1 files changed, 45 insertions, 16 deletions

diff --git a/openbsd-compat/realpath.c b/openbsd-compat/realpath.c
index ba4cea938..a2f090e55 100644
--- a/openbsd-compat/realpath.c
+++ b/openbsd-compat/realpath.c
@@ -1,4 +1,4 @@
-/*      $OpenBSD: realpath.c,v 1.13 2005/08/08 08:05:37 espie Exp $ */
+/*      $OpenBSD: realpath.c,v 1.20 2015/10/13 20:55:37 millert Exp $ */
 /*
  * Copyright (c) 2003 Constantin S. Svintsoff <kostik@iclub.nsu.ru>
  *
@@ -42,6 +42,13 @@
 #include <stddef.h>
 #include <string.h>
 #include <unistd.h>
+#include <limits.h>
+
+#ifndef SYMLOOP_MAX
+# define SYMLOOP_MAX 32
+#endif
+
+/* A slightly modified copy of this file exists in libexec/ld.so */
 
 /*
  * char *realpath(const char *path, char resolved[PATH_MAX]);
@@ -51,16 +58,30 @@
  * in which case the path which caused trouble is left in (resolved).
  */
 char *
-realpath(const char *path, char resolved[PATH_MAX])
+realpath(const char *path, char *resolved)
 {
         struct stat sb;
         char *p, *q, *s;
         size_t left_len, resolved_len;
         unsigned symlinks;
-        int serrno, slen;
+        int serrno, slen, mem_allocated;
         char left[PATH_MAX], next_token[PATH_MAX], symlink[PATH_MAX];
 
+        if (path[0] == '\0') {
+                errno = ENOENT;
+                return (NULL);
+        }
+
         serrno = errno;
+
+        if (resolved == NULL) {
+                resolved = malloc(PATH_MAX);
+                if (resolved == NULL)
+                        return (NULL);
+                mem_allocated = 1;
+        } else
+                mem_allocated = 0;
+
         symlinks = 0;
         if (path[0] == '/') {
                 resolved[0] = '/';
@@ -71,7 +92,10 @@ realpath(const char *path, char resolved[PATH_MAX])
                 left_len = strlcpy(left, path + 1, sizeof(left));
         } else {
                 if (getcwd(resolved, PATH_MAX) == NULL) {
-                        strlcpy(resolved, ".", PATH_MAX);
+                        if (mem_allocated)
+                                free(resolved);
+                        else
+                                strlcpy(resolved, ".", PATH_MAX);
                         return (NULL);
                 }
                 resolved_len = strlen(resolved);
@@ -79,7 +103,7 @@ realpath(const char *path, char resolved[PATH_MAX])
         }
         if (left_len >= sizeof(left) || resolved_len >= PATH_MAX) {
                 errno = ENAMETOOLONG;
-                return (NULL);
+                goto err;
         }
 
         /*
@@ -94,7 +118,7 @@ realpath(const char *path, char resolved[PATH_MAX])
                 s = p ? p : left + left_len;
                 if (s - left >= (ptrdiff_t)sizeof(next_token)) {
                         errno = ENAMETOOLONG;
-                        return (NULL);
+                        goto err;
                 }
                 memcpy(next_token, left, s - left);
                 next_token[s - left] = '\0';
@@ -104,7 +128,7 @@ realpath(const char *path, char resolved[PATH_MAX])
                 if (resolved[resolved_len - 1] != '/') {
                         if (resolved_len + 1 >= PATH_MAX) {
                                 errno = ENAMETOOLONG;
-                                return (NULL);
+                                goto err;
                         }
                         resolved[resolved_len++] = '/';
                         resolved[resolved_len] = '\0';
@@ -135,23 +159,23 @@ realpath(const char *path, char resolved[PATH_MAX])
                 resolved_len = strlcat(resolved, next_token, PATH_MAX);
                 if (resolved_len >= PATH_MAX) {
                         errno = ENAMETOOLONG;
-                        return (NULL);
+                        goto err;
                 }
                 if (lstat(resolved, &sb) != 0) {
                         if (errno == ENOENT && p == NULL) {
                                 errno = serrno;
                                 return (resolved);
                         }
-                        return (NULL);
+                        goto err;
                 }
                 if (S_ISLNK(sb.st_mode)) {
-                        if (symlinks++ > MAXSYMLINKS) {
+                        if (symlinks++ > SYMLOOP_MAX) {
                                 errno = ELOOP;
-                                return (NULL);
+                                goto err;
                         }
                         slen = readlink(resolved, symlink, sizeof(symlink) - 1);
                         if (slen < 0)
-                                return (NULL);
+                                goto err;
                         symlink[slen] = '\0';
                         if (symlink[0] == '/') {
                                 resolved[1] = 0;
@@ -174,15 +198,15 @@ realpath(const char *path, char resolved[PATH_MAX])
                                         if (slen + 1 >=
                                             (ptrdiff_t)sizeof(symlink)) {
                                                 errno = ENAMETOOLONG;
-                                                return (NULL);
+                                                goto err;
                                         }
                                         symlink[slen] = '/';
                                         symlink[slen + 1] = 0;
                                 }
-                                left_len = strlcat(symlink, left, sizeof(left));
-                                if (left_len >= sizeof(left)) {
+                                left_len = strlcat(symlink, left, sizeof(symlink));
+                                if (left_len >= sizeof(symlink)) {
                                         errno = ENAMETOOLONG;
-                                        return (NULL);
+                                        goto err;
                                 }
                         }
                         left_len = strlcpy(left, symlink, sizeof(left));
@@ -196,5 +220,10 @@ realpath(const char *path, char resolved[PATH_MAX])
         if (resolved_len > 1 && resolved[resolved_len - 1] == '/')
                 resolved[resolved_len - 1] = '\0';
         return (resolved);
+
+err:
+        if (mem_allocated)
+                free(resolved);
+        return (NULL);
 }
 #endif /* !defined(HAVE_REALPATH) || defined(BROKEN_REALPATH) */