Isolate: Cleanups, configuration and TODO

[moe.git] / isolate / isolate.c

diff --git a/isolate/isolate.c b/isolate/isolate.c
index dca6c5d27ca6cdb1e72dbb4cd9066e7f7707be17..6ce7b5b77e389135e9afdb0a3c346a349380ea2d 100644 (file)
--- a/isolate/isolate.c
+++ b/isolate/isolate.c
@@ -31,10 +31,9 @@
 #define UNUSED __attribute__((unused))
 #define ARRAY_SIZE(a) (int)(sizeof(a)/sizeof(a[0]))
 
-// FIXME: Make configurable, probably in compile time
-#define BOX_DIR "/tmp/box"
-#define BOX_UID 60000
-#define BOX_GID 60000
+#define BOX_DIR CONFIG_ISOLATE_BOX_DIR
+#define BOX_UID CONFIG_ISOLATE_BOX_UID
+#define BOX_GID CONFIG_ISOLATE_BOX_GID
 
 static int timeout;                    /* milliseconds */
 static int wall_timeout;
@@ -760,16 +759,12 @@ setup_root(void)
   if (mount("none", "root", "tmpfs", 0, "mode=755") < 0)
     die("Cannot mount root ramdisk: %m");
 
-  // FIXME: Make the list of bind-mounts configurable
-  // FIXME: Virtual /dev?
-  // FIXME: Read-only mounts?
-
   static const char * const dirs[] = { "box", "/bin", "/lib", "/usr", "/dev" };
   for (int i=0; i < ARRAY_SIZE(dirs); i++)
     {
       const char *d = dirs[i];
-      char buf[1024];  // FIXME
-      sprintf(buf, "root/%s", (d[0] == '/' ? d+1 : d));
+      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);
@@ -789,33 +784,21 @@ setup_root(void)
     die("Cannot change current directory: %m");
 }
 
-static int
-box_inside(void *arg)
+static void
+setup_credentials(void)
 {
-  write_errors_to_fd = error_pipes[1];
-  close(error_pipes[0]);
-
-  char **argv = arg;
-  int argc = 0;
-  while (argv[argc])
-    argc++;
-
-  struct rlimit rl;
-  char *args[argc+1];
-
-  memcpy(args, argv, argc * sizeof(char *));
-  args[argc] = NULL;
-
-  cg_enter();
-  setup_root();
-
   if (setresgid(BOX_GID, BOX_GID, BOX_GID) < 0)
     die("setresgid: %m");
   if (setgroups(0, NULL) < 0)
     die("setgroups: %m");
   if (setresuid(BOX_UID, BOX_UID, BOX_UID) < 0)
     die("setresuid: %m");
+  setpgrp();
+}
 
+static void
+setup_fds(void)
+{
   if (redir_stdin)
     {
       close(0);
@@ -836,39 +819,54 @@ box_inside(void *arg)
     }
   else
     dup2(1, 2);
-  setpgrp();
+}
 
-  if (memory_limit)
-    {
-      rl.rlim_cur = rl.rlim_max = memory_limit * 1024;
-      if (setrlimit(RLIMIT_AS, &rl) < 0)
-       die("setrlimit(RLIMIT_AS): %m");
-    }
+static void
+setup_rlim(const char *res_name, int res, rlim_t limit)
+{
+  struct rlimit rl = { .rlim_cur = limit, .rlim_max = limit };
+  if (setrlimit(res, &rl) < 0)
+    die("setrlimit(%s, %jd)", res_name, (intmax_t) limit);
+}
 
-  rl.rlim_cur = rl.rlim_max = (stack_limit ? (rlim_t)stack_limit * 1024 : RLIM_INFINITY);
-  if (setrlimit(RLIMIT_STACK, &rl) < 0)
-    die("setrlimit(RLIMIT_STACK): %m");
+static void
+setup_rlimits(void)
+{
+#define RLIM(res, val) setup_rlim("RLIMIT_" #res, RLIMIT_##res, val)
 
-  rl.rlim_cur = rl.rlim_max = 64;
-  if (setrlimit(RLIMIT_NOFILE, &rl) < 0)
-    die("setrlimit(RLIMIT_NOFILE): %m");
+  if (memory_limit)
+    RLIM(AS, memory_limit * 1024);
+
+  RLIM(STACK, (stack_limit ? (rlim_t)stack_limit * 1024 : RLIM_INFINITY));
+  RLIM(NOFILE, 64);
+  RLIM(MEMLOCK, 0);
 
   if (max_processes)
-    {
-      rl.rlim_cur = rl.rlim_max = max_processes;
-      if (setrlimit(RLIMIT_NPROC, &rl) < 0)
-       die("setrlimit(RLIMIT_NPROC): %m");
-    }
+    RLIM(NPROC, max_processes);
 
-  rl.rlim_cur = rl.rlim_max = 0;
-  if (setrlimit(RLIMIT_MEMLOCK, &rl) < 0)
-    die("setrlimit(RLIMIT_MEMLOCK): %m");
+#undef RLIM
+}
 
+static int
+box_inside(void *arg)
+{
+  char **args = arg;
+  write_errors_to_fd = error_pipes[1];
+  close(error_pipes[0]);
+
+  cg_enter();
+  setup_root();
+  setup_credentials();
+  setup_fds();
+  setup_rlimits();
   char **env = setup_environment();
+
   execve(args[0], args, env);
   die("execve(\"%s\"): %m", args[0]);
 }
 
+/*** Commands ***/
+
 static void
 init(void)
 {
@@ -935,6 +933,8 @@ show_version(void)
   printf("Sandbox credentials: uid=%u gid=%u\n", BOX_UID, BOX_GID);
 }
 
+/*** Options ***/
+
 static void
 usage(void)
 {