Ci/add makefile workflow

.github/workflows/build.yml

@@ -0,0 +1,70 @@
+name: Cross-Platform Build
+
+on:
+  push:
+    branches: [master]
+  pull_request:
+    branches: [master]
+
+jobs:
+  build:
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ubuntu-latest, windows-latest]
+        architecture: [x64]
+        include:
+          - os: ubuntu-latest
+            architecture: x64
+            makefile: build/unix/x86_64_linux.mk
+            target: libsnap7.so
+          - os: windows-latest
+            architecture: x64
+            makefile: build/windows/MinGW64/Makefile
+            target: snap7.dll
+    runs-on: ${{ matrix.os }}
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Set up build environment (Linux)
+        if: runner.os == 'Linux'
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y build-essential
+
+      - name: Set up build environment (Windows)
+        if: runner.os == 'Windows'
+        uses: msys2/setup-msys2@v2
+        with:
+          msystem: MINGW64
+          install: mingw-w64-x86_64-gcc mingw-w64-x86_64-binutils make
+
+      - name: Build (Linux)
+        if: runner.os == 'Linux'
+        working-directory: ${{ github.workspace }}
+        run: |
+          make -f ${{ matrix.makefile }}
+          ls -la build/bin/x86_64-linux/
+
+      - name: Build (Windows)
+        if: runner.os == 'Windows'
+        working-directory: ${{ github.workspace }}/build/windows/MinGW64
+        shell: msys2 {0}
+        run: |
+          make
+          ls -la ../../bin/Legacy/win64/
+
+      - name: Upload Linux artifact
+        if: runner.os == 'Linux'
+        uses: actions/upload-artifact@v4
+        with:
+          name: snap7-linux-x64
+          path: build/bin/x86_64-linux/libsnap7.so
+
+      - name: Upload Windows artifact
+        if: runner.os == 'Windows'
+        uses: actions/upload-artifact@v4
+        with:
+          name: snap7-windows-x64
+          path: build/bin/Legacy/win64/snap7.dll

.github/workflows/makefile.yml

@@ -0,0 +1,37 @@
+name: Build projects with Make
+
+on:
+  push:
+    branches: [master]
+  pull_request:
+    branches: [master]
+
+jobs:
+  build:
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ubuntu-latest, windows-latest]
+        architecture: [x64]
+    runs-on: ${{ matrix.os }}
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Set up build environment (Linux)
+        if: runner.os == 'Linux'
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y build-essential
+
+      - name: Set up build environment (Windows)
+        if: runner.os == 'Windows'
+        uses: msys2/setup-msys2@v2
+        with:
+          msystem: MINGW64
+          install: mingw-w64-x86_64-gcc mingw-w64-x86_64-binutils make
+
+      - name: Build
+        run: |
+          cd build
+          make

.github/workflows/smoke-test.yml

@@ -0,0 +1,69 @@
+name: Smoke Test
+
+on:
+  push:
+    branches: [master]
+  pull_request:
+    branches: [master]
+
+jobs:
+  smoke-test:
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ubuntu-latest, windows-latest]
+        architecture: [x64]
+    runs-on: ${{ matrix.os }}
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Set up build environment (Linux)
+        if: runner.os == 'Linux'
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y build-essential
+
+      - name: Set up build environment (Windows)
+        if: runner.os == 'Windows'
+        uses: msys2/setup-msys2@v2
+        with:
+          msystem: MINGW64
+          install: mingw-w64-x86_64-gcc mingw-w64-x86_64-binutils make
+
+      - name: Build library (Linux)
+        if: runner.os == 'Linux'
+        working-directory: ${{ github.workspace }}
+        run: make -f build/unix/x86_64_linux.mk
+
+      - name: Build library (Windows)
+        if: runner.os == 'Windows'
+        working-directory: ${{ github.workspace }}/build/windows/MinGW64
+        shell: msys2 {0}
+        run: make
+
+      - name: Build loopback test (Linux)
+        if: runner.os == 'Linux'
+        working-directory: ${{ github.workspace }}/examples/cpp/x86_64-linux
+        run: make loopback_test
+
+      - name: Build loopback test (Windows)
+        if: runner.os == 'Windows'
+        working-directory: ${{ github.workspace }}/examples/cpp/x86_64-linux
+        shell: msys2 {0}
+        run: make loopback_test
+
+      - name: Run Linux loopback test
+        if: runner.os == 'Linux'
+        working-directory: ${{ github.workspace }}/examples/cpp/x86_64-linux
+        run: |
+          # Start test in background and give it time to run
+          timeout 60 ./loopback_test
+
+      - name: Run Windows loopback test
+        if: runner.os == 'Windows'
+        working-directory: ${{ github.workspace }}/examples/cpp/x86_64-linux
+        shell: msys2 {0}
+        run: |
+          # Start test and give it time to run
+          timeout 60 ./loopback_test.exe

README.md

@@ -14,3 +14,35 @@ For more details I refer to the commit history.
 Please note that this fork is currently at version 1.4.0.
 
 Cleanup, more fixes and documentation will follow.
+
+## License
+
+This repository includes the applicable license texts in the repository root:
+
+- [GPL license text](gpl.txt)
+- [LGPL v3.0 license text](lgpl-3.0.txt)
+
+Please review the applicable license terms before using, modifying,
+or redistributing this software.
+
+## Fork Status
+
+This repository is a community-maintained fork of
+[SCADACS/snap7](https://github.com/SCADACS/snap7).
+
+The original Snap7 project and its contributors retain credit for the
+upstream codebase. This fork adds independently maintained documentation,
+build, testing, security, and integration improvements.
+
+See the repository history and license texts for applicable notices.
+
+## Security
+
+For security considerations when deploying Snap7 in industrial environments,
+see [SECURITY.md](SECURITY.md), [docs/secure-deployment.md](docs/secure-deployment.md),
+and [docs/industrial-networking.md](docs/industrial-networking.md).
+
+## Continuous Integration
+
+This project includes GitHub Actions workflows for cross-platform builds
+and automated smoke tests on Linux and Windows.

SECURITY.md

@@ -0,0 +1,13 @@
+# Security Policy
+
+## Reporting a Vulnerability
+
+Please avoid publishing suspected security vulnerabilities in public issue trackers before maintainers have had an opportunity to assess them.
+
+When a private reporting channel is available, use that channel and include:
+
+- A clear description of the issue
+- Affected versions or commits
+- Steps to reproduce the issue
+- Potential impact
+- Any proposed mitigation, if available

docs/industrial-networking.md

@@ -0,0 +1,49 @@
+# Industrial Networking Guidance
+
+This document provides guidance on network architecture and communication patterns when using Snap7 in industrial environments.
+
+## Network Segmentation
+
+Industrial control systems should be separated from enterprise IT networks using:
+
+- **DMZ / Industrial DMZ**: A controlled boundary between IT and OT networks
+- **Firewalls**: Stateful inspection firewalls with rules allowing only necessary protocols and ports
+- **VLANs**: Logical separation of traffic types (e.g., HMI, historian, engineering, safety)
+- **Unidirectional Gateways (Data Diodes)**: For high-security environments requiring data flow from OT to IT only
+
+## Communication Protocols
+
+Snap7 uses the Siemens S7 protocol over ISO-on-TCP (RFC 1006) typically on port 102. Consider:
+
+- Restricting port 102 access to authorized engineering stations only
+- Using non-standard ports where possible to reduce automated scanning
+- Implementing port knocking or SPA (Single Packet Authorization) for additional obscurity
+
+## Redundancy and Availability
+
+- Design network paths with redundancy for critical communication
+- Implement monitoring for communication loss and latency anomalies
+- Consider PLC-side communication load when multiple clients connect
+- Use Snap7's connection management features to handle reconnections gracefully
+
+## Monitoring and Logging
+
+- Log all connection attempts (successful and failed)
+- Monitor for unusual traffic patterns or unexpected PLC commands
+- Correlate network logs with PLC diagnostic buffers
+- Set up alerts for communication failures on critical assets
+
+## Remote Access
+
+If remote access is required:
+
+- Use a dedicated VPN with multi-factor authentication
+- Implement jump hosts / bastion hosts for engineering access
+- Record and audit all remote sessions
+- Enforce time-limited access with automatic revocation
+
+## References
+
+- IEC 62443 Series - Industrial communication network security
+- NIST SP 800-82 - Guide to Industrial Control Systems Security
+- ISA/IEC 62443-3-3 - System security requirements and security levels

docs/secure-deployment.md

@@ -0,0 +1,29 @@
+# Secure Deployment Guide
+
+This guide provides security-focused deployment recommendations for systems using Snap7 to communicate with Siemens S7 PLCs.
+
+## Network Architecture
+
+- PLCs should not be exposed directly to the internet.
+- Use network segmentation and firewall rules to isolate OT networks from IT networks.
+- Use VPN or controlled remote-access mechanisms for remote engineering access.
+- Limit access to authorized engineering and service networks only.
+- Use least-privilege access where supported by the PLC and network infrastructure.
+
+## Operational Security
+
+- Treat PLC write operations as high-risk actions.
+- Separate development/test devices from production assets.
+- Log, monitor, and review communication failures and unexpected commands.
+- Implement change management procedures for any modifications to PLC programs or configuration.
+
+## Important Limitations
+
+Snap7 is not a substitute for OT network architecture and operational security controls. It provides communication capabilities but does not implement:
+
+- Network-level authentication or encryption (relies on underlying transport)
+- Industrial firewall or intrusion detection
+- Safety system functions
+- Compliance with specific industrial security standards (e.g., IEC 62443)
+
+These controls must be implemented at the network and system architecture level.