Serge E. Hallyn | ab51601 | 2006-10-02 02:18:06 -0700 | [diff] [blame] | 1 | #ifndef _LINUX_NSPROXY_H |
| 2 | #define _LINUX_NSPROXY_H |
| 3 | |
| 4 | #include <linux/spinlock.h> |
| 5 | #include <linux/sched.h> |
| 6 | |
Kirill Korotaev | 6b3286e | 2006-12-08 02:37:56 -0800 | [diff] [blame] | 7 | struct mnt_namespace; |
Serge E. Hallyn | 4865ecf | 2006-10-02 02:18:14 -0700 | [diff] [blame] | 8 | struct uts_namespace; |
Kirill Korotaev | 25b21cb | 2006-10-02 02:18:19 -0700 | [diff] [blame] | 9 | struct ipc_namespace; |
Cedric Le Goater | 9a575a9 | 2006-12-08 02:37:59 -0800 | [diff] [blame] | 10 | struct pid_namespace; |
Al Viro | 5ad4e53 | 2009-03-29 19:50:06 -0400 | [diff] [blame] | 11 | struct fs_struct; |
Serge E. Hallyn | 1651e14 | 2006-10-02 02:18:08 -0700 | [diff] [blame] | 12 | |
Serge E. Hallyn | ab51601 | 2006-10-02 02:18:06 -0700 | [diff] [blame] | 13 | /* |
| 14 | * A structure to contain pointers to all per-process |
| 15 | * namespaces - fs (mount), uts, network, sysvipc, etc. |
| 16 | * |
| 17 | * 'count' is the number of tasks holding a reference. |
| 18 | * The count for each namespace, then, will be the number |
| 19 | * of nsproxies pointing to it, not the number of tasks. |
| 20 | * |
| 21 | * The nsproxy is shared by tasks which share all namespaces. |
| 22 | * As soon as a single namespace is cloned or unshared, the |
| 23 | * nsproxy is copied. |
| 24 | */ |
| 25 | struct nsproxy { |
| 26 | atomic_t count; |
Serge E. Hallyn | 4865ecf | 2006-10-02 02:18:14 -0700 | [diff] [blame] | 27 | struct uts_namespace *uts_ns; |
Kirill Korotaev | 25b21cb | 2006-10-02 02:18:19 -0700 | [diff] [blame] | 28 | struct ipc_namespace *ipc_ns; |
Kirill Korotaev | 6b3286e | 2006-12-08 02:37:56 -0800 | [diff] [blame] | 29 | struct mnt_namespace *mnt_ns; |
Cedric Le Goater | 9a575a9 | 2006-12-08 02:37:59 -0800 | [diff] [blame] | 30 | struct pid_namespace *pid_ns; |
Eric W. Biederman | 772698f | 2007-09-12 11:55:17 +0200 | [diff] [blame] | 31 | struct net *net_ns; |
Serge E. Hallyn | ab51601 | 2006-10-02 02:18:06 -0700 | [diff] [blame] | 32 | }; |
| 33 | extern struct nsproxy init_nsproxy; |
| 34 | |
Pavel Emelyanov | cf7b708 | 2007-10-18 23:39:54 -0700 | [diff] [blame] | 35 | /* |
| 36 | * the namespaces access rules are: |
| 37 | * |
| 38 | * 1. only current task is allowed to change tsk->nsproxy pointer or |
| 39 | * any pointer on the nsproxy itself |
| 40 | * |
| 41 | * 2. when accessing (i.e. reading) current task's namespaces - no |
| 42 | * precautions should be taken - just dereference the pointers |
| 43 | * |
| 44 | * 3. the access to other task namespaces is performed like this |
| 45 | * rcu_read_lock(); |
| 46 | * nsproxy = task_nsproxy(tsk); |
| 47 | * if (nsproxy != NULL) { |
| 48 | * / * |
| 49 | * * work with the namespaces here |
| 50 | * * e.g. get the reference on one of them |
| 51 | * * / |
| 52 | * } / * |
| 53 | * * NULL task_nsproxy() means that this task is |
| 54 | * * almost dead (zombie) |
| 55 | * * / |
| 56 | * rcu_read_unlock(); |
| 57 | * |
| 58 | */ |
| 59 | |
| 60 | static inline struct nsproxy *task_nsproxy(struct task_struct *tsk) |
| 61 | { |
| 62 | return rcu_dereference(tsk->nsproxy); |
| 63 | } |
| 64 | |
Eric W. Biederman | 213dd26 | 2007-07-15 23:41:15 -0700 | [diff] [blame] | 65 | int copy_namespaces(unsigned long flags, struct task_struct *tsk); |
Pavel Emelyanov | cf7b708 | 2007-10-18 23:39:54 -0700 | [diff] [blame] | 66 | void exit_task_namespaces(struct task_struct *tsk); |
| 67 | void switch_task_namespaces(struct task_struct *tsk, struct nsproxy *new); |
Serge E. Hallyn | ab51601 | 2006-10-02 02:18:06 -0700 | [diff] [blame] | 68 | void free_nsproxy(struct nsproxy *ns); |
Badari Pulavarty | e3222c4 | 2007-05-08 00:25:21 -0700 | [diff] [blame] | 69 | int unshare_nsproxy_namespaces(unsigned long, struct nsproxy **, |
Eric W. Biederman | b2e0d987 | 2012-07-26 05:15:35 -0700 | [diff] [blame^] | 70 | struct cred *, struct fs_struct *); |
Al Viro | 6657719 | 2011-06-28 15:41:10 -0400 | [diff] [blame] | 71 | int __init nsproxy_cache_init(void); |
Serge E. Hallyn | ab51601 | 2006-10-02 02:18:06 -0700 | [diff] [blame] | 72 | |
Linus Torvalds | 444f378 | 2007-01-30 13:35:18 -0800 | [diff] [blame] | 73 | static inline void put_nsproxy(struct nsproxy *ns) |
Serge E. Hallyn | ab51601 | 2006-10-02 02:18:06 -0700 | [diff] [blame] | 74 | { |
Linus Torvalds | 444f378 | 2007-01-30 13:35:18 -0800 | [diff] [blame] | 75 | if (atomic_dec_and_test(&ns->count)) { |
Serge E. Hallyn | ab51601 | 2006-10-02 02:18:06 -0700 | [diff] [blame] | 76 | free_nsproxy(ns); |
Linus Torvalds | 444f378 | 2007-01-30 13:35:18 -0800 | [diff] [blame] | 77 | } |
Serge E. Hallyn | ab51601 | 2006-10-02 02:18:06 -0700 | [diff] [blame] | 78 | } |
| 79 | |
Pavel Emelyanov | cf7b708 | 2007-10-18 23:39:54 -0700 | [diff] [blame] | 80 | static inline void get_nsproxy(struct nsproxy *ns) |
Serge E. Hallyn | ab51601 | 2006-10-02 02:18:06 -0700 | [diff] [blame] | 81 | { |
Pavel Emelyanov | cf7b708 | 2007-10-18 23:39:54 -0700 | [diff] [blame] | 82 | atomic_inc(&ns->count); |
Serge E. Hallyn | ab51601 | 2006-10-02 02:18:06 -0700 | [diff] [blame] | 83 | } |
Serge E. Hallyn | 858d72e | 2007-10-18 23:39:45 -0700 | [diff] [blame] | 84 | |
Serge E. Hallyn | ab51601 | 2006-10-02 02:18:06 -0700 | [diff] [blame] | 85 | #endif |