From 4b055f482c205d6612e6e4d148088596440a6e9e Mon Sep 17 00:00:00 2001
From: pumnflqv2 <ggdxz77@163.com>
Date: Tue, 5 Jul 2022 04:28:14 +0800
Subject: [PATCH] ADD file via upload

---
 0/linux/fs/open.c | 208 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 208 insertions(+)
 create mode 100644 0/linux/fs/open.c

diff --git a/0/linux/fs/open.c b/0/linux/fs/open.c
new file mode 100644
index 0000000..3695ff1
--- /dev/null
+++ b/0/linux/fs/open.c
@@ -0,0 +1,208 @@
+/*
+ *  linux/fs/open.c
+ *
+ *  (C) 1991  Linus Torvalds
+ */
+
+#include <string.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <sys/types.h>
+#include <utime.h>
+#include <sys/stat.h>
+
+#include <linux/sched.h>
+#include <linux/tty.h>
+#include <linux/kernel.h>
+#include <asm/segment.h>
+
+int sys_ustat(int dev, struct ustat * ubuf)
+{
+	return -ENOSYS;
+}
+
+int sys_utime(char * filename, struct utimbuf * times)
+{
+	struct m_inode * inode;
+	long actime,modtime;
+
+	if (!(inode=namei(filename)))
+		return -ENOENT;
+	if (times) {
+		actime = get_fs_long((unsigned long *) &times->actime);
+		modtime = get_fs_long((unsigned long *) &times->modtime);
+	} else
+		actime = modtime = CURRENT_TIME;
+	inode->i_atime = actime;
+	inode->i_mtime = modtime;
+	inode->i_dirt = 1;
+	iput(inode);
+	return 0;
+}
+
+/*
+ * XXX should we use the real or effective uid?  BSD uses the real uid,
+ * so as to make this call useful to setuid programs.
+ */
+int sys_access(const char * filename,int mode)
+{
+	struct m_inode * inode;
+	int res, i_mode;
+
+	mode &= 0007;
+	if (!(inode=namei(filename)))
+		return -EACCES;
+	i_mode = res = inode->i_mode & 0777;
+	iput(inode);
+	if (current->uid == inode->i_uid)
+		res >>= 6;
+	else if (current->gid == inode->i_gid)
+		res >>= 6;
+	if ((res & 0007 & mode) == mode)
+		return 0;
+	/*
+	 * XXX we are doing this test last because we really should be
+	 * swapping the effective with the real user id (temporarily),
+	 * and then calling suser() routine.  If we do call the
+	 * suser() routine, it needs to be called last. 
+	 */
+	if ((!current->uid) &&
+	    (!(mode & 1) || (i_mode & 0111)))
+		return 0;
+	return -EACCES;
+}
+
+int sys_chdir(const char * filename)
+{
+	struct m_inode * inode;
+
+	if (!(inode = namei(filename)))
+		return -ENOENT;
+	if (!S_ISDIR(inode->i_mode)) {
+		iput(inode);
+		return -ENOTDIR;
+	}
+	iput(current->pwd);
+	current->pwd = inode;
+	return (0);
+}
+
+int sys_chroot(const char * filename)
+{
+	struct m_inode * inode;
+
+	if (!(inode=namei(filename)))
+		return -ENOENT;
+	if (!S_ISDIR(inode->i_mode)) {
+		iput(inode);
+		return -ENOTDIR;
+	}
+	iput(current->root);
+	current->root = inode;
+	return (0);
+}
+
+int sys_chmod(const char * filename,int mode)
+{
+	struct m_inode * inode;
+
+	if (!(inode=namei(filename)))
+		return -ENOENT;
+	if ((current->euid != inode->i_uid) && !suser()) {
+		iput(inode);
+		return -EACCES;
+	}
+	inode->i_mode = (mode & 07777) | (inode->i_mode & ~07777);
+	inode->i_dirt = 1;
+	iput(inode);
+	return 0;
+}
+
+int sys_chown(const char * filename,int uid,int gid)
+{
+	struct m_inode * inode;
+
+	if (!(inode=namei(filename)))
+		return -ENOENT;
+	if (!suser()) {
+		iput(inode);
+		return -EACCES;
+	}
+	inode->i_uid=uid;
+	inode->i_gid=gid;
+	inode->i_dirt=1;
+	iput(inode);
+	return 0;
+}
+
+int sys_open(const char * filename,int flag,int mode)
+{
+	struct m_inode * inode;
+	struct file * f;
+	int i,fd;
+
+	mode &= 0777 & ~current->umask;
+	for(fd=0 ; fd<NR_OPEN ; fd++)
+		if (!current->filp[fd])
+			break;
+	if (fd>=NR_OPEN)
+		return -EINVAL;
+	current->close_on_exec &= ~(1<<fd);
+	f=0+file_table;
+	for (i=0 ; i<NR_FILE ; i++,f++)
+		if (!f->f_count) break;
+	if (i>=NR_FILE)
+		return -EINVAL;
+	(current->filp[fd]=f)->f_count++;
+	if ((i=open_namei(filename,flag,mode,&inode))<0) {
+		current->filp[fd]=NULL;
+		f->f_count=0;
+		return i;
+	}
+/* ttys are somewhat special (ttyxx major==4, tty major==5) */
+	if (S_ISCHR(inode->i_mode))
+		if (MAJOR(inode->i_zone[0])==4) {
+			if (current->leader && current->tty<0) {
+				current->tty = MINOR(inode->i_zone[0]);
+				tty_table[current->tty].pgrp = current->pgrp;
+			}
+		} else if (MAJOR(inode->i_zone[0])==5)
+			if (current->tty<0) {
+				iput(inode);
+				current->filp[fd]=NULL;
+				f->f_count=0;
+				return -EPERM;
+			}
+/* Likewise with block-devices: check for floppy_change */
+	if (S_ISBLK(inode->i_mode))
+		check_disk_change(inode->i_zone[0]);
+	f->f_mode = inode->i_mode;
+	f->f_flags = flag;
+	f->f_count = 1;
+	f->f_inode = inode;
+	f->f_pos = 0;
+	return (fd);
+}
+
+int sys_creat(const char * pathname, int mode)
+{
+	return sys_open(pathname, O_CREAT | O_TRUNC, mode);
+}
+
+int sys_close(unsigned int fd)
+{	
+	struct file * filp;
+
+	if (fd >= NR_OPEN)
+		return -EINVAL;
+	current->close_on_exec &= ~(1<<fd);
+	if (!(filp = current->filp[fd]))
+		return -EINVAL;
+	current->filp[fd] = NULL;
+	if (filp->f_count == 0)
+		panic("Close: file count is 0");
+	if (--filp->f_count)
+		return (0);
+	iput(filp->f_inode);
+	return (0);
+}