ipc_namespace.h | Explore in Territory

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __IPC_NAMESPACE_H__
#define __IPC_NAMESPACE_H__

#include <linux/err.h>
#include <linux/idr.h>
#include <linux/rwsem.h>
#include <linux/notifier.h>
#include <linux/nsproxy.h>
#include <linux/ns_common.h>
#include <linux/refcount.h>
#include <linux/rhashtable-types.h>
#include <linux/sysctl.h>
#include <linux/percpu_counter.h>

struct user_namespace;

struct ipc_ids { … };

struct ipc_namespace { … } __randomize_layout;

extern struct ipc_namespace init_ipc_ns;
extern spinlock_t mq_lock;

#ifdef CONFIG_SYSVIPC
extern void shm_destroy_orphaned(struct ipc_namespace *ns);
#else /* CONFIG_SYSVIPC */
static inline void shm_destroy_orphaned(struct ipc_namespace *ns) {}
#endif /* CONFIG_SYSVIPC */

#ifdef CONFIG_POSIX_MQUEUE
extern int mq_init_ns(struct ipc_namespace *ns);
/*
 * POSIX Message Queue default values:
 *
 * MIN_*: Lowest value an admin can set the maximum unprivileged limit to
 * DFLT_*MAX: Default values for the maximum unprivileged limits
 * DFLT_{MSG,MSGSIZE}: Default values used when the user doesn't supply
 *   an attribute to the open call and the queue must be created
 * HARD_*: Highest value the maximums can be set to.  These are enforced
 *   on CAP_SYS_RESOURCE apps as well making them inviolate (so make them
 *   suitably high)
 *
 * POSIX Requirements:
 *   Per app minimum openable message queues - 8.  This does not map well
 *     to the fact that we limit the number of queues on a per namespace
 *     basis instead of a per app basis.  So, make the default high enough
 *     that no given app should have a hard time opening 8 queues.
 *   Minimum maximum for HARD_MSGMAX - 32767.  I bumped this to 65536.
 *   Minimum maximum for HARD_MSGSIZEMAX - POSIX is silent on this.  However,
 *     we have run into a situation where running applications in the wild
 *     require this to be at least 5MB, and preferably 10MB, so I set the
 *     value to 16MB in hopes that this user is the worst of the bunch and
 *     the new maximum will handle anyone else.  I may have to revisit this
 *     in the future.
 */
#define DFLT_QUEUESMAX …
#define MIN_MSGMAX …
#define DFLT_MSG …
#define DFLT_MSGMAX …
#define HARD_MSGMAX …
#define MIN_MSGSIZEMAX …
#define DFLT_MSGSIZE …
#define DFLT_MSGSIZEMAX …
#define HARD_MSGSIZEMAX …
#else
static inline int mq_init_ns(struct ipc_namespace *ns) { return 0; }
#endif

#if defined(CONFIG_IPC_NS)
extern struct ipc_namespace *copy_ipcs(unsigned long flags,
	struct user_namespace *user_ns, struct ipc_namespace *ns);

static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns)
{ … }

static inline struct ipc_namespace *get_ipc_ns_not_zero(struct ipc_namespace *ns)
{ … }

extern void put_ipc_ns(struct ipc_namespace *ns);
#else
static inline struct ipc_namespace *copy_ipcs(unsigned long flags,
	struct user_namespace *user_ns, struct ipc_namespace *ns)
{
	if (flags & CLONE_NEWIPC)
		return ERR_PTR(-EINVAL);

	return ns;
}

static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns)
{
	return ns;
}

static inline struct ipc_namespace *get_ipc_ns_not_zero(struct ipc_namespace *ns)
{
	return ns;
}

static inline void put_ipc_ns(struct ipc_namespace *ns)
{
}
#endif

#ifdef CONFIG_POSIX_MQUEUE_SYSCTL

void retire_mq_sysctls(struct ipc_namespace *ns);
bool setup_mq_sysctls(struct ipc_namespace *ns);

#else /* CONFIG_POSIX_MQUEUE_SYSCTL */

static inline void retire_mq_sysctls(struct ipc_namespace *ns)
{
}

static inline bool setup_mq_sysctls(struct ipc_namespace *ns)
{
	return true;
}

#endif /* CONFIG_POSIX_MQUEUE_SYSCTL */

#ifdef CONFIG_SYSVIPC_SYSCTL

bool setup_ipc_sysctls(struct ipc_namespace *ns);
void retire_ipc_sysctls(struct ipc_namespace *ns);

#else /* CONFIG_SYSVIPC_SYSCTL */

static inline void retire_ipc_sysctls(struct ipc_namespace *ns)
{
}

static inline bool setup_ipc_sysctls(struct ipc_namespace *ns)
{
	return true;
}

#endif /* CONFIG_SYSVIPC_SYSCTL */
#endif
linux/include/linux/ipc_namespace.h
