1 files changed, 15 insertions, 8 deletions

diff --git a/src/lib/libc/stdlib/realpath.c b/src/lib/libc/stdlib/realpath.c
index e349b7e068..d01b19e0f2 100644
--- a/src/lib/libc/stdlib/realpath.c
+++ b/src/lib/libc/stdlib/realpath.c
@@ -35,8 +35,7 @@
  */
 
 #if defined(LIBC_SCCS) && !defined(lint)
-/*static char sccsid[] = "from: @(#)realpath.c  8.1 (Berkeley) 2/16/94";*/
-static char *rcsid = "$Id: realpath.c,v 1.1.1.1 1995/10/18 08:42:19 deraadt Exp $";
+static char *rcsid = "$OpenBSD: realpath.c,v 1.7 2002/05/24 21:22:37 deraadt Exp $";
 #endif /* LIBC_SCCS and not lint */
 
 #include <sys/param.h>
@@ -63,13 +62,18 @@ realpath(path, resolved)
         struct stat sb;
         int fd, n, rootd, serrno;
         char *p, *q, wbuf[MAXPATHLEN];
+        int symlinks = 0;
 
         /* Save the starting point. */
         if ((fd = open(".", O_RDONLY)) < 0) {
-                (void)strcpy(resolved, ".");
+                (void)strlcpy(resolved, ".", MAXPATHLEN);
                 return (NULL);
         }
 
+        /* Convert "." -> "" to optimize away a needless lstat() and chdir() */
+        if (path[0] == '.' && path[1] == '\0')
+                path = "";
+
         /*
          * Find the dirname and basename from the path to be resolved.
          * Change directory to the dirname component.
@@ -78,8 +82,7 @@ realpath(path, resolved)
          *     if it is a directory, then change to that directory.
          * get the current directory name and append the basename.
          */
-        (void)strncpy(resolved, path, MAXPATHLEN - 1);
-        resolved[MAXPATHLEN - 1] = '\0';
+        strlcpy(resolved, path, MAXPATHLEN);
 loop:
         q = strrchr(resolved, '/');
         if (q != NULL) {
@@ -99,9 +102,13 @@ loop:
                 p = resolved;
 
         /* Deal with the last component. */
-        if (lstat(p, &sb) == 0) {
+        if (*p != '\0' && lstat(p, &sb) == 0) {
                 if (S_ISLNK(sb.st_mode)) {
-                        n = readlink(p, resolved, MAXPATHLEN);
+                        if (++symlinks > MAXSYMLINKS) {
+                                errno = ELOOP;
+                                goto err1;
+                        }
+                        n = readlink(p, resolved, MAXPATHLEN-1);
                         if (n < 0)
                                 goto err1;
                         resolved[n] = '\0';
@@ -118,7 +125,7 @@ loop:
          * Save the last component name and get the full pathname of
          * the current directory.
          */
-        (void)strcpy(wbuf, p);
+        (void)strlcpy(wbuf, p, sizeof wbuf);
         if (getcwd(resolved, MAXPATHLEN) == 0)
                 goto err1;