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b2441318 | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
ab516013 SH |
2 | #ifndef _LINUX_NSPROXY_H |
3 | #define _LINUX_NSPROXY_H | |
4 | ||
6a2623b1 | 5 | #include <linux/refcount.h> |
ab516013 SH |
6 | #include <linux/spinlock.h> |
7 | #include <linux/sched.h> | |
8 | ||
6b3286ed | 9 | struct mnt_namespace; |
4865ecf1 | 10 | struct uts_namespace; |
25b21cb2 | 11 | struct ipc_namespace; |
9a575a92 | 12 | struct pid_namespace; |
a79a908f | 13 | struct cgroup_namespace; |
5ad4e53b | 14 | struct fs_struct; |
1651e14e | 15 | |
ab516013 SH |
16 | /* |
17 | * A structure to contain pointers to all per-process | |
18 | * namespaces - fs (mount), uts, network, sysvipc, etc. | |
19 | * | |
c2b1df2e AL |
20 | * The pid namespace is an exception -- it's accessed using |
21 | * task_active_pid_ns. The pid namespace here is the | |
22 | * namespace that children will use. | |
23 | * | |
ab516013 SH |
24 | * 'count' is the number of tasks holding a reference. |
25 | * The count for each namespace, then, will be the number | |
26 | * of nsproxies pointing to it, not the number of tasks. | |
27 | * | |
28 | * The nsproxy is shared by tasks which share all namespaces. | |
29 | * As soon as a single namespace is cloned or unshared, the | |
30 | * nsproxy is copied. | |
31 | */ | |
32 | struct nsproxy { | |
2ddd3cac | 33 | refcount_t count; |
4865ecf1 | 34 | struct uts_namespace *uts_ns; |
25b21cb2 | 35 | struct ipc_namespace *ipc_ns; |
6b3286ed | 36 | struct mnt_namespace *mnt_ns; |
c2b1df2e | 37 | struct pid_namespace *pid_ns_for_children; |
772698f6 | 38 | struct net *net_ns; |
769071ac AV |
39 | struct time_namespace *time_ns; |
40 | struct time_namespace *time_ns_for_children; | |
a79a908f | 41 | struct cgroup_namespace *cgroup_ns; |
ab516013 SH |
42 | }; |
43 | extern struct nsproxy init_nsproxy; | |
44 | ||
85e4daae CB |
45 | #define to_ns_common(__ns) \ |
46 | _Generic((__ns), \ | |
47 | struct cgroup_namespace *: &(__ns->ns), \ | |
48 | struct ipc_namespace *: &(__ns->ns), \ | |
49 | struct net *: &(__ns->ns), \ | |
50 | struct pid_namespace *: &(__ns->ns), \ | |
51 | struct mnt_namespace *: &(__ns->ns), \ | |
52 | struct time_namespace *: &(__ns->ns), \ | |
53 | struct user_namespace *: &(__ns->ns), \ | |
54 | struct uts_namespace *: &(__ns->ns)) | |
55 | ||
f2a8d52e CB |
56 | /* |
57 | * A structure to encompass all bits needed to install | |
58 | * a partial or complete new set of namespaces. | |
59 | * | |
60 | * If a new user namespace is requested cred will | |
61 | * point to a modifiable set of credentials. If a pointer | |
62 | * to a modifiable set is needed nsset_cred() must be | |
63 | * used and tested. | |
64 | */ | |
65 | struct nsset { | |
66 | unsigned flags; | |
67 | struct nsproxy *nsproxy; | |
68 | struct fs_struct *fs; | |
69 | const struct cred *cred; | |
70 | }; | |
71 | ||
72 | static inline struct cred *nsset_cred(struct nsset *set) | |
73 | { | |
74 | if (set->flags & CLONE_NEWUSER) | |
75 | return (struct cred *)set->cred; | |
76 | ||
77 | return NULL; | |
78 | } | |
79 | ||
cf7b708c PE |
80 | /* |
81 | * the namespaces access rules are: | |
82 | * | |
83 | * 1. only current task is allowed to change tsk->nsproxy pointer or | |
728dba3a EB |
84 | * any pointer on the nsproxy itself. Current must hold the task_lock |
85 | * when changing tsk->nsproxy. | |
cf7b708c PE |
86 | * |
87 | * 2. when accessing (i.e. reading) current task's namespaces - no | |
88 | * precautions should be taken - just dereference the pointers | |
89 | * | |
90 | * 3. the access to other task namespaces is performed like this | |
728dba3a EB |
91 | * task_lock(task); |
92 | * nsproxy = task->nsproxy; | |
cf7b708c PE |
93 | * if (nsproxy != NULL) { |
94 | * / * | |
95 | * * work with the namespaces here | |
96 | * * e.g. get the reference on one of them | |
97 | * * / | |
98 | * } / * | |
728dba3a | 99 | * * NULL task->nsproxy means that this task is |
cf7b708c PE |
100 | * * almost dead (zombie) |
101 | * * / | |
728dba3a | 102 | * task_unlock(task); |
cf7b708c PE |
103 | * |
104 | */ | |
105 | ||
213dd266 | 106 | int copy_namespaces(unsigned long flags, struct task_struct *tsk); |
cf7b708c PE |
107 | void exit_task_namespaces(struct task_struct *tsk); |
108 | void switch_task_namespaces(struct task_struct *tsk, struct nsproxy *new); | |
2b5f9dad | 109 | int exec_task_namespaces(void); |
ab516013 | 110 | void free_nsproxy(struct nsproxy *ns); |
e3222c4e | 111 | int unshare_nsproxy_namespaces(unsigned long, struct nsproxy **, |
b2e0d987 | 112 | struct cred *, struct fs_struct *); |
66577193 | 113 | int __init nsproxy_cache_init(void); |
ab516013 | 114 | |
444f378b | 115 | static inline void put_nsproxy(struct nsproxy *ns) |
ab516013 | 116 | { |
2ddd3cac | 117 | if (refcount_dec_and_test(&ns->count)) |
ab516013 | 118 | free_nsproxy(ns); |
ab516013 SH |
119 | } |
120 | ||
cf7b708c | 121 | static inline void get_nsproxy(struct nsproxy *ns) |
ab516013 | 122 | { |
2ddd3cac | 123 | refcount_inc(&ns->count); |
ab516013 | 124 | } |
858d72ea | 125 | |
d057c108 CB |
126 | DEFINE_FREE(put_nsproxy, struct nsproxy *, if (_T) put_nsproxy(_T)) |
127 | ||
ab516013 | 128 | #endif |