Getting Started

Prerequisites

• CMake 3.10+
• C11-compatible compiler (gcc / clang)
• libcsp v1.6
• (Optional) Python 3 + pyzmq for ZMQHUB-based testing
• (Optional) Rust toolchain for Rust bindings

Building

git clone https://github.com/dtn-mtp/cspcl.git
cd cspcl
mkdir build && cd build
cmake ..
make
ctest --verbose

CMake Options

Option	Default	Description
CSPCL_BUILD_TESTS	ON	Build unit tests
CSPCL_BUILD_EXAMPLES	ON	Build example applications
CSPCL_USE_FREERTOS	OFF	Target FreeRTOS instead of POSIX
CSPCL_DEBUG	OFF	Enable verbose debug output

Using a custom libcsp location

cmake -DCSP_PATH=/path/to/libcsp ..

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C — First Bundle Transfer

1. Initialize

#include "cspcl.h"

cspcl_t cspcl;

// Initialize with local CSP node address
cspcl_error_t err = cspcl_init(&cspcl, 1);

// Open receive socket (bind to BP port once)
err = cspcl_open_rx_socket(&cspcl);

2. Send a bundle

uint8_t bundle[] = { /* serialized BP7 bundle */ };

err = cspcl_send_bundle(&cspcl, bundle, sizeof(bundle), 2 /* dest CSP addr */);
if (err != CSPCL_OK) {
    fprintf(stderr, "send error: %s\n", cspcl_strerror(err));
}

Large bundles are automatically fragmented using CSP’s SFP — no extra work required.

3. Receive a bundle

uint8_t buf[CSPCL_MAX_BUNDLE_SIZE];
size_t  buf_len = sizeof(buf);
uint8_t src_addr;

err = cspcl_recv_bundle(&cspcl, buf, &buf_len, &src_addr, 5000 /* ms */);
if (err == CSPCL_OK) {
    printf("Received %zu bytes from CSP addr %u\n", buf_len, src_addr);
}

4. Cleanup

cspcl_cleanup(&cspcl);

---

Rust — First Bundle Transfer

Add the dependency:

[dependencies]
cspcl = "0.1"

use cspcl::Cspcl;

fn main() -> Result<(), Box<dyn std::error::Error>> {
    let mut node = Cspcl::init(1)?;
    node.open_rx_socket()?;

    // Send
    let bundle: Vec<u8> = vec![/* BP7 bundle bytes */];
    node.send_bundle(&bundle, 2)?;

    // Receive (5 s timeout)
    let (data, src_addr) = node.recv_bundle(5000)?;
    println!("Received {} bytes from CSP addr {}", data.len(), src_addr);

    Ok(())
}

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Next Steps

• C API Reference — complete function documentation
• uD3TN Integration — use CSPCL with uD3TN
• Unibo Integration — use CSPCL with Unibo-BP
• Architecture — understand how SFP fragmentation works