X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=lib%2Fcareadlinkat.c;h=b36fea28302078d8935dfa78d22effdedf74100a;hb=1276a2c5f24c0c932426aca9c899fa524d2443f2;hp=5f0d43c2e719d34e3d3ee606c00b2c3f304f4a7f;hpb=0f6ac7dc9db3359b624ff31ad563426b437b965e;p=gnulib.git

diff --git a/lib/careadlinkat.c b/lib/careadlinkat.c
index 5f0d43c2e..b36fea283 100644
--- a/lib/careadlinkat.c
+++ b/lib/careadlinkat.c
@@ -1,6 +1,6 @@
 /* Read symbolic links into a buffer without size limitation, relative to fd.
 
-   Copyright (C) 2001, 2003-2004, 2007, 2009-2011 Free Software Foundation,
+   Copyright (C) 2001, 2003-2004, 2007, 2009-2014 Free Software Foundation,
    Inc.
 
    This program is free software: you can redistribute it and/or modify
@@ -18,16 +18,12 @@
 
 /* Written by Paul Eggert, Bruno Haible, and Jim Meyering.  */
 
-#define _GL_USE_STDLIB_ALLOC 1
 #include <config.h>
 
 #include "careadlinkat.h"
 
-#include "allocator.h"
-
 #include <errno.h>
 #include <limits.h>
-#include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
 
@@ -40,23 +36,7 @@
 # define SSIZE_MAX ((ssize_t) (SIZE_MAX / 2))
 #endif
 
-#if ! HAVE_READLINKAT
-/* Ignore FD.  Get the symbolic link value of FILENAME and put it into
-   BUFFER, with size BUFFER_SIZE.  This function acts like readlink
-   but has readlinkat's signature.  */
-ssize_t
-careadlinkatcwd (int fd, char const *filename, char *buffer,
-                 size_t buffer_size)
-{
-  (void) fd;
-  return readlink (filename, buffer, buffer_size);
-}
-#endif
-
-/* A standard allocator.  For now, only careadlinkat needs this, but
-   perhaps it should be moved to the allocator module.  */
-static struct allocator const standard_allocator =
-  { malloc, realloc, free, NULL };
+#include "allocator.h"
 
 /* Assuming the current directory is FD, get the symbolic link value
    of FILENAME as a null-terminated string and put it into a buffer.
@@ -72,7 +52,10 @@ static struct allocator const standard_allocator =
    the returned value if it is nonnull and is not BUFFER.  A null
    ALLOC stands for the standard allocator.
 
-   The PREADLINKAT function specifies how to read links.
+   The PREADLINKAT function specifies how to read links.  It operates
+   like POSIX readlinkat()
+   <http://pubs.opengroup.org/onlinepubs/9699919799/functions/readlink.html>
+   but can assume that its first argument is the same as FD.
 
    If successful, return the buffer address; otherwise return NULL and
    set errno.  */
@@ -90,7 +73,7 @@ careadlinkat (int fd, char const *filename,
   char stack_buf[1024];
 
   if (! alloc)
-    alloc = &standard_allocator;
+    alloc = &stdlib_allocator;
 
   if (! buffer_size)
     {
@@ -135,6 +118,7 @@ careadlinkat (int fd, char const *filename,
           if (buf == stack_buf)
             {
               char *b = (char *) alloc->allocate (link_size);
+              buf_size = link_size;
               if (! b)
                 break;
               memcpy (b, buf, link_size);
@@ -158,6 +142,11 @@ careadlinkat (int fd, char const *filename,
         buf_size *= 2;
       else if (buf_size < buf_size_max)
         buf_size = buf_size_max;
+      else if (buf_size_max < SIZE_MAX)
+        {
+          errno = ENAMETOOLONG;
+          return NULL;
+        }
       else
         break;
       buf = (char *) alloc->allocate (buf_size);
@@ -165,7 +154,7 @@ careadlinkat (int fd, char const *filename,
   while (buf);
 
   if (alloc->die)
-    alloc->die ();
+    alloc->die (buf_size);
   errno = ENOMEM;
   return NULL;
 }