From: Kirill Korotaev Date: Mon, 2 Oct 2006 09:18:20 +0000 (-0700) Subject: [PATCH] IPC namespace - utils X-Git-Tag: v2.6.19-rc1~405 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=73ea41302bab5e02c9e86ab15c509494a550f1db;p=linux-2.6 [PATCH] IPC namespace - utils This patch adds basic IPC namespace functionality to IPC utils: - init_ipc_ns - copy/clone/unshare/free IPC ns - /proc preparations Signed-off-by: Pavel Emelianov Signed-off-by: Kirill Korotaev Cc: "Eric W. Biederman" Cc: Cedric Le Goater Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/include/linux/init_task.h b/include/linux/init_task.h index ceecf69dfa..33c5daacc7 100644 --- a/include/linux/init_task.h +++ b/include/linux/init_task.h @@ -6,6 +6,7 @@ #include #include #include +#include #define INIT_FDTABLE \ { \ @@ -74,8 +75,8 @@ extern struct nsproxy init_nsproxy; .count = ATOMIC_INIT(1), \ .nslock = SPIN_LOCK_UNLOCKED, \ .uts_ns = &init_uts_ns, \ - .ipc_ns = &init_ipc_ns, \ .namespace = NULL, \ + INIT_IPC_NS(ipc_ns) \ } #define INIT_SIGHAND(sighand) { \ diff --git a/include/linux/ipc.h b/include/linux/ipc.h index 36027b10f2..d9e2b3f36c 100644 --- a/include/linux/ipc.h +++ b/include/linux/ipc.h @@ -88,20 +88,38 @@ struct ipc_namespace { }; extern struct ipc_namespace init_ipc_ns; + +#ifdef CONFIG_SYSVIPC +#define INIT_IPC_NS(ns) .ns = &init_ipc_ns, +#else +#define INIT_IPC_NS(ns) +#endif + +#ifdef CONFIG_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); +#else +static inline int copy_ipcs(unsigned long flags, struct task_struct *tsk) +{ + return 0; +} +#endif static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns) { +#ifdef CONFIG_IPC_NS if (ns) kref_get(&ns->kref); +#endif return ns; } static inline void put_ipc_ns(struct ipc_namespace *ns) { +#ifdef CONFIG_IPC_NS kref_put(&ns->kref, free_ipc_ns); +#endif } #endif /* __KERNEL__ */ diff --git a/ipc/util.c b/ipc/util.c index 67b6d178db..42479e4eec 100644 --- a/ipc/util.c +++ b/ipc/util.c @@ -12,6 +12,9 @@ * Mingming Cao * Mar 2006 - support for audit of ipc object properties * Dustin Kirkland + * Jun 2006 - namespaces ssupport + * OpenVZ, SWsoft Inc. + * Pavel Emelianov */ #include @@ -29,6 +32,7 @@ #include #include #include +#include #include @@ -37,10 +41,111 @@ struct ipc_proc_iface { const char *path; const char *header; - struct ipc_ids *ids; + int ids; int (*show)(struct seq_file *, void *); }; +struct ipc_namespace init_ipc_ns = { + .kref = { + .refcount = ATOMIC_INIT(2), + }, +}; + +#ifdef CONFIG_IPC_NS +static struct ipc_namespace *clone_ipc_ns(struct ipc_namespace *old_ns) +{ + int err; + struct ipc_namespace *ns; + + err = -ENOMEM; + ns = kmalloc(sizeof(struct ipc_namespace), GFP_KERNEL); + if (ns == NULL) + goto err_mem; + + err = sem_init_ns(ns); + if (err) + goto err_sem; + err = msg_init_ns(ns); + if (err) + goto err_msg; + err = shm_init_ns(ns); + if (err) + goto err_shm; + + kref_init(&ns->kref); + return ns; + +err_shm: + msg_exit_ns(ns); +err_msg: + sem_exit_ns(ns); +err_sem: + kfree(ns); +err_mem: + return ERR_PTR(err); +} + +int unshare_ipcs(unsigned long unshare_flags, struct ipc_namespace **new_ipc) +{ + struct ipc_namespace *new; + + if (unshare_flags & CLONE_NEWIPC) { + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + + new = clone_ipc_ns(current->nsproxy->ipc_ns); + if (IS_ERR(new)) + return PTR_ERR(new); + + *new_ipc = new; + } + + return 0; +} + +int copy_ipcs(unsigned long flags, struct task_struct *tsk) +{ + struct ipc_namespace *old_ns = tsk->nsproxy->ipc_ns; + struct ipc_namespace *new_ns; + int err = 0; + + if (!old_ns) + return 0; + + get_ipc_ns(old_ns); + + if (!(flags & CLONE_NEWIPC)) + return 0; + + if (!capable(CAP_SYS_ADMIN)) { + err = -EPERM; + goto out; + } + + new_ns = clone_ipc_ns(old_ns); + if (!new_ns) { + err = -ENOMEM; + goto out; + } + + tsk->nsproxy->ipc_ns = new_ns; +out: + put_ipc_ns(old_ns); + return err; +} + +void free_ipc_ns(struct kref *kref) +{ + struct ipc_namespace *ns; + + ns = container_of(kref, struct ipc_namespace, kref); + sem_exit_ns(ns); + msg_exit_ns(ns); + shm_exit_ns(ns); + kfree(ns); +} +#endif + /** * ipc_init - initialise IPC subsystem * @@ -67,7 +172,7 @@ __initcall(ipc_init); * array itself. */ -void __init ipc_init_ids(struct ipc_ids* ids, int size) +void __ipc_init ipc_init_ids(struct ipc_ids* ids, int size) { int i; @@ -110,8 +215,7 @@ static struct file_operations sysvipc_proc_fops; * @show: show routine. */ void __init ipc_init_proc_interface(const char *path, const char *header, - struct ipc_ids *ids, - int (*show)(struct seq_file *, void *)) + int ids, int (*show)(struct seq_file *, void *)) { struct proc_dir_entry *pde; struct ipc_proc_iface *iface; @@ -635,6 +739,9 @@ static void *sysvipc_proc_next(struct seq_file *s, void *it, loff_t *pos) struct ipc_proc_iface *iface = s->private; struct kern_ipc_perm *ipc = it; loff_t p; + struct ipc_ids *ids; + + ids = current->nsproxy->ipc_ns->ids[iface->ids]; /* If we had an ipc id locked before, unlock it */ if (ipc && ipc != SEQ_START_TOKEN) @@ -644,8 +751,8 @@ static void *sysvipc_proc_next(struct seq_file *s, void *it, loff_t *pos) * p = *pos - 1 (because id 0 starts at position 1) * + 1 (because we increment the position by one) */ - for (p = *pos; p <= iface->ids->max_id; p++) { - if ((ipc = ipc_lock(iface->ids, p)) != NULL) { + for (p = *pos; p <= ids->max_id; p++) { + if ((ipc = ipc_lock(ids, p)) != NULL) { *pos = p + 1; return ipc; } @@ -664,12 +771,15 @@ static void *sysvipc_proc_start(struct seq_file *s, loff_t *pos) struct ipc_proc_iface *iface = s->private; struct kern_ipc_perm *ipc; loff_t p; + struct ipc_ids *ids; + + ids = current->nsproxy->ipc_ns->ids[iface->ids]; /* * Take the lock - this will be released by the corresponding * call to stop(). */ - mutex_lock(&iface->ids->mutex); + mutex_lock(&ids->mutex); /* pos < 0 is invalid */ if (*pos < 0) @@ -680,8 +790,8 @@ static void *sysvipc_proc_start(struct seq_file *s, loff_t *pos) return SEQ_START_TOKEN; /* Find the (pos-1)th ipc */ - for (p = *pos - 1; p <= iface->ids->max_id; p++) { - if ((ipc = ipc_lock(iface->ids, p)) != NULL) { + for (p = *pos - 1; p <= ids->max_id; p++) { + if ((ipc = ipc_lock(ids, p)) != NULL) { *pos = p + 1; return ipc; } @@ -693,13 +803,15 @@ static void sysvipc_proc_stop(struct seq_file *s, void *it) { struct kern_ipc_perm *ipc = it; struct ipc_proc_iface *iface = s->private; + struct ipc_ids *ids; /* If we had a locked segment, release it */ if (ipc && ipc != SEQ_START_TOKEN) ipc_unlock(ipc); + ids = current->nsproxy->ipc_ns->ids[iface->ids]; /* Release the lock we took in start() */ - mutex_unlock(&iface->ids->mutex); + mutex_unlock(&ids->mutex); } static int sysvipc_proc_show(struct seq_file *s, void *it) diff --git a/ipc/util.h b/ipc/util.h index 0181553d31..c8fd6b9d77 100644 --- a/ipc/util.h +++ b/ipc/util.h @@ -3,6 +3,8 @@ * Copyright (C) 1999 Christoph Rohland * * ipc helper functions (c) 1999 Manfred Spraul + * namespaces support. 2006 OpenVZ, SWsoft Inc. + * Pavel Emelianov */ #ifndef _IPC_UTIL_H @@ -15,6 +17,14 @@ void sem_init (void); void msg_init (void); void shm_init (void); +int sem_init_ns(struct ipc_namespace *ns); +int msg_init_ns(struct ipc_namespace *ns); +int shm_init_ns(struct ipc_namespace *ns); + +void sem_exit_ns(struct ipc_namespace *ns); +void msg_exit_ns(struct ipc_namespace *ns); +void shm_exit_ns(struct ipc_namespace *ns); + struct ipc_id_ary { int size; struct kern_ipc_perm *p[0]; @@ -31,15 +41,23 @@ struct ipc_ids { }; struct seq_file; -void __init ipc_init_ids(struct ipc_ids* ids, int size); +#ifdef CONFIG_IPC_NS +#define __ipc_init +#else +#define __ipc_init __init +#endif +void __ipc_init ipc_init_ids(struct ipc_ids *ids, int size); #ifdef CONFIG_PROC_FS void __init ipc_init_proc_interface(const char *path, const char *header, - struct ipc_ids *ids, - int (*show)(struct seq_file *, void *)); + int ids, int (*show)(struct seq_file *, void *)); #else #define ipc_init_proc_interface(path, header, ids, show) do {} while (0) #endif +#define IPC_SEM_IDS 0 +#define IPC_MSG_IDS 1 +#define IPC_SHM_IDS 2 + /* must be called with ids->mutex acquired.*/ int ipc_findkey(struct ipc_ids* ids, key_t key); int ipc_addid(struct ipc_ids* ids, struct kern_ipc_perm* new, int size); diff --git a/kernel/fork.c b/kernel/fork.c index d6cc565585..7dc6140baa 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -1589,6 +1589,16 @@ static int unshare_semundo(unsigned long unshare_flags, struct sem_undo_list **n return 0; } +#ifndef CONFIG_IPC_NS +static inline int unshare_ipcs(unsigned long flags, struct ipc_namespace **ns) +{ + if (flags & CLONE_NEWIPC) + return -EINVAL; + + return 0; +} +#endif + /* * unshare allows a process to 'unshare' part of the process * context which was originally shared using clone. copy_*