[Libguestfs] [PATCH v2] inspect: check for errors in files parsed with augeas (RHBZ#1229119)

[Richard W.M. Jones]

On Thu, Oct 15, 2015 at 06:15:28PM +0200, Pino Toscano wrote:
> During the inspection phase, check for errors after aug_load: if any of
> the errors happened in any of the requested files, then report the error
> straight away; ignoring the error means that information would be
> silently lost.  For example, a malformed /etc/fstab would have caused
> the inspection to not handle any of the additional mount points, giving
> cryptic errors later on when trying to access files in any of the mount
> points.
> 
> Now guests with invalid files such as /etc/fstab, /etc/mdadm.conf, and
> /etc/sysconfig/network will cause the inspection to fail, instead of
> being reported with a single mount point ('/').
> ---
>  src/inspect-fs-unix.c | 19 +++++++++++++++++++
>  1 file changed, 19 insertions(+)
> 
> diff --git a/src/inspect-fs-unix.c b/src/inspect-fs-unix.c
> index 3d19276..968aa40 100644
> --- a/src/inspect-fs-unix.c
> +++ b/src/inspect-fs-unix.c
> @@ -1983,6 +1983,9 @@ inspect_with_augeas (guestfs_h *g, struct inspect_fs *fs,
>    int64_t size;
>    int r;
>    CLEANUP_FREE char *pathexpr = NULL;
> +  CLEANUP_FREE_STRING_LIST char **matches = NULL;
> +  char **match;
> +  size_t len;
>  
>    /* Security: Refuse to do this if a config file is too large. */
>    for (i = 0; configfiles[i] != NULL; ++i) {
> @@ -2019,6 +2022,22 @@ inspect_with_augeas (guestfs_h *g, struct inspect_fs *fs,
>    if (guestfs_aug_load (g) == -1)
>      goto out;
>  
> +  /* Check that augeas did not get a parse error for any of the configfiles,
> +   * otherwise we are silently missing information. */
> +  matches = guestfs_aug_match (g, "/augeas/files//error");
> +  for (match = matches; *match != NULL; ++match) {
> +    for (i = 0; configfiles[i] != NULL; ++i) {
> +      len = strlen (configfiles[i]);
> +      if (strlen (*match) == (13 /* len(/augeas/files) */ + len + 6 /* len(/error) */) &&
> +          STRPREFIX(*match, "/augeas/files") &&
> +          STREQLEN(*match + 13, configfiles[i], len) &&
> +          STREQ(*match + 13 + len, "/error")) {
> +        error (g, _("augeas could not parse %s"), configfiles[i]);
> +        goto out;
> +      }
> +    }
> +  }
> +

ACK .. and ugh!  Augeas should make this easier.

Rich.

-- 
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