Virtual network interface limits on Android - Android Software/Hacking General [Developers Only]

Hi,
i have a question: "There is a maximum number of virtual network interfaces in Android?"
Because if i use IW (porting by imlinhao with libnl3) or wpa_supplicant (with wpa_cli) i can create only one network interface.
If i want to create two virtual network interfaces with:
IW i get => command failed: Out of memory (-12)
wpa_supplicant+wpa_cli i get => FAIL and <5>P2P: Failed to add group interface
Where is the problem?
PS: i can't use ip, ifconfig and so on, because the developer of wpa_supplciant said to me that i can't use this softwares for my purposes. It's complicated to explain why, but trust me
In this post i ask only why if i use iw or wpa_supplicant i can't create 2 virtual network interfaces.
Thank u
UPDATE:
I'm sorry, i forgot to say that in wpa_supplicant.conf and p2p_supplicant.conf i'm using "driver_param=use_p2p_group_interface=1" to add more virtual network interfaces. It's important to bypass the driver limitations like: http://wireless.kernel.org/en/developers/p2p/howto where is explained that: "If the driver advertises support, wpa_supplicant will automatically create secondary P2P interfaces. To force this without the driver advertising support, you can add the following to the config file "driver_param=use_p2p_group_interface=1" ".

Related

WiFi and 3g simultaneously Guide - need help following instructions

Hi,
I currently try to follow these instructions...
http://mobisocial.stanford.edu/news...together-by-hacking-connectivityservice-java/
Very hard for me. Don't know what to do.
The goal of COIN project is to use WiFi and 3G connections simultaneously. So it conflicts with the policy of Connectivity Service, but there is no configuration to edit the policy, and it is hard coded. You can find the clue in ConnectivityService.java:handleConnect function.
Our current solution is quite brutal, which is to mask the eyes of Connectivity Service by modifying its message handler entry like the following:
// must be stateless – things change under us.
private class MyHandler extends Handler {
@Override
public void handleMessage(Message msg) {
NetworkInfo info;
//added by COIN to disable Connectivity Service
int networkState = 8; //not any following state
/*use static google dns server for wifi and 3g*/
if (msg.what == NetworkStateTracker.EVENT_STATE_CHANGED) {
SystemProperties.set(“net.dns1″, “8.8.8.8″);
SystemProperties.set(“net.dns2″, “8.8.4.4″);
bumpDns();
}
//////////////////////////////////////////////
//switch (msg.what) {
switch (networkState) {
case NetworkStateTracker.EVENT_STATE_CHANGED:
info = (NetworkInfo) msg.obj;
int type = info.getType();
…..
And then compile the modified ConnectivityService.java in the android source code tree, you can get an new services.jar file in framework directory. Replace the existing services.jar on the cell phone with the following adb commands, then reboot the phone
adb shell “mount -o rw,remount -t yaffs2 /dev/block/mtdblock3 /system”
adb shell “chmod 0777 /system/framework”
adb push services.jar /system/framework
adb shell “chmod 0644 /system/framework/services.jar”
adb shell “chmod 0755 /system/framework”
Click to expand...
Click to collapse
Does he mean I have to compile the whole Android source code again?
So I would need to learn first, how to compile Android, then change this file, compile Android, copy file?
Instant of adb shell, could I also use root explorer?
How device dependant is this? Or how android version dependant?
Could someone offer the compiled file?
No answer yet.
I believe so. This is actually what compelled me to go learn to compile android by myself-- the constant switching between 3g and wifi in a semi-strong wifi zone sucks. For now I am starting with CM7 since it is so popular.
Yes you would need to compile the whole OS and it will only work on an AOSP rom. It will also be very version dependent.
Please let me know if it worked ! I probably don't think it will. Read this on the page:
Pallas Says:
April 13, 2012 at 5:58 am
are you sure the packets are going thru both interfaces?
I think it doesn’t work, simply because you would need two default gateways, leading to some hard problems:
- how does the system choose where to send the packets?
- for outgoing packets: unless the two connections have both statically assigned public IP addresses, which is very unlikely, you will end up with two differently NATed paths, and the client will refuse packets coming from two different ip addresses on the same connection.
- for incoming packets: to let the client send packets to both interfaces, you would need to send them from both interfaces with different source ip addresses: it will not work, the client will get confused. and anyway you would need support at the application level.
to solve all this, you’d need to:
- make an ad-hoc application which understands all this and can send chuncks to both interfaces, then merge all the returning chunks. you’d need support at the application level: for example you’d need http byte range support on both client and server
- divide “equally” the single specific connections thru the two gateways. this may work but it’s pretty hard if you do not have access to advanced routing and traffic shaping at the kernel level. may be possible on a phone with custom compiled aosp rom and modified kernel
gouthamsn said:
Please let me know if it worked ! I probably don't think it will. Read this on the page:
Pallas Says:
April 13, 2012 at 5:58 am
are you sure the packets are going thru both interfaces?
I think it doesn’t work, simply because you would need two default gateways, leading to some hard problems:
- how does the system choose where to send the packets?
- for outgoing packets: unless the two connections have both statically assigned public IP addresses, which is very unlikely, you will end up with two differently NATed paths, and the client will refuse packets coming from two different ip addresses on the same connection.
- for incoming packets: to let the client send packets to both interfaces, you would need to send them from both interfaces with different source ip addresses: it will not work, the client will get confused. and anyway you would need support at the application level.
to solve all this, you’d need to:
- make an ad-hoc application which understands all this and can send chuncks to both interfaces, then merge all the returning chunks. you’d need support at the application level: for example you’d need http byte range support on both client and server
- divide “equally” the single specific connections thru the two gateways. this may work but it’s pretty hard if you do not have access to advanced routing and traffic shaping at the kernel level. may be possible on a phone with custom compiled aosp rom and modified kernel
Click to expand...
Click to collapse
(Probably for your Interest
This project works on a MultiPath-TCP Implementation (follow link to mptcp.info.ucl.ac.be). The hard times you get is compiling the Kernel with the additional files. This Protocol can only work effectively for download Purposes if the Server also has a MPTCP Kernel running. But on the other Hand you can shut down a single connection without loosing the active Connection (Downloads are not interrupted and improved Bandwidth Capacity if your Server is MPTCP-Ready)
Until now this Protocol is only working for Homeservers or similar Projects, where you have full access to the Server and the working Kernel of the system.
I am currently working on implementation of the Protocol for my Bachelor Thesis. I already compiled a working Kernel (Glados Nexus S) and now i'm working on keeping both Interfaces active. I hope this Tut can help me...
Has anybody tried other approaches to this topic? I tried manually loading the wifi-module and configuring it, but i only managed to ping via one Interface.
You managed to make it work?
bagers said:
No answer yet.
Click to expand...
Click to collapse
You managed to make it work? i want to make it also for my master thesis

[Q] Link Bonding in Ubuntu Server 11.04

This isn't related to phones but Does anyone here have experience with bonding ethernet links in Ubuntu Server 11.04? I've searched the Ubuntu forums and get mixed answers.
I have a server which I do Netflow collection on (I'm a Network Engineer). Server has (4) 3Ghz Quad-Core processors, 24Gb of RAM, and 700Gb of disk space along with an NFS mount of 1Tb for backups of the data.
The server also has (4) 1Gbps ethernet interfaces which I would like to bond together and connect to a Cisco switch using LACP (etherchannel) to make them all function as 1 4gig link.
I got the bond interface setup and was able to get the etherchannel on the switch up but can't hit the main IP address of the bond0 interface. I have the slave interface statements set in the interface config. Do I need to give it a master interface in the interface config? Below is my configuration. I'm hoping that one of the Devs here can help being that many of you use Ubuntu for development. I have the bond0 config commented out until i can get this functioning correctly. Eth2 is my primary interface. Thanks:
[email protected]:/etc/network# more interfaces
#This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).
#auto bond0
#iface bond0 inet static
#address 10.255.6.79
#netmask 255.255.255.0
#network 10.255.6.0
#gateway 10.255.6.1
#bond-slaves eth0 eth1 eth3
#LACP configuration
#bond_mode 802.3ad
#bond_miimon 100
#bond_lacp_rate 1
# The loopback network interface
auto lo
iface lo inet loopback
# The primary network interface
auto eth2
iface eth2 inet static
address 10.255.6.79
netmask 255.255.255.0
network 10.255.6.0
broadcast 10.255.6.255
gateway 10.255.6.1
# dns-* options are implemented by the resolvconf package, if installed
dns-nameservers 10.255.6.217 10.255.6.218

Setting up OpenVPN on VPS server, and on ICS/GB clients

Warning: This configuration no longer works for me. Try at your own risk.
Who is this for?:
People who are comfortable installing servers but still need a little bit of spoon-feeding at times. People who already have a VPS and want to use it as a VPN for privacy purposes or to bypass a firewall. If you don't use ICS, your phone needs to be rooted.
I just spent a few hours figuring out VPN issues and want to share the fruits of my labor. This is for people with a server who want to set up both the server and the client. Goal: route all your internet traffic through your server when the VPN is active. You need a VPS or dedicated server to do this. I went with OpenVPN because PPTP VPNs don't work with some ICS roms. I don't know a lot about networking issues, so I can probably help with some linuxy-server setup issues, but a lot of networking is beyond my grasp.
Server config:
The hard part was the server config, which I found helpful information for on two pages. OpenVPN must be installed, and then you must generate keys and a little bit of data for the server. I used instructions here (but if you search for "server generate openvpn keys", there should be a lot of tutorials). On my system the "init-config" command didn't exist, so I basically skipped that step. When finished, copy client1.crt, client1.key, and ca.crt to the phone.
I had a really hard time with the config file, but this little bug report was a fantastic resource. I ended up with the following config file:
Code:
dev tun
server 10.8.0.0 255.255.255.0
ca /etc/openvpn/keys/ca.crt
cert /etc/openvpn/keys/server.crt
key /etc/openvpn/keys/server.key
dh /etc/openvpn/keys/dh1024.pem
verb 5
push "redirect-gateway def1"
push "dhcp-option DNS 8.8.8.8"
push "dhcp-option DNS 8.8.4.4"
keepalive 10 60
ping-timer-rem
persist-tun
persist-key
comp-lzo
status /var/log/openvpn-status.log
log /var/log/openvpn.log
log-append /var/log/openvpn.log
The DNS servers I'm using are google's. OpenDNS would be another good choice.
ICS instructions:
Install OpenVPN for Android. Open it, click "All your precious VPNs", add one and configure it. In the "basic" section, choose your server's hostname. For "type", choose "Certificates". Below that, select "ca.crt", "client1.crt", and "client1.key" in order. (Choose them with the file picker then press the "Select" button.) These are the files you generated on the server and copied to the phone. No other options need to be changed. Press "back" to save and touch the name of the configuration you've created. Enjoy your VPN-based browsing!
Gingerbread instructions (or ICS if you like pain):
Your device needs to be rooted with busybox and kernel tunneling capability. If you're running a popular rooted ROM, you probably have all you need. Install OpenVPN Installer and OpenVPN Settings. Run OpenVPN Installer and install the OpenVPN executable (please read the instructions--this may not work if your phone does not have the file /system/xbin/busybox).
Remember the files I told you to copy to your phone? Put them in /sdcard/openvpn/. Here's the client configuration file I used, which you should save as /sdcard/openvpn/openvpn.conf:
Code:
remote YOUR-SERVER.com
dev tun
client
keepalive 10 60
ping-timer-rem
persist-tun
persist-key
comp-lzo
ca ca.crt
cert client1.crt
key client1.key
mute-replay-warnings
Then open the OpenVPN Settings app and check the two checkboxes to start the server and start the tunnel. Enjoy your VPN-based browsing!
To check whether it worked:
Use a browser to visit whatismyipaddress.com. The result that's displayed should be the IP address of your server.
Any way to make this work with http://tunlr.net/
Sorry, Tunlr.net is not related to OpenVPN.

[APP][4.0+][v1.11 - 20150221] OpenConnect - SSL VPN client for Cisco AnyConnect

Highlights
100% open source (GPLv2+)
No ads
One-click connection (batch mode)
Supports RSA SecurID and TOTP software tokens
Keepalive feature to prevent unnecessary disconnections
Compatible with ARMv7, x86, and MIPS devices
No root required
Based on the popular OpenConnect Linux package
Click to expand...
Click to collapse
Requirements
Android 4.0 (ICS) or higher (with working VpnService + tun infrastructure)
An account on a suitable VPN server
Click to expand...
Click to collapse
Downloads
Binaries are attached to this post under the downloads tab.
Google Play: https://play.google.com/store/apps/details?id=app.openconnect
Source code: https://github.com/cernekee/ics-openconnect
F-Droid: https://f-droid.org/repository/browse/?fdid=app.openconnect
Click to expand...
Click to collapse
(note that the F-Droid binaries are signed by a different key than the official releases)
Changelog
Code:
v1.11 - 2015/02/21
- Fix "Unknown compression type 0" errors when CSTP and DTLS use
different compression settings
Older changelogs:
Code:
v1.10 - 2015/02/08
- Fix CSD script problem on Lollipop (bug #1)
- Fix IPv6 address display on status window (bug #2)
- Enable LZ4 compression support
- Identify as a mobile client when Android or iOS is selected
- Update to OpenConnect v7.04+, GnuTLS 3.2.21
v1.02 - 2014/09/02
- Fix regression on certificate handling
v1.01 - 2014/08/29
- Add Spanish translations (thanks to teosoft)
- Fix regression on CSD scripts starting with "#!/bin/sh"
- Improve error messages on broken ROMs that throw exceptions when
starting a VpnService
- Fix intermittent fragment-related crashes on ICS
v1.00 - 2014/08/10
- Fix problems storing >8kB certificates on some ROMs
- Clean up seldom-used menu items and move some options into General Settings
or About
- Integrate Xposed module for bypassing the VPN confirmation dialog
- Switch to ACRA for problem reporting
v0.96 - 2014/07/06
- Force a minimum MTU of 1280 on KK due to bugs in 4.4.3 and 4.4.4 ROMs:
https://code.google.com/p/android/issues/detail?id=70916
- Fix navigation anomalies (weird Back button behavior) seen after
re-entering OpenConnect from one of the Notifications
v0.95 - 2014/06/14
- Show the auth dialog <message> text in case it contains useful information
- Add German translations (thanks to Ingo Zansinger <[email protected]>)
- Add Chinese translations
- Add Advanced options for changing Dead Peer Detection timeout and enabling Perfect Forward Secrecy
- Clean up a bunch of lint warnings and unused strings/files
- Try to generate a human-readable profile name when adding a new VPN
v0.91 - 2014/06/01
- Fix bugs involving saved authgroups
- Fix batch mode error handling
- Update to GnuTLS 3.2.15 to fix GNUTLS-SA-2014-3 / CVE-2014-3466
v0.9 - 2014/04/26
- Add new "Send feedback" screen
- Add new "SecurID info" screen for RSA soft token users
- Allow changing settings and using other menu options (about, SecurID,
send feedback, etc.) while connected
- Update FAQ and provide some links to relevant XDA posts
v0.81 - 2014/04/06
- Fix potential issue recognizing certificates stored in VPN profiles
created with <= v0.7
v0.8 - 2014/04/02
- Fix hangs after reconnect if DTLS is disabled
- Fix incorrect storage of PKCS#12 certificates
- Remove unnecessary passphrase prompts on unencrypted certificates
- Add a workaround for ASA certificate request quirks
- Fix FC when attempting to import an OpenVPN profile
v0.7 - 2014/03/08
- Update GnuTLS to address CVE-2014-0092
- Fix FC and other misbehavior on IPv6 connections
- Update to libopenconnect 5.99+
- Fix/delete several broken translations
- Minor improvements to the auth form UI
- Switch curl from OpenSSL to GnuTLS and remove advertising clauses
v0.6 - 2014/02/09
- First release in Google Play Store
- Change to new "big O" launcher icon
- Avoid displaying error alerts if the user terminated the connection
- Try to make the libopenconnect build process more robust, and strip *.so
files to conserve space
v0.5 - 2014/02/01
- Fix "living dead" connections (can't pass data after reconnection due to
DTLS parameter mismatches)
- Add FAQ tab in response to user feedback
- Move log window into a tab
- Reorganize action bar so that the most important items (Status/Log/FAQ)
are tabs, and less important items (Settings/About) are in the menu
- Fix KeepAlive socket errors on KitKat devices
- Other UI and documentation fixes
- Add split tunnel configuration options
- Improve icons
v0.2 - 2014/01/18
- Allow SecurID token import via URI or text file
- Newly reworked "status" tab with uptime, error alerts, IP addresses,
etc.
- Fix a couple of bugs involving screen rotation / activity redraw on
the log window
- Prompt for hostname instead of profile name when adding a new VPN, to
help avoid "empty hostname" mistakes
- Numerous other UI improvements and fixes
- Remove "reconnect on boot" until it works properly
- Try to accommodate Linux CSD wrapper scripts starting with "#!/bin/bash"
Click to expand...
Click to collapse
FAQ
Q: What is this app used for?
A: OpenConnect is used to access virtual private networks (VPNs) which utilize the Cisco AnyConnect SSL VPN protocol. A typical use case might involve logging into your workplace remotely to check email after hours.
If in doubt, check with your I.T. administrator to see if a suitable service is available.
Q: How do I get started?
A: In most cases, you'll just need to create a profile and enter the hostname of the VPN gateway. The other fields in the profile are all optional and should be left alone unless there is a specific need to change them.
Once you've set up the profile, select the VPN entry and OpenConnect will attempt to establish a new session. If this fails, the "Log" tab may provide helpful diagnostic information.
Q: How do I authenticate using an SSL client certificate?
A: Copy your certificate files to Android's external storage directory (nominally /sdcard or the Downloads folder), then edit the VPN profile and make the following changes:
P12 or PFX file: select "User certificate", pick the file from the list, then touch "select". Leave "Private key" blank.
Single PEM/CRT/CER file: same as above.
Separate PEM/CRT/CER and KEY files: populate "User certificate" with the certificate file, and "Private key" with the key file.
When finished, delete the certificate files from external storage so they cannot be stolen by other apps.
If you are generating your own keys (e.g. for use with your ocserv gateway), some basic CA setup instructions are posted here.
Q: Will OpenConnect work with non-AnyConnect VPNs?
A: Unfortunately the software design is tied very closely to the AnyConnect requirements and the libopenconnect interfaces. Therefore it only works with Cisco AnyConnect and ocserv gateways.
Q: Will OpenConnect work with Cisco IPsec VPNs running on an ASA?
A: OpenConnect supports SSL VPN (CSTP + DTLS) only.
Q: How do I import a SecurID software token?
A: If you have an URL that starts with "com.rsa.securid.iphone://" or "http://127.0.0.1/securid/" in your email, click on it and tell OpenConnect to add it to the desired VPN profile. If you just have a raw token string then write it to a text file, copy it under /sdcard, click "Token string" in the VPN profile editor, then select the filename.
If you have an "sdtid" XML file, copy it to /sdcard and then import it.
Q: Is it possible to skip all login prompts when connecting?
A: If you have saved your username, password, or other credentials, or if you are using SecurID or certificate authentication, you can try enabling "Batch Mode" in the VPN profile to skip the login dialogs. If you need to change your saved password later or have trouble connecting, just disable batch mode.
The VPN warning dialog is a security feature built into the Android OS. It cannot be bypassed by OpenConnect, but if your device is rooted, you can try installing the Xposed Framework and then activating the Auto VPN Dialog Confirm module. Some notes on this are posted here.
Due to the user interaction required by these dialogs, it is not always possible to reliably start up the VPN in the background. So a "start-on-boot" feature is not currently provided.
Q: How do I improve battery life while the VPN is up?
A: One option is to select "Pause when asleep" under Settings. The downside is that VPN access will be temporarily stopped when the screen is off. Also, ASA gateways sometimes get annoyed with constant reconnections and may prematurely terminate your session after a few days.
Another option is to contact your server administrator and request that they disable dead peer detection (DPD), increase the idle timeout to >1hr, and increase the keepalive interval to ~5min or so.
Q: How do I use OpenConnect with AFWall+?
A: There are a few caveats to keep in mind when using an Android firewall with VPN:
* If you run KitKat, use Android 4.4.2 or higher and AFWall 1.2.8 or higher. Android 4.4 and 4.4.1 have a serious TCP MSS bug which causes stalled connections and/or poor performance. AFWall <=1.2.7 does not have the extra logic needed to handle the routing changes in KitKat.
* Always allow traffic from the VPN app on all interfaces. In particular, you should whitelist VPN traffic from OpenConnect, as OpenConnect sends DNS requests over the VPN interface every few minutes to help keep the connection from timing out.
Q: Are any apps incompatible with VPN?
A: Apps which perform their own DNS resolution, such as Firefox, may have issues picking up the latest system DNS settings when connecting to the VPN. This can be a problem if your system DNS servers are not accessible over the VPN's routes, or if you are trying to look up hostnames that do not have public (internet) DNS entries.
Q: Under what circumstances will OpenConnect request root?
A: There are two root-only features shown under Settings; both are disabled by default. One setting works around a ROM bug in CM9 which sets incorrect permissions on /dev/tun, preventing VpnService from passing traffic to the tunnel interface; the other setting loads tun.ko on ROMs that neglect to load it by default.
Based on user feedback and testing, future releases may autodetect these conditions.
Q: How do I send a problem report?
A: Navigate to Log -> (menu) -> Send log file. Please be sure to furnish a complete, accurate description of the issue you are seeing, as the logs do not always show a smoking gun.
Click to expand...
Click to collapse
TODO
Translations - I will set up the necessary infrastructure if there are volunteers
Compatibility testing
Add x509 certificate parsing/validation in the profile editor
Enable Android keystore support
Proxy support
Split tunnel DNS?
Click to expand...
Click to collapse
MISC
Using OpenConnect + ocserv (on a VPS) to bypass China's Great Firewall (GFW): link
XDA:DevDB Information
OpenConnect, App for the Android General
Contributors
cernekee
Source Code: https://github.com/cernekee/ics-openconnect
Version Information
Status: Testing
Created 2014-01-18
Last Updated 2015-02-21
hello cernekee,
I was using smoothconnect on my note3 and It was working just fine, but now after I update my note3 to kitkat it surfs only couple of things like "play store", google search, and whatsup. but all other web sites and programs do not!!
now I tried out this program "open connect" with some hope but nope, I does the same thing. It only opens play store and google search but no other things.
I wonder what cause this problem, any suggestions please??
msm88now said:
hello cernekee,
I was using smoothconnect on my note3 and It was working just fine, but now after I update my note3 to kitkat it surfs only couple of things like "play store", google search, and whatsup. but all other web sites and programs do not!!
now I tried out this program "open connect" with some hope but nope, I does the same thing. It only opens play store and google search but no other things.
I wonder what cause this problem, any suggestions please??
Click to expand...
Click to collapse
Sometimes an MTU or TCP MSS problem could cause this symptom. What kind of gateway are you connecting to? Are you the admininstrator?
Older versions of KitKat did have an MSS problem; I think 4.4.1+ is OK: https://code.google.com/p/android/issues/detail?id=61948
There are a few other outstanding problems on <= 4.4.2: http://www.androidpolice.com/2014/0...n-routing-fixes-are-planned-for-some-of-them/
Do you see the same problem connecting from other systems, like a Windows PC, or even the Cisco AnyConnect Android app?
Hi cernekee,
I have an openSSL Cisco vpn connection provided by my university, I hooked it with D-615 Dlink router through DHCP.
Cisco AnyConnect for andriod does not work on our university network because it asks for a certificate which my uni does not provide. that's why I'm using smoothconnect.
anyways, right now I have a flawless connection on my all devices on my room's wireless like my both Win7 laptops and my galaxy S2 andriod 4.1.2.
all work except my note 3 after I updated it to (4.4.2). I don't know if it's a IPv6 or MTU problem,
I tried to decrease MTU value in smoothconnect but with no success. as Cisco stated in: AnyConnect Android 4.4 (KitKat) Compatibility Update (CSCul28340)
any suggestions please???
msm88now said:
Hi cernekee,
I have an openSSL Cisco vpn connection provided by my university, I hooked it with D-615 Dlink router through DHCP.
Cisco AnyConnect for andriod does not work on our university network because it asks for a certificate which my uni does not provide.
Click to expand...
Click to collapse
I don't see this university's VPN requesting a certificate (i.e. SSL client cert). It just asks for a group/username/password.
Are you getting an error that says that the gateway is not licensed for mobile, after you enter your password?
that's why I'm using smoothconnect.
anyways, right now I have a flawless connection on my all devices on my room's wireless like my both Win7 laptops and my galaxy S2 andriod 4.1.2.
all work except my note 3 after I updated it to (4.4.2). I don't know if it's a IPv6 or MTU problem,
I tried to decrease MTU value in smoothconnect but with no success. as Cisco stated in: AnyConnect Android 4.4 (KitKat) Compatibility Update (CSCul28340)
any suggestions please???
Click to expand...
Click to collapse
Can you grab a packet capture when you're seeing the connectivity failures, and email me the result? e.g.
Code:
adb push tcpdump /data/local/tmp
adb shell
cd /data/local/tmp
su
chmod 755 tcpdump
./tcpdump -n -i tun0 -w out.pcap
yes that's right, Cisco anyconnect asks only for username/ password but when I try to start a connection it ends up with no license error!
that's way I'm using smoothconnect and now openconnect on my both andriod phones.
now for my problem, I didn't get what do you mean by connectivity failure because I'm not getting any connectivity failure messages on my note3 after update to 4.4.2 neither on smoothconnect nor on openconnect. it connects as usual and I can see some traffic packets are being transfered but I can only surf google serch, youtube and some other stuff like play store and whatsup. whenever I try to surf any other website like for example bbc news the browser( chrome, opera, Dolfin..) just waits and then ends up with nothing like there is no internet connection!
did I explain my problem clearly? is it an Ipv6 problem? I'm really confused and frustrated
msm88now said:
yes that's right, Cisco anyconnect asks only for username/ password but when I try to start a connection it ends up with no license error!
Click to expand...
Click to collapse
OK. This is because the Cisco mobile clients look for an "X-CSTP-License: accept" header from the gateway after authenticating, to see if the operator has paid extra to support the Cisco mobile client. libopenconnect-based clients (including SmoothConnect) do not require this header.
now for my problem, I didn't get what do you mean by connectivity failure because I'm not getting any connectivity failure messages on my note3 after update to 4.4.2 neither on smoothconnect nor on openconnect. it connects as usual and I can see some traffic packets are being transfered but I can only surf google serch, youtube and some other stuff like play store and whatsup. whenever I try to surf any other website like for example bbc news the browser( chrome, opera, Dolfin..) just waits and then ends up with nothing like there is no internet connection!
Click to expand...
Click to collapse
I can take a look at this to see what is happening. Just start up tcpdump to capture the tun0 traffic (see above instructions), then try visiting the BBC news site and maybe a few other non-working sites. Then hit control-C to interrupt tcpdump, make sure there is some data in the pcap file, and email me the pcap file.
cernekee said:
I can take a look at this to see what is happening. Just start up tcpdump to capture the tun0 traffic (see above instructions), then try visiting the BBC news site and maybe a few other non-working sites. Then hit control-C to interrupt tcpdump, make sure there is some data in the pcap file, and email me the pcap file.
Click to expand...
Click to collapse
Hi,
I don't know how to make Tcpdump on my note3 not to mention hitting the control-c on andriod. what instruction did you mean?
msm88now said:
I don't know how to make Tcpdump on my note3 not to mention hitting the control-c on andriod. what instruction did you mean?
Click to expand...
Click to collapse
Do you have a friend who is familiar with ADB, rooting phones, etc. who might be able to help out in person?
You could also try something like Shark for Root, or follow this video. Make sure you capture on the tun0 interface so that we can see what is happening on the VPN tunnel. If you capture from the wifi interface you'll still see traffic, but everything will be encrypted so it will not be possible to diagnose the failure.
I got it. first I rooted my note3 then I followed the instruction in the video and here it is, I hope it's what you asked me for. waiting for your diagnosis, fingers crossed
msm88now said:
I got it. first I rooted my note3 then I followed the instruction in the video and here it is, I hope it's what you asked me for. waiting for your diagnosis, fingers crossed
Click to expand...
Click to collapse
According to this trace (partial screenshot attached), the Note 3 is advertising an MSS of 1460 bytes on IPv4 TCP connections. This looks abnormally high for a VPN interface; the other direction is using an MSS of 1380, which looks more realistic. The MSS for IPv4 would normally be the tun0 MTU minus 40 bytes. I am assuming this means the MSS is being computed from the 1500-byte wlan0/eth0 MTU, not the smaller tun0 MTU.
When Google fixed the MSS bug in Android 4.4.1, they left the following comments in the changelog:
Code:
commit ca5b4e8d0d8219273ecf0961ed6e8c47ab5d798a
Author: JP Abgrall <[email protected]>
Date: Wed Nov 20 17:27:01 2013 -0800
SecondaryTableController: force the MSS to match pmtu on TCP SYN
Without this change, the VPN sets up a tun/ppp that needs a small
MTU, and during TCP SYN the MSS will end up matching the outgoing iface
MTU which is potentially too big.
This leads to connection flakiness. The wrong MSS is visible by
tcpdump-ing on the tun/ppp device.
With this change, the MSS now is correct.
[b]It requires the kernel to be configured with
CONFIG_NETFILTER_XT_TARGET_TCPMSS=y
If kernel is not configured, it silently fails.[/b]
Bug: 11579326
Change-Id: I254d8c39435b92dff91931e461e1efb8b35f6b1e
Note the bolded sentences (emphasis mine). I suspect that your device is running the latest AOSP netd code that has the fix (if the ROM is indeed based on AOSP 4.4.1/4.4.2), but the kernel may be missing the TCPMSS target. If you see an error when running this command as root, it probably means that kernel support is missing:
Code:
iptables -t mangle -A POSTROUTING -p tcp --tcp-flags SYN SYN -d 1.2.3.4 -j TCPMSS --clamp-mss-to-pmtu
Toward the bottom of the page on the original Android 4.4 MSS bug report I see a couple of reports from other Note 3 owners that the problem still isn't fixed for them, so it may be something particular to this device (such as the kernel configuration).
I do not see any evidence of IPv6 usage in your log, which rules out some of the known 4.4.2 VPN issues.
If this does turn out to be a kernel problem, you can try a custom kernel from XDA (assuming you can unlock your bootloader), or you could file a bug report with Samsung asking them to enable CONFIG_NETFILTER_XT_TARGET_TCPMSS=y in the next OTA update. From their end this is a simple, low-risk change.
cernekee;
Note the bolded sentences (emphasis mine). I suspect that your device is running the latest AOSP netd code that has the fix (if the ROM is indeed based on AOSP 4.4.1/4.4.2) said:
iptables -t mangle -A POSTROUTING -p tcp --tcp-flags SYN SYN -d 1.2.3.4 -j TCPMSS --clamp-mss-to-pmtu
[/code]
Toward the bottom of the page on the original Android 4.4 MSS bug report I see a couple of reports from other Note 3 owners that the problem still isn't fixed for them, so it may be something particular to this device (such as the kernel configuration).
I do not see any evidence of IPv6 usage in your log, which rules out some of the known 4.4.2 VPN issues.
If this does turn out to be a kernel problem, you can try a custom kernel from XDA (assuming you can unlock your bootloader), or you could file a bug report with Samsung asking them to enable CONFIG_NETFILTER_XT_TARGET_TCPMSS=y in the next OTA update. From their end this is a simple, low-risk change.
Click to expand...
Click to collapse
as you can see in the attachment I applied the code with no error message. so in this case I assume I have no problem with the kernel? right?
then what causes the problem? and what can I do in order to solve it?
msm88now said:
as you can see in the attachment I applied the code with no error message. so in this case I assume I have no problem with the kernel? right?
then what causes the problem? and what can I do in order to solve it?
Click to expand...
Click to collapse
Can you connect to the VPN, try to access a few "bad" sites, and then post the full output from:
Code:
su
iptables -t mangle -nxvL
cernekee said:
Can you connect to the VPN, try to access a few "bad" sites, and then post the full output from:
Click to expand...
Click to collapse
here is the output after some bad sites access, I also repeated the provisos code during an openconnect session. hope it will help us.
msm88now said:
here is the output after some bad sites access
Click to expand...
Click to collapse
Hmm, on my KitKat device I have an st_mangle_POSTROUTING chain which does the TCPMSS clamping:
Code:
Chain st_mangle_POSTROUTING (1 references)
pkts bytes target prot opt in out source destination
0 0 TCPMSS tcp -- * tun0 0.0.0.0/0 0.0.0.0/0 tcpflags: 0x06/0x02 TCPMSS clamp to PMTU
I did not see this in your output. Maybe Samsung is using an outdated version of netd.
Try running this command as root after bringing up the VPN and see if you are able to pass traffic with the bad sites:
Code:
iptables -t mangle -A POSTROUTING -p tcp -o tun0 --tcp-flags SYN,RST SYN -j TCPMSS --clamp-mss-to-pmtu
If not, post the new "iptables -t mangle -nxvL" output so we can look at the traffic counters.
Also can you attach your /system/bin/netd binary?
Thanks.
cernekee;
Try running this command as root after bringing up the VPN and see if you are able to pass traffic with the bad sites:
[code said:
iptables -t mangle -A POSTROUTING -p tcp -o tun0 --tcp-flags SYN,RST SYN -j TCPMSS --clamp-mss-to-pmtu
Click to expand...
Click to collapse
are kidding me!! it really worked. after I run the the code I tried to access all the bad sites and all of them worked!! but not as fast as my other mobil SG2. I noticed that it takes noticably much longer to access them. but still, It worked and It's fantastic!!
any ways, I rebooted my note3 to see if it will work again but it turned out it didn't! I need to re-enter the code again to make it work. now could you tell me what is my phones problem exactly? despite the re-entering issue I'm very happy that I finally can use internet on my note3 again thanks to you cernekee.
msm88now said:
any ways, I rebooted my note3 to see if it will work again but it turned out it didn't! I need to re-enter the code again to make it work. now could you tell me what is my phones problem exactly?
Click to expand...
Click to collapse
The ROM is supposed to add that rule automatically, but it doesn't.
If you attach your /system/bin/netd binary and output from "getprop" I'll try to figure out why.
cernekee said:
The ROM is supposed to add that rule automatically, but it doesn't.
If you attach your /system/bin/netd binary and output from "getprop" I'll try to figure out why.
Click to expand...
Click to collapse
here I attached them.
I posted a problem report on Samsung's support forum:
http://developer.samsung.com/forum/...&messageId=259244&listLines=15&startId=zzzzz~
Works like a charm with the lastest Slimkat on Nexus 4. Thanks a lot !
Just add a widget to one click connect from the launcher and it will be the best VPN apps that I've use.
Today I've a Tasker task to launch Anyconnect with uri and simulate touchs screen to automate my connection.
@ edit :
Is there a way to don't have the attached screen ?

How to disable ICMP redirects? [Guide]

Surprised nobody did a thread about this, so let me be the first one.
Lets start of what I mean with the title:
http://en.wikipedia.org/wiki/Internet_Control_Message_Protocol#Redirect
The Internet Control Message Protocol (ICMP) is one of the main protocols of the Internet Protocol Suite. It is used by network devices, like routers, to send error messages indicating, for example, that a requested service is not available or that a host or router could not be reached.
Click to expand...
Click to collapse
Now, there is a relatively interesting named attack called "DoubleDIrect".
Link to article :
Link
So what is it? A Man in the middle attack,
“Man-in-the-Middle” attack (MITM) enabling an attacker to redirect a victim’s traffic to the attacker’s device. Once redirected, the attacker can steal credentials and deliver malicious payloads to the victim’s mobile device that can not only quickly infect the device, but also spread throughout a corporate network.
Click to expand...
Click to collapse
There is a trick you can use to disable ICMP redirects to your phone, linux laptop or even windows laptop, to prevent this exploit.
For android you need root and a terminal app.
So, firstly write su
su
then write
echo 0 > /proc/sys/net/ipv4/conf/all/accept_redirects
If you want to check if you have disabled it, all you need to do is write.
cat /proc/sys/net/ipv4/conf/all/accept_redirects
it should answer with 1 if its enabled or 0 if it isnt.
This only works until you restarted your phone. So, best to create a sh file and run it automatically.
I have created a sh, just incase I need to enable or disable it.
The same thing goes for linux if you have a linux machine
For windows, open regedit:
go to HKEY_LOCAL_MACHINE > SYSTEM > currentcontrolset >Services > Tcpip > parameters
and then there is a reg dword called enableICMPredirects, open it and change the value to 0.
The attackers are not only sniffing all the DNS traffic of the victim, but everything that is resolved through it.
Who is at risk?
Quote from the article:
– iOS: The attack works on latest versions of iOS including iOS 8.1.1
– Android: On most Android devices. Including Nexus 5 + Lollipop
– Mac: Mac OS X Yosemite is vulnerable.
Most of GNU/Linux and Windows desktop operating system do not accept ICMP redirect packets.
Click to expand...
Click to collapse
My xperia Z ultra , running 4.4.4 anrdoid kitkat, was vulnerable to this exploit just as my windows 8.1 notebook.
Stay safe!
Edit: if you somehow manage to brick your phone during the rooting process or this, I am not responsible.

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