On Mon, Jun 03, 2019 at 01:12:26PM -0400, Trond Myklebust wrote:
> When attempting to strip the root path, we should first canonicalise
> the root pathname.
>
> Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
> ---
> support/misc/nfsd_path.c | 17 +++++++++++++----
> 1 file changed, 13 insertions(+), 4 deletions(-)
>
> diff --git a/support/misc/nfsd_path.c b/support/misc/nfsd_path.c
> index 2f41a793c534..9b38dd96007f 100644
> --- a/support/misc/nfsd_path.c
> +++ b/support/misc/nfsd_path.c
> @@ -1,6 +1,7 @@
> #include <errno.h>
> #include <sys/types.h>
> #include <sys/stat.h>
> +#include <limits.h>
> #include <stdlib.h>
> #include <unistd.h>
>
> @@ -62,13 +63,21 @@ nfsd_path_nfsd_rootdir(void)
> char *
> nfsd_path_strip_root(char *pathname)
> {
> + char buffer[PATH_MAX];
> const char *dir = nfsd_path_nfsd_rootdir();
> char *ret;
>
> - ret = strstr(pathname, dir);
> - if (!ret || ret != pathname)
> - return pathname;
> - return pathname + strlen(dir);
> + if (!dir)
> + goto out;
> + if (realpath(dir, buffer)) {
> + ret = strstr(pathname, buffer);
> + if (ret == pathname)
> + return pathname + strlen(dir);
> + } else
> + xlog(D_GENERAL, "%s: failed to resolve path %s: %m",
> + __func__, dir);
> +out:
> + return pathname;
I still don't get this.
So in the case strstr doesn't find anything, it returns the path
unchanged.
That means that if the next_mnt() caller asks whether there are any
mounts underneath /rootdir/a/b, and nextdir finds a mountpoint at
/a/b/c, it can return that, right?
--b.
> }
>
> char *
> --
> 2.21.0
