[iproute2-next,v2,2/2] iplink: support for WWAN devices

Commit Message

Sergey Ryazanov June 22, 2021, 11:52 p.m. UTC

The WWAN subsystem has been extended to generalize the per data channel
network interfaces management. This change implements support for WWAN
links handling. And actively uses the earlier introduced ip-link
capability to specify the parent by its device name.

The WWAN interface for a new data channel should be created with a
command like this:

ip link add dev wwan0-2 parentdev wwan0 type wwan linkid 2

Where: wwan0 is the modem HW device name (should be taken from
/sys/class/wwan) and linkid is an identifier of the opened data
channel.

Signed-off-by: Sergey Ryazanov <[e-mail]>
---
To compile this, a new uapi/linux/wwan.h header file should be copied
from the kernel sources.

Changes since v1:
* no changes

Changes since RFC:
* no changes

 ip/Makefile      |  2 +-
 ip/iplink.c      |  3 +-
 ip/iplink_wwan.c | 72 ++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 75 insertions(+), 2 deletions(-)
 create mode 100644 ip/iplink_wwan.c

Patch

diff --git a/ip/Makefile b/ip/Makefile
index 4cad619c..b03af29b 100644
--- a/ip/Makefile
+++ b/ip/Makefile
@@ -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
 
diff --git a/ip/iplink.c b/ip/iplink.c
index 33b7be30..18b2ea25 100644
--- a/ip/iplink.c
+++ b/ip/iplink.c
@@ -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)
diff --git a/ip/iplink_wwan.c b/ip/iplink_wwan.c
new file mode 100644
index 00000000..3510477a
--- /dev/null
+++ b/ip/iplink_wwan.c
@@ -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,
+};