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 1.1.1.3 retrieving revision 1.39 diff -u -p -r1.1.1.3 -r1.39 --- src/lib/libc/gen/getcwd.c 1998/02/02 00:11:25 1.1.1.3 +++ src/lib/libc/gen/getcwd.c 2005/08/13 19:53:53 1.39 @@ -1,3 +1,5 @@ +/* $NetBSD: getcwd.c,v 1.39 2005/08/13 19:53:53 elad Exp $ */ + /* * Copyright (c) 1989, 1991, 1993, 1995 * The Regents of the University of California. All rights reserved. @@ -13,11 +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. * @@ -34,351 +32,204 @@ * SUCH DAMAGE. */ +#include #if defined(LIBC_SCCS) && !defined(lint) +#if 0 static char sccsid[] = "@(#)getcwd.c 8.5 (Berkeley) 2/7/95"; +#else +__RCSID("$NetBSD: getcwd.c,v 1.39 2005/08/13 19:53:53 elad Exp $"); +#endif #endif /* LIBC_SCCS and not lint */ +#include "namespace.h" #include #include -#include +#include #include -#include -#include #include #include #include -static char *getcwd_physical __P((char *, size_t)); - -#define ISDOT(dp) \ - (dp->d_name[0] == '.' && (dp->d_name[1] == '\0' || \ - dp->d_name[1] == '.' && dp->d_name[2] == '\0')) +#include "extern.h" -char * -getcwd(pt, size) - char *pt; - size_t size; -{ - char *pwd; - size_t pwdlen; - dev_t dev; - ino_t ino; - struct stat s; - - /* Check $PWD -- if it's right, it's fast. */ - if ((pwd = getenv("PWD")) != NULL && pwd[0] == '/' && !stat(pwd, &s)) { - dev = s.st_dev; - ino = s.st_ino; - if (!stat(".", &s) && dev == s.st_dev && ino == s.st_ino) { - pwdlen = strlen(pwd); - if (size != 0) { - if (pwdlen + 1 > size) { - errno = ERANGE; - return (NULL); - } - } else if ((pt = malloc(pwdlen + 1)) == NULL) - return (NULL); - memmove(pt, pwd, pwdlen); - pt[pwdlen] = '\0'; - return (pt); - } - } - - return (getcwd_physical(pt, size)); -} +#ifdef __weak_alias +__weak_alias(getcwd,_getcwd) +__weak_alias(realpath,_realpath) +#endif /* - * char *realpath(const char *path, char resolved_path[MAXPATHLEN]); + * 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 * -realpath(path, resolved) - const char *path; - char *resolved; +realpath(const char *path, char *resolved) { struct stat sb; - int fd, n, rootd, serrno; - char *p, *q, wbuf[MAXPATHLEN]; + int idx = 0, n, nlnk = 0, serrno = errno; + const char *q; + char *p, wbuf[2][MAXPATHLEN]; + size_t len; - /* Save the starting point. */ - if ((fd = open(".", O_RDONLY)) < 0) { - (void)strcpy(resolved, "."); - return (NULL); - } + _DIAGASSERT(path != NULL); + _DIAGASSERT(resolved != NULL); /* - * Find the dirname and basename from the path to be resolved. - * Change directory to the dirname component. - * lstat the basename part. - * if it is a symlink, read in the value and loop. - * if it is a directory, then change to that directory. - * get the current directory name and append the basename. + * Build real path one by one with paying an attention to ., + * .. and symbolic link. */ - (void)strncpy(resolved, path, MAXPATHLEN - 1); - resolved[MAXPATHLEN - 1] = '\0'; -loop: - q = strrchr(resolved, '/'); - if (q != NULL) { - p = q + 1; - if (q == resolved) - q = "/"; - else { - do { - --q; - } while (q > resolved && *q == '/'); - q[1] = '\0'; - q = resolved; + + /* + * `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); } - if (chdir(q) < 0) - goto err1; - } else - p = resolved; - - /* Deal with the last component. */ - if (lstat(p, &sb) == 0) { - if (S_ISLNK(sb.st_mode)) { - n = readlink(p, resolved, MAXPATHLEN); - if (n < 0) - goto err1; - resolved[n] = '\0'; + 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 (S_ISDIR(sb.st_mode)) { - if (chdir(p) < 0) - goto err1; - p = ""; + if (path[1] == '.' && q - path == 2) { + /* Trim the last component. */ + if (p != resolved) + while (*--p != '/') + ; + path = q; + goto loop; } } - /* - * Save the last component name and get the full pathname of - * the current directory. - */ - (void)strcpy(wbuf, p); - - /* - * Call the inernal internal version of getcwd which - * does a physical search rather than using the $PWD short-cut - */ - if (getcwd_physical(resolved, MAXPATHLEN) == 0) - goto err1; + /* 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; /* - * Join the two strings together, ensuring that the right thing - * happens if the last component is empty, or the dirname is root. + * If this component is a symlink, toss it and prepend link + * target to unresolved path. */ - if (resolved[0] == '/' && resolved[1] == '\0') - rootd = 1; - else - rootd = 0; + if (lstat(resolved, &sb) == -1) { + 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); + } - if (*wbuf) { - if (strlen(resolved) + strlen(wbuf) + rootd + 1 > MAXPATHLEN) { + /* Append unresolved path to link target and switch to it. */ + if (n + (len = strlen(q)) + 1 > sizeof(wbuf[0])) { errno = ENAMETOOLONG; - goto err1; + return (NULL); } - if (rootd == 0) - (void)strcat(resolved, "/"); - (void)strcat(resolved, wbuf); + memcpy(&wbuf[idx][n], q, len + 1); + path = wbuf[idx]; + idx ^= 1; + + /* If absolute symlink, start from root. */ + if (*path == '/') + p = resolved; + goto loop; } - - /* Go back to where we came from. */ - if (fchdir(fd) < 0) { - serrno = errno; - goto err2; + if (*q == '/' && !S_ISDIR(sb.st_mode)) { + errno = ENOTDIR; + return (NULL); } - /* It's okay if the close fails, what's an fd more or less? */ - (void)close(fd); - return (resolved); - -err1: serrno = errno; - (void)fchdir(fd); -err2: (void)close(fd); - errno = serrno; - return (NULL); + /* Advance both resolved and unresolved path. */ + p += 1 + q - path; + path = q; + goto loop; } -static char * -getcwd_physical(pt, size) - char *pt; - size_t size; +char * +getcwd(char *pt, size_t size) { - 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; + char *npt; /* - * 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. + * If a buffer is specified, the size has to be non-zero. */ - if (pt) { - ptsize = 0; - if (!size) { + if (pt != NULL) { + if (size == 0) { + /* __getcwd(pt, 0) results ERANGE. */ errno = EINVAL; return (NULL); } - ept = pt + size; - } else { - if ((pt = malloc(ptsize = 1024 - 4)) == NULL) - return (NULL); - ept = pt + ptsize; + if (__getcwd(pt, size) >= 0) + return (pt); + return (NULL); } - bpt = ept - 1; - *bpt = '\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 no buffer specified by the user, allocate one as necessary. */ - if ((up = malloc(upsize = 1024 - 4)) == NULL) - 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); + 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); - /* - * 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 = realloc(up, upsize *= 2)) == NULL) - goto err; - bup = up; - 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 = realloc(pt, ptsize *= 2)) == NULL) - 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); - - /* Truncate any file name. */ - *bup = '\0'; - } - -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 (!errno) - errno = save_errno ? save_errno : ENOENT; - /* FALLTHROUGH */ -err: - if (ptsize) - free(pt); - free(up); + free(pt); return (NULL); }