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|
package seccomp
/*
#cgo linux pkg-config: --static libseccomp
#include "seccomp-build.h"
*/
import "C"
import (
"errors"
"fmt"
"runtime"
"syscall"
)
var CPrintln func(v ...any)
// LibraryError represents a libseccomp error.
type LibraryError struct {
Prefix string
Seccomp syscall.Errno
Errno error
}
func (e *LibraryError) Error() string {
if e.Seccomp == 0 {
if e.Errno == nil {
panic("invalid libseccomp error")
}
return fmt.Sprintf("%s: %s", e.Prefix, e.Errno)
}
if e.Errno == nil {
return fmt.Sprintf("%s: %s", e.Prefix, e.Seccomp)
}
return fmt.Sprintf("%s: %s (%s)", e.Prefix, e.Seccomp, e.Errno)
}
func (e *LibraryError) Is(err error) bool {
if e == nil {
return err == nil
}
if ef, ok := err.(*LibraryError); ok {
return *e == *ef
}
return (e.Seccomp != 0 && errors.Is(err, e.Seccomp)) ||
(e.Errno != nil && errors.Is(err, e.Errno))
}
var resPrefix = [...]string{
0: "",
1: "seccomp_init failed",
2: "seccomp_arch_add failed",
3: "seccomp_arch_add failed (multiarch)",
4: "internal libseccomp failure",
5: "seccomp_rule_add failed",
6: "seccomp_export_bpf failed",
7: "seccomp_load failed",
}
type SyscallOpts = C.f_syscall_opts
const (
flagVerbose SyscallOpts = C.F_VERBOSE
// FlagExt are project-specific extensions.
FlagExt SyscallOpts = C.F_EXT
// FlagDenyNS denies namespace setup syscalls.
FlagDenyNS SyscallOpts = C.F_DENY_NS
// FlagDenyTTY denies faking input.
FlagDenyTTY SyscallOpts = C.F_DENY_TTY
// FlagDenyDevel denies development-related syscalls.
FlagDenyDevel SyscallOpts = C.F_DENY_DEVEL
// FlagMultiarch allows multiarch/emulation.
FlagMultiarch SyscallOpts = C.F_MULTIARCH
// FlagLinux32 sets PER_LINUX32.
FlagLinux32 SyscallOpts = C.F_LINUX32
// FlagCan allows AF_CAN.
FlagCan SyscallOpts = C.F_CAN
// FlagBluetooth allows AF_BLUETOOTH.
FlagBluetooth SyscallOpts = C.F_BLUETOOTH
)
func buildFilter(fd int, opts SyscallOpts) error {
var (
arch C.uint32_t = 0
multiarch C.uint32_t = 0
)
switch runtime.GOARCH {
case "386":
arch = C.SCMP_ARCH_X86
case "amd64":
arch = C.SCMP_ARCH_X86_64
multiarch = C.SCMP_ARCH_X86
case "arm":
arch = C.SCMP_ARCH_ARM
case "arm64":
arch = C.SCMP_ARCH_AARCH64
multiarch = C.SCMP_ARCH_ARM
}
// this removes repeated transitions between C and Go execution
// when producing log output via F_println and CPrintln is nil
if CPrintln != nil {
opts |= flagVerbose
}
var ret C.int
res, err := C.f_build_filter(&ret, C.int(fd), arch, multiarch, opts)
if prefix := resPrefix[res]; prefix != "" {
return &LibraryError{
prefix,
-syscall.Errno(ret),
err,
}
}
return err
}
//export F_println
func F_println(v *C.char) {
if CPrintln != nil {
CPrintln(C.GoString(v))
}
}
|
