linux-stable/include/linux/user_namespace.h
Eric W. Biederman b032132c3c userns: Free user namespaces in process context
Add the necessary boiler plate to move freeing of user namespaces into
work queue and thus into process context where things can sleep.

This is a necessary precursor to per user namespace sysctls.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2016-08-08 09:17:18 -05:00

112 lines
2.8 KiB
C

#ifndef _LINUX_USER_NAMESPACE_H
#define _LINUX_USER_NAMESPACE_H
#include <linux/kref.h>
#include <linux/nsproxy.h>
#include <linux/ns_common.h>
#include <linux/sched.h>
#include <linux/err.h>
#define UID_GID_MAP_MAX_EXTENTS 5
struct uid_gid_map { /* 64 bytes -- 1 cache line */
u32 nr_extents;
struct uid_gid_extent {
u32 first;
u32 lower_first;
u32 count;
} extent[UID_GID_MAP_MAX_EXTENTS];
};
#define USERNS_SETGROUPS_ALLOWED 1UL
#define USERNS_INIT_FLAGS USERNS_SETGROUPS_ALLOWED
struct user_namespace {
struct uid_gid_map uid_map;
struct uid_gid_map gid_map;
struct uid_gid_map projid_map;
atomic_t count;
struct user_namespace *parent;
int level;
kuid_t owner;
kgid_t group;
struct ns_common ns;
unsigned long flags;
/* Register of per-UID persistent keyrings for this namespace */
#ifdef CONFIG_PERSISTENT_KEYRINGS
struct key *persistent_keyring_register;
struct rw_semaphore persistent_keyring_register_sem;
#endif
struct work_struct work;
};
extern struct user_namespace init_user_ns;
#ifdef CONFIG_USER_NS
static inline struct user_namespace *get_user_ns(struct user_namespace *ns)
{
if (ns)
atomic_inc(&ns->count);
return ns;
}
extern int create_user_ns(struct cred *new);
extern int unshare_userns(unsigned long unshare_flags, struct cred **new_cred);
extern void __put_user_ns(struct user_namespace *ns);
static inline void put_user_ns(struct user_namespace *ns)
{
if (ns && atomic_dec_and_test(&ns->count))
__put_user_ns(ns);
}
struct seq_operations;
extern const struct seq_operations proc_uid_seq_operations;
extern const struct seq_operations proc_gid_seq_operations;
extern const struct seq_operations proc_projid_seq_operations;
extern ssize_t proc_uid_map_write(struct file *, const char __user *, size_t, loff_t *);
extern ssize_t proc_gid_map_write(struct file *, const char __user *, size_t, loff_t *);
extern ssize_t proc_projid_map_write(struct file *, const char __user *, size_t, loff_t *);
extern ssize_t proc_setgroups_write(struct file *, const char __user *, size_t, loff_t *);
extern int proc_setgroups_show(struct seq_file *m, void *v);
extern bool userns_may_setgroups(const struct user_namespace *ns);
extern bool current_in_userns(const struct user_namespace *target_ns);
#else
static inline struct user_namespace *get_user_ns(struct user_namespace *ns)
{
return &init_user_ns;
}
static inline int create_user_ns(struct cred *new)
{
return -EINVAL;
}
static inline int unshare_userns(unsigned long unshare_flags,
struct cred **new_cred)
{
if (unshare_flags & CLONE_NEWUSER)
return -EINVAL;
return 0;
}
static inline void put_user_ns(struct user_namespace *ns)
{
}
static inline bool userns_may_setgroups(const struct user_namespace *ns)
{
return true;
}
static inline bool current_in_userns(const struct user_namespace *target_ns)
{
return true;
}
#endif
#endif /* _LINUX_USER_H */