Ipc/util.c
22325 /* 22326 * linux/ipc/util.c 22327 * Copyright (C) 1992 Krishna Balasubramanian 22328 * 22329 * Sep 1997 - Call suser() last after "normal" permission 22330 * checks so we get BSD style process accounting right. 22331 * Occurs in several places in the IPC code. Chris 22332 * Evans, <chris@ferret.lmh.ox.ac.uk> 22333 */ 22334 22335 #include <linux/config.h> 22336 #include <linux/mm.h> 22337 #include <linux/shm.h> 22338 #include <linux/init.h> 22339 #include <linux/msg.h> 22340 22341 #if defined(CONFIG_SYSVIPC) 22342 22343 extern void sem_init(void), msg_init(void), 22344 shm_init(void); 22345 22346 void __init ipc_init (void) 22347 { 22348 sem_init(); 22349 msg_init(); 22350 shm_init(); 22351 return; 22352 } 22353 22354 /* Check user, group, other permissions for access to ipc 22355 * resources. return 0 if allowed */ 22356 int ipcperms (struct ipc_perm *ipcp, short flag) 22357 { 22358 /* flag will most probably be 0 or S_...UGO from 22359 * <linux/stat.h> */ 22360 int requested_mode, granted_mode; 22361 22362 requested_mode = (flag >> 6) | (flag >> 3) | flag; 22363 granted_mode = ipcp->mode; 22364 if (current->euid == ipcp->cuid 22365 current->euid == ipcp->uid) 22366 granted_mode >>= 6; 22367 else if (in_group_p(ipcp->cgid) 22368 in_group_p(ipcp->gid)) 22369 granted_mode >>= 3; 22370 /* is there some bit set in requested_mode but not in 22371 * granted_mode? */ 22372 if ((requested_mode & ~granted_mode & 0007) && 22373 !capable(CAP_IPC_OWNER)) 22374 return -1; 22375 22376 return 0; 22377 } 22378 22379 #else 22380 /* Dummy functions when SYSV IPC isn't configured */ 22381 22382 void sem_exit (void) 22383 { 22384 return; 22385 } 22386 22387 int shm_swap (int prio, int gfp_mask) 22388 { 22389 return 0; 22390 } 22391 22392 asmlinkage int sys_semget (key_t key, int nsems, 22393 int semflg) 22394 { 22395 return -ENOSYS; 22396 } 22397 22398 asmlinkage int sys_semop (int semid, struct sembuf *sops, 22399 unsigned nsops) 22400 { 22401 return -ENOSYS; 22402 } 22403 22404 asmlinkage int sys_semctl (int semid, int semnum, 22405 int cmd, union semun arg) 22406 { 22407 return -ENOSYS; 22408 } 22409 22410 asmlinkage int sys_msgget (key_t key, int msgflg) 22411 { 22412 return -ENOSYS; 22413 } 22414 22415 asmlinkage int sys_msgsnd (int msqid, 22416 struct msgbuf *msgp, size_t msgsz, int msgflg) 22417 { 22418 return -ENOSYS; 22419 } 22420 22421 asmlinkage int sys_msgrcv(int msqid, struct msgbuf *msgp, 22422 size_t msgsz, long msgtyp, int msgflg) 22423 { 22424 return -ENOSYS; 22425 } 22426 22427 asmlinkage int sys_msgctl (int msqid, int cmd, 22428 struct msqid_ds *buf) 22429 { 22430 return -ENOSYS; 22431 } 22432 22433 asmlinkage int sys_shmget (key_t key, int size, int flag) 22434 { 22435 return -ENOSYS; 22436 } 22437 22438 asmlinkage int sys_shmat (int shmid, char *shmaddr, 22439 int shmflg, ulong *addr) 22440 { 22441 return -ENOSYS; 22442 } 22443 22444 asmlinkage int sys_shmdt (char *shmaddr) 22445 { 22446 return -ENOSYS; 22447 } 22448 22449 asmlinkage int sys_shmctl (int shmid, int cmd, 22450 struct shmid_ds *buf) 22451 { 22452 return -ENOSYS; 22453 } 22454 22455 void shm_unuse(unsigned long entry, unsigned long page) 22456 { 22457 } 22458 22459 #endif /* CONFIG_SYSVIPC */
