Pingora: return 400 (not 500) on malformed request bodies

[MDA2AV]

Problem

The Pingora probe app reads the POST body with session.read_request_body().await?. On malformed chunk framing, Pingora's body reader returns an Err, the ? propagates out of request_filter, and Pingora emits its default 500 — failing 17 chunk/TE tests (SMUG-CHUNK-NEGATIVE, -HEX-PREFIX, -MISSING-TRAILING-CRLF, MAL-CHUNK-SIZE-OVERFLOW, SMUG-TE-CASE-MISMATCH, …) that expect 400 or close.

Fix

The read loop now catches the error and returns a clean 400. Pingora was already rejecting the bad framing — this just surfaces it as a client error instead of a server error.

Note: this only addresses the 500s. The separate ~47 200 failures are Pingora's lenient parsing + the fact that it's a proxy being scored as a bare origin (request_filter short-circuits, upstream_peer is unreachable!()), which is a deeper modeling question left as-is.

Engine/server change → re-probes Pingora.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[github-actions]

Http11Probe — Compliance Comparison

Server	Score
Pingora	112/161	██████████████░░░░░░ 70%

✅ Baseline Passed

Compliance

Test	Expected	Pingora
BASELINE	2xx	✅200
BARE-LF-REQUEST-LINE	400 or close (pass), 2xx (warn)	⚠️200
BARE-LF-HEADER	400 or close (pass), 2xx (warn)	⚠️200
OBS-FOLD	400	✅400
SP-BEFORE-COLON	400	✅400
MULTI-SP-REQUEST-LINE	400 or 2xx; close/timeout = warn	✅400
MISSING-HOST	400	❌200
INVALID-VERSION	400/505, close, or timeout = warn	✅400
EMPTY-HEADER-NAME	400 or close	✅400
CR-ONLY-LINE-ENDING	400, close, or timeout = warn	✅400
MISSING-TARGET	400, close, or timeout = warn	✅400
FRAGMENT-IN-TARGET	400 or 2xx; 404 = warn	⚠️200
HTTP09-REQUEST	400/close/timeout	✅400
INVALID-HEADER-NAME	400 or close	✅400
HEADER-NO-COLON	400 or close	✅400
DUPLICATE-HOST	400	❌200
CL-NON-NUMERIC	400 or close	❌200
CL-PLUS-SIGN	400 or close	❌200
WHITESPACE-BEFORE-HEADERS	400 or close	✅400
DUPLICATE-HOST-SAME	400	❌200
HOST-WITH-USERINFO	400 or close	❌200
HOST-WITH-PATH	400 or close	❌200
ASTERISK-WITH-GET	400, close, or timeout = warn	❌200
OPTIONS-STAR	2xx or 405; close/timeout = warn	✅200
UNKNOWN-TE-501	400/501 or close	❌200
LEADING-CRLF	400 or 2xx; close/timeout = warn	⚠️200
ABSOLUTE-FORM	2xx preferred; 400/close/timeout = warn	⚠️400
METHOD-CASE	400/405/501 or 2xx; close/timeout = warn	⚠️200
POST-CL-BODY	2xx + echo	✅200
POST-CL-ZERO	2xx or close	✅200
POST-NO-CL-NO-TE	2xx or close	✅200
POST-CL-UNDERSEND	400/close/timeout	✅TimedOut
CHUNKED-BODY	2xx + echo	✅200
CHUNKED-MULTI	2xx + echo	✅200
CHUNKED-EMPTY	2xx or close	✅200
CHUNKED-NO-FINAL	400/close/timeout	✅TimedOut
METHOD-CONNECT	400/405/501 or close	✅400
EXPECT-UNKNOWN	417 or 2xx	⚠️200
GET-WITH-CL-BODY	400 or 2xx	⚠️200
CHUNKED-EXTENSION	2xx preferred; 400 warns	✅200
METHOD-TRACE	405/501 or 2xx	⚠️200
HOST-EMPTY-VALUE	400 or close	❌200
REQUEST-LINE-TAB	400 or 2xx; close/timeout = warn	✅400
VERSION-MISSING-MINOR	400, close, or timeout = warn	✅400
VERSION-LEADING-ZEROS	400, close, or timeout = warn	✅400
VERSION-WHITESPACE	400, close, or timeout = warn	✅400
CONNECTION-CLOSE	2xx + close	✅200
HTTP10-DEFAULT-CLOSE	2xx + close	✅200
HTTP10-NO-HOST	200 or 400	⚠️200
HTTP12-VERSION	200 or 505	❌400
TRACE-WITH-BODY	400/405 or 200	⚠️200
CHUNKED-TRAILER-VALID	2xx + echo	✅200
CHUNKED-HEX-UPPERCASE	2xx + echo	✅200
RANGE-POST	2xx (Range ignored)	✅200
HEAD-NO-BODY	2xx with no body	✅200
UNKNOWN-METHOD	501/405/400 or close	⚠️200
405-ALLOW	405 + Allow header	⚠️200
DATE-HEADER	2xx with Date header	✅200
DATE-FORMAT	IMF-fixdate format	✅200
NO-1XX-HTTP10	non-1xx response	✅200
NO-CL-IN-204	204 without CL, or 405	⚠️200
OPTIONS-ALLOW	2xx with Allow header, or 405	⚠️200
CONTENT-TYPE	2xx with Content-Type	✅200
VERSION-CASE	400, close, or timeout = warn	✅400
LONG-URL-OK	not 414; close/timeout = warn	✅200
SPACE-IN-TARGET	400, close, or timeout = warn	❌200
DUPLICATE-CT	400 or 2xx	⚠️200
TRACE-SENSITIVE	405/501, or 200 without Auth	✅200
RANGE-INVALID	200 or 416	✅200
ACCEPT-NONSENSE	406 or 2xx	⚠️200
POST-UNSUPPORTED-CT	415 or 2xx	✅200

Smuggling

Test	Expected	Pingora
CL-TE-BOTH	400 or 2xx	⚠️200
DUPLICATE-CL	400 or close	✅400
CL-LEADING-ZEROS	400 or 2xx	⚠️200
TE-XCHUNKED	400/501 or close	❌200
TE-TRAILING-SPACE	400/501 or 2xx+close	✅400
TE-SP-BEFORE-COLON	400 or close	✅400
CL-NEGATIVE	400 or close	❌200
CLTE-PIPELINE	400 or close preferred; 2xx acceptable	⚠️200
TECL-PIPELINE	400 or close preferred; 2xx acceptable	⚠️200
CL-TRAILING-SPACE	400 or 2xx	⚠️200
TE-DOUBLE-CHUNKED	400 or 2xx	⚠️200
CL-EXTRA-LEADING-SP	400 or 2xx	⚠️200
TE-CASE-MISMATCH	400 or 2xx	✅400
CL-COMMA-DIFFERENT	400 or close	❌200
TE-NOT-FINAL-CHUNKED	400 or close	❌200
TE-HTTP10	400 or close	✅400
CHUNK-BARE-SEMICOLON	400 or close	❌200
CHUNK-EXT-INVALID-TOKEN	400 or close	❌200
BARE-CR-HEADER-VALUE	400 or close	✅400
CL-OCTAL	400 or close	❌200
CHUNK-UNDERSCORE	400 or close	✅400
TE-EMPTY-VALUE	400 or close	❌200
TE-LEADING-COMMA	400 or 2xx	⚠️200
TE-DUPLICATE-HEADERS	400 or close	✅400
CHUNK-HEX-PREFIX	400 or close	✅400
CHUNK-SIZE-PLUS	400 or close	✅400
CHUNK-SIZE-TRAILING-OWS	400 or close	❌200
CL-HEX-PREFIX	400 or close	❌200
CL-INTERNAL-SPACE	400 or close	❌200
CHUNK-LEADING-SP	400 or close	✅400
CHUNK-MISSING-TRAILING-CRLF	400 or close	✅400
CHUNK-EXT-LF	400 or 2xx	❌TimedOut
CHUNK-SPILL	400 or close	✅400
CHUNK-LF-TERM	400 or 2xx	✅400
CHUNK-EXT-CTRL	400 or close	❌200
CHUNK-EXT-CR	400 or close	✅400
TE-VTAB	400 or close	✅400
TE-FORMFEED	400 or close	✅400
TE-NULL	400 or close	✅400
CHUNK-LF-TRAILER	400 or 2xx	✅400
TE-IDENTITY	400/501 or close	❌200
CHUNK-NEGATIVE	400 or close	✅400
TRANSFER_ENCODING	400 or 2xx	⚠️200
CL-COMMA-SAME	400 or 2xx	⚠️200
CL-COMMA-TRIPLE	400 or 2xx	⚠️200
CHUNKED-WITH-PARAMS	400 or 2xx	⚠️200
EXPECT-100-CL	100, 400 or 2xx	⚠️200
TRAILER-CL	400 or 2xx	⚠️200
TRAILER-TE	400 or 2xx	⚠️200
TRAILER-HOST	400 or 2xx	⚠️200
TRAILER-AUTH	400 or 2xx	⚠️200
HEAD-CL-BODY	400 or 2xx	⚠️200
OPTIONS-CL-BODY	400/405 or 2xx	⚠️200
CL-UNDERSCORE	400 or close	❌200
CL-NEGATIVE-ZERO	400 or close	❌200
CL-DOUBLE-ZERO	400 or 2xx	⚠️200
CL-LEADING-ZEROS-OCTAL	400 or 2xx	⚠️200
TE-OBS-FOLD	400 or 2xx+close	✅400
TE-TRAILING-COMMA	400 or 2xx	⚠️200
TE-TAB-BEFORE-VALUE	400 or 2xx	✅400
ABSOLUTE-URI-HOST-MISMATCH	400 or 2xx	✅400
MULTIPLE-HOST-COMMA	400 or close	❌200
CHUNK-BARE-CR-TERM	400 or close	✅400
TRAILER-CONTENT-TYPE	400 or 2xx	⚠️200
CLTE-CONN-CLOSE	400, or 2xx + close	❌200
TECL-CONN-CLOSE	400, or 2xx + close	❌200
CLTE-DESYNC	400, or close	❌200
CLTE-SMUGGLED-GET	400, or close (no extra response)	❌200
CLTE-SMUGGLED-GET-CL-PLUS	400, or close (no extra response)	❌200
CLTE-SMUGGLED-GET-CL-NON-NUMERIC	400, or close (no extra response)	❌200
CLTE-SMUGGLED-GET-TE-OBS-FOLD	400, or close (no extra response)	✅400
CLTE-SMUGGLED-HEAD	400, or close (no extra response)	❌200
CLTE-SMUGGLED-GET-TE-TRAILING-SPACE	400, or close (no extra response)	❌200
CLTE-SMUGGLED-GET-TE-LEADING-COMMA	400, or close (no extra response)	❌200
CLTE-SMUGGLED-GET-TE-CASE-MISMATCH	400, or close (no extra response)	❌200
TE-DUPLICATE-HEADERS-SMUGGLED-GET	400, or close (no extra response)	❌200
TECL-SMUGGLED-GET	400, or close (no extra response)	❌200
DUPLICATE-CL-SMUGGLED-GET	400, or close (no extra response)	✅400
GET-CL-PREFIX-DESYNC	400/close preferred; extra response on step 2 = warn	✅200
TECL-DESYNC	400, or close	❌200
CL0-BODY-POISON	400/close preferred; poisoned follow-up = warn	⚠️200
GET-CL-BODY-DESYNC	400/close/pass-through; poisoned follow-up = warn	✅200
OPTIONS-CL-BODY-DESYNC	400/close/pass-through; poisoned follow-up = warn	✅200
EXPECT-100-CL-DESYNC	417/400/close preferred; poisoned follow-up = warn	✅200
OPTIONS-TE-OBS-FOLD	400, or 2xx + close	✅400
CHUNK-INVALID-SIZE-DESYNC	400, or close	✅200
PIPELINE-SAFE	2xx + 2xx	✅200

Malformed Input

Test	Expected	Pingora
BINARY-GARBAGE	400/close/timeout	✅400
LONG-URL	400/414/431 or close	❌200
LONG-HEADER-VALUE	400/431 or close	❌200
MANY-HEADERS	400/431 or close	✅400
NUL-IN-URL	400 or close	❌200
CONTROL-CHARS-HEADER	400 or close	✅400
INCOMPLETE-REQUEST	400/close/timeout	✅TimedOut
EMPTY-REQUEST	400/close/timeout	✅TimedOut
LONG-HEADER-NAME	400/431 or close	✅400
LONG-METHOD	400 or close	❌200
NON-ASCII-HEADER-NAME	400 or close	✅400
NON-ASCII-URL	400 or close	❌200
CL-OVERFLOW	400 or close	❌200
WHITESPACE-ONLY-LINE	400/close/timeout	✅400
NUL-IN-HEADER-VALUE	400 or close	✅400
CHUNK-SIZE-OVERFLOW	400 or close	✅400
H2-PREFACE	400/505/close/timeout	✅400
CL-EMPTY	400 or close	❌200
CL-TAB-BEFORE-VALUE	400 or 2xx	⚠️200
URL-BACKSLASH	400 or 2xx/404	⚠️200
URL-OVERLONG-UTF8	400 or close	✅400
URL-PERCENT-NULL	400 or 2xx/404	⚠️200
URL-PERCENT-CRLF	400 or 2xx/404	⚠️200
CHUNK-EXT-64K	400 or 2xx	✅400
RANGE-OVERLAPPING	200/206/400/416	⚠️200
POST-CL-HUGE-NO-BODY	400/413/close/timeout	✅TimedOut

Header Normalization

Test	Expected	Pingora
UNDERSCORE-CL	Reject/drop (pass), normalize (fail), preserve (warn)	⚠️200
SP-BEFORE-COLON-CL	Reject/drop (pass), normalize (fail), preserve (warn)	✅400
TAB-IN-NAME	Reject/drop (pass), normalize (fail), preserve (warn)	✅400
CASE-TE	Reject/drop (pass), normalize casing (fail), preserve (warn)	❌200
UNDERSCORE-TE	Reject/drop (pass), normalize (fail), preserve (warn)	⚠️200

_{Commit: fb39592}

[MDA2AV]

Closing per the same principle as #139: this imposed a 400 where Pingora natively emits a 500 on a body-read error. The probe measures what a framework does when someone uses it, so we keep Pingora's native 500 rather than translate it to 400.