1 changed files with 468 additions and 0 deletions
--- a/sys_update.c
+++ b/sys_update.c
@ -0,0 +1,468 @@
+/*
+ *  linux/kernel/sys.c
+ *
+ *  (C) 1991  Linus Torvalds
+ */
+#include <unistd.h>
+#include <fcntl.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <errno.h>
+#include <linux/sched.h>
+#include <linux/tty.h>
+#include <linux/kernel.h>
+#include <asm/segment.h>
+#include <sys/times.h>
+#include <sys/utsname.h>
+//ADD FOR getcwd    
+struct linux_dirent {
+	long		d_ino;
+	off_t		d_off;
+	unsigned short	d_reclen;
+	char		d_name[];
+};
+long sys_getcwd(char *buf,size_t size)
+{
+	int block=current->pwd->i_zone[0];	
+	int idev=current->pwd->i_dev;
+	int flag=0;
+	struct buffer_head * bh;
+	struct dir_entry * de;
+	struct m_inode *dir=current->pwd,*rdir=current->root;
+	if(dir==rdir) 
+	{
+		flag=1;
+		goto mytag;
+	}
+	unsigned short curinode,finode,tempfi;
+	char name[128],base[128];
+	int entries,i;
+
+	if (!(block = current->pwd->i_zone[0]))
+		return NULL;
+	if (!(bh = bread(current->pwd->i_dev,block)))
+		return NULL;
+	de = (struct dir_entry *) bh->b_data;
+	curinode=de->inode;
+	de++;
+	finode=de->inode; 
+	while (rdir!=dir)
+	{
+		//update father
+		dir=iget(idev,finode); 
+		if (!(block = dir->i_zone[0]))
+			return NULL;
+		if (!(bh = bread(dir->i_dev,block)))
+			return NULL;
+		i = 0;
+		entries = dir->i_size / (sizeof (struct dir_entry));
+		de = (struct dir_entry *) bh->b_data;
+		tempfi=(de+1)->inode;
+		while (i < entries) {
+			if ((char *)de >= BLOCK_SIZE+bh->b_data) {
+				brelse(bh);
+				bh = NULL;
+				if (!(block = bmap(dir,i/DIR_ENTRIES_PER_BLOCK)) ||
+					!(bh = bread(dir->i_dev,block))) {
+					i += DIR_ENTRIES_PER_BLOCK;
+					continue;
+				}
+				de = (struct dir_entry *) bh->b_data;
+			}
+				if(de->inode==curinode)
+				{
+					memset(base,'\0',sizeof(base));
+					strcat(base,"/");
+					strcat(base,de->name);
+					strcat(base,name);
+					strcpy(name,base);
+					break;
+				}
+			de++;
+			i++;
+		}
+		curinode=finode;
+		finode=tempfi;
+	}
+mytag:
+	if(flag) strcpy(name,"/");
+	size_t len=strlen(name);
+	if(size<len && buf!=NULL)
+	{
+		errno=ERANGE;
+		return NULL;
+	}
+	if(!buf)
+		buf=(char*)malloc(len);
+	char *p1=buf;
+	char *p2=name;
+	while(len--)
+		put_fs_byte(*(p2++),p1++);
+	return buf;
+}
+//THE END 
+int sys_getdents(unsigned int fd,struct linux_dirent *dirp,unsigned int count)
+{
+	struct m_inode	*filenode =current->filp[fd]->f_inode;
+	int block,i,entries,sizdir=sizeof(struct dir_entry);
+	struct buffer_head * bh;
+	struct dir_entry * de;
+	struct linux_dirent *initmp,*temp;
+	char *foruse;
+	if(!(temp=(struct linux_dirent *)malloc(count+64)))
+		return NULL;
+	initmp=temp;
+	int size=sizeof(long)+sizeof(off_t)+sizeof(unsigned short);
+	
+	if (!(block = filenode->i_zone[0]))
+		return NULL;
+	if (!(bh = bread(filenode->i_dev,block)))
+		return NULL;
+	de = (struct dir_entry *) bh->b_data;
+	entries=filenode->i_size/(sizeof(struct dir_entry));
+	i=0;
+	int nread=0,pos=0;
+	while(i<entries)
+	{
+		if ((char *)de >= BLOCK_SIZE+bh->b_data) {
+				brelse(bh);
+				bh = NULL;
+				if (!(block = bmap(filenode,i/DIR_ENTRIES_PER_BLOCK)) ||
+					!(bh = bread(filenode->i_dev,block))) {
+					i += DIR_ENTRIES_PER_BLOCK;
+					continue;
+				}
+				pos+=((struct dir_entry *) bh->b_data-(de-1))*sizdir;
+				de = (struct dir_entry *) bh->b_data;
+			}
+		temp->d_ino=de->inode;
+		temp->d_off=pos;
+		strcpy(temp->d_name,de->name);
+		temp->d_reclen=size+sizeof(de->name);
+		nread+=temp->d_reclen;
+		foruse=(char*)temp;
+		foruse+=temp->d_reclen;
+		temp=(struct linux_dirent*)foruse;
+		de++;
+		pos+=sizdir;
+		i++;
+	}
+	if(count<nread)
+	{
+		errno=ERANGE;
+		return -1;
+	}
+	i=nread;
+	char *p1=dirp;
+	char *p2=initmp;
+	while(i--)
+		put_fs_byte(*(p2++),p1++);
+	return nread;
+}
+void pri(struct linux_dirent * dir)
+{
+	printk("[%d %d %d %s] ",dir->d_ino,dir->d_off,dir->d_reclen,dir->d_name);
+}
+int sys_pipe2()
+{
+	return -1;
+}
+unsigned int sys_sleep(unsigned int seconds)
+{
+	sys_signal(SIGALRM,SIG_IGN,NULL);
+	current->alarm=(seconds>0)?(jiffies+HZ*seconds):0;
+	current->state=TASK_INTERRUPTIBLE;
+	current->counter=(current->counter>>1)+current->priority;
+	schedule();
+	return 0;
+}
+int sys_mmap()
+{
+	return -1;
+}
+int sys_munmap()
+{
+	return -1;
+}
+int sys_clone()
+{
+	return -1;
+}
+
+int sys_ftime()
+{
+	return -ENOSYS;
+}
+
+int sys_break()
+{
+	return -ENOSYS;
+}
+
+int sys_ptrace()
+{
+	return -ENOSYS;
+}
+
+int sys_stty()
+{
+	return -ENOSYS;
+}
+
+int sys_gtty()
+{
+	return -ENOSYS;
+}
+
+int sys_rename()
+{
+	return -ENOSYS;
+}
+
+int sys_prof()
+{
+	return -ENOSYS;
+}
+
+int sys_setregid(int rgid, int egid)
+{
+	if (rgid>0) {
+		if ((current->gid == rgid) || 
+		    suser())
+			current->gid = rgid;
+		else
+			return(-EPERM);
+	}
+	if (egid>0) {
+		if ((current->gid == egid) ||
+		    (current->egid == egid) ||
+		    suser()) {
+			current->egid = egid;
+			current->sgid = egid;
+		} else
+			return(-EPERM);
+	}
+	return 0;
+}
+
+int sys_setgid(int gid)
+{
+/*	return(sys_setregid(gid, gid)); */
+	if (suser())
+		current->gid = current->egid = current->sgid = gid;
+	else if ((gid == current->gid) || (gid == current->sgid))
+		current->egid = gid;
+	else
+		return -EPERM;
+	return 0;
+}
+
+int sys_acct()
+{
+	return -ENOSYS;
+}
+
+int sys_phys()
+{
+	return -ENOSYS;
+}
+
+int sys_lock()
+{
+	return -ENOSYS;
+}
+
+int sys_mpx()
+{
+	return -ENOSYS;
+}
+
+int sys_ulimit()
+{
+	return -ENOSYS;
+}
+
+int sys_time(long * tloc)
+{
+	int i;
+
+	i = CURRENT_TIME;
+	if (tloc) {
+		verify_area(tloc,4);
+		put_fs_long(i,(unsigned long *)tloc);
+	}
+	return i;
+}
+
+/*
+ * Unprivileged users may change the real user id to the effective uid
+ * or vice versa.
+ */
+int sys_setreuid(int ruid, int euid)
+{
+	int old_ruid = current->uid;
+	
+	if (ruid>0) {
+		if ((current->euid==ruid) ||
+                    (old_ruid == ruid) ||
+		    suser())
+			current->uid = ruid;
+		else
+			return(-EPERM);
+	}
+	if (euid>0) {
+		if ((old_ruid == euid) ||
+                    (current->euid == euid) ||
+		    suser()) {
+			current->euid = euid;
+			current->suid = euid;
+		} else {
+			current->uid = old_ruid;
+			return(-EPERM);
+		}
+	}
+	return 0;
+}
+
+int sys_setuid(int uid)
+{
+/*	return(sys_setreuid(uid, uid)); */
+	if (suser())
+		current->uid = current->euid = current->suid = uid;
+	else if ((uid == current->uid) || (uid == current->suid))
+		current->euid = uid;
+	else
+		return -EPERM;
+	return(0);
+}
+
+int sys_stime(long * tptr)
+{
+	if (!suser())
+		return -EPERM;
+	startup_time = get_fs_long((unsigned long *)tptr) - jiffies/HZ;
+	return 0;
+}
+
+int sys_times(struct tms * tbuf)
+{
+	if (tbuf) {
+		verify_area(tbuf,sizeof *tbuf);
+		put_fs_long(current->utime,(unsigned long *)&tbuf->tms_utime);
+		put_fs_long(current->stime,(unsigned long *)&tbuf->tms_stime);
+		put_fs_long(current->cutime,(unsigned long *)&tbuf->tms_cutime);
+		put_fs_long(current->cstime,(unsigned long *)&tbuf->tms_cstime);
+	}
+	return jiffies;
+}
+
+int sys_brk(unsigned long end_data_seg)
+{
+	if (end_data_seg >= current->end_code &&
+	    end_data_seg < current->start_stack - 16384)
+		current->brk = end_data_seg;
+	return current->brk;
+}
+
+/*
+ * This needs some heave checking ...
+ * I just haven't get the stomach for it. I also don't fully
+ * understand sessions/pgrp etc. Let somebody who does explain it.
+ */
+int sys_setpgid(int pid, int pgid)
+{
+	int i;
+
+	if (!pid)
+		pid = current->pid;
+	if (!pgid)
+		pgid = current->pid;
+	for (i=0 ; i<NR_TASKS ; i++)
+		if (task[i] && task[i]->pid==pid) {
+			if (task[i]->leader)
+				return -EPERM;
+			if (task[i]->session != current->session)
+				return -EPERM;
+			task[i]->pgrp = pgid;
+			return 0;
+		}
+	return -ESRCH;
+}
+
+int sys_getpgrp(void)
+{
+	return current->pgrp;
+}
+
+int sys_setsid(void)
+{
+	if (current->leader && !suser())
+		return -EPERM;
+	current->leader = 1;
+	current->session = current->pgrp = current->pid;
+	current->tty = -1;
+	return current->pgrp;
+}
+
+int sys_getgroups()
+{
+	return -ENOSYS;
+}
+
+int sys_setgroups()
+{
+	return -ENOSYS;
+}
+
+int sys_uname(struct utsname * name)
+{
+	static struct utsname thisname = {
+		"linux .0","nodename","release ","version ","machine "
+	};
+	int i;
+
+	if (!name) return -ERROR;
+	verify_area(name,sizeof *name);
+	for(i=0;i<sizeof *name;i++)
+		put_fs_byte(((char *) &thisname)[i],i+(char *) name);
+	return 0;
+}
+
+int sys_sethostname()
+{
+	return -ENOSYS;
+}
+
+int sys_getrlimit()
+{
+	return -ENOSYS;
+}
+
+int sys_setrlimit()
+{
+	return -ENOSYS;
+}
+
+int sys_getrusage()
+{
+	return -ENOSYS;
+}
+
+int sys_gettimeofday()
+{
+	return -ENOSYS;
+}
+
+int sys_settimeofday()
+{
+	return -ENOSYS;
+}
+
+
+int sys_umask(int mask)
+{
+	int old = current->umask;
+
+	current->umask = mask & 0777;
+	return (old);
+}