test: Introduce virnetdevopenvswitchtest

Test if our parsing of interface stats as returned by ovs-vsctl
works as expected. To achieve this without having to mock
virCommand* I'm separating parsing of stats into a separate
function.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>

src/libvirt_private.syms

@@ -2501,6 +2501,7 @@ virNetDevOpenvswitchAddPort;
 virNetDevOpenvswitchGetMigrateData;
 virNetDevOpenvswitchGetVhostuserIfname;
 virNetDevOpenvswitchInterfaceGetMaster;
+virNetDevOpenvswitchInterfaceParseStats;
 virNetDevOpenvswitchInterfaceStats;
 virNetDevOpenvswitchRemovePort;
 virNetDevOpenvswitchSetMigrateData;

src/util/virnetdevopenvswitch.c

@@ -299,49 +299,30 @@ int virNetDevOpenvswitchSetMigrateData(char *migrate, const char *ifname)
     return 0;
 }
 
+
 /**
- * virNetDevOpenvswitchInterfaceStats:
+ * virNetDevOpenvswitchInterfaceParseStats:
- * @ifname: the name of the interface
+ * @json: Input string in JSON format
- * @stats: the retrieved domain interface stat
+ * @stats: parsed stats
  *
- * Retrieves the OVS interfaces stats
+ * For given input string @json parse interface statistics and store them into
+ * @stats.
  *
- * Returns 0 in case of success or -1 in case of failure
+ * Returns: 0 on success,
+ *         -1 otherwise (with error reported).
  */
 int
-virNetDevOpenvswitchInterfaceStats(const char *ifname,
+virNetDevOpenvswitchInterfaceParseStats(const char *json,
                                         virDomainInterfaceStatsPtr stats)
 {
-    VIR_AUTOPTR(virCommand) cmd = NULL;
-    VIR_AUTOFREE(char *) output = NULL;
     VIR_AUTOPTR(virJSONValue) jsonStats = NULL;
     virJSONValuePtr jsonMap = NULL;
     size_t i;
 
-    cmd = virCommandNew(OVSVSCTL);
+    stats->rx_bytes = stats->rx_packets = stats->rx_errs = stats->rx_drop = -1;
-    virNetDevOpenvswitchAddTimeout(cmd);
+    stats->tx_bytes = stats->tx_packets = stats->tx_errs = stats->tx_drop = -1;
-    virCommandAddArgList(cmd, "--if-exists", "--format=list", "--data=json",
-                         "--no-headings", "--columns=statistics", "list",
-                         "Interface", ifname, NULL);
-    virCommandSetOutputBuffer(cmd, &output);
 
-    /* The above command returns either:
+    if (!(jsonStats = virJSONValueFromString(json)) ||
-     * 1) empty string if @ifname doesn't exist, or
-     * 2) a JSON array, for instance:
-     *    ["map",[["collisions",0],["rx_bytes",0],["rx_crc_err",0],["rx_dropped",0],
-     *    ["rx_errors",0],["rx_frame_err",0],["rx_over_err",0],["rx_packets",0],
-     *    ["tx_bytes",12406],["tx_dropped",0],["tx_errors",0],["tx_packets",173]]]
-     */
-
-    if (virCommandRun(cmd, NULL) < 0 ||
-        STREQ_NULLABLE(output, "")) {
-        /* no ovs-vsctl or interface 'ifname' doesn't exists in ovs */
-        virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
-                       _("Interface not found"));
-        return -1;
-    }
-
-    if (!(jsonStats = virJSONValueFromString(output)) ||
         !virJSONValueIsArray(jsonStats) ||
         !(jsonMap = virJSONValueArrayGet(jsonStats, 1))) {
         virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
@@ -349,9 +330,6 @@ virNetDevOpenvswitchInterfaceStats(const char *ifname,
         return -1;
     }
 
-    stats->rx_bytes = stats->rx_packets = stats->rx_errs = stats->rx_drop = -1;
-    stats->tx_bytes = stats->tx_packets = stats->tx_errs = stats->tx_drop = -1;
-
     for (i = 0; i < virJSONValueArraySize(jsonMap); i++) {
         virJSONValuePtr item = virJSONValueArrayGet(jsonMap, i);
         virJSONValuePtr jsonKey;
@@ -392,6 +370,51 @@ virNetDevOpenvswitchInterfaceStats(const char *ifname,
         }
     }
 
+    return 0;
+}
+
+/**
+ * virNetDevOpenvswitchInterfaceStats:
+ * @ifname: the name of the interface
+ * @stats: the retrieved domain interface stat
+ *
+ * Retrieves the OVS interfaces stats
+ *
+ * Returns 0 in case of success or -1 in case of failure
+ */
+int
+virNetDevOpenvswitchInterfaceStats(const char *ifname,
+                                   virDomainInterfaceStatsPtr stats)
+{
+    VIR_AUTOPTR(virCommand) cmd = NULL;
+    VIR_AUTOFREE(char *) output = NULL;
+
+    cmd = virCommandNew(OVSVSCTL);
+    virNetDevOpenvswitchAddTimeout(cmd);
+    virCommandAddArgList(cmd, "--if-exists", "--format=list", "--data=json",
+                         "--no-headings", "--columns=statistics", "list",
+                         "Interface", ifname, NULL);
+    virCommandSetOutputBuffer(cmd, &output);
+
+    /* The above command returns either:
+     * 1) empty string if @ifname doesn't exist, or
+     * 2) a JSON array, for instance:
+     *    ["map",[["collisions",0],["rx_bytes",0],["rx_crc_err",0],["rx_dropped",0],
+     *    ["rx_errors",0],["rx_frame_err",0],["rx_over_err",0],["rx_packets",0],
+     *    ["tx_bytes",12406],["tx_dropped",0],["tx_errors",0],["tx_packets",173]]]
+     */
+
+    if (virCommandRun(cmd, NULL) < 0 ||
+        STREQ_NULLABLE(output, "")) {
+        /* no ovs-vsctl or interface 'ifname' doesn't exists in ovs */
+        virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+                       _("Interface not found"));
+        return -1;
+    }
+
+    if (virNetDevOpenvswitchInterfaceParseStats(output, stats) < 0)
+        return -1;
+
     if (stats->rx_bytes == -1 &&
         stats->rx_packets == -1 &&
         stats->rx_errs == -1 &&

src/util/virnetdevopenvswitch.h

@@ -49,6 +49,10 @@ int virNetDevOpenvswitchGetMigrateData(char **migrate, const char *ifname)
 int virNetDevOpenvswitchSetMigrateData(char *migrate, const char *ifname)
     ATTRIBUTE_NONNULL(2) ATTRIBUTE_RETURN_CHECK;
 
+int virNetDevOpenvswitchInterfaceParseStats(const char *json,
+                                            virDomainInterfaceStatsPtr stats)
+    ATTRIBUTE_NONNULL(1) ATTRIBUTE_RETURN_CHECK;
+
 int virNetDevOpenvswitchInterfaceStats(const char *ifname,
                                        virDomainInterfaceStatsPtr stats)
     ATTRIBUTE_NONNULL(1) ATTRIBUTE_RETURN_CHECK;

tests/Makefile.am

@@ -147,6 +147,7 @@ EXTRA_DIST = \
 	virmockstathelpers.c \
 	virnetdaemondata \
 	virnetdevtestdata \
+	virnetdevopenvswitchdata \
 	virnetworkportxml2xmldata \
 	virnwfilterbindingxml2xmldata \
 	virpcitestdata \
@@ -1271,9 +1272,17 @@ virmacmaptest_SOURCES = \
 	virmacmaptest.c testutils.h testutils.c
 virmacmaptest_LDADD = $(LDADDS)
 
-test_programs += virmacmaptest
+virnetdevopenvswitchtest_SOURCES = \
+	virnetdevopenvswitchtest.c testutils.h testutils.c
+virnetdevopenvswitchtest_LDADD = $(LDADDS)
+
+test_programs += \
+	virmacmaptest \
+	virnetdevopenvswitchtest
 else ! WITH_YAJL
-EXTRA_DIST +=  virmacmaptest.c
+EXTRA_DIST += \
+	virmacmaptest.c \
+	virnetdevopenvswitchtest.c
 endif ! WITH_YAJL
 
 virnetdevtest_SOURCES = \

tests/virnetdevopenvswitchdata/stats1.json

@@ -0,0 +1 @@
+["map",[["collisions",1],["rx_bytes",2],["rx_crc_err",3],["rx_dropped",4],["rx_errors",5],["rx_frame_err",6],["rx_over_err",7],["rx_packets",8],["tx_bytes",9],["tx_dropped",10],["tx_errors",11],["tx_packets",12]]]

tests/virnetdevopenvswitchdata/stats2.json

@@ -0,0 +1 @@
+["map",[["collisions",0],["rx_bytes",0],["rx_crc_err",0],["rx_dropped",0],["rx_errors",0],["rx_frame_err",0],["rx_over_err",0],["rx_packets",0],["tx_bytes",12406],["tx_dropped",0],["tx_errors",0],["tx_packets",173]]]

tests/virnetdevopenvswitchtest.c

@@ -0,0 +1,101 @@
+/*
+ * Copyright (C) 2019 Red Hat, Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library.  If not, see
+ * <http://www.gnu.org/licenses/>.
+ */
+
+#include <config.h>
+
+#include "testutils.h"
+#include "virnetdevopenvswitch.h"
+
+#define VIR_FROM_THIS VIR_FROM_NONE
+
+typedef struct _InterfaceParseStatsData InterfaceParseStatsData;
+struct _InterfaceParseStatsData {
+    const char *filename;
+    const virDomainInterfaceStatsStruct stats;
+};
+
+
+static int
+testInterfaceParseStats(const void *opaque)
+{
+    const InterfaceParseStatsData *data = opaque;
+    VIR_AUTOFREE(char *) filename = NULL;
+    VIR_AUTOFREE(char *) buf = NULL;
+    virDomainInterfaceStatsStruct actual;
+
+    if (virAsprintf(&filename, "%s/virnetdevopenvswitchdata/%s",
+                    abs_srcdir, data->filename) < 0)
+        return -1;
+
+    if (virFileReadAll(filename, 1024, &buf) < 0)
+        return -1;
+
+    if (virNetDevOpenvswitchInterfaceParseStats(buf, &actual) < 0)
+        return -1;
+
+    if (memcmp(&actual, &data->stats, sizeof(actual)) != 0) {
+        fprintf(stderr,
+                "Expected stats: %lld %lld %lld %lld %lld %lld %lld %lld\n"
+                "Actual stats: %lld %lld %lld %lld %lld %lld %lld %lld",
+                data->stats.rx_bytes,
+                data->stats.rx_packets,
+                data->stats.rx_errs,
+                data->stats.rx_drop,
+                data->stats.tx_bytes,
+                data->stats.tx_packets,
+                data->stats.tx_errs,
+                data->stats.tx_drop,
+                actual.rx_bytes,
+                actual.rx_packets,
+                actual.rx_errs,
+                actual.rx_drop,
+                actual.tx_bytes,
+                actual.tx_packets,
+                actual.tx_errs,
+                actual.tx_drop);
+
+        return -1;
+    }
+
+    return 0;
+}
+
+
+static int
+mymain(void)
+{
+    int ret = 0;
+
+#define TEST_INTERFACE_STATS(file, \
+                             rxBytes, rxPackets, rxErrs, rxDrop, \
+                             txBytes, txPackets, txErrs, txDrop) \
+    do { \
+        const InterfaceParseStatsData data = {.filename = file, .stats = { \
+                             rxBytes, rxPackets, rxErrs, rxDrop, \
+                             txBytes, txPackets, txErrs, txDrop}}; \
+        if (virTestRun("Interface stats " file, testInterfaceParseStats, &data) < 0) \
+            ret = -1; \
+    } while (0)
+
+    TEST_INTERFACE_STATS("stats1.json", 9, 12, 11, 10, 2, 8, 5, 4);
+    TEST_INTERFACE_STATS("stats2.json", 12406, 173, 0, 0, 0, 0, 0, 0);
+
+    return ret == 0 ? EXIT_SUCCESS : EXIT_FAILURE;
+}
+
+VIR_TEST_MAIN(mymain);