tree 3ce006ebe127483bd7da99831eff78c9a714d340
parent fb3ca3c7ac9ac92e8950678dd144decd1362487b
author Maxim Dounin <mdounin@mdounin.ru> 1594049785 +0300
committer Maxim Dounin <mdounin@mdounin.ru> 1594049785 +0300

gRPC: generate error when response size is wrong.

As long as the "Content-Length" header is given, we now make sure
it exactly matches the size of the response.  If it doesn't,
the response is considered malformed and must not be forwarded
(https://tools.ietf.org/html/rfc7540#section-8.1.2.6).  While it
is not really possible to "not forward" the response which is already
being forwarded, we generate an error instead, which is the closest
equivalent.

Previous behaviour was to pass everything to the client, but this
seems to be suboptimal and causes issues (ticket #1695).  Also this
directly contradicts HTTP/2 specification requirements.

Note that the new behaviour for the gRPC proxy is more strict than that
applied in other variants of proxying.  This is intentional, as HTTP/2
specification requires us to do so, while in other types of proxying
malformed responses from backends are well known and historically
tolerated.