[PATCH] IPC namespace core
This patch set allows to unshare IPCs and have a private set of IPC objects
(sem, shm, msg) inside namespace. Basically, it is another building block of
containers functionality.
This patch implements core IPC namespace changes:
- ipc_namespace structure
- new config option CONFIG_IPC_NS
- adds CLONE_NEWIPC flag
- unshare support
[clg@fr.ibm.com: small fix for unshare of ipc namespace]
[akpm@osdl.org: build fix]
Signed-off-by: Pavel Emelianov <xemul@openvz.org>
Signed-off-by: Kirill Korotaev <dev@openvz.org>
Signed-off-by: Cedric Le Goater <clg@fr.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/include/linux/init_task.h b/include/linux/init_task.h
index e08531e..ceecf69 100644
--- a/include/linux/init_task.h
+++ b/include/linux/init_task.h
@@ -74,6 +74,7 @@
.count = ATOMIC_INIT(1), \
.nslock = SPIN_LOCK_UNLOCKED, \
.uts_ns = &init_uts_ns, \
+ .ipc_ns = &init_ipc_ns, \
.namespace = NULL, \
}
diff --git a/include/linux/ipc.h b/include/linux/ipc.h
index b291189..36027b1 100644
--- a/include/linux/ipc.h
+++ b/include/linux/ipc.h
@@ -2,6 +2,7 @@
#define _LINUX_IPC_H
#include <linux/types.h>
+#include <linux/kref.h>
#define IPC_PRIVATE ((__kernel_key_t) 0)
@@ -68,6 +69,41 @@
void *security;
};
+struct ipc_ids;
+struct ipc_namespace {
+ struct kref kref;
+ struct ipc_ids *ids[3];
+
+ int sem_ctls[4];
+ int used_sems;
+
+ int msg_ctlmax;
+ int msg_ctlmnb;
+ int msg_ctlmni;
+
+ size_t shm_ctlmax;
+ size_t shm_ctlall;
+ int shm_ctlmni;
+ int shm_tot;
+};
+
+extern struct ipc_namespace init_ipc_ns;
+extern void free_ipc_ns(struct kref *kref);
+extern int copy_ipcs(unsigned long flags, struct task_struct *tsk);
+extern int unshare_ipcs(unsigned long flags, struct ipc_namespace **ns);
+
+static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns)
+{
+ if (ns)
+ kref_get(&ns->kref);
+ return ns;
+}
+
+static inline void put_ipc_ns(struct ipc_namespace *ns)
+{
+ kref_put(&ns->kref, free_ipc_ns);
+}
+
#endif /* __KERNEL__ */
#endif /* _LINUX_IPC_H */
diff --git a/include/linux/nsproxy.h b/include/linux/nsproxy.h
index 9c2e0ad..f6baecd 100644
--- a/include/linux/nsproxy.h
+++ b/include/linux/nsproxy.h
@@ -6,6 +6,7 @@
struct namespace;
struct uts_namespace;
+struct ipc_namespace;
/*
* A structure to contain pointers to all per-process
@@ -23,6 +24,7 @@
atomic_t count;
spinlock_t nslock;
struct uts_namespace *uts_ns;
+ struct ipc_namespace *ipc_ns;
struct namespace *namespace;
};
extern struct nsproxy init_nsproxy;
diff --git a/include/linux/sched.h b/include/linux/sched.h
index a973e70..9ba959e 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -25,6 +25,7 @@
#define CLONE_CHILD_SETTID 0x01000000 /* set the TID in the child */
#define CLONE_STOPPED 0x02000000 /* Start in stopped state */
#define CLONE_NEWUTS 0x04000000 /* New utsname group? */
+#define CLONE_NEWIPC 0x08000000 /* New ipcs */
/*
* Scheduling policies
diff --git a/init/Kconfig b/init/Kconfig
index b0ea975..1038293 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -115,6 +115,15 @@
section 6.4 of the Linux Programmer's Guide, available from
<http://www.tldp.org/guides.html>.
+config IPC_NS
+ bool "IPC Namespaces"
+ depends on SYSVIPC
+ default n
+ help
+ Support ipc namespaces. This allows containers, i.e. virtual
+ environments, to use ipc namespaces to provide different ipc
+ objects for different servers. If unsure, say N.
+
config POSIX_MQUEUE
bool "POSIX Message Queues"
depends on NET && EXPERIMENTAL
diff --git a/kernel/fork.c b/kernel/fork.c
index 208dd99..d6cc565 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1608,13 +1608,15 @@
struct sem_undo_list *new_ulist = NULL;
struct nsproxy *new_nsproxy = NULL, *old_nsproxy = NULL;
struct uts_namespace *uts, *new_uts = NULL;
+ struct ipc_namespace *ipc, *new_ipc = NULL;
check_unshare_flags(&unshare_flags);
/* Return -EINVAL for all unsupported flags */
err = -EINVAL;
if (unshare_flags & ~(CLONE_THREAD|CLONE_FS|CLONE_NEWNS|CLONE_SIGHAND|
- CLONE_VM|CLONE_FILES|CLONE_SYSVSEM|CLONE_NEWUTS))
+ CLONE_VM|CLONE_FILES|CLONE_SYSVSEM|
+ CLONE_NEWUTS|CLONE_NEWIPC))
goto bad_unshare_out;
if ((err = unshare_thread(unshare_flags)))
@@ -1633,18 +1635,20 @@
goto bad_unshare_cleanup_fd;
if ((err = unshare_utsname(unshare_flags, &new_uts)))
goto bad_unshare_cleanup_semundo;
+ if ((err = unshare_ipcs(unshare_flags, &new_ipc)))
+ goto bad_unshare_cleanup_uts;
- if (new_ns || new_uts) {
+ if (new_ns || new_uts || new_ipc) {
old_nsproxy = current->nsproxy;
new_nsproxy = dup_namespaces(old_nsproxy);
if (!new_nsproxy) {
err = -ENOMEM;
- goto bad_unshare_cleanup_uts;
+ goto bad_unshare_cleanup_ipc;
}
}
if (new_fs || new_ns || new_sigh || new_mm || new_fd || new_ulist ||
- new_uts) {
+ new_uts || new_ipc) {
task_lock(current);
@@ -1692,12 +1696,22 @@
new_uts = uts;
}
+ if (new_ipc) {
+ ipc = current->nsproxy->ipc_ns;
+ current->nsproxy->ipc_ns = new_ipc;
+ new_ipc = ipc;
+ }
+
task_unlock(current);
}
if (new_nsproxy)
put_nsproxy(new_nsproxy);
+bad_unshare_cleanup_ipc:
+ if (new_ipc)
+ put_ipc_ns(new_ipc);
+
bad_unshare_cleanup_uts:
if (new_uts)
put_uts_ns(new_uts);
diff --git a/kernel/nsproxy.c b/kernel/nsproxy.c
index 8246813..8d6c852 100644
--- a/kernel/nsproxy.c
+++ b/kernel/nsproxy.c
@@ -7,6 +7,10 @@
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation, version 2 of the
* License.
+ *
+ * Jun 2006 - namespaces support
+ * OpenVZ, SWsoft Inc.
+ * Pavel Emelianov <xemul@openvz.org>
*/
#include <linux/module.h>
@@ -62,6 +66,8 @@
get_namespace(ns->namespace);
if (ns->uts_ns)
get_uts_ns(ns->uts_ns);
+ if (ns->ipc_ns)
+ get_ipc_ns(ns->ipc_ns);
}
return ns;
@@ -82,7 +88,7 @@
get_nsproxy(old_ns);
- if (!(flags & (CLONE_NEWNS | CLONE_NEWUTS)))
+ if (!(flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC)))
return 0;
new_ns = clone_namespaces(old_ns);
@@ -94,24 +100,31 @@
tsk->nsproxy = new_ns;
err = copy_namespace(flags, tsk);
- if (err) {
- tsk->nsproxy = old_ns;
- put_nsproxy(new_ns);
- goto out;
- }
+ if (err)
+ goto out_ns;
err = copy_utsname(flags, tsk);
- if (err) {
- if (new_ns->namespace)
- put_namespace(new_ns->namespace);
- tsk->nsproxy = old_ns;
- put_nsproxy(new_ns);
- goto out;
- }
+ if (err)
+ goto out_uts;
+
+ err = copy_ipcs(flags, tsk);
+ if (err)
+ goto out_ipc;
out:
put_nsproxy(old_ns);
return err;
+
+out_ipc:
+ if (new_ns->uts_ns)
+ put_uts_ns(new_ns->uts_ns);
+out_uts:
+ if (new_ns->namespace)
+ put_namespace(new_ns->namespace);
+out_ns:
+ tsk->nsproxy = old_ns;
+ put_nsproxy(new_ns);
+ goto out;
}
void free_nsproxy(struct nsproxy *ns)
@@ -120,5 +133,7 @@
put_namespace(ns->namespace);
if (ns->uts_ns)
put_uts_ns(ns->uts_ns);
+ if (ns->ipc_ns)
+ put_ipc_ns(ns->ipc_ns);
kfree(ns);
}