sent, but they will be protected
+ * by another aia reference.
*/
void
audit_session_nosenders(mach_msg_header_t *msg)
{
mach_no_senders_notification_t *notification = (void *)msg;
ipc_port_t port = notification->not_header.msgh_remote_port;
- ipc_port_t notifyport;
struct auditinfo_addr *port_aia_p = NULL;
- if (!IP_VALID(port))
- return;
- ip_lock(port);
- if (ip_active(port) && IKOT_AU_SESSIONPORT == ip_kotype(port)) {
- port_aia_p = (struct auditinfo_addr *)port->ip_kobject;
- assert(NULL != port_aia_p);
- if (port->ip_mscount <= notification->not_count)
- ipc_kobject_set_atomically(port, IKO_NULL, IKOT_NONE);
- else {
- /* re-arm the notification */
- ip_unlock(port);
- notifyport = ipc_port_make_sonce(port);
- ip_lock(port);
- /* unlocked by ipc_port_nsrequest */
- ipc_port_nsrequest(port, port->ip_mscount, notifyport,
- ¬ifyport);
- return;
- }
+ require_ip_active(port);
+ assert(IKOT_AU_SESSIONPORT == ip_kotype(port));
+ port_aia_p = (struct auditinfo_addr *)ip_get_kobject(port);
+ assert(NULL != port_aia_p);
+
+ audit_session_aiaunref(port_aia_p);
+}
+
+void
+audit_session_portdestroy(ipc_port_t *sessionport)
+{
+ ipc_port_t port = *sessionport;
+
+ if (IP_VALID(port)) {
+ require_ip_active(port);
+ assert(IKOT_AU_SESSIONPORT == ip_kotype(port));
+ ipc_kobject_set_atomically(port, IKO_NULL, IKOT_NONE);
+ ipc_port_dealloc_kernel(port);
+ *sessionport = IP_NULL;
}
- ip_unlock(port);
- if (NULL != port_aia_p)
- audit_session_portaiadestroy(port_aia_p);
- ipc_port_dealloc_kernel(port);
}
#endif /* CONFIG_AUDIT */
projects / apple / xnu.git / blobdiff