From 4fdd560b76dfe4e3df83a8cba5a070ce7142b433 Mon Sep 17 00:00:00 2001 From: Ian Lewis Date: Thu, 13 Jun 2019 15:44:17 -0700 Subject: Set the HOME environment variable (fixes #293) runsc will now set the HOME environment variable as required by POSIX. The user's home directory is retrieved from the /etc/passwd file located on the container's file system during boot. PiperOrigin-RevId: 253120627 --- runsc/boot/user_test.go | 253 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 253 insertions(+) create mode 100644 runsc/boot/user_test.go (limited to 'runsc/boot/user_test.go') diff --git a/runsc/boot/user_test.go b/runsc/boot/user_test.go new file mode 100644 index 000000000..e91be5f0f --- /dev/null +++ b/runsc/boot/user_test.go @@ -0,0 +1,253 @@ +// Copyright 2019 The gVisor Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +package boot + +import ( + "io/ioutil" + "os" + "path/filepath" + "strings" + "syscall" + "testing" + + specs "github.com/opencontainers/runtime-spec/specs-go" + "gvisor.googlesource.com/gvisor/pkg/sentry/context/contexttest" + "gvisor.googlesource.com/gvisor/pkg/sentry/fs" +) + +func setupTempDir() (string, error) { + tmpDir, err := ioutil.TempDir(os.TempDir(), "exec-user-test") + if err != nil { + return "", err + } + return tmpDir, nil +} + +func setupPasswd(contents string, perms os.FileMode) func() (string, error) { + return func() (string, error) { + tmpDir, err := setupTempDir() + if err != nil { + return "", err + } + + if err := os.Mkdir(filepath.Join(tmpDir, "etc"), 0777); err != nil { + return "", err + } + + f, err := os.Create(filepath.Join(tmpDir, "etc", "passwd")) + if err != nil { + return "", err + } + defer f.Close() + + _, err = f.WriteString(contents) + if err != nil { + return "", err + } + + err = f.Chmod(perms) + if err != nil { + return "", err + } + return tmpDir, nil + } +} + +// TestGetExecUserHome tests the getExecUserHome function. +func TestGetExecUserHome(t *testing.T) { + tests := map[string]struct { + uid uint32 + createRoot func() (string, error) + expected string + }{ + "success": { + uid: 1000, + createRoot: setupPasswd("adin::1000:1111::/home/adin:/bin/sh", 0666), + expected: "/home/adin", + }, + "no_passwd": { + uid: 1000, + createRoot: setupTempDir, + expected: "/", + }, + "no_perms": { + uid: 1000, + createRoot: setupPasswd("adin::1000:1111::/home/adin:/bin/sh", 0000), + expected: "/", + }, + "directory": { + uid: 1000, + createRoot: func() (string, error) { + tmpDir, err := setupTempDir() + if err != nil { + return "", err + } + + if err := os.Mkdir(filepath.Join(tmpDir, "etc"), 0777); err != nil { + return "", err + } + + if err := syscall.Mkdir(filepath.Join(tmpDir, "etc", "passwd"), 0666); err != nil { + return "", err + } + + return tmpDir, nil + }, + expected: "/", + }, + // Currently we don't allow named pipes. + "named_pipe": { + uid: 1000, + createRoot: func() (string, error) { + tmpDir, err := setupTempDir() + if err != nil { + return "", err + } + + if err := os.Mkdir(filepath.Join(tmpDir, "etc"), 0777); err != nil { + return "", err + } + + if err := syscall.Mkfifo(filepath.Join(tmpDir, "etc", "passwd"), 0666); err != nil { + return "", err + } + + return tmpDir, nil + }, + expected: "/", + }, + } + + for name, tc := range tests { + t.Run(name, func(t *testing.T) { + tmpDir, err := tc.createRoot() + if err != nil { + t.Fatalf("failed to create root dir: %v", err) + } + + sandEnd, cleanup, err := startGofer(tmpDir) + if err != nil { + t.Fatalf("failed to create gofer: %v", err) + } + defer cleanup() + + ctx := contexttest.Context(t) + conf := &Config{ + RootDir: "unused_root_dir", + Network: NetworkNone, + DisableSeccomp: true, + } + + spec := &specs.Spec{ + Root: &specs.Root{ + Path: tmpDir, + Readonly: true, + }, + // Add /proc mount as tmpfs to avoid needing a kernel. + Mounts: []specs.Mount{ + { + Destination: "/proc", + Type: "tmpfs", + }, + }, + } + + var mns *fs.MountNamespace + setMountNS := func(m *fs.MountNamespace) { + mns = m + ctx.(*contexttest.TestContext).RegisterValue(fs.CtxRoot, mns.Root()) + } + mntr := newContainerMounter(spec, "", []int{sandEnd}, nil, &podMountHints{}) + if err := mntr.setupRootContainer(ctx, ctx, conf, setMountNS); err != nil { + t.Fatalf("failed to create mount namespace: %v", err) + } + + got, err := getExecUserHome(ctx, mns, tc.uid) + if err != nil { + t.Fatalf("failed to get user home: %v", err) + } + + if got != tc.expected { + t.Fatalf("expected %v, got: %v", tc.expected, got) + } + }) + } +} + +// TestFindHomeInPasswd tests the findHomeInPasswd function's passwd file parsing. +func TestFindHomeInPasswd(t *testing.T) { + tests := map[string]struct { + uid uint32 + passwd string + expected string + def string + }{ + "empty": { + uid: 1000, + passwd: "", + expected: "/", + def: "/", + }, + "whitespace": { + uid: 1000, + passwd: " ", + expected: "/", + def: "/", + }, + "full": { + uid: 1000, + passwd: "adin::1000:1111::/home/adin:/bin/sh", + expected: "/home/adin", + def: "/", + }, + // For better or worse, this is how runc works. + "partial": { + uid: 1000, + passwd: "adin::1000:1111:", + expected: "", + def: "/", + }, + "multiple": { + uid: 1001, + passwd: "adin::1000:1111::/home/adin:/bin/sh\nian::1001:1111::/home/ian:/bin/sh", + expected: "/home/ian", + def: "/", + }, + "duplicate": { + uid: 1000, + passwd: "adin::1000:1111::/home/adin:/bin/sh\nian::1000:1111::/home/ian:/bin/sh", + expected: "/home/adin", + def: "/", + }, + "empty_lines": { + uid: 1001, + passwd: "adin::1000:1111::/home/adin:/bin/sh\n\n\nian::1001:1111::/home/ian:/bin/sh", + expected: "/home/ian", + def: "/", + }, + } + + for name, tc := range tests { + t.Run(name, func(t *testing.T) { + got, err := findHomeInPasswd(tc.uid, strings.NewReader(tc.passwd), tc.def) + if err != nil { + t.Fatalf("error parsing passwd: %v", err) + } + if tc.expected != got { + t.Fatalf("expected %v, got: %v", tc.expected, got) + } + }) + } +} -- cgit v1.2.3