gocage/jail/main.go

// Copyright 2021, johan@nosd.in
// +build freebsd
//
// Use libjail.so to get/set jail params
package jail

/*
#cgo CFLAGS: -I /usr/lib
#cgo LDFLAGS: -L. -ljail -lc
#include <stdlib.h>
#include <jail.h>
#include <utmpx.h>
#include <pwd.h>
*/
import "C"
import (
	"strconv"
//    "syscall"
    "unsafe"
)


type Jail struct {
    Name	string
    Jid		int
	Path	string
}


// We can not use jail_getv ou jail_setv because they are variadic C functions (would need a C wrapper)
func GetJails() ([]Jail, error) {
    var jls []Jail
    var jl Jail
    var err error

	// Make "params" a list of 4 jails parameters
    params := make([]C.struct_jailparam, 4)

    // initialize parameter names
    csname := C.CString("name")
    defer C.free(unsafe.Pointer(csname))
    csjid := C.CString("jid")
    defer C.free(unsafe.Pointer(csjid))
    cspath := C.CString("path")
    defer C.free(unsafe.Pointer(cspath))
    cslastjid := C.CString("lastjid")
    defer C.free(unsafe.Pointer(cslastjid))

    // initialize params struct with parameter names
    C.jailparam_init(&params[0], csname)
    C.jailparam_init(&params[1], csjid)
    C.jailparam_init(&params[2], cspath)

    // The key to retrieve jail. lastjid = 0 returns first jail and its jid as jailparam_get return value
    C.jailparam_init(&params[3], cslastjid)

    lastjailid := 0
    cslastjidval := C.CString(strconv.Itoa(lastjailid))
    defer C.free(unsafe.Pointer(cslastjidval))

    C.jailparam_import(&params[3], cslastjidval)

    // loop on existing jails
    for lastjailid >= 0 {
        // get parameter values
        lastjailid = int(C.jailparam_get(&params[0], 4, 0))
        if lastjailid > 0 {
            nametmp := C.jailparam_export(&params[0])
            jl.Name = C.GoString(nametmp)
            // Memory mgmt : Non gere par Go
            C.free(unsafe.Pointer(nametmp))

            jidtmp := C.jailparam_export(&params[1])
            jl.Jid, _ = strconv.Atoi(C.GoString(jidtmp))
            // Memory mgmt : Non gere par Go
            C.free(unsafe.Pointer(jidtmp))
            
			pathtmp := C.jailparam_export(&params[2])
            jl.Path = C.GoString(pathtmp)
            // Memory mgmt : Non gere par Go
            C.free(unsafe.Pointer(pathtmp))

            jls = append(jls, jl)
            //log.Debug("Got jid " + strconv.Itoa(jl.jid) + " with name " + jl.name)

            // Prepare next loop iteration
            cslastjidval := C.CString(strconv.Itoa(lastjailid))
            defer C.free(unsafe.Pointer(cslastjidval))
            C.jailparam_import(&params[3], cslastjidval)
        }
    }

	// Free 4 items of params list
    C.jailparam_free(&params[0], 4)

    return jls, err
}