Please note that diffs are not public domain; they are subject to the copyright notices on the relevant files. =================================================================== RCS file: /ftp/cvs/cvsroot/src/lib/libc/gen/getcwd.c,v retrieving revision 1.3.4.1 retrieving revision 1.38 diff -u -p -r1.3.4.1 -r1.38 --- src/lib/libc/gen/getcwd.c 1995/05/02 19:34:46 1.3.4.1 +++ src/lib/libc/gen/getcwd.c 2005/07/05 02:56:12 1.38 @@ -1,6 +1,11 @@ +/* $NetBSD: getcwd.c,v 1.38 2005/07/05 02:56:12 enami Exp $ */ + /* - * Copyright (c) 1989, 1991 The Regents of the University of California. - * All rights reserved. + * Copyright (c) 1989, 1991, 1993, 1995 + * The Regents of the University of California. All rights reserved. + * + * This code is derived from software contributed to Berkeley by + * Jan-Simon Pendry. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions @@ -10,11 +15,7 @@ * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. - * 3. All advertising materials mentioning features or use of this software - * must display the following acknowledgement: - * This product includes software developed by the University of - * California, Berkeley and its contributors. - * 4. Neither the name of the University nor the names of its contributors + * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * @@ -31,200 +32,211 @@ * SUCH DAMAGE. */ +#include #if defined(LIBC_SCCS) && !defined(lint) -/*static char *sccsid = "from: @(#)getcwd.c 5.11 (Berkeley) 2/24/91";*/ -static char *rcsid = "$Id: getcwd.c,v 1.3.4.1 1995/05/02 19:34:46 jtc Exp $"; +#if 0 +static char sccsid[] = "@(#)getcwd.c 8.5 (Berkeley) 2/7/95"; +#else +__RCSID("$NetBSD: getcwd.c,v 1.38 2005/07/05 02:56:12 enami Exp $"); +#endif #endif /* LIBC_SCCS and not lint */ #include "namespace.h" #include #include + +#include #include -#include -#include #include #include #include -#define ISDOT(dp) \ - (dp->d_name[0] == '.' && (dp->d_name[1] == '\0' || \ - dp->d_name[1] == '.' && dp->d_name[2] == '\0')) +#include "extern.h" +#ifdef __weak_alias +__weak_alias(getcwd,_getcwd) +__weak_alias(realpath,_realpath) +#endif + +/* + * char *realpath(const char *path, char resolved[MAXPATHLEN]); + * + * Find the real name of path, by removing all ".", ".." and symlink + * components. Returns (resolved) on success, or (NULL) on failure, + * in which case the path which caused trouble is left in (resolved). + */ char * -getcwd(pt, size) - char *pt; - size_t size; +realpath(const char *path, char *resolved) { - register struct dirent *dp; - register DIR *dir; - register dev_t dev; - register ino_t ino; - register int first; - register char *bpt, *bup; - struct stat s; - dev_t root_dev; - ino_t root_ino; - size_t ptsize, upsize; - int save_errno; - char *ept, *eup, *up; + struct stat sb; + int idx = 0, n, nlnk = 0, serrno = errno; + const char *q; + char *p, wbuf[2][MAXPATHLEN]; + size_t len; + + _DIAGASSERT(path != NULL); + _DIAGASSERT(resolved != NULL); /* - * If no buffer specified by the user, allocate one as necessary. - * If a buffer is specified, the size has to be non-zero. The path - * is built from the end of the buffer backwards. + * Build real path one by one with paying an attention to ., + * .. and symbolic link. */ - if (pt) { - ptsize = 0; - if (!size) { - errno = EINVAL; - return((char *)NULL); + + /* + * `p' is where we'll put a new component with prepending + * a delimiter. + */ + p = resolved; + + if (*path == 0) { + *p = 0; + errno = ENOENT; + return (NULL); + } + + /* If relative path, start from current working directory. */ + if (*path != '/') { + if (getcwd(resolved, MAXPATHLEN) == NULL) { + p[0] = '.'; + p[1] = 0; + return (NULL); + } + len = strlen(resolved); + if (len > 1) + p += len; + } + +loop: + /* Skip any slash. */ + while (*path == '/') + path++; + + if (*path == 0) { + if (p == resolved) + *p++ = '/'; + *p = 0; + return (resolved); + } + + /* Find the end of this component. */ + q = path; + do + q++; + while (*q != '/' && *q != 0); + + /* Test . or .. */ + if (path[0] == '.') { + if (q - path == 1) { + path = q; + goto loop; + } + if (path[1] == '.' && q - path == 2) { + /* Trim the last component. */ + if (p != resolved) + while (*--p != '/') + ; + path = q; + goto loop; } - ept = pt + size; - } else { - if (!(pt = (char *)malloc(ptsize = 1024 - 4))) - return((char *)NULL); - ept = pt + ptsize; } - bpt = ept - 1; - *bpt = '\0'; + + /* Append this component. */ + if (p - resolved + 1 + q - path + 1 > MAXPATHLEN) { + errno = ENAMETOOLONG; + if (p == resolved) + *p++ = '/'; + *p = 0; + return (NULL); + } + p[0] = '/'; + memcpy(&p[1], path, + /* LINTED We know q > path. */ + q - path); + p[1 + q - path] = 0; /* - * Allocate bytes (1024 - malloc space) for the string of "../"'s. - * Should always be enough (it's 340 levels). If it's not, allocate - * as necessary. Special * case the first stat, it's ".", not "..". + * If this component is a symlink, toss it and prepend link + * target to unresolved path. */ - if (!(up = (char *)malloc(upsize = 1024 - 4))) - goto err; - eup = up + MAXPATHLEN; - bup = up; - up[0] = '.'; - up[1] = '\0'; - - /* Save root values, so know when to stop. */ - if (stat("/", &s)) - goto err; - root_dev = s.st_dev; - root_ino = s.st_ino; - - errno = 0; /* XXX readdir has no error return. */ - - for (first = 1;; first = 0) { - /* Stat the current level. */ - if (lstat(up, &s)) - goto err; - - /* Save current node values. */ - ino = s.st_ino; - dev = s.st_dev; - - /* Check for reaching root. */ - if (root_dev == dev && root_ino == ino) { - *--bpt = '/'; - /* - * It's unclear that it's a requirement to copy the - * path to the beginning of the buffer, but it's always - * been that way and stuff would probably break. - */ - (void)bcopy(bpt, pt, ept - bpt); - free(up); - return(pt); - } - - /* - * Build pointer to the parent directory, allocating memory - * as necessary. Max length is 3 for "../", the largest - * possible component name, plus a trailing NULL. - */ - if (bup + 3 + MAXNAMLEN + 1 >= eup) { - if (!(up = (char *)realloc(up, upsize *= 2))) - goto err; - eup = up + upsize; - } - *bup++ = '.'; - *bup++ = '.'; - *bup = '\0'; - - /* Open and stat parent directory. */ - if (!(dir = opendir(up)) || fstat(dirfd(dir), &s)) - goto err; - - /* Add trailing slash for next directory. */ - *bup++ = '/'; - - /* - * If it's a mount point, have to stat each element because - * the inode number in the directory is for the entry in the - * parent directory, not the inode number of the mounted file. - */ - save_errno = 0; - if (s.st_dev == dev) { - for (;;) { - if (!(dp = readdir(dir))) - goto notfound; - if (dp->d_fileno == ino) - break; - } - } else - for (;;) { - if (!(dp = readdir(dir))) - goto notfound; - if (ISDOT(dp)) - continue; - bcopy(dp->d_name, bup, dp->d_namlen + 1); - - /* Save the first error for later. */ - if (lstat(up, &s)) { - if (!save_errno) - save_errno = errno; - errno = 0; - continue; - } - if (s.st_dev == dev && s.st_ino == ino) - break; - } - - /* - * Check for length of the current name, preceding slash, - * leading slash. - */ - if (bpt - pt <= dp->d_namlen + (first ? 1 : 2)) { - size_t len, off; - - if (!ptsize) { - errno = ERANGE; - goto err; - } - off = bpt - pt; - len = ept - bpt; - if (!(pt = (char *)realloc(pt, ptsize *= 2))) - goto err; - bpt = pt + off; - ept = pt + ptsize; - (void)bcopy(bpt, ept - len, len); - bpt = ept - len; - } - if (!first) - *--bpt = '/'; - bpt -= dp->d_namlen; - bcopy(dp->d_name, bpt, dp->d_namlen); - (void)closedir(dir); + if (lstat(resolved, &sb) == -1) { + /* Allow nonexistent component if this is the last one. */ + while (*q == '/') + q++; + if (*q == 0 && errno == ENOENT) { + errno = serrno; + return (resolved); + } + return (NULL); + } + if (S_ISLNK(sb.st_mode)) { + if (nlnk++ >= MAXSYMLINKS) { + errno = ELOOP; + return (NULL); + } + n = readlink(resolved, wbuf[idx], sizeof(wbuf[0]) - 1); + if (n < 0) + return (NULL); + if (n == 0) { + errno = ENOENT; + return (NULL); + } - /* Truncate any file name. */ - *bup = '\0'; + /* Append unresolved path to link target and switch to it. */ + if (n + (len = strlen(q)) + 1 > sizeof(wbuf[0])) { + errno = ENAMETOOLONG; + return (NULL); + } + memcpy(&wbuf[idx][n], q, len + 1); + path = wbuf[idx]; + idx ^= 1; + + /* If absolute symlink, start from root. */ + if (*path == '/') + p = resolved; + goto loop; + } + if (*q == '/' && !S_ISDIR(sb.st_mode)) { + errno = ENOTDIR; + return (NULL); + } + + /* Advance both resolved and unresolved path. */ + p += 1 + q - path; + path = q; + goto loop; +} + +char * +getcwd(char *pt, size_t size) +{ + char *npt; + + /* + * If a buffer is specified, the size has to be non-zero. + */ + if (pt != NULL) { + if (size == 0) { + /* __getcwd(pt, 0) results ERANGE. */ + errno = EINVAL; + return (NULL); + } + if (__getcwd(pt, size) >= 0) + return (pt); + return (NULL); } -notfound: /* - * If readdir set errno, use it, not any saved error; otherwise, - * didn't find the current directory in its parent directory, set - * errno to ENOENT. + * If no buffer specified by the user, allocate one as necessary. */ - if (!errno) - errno = save_errno ? save_errno : ENOENT; - /* FALLTHROUGH */ -err: - if (ptsize) - free(pt); - free(up); - return((char *)NULL); + size = 1024 >> 1; + do { + if ((npt = realloc(pt, size <<= 1)) == NULL) + break; + pt = npt; + if (__getcwd(pt, size) >= 0) + return (pt); + } while (size <= MAXPATHLEN * 4 && errno == ERANGE); + + free(pt); + return (NULL); }