1 /* $NetBSD: old_getcwd.c,v 1.3 2003/08/07 09:51:08 agc Exp $ */ 2 3 /* 4 * Copyright (c) 1989, 1991, 1993, 1995 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * Jan-Simon Pendry. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 */ 34 35 /* 36 * This file copied from NetBSD's src/lib/libc/gen/getcwd.c 1.15, and edited 37 * to remove namespace stuff and the unused realpath function. 38 */ 39 40 41 #include <sys/cdefs.h> 42 #if defined(LIBC_SCCS) && !defined(lint) 43 #if 0 44 static char sccsid[] = "@(#)getcwd.c 8.5 (Berkeley) 2/7/95"; 45 #else 46 __RCSID("$NetBSD: old_getcwd.c,v 1.3 2003/08/07 09:51:08 agc Exp $"); 47 #endif 48 #endif /* LIBC_SCCS and not lint */ 49 50 #include <sys/param.h> 51 #include <sys/stat.h> 52 53 #include <dirent.h> 54 #include <errno.h> 55 #include <fcntl.h> 56 #include <stdio.h> 57 #include <stdlib.h> 58 #include <string.h> 59 #include <unistd.h> 60 61 #include "getcwd.h" 62 63 #define ISDOT(dp) \ 64 (dp->d_name[0] == '.' && (dp->d_name[1] == '\0' || \ 65 (dp->d_name[1] == '.' && dp->d_name[2] == '\0'))) 66 67 68 #if defined(__SVR4) || defined(__svr4__) 69 #define d_fileno d_ino 70 #endif 71 72 char * 73 old_getcwd(pt, size) 74 char *pt; 75 size_t size; 76 { 77 struct dirent *dp; 78 DIR *dir; 79 dev_t dev; 80 ino_t ino; 81 int first; 82 char *bpt, *bup; 83 struct stat s; 84 dev_t root_dev; 85 ino_t root_ino; 86 size_t ptsize, upsize; 87 int save_errno; 88 char *ept, *eup, *up; 89 size_t dlen; 90 91 /* 92 * If no buffer specified by the user, allocate one as necessary. 93 * If a buffer is specified, the size has to be non-zero. The path 94 * is built from the end of the buffer backwards. 95 */ 96 if (pt) { 97 ptsize = 0; 98 if (!size) { 99 errno = EINVAL; 100 return (NULL); 101 } 102 ept = pt + size; 103 } else { 104 if ((pt = malloc(ptsize = 1024 - 4)) == NULL) 105 return (NULL); 106 ept = pt + ptsize; 107 } 108 bpt = ept - 1; 109 *bpt = '\0'; 110 111 /* 112 * Allocate bytes (1024 - malloc space) for the string of "../"'s. 113 * Should always be enough (it's 340 levels). If it's not, allocate 114 * as necessary. Special case the first stat, it's ".", not "..". 115 */ 116 if ((up = malloc(upsize = 1024 - 4)) == NULL) 117 goto err; 118 eup = up + MAXPATHLEN; 119 bup = up; 120 up[0] = '.'; 121 up[1] = '\0'; 122 123 /* Save root values, so know when to stop. */ 124 if (stat("/", &s)) 125 goto err; 126 root_dev = s.st_dev; 127 root_ino = s.st_ino; 128 129 errno = 0; /* XXX readdir has no error return. */ 130 131 for (first = 1;; first = 0) { 132 /* Stat the current level. */ 133 if (lstat(up, &s)) 134 goto err; 135 136 /* Save current node values. */ 137 ino = s.st_ino; 138 dev = s.st_dev; 139 140 /* Check for reaching root. */ 141 if (root_dev == dev && root_ino == ino) { 142 *--bpt = '/'; 143 /* 144 * It's unclear that it's a requirement to copy the 145 * path to the beginning of the buffer, but it's always 146 * been that way and stuff would probably break. 147 */ 148 memmove(pt, bpt, (size_t)(ept - bpt)); 149 free(up); 150 return (pt); 151 } 152 153 /* 154 * Build pointer to the parent directory, allocating memory 155 * as necessary. Max length is 3 for "../", the largest 156 * possible component name, plus a trailing NULL. 157 */ 158 if (bup + 3 + MAXNAMLEN + 1 >= eup) { 159 if ((up = realloc(up, upsize *= 2)) == NULL) 160 goto err; 161 bup = up; 162 eup = up + upsize; 163 } 164 *bup++ = '.'; 165 *bup++ = '.'; 166 *bup = '\0'; 167 168 /* Open and stat parent directory. */ 169 if (!(dir = opendir(up)) || fstat(dirfd(dir), &s)) 170 goto err; 171 172 /* Add trailing slash for next directory. */ 173 *bup++ = '/'; 174 175 /* 176 * If it's a mount point, have to stat each element because 177 * the inode number in the directory is for the entry in the 178 * parent directory, not the inode number of the mounted file. 179 */ 180 save_errno = 0; 181 if (s.st_dev == dev) { 182 for (;;) { 183 if (!(dp = readdir(dir))) 184 goto notfound; 185 if (dp->d_fileno == ino) { 186 #if defined(__SVR4) || defined(__svr4__) 187 dlen = strlen(dp->d_name); 188 #else 189 dlen = dp->d_namlen; 190 #endif 191 break; 192 } 193 } 194 } else 195 for (;;) { 196 if (!(dp = readdir(dir))) 197 goto notfound; 198 if (ISDOT(dp)) 199 continue; 200 #if defined(__SVR4) || defined(__svr4__) 201 dlen = strlen(dp->d_name); 202 #else 203 dlen = dp->d_namlen; 204 #endif 205 memmove(bup, dp->d_name, dlen + 1); 206 207 /* Save the first error for later. */ 208 if (lstat(up, &s)) { 209 if (!save_errno) 210 save_errno = errno; 211 errno = 0; 212 continue; 213 } 214 if (s.st_dev == dev && s.st_ino == ino) 215 break; 216 } 217 218 /* 219 * Check for length of the current name, preceding slash, 220 * leading slash. 221 */ 222 if (bpt - pt <= dlen + (first ? 1 : 2)) { 223 size_t len, off; 224 225 if (!ptsize) { 226 errno = ERANGE; 227 goto err; 228 } 229 off = bpt - pt; 230 len = ept - bpt; 231 if ((pt = realloc(pt, ptsize *= 2)) == NULL) 232 goto err; 233 bpt = pt + off; 234 ept = pt + ptsize; 235 memmove(ept - len, bpt, len); 236 bpt = ept - len; 237 } 238 if (!first) 239 *--bpt = '/'; 240 bpt -= dlen; 241 memmove(bpt, dp->d_name, dlen); 242 (void)closedir(dir); 243 244 /* Truncate any file name. */ 245 *bup = '\0'; 246 } 247 248 notfound: 249 /* 250 * If readdir set errno, use it, not any saved error; otherwise, 251 * didn't find the current directory in its parent directory, set 252 * errno to ENOENT. 253 */ 254 if (!errno) 255 errno = save_errno ? save_errno : ENOENT; 256 /* FALLTHROUGH */ 257 err: 258 if (ptsize) 259 free(pt); 260 free(up); 261 return (NULL); 262 } 263
Indexes created Mon Sep 22 13:09:51 GMT 2025