Frequent warnings related to connection close handling

[elazarl]

Frequent warnings related to connection close handling

[galileox7]

I still get this issue

2016/10/22 15:02:37 [041] WARN: Error copying to client: read tcp 127.0.0.1:1272->127.0.0.1:54737: write tcp 127.0.0.1:1892->127.0.0.1:54737: use of closed network connection

[elazarl]

Thanks for reporting the bug.

This is a known problem, I suspect it's caused by unsynchronized closing of the tunneled TLS connection. I'm still investigating.

Does it have any effect on the actual usage of the proxy?

[ismail]

No effect whatsoever, everything seems to work fine. Thanks for this great library btw!

[archlichking]

I have met the same bug. Functions defined in proxy.OnRequest().DoFunc() and proxy.OnResponse().DoFunc() would not be executed due to this bug.

[elazarl]

Thanks Lei.

How can I reproduce the bug?
On Aug 19, 2014 2:53 AM, "Lei Zhu" [email protected] wrote:

I have met the same bug. Functions defined in proxy.OnRequest().DoFunc()
and proxy.OnResponse().DoFunc() would not be executed due to this bug.

—
Reply to this email directly or view it on GitHub
#48 (comment).

[archlichking]

Hi Elazar, I'm more than happy to share what I have so far.

package main

import (
    "github.com/elazarl/goproxy"
    "log"
    "net/http"
)

func main() {

    proxy := goproxy.NewProxyHttpServer()
    proxy.Verbose = true
    proxy.OnRequest().DoFunc(
        func(r *http.Request, ctx *goproxy.ProxyCtx) (*http.Request, *http.Response) {

            log.Printf("inside the onRequest for proxy %s", r.RequestURI)
            return r, nil
        })

    proxy.OnResponse().DoFunc(
        func(resp *http.Response, ctx *goproxy.ProxyCtx) *http.Response {
            log.Printf("inside the onResponse for proxy %s", resp.Request.URL)
            return resp
        })

    log.Fatal(http.ListenAndServe(":2222", proxy))
}

Here are the steps

1. execute curl -x http://localhost:2222 "http://mobile.walmart.com/m/j?service=Vod&method=getVod&e=1&e=1&40cc=1", which is a http call, will execute OnRequest().DoFunc() and OnResponse().DoFunc() with no problem.
2. execute curl -x http://localhost:2222 "https://mobile.walmart.com/m/j?service=Authentication&method=guestLogin&e=1", which is a https call with GET (...), will output a

2014/08/19 10:11:40 [005] INFO: Running 0 CONNECT handlers
2014/08/19 10:11:40 [005] INFO: Accepting CONNECT to mobile.walmart.com:443
2014/08/19 10:11:41 [005] WARN: Error copying to client read tcp 23.204.59.140:443: use of closed network connection

Notice that OnRequest().DoFunc() and OnResponse().DoFunc() are not executed.

Hope this would help.

[elazarl]

@archlichking Thanks. Sorry for not getting back to you earlier.

What you're describing is a different problem. In order to intercept https connections you must use MITM. See this example.

I still need to investigate the warning though, which is unrelated to the fact non-MITM https connections are not triggered.

[elazarl]

@ismail thanks for the bug report. Please let me know if it works better now.

[archlichking]

@elazarl Thanks for making this awesome library. MITM works perfectly for me.

[amlwwalker]

I still get this regularly - the error:
2015/06/23 00:15:44 [150] WARN: Error copying to client: use of closed network connection