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 #include <linux/percpu_counter.h> 15 16 struct user_namespace; 17 18 struct ipc_ids { 19 int in_use; 20 unsigned short seq; 21 struct rw_semaphore rwsem; 22 struct idr ipcs_idr; 23 int max_idx; 24 int last_idx; /* For wrap around detection */ 25 #ifdef CONFIG_CHECKPOINT_RESTORE 26 int next_id; 27 #endif 28 struct rhashtable key_ht; 29 }; 30 31 struct ipc_namespace { 32 struct ipc_ids ids[3]; 33 34 int sem_ctls[4]; 35 int used_sems; 36 37 unsigned int msg_ctlmax; 38 unsigned int msg_ctlmnb; 39 unsigned int msg_ctlmni; 40 struct percpu_counter percpu_msg_bytes; 41 struct percpu_counter percpu_msg_hdrs; 42 43 size_t shm_ctlmax; 44 size_t shm_ctlall; 45 unsigned long shm_tot; 46 int shm_ctlmni; 47 /* 48 * Defines whether IPC_RMID is forced for _all_ shm segments regardless 49 * of shmctl() 50 */ 51 int shm_rmid_forced; 52 53 struct notifier_block ipcns_nb; 54 55 /* The kern_mount of the mqueuefs sb. We take a ref on it */ 56 struct vfsmount *mq_mnt; 57 58 /* # queues in this ns, protected by mq_lock */ 59 unsigned int mq_queues_count; 60 61 /* next fields are set through sysctl */ 62 unsigned int mq_queues_max; /* initialized to DFLT_QUEUESMAX */ 63 unsigned int mq_msg_max; /* initialized to DFLT_MSGMAX */ 64 unsigned int mq_msgsize_max; /* initialized to DFLT_MSGSIZEMAX */ 65 unsigned int mq_msg_default; 66 unsigned int mq_msgsize_default; 67 68 struct ctl_table_set mq_set; 69 struct ctl_table_header *mq_sysctls; 70 71 struct ctl_table_set ipc_set; 72 struct ctl_table_header *ipc_sysctls; 73 74 /* user_ns which owns the ipc ns */ 75 struct user_namespace *user_ns; 76 struct ucounts *ucounts; 77 78 struct llist_node mnt_llist; 79 80 struct ns_common ns; 81 } __randomize_layout; 82 83 extern struct ipc_namespace init_ipc_ns; 84 extern spinlock_t mq_lock; 85 86 #ifdef CONFIG_SYSVIPC 87 extern void shm_destroy_orphaned(struct ipc_namespace *ns); 88 #else /* CONFIG_SYSVIPC */ shm_destroy_orphaned(struct ipc_namespace * ns)89 static inline void shm_destroy_orphaned(struct ipc_namespace *ns) {} 90 #endif /* CONFIG_SYSVIPC */ 91 92 #ifdef CONFIG_POSIX_MQUEUE 93 extern int mq_init_ns(struct ipc_namespace *ns); 94 /* 95 * POSIX Message Queue default values: 96 * 97 * MIN_*: Lowest value an admin can set the maximum unprivileged limit to 98 * DFLT_*MAX: Default values for the maximum unprivileged limits 99 * DFLT_{MSG,MSGSIZE}: Default values used when the user doesn't supply 100 * an attribute to the open call and the queue must be created 101 * HARD_*: Highest value the maximums can be set to. These are enforced 102 * on CAP_SYS_RESOURCE apps as well making them inviolate (so make them 103 * suitably high) 104 * 105 * POSIX Requirements: 106 * Per app minimum openable message queues - 8. This does not map well 107 * to the fact that we limit the number of queues on a per namespace 108 * basis instead of a per app basis. So, make the default high enough 109 * that no given app should have a hard time opening 8 queues. 110 * Minimum maximum for HARD_MSGMAX - 32767. I bumped this to 65536. 111 * Minimum maximum for HARD_MSGSIZEMAX - POSIX is silent on this. However, 112 * we have run into a situation where running applications in the wild 113 * require this to be at least 5MB, and preferably 10MB, so I set the 114 * value to 16MB in hopes that this user is the worst of the bunch and 115 * the new maximum will handle anyone else. I may have to revisit this 116 * in the future. 117 */ 118 #define DFLT_QUEUESMAX 256 119 #define MIN_MSGMAX 1 120 #define DFLT_MSG 10U 121 #define DFLT_MSGMAX 10 122 #define HARD_MSGMAX 65536 123 #define MIN_MSGSIZEMAX 128 124 #define DFLT_MSGSIZE 8192U 125 #define DFLT_MSGSIZEMAX 8192 126 #define HARD_MSGSIZEMAX (16*1024*1024) 127 #else mq_init_ns(struct ipc_namespace * ns)128 static inline int mq_init_ns(struct ipc_namespace *ns) { return 0; } 129 #endif 130 131 #if defined(CONFIG_IPC_NS) 132 extern struct ipc_namespace *copy_ipcs(unsigned long flags, 133 struct user_namespace *user_ns, struct ipc_namespace *ns); 134 get_ipc_ns(struct ipc_namespace * ns)135 static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns) 136 { 137 if (ns) 138 refcount_inc(&ns->ns.count); 139 return ns; 140 } 141 get_ipc_ns_not_zero(struct ipc_namespace * ns)142 static inline struct ipc_namespace *get_ipc_ns_not_zero(struct ipc_namespace *ns) 143 { 144 if (ns) { 145 if (refcount_inc_not_zero(&ns->ns.count)) 146 return ns; 147 } 148 149 return NULL; 150 } 151 152 extern void put_ipc_ns(struct ipc_namespace *ns); 153 #else copy_ipcs(unsigned long flags,struct user_namespace * user_ns,struct ipc_namespace * ns)154 static inline struct ipc_namespace *copy_ipcs(unsigned long flags, 155 struct user_namespace *user_ns, struct ipc_namespace *ns) 156 { 157 if (flags & CLONE_NEWIPC) 158 return ERR_PTR(-EINVAL); 159 160 return ns; 161 } 162 get_ipc_ns(struct ipc_namespace * ns)163 static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns) 164 { 165 return ns; 166 } 167 get_ipc_ns_not_zero(struct ipc_namespace * ns)168 static inline struct ipc_namespace *get_ipc_ns_not_zero(struct ipc_namespace *ns) 169 { 170 return ns; 171 } 172 put_ipc_ns(struct ipc_namespace * ns)173 static inline void put_ipc_ns(struct ipc_namespace *ns) 174 { 175 } 176 #endif 177 178 #ifdef CONFIG_POSIX_MQUEUE_SYSCTL 179 180 void retire_mq_sysctls(struct ipc_namespace *ns); 181 bool setup_mq_sysctls(struct ipc_namespace *ns); 182 183 #else /* CONFIG_POSIX_MQUEUE_SYSCTL */ 184 retire_mq_sysctls(struct ipc_namespace * ns)185 static inline void retire_mq_sysctls(struct ipc_namespace *ns) 186 { 187 } 188 setup_mq_sysctls(struct ipc_namespace * ns)189 static inline bool setup_mq_sysctls(struct ipc_namespace *ns) 190 { 191 return true; 192 } 193 194 #endif /* CONFIG_POSIX_MQUEUE_SYSCTL */ 195 196 #ifdef CONFIG_SYSVIPC_SYSCTL 197 198 bool setup_ipc_sysctls(struct ipc_namespace *ns); 199 void retire_ipc_sysctls(struct ipc_namespace *ns); 200 201 #else /* CONFIG_SYSVIPC_SYSCTL */ 202 retire_ipc_sysctls(struct ipc_namespace * ns)203 static inline void retire_ipc_sysctls(struct ipc_namespace *ns) 204 { 205 } 206 setup_ipc_sysctls(struct ipc_namespace * ns)207 static inline bool setup_ipc_sysctls(struct ipc_namespace *ns) 208 { 209 return true; 210 } 211 212 #endif /* CONFIG_SYSVIPC_SYSCTL */ 213 #endif 214