tun

The tun module (built on songgao/water) creates a TUN virtual network interface and reads/writes raw IP packets — the building block for VPNs and custom tunnels. It requires root privileges; open fails without them. Import it with import tun.

Functions

Function	Signature	Description
`open`	`tun.open(opts?) → int`	Create a TUN interface; returns a handle (`-1` on error)
`read`	`tun.read(h: int, maxBytes: int) → string`	Read raw packet bytes (`""` on EOF/error)
`write`	`tun.write(h: int, bytes: string) → bool`	Write a raw packet
`name`	`tun.name(h: int) → string`	Interface name, e.g. `"utun5"` or `"tun0"`
`close`	`tun.close(h: int) → bool`	Close the interface

Example

import tun

let h = tun.open()
if h == -1 {
    println("need root to open a TUN device")
    exit(1)
}

println("interface: " + tun.name(h))

while true {
    let packet = tun.read(h, 2048)
    if packet == "" { break }
    // inspect or forward the raw IP packet
}

tun.close(h)

Standard library · View as Markdown · llms-full.txt