is_valid_ip: accept RFC 3986 bracketed IPv6 in X-Forwarded-For#3667
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HrachShah wants to merge 1 commit into
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is_valid_ip: accept RFC 3986 bracketed IPv6 in X-Forwarded-For#3667HrachShah wants to merge 1 commit into
HrachShah wants to merge 1 commit into
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Some load balancers (e.g. Fortigate) emit IPv6 addresses in X-Forwarded-For in the URI-reference bracketed form, e.g. '[2620:0:d60:ac1a::10]'. The existing is_valid_ip check calls getaddrinfo, which rejects the bracketed form with EAI_NONAME, so these forwarded addresses were silently dropped and the request fell back to the connection peer. Strip the brackets inside is_valid_ip so the bracketed form is accepted and validated as a normal IPv6 address, and unwrap the brackets in _apply_xheaders so the stored remote_ip is always the bare address. Fixes tornadoweb#3561.
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What
is_valid_ip(used to validateX-Forwarded-For/X-Real-IPheaders in
_apply_xheaders) callsgetaddrinfo, which rejects theRFC 3986 URI-reference bracketed IPv6 form (e.g.
[2620:0:d60:ac1a::10])with
EAI_NONAME. Load balancers such as Fortigate emit IPv6 in thisform, so the forwarded address was silently dropped and the request
fell back to the connection peer.
Strip the brackets inside
is_valid_ipso the bracketed form isaccepted and validated as a normal IPv6 address, and unwrap the
brackets in
_apply_xheadersso the storedremote_ipis alwaysthe bare address.
Fixes #3561.