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 16struct user_namespace; 17 18struct 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 31struct 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 83extern struct ipc_namespace init_ipc_ns; 84extern spinlock_t mq_lock; 85 86#ifdef CONFIG_SYSVIPC 87extern void shm_destroy_orphaned(struct ipc_namespace *ns); 88#else /* CONFIG_SYSVIPC */ 89static inline void shm_destroy_orphaned(struct ipc_namespace *ns) {} 90#endif /* CONFIG_SYSVIPC */ 91 92#ifdef CONFIG_POSIX_MQUEUE 93extern 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 128static inline int mq_init_ns(struct ipc_namespace *ns) { return 0; } 129#endif 130 131#if defined(CONFIG_IPC_NS) 132extern struct ipc_namespace *copy_ipcs(unsigned long flags, 133 struct user_namespace *user_ns, struct ipc_namespace *ns); 134 135static 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 142static 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 152extern void put_ipc_ns(struct ipc_namespace *ns); 153#else 154static 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 163static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns) 164{ 165 return ns; 166} 167 168static inline struct ipc_namespace *get_ipc_ns_not_zero(struct ipc_namespace *ns) 169{ 170 return ns; 171} 172 173static inline void put_ipc_ns(struct ipc_namespace *ns) 174{ 175} 176#endif 177 178#ifdef CONFIG_POSIX_MQUEUE_SYSCTL 179 180void retire_mq_sysctls(struct ipc_namespace *ns); 181bool setup_mq_sysctls(struct ipc_namespace *ns); 182 183#else /* CONFIG_POSIX_MQUEUE_SYSCTL */ 184 185static inline void retire_mq_sysctls(struct ipc_namespace *ns) 186{ 187} 188 189static 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 198bool setup_ipc_sysctls(struct ipc_namespace *ns); 199void retire_ipc_sysctls(struct ipc_namespace *ns); 200 201#else /* CONFIG_SYSVIPC_SYSCTL */ 202 203static inline void retire_ipc_sysctls(struct ipc_namespace *ns) 204{ 205} 206 207static inline bool setup_ipc_sysctls(struct ipc_namespace *ns) 208{ 209 return true; 210} 211 212#endif /* CONFIG_SYSVIPC_SYSCTL */ 213#endif 214