net/bpf/test_run.c

   1 /* Copyright (c) 2017 Facebook
   2  *
   3  * This program is free software; you can redistribute it and/or
   4  * modify it under the terms of version 2 of the GNU General Public
   5  * License as published by the Free Software Foundation.
   6  */
   7 #include <linux/bpf.h>
   8 #include <linux/slab.h>
   9 #include <linux/vmalloc.h>
  10 #include <linux/etherdevice.h>
  11 #include <linux/filter.h>
  12 #include <linux/sched/signal.h>
  13
  14 static __always_inline u32 bpf_test_run_one(struct bpf_prog *prog, void *ctx)
  15 {
  16         u32 ret;
  17
  18         preempt_disable();
  19         rcu_read_lock();
  20         ret = BPF_PROG_RUN(prog, ctx);
  21         rcu_read_unlock();
  22         preempt_enable();
  23
  24         return ret;
  25 }
  26
  27 static u32 bpf_test_run(struct bpf_prog *prog, void *ctx, u32 repeat, u32 *time)
  28 {
  29         u64 time_start, time_spent = 0;
  30         u32 ret = 0, i;
  31
  32         if (!repeat)
  33                 repeat = 1;
  34         time_start = ktime_get_ns();
  35         for (i = 0; i < repeat; i++) {
  36                 ret = bpf_test_run_one(prog, ctx);
  37                 if (need_resched()) {
  38                         if (signal_pending(current))
  39                                 break;
  40                         time_spent += ktime_get_ns() - time_start;
  41                         cond_resched();
  42                         time_start = ktime_get_ns();
  43                 }
  44         }
  45         time_spent += ktime_get_ns() - time_start;
  46         do_div(time_spent, repeat);
  47         *time = time_spent > U32_MAX ? U32_MAX : (u32)time_spent;
  48
  49         return ret;
  50 }
  51
  52 static int bpf_test_finish(const union bpf_attr *kattr,
  53                            union bpf_attr __user *uattr, const void *data,
  54                            u32 size, u32 retval, u32 duration)
  55 {
  56         void __user *data_out = u64_to_user_ptr(kattr->test.data_out);
  57         int err = -EFAULT;
  58
  59         if (data_out && copy_to_user(data_out, data, size))
  60                 goto out;
  61         if (copy_to_user(&uattr->test.data_size_out, &size, sizeof(size)))
  62                 goto out;
  63         if (copy_to_user(&uattr->test.retval, &retval, sizeof(retval)))
  64                 goto out;
  65         if (copy_to_user(&uattr->test.duration, &duration, sizeof(duration)))
  66                 goto out;
  67         err = 0;
  68 out:
  69         return err;
  70 }
  71
  72 static void *bpf_test_init(const union bpf_attr *kattr, u32 size,
  73                            u32 headroom, u32 tailroom)
  74 {
  75         void __user *data_in = u64_to_user_ptr(kattr->test.data_in);
  76         void *data;
  77
  78         if (size < ETH_HLEN || size > PAGE_SIZE - headroom - tailroom)
  79                 return ERR_PTR(-EINVAL);
  80
  81         data = kzalloc(size + headroom + tailroom, GFP_USER);
  82         if (!data)
  83                 return ERR_PTR(-ENOMEM);
  84
  85         if (copy_from_user(data + headroom, data_in, size)) {
  86                 kfree(data);
  87                 return ERR_PTR(-EFAULT);
  88         }
  89         return data;
  90 }
  91
  92 int bpf_prog_test_run_skb(struct bpf_prog *prog, const union bpf_attr *kattr,
  93                           union bpf_attr __user *uattr)
  94 {
  95         bool is_l2 = false, is_direct_pkt_access = false;
  96         u32 size = kattr->test.data_size_in;
  97         u32 repeat = kattr->test.repeat;
  98         u32 retval, duration;
  99         int hh_len = ETH_HLEN;
 100         struct sk_buff *skb;
 101         void *data;
 102         int ret;
 103
 104         data = bpf_test_init(kattr, size, NET_SKB_PAD + NET_IP_ALIGN,
 105                              SKB_DATA_ALIGN(sizeof(struct skb_shared_info)));
 106         if (IS_ERR(data))
 107                 return PTR_ERR(data);
 108
 109         switch (prog->type) {
 110         case BPF_PROG_TYPE_SCHED_CLS:
 111         case BPF_PROG_TYPE_SCHED_ACT:
 112                 is_l2 = true;
 113                 /* fall through */
 114         case BPF_PROG_TYPE_LWT_IN:
 115         case BPF_PROG_TYPE_LWT_OUT:
 116         case BPF_PROG_TYPE_LWT_XMIT:
 117                 is_direct_pkt_access = true;
 118                 break;
 119         default:
 120                 break;
 121         }
 122
 123         skb = build_skb(data, 0);
 124         if (!skb) {
 125                 kfree(data);
 126                 return -ENOMEM;
 127         }
 128
 129         skb_reserve(skb, NET_SKB_PAD + NET_IP_ALIGN);
 130         __skb_put(skb, size);
 131         skb->protocol = eth_type_trans(skb, current->nsproxy->net_ns->loopback_dev);
 132         skb_reset_network_header(skb);
 133
 134         if (is_l2)
 135                 __skb_push(skb, hh_len);
 136         if (is_direct_pkt_access)
 137                 bpf_compute_data_pointers(skb);
 138         retval = bpf_test_run(prog, skb, repeat, &duration);
 139         if (!is_l2) {
 140                 if (skb_headroom(skb) < hh_len) {
 141                         int nhead = HH_DATA_ALIGN(hh_len - skb_headroom(skb));
 142
 143                         if (pskb_expand_head(skb, nhead, 0, GFP_USER)) {
 144                                 kfree_skb(skb);
 145                                 return -ENOMEM;
 146                         }
 147                 }
 148                 memset(__skb_push(skb, hh_len), 0, hh_len);
 149         }
 150
 151         size = skb->len;
 152         /* bpf program can never convert linear skb to non-linear */
 153         if (WARN_ON_ONCE(skb_is_nonlinear(skb)))
 154                 size = skb_headlen(skb);
 155         ret = bpf_test_finish(kattr, uattr, skb->data, size, retval, duration);
 156         kfree_skb(skb);
 157         return ret;
 158 }
 159
 160 int bpf_prog_test_run_xdp(struct bpf_prog *prog, const union bpf_attr *kattr,
 161                           union bpf_attr __user *uattr)
 162 {
 163         u32 size = kattr->test.data_size_in;
 164         u32 repeat = kattr->test.repeat;
 165         struct netdev_rx_queue *rxqueue;
 166         struct xdp_buff xdp = {};
 167         u32 retval, duration;
 168         void *data;
 169         int ret;
 170
 171         data = bpf_test_init(kattr, size, XDP_PACKET_HEADROOM + NET_IP_ALIGN, 0);
 172         if (IS_ERR(data))
 173                 return PTR_ERR(data);
 174
 175         xdp.data_hard_start = data;
 176         xdp.data = data + XDP_PACKET_HEADROOM + NET_IP_ALIGN;
 177         xdp.data_meta = xdp.data;
 178         xdp.data_end = xdp.data + size;
 179
 180         rxqueue = __netif_get_rx_queue(current->nsproxy->net_ns->loopback_dev, 0);
 181         xdp.rxq = &rxqueue->xdp_rxq;
 182
 183         retval = bpf_test_run(prog, &xdp, repeat, &duration);
 184         if (xdp.data != data + XDP_PACKET_HEADROOM + NET_IP_ALIGN ||
 185             xdp.data_end != xdp.data + size)
 186                 size = xdp.data_end - xdp.data;
 187         ret = bpf_test_finish(kattr, uattr, xdp.data, size, retval, duration);
 188         kfree(data);
 189         return ret;
 190 }