| 1 | |
| 2 | * Copyright (C) 2006 IBM Corporation
|
| 3 | *
|
| 4 | * Author: Serge Hallyn <[email protected]>
|
| 5 | *
|
| 6 | * This program is free software; you can redistribute it and/or
|
| 7 | * modify it under the terms of the GNU General Public License as
|
| 8 | * published by the Free Software Foundation, version 2 of the
|
| 9 | * License.
|
| 10 | *
|
| 11 | * Jun 2006 - namespaces support
|
| 12 | * OpenVZ, SWsoft Inc.
|
| 13 | * Pavel Emelianov <[email protected]>
|
| 14 |
|
| 15 |
|
| 16 | #include <linux/module.h>
|
| 17 | #include <linux/version.h>
|
| 18 | #include <linux/nsproxy.h>
|
| 19 | #include <linux/init_task.h>
|
| 20 | #include <linux/mnt_namespace.h>
|
| 21 | #include <linux/utsname.h>
|
| 22 | #include <linux/pid_namespace.h>
|
| 23 |
|
| 24 | struct nsproxy init_nsproxy = INIT_NSPROXY(init_nsproxy);
|
| 25 |
|
| 26 | static inline void get_nsproxy(struct nsproxy *ns)
|
| 27 | {
|
| 28 | atomic_inc(&ns->count);
|
| 29 | }
|
| 30 |
|
| 31 | void get_task_namespaces(struct task_struct *tsk)
|
| 32 | {
|
| 33 | struct nsproxy *ns = tsk->nsproxy;
|
| 34 | if (ns) {
|
| 35 | get_nsproxy(ns);
|
| 36 | }
|
| 37 | }
|
| 38 |
|
| 39 | |
| 40 | * creates a copy of "orig" with refcount 1.
|
| 41 | * This does not grab references to the contained namespaces,
|
| 42 | * so that needs to be done by dup_namespaces.
|
| 43 |
|
| 44 | static inline struct nsproxy *clone_namespaces(struct nsproxy *orig)
|
| 45 | {
|
| 46 | struct nsproxy *ns;
|
| 47 |
|
| 48 | ns = kmemdup(orig, sizeof(struct nsproxy), GFP_KERNEL);
|
| 49 | if (ns)
|
| 50 | atomic_set(&ns->count, 1);
|
| 51 | return ns;
|
| 52 | }
|
| 53 |
|
| 54 | |
| 55 | * copies the nsproxy, setting refcount to 1, and grabbing a
|
| 56 | * reference to all contained namespaces. Called from
|
| 57 | * sys_unshare()
|
| 58 |
|
| 59 | struct nsproxy *dup_namespaces(struct nsproxy *orig)
|
| 60 | {
|
| 61 | struct nsproxy *ns = clone_namespaces(orig);
|
| 62 |
|
| 63 | if (ns) {
|
| 64 | if (ns->mnt_ns)
|
| 65 | get_mnt_ns(ns->mnt_ns);
|
| 66 | if (ns->uts_ns)
|
| 67 | get_uts_ns(ns->uts_ns);
|
| 68 | if (ns->ipc_ns)
|
| 69 | get_ipc_ns(ns->ipc_ns);
|
| 70 | if (ns->pid_ns)
|
| 71 | get_pid_ns(ns->pid_ns);
|
| 72 | }
|
| 73 |
|
| 74 | return ns;
|
| 75 | }
|
| 76 |
|
| 77 | |
| 78 | * called from clone. This now handles copy for nsproxy and all
|
| 79 | * namespaces therein.
|
| 80 |
|
| 81 | int copy_namespaces(int flags, struct task_struct *tsk)
|
| 82 | {
|
| 83 | struct nsproxy *old_ns = tsk->nsproxy;
|
| 84 | struct nsproxy *new_ns;
|
| 85 | int err = 0;
|
| 86 |
|
| 87 | if (!old_ns)
|
| 88 | return 0;
|
| 89 |
|
| 90 | get_nsproxy(old_ns);
|
| 91 |
|
| 92 | if (!(flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC)))
|
| 93 | return 0;
|
| 94 |
|
| 95 | new_ns = clone_namespaces(old_ns);
|
| 96 | if (!new_ns) {
|
| 97 | err = -ENOMEM;
|
| 98 | goto out;
|
| 99 | }
|
| 100 |
|
| 101 | tsk->nsproxy = new_ns;
|
| 102 |
|
| 103 | err = copy_mnt_ns(flags, tsk);
|
| 104 | if (err)
|
| 105 | goto out_ns;
|
| 106 |
|
| 107 | err = copy_utsname(flags, tsk);
|
| 108 | if (err)
|
| 109 | goto out_uts;
|
| 110 |
|
| 111 | err = copy_ipcs(flags, tsk);
|
| 112 | if (err)
|
| 113 | goto out_ipc;
|
| 114 |
|
| 115 | err = copy_pid_ns(flags, tsk);
|
| 116 | if (err)
|
| 117 | goto out_pid;
|
| 118 |
|
| 119 | out:
|
| 120 | put_nsproxy(old_ns);
|
| 121 | return err;
|
| 122 |
|
| 123 | out_pid:
|
| 124 | if (new_ns->ipc_ns)
|
| 125 | put_ipc_ns(new_ns->ipc_ns);
|
| 126 | out_ipc:
|
| 127 | if (new_ns->uts_ns)
|
| 128 | put_uts_ns(new_ns->uts_ns);
|
| 129 | out_uts:
|
| 130 | if (new_ns->mnt_ns)
|
| 131 | put_mnt_ns(new_ns->mnt_ns);
|
| 132 | out_ns:
|
| 133 | tsk->nsproxy = old_ns;
|
| 134 | kfree(new_ns);
|
| 135 | goto out;
|
| 136 | }
|
| 137 |
|
| 138 | void free_nsproxy(struct nsproxy *ns)
|
| 139 | {
|
| 140 | if (ns->mnt_ns)
|
| 141 | put_mnt_ns(ns->mnt_ns);
|
| 142 | if (ns->uts_ns)
|
| 143 | put_uts_ns(ns->uts_ns);
|
| 144 | if (ns->ipc_ns)
|
| 145 | put_ipc_ns(ns->ipc_ns);
|
| 146 | if (ns->pid_ns)
|
| 147 | put_pid_ns(ns->pid_ns);
|
| 148 | kfree(ns);
|
| 149 | }
|