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      1 /*
      2  * CDDL HEADER START
      3  *
      4  * The contents of this file are subject to the terms of the
      5  * Common Development and Distribution License (the "License").
      6  * You may not use this file except in compliance with the License.
      7  *
      8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
      9  * or http://www.opensolaris.org/os/licensing.
     10  * See the License for the specific language governing permissions
     11  * and limitations under the License.
     12  *
     13  * When distributing Covered Code, include this CDDL HEADER in each
     14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
     15  * If applicable, add the following below this CDDL HEADER, with the
     16  * fields enclosed by brackets "[]" replaced with your own identifying
     17  * information: Portions Copyright [yyyy] [name of copyright owner]
     18  *
     19  * CDDL HEADER END
     20  */
     21 /*
     22  * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
     23  * Use is subject to license terms.
     24  */
     25 
     26 /*	Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T	*/
     27 /*	  All Rights Reserved  	*/
     28 
     29 /*
     30  * Portions of this source code were derived from Berkeley 4.3 BSD
     31  * under license from the Regents of the University of California.
     32  */
     33 
     34 #pragma ident	"@(#)symlink.c	1.12	07/12/26 SMI"
     35 
     36 #include <sys/param.h>
     37 #include <sys/isa_defs.h>
     38 #include <sys/types.h>
     39 #include <sys/sysmacros.h>
     40 #include <sys/systm.h>
     41 #include <sys/errno.h>
     42 #include <sys/pathname.h>
     43 #include <sys/vfs.h>
     44 #include <sys/vnode.h>
     45 #include <sys/proc.h>
     46 #include <sys/uio.h>
     47 #include <sys/debug.h>
     48 #include <c2/audit.h>
     49 #include <fs/fs_subr.h>
     50 
     51 /*
     52  * Create a symbolic link.  Similar to link or rename except target
     53  * name is passed as string argument, not converted to vnode reference.
     54  */
     55 int
     56 symlink(char *target, char *linkname)
     57 {
     58 	vnode_t *dvp;
     59 	struct vattr vattr;
     60 	struct pathname lpn;
     61 	char *tbuf;
     62 	size_t tlen;
     63 	int error;
     64 	int estale_retry = 0;
     65 
     66 top:
     67 	if (error = pn_get(linkname, UIO_USERSPACE, &lpn))
     68 		return (set_errno(error));
     69 	if (error = lookuppn(&lpn, NULL, NO_FOLLOW, &dvp, NULLVPP)) {
     70 		pn_free(&lpn);
     71 		if ((error == ESTALE) && fs_need_estale_retry(estale_retry++))
     72 			goto top;
     73 		return (set_errno(error));
     74 	}
     75 	if (vn_is_readonly(dvp))
     76 		error = EROFS;
     77 	else if (pn_fixslash(&lpn))
     78 		error = ENOTDIR;
     79 	else {
     80 		tbuf = kmem_alloc(MAXPATHLEN, KM_SLEEP);
     81 		if ((error = copyinstr(target, tbuf, MAXPATHLEN, &tlen)) == 0) {
     82 			vattr.va_type = VLNK;
     83 			vattr.va_mode = 0777;
     84 			vattr.va_mask = AT_TYPE|AT_MODE;
     85 			error = VOP_SYMLINK(dvp, lpn.pn_path, &vattr,
     86 			    tbuf, CRED(), NULL, 0);
     87 			if (audit_active)
     88 				audit_symlink_create(dvp, lpn.pn_path,
     89 				    tbuf, error);
     90 		}
     91 		kmem_free(tbuf, MAXPATHLEN);
     92 	}
     93 	pn_free(&lpn);
     94 	VN_RELE(dvp);
     95 	if (error) {
     96 		if ((error == ESTALE) && fs_need_estale_retry(estale_retry++))
     97 			goto top;
     98 		return (set_errno(error));
     99 	}
    100 	return (0);
    101 }
    102