linux-stable/net/bpf/test_run.c
David Miller 586f852597 bpf: Align packet data properly in program testing framework.
Make sure we apply NET_IP_ALIGN when reserving headroom for SKB
and XDP test runs, just like a real driver would.

Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
2017-05-02 11:46:28 -04:00

173 lines
4.3 KiB
C

/* Copyright (c) 2017 Facebook
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of version 2 of the GNU General Public
* License as published by the Free Software Foundation.
*/
#include <linux/bpf.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/etherdevice.h>
#include <linux/filter.h>
#include <linux/sched/signal.h>
static __always_inline u32 bpf_test_run_one(struct bpf_prog *prog, void *ctx)
{
u32 ret;
preempt_disable();
rcu_read_lock();
ret = BPF_PROG_RUN(prog, ctx);
rcu_read_unlock();
preempt_enable();
return ret;
}
static u32 bpf_test_run(struct bpf_prog *prog, void *ctx, u32 repeat, u32 *time)
{
u64 time_start, time_spent = 0;
u32 ret = 0, i;
if (!repeat)
repeat = 1;
time_start = ktime_get_ns();
for (i = 0; i < repeat; i++) {
ret = bpf_test_run_one(prog, ctx);
if (need_resched()) {
if (signal_pending(current))
break;
time_spent += ktime_get_ns() - time_start;
cond_resched();
time_start = ktime_get_ns();
}
}
time_spent += ktime_get_ns() - time_start;
do_div(time_spent, repeat);
*time = time_spent > U32_MAX ? U32_MAX : (u32)time_spent;
return ret;
}
static int bpf_test_finish(const union bpf_attr *kattr,
union bpf_attr __user *uattr, const void *data,
u32 size, u32 retval, u32 duration)
{
void __user *data_out = u64_to_user_ptr(kattr->test.data_out);
int err = -EFAULT;
if (data_out && copy_to_user(data_out, data, size))
goto out;
if (copy_to_user(&uattr->test.data_size_out, &size, sizeof(size)))
goto out;
if (copy_to_user(&uattr->test.retval, &retval, sizeof(retval)))
goto out;
if (copy_to_user(&uattr->test.duration, &duration, sizeof(duration)))
goto out;
err = 0;
out:
return err;
}
static void *bpf_test_init(const union bpf_attr *kattr, u32 size,
u32 headroom, u32 tailroom)
{
void __user *data_in = u64_to_user_ptr(kattr->test.data_in);
void *data;
if (size < ETH_HLEN || size > PAGE_SIZE - headroom - tailroom)
return ERR_PTR(-EINVAL);
data = kzalloc(size + headroom + tailroom, GFP_USER);
if (!data)
return ERR_PTR(-ENOMEM);
if (copy_from_user(data + headroom, data_in, size)) {
kfree(data);
return ERR_PTR(-EFAULT);
}
return data;
}
int bpf_prog_test_run_skb(struct bpf_prog *prog, const union bpf_attr *kattr,
union bpf_attr __user *uattr)
{
bool is_l2 = false, is_direct_pkt_access = false;
u32 size = kattr->test.data_size_in;
u32 repeat = kattr->test.repeat;
u32 retval, duration;
struct sk_buff *skb;
void *data;
int ret;
data = bpf_test_init(kattr, size, NET_SKB_PAD + NET_IP_ALIGN,
SKB_DATA_ALIGN(sizeof(struct skb_shared_info)));
if (IS_ERR(data))
return PTR_ERR(data);
switch (prog->type) {
case BPF_PROG_TYPE_SCHED_CLS:
case BPF_PROG_TYPE_SCHED_ACT:
is_l2 = true;
/* fall through */
case BPF_PROG_TYPE_LWT_IN:
case BPF_PROG_TYPE_LWT_OUT:
case BPF_PROG_TYPE_LWT_XMIT:
is_direct_pkt_access = true;
break;
default:
break;
}
skb = build_skb(data, 0);
if (!skb) {
kfree(data);
return -ENOMEM;
}
skb_reserve(skb, NET_SKB_PAD + NET_IP_ALIGN);
__skb_put(skb, size);
skb->protocol = eth_type_trans(skb, current->nsproxy->net_ns->loopback_dev);
skb_reset_network_header(skb);
if (is_l2)
__skb_push(skb, ETH_HLEN);
if (is_direct_pkt_access)
bpf_compute_data_end(skb);
retval = bpf_test_run(prog, skb, repeat, &duration);
if (!is_l2)
__skb_push(skb, ETH_HLEN);
size = skb->len;
/* bpf program can never convert linear skb to non-linear */
if (WARN_ON_ONCE(skb_is_nonlinear(skb)))
size = skb_headlen(skb);
ret = bpf_test_finish(kattr, uattr, skb->data, size, retval, duration);
kfree_skb(skb);
return ret;
}
int bpf_prog_test_run_xdp(struct bpf_prog *prog, const union bpf_attr *kattr,
union bpf_attr __user *uattr)
{
u32 size = kattr->test.data_size_in;
u32 repeat = kattr->test.repeat;
struct xdp_buff xdp = {};
u32 retval, duration;
void *data;
int ret;
data = bpf_test_init(kattr, size, XDP_PACKET_HEADROOM + NET_IP_ALIGN, 0);
if (IS_ERR(data))
return PTR_ERR(data);
xdp.data_hard_start = data;
xdp.data = data + XDP_PACKET_HEADROOM + NET_IP_ALIGN;
xdp.data_end = xdp.data + size;
retval = bpf_test_run(prog, &xdp, repeat, &duration);
if (xdp.data != data + XDP_PACKET_HEADROOM + NET_IP_ALIGN)
size = xdp.data_end - xdp.data;
ret = bpf_test_finish(kattr, uattr, xdp.data, size, retval, duration);
kfree(data);
return ret;
}