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 struct ctl_table_set ipc_set; 71 struct ctl_table_header *ipc_sysctls; 72 73 /* user_ns which owns the ipc ns */ 74 struct user_namespace *user_ns; 75 struct ucounts *ucounts; 76 77 struct llist_node mnt_llist; 78 79 struct ns_common ns; 80 } __randomize_layout; 81 82 extern struct ipc_namespace init_ipc_ns; 83 extern spinlock_t mq_lock; 84 85 #ifdef CONFIG_SYSVIPC 86 extern void shm_destroy_orphaned(struct ipc_namespace *ns); 87 #else /* CONFIG_SYSVIPC */ 88 static inline void shm_destroy_orphaned(struct ipc_namespace *ns) {} 89 #endif /* CONFIG_SYSVIPC */ 90 91 #ifdef CONFIG_POSIX_MQUEUE 92 extern int mq_init_ns(struct ipc_namespace *ns); 93 /* 94 * POSIX Message Queue default values: 95 * 96 * MIN_*: Lowest value an admin can set the maximum unprivileged limit to 97 * DFLT_*MAX: Default values for the maximum unprivileged limits 98 * DFLT_{MSG,MSGSIZE}: Default values used when the user doesn't supply 99 * an attribute to the open call and the queue must be created 100 * HARD_*: Highest value the maximums can be set to. These are enforced 101 * on CAP_SYS_RESOURCE apps as well making them inviolate (so make them 102 * suitably high) 103 * 104 * POSIX Requirements: 105 * Per app minimum openable message queues - 8. This does not map well 106 * to the fact that we limit the number of queues on a per namespace 107 * basis instead of a per app basis. So, make the default high enough 108 * that no given app should have a hard time opening 8 queues. 109 * Minimum maximum for HARD_MSGMAX - 32767. I bumped this to 65536. 110 * Minimum maximum for HARD_MSGSIZEMAX - POSIX is silent on this. However, 111 * we have run into a situation where running applications in the wild 112 * require this to be at least 5MB, and preferably 10MB, so I set the 113 * value to 16MB in hopes that this user is the worst of the bunch and 114 * the new maximum will handle anyone else. I may have to revisit this 115 * in the future. 116 */ 117 #define DFLT_QUEUESMAX 256 118 #define MIN_MSGMAX 1 119 #define DFLT_MSG 10U 120 #define DFLT_MSGMAX 10 121 #define HARD_MSGMAX 65536 122 #define MIN_MSGSIZEMAX 128 123 #define DFLT_MSGSIZE 8192U 124 #define DFLT_MSGSIZEMAX 8192 125 #define HARD_MSGSIZEMAX (16*1024*1024) 126 #else 127 static inline int mq_init_ns(struct ipc_namespace *ns) { return 0; } 128 #endif 129 130 #if defined(CONFIG_IPC_NS) 131 extern struct ipc_namespace *copy_ipcs(unsigned long flags, 132 struct user_namespace *user_ns, struct ipc_namespace *ns); 133 134 static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns) 135 { 136 if (ns) 137 refcount_inc(&ns->ns.count); 138 return ns; 139 } 140 141 static inline struct ipc_namespace *get_ipc_ns_not_zero(struct ipc_namespace *ns) 142 { 143 if (ns) { 144 if (refcount_inc_not_zero(&ns->ns.count)) 145 return ns; 146 } 147 148 return NULL; 149 } 150 151 extern void put_ipc_ns(struct ipc_namespace *ns); 152 #else 153 static inline struct ipc_namespace *copy_ipcs(unsigned long flags, 154 struct user_namespace *user_ns, struct ipc_namespace *ns) 155 { 156 if (flags & CLONE_NEWIPC) 157 return ERR_PTR(-EINVAL); 158 159 return ns; 160 } 161 162 static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns) 163 { 164 return ns; 165 } 166 167 static inline struct ipc_namespace *get_ipc_ns_not_zero(struct ipc_namespace *ns) 168 { 169 return ns; 170 } 171 172 static inline void put_ipc_ns(struct ipc_namespace *ns) 173 { 174 } 175 #endif 176 177 #ifdef CONFIG_POSIX_MQUEUE_SYSCTL 178 179 void retire_mq_sysctls(struct ipc_namespace *ns); 180 bool setup_mq_sysctls(struct ipc_namespace *ns); 181 182 #else /* CONFIG_POSIX_MQUEUE_SYSCTL */ 183 184 static inline void retire_mq_sysctls(struct ipc_namespace *ns) 185 { 186 } 187 188 static inline bool setup_mq_sysctls(struct ipc_namespace *ns) 189 { 190 return true; 191 } 192 193 #endif /* CONFIG_POSIX_MQUEUE_SYSCTL */ 194 195 #ifdef CONFIG_SYSVIPC_SYSCTL 196 197 bool setup_ipc_sysctls(struct ipc_namespace *ns); 198 void retire_ipc_sysctls(struct ipc_namespace *ns); 199 200 #else /* CONFIG_SYSVIPC_SYSCTL */ 201 202 static inline void retire_ipc_sysctls(struct ipc_namespace *ns) 203 { 204 } 205 206 static inline bool setup_ipc_sysctls(struct ipc_namespace *ns) 207 { 208 return true; 209 } 210 211 #endif /* CONFIG_SYSVIPC_SYSCTL */ 212 #endif 213