1*0Sstevel@tonic-gate /* 2*0Sstevel@tonic-gate * Copyright (c) 1994 3*0Sstevel@tonic-gate * The Regents of the University of California. All rights reserved. 4*0Sstevel@tonic-gate * 5*0Sstevel@tonic-gate * This code is derived from software contributed to Berkeley by 6*0Sstevel@tonic-gate * Jan-Simon Pendry. 7*0Sstevel@tonic-gate * 8*0Sstevel@tonic-gate * Redistribution and use in source and binary forms, with or without 9*0Sstevel@tonic-gate * modification, are permitted provided that the following conditions 10*0Sstevel@tonic-gate * are met: 11*0Sstevel@tonic-gate * 1. Redistributions of source code must retain the above copyright 12*0Sstevel@tonic-gate * notice, this list of conditions and the following disclaimer. 13*0Sstevel@tonic-gate * 2. Redistributions in binary form must reproduce the above copyright 14*0Sstevel@tonic-gate * notice, this list of conditions and the following disclaimer in the 15*0Sstevel@tonic-gate * documentation and/or other materials provided with the distribution. 16*0Sstevel@tonic-gate * 17*0Sstevel@tonic-gate * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18*0Sstevel@tonic-gate * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19*0Sstevel@tonic-gate * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20*0Sstevel@tonic-gate * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21*0Sstevel@tonic-gate * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22*0Sstevel@tonic-gate * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23*0Sstevel@tonic-gate * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24*0Sstevel@tonic-gate * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25*0Sstevel@tonic-gate * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26*0Sstevel@tonic-gate * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27*0Sstevel@tonic-gate * SUCH DAMAGE. 28*0Sstevel@tonic-gate */ 29*0Sstevel@tonic-gate 30*0Sstevel@tonic-gate #include "includes.h" 31*0Sstevel@tonic-gate 32*0Sstevel@tonic-gate #if !defined(HAVE_REALPATH) || defined(BROKEN_REALPATH) 33*0Sstevel@tonic-gate 34*0Sstevel@tonic-gate #if defined(LIBC_SCCS) && !defined(lint) 35*0Sstevel@tonic-gate static char *rcsid = "$OpenBSD: realpath.c,v 1.7 2002/05/24 21:22:37 deraadt Exp $"; 36*0Sstevel@tonic-gate #endif /* LIBC_SCCS and not lint */ 37*0Sstevel@tonic-gate 38*0Sstevel@tonic-gate #include <sys/param.h> 39*0Sstevel@tonic-gate #include <sys/stat.h> 40*0Sstevel@tonic-gate 41*0Sstevel@tonic-gate #include <errno.h> 42*0Sstevel@tonic-gate #include <fcntl.h> 43*0Sstevel@tonic-gate #include <stdlib.h> 44*0Sstevel@tonic-gate #include <string.h> 45*0Sstevel@tonic-gate #include <unistd.h> 46*0Sstevel@tonic-gate 47*0Sstevel@tonic-gate /* 48*0Sstevel@tonic-gate * MAXSYMLINKS 49*0Sstevel@tonic-gate */ 50*0Sstevel@tonic-gate #ifndef MAXSYMLINKS 51*0Sstevel@tonic-gate #define MAXSYMLINKS 5 52*0Sstevel@tonic-gate #endif 53*0Sstevel@tonic-gate 54*0Sstevel@tonic-gate /* 55*0Sstevel@tonic-gate * char *realpath(const char *path, char resolved_path[MAXPATHLEN]); 56*0Sstevel@tonic-gate * 57*0Sstevel@tonic-gate * Find the real name of path, by removing all ".", ".." and symlink 58*0Sstevel@tonic-gate * components. Returns (resolved) on success, or (NULL) on failure, 59*0Sstevel@tonic-gate * in which case the path which caused trouble is left in (resolved). 60*0Sstevel@tonic-gate */ 61*0Sstevel@tonic-gate char * 62*0Sstevel@tonic-gate realpath(const char *path, char *resolved) 63*0Sstevel@tonic-gate { 64*0Sstevel@tonic-gate struct stat sb; 65*0Sstevel@tonic-gate int fd, n, rootd, serrno = 0; 66*0Sstevel@tonic-gate char *p, *q, wbuf[MAXPATHLEN], start[MAXPATHLEN]; 67*0Sstevel@tonic-gate int symlinks = 0; 68*0Sstevel@tonic-gate 69*0Sstevel@tonic-gate /* Save the starting point. */ 70*0Sstevel@tonic-gate getcwd(start,MAXPATHLEN); 71*0Sstevel@tonic-gate if ((fd = open(".", O_RDONLY)) < 0) { 72*0Sstevel@tonic-gate (void)strlcpy(resolved, ".", MAXPATHLEN); 73*0Sstevel@tonic-gate return (NULL); 74*0Sstevel@tonic-gate } 75*0Sstevel@tonic-gate close(fd); 76*0Sstevel@tonic-gate 77*0Sstevel@tonic-gate /* Convert "." -> "" to optimize away a needless lstat() and chdir() */ 78*0Sstevel@tonic-gate if (path[0] == '.' && path[1] == '\0') 79*0Sstevel@tonic-gate path = ""; 80*0Sstevel@tonic-gate 81*0Sstevel@tonic-gate /* 82*0Sstevel@tonic-gate * Find the dirname and basename from the path to be resolved. 83*0Sstevel@tonic-gate * Change directory to the dirname component. 84*0Sstevel@tonic-gate * lstat the basename part. 85*0Sstevel@tonic-gate * if it is a symlink, read in the value and loop. 86*0Sstevel@tonic-gate * if it is a directory, then change to that directory. 87*0Sstevel@tonic-gate * get the current directory name and append the basename. 88*0Sstevel@tonic-gate */ 89*0Sstevel@tonic-gate strlcpy(resolved, path, MAXPATHLEN); 90*0Sstevel@tonic-gate loop: 91*0Sstevel@tonic-gate q = strrchr(resolved, '/'); 92*0Sstevel@tonic-gate if (q != NULL) { 93*0Sstevel@tonic-gate p = q + 1; 94*0Sstevel@tonic-gate if (q == resolved) 95*0Sstevel@tonic-gate q = "/"; 96*0Sstevel@tonic-gate else { 97*0Sstevel@tonic-gate do { 98*0Sstevel@tonic-gate --q; 99*0Sstevel@tonic-gate } while (q > resolved && *q == '/'); 100*0Sstevel@tonic-gate q[1] = '\0'; 101*0Sstevel@tonic-gate q = resolved; 102*0Sstevel@tonic-gate } 103*0Sstevel@tonic-gate if (chdir(q) < 0) 104*0Sstevel@tonic-gate goto err1; 105*0Sstevel@tonic-gate } else 106*0Sstevel@tonic-gate p = resolved; 107*0Sstevel@tonic-gate 108*0Sstevel@tonic-gate /* Deal with the last component. */ 109*0Sstevel@tonic-gate if (*p != '\0' && lstat(p, &sb) == 0) { 110*0Sstevel@tonic-gate if (S_ISLNK(sb.st_mode)) { 111*0Sstevel@tonic-gate if (++symlinks > MAXSYMLINKS) { 112*0Sstevel@tonic-gate serrno = ELOOP; 113*0Sstevel@tonic-gate goto err1; 114*0Sstevel@tonic-gate } 115*0Sstevel@tonic-gate n = readlink(p, resolved, MAXPATHLEN-1); 116*0Sstevel@tonic-gate if (n < 0) 117*0Sstevel@tonic-gate goto err1; 118*0Sstevel@tonic-gate resolved[n] = '\0'; 119*0Sstevel@tonic-gate goto loop; 120*0Sstevel@tonic-gate } 121*0Sstevel@tonic-gate if (S_ISDIR(sb.st_mode)) { 122*0Sstevel@tonic-gate if (chdir(p) < 0) 123*0Sstevel@tonic-gate goto err1; 124*0Sstevel@tonic-gate p = ""; 125*0Sstevel@tonic-gate } 126*0Sstevel@tonic-gate } 127*0Sstevel@tonic-gate 128*0Sstevel@tonic-gate /* 129*0Sstevel@tonic-gate * Save the last component name and get the full pathname of 130*0Sstevel@tonic-gate * the current directory. 131*0Sstevel@tonic-gate */ 132*0Sstevel@tonic-gate (void)strlcpy(wbuf, p, sizeof wbuf); 133*0Sstevel@tonic-gate if (getcwd(resolved, MAXPATHLEN) == 0) 134*0Sstevel@tonic-gate goto err1; 135*0Sstevel@tonic-gate 136*0Sstevel@tonic-gate /* 137*0Sstevel@tonic-gate * Join the two strings together, ensuring that the right thing 138*0Sstevel@tonic-gate * happens if the last component is empty, or the dirname is root. 139*0Sstevel@tonic-gate */ 140*0Sstevel@tonic-gate if (resolved[0] == '/' && resolved[1] == '\0') 141*0Sstevel@tonic-gate rootd = 1; 142*0Sstevel@tonic-gate else 143*0Sstevel@tonic-gate rootd = 0; 144*0Sstevel@tonic-gate 145*0Sstevel@tonic-gate if (*wbuf) { 146*0Sstevel@tonic-gate if (strlen(resolved) + strlen(wbuf) + rootd + 1 > MAXPATHLEN) { 147*0Sstevel@tonic-gate serrno = ENAMETOOLONG; 148*0Sstevel@tonic-gate goto err1; 149*0Sstevel@tonic-gate } 150*0Sstevel@tonic-gate if (rootd == 0) 151*0Sstevel@tonic-gate (void)strcat(resolved, "/"); 152*0Sstevel@tonic-gate (void)strcat(resolved, wbuf); 153*0Sstevel@tonic-gate } 154*0Sstevel@tonic-gate 155*0Sstevel@tonic-gate /* Go back to where we came from. */ 156*0Sstevel@tonic-gate if (chdir(start) < 0) { 157*0Sstevel@tonic-gate serrno = errno; 158*0Sstevel@tonic-gate goto err2; 159*0Sstevel@tonic-gate } 160*0Sstevel@tonic-gate return (resolved); 161*0Sstevel@tonic-gate 162*0Sstevel@tonic-gate err1: chdir(start); 163*0Sstevel@tonic-gate err2: errno = serrno; 164*0Sstevel@tonic-gate return (NULL); 165*0Sstevel@tonic-gate } 166*0Sstevel@tonic-gate #endif /* !defined(HAVE_REALPATH) || defined(BROKEN_REALPATH) */ 167*0Sstevel@tonic-gate 168*0Sstevel@tonic-gate #pragma ident "%Z%%M% %I% %E% SMI" 169