GoodbyeDPI README

The project's README from github.com/ValdikSS/GoodbyeDPI. As one markdown file: README.md.

GoodbyeDPI — Deep Packet Inspection circumvention utility

This software designed to bypass Deep Packet Inspection systems found in many Internet Service Providers which block access to certain websites.

It handles DPI connected using optical splitter or port mirroring (Passive DPI) which do not block any data but just replying faster than requested destination, and Active DPI connected in sequence.

Windows 7, 8, 8.1, 10 or 11 with administrator privileges required.

Quick start

These scripts launch GoodbyeDPI in recommended mode with DNS resolver redirection to Yandex DNS on non-standard port (to prevent DNS poisoning).
If it works — congratulations! You can use it as-is or configure further.

How to use

Download latest version from Releases page and run.

Supported arguments

To get relevant information about your version of the program, use the -h (--help) argument at startup.

Usage: goodbyedpi.exe [OPTION...]
 -p          block passive DPI
 -q          block QUIC/HTTP3
 -r          replace Host with hoSt
 -s          remove space between host header and its value
 -m          mix Host header case (test.com -> tEsT.cOm)
 -f <value>  set HTTP fragmentation to value
 -k <value>  enable HTTP persistent (keep-alive) fragmentation and set it to value
 -n          do not wait for first segment ACK when -k is enabled
 -e <value>  set HTTPS fragmentation to value
 -a          additional space between Method and Request-URI (enables -s, may break sites)
 -w          try to find and parse HTTP traffic on all processed ports (not only on port 80)
 --port        <value>    additional TCP port to perform fragmentation on (and HTTP tricks with -w)
 --ip-id       <value>    handle additional IP ID (decimal, drop redirects and TCP RSTs with this ID).
                          This option can be supplied multiple times.
 --dns-addr    <value>    redirect UDP DNS requests to the supplied IP address (experimental)
 --dns-port    <value>    redirect UDP DNS requests to the supplied port (53 by default)
 --dnsv6-addr  <value>    redirect UDPv6 DNS requests to the supplied IPv6 address (experimental)
 --dnsv6-port  <value>    redirect UDPv6 DNS requests to the supplied port (53 by default)
 --dns-verb               print verbose DNS redirection messages
 --blacklist   <txtfile>  perform circumvention tricks only to host names and subdomains from
                          supplied text file (HTTP Host/TLS SNI).
                          This option can be supplied multiple times.
 --allow-no-sni           perform circumvention if TLS SNI can't be detected with --blacklist enabled.
 --frag-by-sni            if SNI is detected in TLS packet, fragment the packet right before SNI value.
 --set-ttl     <value>    activate Fake Request Mode and send it with supplied TTL value.
                          DANGEROUS! May break websites in unexpected ways. Use with care (or --blacklist).
 --auto-ttl    [a1-a2-m]  activate Fake Request Mode, automatically detect TTL and decrease
                          it based on a distance. If the distance is shorter than a2, TTL is decreased
                          by a2. If it's longer, (a1; a2) scale is used with the distance as a weight.
                          If the resulting TTL is more than m(ax), set it to m.
                          Default (if set): --auto-ttl 1-4-10. Also sets --min-ttl 3.
                          DANGEROUS! May break websites in unexpected ways. Use with care (or --blacklist).
 --min-ttl     <value>    minimum TTL distance (128/64 - TTL) for which to send Fake Request
                          in --set-ttl and --auto-ttl modes.
 --wrong-chksum           activate Fake Request Mode and send it with incorrect TCP checksum.
                          May not work in a VM or with some routers, but is safer than set-ttl.
 --wrong-seq              activate Fake Request Mode and send it with TCP SEQ/ACK in the past.
 --native-frag            fragment (split) the packets by sending them in smaller packets, without
                          shrinking the Window Size. Works faster (does not slow down the connection)
                          and better.
 --reverse-frag           fragment (split) the packets just as --native-frag, but send them in the
                          reversed order. Works with the websites which could not handle segmented
                          HTTPS TLS ClientHello (because they receive the TCP flow "combined").
 --fake-from-hex <value>  Load fake packets for Fake Request Mode from HEX values (like 1234abcDEF).
                          This option can be supplied multiple times, in this case each fake packet
                          would be sent on every request in the command line argument order.
 --fake-with-sni <value>  Generate fake packets for Fake Request Mode with given SNI domain name.
                          The packets mimic Mozilla Firefox 130 TLS ClientHello packet
                          (with random generated fake SessionID, key shares and ECH grease).
                          Can be supplied multiple times for multiple fake packets.
 --fake-gen <value>       Generate random-filled fake packets for Fake Request Mode, value of them
                          (up to 30).
 --fake-resend <value>    Send each fake packet value number of times.
                          Default: 1 (send each packet once).
 --max-payload [value]    packets with TCP payload data more than [value] won't be processed.
                          Use this option to reduce CPU usage by skipping huge amount of data
                          (like file transfers) in already established sessions.
                          May skip some huge HTTP requests from being processed.
                          Default (if set): --max-payload 1200.


LEGACY modesets:
 -1          -p -r -s -f 2 -k 2 -n -e 2 (most compatible mode)
 -2          -p -r -s -f 2 -k 2 -n -e 40 (better speed for HTTPS yet still compatible)
 -3          -p -r -s -e 40 (better speed for HTTP and HTTPS)
 -4          -p -r -s (best speed)

Modern modesets (more stable, more compatible, faster):
 -5          -f 2 -e 2 --auto-ttl --reverse-frag --max-payload
 -6          -f 2 -e 2 --wrong-seq --reverse-frag --max-payload
 -7          -f 2 -e 2 --wrong-chksum --reverse-frag --max-payload
 -8          -f 2 -e 2 --wrong-seq --wrong-chksum --reverse-frag --max-payload
 -9          -f 2 -e 2 --wrong-seq --wrong-chksum --reverse-frag --max-payload -q (this is the default)

 Note: combination of --wrong-seq and --wrong-chksum generates two different fake packets.

How to check

To check if your ISP's DPI could be circumvented, first make sure that your provider does not poison DNS answers by enabling "Secure DNS (DNS over HTTPS)" option in your browser.

Then run the goodbyedpi.exe executable without any options. If it works — congratulations! You can use it as-is or configure further, for example by using --blacklist option if the list of blocked websites is known and available for your country.

If your provider intercepts DNS requests, you may want to use --dns-addr option to a public DNS resolver running on non-standard port (such as Yandex DNS 77.88.8.8:1253) or configure DNS over HTTPS/TLS using third-party applications.

Check the .cmd scripts and modify it according to your preference and network conditions.

How does it work

Passive DPI

Most Passive DPI send HTTP 302 Redirect if you try to access blocked website over HTTP and TCP Reset in case of HTTPS, faster than destination website. Packets sent by DPI usually have IP Identification field equal to 0x0000 or 0x0001, as seen with Russian providers. These packets, if they redirect you to another website (censorship page), are blocked by GoodbyeDPI.

Active DPI

Active DPI is more tricky to fool. Currently the software uses 7 methods to circumvent Active DPI:

These methods should not break any website as they're fully compatible with TCP and HTTP standards, yet it's sufficient to prevent DPI data classification and to circumvent censorship. Additional space may break some websites, although it's acceptable by HTTP/1.1 specification (see 19.3 Tolerant Applications).

The program loads WinDivert driver which uses Windows Filtering Platform to set filters and redirect packets to the userspace. It's running as long as console window is visible and terminates when you close the window.

How to build from source

This project can be built using GNU Make and mingw. The only dependency is WinDivert.

To build x86 exe run:

make CPREFIX=i686-w64-mingw32- WINDIVERTHEADERS=/path/to/windivert/include WINDIVERTLIBS=/path/to/windivert/x86

And for x86_64:

make CPREFIX=x86_64-w64-mingw32- BIT64=1 WINDIVERTHEADERS=/path/to/windivert/include WINDIVERTLIBS=/path/to/windivert/amd64

How to install as Windows Service

Check examples in service_install_russia_blacklist.cmd, service_install_russia_blacklist_dnsredir.cmd and service_remove.cmd scripts.

Modify them according to your own needs.

Known issues

Similar projects

Kudos

Thanks @basil00 for WinDivert. That's the main part of this program.

Thanks for every BlockCheck contributor. It would be impossible to understand DPI behaviour without this utility.

GoodbyeDPI (ValdikSS/GoodbyeDPI)

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28.8K ·GitHub
GoodbyeDPI
What is this?A free Windows utility that bypasses Deep Packet Inspection (DPI) systems ISPs use to block websites. It handles both passive DPI (optical splitter or port mirroring) and active DPI connected in sequence.
Is it a VPN or does it work some other way?Neither — it does not tunnel your traffic anywhere. The WinDivert driver intercepts packets and alters or injects them (fragmentation, fake packets, tweaked headers) so the DPI cannot classify and block them.
How do I get it running on my PC?Download the latest build from the Releases page, unpack it and run 1_russia_blacklist_dnsredir.cmd (for Russia) or 2_any_country_dnsredir.cmd (for other countries). They launch it in a recommended mode with DNS redirection to Yandex DNS on a non-standard port.
Which Windows versions does it support, and do I need admin rights?Windows 7, 8, 8.1, 10 or 11 with administrator privileges. The WinDivert driver it depends on ships with the program; only building from source needs extra tools (GNU Make and mingw).
Are there known conflicts with other software or network hardware?A few: disable Advanced Stream Detect on Intel/Qualcomm Killer network cards, start QUIK trading software before GoodbyeDPI, and heavily outdated Windows 7 installs need update KB3033929 to load the WinDivert driver.
How do I check whether it will work with my ISP?First switch your browser to DNS over HTTPS (the README shows the Chrome and Firefox settings using NextDNS) so DNS poisoning is ruled out, then run goodbyedpi.exe without any options. If blocked sites open, it works, and you can fine-tune later with options like --blacklist.
How does it actually fool the DPI systems?It uses seven tricks: TCP-level fragmentation of the first data packet and of keep-alive HTTP sessions, Host header mangling (replacing it with 'hoSt', mixing case, removing the space after the colon), extra space between the HTTP method and URI, and fake packets with low TTL, bad checksums or wrong sequence numbers that reach the DPI but never the destination.
Will it break or slow down the websites I visit?The methods are designed to be fully compatible with TCP and HTTP standards, so sites should keep working normally. One caveat: the extra-space trick, although acceptable per HTTP/1.1, may break some websites.
Can it run in the background, or do I have to keep the console window open?By default it runs only while its console window is visible and terminates when you close it. To keep it running there are service_install scripts that register GoodbyeDPI as a Windows Service — adjust them to your needs.
I'm on macOS, Linux or Android — is there anything like this for me?The README lists similar projects: zapret and Green Tunnel for macOS, Linux and Windows, PowerTunnel and SpoofDPI for desktops plus Android builds, ByeDPI for Android without root, and youtubeUnblock for OpenWRT routers and Linux.
What are similar projects?russia-mobile-internet-whitelist, mtproto.zig, vpn-configs-for-russia, fq-book, zapret-discord-youtube, GoLiveBypass, zapret, hosts
Which topics is it in?dpi, anticensorship, bypass, network, privacy-tools, anti-censorship, dns, censorship-circumvention, c, utility, networking, command-line-tool
Creator
ValdikSS
Size
0.2 MB
Stars
28.8K
Updated
CommitJan 19Release0.2.2Mar 21
Age
9y
Commits · 90 Days