Cleaner semantics for _gpgrt_process_spawn without a callback.

* src/gpg-error.h.in (@define:struct_spawn_cb_arg@): Remove.
(gpgrt_spawn_actions_t): New.
(@define:spawn_actions_functions@): New.
* src/gpgrt-int.h (_gpgrt_spawn_actions_new)
(_gpgrt_spawn_actions_release, _gpgrt_spawn_actions_set_envvars)
(_gpgrt_spawn_actions_set_redirect): New.
[HAVE_W32_SYSTEM] (_gpgrt_spawn_actions_set_inherit_handles): New.
[!HAVE_W32_SYSTEM] (_gpgrt_spawn_actions_set_inherit_fds)
(_gpgrt_spawn_actions_set_atfork): New.
(_gpgrt_process_spawn): Use gpgrt_spawn_actions_t.
(_gpgrt_spawn_helper): Remove.
* src/mkheader.c: Emit gpgrt_spawn_actions_* definition.
* src/spawn-posix.c(_gpgrt_spawn_actions_new)
(_gpgrt_spawn_actions_release, _gpgrt_spawn_actions_set_envvars)
(_gpgrt_spawn_actions_set_redirect)
(_gpgrt_spawn_actions_set_inherit_fds)
(_gpgrt_spawn_actions_set_atfork): New.
(spawn_detached, _gpgrt_process_spawn): Use gpgrt_spawn_actions_t.
(_gpgrt_spawn_helper): Remove.
* src/spawn-w32.c: Ditto, with
_gpgrt_spawn_actions_set_inherit_handles, but no
_gpgrt_spawn_actions_set_atfork.

--

GnuPG-bug-id: 6249
Signed-off-by: NIIBE Yutaka <[email protected]>

1 files changed, 89 insertions, 41 deletions

diff --git a/src/spawn-posix.c b/src/spawn-posix.c
index 1c9f7ff..f31b9c5 100644
--- a/src/spawn-posix.c
+++ b/src/spawn-posix.c
@@ -154,7 +154,7 @@ get_max_fds (void)
  * which shall not be closed.  This list shall be sorted in ascending
  * order with the end marked by -1.  */
 void
-_gpgrt_close_all_fds (int first, int *except)
+_gpgrt_close_all_fds (int first, const int *except)
 {
   int max_fd = get_max_fds ();
   int fd, i, except_start;
@@ -287,32 +287,47 @@ posix_open_null (int for_write)
   return fd;
 }
 
+struct gpgrt_spawn_actions {
+  int fd[3];
+  const int *except_fds;
+  char **env;
+  void (*atfork) (void *);
+  void *atfork_arg;
+};
+
 static void
-my_exec (const char *pgmname, const char *argv[], struct spawn_cb_arg *sca)
+my_exec (const char *pgmname, const char *argv[],
+         gpgrt_spawn_actions_t act)
 {
   int i;
 
   /* Assign /dev/null to unused FDs.  */
   for (i = 0; i <= 2; i++)
-    if (sca->fds[i] == -1)
-      sca->fds[i] = posix_open_null (i);
+    if (act->fd[i] == -1)
+      act->fd[i] = posix_open_null (i);
 
   /* Connect the standard files.  */
   for (i = 0; i <= 2; i++)
-    if (sca->fds[i] != i)
+    if (act->fd[i] != i)
       {
-        if (dup2 (sca->fds[i], i) == -1)
+        if (dup2 (act->fd[i], i) == -1)
           _gpgrt_log_fatal ("dup2 std%s failed: %s\n",
                             i==0?"in":i==1?"out":"err", strerror (errno));
         /*
-         * We don't close sca.fds[i] here, but close them by
+         * We don't close act->fd[i] here, but close them by
          * close_all_fds.  Note that there may be same one in three of
-         * sca->fds[i].
+         * act->fd[i].
          */
       }
 
   /* Close all other files.  */
-  _gpgrt_close_all_fds (3, sca->except_fds);
+  _gpgrt_close_all_fds (3, act->except_fds);
+
+  if (act->env)
+    environ = act->env;
+
+  if (act->atfork)
+    act->atfork (act->atfork_arg);
 
   execv (pgmname, (char *const *)argv);
   /* No way to print anything, as we have may have closed all streams. */
@@ -320,24 +335,9 @@ my_exec (const char *pgmname, const char *argv[], struct spawn_cb_arg *sca)
 }
 
 
-static void
-call_spawn_cb (struct spawn_cb_arg *sca,
-               int fd_in, int fd_out, int fd_err,
-               void (*spawn_cb) (struct spawn_cb_arg *), void *spawn_cb_arg)
-{
-  sca->fds[0] = fd_in;
-  sca->fds[1] = fd_out;
-  sca->fds[2] = fd_err;
-  sca->except_fds = NULL;
-  sca->arg = spawn_cb_arg;
-  if (spawn_cb)
-    (*spawn_cb) (sca);
-}
-
-
 static gpg_err_code_t
 spawn_detached (const char *pgmname, const char *argv[],
-                void (*spawn_cb) (struct spawn_cb_arg *), void *spawn_cb_arg)
+                gpgrt_spawn_actions_t act)
 {
   gpg_err_code_t ec;
   pid_t pid;
@@ -370,7 +370,6 @@ spawn_detached (const char *pgmname, const char *argv[],
   if (!pid)
     {
       pid_t pid2;
-      struct spawn_cb_arg sca;
 
       if (setsid() == -1 || chdir ("/"))
         _exit (1);
@@ -381,9 +380,7 @@ spawn_detached (const char *pgmname, const char *argv[],
       if (pid2)
         _exit (0);  /* Let the parent exit immediately. */
 
-      call_spawn_cb (&sca, -1, -1, -1, spawn_cb, spawn_cb_arg);
-
-      my_exec (pgmname, argv, &sca);
+      my_exec (pgmname, argv, act);
       /*NOTREACHED*/
     }
 
@@ -402,11 +399,62 @@ spawn_detached (const char *pgmname, const char *argv[],
   return 0;
 }
 
+gpg_err_code_t
+_gpgrt_spawn_actions_new (gpgrt_spawn_actions_t *r_act)
+{
+  gpgrt_spawn_actions_t act;
+  int i;
+
+  *r_act = NULL;
+
+  act = xtrycalloc (1, sizeof (struct gpgrt_spawn_actions));
+  if (act == NULL)
+    return _gpg_err_code_from_syserror ();
+
+  for (i = 0; i <= 2; i++)
+    act->fd[i] = -1;
+
+  *r_act = act;
+  return 0;
+}
+
+void
+_gpgrt_spawn_actions_release (gpgrt_spawn_actions_t act)
+{
+  if (!act)
+    return;
+
+  xfree (act);
+}
+
+void
+_gpgrt_spawn_actions_set_envvars (gpgrt_spawn_actions_t act, char **env)
+{
+  act->env = env;
+}
+
+void
+_gpgrt_spawn_actions_set_atfork (gpgrt_spawn_actions_t act,
+                                 void (*atfork)(void *), void *arg)
+{
+  act->atfork = atfork;
+  act->atfork_arg = arg;
+}
+
 void
-_gpgrt_spawn_helper (struct spawn_cb_arg *sca)
+_gpgrt_spawn_actions_set_redirect (gpgrt_spawn_actions_t act,
+                                   int in, int out, int err)
 {
-  int *user_except = sca->arg;
-  sca->except_fds = user_except;
+  act->fd[0] = in;
+  act->fd[1] = out;
+  act->fd[2] = err;
+}
+
+void
+_gpgrt_spawn_actions_set_inherit_fds (gpgrt_spawn_actions_t act,
+                                      const int *fds)
+{
+  act->except_fds = fds;
 }
 
 struct gpgrt_process {
@@ -422,9 +470,7 @@ struct gpgrt_process {
 
 gpg_err_code_t
 _gpgrt_process_spawn (const char *pgmname, const char *argv1[],
-                      unsigned int flags,
-                      void (*spawn_cb) (struct spawn_cb_arg *),
-                      void *spawn_cb_arg,
+                      unsigned int flags, gpgrt_spawn_actions_t act,
                       gpgrt_process_t *r_process)
 {
   gpg_err_code_t ec;
@@ -472,7 +518,7 @@ _gpgrt_process_spawn (const char *pgmname, const char *argv1[],
           return GPG_ERR_INV_ARG;
         }
 
-      return spawn_detached (pgmname, argv, spawn_cb, spawn_cb_arg);
+      return spawn_detached (pgmname, argv, act);
     }
 
   process = xtrycalloc (1, sizeof (struct gpgrt_process));
@@ -601,8 +647,6 @@ _gpgrt_process_spawn (const char *pgmname, const char *argv1[],
 
   if (!pid)
     {
-      struct spawn_cb_arg sca;
-
       if (fd_in[1] >= 0)
         close (fd_in[1]);
       if (fd_out[0] >= 0)
@@ -610,11 +654,15 @@ _gpgrt_process_spawn (const char *pgmname, const char *argv1[],
       if (fd_err[0] >= 0)
         close (fd_err[0]);
 
-      call_spawn_cb (&sca, fd_in[0], fd_out[1], fd_err[1],
-                     spawn_cb, spawn_cb_arg);
+      if (act->fd[0] < 0)
+        act->fd[0] = fd_in[0];
+      if (act->fd[1] < 0)
+        act->fd[1] = fd_out[1];
+      if (act->fd[2] < 0)
+        act->fd[2] = fd_err[1];
 
       /* Run child. */
-      my_exec (pgmname, argv, &sca);
+      my_exec (pgmname, argv, act);
       /*NOTREACHED*/
     }