7:08 a.m.
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 | 85 +++++++++++++++++++++++++++++++++++++++-----------
1 file changed, 66 insertions(+), 19 deletions(-)
diff --git a/src/rpc/virnetsocket.c b/src/rpc/virnetsocket.c
index a94b2bc..f913365 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;
@@ -540,10 +544,10 @@ int virNetSocketNewConnectUNIX(const char *path,
const char *binary,
virNetSocketPtr *retsock)
{
+ char *buf = NULL;
+ int fd, passfd;
virSocketAddr localAddr;
virSocketAddr remoteAddr;
- int fd;
- int retries = 0;
memset(&localAddr, 0, sizeof(localAddr));
memset(&remoteAddr, 0, sizeof(remoteAddr));
@@ -570,25 +574,65 @@ int virNetSocketNewConnectUNIX(const char *path,
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 (connect(fd, &remoteAddr.data.sa, remoteAddr.len) < 0 &&
!spawnDaemon) {
+ virReportSystemError(errno, _("Failed to connect socket to
'%s'"),
+ path);
+ goto error;
+ } else if (spawnDaemon) {
+ int status = 0;
+ pid_t pid = 0;
+
+ if ((passfd = socket(PF_UNIX, SOCK_STREAM, 0)) < 0) {
+ virReportSystemError(errno, "%s", _("Failed to create
socket"));
+ goto error;
+ }
+
+ /*
+ * We have to fork() here, because umask() is set
+ * per-process, chmod() is racy and fchmod() has undefined
+ * behaviour on sockets according to POSIX, so it doesn't
+ * work outside Linux.
+ */
+ if ((pid = virFork()) < 0)
+ goto error;
+
+ if (pid == 0) {
+ umask(0077);
+ if (bind(passfd, &remoteAddr.data.sa, remoteAddr.len) < 0)
+ _exit(EXIT_FAILURE);
+
+ _exit(EXIT_SUCCESS);
+ }
+
+ if (virProcessWait(pid, &status, false) < 0)
+ goto error;
- retries++;
- usleep(1000 * 100 * retries);
+ if (status != EXIT_SUCCESS) {
+ /*
+ * OK, so the subprocces failed to bind() the socket. This may mean
+ * that another daemon was starting at the same time and succeeded
+ * with its bind(). So we'll try connecting again, but this time
+ * without spawning the daemon.
+ */
+ spawnDaemon = false;
goto retry;
}
- virReportSystemError(errno,
- _("Failed to connect socket to '%s'"),
- path);
- goto error;
+ if (listen(passfd, 0) < 0) {
+ virReportSystemError(errno, "%s",
+ _("Failed to listen on socket that's about
"
+ "to be passed to the daemon"));
+ goto error;
+ }
+
+ if (connect(fd, &remoteAddr.data.sa, remoteAddr.len) < 0) {
+ virReportSystemError(errno, _("Failed to connect socket to
'%s'"),
+ path);
+ goto error;
+ }
+
+ if (virNetSocketForkDaemon(binary, passfd) < 0)
+ goto error;
}
localAddr.len = sizeof(localAddr.data);
@@ -603,7 +647,10 @@ int virNetSocketNewConnectUNIX(const char *path,
return 0;
error:
+ VIR_FREE(buf);
VIR_FORCE_CLOSE(fd);
+ if (spawnDaemon)
+ unlink(path);
return -1;
}
#else
--
2.0.4