[src/trunk]: src/lib Support vfork. Add rumpclient wrapper for daemon(3).

[pooka <pooka%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/b8f9d1ce3f7f
branches:  trunk
changeset: 762137:b8f9d1ce3f7f
user:      pooka <pooka%NetBSD.org@localhost>
date:      Wed Feb 16 17:56:46 2011 +0000

description:
Support vfork.  Add rumpclient wrapper for daemon(3).

diffstat:

 lib/librumpclient/rumpclient.c |  65 +++++++++++++++++++++++++++++------------
 lib/librumpclient/rumpclient.h |  45 +++++++++++++++++++++++++++-
 lib/librumphijack/hijack.c     |   8 +++-
 3 files changed, 92 insertions(+), 26 deletions(-)

diffs (214 lines):

diff -r c1382ea315e7 -r b8f9d1ce3f7f lib/librumpclient/rumpclient.c
--- a/lib/librumpclient/rumpclient.c    Wed Feb 16 17:53:31 2011 +0000
+++ b/lib/librumpclient/rumpclient.c    Wed Feb 16 17:56:46 2011 +0000
@@ -1,4 +1,4 @@
-/*      $NetBSD: rumpclient.c,v 1.30 2011/02/16 15:33:47 pooka Exp $   */
+/*      $NetBSD: rumpclient.c,v 1.31 2011/02/16 17:56:46 pooka Exp $   */
 
 /*
  * Copyright (c) 2010, 2011 Antti Kantee.  All Rights Reserved.
@@ -803,6 +803,8 @@
 
 struct rumpclient_fork {
        uint32_t fork_auth[AUTHLEN];
+       struct spclient fork_spc;
+       int fork_kq;
 };
 
 struct rumpclient_fork *
@@ -828,6 +830,9 @@
        memcpy(rpf->fork_auth, resp, sizeof(rpf->fork_auth));
        free(resp);
 
+       rpf->fork_spc = clispc;
+       rpf->fork_kq = kq;
+
  out:
        pthread_sigmask(SIG_SETMASK, &omask, NULL);
        return rpf;
@@ -863,6 +868,21 @@
 }
 
 void
+rumpclient_fork_cancel(struct rumpclient_fork *rpf)
+{
+
+       /* EUNIMPL */
+}
+
+void
+rumpclient_fork_vparent(struct rumpclient_fork *rpf)
+{
+
+       clispc = rpf->fork_spc;
+       kq = rpf->fork_kq;
+}
+
+void
 rumpclient_setconnretry(time_t timeout)
 {
 
@@ -930,27 +950,10 @@
 }
 
 pid_t
-rumpclient_fork(pid_t (*forkfn)(void))
+rumpclient_fork()
 {
-       struct rumpclient_fork *rf;
-       pid_t rv;
 
-       if ((rf = rumpclient_prefork()) == NULL)
-               return -1;
-                
-       switch ((rv = forkfn())) {
-       case -1:
-               /* XXX: cancel rf */
-               break;
-       case 0:
-               if (rumpclient_fork_init(rf) == -1)
-                       rv = -1;
-               break;
-       default:
-               break;
-       }
-
-       return rv;
+       return rumpclient__dofork(fork);
 }
 
 /*
@@ -1015,3 +1018,25 @@
        errno = sverrno;
        return rv;
 }
+
+int
+rumpclient_daemon(int nochdir, int noclose)
+{
+       struct rumpclient_fork *rf;
+       int sverrno;
+
+       if ((rf = rumpclient_prefork()) == NULL)
+               return -1;
+
+       if (daemon(nochdir, noclose) == -1) {
+               sverrno = errno;
+               rumpclient_fork_cancel(rf);
+               errno = sverrno;
+               return -1;
+       }
+
+       if (rumpclient_fork_init(rf) == -1)
+               return -1;
+
+       return 0;
+}
diff -r c1382ea315e7 -r b8f9d1ce3f7f lib/librumpclient/rumpclient.h
--- a/lib/librumpclient/rumpclient.h    Wed Feb 16 17:53:31 2011 +0000
+++ b/lib/librumpclient/rumpclient.h    Wed Feb 16 17:56:46 2011 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: rumpclient.h,v 1.7 2011/02/16 15:33:47 pooka Exp $     */
+/*     $NetBSD: rumpclient.h,v 1.8 2011/02/16 17:56:46 pooka Exp $     */
 
 /*-
  * Copyright (c) 2010 Antti Kantee.  All Rights Reserved.
@@ -30,17 +30,23 @@
 
 #include <sys/types.h>
 
+struct rumpclient_fork;
+
+#define rumpclient_vfork() rumpclient__dofork(vfork)
+
 __BEGIN_DECLS
 
 int rumpclient_syscall(int, const void *, size_t, register_t *);
 int rumpclient_init(void);
 
-struct rumpclient_fork;
 struct rumpclient_fork *rumpclient_prefork(void);
 int                    rumpclient_fork_init(struct rumpclient_fork *);
+void                   rumpclient_fork_cancel(struct rumpclient_fork *);
+void                   rumpclient_fork_vparent(struct rumpclient_fork *);
 
-int rumpclient_fork(pid_t (*forkfn)(void));
+int rumpclient_fork(void);
 int rumpclient_exec(const char *, char *const [], char *const[]);
+int rumpclient_daemon(int, int);
 
 #define RUMPCLIENT_RETRYCONN_INFTIME ((time_t)-1)
 #define RUMPCLIENT_RETRYCONN_ONCE ((time_t)-2)
@@ -54,6 +60,39 @@
 };
 int rumpclient__closenotify(int *, enum rumpclient_closevariant);
 
+/*
+ * vfork needs to be implemented as an inline to make everything
+ * run in the caller's stackframe.
+ */
+static inline pid_t
+rumpclient__dofork(pid_t (*forkfn)(void))
+{
+       struct rumpclient_fork *rf;
+       pid_t pid;
+       int childran = 0;
+
+       if ((rf = rumpclient_prefork()) == NULL)
+               return -1;
+                
+       switch ((pid = forkfn())) {
+       case -1:
+               rumpclient_fork_cancel(rf);
+               break;
+       case 0:
+               childran = 1;
+               if (rumpclient_fork_init(rf) == -1)
+                       pid = -1;
+               break;
+       default:
+               /* XXX: multithreaded vforker?  do they exist? */
+               if (childran)
+                       rumpclient_fork_vparent(rf);
+               break;
+       }
+
+       return pid;
+}
+
 __END_DECLS
 
 #endif /* _RUMP_RUMPCLIENT_H_ */
diff -r c1382ea315e7 -r b8f9d1ce3f7f lib/librumphijack/hijack.c
--- a/lib/librumphijack/hijack.c        Wed Feb 16 17:53:31 2011 +0000
+++ b/lib/librumphijack/hijack.c        Wed Feb 16 17:56:46 2011 +0000
@@ -1,4 +1,4 @@
-/*      $NetBSD: hijack.c,v 1.42 2011/02/16 15:33:46 pooka Exp $       */
+/*      $NetBSD: hijack.c,v 1.43 2011/02/16 17:56:46 pooka Exp $       */
 
 /*-
  * Copyright (c) 2011 Antti Kantee.  All Rights Reserved.
@@ -26,7 +26,7 @@
  */
 
 #include <sys/cdefs.h>
-__RCSID("$NetBSD: hijack.c,v 1.42 2011/02/16 15:33:46 pooka Exp $");
+__RCSID("$NetBSD: hijack.c,v 1.43 2011/02/16 17:56:46 pooka Exp $");
 
 #define __ssp_weak_name(fun) _hijack_ ## fun
 
@@ -601,11 +601,13 @@
 
        DPRINTF(("fork\n"));
 
-       rv = rumpclient_fork(host_fork);
+       rv = rumpclient__dofork(host_fork);
 
        DPRINTF(("fork returns %d\n", rv));
        return rv;
 }
+/* we do not have the luxury of not requiring a stackframe */
+__strong_alias(__vfork14,fork);
 
 int
 daemon(int nochdir, int noclose)