mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-27 14:43:58 +08:00
f36f8c75ae
Add support for per-user_namespace registers of persistent per-UID kerberos caches held within the kernel. This allows the kerberos cache to be retained beyond the life of all a user's processes so that the user's cron jobs can work. The kerberos cache is envisioned as a keyring/key tree looking something like: struct user_namespace \___ .krb_cache keyring - The register \___ _krb.0 keyring - Root's Kerberos cache \___ _krb.5000 keyring - User 5000's Kerberos cache \___ _krb.5001 keyring - User 5001's Kerberos cache \___ tkt785 big_key - A ccache blob \___ tkt12345 big_key - Another ccache blob Or possibly: struct user_namespace \___ .krb_cache keyring - The register \___ _krb.0 keyring - Root's Kerberos cache \___ _krb.5000 keyring - User 5000's Kerberos cache \___ _krb.5001 keyring - User 5001's Kerberos cache \___ tkt785 keyring - A ccache \___ krbtgt/REDHAT.COM@REDHAT.COM big_key \___ http/REDHAT.COM@REDHAT.COM user \___ afs/REDHAT.COM@REDHAT.COM user \___ nfs/REDHAT.COM@REDHAT.COM user \___ krbtgt/KERNEL.ORG@KERNEL.ORG big_key \___ http/KERNEL.ORG@KERNEL.ORG big_key What goes into a particular Kerberos cache is entirely up to userspace. Kernel support is limited to giving you the Kerberos cache keyring that you want. The user asks for their Kerberos cache by: krb_cache = keyctl_get_krbcache(uid, dest_keyring); The uid is -1 or the user's own UID for the user's own cache or the uid of some other user's cache (requires CAP_SETUID). This permits rpc.gssd or whatever to mess with the cache. The cache returned is a keyring named "_krb.<uid>" that the possessor can read, search, clear, invalidate, unlink from and add links to. Active LSMs get a chance to rule on whether the caller is permitted to make a link. Each uid's cache keyring is created when it first accessed and is given a timeout that is extended each time this function is called so that the keyring goes away after a while. The timeout is configurable by sysctl but defaults to three days. Each user_namespace struct gets a lazily-created keyring that serves as the register. The cache keyrings are added to it. This means that standard key search and garbage collection facilities are available. The user_namespace struct's register goes away when it does and anything left in it is then automatically gc'd. Signed-off-by: David Howells <dhowells@redhat.com> Tested-by: Simo Sorce <simo@redhat.com> cc: Serge E. Hallyn <serge.hallyn@ubuntu.com> cc: Eric W. Biederman <ebiederm@xmission.com>
93 lines
2.2 KiB
C
93 lines
2.2 KiB
C
#ifndef _LINUX_USER_NAMESPACE_H
|
|
#define _LINUX_USER_NAMESPACE_H
|
|
|
|
#include <linux/kref.h>
|
|
#include <linux/nsproxy.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];
|
|
};
|
|
|
|
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;
|
|
unsigned int proc_inum;
|
|
|
|
/* 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
|
|
};
|
|
|
|
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 free_user_ns(struct user_namespace *ns);
|
|
|
|
static inline void put_user_ns(struct user_namespace *ns)
|
|
{
|
|
if (ns && atomic_dec_and_test(&ns->count))
|
|
free_user_ns(ns);
|
|
}
|
|
|
|
struct seq_operations;
|
|
extern struct seq_operations proc_uid_seq_operations;
|
|
extern struct seq_operations proc_gid_seq_operations;
|
|
extern 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 *);
|
|
#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)
|
|
{
|
|
}
|
|
|
|
#endif
|
|
|
|
#endif /* _LINUX_USER_H */
|