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 #include <linux/sysctl.h> 14 15 struct user_namespace; 16 17 struct ipc_ids { 18 int in_use; 19 unsigned short seq; 20 struct rw_semaphore rwsem; 21 struct idr ipcs_idr; 22 int max_idx; 23 int last_idx; /* For wrap around detection */ 24 #ifdef CONFIG_CHECKPOINT_RESTORE 25 int next_id; 26 #endif 27 struct rhashtable key_ht; 28 }; 29 30 struct ipc_namespace { 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 struct ctl_table_set mq_set; 68 struct ctl_table_header *mq_sysctls; 69 70 /* user_ns which owns the ipc ns */ 71 struct user_namespace *user_ns; 72 struct ucounts *ucounts; 73 74 struct llist_node mnt_llist; 75 76 struct ns_common ns; 77 } __randomize_layout; 78 79 extern struct ipc_namespace init_ipc_ns; 80 extern spinlock_t mq_lock; 81 82 #ifdef CONFIG_SYSVIPC 83 extern void shm_destroy_orphaned(struct ipc_namespace *ns); 84 #else /* CONFIG_SYSVIPC */ 85 static inline void shm_destroy_orphaned(struct ipc_namespace *ns) {} 86 #endif /* CONFIG_SYSVIPC */ 87 88 #ifdef CONFIG_POSIX_MQUEUE 89 extern int mq_init_ns(struct ipc_namespace *ns); 90 /* 91 * POSIX Message Queue default values: 92 * 93 * MIN_*: Lowest value an admin can set the maximum unprivileged limit to 94 * DFLT_*MAX: Default values for the maximum unprivileged limits 95 * DFLT_{MSG,MSGSIZE}: Default values used when the user doesn't supply 96 * an attribute to the open call and the queue must be created 97 * HARD_*: Highest value the maximums can be set to. These are enforced 98 * on CAP_SYS_RESOURCE apps as well making them inviolate (so make them 99 * suitably high) 100 * 101 * POSIX Requirements: 102 * Per app minimum openable message queues - 8. This does not map well 103 * to the fact that we limit the number of queues on a per namespace 104 * basis instead of a per app basis. So, make the default high enough 105 * that no given app should have a hard time opening 8 queues. 106 * Minimum maximum for HARD_MSGMAX - 32767. I bumped this to 65536. 107 * Minimum maximum for HARD_MSGSIZEMAX - POSIX is silent on this. However, 108 * we have run into a situation where running applications in the wild 109 * require this to be at least 5MB, and preferably 10MB, so I set the 110 * value to 16MB in hopes that this user is the worst of the bunch and 111 * the new maximum will handle anyone else. I may have to revisit this 112 * in the future. 113 */ 114 #define DFLT_QUEUESMAX 256 115 #define MIN_MSGMAX 1 116 #define DFLT_MSG 10U 117 #define DFLT_MSGMAX 10 118 #define HARD_MSGMAX 65536 119 #define MIN_MSGSIZEMAX 128 120 #define DFLT_MSGSIZE 8192U 121 #define DFLT_MSGSIZEMAX 8192 122 #define HARD_MSGSIZEMAX (16*1024*1024) 123 #else 124 static inline int mq_init_ns(struct ipc_namespace *ns) { return 0; } 125 #endif 126 127 #if defined(CONFIG_IPC_NS) 128 extern struct ipc_namespace *copy_ipcs(unsigned long flags, 129 struct user_namespace *user_ns, struct ipc_namespace *ns); 130 131 static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns) 132 { 133 if (ns) 134 refcount_inc(&ns->ns.count); 135 return ns; 136 } 137 138 static inline struct ipc_namespace *get_ipc_ns_not_zero(struct ipc_namespace *ns) 139 { 140 if (ns) { 141 if (refcount_inc_not_zero(&ns->ns.count)) 142 return ns; 143 } 144 145 return NULL; 146 } 147 148 extern void put_ipc_ns(struct ipc_namespace *ns); 149 #else 150 static inline struct ipc_namespace *copy_ipcs(unsigned long flags, 151 struct user_namespace *user_ns, struct ipc_namespace *ns) 152 { 153 if (flags & CLONE_NEWIPC) 154 return ERR_PTR(-EINVAL); 155 156 return ns; 157 } 158 159 static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns) 160 { 161 return ns; 162 } 163 164 static inline struct ipc_namespace *get_ipc_ns_not_zero(struct ipc_namespace *ns) 165 { 166 return ns; 167 } 168 169 static inline void put_ipc_ns(struct ipc_namespace *ns) 170 { 171 } 172 #endif 173 174 #ifdef CONFIG_POSIX_MQUEUE_SYSCTL 175 176 void retire_mq_sysctls(struct ipc_namespace *ns); 177 bool setup_mq_sysctls(struct ipc_namespace *ns); 178 179 #else /* CONFIG_POSIX_MQUEUE_SYSCTL */ 180 181 static inline void retire_mq_sysctls(struct ipc_namespace *ns) 182 { 183 } 184 185 static inline bool setup_mq_sysctls(struct ipc_namespace *ns) 186 { 187 return true; 188 } 189 190 #endif /* CONFIG_POSIX_MQUEUE_SYSCTL */ 191 #endif 192