[Tool Name] - [Brief Description]¶

What it does¶

[Tool name] is an eBPF-based tool that [brief description of what the tool monitors or does].

Use Cases¶

Use case 1: Description of when to use this tool
Use case 2: Another scenario where this tool is useful
Use case 3: Additional use case

How it works¶

Kernel Hook¶

The tool attaches to the [tracepoint/kprobe name] [tracepoint/kprobe], which is triggered whenever [describe when the event occurs].

SEC("[tracepoint/kprobe path]")
int [function_name](struct [context_type] *ctx) {
    // Program logic here
    return 0;
}

Data Flow¶

[Event Type] Event
        ↓
[tracepoint/kprobe name]
        ↓
eBPF Program ([filename].c)
        ↓
Ring Buffer (events map)
        ↓
Go Application ([filename].go)
        ↓
Console Output

eBPF Program Details¶

Data Structure¶

struct data_t {
    u32 field1;          // Description of field1
    char field2[16];     // Description of field2
    // Add more fields as needed
};

Ring Buffer¶

struct {
    __uint(type, BPF_MAP_TYPE_RINGBUF);
    __uint(max_entries, 1 << 24);  // 16MB buffer
} events SEC(".maps");

Program Logic¶

Step 1: Description of what the program does first
Step 2: Description of the second step
Step 3: Description of the third step
Step 4: Description of the final step

Implementation Details¶

eBPF Program (`bpf/[filename].c`)¶

#include "common.h"

struct data_t {
    // Define your data structure here
};

// Define the ring buffer
struct {
    __uint(type, BPF_MAP_TYPE_RINGBUF);
    __uint(max_entries, 1 << 24);
} events SEC(".maps");

SEC("[tracepoint/kprobe path]")
int [function_name](struct [context_type] *ctx) {
    struct data_t *data = bpf_ringbuf_reserve(&events, sizeof(struct data_t), 0);
    if (!data) {
        return 0; // Skip event if ring buffer reservation fails
    }

    // Your eBPF program logic here

    bpf_ringbuf_submit(data, 0); // Submit data to ring buffer
    return 0;
}

char _license[] SEC("license") = "GPL";

Go Application (`cmd/[filename].go`)¶

The Go application: 1. Loads the eBPF program into the kernel 2. Attaches to the [tracepoint/kprobe] using the cilium/ebpf library 3. Reads events from the ring buffer 4. Applies filters (if any) 5. Displays results in a formatted table

Usage¶

Basic Usage¶

# Basic command to run the tool
sudo ./ebee [tool-name]

Filtering Options¶

# Example filtering options
sudo ./ebee [tool-name] --option value

# Another example
sudo ./ebee [tool-name] --another-option "value"

Example Output¶

[Header line]
[Column headers]
[Example data rows]

Technical Deep Dive¶

Kernel [Tracepoint/Kprobe] Details¶

The [tracepoint/kprobe name] is defined in the Linux kernel source:

// From kernel source: [file path]
TRACE_EVENT([event_name],
    // Tracepoint definition
);

Performance Considerations¶

Ring Buffer Size: 16MB buffer can handle high-frequency events
Zero-Copy: Ring buffer provides efficient kernel-to-userspace communication
Minimal Overhead: eBPF program executes quickly with minimal impact

Limitations¶

Limitation 1: Description of limitation
Limitation 2: Another limitation
Limitation 3: Additional limitation

Troubleshooting¶

Common Issues¶

"permission denied"

# Solution: Run with sudo
sudo ./ebee [tool-name]

"[specific error]"
```
# Solution or debug command
```
"no events showing"
```
# How to test if the tool is working
```

Debug Commands¶

# Check if eBPF program is loaded
sudo bpftool prog list | grep [tool-name]

# Check [tracepoint/kprobe] attachment
sudo cat /sys/kernel/debug/tracing/events/[category]/[event]/enable

# Monitor kernel logs
dmesg | tail

Extending [Tool Name]¶

Adding More Information¶

You could extend the tool to capture additional information:

struct data_t {
    // Existing fields
    // New fields you could add
};

Advanced Features¶

Describe potential advanced features:

// Example of advanced feature implementation

Related tool 1: Brief description
Related tool 2: Brief description
Related tool 3: Brief description