Using a value with a non-sanatized length will result to an exhaust of workspace

[Jonathan Huot]

Hi,

If we try to use any functions with a http header (a value with a variable length), which is a bit less than current thread workspace size, the vmod call will return a valid string, but workspace will be exhausted for other vmods, or even for varnish core itself.

It is a bit annoying because when thread workspace is exhausted, we're not killing the thread or the request, varnish instance is killing itself.

Length could be sanatized before calling this vmodule, but it might be safer to handle this problem from the inside, or at least give an example of how-to handle this from the outside (in VCL).

Thanks

[Jonathan Huot]

This issue is more a generic problem to all VMODs and usage of WS when handling unknown length.