From 41510fba34cda98cb85a8d04e46dcfdd9a91aa61 Mon Sep 17 00:00:00 2001

From: =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= <marcandre.lureau@redhat.com>

Date: Thu, 24 Dec 2020 12:53:03 -0500

Subject: [PATCH 3/5] util: Introduce qemu_get_host_name()

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RH-Author: Marc-André Lureau <marcandre.lureau@redhat.com>

Message-id: <20201224125304.62697-3-marcandre.lureau@redhat.com>

Patchwork-id: 100499

O-Subject: [RHEL-8.4.0 qemu-kvm PATCH 2/3] util: Introduce qemu_get_host_name()

Bugzilla: 1910326

RH-Acked-by: Daniel P. Berrange <berrange@redhat.com>

RH-Acked-by: Stefan Hajnoczi <stefanha@redhat.com>

RH-Acked-by: Philippe Mathieu-Daudé <philmd@redhat.com>

From: Michal Privoznik <mprivozn@redhat.com>

This function offers operating system agnostic way to fetch host

name. It is implemented for both POSIX-like and Windows systems.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>

Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>

Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>

Cc: qemu-stable@nongnu.org

Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>

(cherry picked from commit e47f4765afcab2b78dfa5b0115abf64d1d49a5d3)

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>

Signed-off-by: Danilo C. L. de Paula <ddepaula@redhat.com>

---

 include/qemu/osdep.h | 10 ++++++++++

 util/oslib-posix.c   | 35 +++++++++++++++++++++++++++++++++++

 util/oslib-win32.c   | 13 +++++++++++++

 3 files changed, 58 insertions(+)

diff --git a/include/qemu/osdep.h b/include/qemu/osdep.h

index 0f97d68586a..d427e81a427 100644

--- a/include/qemu/osdep.h

+++ b/include/qemu/osdep.h

@@ -620,4 +620,14 @@ static inline void qemu_reset_optind(void)

 #endif

 }

+/**

+ * qemu_get_host_name:

+ * @errp: Error object

+ *

+ * Operating system agnostic way of querying host name.

+ *

+ * Returns allocated hostname (caller should free), NULL on failure.

+ */

+char *qemu_get_host_name(Error **errp);

+

 #endif

diff --git a/util/oslib-posix.c b/util/oslib-posix.c

index 5a291cc9820..8f88e4dbe10 100644

--- a/util/oslib-posix.c

+++ b/util/oslib-posix.c

@@ -726,3 +726,38 @@ 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);

+}

diff --git a/util/oslib-win32.c b/util/oslib-win32.c

index e9b14ab1784..3b49d272972 100644

--- a/util/oslib-win32.c

+++ b/util/oslib-win32.c

@@ -808,3 +808,16 @@ bool qemu_write_pidfile(const char *filename, Error **errp)

     }

     return true;

 }

+

+char *qemu_get_host_name(Error **errp)

+{

+    wchar_t tmp[MAX_COMPUTERNAME_LENGTH + 1];

+    DWORD size = G_N_ELEMENTS(tmp);

+

+    if (GetComputerNameW(tmp, &size) == 0) {

+        error_setg_win32(errp, GetLastError(), "failed close handle");

+        return NULL;

+    }

+

+    return g_utf16_to_utf8(tmp, size, NULL, NULL, NULL);

+}

-- 

2.27.0