cosmopolitan/test/libc/calls/unveil_test.c
Justine Tunney 8f522cb702
Make improvements
This change progresses our AARCH64 support:

- The AARCH64 build and tests are now passing
- Add 128-bit floating-point support to printf()
- Fix clone() so it initializes cosmo's x28 TLS register
- Fix TLS memory layout issue with aarch64 _Alignas vars
- Revamp microbenchmarking tools so they work on aarch64
- Make some subtle improvements to aarch64 crash reporting
- Make kisdangerous() memory checks more accurate on aarch64
- Remove sys_open() since it's not available on Linux AARCH64

This change makes general improvements to Cosmo and Redbean:

- Introduce GetHostIsa() function in Redbean
- You can now feature check using pledge(0, 0)
- You can now feature check using unveil("",0)
- Refactor some more x86-specific asm comments
- Refactor and write docs for some libm functions
- Make the mmap() API behave more similar to Linux
- Fix WIFSIGNALED() which wrongly returned true for zero
- Rename some obscure cosmo keywords from noFOO to dontFOO
2023-06-03 08:12:22 -07:00

388 lines
13 KiB
C

/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2022 Justine Alexandra Roberts Tunney │
│ │
│ Permission to use, copy, modify, and/or distribute this software for │
│ any purpose with or without fee is hereby granted, provided that the │
│ above copyright notice and this permission notice appear in all copies. │
│ │
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
│ PERFORMANCE OF THIS SOFTWARE. │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/calls/calls.h"
#include "libc/calls/landlock.h"
#include "libc/calls/struct/dirent.h"
#include "libc/calls/struct/stat.h"
#include "libc/calls/syscall-sysv.internal.h"
#include "libc/dce.h"
#include "libc/errno.h"
#include "libc/intrin/kprintf.h"
#include "libc/mem/copyfd.internal.h"
#include "libc/mem/gc.h"
#include "libc/runtime/internal.h"
#include "libc/runtime/runtime.h"
#include "libc/sock/sock.h"
#include "libc/stdio/stdio.h"
#include "libc/str/str.h"
#include "libc/sysv/consts/af.h"
#include "libc/sysv/consts/map.h"
#include "libc/sysv/consts/msync.h"
#include "libc/sysv/consts/o.h"
#include "libc/sysv/consts/prot.h"
#include "libc/sysv/consts/s.h"
#include "libc/sysv/consts/sig.h"
#include "libc/sysv/consts/sock.h"
#include "libc/testlib/subprocess.h"
#include "libc/testlib/testlib.h"
#include "libc/thread/spawn.h"
#include "libc/x/x.h"
#include "libc/x/xasprintf.h"
#define EACCES_OR_ENOENT (IsOpenbsd() ? ENOENT : EACCES)
char testlib_enable_tmp_setup_teardown;
struct stat st;
bool HasUnveilSupport(void) {
return unveil("", 0) >= 0;
}
bool UnveilCanSecureTruncate(void) {
int abi = unveil("", 0);
return abi == 0 || abi >= 3;
}
void SetUpOnce(void) {
__enable_threads();
if (!HasUnveilSupport()) {
fprintf(stderr, "warning: unveil() not supported on this system: %m\n");
exit(0);
}
}
void SetUp(void) {
// make sure zipos maps executable into memory early
ASSERT_SYS(0, 0, stat("/zip/life.elf", &st));
}
TEST(unveil, api_differences) {
SPAWN(fork);
ASSERT_SYS(0, 0, mkdir("foo", 0755));
ASSERT_SYS(0, 0, unveil("foo", "r"));
if (IsOpenbsd()) {
// openbsd imposes restrictions immediately
ASSERT_SYS(ENOENT, -1, open("/", O_RDONLY | O_DIRECTORY));
} else {
// restrictions on linux don't go into effect until unveil(0,0)
ASSERT_SYS(0, 3, open(".", O_RDONLY | O_DIRECTORY));
ASSERT_SYS(0, 0, close(3));
}
ASSERT_SYS(0, 0, unveil(0, 0));
// error numbers are inconsistent
ASSERT_SYS(EACCES_OR_ENOENT, -1, open("/", O_RDONLY | O_DIRECTORY));
// wut
if (IsLinux()) {
ASSERT_SYS(0, 3, open("/", O_PATH)); // wut
ASSERT_SYS(0, 0, stat("/", &st)); // wut
}
EXITS(0);
}
TEST(unveil, rx_readOnlyPreexistingExecutable_worksFine) {
SPAWN(fork);
ASSERT_SYS(0, 0, mkdir("folder", 0755));
testlib_extract("/zip/life.elf", "folder/life.elf", 0755);
ASSERT_SYS(0, 0, unveil("folder", "rx"));
ASSERT_SYS(0, 0, unveil(0, 0));
SPAWN(fork);
execl("folder/life.elf", "folder/life.elf", 0);
kprintf("execve failed! %s\n", strerror(errno));
_Exit(127);
EXITS(42);
EXITS(0);
}
TEST(unveil, r_noExecutePreexistingExecutable_raisesEacces) {
SPAWN(fork);
ASSERT_SYS(0, 0, mkdir("folder", 0755));
testlib_extract("/zip/life.elf", "folder/life.elf", 0755);
ASSERT_SYS(0, 0, unveil("folder", "r"));
ASSERT_SYS(0, 0, unveil(0, 0));
SPAWN(fork);
ASSERT_SYS(EACCES, -1, execl("folder/life.elf", "folder/life.elf", 0));
EXITS(0);
EXITS(0);
}
TEST(unveil, canBeUsedAgainAfterVfork) {
ASSERT_SYS(0, 0, touch("bad", 0644));
ASSERT_SYS(0, 0, touch("good", 0644));
SPAWN(fork);
SPAWN(vfork);
ASSERT_SYS(0, 0, unveil("bad", "r"));
ASSERT_SYS(0, 0, unveil("good", "r"));
ASSERT_SYS(0, 0, unveil(0, 0));
ASSERT_SYS(0, 3, open("bad", 0));
EXITS(0);
ASSERT_SYS(0, 0, unveil("good", "r"));
ASSERT_SYS(0, 0, unveil(0, 0));
ASSERT_SYS(0, 3, open("good", 0));
ASSERT_SYS(EACCES_OR_ENOENT, -1, open("bad", 0));
EXITS(0);
}
TEST(unveil, rwc_createExecutableFile_isAllowedButCantBeRun) {
SPAWN(fork);
ASSERT_SYS(0, 0, mkdir("folder", 0755));
ASSERT_SYS(0, 0, unveil("folder", "rwc"));
ASSERT_SYS(0, 0, unveil(0, 0));
testlib_extract("/zip/life.elf", "folder/life.elf", 0755);
SPAWN(fork);
ASSERT_SYS(0, 0, stat("folder/life.elf", &st));
ASSERT_SYS(EACCES, -1, execl("folder/life.elf", "folder/life.elf", 0));
EXITS(0);
EXITS(0);
}
TEST(unveil, rwcx_createExecutableFile_canAlsoBeRun) {
SPAWN(fork);
ASSERT_SYS(0, 0, mkdir("folder", 0755));
ASSERT_SYS(0, 0, unveil("folder", "rwcx"));
ASSERT_SYS(0, 0, unveil(0, 0));
testlib_extract("/zip/life.elf", "folder/life.elf", 0755);
SPAWN(fork);
ASSERT_SYS(0, 0, stat("folder/life.elf", &st));
execl("folder/life.elf", "folder/life.elf", 0);
kprintf("execve failed! %s\n", strerror(errno));
_Exit(127);
EXITS(42);
EXITS(0);
}
TEST(unveil, dirfdHacking_doesntWork) {
SPAWN(fork);
ASSERT_SYS(0, 0, mkdir("jail", 0755));
ASSERT_SYS(0, 0, mkdir("garden", 0755));
ASSERT_SYS(0, 0, touch("garden/secret.txt", 0644));
ASSERT_SYS(0, 3, open("garden", O_RDONLY | O_DIRECTORY));
ASSERT_SYS(0, 0, unveil("jail", "rw"));
ASSERT_SYS(0, 0, unveil(0, 0));
ASSERT_SYS(EACCES_OR_ENOENT, -1, openat(3, "secret.txt", O_RDONLY));
EXITS(0);
}
TEST(unveil, mostRestrictivePolicy) {
if (IsOpenbsd()) return; // openbsd behaves oddly; see docs
SPAWN(fork);
ASSERT_SYS(0, 0, mkdir("jail", 0755));
ASSERT_SYS(0, 0, mkdir("garden", 0755));
ASSERT_SYS(0, 0, touch("garden/secret.txt", 0644));
ASSERT_SYS(0, 0, unveil(0, 0));
ASSERT_SYS(EACCES_OR_ENOENT, -1, open("jail", O_RDONLY | O_DIRECTORY));
ASSERT_SYS(EACCES_OR_ENOENT, -1, open("garden/secret.txt", O_RDONLY));
EXITS(0);
}
TEST(unveil, overlappingDirectories_inconsistentBehavior) {
SPAWN(fork);
ASSERT_SYS(0, 0, makedirs("f1/f2", 0755));
testlib_extract("/zip/life.elf", "f1/f2/life.elf", 0755);
ASSERT_SYS(0, 0, unveil("f1", "x"));
ASSERT_SYS(0, 0, unveil("f1/f2", "r"));
ASSERT_SYS(0, 0, unveil(0, 0));
if (IsOpenbsd()) {
// OpenBSD favors the most restrictive policy
SPAWN(fork);
ASSERT_SYS(0, 0, stat("f1/f2/life.elf", &st));
ASSERT_SYS(EACCES, -1, execl("f1/f2/life.elf", "f1/f2/life.elf", 0));
EXITS(0);
} else {
// Landlock (Linux) uses the union of policies
//
// TODO(jart): this test flakes on github actions. it reports an
// exit code of 0! find out why this is happening...
// so far it's happened to MODE=rel and MODE=tiny...
//
// SPAWN(fork);
// ASSERT_SYS(0, 0, stat("f1/f2/life.elf", &st));
// execl("f1/f2/life.elf", "f1/f2/life.elf", 0);
// kprintf("execve failed! %s\n", strerror(errno));
// _Exit(127);
// EXITS(42);
}
EXITS(0);
}
TEST(unveil, usedTwice_allowedOnLinux) {
if (IsOpenbsd()) return;
SPAWN(fork);
ASSERT_SYS(0, 0, mkdir("jail", 0755));
ASSERT_SYS(0, 0, xbarf("jail/ok.txt", "hello", 5));
ASSERT_SYS(0, 0, mkdir("garden", 0755));
ASSERT_SYS(0, 0, xbarf("garden/secret.txt", "hello", 5));
ASSERT_SYS(0, 0, mkdir("heaven", 0755));
ASSERT_SYS(0, 0, xbarf("heaven/verysecret.txt", "hello", 5));
ASSERT_SYS(0, 0, unveil("jail", "rw"));
ASSERT_SYS(0, 0, unveil("garden", "rw"));
ASSERT_SYS(0, 0, unveil(0, 0));
ASSERT_SYS(0, 3, open("garden/secret.txt", O_RDONLY));
ASSERT_SYS(0, 0, unveil("jail", "rw"));
ASSERT_SYS(0, 0, unveil("heaven", "rw")); // not allowed, superset of parent
ASSERT_SYS(0, 0, unveil(0, 0));
ASSERT_SYS(0, 4, open("jail/ok.txt", O_RDONLY));
ASSERT_SYS(EACCES, -1, open("garden/secret.txt", O_RDONLY));
ASSERT_SYS(EACCES, -1, open("heaven/verysecret.txt", O_RDONLY));
EXITS(0);
}
TEST(unveil, truncate_isForbiddenBySeccomp) {
SPAWN(fork);
ASSERT_SYS(0, 0, mkdir("jail", 0755));
ASSERT_SYS(0, 0, mkdir("garden", 0755));
ASSERT_SYS(0, 0, xbarf("garden/secret.txt", "hello", 5));
ASSERT_SYS(0, 0, unveil("jail", "rw"));
ASSERT_SYS(0, 0, unveil(0, 0));
ASSERT_SYS(!UnveilCanSecureTruncate() ? EPERM : EACCES_OR_ENOENT, -1,
truncate("garden/secret.txt", 0));
if (IsLinux()) {
ASSERT_SYS(0, 0, stat("garden/secret.txt", &st));
ASSERT_EQ(5, st.st_size);
}
EXITS(0);
}
TEST(unveil, ftruncate_isForbidden) {
if (IsOpenbsd()) return; // b/c O_PATH is a Linux thing
SPAWN(fork);
ASSERT_SYS(0, 0, mkdir("jail", 0755));
ASSERT_SYS(0, 0, mkdir("garden", 0755));
ASSERT_SYS(0, 0, xbarf("garden/secret.txt", "hello", 5));
ASSERT_SYS(0, 0, unveil("jail", "rw"));
ASSERT_SYS(0, 0, unveil(0, 0));
ASSERT_SYS(0, 3, open("garden/secret.txt", O_PATH));
ASSERT_SYS(EBADF, -1, ftruncate(3, 0));
ASSERT_SYS(0, 0, close(3));
ASSERT_SYS(0, 0, stat("garden/secret.txt", &st));
ASSERT_EQ(5, st.st_size);
EXITS(0);
}
TEST(unveil, procfs_isForbiddenByDefault) {
if (IsOpenbsd()) return;
SPAWN(fork);
ASSERT_SYS(0, 0, mkdir("jail", 0755));
ASSERT_SYS(0, 0, unveil("jail", "rw"));
ASSERT_SYS(0, 0, unveil(0, 0));
ASSERT_SYS(EACCES, -1, open("/proc/self/cmdline", O_RDONLY));
EXITS(0);
}
int Worker(void *arg, int tid) {
ASSERT_SYS(EACCES_OR_ENOENT, -1, open("garden/secret.txt", O_RDONLY));
return 0;
}
TEST(unveil, isInheritedAcrossThreads) {
struct spawn t;
SPAWN(fork);
ASSERT_SYS(0, 0, mkdir("jail", 0755));
ASSERT_SYS(0, 0, mkdir("garden", 0755));
ASSERT_SYS(0, 0, xbarf("garden/secret.txt", "hello", 5));
ASSERT_SYS(0, 0, unveil("jail", "rw"));
ASSERT_SYS(0, 0, unveil(0, 0));
ASSERT_SYS(0, 0, _spawn(Worker, 0, &t));
EXPECT_SYS(0, 0, _join(&t));
EXITS(0);
}
int Worker2(void *arg, int tid) {
ASSERT_SYS(0, 0, unveil("jail", "rw"));
ASSERT_SYS(0, 0, unveil(0, 0));
ASSERT_SYS(EACCES_OR_ENOENT, -1, open("garden/secret.txt", O_RDONLY));
return 0;
}
TEST(unveil, isThreadSpecificOnLinux_isProcessWideOnOpenbsd) {
struct spawn t;
SPAWN(fork);
ASSERT_SYS(0, 0, mkdir("jail", 0755));
ASSERT_SYS(0, 0, mkdir("garden", 0755));
ASSERT_SYS(0, 0, xbarf("garden/secret.txt", "hello", 5));
ASSERT_SYS(0, 0, _spawn(Worker2, 0, &t));
EXPECT_SYS(0, 0, _join(&t));
if (IsOpenbsd()) {
ASSERT_SYS(ENOENT, -1, open("garden/secret.txt", O_RDONLY));
} else {
ASSERT_SYS(0, 3, open("garden/secret.txt", O_RDONLY));
}
EXITS(0);
}
TEST(unveil, usedTwice_forbidden_worksWithPledge) {
int ws, pid;
bool *gotsome;
ASSERT_NE(-1, (gotsome = _mapshared(FRAMESIZE)));
ASSERT_NE(-1, (pid = fork()));
if (!pid) {
// install our first seccomp filter
ASSERT_SYS(0, 0, pledge("stdio rpath wpath cpath unveil", 0));
ASSERT_SYS(0, 0, mkdir("jail", 0755));
ASSERT_SYS(0, 0, mkdir("garden", 0755));
ASSERT_SYS(0, 0, xbarf("garden/secret.txt", "hello", 5));
ASSERT_SYS(0, 0, unveil("jail", "rw"));
// committing and locking causes a new bpf filter to be installed
ASSERT_SYS(0, 0, unveil(0, 0));
ASSERT_SYS(EACCES_OR_ENOENT, -1, open("garden/secret.txt", O_RDONLY));
// verify the second filter is working
ASSERT_SYS(EACCES_OR_ENOENT, -1, open("garden/secret.txt", O_RDONLY));
// verify the first filter is still working
*gotsome = true;
socket(AF_UNIX, SOCK_STREAM, 0);
_Exit(0);
}
ASSERT_NE(-1, wait(&ws));
ASSERT_TRUE(*gotsome);
ASSERT_TRUE(WIFSIGNALED(ws));
ASSERT_EQ(IsOpenbsd() ? SIGABRT : SIGSYS, WTERMSIG(ws));
EXPECT_SYS(0, 0, munmap(gotsome, FRAMESIZE));
}
TEST(unveil, lotsOfPaths) {
int i, n;
SPAWN(fork);
n = 100;
for (i = 0; i < n; ++i) {
ASSERT_SYS(0, 0, touch(xasprintf("%d", i), 0644));
ASSERT_SYS(0, 0, touch(xasprintf("%d-", i), 0644));
}
for (i = 0; i < n; ++i) {
ASSERT_SYS(0, 0, unveil(xasprintf("%d", i), "rw"));
}
ASSERT_SYS(0, 0, unveil(0, 0));
for (i = 0; i < n; ++i) {
ASSERT_SYS(0, 3, open(xasprintf("%d", i), O_RDONLY));
ASSERT_SYS(0, 0, close(3));
ASSERT_SYS(EACCES_OR_ENOENT, -1, open(xasprintf("%d-", i), O_RDONLY));
}
EXITS(0);
}
TEST(unveil, reparent) {
return; // need abi 2 :'(
SPAWN(fork);
ASSERT_SYS(0, 0, mkdir("x", 0755));
ASSERT_SYS(0, 0, unveil("x", "rwc"));
ASSERT_SYS(0, 0, unveil(0, 0));
ASSERT_SYS(0, 0, mkdir("x/y", 0755));
ASSERT_SYS(0, 0, touch("x/y/z", 0644));
ASSERT_SYS(0, 0, rename("x/y/z", "x/z"));
EXITS(0);
}