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