[U-Boot] [PATCH v2] net: Do not overwrite options found in overloaded 'file' field

[Joe Hershberger]

Hi Stefan,

On Thu, Sep 3, 2015 at 5:31 PM, Stefan Brüns
<stefan.bruens at rwth-aachen.de> wrote:
> If 'file' is overloaded, it is wrong to get or put the bootfile name
> from it/to it.
>
> Signed-off-by: Stefan Brüns <stefan.bruens at rwth-aachen.de>
> Acked-by: Joe Hershberger <joe.hershberger at ni.com>
> ---
>
> v2: added missing break before empty "case 53:", no functional change
>
>  net/bootp.c | 41 +++++++++++++++--------------------------
>  1 file changed, 15 insertions(+), 26 deletions(-)
>
> diff --git a/net/bootp.c b/net/bootp.c
> index 7fd29ee..72a956d 100644
> --- a/net/bootp.c
> +++ b/net/bootp.c
> @@ -64,6 +64,9 @@ char net_root_path[64] = {0,}; /* Our bootpath */
>  static dhcp_state_t dhcp_state = INIT;
>  static u32 dhcp_leasetime;
>  static struct in_addr dhcp_server_ip;
> +static u8 dhcp_option_overload;
> +#define OVERLOAD_FILE 1
> +#define OVERLOAD_SNAME 2
>  static void dhcp_handler(uchar *pkt, unsigned dest, struct in_addr sip,
>                         unsigned src, unsigned len);
>
> @@ -146,9 +149,11 @@ static void store_net_params(struct bootp_hdr *bp)
>                 net_copy_ip(&net_server_ip, &bp->bp_siaddr);
>         memcpy(net_server_ethaddr,
>                ((struct ethernet_hdr *)net_rx_packet)->et_src, 6);
> -       if (strlen(bp->bp_file) > 0)
> +       if (!(dhcp_option_overload & OVERLOAD_FILE) &&
> +           (strlen(bp->bp_file) > 0)) {

It seems that this fails to compile if CONFIG_CMD_DHCP is not defined
(since the variables only exist inside that guard.

I've fixed it up in place like this:

@@ -146,9 +149,14 @@ static void store_net_params(struct bootp_hdr *bp)
                net_copy_ip(&net_server_ip, &bp->bp_siaddr);
        memcpy(net_server_ethaddr,
               ((struct ethernet_hdr *)net_rx_packet)->et_src, 6);
-       if (strlen(bp->bp_file) > 0)
+       if (
+#if defined(CONFIG_CMD_DHCP)
+           !(dhcp_option_overload & OVERLOAD_FILE) &&
+#endif
+           (strlen(bp->bp_file) > 0)) {
                copy_filename(net_boot_file_name, bp->bp_file,
                              sizeof(net_boot_file_name));
+       }

        debug("net_boot_file_name: %s\n", net_boot_file_name);

------

Let me know if that is not how you would like it fixed.

>                 copy_filename(net_boot_file_name, bp->bp_file,
>                               sizeof(net_boot_file_name));
> +       }
>
>         debug("net_boot_file_name: %s\n", net_boot_file_name);
>
> @@ -770,6 +775,7 @@ static void dhcp_process_options(uchar *popt, struct bootp_hdr *bp)
>  #if defined(CONFIG_CMD_SNTP) && defined(CONFIG_BOOTP_TIMEOFFSET)
>         int *to_ptr;
>  #endif
> +       dhcp_option_overload = 0;
>
>         while (popt < end && *popt != 0xff) {
>                 oplen = *(popt + 1);
> @@ -821,6 +827,9 @@ static void dhcp_process_options(uchar *popt, struct bootp_hdr *bp)
>                 case 51:
>                         net_copy_u32(&dhcp_leasetime, (u32 *)(popt + 2));
>                         break;
> +               case 52:
> +                       dhcp_option_overload = popt[2];
> +                       break;
>                 case 53:        /* Ignore Message Type Option */
>                         break;
>                 case 54:
> @@ -832,31 +841,11 @@ static void dhcp_process_options(uchar *popt, struct bootp_hdr *bp)
>                         break;
>                 case 66:        /* Ignore TFTP server name */
>                         break;
> -               case 67:        /* vendor opt bootfile */
> -                       /*
> -                        * I can't use dhcp_vendorex_proc here because I need
> -                        * to write into the bootp packet - even then I had to
> -                        * pass the bootp packet pointer into here as the
> -                        * second arg
> -                        */
> -                       size = truncate_sz("Opt Boot File",
> -                                           sizeof(bp->bp_file),
> -                                           oplen);
> -                       if (bp->bp_file[0] == '\0' && size > 0) {
> -                               /*
> -                                * only use vendor boot file if we didn't
> -                                * receive a boot file in the main non-vendor
> -                                * part of the packet - god only knows why
> -                                * some vendors chose not to use this perfectly
> -                                * good spot to store the boot file (join on
> -                                * Tru64 Unix) it seems mind bogglingly crazy
> -                                * to me
> -                                */
> -                               printf("*** WARNING: using vendor "
> -                                      "optional boot file\n");
> -                               memcpy(bp->bp_file, popt + 2, size);
> -                               bp->bp_file[size] = '\0';
> -                       }
> +               case 67:        /* Bootfile option */
> +                       size = truncate_sz("Bootfile",
> +                                          sizeof(net_boot_file_name), oplen);
> +                       memcpy(&net_boot_file_name, popt + 2, size);
> +                       net_boot_file_name[size] = 0;
>                         break;
>                 default:
>  #if defined(CONFIG_BOOTP_VENDOREX)
> --
> 2.1.4
>
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