netdevsim: add bpf offload support

Add support for loading programs for netdevsim devices and
expose the related information via DebugFS.  Both offload
of XDP and cls_bpf programs is supported.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
This commit is contained in:
Jakub Kicinski 2017-12-01 15:08:59 -08:00 коммит произвёл Daniel Borkmann
Родитель 83c9e13aa3
Коммит 31d3ad8329
4 изменённых файлов: 529 добавлений и 1 удалений

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@ -4,3 +4,4 @@ obj-$(CONFIG_NETDEVSIM) += netdevsim.o
netdevsim-objs := \
netdev.o \
bpf.o \

373
drivers/net/netdevsim/bpf.c Normal file
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@ -0,0 +1,373 @@
/*
* 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/bpf.h>
#include <linux/bpf_verifier.h>
#include <linux/debugfs.h>
#include <linux/kernel.h>
#include <linux/rtnetlink.h>
#include <net/pkt_cls.h>
#include "netdevsim.h"
struct nsim_bpf_bound_prog {
struct netdevsim *ns;
struct bpf_prog *prog;
struct dentry *ddir;
const char *state;
bool is_loaded;
struct list_head l;
};
static int nsim_debugfs_bpf_string_read(struct seq_file *file, void *data)
{
const char **str = file->private;
if (*str)
seq_printf(file, "%s\n", *str);
return 0;
}
static int nsim_debugfs_bpf_string_open(struct inode *inode, struct file *f)
{
return single_open(f, nsim_debugfs_bpf_string_read, inode->i_private);
}
static const struct file_operations nsim_bpf_string_fops = {
.owner = THIS_MODULE,
.open = nsim_debugfs_bpf_string_open,
.release = single_release,
.read = seq_read,
.llseek = seq_lseek
};
static int
nsim_bpf_verify_insn(struct bpf_verifier_env *env, int insn_idx, int prev_insn)
{
struct nsim_bpf_bound_prog *state;
state = env->prog->aux->offload->dev_priv;
if (state->ns->bpf_bind_verifier_delay && !insn_idx)
msleep(state->ns->bpf_bind_verifier_delay);
return 0;
}
static const struct bpf_ext_analyzer_ops nsim_bpf_analyzer_ops = {
.insn_hook = nsim_bpf_verify_insn,
};
static bool nsim_xdp_offload_active(struct netdevsim *ns)
{
return ns->xdp_prog_mode == XDP_ATTACHED_HW;
}
static void nsim_prog_set_loaded(struct bpf_prog *prog, bool loaded)
{
struct nsim_bpf_bound_prog *state;
if (!prog || !prog->aux->offload)
return;
state = prog->aux->offload->dev_priv;
state->is_loaded = loaded;
}
static int
nsim_bpf_offload(struct netdevsim *ns, struct bpf_prog *prog, bool oldprog)
{
nsim_prog_set_loaded(ns->bpf_offloaded, false);
WARN(!!ns->bpf_offloaded != oldprog,
"bad offload state, expected offload %sto be active",
oldprog ? "" : "not ");
ns->bpf_offloaded = prog;
ns->bpf_offloaded_id = prog ? prog->aux->id : 0;
nsim_prog_set_loaded(prog, true);
return 0;
}
int nsim_bpf_setup_tc_block_cb(enum tc_setup_type type,
void *type_data, void *cb_priv)
{
struct tc_cls_bpf_offload *cls_bpf = type_data;
struct bpf_prog *prog = cls_bpf->prog;
struct netdevsim *ns = cb_priv;
bool skip_sw;
if (type != TC_SETUP_CLSBPF ||
!tc_can_offload(ns->netdev) ||
cls_bpf->common.protocol != htons(ETH_P_ALL) ||
cls_bpf->common.chain_index)
return -EOPNOTSUPP;
skip_sw = cls_bpf->gen_flags & TCA_CLS_FLAGS_SKIP_SW;
if (nsim_xdp_offload_active(ns))
return -EBUSY;
if (!ns->bpf_tc_accept)
return -EOPNOTSUPP;
/* Note: progs without skip_sw will probably not be dev bound */
if (prog && !prog->aux->offload && !ns->bpf_tc_non_bound_accept)
return -EOPNOTSUPP;
switch (cls_bpf->command) {
case TC_CLSBPF_REPLACE:
return nsim_bpf_offload(ns, prog, true);
case TC_CLSBPF_ADD:
return nsim_bpf_offload(ns, prog, false);
case TC_CLSBPF_DESTROY:
return nsim_bpf_offload(ns, NULL, true);
default:
return -EOPNOTSUPP;
}
}
int nsim_bpf_disable_tc(struct netdevsim *ns)
{
if (ns->bpf_offloaded && !nsim_xdp_offload_active(ns))
return -EBUSY;
return 0;
}
static int nsim_xdp_offload_prog(struct netdevsim *ns, struct netdev_bpf *bpf)
{
if (!nsim_xdp_offload_active(ns) && !bpf->prog)
return 0;
if (!nsim_xdp_offload_active(ns) && bpf->prog && ns->bpf_offloaded) {
NSIM_EA(bpf->extack, "TC program is already loaded");
return -EBUSY;
}
return nsim_bpf_offload(ns, bpf->prog, nsim_xdp_offload_active(ns));
}
static int nsim_xdp_set_prog(struct netdevsim *ns, struct netdev_bpf *bpf)
{
int err;
if (ns->xdp_prog && (bpf->flags ^ ns->xdp_flags) & XDP_FLAGS_MODES) {
NSIM_EA(bpf->extack, "program loaded with different flags");
return -EBUSY;
}
if (bpf->command == XDP_SETUP_PROG && !ns->bpf_xdpdrv_accept) {
NSIM_EA(bpf->extack, "driver XDP disabled in DebugFS");
return -EOPNOTSUPP;
}
if (bpf->command == XDP_SETUP_PROG_HW && !ns->bpf_xdpoffload_accept) {
NSIM_EA(bpf->extack, "XDP offload disabled in DebugFS");
return -EOPNOTSUPP;
}
if (bpf->command == XDP_SETUP_PROG_HW) {
err = nsim_xdp_offload_prog(ns, bpf);
if (err)
return err;
}
if (ns->xdp_prog)
bpf_prog_put(ns->xdp_prog);
ns->xdp_prog = bpf->prog;
ns->xdp_flags = bpf->flags;
if (!bpf->prog)
ns->xdp_prog_mode = XDP_ATTACHED_NONE;
else if (bpf->command == XDP_SETUP_PROG)
ns->xdp_prog_mode = XDP_ATTACHED_DRV;
else
ns->xdp_prog_mode = XDP_ATTACHED_HW;
return 0;
}
int nsim_bpf_create_prog(struct netdevsim *ns, struct bpf_prog *prog)
{
struct nsim_bpf_bound_prog *state;
char name[16];
int err;
state = kzalloc(sizeof(*state), GFP_KERNEL);
if (!state)
return -ENOMEM;
state->ns = ns;
state->prog = prog;
state->state = "verify";
/* Program id is not populated yet when we create the state. */
sprintf(name, "%u", ns->prog_id_gen++);
state->ddir = debugfs_create_dir(name, ns->ddir_bpf_bound_progs);
if (IS_ERR(state->ddir)) {
err = PTR_ERR(state->ddir);
kfree(state);
return err;
}
debugfs_create_u32("id", 0400, state->ddir, &prog->aux->id);
debugfs_create_file("state", 0400, state->ddir,
&state->state, &nsim_bpf_string_fops);
debugfs_create_bool("loaded", 0400, state->ddir, &state->is_loaded);
list_add_tail(&state->l, &ns->bpf_bound_progs);
prog->aux->offload->dev_priv = state;
return 0;
}
void nsim_bpf_destroy_prog(struct bpf_prog *prog)
{
struct nsim_bpf_bound_prog *state;
state = prog->aux->offload->dev_priv;
WARN(state->is_loaded,
"offload state destroyed while program still bound");
debugfs_remove_recursive(state->ddir);
list_del(&state->l);
kfree(state);
}
static int nsim_setup_prog_checks(struct netdevsim *ns, struct netdev_bpf *bpf)
{
if (bpf->prog && bpf->prog->aux->offload) {
NSIM_EA(bpf->extack, "attempt to load offloaded prog to drv");
return -EINVAL;
}
if (ns->netdev->mtu > NSIM_XDP_MAX_MTU) {
NSIM_EA(bpf->extack, "MTU too large w/ XDP enabled");
return -EINVAL;
}
if (nsim_xdp_offload_active(ns)) {
NSIM_EA(bpf->extack, "xdp offload active, can't load drv prog");
return -EBUSY;
}
return 0;
}
static int
nsim_setup_prog_hw_checks(struct netdevsim *ns, struct netdev_bpf *bpf)
{
struct nsim_bpf_bound_prog *state;
if (!bpf->prog)
return 0;
if (!bpf->prog->aux->offload) {
NSIM_EA(bpf->extack, "xdpoffload of non-bound program");
return -EINVAL;
}
if (bpf->prog->aux->offload->netdev != ns->netdev) {
NSIM_EA(bpf->extack, "program bound to different dev");
return -EINVAL;
}
state = bpf->prog->aux->offload->dev_priv;
if (WARN_ON(strcmp(state->state, "xlated"))) {
NSIM_EA(bpf->extack, "offloading program in bad state");
return -EINVAL;
}
return 0;
}
int nsim_bpf(struct net_device *dev, struct netdev_bpf *bpf)
{
struct netdevsim *ns = netdev_priv(dev);
struct nsim_bpf_bound_prog *state;
int err;
ASSERT_RTNL();
switch (bpf->command) {
case BPF_OFFLOAD_VERIFIER_PREP:
if (!ns->bpf_bind_accept)
return -EOPNOTSUPP;
err = nsim_bpf_create_prog(ns, bpf->verifier.prog);
if (err)
return err;
bpf->verifier.ops = &nsim_bpf_analyzer_ops;
return 0;
case BPF_OFFLOAD_TRANSLATE:
state = bpf->offload.prog->aux->offload->dev_priv;
state->state = "xlated";
return 0;
case BPF_OFFLOAD_DESTROY:
nsim_bpf_destroy_prog(bpf->offload.prog);
return 0;
case XDP_QUERY_PROG:
bpf->prog_attached = ns->xdp_prog_mode;
bpf->prog_id = ns->xdp_prog ? ns->xdp_prog->aux->id : 0;
bpf->prog_flags = ns->xdp_prog ? ns->xdp_flags : 0;
return 0;
case XDP_SETUP_PROG:
err = nsim_setup_prog_checks(ns, bpf);
if (err)
return err;
return nsim_xdp_set_prog(ns, bpf);
case XDP_SETUP_PROG_HW:
err = nsim_setup_prog_hw_checks(ns, bpf);
if (err)
return err;
return nsim_xdp_set_prog(ns, bpf);
default:
return -EINVAL;
}
}
int nsim_bpf_init(struct netdevsim *ns)
{
INIT_LIST_HEAD(&ns->bpf_bound_progs);
debugfs_create_u32("bpf_offloaded_id", 0400, ns->ddir,
&ns->bpf_offloaded_id);
ns->bpf_bind_accept = true;
debugfs_create_bool("bpf_bind_accept", 0600, ns->ddir,
&ns->bpf_bind_accept);
debugfs_create_u32("bpf_bind_verifier_delay", 0600, ns->ddir,
&ns->bpf_bind_verifier_delay);
ns->ddir_bpf_bound_progs =
debugfs_create_dir("bpf_bound_progs", ns->ddir);
ns->bpf_tc_accept = true;
debugfs_create_bool("bpf_tc_accept", 0600, ns->ddir,
&ns->bpf_tc_accept);
debugfs_create_bool("bpf_tc_non_bound_accept", 0600, ns->ddir,
&ns->bpf_tc_non_bound_accept);
ns->bpf_xdpdrv_accept = true;
debugfs_create_bool("bpf_xdpdrv_accept", 0600, ns->ddir,
&ns->bpf_xdpdrv_accept);
ns->bpf_xdpoffload_accept = true;
debugfs_create_bool("bpf_xdpoffload_accept", 0600, ns->ddir,
&ns->bpf_xdpoffload_accept);
return 0;
}
void nsim_bpf_uninit(struct netdevsim *ns)
{
WARN_ON(!list_empty(&ns->bpf_bound_progs));
WARN_ON(ns->xdp_prog);
WARN_ON(ns->bpf_offloaded);
}

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@ -13,16 +13,45 @@
* 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"
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;
return 0;
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 netdev_tx_t nsim_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
struct netdevsim *ns = netdev_priv(dev);
@ -41,6 +70,19 @@ 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)
{
@ -54,12 +96,66 @@ nsim_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats)
} 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_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_setup_tc = nsim_setup_tc,
.ndo_set_features = nsim_set_features,
.ndo_bpf = nsim_bpf,
};
static void nsim_setup(struct net_device *dev)
@ -80,6 +176,7 @@ static void nsim_setup(struct net_device *dev)
NETIF_F_FRAGLIST |
NETIF_F_HW_CSUM |
NETIF_F_TSO;
dev->hw_features |= NETIF_F_HW_TC;
dev->max_mtu = ETH_MAX_MTU;
}
@ -102,14 +199,31 @@ static struct rtnl_link_ops nsim_link_ops __read_mostly = {
.validate = nsim_validate,
};
struct dentry *nsim_ddir;
static int __init nsim_module_init(void)
{
return rtnl_link_register(&nsim_link_ops);
int err;
nsim_ddir = debugfs_create_dir(DRV_NAME, NULL);
if (IS_ERR(nsim_ddir))
return PTR_ERR(nsim_ddir);
err = rtnl_link_register(&nsim_link_ops);
if (err)
goto err_debugfs_destroy;
return 0;
err_debugfs_destroy:
debugfs_remove_recursive(nsim_ddir);
return err;
}
static void __exit nsim_module_exit(void)
{
rtnl_link_unregister(&nsim_link_ops);
debugfs_remove_recursive(nsim_ddir);
}
module_init(nsim_module_init);

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@ -14,13 +14,53 @@
*/
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/netdevice.h>
#include <linux/u64_stats_sync.h>
#define DRV_NAME "netdevsim"
#define NSIM_XDP_MAX_MTU 4000
#define NSIM_EA(extack, msg) NL_SET_ERR_MSG_MOD((extack), msg)
struct bpf_prog;
struct dentry;
struct netdevsim {
struct net_device *netdev;
u64 tx_packets;
u64 tx_bytes;
struct u64_stats_sync syncp;
struct dentry *ddir;
struct bpf_prog *bpf_offloaded;
u32 bpf_offloaded_id;
u32 xdp_flags;
int xdp_prog_mode;
struct bpf_prog *xdp_prog;
u32 prog_id_gen;
bool bpf_bind_accept;
u32 bpf_bind_verifier_delay;
struct dentry *ddir_bpf_bound_progs;
struct list_head bpf_bound_progs;
bool bpf_tc_accept;
bool bpf_tc_non_bound_accept;
bool bpf_xdpdrv_accept;
bool bpf_xdpoffload_accept;
};
extern struct dentry *nsim_ddir;
int nsim_bpf_init(struct netdevsim *ns);
void nsim_bpf_uninit(struct netdevsim *ns);
int nsim_bpf(struct net_device *dev, struct netdev_bpf *bpf);
int nsim_bpf_disable_tc(struct netdevsim *ns);
int nsim_bpf_setup_tc_block_cb(enum tc_setup_type type,
void *type_data, void *cb_priv);