fortify/helper/bwrap.go

143 lines
3.4 KiB
Go

package helper
import (
"errors"
"io"
"os/exec"
"strconv"
"sync"
"git.ophivana.moe/security/fortify/helper/bwrap"
)
// BubblewrapName is the file name or path to bubblewrap.
var BubblewrapName = "bwrap"
type bubblewrap struct {
// bwrap child file name
name string
// bwrap pipes
p *pipes
// returns an array of arguments passed directly
// to the child process spawned by bwrap
argF func(argsFD, statFD int) []string
// pipes received by the child
// nil if no pipes are required
cp *pipes
lock sync.RWMutex
*exec.Cmd
}
func (b *bubblewrap) StartNotify(ready chan error) error {
b.lock.Lock()
defer b.lock.Unlock()
if ready != nil && b.cp == nil {
panic("attempted to start with status monitoring on a bwrap child initialised without pipes")
}
// Check for doubled Start calls before we defer failure cleanup. If the prior
// call to Start succeeded, we don't want to spuriously close its pipes.
if b.Cmd.Process != nil {
return errors.New("exec: already started")
}
// prepare bwrap pipe and args
if argsFD, _, err := b.p.prepareCmd(b.Cmd); err != nil {
return err
} else {
b.Cmd.Args = append(b.Cmd.Args, "--args", strconv.Itoa(argsFD), "--", b.name)
}
// prepare child args and pipes if enabled
if b.cp != nil {
b.cp.ready = ready
if argsFD, statFD, err := b.cp.prepareCmd(b.Cmd); err != nil {
return err
} else {
b.Cmd.Args = append(b.Cmd.Args, b.argF(argsFD, statFD)...)
}
} else {
b.Cmd.Args = append(b.Cmd.Args, b.argF(-1, -1)...)
}
if ready != nil {
b.Cmd.Env = append(b.Cmd.Env, FortifyHelper+"=1", FortifyStatus+"=1")
} else if b.cp != nil {
b.Cmd.Env = append(b.Cmd.Env, FortifyHelper+"=1", FortifyStatus+"=0")
} else {
b.Cmd.Env = append(b.Cmd.Env, FortifyHelper+"=1", FortifyStatus+"=-1")
}
if err := b.Cmd.Start(); err != nil {
return err
}
// write bwrap args first
if err := b.p.readyWriteArgs(); err != nil {
return err
}
// write child args if enabled
if b.cp != nil {
if err := b.cp.readyWriteArgs(); err != nil {
return err
}
}
return nil
}
func (b *bubblewrap) Close() error {
if b.cp == nil {
panic("attempted to close bwrap child initialised without pipes")
}
return b.cp.closeStatus()
}
func (b *bubblewrap) Start() error {
return b.StartNotify(nil)
}
func (b *bubblewrap) Unwrap() *exec.Cmd {
return b.Cmd
}
// MustNewBwrap initialises a new Bwrap instance with wt as the null-terminated argument writer.
// If wt is nil, the child process spawned by bwrap will not get an argument pipe.
// Function argF returns an array of arguments passed directly to the child process.
func MustNewBwrap(conf *bwrap.Config, wt io.WriterTo, name string, argF func(argsFD, statFD int) []string) Helper {
b, err := NewBwrap(conf, wt, name, argF)
if err != nil {
panic(err.Error())
} else {
return b
}
}
// NewBwrap initialises a new Bwrap instance with wt as the null-terminated argument writer.
// If wt is nil, the child process spawned by bwrap will not get an argument pipe.
// Function argF returns an array of arguments passed directly to the child process.
func NewBwrap(conf *bwrap.Config, wt io.WriterTo, name string, argF func(argsFD, statFD int) []string) (Helper, error) {
b := new(bubblewrap)
if args, err := NewCheckedArgs(conf.Args()); err != nil {
return nil, err
} else {
b.p = &pipes{args: args}
}
b.argF = argF
b.name = name
if wt != nil {
b.cp = &pipes{args: wt}
}
b.Cmd = execCommand(BubblewrapName)
return b, nil
}