Import of Linus's Linux 1.1.68

1 files changed, 150 insertions, 0 deletions

diff --git a/ipc/util.c b/ipc/util.c
new file mode 100644
index 000000000..fb0e6970d
--- /dev/null
+++ b/ipc/util.c
@@ -0,0 +1,150 @@
+/*
+ * 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 */