From 739949e0abc1cc4e4849a7bb156faa5e7d28d9c8 Mon Sep 17 00:00:00 2001
From: Edward Haas <edwardh@redhat.com>
Date: Tue, 2 Mar 2021 10:11:50 +0200
Subject: [PATCH] state, filter: Fix the interpretation of ifaces names

In scenarios where an interface has only numeric characters, the
application panics with a failure to extract a string type from a Go
interface (which is actually a float64).

In order to fix the problem, the parsing of the interface name is performed
using a dedicated interface-state structure.

Note: The usage of the interface name in this context is solely limited
for the filter matching.
This change does not solve the problem of incorrectly representing valid
numeric values like `0xfe` and `1.0` (they are now seen as 254 and 1).

Signed-off-by: Edward Haas <edwardh@redhat.com>
---
 pkg/state/filter.go      | 15 ++++++++-----
 pkg/state/filter_test.go | 47 ++++++++++++++++++++++++++++++++++++++++
 pkg/state/type.go        |  8 +++++++
 3 files changed, 65 insertions(+), 5 deletions(-)

diff --git a/pkg/state/filter.go b/pkg/state/filter.go
index d1b2d8e172..381a01ffcb 100644
--- a/pkg/state/filter.go
+++ b/pkg/state/filter.go
@@ -73,11 +73,11 @@ func filterOutDynamicAttributes(iface map[string]interface{}) {
 	delete(options, "hello-timer")
 }
 
-func filterOutInterfaces(ifaces []interface{}, interfacesFilterGlob glob.Glob) []interface{} {
+func filterOutInterfaces(ifaces []interface{}, ifacesNames []Interface, interfacesFilterGlob glob.Glob) []interface{} {
 	filteredInterfaces := []interface{}{}
-	for _, iface := range ifaces {
-		name := iface.(map[string]interface{})["name"]
-		if !interfacesFilterGlob.Match(name.(string)) {
+	for i, iface := range ifaces {
+		name := ifacesNames[i].Name
+		if !interfacesFilterGlob.Match(name) {
 			filterOutDynamicAttributes(iface.(map[string]interface{}))
 			filteredInterfaces = append(filteredInterfaces, iface)
 		}
@@ -92,7 +92,12 @@ func filterOut(currentState shared.State, interfacesFilterGlob glob.Glob) (share
 		return currentState, err
 	}
 
-	state.Interfaces = filterOutInterfaces(state.Interfaces, interfacesFilterGlob)
+	var ifacesState InterfacesState
+	if err := yaml.Unmarshal(currentState.Raw, &ifacesState); err != nil {
+		return currentState, err
+	}
+
+	state.Interfaces = filterOutInterfaces(state.Interfaces, ifacesState.Interfaces, interfacesFilterGlob)
 	if state.Routes != nil {
 		state.Routes.Running = filterOutRoutes(state.Routes.Running, interfacesFilterGlob)
 		state.Routes.Config = filterOutRoutes(state.Routes.Config, interfacesFilterGlob)
diff --git a/pkg/state/filter_test.go b/pkg/state/filter_test.go
index c87149ffef..0e20505787 100644
--- a/pkg/state/filter_test.go
+++ b/pkg/state/filter_test.go
@@ -331,4 +331,51 @@ interfaces:
 		})
 	})
 
+	Context("when the interfaces have (only) numeric characters", func() {
+		BeforeEach(func() {
+			state = nmstate.NewState(`
+interfaces:
+- name: eth0
+- name: 0
+- name: 1101010
+`)
+			filteredState = nmstate.NewState(`
+interfaces:
+- name: eth0
+- name: 1101010
+`)
+			interfacesFilterGlob = glob.MustCompile("0*")
+		})
+
+		It("should filter out interfaces correctly", func() {
+			returnedState, err := filterOut(state, interfacesFilterGlob)
+			Expect(err).NotTo(HaveOccurred())
+			Expect(returnedState).To(MatchYAML(filteredState))
+		})
+	})
+
+	Context("when the interfaces have special numeric characters", func() {
+		BeforeEach(func() {
+			state = nmstate.NewState(`
+interfaces:
+- name: eth0
+- name: 0.0
+- name: 1.0
+- name: 0xfe
+`)
+			filteredState = nmstate.NewState(`
+interfaces:
+- name: eth0
+- name: 0
+- name: 254
+`)
+			interfacesFilterGlob = glob.MustCompile("1*")
+		})
+
+		It("should filter out interfaces correctly but they are not represented correctly", func() {
+			returnedState, err := filterOut(state, interfacesFilterGlob)
+			Expect(err).NotTo(HaveOccurred())
+			Expect(returnedState).To(MatchYAML(filteredState))
+		})
+	})
 })
diff --git a/pkg/state/type.go b/pkg/state/type.go
index 98b69b6a08..a1882b38e2 100644
--- a/pkg/state/type.go
+++ b/pkg/state/type.go
@@ -9,3 +9,11 @@ type Routes struct {
 	Config  []interface{} `json:"config"`
 	Running []interface{} `json:"running"`
 }
+
+type InterfacesState struct {
+	Interfaces []Interface `json:"interfaces"`
+}
+
+type Interface struct {
+	Name string `json:"name"`
+}