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netdev-genl: create a simple family for netdev stuff

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Add a Netlink spec-compatible family for netdevs.
This is a very simple implementation without much
thought going into it.

It allows us to reap all the benefits of Netlink specs,
one can use the generic client to issue the commands:

  $ ./cli.py --spec netdev.yaml --dump dev_get
  [{'ifindex': 1, 'xdp-features': set()},
   {'ifindex': 2, 'xdp-features': {'basic', 'ndo-xmit', 'redirect'}},
   {'ifindex': 3, 'xdp-features': {'rx-sg'}}]

the generic python library does not have flags-by-name
support, yet, but we also don't have to carry strings
in the messages, as user space can get the names from
the spec.

Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Co-developed-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Co-developed-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Co-developed-by: Marek Majtyka <alardam@gmail.com>
Signed-off-by: Marek Majtyka <alardam@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Link: https://lore.kernel.org/r/327ad9c9868becbe1e601b580c962549c8cd81f2.1675245258.git.lorenzo@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
Jakub Kicinski 2023-02-01 11:24:17 +01:00 committed by Alexei Starovoitov
parent 150809082a
commit d3d854fd6a
10 changed files with 477 additions and 1 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

100
Documentation/netlink/specs/netdev.yaml Normal file
View file

@ -0,0 +1,100 @@
name: netdev
doc:
netdev configuration over generic netlink.
definitions:
-
type: flags
name: xdp-act
entries:
-
name: basic
doc:
XDP feautues set supported by all drivers
(XDP_ABORTED, XDP_DROP, XDP_PASS, XDP_TX)
-
name: redirect
doc:
The netdev supports XDP_REDIRECT
-
name: ndo-xmit
doc:
This feature informs if netdev implements ndo_xdp_xmit callback.
-
name: xsk-zerocopy
doc:
This feature informs if netdev supports AF_XDP in zero copy mode.
-
name: hw-offload
doc:
This feature informs if netdev supports XDP hw oflloading.
-
name: rx-sg
doc:
This feature informs if netdev implements non-linear XDP buffer
support in the driver napi callback.
-
name: ndo-xmit-sg
doc:
This feature informs if netdev implements non-linear XDP buffer
support in ndo_xdp_xmit callback.
attribute-sets:
-
name: dev
attributes:
-
name: ifindex
doc: netdev ifindex
type: u32
value: 1
checks:
min: 1
-
name: pad
type: pad
-
name: xdp-features
doc: Bitmask of enabled xdp-features.
type: u64
enum: xdp-act
enum-as-flags: true
operations:
list:
-
name: dev-get
doc: Get / dump information about a netdev.
value: 1
attribute-set: dev
do:
request:
attributes:
- ifindex
reply: &dev-all
attributes:
- ifindex
- xdp-features
dump:
reply: *dev-all
-
name: dev-add-ntf
doc: Notification about device appearing.
notify: dev-get
mcgrp: mgmt
-
name: dev-del-ntf
doc: Notification about device disappearing.
notify: dev-get
mcgrp: mgmt
-
name: dev-change-ntf
doc: Notification about device configuration being changed.
notify: dev-get
mcgrp: mgmt
mcast-groups:
list:
-
name: mgmt

3
include/linux/netdevice.h
View file

@ -47,6 +47,7 @@
#include <uapi/linux/netdevice.h>
#include <uapi/linux/if_bonding.h>
#include <uapi/linux/pkt_cls.h>
#include <uapi/linux/netdev.h>
#include <linux/hashtable.h>
#include <linux/rbtree.h>
#include <net/net_trackers.h>
@ -2055,6 +2056,7 @@ struct net_device {
/* Read-mostly cache-line for fast-path access */
unsigned int flags;
xdp_features_t xdp_features;
unsigned long long priv_flags;
const struct net_device_ops *netdev_ops;
const struct xdp_metadata_ops *xdp_metadata_ops;
@ -2839,6 +2841,7 @@ enum netdev_cmd {
NETDEV_OFFLOAD_XSTATS_DISABLE,
NETDEV_OFFLOAD_XSTATS_REPORT_USED,
NETDEV_OFFLOAD_XSTATS_REPORT_DELTA,
NETDEV_XDP_FEAT_CHANGE,
};
const char *netdev_cmd_to_name(enum netdev_cmd cmd);

3
include/net/xdp.h
View file

@ -7,6 +7,7 @@
#define __LINUX_NET_XDP_H__
#include <linux/skbuff.h> /* skb_shared_info */
#include <uapi/linux/netdev.h>
/**
* DOC: XDP RX-queue information
@ -43,6 +44,8 @@ enum xdp_mem_type {
MEM_TYPE_MAX,
};
typedef u32 xdp_features_t;
/* XDP flags for ndo_xdp_xmit */
#define XDP_XMIT_FLUSH (1U << 0) /* doorbell signal consumer */
#define XDP_XMIT_FLAGS_MASK XDP_XMIT_FLUSH

59
include/uapi/linux/netdev.h Normal file
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@ -0,0 +1,59 @@
/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
/* Do not edit directly, auto-generated from: */
/* Documentation/netlink/specs/netdev.yaml */
/* YNL-GEN uapi header */
#ifndef _UAPI_LINUX_NETDEV_H
#define _UAPI_LINUX_NETDEV_H
#define NETDEV_FAMILY_NAME "netdev"
#define NETDEV_FAMILY_VERSION 1
/**
* enum netdev_xdp_act
* @NETDEV_XDP_ACT_BASIC: XDP feautues set supported by all drivers
* (XDP_ABORTED, XDP_DROP, XDP_PASS, XDP_TX)
* @NETDEV_XDP_ACT_REDIRECT: The netdev supports XDP_REDIRECT
* @NETDEV_XDP_ACT_NDO_XMIT: This feature informs if netdev implements
* ndo_xdp_xmit callback.
* @NETDEV_XDP_ACT_XSK_ZEROCOPY: This feature informs if netdev supports AF_XDP
* in zero copy mode.
* @NETDEV_XDP_ACT_HW_OFFLOAD: This feature informs if netdev supports XDP hw
* oflloading.
* @NETDEV_XDP_ACT_RX_SG: This feature informs if netdev implements non-linear
* XDP buffer support in the driver napi callback.
* @NETDEV_XDP_ACT_NDO_XMIT_SG: This feature informs if netdev implements
* non-linear XDP buffer support in ndo_xdp_xmit callback.
*/
enum netdev_xdp_act {
NETDEV_XDP_ACT_BASIC = 1,
NETDEV_XDP_ACT_REDIRECT = 2,
NETDEV_XDP_ACT_NDO_XMIT = 4,
NETDEV_XDP_ACT_XSK_ZEROCOPY = 8,
NETDEV_XDP_ACT_HW_OFFLOAD = 16,
NETDEV_XDP_ACT_RX_SG = 32,
NETDEV_XDP_ACT_NDO_XMIT_SG = 64,
};
enum {
NETDEV_A_DEV_IFINDEX = 1,
NETDEV_A_DEV_PAD,
NETDEV_A_DEV_XDP_FEATURES,
__NETDEV_A_DEV_MAX,
NETDEV_A_DEV_MAX = (__NETDEV_A_DEV_MAX - 1)
};
enum {
NETDEV_CMD_DEV_GET = 1,
NETDEV_CMD_DEV_ADD_NTF,
NETDEV_CMD_DEV_DEL_NTF,
NETDEV_CMD_DEV_CHANGE_NTF,
__NETDEV_CMD_MAX,
NETDEV_CMD_MAX = (__NETDEV_CMD_MAX - 1)
};
#define NETDEV_MCGRP_MGMT "mgmt"
#endif /* _UAPI_LINUX_NETDEV_H */

3
net/core/Makefile
View file

@ -12,7 +12,8 @@ obj-$(CONFIG_SYSCTL) += sysctl_net_core.o
obj-y += dev.o dev_addr_lists.o dst.o netevent.o \
neighbour.o rtnetlink.o utils.o link_watch.o filter.o \
sock_diag.o dev_ioctl.o tso.o sock_reuseport.o \
fib_notifier.o xdp.o flow_offload.o gro.o
fib_notifier.o xdp.o flow_offload.o gro.o \
netdev-genl.o netdev-genl-gen.o
obj-$(CONFIG_NETDEV_ADDR_LIST_TEST) += dev_addr_lists_test.o

1
net/core/dev.c
View file

@ -1614,6 +1614,7 @@ const char *netdev_cmd_to_name(enum netdev_cmd cmd)
N(SVLAN_FILTER_PUSH_INFO) N(SVLAN_FILTER_DROP_INFO)
N(PRE_CHANGEADDR) N(OFFLOAD_XSTATS_ENABLE) N(OFFLOAD_XSTATS_DISABLE)
N(OFFLOAD_XSTATS_REPORT_USED) N(OFFLOAD_XSTATS_REPORT_DELTA)
N(XDP_FEAT_CHANGE)
}
#undef N
return "UNKNOWN_NETDEV_EVENT";

48
net/core/netdev-genl-gen.c Normal file
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@ -0,0 +1,48 @@
// SPDX-License-Identifier: BSD-3-Clause
/* Do not edit directly, auto-generated from: */
/* Documentation/netlink/specs/netdev.yaml */
/* YNL-GEN kernel source */
#include <net/netlink.h>
#include <net/genetlink.h>
#include "netdev-genl-gen.h"
#include <linux/netdev.h>
/* NETDEV_CMD_DEV_GET - do */
static const struct nla_policy netdev_dev_get_nl_policy[NETDEV_A_DEV_IFINDEX + 1] = {
[NETDEV_A_DEV_IFINDEX] = NLA_POLICY_MIN(NLA_U32, 1),
};
/* Ops table for netdev */
static const struct genl_split_ops netdev_nl_ops[2] = {
{
.cmd = NETDEV_CMD_DEV_GET,
.doit = netdev_nl_dev_get_doit,
.policy = netdev_dev_get_nl_policy,
.maxattr = NETDEV_A_DEV_IFINDEX,
.flags = GENL_CMD_CAP_DO,
},
{
.cmd = NETDEV_CMD_DEV_GET,
.dumpit = netdev_nl_dev_get_dumpit,
.flags = GENL_CMD_CAP_DUMP,
},
};
static const struct genl_multicast_group netdev_nl_mcgrps[] = {
[NETDEV_NLGRP_MGMT] = { "mgmt", },
};
struct genl_family netdev_nl_family __ro_after_init = {
.name = NETDEV_FAMILY_NAME,
.version = NETDEV_FAMILY_VERSION,
.netnsok = true,
.parallel_ops = true,
.module = THIS_MODULE,
.split_ops = netdev_nl_ops,
.n_split_ops = ARRAY_SIZE(netdev_nl_ops),
.mcgrps = netdev_nl_mcgrps,
.n_mcgrps = ARRAY_SIZE(netdev_nl_mcgrps),
};

23
net/core/netdev-genl-gen.h Normal file
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@ -0,0 +1,23 @@
/* SPDX-License-Identifier: BSD-3-Clause */
/* Do not edit directly, auto-generated from: */
/* Documentation/netlink/specs/netdev.yaml */
/* YNL-GEN kernel header */
#ifndef _LINUX_NETDEV_GEN_H
#define _LINUX_NETDEV_GEN_H
#include <net/netlink.h>
#include <net/genetlink.h>
#include <linux/netdev.h>
int netdev_nl_dev_get_doit(struct sk_buff *skb, struct genl_info *info);
int netdev_nl_dev_get_dumpit(struct sk_buff *skb, struct netlink_callback *cb);
enum {
NETDEV_NLGRP_MGMT,
};
extern struct genl_family netdev_nl_family;
#endif /* _LINUX_NETDEV_GEN_H */

179
net/core/netdev-genl.c Normal file
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@ -0,0 +1,179 @@
// SPDX-License-Identifier: GPL-2.0-only
#include <linux/netdevice.h>
#include <linux/notifier.h>
#include <linux/rtnetlink.h>
#include <net/net_namespace.h>
#include <net/sock.h>
#include "netdev-genl-gen.h"
static int
netdev_nl_dev_fill(struct net_device *netdev, struct sk_buff *rsp,
u32 portid, u32 seq, int flags, u32 cmd)
{
void *hdr;
hdr = genlmsg_put(rsp, portid, seq, &netdev_nl_family, flags, cmd);
if (!hdr)
return -EMSGSIZE;
if (nla_put_u32(rsp, NETDEV_A_DEV_IFINDEX, netdev->ifindex) ||
nla_put_u64_64bit(rsp, NETDEV_A_DEV_XDP_FEATURES,
netdev->xdp_features, NETDEV_A_DEV_PAD)) {
genlmsg_cancel(rsp, hdr);
return -EINVAL;
}
genlmsg_end(rsp, hdr);
return 0;
}
static void
netdev_genl_dev_notify(struct net_device *netdev, int cmd)
{
struct sk_buff *ntf;
if (!genl_has_listeners(&netdev_nl_family, dev_net(netdev),
NETDEV_NLGRP_MGMT))
return;
ntf = genlmsg_new(GENLMSG_DEFAULT_SIZE, GFP_KERNEL);
if (!ntf)
return;
if (netdev_nl_dev_fill(netdev, ntf, 0, 0, 0, cmd)) {
nlmsg_free(ntf);
return;
}
genlmsg_multicast_netns(&netdev_nl_family, dev_net(netdev), ntf,
0, NETDEV_NLGRP_MGMT, GFP_KERNEL);
}
int netdev_nl_dev_get_doit(struct sk_buff *skb, struct genl_info *info)
{
struct net_device *netdev;
struct sk_buff *rsp;
u32 ifindex;
int err;
if (GENL_REQ_ATTR_CHECK(info, NETDEV_A_DEV_IFINDEX))
return -EINVAL;
ifindex = nla_get_u32(info->attrs[NETDEV_A_DEV_IFINDEX]);
rsp = genlmsg_new(GENLMSG_DEFAULT_SIZE, GFP_KERNEL);
if (!rsp)
return -ENOMEM;
rtnl_lock();
netdev = __dev_get_by_index(genl_info_net(info), ifindex);
if (netdev)
err = netdev_nl_dev_fill(netdev, rsp, info->snd_portid,
info->snd_seq, 0, info->genlhdr->cmd);
else
err = -ENODEV;
rtnl_unlock();
if (err)
goto err_free_msg;
return genlmsg_reply(rsp, info);
err_free_msg:
nlmsg_free(rsp);
return err;
}
int netdev_nl_dev_get_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
{
struct net *net = sock_net(skb->sk);
struct net_device *netdev;
int idx = 0, s_idx;
int h, s_h;
int err;
s_h = cb->args[0];
s_idx = cb->args[1];
rtnl_lock();
for (h = s_h; h < NETDEV_HASHENTRIES; h++, s_idx = 0) {
struct hlist_head *head;
idx = 0;
head = &net->dev_index_head[h];
hlist_for_each_entry(netdev, head, index_hlist) {
if (idx < s_idx)
goto cont;
err = netdev_nl_dev_fill(netdev, skb,
NETLINK_CB(cb->skb).portid,
cb->nlh->nlmsg_seq, 0,
NETDEV_CMD_DEV_GET);
if (err < 0)
break;
cont:
idx++;
}
}
rtnl_unlock();
if (err != -EMSGSIZE)
return err;
cb->args[1] = idx;
cb->args[0] = h;
cb->seq = net->dev_base_seq;
return skb->len;
}
static int netdev_genl_netdevice_event(struct notifier_block *nb,
unsigned long event, void *ptr)
{
struct net_device *netdev = netdev_notifier_info_to_dev(ptr);
switch (event) {
case NETDEV_REGISTER:
netdev_genl_dev_notify(netdev, NETDEV_CMD_DEV_ADD_NTF);
break;
case NETDEV_UNREGISTER:
netdev_genl_dev_notify(netdev, NETDEV_CMD_DEV_DEL_NTF);
break;
case NETDEV_XDP_FEAT_CHANGE:
netdev_genl_dev_notify(netdev, NETDEV_CMD_DEV_CHANGE_NTF);
break;
}
return NOTIFY_OK;
}
static struct notifier_block netdev_genl_nb = {
.notifier_call = netdev_genl_netdevice_event,
};
static int __init netdev_genl_init(void)
{
int err;
err = register_netdevice_notifier(&netdev_genl_nb);
if (err)
return err;
err = genl_register_family(&netdev_nl_family);
if (err)
goto err_unreg_ntf;
return 0;
err_unreg_ntf:
unregister_netdevice_notifier(&netdev_genl_nb);
return err;
}
subsys_initcall(netdev_genl_init);

59
tools/include/uapi/linux/netdev.h Normal file
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@ -0,0 +1,59 @@
/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
/* Do not edit directly, auto-generated from: */
/* Documentation/netlink/specs/netdev.yaml */
/* YNL-GEN uapi header */
#ifndef _UAPI_LINUX_NETDEV_H
#define _UAPI_LINUX_NETDEV_H
#define NETDEV_FAMILY_NAME "netdev"
#define NETDEV_FAMILY_VERSION 1
/**
* enum netdev_xdp_act
* @NETDEV_XDP_ACT_BASIC: XDP feautues set supported by all drivers
* (XDP_ABORTED, XDP_DROP, XDP_PASS, XDP_TX)
* @NETDEV_XDP_ACT_REDIRECT: The netdev supports XDP_REDIRECT
* @NETDEV_XDP_ACT_NDO_XMIT: This feature informs if netdev implements
* ndo_xdp_xmit callback.
* @NETDEV_XDP_ACT_XSK_ZEROCOPY: This feature informs if netdev supports AF_XDP
* in zero copy mode.
* @NETDEV_XDP_ACT_HW_OFFLOAD: This feature informs if netdev supports XDP hw
* oflloading.
* @NETDEV_XDP_ACT_RX_SG: This feature informs if netdev implements non-linear
* XDP buffer support in the driver napi callback.
* @NETDEV_XDP_ACT_NDO_XMIT_SG: This feature informs if netdev implements
* non-linear XDP buffer support in ndo_xdp_xmit callback.
*/
enum netdev_xdp_act {
NETDEV_XDP_ACT_BASIC = 1,
NETDEV_XDP_ACT_REDIRECT = 2,
NETDEV_XDP_ACT_NDO_XMIT = 4,
NETDEV_XDP_ACT_XSK_ZEROCOPY = 8,
NETDEV_XDP_ACT_HW_OFFLOAD = 16,
NETDEV_XDP_ACT_RX_SG = 32,
NETDEV_XDP_ACT_NDO_XMIT_SG = 64,
};
enum {
NETDEV_A_DEV_IFINDEX = 1,
NETDEV_A_DEV_PAD,
NETDEV_A_DEV_XDP_FEATURES,
__NETDEV_A_DEV_MAX,
NETDEV_A_DEV_MAX = (__NETDEV_A_DEV_MAX - 1)
};
enum {
NETDEV_CMD_DEV_GET = 1,
NETDEV_CMD_DEV_ADD_NTF,
NETDEV_CMD_DEV_DEL_NTF,
NETDEV_CMD_DEV_CHANGE_NTF,
__NETDEV_CMD_MAX,
NETDEV_CMD_MAX = (__NETDEV_CMD_MAX - 1)
};
#define NETDEV_MCGRP_MGMT "mgmt"
#endif /* _UAPI_LINUX_NETDEV_H */