Merge remote-tracking branch 'remotes/mdroth/tags/qga-pull-2020-07-13-tag' into staging

qemu-ga patch queue for hard-freeze

* fix erroneously reporting stale hostname in guest-get-host-name
* fix regression where guest-shutdown asserts when called
* fix race condition with guest-fs-freeze/thaw on w32

# gpg: Signature made Tue 14 Jul 2020 05:47:11 BST
# gpg:                using RSA key CEACC9E15534EBABB82D3FA03353C9CEF108B584
# gpg:                issuer "mdroth@linux.vnet.ibm.com"
# gpg: Good signature from "Michael Roth <flukshun@gmail.com>" [full]
# gpg:                 aka "Michael Roth <mdroth@utexas.edu>" [full]
# gpg:                 aka "Michael Roth <mdroth@linux.vnet.ibm.com>" [full]
# Primary key fingerprint: CEAC C9E1 5534 EBAB B82D  3FA0 3353 C9CE F108 B584

* remotes/mdroth/tags/qga-pull-2020-07-13-tag:
  qga: Use qemu_get_host_name() instead of g_get_host_name()
  util: Introduce qemu_get_host_name()
  qga: fix assert regression on guest-shutdown
  qga-win: Fix QGA VSS Provider service stop failure

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 35 insertions, 0 deletions

diff --git a/util/oslib-posix.c b/util/oslib-posix.c
index 72907d4d7f..e60aea85b6 100644
--- a/util/oslib-posix.c
+++ b/util/oslib-posix.c
@@ -794,3 +794,38 @@ void sigaction_invoke(struct sigaction *action,
     }
     action->sa_sigaction(info->ssi_signo, &si, NULL);
 }
+
+#ifndef HOST_NAME_MAX
+# ifdef _POSIX_HOST_NAME_MAX
+#  define HOST_NAME_MAX _POSIX_HOST_NAME_MAX
+# else
+#  define HOST_NAME_MAX 255
+# endif
+#endif
+
+char *qemu_get_host_name(Error **errp)
+{
+    long len = -1;
+    g_autofree char *hostname = NULL;
+
+#ifdef _SC_HOST_NAME_MAX
+    len = sysconf(_SC_HOST_NAME_MAX);
+#endif /* _SC_HOST_NAME_MAX */
+
+    if (len < 0) {
+        len = HOST_NAME_MAX;
+    }
+
+    /* Unfortunately, gethostname() below does not guarantee a
+     * NULL terminated string. Therefore, allocate one byte more
+     * to be sure. */
+    hostname = g_new0(char, len + 1);
+
+    if (gethostname(hostname, len) < 0) {
+        error_setg_errno(errp, errno,
+                         "cannot get hostname");
+        return NULL;
+    }
+
+    return g_steal_pointer(&hostname);
+}