ip link: add sub-command to view and change DSA conduit interface

Support the "dsa" kind of rtnl_link_ops exported by the kernel, and
export reads/writes to IFLA_DSA_MASTER.

Examples:

$ ip link set swp0 type dsa conduit eth1

$ ip -d link show dev swp0
    (...)
    dsa conduit eth0

$ ip -d -j link show swp0
[
	{
		"link": "eth1",
		"linkinfo": {
			"info_kind": "dsa",
			"info_data": {
				"conduit": "eth1"
			}
		},
	}
]

Note that by construction and as shown in the example, the IFLA_LINK
reported by a DSA user port is identical to what is reported through
IFLA_DSA_MASTER. However IFLA_LINK is not writable, and overloading its
meaning to make it writable would clash with other users of IFLA_LINK
(vlan etc) for which writing this property does not make sense.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David Ahern <dsahern@kernel.org>

diff --git a/ip/Makefile b/ip/Makefile
index 6c2e072049a2af9b49f54e38332b03c13ea27611..8fd9e295f344a9f1b3200902a418c4c850492b12 100644 (file)
--- a/ip/Makefile
+++ b/ip/Makefile
@@ -8,7 +8,7 @@ IPOBJ=ip.o ipaddress.o ipaddrlabel.o iproute.o iprule.o ipnetns.o \
     iplink_macvlan.o ipl2tp.o link_vti.o link_vti6.o link_xfrm.o \
     iplink_vxlan.o tcp_metrics.o iplink_ipoib.o ipnetconf.o link_ip6tnl.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_bridge.o iplink_bridge_slave.o iplink_dsa.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 iplink_wwan.o ipioam6.o \

diff --git a/ip/iplink.c b/ip/iplink.c
index ad22f2d75d3a78ef42c8cbb5da2fe919ae43488d..c8f0b3841344a322251b1dd80a3e722ffc3f3f96 100644 (file)
--- a/ip/iplink.c
+++ b/ip/iplink.c
@@ -48,7 +48,7 @@ void iplink_types_usage(void)
        /* Remember to add new entry here if new type is added. */
        fprintf(stderr,
                "TYPE := { amt | bareudp | bond | bond_slave | bridge | bridge_slave |\n"
-               "          dummy | erspan | geneve | gre | gretap | gtp | ifb |\n"
+               "          dsa | dummy | erspan | geneve | gre | gretap | gtp | ifb |\n"
                "          ip6erspan | ip6gre | ip6gretap | ip6tnl |\n"
                "          ipip | ipoib | ipvlan | ipvtap |\n"
                "          macsec | macvlan | macvtap |\n"

diff --git a/ip/iplink_dsa.c b/ip/iplink_dsa.c
new file mode 100644 (file)
index 0000000..e3f3f8a
--- /dev/null
+++ b/ip/iplink_dsa.c
@@ -0,0 +1,68 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * iplink_dsa.c                DSA switch support
+ */
+
+#include "utils.h"
+#include "ip_common.h"
+
+static void print_usage(FILE *f)
+{
+       fprintf(f, "Usage: ... dsa [ conduit DEVICE ]\n");
+}
+
+static int dsa_parse_opt(struct link_util *lu, int argc, char **argv,
+                        struct nlmsghdr *n)
+{
+       while (argc > 0) {
+               if (strcmp(*argv, "conduit") == 0 ||
+                   strcmp(*argv, "master") == 0) {
+                       __u32 ifindex;
+
+                       NEXT_ARG();
+                       ifindex = ll_name_to_index(*argv);
+                       if (!ifindex)
+                               invarg("Device does not exist\n", *argv);
+                       addattr_l(n, 1024, IFLA_DSA_MASTER, &ifindex, 4);
+               } else if (strcmp(*argv, "help") == 0) {
+                       print_usage(stderr);
+                       return -1;
+               } else {
+                       fprintf(stderr, "dsa: unknown command \"%s\"?\n", *argv);
+                       print_usage(stderr);
+                       return -1;
+               }
+               argc--;
+               argv++;
+       }
+
+       return 0;
+}
+
+static void dsa_print_opt(struct link_util *lu, FILE *f, struct rtattr *tb[])
+{
+       if (!tb)
+               return;
+
+       if (tb[IFLA_DSA_MASTER]) {
+               __u32 conduit = rta_getattr_u32(tb[IFLA_DSA_MASTER]);
+
+               print_string(PRINT_ANY,
+                            "conduit", "conduit %s ",
+                            ll_index_to_name(conduit));
+       }
+}
+
+static void dsa_print_help(struct link_util *lu, int argc, char **argv,
+                          FILE *f)
+{
+       print_usage(f);
+}
+
+struct link_util dsa_link_util = {
+       .id             = "dsa",
+       .maxattr        = IFLA_DSA_MAX,
+       .parse_opt      = dsa_parse_opt,
+       .print_opt      = dsa_print_opt,
+       .print_help     = dsa_print_help,
+};

diff --git a/man/man8/ip-link.8.in b/man/man8/ip-link.8.in
index c45c10622251782e312bca004a471d8b8831293f..fc9d62fc5767627ee98349600d947c1f0f6bfc22 100644 (file)
--- a/man/man8/ip-link.8.in
+++ b/man/man8/ip-link.8.in
@@ -213,6 +213,7 @@ ip-link \- network device configuration
 .BR bond " | "
 .BR bridge " | "
 .BR can " | "
+.BR dsa " | "
 .BR dummy " | "
 .BR erspan " |"
 .BR geneve " |"
@@ -304,6 +305,9 @@ Link types:
 .B can
 - Controller Area Network
 .sp
+.B dsa
+- Distributed Switch Architecture
+.sp
 .B dummy
 - Dummy network interface
 .sp
@@ -2637,6 +2641,32 @@ as well as the actual used bcqueuelen are listed to better help
 the user understand the setting.
 .in -8
 
+.TP
+DSA user port support
+For a link having the DSA user port type, the following additional arguments
+are supported:
+
+.B "ip link set type dsa "
+[
+.BI conduit " DEVICE"
+]
+
+.in +8
+.sp
+.BI conduit " DEVICE"
+- change the DSA conduit (host network interface) responsible for handling the
+locally terminated traffic for the given DSA switch user port. For a
+description of which network interfaces are suitable for serving as conduit
+interfaces of this user port, please see
+https://www.kernel.org/doc/html/latest/networking/dsa/configuration.html#affinity-of-user-ports-to-cpu-ports
+as well as what is supported by the driver in use.
+
+.sp
+.BI master " DEVICE"
+- this is a synonym for "conduit".
+
+.in -8
+
 .SS  ip link show - display device attributes
 
 .TP
@@ -2793,6 +2823,11 @@ erspan_ver 2 erspan_dir ingress erspan_hwid 17
 .RS 4
 Creates a IP6ERSPAN version 2 interface named ip6erspan00.
 .RE
+.PP
+ip link set dev swp0 type dsa conduit eth1
+.RS 4
+Changes the conduit interface of the swp0 user port to eth1.
+.RE
 
 .SH SEE ALSO
 .br