mirror of https://github.com/status-im/consul.git
130 lines
2.8 KiB
Go
130 lines
2.8 KiB
Go
package acl
|
|
|
|
import (
|
|
"crypto/md5"
|
|
"fmt"
|
|
|
|
"github.com/hashicorp/golang-lru"
|
|
)
|
|
|
|
// FaultFunc is a function used to fault in the rules for an
|
|
// ACL given it's ID
|
|
type FaultFunc func(id string) (string, error)
|
|
|
|
// aclEntry allows us to store the ACL with it's policy ID
|
|
type aclEntry struct {
|
|
ACL ACL
|
|
PolicyID string
|
|
}
|
|
|
|
// Cache is used to implement policy and ACL caching
|
|
type Cache struct {
|
|
aclCache *lru.Cache
|
|
faultfn FaultFunc
|
|
parent ACL
|
|
policyCache *lru.Cache
|
|
}
|
|
|
|
// NewCache contructs a new policy and ACL cache of a given size
|
|
func NewCache(size int, parent ACL, faultfn FaultFunc) (*Cache, error) {
|
|
if size <= 0 {
|
|
return nil, fmt.Errorf("Must provide positive cache size")
|
|
}
|
|
pc, _ := lru.New(size)
|
|
ac, _ := lru.New(size)
|
|
c := &Cache{
|
|
aclCache: ac,
|
|
faultfn: faultfn,
|
|
parent: parent,
|
|
policyCache: pc,
|
|
}
|
|
return c, nil
|
|
}
|
|
|
|
// GetPolicy is used to get a potentially cached policy set.
|
|
// If not cached, it will be parsed, and then cached.
|
|
func (c *Cache) GetPolicy(rules string) (*Policy, error) {
|
|
return c.getPolicy(c.ruleID(rules), rules)
|
|
}
|
|
|
|
// getPolicy is an internal method to get a cached policy,
|
|
// but it assumes a pre-computed ID
|
|
func (c *Cache) getPolicy(id, rules string) (*Policy, error) {
|
|
raw, ok := c.policyCache.Get(id)
|
|
if ok {
|
|
return raw.(*Policy), nil
|
|
}
|
|
policy, err := Parse(rules)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
policy.ID = id
|
|
c.policyCache.Add(id, policy)
|
|
return policy, nil
|
|
|
|
}
|
|
|
|
// ruleID is used to generate an ID for a rule
|
|
func (c *Cache) ruleID(rules string) string {
|
|
return fmt.Sprintf("%x", md5.Sum([]byte(rules)))
|
|
}
|
|
|
|
// GetACLPolicy is used to get the potentially cached ACL
|
|
// policy. If not cached, it will be generated and then cached.
|
|
func (c *Cache) GetACLPolicy(id string) (*Policy, error) {
|
|
// Check for a cached acl
|
|
if raw, ok := c.aclCache.Get(id); ok {
|
|
cached := raw.(aclEntry)
|
|
if raw, ok := c.policyCache.Get(cached.PolicyID); ok {
|
|
return raw.(*Policy), nil
|
|
}
|
|
}
|
|
|
|
// Fault in the rules
|
|
rules, err := c.faultfn(id)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
// Get cached
|
|
return c.GetPolicy(rules)
|
|
}
|
|
|
|
// GetACL is used to get a potentially cached ACL policy.
|
|
// If not cached, it will be generated and then cached.
|
|
func (c *Cache) GetACL(id string) (ACL, error) {
|
|
// Look for the ACL directly
|
|
raw, ok := c.aclCache.Get(id)
|
|
if ok {
|
|
return raw.(aclEntry).ACL, nil
|
|
}
|
|
|
|
// Get the rules
|
|
rules, err := c.faultfn(id)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
ruleID := c.ruleID(rules)
|
|
|
|
// Get the policy
|
|
policy, err := c.getPolicy(ruleID, rules)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
// Get the ACL
|
|
acl, err := New(c.parent, policy)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
// Cache and return the ACL
|
|
c.aclCache.Add(id, aclEntry{acl, ruleID})
|
|
return acl, nil
|
|
}
|
|
|
|
// ClearACL is used to clear the ACL cache if any
|
|
func (c *Cache) ClearACL(id string) {
|
|
c.aclCache.Remove(id)
|
|
}
|