From cd0cc50a19fd7a392c560364f8ebb260a9471899 Mon Sep 17 00:00:00 2001 From: William Mantly Date: Fri, 10 Jul 2026 13:05:43 -0400 Subject: [PATCH] Fix HTTP/2 coalescing cross-routing in targetinfo.lua Hosts that share one wildcard cert (e.g. hassio.718it.biz and metrics.718it.biz under *.718it.biz) resolve to the same IP, so browsers coalesce them onto a single HTTP/2 connection. The SSL request_domain phase resolves the connection's first host and caches it in ngx.ctx.targetInfo; the unguarded `if targetInfo then return targetInfo` then handed that first host's target to every coalesced request on the connection -- e.g. hassio.718it.biz served from metrics' 192.168.1.8:8088. Confirmed via debug logging: for GET requests to hassio.718it.biz on a coalesced connection, ngx.ctx already held metrics' IP and the function short-circuited to it. Guard the reuse by host: only return the cached target when ngx.ctx.targetInfo_domain matches the requested domain, and record that domain whenever a target is resolved. A coalesced request for a different host now re-resolves against its actual Host header. Co-Authored-By: Claude Opus 4.8 --- ops/nginx_conf/targetinfo.lua | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/ops/nginx_conf/targetinfo.lua b/ops/nginx_conf/targetinfo.lua index 67c2702..c1dd15e 100644 --- a/ops/nginx_conf/targetinfo.lua +++ b/ops/nginx_conf/targetinfo.lua @@ -13,7 +13,14 @@ print("In targetInfo module") -- Main function of the module function M.get(ngx, domain, targetInfo) - if targetInfo then + -- Reuse a previously-resolved target ONLY when it was resolved for this + -- exact host. HTTP/2 connection coalescing lets a browser serve several + -- hostnames that share one wildcard cert (e.g. *.718it.biz) over a single + -- connection; the SSL phase (request_domain) resolves and caches the + -- connection's first host in ngx.ctx.targetInfo. Without the domain check + -- below, every coalesced request on that connection would be handed the + -- first host's target -- e.g. hassio.718it.biz served from metrics.718it.biz. + if targetInfo and ngx.ctx.targetInfo_domain == domain then return targetInfo end @@ -68,6 +75,10 @@ function M.get(ngx, domain, targetInfo) end ngx.ctx.targetInfo = res + -- Remember which host this target was resolved for, so the reuse guard at + -- the top can tell a genuine cache hit from a coalesced request for a + -- different host on the same connection. + ngx.ctx.targetInfo_domain = domain ngx.ctx.toAllow = true return res