Merge branch 'bpf-xdp-stack-uninit-and-offload-tests'

Jakub Kicinski says:

====================
The purpose of this series is to add a software model of BPF offloads
to make it easier for everyone to test them and make some of the more
arcane rules and assumptions more clear.

The series starts with 3 patches aiming to make XDP handling in the
drivers less error prone.  Currently driver authors have to remember
to free XDP programs if XDP is active during unregister.  With this
series the core will disable XDP on its own.  It will take place
after close, drivers are not expected to perform reconfiguration
when disabling XDP on a downed device.

Next two patches add the software netdev driver, followed by a python
test which exercises all the corner cases which came to my mind.

Test needs to be run as root.  It will print basic information to
stdout, but can also create a more detailed log of all commands
when --log option is passed.  Log is in Emacs Org-mode format.

  ./tools/testing/selftests/bpf/test_offload.py --log /tmp/log

Last two patches replace the SR-IOV API implementation of dummy.

v3:
 - move the freeing of vfs to release (Phil).
v2:
 - free device from the release function;
 - use bus-based name generatin instead of netdev name.
v1:
 - replace the SR-IOV API implementation of dummy;
 - make the dev_xdp_uninstall() also handle the XDP generic (Daniel).
====================

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

1 files changed, 502 insertions, 0 deletions

diff --git a/drivers/net/netdevsim/netdev.c b/drivers/net/netdevsim/netdev.c
new file mode 100644
index 000000000000..eb8c679fca9f
--- /dev/null
+++ b/drivers/net/netdevsim/netdev.c
@@ -0,0 +1,502 @@
+/*
+ * Copyright (C) 2017 Netronome Systems, Inc.
+ *
+ * This software is licensed under the GNU General License Version 2,
+ * June 1991 as shown in the file COPYING in the top-level directory of this
+ * source tree.
+ *
+ * THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS"
+ * WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING,
+ * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE
+ * OF THE PROGRAM IS WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME
+ * THE COST OF ALL NECESSARY SERVICING, REPAIR OR CORRECTION.
+ */
+
+#include <linux/debugfs.h>
+#include <linux/etherdevice.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <linux/slab.h>
+#include <net/netlink.h>
+#include <net/pkt_cls.h>
+#include <net/rtnetlink.h>
+
+#include "netdevsim.h"
+
+struct nsim_vf_config {
+	int link_state;
+	u16 min_tx_rate;
+	u16 max_tx_rate;
+	u16 vlan;
+	__be16 vlan_proto;
+	u16 qos;
+	u8 vf_mac[ETH_ALEN];
+	bool spoofchk_enabled;
+	bool trusted;
+	bool rss_query_enabled;
+};
+
+static u32 nsim_dev_id;
+
+static int nsim_num_vf(struct device *dev)
+{
+	struct netdevsim *ns = to_nsim(dev);
+
+	return ns->num_vfs;
+}
+
+static struct bus_type nsim_bus = {
+	.name		= DRV_NAME,
+	.dev_name	= DRV_NAME,
+	.num_vf		= nsim_num_vf,
+};
+
+static int nsim_vfs_enable(struct netdevsim *ns, unsigned int num_vfs)
+{
+	ns->vfconfigs = kcalloc(num_vfs, sizeof(struct nsim_vf_config),
+				GFP_KERNEL);
+	if (!ns->vfconfigs)
+		return -ENOMEM;
+	ns->num_vfs = num_vfs;
+
+	return 0;
+}
+
+static void nsim_vfs_disable(struct netdevsim *ns)
+{
+	kfree(ns->vfconfigs);
+	ns->vfconfigs = NULL;
+	ns->num_vfs = 0;
+}
+
+static ssize_t
+nsim_numvfs_store(struct device *dev, struct device_attribute *attr,
+		  const char *buf, size_t count)
+{
+	struct netdevsim *ns = to_nsim(dev);
+	unsigned int num_vfs;
+	int ret;
+
+	ret = kstrtouint(buf, 0, &num_vfs);
+	if (ret)
+		return ret;
+
+	rtnl_lock();
+	if (ns->num_vfs == num_vfs)
+		goto exit_good;
+	if (ns->num_vfs && num_vfs) {
+		ret = -EBUSY;
+		goto exit_unlock;
+	}
+
+	if (num_vfs) {
+		ret = nsim_vfs_enable(ns, num_vfs);
+		if (ret)
+			goto exit_unlock;
+	} else {
+		nsim_vfs_disable(ns);
+	}
+exit_good:
+	ret = count;
+exit_unlock:
+	rtnl_unlock();
+
+	return ret;
+}
+
+static ssize_t
+nsim_numvfs_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct netdevsim *ns = to_nsim(dev);
+
+	return sprintf(buf, "%u\n", ns->num_vfs);
+}
+
+static struct device_attribute nsim_numvfs_attr =
+	__ATTR(sriov_numvfs, 0664, nsim_numvfs_show, nsim_numvfs_store);
+
+static struct attribute *nsim_dev_attrs[] = {
+	&nsim_numvfs_attr.attr,
+	NULL,
+};
+
+static const struct attribute_group nsim_dev_attr_group = {
+	.attrs = nsim_dev_attrs,
+};
+
+static const struct attribute_group *nsim_dev_attr_groups[] = {
+	&nsim_dev_attr_group,
+	NULL,
+};
+
+static void nsim_dev_release(struct device *dev)
+{
+	struct netdevsim *ns = to_nsim(dev);
+
+	nsim_vfs_disable(ns);
+	free_netdev(ns->netdev);
+}
+
+struct device_type nsim_dev_type = {
+	.groups = nsim_dev_attr_groups,
+	.release = nsim_dev_release,
+};
+
+static int nsim_init(struct net_device *dev)
+{
+	struct netdevsim *ns = netdev_priv(dev);
+	int err;
+
+	ns->netdev = dev;
+	ns->ddir = debugfs_create_dir(netdev_name(dev), nsim_ddir);
+
+	err = nsim_bpf_init(ns);
+	if (err)
+		goto err_debugfs_destroy;
+
+	ns->dev.id = nsim_dev_id++;
+	ns->dev.bus = &nsim_bus;
+	ns->dev.type = &nsim_dev_type;
+	err = device_register(&ns->dev);
+	if (err)
+		goto err_bpf_uninit;
+
+	SET_NETDEV_DEV(dev, &ns->dev);
+
+	return 0;
+
+err_bpf_uninit:
+	nsim_bpf_uninit(ns);
+err_debugfs_destroy:
+	debugfs_remove_recursive(ns->ddir);
+	return err;
+}
+
+static void nsim_uninit(struct net_device *dev)
+{
+	struct netdevsim *ns = netdev_priv(dev);
+
+	debugfs_remove_recursive(ns->ddir);
+	nsim_bpf_uninit(ns);
+}
+
+static void nsim_free(struct net_device *dev)
+{
+	struct netdevsim *ns = netdev_priv(dev);
+
+	device_unregister(&ns->dev);
+	/* netdev and vf state will be freed out of device_release() */
+}
+
+static netdev_tx_t nsim_start_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+	struct netdevsim *ns = netdev_priv(dev);
+
+	u64_stats_update_begin(&ns->syncp);
+	ns->tx_packets++;
+	ns->tx_bytes += skb->len;
+	u64_stats_update_end(&ns->syncp);
+
+	dev_kfree_skb(skb);
+
+	return NETDEV_TX_OK;
+}
+
+static void nsim_set_rx_mode(struct net_device *dev)
+{
+}
+
+static int nsim_change_mtu(struct net_device *dev, int new_mtu)
+{
+	struct netdevsim *ns = netdev_priv(dev);
+
+	if (ns->xdp_prog_mode == XDP_ATTACHED_DRV &&
+	    new_mtu > NSIM_XDP_MAX_MTU)
+		return -EBUSY;
+
+	dev->mtu = new_mtu;
+
+	return 0;
+}
+
+static void
+nsim_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats)
+{
+	struct netdevsim *ns = netdev_priv(dev);
+	unsigned int start;
+
+	do {
+		start = u64_stats_fetch_begin(&ns->syncp);
+		stats->tx_bytes = ns->tx_bytes;
+		stats->tx_packets = ns->tx_packets;
+	} while (u64_stats_fetch_retry(&ns->syncp, start));
+}
+
+static int
+nsim_setup_tc_block_cb(enum tc_setup_type type, void *type_data, void *cb_priv)
+{
+	return nsim_bpf_setup_tc_block_cb(type, type_data, cb_priv);
+}
+
+static int
+nsim_setup_tc_block(struct net_device *dev, struct tc_block_offload *f)
+{
+	struct netdevsim *ns = netdev_priv(dev);
+
+	if (f->binder_type != TCF_BLOCK_BINDER_TYPE_CLSACT_INGRESS)
+		return -EOPNOTSUPP;
+
+	switch (f->command) {
+	case TC_BLOCK_BIND:
+		return tcf_block_cb_register(f->block, nsim_setup_tc_block_cb,
+					     ns, ns);
+	case TC_BLOCK_UNBIND:
+		tcf_block_cb_unregister(f->block, nsim_setup_tc_block_cb, ns);
+		return 0;
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static int nsim_set_vf_mac(struct net_device *dev, int vf, u8 *mac)
+{
+	struct netdevsim *ns = netdev_priv(dev);
+
+	/* Only refuse multicast addresses, zero address can mean unset/any. */
+	if (vf >= ns->num_vfs || is_multicast_ether_addr(mac))
+		return -EINVAL;
+	memcpy(ns->vfconfigs[vf].vf_mac, mac, ETH_ALEN);
+
+	return 0;
+}
+
+static int nsim_set_vf_vlan(struct net_device *dev, int vf,
+			    u16 vlan, u8 qos, __be16 vlan_proto)
+{
+	struct netdevsim *ns = netdev_priv(dev);
+
+	if (vf >= ns->num_vfs || vlan > 4095 || qos > 7)
+		return -EINVAL;
+
+	ns->vfconfigs[vf].vlan = vlan;
+	ns->vfconfigs[vf].qos = qos;
+	ns->vfconfigs[vf].vlan_proto = vlan_proto;
+
+	return 0;
+}
+
+static int nsim_set_vf_rate(struct net_device *dev, int vf, int min, int max)
+{
+	struct netdevsim *ns = netdev_priv(dev);
+
+	if (vf >= ns->num_vfs)
+		return -EINVAL;
+
+	ns->vfconfigs[vf].min_tx_rate = min;
+	ns->vfconfigs[vf].max_tx_rate = max;
+
+	return 0;
+}
+
+static int nsim_set_vf_spoofchk(struct net_device *dev, int vf, bool val)
+{
+	struct netdevsim *ns = netdev_priv(dev);
+
+	if (vf >= ns->num_vfs)
+		return -EINVAL;
+	ns->vfconfigs[vf].spoofchk_enabled = val;
+
+	return 0;
+}
+
+static int nsim_set_vf_rss_query_en(struct net_device *dev, int vf, bool val)
+{
+	struct netdevsim *ns = netdev_priv(dev);
+
+	if (vf >= ns->num_vfs)
+		return -EINVAL;
+	ns->vfconfigs[vf].rss_query_enabled = val;
+
+	return 0;
+}
+
+static int nsim_set_vf_trust(struct net_device *dev, int vf, bool val)
+{
+	struct netdevsim *ns = netdev_priv(dev);
+
+	if (vf >= ns->num_vfs)
+		return -EINVAL;
+	ns->vfconfigs[vf].trusted = val;
+
+	return 0;
+}
+
+static int
+nsim_get_vf_config(struct net_device *dev, int vf, struct ifla_vf_info *ivi)
+{
+	struct netdevsim *ns = netdev_priv(dev);
+
+	if (vf >= ns->num_vfs)
+		return -EINVAL;
+
+	ivi->vf = vf;
+	ivi->linkstate = ns->vfconfigs[vf].link_state;
+	ivi->min_tx_rate = ns->vfconfigs[vf].min_tx_rate;
+	ivi->max_tx_rate = ns->vfconfigs[vf].max_tx_rate;
+	ivi->vlan = ns->vfconfigs[vf].vlan;
+	ivi->vlan_proto = ns->vfconfigs[vf].vlan_proto;
+	ivi->qos = ns->vfconfigs[vf].qos;
+	memcpy(&ivi->mac, ns->vfconfigs[vf].vf_mac, ETH_ALEN);
+	ivi->spoofchk = ns->vfconfigs[vf].spoofchk_enabled;
+	ivi->trusted = ns->vfconfigs[vf].trusted;
+	ivi->rss_query_en = ns->vfconfigs[vf].rss_query_enabled;
+
+	return 0;
+}
+
+static int nsim_set_vf_link_state(struct net_device *dev, int vf, int state)
+{
+	struct netdevsim *ns = netdev_priv(dev);
+
+	if (vf >= ns->num_vfs)
+		return -EINVAL;
+
+	switch (state) {
+	case IFLA_VF_LINK_STATE_AUTO:
+	case IFLA_VF_LINK_STATE_ENABLE:
+	case IFLA_VF_LINK_STATE_DISABLE:
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	ns->vfconfigs[vf].link_state = state;
+
+	return 0;
+}
+
+static int
+nsim_setup_tc(struct net_device *dev, enum tc_setup_type type, void *type_data)
+{
+	switch (type) {
+	case TC_SETUP_BLOCK:
+		return nsim_setup_tc_block(dev, type_data);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static int
+nsim_set_features(struct net_device *dev, netdev_features_t features)
+{
+	struct netdevsim *ns = netdev_priv(dev);
+
+	if ((dev->features & NETIF_F_HW_TC) > (features & NETIF_F_HW_TC))
+		return nsim_bpf_disable_tc(ns);
+
+	return 0;
+}
+
+static const struct net_device_ops nsim_netdev_ops = {
+	.ndo_init		= nsim_init,
+	.ndo_uninit		= nsim_uninit,
+	.ndo_start_xmit		= nsim_start_xmit,
+	.ndo_set_rx_mode	= nsim_set_rx_mode,
+	.ndo_set_mac_address	= eth_mac_addr,
+	.ndo_validate_addr	= eth_validate_addr,
+	.ndo_change_mtu		= nsim_change_mtu,
+	.ndo_get_stats64	= nsim_get_stats64,
+	.ndo_set_vf_mac		= nsim_set_vf_mac,
+	.ndo_set_vf_vlan	= nsim_set_vf_vlan,
+	.ndo_set_vf_rate	= nsim_set_vf_rate,
+	.ndo_set_vf_spoofchk	= nsim_set_vf_spoofchk,
+	.ndo_set_vf_trust	= nsim_set_vf_trust,
+	.ndo_get_vf_config	= nsim_get_vf_config,
+	.ndo_set_vf_link_state	= nsim_set_vf_link_state,
+	.ndo_set_vf_rss_query_en = nsim_set_vf_rss_query_en,
+	.ndo_setup_tc		= nsim_setup_tc,
+	.ndo_set_features	= nsim_set_features,
+	.ndo_bpf		= nsim_bpf,
+};
+
+static void nsim_setup(struct net_device *dev)
+{
+	ether_setup(dev);
+	eth_hw_addr_random(dev);
+
+	dev->netdev_ops = &nsim_netdev_ops;
+	dev->priv_destructor = nsim_free;
+
+	dev->tx_queue_len = 0;
+	dev->flags |= IFF_NOARP;
+	dev->flags &= ~IFF_MULTICAST;
+	dev->priv_flags |= IFF_LIVE_ADDR_CHANGE |
+			   IFF_NO_QUEUE;
+	dev->features |= NETIF_F_HIGHDMA |
+			 NETIF_F_SG |
+			 NETIF_F_FRAGLIST |
+			 NETIF_F_HW_CSUM |
+			 NETIF_F_TSO;
+	dev->hw_features |= NETIF_F_HW_TC;
+	dev->max_mtu = ETH_MAX_MTU;
+}
+
+static int nsim_validate(struct nlattr *tb[], struct nlattr *data[],
+			 struct netlink_ext_ack *extack)
+{
+	if (tb[IFLA_ADDRESS]) {
+		if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
+			return -EINVAL;
+		if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
+			return -EADDRNOTAVAIL;
+	}
+	return 0;
+}
+
+static struct rtnl_link_ops nsim_link_ops __read_mostly = {
+	.kind		= DRV_NAME,
+	.priv_size	= sizeof(struct netdevsim),
+	.setup		= nsim_setup,
+	.validate	= nsim_validate,
+};
+
+struct dentry *nsim_ddir;
+
+static int __init nsim_module_init(void)
+{
+	int err;
+
+	nsim_ddir = debugfs_create_dir(DRV_NAME, NULL);
+	if (IS_ERR(nsim_ddir))
+		return PTR_ERR(nsim_ddir);
+
+	err = bus_register(&nsim_bus);
+	if (err)
+		goto err_debugfs_destroy;
+
+	err = rtnl_link_register(&nsim_link_ops);
+	if (err)
+		goto err_unreg_bus;
+
+	return 0;
+
+err_unreg_bus:
+	bus_unregister(&nsim_bus);
+err_debugfs_destroy:
+	debugfs_remove_recursive(nsim_ddir);
+	return err;
+}
+
+static void __exit nsim_module_exit(void)
+{
+	rtnl_link_unregister(&nsim_link_ops);
+	bus_unregister(&nsim_bus);
+	debugfs_remove_recursive(nsim_ddir);
+}
+
+module_init(nsim_module_init);
+module_exit(nsim_module_exit);
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_RTNL_LINK(DRV_NAME);