open-vault/vault/router.go
2015-03-05 17:23:56 -08:00

146 lines
3.1 KiB
Go

package vault
import (
"fmt"
"strings"
"sync"
"github.com/armon/go-radix"
)
// Router is used to do prefix based routing of a request to a logical backend
type Router struct {
l sync.RWMutex
root *radix.Tree
}
// NewRouter returns a new router
func NewRouter() *Router {
r := &Router{
root: radix.New(),
}
return r
}
// mountEntry is used to represent a mount point
type mountEntry struct {
backend LogicalBackend
view *BarrierView
rootPaths *radix.Tree
}
// Mount is used to expose a logical backend at a given prefix
func (r *Router) Mount(backend LogicalBackend, prefix string, view *BarrierView) error {
r.l.Lock()
defer r.l.Unlock()
// Check if this is a nested mount
if existing, _, ok := r.root.LongestPrefix(prefix); ok && existing != "" {
return fmt.Errorf("cannot mount under existing mount '%s'", existing)
}
// Get the root paths
paths := backend.RootPaths()
var rootPaths *radix.Tree
if len(paths) > 0 {
rootPaths = radix.New()
}
for _, path := range paths {
// Check if this is a prefix or exact match
prefixMatch := len(path) >= 1 && path[len(path)-1] == '*'
if prefixMatch {
path = path[:len(path)-1]
}
rootPaths.Insert(path, prefixMatch)
}
// Create a mount entry
me := &mountEntry{
backend: backend,
view: view,
rootPaths: rootPaths,
}
r.root.Insert(prefix, me)
return nil
}
// Unmount is used to remove a logical backend from a given prefix
func (r *Router) Unmount(prefix string) error {
r.l.Lock()
defer r.l.Unlock()
r.root.Delete(prefix)
return nil
}
// Remount is used to change the mount location of a logical backend
func (r *Router) Remount(src, dst string) error {
r.l.Lock()
defer r.l.Unlock()
// Check for existing mount
raw, ok := r.root.Get(src)
if !ok {
return fmt.Errorf("no mount at '%s'", src)
}
// Update the mount point
r.root.Delete(src)
r.root.Insert(dst, raw)
return nil
}
// Route is used to route a given request
func (r *Router) Route(req *Request) (*Response, error) {
// Find the mount point
r.l.RLock()
mount, raw, ok := r.root.LongestPrefix(req.Path)
r.l.RUnlock()
if !ok {
return nil, fmt.Errorf("no handler for route '%s'", req.Path)
}
me := raw.(*mountEntry)
// Adjust the path, attach the barrier view
original := req.Path
req.Path = strings.TrimPrefix(req.Path, mount)
req.View = me.view
// Reset the request before returning
defer func() {
req.Path = original
req.View = nil
}()
// Invoke the backend
return me.backend.HandleRequest(req)
}
// RootPath checks if the given path requires root privileges
func (r *Router) RootPath(path string) bool {
r.l.RLock()
mount, raw, ok := r.root.LongestPrefix(path)
r.l.RUnlock()
if !ok {
return false
}
me := raw.(*mountEntry)
// Trim to get remaining path
remain := strings.TrimPrefix(path, mount)
// Check the rootPaths of this backend
match, raw, ok := me.rootPaths.LongestPrefix(remain)
if !ok {
return false
}
prefixMatch := raw.(bool)
// Handle the prefix match case
if prefixMatch {
return strings.HasPrefix(remain, match)
}
// Handle the exact match case
return match == remain
}