tests: posix: net: add tests for if_nameindex et al

Add tests for if_indextoname(), if_freenameindex(),
if_nameindex(), and if_nametoindex().

Signed-off-by: Chris Friedt <chrisfriedt@gmail.com>

tests/posix/net/src/if.c

@@ -0,0 +1,80 @@
+/*
+ * Copyright (c) 2024, Friedt Professional Engineering Services, Inc
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <zephyr/logging/log.h>
+#include <zephyr/net/net_if.h>
+#include <zephyr/posix/net/if.h>
+#include <zephyr/sys/util.h>
+#include <zephyr/ztest.h>
+
+ZTEST(net, test_if_indextoname)
+{
+	char *name;
+	size_t n = 0;
+	struct net_if *iface;
+	char a[IF_NAMESIZE];
+	char b[IF_NAMESIZE];
+
+	NET_IFACE_COUNT(&n);
+	TC_PRINT("%zu interfaces\n", n);
+	for (size_t i = 0; i < n; i++) {
+		memset(a, 0, sizeof(a));
+		memset(b, 0, sizeof(b));
+		name = if_indextoname(i + 1, a);
+		zassert_equal(name, a);
+		TC_PRINT("interface %zu: %s\n", i + 1, name);
+		iface = net_if_get_by_index(i + 1);
+		zassert_not_null(iface);
+		zassert_true(net_if_get_name(iface, b, IF_NAMESIZE) >= 0);
+		zassert_mem_equal(a, b, IF_NAMESIZE);
+	}
+}
+
+ZTEST(net, test_if_freenameindex)
+{
+	if_freenameindex(NULL);
+	if_freenameindex(if_nameindex());
+}
+
+ZTEST(net, test_if_nameindex)
+{
+	size_t n = 0;
+	struct if_nameindex *ni;
+
+	NET_IFACE_COUNT(&n);
+	TC_PRINT("%zu interfaces\n", n);
+
+	ni = if_nameindex();
+	if (ni == NULL) {
+		zassert_equal(errno, ENOBUFS);
+		return;
+	}
+
+	for (size_t i = 0; i < n; i++) {
+		zassert_equal(i + 1, ni[i].if_index);
+		zassert_not_null(ni[i].if_name);
+		TC_PRINT("interface %zu: %s\n", i + 1, ni[i].if_name);
+		zassert_equal(0, ni[n].if_index);
+		zassert_is_null(ni[n].if_name);
+	}
+
+	if_freenameindex(ni);
+}
+
+ZTEST(net, test_if_nametoindex)
+{
+	size_t n = 0;
+	char buf[IF_NAMESIZE];
+
+	NET_IFACE_COUNT(&n);
+	TC_PRINT("%zu interfaces\n", n);
+	for (size_t i = 0; i < n; i++) {
+		memset(buf, 0, sizeof(buf));
+		zassert_not_null(if_indextoname(i + 1, buf));
+		TC_PRINT("interface %zu: %s\n", i + 1, buf);
+		zassert_equal(i + 1, if_nametoindex(buf));
+	}
+}

tests/posix/net/testcase.yaml

@@ -1,6 +1,12 @@
 common:
   depends_on: netif
+  # native_sim uses if_*() from the native libc
+  filter: not CONFIG_NATIVE_LIBC
+  integration_platforms:
+    - qemu_x86
   min_ram: 16
+  platform_allow:
+    - qemu_x86
   tags:
     - iface
     - net