git.rot13.org Git - linux/blob - 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         u32 copy_size = size;
  79
  80         /* Clamp copy if the user has provided a size hint, but copy the full
  81          * buffer if not to retain old behaviour.
  82          */
  83         if (kattr->test.data_size_out &&
  84             copy_size > kattr->test.data_size_out) {
  85                 copy_size = kattr->test.data_size_out;
  86                 err = -ENOSPC;
  87         }
  88
  89         if (data_out && copy_to_user(data_out, data, copy_size))
  90                 goto out;
  91         if (copy_to_user(&uattr->test.data_size_out, &size, sizeof(size)))
  92                 goto out;
  93         if (copy_to_user(&uattr->test.retval, &retval, sizeof(retval)))
  94                 goto out;
  95         if (copy_to_user(&uattr->test.duration, &duration, sizeof(duration)))
  96                 goto out;
  97         if (err != -ENOSPC)
  98                 err = 0;
  99 out:
 100         return err;
 101 }
 102
 103 static void *bpf_test_init(const union bpf_attr *kattr, u32 size,
 104                            u32 headroom, u32 tailroom)
 105 {
 106         void __user *data_in = u64_to_user_ptr(kattr->test.data_in);
 107         void *data;
 108
 109         if (size < ETH_HLEN || size > PAGE_SIZE - headroom - tailroom)
 110                 return ERR_PTR(-EINVAL);
 111
 112         data = kzalloc(size + headroom + tailroom, GFP_USER);
 113         if (!data)
 114                 return ERR_PTR(-ENOMEM);
 115
 116         if (copy_from_user(data + headroom, data_in, size)) {
 117                 kfree(data);
 118                 return ERR_PTR(-EFAULT);
 119         }
 120         return data;
 121 }
 122
 123 int bpf_prog_test_run_skb(struct bpf_prog *prog, const union bpf_attr *kattr,
 124                           union bpf_attr __user *uattr)
 125 {
 126         bool is_l2 = false, is_direct_pkt_access = false;
 127         u32 size = kattr->test.data_size_in;
 128         u32 repeat = kattr->test.repeat;
 129         u32 retval, duration;
 130         int hh_len = ETH_HLEN;
 131         struct sk_buff *skb;
 132         struct sock *sk;
 133         void *data;
 134         int ret;
 135
 136         data = bpf_test_init(kattr, size, NET_SKB_PAD + NET_IP_ALIGN,
 137                              SKB_DATA_ALIGN(sizeof(struct skb_shared_info)));
 138         if (IS_ERR(data))
 139                 return PTR_ERR(data);
 140
 141         switch (prog->type) {
 142         case BPF_PROG_TYPE_SCHED_CLS:
 143         case BPF_PROG_TYPE_SCHED_ACT:
 144                 is_l2 = true;
 145                 /* fall through */
 146         case BPF_PROG_TYPE_LWT_IN:
 147         case BPF_PROG_TYPE_LWT_OUT:
 148         case BPF_PROG_TYPE_LWT_XMIT:
 149                 is_direct_pkt_access = true;
 150                 break;
 151         default:
 152                 break;
 153         }
 154
 155         sk = kzalloc(sizeof(struct sock), GFP_USER);
 156         if (!sk) {
 157                 kfree(data);
 158                 return -ENOMEM;
 159         }
 160         sock_net_set(sk, current->nsproxy->net_ns);
 161         sock_init_data(NULL, sk);
 162
 163         skb = build_skb(data, 0);
 164         if (!skb) {
 165                 kfree(data);
 166                 kfree(sk);
 167                 return -ENOMEM;
 168         }
 169         skb->sk = sk;
 170
 171         skb_reserve(skb, NET_SKB_PAD + NET_IP_ALIGN);
 172         __skb_put(skb, size);
 173         skb->protocol = eth_type_trans(skb, current->nsproxy->net_ns->loopback_dev);
 174         skb_reset_network_header(skb);
 175
 176         if (is_l2)
 177                 __skb_push(skb, hh_len);
 178         if (is_direct_pkt_access)
 179                 bpf_compute_data_pointers(skb);
 180         ret = bpf_test_run(prog, skb, repeat, &retval, &duration);
 181         if (ret) {
 182                 kfree_skb(skb);
 183                 kfree(sk);
 184                 return ret;
 185         }
 186         if (!is_l2) {
 187                 if (skb_headroom(skb) < hh_len) {
 188                         int nhead = HH_DATA_ALIGN(hh_len - skb_headroom(skb));
 189
 190                         if (pskb_expand_head(skb, nhead, 0, GFP_USER)) {
 191                                 kfree_skb(skb);
 192                                 kfree(sk);
 193                                 return -ENOMEM;
 194                         }
 195                 }
 196                 memset(__skb_push(skb, hh_len), 0, hh_len);
 197         }
 198
 199         size = skb->len;
 200         /* bpf program can never convert linear skb to non-linear */
 201         if (WARN_ON_ONCE(skb_is_nonlinear(skb)))
 202                 size = skb_headlen(skb);
 203         ret = bpf_test_finish(kattr, uattr, skb->data, size, retval, duration);
 204         kfree_skb(skb);
 205         kfree(sk);
 206         return ret;
 207 }
 208
 209 int bpf_prog_test_run_xdp(struct bpf_prog *prog, const union bpf_attr *kattr,
 210                           union bpf_attr __user *uattr)
 211 {
 212         u32 size = kattr->test.data_size_in;
 213         u32 repeat = kattr->test.repeat;
 214         struct netdev_rx_queue *rxqueue;
 215         struct xdp_buff xdp = {};
 216         u32 retval, duration;
 217         void *data;
 218         int ret;
 219
 220         data = bpf_test_init(kattr, size, XDP_PACKET_HEADROOM + NET_IP_ALIGN, 0);
 221         if (IS_ERR(data))
 222                 return PTR_ERR(data);
 223
 224         xdp.data_hard_start = data;
 225         xdp.data = data + XDP_PACKET_HEADROOM + NET_IP_ALIGN;
 226         xdp.data_meta = xdp.data;
 227         xdp.data_end = xdp.data + size;
 228
 229         rxqueue = __netif_get_rx_queue(current->nsproxy->net_ns->loopback_dev, 0);
 230         xdp.rxq = &rxqueue->xdp_rxq;
 231
 232         ret = bpf_test_run(prog, &xdp, repeat, &retval, &duration);
 233         if (ret)
 234                 goto out;
 235         if (xdp.data != data + XDP_PACKET_HEADROOM + NET_IP_ALIGN ||
 236             xdp.data_end != xdp.data + size)
 237                 size = xdp.data_end - xdp.data;
 238         ret = bpf_test_finish(kattr, uattr, xdp.data, size, retval, duration);
 239 out:
 240         kfree(data);
 241         return ret;
 242 }