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 int bpf_test_run(struct bpf_prog *prog, void *ctx, u32 repeat, u32 *ret,
  32                         u32 *time)
  33 {
  34         struct bpf_cgroup_storage *storage[MAX_BPF_CGROUP_STORAGE_TYPE] = { 0 };
  35         enum bpf_cgroup_storage_type stype;
  36         u64 time_start, time_spent = 0;
  37         u32 i;
  38
  39         for_each_cgroup_storage_type(stype) {
  40                 storage[stype] = bpf_cgroup_storage_alloc(prog, stype);
  41                 if (IS_ERR(storage[stype])) {
  42                         storage[stype] = NULL;
  43                         for_each_cgroup_storage_type(stype)
  44                                 bpf_cgroup_storage_free(storage[stype]);
  45                         return -ENOMEM;
  46                 }
  47         }
  48
  49         if (!repeat)
  50                 repeat = 1;
  51         time_start = ktime_get_ns();
  52         for (i = 0; i < repeat; i++) {
  53                 *ret = bpf_test_run_one(prog, ctx, storage);
  54                 if (need_resched()) {
  55                         if (signal_pending(current))
  56                                 break;
  57                         time_spent += ktime_get_ns() - time_start;
  58                         cond_resched();
  59                         time_start = ktime_get_ns();
  60                 }
  61         }
  62         time_spent += ktime_get_ns() - time_start;
  63         do_div(time_spent, repeat);
  64         *time = time_spent > U32_MAX ? U32_MAX : (u32)time_spent;
  65
  66         for_each_cgroup_storage_type(stype)
  67                 bpf_cgroup_storage_free(storage[stype]);
  68
  69         return 0;
  70 }
  71
  72 static int bpf_test_finish(const union bpf_attr *kattr,
  73                            union bpf_attr __user *uattr, const void *data,
  74                            u32 size, u32 retval, u32 duration)
  75 {
  76         void __user *data_out = u64_to_user_ptr(kattr->test.data_out);
  77         int err = -EFAULT;
  78
  79         if (data_out && copy_to_user(data_out, data, size))
  80                 goto out;
  81         if (copy_to_user(&uattr->test.data_size_out, &size, sizeof(size)))
  82                 goto out;
  83         if (copy_to_user(&uattr->test.retval, &retval, sizeof(retval)))
  84                 goto out;
  85         if (copy_to_user(&uattr->test.duration, &duration, sizeof(duration)))
  86                 goto out;
  87         err = 0;
  88 out:
  89         return err;
  90 }
  91
  92 static void *bpf_test_init(const union bpf_attr *kattr, u32 size,
  93                            u32 headroom, u32 tailroom)
  94 {
  95         void __user *data_in = u64_to_user_ptr(kattr->test.data_in);
  96         void *data;
  97
  98         if (size < ETH_HLEN || size > PAGE_SIZE - headroom - tailroom)
  99                 return ERR_PTR(-EINVAL);
 100
 101         data = kzalloc(size + headroom + tailroom, GFP_USER);
 102         if (!data)
 103                 return ERR_PTR(-ENOMEM);
 104
 105         if (copy_from_user(data + headroom, data_in, size)) {
 106                 kfree(data);
 107                 return ERR_PTR(-EFAULT);
 108         }
 109         return data;
 110 }
 111
 112 int bpf_prog_test_run_skb(struct bpf_prog *prog, const union bpf_attr *kattr,
 113                           union bpf_attr __user *uattr)
 114 {
 115         bool is_l2 = false, is_direct_pkt_access = false;
 116         u32 size = kattr->test.data_size_in;
 117         u32 repeat = kattr->test.repeat;
 118         u32 retval, duration;
 119         int hh_len = ETH_HLEN;
 120         struct sk_buff *skb;
 121         struct sock *sk;
 122         void *data;
 123         int ret;
 124
 125         data = bpf_test_init(kattr, size, NET_SKB_PAD + NET_IP_ALIGN,
 126                              SKB_DATA_ALIGN(sizeof(struct skb_shared_info)));
 127         if (IS_ERR(data))
 128                 return PTR_ERR(data);
 129
 130         switch (prog->type) {
 131         case BPF_PROG_TYPE_SCHED_CLS:
 132         case BPF_PROG_TYPE_SCHED_ACT:
 133                 is_l2 = true;
 134                 /* fall through */
 135         case BPF_PROG_TYPE_LWT_IN:
 136         case BPF_PROG_TYPE_LWT_OUT:
 137         case BPF_PROG_TYPE_LWT_XMIT:
 138                 is_direct_pkt_access = true;
 139                 break;
 140         default:
 141                 break;
 142         }
 143
 144         sk = kzalloc(sizeof(struct sock), GFP_USER);
 145         if (!sk) {
 146                 kfree(data);
 147                 return -ENOMEM;
 148         }
 149         sock_net_set(sk, current->nsproxy->net_ns);
 150         sock_init_data(NULL, sk);
 151
 152         skb = build_skb(data, 0);
 153         if (!skb) {
 154                 kfree(data);
 155                 kfree(sk);
 156                 return -ENOMEM;
 157         }
 158         skb->sk = sk;
 159
 160         skb_reserve(skb, NET_SKB_PAD + NET_IP_ALIGN);
 161         __skb_put(skb, size);
 162         skb->protocol = eth_type_trans(skb, current->nsproxy->net_ns->loopback_dev);
 163         skb_reset_network_header(skb);
 164
 165         if (is_l2)
 166                 __skb_push(skb, hh_len);
 167         if (is_direct_pkt_access)
 168                 bpf_compute_data_pointers(skb);
 169         ret = bpf_test_run(prog, skb, repeat, &retval, &duration);
 170         if (ret) {
 171                 kfree_skb(skb);
 172                 kfree(sk);
 173                 return ret;
 174         }
 175         if (!is_l2) {
 176                 if (skb_headroom(skb) < hh_len) {
 177                         int nhead = HH_DATA_ALIGN(hh_len - skb_headroom(skb));
 178
 179                         if (pskb_expand_head(skb, nhead, 0, GFP_USER)) {
 180                                 kfree_skb(skb);
 181                                 kfree(sk);
 182                                 return -ENOMEM;
 183                         }
 184                 }
 185                 memset(__skb_push(skb, hh_len), 0, hh_len);
 186         }
 187
 188         size = skb->len;
 189         /* bpf program can never convert linear skb to non-linear */
 190         if (WARN_ON_ONCE(skb_is_nonlinear(skb)))
 191                 size = skb_headlen(skb);
 192         ret = bpf_test_finish(kattr, uattr, skb->data, size, retval, duration);
 193         kfree_skb(skb);
 194         kfree(sk);
 195         return ret;
 196 }
 197
 198 int bpf_prog_test_run_xdp(struct bpf_prog *prog, const union bpf_attr *kattr,
 199                           union bpf_attr __user *uattr)
 200 {
 201         u32 size = kattr->test.data_size_in;
 202         u32 repeat = kattr->test.repeat;
 203         struct netdev_rx_queue *rxqueue;
 204         struct xdp_buff xdp = {};
 205         u32 retval, duration;
 206         void *data;
 207         int ret;
 208
 209         data = bpf_test_init(kattr, size, XDP_PACKET_HEADROOM + NET_IP_ALIGN, 0);
 210         if (IS_ERR(data))
 211                 return PTR_ERR(data);
 212
 213         xdp.data_hard_start = data;
 214         xdp.data = data + XDP_PACKET_HEADROOM + NET_IP_ALIGN;
 215         xdp.data_meta = xdp.data;
 216         xdp.data_end = xdp.data + size;
 217
 218         rxqueue = __netif_get_rx_queue(current->nsproxy->net_ns->loopback_dev, 0);
 219         xdp.rxq = &rxqueue->xdp_rxq;
 220
 221         ret = bpf_test_run(prog, &xdp, repeat, &retval, &duration);
 222         if (ret)
 223                 goto out;
 224         if (xdp.data != data + XDP_PACKET_HEADROOM + NET_IP_ALIGN ||
 225             xdp.data_end != xdp.data + size)
 226                 size = xdp.data_end - xdp.data;
 227         ret = bpf_test_finish(kattr, uattr, xdp.data, size, retval, duration);
 228 out:
 229         kfree(data);
 230         return ret;
 231 }