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/*
* linux/ipc/util.c
* Copyright (C) 1992 Krishna Balasubramanian
*/
#include <linux/config.h>
#include <linux/errno.h>
#include <asm/segment.h>
#include <linux/sched.h>
#include <linux/sem.h>
#include <linux/msg.h>
#include <linux/shm.h>
#include <linux/stat.h>
void ipc_init (void);
asmlinkage int sys_ipc (uint call, int first, int second, int third, void *ptr);
#ifdef CONFIG_SYSVIPC
int ipcperms (struct ipc_perm *ipcp, short flag);
extern void sem_init (void), msg_init (void), shm_init (void);
extern int sys_semget (key_t key, int nsems, int semflg);
extern int sys_semop (int semid, struct sembuf *sops, unsigned nsops);
extern int sys_semctl (int semid, int semnum, int cmd, union semun arg);
extern int sys_msgget (key_t key, int msgflg);
extern int sys_msgsnd (int msqid, struct msgbuf *msgp, int msgsz, int msgflg);
extern int sys_msgrcv (int msqid, struct msgbuf *msgp, int msgsz, long msgtyp,
int msgflg);
extern int sys_msgctl (int msqid, int cmd, struct msqid_ds *buf);
extern int sys_shmget (key_t key, int size, int flag);
extern int sys_shmat (int shmid, char *shmaddr, int shmflg, ulong *addr);
extern int sys_shmdt (char *shmaddr);
extern int sys_shmctl (int shmid, int cmd, struct shmid_ds *buf);
void ipc_init (void)
{
sem_init();
msg_init();
shm_init();
return;
}
/*
* Check user, group, other permissions for access
* to ipc resources. return 0 if allowed
*/
int ipcperms (struct ipc_perm *ipcp, short flag)
{ /* flag will most probably be 0 or S_...UGO from <linux/stat.h> */
int requested_mode, granted_mode;
if (suser())
return 0;
requested_mode = (flag >> 6) | (flag >> 3) | flag;
granted_mode = ipcp->mode;
if (current->euid == ipcp->cuid || current->euid == ipcp->uid)
granted_mode >>= 6;
else if (in_group_p(ipcp->cgid) || in_group_p(ipcp->gid))
granted_mode >>= 3;
/* is there some bit set in requested_mode but not in granted_mode? */
if (requested_mode & ~granted_mode & 0007)
return -1;
return 0;
}
asmlinkage int sys_ipc (uint call, int first, int second, int third, void *ptr)
{
if (call <= SEMCTL)
switch (call) {
case SEMOP:
return sys_semop (first, (struct sembuf *)ptr, second);
case SEMGET:
return sys_semget (first, second, third);
case SEMCTL: {
union semun fourth;
int err;
if (!ptr)
return -EINVAL;
if ((err = verify_area (VERIFY_READ, ptr, sizeof(long))))
return err;
fourth.__pad = (void *) get_fs_long(ptr);
return sys_semctl (first, second, third, fourth);
}
default:
return -EINVAL;
}
if (call <= MSGCTL)
switch (call) {
case MSGSND:
return sys_msgsnd (first, (struct msgbuf *) ptr,
second, third);
case MSGRCV: {
struct ipc_kludge tmp;
int err;
if (!ptr)
return -EINVAL;
if ((err = verify_area (VERIFY_READ, ptr, sizeof(tmp))))
return err;
memcpy_fromfs (&tmp,(struct ipc_kludge *) ptr,
sizeof (tmp));
return sys_msgrcv (first, tmp.msgp, second, tmp.msgtyp,
third);
}
case MSGGET:
return sys_msgget ((key_t) first, second);
case MSGCTL:
return sys_msgctl (first, second, (struct msqid_ds *) ptr);
default:
return -EINVAL;
}
if (call <= SHMCTL)
switch (call) {
case SHMAT:
return sys_shmat (first, (char *) ptr, second,
(ulong *) third);
case SHMDT:
return sys_shmdt ((char *)ptr);
case SHMGET:
return sys_shmget (first, second, third);
case SHMCTL:
return sys_shmctl (first, second, (struct shmid_ds *) ptr);
default:
return -EINVAL;
}
return -EINVAL;
}
#else /* not CONFIG_SYSVIPC */
asmlinkage int sys_ipc (uint call, int first, int second, int third, void *ptr)
{
return -ENOSYS;
}
void sem_exit (void)
{
return;
}
int shm_swap (int prio)
{
return 0;
}
void shm_no_page (unsigned long *ptent)
{
return;
}
#endif /* CONFIG_SYSVIPC */
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