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, Version 1.0 only 6 * (the "License"). You may not use this file except in compliance 7 * with the License. 8 * 9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 10 * or http://www.opensolaris.org/os/licensing. 11 * See the License for the specific language governing permissions 12 * and limitations under the License. 13 * 14 * When distributing Covered Code, include this CDDL HEADER in each 15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 16 * If applicable, add the following below this CDDL HEADER, with the 17 * fields enclosed by brackets "[]" replaced with your own identifying 18 * information: Portions Copyright [yyyy] [name of copyright owner] 19 * 20 * CDDL HEADER END 21 */ 22 /* 23 * Copyright 2004 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27 #pragma ident "%Z%%M% %I% %E% SMI" 28 29 #include <sys/copyops.h> 30 #include <sys/errno.h> 31 #include <sys/kmem.h> 32 #include <sys/param.h> 33 #include <sys/pathname.h> 34 #include <sys/sysmacros.h> 35 #include <sys/systm.h> 36 #include <sys/types.h> 37 #include <sys/vnode.h> 38 39 int 40 getcwd(char *buf, size_t buflen) 41 { 42 int ret; 43 char *kbuf; 44 size_t kbuflen; 45 46 /* 47 * The user should be able to specify any size buffer, but we don't want 48 * to arbitrarily allocate huge kernel buffers just because the user 49 * requests it. So we'll start with MAXPATHLEN (which should hold any 50 * normal path), and only increase it if we fail with ERANGE. 51 */ 52 kbuflen = MIN(buflen, MAXPATHLEN); 53 54 for (;;) { 55 kbuf = kmem_alloc(kbuflen, KM_SLEEP); 56 57 if ((ret = dogetcwd(kbuf, kbuflen)) == 0) 58 ret = copyout(kbuf, buf, strlen(kbuf) + 1); 59 60 kmem_free(kbuf, kbuflen); 61 62 if (ret == ENAMETOOLONG) { 63 /* 64 * If the user's buffer really was too small, give up. 65 * For some reason, getcwd() uses ERANGE for this case. 66 */ 67 if (kbuflen == buflen) { 68 ret = ERANGE; 69 break; 70 } 71 kbuflen = MIN(kbuflen * 2, buflen); 72 } else { 73 break; 74 } 75 } 76 77 if (ret) 78 return (set_errno(ret)); 79 80 return (ret); 81 } 82