1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __IPC_NAMESPACE_H__
3 #define __IPC_NAMESPACE_H__
4
5 #include <linux/err.h>
6 #include <linux/idr.h>
7 #include <linux/rwsem.h>
8 #include <linux/notifier.h>
9 #include <linux/nsproxy.h>
10 #include <linux/ns_common.h>
11 #include <linux/refcount.h>
12 #include <linux/rhashtable-types.h>
13
14 struct user_namespace;
15
16 struct ipc_ids {
17 int in_use;
18 unsigned short seq;
19 struct rw_semaphore rwsem;
20 struct idr ipcs_idr;
21 int max_idx;
22 int last_idx; /* For wrap around detection */
23 #ifdef CONFIG_CHECKPOINT_RESTORE
24 int next_id;
25 #endif
26 struct rhashtable key_ht;
27 };
28
29 struct ipc_namespace {
30 refcount_t count;
31 struct ipc_ids ids[3];
32
33 int sem_ctls[4];
34 int used_sems;
35
36 unsigned int msg_ctlmax;
37 unsigned int msg_ctlmnb;
38 unsigned int msg_ctlmni;
39 atomic_t msg_bytes;
40 atomic_t msg_hdrs;
41
42 size_t shm_ctlmax;
43 size_t shm_ctlall;
44 unsigned long shm_tot;
45 int shm_ctlmni;
46 /*
47 * Defines whether IPC_RMID is forced for _all_ shm segments regardless
48 * of shmctl()
49 */
50 int shm_rmid_forced;
51
52 struct notifier_block ipcns_nb;
53
54 /* The kern_mount of the mqueuefs sb. We take a ref on it */
55 struct vfsmount *mq_mnt;
56
57 /* # queues in this ns, protected by mq_lock */
58 unsigned int mq_queues_count;
59
60 /* next fields are set through sysctl */
61 unsigned int mq_queues_max; /* initialized to DFLT_QUEUESMAX */
62 unsigned int mq_msg_max; /* initialized to DFLT_MSGMAX */
63 unsigned int mq_msgsize_max; /* initialized to DFLT_MSGSIZEMAX */
64 unsigned int mq_msg_default;
65 unsigned int mq_msgsize_default;
66
67 /* user_ns which owns the ipc ns */
68 struct user_namespace *user_ns;
69 struct ucounts *ucounts;
70
71 struct llist_node mnt_llist;
72
73 struct ns_common ns;
74 } __randomize_layout;
75
76 extern struct ipc_namespace init_ipc_ns;
77 extern spinlock_t mq_lock;
78
79 #ifdef CONFIG_SYSVIPC
80 extern void shm_destroy_orphaned(struct ipc_namespace *ns);
81 #else /* CONFIG_SYSVIPC */
shm_destroy_orphaned(struct ipc_namespace * ns)82 static inline void shm_destroy_orphaned(struct ipc_namespace *ns) {}
83 #endif /* CONFIG_SYSVIPC */
84
85 #ifdef CONFIG_POSIX_MQUEUE
86 extern int mq_init_ns(struct ipc_namespace *ns);
87 /*
88 * POSIX Message Queue default values:
89 *
90 * MIN_*: Lowest value an admin can set the maximum unprivileged limit to
91 * DFLT_*MAX: Default values for the maximum unprivileged limits
92 * DFLT_{MSG,MSGSIZE}: Default values used when the user doesn't supply
93 * an attribute to the open call and the queue must be created
94 * HARD_*: Highest value the maximums can be set to. These are enforced
95 * on CAP_SYS_RESOURCE apps as well making them inviolate (so make them
96 * suitably high)
97 *
98 * POSIX Requirements:
99 * Per app minimum openable message queues - 8. This does not map well
100 * to the fact that we limit the number of queues on a per namespace
101 * basis instead of a per app basis. So, make the default high enough
102 * that no given app should have a hard time opening 8 queues.
103 * Minimum maximum for HARD_MSGMAX - 32767. I bumped this to 65536.
104 * Minimum maximum for HARD_MSGSIZEMAX - POSIX is silent on this. However,
105 * we have run into a situation where running applications in the wild
106 * require this to be at least 5MB, and preferably 10MB, so I set the
107 * value to 16MB in hopes that this user is the worst of the bunch and
108 * the new maximum will handle anyone else. I may have to revisit this
109 * in the future.
110 */
111 #define DFLT_QUEUESMAX 256
112 #define MIN_MSGMAX 1
113 #define DFLT_MSG 10U
114 #define DFLT_MSGMAX 10
115 #define HARD_MSGMAX 65536
116 #define MIN_MSGSIZEMAX 128
117 #define DFLT_MSGSIZE 8192U
118 #define DFLT_MSGSIZEMAX 8192
119 #define HARD_MSGSIZEMAX (16*1024*1024)
120 #else
mq_init_ns(struct ipc_namespace * ns)121 static inline int mq_init_ns(struct ipc_namespace *ns) { return 0; }
122 #endif
123
124 #if defined(CONFIG_IPC_NS)
125 extern struct ipc_namespace *copy_ipcs(unsigned long flags,
126 struct user_namespace *user_ns, struct ipc_namespace *ns);
127
get_ipc_ns(struct ipc_namespace * ns)128 static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns)
129 {
130 if (ns)
131 refcount_inc(&ns->count);
132 return ns;
133 }
134
get_ipc_ns_not_zero(struct ipc_namespace * ns)135 static inline struct ipc_namespace *get_ipc_ns_not_zero(struct ipc_namespace *ns)
136 {
137 if (ns) {
138 if (refcount_inc_not_zero(&ns->count))
139 return ns;
140 }
141
142 return NULL;
143 }
144
145 extern void put_ipc_ns(struct ipc_namespace *ns);
146 #else
copy_ipcs(unsigned long flags,struct user_namespace * user_ns,struct ipc_namespace * ns)147 static inline struct ipc_namespace *copy_ipcs(unsigned long flags,
148 struct user_namespace *user_ns, struct ipc_namespace *ns)
149 {
150 if (flags & CLONE_NEWIPC)
151 return ERR_PTR(-EINVAL);
152
153 return ns;
154 }
155
get_ipc_ns(struct ipc_namespace * ns)156 static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns)
157 {
158 return ns;
159 }
160
get_ipc_ns_not_zero(struct ipc_namespace * ns)161 static inline struct ipc_namespace *get_ipc_ns_not_zero(struct ipc_namespace *ns)
162 {
163 return ns;
164 }
165
put_ipc_ns(struct ipc_namespace * ns)166 static inline void put_ipc_ns(struct ipc_namespace *ns)
167 {
168 }
169 #endif
170
171 #ifdef CONFIG_POSIX_MQUEUE_SYSCTL
172
173 struct ctl_table_header;
174 extern struct ctl_table_header *mq_register_sysctl_table(void);
175
176 #else /* CONFIG_POSIX_MQUEUE_SYSCTL */
177
mq_register_sysctl_table(void)178 static inline struct ctl_table_header *mq_register_sysctl_table(void)
179 {
180 return NULL;
181 }
182
183 #endif /* CONFIG_POSIX_MQUEUE_SYSCTL */
184 #endif
185