[libvirt] [PATCH] audit: Log only an info message if audit_level < 2 and audit is not supported

[Marc Hartmayer]

Replace the error message during startup of libvirtd with an info
message if audit_level < 2 and audit is not supported by the
kernel. Audit is not supported by the current kernel if the kernel
does not have audit compiled in or if audit is disabled (e.g. by the
kernel cmdline).

Signed-off-by: Marc Hartmayer <mhartmay at linux.vnet.ibm.com>
Reviewed-by: Boris Fiuczynski <fiuczy at linux.vnet.ibm.com>
---
 daemon/libvirtd.c   |  2 +-
 src/util/viraudit.c | 17 +++++++++++++++--
 src/util/viraudit.h |  2 +-
 3 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/daemon/libvirtd.c b/daemon/libvirtd.c
index 589b32192e3d..6bbff0d45684 100644
--- a/daemon/libvirtd.c
+++ b/daemon/libvirtd.c
@@ -1418,7 +1418,7 @@ int main(int argc, char **argv) {
 
     if (config->audit_level) {
         VIR_DEBUG("Attempting to configure auditing subsystem");
-        if (virAuditOpen() < 0) {
+        if (virAuditOpen(config->audit_level) < 0) {
             if (config->audit_level > 1) {
                 ret = VIR_DAEMON_ERR_AUDIT;
                 goto cleanup;
diff --git a/src/util/viraudit.c b/src/util/viraudit.c
index 17e58b3a9574..9b755e384f24 100644
--- a/src/util/viraudit.c
+++ b/src/util/viraudit.c
@@ -55,11 +55,24 @@ static int auditfd = -1;
 #endif
 static bool auditlog;
 
-int virAuditOpen(void)
+int virAuditOpen(unsigned int audit_level)
 {
 #if WITH_AUDIT
     if ((auditfd = audit_open()) < 0) {
-        virReportSystemError(errno, "%s", _("Unable to initialize audit layer"));
+        /* You get these error codes only when the kernel does not
+         * have audit compiled in or it's disabled (e.g. by the kernel
+         * cmdline) */
+        if (errno == EINVAL || errno == EPROTONOSUPPORT ||
+            errno == EAFNOSUPPORT) {
+            const char msg[] = "Audit is not supported by the kernel";
+            if (audit_level < 2)
+                VIR_INFO("%s", _(msg));
+            else
+                virReportError(VIR_FROM_THIS, "%s", _(msg));
+        } else {
+            virReportSystemError(errno, "%s", _("Unable to initialize audit layer"));
+        }
+
         return -1;
     }
 
diff --git a/src/util/viraudit.h b/src/util/viraudit.h
index edaddf3c886f..e0471be1a85d 100644
--- a/src/util/viraudit.h
+++ b/src/util/viraudit.h
@@ -32,7 +32,7 @@ typedef enum {
     VIR_AUDIT_RECORD_RESOURCE,
 } virAuditRecordType;
 
-int virAuditOpen(void);
+int virAuditOpen(unsigned int audit_level);
 
 void virAuditLog(bool enabled);
 
-- 
2.13.4