1300842 - "Proxy Server is refusing connections" message displayed in Firefox Beta Android App when no proxy used to connect to network

Status: RESOLVED WORKSFORME

(Firefox for Android Graveyard :: General, defect)

Description

[Kaartic Sivaraam]

Attachment: Screenshot of Firefix Beta displaying error message.

User Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:51.0) Gecko/20100101 Firefox/51.0
Build ID: 20160830030201
Firefox for Android

Steps to reproduce:

1. Set up proxy for your Firefox browser used in desktop (bug may be due to setting proxy in desktop).
2. Use Firefox Sync to sync Firefox Beta App with the Firefox desktop browser.
3. Make sure the Android device is not connected to any network.
4. Try loading a webpage.


Actual results:

"The proxy server is refusing connections" error message is displayed, although I do not use any kind of proxy for connecting to the network from my Android device.


Expected results:

"Server not found" error (or) similar errors that specify that no network connection is available.

Comment 1

[Kevin Brosnan [Ex-Mozilla]]

Sync does not sync proxy prefs. In about:config only prefs that start with services.sync.prefs.sync are synced. None of the network.proxy prefs are listed. Your error must come from another source.

What do you mean by not connected to any network? Airplane mode? WiFi off, mobile data on? WiFi on, mobile data off? WiFi off, mobile data off?

Comment 2

[Kaartic Sivaraam]

Firefox sync did not sync the Proxy settings I use for my desktop.I am able to surf when I am connected to the network. The problem is when I am not connected to the network( WiFi - Off, Mobile Data - Off), and I try to load any webpage "The proxy server is refusing connections" message is displayed. The screenshot I have  attached shows the error that is displayed.

Comment 3

[Kaartic Sivaraam]

The User agent and build ID seems to be that of my desktop browser. How do I change it?

Comment 4

[Kevin Brosnan [Ex-Mozilla]]

Comments are not editable. You can copy and paste the user agent info from about:support but that is not really needed as the bug is in the Android component and platform info is set to Android.

I cannot reproduce this behavior on Firefox for Android 49 with Sync enabled. I get "Server not found"

Comment 5

[Kaartic Sivaraam]

Did you try it with the Firefox Beta version.

Comment 6

[Kaartic Sivaraam]

I tried to load a webpage when my phone was offline, after clearing the app data and still it shows "The proxy server is refusing connections" error. 

I then tried reinstalling the app and tried to load a webpage when the phone was offline, It showed "Server not found" error. When I repeated this after enabling Firefox Sync, I get "The proxy server is refusing connections" error.

I hence confirm that it is due to Firefox Sync.

Comment 7

[Kevin Brosnan [Ex-Mozilla]]

I don't have any idea what is going on. I still suspect your ISP. Trying one of the platform engineers.

Comment 8

[James Willcox (:snorp) ([e-mail]) (he/him)]

Hmm. Newman, any idea what could be going on here?

Comment 9

[Richard Newman [:rnewman]]

We don't sync prefs of any kind between desktop and Android. Neither do we sync add-ons: only passwords, history, tabs, and bookmarks. 

We do have code in the tree to try to configure a proxy based on the Android OS settings; it is possible that Sync touching that functionality is causing a difference in observed behavior. It's not due to prefs syncing between the two platforms. 

Could you post a screenshot of your Android browser showing the error?

Comment 10

[Kaartic Sivaraam]

I have already attached one.

There is no problem with browsing when I'm online(proxy settings do not interfere). The problem occurs only if the device is offline and I try to load  a web page. It shows the error "The proxy server is refusing connections" error although my ISP does not require me to use a proxy. 

I doubt the problem is due to "Sync" because the "Server not found" error is displayed when I remove proxy from my desktop browsers and sync the settings through a direct connection.

Comment 11

[Richard Newman [:rnewman]]

I just tested this on 42 and 49, and didn't get a proxy-related error message with Sync enabled. If I get time later I'll test with 50-51.

When you open Android settings, wifi, long-tap the network you usually use, hit Modify, tap Advanced Options, what do you see under Proxy?

Do you have a VPN configured (even if not in use)?

If you open about:config in Firefox on your Android device, search for "proxy", what do you see? I'm particularly interested in network.proxy.http, network.proxy.ssl, and network.proxy.autoconfig_url.

Comment 12

[Kaartic Sivaraam]

I access the Internet through a network that is provided by my college's hostel. They "do not allow" mobile phones to connect to the network. They only allow laptops, so I "only" use mobile data to access the network in my phone.

They recently changed the way they filter the network access requests. Previously they were using a "proxy server" to filter the network access requests. They are now using Cyberoam, which seem to be filtering the requests through the "direct connection".  So, I am now unable to test this issue, as they Cyberoam.

I would like you to notice that after they changed to Cyberoam, and after my desktop browsers started syncing "through direct connection", I now get the "Server not found error" instead of the "The proxy server is refusing connections" error.

I guess you do not use a proxy server to connect access the network normally. It would be helpful if you can you tell me how you "Synced your Firefox account" through a proxy server(i.e) how do you set up a proxy server, so I could test with this bug. In the mean time, I would be searching for ways to do the same.

Comment 13

[Richard Newman [:rnewman]]

(In reply to Kaartic Sivaraam from comment #12)

> I guess you do not use a proxy server to connect access the network
> normally. It would be helpful if you can you tell me how you "Synced your
> Firefox account" through a proxy server(i.e) how do you set up a proxy
> server, so I could test with this bug. In the mean time, I would be
> searching for ways to do the same.

I do not use a proxy. More importantly, you didn't configure a proxy in Firefox, and Sync doesn't sync one, so that's not relevant.

What I was testing was: could I reproduce your error in Firefox without any changes to Android? I could not. That's why I asked you about the Android-level proxy and VPN configuration on your device.

My suspicion is that the network you use is using WPAD with support from an app on your device, or was manually configured with a proxy, or is being transparently routed to a proxy (and Firefox is somehow picking that up). When Sync is configured it does background Android network access, which might be enough to cause the main browser app to think a proxy is still configured even when your device is offline.

(That might be as simple as a reversed order of checks somewhere. docshell checks for NS_ERROR_OFFLINE before it checks for NS_ERROR_PROXY_CONNECTION_REFUSED, but that doesn't mean that something else isn't wrong.)

We then try to contact the proxy to load a page, and cannot. Because we tried to reach the proxy, we report "proxy is refusing connections".

If you're able to test again with your configured proxy, and find out the information I asked for in Comment 11, then we might be able to figure our the root cause. If not, and if this now works for you, then I'll resolve this as INCOMPLETE.

Comment 14

[Kaartic Sivaraam]

Attachment: Picture to illustrate the scenario of the bug

This picture illustrates the scenario in which I fohnd the bug.

Comment 15

[Kaartic Sivaraam]

I think you still don't get my situation. Let me explain it clearly. Please take some time (when you find it)  to read this and understand what is going on.

Details:
I use Firefox Nightly in my laptop in both Windows and Debian.I use Firefox Beta in my Android device. I use "Firefox sync" to sync between the browsers.

Laptop (used proxy previously):
The laptop connects to the Wi-Fi provided by my hostel. The network is monitored to avoid students from accessing inappropriate content. They previously used a "proxy server" for monitoring the network, and switched to "Cyberoam" recently after I filed this bug. Cyberoam seems to be configured to filter content "without the need for a proxy server" (i.e.) we browse through the direct connection, but content gets monitored as usual. 

Mobile (did not use proxy at any time):
I "do not" connect my mobile browser to the hostel Wi-Fi. I "only" use the data service provided by my cellular network service provider, who "does not" use any kind of proxy to provide me the service. My mobile does not connect through a proxy in any way. I also "do not" use a VPN or have any VPN service configured in my device. That said, the possibility of a proxy server in my device is "completely ruled out".

I do not use Firefox sync to sync any other browser other than the above three.

The Scenario:
With Proxy (before filing this bug): 
My laptop was accessing the network through the proxy server and thus "Firefox sync" was syncing through the server. My mobile device used only the "Mobile data" network and without any proxy server involved. I unknowingly tried to load a web page in my Mobile browser(Firefox Beta) without turning on my "Mobile data" and got the "The proxy server is refusing connections" error. This is what puzzled me as there is  no way for a "proxy server" interfering in my mobile and as the other browsers in my mobile (Chrome etc.) do not show such errors.

Without proxy ( a few days after filing this bug):
The started using Cyberoam in the hostel and I removed the proxy server configurations " from my desktop browser's settings. Firefox sync now syncs through a direct connection. I then tried to load a web page without turning on the "Mobile data" and it displayed the "Server not found" error. This makes me doubt Firefox sync.

This is the scenario. I have also attached an image to illustrate what I have said above.

Comment 16

[Kaartic Sivaraam]

I have explained my scenario in the previous comment. I just wanted to know how you were able to configure a "working proxy" to test this bug? By a "working proxy" I mean a proxy server that receives your requests and forwards it to the web correctly and vice versa. A "working proxy"  is the key part of this bug.

Comment 17

[Richard Newman [:rnewman]]

> My mobile does not
> connect through a proxy in any way.

Are you sure? APN configurations can include a proxy server, and it's possible to get these mixed up (e.g., put an MMS proxy in for the general proxy).


> I do not use Firefox sync to sync any other browser other than the above
> three.

Sync absolutely has no way of transferring proxy settings or preferences between desktop Firefox and your mobile device. You might as well cut off the entire left side of your diagram.

The only thing it could do is cause Android OS proxy settings to apply to Firefox, which of course isn't a Firefox bug.


Another way of phrasing your scenario is:

* Before: the wifi at my hostel has a proxy configured. When mobile data is turned off on my phone, I get an error about proxy refusing connections.
* After: they removed the proxy. When mobile data is turned off on my phone, I get "server not found".


As such, the following are the only possibilities:

* Your device is connecting to your hostel wifi. This doesn't mean it's able to load pages, and it doesn't mean that Android will show the wifi icon in the top bar, but the configuration might be live. Based on your detailed scenarios, this is by far the most likely situation.

If you were able to reproduce the proxy error message in Airplane Mode, or with wifi switched off (not just disconnected), and you had connected to an unproxied wifi network prior, in order to 'clean' settings, then we can move on.

* You have a Firefox add-on installed that's using a proxy mechanism.

* You have an application on your device (e.g., syncing wifi credentials) that's applying a proxy configuration to Android.

* You have at some point used a USB/Bluetooth/other hotspot feature to or from your desktop, and it's still involved.


(In reply to Kaartic Sivaraam from comment #16)
> I have explained my scenario in the previous comment. I just wanted to know
> how you were able to configure a "working proxy" to test this bug? By a
> "working proxy" I mean a proxy server that receives your requests and
> forwards it to the web correctly and vice versa. A "working proxy"  is the
> key part of this bug.

Your description confirms that a proxy is only a part of this bug if it's not a Firefox bug! Either the bug is reproducible without a proxy, or you've somehow configured Firefox or Android to use a proxy server, in which case you're getting the correct error message!

Comment 18

[Kaartic Sivaraam]

(In reply to Richard Newman [:rnewman] from comment #17)

> Are you sure? APN configurations can include a proxy server, and it's
> possible to get these mixed up (e.g., put an MMS proxy in for the general
> proxy).
I have checked them anf there id no proxy configuration s in my APN.

> Sync absolutely has no way of transferring proxy settings or preferences
> between desktop Firefox and your mobile device. You might as well cut off
> the entire left side of your diagram.
> 
> The only thing it could do is cause Android OS proxy settings to apply to
> Firefox, which of course isn't a Firefox bug.

Sync "did not" sync my desktops' proxy settings. I am able to browse normally. The problem is only with the error message displayed when my device is offline.

> * You have a Firefox add-on installed that's using a proxy mechanism.
I just now came to know that we could have add-ons in mobile devices too. So, that's not possible.
 
> * You have an application on your device (e.g., syncing wifi credentials)
> that's applying a proxy configuration to Android.
I do not use any such application.

> * You have at some point used a USB/Bluetooth/other hotspot feature to or
> from your desktop, and it's still involved.

It may be a possibility but I can confirm this only if I am able to confirm this only if my desktop browser starts using a proxy server again.

> Your description confirms that a proxy is only a part of this bug if it's
> not a Firefox bug! Either the bug is reproducible without a proxy, or you've
> somehow configured Firefox or Android to use a proxy server, in which case
> you're getting the correct error message!

You know something, I filed this bug only because my mobile was not using any proxy server in any way when I saw that error message. I wanted to know how you set up the "working proxy" for the desktop browser, not for the mobile, because that's what is missing for me now to test this bug. Can you please explain how you tested in Firefox 49 as you have said in Comment 11? That could clear some doubts I have.

Comment 19

[Kaartic Sivaraam]

Please  bear with the typos above. I typed it in my mobile and didn't find it before saving it.

there id. -> there is

Comment 20

[Richard Newman [:rnewman]]

(In reply to Kaartic Sivaraam from comment #18)

> You know something, I filed this bug only because my mobile was not using
> any proxy server in any way when I saw that error message. I wanted to know
> how you set up the "working proxy" for the desktop browser, not for the
> mobile, because that's what is missing for me now to test this bug. Can you
> please explain how you tested in Firefox 49 as you have said in Comment 11?
> That could clear some doubts I have.

You have very strongly asserted that:

* You have never connected your device to your hostel wifi
* You have never configured a proxy on your device
* You have never run an app that touches network configuration
* You have never installed an add-on

… so you have a device that is utterly bone-stock from a network perspective.

We know for sure that Sync doesn't sync proxy configurations, so there's no need to set up an unrelated desktop device with an unrelated proxy on an unrelated network.

The only thing I wanted to verify was: is it possible for Firefox for Android to report a proxy-related error message in such a configuration, when no proxy was configured, particularly if Sync were involved?

As such I did not test any behavior with a proxy configured: I replicated your steps, which is to say I took a device that has never done any of the things above, and I tried to see the error you saw.

I could not reproduce an issue based on the facts you've provided. As such, I can conclude one of two things:

* The facts are missing a step, or
* Your mobile network configuration is not as simple as you say it is.

The only reason I haven't closed this bug as WORKSFORME is because I haven't tested permutations involving configuring then removing proxy settings… but you have asserted that you've never done that.

Comment 21

[Kaartic Sivaraam]

Ok give me some time. I'll come back after clearing certain doubts I have.

Comment 22

[Kaartic Sivaraam]

BTW Thank you @rnewman for patiently handling this problem. I'll reply when I get my doubts cleared. Thanks again.

Comment 23

[Kaartic Sivaraam]

I think I have no other choice than giving up. I tried to bring back the environment in which I saw the error message (i.e.) I tried to set up a proxy server using the software named "FreeProxy" (I could only set up a HTTP proxy using it. I couldn't set up the SOCKS proxy, which was the one used by my hostel) and tried to reproduce the error message ,but I failed. This may be due to the fact that I couldn't set up the complete environment in which I saw the error message (i.e.) The proxy service provided using the software may not have stood up to the one that was provided by the Proxy server used by the hostel previously. Moreover, the type of proxy (HTTP vs SOCKS) used were different. 

Thus there is no other way than to close this bug, as my browsers are now in a completely different environment from the one they were in when I started this bug report and you cannot bring the "The proxy server is refusing connections" error when there is no proxy server in your environment.

Sorry if I have disturbed you a lot (@rnewman) regarding this issue. I didn't expect that the environment would change when I started this bug report.

Comment 24

[Kaartic Sivaraam]

Please close this bug with the appropriate status @rnewman, as I could not find the correct one.

Comment 25

[Richard Newman [:rnewman]]

Thanks for trying to repro!