[RFC 0/6] WWAN netdev creation framework tweaks

@@ -341,6 +341,12 @@ enum {
 	IFLA_ALT_IFNAME, /* Alternative ifname */
 	IFLA_PERM_ADDRESS,
 	IFLA_PROTO_DOWN_REASON,
+
+	/* device (sysfs) name as parent, used instead
+	 * of IFLA_LINK where there's no parent netdev
+	 */
+	IFLA_PARENT_DEV_NAME,
+
 	__IFLA_MAX
 };
 

@@ -0,0 +1,16 @@
+/* SPDX-License-Identifier: GPL-2.0-only WITH Linux-syscall-note */
+/*
+ * Copyright (C) 2021 Intel Corporation.
+ */
+#ifndef _UAPI_WWAN_H_
+#define _UAPI_WWAN_H_
+
+enum {
+	IFLA_WWAN_UNSPEC,
+	IFLA_WWAN_LINK_ID, /* u32 */
+
+	__IFLA_WWAN_MAX
+};
+#define IFLA_WWAN_MAX (__IFLA_WWAN_MAX - 1)
+
+#endif /* _UAPI_WWAN_H_ */

@@ -1176,6 +1176,13 @@ int print_linkinfo(struct nlmsghdr *n, void *arg)
 						   RTA_PAYLOAD(tb[IFLA_PHYS_SWITCH_ID]),
 						   b1, sizeof(b1)));
 		}
+
+		if (tb[IFLA_PARENT_DEV_NAME]) {
+			print_string(PRINT_ANY,
+				     "parentdev_name",
+				     "parentdev-name %s ",
+				     rta_getattr_str(tb[IFLA_PARENT_DEV_NAME]));
+		}
 	}
 
 	if ((do_link || show_details) && tb[IFLA_IFALIAS]) {

@@ -63,7 +63,7 @@ void iplink_usage(void)
 {
 	if (iplink_have_newlink()) {
 		fprintf(stderr,
-			"Usage: ip link add [link DEV] [ name ] NAME\n"
+			"Usage: ip link add [link DEV | parentdev-name NAME] [ name ] NAME\n"
 			"		    [ txqueuelen PACKETS ]\n"
 			"		    [ address LLADDR ]\n"
 			"		    [ broadcast LLADDR ]\n"

@@ -938,6 +938,10 @@ int iplink_parse(int argc, char **argv, struct iplink_req *req, char **type)
 				       *argv);
 			addattr32(&req->n, sizeof(*req),
 				  IFLA_GSO_MAX_SEGS, max_segs);
+		} else if (strcmp(*argv, "parentdev-name") == 0) {
+			NEXT_ARG();
+			addattr_l(&req->n, sizeof(*req), IFLA_PARENT_DEV_NAME,
+				  *argv, strlen(*argv) + 1);
 		} else {
 			if (matches(*argv, "help") == 0)
 				usage();

@@ -376,12 +376,12 @@ int __rtnl_link_register(struct rtnl_link_ops *ops)
 	if (rtnl_link_ops_get(ops->kind))
 		return -EEXIST;
 
-	/* The check for setup is here because if ops
+	/* The check for alloc/setup is here because if ops
 	 * does not have that filled up, it is not possible
 	 * to use the ops for creating device. So do not
 	 * fill up dellink as well. That disables rtnl_dellink.
 	 */
-	if (ops->setup && !ops->dellink)
+	if ((ops->alloc || ops->setup) && !ops->dellink)
 		ops->dellink = unregister_netdevice_queue;
 
 	list_add_tail(&ops->list, &link_ops);

@@ -3421,7 +3421,7 @@ static int __rtnl_newlink(struct sk_buff *skb, struct nlmsghdr *nlh,
 		return -EOPNOTSUPP;
 	}
 
-	if (!ops->setup)
+	if (!ops->alloc && !ops->setup)
 		return -EOPNOTSUPP;
 
 	if (!ifname[0]) {

@@ -1819,6 +1819,11 @@ static int rtnl_fill_ifinfo(struct sk_buff *skb,
 	if (rtnl_fill_prop_list(skb, dev))
 		goto nla_put_failure;
 
+	if (dev->dev.parent &&
+	    nla_put_string(skb, IFLA_PARENT_DEV_NAME,
+			   dev_name(dev->dev.parent)))
+		goto nla_put_failure;
+
 	nlmsg_end(skb, nlh);
 	return 0;
 

@@ -737,7 +737,8 @@ static int __init wwan_init(void)
 		goto destroy;
 	}
 
-	err = 0;
+	return 0;
+
 destroy:
 	class_destroy(wwan_class);
 unregister:

@@ -11,7 +11,7 @@ IPOBJ=ip.o ipaddress.o ipaddrlabel.o iproute.o iprule.o ipnetns.o \
     iplink_bridge.o iplink_bridge_slave.o ipfou.o iplink_ipvlan.o \
     iplink_geneve.o iplink_vrf.o iproute_lwtunnel.o ipmacsec.o ipila.o \
     ipvrf.o iplink_xstats.o ipseg6.o iplink_netdevsim.o iplink_rmnet.o \
-    ipnexthop.o ipmptcp.o iplink_bareudp.o
+    ipnexthop.o ipmptcp.o iplink_bareudp.o iplink_wwan.o
 
 RTMONOBJ=rtmon.o
 

@@ -56,7 +56,8 @@ void iplink_types_usage(void)
 		"          ipip | ipoib | ipvlan | ipvtap |\n"
 		"          macsec | macvlan | macvtap |\n"
 		"          netdevsim | nlmon | rmnet | sit | team | team_slave |\n"
-		"          vcan | veth | vlan | vrf | vti | vxcan | vxlan | xfrm }\n");
+		"          vcan | veth | vlan | vrf | vti | vxcan | vxlan | wwan |\n"
+		"          xfrm }\n");
 }
 
 void iplink_usage(void)

@@ -0,0 +1,72 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#include <stdio.h>
+#include <linux/netlink.h>
+#include <linux/wwan.h>
+
+#include "utils.h"
+#include "ip_common.h"
+
+static void print_explain(FILE *f)
+{
+	fprintf(f,
+		"Usage: ... wwan linkid LINKID\n"
+		"\n"
+		"Where: LINKID := 0-4294967295\n"
+	);
+}
+
+static void explain(void)
+{
+	print_explain(stderr);
+}
+
+static int wwan_parse_opt(struct link_util *lu, int argc, char **argv,
+			  struct nlmsghdr *n)
+{
+	while (argc > 0) {
+		if (matches(*argv, "linkid") == 0) {
+			__u32 linkid;
+
+			NEXT_ARG();
+			if (get_u32(&linkid, *argv, 0))
+				invarg("linkid", *argv);
+			addattr32(n, 1024, IFLA_WWAN_LINK_ID, linkid);
+		} else if (matches(*argv, "help") == 0) {
+			explain();
+			return -1;
+		} else {
+			fprintf(stderr, "wwan: unknown command \"%s\"?\n",
+				*argv);
+			explain();
+			return -1;
+		}
+		argc--, argv++;
+	}
+
+	return 0;
+}
+
+static void wwan_print_opt(struct link_util *lu, FILE *f, struct rtattr *tb[])
+{
+	if (!tb)
+		return;
+
+	if (tb[IFLA_WWAN_LINK_ID])
+		print_uint(PRINT_ANY, "linkid", "linkid %u ",
+			   rta_getattr_u32(tb[IFLA_WWAN_LINK_ID]));
+}
+
+static void wwan_print_help(struct link_util *lu, int argc, char **argv,
+			    FILE *f)
+{
+	print_explain(f);
+}
+
+struct link_util wwan_link_util = {
+	.id		= "wwan",
+	.maxattr	= IFLA_WWAN_MAX,
+	.parse_opt	= wwan_parse_opt,
+	.print_opt	= wwan_print_opt,
+	.print_help	= wwan_print_help,
+};