Initial s390-tools-2.0.0 import

This commit is based on the s390-tools-1.39.0 version.

Changes on top of s390-tools-1.39.0:

 - Add MIT license to all source files
 - Add LICENSE file
 - Transform REAMDE to README.md (markdown)
 - Add AUTHORS.md file
 - Add CONTRIBUTING.md file
 - Move changelog from README to CHANGELOG.md file

Reviewed-by: Stefan Haberland <sth@linux.vnet.ibm.com>
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>

zdev/src/net.c

@@ -0,0 +1,110 @@
+/*
+ * zdev - Modify and display the persistent configuration of devices
+ *
+ * Copyright IBM Corp. 2016, 2017
+ *
+ * s390-tools is free software; you can redistribute it and/or modify
+ * it under the terms of the MIT license. See LICENSE for details.
+ */
+
+#include <ctype.h>
+#include <stdbool.h>
+#include <string.h>
+
+#include "devnode.h"
+#include "misc.h"
+#include "net.h"
+#include "path.h"
+
+struct add_linked_cb_data {
+	struct util_list *list;
+	const char *prefix;
+	size_t prefix_len;
+	bool result;
+};
+
+/* Add a devnode to data->list for each sysfs link that indicates a linked
+ * device. */
+static exit_code_t add_linked_cb(const char *abs_path, const char *rel_path,
+				 void *data)
+{
+	struct add_linked_cb_data *cb_data = data;
+	const char *name;
+	struct devnode *d;
+
+	if (starts_with(rel_path, cb_data->prefix)) {
+		name = rel_path + cb_data->prefix_len;
+		d = devnode_new(NETDEV, 0, 0, name);
+		ptrlist_add(cb_data->list, d);
+		cb_data->result = true;
+	}
+
+	return EXIT_OK;
+}
+
+/* Add devnodes for all networking devices that are linked to @devnode via
+ * a link starting with @prefix to @list. */
+static bool add_devnodes_from_link(struct util_list *list,
+				   struct devnode *devnode, const char *prefix)
+{
+	struct add_linked_cb_data cb_data;
+	char *path;
+
+	cb_data.list = list;
+	cb_data.prefix = prefix;
+	cb_data.prefix_len = strlen(prefix);
+	cb_data.result = false;
+	path = path_get_sys_class("net", devnode->name);
+	path_for_each(path, add_linked_cb, &cb_data);
+	free(path);
+
+	return cb_data.result;
+}
+
+/* Add devnodes for all devices to @list that are linked as "lower" devices
+ * of network interface @devnode. */
+bool net_add_linked_devnodes(struct util_list *list, struct devnode *devnode)
+{
+	return add_devnodes_from_link(list, devnode, "lower_");
+}
+
+#define DEVICE_PREFIX	"Device:"
+
+/* If @devnode refers to a vlan device, add a devnode representing its
+ * base device to @list. */
+bool net_add_vlan_base(struct util_list *list, struct devnode *devnode)
+{
+	char *path, *text, *name, *end;
+	bool rc = false;
+
+	path = path_get("/proc/net/vlan/%s", devnode->name);
+	text = misc_read_text_file(path, 0, err_ignore);
+	if (!text)
+		goto out;
+
+	name = strstr(text, DEVICE_PREFIX);
+	if (!name)
+		goto out;
+	name += sizeof(DEVICE_PREFIX) - 1;
+
+	for (; *name && isspace(*name); name++) ;
+	for (end = name; *end && !isspace(*end); end++) ;
+	if (name == end)
+		goto out;
+	*end = 0;
+	ptrlist_add(list, devnode_new(NETDEV, 0, 0, name));
+	rc = true;
+
+out:
+	free(text);
+	free(path);
+
+	return rc;
+}
+
+/* If @devnode refers to a bonding device, add a devnode representing its
+ * base device to @list. */
+bool net_add_bonding_base(struct util_list *list, struct devnode *devnode)
+{
+	return add_devnodes_from_link(list, devnode, "slave_");
+}