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.h> 13 14 struct user_namespace; 15 16 struct ipc_ids { 17 int in_use; 18 unsigned short seq; 19 bool tables_initialized; 20 struct rw_semaphore rwsem; 21 struct idr ipcs_idr; 22 int max_id; 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 ns_common ns; 72 } __randomize_layout; 73 74 extern struct ipc_namespace init_ipc_ns; 75 extern spinlock_t mq_lock; 76 77 #ifdef CONFIG_SYSVIPC 78 extern void shm_destroy_orphaned(struct ipc_namespace *ns); 79 #else /* CONFIG_SYSVIPC */ 80 static inline void shm_destroy_orphaned(struct ipc_namespace *ns) {} 81 #endif /* CONFIG_SYSVIPC */ 82 83 #ifdef CONFIG_POSIX_MQUEUE 84 extern int mq_init_ns(struct ipc_namespace *ns); 85 /* 86 * POSIX Message Queue default values: 87 * 88 * MIN_*: Lowest value an admin can set the maximum unprivileged limit to 89 * DFLT_*MAX: Default values for the maximum unprivileged limits 90 * DFLT_{MSG,MSGSIZE}: Default values used when the user doesn't supply 91 * an attribute to the open call and the queue must be created 92 * HARD_*: Highest value the maximums can be set to. These are enforced 93 * on CAP_SYS_RESOURCE apps as well making them inviolate (so make them 94 * suitably high) 95 * 96 * POSIX Requirements: 97 * Per app minimum openable message queues - 8. This does not map well 98 * to the fact that we limit the number of queues on a per namespace 99 * basis instead of a per app basis. So, make the default high enough 100 * that no given app should have a hard time opening 8 queues. 101 * Minimum maximum for HARD_MSGMAX - 32767. I bumped this to 65536. 102 * Minimum maximum for HARD_MSGSIZEMAX - POSIX is silent on this. However, 103 * we have run into a situation where running applications in the wild 104 * require this to be at least 5MB, and preferably 10MB, so I set the 105 * value to 16MB in hopes that this user is the worst of the bunch and 106 * the new maximum will handle anyone else. I may have to revisit this 107 * in the future. 108 */ 109 #define DFLT_QUEUESMAX 256 110 #define MIN_MSGMAX 1 111 #define DFLT_MSG 10U 112 #define DFLT_MSGMAX 10 113 #define HARD_MSGMAX 65536 114 #define MIN_MSGSIZEMAX 128 115 #define DFLT_MSGSIZE 8192U 116 #define DFLT_MSGSIZEMAX 8192 117 #define HARD_MSGSIZEMAX (16*1024*1024) 118 #else 119 static inline int mq_init_ns(struct ipc_namespace *ns) { return 0; } 120 #endif 121 122 #if defined(CONFIG_IPC_NS) 123 extern struct ipc_namespace *copy_ipcs(unsigned long flags, 124 struct user_namespace *user_ns, struct ipc_namespace *ns); 125 126 static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns) 127 { 128 if (ns) 129 refcount_inc(&ns->count); 130 return ns; 131 } 132 133 extern void put_ipc_ns(struct ipc_namespace *ns); 134 #else 135 static inline struct ipc_namespace *copy_ipcs(unsigned long flags, 136 struct user_namespace *user_ns, struct ipc_namespace *ns) 137 { 138 if (flags & CLONE_NEWIPC) 139 return ERR_PTR(-EINVAL); 140 141 return ns; 142 } 143 144 static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns) 145 { 146 return ns; 147 } 148 149 static inline void put_ipc_ns(struct ipc_namespace *ns) 150 { 151 } 152 #endif 153 154 #ifdef CONFIG_POSIX_MQUEUE_SYSCTL 155 156 struct ctl_table_header; 157 extern struct ctl_table_header *mq_register_sysctl_table(void); 158 159 #else /* CONFIG_POSIX_MQUEUE_SYSCTL */ 160 161 static inline struct ctl_table_header *mq_register_sysctl_table(void) 162 { 163 return NULL; 164 } 165 166 #endif /* CONFIG_POSIX_MQUEUE_SYSCTL */ 167 #endif 168