acl: support for user events

acl/acl.go

@@ -52,6 +52,12 @@ type ACL interface {
 	// ServiceRead checks for permission to read a given service
 	ServiceRead(string) bool
 
+	// EventRead determines if a specific event can be queried.
+	EventRead(string) bool
+
+	// EventWrite determines if a specific event may be fired.
+	EventWrite(string) bool
+
 	// ACLList checks for permission to list all the ACLs
 	ACLList() bool
 
@@ -87,6 +93,14 @@ func (s *StaticACL) ServiceWrite(string) bool {
 	return s.defaultAllow
 }
 
+func (s *StaticACL) EventRead(string) bool {
+	return s.defaultAllow
+}
+
+func (s *StaticACL) EventWrite(string) bool {
+	return s.defaultAllow
+}
+
 func (s *StaticACL) ACLList() bool {
 	return s.allowManage
 }
@@ -136,6 +150,9 @@ type PolicyACL struct {
 
 	// serviceRules contains the service policies
 	serviceRules *radix.Tree
+
+	// eventRules contains the user event policies
+	eventRules *radix.Tree
 }
 
 // New is used to construct a policy based ACL from a set of policies
@@ -145,6 +162,7 @@ func New(parent ACL, policy *Policy) (*PolicyACL, error) {
 		parent:       parent,
 		keyRules:     radix.New(),
 		serviceRules: radix.New(),
+		eventRules:   radix.New(),
 	}
 
 	// Load the key policy
@@ -156,6 +174,12 @@ func New(parent ACL, policy *Policy) (*PolicyACL, error) {
 	for _, sp := range policy.Services {
 		p.serviceRules.Insert(sp.Name, sp.Policy)
 	}
+
+	// Load the event policy
+	for _, ep := range policy.Events {
+		p.eventRules.Insert(ep.Event, ep.Policy)
+	}
+
 	return p, nil
 }
 
@@ -266,6 +290,37 @@ func (p *PolicyACL) ServiceWrite(name string) bool {
 	return p.parent.ServiceWrite(name)
 }
 
+// EventRead is used to determine if the policy allows for a
+// specific user event to be read.
+func (p *PolicyACL) EventRead(name string) bool {
+	// Longest-prefix match on event names
+	if _, rule, ok := p.eventRules.LongestPrefix(name); ok {
+		switch rule {
+		case EventPolicyRead:
+			return true
+		case EventPolicyWrite:
+			return true
+		default:
+			return false
+		}
+	}
+
+	// Nothing matched, use parent
+	return p.parent.EventRead(name)
+}
+
+// EventWrite is used to determine if new events can be created
+// (fired) by the policy.
+func (p *PolicyACL) EventWrite(name string) bool {
+	// Longest-prefix match event names
+	if _, rule, ok := p.eventRules.LongestPrefix(name); ok {
+		return rule == EventPolicyWrite
+	}
+
+	// No match, use parent
+	return p.parent.EventWrite(name)
+}
+
 // ACLList checks if listing of ACLs is allowed
 func (p *PolicyACL) ACLList() bool {
 	return p.parent.ACLList()

acl/acl_test.go

@@ -66,6 +66,18 @@ func TestStaticACL(t *testing.T) {
 	if none.ServiceWrite("foobar") {
 		t.Fatalf("should not allow")
 	}
+	if none.EventRead("foobar") {
+		t.Fatalf("should not allow")
+	}
+	if none.EventRead("") {
+		t.Fatalf("should not allow")
+	}
+	if none.EventWrite("foobar") {
+		t.Fatalf("should not allow")
+	}
+	if none.EventWrite("") {
+		t.Fatalf("should not allow")
+	}
 	if none.ACLList() {
 		t.Fatalf("should not noneow")
 	}
@@ -132,6 +144,20 @@ func TestPolicyACL(t *testing.T) {
 				Policy: ServicePolicyWrite,
 			},
 		},
+		Events: []*EventPolicy{
+			&EventPolicy{
+				Event:  "",
+				Policy: EventPolicyRead,
+			},
+			&EventPolicy{
+				Event:  "foo",
+				Policy: EventPolicyWrite,
+			},
+			&EventPolicy{
+				Event:  "bar",
+				Policy: EventPolicyDeny,
+			},
+		},
 	}
 	acl, err := New(all, policy)
 	if err != nil {
@@ -188,6 +214,27 @@ func TestPolicyACL(t *testing.T) {
 			t.Fatalf("Write fail: %#v", c)
 		}
 	}
+
+	type eventcase struct {
+		inp   string
+		read  bool
+		write bool
+	}
+	eventcases := []eventcase{
+		{"foo", true, true},
+		{"foobar", true, true},
+		{"bar", false, false},
+		{"barbaz", false, false},
+		{"baz", true, false},
+	}
+	for _, c := range eventcases {
+		if c.read != acl.EventRead(c.inp) {
+			t.Fatalf("Event fail: %#v", c)
+		}
+		if c.write != acl.EventWrite(c.inp) {
+			t.Fatalf("Event fail: %#v", c)
+		}
+	}
 }
 
 func TestPolicyACL_Parent(t *testing.T) {

acl/policy.go

@@ -13,6 +13,9 @@ const (
 	ServicePolicyDeny  = "deny"
 	ServicePolicyRead  = "read"
 	ServicePolicyWrite = "write"
+	EventPolicyRead    = "read"
+	EventPolicyWrite   = "write"
+	EventPolicyDeny    = "deny"
 )
 
 // Policy is used to represent the policy specified by
@@ -21,6 +24,7 @@ type Policy struct {
 	ID       string           `hcl:"-"`
 	Keys     []*KeyPolicy     `hcl:"key,expand"`
 	Services []*ServicePolicy `hcl:"service,expand"`
+	Events   []*EventPolicy   `hcl:"event,expand"`
 }
 
 // KeyPolicy represents a policy for a key
@@ -43,6 +47,16 @@ func (k *ServicePolicy) GoString() string {
 	return fmt.Sprintf("%#v", *k)
 }
 
+// EventPolicy represents a user event policy.
+type EventPolicy struct {
+	Event  string `hcl:",key"`
+	Policy string
+}
+
+func (e *EventPolicy) GoString() string {
+	return fmt.Sprintf("%#v", *e)
+}
+
 // Parse is used to parse the specified ACL rules into an
 // intermediary set of policies, before being compiled into
 // the ACL
@@ -80,5 +94,16 @@ func Parse(rules string) (*Policy, error) {
 		}
 	}
 
+	// Validate the user event policies
+	for _, ep := range p.Events {
+		switch ep.Policy {
+		case EventPolicyRead:
+		case EventPolicyWrite:
+		case EventPolicyDeny:
+		default:
+			return nil, fmt.Errorf("Invalid event policy: %#v", ep)
+		}
+	}
+
 	return p, nil
 }

acl/policy_test.go

@@ -24,6 +24,15 @@ service "" {
 }
 service "foo" {
 	policy = "read"
+}
+event "" {
+	policy = "read"
+}
+event "foo" {
+	policy = "write"
+}
+event "bar" {
+	policy = "deny"
 }
 	`
 	exp := &Policy{
@@ -55,6 +64,20 @@ service "foo" {
 				Policy: ServicePolicyRead,
 			},
 		},
+		Events: []*EventPolicy{
+			&EventPolicy{
+				Event:  "",
+				Policy: EventPolicyRead,
+			},
+			&EventPolicy{
+				Event:  "foo",
+				Policy: EventPolicyWrite,
+			},
+			&EventPolicy{
+				Event:  "bar",
+				Policy: EventPolicyDeny,
+			},
+		},
 	}
 
 	out, err := Parse(inp)
@@ -90,6 +113,17 @@ func TestParse_JSON(t *testing.T) {
 		"foo": {
 			"policy": "read"
 		}
+	},
+	"event": {
+		"": {
+			"policy": "read"
+		},
+		"foo": {
+			"policy": "write"
+		},
+		"bar": {
+			"policy": "deny"
+		}
 	}
 }`
 	exp := &Policy{
@@ -121,6 +155,20 @@ func TestParse_JSON(t *testing.T) {
 				Policy: ServicePolicyRead,
 			},
 		},
+		Events: []*EventPolicy{
+			&EventPolicy{
+				Event:  "",
+				Policy: EventPolicyRead,
+			},
+			&EventPolicy{
+				Event:  "foo",
+				Policy: EventPolicyWrite,
+			},
+			&EventPolicy{
+				Event:  "bar",
+				Policy: EventPolicyDeny,
+			},
+		},
 	}
 
 	out, err := Parse(inp)