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                                             struct bpf_cgroup_storage *storage)
  16 {
  17         u32 ret;
  18
  19         preempt_disable();
  20         rcu_read_lock();
  21         bpf_cgroup_storage_set(storage);
  22         ret = BPF_PROG_RUN(prog, ctx);
  23         rcu_read_unlock();
  24         preempt_enable();
  25
  26         return ret;
  27 }
  28
  29 static u32 bpf_test_run(struct bpf_prog *prog, void *ctx, u32 repeat, u32 *time)
  30 {
  31         struct bpf_cgroup_storage *storage = NULL;
  32         u64 time_start, time_spent = 0;
  33         u32 ret = 0, i;
  34
  35         storage = bpf_cgroup_storage_alloc(prog);
  36         if (IS_ERR(storage))
  37                 return PTR_ERR(storage);
  38
  39         if (!repeat)
  40                 repeat = 1;
  41         time_start = ktime_get_ns();
  42         for (i = 0; i < repeat; i++) {
  43                 ret = bpf_test_run_one(prog, ctx, storage);
  44                 if (need_resched()) {
  45                         if (signal_pending(current))
  46                                 break;
  47                         time_spent += ktime_get_ns() - time_start;
  48                         cond_resched();
  49                         time_start = ktime_get_ns();
  50                 }
  51         }
  52         time_spent += ktime_get_ns() - time_start;
  53         do_div(time_spent, repeat);
  54         *time = time_spent > U32_MAX ? U32_MAX : (u32)time_spent;
  55
  56         bpf_cgroup_storage_free(storage);
  57
  58         return ret;
  59 }
  60
  61 static int bpf_test_finish(const union bpf_attr *kattr,
  62                            union bpf_attr __user *uattr, const void *data,
  63                            u32 size, u32 retval, u32 duration)
  64 {
  65         void __user *data_out = u64_to_user_ptr(kattr->test.data_out);
  66         int err = -EFAULT;
  67
  68         if (data_out && copy_to_user(data_out, data, size))
  69                 goto out;
  70         if (copy_to_user(&uattr->test.data_size_out, &size, sizeof(size)))
  71                 goto out;
  72         if (copy_to_user(&uattr->test.retval, &retval, sizeof(retval)))
  73                 goto out;
  74         if (copy_to_user(&uattr->test.duration, &duration, sizeof(duration)))
  75                 goto out;
  76         err = 0;
  77 out:
  78         return err;
  79 }
  80
  81 static void *bpf_test_init(const union bpf_attr *kattr, u32 size,
  82                            u32 headroom, u32 tailroom)
  83 {
  84         void __user *data_in = u64_to_user_ptr(kattr->test.data_in);
  85         void *data;
  86
  87         if (size < ETH_HLEN || size > PAGE_SIZE - headroom - tailroom)
  88                 return ERR_PTR(-EINVAL);
  89
  90         size = SKB_DATA_ALIGN(size);
  91         data = kzalloc(size + headroom + tailroom, GFP_USER);
  92         if (!data)
  93                 return ERR_PTR(-ENOMEM);
  94
  95         if (copy_from_user(data + headroom, data_in, size)) {
  96                 kfree(data);
  97                 return ERR_PTR(-EFAULT);
  98         }
  99         return data;
 100 }
 101
 102 int bpf_prog_test_run_skb(struct bpf_prog *prog, const union bpf_attr *kattr,
 103                           union bpf_attr __user *uattr)
 104 {
 105         bool is_l2 = false, is_direct_pkt_access = false;
 106         u32 size = kattr->test.data_size_in;
 107         u32 repeat = kattr->test.repeat;
 108         u32 retval, duration;
 109         int hh_len = ETH_HLEN;
 110         struct sk_buff *skb;
 111         void *data;
 112         int ret;
 113
 114         data = bpf_test_init(kattr, size, NET_SKB_PAD + NET_IP_ALIGN,
 115                              SKB_DATA_ALIGN(sizeof(struct skb_shared_info)));
 116         if (IS_ERR(data))
 117                 return PTR_ERR(data);
 118
 119         switch (prog->type) {
 120         case BPF_PROG_TYPE_SCHED_CLS:
 121         case BPF_PROG_TYPE_SCHED_ACT:
 122                 is_l2 = true;
 123                 /* fall through */
 124         case BPF_PROG_TYPE_LWT_IN:
 125         case BPF_PROG_TYPE_LWT_OUT:
 126         case BPF_PROG_TYPE_LWT_XMIT:
 127                 is_direct_pkt_access = true;
 128                 break;
 129         default:
 130                 break;
 131         }
 132
 133         skb = build_skb(data, 0);
 134         if (!skb) {
 135                 kfree(data);
 136                 return -ENOMEM;
 137         }
 138
 139         skb_reserve(skb, NET_SKB_PAD + NET_IP_ALIGN);
 140         __skb_put(skb, size);
 141         skb->protocol = eth_type_trans(skb, current->nsproxy->net_ns->loopback_dev);
 142         skb_reset_network_header(skb);
 143
 144         if (is_l2)
 145                 __skb_push(skb, hh_len);
 146         if (is_direct_pkt_access)
 147                 bpf_compute_data_pointers(skb);
 148         retval = bpf_test_run(prog, skb, repeat, &duration);
 149         if (!is_l2) {
 150                 if (skb_headroom(skb) < hh_len) {
 151                         int nhead = HH_DATA_ALIGN(hh_len - skb_headroom(skb));
 152
 153                         if (pskb_expand_head(skb, nhead, 0, GFP_USER)) {
 154                                 kfree_skb(skb);
 155                                 return -ENOMEM;
 156                         }
 157                 }
 158                 memset(__skb_push(skb, hh_len), 0, hh_len);
 159         }
 160
 161         size = skb->len;
 162         /* bpf program can never convert linear skb to non-linear */
 163         if (WARN_ON_ONCE(skb_is_nonlinear(skb)))
 164                 size = skb_headlen(skb);
 165         ret = bpf_test_finish(kattr, uattr, skb->data, size, retval, duration);
 166         kfree_skb(skb);
 167         return ret;
 168 }
 169
 170 int bpf_prog_test_run_xdp(struct bpf_prog *prog, const union bpf_attr *kattr,
 171                           union bpf_attr __user *uattr)
 172 {
 173         u32 size = kattr->test.data_size_in;
 174         u32 repeat = kattr->test.repeat;
 175         struct netdev_rx_queue *rxqueue;
 176         struct xdp_buff xdp = {};
 177         u32 retval, duration;
 178         void *data;
 179         int ret;
 180
 181         data = bpf_test_init(kattr, size, XDP_PACKET_HEADROOM + NET_IP_ALIGN, 0);
 182         if (IS_ERR(data))
 183                 return PTR_ERR(data);
 184
 185         xdp.data_hard_start = data;
 186         xdp.data = data + XDP_PACKET_HEADROOM + NET_IP_ALIGN;
 187         xdp.data_meta = xdp.data;
 188         xdp.data_end = xdp.data + size;
 189
 190         rxqueue = __netif_get_rx_queue(current->nsproxy->net_ns->loopback_dev, 0);
 191         xdp.rxq = &rxqueue->xdp_rxq;
 192
 193         retval = bpf_test_run(prog, &xdp, repeat, &duration);
 194         if (xdp.data != data + XDP_PACKET_HEADROOM + NET_IP_ALIGN ||
 195             xdp.data_end != xdp.data + size)
 196                 size = xdp.data_end - xdp.data;
 197         ret = bpf_test_finish(kattr, uattr, xdp.data, size, retval, duration);
 198         kfree(data);
 199         return ret;
 200 }