Merge pull request #23 from bmork/ethtool

Optionally use ethtool statistics counters instead of /proc/net/dev

Makefile.am

@@ -8,7 +8,7 @@ AM_CPPFLAGS           = -DSYSCONFDIR=\"@sysconfdir@\" -DRUNSTATEDIR=\"@runstated
 mini_snmpd_SOURCES    = mini-snmpd.c mini-snmpd.h linux.c freebsd.c mib.c	\
 			globals.c protocol.c utils.c compat.h
 if HAVE_CONFUSE
-mini_snmpd_SOURCES   += conf.c
+mini_snmpd_SOURCES   += conf.c linux_ethtool.c
 endif
 mini_snmpd_CPPFLAGS   = $(AM_CPPFLAGS)
 mini_snmpd_CFLAGS     = -W -Wall -Wextra -std=gnu99

conf.c

@@ -17,6 +17,7 @@
 #include <stdarg.h>
 #include <string.h>
 #include <unistd.h>
+#include "ethtool-conf.h"
 #include "mini-snmpd.h"
 
 static cfg_t *cfg = NULL;
@@ -66,6 +67,21 @@ static size_t get_list(cfg_t *cfg, const char *key, char **list, size_t len)
 int read_config(char *file)
 {
 	int rc = 0;
+	cfg_opt_t ethtool_opts[] = {
+		CFG_STR("rx_bytes", NULL, CFGF_NONE),
+		CFG_STR("rx_mc_packets", NULL, CFGF_NONE),
+		CFG_STR("rx_bc_packets", NULL, CFGF_NONE),
+		CFG_STR("rx_packets", NULL, CFGF_NONE),
+		CFG_STR("rx_errors", NULL, CFGF_NONE),
+		CFG_STR("rx_drops", NULL, CFGF_NONE),
+		CFG_STR("tx_bytes", NULL, CFGF_NONE),
+		CFG_STR("tx_mc_packets", NULL, CFGF_NONE),
+		CFG_STR("tx_bc_packets", NULL, CFGF_NONE),
+		CFG_STR("tx_packets", NULL, CFGF_NONE),
+		CFG_STR("tx_errors", NULL, CFGF_NONE),
+		CFG_STR("tx_drops", NULL, CFGF_NONE),
+		CFG_END()
+	};
 	cfg_opt_t opts[] = {
 		CFG_STR ("location", NULL, CFGF_NONE),
 		CFG_STR ("contact", NULL, CFGF_NONE),
@@ -76,6 +92,7 @@ int read_config(char *file)
 		CFG_STR ("vendor", VENDOR, CFGF_NONE),
 		CFG_STR_LIST("disk-table", "/", CFGF_NONE),
 		CFG_STR_LIST("iface-table", NULL, CFGF_NONE),
+		CFG_SEC("ethtool", ethtool_opts, CFGF_MULTI | CFGF_TITLE | CFGF_NO_TITLE_DUPES),
 		CFG_END()
 	};
 
@@ -118,6 +135,8 @@ int read_config(char *file)
 
 	g_vendor      = get_string(cfg, "vendor");
 
+	ethtool_xlate_cfg(cfg);
+
 error:
 	cfg_free(cfg);
 	return rc;

configure.ac

@@ -52,6 +52,10 @@ AC_ARG_ENABLE(ipv6,
    AS_HELP_STRING([--disable-ipv6], [Disable IPv6 support, enabled by default]),
    	[enable_ipv6=$enableval], [enable_ipv6=yes])
 
+AC_ARG_ENABLE(ethtool,
+   AS_HELP_STRING([--enable-ethtool], [Enable ethtool interface stats, disabled by default]),
+   	[enable_ethtool=$enableval], [enable_ethtool=no])
+
 ### Enable features ###########################################################################
 AS_IF([test "x$with_vendor" != "xno"],[
 	AS_IF([test "x$vendor" = "xyes"],[
@@ -74,6 +78,9 @@ AS_IF([test "x$enable_demo" = "xyes"],[
 AS_IF([test "x$enable_ipv6" != "xno"],[
    AC_DEFINE(CONFIG_ENABLE_IPV6, 1, [Define to enable IPv6 support.])])
 
+AS_IF([test "x$enable_ethtool" != "xno"],[
+   AC_DEFINE(CONFIG_ENABLE_ETHTOOL, 1, [Define to enable ethtool stats.])])
+
 # Check where to install the systemd .service file
 AS_IF([test "x$with_systemd" = "xyes" -o "x$with_systemd" = "xauto"], [
      def_systemd=$($PKG_CONFIG --variable=systemdsystemunitdir systemd)
@@ -124,6 +131,7 @@ cat <<EOF
   mini-snmpd.conf...: $with_config
   demo mode.........: $enable_demo
   systemd...........: $with_systemd
+  ethtool stats.....: $enable_ethtool
 
 ------------- Compiler version --------------
 $($CC --version || true)

ethtool-conf.h

@@ -0,0 +1,37 @@
+/* Linux ethtool helpers
+ *
+ * Copyright (C) 2020  Bjørn Mork <bjorn@mork.no>
+ *
+ * This file may be distributed and/or modified under the terms of the
+ * GNU General Public License version 2 as published by the Free Software
+ * Foundation and appearing in the file LICENSE.GPL included in the
+ * packaging of this file.
+ *
+ * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
+ * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * See COPYING for GPL licensing information.
+ */
+
+#ifndef ETHTOOL_CONF_H_
+#define ETHTOOL_CONF_H_
+
+#include <confuse.h>
+#include "config.h"
+#include "mini-snmpd.h"
+
+#ifdef CONFIG_ENABLE_ETHTOOL
+void ethtool_xlate_cfg(cfg_t *cfg);
+#else
+static inline void ethtool_xlate_cfg(cfg_t *cfg)
+{
+	if (cfg_size(cfg, "ethtool") > 0)
+		logit(LOG_WARNING, 0, "No ethtool support. Ignoring config section");
+}
+#endif
+
+#endif /* ETHTOOL_CONF_H_ */
+
+/* vim: ts=4 sts=4 sw=4 nowrap
+ */
+

linux.c

@@ -262,18 +262,20 @@ void get_netinfo(netinfo_t *netinfo)
 			sll = (struct sockaddr_ll *)ifa->ifa_addr;
 			memcpy(netinfo->mac_addr[i], sll->sll_addr, sizeof(netinfo->mac_addr[i]));
 
-			/* XXX: Tx multicast and Rx/Tx broadcast not available atm. */
-			fields[i].prefix    = g_interface_list[i];
-			fields[i].len       = 12;
-			fields[i].value[0]  = &netinfo->rx_bytes[i];
-			fields[i].value[1]  = &netinfo->rx_packets[i];
-			fields[i].value[2]  = &netinfo->rx_errors[i];
-			fields[i].value[3]  = &netinfo->rx_drops[i];
-			fields[i].value[7]  = &netinfo->rx_mc_packets[i];
-			fields[i].value[8]  = &netinfo->tx_bytes[i];
-			fields[i].value[9]  = &netinfo->tx_packets[i];
-			fields[i].value[10] = &netinfo->tx_errors[i];
-			fields[i].value[11] = &netinfo->tx_drops[i];
+			if (ethtool_gstats(i, netinfo, &fields[i]) < 0) {
+				/* XXX: Tx multicast and Rx/Tx broadcast not available atm. */
+				fields[i].prefix    = g_interface_list[i];
+				fields[i].len       = 12;
+				fields[i].value[0]  = &netinfo->rx_bytes[i];
+				fields[i].value[1]  = &netinfo->rx_packets[i];
+				fields[i].value[2]  = &netinfo->rx_errors[i];
+				fields[i].value[3]  = &netinfo->rx_drops[i];
+				fields[i].value[7]  = &netinfo->rx_mc_packets[i];
+				fields[i].value[8]  = &netinfo->tx_bytes[i];
+				fields[i].value[9]  = &netinfo->tx_packets[i];
+				fields[i].value[10] = &netinfo->tx_errors[i];
+				fields[i].value[11] = &netinfo->tx_drops[i];
+			}
 
 			if (-1 == read_file_value(&netinfo->if_mtu[i], "/sys/class/net/%s/mtu", g_interface_list[i]))
 				netinfo->if_mtu[i] = 1500; /* Fallback */