[libvirt PATCH 1/2] util: fix syslog facility value

Daniel P. Berrangé berrange at redhat.com
Tue Jan 18 16:49:00 UTC 2022

We set SYSLOG_PRIORITY when sending to journald to avoid our
messages getting tagged with the default facility which is
used for the kernel.


  commit fd00f0e6c75b00c3d97be8670afcd9094b823855
  Author: Guido Günther <agx at sigxcpu.org>
  Date:   Mon Sep 21 20:06:55 2015 +0200

    Use daemon log facility for journald

used the LOG_nnn constants from the syslog header without realizing
that these values have a bit-shift applied. While Linux defines a
LOG_FAC() macros to undo the bit-shift this doesn't appear to be
standardized. So the safe thing is to just use the raw value since
these values are fixed by RFC 5424.

Signed-off-by: Daniel P. Berrangé <berrange at redhat.com>
 src/util/virlog.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/util/virlog.c b/src/util/virlog.c
index b44ad0ef6c..72b0613dfb 100644
--- a/src/util/virlog.c
+++ b/src/util/virlog.c
@@ -925,7 +925,13 @@ virLogOutputToJournald(virLogSource *source,
     journalAddString(&state, "MESSAGE", rawstr);
     journalAddInt(&state, "PRIORITY",
-    journalAddInt(&state, "SYSLOG_FACILITY", LOG_DAEMON);
+    /* See RFC 5424 section 6.2.1
+     *
+     * Don't use LOG_nnn constants as those have a bit-shift
+     * applied for use with syslog()  API, while journald
+     * needs the raw value
+     */
+    journalAddInt(&state, "SYSLOG_FACILITY", 3);
     journalAddString(&state, "LIBVIRT_SOURCE", source->name);
     if (filename)
         journalAddString(&state, "CODE_FILE", filename);

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