Solnix Language Keywords Reference

This document lists all available keywords in the Solnix language and provides brief descriptions of how each works.

Core Program Structure Keywords

unit

Defines a BPF program unit (eBPF program). Each unit represents a single eBPF program that can be attached to various kernel hooks.

Usage:

unit program_name {
    // program body
}

section

Specifies the section name for the eBPF program. This determines where the program will be attached in the kernel (e.g., tracepoints, kprobes, XDP, etc.).

Usage:

section: "tracepoint/syscalls/sys_enter_execve";

license

Declares the license for the eBPF program. Required for kernel verification. Common values: "GPL", "Dual BSD/GPL".

Usage:

license: "GPL";

Variable Declaration Keywords

reg

Declares a register variable. Register variables are stored in CPU registers and are mutable. They are the primary way to store and manipulate data in eBPF programs.

Usage:

reg my_var = 10;
reg result = a + b;

imm

Declares an immediate (constant) variable. Immutable variables that hold constant values. Useful for values that won't change during program execution.

Usage:

imm k0 = 0;
imm index = 5;

heap

Declares a heap variable that references data from a BPF map. Used to access values stored in maps. The value is obtained via a map lookup operation.

Usage:

heap p0 = results.lookup(k0);

Map Declaration Keywords

map

Declares a BPF map. Maps are shared data structures between eBPF programs and user space, or between multiple eBPF programs.

Usage:

map map_name {
    type: .array;
    key: u32;
    value: u64;
    max: 8;
}

type

Specifies the map type within a map declaration. Must be prefixed with a dot (.). Available map types: - .hash - Hash table map - .array - Array map - .ringbuf - Ring buffer map - .lru_hash - LRU hash map - .prog_array - Program array map

Usage:

type: .array;

key

Specifies the key type for a map. Must be one of: u32, u64, i32, i64.

Usage:

key: u32;

value

Specifies the value type for a map. Must be one of: u32, u64, i32, i64.

Usage:

value: u64;

max

Specifies the maximum number of entries in a map. Must be a non-negative integer.

Usage:

max: 1024;

Control Flow Keywords

if

Conditional statement that executes code based on a guard condition.

Usage:

if guard (condition_var) {
    // code block
}

guard

Used with if to specify the guard condition. The condition is checked against a variable.

Usage:

if guard (my_var) {
    // executes if my_var is non-zero
}

return

Returns a value from the eBPF program. The return value typically indicates success (0) or error codes.

Usage:

return 0;
return error_code;

Type Keywords

These are also recognized as keywords but represent primitive types:

• u32 - 32-bit unsigned integer
• u64 - 64-bit unsigned integer
• i32 - 32-bit signed integer
• i64 - 64-bit signed integer

Usage:

key: u32;
value: u64;

Summary

Total Keywords: 13 1. unit - Program definition 2. section - Section name declaration 3. license - License declaration 4. reg - Register variable declaration 5. imm - Immediate/constant variable declaration 6. heap - Heap variable (map lookup) declaration 7. map - Map declaration 8. type - Map type specification 9. key - Map key type specification 10. value - Map value type specification 11. max - Map max entries specification 12. if - Conditional statement 13. guard - Guard condition (used with if) 14. return - Return statement

Type Keywords: 4 - u32, u64, i32, i64

Map Type Keywords: 5 (used with type:) - hash, array, ringbuf, lru_hash, prog_array