[4/7,v3] support/download: return different exit codes for different failures

Return different exit codes depending on the error that occured:

  0: no error (hash file missing, or all hashes match)
  1: unknown option
  2: hash file exists, but at least one hash in error
  3: hash file exists, but no hash for file to check
  4: hash file exists, but at least one hash type unknown

This will be used in a later patch to decide whether the downloaded file
should be kept or removed.

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Samuel Martin <s.martin49@gmail.com>
Cc: Arnout Vandecappelle <arnout@mind.be>

---
Changes v2 -> v3:
  - further differentiate errors for unknown hashes and unknown
    command-line options  (Arnout)

Changes v1 -> v2:
  - typoes in script and commit  (Samuel)
---
 support/download/check-hash | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

Yann,

On Sun, Mar 22, 2015 at 4:21 PM, Yann E. MORIN <yann.morin.1998@free.fr> wrote:
> Return different exit codes depending on the error that occured:
>
>   0: no error (hash file missing, or all hashes match)
>   1: unknown option
>   2: hash file exists, but at least one hash in error
>   3: hash file exists, but no hash for file to check
>   4: hash file exists, but at least one hash type unknown
>
> This will be used in a later patch to decide whether the downloaded file
> should be kept or removed.
>
> Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
> Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
> Cc: Samuel Martin <s.martin49@gmail.com>
> Cc: Arnout Vandecappelle <arnout@mind.be>
>
> ---
> Changes v2 -> v3:
>   - further differentiate errors for unknown hashes and unknown
>     command-line options  (Arnout)
>
> Changes v1 -> v2:
>   - typoes in script and commit  (Samuel)
> ---
>  support/download/check-hash | 15 ++++++++++++---
>  1 file changed, 12 insertions(+), 3 deletions(-)
>
> diff --git a/support/download/check-hash b/support/download/check-hash
> index d0a4ab9..0234ab0 100755
> --- a/support/download/check-hash
> +++ b/support/download/check-hash
> @@ -9,6 +9,15 @@ set -e
>  #   $3: the final basename of the file, to which it will be ultimately
>  #       saved as, to be able to match it to the corresponding hashes
>  #       in the .hash file
> +#
> +# Exit codes:
> +#   0:  the hash file exists and the file to check matches all its hashes,
> +#       or the hash file does not exist
> +#   1:  unknown command-line option
> +#   2:  the hash file exists and the file to check does not match at least
> +#       of its hashes
maybe s/of its hashes/one of its hashes/

> +#   3:  the hash file exists and there was no hash to check the file against
> +#   4:  the hash file exists and at least one hash type is unknown
>
>  while getopts :q OPT; do
>      case "${OPT}" in
> @@ -46,7 +55,7 @@ check_one_hash() {
>          *) # Unknown hash, exit with error
>              printf "ERROR: unknown hash '%s' for '%s'\n"  \
>                     "${_h}" "${base}" >&2
> -            exit 1
> +            exit 4
>              ;;
>      esac
>
> @@ -62,7 +71,7 @@ check_one_hash() {
>      printf "ERROR: got     : %s\n" "${_hash}" >&2
>      printf "ERROR: Incomplete download, or man-in-the-middle (MITM) attack\n" >&2
>
> -    exit 1
> +    exit 2
>  }
>
>  # Do we know one or more hashes for that file?
> @@ -85,7 +94,7 @@ done <"${h_file}"
>  if [ ${nb_checks} -eq 0 ]; then
>      if [ -n "${BR2_ENFORCE_CHECK_HASH}" ]; then
>          printf "ERROR: No hash found for %s\n" "${base}" >&2
> -        exit 1
> +        exit 3
>      else
>          printf "WARNING: No hash found for %s\n" "${base}" >&2
>      fi
> --
> 1.9.1
>

Regards,

Samuel, All,

On 2015-03-23 14:03 +0100, Samuel Martin spake thusly:
> On Sun, Mar 22, 2015 at 4:21 PM, Yann E. MORIN <yann.morin.1998@free.fr> wrote:
[--SNIP--]
> > diff --git a/support/download/check-hash b/support/download/check-hash
> > index d0a4ab9..0234ab0 100755
> > --- a/support/download/check-hash
> > +++ b/support/download/check-hash
> > @@ -9,6 +9,15 @@ set -e
> >  #   $3: the final basename of the file, to which it will be ultimately
> >  #       saved as, to be able to match it to the corresponding hashes
> >  #       in the .hash file
> > +#
> > +# Exit codes:
> > +#   0:  the hash file exists and the file to check matches all its hashes,
> > +#       or the hash file does not exist
> > +#   1:  unknown command-line option
> > +#   2:  the hash file exists and the file to check does not match at least
> > +#       of its hashes
> maybe s/of its hashes/one of its hashes/

Yes, good catch! I'll fix before resubmitting.

Regards,
Yann E. MORIN.