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 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 llist_node mnt_llist; 71 72 struct ns_common ns; 73 } __randomize_layout; 74 75 extern struct ipc_namespace init_ipc_ns; 76 extern spinlock_t mq_lock; 77 78 #ifdef CONFIG_SYSVIPC 79 extern void shm_destroy_orphaned(struct ipc_namespace *ns); 80 #else /* CONFIG_SYSVIPC */ 81 static inline void shm_destroy_orphaned(struct ipc_namespace *ns) {} 82 #endif /* CONFIG_SYSVIPC */ 83 84 #ifdef CONFIG_POSIX_MQUEUE 85 extern int mq_init_ns(struct ipc_namespace *ns); 86 /* 87 * POSIX Message Queue default values: 88 * 89 * MIN_*: Lowest value an admin can set the maximum unprivileged limit to 90 * DFLT_*MAX: Default values for the maximum unprivileged limits 91 * DFLT_{MSG,MSGSIZE}: Default values used when the user doesn't supply 92 * an attribute to the open call and the queue must be created 93 * HARD_*: Highest value the maximums can be set to. These are enforced 94 * on CAP_SYS_RESOURCE apps as well making them inviolate (so make them 95 * suitably high) 96 * 97 * POSIX Requirements: 98 * Per app minimum openable message queues - 8. This does not map well 99 * to the fact that we limit the number of queues on a per namespace 100 * basis instead of a per app basis. So, make the default high enough 101 * that no given app should have a hard time opening 8 queues. 102 * Minimum maximum for HARD_MSGMAX - 32767. I bumped this to 65536. 103 * Minimum maximum for HARD_MSGSIZEMAX - POSIX is silent on this. However, 104 * we have run into a situation where running applications in the wild 105 * require this to be at least 5MB, and preferably 10MB, so I set the 106 * value to 16MB in hopes that this user is the worst of the bunch and 107 * the new maximum will handle anyone else. I may have to revisit this 108 * in the future. 109 */ 110 #define DFLT_QUEUESMAX 256 111 #define MIN_MSGMAX 1 112 #define DFLT_MSG 10U 113 #define DFLT_MSGMAX 10 114 #define HARD_MSGMAX 65536 115 #define MIN_MSGSIZEMAX 128 116 #define DFLT_MSGSIZE 8192U 117 #define DFLT_MSGSIZEMAX 8192 118 #define HARD_MSGSIZEMAX (16*1024*1024) 119 #else 120 static inline int mq_init_ns(struct ipc_namespace *ns) { return 0; } 121 #endif 122 123 #if defined(CONFIG_IPC_NS) 124 extern struct ipc_namespace *copy_ipcs(unsigned long flags, 125 struct user_namespace *user_ns, struct ipc_namespace *ns); 126 127 static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns) 128 { 129 if (ns) 130 refcount_inc(&ns->ns.count); 131 return ns; 132 } 133 134 static inline struct ipc_namespace *get_ipc_ns_not_zero(struct ipc_namespace *ns) 135 { 136 if (ns) { 137 if (refcount_inc_not_zero(&ns->ns.count)) 138 return ns; 139 } 140 141 return NULL; 142 } 143 144 extern void put_ipc_ns(struct ipc_namespace *ns); 145 #else 146 static inline struct ipc_namespace *copy_ipcs(unsigned long flags, 147 struct user_namespace *user_ns, struct ipc_namespace *ns) 148 { 149 if (flags & CLONE_NEWIPC) 150 return ERR_PTR(-EINVAL); 151 152 return ns; 153 } 154 155 static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns) 156 { 157 return ns; 158 } 159 160 static inline struct ipc_namespace *get_ipc_ns_not_zero(struct ipc_namespace *ns) 161 { 162 return ns; 163 } 164 165 static inline void put_ipc_ns(struct ipc_namespace *ns) 166 { 167 } 168 #endif 169 170 #ifdef CONFIG_POSIX_MQUEUE_SYSCTL 171 172 struct ctl_table_header; 173 extern struct ctl_table_header *mq_register_sysctl_table(void); 174 175 #else /* CONFIG_POSIX_MQUEUE_SYSCTL */ 176 177 static inline struct ctl_table_header *mq_register_sysctl_table(void) 178 { 179 return NULL; 180 } 181 182 #endif /* CONFIG_POSIX_MQUEUE_SYSCTL */ 183 #endif 184