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 int bpf_test_run(struct bpf_prog *prog, void *ctx, u32 repeat,
  17                         u32 *retval, u32 *time)
  18 {
  19         struct bpf_cgroup_storage *storage[MAX_BPF_CGROUP_STORAGE_TYPE] = { 0 };
  20         enum bpf_cgroup_storage_type stype;
  21         u64 time_start, time_spent = 0;
  22         int ret = 0;
  23         u32 i;
  24
  25         for_each_cgroup_storage_type(stype) {
  26                 storage[stype] = bpf_cgroup_storage_alloc(prog, stype);
  27                 if (IS_ERR(storage[stype])) {
  28                         storage[stype] = NULL;
  29                         for_each_cgroup_storage_type(stype)
  30                                 bpf_cgroup_storage_free(storage[stype]);
  31                         return -ENOMEM;
  32                 }
  33         }
  34
  35         if (!repeat)
  36                 repeat = 1;
  37
  38         rcu_read_lock();
  39         preempt_disable();
  40         time_start = ktime_get_ns();
  41         for (i = 0; i < repeat; i++) {
  42                 bpf_cgroup_storage_set(storage);
  43                 *retval = BPF_PROG_RUN(prog, ctx);
  44
  45                 if (signal_pending(current)) {
  46                         ret = -EINTR;
  47                         break;
  48                 }
  49
  50                 if (need_resched()) {
  51                         time_spent += ktime_get_ns() - time_start;
  52                         preempt_enable();
  53                         rcu_read_unlock();
  54
  55                         cond_resched();
  56
  57                         rcu_read_lock();
  58                         preempt_disable();
  59                         time_start = ktime_get_ns();
  60                 }
  61         }
  62         time_spent += ktime_get_ns() - time_start;
  63         preempt_enable();
  64         rcu_read_unlock();
  65
  66         do_div(time_spent, repeat);
  67         *time = time_spent > U32_MAX ? U32_MAX : (u32)time_spent;
  68
  69         for_each_cgroup_storage_type(stype)
  70                 bpf_cgroup_storage_free(storage[stype]);
  71
  72         return ret;
  73 }
  74
  75 static int bpf_test_finish(const union bpf_attr *kattr,
  76                            union bpf_attr __user *uattr, const void *data,
  77                            u32 size, u32 retval, u32 duration)
  78 {
  79         void __user *data_out = u64_to_user_ptr(kattr->test.data_out);
  80         int err = -EFAULT;
  81         u32 copy_size = size;
  82
  83         /* Clamp copy if the user has provided a size hint, but copy the full
  84          * buffer if not to retain old behaviour.
  85          */
  86         if (kattr->test.data_size_out &&
  87             copy_size > kattr->test.data_size_out) {
  88                 copy_size = kattr->test.data_size_out;
  89                 err = -ENOSPC;
  90         }
  91
  92         if (data_out && copy_to_user(data_out, data, copy_size))
  93                 goto out;
  94         if (copy_to_user(&uattr->test.data_size_out, &size, sizeof(size)))
  95                 goto out;
  96         if (copy_to_user(&uattr->test.retval, &retval, sizeof(retval)))
  97                 goto out;
  98         if (copy_to_user(&uattr->test.duration, &duration, sizeof(duration)))
  99                 goto out;
 100         if (err != -ENOSPC)
 101                 err = 0;
 102 out:
 103         return err;
 104 }
 105
 106 static void *bpf_test_init(const union bpf_attr *kattr, u32 size,
 107                            u32 headroom, u32 tailroom)
 108 {
 109         void __user *data_in = u64_to_user_ptr(kattr->test.data_in);
 110         void *data;
 111
 112         if (size < ETH_HLEN || size > PAGE_SIZE - headroom - tailroom)
 113                 return ERR_PTR(-EINVAL);
 114
 115         data = kzalloc(size + headroom + tailroom, GFP_USER);
 116         if (!data)
 117                 return ERR_PTR(-ENOMEM);
 118
 119         if (copy_from_user(data + headroom, data_in, size)) {
 120                 kfree(data);
 121                 return ERR_PTR(-EFAULT);
 122         }
 123         return data;
 124 }
 125
 126 int bpf_prog_test_run_skb(struct bpf_prog *prog, const union bpf_attr *kattr,
 127                           union bpf_attr __user *uattr)
 128 {
 129         bool is_l2 = false, is_direct_pkt_access = false;
 130         u32 size = kattr->test.data_size_in;
 131         u32 repeat = kattr->test.repeat;
 132         u32 retval, duration;
 133         int hh_len = ETH_HLEN;
 134         struct sk_buff *skb;
 135         struct sock *sk;
 136         void *data;
 137         int ret;
 138
 139         data = bpf_test_init(kattr, size, NET_SKB_PAD + NET_IP_ALIGN,
 140                              SKB_DATA_ALIGN(sizeof(struct skb_shared_info)));
 141         if (IS_ERR(data))
 142                 return PTR_ERR(data);
 143
 144         switch (prog->type) {
 145         case BPF_PROG_TYPE_SCHED_CLS:
 146         case BPF_PROG_TYPE_SCHED_ACT:
 147                 is_l2 = true;
 148                 /* fall through */
 149         case BPF_PROG_TYPE_LWT_IN:
 150         case BPF_PROG_TYPE_LWT_OUT:
 151         case BPF_PROG_TYPE_LWT_XMIT:
 152                 is_direct_pkt_access = true;
 153                 break;
 154         default:
 155                 break;
 156         }
 157
 158         sk = kzalloc(sizeof(struct sock), GFP_USER);
 159         if (!sk) {
 160                 kfree(data);
 161                 return -ENOMEM;
 162         }
 163         sock_net_set(sk, current->nsproxy->net_ns);
 164         sock_init_data(NULL, sk);
 165
 166         skb = build_skb(data, 0);
 167         if (!skb) {
 168                 kfree(data);
 169                 kfree(sk);
 170                 return -ENOMEM;
 171         }
 172         skb->sk = sk;
 173
 174         skb_reserve(skb, NET_SKB_PAD + NET_IP_ALIGN);
 175         __skb_put(skb, size);
 176         skb->protocol = eth_type_trans(skb, current->nsproxy->net_ns->loopback_dev);
 177         skb_reset_network_header(skb);
 178
 179         if (is_l2)
 180                 __skb_push(skb, hh_len);
 181         if (is_direct_pkt_access)
 182                 bpf_compute_data_pointers(skb);
 183         ret = bpf_test_run(prog, skb, repeat, &retval, &duration);
 184         if (ret) {
 185                 kfree_skb(skb);
 186                 kfree(sk);
 187                 return ret;
 188         }
 189         if (!is_l2) {
 190                 if (skb_headroom(skb) < hh_len) {
 191                         int nhead = HH_DATA_ALIGN(hh_len - skb_headroom(skb));
 192
 193                         if (pskb_expand_head(skb, nhead, 0, GFP_USER)) {
 194                                 kfree_skb(skb);
 195                                 kfree(sk);
 196                                 return -ENOMEM;
 197                         }
 198                 }
 199                 memset(__skb_push(skb, hh_len), 0, hh_len);
 200         }
 201
 202         size = skb->len;
 203         /* bpf program can never convert linear skb to non-linear */
 204         if (WARN_ON_ONCE(skb_is_nonlinear(skb)))
 205                 size = skb_headlen(skb);
 206         ret = bpf_test_finish(kattr, uattr, skb->data, size, retval, duration);
 207         kfree_skb(skb);
 208         kfree(sk);
 209         return ret;
 210 }
 211
 212 int bpf_prog_test_run_xdp(struct bpf_prog *prog, const union bpf_attr *kattr,
 213                           union bpf_attr __user *uattr)
 214 {
 215         u32 size = kattr->test.data_size_in;
 216         u32 repeat = kattr->test.repeat;
 217         struct netdev_rx_queue *rxqueue;
 218         struct xdp_buff xdp = {};
 219         u32 retval, duration;
 220         void *data;
 221         int ret;
 222
 223         data = bpf_test_init(kattr, size, XDP_PACKET_HEADROOM + NET_IP_ALIGN, 0);
 224         if (IS_ERR(data))
 225                 return PTR_ERR(data);
 226
 227         xdp.data_hard_start = data;
 228         xdp.data = data + XDP_PACKET_HEADROOM + NET_IP_ALIGN;
 229         xdp.data_meta = xdp.data;
 230         xdp.data_end = xdp.data + size;
 231
 232         rxqueue = __netif_get_rx_queue(current->nsproxy->net_ns->loopback_dev, 0);
 233         xdp.rxq = &rxqueue->xdp_rxq;
 234
 235         ret = bpf_test_run(prog, &xdp, repeat, &retval, &duration);
 236         if (ret)
 237                 goto out;
 238         if (xdp.data != data + XDP_PACKET_HEADROOM + NET_IP_ALIGN ||
 239             xdp.data_end != xdp.data + size)
 240                 size = xdp.data_end - xdp.data;
 241         ret = bpf_test_finish(kattr, uattr, xdp.data, size, retval, duration);
 242 out:
 243         kfree(data);
 244         return ret;
 245 }