ip: add rmnet initial support

This patch adds basic support for Qualcomm rmnet devices.

Signed-off-by: Daniele Palmas <dnlplm@gmail.com>
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>

ip/Makefile

@@ -10,7 +10,7 @@ IPOBJ=ip.o ipaddress.o ipaddrlabel.o iproute.o iprule.o ipnetns.o \
     link_iptnl.o link_gre6.o iplink_bond.o iplink_bond_slave.o iplink_hsr.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
+    ipvrf.o iplink_xstats.o ipseg6.o iplink_netdevsim.o iplink_rmnet.o
 
 RTMONOBJ=rtmon.o
 

ip/iplink.c

@@ -121,7 +121,7 @@ void iplink_usage(void)
 			"          bridge | bond | team | ipoib | ip6tnl | ipip | sit | vxlan |\n"
 			"          gre | gretap | erspan | ip6gre | ip6gretap | ip6erspan |\n"
 			"          vti | nlmon | team_slave | bond_slave | ipvlan | geneve |\n"
-			"          bridge_slave | vrf | macsec | netdevsim }\n");
+			"          bridge_slave | vrf | macsec | netdevsim | rmnet }\n");
 	}
 	exit(-1);
 }

ip/iplink_rmnet.c

@@ -0,0 +1,81 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * iplink_rmnet.c	RMNET device support
+ *
+ * Authors:     Daniele Palmas <dnlplm@gmail.com>
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "utils.h"
+#include "ip_common.h"
+
+static void print_explain(FILE *f)
+{
+	fprintf(f,
+		"Usage: ... rmnet mux_id MUXID\n"
+		"\n"
+		"MUXID := 1-254\n"
+	);
+}
+
+static void explain(void)
+{
+	print_explain(stderr);
+}
+
+static int rmnet_parse_opt(struct link_util *lu, int argc, char **argv,
+			   struct nlmsghdr *n)
+{
+	__u16 mux_id;
+
+	while (argc > 0) {
+		if (matches(*argv, "mux_id") == 0) {
+			NEXT_ARG();
+			if (get_u16(&mux_id, *argv, 0))
+				invarg("mux_id is invalid", *argv);
+			addattr16(n, 1024, IFLA_RMNET_MUX_ID, mux_id);
+		} else if (matches(*argv, "help") == 0) {
+			explain();
+			return -1;
+		} else {
+			fprintf(stderr, "rmnet: unknown command \"%s\"?\n", *argv);
+			explain();
+			return -1;
+		}
+		argc--, argv++;
+	}
+
+	return 0;
+}
+
+static void rmnet_print_opt(struct link_util *lu, FILE *f, struct rtattr *tb[])
+{
+	if (!tb)
+		return;
+
+	if (!tb[IFLA_RMNET_MUX_ID] ||
+	    RTA_PAYLOAD(tb[IFLA_RMNET_MUX_ID]) < sizeof(__u16))
+		return;
+
+	print_uint(PRINT_ANY,
+		   "mux_id",
+		   "mux_id %u ",
+		   rta_getattr_u16(tb[IFLA_RMNET_MUX_ID]));
+}
+
+static void rmnet_print_help(struct link_util *lu, int argc, char **argv,
+			     FILE *f)
+{
+	print_explain(f);
+}
+
+struct link_util rmnet_link_util = {
+	.id		= "rmnet",
+	.maxattr	= IFLA_RMNET_MAX,
+	.parse_opt	= rmnet_parse_opt,
+	.print_opt	= rmnet_print_opt,
+	.print_help	= rmnet_print_help,
+};

man/man8/ip-link.8.in

@@ -219,7 +219,8 @@ ip-link \- network device configuration
 .BR geneve " |"
 .BR vrf " |"
 .BR macsec " |"
-.BR netdevsim " ]"
+.BR netdevsim " |"
+.BR rmnet " ]"
 
 .ti -8
 .IR ETYPE " := [ " TYPE " |"
@@ -342,6 +343,9 @@ Link types:
 .sp
 .BR netdevsim
 - Interface for netdev API tests
+.sp
+.BR rmnet
+- Qualcomm rmnet device
 .in -8
 
 .TP
@@ -1651,6 +1655,21 @@ the following additional arguments are supported:
 
 .in -8
 
+.TP
+RMNET Type Support
+For a link of type
+.I RMNET
+the following additional arguments are supported:
+
+.BI "ip link add link " DEVICE " name " NAME " type rmnet mux_id " MUXID
+
+.in +8
+.sp
+.BI mux_id " MUXID "
+- specifies the mux identifier for the rmnet device, possible values 1-254.
+
+.in -8
+
 .SS ip link delete - delete virtual link
 
 .TP