- (dtucker) [configure.ac openbsd-compat/realpath.c] Sync up with realpath

   rev 1.11 from OpenBSD and make it use fchdir if available.  ok djm@

1 files changed, 51 insertions, 18 deletions

diff --git a/openbsd-compat/realpath.c b/openbsd-compat/realpath.c
index 218fbecb2..7f73bd998 100644
--- a/openbsd-compat/realpath.c
+++ b/openbsd-compat/realpath.c
@@ -37,7 +37,7 @@
 #if !defined(HAVE_REALPATH) || defined(BROKEN_REALPATH)
 
 #if defined(LIBC_SCCS) && !defined(lint)
-static char *rcsid = "$OpenBSD: realpath.c,v 1.10 2003/08/01 21:04:59 millert Exp $";
+static char *rcsid = "$OpenBSD: realpath.c,v 1.11 2004/11/30 15:12:59 millert Exp $";
 #endif /* LIBC_SCCS and not lint */
 
 #include <sys/param.h>
@@ -67,17 +67,25 @@ char *
 realpath(const char *path, char *resolved)
 {
         struct stat sb;
-        int fd, n, needslash, serrno = 0;
-        char *p, *q, wbuf[MAXPATHLEN], start[MAXPATHLEN];
+        int fd, n, needslash, serrno;
+        char *p, *q, wbuf[MAXPATHLEN];
         int symlinks = 0;
 
         /* Save the starting point. */
-        getcwd(start,MAXPATHLEN);       
+#ifndef HAVE_FCHDIR
+        char start[MAXPATHLEN];
+        /* this is potentially racy but without fchdir we have no option */
+        if (getcwd(start, sizeof(start)) == NULL) {
+                resolved[0] = '.';
+                resolved[1] = '\0';
+                return (NULL);
+        }
+#endif
         if ((fd = open(".", O_RDONLY)) < 0) {
-                (void)strlcpy(resolved, ".", MAXPATHLEN);
+                resolved[0] = '.';
+                resolved[1] = '\0';
                 return (NULL);
         }
-        close(fd);
 
         /* Convert "." -> "" to optimize away a needless lstat() and chdir() */
         if (path[0] == '.' && path[1] == '\0')
@@ -91,7 +99,10 @@ realpath(const char *path, char *resolved)
          *     if it is a directory, then change to that directory.
          * get the current directory name and append the basename.
          */
-        strlcpy(resolved, path, MAXPATHLEN);
+        if (strlcpy(resolved, path, MAXPATHLEN) >= MAXPATHLEN) {
+                serrno = ENAMETOOLONG;
+                goto err2;
+        }
 loop:
         q = strrchr(resolved, '/');
         if (q != NULL) {
@@ -114,11 +125,10 @@ loop:
         if (*p != '\0' && lstat(p, &sb) == 0) {
                 if (S_ISLNK(sb.st_mode)) {
                         if (++symlinks > MAXSYMLINKS) {
-                                serrno = ELOOP;
+                                errno = ELOOP;
                                 goto err1;
                         }
-                        n = readlink(p, resolved, MAXPATHLEN-1);
-                        if (n < 0)
+                        if ((n = readlink(p, resolved, MAXPATHLEN-1)) < 0)
                                 goto err1;
                         resolved[n] = '\0';
                         goto loop;
@@ -134,8 +144,11 @@ loop:
          * Save the last component name and get the full pathname of
          * the current directory.
          */
-        (void)strlcpy(wbuf, p, sizeof wbuf);
-        if (getcwd(resolved, MAXPATHLEN) == 0)
+        if (strlcpy(wbuf, p, sizeof(wbuf)) >= sizeof(wbuf)) {
+                errno = ENAMETOOLONG;
+                goto err1;
+        }
+        if (getcwd(resolved, MAXPATHLEN) == NULL)
                 goto err1;
 
         /*
@@ -149,23 +162,43 @@ loop:
 
         if (*wbuf) {
                 if (strlen(resolved) + strlen(wbuf) + needslash >= MAXPATHLEN) {
-                        serrno = ENAMETOOLONG;
+                        errno = ENAMETOOLONG;
+                        goto err1;
+                }
+                if (needslash) {
+                        if (strlcat(resolved, "/", MAXPATHLEN) >= MAXPATHLEN) {
+                                errno = ENAMETOOLONG;
+                                goto err1;
+                        }
+                }
+                if (strlcat(resolved, wbuf, MAXPATHLEN) >= MAXPATHLEN) {
+                        errno = ENAMETOOLONG;
                         goto err1;
                 }
-                if (needslash)
-                        strlcat(resolved, "/", MAXPATHLEN);
-                strlcat(resolved, wbuf, MAXPATHLEN);
         }
 
         /* Go back to where we came from. */
+#ifdef HAVE_FCHDIR
+        if (fchdir(fd) < 0) {
+#else
         if (chdir(start) < 0) {
+#endif
                 serrno = errno;
                 goto err2;
         }
+
+        /* It's okay if the close fails, what's an fd more or less? */
+        (void)close(fd);
         return (resolved);
 
-err1:   chdir(start);
-err2:   errno = serrno;
+err1:   serrno = errno;
+#ifdef HAVE_FCHDIR
+        (void)fchdir(fd);
+#else
+        chdir(start);
+#endif
+err2:   (void)close(fd);
+        errno = serrno;
         return (NULL);
 }
 #endif /* !defined(HAVE_REALPATH) || defined(BROKEN_REALPATH) */