huffman decoder does not work as expected with TCP segmentation 1 byte

[RomanBelozerov]

Scope

1 case:
Send h2 request with TCP segmentation 1 byte and header from: testuser@example.com. Header value contain "@",

AR: Tempesta forwarded request with header from: testuserj.I7iB0nWaN
ER: Tempesta forwarded request with header from: testuser@example.com

2 case:
For frang config:

frang_limits {
    http_host_required true;
}

Send h2 request with TCP segmentation 1 byte and header host: [20:11:abb::1]:443
AR: Tempesta returns 400 response and dmesg warning

[ 5097.963690] [tempesta fw] Warning: HTTP/2 request dropped: state=Req_HdrHostV input=0x71('qc1611:abb::1x64'), len=18, off=0
[ 5097.965653] [tempesta fw] Warning: failed to parse request: 127.0.0.1

ER: Tempesta returns 403 response

3 case:
Send h2 request with TCP segmentation 1 byte and header accept: */*:
AR: Tempesta returns 400 response and dmesg warning

[ 6228.625399] [tempesta fw] Warning: HTTP/2 request dropped: state=Req_HdrAcceptV input=0x4a('JbY'), len=3, off=0
[ 6228.627713] [tempesta fw] Warning: failed to parse request: 127.0.0.1

ER: Tempesta forwards request to server.

Testing

• t_http_rules.test_h2_http_rules.HttpRulesH2.test_scheduler with -T 1 option or;
• run any h2 tests with TCP segmentation 1 byte and request header with "@" (For example - from: testuser@example.com) or;
• t_frang.test_host_required.FrangHostRequiredH2TestCase.test_h2_host_header_as_ipv6 and test_h2_authority_header_as_ipv6 with -T 1 option or;
• sessions.test_js_challenge.JSChallengeH2.test_get_challenge with -T 1 option.

[EvgeniiMekhanik]

Closed by PR #1874