Examples

Explore example Solnix programs and common use cases.

Tracepoint Example

This example demonstrates a simple tracepoint program that performs arithmetic operations and stores the result in a map.

map results { // (1)
    type: .array;
    key: u32;
    value: u64;
    max: 8;
}

unit sample_tracepoint {
    section: "tracepoint/syscalls/sys_enter_execve"; // (2)
    license: "GPL";

    reg a = 10;
    reg b = 20;

    reg c = a + b;   // (3)

    imm k0 = 0; heap p0 = results.lookup(k0); *p0 = c; // (4)

    return 0;
}

1. Defines an array map results with 8 entries.
2. Attaches to the sys_enter_execve tracepoint.
3. Performs addition of two register variables.
4. Stores the result in the map at index 0.

XDP Packet Filter Example

This example shows an XDP program that counts packets per source IP address using a hash map.

map connection_counter {
    type: .hash;
    key: u32;
    value: u64;
    max: 1024;
}

unit filter_packets {
    section: "xdp";
    license: "GPL";

    reg src_ip = ctx.load_u32(26);
    heap count_ptr = connection_counter.lookup(src_ip);

    if guard(count_ptr) {
        *count_ptr += 1;
    }

    return 1;
}

This program: - Defines a hash map to track connection counts per IP address - Attaches to the XDP hook for network packet processing - Loads the source IP address from the packet context - Increments a counter for each source IP if an entry exists - Returns 1 to pass the packet