112 lines
3.8 KiB
Go
112 lines
3.8 KiB
Go
// Copyright 2018 The gVisor Authors.
|
|
//
|
|
// Licensed under the Apache License, Version 2.0 (the "License");
|
|
// you may not use this file except in compliance with the License.
|
|
// You may obtain a copy of the License at
|
|
//
|
|
// http://www.apache.org/licenses/LICENSE-2.0
|
|
//
|
|
// Unless required by applicable law or agreed to in writing, software
|
|
// distributed under the License is distributed on an "AS IS" BASIS,
|
|
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
// See the License for the specific language governing permissions and
|
|
// limitations under the License.
|
|
|
|
// Package syscalls is the interface from the application to the kernel.
|
|
// Traditionally, syscalls is the interface that is used by applications to
|
|
// request services from the kernel of a operating system. We provide a
|
|
// user-mode kernel that needs to handle those requests coming from unmodified
|
|
// applications. Therefore, we still use the term "syscalls" to denote this
|
|
// interface.
|
|
//
|
|
// Note that the stubs in this package may merely provide the interface, not
|
|
// the actual implementation. It just makes writing syscall stubs
|
|
// straightforward.
|
|
package syscalls
|
|
|
|
import (
|
|
"fmt"
|
|
|
|
"gvisor.dev/gvisor/pkg/abi/linux"
|
|
"gvisor.dev/gvisor/pkg/sentry/arch"
|
|
"gvisor.dev/gvisor/pkg/sentry/kernel"
|
|
"gvisor.dev/gvisor/pkg/syserror"
|
|
)
|
|
|
|
// Supported returns a syscall that is fully supported.
|
|
func Supported(name string, fn kernel.SyscallFn) kernel.Syscall {
|
|
return kernel.Syscall{
|
|
Name: name,
|
|
Fn: fn,
|
|
SupportLevel: kernel.SupportFull,
|
|
Note: "Fully Supported.",
|
|
}
|
|
}
|
|
|
|
// PartiallySupported returns a syscall that has a partial implementation.
|
|
func PartiallySupported(name string, fn kernel.SyscallFn, note string, urls []string) kernel.Syscall {
|
|
return kernel.Syscall{
|
|
Name: name,
|
|
Fn: fn,
|
|
SupportLevel: kernel.SupportPartial,
|
|
Note: note,
|
|
URLs: urls,
|
|
}
|
|
}
|
|
|
|
// Error returns a syscall handler that will always give the passed error.
|
|
func Error(name string, err error, note string, urls []string) kernel.Syscall {
|
|
if note != "" {
|
|
note = note + "; "
|
|
}
|
|
return kernel.Syscall{
|
|
Name: name,
|
|
Fn: func(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
|
|
return 0, nil, err
|
|
},
|
|
SupportLevel: kernel.SupportUnimplemented,
|
|
Note: fmt.Sprintf("%sReturns %q.", note, err.Error()),
|
|
URLs: urls,
|
|
}
|
|
}
|
|
|
|
// ErrorWithEvent gives a syscall function that sends an unimplemented
|
|
// syscall event via the event channel and returns the passed error.
|
|
func ErrorWithEvent(name string, err error, note string, urls []string) kernel.Syscall {
|
|
if note != "" {
|
|
note = note + "; "
|
|
}
|
|
return kernel.Syscall{
|
|
Name: name,
|
|
Fn: func(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
|
|
t.Kernel().EmitUnimplementedEvent(t)
|
|
return 0, nil, err
|
|
},
|
|
SupportLevel: kernel.SupportUnimplemented,
|
|
Note: fmt.Sprintf("%sReturns %q.", note, err.Error()),
|
|
URLs: urls,
|
|
}
|
|
}
|
|
|
|
// CapError gives a syscall function that checks for capability c. If the task
|
|
// has the capability, it returns ENOSYS, otherwise EPERM. To unprivileged
|
|
// tasks, it will seem like there is an implementation.
|
|
func CapError(name string, c linux.Capability, note string, urls []string) kernel.Syscall {
|
|
if note != "" {
|
|
note = note + "; "
|
|
}
|
|
return kernel.Syscall{
|
|
Name: name,
|
|
Fn: func(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
|
|
if !t.HasCapability(c) {
|
|
return 0, nil, syserror.EPERM
|
|
}
|
|
t.Kernel().EmitUnimplementedEvent(t)
|
|
return 0, nil, syserror.ENOSYS
|
|
},
|
|
SupportLevel: kernel.SupportUnimplemented,
|
|
Note: fmt.Sprintf("%sReturns %q if the process does not have %s; %q otherwise.", note, syserror.EPERM, c.String(), syserror.ENOSYS),
|
|
URLs: urls,
|
|
}
|
|
}
|