[U-Boot] [PATCH v2 1/3] net: Prefer command line arguments

[Joe Hershberger]

On Thu, Jun 14, 2018 at 5:04 AM, Alexander Graf <agraf at suse.de> wrote:
> We can call commands like dhcp and bootp without arguments or with
> explicit command line arguments that really should tell the code where
> to look for files instead.
>
> Unfortunately, the current code simply overwrites command line arguments
> in the dhcp case with dhcp values.
>
> This patch allows the code to preserve the command line values if they
> were set on the command line. That way the semantics are slightly more
> intuitive.
>
> The reason this patch does that by introducing a new variable is that we
> can not rely on net_boot_file_name[0] being unset, as today it's
> completely legal to call "dhcp" and afterwards run "tftp" and expect the
> latter to repeat the same query as before. I would prefer not to break
> that behavior in case anyone relies on it.
>
> Signed-off-by: Alexander Graf <agraf at suse.de>
> ---
>  cmd/net.c     | 10 ++++++++--
>  include/net.h |  2 ++
>  net/bootp.c   |  3 ++-
>  net/net.c     |  2 ++
>  4 files changed, 14 insertions(+), 3 deletions(-)
>
> diff --git a/cmd/net.c b/cmd/net.c
> index f83839c35e..eca6dd8918 100644
> --- a/cmd/net.c
> +++ b/cmd/net.c
> @@ -183,6 +183,8 @@ static int netboot_common(enum proto_t proto, cmd_tbl_t *cmdtp, int argc,
>         int   size;
>         ulong addr;
>
> +       net_boot_file_name_explicit = false;
> +
>         /* pre-set load_addr */
>         s = env_get("loadaddr");
>         if (s != NULL)
> @@ -199,15 +201,18 @@ static int netboot_common(enum proto_t proto, cmd_tbl_t *cmdtp, int argc,
>                  * mis-interpreted as a valid number.
>                  */
>                 addr = simple_strtoul(argv[1], &end, 16);
> -               if (end == (argv[1] + strlen(argv[1])))
> +               if (end == (argv[1] + strlen(argv[1]))) {
>                         load_addr = addr;
> -               else
> +               } else {
> +                       net_boot_file_name_explicit = true;
>                         copy_filename(net_boot_file_name, argv[1],
>                                       sizeof(net_boot_file_name));
> +               }
>                 break;
>
>         case 3:
>                 load_addr = simple_strtoul(argv[1], NULL, 16);
> +               net_boot_file_name_explicit = true;
>                 copy_filename(net_boot_file_name, argv[2],
>                               sizeof(net_boot_file_name));
>
> @@ -220,6 +225,7 @@ static int netboot_common(enum proto_t proto, cmd_tbl_t *cmdtp, int argc,
>                         printf("Invalid address/size\n");
>                         return CMD_RET_USAGE;
>                 }
> +               net_boot_file_name_explicit = true;
>                 copy_filename(net_boot_file_name, argv[3],
>                               sizeof(net_boot_file_name));
>                 break;
> diff --git a/include/net.h b/include/net.h
> index 5760685556..a259b7c530 100644
> --- a/include/net.h
> +++ b/include/net.h
> @@ -539,6 +539,8 @@ enum proto_t {
>  };
>
>  extern char    net_boot_file_name[1024];/* Boot File name */
> +/* Indicates whether the file name was specified on the command line */
> +extern bool    net_boot_file_name_explicit;
>  /* The actual transferred size of the bootfile (in bytes) */
>  extern u32     net_boot_file_size;
>  /* Boot file size in blocks as reported by the DHCP server */
> diff --git a/net/bootp.c b/net/bootp.c
> index 9d7cb5d30c..f3da8572b7 100644
> --- a/net/bootp.c
> +++ b/net/bootp.c
> @@ -157,7 +157,8 @@ static void store_net_params(struct bootp_hdr *bp)
>  #if defined(CONFIG_CMD_DHCP)
>             !(dhcp_option_overload & OVERLOAD_FILE) &&
>  #endif
> -           (strlen(bp->bp_file) > 0)) {
> +           (strlen(bp->bp_file) > 0) &&
> +           !net_boot_file_name_explicit) {

This seems like a reasonable check, but it also needs to happen in the
case that the file is passed under option 67.

>                 copy_filename(net_boot_file_name, bp->bp_file,
>                               sizeof(net_boot_file_name));
>         }
> diff --git a/net/net.c b/net/net.c
> index a4932f46d9..510d491271 100644
> --- a/net/net.c
> +++ b/net/net.c
> @@ -165,6 +165,8 @@ ushort              net_native_vlan = 0xFFFF;
>
>  /* Boot File name */
>  char net_boot_file_name[1024];
> +/* Indicates whether the file name was specified on the command line */
> +bool net_boot_file_name_explicit;
>  /* The actual transferred size of the bootfile (in bytes) */
>  u32 net_boot_file_size;
>  /* Boot file size in blocks as reported by the DHCP server */
> --
> 2.12.3
>
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