carlos / platform Public

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1	//go:build linux && rootrunner
2
3	package host
4
5	import (
6	"bufio"
7	"errors"
8	"fmt"
9	"os"
10	"os/exec"
11	"path/filepath"
12	"strconv"
13	"strings"
14	"syscall"
15	"testing"
16
17	"github.com/carlosframework/platform/internal/release"
18	"golang.org/x/sys/unix"
19	)
20
21	func TestPlan14GenerationDescriptorTransferRootRunner(t *testing.T) {
22	const modeKey = "PLAN14_E44_TRANSFER"
23	path := os.Getenv("PLAN14_E44_TRANSFER_PATH")
24	switch os.Getenv(modeKey) {
25	case "mount":
26	if err := unix.Mount("tmpfs", filepath.Dir(path), "tmpfs", 0, "mode=0755"); err != nil {
27	t.Fatal(err)
28	}
29	defer unix.Unmount(filepath.Dir(path), 0)
30	cmd := exec.Command(os.Args[0], "-test.run=^TestPlan14GenerationDescriptorTransferRootRunner$", "-test.timeout=30s")
31	cmd.Env = append(os.Environ(), modeKey+"=receive")
32	cmd.Dir = "/"
33	cmd.ExtraFiles = []*os.File{os.NewFile(3, "transfer")}
34	cmd.Stdout, cmd.Stderr = os.Stdout, os.Stderr
35	cmd.SysProcAttr = &syscall.SysProcAttr{Credential: &syscall.Credential{Uid: 65534, Gid: 65534, Groups: []uint32{65534}}}
36	if err := cmd.Run(); err != nil {
37	t.Fatal(err)
38	}
39	return
40	case "receive":
41	if os.Geteuid() != 65534 {
42	t.Fatal("receiver must be unprivileged")
43	}
44	if _, err := os.ReadFile(path); !errors.Is(err, os.ErrNotExist) {
45	t.Fatal("staged path not masked", err)
46	}
47	fmt.Printf("READY %d\n", os.Getpid())
48	data, control := make([]byte, 1), make([]byte, unix.CmsgSpace(4))
49	_, n, _, _, err := unix.Recvmsg(3, data, control, 0)
50	if err != nil {
51	t.Fatal(err)
52	}
53	messages, err := unix.ParseSocketControlMessage(control[:n])
54	if err != nil || len(messages) != 1 {
55	t.Fatal("rights message", err)
56	}
57	fds, err := unix.ParseUnixRights(&messages[0])
58	if err != nil || len(fds) != 1 {
59	t.Fatal("rights descriptor", err)
60	}
61	file := os.NewFile(uintptr(fds[0]), "unreserved")
62	defer file.Close()
63	body := make([]byte, 10)
64	if n, err := file.Read(body); err != nil || string(body[:n]) != "unreserved" {
65	t.Fatal("received staged bytes", string(body), err)
66	}
67	fmt.Printf("HELD %d\n", fds[0])
68	if _, err := unix.Read(3, data); err != nil {
69	t.Fatal(err)
70	}
71	return
72	case "send":
73	if os.Geteuid() != 65534 {
74	t.Fatal("sender must be unprivileged")
75	}
76	file, err := os.Open(path)
77	if err != nil {
78	t.Fatal(err)
79	}
80	defer file.Close()
81	if err := unix.Sendmsg(3, []byte{1}, unix.UnixRights(int(file.Fd())), nil, 0); err != nil {
82	t.Fatal(err)
83	}
84	return
85	}
86	dir := generationRootRunnerDir(t)
87	body, err := os.ReadFile(os.Args[0])
88	if err != nil {
89	t.Fatal(err)
90	}
91	binary := filepath.Join(dir, "transfer.test")
92	if err := os.WriteFile(binary, body, 0755); err != nil {
93	t.Fatal(err)
94	}
95	path = filepath.Join(dir, "versions", "unreserved")
96	if err := os.Mkdir(filepath.Dir(path), 0755); err != nil {
97	t.Fatal(err)
98	}
99	if err := os.WriteFile(path, []byte("unreserved"), 0644); err != nil {
100	t.Fatal(err)
101	}
102	sockets, err := unix.Socketpair(unix.AF_UNIX, unix.SOCK_STREAM|unix.SOCK_CLOEXEC, 0)
103	if err != nil {
104	t.Fatal(err)
105	}
106	parent, child := os.NewFile(uintptr(sockets[0]), "parent"), os.NewFile(uintptr(sockets[1]), "child")
107	defer parent.Close()
108	defer child.Close()
109	cmd := exec.CommandContext(t.Context(), "unshare", "--mount", binary, "-test.run=^TestPlan14GenerationDescriptorTransferRootRunner$", "-test.timeout=45s")
110	cmd.Dir = dir
111	cmd.Env = append(os.Environ(), modeKey+"=mount", "PLAN14_E44_TRANSFER_PATH="+path)
112	cmd.ExtraFiles = []*os.File{child}
113	cmd.Stderr = os.Stderr
114	output, err := cmd.StdoutPipe()
115	if err != nil {
116	t.Fatal(err)
117	}
118	if err := cmd.Start(); err != nil {
119	t.Fatal(err)
120	}
121	defer func() { cmd.Process.Kill(); cmd.Wait() }()
122	scan := bufio.NewScanner(output)
123	number := func(prefix string) int {
124	t.Helper()
125	for scan.Scan() {
126	if s, ok := strings.CutPrefix(scan.Text(), prefix); ok {
127	n, err := strconv.Atoi(s)
128	if err != nil {
129	t.Fatal(err)
130	}
131	return n
132	}
133	t.Log(scan.Text())
134	}
135	t.Fatal("missing child observation", prefix, scan.Err())
136	return 0
137	}
138	pid := number("READY ")
139	sender := exec.CommandContext(t.Context(), binary, "-test.run=^TestPlan14GenerationDescriptorTransferRootRunner$", "-test.timeout=15s")
140	sender.Dir = dir
141	sender.Env = append(os.Environ(), modeKey+"=send", "PLAN14_E44_TRANSFER_PATH="+path)
142	sender.ExtraFiles = []*os.File{parent}
143	sender.SysProcAttr = &syscall.SysProcAttr{Credential: &syscall.Credential{Uid: 65534, Gid: 65534, Groups: []uint32{65534}}}
144	if out, err := sender.CombinedOutput(); err != nil {
145	t.Fatalf("unprivileged sender: %v %s", err, out)
146	}
147	fd := number("HELD ")
148	if err := generationLinkRef(fmt.Sprintf("/proc/%d/fd/%d", pid, fd), release.GenerationBinding{Path: path, Tree: filepath.Dir(path)}); err == nil {
149	t.Fatal("transferred staged descriptor was missed")
150	}
151	t.Setenv("CARLOS_OPT_DIR", dir)
152	if _, _, err := productionGenerationKernelCensus(t.Context()); err == nil {
153	t.Fatal("uncontained descriptor recipient certified")
154	}
155	if _, err := parent.Write([]byte{1}); err != nil {
156	t.Fatal(err)
157	}
158	for scan.Scan() {
159	t.Log(scan.Text())
160	}
161	if err := cmd.Wait(); err != nil {
162	t.Fatal(err)
163	}
164	}
165