exile.h/test.c
Albert S 7115ef8b4d Begin an pledge()-like implementation
This begins a pledge() implementation. This also
retires the previous syscall grouping approach,
as pledge() is the superior mechanism.

Squashed:
test: Begin basic pledge test
pledge: Begin EXILE_SYSCALL_PLEDGE_UNIX/EXILE_SYSCALL_PLEDGE_INET
test: Add pledge socket test
Introduce EXILE_SYSCALL_PLEDGE_DENY_ERROR, remove exile_policy->pledge_policy
pledge: Add PROT_EXEC
2021-12-27 12:35:54 +01:00

488 righe
11 KiB
C

#include "exile.h"
#include <stdbool.h>
#include <sys/types.h>
#include <dirent.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/wait.h>
int xexile_enable_policy(struct exile_policy *policy)
{
int ret = exile_enable_policy(policy);
if(ret != 0)
{
fprintf(stderr, "exile_enable_policy() failed: %i\n", ret);
exit(EXIT_FAILURE);
}
return 0;
}
int test_default_main()
{
struct exile_policy *policy = exile_init_policy();
return xexile_enable_policy(policy);
}
static int test_expected_kill(int (*f)())
{
pid_t pid = fork();
if(pid == 0)
{
return f();
}
int status = 0;
waitpid(pid, &status, 0);
if(WIFSIGNALED(status))
{
int c = WTERMSIG(status);
if(c == SIGSYS)
{
printf("Got expected signal\n");
return 0;
}
printf("Unexpected status code: %i\n", c);
return 1;
}
else
{
int c = WEXITSTATUS(status);
printf("Process was not killed, test fails. Status code of exit: %i\n", c);
return 1;
}
return 0;
}
static int test_successful_exit(int (*f)())
{
pid_t pid = fork();
if(pid == 0)
{
return f();
}
int status = 0;
waitpid(pid, &status, 0);
if(WIFSIGNALED(status))
{
int c = WTERMSIG(status);
printf("Received signal, which was not expected. Signal was: %i\n", c);
return 1;
}
else
{
int c = WEXITSTATUS(status);
if(c != 0)
{
printf("Process failed to exit properly. Status code is: %i\n", c);
}
return c;
}
printf("Process exited sucessfully as expected");
return 0;
}
static int do_test_seccomp_blacklisted()
{
struct exile_policy *policy = exile_init_policy();
exile_append_syscall_policy(policy,EXILE_SYS(getuid), EXILE_SYSCALL_DENY_KILL_PROCESS, NULL, 0);
exile_append_syscall_default_policy(policy, EXILE_SYSCALL_ALLOW);
xexile_enable_policy(policy);
uid_t pid = syscall(EXILE_SYS(geteuid));
pid = syscall(EXILE_SYS(getuid));
return 0;
}
int test_seccomp_blacklisted()
{
return test_expected_kill(&do_test_seccomp_blacklisted);
}
static int do_test_seccomp_blacklisted_call_permitted()
{
struct exile_policy *policy = exile_init_policy();
exile_append_syscall_policy(policy, EXILE_SYS(getuid), EXILE_SYSCALL_DENY_KILL_PROCESS, NULL, 0);
exile_append_syscall_default_policy(policy, EXILE_SYSCALL_ALLOW);
xexile_enable_policy(policy);
//geteuid is not blacklisted, so must succeed
uid_t pid = syscall(EXILE_SYS(geteuid));
return 0;
}
int test_seccomp_blacklisted_call_permitted()
{
return test_successful_exit(&do_test_seccomp_blacklisted_call_permitted);
}
static int do_test_seccomp_x32_kill()
{
struct exile_policy *policy = exile_init_policy();
exile_append_syscall_policy(policy, EXILE_SYS(getuid), EXILE_SYSCALL_DENY_KILL_PROCESS, NULL, 0);
exile_append_syscall_default_policy(policy, EXILE_SYSCALL_ALLOW);
xexile_enable_policy(policy);
/* Attempt to bypass by falling back to x32 should be blocked */
syscall(EXILE_SYS(getuid)+__X32_SYSCALL_BIT);
return 0;
}
int test_seccomp_x32_kill()
{
return test_expected_kill(&do_test_seccomp_x32_kill);
}
/* Tests whether seccomp rules end with a policy matching all syscalls */
int test_seccomp_require_last_matchall()
{
struct exile_policy *policy = exile_init_policy();
exile_append_syscall_policy(policy, EXILE_SYS(getuid), EXILE_SYSCALL_DENY_KILL_PROCESS, NULL, 0);
int status = exile_enable_policy(policy);
if(status == 0)
{
printf("Failed. Should not have been enabled!");
return 1;
}
return 0;
}
static int do_test_seccomp_errno()
{
struct exile_policy *policy = exile_init_policy();
exile_append_syscall_policy(policy, EXILE_SYS(close),EXILE_SYSCALL_DENY_RET_ERROR, NULL, 0);
exile_append_syscall_default_policy(policy, EXILE_SYSCALL_ALLOW);
xexile_enable_policy(policy);
uid_t id = syscall(EXILE_SYS(getuid));
int fd = syscall(EXILE_SYS(close), 0);
printf("close() return code: %i, errno: %s\n", fd, strerror(errno));
return fd == -1 ? 0 : 1;
}
int test_seccomp_errno()
{
return test_successful_exit(&do_test_seccomp_errno);
}
int test_seccomp_argfilter_allowed()
{
struct exile_policy *policy = exile_init_policy();
struct sock_filter argfilter[2] =
{
BPF_STMT(BPF_LD+BPF_W+BPF_ABS, (offsetof(struct seccomp_data, args[1]))),
BPF_JUMP(BPF_JMP+BPF_JSET+BPF_K, O_WRONLY, 0, EXILE_SYSCALL_EXIT_BPF_NO_MATCH)
};
exile_append_syscall_policy(policy, EXILE_SYS(open),EXILE_SYSCALL_DENY_RET_ERROR, argfilter, 2);
exile_append_syscall_default_policy(policy, EXILE_SYSCALL_ALLOW);
xexile_enable_policy(policy);
char *t = "/dev/random";
int ret = (int) syscall(EXILE_SYS(open),t, O_RDONLY);
if(ret == -1)
{
printf("Failed: open was expected to succeed, but returned %i\n", ret);
return 1;
}
return 0;
}
int test_seccomp_argfilter_filtered()
{
struct exile_policy *policy = exile_init_policy();
struct sock_filter argfilter[2] =
{
BPF_STMT(BPF_LD+BPF_W+BPF_ABS, (offsetof(struct seccomp_data, args[1]))),
BPF_JUMP(BPF_JMP+BPF_JSET+BPF_K, O_WRONLY, 0, EXILE_SYSCALL_EXIT_BPF_NO_MATCH)
};
exile_append_syscall_policy(policy, EXILE_SYS(open),EXILE_SYSCALL_DENY_RET_ERROR, argfilter, 2);
exile_append_syscall_default_policy(policy, EXILE_SYSCALL_ALLOW);
xexile_enable_policy(policy);
char *t = "/dev/random";
int ret = (int) syscall(EXILE_SYS(open),t, O_WRONLY);
if(ret != -1)
{
printf("Failed: open was expected to fail, but returned %i\n", ret);
return 1;
}
return 0;
}
int test_seccomp_argfilter_mixed()
{
struct exile_policy *policy = exile_init_policy();
struct sock_filter argfilter[2] =
{
BPF_STMT(BPF_LD+BPF_W+BPF_ABS, (offsetof(struct seccomp_data, args[1]))),
BPF_JUMP(BPF_JMP+BPF_JSET+BPF_K, O_WRONLY, 0, EXILE_SYSCALL_EXIT_BPF_NO_MATCH)
};
exile_append_syscall_policy(policy, EXILE_SYS(stat),EXILE_SYSCALL_DENY_RET_ERROR, NULL,0);
exile_append_syscall_policy(policy, EXILE_SYS(open),EXILE_SYSCALL_DENY_RET_ERROR, argfilter, 2);
exile_append_syscall_policy(policy, EXILE_SYS(getpid),EXILE_SYSCALL_DENY_RET_ERROR, NULL, 0);
exile_append_syscall_default_policy(policy, EXILE_SYSCALL_ALLOW);
xexile_enable_policy(policy);
struct stat statbuf;
int s = (int) syscall(EXILE_SYS(stat), "/dev/urandom", &statbuf);
if(s != -1)
{
printf("Failed: stat was expected to fail, but returned %i\n", s);
return 1;
}
pid_t p = (pid_t) syscall(EXILE_SYS(getpid));
if(p != -1)
{
printf("Failed: getpid was expected to fail, but returned %i\n", p);
return 1;
}
char *t = "/dev/random";
int ret = (int) syscall(EXILE_SYS(open),t, O_WRONLY);
if(ret != -1)
{
printf("Failed: open was expected to fail, but returned %i\n", ret);
return 1;
}
ret = (int) syscall(EXILE_SYS(open), t, O_RDONLY);
if(ret == -1)
{
printf("Failed: open with O_RDONLY was expected to succeed, but returned %i\n", ret);
return 1;
}
return 0;
}
int do_test_seccomp_pledge_socket()
{
struct exile_policy *policy = exile_init_policy();
policy->pledge_promises = EXILE_SYSCALL_PLEDGE_STDIO | EXILE_SYSCALL_PLEDGE_INET | EXILE_SYSCALL_PLEDGE_DENY_ERROR;
xexile_enable_policy(policy);
int s = socket(AF_INET, SOCK_STREAM, 0);
if(s == -1)
{
printf("Failed: socket was expected to succeed, but returned %i\n", s);
return 1;
}
s = socket(AF_UNIX, SOCK_DGRAM, 0);
if(s != -1)
{
printf("Failed: socket was expected to fail, but returned %i\n", s);
return 1;
}
return 0;
}
int do_test_seccomp_pledge_open()
{
struct exile_policy *policy = exile_init_policy();
policy->pledge_promises = EXILE_SYSCALL_PLEDGE_STDIO | EXILE_SYSCALL_PLEDGE_RPATH | EXILE_SYSCALL_PLEDGE_DENY_ERROR;
xexile_enable_policy(policy);
int ret = open("/dev/urandom", O_WRONLY | O_APPEND);
if(ret != -1)
{
printf("Failed: open was expected to fail, but returned %i\n", ret);
return 1;
}
ret = open("/dev/urandom", O_RDWR);
if(ret != -1)
{
printf("Failed: open O_RDWR was expected to fail, but returned %i\n", ret);
return 1;
}
ret = open("/dev/urandom", O_RDONLY);
if(ret == -1)
{
printf("Failed: open was expected to succceed, but returned %i\n", ret);
return 1;
}
return 0;
}
int test_seccomp_pledge()
{
int ret = test_successful_exit(&do_test_seccomp_pledge_open);
if(ret != 0)
{
printf("Failed: do_test_seccomp_pledge_open()\n");
return 1;
}
ret = test_successful_exit(&do_test_seccomp_pledge_socket);
if(ret != 0)
{
printf("Failed: do_test_seccomp_pledge_socket()\n");
return 1;
}
return 0;
}
#if HAVE_LANDLOCK == 1
int test_landlock()
{
struct exile_policy *policy = exile_init_policy();
exile_append_path_policy(policy, EXILE_FS_ALLOW_ALL_READ, "/proc/self/fd");
xexile_enable_policy(policy);
int fd = open("/", O_RDONLY | O_CLOEXEC);
if(fd < 0)
{
return 0;
}
return 1;
}
int test_landlock_deny_write()
{
struct exile_policy *policy = exile_init_policy();
exile_append_path_policy(policy, EXILE_FS_ALLOW_ALL_READ, "/tmp/");
xexile_enable_policy(policy);
int fd = open("/tmp/a", O_WRONLY | O_CLOEXEC);
if(fd < 0)
{
return 0;
}
return 1;
}
#else
int test_landlock()
{
return 2;
}
int test_landlock_deny_write()
{
return 2;
}
#endif
int test_nofs()
{
struct exile_policy *policy = exile_init_policy();
policy->no_fs = 1;
xexile_enable_policy(policy);
int s = socket(AF_INET,SOCK_STREAM,0);
if(s == -1)
{
fprintf(stderr, "Failed to open socket but this was not requested by policy\n");
return 1;
}
/* Expect seccomp to take care of this */
if(open("/test", O_CREAT | O_WRONLY) >= 0)
{
fprintf(stderr, "Failed: We do not expect write access\n");
return 1;
}
return 0;
}
int test_no_new_fds()
{
struct exile_policy *policy = exile_init_policy();
policy->no_new_fds = 1;
xexile_enable_policy(policy);
if(open("/tmp/test", O_CREAT | O_WRONLY) >= 0)
{
fprintf(stderr, "Failed: Could open new file descriptor\n");
return -1;
}
int s = socket(AF_INET,SOCK_STREAM,0);
if(s >= 0)
{
fprintf(stderr, "Failed: socket got opened but policy denied\n");
return -1;
}
return 0;
}
struct dispatcher
{
char *name;
int (*f)();
};
struct dispatcher dispatchers[] = {
{ "default", &test_default_main },
{ "seccomp-blacklisted", &test_seccomp_blacklisted},
{ "seccomp-blacklisted-permitted", &test_seccomp_blacklisted_call_permitted},
{ "seccomp-x32-kill", &test_seccomp_x32_kill},
{ "seccomp-require-last-matchall", &test_seccomp_require_last_matchall},
{ "seccomp-errno", &test_seccomp_errno},
{ "seccomp-argfilter-allowed", &test_seccomp_argfilter_allowed},
{ "seccomp-argfilter-filtered", &test_seccomp_argfilter_filtered},
{ "seccomp-argfilter-mixed", &test_seccomp_argfilter_mixed},
{ "seccomp-pledge", &test_seccomp_pledge},
{ "landlock", &test_landlock},
{ "landlock-deny-write", &test_landlock_deny_write },
{ "no_fs", &test_nofs},
{ "no_new_fds", &test_no_new_fds}
};
int main(int argc, char *argv[])
{
if(argc < 2)
{
fprintf(stderr, "Usage: %s [testname]\n", argv[0]);
return EXIT_FAILURE;
}
char *test = argv[1];
if(strcmp(test, "--dumptests") == 0)
{
for(unsigned int i = 0; i < sizeof(dispatchers)/sizeof(dispatchers[0]); i++)
{
printf("%s\n", dispatchers[i].name);
}
return EXIT_SUCCESS;
}
for(unsigned int i = 0; i < sizeof(dispatchers)/sizeof(dispatchers[0]); i++)
{
struct dispatcher *current = &dispatchers[i];
if(strcmp(current->name, test) == 0)
{
return current->f();
}
}
fprintf(stderr, "Unknown test\n");
return EXIT_FAILURE;
}