check_snmp: Handle SNMPv3 noAuthNoPriv properly

The SNMPv3 noAuthNoPriv security level, somewhat unintuitively, requires
a security name to be passed along together with the request. Check_snmp
previously did not do this, causing snmpget to throw an error:

"External command error: No log handling enabled - turning on stderr
logging
snmpget: No securityName specified"

This patch fixes the issue by always providing the security name when
noAuthNoPriv is specified.

See also:
https:://bugs.op5.com/view.php?id=8385.

Signed-off-by: Anton Lofgren <alofgren@op5.com>

1 files changed, 6 insertions, 4 deletions

diff --git a/plugins/check_snmp.c b/plugins/check_snmp.c
index d516fbc1..2c62a230 100644
--- a/plugins/check_snmp.c
+++ b/plugins/check_snmp.c
@@ -963,11 +963,16 @@ validate_arguments ()
                 if (seclevel == NULL)
                         xasprintf(&seclevel, "noAuthNoPriv");
 
+                if (secname == NULL)
+                        die(STATE_UNKNOWN, _("Required parameter: %s\n"), "secname");
+
                 if (strcmp(seclevel, "noAuthNoPriv") == 0) {
-                        numauthpriv = 2;
+                        numauthpriv = 4;
                         authpriv = calloc (numauthpriv, sizeof (char *));
                         authpriv[0] = strdup ("-l");
                         authpriv[1] = strdup ("noAuthNoPriv");
+                        authpriv[2] = strdup ("-u");
+                        authpriv[3] = strdup (secname);
                 } else {
                         if (! ( (strcmp(seclevel, "authNoPriv")==0) || (strcmp(seclevel, "authPriv")==0) ) ) {
                                 usage2 (_("Invalid seclevel"), seclevel);
@@ -976,9 +981,6 @@ validate_arguments ()
                         if (authproto == NULL )
                                 xasprintf(&authproto, DEFAULT_AUTH_PROTOCOL);
 
-                        if (secname == NULL)
-                                die(STATE_UNKNOWN, _("Required parameter: %s\n"), "secname");
-
                         if (authpasswd == NULL)
                                 die(STATE_UNKNOWN, _("Required parameter: %s\n"), "authpasswd");