tree 98c535baab8432989b2127c5ce3a89ede7074bed
parent a87546624369ef94546907d90a17da9c985399fd
author Willy Tarreau <w@1wt.eu> 1545402890 +0100
committer Willy Tarreau <w@1wt.eu> 1545648300 +0100
encoding latin1

MEDIUM: mux-h2: remove padlen during headers phase

Three types of frames may be padded : DATA, HEADERS and PUSH_PROMISE.
Currently, each of these independently deals with padding and needs to
wait for and skip the initial padlen byte. Not only this complicates
frame processing, but it makes it very hard to process CONTINUATION
frames after a padded HEADERS frame, and makes it complicated to perform
atomic calls to h2s_decode_headers(), which are needed if we want to be
able to maintain the HPACK decompressor's context even when dropping
streams.

This patch takes a different approach : the padding is checked when
parsing the frame header, the padlen byte is waited for and parsed,
and the dpl value is updated with this padlen value. This will allow
the frame parsers to decide to overwrite the padding if needed when
merging adjacent frames.