/*
- * A Simple Testing Sandbox
+ * A Simple Sandbox for MO-Eval
*
- * (c) 2001--2004 Martin Mares <mj@ucw.cz>
+ * (c) 2001--2008 Martin Mares <mj@ucw.cz>
*/
#define _LARGEFILE64_SOURCE
#define UNUSED __attribute__((unused))
static int filter_syscalls; /* 0=off, 1=liberal, 2=totalitarian */
-static int timeout;
+static int timeout; /* milliseconds */
+static int wall_timeout;
static int pass_environ;
-static int use_wall_clock;
static int file_access;
static int verbose;
static int memory_limit;
-static int allow_times;
static char *redir_stdin, *redir_stdout;
static char *set_cwd;
static pid_t box_pid;
static int is_ptraced;
static volatile int timer_tick;
-static time_t start_time;
+static struct timeval start_time;
static int ticks_per_sec;
+static int exec_seen;
#if defined(__GLIBC__) && __GLIBC__ == 2 && __GLIBC_MINOR__ > 0
/* glibc 2.1 or newer -> has lseek64 */
}
static void __attribute__((format(printf,1,2)))
-log(char *msg, ...)
+msg(char *msg, ...)
{
va_list args;
va_start(args, msg);
va_end(args);
}
+static const char * const syscall_tab[] = {
+#include "syscall-table.h"
+};
+#define NUM_SYSCALLS (sizeof(syscall_tab)/sizeof(syscall_tab[0]))
+#define NUM_ACTIONS (NUM_SYSCALLS+64)
+
+enum syscall_action {
+ SC_DEFAULT, // Use the default action
+ SC_NO, // Always forbid
+ SC_YES, // Always permit
+ SC_FILENAME, // Permit if arg1 is a known filename
+ SC_LIBERAL = 128, // Valid only in liberal mode
+};
+
+static unsigned char syscall_action[NUM_ACTIONS] = {
+#define S(x) [__NR_##x]
+
+ // Syscalls permitted for specific file names
+ S(open) = SC_FILENAME,
+ S(creat) = SC_FILENAME,
+ S(unlink) = SC_FILENAME,
+ S(oldstat) = SC_FILENAME,
+ S(access) = SC_FILENAME,
+ S(oldlstat) = SC_FILENAME,
+ S(truncate) = SC_FILENAME,
+ S(stat) = SC_FILENAME,
+ S(lstat) = SC_FILENAME,
+ S(truncate64) = SC_FILENAME,
+ S(stat64) = SC_FILENAME,
+ S(lstat64) = SC_FILENAME,
+ S(readlink) = SC_FILENAME,
+
+ // Syscalls permitted always
+ S(exit) = SC_YES,
+ S(read) = SC_YES,
+ S(write) = SC_YES,
+ S(close) = SC_YES,
+ S(lseek) = SC_YES,
+ S(getpid) = SC_YES,
+ S(getuid) = SC_YES,
+ S(oldfstat) = SC_YES,
+ S(dup) = SC_YES,
+ S(brk) = SC_YES,
+ S(getgid) = SC_YES,
+ S(geteuid) = SC_YES,
+ S(getegid) = SC_YES,
+ S(dup2) = SC_YES,
+ S(ftruncate) = SC_YES,
+ S(fstat) = SC_YES,
+ S(personality) = SC_YES,
+ S(_llseek) = SC_YES,
+ S(readv) = SC_YES,
+ S(writev) = SC_YES,
+ S(getresuid) = SC_YES,
+#ifdef __NR_pread64
+ S(pread64) = SC_YES,
+ S(pwrite64) = SC_YES,
+#else
+ S(pread) = SC_YES,
+ S(pwrite) = SC_YES,
+#endif
+ S(ftruncate64) = SC_YES,
+ S(fstat64) = SC_YES,
+ S(fcntl) = SC_YES,
+ S(fcntl64) = SC_YES,
+ S(mmap) = SC_YES,
+ S(munmap) = SC_YES,
+ S(ioctl) = SC_YES,
+ S(uname) = SC_YES,
+ S(gettid) = SC_YES,
+ S(set_thread_area) = SC_YES,
+ S(get_thread_area) = SC_YES,
+ S(exit_group) = SC_YES,
+
+ // Syscalls permitted only in liberal mode
+ S(time) = SC_YES | SC_LIBERAL,
+ S(alarm) = SC_YES | SC_LIBERAL,
+ S(pause) = SC_YES | SC_LIBERAL,
+ S(signal) = SC_YES | SC_LIBERAL,
+ S(fchmod) = SC_YES | SC_LIBERAL,
+ S(sigaction) = SC_YES | SC_LIBERAL,
+ S(sgetmask) = SC_YES | SC_LIBERAL,
+ S(ssetmask) = SC_YES | SC_LIBERAL,
+ S(sigsuspend) = SC_YES | SC_LIBERAL,
+ S(sigpending) = SC_YES | SC_LIBERAL,
+ S(getrlimit) = SC_YES | SC_LIBERAL,
+ S(getrusage) = SC_YES | SC_LIBERAL,
+ S(gettimeofday) = SC_YES | SC_LIBERAL,
+ S(select) = SC_YES | SC_LIBERAL,
+ S(readdir) = SC_YES | SC_LIBERAL,
+ S(setitimer) = SC_YES | SC_LIBERAL,
+ S(getitimer) = SC_YES | SC_LIBERAL,
+ S(sigreturn) = SC_YES | SC_LIBERAL,
+ S(mprotect) = SC_YES | SC_LIBERAL,
+ S(sigprocmask) = SC_YES | SC_LIBERAL,
+ S(getdents) = SC_YES | SC_LIBERAL,
+ S(getdents64) = SC_YES | SC_LIBERAL,
+ S(_newselect) = SC_YES | SC_LIBERAL,
+ S(fdatasync) = SC_YES | SC_LIBERAL,
+ S(mremap) = SC_YES | SC_LIBERAL,
+ S(poll) = SC_YES | SC_LIBERAL,
+ S(getcwd) = SC_YES | SC_LIBERAL,
+ S(nanosleep) = SC_YES | SC_LIBERAL,
+ S(rt_sigreturn) = SC_YES | SC_LIBERAL,
+ S(rt_sigaction) = SC_YES | SC_LIBERAL,
+ S(rt_sigprocmask) = SC_YES | SC_LIBERAL,
+ S(rt_sigpending) = SC_YES | SC_LIBERAL,
+ S(rt_sigtimedwait) = SC_YES | SC_LIBERAL,
+ S(rt_sigqueueinfo) = SC_YES | SC_LIBERAL,
+ S(rt_sigsuspend) = SC_YES | SC_LIBERAL,
+ S(mmap2) = SC_YES | SC_LIBERAL,
+ S(_sysctl) = SC_YES | SC_LIBERAL,
+#undef S
+};
+
+static const char *
+syscall_name(unsigned int id, char *buf)
+{
+ if (id < NUM_SYSCALLS && syscall_tab[id])
+ return syscall_tab[id];
+ else
+ {
+ sprintf(buf, "#%d", id);
+ return buf;
+ }
+}
+
+static int
+syscall_by_name(char *name)
+{
+ for (unsigned int i=0; i<sizeof(syscall_tab)/sizeof(syscall_tab[0]); i++)
+ if (!strcmp(syscall_tab[i], name))
+ return i;
+ return -1;
+}
+
static void
valid_filename(unsigned long addr)
{
static int mem_fd;
if (!file_access)
- die("File access forbidden.");
+ die("File access forbidden");
if (file_access >= 9)
return;
if (l > remains)
l = remains;
if (!l)
- die("Access to file with name too long.");
+ die("Access to file with name too long");
if (long_seek(mem_fd, addr, SEEK_SET) < 0)
die("long_seek(mem): %m");
remains = read(mem_fd, end, l);
if (remains < 0)
die("read(mem): %m");
if (!remains)
- die("Access to file with name out of memory.");
+ die("Access to file with name out of memory");
end += l;
addr += l;
}
}
while (*p++);
- log("[%s] ", namebuf);
+ msg("[%s] ", namebuf);
if (file_access >= 3)
return;
if (!strchr(namebuf, '/') && strcmp(namebuf, ".."))
!strncmp(namebuf, "/usr/share/zoneinfo/", 20))
return;
}
- die("Forbidden access to file `%s'.", namebuf);
+ die("Forbidden access to file `%s'", namebuf);
}
static int
valid_syscall(struct user *u)
{
- switch (u->regs.orig_eax)
+ unsigned int sys = u->regs.orig_eax;
+ enum syscall_action act = (sys < NUM_ACTIONS) ? syscall_action[sys] : SC_DEFAULT;
+
+ if (act & SC_LIBERAL)
{
- case __NR_execve:
- {
- static int exec_counter;
- return !exec_counter++;
- }
- case __NR_open:
- case __NR_creat:
- case __NR_unlink:
- case __NR_oldstat:
- case __NR_access:
- case __NR_oldlstat:
- case __NR_truncate:
- case __NR_stat:
- case __NR_lstat:
- case __NR_truncate64:
- case __NR_stat64:
- case __NR_lstat64:
- case __NR_readlink:
- valid_filename(u->regs.ebx);
+ if (filter_syscalls == 1)
+ act &= ~SC_LIBERAL;
+ else
+ act = SC_DEFAULT;
+ }
+ switch (act)
+ {
+ case SC_YES:
return 1;
- case __NR_exit:
- case __NR_read:
- case __NR_write:
- case __NR_close:
- case __NR_lseek:
- case __NR_getpid:
- case __NR_getuid:
- case __NR_oldfstat:
- case __NR_dup:
- case __NR_brk:
- case __NR_getgid:
- case __NR_geteuid:
- case __NR_getegid:
- case __NR_dup2:
- case __NR_ftruncate:
- case __NR_fstat:
- case __NR_personality:
- case __NR__llseek:
- case __NR_readv:
- case __NR_writev:
- case __NR_getresuid:
-#ifdef __NR_pread64
- case __NR_pread64:
- case __NR_pwrite64:
-#else
- case __NR_pread:
- case __NR_pwrite:
-#endif
- case __NR_ftruncate64:
- case __NR_fstat64:
- case __NR_fcntl:
- case __NR_fcntl64:
- case __NR_mmap:
- case __NR_munmap:
- case __NR_ioctl:
- case __NR_uname:
- case __NR_gettid:
- case __NR_set_thread_area:
- case __NR_get_thread_area:
- case __NR_exit_group:
+ case SC_NO:
+ return 0;
+ case SC_FILENAME:
+ valid_filename(u->regs.ebx);
return 1;
- case __NR_time:
- case __NR_alarm:
- case __NR_pause:
- case __NR_signal:
- case __NR_fchmod:
- case __NR_sigaction:
- case __NR_sgetmask:
- case __NR_ssetmask:
- case __NR_sigsuspend:
- case __NR_sigpending:
- case __NR_getrlimit:
- case __NR_getrusage:
- case __NR_gettimeofday:
- case __NR_select:
- case __NR_readdir:
- case __NR_setitimer:
- case __NR_getitimer:
- case __NR_sigreturn:
- case __NR_mprotect:
- case __NR_sigprocmask:
- case __NR_getdents:
- case __NR_getdents64:
- case __NR__newselect:
- case __NR_fdatasync:
- case __NR_mremap:
- case __NR_poll:
- case __NR_getcwd:
- case __NR_nanosleep:
- case __NR_rt_sigreturn:
- case __NR_rt_sigaction:
- case __NR_rt_sigprocmask:
- case __NR_rt_sigpending:
- case __NR_rt_sigtimedwait:
- case __NR_rt_sigqueueinfo:
- case __NR_rt_sigsuspend:
- case __NR_mmap2:
- case __NR__sysctl:
- return (filter_syscalls == 1);
- case __NR_times:
- return allow_times;
+ default: ;
+ }
+
+ switch (sys)
+ {
case __NR_kill:
if (u->regs.ebx == box_pid)
- die("Commited suicide by signal %d.", (int)u->regs.ecx);
+ die("Committed suicide by signal %d", (int)u->regs.ecx);
return 0;
case __NR_tgkill:
if (u->regs.ebx == box_pid && u->regs.ecx == box_pid)
- die("Commited suicide by signal %d.", (int)u->regs.edx);
+ die("Committed suicide by signal %d", (int)u->regs.edx);
return 0;
default:
return 0;
signal_int(int unused UNUSED)
{
/* Interrupts are fatal, so no synchronization requirements. */
- die("Interrupted.");
+ die("Interrupted");
}
static void
check_timeout(void)
{
- int sec;
-
- if (use_wall_clock)
- sec = time(NULL) - start_time;
- else
+ if (wall_timeout)
+ {
+ struct timeval now, wall;
+ int wall_ms;
+ gettimeofday(&now, NULL);
+ timersub(&now, &start_time, &wall);
+ wall_ms = wall.tv_sec*1000 + wall.tv_usec/1000;
+ if (wall_ms > wall_timeout)
+ die("Time limit exceeded (wall clock)");
+ if (verbose > 1)
+ fprintf(stderr, "[wall time check: %d msec]\n", wall_ms);
+ }
+ if (timeout)
{
char buf[4096], *x;
- int c, utime, stime;
+ int c, utime, stime, ms;
static int proc_status_fd;
if (!proc_status_fd)
{
x++;
if (sscanf(x, "%*c %*d %*d %*d %*d %*d %*d %*d %*d %*d %*d %d %d", &utime, &stime) != 2)
die("proc syntax error 2");
- sec = (utime + stime)/ticks_per_sec;
+ ms = (utime + stime) * 1000 / ticks_per_sec;
+ if (verbose > 1)
+ fprintf(stderr, "[time check: %d msec]\n", ms);
+ if (ms > timeout)
+ die("Time limit exceeded");
}
- if (verbose > 1)
- fprintf(stderr, "[timecheck: %d seconds]\n", sec);
- if (sec > timeout)
- die("Time limit exceeded.");
}
static void
bzero(&sa, sizeof(sa));
sa.sa_handler = signal_int;
sigaction(SIGINT, &sa, NULL);
- start_time = time(NULL);
+ gettimeofday(&start_time, NULL);
ticks_per_sec = sysconf(_SC_CLK_TCK);
if (ticks_per_sec <= 0)
die("Invalid ticks_per_sec!");
- if (timeout)
+ if (timeout || wall_timeout)
{
sa.sa_handler = signal_alarm;
sigaction(SIGALRM, &sa, NULL);
die("wait4: unknown pid %d exited!", p);
if (WIFEXITED(stat))
{
- struct timeval total;
- int wall;
+ struct timeval total, now, wall;
+ int total_ms, wall_ms;
box_pid = 0;
if (WEXITSTATUS(stat))
- die("Exited with error status %d.", WEXITSTATUS(stat));
+ die("Exited with error status %d", WEXITSTATUS(stat));
timeradd(&rus.ru_utime, &rus.ru_stime, &total);
- wall = time(NULL) - start_time;
- if ((use_wall_clock ? wall : total.tv_sec) > timeout)
- die("Time limit exceeded (after exit).");
- fprintf(stderr, "OK (%d sec real, %d sec wall, %d syscalls)\n", (int) total.tv_sec, wall, syscall_count);
+ total_ms = total.tv_sec*1000 + total.tv_usec/1000;
+ gettimeofday(&now, NULL);
+ timersub(&now, &start_time, &wall);
+ wall_ms = wall.tv_sec*1000 + wall.tv_usec/1000;
+ if (timeout && total_ms > timeout)
+ die("Time limit exceeded");
+ if (wall_timeout && wall_ms > wall_timeout)
+ die("Time limit exceeded (wall clock)");
+ fprintf(stderr, "OK (%d.%03d sec real, %d.%03d sec wall, %d syscalls)\n",
+ (int) total.tv_sec, (int) total.tv_usec/1000,
+ (int) wall.tv_sec, (int) wall.tv_usec/1000,
+ syscall_count);
exit(0);
}
if (WIFSIGNALED(stat))
{
box_pid = 0;
- die("Caught fatal signal %d.", WTERMSIG(stat));
+ die("Caught fatal signal %d%s", WTERMSIG(stat), (syscall_count ? "" : " during startup"));
}
if (WIFSTOPPED(stat))
{
die("ptrace(PTRACE_GETREGS): %m");
stop_count++;
if (!stop_count) /* Traceme request */
- log(">> Traceme request caught\n");
+ msg(">> Traceme request caught\n");
else if (stop_count & 1) /* Syscall entry */
{
- log(">> Syscall %3ld (%08lx,%08lx,%08lx) ", u.regs.orig_eax, u.regs.ebx, u.regs.ecx, u.regs.edx);
- syscall_count++;
- if (!valid_syscall(&u))
+ char namebuf[32];
+ msg(">> Syscall %-12s (%08lx,%08lx,%08lx) ", syscall_name(u.regs.orig_eax, namebuf), u.regs.ebx, u.regs.ecx, u.regs.edx);
+ if (!exec_seen)
+ {
+ msg("[master] ");
+ if (u.regs.orig_eax == __NR_execve)
+ exec_seen = 1;
+ }
+ else if (valid_syscall(&u))
+ syscall_count++;
+ else
{
/*
* Unfortunately, PTRACE_KILL kills _after_ the syscall completes,
u.regs.orig_eax = 0xffffffff;
if (ptrace(PTRACE_SETREGS, box_pid, NULL, &u) < 0)
die("ptrace(PTRACE_SETREGS): %m");
- die("Forbidden syscall %d.", sys);
+ die("Forbidden syscall %s", syscall_name(sys, namebuf));
}
}
else /* Syscall return */
- log("= %ld\n", u.regs.eax);
+ msg("= %ld\n", u.regs.eax);
ptrace(PTRACE_SYSCALL, box_pid, 0, 0);
}
else if (sig != SIGSTOP && sig != SIGXCPU && sig != SIGXFSZ)
{
- log(">> Signal %d\n", sig);
+ msg(">> Signal %d\n", sig);
ptrace(PTRACE_SYSCALL, box_pid, 0, sig);
}
else
- die("Received signal %d.", sig);
+ die("Received signal %d", sig);
}
else
die("wait4: unknown status %x, giving up!", stat);
{
struct rlimit rl;
char *args[argc+1];
- char *env[1] = { NULL };
+ char *env[] = { "LIBC_FATAL_STDERR_=1", NULL };
memcpy(args, argv, argc * sizeof(char *));
args[argc] = NULL;
rl.rlim_cur = rl.rlim_max = 64;
if (setrlimit(RLIMIT_NOFILE, &rl) < 0)
die("setrlimit: %m");
- if (filter_syscalls && ptrace(PTRACE_TRACEME) < 0)
- die("ptrace(PTRACE_TRACEME): %m");
+ if (filter_syscalls)
+ {
+ if (ptrace(PTRACE_TRACEME) < 0)
+ die("ptrace(PTRACE_TRACEME): %m");
+ /* Trick: Make sure that we are stopped until the boxkeeper wakes up. */
+ signal(SIGCHLD, SIG_IGN);
+ raise(SIGCHLD);
+ }
execve(args[0], args, (pass_environ ? environ : env));
die("execve(\"%s\"): %m", args[0]);
}
-i <file>\tRedirect stdin from <file>\n\
-m <size>\tLimit address space to <size> KB\n\
-o <file>\tRedirect stdout to <file>\n\
--t <time>\tStop after <time> seconds\n\
+-t <time>\tSet run time limit (seconds, fractions allowed)\n\
-T\t\tAllow syscalls for measuring run time\n\
-v\t\tBe verbose\n\
--w\t\tMeasure wall clock time instead of run time\n\
+-w <time>\tSet wall clock time limit (seconds, fractions allowed)\n\
");
exit(1);
}
int c;
uid_t uid;
- while ((c = getopt(argc, argv, "a:c:efi:m:o:t:Tvw")) >= 0)
+ while ((c = getopt(argc, argv, "a:c:efi:m:o:t:Tvw:")) >= 0)
switch (c)
{
case 'a':
redir_stdout = optarg;
break;
case 't':
- timeout = atol(optarg);
+ timeout = 1000*atof(optarg);
break;
case 'T':
- allow_times++;
+ syscall_action[__NR_times] = SC_YES;
break;
case 'v':
verbose++;
break;
case 'w':
- use_wall_clock = 1;
+ wall_timeout = 1000*atof(optarg);
break;
default:
usage();
projects / eval.git / blobdiff