Merge branch 'tools-ynl-c-basic-netlink-raw-support'

Jakub Kicinski says:

====================
tools: ynl: c: basic netlink-raw support

Basic support for netlink-raw AKA classic netlink in user space C codegen.
This series is enough to read routes and addresses from the kernel
(see the samples in patches 12 and 13).

Specs need to be slightly adjusted and decorated with the c naming info.

In terms of codegen this series includes just the basic plumbing required
to skip genlmsghdr and handle request types which may technically also
be legal in genetlink-legacy but are very uncommon there.

Subsequent series will add support for:
 - handling CRUD-style notifications
 - code gen for array types classic netlink uses
 - sub-message support

v1: https://lore.kernel.org/20250409000400.492371-1-kuba@kernel.org
====================

Link: https://patch.msgid.link/20250410014658.782120-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Documentation/netlink/specs/rt-addr.yaml

@@ -2,6 +2,7 @@
 
 name: rt-addr
 protocol: netlink-raw
+uapi-header: linux/rtnetlink.h
 protonum: 0
 
 doc:
@@ -49,6 +50,8 @@ definitions:
   -
     name: ifa-flags
     type: flags
+    name-prefix: ifa-f-
+    enum-name:
     entries:
       -
         name: secondary
@@ -124,6 +127,7 @@ attribute-sets:
 operations:
   fixed-header: ifaddrmsg
   enum-model: directional
+  name-prefix: rtm-
   list:
     -
       name: newaddr
@@ -133,11 +137,6 @@ operations:
         request:
           value: 20
           attributes: &ifaddr-all
-            - ifa-family
-            - ifa-flags
-            - ifa-prefixlen
-            - ifa-scope
-            - ifa-index
             - address
             - label
             - local
@@ -150,11 +149,6 @@ operations:
         request:
           value: 21
           attributes:
-            - ifa-family
-            - ifa-flags
-            - ifa-prefixlen
-            - ifa-scope
-            - ifa-index
             - address
             - local
     -
@@ -164,8 +158,7 @@ operations:
       dump:
         request:
           value: 22
-          attributes:
-            - ifa-index
+          attributes: []
         reply:
           value: 20
           attributes: *ifaddr-all
@@ -177,9 +170,7 @@ operations:
       do:
         request:
           value: 58
-          attributes:
-            - ifa-family
-            - ifa-index
+          attributes: []
         reply:
           value: 58
           attributes: &mcaddr-attrs
@@ -188,8 +179,7 @@ operations:
       dump:
         request:
           value: 58
-          attributes:
-            - ifa-family
+          attributes: []
         reply:
           value: 58
           attributes: *mcaddr-attrs

Documentation/netlink/specs/rt-route.yaml

@@ -2,6 +2,7 @@
 
 name: rt-route
 protocol: netlink-raw
+uapi-header: linux/rtnetlink.h
 protonum: 0
 
 doc:
@@ -11,6 +12,7 @@ definitions:
   -
     name: rtm-type
     name-prefix: rtn-
+    enum-name:
     type: enum
     entries:
       - unspec
@@ -245,21 +247,19 @@ attribute-sets:
 
 operations:
   enum-model: directional
+  fixed-header: rtmsg
+  name-prefix: rtm-
   list:
     -
       name: getroute
       doc: Dump route information.
       attribute-set: route-attrs
-      fixed-header: rtmsg
       do:
         request:
           value: 26
           attributes:
-            - rtm-family
             - src
-            - rtm-src-len
             - dst
-            - rtm-dst-len
             - iif
             - oif
             - ip-proto
@@ -271,15 +271,6 @@ operations:
         reply:
           value: 24
           attributes: &all-route-attrs
-            - rtm-family
-            - rtm-dst-len
-            - rtm-src-len
-            - rtm-tos
-            - rtm-table
-            - rtm-protocol
-            - rtm-scope
-            - rtm-type
-            - rtm-flags
             - dst
             - src
             - iif
@@ -311,8 +302,7 @@ operations:
       dump:
         request:
           value: 26
-          attributes:
-            - rtm-family
+          attributes: []
         reply:
           value: 24
           attributes: *all-route-attrs
@@ -320,7 +310,6 @@ operations:
       name: newroute
       doc: Create a new route
       attribute-set: route-attrs
-      fixed-header: rtmsg
       do:
         request:
           value: 24
@@ -329,7 +318,6 @@ operations:
       name: delroute
       doc: Delete an existing route
       attribute-set: route-attrs
-      fixed-header: rtmsg
       do:
         request:
           value: 25

Documentation/userspace-api/netlink/netlink-raw.rst

@@ -62,7 +62,7 @@ Sub-messages
 ------------
 
 Several raw netlink families such as
-:doc:`rt_link<../../networking/netlink_spec/rt_link>` and
+:doc:`rt-link<../../networking/netlink_spec/rt-link>` and
 :doc:`tc<../../networking/netlink_spec/tc>` use attribute nesting as an
 abstraction to carry module specific information.
 

tools/net/ynl/Makefile.deps

@@ -29,4 +29,6 @@ CFLAGS_nfsd:=$(call get_hdr_inc,_LINUX_NFSD_NETLINK_H,nfsd_netlink.h)
 CFLAGS_ovs_datapath:=$(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})
+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/lib/ynl-priv.h

@@ -94,6 +94,9 @@ struct ynl_ntf_base_type {
 	unsigned char data[] __attribute__((aligned(8)));
 };
 
+struct nlmsghdr *ynl_msg_start_req(struct ynl_sock *ys, __u32 id);
+struct nlmsghdr *ynl_msg_start_dump(struct ynl_sock *ys, __u32 id);
+
 struct nlmsghdr *
 ynl_gemsg_start_req(struct ynl_sock *ys, __u32 id, __u8 cmd, __u8 version);
 struct nlmsghdr *

tools/net/ynl/lib/ynl.c

@@ -451,14 +451,14 @@ ynl_gemsg_start(struct ynl_sock *ys, __u32 id, __u16 flags,
 	return nlh;
 }
 
-void ynl_msg_start_req(struct ynl_sock *ys, __u32 id)
+struct nlmsghdr *ynl_msg_start_req(struct ynl_sock *ys, __u32 id)
 {
-	ynl_msg_start(ys, id, NLM_F_REQUEST | NLM_F_ACK);
+	return ynl_msg_start(ys, id, NLM_F_REQUEST | NLM_F_ACK);
 }
 
-void ynl_msg_start_dump(struct ynl_sock *ys, __u32 id)
+struct nlmsghdr *ynl_msg_start_dump(struct ynl_sock *ys, __u32 id)
 {
-	ynl_msg_start(ys, id, NLM_F_REQUEST | NLM_F_ACK | NLM_F_DUMP);
+	return ynl_msg_start(ys, id, NLM_F_REQUEST | NLM_F_ACK | NLM_F_DUMP);
 }
 
 struct nlmsghdr *
@@ -663,6 +663,7 @@ ynl_sock_create(const struct ynl_family *yf, struct ynl_error *yse)
 	struct sockaddr_nl addr;
 	struct ynl_sock *ys;
 	socklen_t addrlen;
+	int sock_type;
 	int one = 1;
 
 	ys = malloc(sizeof(*ys) + 2 * YNL_SOCKET_BUFFER_SIZE);
@@ -675,7 +676,9 @@ ynl_sock_create(const struct ynl_family *yf, struct ynl_error *yse)
 	ys->rx_buf = &ys->raw_buf[YNL_SOCKET_BUFFER_SIZE];
 	ys->ntf_last_next = &ys->ntf_first;
 
-	ys->socket = socket(AF_NETLINK, SOCK_RAW, NETLINK_GENERIC);
+	sock_type = yf->is_classic ? yf->classic_id : NETLINK_GENERIC;
+
+	ys->socket = socket(AF_NETLINK, SOCK_RAW, sock_type);
 	if (ys->socket < 0) {
 		__perr(yse, "failed to create a netlink socket");
 		goto err_free_sock;
@@ -708,8 +711,9 @@ ynl_sock_create(const struct ynl_family *yf, struct ynl_error *yse)
 	ys->portid = addr.nl_pid;
 	ys->seq = random();
 
-
-	if (ynl_sock_read_family(ys, yf->name)) {
+	if (yf->is_classic) {
+		ys->family_id = yf->classic_id;
+	} else if (ynl_sock_read_family(ys, yf->name)) {
 		if (yse)
 			memcpy(yse, &ys->err, sizeof(*yse));
 		goto err_close_sock;
@@ -791,13 +795,21 @@ static int ynl_ntf_parse(struct ynl_sock *ys, const struct nlmsghdr *nlh)
 	struct ynl_parse_arg yarg = { .ys = ys, };
 	const struct ynl_ntf_info *info;
 	struct ynl_ntf_base_type *rsp;
-	struct genlmsghdr *gehdr;
+	__u32 cmd;
 	int ret;
 
-	gehdr = ynl_nlmsg_data(nlh);
-	if (gehdr->cmd >= ys->family->ntf_info_size)
+	if (ys->family->is_classic) {
+		cmd = nlh->nlmsg_type;
+	} else {
+		struct genlmsghdr *gehdr;
+
+		gehdr = ynl_nlmsg_data(nlh);
+		cmd = gehdr->cmd;
+	}
+
+	if (cmd >= ys->family->ntf_info_size)
 		return YNL_PARSE_CB_ERROR;
-	info = &ys->family->ntf_info[gehdr->cmd];
+	info = &ys->family->ntf_info[cmd];
 	if (!info->cb)
 		return YNL_PARSE_CB_ERROR;
 
@@ -811,7 +823,7 @@ static int ynl_ntf_parse(struct ynl_sock *ys, const struct nlmsghdr *nlh)
 		goto err_free;
 
 	rsp->family = nlh->nlmsg_type;
-	rsp->cmd = gehdr->cmd;
+	rsp->cmd = cmd;
 
 	*ys->ntf_last_next = rsp;
 	ys->ntf_last_next = &rsp->next;
@@ -863,18 +875,23 @@ int ynl_error_parse(struct ynl_parse_arg *yarg, const char *msg)
 static int
 ynl_check_alien(struct ynl_sock *ys, const struct nlmsghdr *nlh, __u32 rsp_cmd)
 {
-	struct genlmsghdr *gehdr;
+	if (ys->family->is_classic) {
+		if (nlh->nlmsg_type != rsp_cmd)
+			return ynl_ntf_parse(ys, nlh);
+	} else {
+		struct genlmsghdr *gehdr;
 
-	if (ynl_nlmsg_data_len(nlh) < sizeof(*gehdr)) {
-		yerr(ys, YNL_ERROR_INV_RESP,
-		     "Kernel responded with truncated message");
-		return -1;
+		if (ynl_nlmsg_data_len(nlh) < sizeof(*gehdr)) {
+			yerr(ys, YNL_ERROR_INV_RESP,
+			     "Kernel responded with truncated message");
+			return -1;
+		}
+
+		gehdr = ynl_nlmsg_data(nlh);
+		if (gehdr->cmd != rsp_cmd)
+			return ynl_ntf_parse(ys, nlh);
 	}
 
-	gehdr = ynl_nlmsg_data(nlh);
-	if (gehdr->cmd != rsp_cmd)
-		return ynl_ntf_parse(ys, nlh);
-
 	return 0;
 }
 

tools/net/ynl/lib/ynl.h

@@ -2,6 +2,7 @@
 #ifndef __YNL_C_H
 #define __YNL_C_H 1
 
+#include <stdbool.h>
 #include <stddef.h>
 #include <linux/genetlink.h>
 #include <linux/types.h>
@@ -48,6 +49,8 @@ struct ynl_family {
 /* private: */
 	const char *name;
 	size_t hdr_len;
+	bool is_classic;
+	__u16 classic_id;
 	const struct ynl_ntf_info *ntf_info;
 	unsigned int ntf_info_size;
 };

tools/net/ynl/pyynl/ynl_gen_c.py

@@ -971,9 +971,6 @@ class Family(SpecFamily):
     def resolve(self):
         self.resolve_up(super())
 
-        if self.yaml.get('protocol', 'genetlink') not in {'genetlink', 'genetlink-c', 'genetlink-legacy'}:
-            raise Exception("Codegen only supported for genetlink")
-
         self.c_name = c_lower(self.ident_name)
         if 'name-prefix' in self.yaml['operations']:
             self.op_prefix = c_upper(self.yaml['operations']['name-prefix'])
@@ -1020,6 +1017,9 @@ class Family(SpecFamily):
     def new_operation(self, elem, req_value, rsp_value):
         return Operation(self, elem, req_value, rsp_value)
 
+    def is_classic(self):
+        return self.proto == 'netlink-raw'
+
     def _mark_notify(self):
         for op in self.msgs.values():
             if 'notify' in op:
@@ -1212,6 +1212,7 @@ class RenderInfo:
 
         # 'do' and 'dump' response parsing is identical
         self.type_consistent = True
+        self.type_oneside = False
         if op_mode != 'do' and 'dump' in op:
             if 'do' in op:
                 if ('reply' in op['do']) != ('reply' in op["dump"]):
@@ -1219,7 +1220,8 @@ class RenderInfo:
                 elif 'reply' in op['do'] and op["do"]["reply"] != op["dump"]["reply"]:
                     self.type_consistent = False
             else:
-                self.type_consistent = False
+                self.type_consistent = True
+                self.type_oneside = True
 
         self.attr_set = attr_set
         if not self.attr_set:
@@ -1247,6 +1249,9 @@ class RenderInfo:
         if op_mode == 'event':
             self.struct['reply'] = Struct(family, self.attr_set, type_list=op['event']['attributes'])
 
+    def type_empty(self, key):
+        return len(self.struct[key].attr_list) == 0 and self.fixed_hdr is None
+
 
 class CodeWriter:
     def __init__(self, nlib, out_file=None, overwrite=True):
@@ -1513,7 +1518,9 @@ def op_prefix(ri, direction, deref=False):
         suffix += f"{direction_to_suffix[direction]}"
     else:
         if direction == 'request':
-            suffix += '_req_dump'
+            suffix += '_req'
+            if not ri.type_oneside:
+                suffix += '_dump'
         else:
             if ri.type_consistent:
                 if deref:
@@ -1707,7 +1714,10 @@ def _multi_parse(ri, struct, init_lines, local_vars):
         ri.cw.p(f'dst->{arg} = {arg};')
 
     if ri.fixed_hdr:
-        ri.cw.p('hdr = ynl_nlmsg_data_offset(nlh, sizeof(struct genlmsghdr));')
+        if ri.family.is_classic():
+            ri.cw.p('hdr = ynl_nlmsg_data(nlh);')
+        else:
+            ri.cw.p('hdr = ynl_nlmsg_data_offset(nlh, sizeof(struct genlmsghdr));')
         ri.cw.p(f"memcpy(&dst->_hdr, hdr, sizeof({ri.fixed_hdr}));")
     for anest in sorted(all_multi):
         aspec = struct[anest]
@@ -1854,7 +1864,10 @@ def print_req(ri):
     ri.cw.block_start()
     ri.cw.write_func_lvar(local_vars)
 
-    ri.cw.p(f"nlh = ynl_gemsg_start_req(ys, {ri.nl.get_family_id()}, {ri.op.enum_name}, 1);")
+    if ri.family.is_classic():
+        ri.cw.p(f"nlh = ynl_msg_start_req(ys, {ri.op.enum_name});")
+    else:
+        ri.cw.p(f"nlh = ynl_gemsg_start_req(ys, {ri.nl.get_family_id()}, {ri.op.enum_name}, 1);")
 
     ri.cw.p(f"ys->req_policy = &{ri.struct['request'].render_name}_nest;")
     if 'reply' in ri.op[ri.op_mode]:
@@ -1923,7 +1936,10 @@ def print_dump(ri):
     else:
         ri.cw.p(f'yds.rsp_cmd = {ri.op.rsp_value};')
     ri.cw.nl()
-    ri.cw.p(f"nlh = ynl_gemsg_start_dump(ys, {ri.nl.get_family_id()}, {ri.op.enum_name}, 1);")
+    if ri.family.is_classic():
+        ri.cw.p(f"nlh = ynl_msg_start_dump(ys, {ri.op.enum_name});")
+    else:
+        ri.cw.p(f"nlh = ynl_gemsg_start_dump(ys, {ri.nl.get_family_id()}, {ri.op.enum_name}, 1);")
 
     if ri.fixed_hdr:
         ri.cw.p("hdr_len = sizeof(req->_hdr);")
@@ -1983,7 +1999,7 @@ def _print_type(ri, direction, struct):
     if not direction and ri.type_name_conflict:
         suffix += '_'
 
-    if ri.op_mode == 'dump':
+    if ri.op_mode == 'dump' and not ri.type_oneside:
         suffix += '_dump'
 
     ri.cw.block_start(line=f"struct {ri.family.c_name}{suffix}")
@@ -2034,7 +2050,7 @@ def print_type_helpers(ri, direction, deref=False):
 
 
 def print_req_type_helpers(ri):
-    if len(ri.struct["request"].attr_list) == 0:
+    if ri.type_empty("request"):
         return
     print_alloc_wrapper(ri, "request")
     print_type_helpers(ri, "request")
@@ -2057,7 +2073,7 @@ def print_parse_prototype(ri, direction, terminate=True):
 
 
 def print_req_type(ri):
-    if len(ri.struct["request"].attr_list) == 0:
+    if ri.type_empty("request"):
         return
     print_type(ri, "request")
 
@@ -2710,7 +2726,7 @@ def render_user_family(family, cw, prototype):
         return
 
     if family.ntfs:
-        cw.block_start(line=f"static const struct ynl_ntf_info {family['name']}_ntf_info[] = ")
+        cw.block_start(line=f"static const struct ynl_ntf_info {family.c_name}_ntf_info[] = ")
         for ntf_op_name, ntf_op in family.ntfs.items():
             if 'notify' in ntf_op:
                 op = family.ops[ntf_op['notify']]
@@ -2730,13 +2746,18 @@ def render_user_family(family, cw, prototype):
 
     cw.block_start(f'{symbol} = ')
     cw.p(f'.name\t\t= "{family.c_name}",')
-    if family.fixed_header:
+    if family.is_classic():
+        cw.p(f'.is_classic\t= true,')
+        cw.p(f'.classic_id\t= {family.get("protonum")},')
+    if family.is_classic():
+        cw.p(f'.hdr_len\t= sizeof(struct {c_lower(family.fixed_header)}),')
+    elif family.fixed_header:
         cw.p(f'.hdr_len\t= sizeof(struct genlmsghdr) + sizeof(struct {c_lower(family.fixed_header)}),')
     else:
         cw.p('.hdr_len\t= sizeof(struct genlmsghdr),')
     if family.ntfs:
-        cw.p(f".ntf_info\t= {family['name']}_ntf_info,")
-        cw.p(f".ntf_info_size\t= YNL_ARRAY_SIZE({family['name']}_ntf_info),")
+        cw.p(f".ntf_info\t= {family.c_name}_ntf_info,")
+        cw.p(f".ntf_info_size\t= YNL_ARRAY_SIZE({family.c_name}_ntf_info),")
     cw.block_end(line=';')
 
 
@@ -2962,7 +2983,7 @@ def main():
                     ri = RenderInfo(cw, parsed, args.mode, op, 'dump')
                     print_req_type(ri)
                     print_req_type_helpers(ri)
-                    if not ri.type_consistent:
+                    if not ri.type_consistent or ri.type_oneside:
                         print_rsp_type(ri)
                     print_wrapped_type(ri)
                     print_dump_prototype(ri)
@@ -3040,7 +3061,7 @@ def main():
                 if 'dump' in op:
                     cw.p(f"/* {op.enum_name} - dump */")
                     ri = RenderInfo(cw, parsed, args.mode, op, "dump")
-                    if not ri.type_consistent:
+                    if not ri.type_consistent or ri.type_oneside:
                         parse_rsp_msg(ri, deref=True)
                     print_req_free(ri)
                     print_dump_type_free(ri)

tools/net/ynl/samples/.gitignore

@@ -2,4 +2,6 @@ ethtool
 devlink
 netdev
 ovs
-page-pool
+page-pool
+rt-addr
+rt-route

tools/net/ynl/samples/rt-addr.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-addr-user.h"
+
+static void rt_addr_print(struct rt_addr_getaddr_rsp *a)
+{
+	char ifname[IF_NAMESIZE];
+	char addr_str[64];
+	const char *addr;
+	const char *name;
+
+	name = if_indextoname(a->_hdr.ifa_index, ifname);
+	if (name)
+		printf("%16s: ", name);
+
+	switch (a->_present.address_len) {
+	case 4:
+		addr = inet_ntop(AF_INET, a->address,
+				 addr_str, sizeof(addr_str));
+		break;
+	case 16:
+		addr = inet_ntop(AF_INET6, a->address,
+				 addr_str, sizeof(addr_str));
+		break;
+	default:
+		addr = NULL;
+		break;
+	}
+	if (addr)
+		printf("%s", addr);
+	else
+		printf("[%d]", a->_present.address_len);
+
+	printf("\n");
+}
+
+int main(int argc, char **argv)
+{
+	struct rt_addr_getaddr_list *rsp;
+	struct rt_addr_getaddr_req *req;
+	struct ynl_error yerr;
+	struct ynl_sock *ys;
+
+	ys = ynl_sock_create(&ynl_rt_addr_family, &yerr);
+	if (!ys) {
+		fprintf(stderr, "YNL: %s\n", yerr.msg);
+		return 1;
+	}
+
+	req = rt_addr_getaddr_req_alloc();
+	if (!req)
+		goto err_destroy;
+
+	rsp = rt_addr_getaddr_dump(ys, req);
+	rt_addr_getaddr_req_free(req);
+	if (!rsp)
+		goto err_close;
+
+	if (ynl_dump_empty(rsp))
+		fprintf(stderr, "Error: no addresses reported\n");
+	ynl_dump_foreach(rsp, addr)
+		rt_addr_print(addr);
+	rt_addr_getaddr_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;
+}

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;
+}

tools/testing/selftests/net/lib/py/ynl.py

@@ -39,12 +39,12 @@ class EthtoolFamily(YnlFamily):
 
 class RtnlFamily(YnlFamily):
     def __init__(self, recv_size=0):
-        super().__init__((SPEC_PATH / Path('rt_link.yaml')).as_posix(),
+        super().__init__((SPEC_PATH / Path('rt-link.yaml')).as_posix(),
                          schema='', recv_size=recv_size)
 
 class RtnlAddrFamily(YnlFamily):
     def __init__(self, recv_size=0):
-        super().__init__((SPEC_PATH / Path('rt_addr.yaml')).as_posix(),
+        super().__init__((SPEC_PATH / Path('rt-addr.yaml')).as_posix(),
                          schema='', recv_size=recv_size)
 
 class NetdevFamily(YnlFamily):