tools: ynl: generate code for rt-route and add a sample

YNL C can now generate code for simple classic netlink families.
Include rt-route in the Makefile for generation and add a sample.

    $ ./tools/net/ynl/samples/rt-route
    oif: wlp0s20f3        gateway: 192.168.1.1
    oif: wlp0s20f3        dst: 192.168.1.0/24
    oif: vpn0             dst: fe80::/64
    oif: wlp0s20f3        dst: fe80::/64
    oif: wlp0s20f3        gateway: fe80::200:5eff:fe00:201

Reviewed-by: Jacob Keller <[email protected]>
Reviewed-by: Donald Hunter <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

Author: kuba-moo

tools/net/ynl/Makefile.deps

@@ -30,4 +30,5 @@ CFLAGS_ovs_datapath:=$(call get_hdr_inc,__LINUX_OPENVSWITCH_H,openvswitch.h)
 CFLAGS_ovs_flow:=$(call get_hdr_inc,__LINUX_OPENVSWITCH_H,openvswitch.h)
 CFLAGS_ovs_vport:=$(call get_hdr_inc,__LINUX_OPENVSWITCH_H,openvswitch.h)
 CFLAGS_rt-addr:=$(call get_hdr_inc,__LINUX_RTNETLINK_H,rtnetlink.h)
+CFLAGS_rt-route:=$(call get_hdr_inc,__LINUX_RTNETLINK_H,rtnetlink.h)
 CFLAGS_tcp_metrics:=$(call get_hdr_inc,_LINUX_TCP_METRICS_H,tcp_metrics.h)

tools/net/ynl/generated/Makefile

@@ -25,7 +25,7 @@ SPECS_DIR:=../../../../Documentation/netlink/specs
 GENS_PATHS=$(shell grep -nrI --files-without-match \
 		'protocol: netlink' \
 		$(SPECS_DIR))
-GENS=$(patsubst $(SPECS_DIR)/%.yaml,%,${GENS_PATHS}) rt-addr
+GENS=$(patsubst $(SPECS_DIR)/%.yaml,%,${GENS_PATHS}) rt-addr rt-route
 SRCS=$(patsubst %,%-user.c,${GENS})
 HDRS=$(patsubst %,%-user.h,${GENS})
 OBJS=$(patsubst %,%-user.o,${GENS})

tools/net/ynl/samples/.gitignore

@@ -4,3 +4,4 @@ netdev
 ovs
 page-pool
 rt-addr
+rt-route

tools/net/ynl/samples/rt-route.c

@@ -0,0 +1,80 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <stdio.h>
+#include <string.h>
+
+#include <ynl.h>
+
+#include <arpa/inet.h>
+#include <net/if.h>
+
+#include "rt-route-user.h"
+
+static void rt_route_print(struct rt_route_getroute_rsp *r)
+{
+	char ifname[IF_NAMESIZE];
+	char route_str[64];
+	const char *route;
+	const char *name;
+
+	/* Ignore local */
+	if (r->_hdr.rtm_table == RT_TABLE_LOCAL)
+		return;
+
+	if (r->_present.oif) {
+		name = if_indextoname(r->oif, ifname);
+		if (name)
+			printf("oif: %-16s ", name);
+	}
+
+	if (r->_present.dst_len) {
+		route = inet_ntop(r->_hdr.rtm_family, r->dst,
+				  route_str, sizeof(route_str));
+		printf("dst: %s/%d", route, r->_hdr.rtm_dst_len);
+	}
+
+	if (r->_present.gateway_len) {
+		route = inet_ntop(r->_hdr.rtm_family, r->gateway,
+				  route_str, sizeof(route_str));
+		printf("gateway: %s ", route);
+	}
+
+	printf("\n");
+}
+
+int main(int argc, char **argv)
+{
+	struct rt_route_getroute_req_dump *req;
+	struct rt_route_getroute_list *rsp;
+	struct ynl_error yerr;
+	struct ynl_sock *ys;
+
+	ys = ynl_sock_create(&ynl_rt_route_family, &yerr);
+	if (!ys) {
+		fprintf(stderr, "YNL: %s\n", yerr.msg);
+		return 1;
+	}
+
+	req = rt_route_getroute_req_dump_alloc();
+	if (!req)
+		goto err_destroy;
+
+	rsp = rt_route_getroute_dump(ys, req);
+	rt_route_getroute_req_dump_free(req);
+	if (!rsp)
+		goto err_close;
+
+	if (ynl_dump_empty(rsp))
+		fprintf(stderr, "Error: no routeesses reported\n");
+	ynl_dump_foreach(rsp, route)
+		rt_route_print(route);
+	rt_route_getroute_list_free(rsp);
+
+	ynl_sock_destroy(ys);
+	return 0;
+
+err_close:
+	fprintf(stderr, "YNL: %s\n", ys->err.msg);
+err_destroy:
+	ynl_sock_destroy(ys);
+	return 2;
+}