Add unit tests for switch_id(), including tests for capabilities

This commit is contained in:
Nick Mathewson 2015-11-06 15:35:15 -05:00
parent e8cc839e41
commit fd0c6671d1
4 changed files with 222 additions and 3 deletions

2
.gitignore vendored
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@ -172,6 +172,7 @@ cscope.*
/src/test/test-child /src/test/test-child
/src/test/test-memwipe /src/test/test-memwipe
/src/test/test-ntor-cl /src/test/test-ntor-cl
/src/test/test-switch-id
/src/test/test_workqueue /src/test/test_workqueue
/src/test/test.exe /src/test/test.exe
/src/test/test-slow.exe /src/test/test-slow.exe
@ -179,6 +180,7 @@ cscope.*
/src/test/test-child.exe /src/test/test-child.exe
/src/test/test-ntor-cl.exe /src/test/test-ntor-cl.exe
/src/test/test-memwipe.exe /src/test/test-memwipe.exe
/src/test/test-switch-id.exe
/src/test/test_workqueue.exe /src/test/test_workqueue.exe
/src/test/test_zero_length_keys.sh /src/test/test_zero_length_keys.sh
/src/test/test_ntor.sh /src/test/test_ntor.sh

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@ -4,14 +4,16 @@ export SHELL=@SHELL@
export abs_top_srcdir=@abs_top_srcdir@ export abs_top_srcdir=@abs_top_srcdir@
export builddir=@builddir@ export builddir=@builddir@
TESTSCRIPTS = src/test/test_zero_length_keys.sh TESTSCRIPTS = src/test/test_zero_length_keys.sh \
src/test/test_switch_id.sh
if USEPYTHON if USEPYTHON
TESTSCRIPTS += src/test/test_ntor.sh src/test/test_bt.sh TESTSCRIPTS += src/test/test_ntor.sh src/test/test_bt.sh
endif endif
TESTS += src/test/test src/test/test-slow src/test/test-memwipe \ TESTS += src/test/test src/test/test-slow src/test/test-memwipe \
src/test/test_workqueue src/test/test_keygen.sh $(TESTSCRIPTS) src/test/test_workqueue src/test/test_keygen.sh \
$(TESTSCRIPTS)
# These flavors are run using automake's test-driver and test-network.sh # These flavors are run using automake's test-driver and test-network.sh
TEST_CHUTNEY_FLAVORS = basic-min bridges-min hs-min bridges+hs TEST_CHUTNEY_FLAVORS = basic-min bridges-min hs-min bridges+hs
@ -33,7 +35,8 @@ noinst_PROGRAMS+= \
src/test/test-slow \ src/test/test-slow \
src/test/test-memwipe \ src/test/test-memwipe \
src/test/test-child \ src/test/test-child \
src/test/test_workqueue src/test/test_workqueue \
src/test/test-switch-id
endif endif
src_test_AM_CPPFLAGS = -DSHARE_DATADIR="\"$(datadir)\"" \ src_test_AM_CPPFLAGS = -DSHARE_DATADIR="\"$(datadir)\"" \
@ -131,6 +134,14 @@ src_test_test_workqueue_SOURCES = \
src_test_test_workqueue_CPPFLAGS= $(src_test_AM_CPPFLAGS) src_test_test_workqueue_CPPFLAGS= $(src_test_AM_CPPFLAGS)
src_test_test_workqueue_CFLAGS = $(AM_CFLAGS) $(TEST_CFLAGS) src_test_test_workqueue_CFLAGS = $(AM_CFLAGS) $(TEST_CFLAGS)
src_test_test_switch_id_SOURCES = \
src/test/test_switch_id.c
src_test_test_switch_id_CPPFLAGS= $(src_test_AM_CPPFLAGS)
src_test_test_switch_id_CFLAGS = $(AM_CFLAGS) $(TEST_CFLAGS)
src_test_test_switch_id_LDADD = \
src/common/libor-testing.a \
@TOR_ZLIB_LIBS@ @TOR_LIB_MATH@
src_test_test_LDFLAGS = @TOR_LDFLAGS_zlib@ @TOR_LDFLAGS_openssl@ \ src_test_test_LDFLAGS = @TOR_LDFLAGS_zlib@ @TOR_LDFLAGS_openssl@ \
@TOR_LDFLAGS_libevent@ @TOR_LDFLAGS_libevent@
src_test_test_LDADD = src/or/libtor-testing.a src/common/libor-testing.a \ src_test_test_LDADD = src/or/libtor-testing.a src/common/libor-testing.a \

181
src/test/test_switch_id.c Normal file
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@ -0,0 +1,181 @@
/* Copyright (c) 2015, The Tor Project, Inc. */
/* See LICENSE for licensing information */
#include "or.h"
#ifdef HAVE_SYS_CAPABILITY_H
#include <sys/capability.h>
#endif
#define TEST_BUILT_WITH_CAPS 0
#define TEST_HAVE_CAPS 1
#define TEST_ROOT_CAN_BIND_LOW 2
#define TEST_SETUID 3
#define TEST_SETUID_KEEPCAPS 4
#define TEST_SETUID_STRICT 5
static const char *username;
static const struct {
const char *name;
int test_id;
} which_test[] = {
{ "built-with-caps", TEST_BUILT_WITH_CAPS },
{ "have-caps", TEST_HAVE_CAPS },
{ "root-bind-low", TEST_ROOT_CAN_BIND_LOW },
{ "setuid", TEST_SETUID },
{ "setuid-keepcaps", TEST_SETUID_KEEPCAPS },
{ "setuid-strict", TEST_SETUID_STRICT },
{ NULL, 0 }
};
/* 0 on no, 1 on yes, -1 on failure. */
static int
check_can_bind_low_ports(void)
{
int port;
struct sockaddr_in sin;
memset(&sin, 0, sizeof(sin));
sin.sin_family = AF_INET;
for (port = 600; port < 1024; ++port) {
sin.sin_port = htons(port);
tor_socket_t fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
if (! SOCKET_OK(fd)) {
perror("socket");
return -1;
}
int one = 1;
if (setsockopt(fd, SOL_SOCKET,SO_REUSEADDR, &one, sizeof(one))) {
perror("setsockopt");
tor_close_socket_simple(fd);
return -1;
}
int res = bind(fd, (struct sockaddr *)&sin, sizeof(sin));
tor_close_socket_simple(fd);
if (res == 0) {
/* bind was successful */
return 1;
} else if (errno == EACCES || errno == EPERM) {
/* Got a permission-denied error. */
return 0;
} else if (errno == EADDRINUSE) {
/* Huh; somebody is using that port. */
} else {
perror("bind");
}
}
return -1;
}
int
main(int argc, char **argv)
{
const char *testname;
if (argc != 3) {
fprintf(stderr, "I want 2 arguments: a username and a command.\n");
return 1;
}
if (getuid() != 0) {
fprintf(stderr, "This test only works when it's run as root.\n");
return 1;
}
username = argv[1];
testname = argv[2];
int test_id = -1;
int i;
for (i = 0; which_test[i].name; ++i) {
if (!strcmp(which_test[i].name, testname)) {
test_id = which_test[i].test_id;
break;
}
}
if (test_id == -1) {
fprintf(stderr, "Unrecognized test '%s'\n", testname);
return 1;
}
#ifdef HAVE_LINUX_CAPABILITIES
const int have_cap_support = 1;
#else
const int have_cap_support = 0;
#endif
int okay;
init_logging(1);
log_severity_list_t sev;
memset(&sev, 0, sizeof(sev));
set_log_severity_config(LOG_WARN, LOG_ERR, &sev);
add_stream_log(&sev, "", fileno(stderr));
switch (test_id)
{
case TEST_BUILT_WITH_CAPS:
/* Succeed if we were built with capability support. */
okay = have_cap_support;
break;
case TEST_HAVE_CAPS:
/* Succeed if "capabilities work" == "we were built with capability
* support." */
okay = have_cap_support == have_capability_support();
break;
case TEST_ROOT_CAN_BIND_LOW:
/* Succeed if root can bind low ports. */
okay = check_can_bind_low_ports() == 1;
break;
case TEST_SETUID:
/* Succeed if we can do a setuid with no capability retention, and doing
* so makes us lose the ability to bind low ports */
case TEST_SETUID_KEEPCAPS:
/* Succeed if we can do a setuid with capability retention, and doing so
* does not make us lose the ability to bind low ports */
{
int keepcaps = (test_id == TEST_SETUID_KEEPCAPS);
okay = switch_id(username, keepcaps ? SWITCH_ID_KEEP_BINDLOW : 0) == 0;
if (okay) {
okay = check_can_bind_low_ports() == keepcaps;
}
break;
}
case TEST_SETUID_STRICT:
/* Succeed if, after a setuid, we cannot setuid back, and we cannot
* re-grab any capabilities. */
okay = switch_id(username, SWITCH_ID_KEEP_BINDLOW) == 0;
if (okay) {
/* We'd better not be able to setuid back! */
if (setuid(0) == 0 || errno != EPERM) {
okay = 0;
}
}
#ifdef HAVE_LINUX_CAPABILITIES
if (okay) {
cap_t caps = cap_get_proc();
const cap_value_t caplist[] = {
CAP_SETUID,
};
cap_set_flag(caps, CAP_PERMITTED, 1, caplist, CAP_SET);
if (cap_set_proc(caps) == 0 || errno != EPERM) {
okay = 0;
}
cap_free(caps);
}
#endif
break;
default:
fprintf(stderr, "Unsupported test '%s'\n", testname);
okay = 0;
break;
}
if (!okay) {
fprintf(stderr, "Test %s failed!\n", testname);
}
return (okay ? 0 : 1);
}

25
src/test/test_switch_id.sh Executable file
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@ -0,0 +1,25 @@
#!/bin/sh
if test "`id -u`" != '0'; then
echo "This test only works when run as root. Skipping." >&2
exit 77
fi
if test "`id -u nobody`" = ""; then
echo "This test requires that your system have a 'nobody' user. Sorry." >&2
exit 1
fi
"${builddir:-.}/src/test/test-switch-id" nobody setuid || exit 1
"${builddir:-.}/src/test/test-switch-id" nobody root-bind-low || exit 1
"${builddir:-.}/src/test/test-switch-id" nobody setuid-strict || exit 1
"${builddir:-.}/src/test/test-switch-id" nobody built-with-caps || exit 0
# ... Go beyond this point only if we were built with capability support.
"${builddir:-.}/src/test/test-switch-id" nobody have-caps || exit 1
"${builddir:-.}/src/test/test-switch-id" nobody setuid-keepcaps || exit 1
echo "All okay"
exit 0