+chdir()
+{
+
+ chdirec(&u.u_cdir);
+}
+
+chroot()
+{
+
+ if (suser())
+ chdirec(&u.u_rdir);
+}
+
+chdirec(ipp)
+register struct inode **ipp;
+{
+ register struct inode *ip;
+ struct a {
+ char *fname;
+ };
+
+ ip = namei(uchar, 0, 1);
+ if(ip == NULL)
+ return;
+ if((ip->i_mode&IFMT) != IFDIR) {
+ u.u_error = ENOTDIR;
+ goto bad;
+ }
+ if(access(ip, IEXEC))
+ goto bad;
+ iunlock(ip);
+ if (*ipp)
+ irele(*ipp);
+ *ipp = ip;
+ return;
+
+bad:
+ iput(ip);
+}
+
+/*
+ * Open system call.
+ */
+open()
+{
+ register struct inode *ip;
+ register struct a {
+ char *fname;
+ int rwmode;
+ } *uap;
+
+ uap = (struct a *)u.u_ap;
+ ip = namei(uchar, 0, 1);
+ if (ip == NULL)
+ return;
+ open1(ip, ++uap->rwmode, 0);
+}
+
+/*
+ * Creat system call.
+ */
+creat()
+{
+ register struct inode *ip;
+ register struct a {
+ char *fname;
+ int fmode;
+ } *uap;
+
+ uap = (struct a *)u.u_ap;
+ ip = namei(uchar, 1, 1);
+ if (ip == NULL) {
+ if (u.u_error)
+ return;
+ ip = maknode(uap->fmode&07777&(~ISVTX));
+ if (ip==NULL)
+ return;
+ open1(ip, FWRITE, 2);
+ } else
+ open1(ip, FWRITE, 1);
+}
+
+/*
+ * Common code for open and creat.
+ * Check permissions, allocate an open file structure,
+ * and call the device open routine if any.
+ */
+open1(ip, mode, trf)
+ register struct inode *ip;
+ register mode;
+{
+ register struct file *fp;
+ int i;
+
+ if (trf != 2) {
+ if (mode&FREAD)
+ (void) access(ip, IREAD);
+ if (mode&FWRITE) {
+ (void) access(ip, IWRITE);
+ if ((ip->i_mode&IFMT) == IFDIR)
+ u.u_error = EISDIR;
+ }
+ }
+ if (u.u_error) {
+ iput(ip);
+ return;
+ }
+ if (trf == 1)
+ itrunc(ip);
+ iunlock(ip);
+ if ((fp = falloc()) == NULL)
+ goto out;
+ fp->f_flag = mode&(FREAD|FWRITE);
+ i = u.u_r.r_val1;
+ fp->f_inode = ip;
+ openi(ip, mode&(FREAD|FWRITE));
+ if (u.u_error == 0)
+ return;
+ u.u_ofile[i] = NULL;
+ fp->f_count--;
+out:
+ irele(ip);
+}
+
+/*
+ * Mknod system call
+ */
+mknod()
+{
+ register struct inode *ip;
+ register struct a {
+ char *fname;
+ int fmode;
+ int dev;
+ } *uap;
+
+ uap = (struct a *)u.u_ap;
+ if (suser()) {
+ ip = namei(uchar, 1, 0);
+ if (ip != NULL) {
+ u.u_error = EEXIST;
+ goto out;
+ }
+ }
+ if (u.u_error)
+ return;
+ ip = maknode(uap->fmode);
+ if (ip == NULL)
+ return;
+ if (uap->dev) {
+ /*
+ * Want to be able to use this to make badblock
+ * inodes, so don't truncate the dev number.
+ */
+ ip->i_rdev = uap->dev;
+ ip->i_flag |= IACC|IUPD|ICHG;
+ }
+
+out:
+ iput(ip);
+}
+
+/*
+ * link system call
+ */
+link()
+{
+ register struct inode *ip, *xp;
+ register struct a {
+ char *target;
+ char *linkname;
+ } *uap;
+
+ uap = (struct a *)u.u_ap;
+ ip = namei(uchar, 0, 1); /* well, this routine is doomed anyhow */
+ if (ip == NULL)
+ return;
+ if ((ip->i_mode&IFMT)==IFDIR && !suser())
+ goto out1;
+ ip->i_nlink++;
+ ip->i_flag |= ICHG;
+ iupdat(ip, &time, &time, 1);
+ iunlock(ip);
+ u.u_dirp = (caddr_t)uap->linkname;
+ xp = namei(uchar, 1, 0);
+ if (xp != NULL) {
+ u.u_error = EEXIST;
+ iput(xp);
+ goto out;
+ }
+ if (u.u_error)
+ goto out;
+ if (u.u_pdir->i_dev != ip->i_dev) {
+ iput(u.u_pdir);
+ u.u_error = EXDEV;
+ goto out;
+ }
+ wdir(ip);
+out:
+ if (u.u_error) {
+ ip->i_nlink--;
+ ip->i_flag |= ICHG;
+ }
+out1:
+ irele(ip);
+}
+
+/*
+ * symlink -- make a symbolic link
+ */
+symlink()
+{
+ register struct a {
+ char *target;
+ char *linkname;
+ } *uap;
+ register struct inode *ip;
+ register char *tp;
+ register c, nc;
+
+ uap = (struct a *)u.u_ap;
+ tp = uap->target;
+ nc = 0;
+ while (c = fubyte(tp)) {
+ if (c < 0) {
+ u.u_error = EFAULT;
+ return;
+ }
+ tp++;
+ nc++;
+ }
+ u.u_dirp = uap->linkname;
+ ip = namei(uchar, 1, 0);
+ if (ip) {
+ iput(ip);
+ u.u_error = EEXIST;
+ return;
+ }
+ if (u.u_error)
+ return;
+ ip = maknode(IFLNK | 0777);
+ if (ip == NULL)
+ return;
+ u.u_base = uap->target;
+ u.u_count = nc;
+ u.u_offset = 0;
+ u.u_segflg = 0;
+ writei(ip);
+ iput(ip);
+}
+
+/*
+ * Unlink system call.
+ * Hard to avoid races here, especially
+ * in unlinking directories.
+ */
+unlink()
+{
+ register struct inode *ip, *pp;
+ struct a {
+ char *fname;
+ };
+ struct fs *fs;
+ struct buf *bp;
+ int lbn, bn, base;
+ int unlinkingdot = 0;
+
+ pp = namei(uchar, 2, 0);
+ if(pp == NULL)
+ return;
+ /*
+ * Check for unlink(".")
+ * to avoid hanging on the iget
+ */
+ if (pp->i_number == u.u_dent.d_ino) {
+ ip = pp;
+ ip->i_count++;
+ unlinkingdot++;
+ } else
+ ip = iget(pp->i_dev, pp->i_fs, u.u_dent.d_ino);
+ if(ip == NULL)
+ goto out1;
+ if((ip->i_mode&IFMT)==IFDIR && !suser())
+ goto out;
+ /*
+ * Don't unlink a mounted file.
+ */
+ if (ip->i_dev != pp->i_dev) {
+ u.u_error = EBUSY;
+ goto out;
+ }
+ if (ip->i_flag&ITEXT)
+ xrele(ip); /* try once to free text */
+/*
+ if ((ip->i_flag&ITEXT) && ip->i_nlink==1) {
+ u.u_error = ETXTBSY;
+ goto out;
+ }
+*/
+ if (u.u_count == 0) {
+ /*
+ * first entry in block, so set d_ino to zero.
+ */
+ u.u_base = (caddr_t)&u.u_dent;
+ u.u_count = DIRSIZ(&u.u_dent);
+ u.u_dent.d_ino = 0;
+ writei(pp);
+ } else {
+ /*
+ * updating preceeding entry to skip over current entry.
+ */
+ fs = pp->i_fs;
+ lbn = lblkno(fs, u.u_offset);
+ base = blkoff(fs, u.u_offset);
+ bn = fsbtodb(fs, bmap(pp, lbn, B_WRITE, base + u.u_count));
+ bp = bread(pp->i_dev, bn, blksize(fs, pp, lbn));
+ if (bp->b_flags & B_ERROR) {
+ brelse(bp);
+ goto out;
+ }
+ ((struct direct *)(bp->b_un.b_addr + base))->d_reclen +=
+ u.u_dent.d_reclen;
+ bwrite(bp);
+ pp->i_flag |= IUPD|ICHG;
+ }
+ ip->i_nlink--;
+ ip->i_flag |= ICHG;
+
+out:
+ if (unlinkingdot)
+ irele(ip);
+ else
+ iput(ip);
+out1:
+ iput(pp);
+}
+
+/*
+ * Seek system call
+ */
+seek()
+{
+ register struct file *fp;
+ register struct a {
+ int fdes;
+ off_t off;
+ int sbase;
+ } *uap;
+
+ uap = (struct a *)u.u_ap;
+ fp = getf(uap->fdes);
+ if (fp == NULL)
+ return;
+ if (fp->f_flag&FSOCKET) {
+ u.u_error = ESPIPE;
+ return;
+ }
+ if (uap->sbase == 1)
+ uap->off += fp->f_offset;
+ else if (uap->sbase == 2)
+ uap->off += fp->f_inode->i_size;
+ fp->f_offset = uap->off;
+ u.u_r.r_off = uap->off;
+}
+
+/*
+ * Access system call
+ */
+saccess()
+{
+ register svuid, svgid;
+ register struct inode *ip;
+ register struct a {
+ char *fname;
+ int fmode;
+ } *uap;
+
+ uap = (struct a *)u.u_ap;
+ svuid = u.u_uid;
+ svgid = u.u_gid;
+ u.u_uid = u.u_ruid;
+ u.u_gid = u.u_rgid;
+ ip = namei(uchar, 0, 1);
+ if (ip != NULL) {
+ if (uap->fmode&(IREAD>>6))
+ (void) access(ip, IREAD);
+ if (uap->fmode&(IWRITE>>6))
+ (void) access(ip, IWRITE);
+ if (uap->fmode&(IEXEC>>6))
+ (void) access(ip, IEXEC);
+ iput(ip);
+ }
+ u.u_uid = svuid;
+ u.u_gid = svgid;
+}
+
projects / unix-history / blobdiff