1ab516013SSerge E. Hallyn /* 2ab516013SSerge E. Hallyn * Copyright (C) 2006 IBM Corporation 3ab516013SSerge E. Hallyn * 4ab516013SSerge E. Hallyn * Author: Serge Hallyn <serue@us.ibm.com> 5ab516013SSerge E. Hallyn * 6ab516013SSerge E. Hallyn * This program is free software; you can redistribute it and/or 7ab516013SSerge E. Hallyn * modify it under the terms of the GNU General Public License as 8ab516013SSerge E. Hallyn * published by the Free Software Foundation, version 2 of the 9ab516013SSerge E. Hallyn * License. 1025b21cb2SKirill Korotaev * 1125b21cb2SKirill Korotaev * Jun 2006 - namespaces support 1225b21cb2SKirill Korotaev * OpenVZ, SWsoft Inc. 1325b21cb2SKirill Korotaev * Pavel Emelianov <xemul@openvz.org> 14ab516013SSerge E. Hallyn */ 15ab516013SSerge E. Hallyn 16ab516013SSerge E. Hallyn #include <linux/module.h> 17ab516013SSerge E. Hallyn #include <linux/version.h> 18ab516013SSerge E. Hallyn #include <linux/nsproxy.h> 190437eb59SSerge E. Hallyn #include <linux/init_task.h> 206b3286edSKirill Korotaev #include <linux/mnt_namespace.h> 214865ecf1SSerge E. Hallyn #include <linux/utsname.h> 229a575a92SCedric Le Goater #include <linux/pid_namespace.h> 239dd776b6SEric W. Biederman #include <net/net_namespace.h> 24ae5e1b22SPavel Emelyanov #include <linux/ipc_namespace.h> 250437eb59SSerge E. Hallyn 2698c0d07cSCedric Le Goater static struct kmem_cache *nsproxy_cachep; 2798c0d07cSCedric Le Goater 280437eb59SSerge E. Hallyn struct nsproxy init_nsproxy = INIT_NSPROXY(init_nsproxy); 29ab516013SSerge E. Hallyn 30ab516013SSerge E. Hallyn /* 31ab516013SSerge E. Hallyn * creates a copy of "orig" with refcount 1. 32ab516013SSerge E. Hallyn */ 33e3222c4eSBadari Pulavarty static inline struct nsproxy *clone_nsproxy(struct nsproxy *orig) 34ab516013SSerge E. Hallyn { 35ab516013SSerge E. Hallyn struct nsproxy *ns; 36ab516013SSerge E. Hallyn 3798c0d07cSCedric Le Goater ns = kmem_cache_alloc(nsproxy_cachep, GFP_KERNEL); 3898c0d07cSCedric Le Goater if (ns) { 3998c0d07cSCedric Le Goater memcpy(ns, orig, sizeof(struct nsproxy)); 40ab516013SSerge E. Hallyn atomic_set(&ns->count, 1); 4198c0d07cSCedric Le Goater } 42ab516013SSerge E. Hallyn return ns; 43ab516013SSerge E. Hallyn } 44ab516013SSerge E. Hallyn 45ab516013SSerge E. Hallyn /* 46e3222c4eSBadari Pulavarty * Create new nsproxy and all of its the associated namespaces. 47e3222c4eSBadari Pulavarty * Return the newly created nsproxy. Do not attach this to the task, 48e3222c4eSBadari Pulavarty * leave it to the caller to do proper locking and attach it to task. 49ab516013SSerge E. Hallyn */ 50213dd266SEric W. Biederman static struct nsproxy *create_new_namespaces(unsigned long flags, 51213dd266SEric W. Biederman struct task_struct *tsk, struct fs_struct *new_fs) 52ab516013SSerge E. Hallyn { 53e3222c4eSBadari Pulavarty struct nsproxy *new_nsp; 54467e9f4bSCedric Le Goater int err; 55ab516013SSerge E. Hallyn 56e3222c4eSBadari Pulavarty new_nsp = clone_nsproxy(tsk->nsproxy); 57e3222c4eSBadari Pulavarty if (!new_nsp) 58e3222c4eSBadari Pulavarty return ERR_PTR(-ENOMEM); 591651e14eSSerge E. Hallyn 60e3222c4eSBadari Pulavarty new_nsp->mnt_ns = copy_mnt_ns(flags, tsk->nsproxy->mnt_ns, new_fs); 61467e9f4bSCedric Le Goater if (IS_ERR(new_nsp->mnt_ns)) { 62467e9f4bSCedric Le Goater err = PTR_ERR(new_nsp->mnt_ns); 63e3222c4eSBadari Pulavarty goto out_ns; 64467e9f4bSCedric Le Goater } 65e3222c4eSBadari Pulavarty 66e3222c4eSBadari Pulavarty new_nsp->uts_ns = copy_utsname(flags, tsk->nsproxy->uts_ns); 67467e9f4bSCedric Le Goater if (IS_ERR(new_nsp->uts_ns)) { 68467e9f4bSCedric Le Goater err = PTR_ERR(new_nsp->uts_ns); 69e3222c4eSBadari Pulavarty goto out_uts; 70467e9f4bSCedric Le Goater } 71e3222c4eSBadari Pulavarty 72e3222c4eSBadari Pulavarty new_nsp->ipc_ns = copy_ipcs(flags, tsk->nsproxy->ipc_ns); 73467e9f4bSCedric Le Goater if (IS_ERR(new_nsp->ipc_ns)) { 74467e9f4bSCedric Le Goater err = PTR_ERR(new_nsp->ipc_ns); 75e3222c4eSBadari Pulavarty goto out_ipc; 76467e9f4bSCedric Le Goater } 77e3222c4eSBadari Pulavarty 782894d650SSukadev Bhattiprolu new_nsp->pid_ns = copy_pid_ns(flags, task_active_pid_ns(tsk)); 79467e9f4bSCedric Le Goater if (IS_ERR(new_nsp->pid_ns)) { 80467e9f4bSCedric Le Goater err = PTR_ERR(new_nsp->pid_ns); 81e3222c4eSBadari Pulavarty goto out_pid; 82467e9f4bSCedric Le Goater } 83e3222c4eSBadari Pulavarty 84acce292cSCedric Le Goater new_nsp->user_ns = copy_user_ns(flags, tsk->nsproxy->user_ns); 85467e9f4bSCedric Le Goater if (IS_ERR(new_nsp->user_ns)) { 86467e9f4bSCedric Le Goater err = PTR_ERR(new_nsp->user_ns); 87acce292cSCedric Le Goater goto out_user; 88467e9f4bSCedric Le Goater } 89acce292cSCedric Le Goater 909dd776b6SEric W. Biederman new_nsp->net_ns = copy_net_ns(flags, tsk->nsproxy->net_ns); 919dd776b6SEric W. Biederman if (IS_ERR(new_nsp->net_ns)) { 929dd776b6SEric W. Biederman err = PTR_ERR(new_nsp->net_ns); 939dd776b6SEric W. Biederman goto out_net; 949dd776b6SEric W. Biederman } 959dd776b6SEric W. Biederman 96e3222c4eSBadari Pulavarty return new_nsp; 97e3222c4eSBadari Pulavarty 989dd776b6SEric W. Biederman out_net: 999dd776b6SEric W. Biederman if (new_nsp->user_ns) 1009dd776b6SEric W. Biederman put_user_ns(new_nsp->user_ns); 101acce292cSCedric Le Goater out_user: 102acce292cSCedric Le Goater if (new_nsp->pid_ns) 103acce292cSCedric Le Goater put_pid_ns(new_nsp->pid_ns); 104e3222c4eSBadari Pulavarty out_pid: 105e3222c4eSBadari Pulavarty if (new_nsp->ipc_ns) 106e3222c4eSBadari Pulavarty put_ipc_ns(new_nsp->ipc_ns); 107e3222c4eSBadari Pulavarty out_ipc: 108e3222c4eSBadari Pulavarty if (new_nsp->uts_ns) 109e3222c4eSBadari Pulavarty put_uts_ns(new_nsp->uts_ns); 110e3222c4eSBadari Pulavarty out_uts: 111e3222c4eSBadari Pulavarty if (new_nsp->mnt_ns) 112e3222c4eSBadari Pulavarty put_mnt_ns(new_nsp->mnt_ns); 113e3222c4eSBadari Pulavarty out_ns: 11498c0d07cSCedric Le Goater kmem_cache_free(nsproxy_cachep, new_nsp); 115467e9f4bSCedric Le Goater return ERR_PTR(err); 116ab516013SSerge E. Hallyn } 117ab516013SSerge E. Hallyn 118ab516013SSerge E. Hallyn /* 119ab516013SSerge E. Hallyn * called from clone. This now handles copy for nsproxy and all 120ab516013SSerge E. Hallyn * namespaces therein. 121ab516013SSerge E. Hallyn */ 122213dd266SEric W. Biederman int copy_namespaces(unsigned long flags, struct task_struct *tsk) 123ab516013SSerge E. Hallyn { 124ab516013SSerge E. Hallyn struct nsproxy *old_ns = tsk->nsproxy; 1251651e14eSSerge E. Hallyn struct nsproxy *new_ns; 1261651e14eSSerge E. Hallyn int err = 0; 127ab516013SSerge E. Hallyn 128ab516013SSerge E. Hallyn if (!old_ns) 129ab516013SSerge E. Hallyn return 0; 130ab516013SSerge E. Hallyn 131ab516013SSerge E. Hallyn get_nsproxy(old_ns); 132ab516013SSerge E. Hallyn 13330e49c26SPavel Emelyanov if (!(flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC | 13430e49c26SPavel Emelyanov CLONE_NEWUSER | CLONE_NEWPID | CLONE_NEWNET))) 135ab516013SSerge E. Hallyn return 0; 1361651e14eSSerge E. Hallyn 137e3222c4eSBadari Pulavarty if (!capable(CAP_SYS_ADMIN)) { 138e3222c4eSBadari Pulavarty err = -EPERM; 139e3222c4eSBadari Pulavarty goto out; 140e3222c4eSBadari Pulavarty } 141e3222c4eSBadari Pulavarty 14202fdb36aSSerge E. Hallyn /* 14302fdb36aSSerge E. Hallyn * CLONE_NEWIPC must detach from the undolist: after switching 14402fdb36aSSerge E. Hallyn * to a new ipc namespace, the semaphore arrays from the old 14502fdb36aSSerge E. Hallyn * namespace are unreachable. In clone parlance, CLONE_SYSVSEM 14602fdb36aSSerge E. Hallyn * means share undolist with parent, so we must forbid using 14702fdb36aSSerge E. Hallyn * it along with CLONE_NEWIPC. 14802fdb36aSSerge E. Hallyn */ 14902fdb36aSSerge E. Hallyn if ((flags & CLONE_NEWIPC) && (flags & CLONE_SYSVSEM)) { 15002fdb36aSSerge E. Hallyn err = -EINVAL; 15102fdb36aSSerge E. Hallyn goto out; 15202fdb36aSSerge E. Hallyn } 15302fdb36aSSerge E. Hallyn 154e3222c4eSBadari Pulavarty new_ns = create_new_namespaces(flags, tsk, tsk->fs); 155e3222c4eSBadari Pulavarty if (IS_ERR(new_ns)) { 156e3222c4eSBadari Pulavarty err = PTR_ERR(new_ns); 1571651e14eSSerge E. Hallyn goto out; 1581651e14eSSerge E. Hallyn } 1591651e14eSSerge E. Hallyn 160858d72eaSSerge E. Hallyn err = ns_cgroup_clone(tsk); 161858d72eaSSerge E. Hallyn if (err) { 162858d72eaSSerge E. Hallyn put_nsproxy(new_ns); 163858d72eaSSerge E. Hallyn goto out; 164858d72eaSSerge E. Hallyn } 165858d72eaSSerge E. Hallyn 1661651e14eSSerge E. Hallyn tsk->nsproxy = new_ns; 167858d72eaSSerge E. Hallyn 1681651e14eSSerge E. Hallyn out: 169444f378bSLinus Torvalds put_nsproxy(old_ns); 1701651e14eSSerge E. Hallyn return err; 171ab516013SSerge E. Hallyn } 172ab516013SSerge E. Hallyn 173ab516013SSerge E. Hallyn void free_nsproxy(struct nsproxy *ns) 174ab516013SSerge E. Hallyn { 1756b3286edSKirill Korotaev if (ns->mnt_ns) 1766b3286edSKirill Korotaev put_mnt_ns(ns->mnt_ns); 1774865ecf1SSerge E. Hallyn if (ns->uts_ns) 1784865ecf1SSerge E. Hallyn put_uts_ns(ns->uts_ns); 17925b21cb2SKirill Korotaev if (ns->ipc_ns) 18025b21cb2SKirill Korotaev put_ipc_ns(ns->ipc_ns); 1819a575a92SCedric Le Goater if (ns->pid_ns) 1829a575a92SCedric Le Goater put_pid_ns(ns->pid_ns); 183acce292cSCedric Le Goater if (ns->user_ns) 184acce292cSCedric Le Goater put_user_ns(ns->user_ns); 1859dd776b6SEric W. Biederman put_net(ns->net_ns); 18698c0d07cSCedric Le Goater kmem_cache_free(nsproxy_cachep, ns); 187ab516013SSerge E. Hallyn } 188e3222c4eSBadari Pulavarty 189e3222c4eSBadari Pulavarty /* 190e3222c4eSBadari Pulavarty * Called from unshare. Unshare all the namespaces part of nsproxy. 1914e71e474SCedric Le Goater * On success, returns the new nsproxy. 192e3222c4eSBadari Pulavarty */ 193e3222c4eSBadari Pulavarty int unshare_nsproxy_namespaces(unsigned long unshare_flags, 194e3222c4eSBadari Pulavarty struct nsproxy **new_nsp, struct fs_struct *new_fs) 195e3222c4eSBadari Pulavarty { 196e3222c4eSBadari Pulavarty int err = 0; 197e3222c4eSBadari Pulavarty 19877ec739dSSerge E. Hallyn if (!(unshare_flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC | 1999dd776b6SEric W. Biederman CLONE_NEWUSER | CLONE_NEWNET))) 200e3222c4eSBadari Pulavarty return 0; 201e3222c4eSBadari Pulavarty 202e3222c4eSBadari Pulavarty if (!capable(CAP_SYS_ADMIN)) 203e3222c4eSBadari Pulavarty return -EPERM; 204e3222c4eSBadari Pulavarty 205e3222c4eSBadari Pulavarty *new_nsp = create_new_namespaces(unshare_flags, current, 206e3222c4eSBadari Pulavarty new_fs ? new_fs : current->fs); 207858d72eaSSerge E. Hallyn if (IS_ERR(*new_nsp)) { 208e3222c4eSBadari Pulavarty err = PTR_ERR(*new_nsp); 209858d72eaSSerge E. Hallyn goto out; 210858d72eaSSerge E. Hallyn } 211858d72eaSSerge E. Hallyn 212858d72eaSSerge E. Hallyn err = ns_cgroup_clone(current); 213858d72eaSSerge E. Hallyn if (err) 214858d72eaSSerge E. Hallyn put_nsproxy(*new_nsp); 215858d72eaSSerge E. Hallyn 216858d72eaSSerge E. Hallyn out: 217e3222c4eSBadari Pulavarty return err; 218e3222c4eSBadari Pulavarty } 21998c0d07cSCedric Le Goater 220cf7b708cSPavel Emelyanov void switch_task_namespaces(struct task_struct *p, struct nsproxy *new) 221cf7b708cSPavel Emelyanov { 222cf7b708cSPavel Emelyanov struct nsproxy *ns; 223cf7b708cSPavel Emelyanov 224cf7b708cSPavel Emelyanov might_sleep(); 225cf7b708cSPavel Emelyanov 226cf7b708cSPavel Emelyanov ns = p->nsproxy; 227cf7b708cSPavel Emelyanov 228cf7b708cSPavel Emelyanov rcu_assign_pointer(p->nsproxy, new); 229cf7b708cSPavel Emelyanov 230cf7b708cSPavel Emelyanov if (ns && atomic_dec_and_test(&ns->count)) { 231cf7b708cSPavel Emelyanov /* 232cf7b708cSPavel Emelyanov * wait for others to get what they want from this nsproxy. 233cf7b708cSPavel Emelyanov * 234cf7b708cSPavel Emelyanov * cannot release this nsproxy via the call_rcu() since 235cf7b708cSPavel Emelyanov * put_mnt_ns() will want to sleep 236cf7b708cSPavel Emelyanov */ 237cf7b708cSPavel Emelyanov synchronize_rcu(); 238cf7b708cSPavel Emelyanov free_nsproxy(ns); 239cf7b708cSPavel Emelyanov } 240cf7b708cSPavel Emelyanov } 241cf7b708cSPavel Emelyanov 242cf7b708cSPavel Emelyanov void exit_task_namespaces(struct task_struct *p) 243cf7b708cSPavel Emelyanov { 244cf7b708cSPavel Emelyanov switch_task_namespaces(p, NULL); 245cf7b708cSPavel Emelyanov } 246cf7b708cSPavel Emelyanov 24798c0d07cSCedric Le Goater static int __init nsproxy_cache_init(void) 24898c0d07cSCedric Le Goater { 249db8906daSPavel Emelyanov nsproxy_cachep = KMEM_CACHE(nsproxy, SLAB_PANIC); 25098c0d07cSCedric Le Goater return 0; 25198c0d07cSCedric Le Goater } 25298c0d07cSCedric Le Goater 25398c0d07cSCedric Le Goater module_init(nsproxy_cache_init); 254