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 #include <net/sock.h>
  14 #include <net/tcp.h>
  15
  16 static __always_inline u32 bpf_test_run_one(struct bpf_prog *prog, void *ctx,
  17                 struct bpf_cgroup_storage *storage[MAX_BPF_CGROUP_STORAGE_TYPE])
  18 {
  19         u32 ret;
  20
  21         preempt_disable();
  22         rcu_read_lock();
  23         bpf_cgroup_storage_set(storage);
  24         ret = BPF_PROG_RUN(prog, ctx);
  25         rcu_read_unlock();
  26         preempt_enable();
  27
  28         return ret;
  29 }
  30
  31 static u32 bpf_test_run(struct bpf_prog *prog, void *ctx, u32 repeat, u32 *time)
  32 {
  33         struct bpf_cgroup_storage *storage[MAX_BPF_CGROUP_STORAGE_TYPE] = { 0 };
  34         enum bpf_cgroup_storage_type stype;
  35         u64 time_start, time_spent = 0;
  36         u32 ret = 0, i;
  37
  38         for_each_cgroup_storage_type(stype) {
  39                 storage[stype] = bpf_cgroup_storage_alloc(prog, stype);
  40                 if (IS_ERR(storage[stype])) {
  41                         storage[stype] = NULL;
  42                         for_each_cgroup_storage_type(stype)
  43                                 bpf_cgroup_storage_free(storage[stype]);
  44                         return -ENOMEM;
  45                 }
  46         }
  47
  48         if (!repeat)
  49                 repeat = 1;
  50         time_start = ktime_get_ns();
  51         for (i = 0; i < repeat; i++) {
  52                 ret = bpf_test_run_one(prog, ctx, storage);
  53                 if (need_resched()) {
  54                         if (signal_pending(current))
  55                                 break;
  56                         time_spent += ktime_get_ns() - time_start;
  57                         cond_resched();
  58                         time_start = ktime_get_ns();
  59                 }
  60         }
  61         time_spent += ktime_get_ns() - time_start;
  62         do_div(time_spent, repeat);
  63         *time = time_spent > U32_MAX ? U32_MAX : (u32)time_spent;
  64
  65         for_each_cgroup_storage_type(stype)
  66                 bpf_cgroup_storage_free(storage[stype]);
  67
  68         return ret;
  69 }
  70
  71 static int bpf_test_finish(const union bpf_attr *kattr,
  72                            union bpf_attr __user *uattr, const void *data,
  73                            u32 size, u32 retval, u32 duration)
  74 {
  75         void __user *data_out = u64_to_user_ptr(kattr->test.data_out);
  76         int err = -EFAULT;
  77         u32 copy_size = size;
  78
  79         /* Clamp copy if the user has provided a size hint, but copy the full
  80          * buffer if not to retain old behaviour.
  81          */
  82         if (kattr->test.data_size_out &&
  83             copy_size > kattr->test.data_size_out) {
  84                 copy_size = kattr->test.data_size_out;
  85                 err = -ENOSPC;
  86         }
  87
  88         if (data_out && copy_to_user(data_out, data, copy_size))
  89                 goto out;
  90         if (copy_to_user(&uattr->test.data_size_out, &size, sizeof(size)))
  91                 goto out;
  92         if (copy_to_user(&uattr->test.retval, &retval, sizeof(retval)))
  93                 goto out;
  94         if (copy_to_user(&uattr->test.duration, &duration, sizeof(duration)))
  95                 goto out;
  96         if (err != -ENOSPC)
  97                 err = 0;
  98 out:
  99         return err;
 100 }
 101
 102 static void *bpf_test_init(const union bpf_attr *kattr, u32 size,
 103                            u32 headroom, u32 tailroom)
 104 {
 105         void __user *data_in = u64_to_user_ptr(kattr->test.data_in);
 106         void *data;
 107
 108         if (size < ETH_HLEN || size > PAGE_SIZE - headroom - tailroom)
 109                 return ERR_PTR(-EINVAL);
 110
 111         data = kzalloc(size + headroom + tailroom, GFP_USER);
 112         if (!data)
 113                 return ERR_PTR(-ENOMEM);
 114
 115         if (copy_from_user(data + headroom, data_in, size)) {
 116                 kfree(data);
 117                 return ERR_PTR(-EFAULT);
 118         }
 119         return data;
 120 }
 121
 122 int bpf_prog_test_run_skb(struct bpf_prog *prog, const union bpf_attr *kattr,
 123                           union bpf_attr __user *uattr)
 124 {
 125         bool is_l2 = false, is_direct_pkt_access = false;
 126         u32 size = kattr->test.data_size_in;
 127         u32 repeat = kattr->test.repeat;
 128         u32 retval, duration;
 129         int hh_len = ETH_HLEN;
 130         struct sk_buff *skb;
 131         struct sock *sk;
 132         void *data;
 133         int ret;
 134
 135         data = bpf_test_init(kattr, size, NET_SKB_PAD + NET_IP_ALIGN,
 136                              SKB_DATA_ALIGN(sizeof(struct skb_shared_info)));
 137         if (IS_ERR(data))
 138                 return PTR_ERR(data);
 139
 140         switch (prog->type) {
 141         case BPF_PROG_TYPE_SCHED_CLS:
 142         case BPF_PROG_TYPE_SCHED_ACT:
 143                 is_l2 = true;
 144                 /* fall through */
 145         case BPF_PROG_TYPE_LWT_IN:
 146         case BPF_PROG_TYPE_LWT_OUT:
 147         case BPF_PROG_TYPE_LWT_XMIT:
 148                 is_direct_pkt_access = true;
 149                 break;
 150         default:
 151                 break;
 152         }
 153
 154         sk = kzalloc(sizeof(struct sock), GFP_USER);
 155         if (!sk) {
 156                 kfree(data);
 157                 return -ENOMEM;
 158         }
 159         sock_net_set(sk, current->nsproxy->net_ns);
 160         sock_init_data(NULL, sk);
 161
 162         skb = build_skb(data, 0);
 163         if (!skb) {
 164                 kfree(data);
 165                 kfree(sk);
 166                 return -ENOMEM;
 167         }
 168         skb->sk = sk;
 169
 170         skb_reserve(skb, NET_SKB_PAD + NET_IP_ALIGN);
 171         __skb_put(skb, size);
 172         skb->protocol = eth_type_trans(skb, current->nsproxy->net_ns->loopback_dev);
 173         skb_reset_network_header(skb);
 174
 175         if (is_l2)
 176                 __skb_push(skb, hh_len);
 177         if (is_direct_pkt_access)
 178                 bpf_compute_data_pointers(skb);
 179         retval = bpf_test_run(prog, skb, repeat, &duration);
 180         if (!is_l2) {
 181                 if (skb_headroom(skb) < hh_len) {
 182                         int nhead = HH_DATA_ALIGN(hh_len - skb_headroom(skb));
 183
 184                         if (pskb_expand_head(skb, nhead, 0, GFP_USER)) {
 185                                 kfree_skb(skb);
 186                                 kfree(sk);
 187                                 return -ENOMEM;
 188                         }
 189                 }
 190                 memset(__skb_push(skb, hh_len), 0, hh_len);
 191         }
 192
 193         size = skb->len;
 194         /* bpf program can never convert linear skb to non-linear */
 195         if (WARN_ON_ONCE(skb_is_nonlinear(skb)))
 196                 size = skb_headlen(skb);
 197         ret = bpf_test_finish(kattr, uattr, skb->data, size, retval, duration);
 198         kfree_skb(skb);
 199         kfree(sk);
 200         return ret;
 201 }
 202
 203 int bpf_prog_test_run_xdp(struct bpf_prog *prog, const union bpf_attr *kattr,
 204                           union bpf_attr __user *uattr)
 205 {
 206         u32 size = kattr->test.data_size_in;
 207         u32 repeat = kattr->test.repeat;
 208         struct netdev_rx_queue *rxqueue;
 209         struct xdp_buff xdp = {};
 210         u32 retval, duration;
 211         void *data;
 212         int ret;
 213
 214         data = bpf_test_init(kattr, size, XDP_PACKET_HEADROOM + NET_IP_ALIGN, 0);
 215         if (IS_ERR(data))
 216                 return PTR_ERR(data);
 217
 218         xdp.data_hard_start = data;
 219         xdp.data = data + XDP_PACKET_HEADROOM + NET_IP_ALIGN;
 220         xdp.data_meta = xdp.data;
 221         xdp.data_end = xdp.data + size;
 222
 223         rxqueue = __netif_get_rx_queue(current->nsproxy->net_ns->loopback_dev, 0);
 224         xdp.rxq = &rxqueue->xdp_rxq;
 225
 226         retval = bpf_test_run(prog, &xdp, repeat, &duration);
 227         if (xdp.data != data + XDP_PACKET_HEADROOM + NET_IP_ALIGN ||
 228             xdp.data_end != xdp.data + size)
 229                 size = xdp.data_end - xdp.data;
 230         ret = bpf_test_finish(kattr, uattr, xdp.data, size, retval, duration);
 231         kfree(data);
 232         return ret;
 233 }