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