va_end(args);
}
+/*** Utility functions ***/
+
static void *
xmalloc(size_t size)
{
return p;
}
+static char *
+xstrdup(char *str)
+{
+ char *p = strdup(str);
+ if (!p)
+ die("Out of memory");
+ return p;
+}
+
+static int dir_exists(char *path)
+{
+ struct stat st;
+ return (stat(path, &st) >= 0 && S_ISDIR(st.st_mode));
+}
+
/*** Environment rules ***/
struct env_rule {
return env;
}
+/*** Mount rules ***/
+
+struct dir_rule {
+ char *inside; // A relative path
+ char *outside; // This can be:
+ // - an absolute path
+ // - a relative path starting with "./"
+ // - one of the above prefixed with "?" to mean "only if exists"
+ // - "procfs"
+ struct dir_rule *next;
+};
+
+static struct dir_rule *first_dir_rule;
+static struct dir_rule **last_dir_rule = &first_dir_rule;
+
+static int add_dir_rule(char *in, char *out)
+{
+ // Make sure that "in" is relative
+ while (in[0] == '/')
+ in++;
+ if (!*in)
+ return 0;
+
+ // Check "out"
+ if (out)
+ {
+ char *o = out;
+ if (*o == '?')
+ o++;
+ if (!(o[0] == '/' ||
+ !strncmp(o, "./", 2) ||
+ !strcmp(o, "procfs")))
+ return 0;
+ }
+
+ // Override an existing rule
+ for (struct dir_rule *r = first_dir_rule; r; r=r->next)
+ if (!strcmp(r->inside, in))
+ {
+ r->outside = out;
+ return 1;
+ }
+
+ // Add a new rule
+ struct dir_rule *r = xmalloc(sizeof(*r));
+ r->inside = in;
+ r->outside = out;
+ *last_dir_rule = r;
+ last_dir_rule = &r->next;
+ r->next = NULL;
+
+ return 1;
+}
+
+static int set_dir_action(char *arg)
+{
+ arg = xstrdup(arg);
+ char *sep = strchr(arg, '=');
+
+ if (sep)
+ {
+ *sep++ = 0;
+ return add_dir_rule(arg, (*sep ? sep : NULL));
+ }
+ else
+ {
+ char *out = xmalloc(1 + strlen(arg) + 1);
+ sprintf(out, "/%s", arg);
+ return add_dir_rule(arg, out);
+ }
+}
+
+static void init_dir_rules(void)
+{
+ set_dir_action("box=./box");
+ set_dir_action("bin");
+ set_dir_action("dev");
+ set_dir_action("lib");
+ set_dir_action("lib64=?/lib64");
+ set_dir_action("proc=procfs");
+ set_dir_action("usr");
+}
+
+static void make_dir(char *path)
+{
+ char *sep = path;
+ for (;;)
+ {
+ sep = strchr(sep, '/');
+ if (sep)
+ *sep = 0;
+
+ if (dir_exists(path))
+ {
+ if (sep)
+ *sep = '/';
+ return;
+ }
+
+ if (mkdir(path, 0777) < 0)
+ die("Cannot create directory %s: %m\n", path);
+
+ if (!sep)
+ return;
+ *sep++ = '/';
+ }
+}
+
+static void apply_dir_rules(void)
+{
+ for (struct dir_rule *r = first_dir_rule; r; r=r->next)
+ {
+ char *in = r->inside;
+ char *out = r->outside;
+ if (!out)
+ {
+ msg("Not binding anything on %s\n", r->inside);
+ continue;
+ }
+
+ if (out[0] == '?')
+ {
+ out++;
+ if (!dir_exists(out))
+ {
+ msg("Not binding %s on %s (does not exist)\n", out, r->inside);
+ continue;
+ }
+ }
+
+ char root_in[1024];
+ snprintf(root_in, sizeof(root_in), "root/%s", in);
+ make_dir(root_in);
+
+ if (!strcmp(out, "procfs"))
+ {
+ msg("Mounting procfs on %s\n", in);
+ if (mount("none", root_in, "proc", 0, "") < 0)
+ die("Cannot mount proc on %s: %m", in);
+ }
+ else
+ {
+ msg("Binding %s on %s\n", out, in);
+ if (mount(out, root_in, "none", MS_BIND | MS_NOSUID | MS_NODEV, "") < 0)
+ die("Cannot bind %s on %s: %m", out, in);
+ }
+ }
+}
+
/*** Control groups ***/
static char cg_path[256];
if (!cg_enable)
return;
- struct stat st;
- if (stat(cg_root, &st) < 0 || !S_ISDIR(st.st_mode))
+ if (!dir_exists(cg_root))
die("Control group filesystem at %s not mounted", cg_root);
snprintf(cg_path, sizeof(cg_path), "%s/box-%d", cg_root, BOX_UID);
if (mount("none", "root", "tmpfs", 0, "mode=755") < 0)
die("Cannot mount root ramdisk: %m");
- static const char * const dirs[] = { "box", "/bin", "/lib", "/lib64", "/usr", "/dev" };
- for (int i=0; i < ARRAY_SIZE(dirs); i++)
- {
- const char *d = dirs[i];
- char buf[1024];
- snprintf(buf, sizeof(buf), "root/%s", (d[0] == '/' ? d+1 : d));
- msg("Binding %s on %s\n", d, buf);
- if (mkdir(buf, 0755) < 0)
- die("mkdir(%s): %m", buf);
- if (mount(d, buf, "none", MS_BIND | MS_NOSUID | MS_NODEV, "") < 0)
- die("Cannot bind %s on %s: %m", d, buf);
- }
-
- if (mkdir("root/proc", 0755) < 0)
- die("Cannot create proc: %m");
- if (mount("none", "root/proc", "proc", 0, "") < 0)
- die("Cannot mount proc: %m");
+ apply_dir_rules();
if (chroot("root") < 0)
die("Chroot failed: %m");
static void
cleanup(void)
{
- struct stat st;
- if (stat("box", &st) < 0 || !S_ISDIR(st.st_mode))
+ if (!dir_exists("box"))
die("Box directory not found, there isn't anything to clean up");
msg("Deleting sandbox directory\n");
static void
run(char **argv)
{
- struct stat st;
- if (stat("box", &st) < 0 || !S_ISDIR(st.st_mode))
+ if (!dir_exists("box"))
die("Box directory not found, did you run `isolate --init'?");
char cmd[256];
-c, --cg[=<parent>]\tPut process in a control group (optionally a sub-group of <parent>)\n\
--cg-mem=<size>\tLimit memory usage of the control group to <size> KB\n\
--cg-timing\t\tTime limits affects total run time of the control group\n\
+-d, --dir=<dir>\t\tMake a directory <dir> visible inside the sandbox\n\
+-d, --dir=<in>=<out>\tMake a directory <out> outside visible as <in> inside\n\
+-d, --dir=<in>=\t\tDelete a previously defined directory rule (even a default one)\n\
-E, --env=<var>\t\tInherit the environment variable <var> from the parent process\n\
-E, --env=<var>=<val>\tSet the environment variable <var> to <val>; unset it if <var> is empty\n\
-x, --extra-time=<time>\tSet extra timeout, before which a timing-out program is not yet killed,\n\
OPT_CG_TIMING,
};
-static const char short_opts[] = "c::eE:i:k:m:M:o:p::r:t:vw:x:";
+static const char short_opts[] = "c::d:eE:i:k:m:M:o:p::r:t:vw:x:";
static const struct option long_opts[] = {
{ "cg", 2, NULL, 'c' },
{ "cg-mem", 1, NULL, OPT_CG_MEM },
{ "cg-timing", 0, NULL, OPT_CG_TIMING },
{ "cleanup", 0, NULL, OPT_CLEANUP },
+ { "dir", 1, NULL, 'd' },
{ "env", 1, NULL, 'E' },
{ "extra-time", 1, NULL, 'x' },
{ "full-env", 0, NULL, 'e' },
int c;
enum opt_code mode = 0;
+ init_dir_rules();
+
while ((c = getopt_long(argc, argv, short_opts, long_opts, NULL)) >= 0)
switch (c)
{
cg_root = optarg;
cg_enable = 1;
break;
+ case 'd':
+ if (!set_dir_action(optarg))
+ usage();
+ break;
case 'e':
pass_environ = 1;
break;
projects / eval.git / commitdiff