OpenCloudOS-Kernel/drivers/net/netdevsim/bpf.c

643 lines
15 KiB
C

/*
* 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/mutex.h>
#include <linux/rtnetlink.h>
#include <net/pkt_cls.h>
#include "netdevsim.h"
#define pr_vlog(env, fmt, ...) \
bpf_verifier_log_write(env, "[netdevsim] " fmt, ##__VA_ARGS__)
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;
};
#define NSIM_BPF_MAX_KEYS 2
struct nsim_bpf_bound_map {
struct netdevsim *ns;
struct bpf_offloaded_map *map;
struct mutex mutex;
struct nsim_map_entry {
void *key;
void *value;
} entry[NSIM_BPF_MAX_KEYS];
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);
if (insn_idx == env->prog->len - 1)
pr_vlog(env, "Hello from netdevsim!\n");
return 0;
}
static const struct bpf_prog_offload_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;
struct bpf_prog *oldprog;
if (type != TC_SETUP_CLSBPF) {
NSIM_EA(cls_bpf->common.extack,
"only offload of BPF classifiers supported");
return -EOPNOTSUPP;
}
if (!tc_cls_can_offload_and_chain0(ns->netdev, &cls_bpf->common))
return -EOPNOTSUPP;
if (cls_bpf->common.protocol != htons(ETH_P_ALL)) {
NSIM_EA(cls_bpf->common.extack,
"only ETH_P_ALL supported as filter protocol");
return -EOPNOTSUPP;
}
if (!ns->bpf_tc_accept) {
NSIM_EA(cls_bpf->common.extack,
"netdevsim configured to reject BPF TC offload");
return -EOPNOTSUPP;
}
/* Note: progs without skip_sw will probably not be dev bound */
if (prog && !prog->aux->offload && !ns->bpf_tc_non_bound_accept) {
NSIM_EA(cls_bpf->common.extack,
"netdevsim configured to reject unbound programs");
return -EOPNOTSUPP;
}
if (cls_bpf->command != TC_CLSBPF_OFFLOAD)
return -EOPNOTSUPP;
oldprog = cls_bpf->oldprog;
/* Don't remove if oldprog doesn't match driver's state */
if (ns->bpf_offloaded != oldprog) {
oldprog = NULL;
if (!cls_bpf->prog)
return 0;
if (ns->bpf_offloaded) {
NSIM_EA(cls_bpf->common.extack,
"driver and netdev offload states mismatch");
return -EBUSY;
}
}
return nsim_bpf_offload(ns, cls_bpf->prog, oldprog);
}
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;
}
static int nsim_bpf_create_prog(struct netdevsim *ns, struct bpf_prog *prog)
{
struct nsim_bpf_bound_prog *state;
char name[16];
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_OR_NULL(state->ddir)) {
kfree(state);
return -ENOMEM;
}
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;
}
static 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;
}
static bool
nsim_map_key_match(struct bpf_map *map, struct nsim_map_entry *e, void *key)
{
return e->key && !memcmp(key, e->key, map->key_size);
}
static int nsim_map_key_find(struct bpf_offloaded_map *offmap, void *key)
{
struct nsim_bpf_bound_map *nmap = offmap->dev_priv;
unsigned int i;
for (i = 0; i < ARRAY_SIZE(nmap->entry); i++)
if (nsim_map_key_match(&offmap->map, &nmap->entry[i], key))
return i;
return -ENOENT;
}
static int
nsim_map_alloc_elem(struct bpf_offloaded_map *offmap, unsigned int idx)
{
struct nsim_bpf_bound_map *nmap = offmap->dev_priv;
nmap->entry[idx].key = kmalloc(offmap->map.key_size, GFP_USER);
if (!nmap->entry[idx].key)
return -ENOMEM;
nmap->entry[idx].value = kmalloc(offmap->map.value_size, GFP_USER);
if (!nmap->entry[idx].value) {
kfree(nmap->entry[idx].key);
nmap->entry[idx].key = NULL;
return -ENOMEM;
}
return 0;
}
static int
nsim_map_get_next_key(struct bpf_offloaded_map *offmap,
void *key, void *next_key)
{
struct nsim_bpf_bound_map *nmap = offmap->dev_priv;
int idx = -ENOENT;
mutex_lock(&nmap->mutex);
if (key)
idx = nsim_map_key_find(offmap, key);
if (idx == -ENOENT)
idx = 0;
else
idx++;
for (; idx < ARRAY_SIZE(nmap->entry); idx++) {
if (nmap->entry[idx].key) {
memcpy(next_key, nmap->entry[idx].key,
offmap->map.key_size);
break;
}
}
mutex_unlock(&nmap->mutex);
if (idx == ARRAY_SIZE(nmap->entry))
return -ENOENT;
return 0;
}
static int
nsim_map_lookup_elem(struct bpf_offloaded_map *offmap, void *key, void *value)
{
struct nsim_bpf_bound_map *nmap = offmap->dev_priv;
int idx;
mutex_lock(&nmap->mutex);
idx = nsim_map_key_find(offmap, key);
if (idx >= 0)
memcpy(value, nmap->entry[idx].value, offmap->map.value_size);
mutex_unlock(&nmap->mutex);
return idx < 0 ? idx : 0;
}
static int
nsim_map_update_elem(struct bpf_offloaded_map *offmap,
void *key, void *value, u64 flags)
{
struct nsim_bpf_bound_map *nmap = offmap->dev_priv;
int idx, err = 0;
mutex_lock(&nmap->mutex);
idx = nsim_map_key_find(offmap, key);
if (idx < 0 && flags == BPF_EXIST) {
err = idx;
goto exit_unlock;
}
if (idx >= 0 && flags == BPF_NOEXIST) {
err = -EEXIST;
goto exit_unlock;
}
if (idx < 0) {
for (idx = 0; idx < ARRAY_SIZE(nmap->entry); idx++)
if (!nmap->entry[idx].key)
break;
if (idx == ARRAY_SIZE(nmap->entry)) {
err = -E2BIG;
goto exit_unlock;
}
err = nsim_map_alloc_elem(offmap, idx);
if (err)
goto exit_unlock;
}
memcpy(nmap->entry[idx].key, key, offmap->map.key_size);
memcpy(nmap->entry[idx].value, value, offmap->map.value_size);
exit_unlock:
mutex_unlock(&nmap->mutex);
return err;
}
static int nsim_map_delete_elem(struct bpf_offloaded_map *offmap, void *key)
{
struct nsim_bpf_bound_map *nmap = offmap->dev_priv;
int idx;
if (offmap->map.map_type == BPF_MAP_TYPE_ARRAY)
return -EINVAL;
mutex_lock(&nmap->mutex);
idx = nsim_map_key_find(offmap, key);
if (idx >= 0) {
kfree(nmap->entry[idx].key);
kfree(nmap->entry[idx].value);
memset(&nmap->entry[idx], 0, sizeof(nmap->entry[idx]));
}
mutex_unlock(&nmap->mutex);
return idx < 0 ? idx : 0;
}
static const struct bpf_map_dev_ops nsim_bpf_map_ops = {
.map_get_next_key = nsim_map_get_next_key,
.map_lookup_elem = nsim_map_lookup_elem,
.map_update_elem = nsim_map_update_elem,
.map_delete_elem = nsim_map_delete_elem,
};
static int
nsim_bpf_map_alloc(struct netdevsim *ns, struct bpf_offloaded_map *offmap)
{
struct nsim_bpf_bound_map *nmap;
int i, err;
if (WARN_ON(offmap->map.map_type != BPF_MAP_TYPE_ARRAY &&
offmap->map.map_type != BPF_MAP_TYPE_HASH))
return -EINVAL;
if (offmap->map.max_entries > NSIM_BPF_MAX_KEYS)
return -ENOMEM;
if (offmap->map.map_flags)
return -EINVAL;
nmap = kzalloc(sizeof(*nmap), GFP_USER);
if (!nmap)
return -ENOMEM;
offmap->dev_priv = nmap;
nmap->ns = ns;
nmap->map = offmap;
mutex_init(&nmap->mutex);
if (offmap->map.map_type == BPF_MAP_TYPE_ARRAY) {
for (i = 0; i < ARRAY_SIZE(nmap->entry); i++) {
u32 *key;
err = nsim_map_alloc_elem(offmap, i);
if (err)
goto err_free;
key = nmap->entry[i].key;
*key = i;
}
}
offmap->dev_ops = &nsim_bpf_map_ops;
list_add_tail(&nmap->l, &ns->bpf_bound_maps);
return 0;
err_free:
while (--i >= 0) {
kfree(nmap->entry[i].key);
kfree(nmap->entry[i].value);
}
kfree(nmap);
return err;
}
static void nsim_bpf_map_free(struct bpf_offloaded_map *offmap)
{
struct nsim_bpf_bound_map *nmap = offmap->dev_priv;
unsigned int i;
for (i = 0; i < ARRAY_SIZE(nmap->entry); i++) {
kfree(nmap->entry[i].key);
kfree(nmap->entry[i].value);
}
list_del_init(&nmap->l);
mutex_destroy(&nmap->mutex);
kfree(nmap);
}
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);
case BPF_OFFLOAD_MAP_ALLOC:
if (!ns->bpf_map_accept)
return -EOPNOTSUPP;
return nsim_bpf_map_alloc(ns, bpf->offmap);
case BPF_OFFLOAD_MAP_FREE:
nsim_bpf_map_free(bpf->offmap);
return 0;
default:
return -EINVAL;
}
}
int nsim_bpf_init(struct netdevsim *ns)
{
INIT_LIST_HEAD(&ns->bpf_bound_progs);
INIT_LIST_HEAD(&ns->bpf_bound_maps);
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);
if (IS_ERR_OR_NULL(ns->ddir_bpf_bound_progs))
return -ENOMEM;
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);
ns->bpf_map_accept = true;
debugfs_create_bool("bpf_map_accept", 0600, ns->ddir,
&ns->bpf_map_accept);
return 0;
}
void nsim_bpf_uninit(struct netdevsim *ns)
{
WARN_ON(!list_empty(&ns->bpf_bound_progs));
WARN_ON(!list_empty(&ns->bpf_bound_maps));
WARN_ON(ns->xdp_prog);
WARN_ON(ns->bpf_offloaded);
}