Import Upstream version 2.0.0+dfsgupstream/2.0.0+dfsg

1 files changed, 132 insertions, 0 deletions

diff --git a/src/lib/arch/unix/ArchDaemonUnix.cpp b/src/lib/arch/unix/ArchDaemonUnix.cpp
new file mode 100644
index 0000000..a03bf7a
--- /dev/null
+++ b/src/lib/arch/unix/ArchDaemonUnix.cpp
@@ -0,0 +1,132 @@
+/*
+ * barrier -- mouse and keyboard sharing utility
+ * Copyright (C) 2012-2016 Symless Ltd.
+ * Copyright (C) 2002 Chris Schoeneman
+ * 
+ * This package is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * found in the file LICENSE that should have accompanied this file.
+ * 
+ * This package 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, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "arch/unix/ArchDaemonUnix.h"
+
+#include "arch/unix/XArchUnix.h"
+#include "base/Log.h"
+
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <cstdlib>
+
+//
+// ArchDaemonUnix
+//
+
+ArchDaemonUnix::ArchDaemonUnix()
+{
+    // do nothing
+}
+
+ArchDaemonUnix::~ArchDaemonUnix()
+{
+    // do nothing
+}
+
+
+#ifdef __APPLE__
+
+// In Mac OS X, fork()'d child processes can't use most APIs (the frameworks
+// that Barrier uses in fact prevent it and make the process just up and die),
+// so need to exec a copy of the program that doesn't fork so isn't limited.
+int
+execSelfNonDaemonized()
+{
+    extern char** NXArgv;
+    char** selfArgv = NXArgv;
+    
+    setenv("_BARRIER_DAEMONIZED", "", 1);
+    
+    execvp(selfArgv[0], selfArgv);
+    return 0;
+}
+
+bool alreadyDaemonized() {
+    return getenv("_BARRIER_DAEMONIZED") != NULL;
+}
+
+#endif
+
+int
+ArchDaemonUnix::daemonize(const char* name, DaemonFunc func)
+{
+#ifdef __APPLE__
+    if (alreadyDaemonized())
+        return func(1, &name);
+#endif
+    
+    // fork so shell thinks we're done and so we're not a process
+    // group leader
+    switch (fork()) {
+    case -1:
+        // failed
+        throw XArchDaemonFailed(new XArchEvalUnix(errno));
+
+    case 0:
+        // child
+        break;
+
+    default:
+        // parent exits
+        exit(0);
+    }
+
+    // become leader of a new session
+    setsid();
+    
+#ifndef __APPLE__
+    // NB: don't run chdir on apple; causes strange behaviour.
+    // chdir to root so we don't keep mounted filesystems points busy
+    // TODO: this is a bit of a hack - can we find a better solution?
+    int chdirErr = chdir("/");
+    if (chdirErr)
+        // NB: file logging actually isn't working at this point!
+        LOG((CLOG_ERR "chdir error: %i", chdirErr));
+#endif
+
+    // mask off permissions for any but owner
+    umask(077);
+
+    // close open files.  we only expect stdin, stdout, stderr to be open.
+    close(0);
+    close(1);
+    close(2);
+
+    // attach file descriptors 0, 1, 2 to /dev/null so inadvertent use
+    // of standard I/O safely goes in the bit bucket.
+    open("/dev/null", O_RDONLY);
+    open("/dev/null", O_RDWR);
+    
+    int dupErr = dup(1);
+
+    if (dupErr < 0) {
+        // NB: file logging actually isn't working at this point!
+        LOG((CLOG_ERR "dup error: %i", dupErr));
+    }
+    
+#ifdef __APPLE__
+    return execSelfNonDaemonized();
+#endif
+    
+    // invoke function
+    return func(1, &name);
+}