From: Enrico Scholz Date: Mon, 15 Mar 2004 21:39:55 +0000 (+0000) Subject: initial checkin X-Git-Tag: VERSION_0_10~320 X-Git-Url: http://git.linux-vserver.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=223765ca7755a7b3292c11346b27bdfae8f27b78;p=util-vserver.git initial checkin git-svn-id: http://svn.linux-vserver.org/svn/util-vserver/trunk@1254 94cd875c-1c1d-0410-91d2-eb244daf1a30 --- diff --git a/util-vserver/src/context-sync.hc b/util-vserver/src/context-sync.hc new file mode 100644 index 0000000..ed050a0 --- /dev/null +++ b/util-vserver/src/context-sync.hc @@ -0,0 +1,89 @@ +// $Id$ --*- c -*-- + +// Copyright (C) 2004 Enrico Scholz +// +// This program is free software; you can redistribute it and/or modify +// it under the terms of the GNU General Public License as published by +// the Free Software Foundation; version 2 of the License. +// +// This program is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +// GNU General Public License for more details. +// +// You should have received a copy of the GNU General Public License +// along with this program; if not, write to the Free Software +// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + + +/// \args p[0] used for parent -> child sync (child waits till parent is in deathrow) +/// \args p[1] used for child -> parent sync (recognize execv() errors) +static inline ALWAYSINLINE int +initSync(int p[2][2], bool do_disconnect) +{ + if (!do_disconnect) return 0; + + Epipe(p[0]); + Epipe(p[1]); + fcntl(p[1][1], F_SETFD, FD_CLOEXEC); + return Efork(); +} + +static inline ALWAYSINLINE void +doSyncStage0(int p[2][2], bool do_disconnect) +{ + char c; + if (!do_disconnect) return; + + Eclose(p[0][1]); + Eread (p[0][0], &c, 1); + Eclose(p[0][0]); +} + +static inline ALWAYSINLINE void +doSyncStage1(int p[2][2], bool do_disconnect) +{ + int fd; + + if (!do_disconnect) return; + + fd = Eopen("/dev/null", O_RDONLY|O_NONBLOCK, 0); + Esetsid(); + Edup2(fd, 0); + Eclose(p[1][0]); + if (fd!=0) Eclose(fd); + Ewrite(p[1][1], ".", 1); +} + +static inline ALWAYSINLINE void +doSyncStage2(int p[2][2], bool do_disconnect) +{ + if (!do_disconnect) return; + + Ewrite(p[1][1], "X", 1); +} + +/// \args p[0] used for parent -> child sync (child waits till parent is in deathrow) +/// \args p[1] used for child -> parent sync (recognize execv() errors) +static void +waitOnSync(pid_t pid, int p[2][2], bool is_prevent_race) +{ + char c; + size_t l; + + if (is_prevent_race && + !jailIntoTempDir(0)) { + perror(ENSC_WRAPPERS_PREFIX "jailIntoTempDir()"); + exit(255); + } + + Eclose(p[0][0]); + Ewrite(p[0][1], "X", 1); + Eclose(p[0][1]); + + Eclose(p[1][1]); + l = Eread(p[1][0], &c, 1); + if (l!=1) exitLikeProcess(pid); + l = Eread(p[1][0], &c, 1); + if (l!=0) exitLikeProcess(pid); +}