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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 | /* * linux/ipc/util.h * Copyright (C) 1999 Christoph Rohland * * ipc helper functions (c) 1999 Manfred Spraul <manfreds@colorfullife.com> */ #define USHRT_MAX 0xffff #define SEQ_MULTIPLIER (IPCMNI) void sem_init (void); void msg_init (void); void shm_init (void); struct ipc_ids { int size; int in_use; int max_id; unsigned short seq; unsigned short seq_max; struct semaphore sem; spinlock_t ary; struct ipc_id* entries; }; struct ipc_id { struct kern_ipc_perm* p; }; void __init ipc_init_ids(struct ipc_ids* ids, int size); /* must be called with ids->sem acquired.*/ int ipc_findkey(struct ipc_ids* ids, key_t key); int ipc_addid(struct ipc_ids* ids, struct kern_ipc_perm* new, int size); /* must be called with both locks acquired. */ struct kern_ipc_perm* ipc_rmid(struct ipc_ids* ids, int id); int ipcperms (struct kern_ipc_perm *ipcp, short flg); /* for rare, potentially huge allocations. * both function can sleep */ void* ipc_alloc(int size); void ipc_free(void* ptr, int size); extern inline void ipc_lockall(struct ipc_ids* ids) { spin_lock(&ids->ary); } extern inline struct kern_ipc_perm* ipc_get(struct ipc_ids* ids, int id) { struct kern_ipc_perm* out; int lid = id % SEQ_MULTIPLIER; if(lid > ids->size) return NULL; out = ids->entries[lid].p; return out; } extern inline void ipc_unlockall(struct ipc_ids* ids) { spin_unlock(&ids->ary); } extern inline struct kern_ipc_perm* ipc_lock(struct ipc_ids* ids, int id) { struct kern_ipc_perm* out; int lid = id % SEQ_MULTIPLIER; if(lid > ids->size) return NULL; spin_lock(&ids->ary); out = ids->entries[lid].p; if(out==NULL) spin_unlock(&ids->ary); return out; } extern inline void ipc_unlock(struct ipc_ids* ids, int id) { spin_unlock(&ids->ary); } extern inline int ipc_buildid(struct ipc_ids* ids, int id, int seq) { return SEQ_MULTIPLIER*seq + id; } extern inline int ipc_checkid(struct ipc_ids* ids, struct kern_ipc_perm* ipcp, int uid) { if(uid/SEQ_MULTIPLIER != ipcp->seq) return 1; return 0; } void kernel_to_ipc64_perm(struct kern_ipc_perm *in, struct ipc64_perm *out); void ipc64_perm_to_ipc_perm(struct ipc64_perm *in, struct ipc_perm *out); #ifdef __ia64__ /* On IA-64, we always use the "64-bit version" of the IPC structures. */ # define ipc_parse_version(cmd) IPC_64 #else int ipc_parse_version (int *cmd); #endif |