ipc_namespace.h (5560B)
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 15struct user_namespace; 16 17struct 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 30struct 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 82extern struct ipc_namespace init_ipc_ns; 83extern spinlock_t mq_lock; 84 85#ifdef CONFIG_SYSVIPC 86extern void shm_destroy_orphaned(struct ipc_namespace *ns); 87#else /* CONFIG_SYSVIPC */ 88static inline void shm_destroy_orphaned(struct ipc_namespace *ns) {} 89#endif /* CONFIG_SYSVIPC */ 90 91#ifdef CONFIG_POSIX_MQUEUE 92extern 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 127static inline int mq_init_ns(struct ipc_namespace *ns) { return 0; } 128#endif 129 130#if defined(CONFIG_IPC_NS) 131extern struct ipc_namespace *copy_ipcs(unsigned long flags, 132 struct user_namespace *user_ns, struct ipc_namespace *ns); 133 134static 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 141static 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 151extern void put_ipc_ns(struct ipc_namespace *ns); 152#else 153static 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 162static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns) 163{ 164 return ns; 165} 166 167static inline struct ipc_namespace *get_ipc_ns_not_zero(struct ipc_namespace *ns) 168{ 169 return ns; 170} 171 172static inline void put_ipc_ns(struct ipc_namespace *ns) 173{ 174} 175#endif 176 177#ifdef CONFIG_POSIX_MQUEUE_SYSCTL 178 179void retire_mq_sysctls(struct ipc_namespace *ns); 180bool setup_mq_sysctls(struct ipc_namespace *ns); 181 182#else /* CONFIG_POSIX_MQUEUE_SYSCTL */ 183 184static inline void retire_mq_sysctls(struct ipc_namespace *ns) 185{ 186} 187 188static 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 197bool setup_ipc_sysctls(struct ipc_namespace *ns); 198void retire_ipc_sysctls(struct ipc_namespace *ns); 199 200#else /* CONFIG_SYSVIPC_SYSCTL */ 201 202static inline void retire_ipc_sysctls(struct ipc_namespace *ns) 203{ 204} 205 206static inline bool setup_ipc_sysctls(struct ipc_namespace *ns) 207{ 208 return true; 209} 210 211#endif /* CONFIG_SYSVIPC_SYSCTL */ 212#endif