[PATCH iproute2-next v3] iproute2: Add 'netshaper' command to 'ip link' for netdev shaping

[PATCH iproute2-next v3] iproute2: Add 'netshaper' command to 'ip link' for netdev shaping

[Erni Sri Satya Vennela]

Add support for the netshaper Generic Netlink
family to iproute2. Introduce a new subcommand to `ip link` for
configuring netshaper parameters directly from userspace.

This interface allows users to set shaping attributes (such as speed)
which are passed to the kernel to perform the corresponding netshaper
operation.

Example usage:
$ip link netshaper { set | get | delete } dev DEVNAME \
                   handle scope SCOPE id ID \
                   [ speed SPEED ]

Internally, this triggers a kernel call to apply the shaping
configuration to the specified network device.

Currently, the tool supports the following functionalities:
- Setting speed in Mbps, enabling bandwidth clamping for
  a network device that support netshaper operations.
- Deleting the current configuration.
- Querying the existing configuration.

Additional netshaper operations will be integrated into the tool
as per requirement.

This change enables easy and scriptable configuration of bandwidth
shaping for  devices that use the netshaper Netlink family.

Corresponding net-next patches:
1) https://lore.kernel.org/all/cover.1728460186.git.pabeni@redhat.com/
2) https://lore.kernel.org/lkml/1750144656-2021-1-git-send-email-ernis@linux.microsoft.com/

Install pkg-config and libmnl* packages to print kernel extack
errors to stdout.

Signed-off-by: Erni Sri Satya Vennela <ernis@linux.microsoft.com>
---
Please add include/uapi/linux/net_shaper.h from kernel source tree
for this patch.
---
Changes in v3:
* Use strcmp instead of matches.
* Use get_rate64 instead get_unsigned for speed parameter.
* Remove speed_mbps in do_cmd() to reduce redundancy.
* Update the usage of speed parameter in the command.
Changes in v2:
* Use color coding for printing device name in stdout.
* Use clang-format to format the code inline.
* Use __u64 for speed_bps.
* Remove include/uapi/linux/netshaper.h file. 
---
 ip/Makefile           |   2 +-
 ip/iplink.c           |  12 +++
 ip/iplink_netshaper.c | 189 ++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 202 insertions(+), 1 deletion(-)
 create mode 100644 ip/iplink_netshaper.c

diff --git a/ip/Makefile b/ip/Makefile
index 3535ba78..18218c3b 100644
--- a/ip/Makefile
+++ b/ip/Makefile
@@ -4,7 +4,7 @@ IPOBJ=ip.o ipaddress.o ipaddrlabel.o iproute.o iprule.o ipnetns.o \
     ipmaddr.o ipmonitor.o ipmroute.o ipprefix.o iptuntap.o iptoken.o \
     ipxfrm.o xfrm_state.o xfrm_policy.o xfrm_monitor.o iplink_dummy.o \
     iplink_ifb.o iplink_nlmon.o iplink_team.o iplink_vcan.o iplink_vxcan.o \
-    iplink_vlan.o link_veth.o link_gre.o iplink_can.o iplink_xdp.o \
+    iplink_vlan.o iplink_netshaper.o link_veth.o link_gre.o iplink_can.o iplink_xdp.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 \
diff --git a/ip/iplink.c b/ip/iplink.c
index 59e8caf4..daa4603d 100644
--- a/ip/iplink.c
+++ b/ip/iplink.c
@@ -1509,6 +1509,15 @@ static void do_help(int argc, char **argv)
 		usage();
 }
 
+static int iplink_netshaper(int argc, char **argv)
+{
+	struct link_util *lu;
+
+	lu = get_link_kind("netshaper");
+
+	return lu->parse_opt(lu, argc, argv, NULL);
+}
+
 int do_iplink(int argc, char **argv)
 {
 	if (argc < 1)
@@ -1545,6 +1554,9 @@ int do_iplink(int argc, char **argv)
 	if (matches(*argv, "property") == 0)
 		return iplink_prop(argc-1, argv+1);
 
+	if (strcmp(*argv, "netshaper") == 0)
+		return iplink_netshaper(argc-1, argv+1);
+
 	if (matches(*argv, "help") == 0) {
 		do_help(argc-1, argv+1);
 		return 0;
diff --git a/ip/iplink_netshaper.c b/ip/iplink_netshaper.c
new file mode 100644
index 00000000..30ee6c3e
--- /dev/null
+++ b/ip/iplink_netshaper.c
@@ -0,0 +1,189 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * iplink_netshaper.c netshaper H/W shaping support
+ *
+ * Authors:        Erni Sri Satya Vennela <ernis@linux.microsoft.com>
+ */
+#include <stdio.h>
+#include <string.h>
+#include <linux/genetlink.h>
+#include <linux/netlink.h>
+#include <linux/rtnetlink.h>
+#include <uapi/linux/netshaper.h>
+#include "utils.h"
+#include "ip_common.h"
+#include "libgenl.h"
+
+/* netlink socket */
+static struct rtnl_handle gen_rth = { .fd = -1 };
+static int genl_family = -1;
+
+static void usage(void)
+{
+	fprintf(stderr,
+		"Usage:	ip link netshaper set dev DEVNAME handle scope HANDLE_SCOPE id HANDLE_ID speed SPEED\n"
+		"	ip link netshaper delete dev DEVNAME handle scope HANDLE_SCOPE id HANDLE_ID\n"
+		"	ip link netshaper get dev DEVNAME handle scope HANDLE_SCOPE id HANDLE_ID\n"
+		"Where:	DEVNAME		:= STRING\n"
+		"	HANDLE_SCOPE	:= { netdev | queue | node }\n"
+		"	HANDLE_ID	:= UINT\n"
+		"	SPEED		:= UINT{ kbit | mbit | gbit }\n");
+
+	exit(-1);
+}
+
+static void print_netshaper_attrs(struct nlmsghdr *answer)
+{
+	struct genlmsghdr *ghdr = NLMSG_DATA(answer);
+	int len = answer->nlmsg_len - NLMSG_LENGTH(GENL_HDRLEN);
+	struct rtattr *tb[NET_SHAPER_A_MAX + 1] = {};
+	__u32 speed_mbps;
+	__u64 speed_bps;
+	int ifindex;
+
+	parse_rtattr(tb, NET_SHAPER_A_MAX,
+		     (struct rtattr *)((char *)ghdr + GENL_HDRLEN), len);
+
+	for (int i = 1; i <= NET_SHAPER_A_MAX; ++i) {
+		if (!tb[i])
+			continue;
+		switch (i) {
+		case NET_SHAPER_A_BW_MAX:
+			speed_bps = rta_getattr_u64(tb[i]);
+			speed_mbps = (speed_bps / 1000000);
+			print_uint(PRINT_ANY, "speed", "speed: %u mbps\n",
+				   speed_mbps);
+			break;
+		case NET_SHAPER_A_IFINDEX:
+			ifindex = rta_getattr_u32(tb[i]);
+			print_color_string(PRINT_ANY, COLOR_IFNAME, "dev",
+					   "dev: %s\n",
+					   ll_index_to_name(ifindex));
+			break;
+		default:
+			break;
+		}
+	}
+}
+
+static int do_cmd(int argc, char **argv, struct nlmsghdr *n, int cmd)
+{
+	GENL_REQUEST(req, 1024, genl_family, 0, NET_SHAPER_FAMILY_VERSION, cmd,
+		     NLM_F_REQUEST | NLM_F_ACK);
+
+	struct nlmsghdr *answer;
+	__u64 speed_bps = 0;
+	int ifindex = -1;
+	int handle_scope = NET_SHAPER_SCOPE_UNSPEC;
+	__u32 handle_id = 0;
+	bool handle_present = false;
+	int err;
+
+	while (argc > 0) {
+		if (strcmp(*argv, "dev") == 0) {
+			NEXT_ARG();
+			ifindex = ll_name_to_index(*argv);
+		} else if (strcmp(*argv, "speed") == 0) {
+			NEXT_ARG();
+			if(get_rate64(&speed_bps, *argv)) {
+				fprintf(stderr, "Invalid speed value\n");
+				return -1;
+			}
+			/*Convert Bps to bps*/
+			speed_bps *= 8;
+		} else if (strcmp(*argv, "handle") == 0) {
+			handle_present = true;
+			NEXT_ARG();
+			if (strcmp(*argv, "scope") == 0) {
+				NEXT_ARG();
+				if (strcmp(*argv, "netdev") == 0) {
+					handle_scope = NET_SHAPER_SCOPE_NETDEV;
+				} else if (strcmp(*argv, "queue") == 0) {
+					handle_scope = NET_SHAPER_SCOPE_QUEUE;
+				} else if (strcmp(*argv, "node") == 0) {
+					handle_scope = NET_SHAPER_SCOPE_NODE;
+				} else {
+					fprintf(stderr, "Invalid scope\n");
+					return -1;
+				}
+
+				NEXT_ARG();
+				if (strcmp(*argv, "id") == 0) {
+					NEXT_ARG();
+					if (get_unsigned(&handle_id, *argv, 10)) {
+						fprintf(stderr,
+							"Invalid handle id\n");
+						return -1;
+					}
+				}
+			}
+		} else {
+			fprintf(stderr, "What is \"%s\"\n", *argv);
+			usage();
+		}
+		argc--;
+		argv++;
+	}
+
+	if (ifindex == -1)
+		missarg("dev");
+
+	if (!handle_present)
+		missarg("handle");
+
+	if (cmd == NET_SHAPER_CMD_SET && speed_bps == 0)
+		missarg("speed");
+
+	addattr32(&req.n, sizeof(req), NET_SHAPER_A_IFINDEX, ifindex);
+
+	struct rtattr *handle = addattr_nest(&req.n, sizeof(req),
+					     NET_SHAPER_A_HANDLE | NLA_F_NESTED);
+	addattr32(&req.n, sizeof(req), NET_SHAPER_A_HANDLE_SCOPE, handle_scope);
+	addattr32(&req.n, sizeof(req), NET_SHAPER_A_HANDLE_ID, handle_id);
+	addattr_nest_end(&req.n, handle);
+
+	if (cmd == NET_SHAPER_CMD_SET)
+		addattr64(&req.n, sizeof(req), NET_SHAPER_A_BW_MAX, speed_bps);
+
+	err = rtnl_talk(&gen_rth, &req.n, &answer);
+	if (err < 0) {
+		printf("Kernel command failed: %d\n", err);
+		return err;
+	}
+
+	if (cmd == NET_SHAPER_CMD_GET)
+		print_netshaper_attrs(answer);
+
+	return err;
+}
+
+static int netshaper_parse_opt(struct link_util *lu, int argc, char **argv,
+			       struct nlmsghdr *n)
+{
+	if (argc < 1)
+		usage();
+	if (strcmp(*argv, "help") == 0)
+		usage();
+
+	if (genl_init_handle(&gen_rth, NET_SHAPER_FAMILY_NAME, &genl_family))
+		exit(1);
+
+	if (strcmp(*argv, "set") == 0)
+		return do_cmd(argc - 1, argv + 1, n, NET_SHAPER_CMD_SET);
+
+	if (strcmp(*argv, "delete") == 0)
+		return do_cmd(argc - 1, argv + 1, n, NET_SHAPER_CMD_DELETE);
+
+	if (strcmp(*argv, "get") == 0)
+		return do_cmd(argc - 1, argv + 1, n, NET_SHAPER_CMD_GET);
+
+	fprintf(stderr,
+		"Command \"%s\" is unknown, try \"ip link netshaper help\".\n",
+		*argv);
+	exit(-1);
+}
+
+struct link_util netshaper_link_util = {
+	.id = "netshaper",
+	.parse_opt = netshaper_parse_opt,
+};
-- 
2.43.0

RE: [PATCH iproute2-next v3] iproute2: Add 'netshaper' command to 'ip link' for netdev shaping

[Haiyang Zhang]

> -----Original Message-----
> From: Erni Sri Satya Vennela <ernis@linux.microsoft.com>
> Sent: Monday, August 11, 2025 3:05 AM
> To: stephen@networkplumber.org; dsahern@gmail.com; netdev@vger.kernel.org
> Cc: Haiyang Zhang <haiyangz@microsoft.com>;
> shradhagupta@linux.microsoft.com; Saurabh Singh Sengar
> <ssengar@microsoft.com>; Dipayaan Roy <dipayanroy@microsoft.com>; Erni Sri
> Satya Vennela <ernis@microsoft.com>; Erni Sri Satya Vennela
> <ernis@linux.microsoft.com>
> Subject: [PATCH iproute2-next v3] iproute2: Add 'netshaper' command to 'ip
> link' for netdev shaping
>
> Add support for the netshaper Generic Netlink
> family to iproute2. Introduce a new subcommand to `ip link` for
> configuring netshaper parameters directly from userspace.
>
> This interface allows users to set shaping attributes (such as speed)
> which are passed to the kernel to perform the corresponding netshaper
> operation.
>
> Example usage:
> $ip link netshaper { set | get | delete } dev DEVNAME \
>                    handle scope SCOPE id ID \
>                    [ speed SPEED ]
>
> Internally, this triggers a kernel call to apply the shaping
> configuration to the specified network device.
>
> Currently, the tool supports the following functionalities:
> - Setting speed in Mbps, enabling bandwidth clamping for
>   a network device that support netshaper operations.
> - Deleting the current configuration.
> - Querying the existing configuration.
>
> Additional netshaper operations will be integrated into the tool
> as per requirement.
>
> This change enables easy and scriptable configuration of bandwidth
> shaping for  devices that use the netshaper Netlink family.
>
> Corresponding net-next patches:
> 1)
> https://lore.ker/
> nel.org%2Fall%2Fcover.1728460186.git.pabeni%40redhat.com%2F&data=05%7C02%7
> Chaiyangz%40microsoft.com%7C0ac998f8db0c4cf31d8208ddd8a5658b%7C72f988bf86f
> 141af91ab2d7cd011db47%7C1%7C0%7C638904927080914227%7CUnknown%7CTWFpbGZsb3d
> 8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpb
> CIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=WY7zqpx5F9Wnf0WbHUIxMDGbwmjwQysjTdD
> cPAZ5jzM%3D&reserved=0
> 2)
> https://lore.ker/
> nel.org%2Flkml%2F1750144656-2021-1-git-send-email-
> ernis%40linux.microsoft.com%2F&data=05%7C02%7Chaiyangz%40microsoft.com%7C0
> ac998f8db0c4cf31d8208ddd8a5658b%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0
> %7C638904927080928775%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYi
> OiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C
> %7C&sdata=TmzKYLtKlU%2FphFWfa13toeOmJGAU1RgBBtRvp%2F3Wg5s%3D&reserved=0
>
> Install pkg-config and libmnl* packages to print kernel extack
> errors to stdout.
>
> Signed-off-by: Erni Sri Satya Vennela <ernis@linux.microsoft.com>

Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>

Re: [PATCH iproute2-next v3] iproute2: Add 'netshaper' command to 'ip link' for netdev shaping

[Stephen Hemminger]

On Mon, 11 Aug 2025 00:05:02 -0700
Erni Sri Satya Vennela <ernis@linux.microsoft.com> wrote:

> Add support for the netshaper Generic Netlink
> family to iproute2. Introduce a new subcommand to `ip link` for
> configuring netshaper parameters directly from userspace.
> 
> This interface allows users to set shaping attributes (such as speed)
> which are passed to the kernel to perform the corresponding netshaper
> operation.
> 
> Example usage:
> $ip link netshaper { set | get | delete } dev DEVNAME \
>                    handle scope SCOPE id ID \
>                    [ speed SPEED ]
> 
> Internally, this triggers a kernel call to apply the shaping
> configuration to the specified network device.
> 
> Currently, the tool supports the following functionalities:
> - Setting speed in Mbps, enabling bandwidth clamping for
>   a network device that support netshaper operations.
> - Deleting the current configuration.
> - Querying the existing configuration.
> 
> Additional netshaper operations will be integrated into the tool
> as per requirement.
> 
> This change enables easy and scriptable configuration of bandwidth
> shaping for  devices that use the netshaper Netlink family.
> 
> Corresponding net-next patches:
> 1) https://lore.kernel.org/all/cover.1728460186.git.pabeni@redhat.com/
> 2) https://lore.kernel.org/lkml/1750144656-2021-1-git-send-email-ernis@linux.microsoft.com/
> 
> Install pkg-config and libmnl* packages to print kernel extack
> errors to stdout.
> 
> Signed-off-by: Erni Sri Satya Vennela <ernis@linux.microsoft.com>
> ---
> Please add include/uapi/linux/net_shaper.h from kernel source tree
> for this patch.
> ---
> Changes in v3:
> * Use strcmp instead of matches.
> * Use get_rate64 instead get_unsigned for speed parameter.
> * Remove speed_mbps in do_cmd() to reduce redundancy.
> * Update the usage of speed parameter in the command.
> Changes in v2:
> * Use color coding for printing device name in stdout.
> * Use clang-format to format the code inline.
> * Use __u64 for speed_bps.
> * Remove include/uapi/linux/netshaper.h file. 
> ---
>  ip/Makefile           |   2 +-
>  ip/iplink.c           |  12 +++
>  ip/iplink_netshaper.c | 189 ++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 202 insertions(+), 1 deletion(-)
>  create mode 100644 ip/iplink_netshaper.c

No documentation.
No tests?

> 
> diff --git a/ip/Makefile b/ip/Makefile
> index 3535ba78..18218c3b 100644
> --- a/ip/Makefile
> +++ b/ip/Makefile
> @@ -4,7 +4,7 @@ IPOBJ=ip.o ipaddress.o ipaddrlabel.o iproute.o iprule.o ipnetns.o \
>      ipmaddr.o ipmonitor.o ipmroute.o ipprefix.o iptuntap.o iptoken.o \
>      ipxfrm.o xfrm_state.o xfrm_policy.o xfrm_monitor.o iplink_dummy.o \
>      iplink_ifb.o iplink_nlmon.o iplink_team.o iplink_vcan.o iplink_vxcan.o \
> -    iplink_vlan.o link_veth.o link_gre.o iplink_can.o iplink_xdp.o \
> +    iplink_vlan.o iplink_netshaper.o link_veth.o link_gre.o iplink_can.o iplink_xdp.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 \
> diff --git a/ip/iplink.c b/ip/iplink.c
> index 59e8caf4..daa4603d 100644
> --- a/ip/iplink.c
> +++ b/ip/iplink.c
> @@ -1509,6 +1509,15 @@ static void do_help(int argc, char **argv)
>  		usage();
>  }
>  
> +static int iplink_netshaper(int argc, char **argv)
> +{
> +	struct link_util *lu;
> +
> +	lu = get_link_kind("netshaper");
> +
> +	return lu->parse_opt(lu, argc, argv, NULL);
> +}
> +
>  int do_iplink(int argc, char **argv)
>  {
>  	if (argc < 1)
> @@ -1545,6 +1554,9 @@ int do_iplink(int argc, char **argv)
>  	if (matches(*argv, "property") == 0)
>  		return iplink_prop(argc-1, argv+1);
>  
> +	if (strcmp(*argv, "netshaper") == 0)
> +		return iplink_netshaper(argc-1, argv+1);
> +
>  	if (matches(*argv, "help") == 0) {
>  		do_help(argc-1, argv+1);
>  		return 0;
> diff --git a/ip/iplink_netshaper.c b/ip/iplink_netshaper.c
> new file mode 100644
> index 00000000..30ee6c3e
> --- /dev/null
> +++ b/ip/iplink_netshaper.c
> @@ -0,0 +1,189 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * iplink_netshaper.c netshaper H/W shaping support
> + *
> + * Authors:        Erni Sri Satya Vennela <ernis@linux.microsoft.com>
> + */
> +#include <stdio.h>
> +#include <string.h>
> +#include <linux/genetlink.h>
> +#include <linux/netlink.h>
> +#include <linux/rtnetlink.h>
> +#include <uapi/linux/netshaper.h>
> +#include "utils.h"
> +#include "ip_common.h"
> +#include "libgenl.h"
> +
> +/* netlink socket */
> +static struct rtnl_handle gen_rth = { .fd = -1 };
> +static int genl_family = -1;
> +
> +static void usage(void)
> +{
> +	fprintf(stderr,
> +		"Usage:	ip link netshaper set dev DEVNAME handle scope HANDLE_SCOPE id HANDLE_ID speed SPEED\n"
> +		"	ip link netshaper delete dev DEVNAME handle scope HANDLE_SCOPE id HANDLE_ID\n"
> +		"	ip link netshaper get dev DEVNAME handle scope HANDLE_SCOPE id HANDLE_ID\n"

Seems like netshaper is property of the device not a top level object, the syntax
here is awkward. Open to better suggestions. Looks to me that netshaper should be property of
device not top level object.

Or netshaper is like neighbour and route and really wants to be not part of link command.

Also no other ip commands use show not get.
The verb "get" is only used for things like getting a route or neighbor with a particular address.


> +		"Where:	DEVNAME		:= STRING\n"
> +		"	HANDLE_SCOPE	:= { netdev | queue | node }\n"
> +		"	HANDLE_ID	:= UINT\n"
> +		"	SPEED		:= UINT{ kbit | mbit | gbit }\n");
> +
> +	exit(-1);
> +}
> +
> +static void print_netshaper_attrs(struct nlmsghdr *answer)
> +{
> +	struct genlmsghdr *ghdr = NLMSG_DATA(answer);
> +	int len = answer->nlmsg_len - NLMSG_LENGTH(GENL_HDRLEN);
> +	struct rtattr *tb[NET_SHAPER_A_MAX + 1] = {};
> +	__u32 speed_mbps;
> +	__u64 speed_bps;
> +	int ifindex;
> +
> +	parse_rtattr(tb, NET_SHAPER_A_MAX,
> +		     (struct rtattr *)((char *)ghdr + GENL_HDRLEN), len);
> +
> +	for (int i = 1; i <= NET_SHAPER_A_MAX; ++i) {
> +		if (!tb[i])
> +			continue;
> +		switch (i) {
> +		case NET_SHAPER_A_BW_MAX:
> +			speed_bps = rta_getattr_u64(tb[i]);
> +			speed_mbps = (speed_bps / 1000000);
> +			print_uint(PRINT_ANY, "speed", "speed: %u mbps\n",
> +				   speed_mbps);
> +			break;
> +		case NET_SHAPER_A_IFINDEX:
> +			ifindex = rta_getattr_u32(tb[i]);
> +			print_color_string(PRINT_ANY, COLOR_IFNAME, "dev",
> +					   "dev: %s\n",
> +					   ll_index_to_name(ifindex));
> +			break;
> +		default:
> +			break;
> +		}
> +	}
> +}
> +
> +static int do_cmd(int argc, char **argv, struct nlmsghdr *n, int cmd)
> +{
> +	GENL_REQUEST(req, 1024, genl_family, 0, NET_SHAPER_FAMILY_VERSION, cmd,
> +		     NLM_F_REQUEST | NLM_F_ACK);
> +
> +	struct nlmsghdr *answer;
> +	__u64 speed_bps = 0;
> +	int ifindex = -1;
> +	int handle_scope = NET_SHAPER_SCOPE_UNSPEC;
> +	__u32 handle_id = 0;
> +	bool handle_present = false;
> +	int err;
> +
> +	while (argc > 0) {
> +		if (strcmp(*argv, "dev") == 0) {
> +			NEXT_ARG();
> +			ifindex = ll_name_to_index(*argv);
> +		} else if (strcmp(*argv, "speed") == 0) {
> +			NEXT_ARG();
> +			if(get_rate64(&speed_bps, *argv)) {
> +				fprintf(stderr, "Invalid speed value\n");
> +				return -1;
> +			}
> +			/*Convert Bps to bps*/
> +			speed_bps *= 8;
> +		} else if (strcmp(*argv, "handle") == 0) {
> +			handle_present = true;
> +			NEXT_ARG();
> +			if (strcmp(*argv, "scope") == 0) {
> +				NEXT_ARG();
> +				if (strcmp(*argv, "netdev") == 0) {
> +					handle_scope = NET_SHAPER_SCOPE_NETDEV;
> +				} else if (strcmp(*argv, "queue") == 0) {
> +					handle_scope = NET_SHAPER_SCOPE_QUEUE;
> +				} else if (strcmp(*argv, "node") == 0) {
> +					handle_scope = NET_SHAPER_SCOPE_NODE;
> +				} else {
> +					fprintf(stderr, "Invalid scope\n");
> +					return -1;
> +				}
> +
> +				NEXT_ARG();
> +				if (strcmp(*argv, "id") == 0) {
> +					NEXT_ARG();
> +					if (get_unsigned(&handle_id, *argv, 10)) {
> +						fprintf(stderr,
> +							"Invalid handle id\n");
> +						return -1;
> +					}
> +				}
> +			}
> +		} else {
> +			fprintf(stderr, "What is \"%s\"\n", *argv);
> +			usage();
> +		}
> +		argc--;
> +		argv++;
> +	}
> +
> +	if (ifindex == -1)
> +		missarg("dev");
> +
> +	if (!handle_present)
> +		missarg("handle");
> +
> +	if (cmd == NET_SHAPER_CMD_SET && speed_bps == 0)
> +		missarg("speed");
> +
> +	addattr32(&req.n, sizeof(req), NET_SHAPER_A_IFINDEX, ifindex);
> +
> +	struct rtattr *handle = addattr_nest(&req.n, sizeof(req),
> +					     NET_SHAPER_A_HANDLE | NLA_F_NESTED);
> +	addattr32(&req.n, sizeof(req), NET_SHAPER_A_HANDLE_SCOPE, handle_scope);
> +	addattr32(&req.n, sizeof(req), NET_SHAPER_A_HANDLE_ID, handle_id);
> +	addattr_nest_end(&req.n, handle);
> +
> +	if (cmd == NET_SHAPER_CMD_SET)
> +		addattr64(&req.n, sizeof(req), NET_SHAPER_A_BW_MAX, speed_bps);
> +
> +	err = rtnl_talk(&gen_rth, &req.n, &answer);
> +	if (err < 0) {
> +		printf("Kernel command failed: %d\n", err);
> +		return err;
> +	}
> +
> +	if (cmd == NET_SHAPER_CMD_GET)
> +		print_netshaper_attrs(answer);
> +
> +	return err;
> +}
> +
> +static int netshaper_parse_opt(struct link_util *lu, int argc, char **argv,
> +			       struct nlmsghdr *n)
> +{
> +	if (argc < 1)
> +		usage();
> +	if (strcmp(*argv, "help") == 0)
> +		usage();
> +
> +	if (genl_init_handle(&gen_rth, NET_SHAPER_FAMILY_NAME, &genl_family))
> +		exit(1);
> +
> +	if (strcmp(*argv, "set") == 0)
> +		return do_cmd(argc - 1, argv + 1, n, NET_SHAPER_CMD_SET);
> +
> +	if (strcmp(*argv, "delete") == 0)
> +		return do_cmd(argc - 1, argv + 1, n, NET_SHAPER_CMD_DELETE);
> +
> +	if (strcmp(*argv, "get") == 0)
> +		return do_cmd(argc - 1, argv + 1, n, NET_SHAPER_CMD_GET);
> +
> +	fprintf(stderr,
> +		"Command \"%s\" is unknown, try \"ip link netshaper help\".\n",
> +		*argv);
> +	exit(-1);
> +}
> +
> +struct link_util netshaper_link_util = {
> +	.id = "netshaper",
> +	.parse_opt = netshaper_parse_opt,
> +};


Please add a print_opt functionality.
Very useful to see what kernel thinks state is. 

Re: [PATCH iproute2-next v3] iproute2: Add 'netshaper' command to 'ip link' for netdev shaping

[Stephen Hemminger]

On Mon, 11 Aug 2025 00:05:02 -0700
Erni Sri Satya Vennela <ernis@linux.microsoft.com> wrote:

> Add support for the netshaper Generic Netlink
> family to iproute2. Introduce a new subcommand to `ip link` for
> configuring netshaper parameters directly from userspace.
> 
> This interface allows users to set shaping attributes (such as speed)
> which are passed to the kernel to perform the corresponding netshaper
> operation.
> 
> Example usage:
> $ip link netshaper { set | get | delete } dev DEVNAME \
>                    handle scope SCOPE id ID \
>                    [ speed SPEED ]


The choice of ip link is awkward and doesn't match other options.
I can think of some better other choices:

  1. netshaper could be a property of the device. But the choice of using genetlink
     instead of regular ip netlink attributes makes this hard.
  2. netshaper could be part of devlink. Since it is more targeted at hardware
     device attributes.
  3. netshaper could be a standalone command like bridge, dcb, devlink, rdma, tipc and vdpa.

What ever choice the command line options need to follow similar syntax to other iproute commands.

Re: [PATCH iproute2-next v3] iproute2: Add 'netshaper' command to 'ip link' for netdev shaping

[Jakub Kicinski]

On Sat, 16 Aug 2025 15:55:10 -0700 Stephen Hemminger wrote:
> On Mon, 11 Aug 2025 00:05:02 -0700
> Erni Sri Satya Vennela <ernis@linux.microsoft.com> wrote:
> 
> > Add support for the netshaper Generic Netlink
> > family to iproute2. Introduce a new subcommand to `ip link` for
> > configuring netshaper parameters directly from userspace.
> > 
> > This interface allows users to set shaping attributes (such as speed)
> > which are passed to the kernel to perform the corresponding netshaper
> > operation.
> > 
> > Example usage:
> > $ip link netshaper { set | get | delete } dev DEVNAME \
> >                    handle scope SCOPE id ID \
> >                    [ speed SPEED ]  
> 
> The choice of ip link is awkward and doesn't match other options.
> I can think of some better other choices:
> 
>   1. netshaper could be a property of the device. But the choice of using genetlink
>      instead of regular ip netlink attributes makes this hard.
>   2. netshaper could be part of devlink. Since it is more targeted at hardware
>      device attributes.
>   3. netshaper could be a standalone command like bridge, dcb, devlink, rdma, tipc and vdpa.
> 
> What ever choice the command line options need to follow similar syntax to other iproute commands.

I think historically we gravitated towards option 3 -- each family has
a command? But indeed we could fold it together with something like
the netdev family without much issue, they are both key'd on netdevs.

Somewhat related -- what's your take on integrating / vendoring in YNL?
mnl doesn't provide any extack support..

Re: [PATCH iproute2-next v3] iproute2: Add 'netshaper' command to 'ip link' for netdev shaping

[David Ahern]

On 8/18/25 9:36 AM, Jakub Kicinski wrote:
> Somewhat related -- what's your take on integrating / vendoring in YNL?

I feel like this has been brought up a few times.

Is there a specific proposal or any patches to review?

Re: [PATCH iproute2-next v3] iproute2: Add 'netshaper' command to 'ip link' for netdev shaping

[Jakub Kicinski]

On Mon, 18 Aug 2025 09:41:29 -0600 David Ahern wrote:
> On 8/18/25 9:36 AM, Jakub Kicinski wrote:
> > Somewhat related -- what's your take on integrating / vendoring in YNL?  
> 
> I feel like this has been brought up a few times.
> 
> Is there a specific proposal or any patches to review?

Not AFAIK. Erni is being asked to rethink his approach here, and 
if we're going with a new command perhaps YNL should be on the table.

I'd be very interested to get a final ruling on YNL integration 
into iproute2 -- given its inability to work as a shared object /
library it's not unreasonable for the answer to be "no". 

The page pool sample in the kernel sources is very useful, I find
myself copying to various systems during debug. If there's no clear
path to YNL integration with iproute2 it's time for that sample to
be come a real CLI tool.

Re: [PATCH iproute2-next v3] iproute2: Add 'netshaper' command to 'ip link' for netdev shaping

[David Ahern]

On 8/18/25 10:00 AM, Jakub Kicinski wrote:
> I'd be very interested to get a final ruling on YNL integration into
> iproute2 -- given its inability to work as a shared object / library
> it's not unreasonable for the answer to be "no".

kind of hard to answer that without some proposal with details on what
an integration of ynl would look like

Re: [PATCH iproute2-next v3] iproute2: Add 'netshaper' command to 'ip link' for netdev shaping

[Erni Sri Satya Vennela]

On Sat, Aug 16, 2025 at 11:05:07AM -0700, Stephen Hemminger wrote:
> On Mon, 11 Aug 2025 00:05:02 -0700
> Erni Sri Satya Vennela <ernis@linux.microsoft.com> wrote:
> 
> > Add support for the netshaper Generic Netlink
> > family to iproute2. Introduce a new subcommand to `ip link` for
> > configuring netshaper parameters directly from userspace.
> > 
> > This interface allows users to set shaping attributes (such as speed)
> > which are passed to the kernel to perform the corresponding netshaper
> > operation.
> > 
> > Example usage:
> > $ip link netshaper { set | get | delete } dev DEVNAME \
> >                    handle scope SCOPE id ID \
> >                    [ speed SPEED ]
> > 
> > Internally, this triggers a kernel call to apply the shaping
> > configuration to the specified network device.
> > 
> > Currently, the tool supports the following functionalities:
> > - Setting speed in Mbps, enabling bandwidth clamping for
> >   a network device that support netshaper operations.
> > - Deleting the current configuration.
> > - Querying the existing configuration.
> > 
> > Additional netshaper operations will be integrated into the tool
> > as per requirement.
> > 
> > This change enables easy and scriptable configuration of bandwidth
> > shaping for  devices that use the netshaper Netlink family.
> > 
> > Corresponding net-next patches:
> > 1) https://lore.kernel.org/all/cover.1728460186.git.pabeni@redhat.com/
> > 2) https://lore.kernel.org/lkml/1750144656-2021-1-git-send-email-ernis@linux.microsoft.com/
> > 
> > Install pkg-config and libmnl* packages to print kernel extack
> > errors to stdout.
> > 
> > Signed-off-by: Erni Sri Satya Vennela <ernis@linux.microsoft.com>
> > ---
> > Please add include/uapi/linux/net_shaper.h from kernel source tree
> > for this patch.
> > ---
> > Changes in v3:
> > * Use strcmp instead of matches.
> > * Use get_rate64 instead get_unsigned for speed parameter.
> > * Remove speed_mbps in do_cmd() to reduce redundancy.
> > * Update the usage of speed parameter in the command.
> > Changes in v2:
> > * Use color coding for printing device name in stdout.
> > * Use clang-format to format the code inline.
> > * Use __u64 for speed_bps.
> > * Remove include/uapi/linux/netshaper.h file. 
> > ---
> >  ip/Makefile           |   2 +-
> >  ip/iplink.c           |  12 +++
> >  ip/iplink_netshaper.c | 189 ++++++++++++++++++++++++++++++++++++++++++
> >  3 files changed, 202 insertions(+), 1 deletion(-)
> >  create mode 100644 ip/iplink_netshaper.c
> 
> No documentation.
> No tests?
I will share the documentation on netshapers, specifically covering
how to use the ip command for this use case.
> 
> > 
> > diff --git a/ip/Makefile b/ip/Makefile
> > index 3535ba78..18218c3b 100644
> > --- a/ip/Makefile
> > +++ b/ip/Makefile
> > @@ -4,7 +4,7 @@ IPOBJ=ip.o ipaddress.o ipaddrlabel.o iproute.o iprule.o ipnetns.o \
> >      ipmaddr.o ipmonitor.o ipmroute.o ipprefix.o iptuntap.o iptoken.o \
> >      ipxfrm.o xfrm_state.o xfrm_policy.o xfrm_monitor.o iplink_dummy.o \
> >      iplink_ifb.o iplink_nlmon.o iplink_team.o iplink_vcan.o iplink_vxcan.o \
> > -    iplink_vlan.o link_veth.o link_gre.o iplink_can.o iplink_xdp.o \
> > +    iplink_vlan.o iplink_netshaper.o link_veth.o link_gre.o iplink_can.o iplink_xdp.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 \
> > diff --git a/ip/iplink.c b/ip/iplink.c
> > index 59e8caf4..daa4603d 100644
> > --- a/ip/iplink.c
> > +++ b/ip/iplink.c
> > @@ -1509,6 +1509,15 @@ static void do_help(int argc, char **argv)
> >  		usage();
> >  }
> >  
> > +static int iplink_netshaper(int argc, char **argv)
> > +{
> > +	struct link_util *lu;
> > +
> > +	lu = get_link_kind("netshaper");
> > +
> > +	return lu->parse_opt(lu, argc, argv, NULL);
> > +}
> > +
> >  int do_iplink(int argc, char **argv)
> >  {
> >  	if (argc < 1)
> > @@ -1545,6 +1554,9 @@ int do_iplink(int argc, char **argv)
> >  	if (matches(*argv, "property") == 0)
> >  		return iplink_prop(argc-1, argv+1);
> >  
> > +	if (strcmp(*argv, "netshaper") == 0)
> > +		return iplink_netshaper(argc-1, argv+1);
> > +
> >  	if (matches(*argv, "help") == 0) {
> >  		do_help(argc-1, argv+1);
> >  		return 0;
> > diff --git a/ip/iplink_netshaper.c b/ip/iplink_netshaper.c
> > new file mode 100644
> > index 00000000..30ee6c3e
> > --- /dev/null
> > +++ b/ip/iplink_netshaper.c
> > @@ -0,0 +1,189 @@
> > +/* SPDX-License-Identifier: GPL-2.0 */
> > +/*
> > + * iplink_netshaper.c netshaper H/W shaping support
> > + *
> > + * Authors:        Erni Sri Satya Vennela <ernis@linux.microsoft.com>
> > + */
> > +#include <stdio.h>
> > +#include <string.h>
> > +#include <linux/genetlink.h>
> > +#include <linux/netlink.h>
> > +#include <linux/rtnetlink.h>
> > +#include <uapi/linux/netshaper.h>
> > +#include "utils.h"
> > +#include "ip_common.h"
> > +#include "libgenl.h"
> > +
> > +/* netlink socket */
> > +static struct rtnl_handle gen_rth = { .fd = -1 };
> > +static int genl_family = -1;
> > +
> > +static void usage(void)
> > +{
> > +	fprintf(stderr,
> > +		"Usage:	ip link netshaper set dev DEVNAME handle scope HANDLE_SCOPE id HANDLE_ID speed SPEED\n"
> > +		"	ip link netshaper delete dev DEVNAME handle scope HANDLE_SCOPE id HANDLE_ID\n"
> > +		"	ip link netshaper get dev DEVNAME handle scope HANDLE_SCOPE id HANDLE_ID\n"
> 
> Seems like netshaper is property of the device not a top level object, the syntax
> here is awkward. Open to better suggestions. Looks to me that netshaper should be property of
> device not top level object.
> 
> Or netshaper is like neighbour and route and really wants to be not part of link command.
> 
> Also no other ip commands use show not get.
> The verb "get" is only used for things like getting a route or neighbor with a particular address.

Okay. I will change the code accordingly.
> 
> 
> > +		"Where:	DEVNAME		:= STRING\n"
> > +		"	HANDLE_SCOPE	:= { netdev | queue | node }\n"
> > +		"	HANDLE_ID	:= UINT\n"
> > +		"	SPEED		:= UINT{ kbit | mbit | gbit }\n");
> > +
> > +	exit(-1);
> > +}
> > +
> > +static void print_netshaper_attrs(struct nlmsghdr *answer)
> > +{
> > +	struct genlmsghdr *ghdr = NLMSG_DATA(answer);
> > +	int len = answer->nlmsg_len - NLMSG_LENGTH(GENL_HDRLEN);
> > +	struct rtattr *tb[NET_SHAPER_A_MAX + 1] = {};
> > +	__u32 speed_mbps;
> > +	__u64 speed_bps;
> > +	int ifindex;
> > +
> > +	parse_rtattr(tb, NET_SHAPER_A_MAX,
> > +		     (struct rtattr *)((char *)ghdr + GENL_HDRLEN), len);
> > +
> > +	for (int i = 1; i <= NET_SHAPER_A_MAX; ++i) {
> > +		if (!tb[i])
> > +			continue;
> > +		switch (i) {
> > +		case NET_SHAPER_A_BW_MAX:
> > +			speed_bps = rta_getattr_u64(tb[i]);
> > +			speed_mbps = (speed_bps / 1000000);
> > +			print_uint(PRINT_ANY, "speed", "speed: %u mbps\n",
> > +				   speed_mbps);
> > +			break;
> > +		case NET_SHAPER_A_IFINDEX:
> > +			ifindex = rta_getattr_u32(tb[i]);
> > +			print_color_string(PRINT_ANY, COLOR_IFNAME, "dev",
> > +					   "dev: %s\n",
> > +					   ll_index_to_name(ifindex));
> > +			break;
> > +		default:
> > +			break;
> > +		}
> > +	}
> > +}
> > +
> > +static int do_cmd(int argc, char **argv, struct nlmsghdr *n, int cmd)
> > +{
> > +	GENL_REQUEST(req, 1024, genl_family, 0, NET_SHAPER_FAMILY_VERSION, cmd,
> > +		     NLM_F_REQUEST | NLM_F_ACK);
> > +
> > +	struct nlmsghdr *answer;
> > +	__u64 speed_bps = 0;
> > +	int ifindex = -1;
> > +	int handle_scope = NET_SHAPER_SCOPE_UNSPEC;
> > +	__u32 handle_id = 0;
> > +	bool handle_present = false;
> > +	int err;
> > +
> > +	while (argc > 0) {
> > +		if (strcmp(*argv, "dev") == 0) {
> > +			NEXT_ARG();
> > +			ifindex = ll_name_to_index(*argv);
> > +		} else if (strcmp(*argv, "speed") == 0) {
> > +			NEXT_ARG();
> > +			if(get_rate64(&speed_bps, *argv)) {
> > +				fprintf(stderr, "Invalid speed value\n");
> > +				return -1;
> > +			}
> > +			/*Convert Bps to bps*/
> > +			speed_bps *= 8;
> > +		} else if (strcmp(*argv, "handle") == 0) {
> > +			handle_present = true;
> > +			NEXT_ARG();
> > +			if (strcmp(*argv, "scope") == 0) {
> > +				NEXT_ARG();
> > +				if (strcmp(*argv, "netdev") == 0) {
> > +					handle_scope = NET_SHAPER_SCOPE_NETDEV;
> > +				} else if (strcmp(*argv, "queue") == 0) {
> > +					handle_scope = NET_SHAPER_SCOPE_QUEUE;
> > +				} else if (strcmp(*argv, "node") == 0) {
> > +					handle_scope = NET_SHAPER_SCOPE_NODE;
> > +				} else {
> > +					fprintf(stderr, "Invalid scope\n");
> > +					return -1;
> > +				}
> > +
> > +				NEXT_ARG();
> > +				if (strcmp(*argv, "id") == 0) {
> > +					NEXT_ARG();
> > +					if (get_unsigned(&handle_id, *argv, 10)) {
> > +						fprintf(stderr,
> > +							"Invalid handle id\n");
> > +						return -1;
> > +					}
> > +				}
> > +			}
> > +		} else {
> > +			fprintf(stderr, "What is \"%s\"\n", *argv);
> > +			usage();
> > +		}
> > +		argc--;
> > +		argv++;
> > +	}
> > +
> > +	if (ifindex == -1)
> > +		missarg("dev");
> > +
> > +	if (!handle_present)
> > +		missarg("handle");
> > +
> > +	if (cmd == NET_SHAPER_CMD_SET && speed_bps == 0)
> > +		missarg("speed");
> > +
> > +	addattr32(&req.n, sizeof(req), NET_SHAPER_A_IFINDEX, ifindex);
> > +
> > +	struct rtattr *handle = addattr_nest(&req.n, sizeof(req),
> > +					     NET_SHAPER_A_HANDLE | NLA_F_NESTED);
> > +	addattr32(&req.n, sizeof(req), NET_SHAPER_A_HANDLE_SCOPE, handle_scope);
> > +	addattr32(&req.n, sizeof(req), NET_SHAPER_A_HANDLE_ID, handle_id);
> > +	addattr_nest_end(&req.n, handle);
> > +
> > +	if (cmd == NET_SHAPER_CMD_SET)
> > +		addattr64(&req.n, sizeof(req), NET_SHAPER_A_BW_MAX, speed_bps);
> > +
> > +	err = rtnl_talk(&gen_rth, &req.n, &answer);
> > +	if (err < 0) {
> > +		printf("Kernel command failed: %d\n", err);
> > +		return err;
> > +	}
> > +
> > +	if (cmd == NET_SHAPER_CMD_GET)
> > +		print_netshaper_attrs(answer);
> > +
> > +	return err;
> > +}
> > +
> > +static int netshaper_parse_opt(struct link_util *lu, int argc, char **argv,
> > +			       struct nlmsghdr *n)
> > +{
> > +	if (argc < 1)
> > +		usage();
> > +	if (strcmp(*argv, "help") == 0)
> > +		usage();
> > +
> > +	if (genl_init_handle(&gen_rth, NET_SHAPER_FAMILY_NAME, &genl_family))
> > +		exit(1);
> > +
> > +	if (strcmp(*argv, "set") == 0)
> > +		return do_cmd(argc - 1, argv + 1, n, NET_SHAPER_CMD_SET);
> > +
> > +	if (strcmp(*argv, "delete") == 0)
> > +		return do_cmd(argc - 1, argv + 1, n, NET_SHAPER_CMD_DELETE);
> > +
> > +	if (strcmp(*argv, "get") == 0)
> > +		return do_cmd(argc - 1, argv + 1, n, NET_SHAPER_CMD_GET);
> > +
> > +	fprintf(stderr,
> > +		"Command \"%s\" is unknown, try \"ip link netshaper help\".\n",
> > +		*argv);
> > +	exit(-1);
> > +}
> > +
> > +struct link_util netshaper_link_util = {
> > +	.id = "netshaper",
> > +	.parse_opt = netshaper_parse_opt,
> > +};
> 
> 
> Please add a print_opt functionality.
> Very useful to see what kernel thinks state is. 

Thankyou for the clarification. I'll make sure to integrate these
changes in the next version.

Re: [PATCH iproute2-next v3] iproute2: Add 'netshaper' command to 'ip link' for netdev shaping

[Erni Sri Satya Vennela]

On Sat, Aug 16, 2025 at 03:55:10PM -0700, Stephen Hemminger wrote:
> On Mon, 11 Aug 2025 00:05:02 -0700
> Erni Sri Satya Vennela <ernis@linux.microsoft.com> wrote:
> 
> > Add support for the netshaper Generic Netlink
> > family to iproute2. Introduce a new subcommand to `ip link` for
> > configuring netshaper parameters directly from userspace.
> > 
> > This interface allows users to set shaping attributes (such as speed)
> > which are passed to the kernel to perform the corresponding netshaper
> > operation.
> > 
> > Example usage:
> > $ip link netshaper { set | get | delete } dev DEVNAME \
> >                    handle scope SCOPE id ID \
> >                    [ speed SPEED ]
> 
> 
> The choice of ip link is awkward and doesn't match other options.
> I can think of some better other choices:
> 
>   1. netshaper could be a property of the device. But the choice of using genetlink
>      instead of regular ip netlink attributes makes this hard.
>   2. netshaper could be part of devlink. Since it is more targeted at hardware
>      device attributes.
>   3. netshaper could be a standalone command like bridge, dcb, devlink, rdma, tipc and vdpa.
> 
> What ever choice the command line options need to follow similar syntax to other iproute commands.

Thankyou for the suggestions.
After internal discussions, I have decided to proceed with
implementing netshaper as a standalone command.

Re: [PATCH iproute2-next v3] iproute2: Add 'netshaper' command to 'ip link' for netdev shaping

[Erni Sri Satya Vennela]

On Mon, Aug 18, 2025 at 08:36:12AM -0700, Jakub Kicinski wrote:
> On Sat, 16 Aug 2025 15:55:10 -0700 Stephen Hemminger wrote:
> > On Mon, 11 Aug 2025 00:05:02 -0700
> > Erni Sri Satya Vennela <ernis@linux.microsoft.com> wrote:
> > 
> > > Add support for the netshaper Generic Netlink
> > > family to iproute2. Introduce a new subcommand to `ip link` for
> > > configuring netshaper parameters directly from userspace.
> > > 
> > > This interface allows users to set shaping attributes (such as speed)
> > > which are passed to the kernel to perform the corresponding netshaper
> > > operation.
> > > 
> > > Example usage:
> > > $ip link netshaper { set | get | delete } dev DEVNAME \
> > >                    handle scope SCOPE id ID \
> > >                    [ speed SPEED ]  
> > 
> > The choice of ip link is awkward and doesn't match other options.
> > I can think of some better other choices:
> > 
> >   1. netshaper could be a property of the device. But the choice of using genetlink
> >      instead of regular ip netlink attributes makes this hard.
> >   2. netshaper could be part of devlink. Since it is more targeted at hardware
> >      device attributes.
> >   3. netshaper could be a standalone command like bridge, dcb, devlink, rdma, tipc and vdpa.
> > 
> > What ever choice the command line options need to follow similar syntax to other iproute commands.
> 
> I think historically we gravitated towards option 3 -- each family has
> a command? But indeed we could fold it together with something like
> the netdev family without much issue, they are both key'd on netdevs.
> 
> Somewhat related -- what's your take on integrating / vendoring in YNL?
> mnl doesn't provide any extack support..

I have done some tests and found that if we install pkg-config and
libmnl packages beforehand. The extack error messages from the kernel
are being printed to the stdout.

Example 1:
$ sudo ip link netshaper set dev <interface> handle scope queue id 1
speed 15gbit

Error: mana: net shaper scope should be netdev.
Kernel command failed: -1

Example 2:
$ sudo ip link netshaper set dev <interface> handle scope netdev id 2
speed 15gbit

Error: mana: Cannot create multiple shapers.
Kernel command failed: -1

Re: [PATCH iproute2-next v3] iproute2: Add 'netshaper' command to 'ip link' for netdev shaping

[Erni Sri Satya Vennela]

On Mon, Aug 18, 2025 at 09:00:10AM -0700, Jakub Kicinski wrote:
> On Mon, 18 Aug 2025 09:41:29 -0600 David Ahern wrote:
> > On 8/18/25 9:36 AM, Jakub Kicinski wrote:
> > > Somewhat related -- what's your take on integrating / vendoring in YNL?  
> > 
> > I feel like this has been brought up a few times.
> > 
> > Is there a specific proposal or any patches to review?
> 
> Not AFAIK. Erni is being asked to rethink his approach here, and 
> if we're going with a new command perhaps YNL should be on the table.
> 
Thank you for the feedback and for suggesting integration with the ynl
tool.

For the current implementation, I have followed your earlier guidance
( while implementing bandwidth clamping for MANA interface ) and used 
netlink commands similar to those used by ynl to support netshaper
operations from the kernel.

Ref: https://lore.kernel.org/all/20250421170349.003861f2@kernel.org/

> I'd be very interested to get a final ruling on YNL integration 
> into iproute2 -- given its inability to work as a shared object /
> library it's not unreasonable for the answer to be "no". 

This approach, to use netshaper as separate command in iproute2, seemed
like the most practical path forward to address shaping support without
introducing additional complexity.
> 
> The page pool sample in the kernel sources is very useful, I find
> myself copying to various systems during debug. If there's no clear
> path to YNL integration with iproute2 it's time for that sample to
> be come a real CLI tool.

Re: [PATCH iproute2-next v3] iproute2: Add 'netshaper' command to 'ip link' for netdev shaping

[Jakub Kicinski]

On Thu, 21 Aug 2025 04:06:07 -0700 Erni Sri Satya Vennela wrote:
> > Somewhat related -- what's your take on integrating / vendoring in YNL?
> > mnl doesn't provide any extack support..  
> 
> I have done some tests and found that if we install pkg-config and
> libmnl packages beforehand. The extack error messages from the kernel
> are being printed to the stdout.

Sorry, I wasn't very precise, it supports printing the string messages.
But nothing that requires actually understanding the message.
No bad attribute errors, no missing attribute errors, no policy errors.

Re: [PATCH iproute2-next v3] iproute2: Add 'netshaper' command to 'ip link' for netdev shaping

[Erni Sri Satya Vennela]

On Thu, Aug 21, 2025 at 07:12:59AM -0700, Jakub Kicinski wrote:
> On Thu, 21 Aug 2025 04:06:07 -0700 Erni Sri Satya Vennela wrote:
> > > Somewhat related -- what's your take on integrating / vendoring in YNL?
> > > mnl doesn't provide any extack support..  
> > 
> > I have done some tests and found that if we install pkg-config and
> > libmnl packages beforehand. The extack error messages from the kernel
> > are being printed to the stdout.
> 
> Sorry, I wasn't very precise, it supports printing the string messages.
> But nothing that requires actually understanding the message.
> No bad attribute errors, no missing attribute errors, no policy errors.

Are you referring to the following error logs from the ynl tool?

$./tools/net/ynl/pyynl/cli.py
 --spec Documentation/netlink/specs/net_shaper.yaml
 --do set 
 --json '{"ifindex":'3',
	  "handle":{"scope": "netdev", "id":'1' },
	  "bw-max": 200001000 }'

Netlink error: Invalid argument
nl_len = 92 (76) nl_flags = 0x300 nl_type = 2
        error: -22
        extack: {'msg': 'mana: Please use multiples of 100Mbps for
bandwidth'}

If yes, would it be reasonable to add support in iproute2 itself for
displaying such error logs?

Re: [PATCH iproute2-next v3] iproute2: Add 'netshaper' command to 'ip link' for netdev shaping

[Stephen Hemminger]

On Sun, 24 Aug 2025 06:40:17 -0700
Erni Sri Satya Vennela <ernis@linux.microsoft.com> wrote:

> On Thu, Aug 21, 2025 at 07:12:59AM -0700, Jakub Kicinski wrote:
> > On Thu, 21 Aug 2025 04:06:07 -0700 Erni Sri Satya Vennela wrote:  
> > > > Somewhat related -- what's your take on integrating / vendoring in YNL?
> > > > mnl doesn't provide any extack support..    
> > > 
> > > I have done some tests and found that if we install pkg-config and
> > > libmnl packages beforehand. The extack error messages from the kernel
> > > are being printed to the stdout.  
> > 
> > Sorry, I wasn't very precise, it supports printing the string messages.
> > But nothing that requires actually understanding the message.
> > No bad attribute errors, no missing attribute errors, no policy errors.  
> 
> Are you referring to the following error logs from the ynl tool?
> 
> $./tools/net/ynl/pyynl/cli.py
>  --spec Documentation/netlink/specs/net_shaper.yaml
>  --do set 
>  --json '{"ifindex":'3',
> 	  "handle":{"scope": "netdev", "id":'1' },
> 	  "bw-max": 200001000 }'
> 
> Netlink error: Invalid argument
> nl_len = 92 (76) nl_flags = 0x300 nl_type = 2
>         error: -22
>         extack: {'msg': 'mana: Please use multiples of 100Mbps for
> bandwidth'}
> 
> If yes, would it be reasonable to add support in iproute2 itself for
> displaying such error logs?

other parts of iproute2 already use libmnl to display extack messages.

Re: [PATCH iproute2-next v3] iproute2: Add 'netshaper' command to 'ip link' for netdev shaping

[Jakub Kicinski]

On Sun, 24 Aug 2025 06:40:17 -0700 Erni Sri Satya Vennela wrote:
> > Sorry, I wasn't very precise, it supports printing the string messages.
> > But nothing that requires actually understanding the message.
> > No bad attribute errors, no missing attribute errors, no policy errors.  
> 
> Are you referring to the following error logs from the ynl tool?
> 
> $./tools/net/ynl/pyynl/cli.py
>  --spec Documentation/netlink/specs/net_shaper.yaml
>  --do set 
>  --json '{"ifindex":'3',
> 	  "handle":{"scope": "netdev", "id":'1' },
> 	  "bw-max": 200001000 }'
> 
> Netlink error: Invalid argument
> nl_len = 92 (76) nl_flags = 0x300 nl_type = 2
>         error: -22
>         extack: {'msg': 'mana: Please use multiples of 100Mbps for
> bandwidth'}

Not 'msg', the other types, for example miss-type, bad-attr:

$ ynl --family net_shaper --do get
Netlink error: Invalid argument
nl_len = 44 (28) nl_flags = 0x300 nl_type = 2
	error: -22
	extack: {'miss-type': 'ifindex', 'miss-type-doc': 'Interface index owning the specified shaper.'}

$ ynl --family net_shaper --do get --json '{"ifindex": 1}'
Netlink error: Operation not supported
nl_len = 44 (28) nl_flags = 0x300 nl_type = 2
	error: -95
	extack: {'bad-attr': '.ifindex'}

> If yes, would it be reasonable to add support in iproute2 itself for
> displaying such error logs?

Re: [PATCH iproute2-next v3] iproute2: Add 'netshaper' command to 'ip link' for netdev shaping

[Stephen Hemminger]

On Thu, 21 Aug 2025 04:06:07 -0700
Erni Sri Satya Vennela <ernis@linux.microsoft.com> wrote:

> On Mon, Aug 18, 2025 at 08:36:12AM -0700, Jakub Kicinski wrote:
> > On Sat, 16 Aug 2025 15:55:10 -0700 Stephen Hemminger wrote:  
> > > On Mon, 11 Aug 2025 00:05:02 -0700
> > > Erni Sri Satya Vennela <ernis@linux.microsoft.com> wrote:
> > >   
> > > > Add support for the netshaper Generic Netlink
> > > > family to iproute2. Introduce a new subcommand to `ip link` for
> > > > configuring netshaper parameters directly from userspace.
> > > > 
> > > > This interface allows users to set shaping attributes (such as speed)
> > > > which are passed to the kernel to perform the corresponding netshaper
> > > > operation.
> > > > 
> > > > Example usage:
> > > > $ip link netshaper { set | get | delete } dev DEVNAME \
> > > >                    handle scope SCOPE id ID \
> > > >                    [ speed SPEED ]    
> > > 
> > > The choice of ip link is awkward and doesn't match other options.
> > > I can think of some better other choices:
> > > 
> > >   1. netshaper could be a property of the device. But the choice of using genetlink
> > >      instead of regular ip netlink attributes makes this hard.
> > >   2. netshaper could be part of devlink. Since it is more targeted at hardware
> > >      device attributes.
> > >   3. netshaper could be a standalone command like bridge, dcb, devlink, rdma, tipc and vdpa.
> > > 
> > > What ever choice the command line options need to follow similar syntax to other iproute commands.  
> > 
> > I think historically we gravitated towards option 3 -- each family has
> > a command? But indeed we could fold it together with something like
> > the netdev family without much issue, they are both key'd on netdevs.
> > 
> > Somewhat related -- what's your take on integrating / vendoring in YNL?
> > mnl doesn't provide any extack support..  

No YNL integration with iproute adds too much.

Re: [PATCH iproute2-next v3] iproute2: Add 'netshaper' command to 'ip link' for netdev shaping

[Erni Sri Satya Vennela]

On Mon, Aug 25, 2025 at 09:16:22AM -0700, Stephen Hemminger wrote:
> On Thu, 21 Aug 2025 04:06:07 -0700
> Erni Sri Satya Vennela <ernis@linux.microsoft.com> wrote:
> 
> > On Mon, Aug 18, 2025 at 08:36:12AM -0700, Jakub Kicinski wrote:
> > > On Sat, 16 Aug 2025 15:55:10 -0700 Stephen Hemminger wrote:  
> > > > On Mon, 11 Aug 2025 00:05:02 -0700
> > > > Erni Sri Satya Vennela <ernis@linux.microsoft.com> wrote:
> > > >   
> > > > > Add support for the netshaper Generic Netlink
> > > > > family to iproute2. Introduce a new subcommand to `ip link` for
> > > > > configuring netshaper parameters directly from userspace.
> > > > > 
> > > > > This interface allows users to set shaping attributes (such as speed)
> > > > > which are passed to the kernel to perform the corresponding netshaper
> > > > > operation.
> > > > > 
> > > > > Example usage:
> > > > > $ip link netshaper { set | get | delete } dev DEVNAME \
> > > > >                    handle scope SCOPE id ID \
> > > > >                    [ speed SPEED ]    
> > > > 
> > > > The choice of ip link is awkward and doesn't match other options.
> > > > I can think of some better other choices:
> > > > 
> > > >   1. netshaper could be a property of the device. But the choice of using genetlink
> > > >      instead of regular ip netlink attributes makes this hard.
> > > >   2. netshaper could be part of devlink. Since it is more targeted at hardware
> > > >      device attributes.
> > > >   3. netshaper could be a standalone command like bridge, dcb, devlink, rdma, tipc and vdpa.
> > > > 
> > > > What ever choice the command line options need to follow similar syntax to other iproute commands.  
> > > 
> > > I think historically we gravitated towards option 3 -- each family has
> > > a command? But indeed we could fold it together with something like
> > > the netdev family without much issue, they are both key'd on netdevs.
> > > 
> > > Somewhat related -- what's your take on integrating / vendoring in YNL?
> > > mnl doesn't provide any extack support..  
> 
> No YNL integration with iproute adds too much.

Thankyou Stephen and Jakub for the feedback.
After reviewing the discussion,  I will proceed with the next version
of the patch with netshaper as a standalone command.

I appreciate the perspectives shared and will keep YNL in mind for
future work.