[Midnightbsd-cvs] src [10541] trunk/lib/libc/stdlib/realpath.c: update realpath

laffer1 at midnightbsd.org laffer1 at midnightbsd.org
Thu Jun 7 19:03:10 EDT 2018


Revision: 10541
          http://svnweb.midnightbsd.org/src/?rev=10541
Author:   laffer1
Date:     2018-06-07 19:03:09 -0400 (Thu, 07 Jun 2018)
Log Message:
-----------
update realpath

Modified Paths:
--------------
    trunk/lib/libc/stdlib/realpath.c

Modified: trunk/lib/libc/stdlib/realpath.c
===================================================================
--- trunk/lib/libc/stdlib/realpath.c	2018-06-07 23:02:50 UTC (rev 10540)
+++ trunk/lib/libc/stdlib/realpath.c	2018-06-07 23:03:09 UTC (rev 10541)
@@ -1,3 +1,4 @@
+/* $MidnightBSD$ */
 /*
  * Copyright (c) 2003 Constantin S. Svintsoff <kostik at iclub.nsu.ru>
  *
@@ -30,7 +31,7 @@
 static char sccsid[] = "@(#)realpath.c	8.1 (Berkeley) 2/16/94";
 #endif /* LIBC_SCCS and not lint */
 #include <sys/cdefs.h>
-__FBSDID("$FreeBSD$");
+__FBSDID("$FreeBSD: stable/10/lib/libc/stdlib/realpath.c 319131 2017-05-29 13:00:39Z kib $");
 
 #include "namespace.h"
 #include <sys/param.h>
@@ -47,31 +48,16 @@
  * components.  Returns (resolved) on success, or (NULL) on failure,
  * in which case the path which caused trouble is left in (resolved).
  */
-char *
-realpath(const char * __restrict path, char * __restrict resolved)
+static char *
+realpath1(const char *path, char *resolved)
 {
 	struct stat sb;
-	char *p, *q, *s;
-	size_t left_len, resolved_len;
+	char *p, *q;
+	size_t left_len, resolved_len, next_token_len;
 	unsigned symlinks;
-	int m, slen;
+	ssize_t slen;
 	char left[PATH_MAX], next_token[PATH_MAX], symlink[PATH_MAX];
 
-	if (path == NULL) {
-		errno = EINVAL;
-		return (NULL);
-	}
-	if (path[0] == '\0') {
-		errno = ENOENT;
-		return (NULL);
-	}
-	if (resolved == NULL) {
-		resolved = malloc(PATH_MAX);
-		if (resolved == NULL)
-			return (NULL);
-		m = 1;
-	} else
-		m = 0;
 	symlinks = 0;
 	if (path[0] == '/') {
 		resolved[0] = '/';
@@ -82,12 +68,8 @@
 		left_len = strlcpy(left, path + 1, sizeof(left));
 	} else {
 		if (getcwd(resolved, PATH_MAX) == NULL) {
-			if (m)
-				free(resolved);
-			else {
-				resolved[0] = '.';
-				resolved[1] = '\0';
-			}
+			resolved[0] = '.';
+			resolved[1] = '\0';
 			return (NULL);
 		}
 		resolved_len = strlen(resolved);
@@ -94,8 +76,6 @@
 		left_len = strlcpy(left, path, sizeof(left));
 	}
 	if (left_len >= sizeof(left) || resolved_len >= PATH_MAX) {
-		if (m)
-			free(resolved);
 		errno = ENAMETOOLONG;
 		return (NULL);
 	}
@@ -109,22 +89,21 @@
 		 * and its length.
 		 */
 		p = strchr(left, '/');
-		s = p ? p : left + left_len;
-		if (s - left >= sizeof(next_token)) {
-			if (m)
-				free(resolved);
-			errno = ENAMETOOLONG;
-			return (NULL);
+
+		next_token_len = p != NULL ? p - left : left_len;
+		memcpy(next_token, left, next_token_len);
+		next_token[next_token_len] = '\0';
+
+		if (p != NULL) {
+			left_len -= next_token_len + 1;
+			memmove(left, p + 1, left_len + 1);
+		} else {
+			left[0] = '\0';
+			left_len = 0;
 		}
-		memcpy(next_token, left, s - left);
-		next_token[s - left] = '\0';
-		left_len -= s - left;
-		if (p != NULL)
-			memmove(left, s + 1, left_len + 1);
+
 		if (resolved[resolved_len - 1] != '/') {
 			if (resolved_len + 1 >= PATH_MAX) {
-				if (m)
-					free(resolved);
 				errno = ENAMETOOLONG;
 				return (NULL);
 			}
@@ -132,31 +111,11 @@
 			resolved[resolved_len] = '\0';
 		}
 		if (next_token[0] == '\0') {
-			/*
-			 * Handle consequential slashes.  The path
-			 * before slash shall point to a directory.
-			 *
-			 * Only the trailing slashes are not covered
-			 * by other checks in the loop, but we verify
-			 * the prefix for any (rare) "//" or "/\0"
-			 * occurence to not implement lookahead.
-			 */
-			if (lstat(resolved, &sb) != 0) {
-				if (m)
-					free(resolved);
-				return (NULL);
-			}
-			if (!S_ISDIR(sb.st_mode)) {
-				if (m)
-					free(resolved);
-				errno = ENOTDIR;
-				return (NULL);
-			}
+			/* Handle consequential slashes. */
 			continue;
-		}
-		else if (strcmp(next_token, ".") == 0)
+		} else if (strcmp(next_token, ".") == 0) {
 			continue;
-		else if (strcmp(next_token, "..") == 0) {
+		} else if (strcmp(next_token, "..") == 0) {
 			/*
 			 * Strip the last path component except when we have
 			 * single "/"
@@ -175,27 +134,24 @@
 		 */
 		resolved_len = strlcat(resolved, next_token, PATH_MAX);
 		if (resolved_len >= PATH_MAX) {
-			if (m)
-				free(resolved);
 			errno = ENAMETOOLONG;
 			return (NULL);
 		}
-		if (lstat(resolved, &sb) != 0) {
-			if (m)
-				free(resolved);
+		if (lstat(resolved, &sb) != 0)
 			return (NULL);
-		}
 		if (S_ISLNK(sb.st_mode)) {
 			if (symlinks++ > MAXSYMLINKS) {
-				if (m)
-					free(resolved);
 				errno = ELOOP;
 				return (NULL);
 			}
-			slen = readlink(resolved, symlink, sizeof(symlink) - 1);
-			if (slen < 0) {
-				if (m)
-					free(resolved);
+			slen = readlink(resolved, symlink, sizeof(symlink));
+			if (slen <= 0 || slen >= sizeof(symlink)) {
+				if (slen < 0)
+					; /* keep errno from readlink(2) call */
+				else if (slen == 0)
+					errno = ENOENT;
+				else
+					errno = ENAMETOOLONG;
 				return (NULL);
 			}
 			symlink[slen] = '\0';
@@ -202,9 +158,8 @@
 			if (symlink[0] == '/') {
 				resolved[1] = 0;
 				resolved_len = 1;
-			} else if (resolved_len > 1) {
+			} else {
 				/* Strip the last path component. */
-				resolved[resolved_len - 1] = '\0';
 				q = strrchr(resolved, '/') + 1;
 				*q = '\0';
 				resolved_len = q - resolved;
@@ -218,8 +173,6 @@
 			if (p != NULL) {
 				if (symlink[slen - 1] != '/') {
 					if (slen + 1 >= sizeof(symlink)) {
-						if (m)
-							free(resolved);
 						errno = ENAMETOOLONG;
 						return (NULL);
 					}
@@ -228,14 +181,15 @@
 				}
 				left_len = strlcat(symlink, left,
 				    sizeof(symlink));
-				if (left_len >= sizeof(left)) {
-					if (m)
-						free(resolved);
+				if (left_len >= sizeof(symlink)) {
 					errno = ENAMETOOLONG;
 					return (NULL);
 				}
 			}
 			left_len = strlcpy(left, symlink, sizeof(left));
+		} else if (!S_ISDIR(sb.st_mode) && p != NULL) {
+			errno = ENOTDIR;
+			return (NULL);
 		}
 	}
 
@@ -247,3 +201,29 @@
 		resolved[resolved_len - 1] = '\0';
 	return (resolved);
 }
+
+char *
+realpath(const char * __restrict path, char * __restrict resolved)
+{
+	char *m, *res;
+
+	if (path == NULL) {
+		errno = EINVAL;
+		return (NULL);
+	}
+	if (path[0] == '\0') {
+		errno = ENOENT;
+		return (NULL);
+	}
+	if (resolved != NULL) {
+		m = NULL;
+	} else {
+		m = resolved = malloc(PATH_MAX);
+		if (resolved == NULL)
+			return (NULL);
+	}
+	res = realpath1(path, resolved);
+	if (res == NULL)
+		free(m);
+	return (res);
+}



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