SentryPeer - A Distributed Peer To Peer List Of Bad Actor IP Addresses And Phone Numbers Collected Via A SIP Honeypot

A distributed list of bad actor IP addresses and phone numbers collected via a SIP Honeypot.


This is basically a fraud detection tool. It lets bad actors try to make phone calls and saves the IP address they came from and number they tried to call. Those details are then used to block them at the service providers network and the next time a user/customer tries to call a collected number, it's blocked.

Traditionally this data is shipped to a central place, so you don't own the data you've collected. This project is all about Peer to Peer sharing of that data. The user owning the data and various Service Provider / Network Provider related feeds of the data is the key bit for me. I'm sick of all the services out there that keep it and sell it. If you've collected it, you should have the choice to keep it and/or opt in to share it with other SentryPeer community members via p2p methods.

The sharing part...you only get other users' data if you share yours. That's the key. It could be used (the sharing of data logic/feature) in many projects too if I get it right :-)


Here's a mockup of the web UI which is subject to change.


  • All code Free/Libre and Open Source Software
  • FAST
  • User owns their data
  • User can submit their own data if they want to - opt out (default is to submit data)
  • User gets other users' data (Tit for tat?) ONLY IF they opt in to submit their data to the pool (DHT? - need to do a PoC)
  • Peer to Peer sharing of data - Zyre (Zeromq)
  • UDP transport
  • TCP transport
  • TLS transport
  • Data is max 7(?) days old as useless otherwise
  • SIP responsive mode can be enabled to collect data - cli / env flag
  • Local data copy for fast access - cli / env db location flag
  • Local API for fast access - cli / env flag
  • Local Web GUI for fast access - cli / env flag
  • Fail2Ban support via syslog as per feature request
  • Peer to Peer data replication - feature / cli flag
  • Local sqlite/lmdb database - feature / cli flag
  • Analytics - opt in
  • SDKs/libs for external access - CGRateS to start with or our own firewall with nftables
  • Small binary size for IoT usage
  • Cross-platform
  • Firewall options to use distributed data in real time - DHT?
  • Container on Docker Hub for latest build
  • BGP agent to peer with for blackholing collected IP addresses (similar to Team Cymru Bogon Router Server Project)
  • SIP agent to return 404 or default destination for SIP redirects


TBD :-)

I started this because I wanted to do C network programming as all the projects I use daily are in C like PostgreSQL, OpenLDAP, FreeSWITCH, OpenSIPS, Asterisk etc. See Episode 414: Jens Gustedt on Modern C for why C is a good choice. For those interested, see my full podcast show list (https://www.se-radio.net/team/gavin-henry/) for Software Engineering Radio



You can run the latest version of SentryPeer with Docker. The latest version is available from Docker Hub. Or build yourself:

sudo docker build -t sentrypeer .sudo docker run -d -p 5060:5060 -p 8082:8082 sentrypeer:latest

Then you can check at http://localhost:8082/ip-addresses and http://localhost:5060/health-check to see if it's running.

Environment Variables


Either set these in the Dockerfile or in your Dockerfile.env file or docker run command.


Debian or Fedora packages are always available from the release page for the current version of SentryPeer:


Building from source

You have two options for installation from source. CMake or autotools. Autotools is recommended at the moment. A release is an autotools build.

If you are a Fedora user, you can install this via Fedora copr:


If you are going to build from this repository, you will need to have the following installed:

  • git, autoconf, automake and autoconf-archive (Debian/Ubuntu)
  • libosip2-dev (Debian/Ubuntu) or libosip2-devel (Fedora)
  • libsqlite3-dev (Debian/Ubuntu) or sqlite-devel (Fedora)
  • uuid-dev (Debian/Ubuntu) or libuuid-devel (Fedora)
  • libmicrohttpd-dev (Debian/Ubuntu) or libmicrohttpd-devel (Fedora)
  • libjansson-dev (Debian/Ubuntu) or jansson-devel (Fedora)
  • libpcre2-dev (Debian/Ubuntu) or pcre2-devel (Fedora)
  • libcurl-dev (Debian/Ubuntu) or libcurl-devel (Fedora)
  • libcmocka-dev (Debian/Ubuntu) or libcmocka-devel (Fedora) - for unit tests


sudo apt-get install git build-essential autoconf-archive autoconf automake libosip2-dev libsqlite3-dev \libcmocka-dev uuid-dev libcurl-dev libpcre2-dev libjansson-dev libmicrohttpd-dev 


sudo dnf install git autoconf automake autoconf-archive libosip2-devel libsqlite3-devel libcmocka-devel \libuuid-devel libmicrohttpd-devel jansson-devel libcurl-devel pcre2-devel


brew install git autoconf automake autoconf-archive libosip cmocka libmicrohttpd jansson libcurl libpcre2

then (make check is highly recommended):

./bootstrap.sh./configuremakemake checkmake install

Homebrew (macOS or Linux):

We have a Homebrew Tap for this project (until we get more popular):

brew tap sentrypeer/sentrypeerbrew install sentrypeer

Running SentryPeer

Once built, you can run like so to start in debug mode, respond to SIP probes, enable the RESTful API, enable the Web GUI SPA and enable syslog logging (use a package if you want systemd):

./sentrypeer -adrswStarting sentrypeer...API mode enabled, starting http daemon...Web GUI mode enabled...Configuring local address...Creating socket...Binding socket to local address...Listening for incoming connections...SIP responsive mode enabled. Will reply to SIP probes...

when you get a probe request, you can see something like the following in the terminal:

Received (411 bytes): OPTIONS sip:[email protected] SIP/2.0Via: SIP/2.0/UDP;branch=z9hG4bK-515761064;rportContent-Length: 0From: "sipvicious"<sip:[email protected]>;tag=6434396633623535313363340131363131333837383137Accept: application/sdpUser-Agent: friendly-scannerTo: "sipvicious"<sip:[email protected]>Contact: sip:[email protected]:5173CSeq: 1 OPTIONSCall-ID: 679894155883566215079442Max-Forwards: 70read_packet_buf size is: 1024: read_packet_buf length is: 468: bytes_received size is: 411: Bad Actor is:Event Timestamp: 2021-11-23 20:13:36.427515810Event UUID: fac3fa20-8c2c-445b-8661-50a70fa9e873SIP Message: OPTIONS sip:[email protected] SIP/2.0Via: SIP/2.0/UDP;branch=z9hG4bK-515761064;rportFrom: "sipvicious" <sip:[email protected]>;tag=643439663362353531336334013136313   1333837383137To: "sipvicious" <sip:[email protected]>Call-ID: 679894155883566215079442CSeq: 1 OPTIONSContact: <sip:[email protected]:5173>Accept: application/sdpUser-agent: friendly-scannerMax-forwards: 70Content-Length: 0Source IP: Number: 100SIP Method: OPTIONSTransport Type: UDPUser Agent: friendly-scannerCollected Method: passiveCreated by Node Id: fac3fa20-8c2c-445b-8661-50a70fa9e873

You can see the data in the sqlite3 database called sentrypeer.db using sqlitebrowser or sqlite3 command line tool.

Here's a screenshot of the database opened using sqlitebrowser (it's big, so I'll just link to the image):

sqlitebrowser exploring the sentrypeer.db


The RESTful API is almost complete and the web UI is coming soon. Please click the Watch button to be notified when they are ready and hit Like to follow the development :-)

Right now you can call /health-check, like so:

curl -v -H "Content-Type: application/json" http://localhost:8082/health-check* Connected to localhost ( port 8082 (#0)> GET /health-check HTTP/1.1> Host: localhost:8082> User-Agent: curl/7.79.1> Accept: */*> Content-Type: application/json>< HTTP/1.1 200 OK< Connection: Keep-Alive< Content-Length: 81< X-SentryPeer-Version: 0.0.3< X-Powered-By: SentryPeer< Content-Type: application/json< Date: Tue, 21 Dec 2021 18:27:15 GMT<{  "status": "OK",  "message": "Hello from SentryPeer!",  "version": "0.0.3" }

and /ip-addresses:

curl -v -H "Content-Type: application/json" http://localhost:8082/ip-addresses* Connected to localhost ( port 8082 (#0)> GET /ip-addresses HTTP/1.1> Host: localhost:8082> User-Agent: curl/7.79.1> Accept: */*> Content-Type: application/json> < HTTP/1.1 200 OK< Connection: Keep-Alive< Content-Length: 6495< X-SentryPeer-Version: 0.0.3< X-Powered-By: SentryPeer< Content-Type: application/json< Date: Tue, 21 Dec 2021 18:29:13 GMT< {  "ip_addresses_total": 2,  "ip_addresses": [    {      "ip_address": ""    },    {      "ip_address": ""    }    ...  ]}

and lastly /ip-address/{ip-address}:

curl -v -H "Content-Type: application/json" http://localhost:8082/ip-address/* Connected to localhost ( port 8082 (#0)> GET /ip-addresses/ HTTP/1.1> Host: localhost:8082> User-Agent: curl/7.79.1> Accept: */*> Content-Type: application/json> < HTTP/1.1 404 Not Found< Connection: Keep-Alive< Content-Length: 37< X-SentryPeer-Version: 0.0.3< X-Powered-By: SentryPeer< Content-Type: application/json< Date: Tue, 21 Dec 2021 18:33:51 GMT< {  "message": "No bad actor found"}

Syslog and Fail2ban

With sentrypeer -s, you parse syslog and use Fail2Ban to block the IP address of the bad actor.

Nov 30 21:32:16 localhost.localdomain sentrypeer[303741]: Source IP:, Method: OPTIONS, Agent: sipsak 0.9.7  


Great reading - How to choose a license for your own work

This work is dual-licensed under GPL 2.0 and GPL 3.0.

SPDX-License-Identifier: GPL-2.0-only OR GPL-3.0-only



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SENTRYPEER is a registered trademark of Gavin Henry

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