fortify/internal/system/link.go

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package system
import (
"fmt"
"os"
"git.gensokyo.uk/security/fortify/internal/fmsg"
)
// Link registers an Op that links dst to src.
func (sys *I) Link(oldname, newname string) *I { return sys.LinkFileType(Process, oldname, newname) }
// LinkFileType registers a file linking Op labelled with type et.
func (sys *I) LinkFileType(et Enablement, oldname, newname string) *I {
sys.lock.Lock()
defer sys.lock.Unlock()
sys.ops = append(sys.ops, &Hardlink{et, newname, oldname})
return sys
}
type Hardlink struct {
et Enablement
dst, src string
}
func (l *Hardlink) Type() Enablement { return l.et }
func (l *Hardlink) apply(_ *I) error {
fmsg.VPrintln("linking ", l)
return fmsg.WrapErrorSuffix(os.Link(l.src, l.dst),
fmt.Sprintf("cannot link %q:", l.dst))
}
func (l *Hardlink) revert(_ *I, ec *Criteria) error {
if ec.hasType(l) {
fmsg.VPrintf("removing hard link %q", l.dst)
return fmsg.WrapErrorSuffix(os.Remove(l.dst),
fmt.Sprintf("cannot remove hard link %q:", l.dst))
} else {
fmsg.VPrintf("skipping hard link %q", l.dst)
return nil
}
}
func (l *Hardlink) Is(o Op) bool {
l0, ok := o.(*Hardlink)
return ok && l0 != nil && *l == *l0
}
func (l *Hardlink) Path() string { return l.src }
func (l *Hardlink) String() string { return fmt.Sprintf("%q from %q", l.dst, l.src) }