tree a6ef07ccf1ebc0c91cc99ba419f92744c1ce1cae
parent c73c09c3904ce6a210970374bd1bc507ef1f8cc2
author Leo Blöcher <leo.bloecher@gmail.com> 1682268956 +0000
committer Damien Neil <dneil@google.com> 1688595794 +0000

http2: handle trailing colon in authorityAddr

This change modifies the authorityAddr result for authorities with empty
port information, such as "example.com:". Previously, such authorities
passed through the function unchanged. This conflicts with the result
from net/http's canonicalAddr, which returns "example.com:443" (for
HTTPS).

net/http's canonicalAddr result is passed to http2's upgradeFn (defined
inside http2.configureTransports) from net/http's (*Transport).dialConn.
The connection is then added to http2's cache under the canonicalAddr
key. However, cache lookups are performed in (*Transport).RoundTripOpt
using the result from authorityAddr applied directly to the input URL.
The lookup thus fails if authorityAddr and canonicalAddr don't agree.

http2's lookup error propagates upwards to net/http's
(*Transport).roundTrip, where the request is retried. The end result is
an infinite loop of the request being repeated, each time with a freshly
dialed connection, that can only be stopped by a timeout.

Aligning the results of http2's authorityAddr and net/http's
canonicalAddr fixes the bug. While an authority with a trailing colon is
invalid per URL specifications, I have personally come across
misconfigured web servers emitting such URLs as redirects. This is how I
discovered this issue in http2.

Change-Id: If47aa61b8d256d76a3451090076e6eb5ff596c9e
GitHub-Last-Rev: cb0470115705139cfc60a3d27ec432363fd54a1c
GitHub-Pull-Request: golang/net#170
Reviewed-on: https://go-review.googlesource.com/c/net/+/487915
Run-TryBot: Damien Neil <dneil@google.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Damien Neil <dneil@google.com>