Re: [AD] dat/grabber and pack_fopen_chunk

[Peter Wang <tjaden@xxxxxxxxxx>]

On 2006-01-22, Evert Glebbeek <eglebbk@xxxxxxxxxx> wrote:
> On Sunday 22 January 2006 15:23, Evert Glebbeek wrote:
> > Hmm... it seems that I can reproduce the crash in Linux by running the 
> > grabber from a directory for which I do not have write permission 
> (eg, /). 
> > This is at least comforting because it makes it easier for me to debug 
> and 
> > test the problem in pack_fopen_chunk.
> 
> Ok, patch for pack_fopen_chunk attached. It tries to determine the path to 
> the temporary directory, using GetTempPath in Windows and trying $TEMP, 
> $TMP, /tmp and $HOME before . on other platforms. It then concatenates the 
> name of the temporary file (as generated using the existing code) to that 
> path and opens the file.
> Tested and working in Linux, but can do with some more testing.
> The code itself is pretty ugly, and I vote it be cleaned up by whomever 
> feels like doing that!

Only just tried it today.

> Index: src/file.c
> ===================================================================
> --- src/file.c	(revision 5662)
> +++ src/file.c	(working copy)
> @@ -1904,13 +1904,56 @@
>  
>        /* write a sub-chunk */ 
>        int tmp_fd = -1;
> +      char *tmp_dir = NULL;
> +      char *tmp_name = NULL;
> +      #ifndef HAVE_MKSTEMP
> +      char* tmpnam_string;
> +      #endif
>  
> +      #ifdef ALLEGRO_WINDOWS
> +         int size;
> +         int new_size = 64;
> +         
> +         /* Get the path of the temporary directory */
> +         do {
> +            size = new_size;
> +            tmp_dir = realloc(tmp_dir, size);
> +            new_size = GetTempPath(size, tmp_dir);

When compiling with mingw (WARNMODE=1)

src/file.c: In function `pack_fopen_chunk':
src/file.c:1921: warning: implicit declaration of function `GetTempPath'
src/file.c:1926: warning: zero-length printf format string
src/file.c:1969: warning: implicit declaration of function `mkstemp'
make: *** [obj/mingw32/alld/file.o] Error 1

[...]
>        /* the file is open in read/write mode, even if the pack file
>         * seems to be in write only mode
>         */
>        #ifdef HAVE_MKSTEMP
>  
> -         char tmp_name[] = "XXXXXX";
> +         tmp_name = malloc(strlen(tmp_dir) + 16);
> +         sprintf(tmp_name, "%s/XXXXXX", tmp_dir);
>           tmp_fd = mkstemp(tmp_name);
>  
>        #else
> @@ -1918,7 +1961,13 @@
>           /* note: since the filename creation and the opening are not
>            * an atomic operation, this is not secure
>            */
> -         char *tmp_name = tmpnam(NULL);
> +         tmpnam_string = tmpnam(NULL);
> +         tmp_name = malloc(strlen(tmp_dir) + strlen(tmpnam_string) + 2);
> +         sprintf(tmp_name, "%s/%s", tmp_dir, tmpnam_string);
> +         free(tmpnam_string);
> +
> +         tmp_fd = mkstemp(tmp_name);

Er, this appears in the #if_n_def HAVE_MKSTEMP section.

Peter