[libvirt] [PATCH v2 8/8] rpc: pass listen FD to the daemon being started
This eliminates the need for active waiting.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=927369
Signed-off-by: Martin Kletzander <mkletzan(a)redhat.com>
---
src/rpc/virnetsocket.c | 58 +++++++++++++++++++++++++++++++++-----------------
1 file changed, 39 insertions(+), 19 deletions(-)
diff --git a/src/rpc/virnetsocket.c b/src/rpc/virnetsocket.c
index a94b2bc..c00209c 100644
--- a/src/rpc/virnetsocket.c
+++ b/src/rpc/virnetsocket.c
@@ -1,7 +1,7 @@
/*
* virnetsocket.c: generic network socket handling
*
- * Copyright (C) 2006-2013 Red Hat, Inc.
+ * Copyright (C) 2006-2014 Red Hat, Inc.
* Copyright (C) 2006 Daniel P. Berrange
*
* This library is free software; you can redistribute it and/or
@@ -121,7 +121,7 @@ VIR_ONCE_GLOBAL_INIT(virNetSocket)
#ifndef WIN32
-static int virNetSocketForkDaemon(const char *binary)
+static int virNetSocketForkDaemon(const char *binary, int passfd)
{
int ret;
virCommandPtr cmd = virCommandNewArgList(binary,
@@ -134,6 +134,10 @@ static int virNetSocketForkDaemon(const char *binary)
virCommandAddEnvPassBlockSUID(cmd, "XDG_RUNTIME_DIR", NULL);
virCommandClearCaps(cmd);
virCommandDaemonize(cmd);
+ if (passfd) {
+ virCommandPassFD(cmd, passfd, VIR_COMMAND_PASS_FD_CLOSE_PARENT);
+ virCommandPassListenFDs(cmd);
+ }
ret = virCommandRun(cmd, NULL);
virCommandFree(cmd);
return ret;
@@ -542,8 +546,7 @@ int virNetSocketNewConnectUNIX(const char *path,
{
virSocketAddr localAddr;
virSocketAddr remoteAddr;
- int fd;
- int retries = 0;
+ int fd, passfd;
memset(&localAddr, 0, sizeof(localAddr));
memset(&remoteAddr, 0, sizeof(remoteAddr));
@@ -569,28 +572,45 @@ int virNetSocketNewConnectUNIX(const char *path,
if (remoteAddr.data.un.sun_path[0] == '@')
remoteAddr.data.un.sun_path[0] = '\0';
- retry:
- if (connect(fd, &remoteAddr.data.sa, remoteAddr.len) < 0) {
- if ((errno == ECONNREFUSED ||
- errno == ENOENT) &&
- spawnDaemon && retries < 20) {
- VIR_DEBUG("Connection refused for %s, trying to spawn %s",
- path, binary);
- if (retries == 0 &&
- virNetSocketForkDaemon(binary) < 0)
- goto error;
+ if (spawnDaemon) {
+ if ((passfd = socket(PF_UNIX, SOCK_STREAM, 0)) < 0) {
+ virReportSystemError(errno, "%s", _("Failed to create
socket"));
+ goto error;
+ }
- retries++;
- usleep(1000 * 100 * retries);
- goto retry;
+ /*
+ * We cannot do the umask() trick here because that's not
+ * thread-safe. fchmod(), however, is not guaranteed to work on
+ * some BSD favours, but *should* work on Linux before the socket
+ * is bound. POSIX says the behaviour of fchmod() called on
+ * socket is unspecified, though.
+ */
+ if (fchmod(passfd, 0700) < 0) {
+ virReportSystemError(errno, "%s",
+ _("Failed to change permissions on socket"));
+ goto error;
}
- virReportSystemError(errno,
- _("Failed to connect socket to '%s'"),
+ if (bind(passfd, &remoteAddr.data.sa, remoteAddr.len) < 0) {
+ virReportSystemError(errno, _("Failed to bind socket to %s"),
path);
+ goto error;
+ }
+
+ if (listen(passfd, 0) < 0) {
+ virReportSystemError(errno, "%s", _("Failed to listen on
socket to"));
+ goto error;
+ }
+ }
+
+ if (connect(fd, &remoteAddr.data.sa, remoteAddr.len) < 0) {
+ virReportSystemError(errno, _("Failed to connect socket to
'%s'"),
path);
goto error;
}
+ if (spawnDaemon && virNetSocketForkDaemon(binary, passfd) < 0)
+ goto error;
+
localAddr.len = sizeof(localAddr.data);
if (getsockname(fd, &localAddr.data.sa, &localAddr.len) < 0) {
virReportSystemError(errno, "%s", _("Unable to get local socket
name"));
--
2.0.0