net/bpf/test_run.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /* Copyright (c) 2017 Facebook
   3  */
   4 #include <linux/bpf.h>
   5 #include <linux/slab.h>
   6 #include <linux/vmalloc.h>
   7 #include <linux/etherdevice.h>
   8 #include <linux/filter.h>
   9 #include <linux/sched/signal.h>
  10 #include <net/bpf_sk_storage.h>
  11 #include <net/sock.h>
  12 #include <net/tcp.h>
  13
  14 #define CREATE_TRACE_POINTS
  15 #include <trace/events/bpf_test_run.h>
  16
  17 static int bpf_test_run(struct bpf_prog *prog, void *ctx, u32 repeat,
  18                         u32 *retval, u32 *time, bool xdp)
  19 {
  20         struct bpf_cgroup_storage *storage[MAX_BPF_CGROUP_STORAGE_TYPE] = { NULL };
  21         enum bpf_cgroup_storage_type stype;
  22         u64 time_start, time_spent = 0;
  23         int ret = 0;
  24         u32 i;
  25
  26         for_each_cgroup_storage_type(stype) {
  27                 storage[stype] = bpf_cgroup_storage_alloc(prog, stype);
  28                 if (IS_ERR(storage[stype])) {
  29                         storage[stype] = NULL;
  30                         for_each_cgroup_storage_type(stype)
  31                                 bpf_cgroup_storage_free(storage[stype]);
  32                         return -ENOMEM;
  33                 }
  34         }
  35
  36         if (!repeat)
  37                 repeat = 1;
  38
  39         rcu_read_lock();
  40         preempt_disable();
  41         time_start = ktime_get_ns();
  42         for (i = 0; i < repeat; i++) {
  43                 bpf_cgroup_storage_set(storage);
  44
  45                 if (xdp)
  46                         *retval = bpf_prog_run_xdp(prog, ctx);
  47                 else
  48                         *retval = BPF_PROG_RUN(prog, ctx);
  49
  50                 if (signal_pending(current)) {
  51                         ret = -EINTR;
  52                         break;
  53                 }
  54
  55                 if (need_resched()) {
  56                         time_spent += ktime_get_ns() - time_start;
  57                         preempt_enable();
  58                         rcu_read_unlock();
  59
  60                         cond_resched();
  61
  62                         rcu_read_lock();
  63                         preempt_disable();
  64                         time_start = ktime_get_ns();
  65                 }
  66         }
  67         time_spent += ktime_get_ns() - time_start;
  68         preempt_enable();
  69         rcu_read_unlock();
  70
  71         do_div(time_spent, repeat);
  72         *time = time_spent > U32_MAX ? U32_MAX : (u32)time_spent;
  73
  74         for_each_cgroup_storage_type(stype)
  75                 bpf_cgroup_storage_free(storage[stype]);
  76
  77         return ret;
  78 }
  79
  80 static int bpf_test_finish(const union bpf_attr *kattr,
  81                            union bpf_attr __user *uattr, const void *data,
  82                            u32 size, u32 retval, u32 duration)
  83 {
  84         void __user *data_out = u64_to_user_ptr(kattr->test.data_out);
  85         int err = -EFAULT;
  86         u32 copy_size = size;
  87
  88         /* Clamp copy if the user has provided a size hint, but copy the full
  89          * buffer if not to retain old behaviour.
  90          */
  91         if (kattr->test.data_size_out &&
  92             copy_size > kattr->test.data_size_out) {
  93                 copy_size = kattr->test.data_size_out;
  94                 err = -ENOSPC;
  95         }
  96
  97         if (data_out && copy_to_user(data_out, data, copy_size))
  98                 goto out;
  99         if (copy_to_user(&uattr->test.data_size_out, &size, sizeof(size)))
 100                 goto out;
 101         if (copy_to_user(&uattr->test.retval, &retval, sizeof(retval)))
 102                 goto out;
 103         if (copy_to_user(&uattr->test.duration, &duration, sizeof(duration)))
 104                 goto out;
 105         if (err != -ENOSPC)
 106                 err = 0;
 107 out:
 108         trace_bpf_test_finish(&err);
 109         return err;
 110 }
 111
 112 /* Integer types of various sizes and pointer combinations cover variety of
 113  * architecture dependent calling conventions. 7+ can be supported in the
 114  * future.
 115  */
 116 int noinline bpf_fentry_test1(int a)
 117 {
 118         return a + 1;
 119 }
 120
 121 int noinline bpf_fentry_test2(int a, u64 b)
 122 {
 123         return a + b;
 124 }
 125
 126 int noinline bpf_fentry_test3(char a, int b, u64 c)
 127 {
 128         return a + b + c;
 129 }
 130
 131 int noinline bpf_fentry_test4(void *a, char b, int c, u64 d)
 132 {
 133         return (long)a + b + c + d;
 134 }
 135
 136 int noinline bpf_fentry_test5(u64 a, void *b, short c, int d, u64 e)
 137 {
 138         return a + (long)b + c + d + e;
 139 }
 140
 141 int noinline bpf_fentry_test6(u64 a, void *b, short c, int d, void *e, u64 f)
 142 {
 143         return a + (long)b + c + d + (long)e + f;
 144 }
 145
 146 static void *bpf_test_init(const union bpf_attr *kattr, u32 size,
 147                            u32 headroom, u32 tailroom)
 148 {
 149         void __user *data_in = u64_to_user_ptr(kattr->test.data_in);
 150         void *data;
 151
 152         if (size < ETH_HLEN || size > PAGE_SIZE - headroom - tailroom)
 153                 return ERR_PTR(-EINVAL);
 154
 155         data = kzalloc(size + headroom + tailroom, GFP_USER);
 156         if (!data)
 157                 return ERR_PTR(-ENOMEM);
 158
 159         if (copy_from_user(data + headroom, data_in, size)) {
 160                 kfree(data);
 161                 return ERR_PTR(-EFAULT);
 162         }
 163         if (bpf_fentry_test1(1) != 2 ||
 164             bpf_fentry_test2(2, 3) != 5 ||
 165             bpf_fentry_test3(4, 5, 6) != 15 ||
 166             bpf_fentry_test4((void *)7, 8, 9, 10) != 34 ||
 167             bpf_fentry_test5(11, (void *)12, 13, 14, 15) != 65 ||
 168             bpf_fentry_test6(16, (void *)17, 18, 19, (void *)20, 21) != 111) {
 169                 kfree(data);
 170                 return ERR_PTR(-EFAULT);
 171         }
 172         return data;
 173 }
 174
 175 static void *bpf_ctx_init(const union bpf_attr *kattr, u32 max_size)
 176 {
 177         void __user *data_in = u64_to_user_ptr(kattr->test.ctx_in);
 178         void __user *data_out = u64_to_user_ptr(kattr->test.ctx_out);
 179         u32 size = kattr->test.ctx_size_in;
 180         void *data;
 181         int err;
 182
 183         if (!data_in && !data_out)
 184                 return NULL;
 185
 186         data = kzalloc(max_size, GFP_USER);
 187         if (!data)
 188                 return ERR_PTR(-ENOMEM);
 189
 190         if (data_in) {
 191                 err = bpf_check_uarg_tail_zero(data_in, max_size, size);
 192                 if (err) {
 193                         kfree(data);
 194                         return ERR_PTR(err);
 195                 }
 196
 197                 size = min_t(u32, max_size, size);
 198                 if (copy_from_user(data, data_in, size)) {
 199                         kfree(data);
 200                         return ERR_PTR(-EFAULT);
 201                 }
 202         }
 203         return data;
 204 }
 205
 206 static int bpf_ctx_finish(const union bpf_attr *kattr,
 207                           union bpf_attr __user *uattr, const void *data,
 208                           u32 size)
 209 {
 210         void __user *data_out = u64_to_user_ptr(kattr->test.ctx_out);
 211         int err = -EFAULT;
 212         u32 copy_size = size;
 213
 214         if (!data || !data_out)
 215                 return 0;
 216
 217         if (copy_size > kattr->test.ctx_size_out) {
 218                 copy_size = kattr->test.ctx_size_out;
 219                 err = -ENOSPC;
 220         }
 221
 222         if (copy_to_user(data_out, data, copy_size))
 223                 goto out;
 224         if (copy_to_user(&uattr->test.ctx_size_out, &size, sizeof(size)))
 225                 goto out;
 226         if (err != -ENOSPC)
 227                 err = 0;
 228 out:
 229         return err;
 230 }
 231
 232 /**
 233  * range_is_zero - test whether buffer is initialized
 234  * @buf: buffer to check
 235  * @from: check from this position
 236  * @to: check up until (excluding) this position
 237  *
 238  * This function returns true if the there is a non-zero byte
 239  * in the buf in the range [from,to).
 240  */
 241 static inline bool range_is_zero(void *buf, size_t from, size_t to)
 242 {
 243         return !memchr_inv((u8 *)buf + from, 0, to - from);
 244 }
 245
 246 static int convert___skb_to_skb(struct sk_buff *skb, struct __sk_buff *__skb)
 247 {
 248         struct qdisc_skb_cb *cb = (struct qdisc_skb_cb *)skb->cb;
 249
 250         if (!__skb)
 251                 return 0;
 252
 253         /* make sure the fields we don't use are zeroed */
 254         if (!range_is_zero(__skb, 0, offsetof(struct __sk_buff, mark)))
 255                 return -EINVAL;
 256
 257         /* mark is allowed */
 258
 259         if (!range_is_zero(__skb, offsetofend(struct __sk_buff, mark),
 260                            offsetof(struct __sk_buff, priority)))
 261                 return -EINVAL;
 262
 263         /* priority is allowed */
 264
 265         if (!range_is_zero(__skb, offsetofend(struct __sk_buff, priority),
 266                            offsetof(struct __sk_buff, cb)))
 267                 return -EINVAL;
 268
 269         /* cb is allowed */
 270
 271         if (!range_is_zero(__skb, offsetofend(struct __sk_buff, cb),
 272                            offsetof(struct __sk_buff, tstamp)))
 273                 return -EINVAL;
 274
 275         /* tstamp is allowed */
 276         /* wire_len is allowed */
 277         /* gso_segs is allowed */
 278
 279         if (!range_is_zero(__skb, offsetofend(struct __sk_buff, gso_segs),
 280                            sizeof(struct __sk_buff)))
 281                 return -EINVAL;
 282
 283         skb->mark = __skb->mark;
 284         skb->priority = __skb->priority;
 285         skb->tstamp = __skb->tstamp;
 286         memcpy(&cb->data, __skb->cb, QDISC_CB_PRIV_LEN);
 287
 288         if (__skb->wire_len == 0) {
 289                 cb->pkt_len = skb->len;
 290         } else {
 291                 if (__skb->wire_len < skb->len ||
 292                     __skb->wire_len > GSO_MAX_SIZE)
 293                         return -EINVAL;
 294                 cb->pkt_len = __skb->wire_len;
 295         }
 296
 297         if (__skb->gso_segs > GSO_MAX_SEGS)
 298                 return -EINVAL;
 299         skb_shinfo(skb)->gso_segs = __skb->gso_segs;
 300
 301         return 0;
 302 }
 303
 304 static void convert_skb_to___skb(struct sk_buff *skb, struct __sk_buff *__skb)
 305 {
 306         struct qdisc_skb_cb *cb = (struct qdisc_skb_cb *)skb->cb;
 307
 308         if (!__skb)
 309                 return;
 310
 311         __skb->mark = skb->mark;
 312         __skb->priority = skb->priority;
 313         __skb->tstamp = skb->tstamp;
 314         memcpy(__skb->cb, &cb->data, QDISC_CB_PRIV_LEN);
 315         __skb->wire_len = cb->pkt_len;
 316         __skb->gso_segs = skb_shinfo(skb)->gso_segs;
 317 }
 318
 319 int bpf_prog_test_run_skb(struct bpf_prog *prog, const union bpf_attr *kattr,
 320                           union bpf_attr __user *uattr)
 321 {
 322         bool is_l2 = false, is_direct_pkt_access = false;
 323         u32 size = kattr->test.data_size_in;
 324         u32 repeat = kattr->test.repeat;
 325         struct __sk_buff *ctx = NULL;
 326         u32 retval, duration;
 327         int hh_len = ETH_HLEN;
 328         struct sk_buff *skb;
 329         struct sock *sk;
 330         void *data;
 331         int ret;
 332
 333         data = bpf_test_init(kattr, size, NET_SKB_PAD + NET_IP_ALIGN,
 334                              SKB_DATA_ALIGN(sizeof(struct skb_shared_info)));
 335         if (IS_ERR(data))
 336                 return PTR_ERR(data);
 337
 338         ctx = bpf_ctx_init(kattr, sizeof(struct __sk_buff));
 339         if (IS_ERR(ctx)) {
 340                 kfree(data);
 341                 return PTR_ERR(ctx);
 342         }
 343
 344         switch (prog->type) {
 345         case BPF_PROG_TYPE_SCHED_CLS:
 346         case BPF_PROG_TYPE_SCHED_ACT:
 347                 is_l2 = true;
 348                 /* fall through */
 349         case BPF_PROG_TYPE_LWT_IN:
 350         case BPF_PROG_TYPE_LWT_OUT:
 351         case BPF_PROG_TYPE_LWT_XMIT:
 352                 is_direct_pkt_access = true;
 353                 break;
 354         default:
 355                 break;
 356         }
 357
 358         sk = kzalloc(sizeof(struct sock), GFP_USER);
 359         if (!sk) {
 360                 kfree(data);
 361                 kfree(ctx);
 362                 return -ENOMEM;
 363         }
 364         sock_net_set(sk, current->nsproxy->net_ns);
 365         sock_init_data(NULL, sk);
 366
 367         skb = build_skb(data, 0);
 368         if (!skb) {
 369                 kfree(data);
 370                 kfree(ctx);
 371                 kfree(sk);
 372                 return -ENOMEM;
 373         }
 374         skb->sk = sk;
 375
 376         skb_reserve(skb, NET_SKB_PAD + NET_IP_ALIGN);
 377         __skb_put(skb, size);
 378         skb->protocol = eth_type_trans(skb, current->nsproxy->net_ns->loopback_dev);
 379         skb_reset_network_header(skb);
 380
 381         if (is_l2)
 382                 __skb_push(skb, hh_len);
 383         if (is_direct_pkt_access)
 384                 bpf_compute_data_pointers(skb);
 385         ret = convert___skb_to_skb(skb, ctx);
 386         if (ret)
 387                 goto out;
 388         ret = bpf_test_run(prog, skb, repeat, &retval, &duration, false);
 389         if (ret)
 390                 goto out;
 391         if (!is_l2) {
 392                 if (skb_headroom(skb) < hh_len) {
 393                         int nhead = HH_DATA_ALIGN(hh_len - skb_headroom(skb));
 394
 395                         if (pskb_expand_head(skb, nhead, 0, GFP_USER)) {
 396                                 ret = -ENOMEM;
 397                                 goto out;
 398                         }
 399                 }
 400                 memset(__skb_push(skb, hh_len), 0, hh_len);
 401         }
 402         convert_skb_to___skb(skb, ctx);
 403
 404         size = skb->len;
 405         /* bpf program can never convert linear skb to non-linear */
 406         if (WARN_ON_ONCE(skb_is_nonlinear(skb)))
 407                 size = skb_headlen(skb);
 408         ret = bpf_test_finish(kattr, uattr, skb->data, size, retval, duration);
 409         if (!ret)
 410                 ret = bpf_ctx_finish(kattr, uattr, ctx,
 411                                      sizeof(struct __sk_buff));
 412 out:
 413         kfree_skb(skb);
 414         bpf_sk_storage_free(sk);
 415         kfree(sk);
 416         kfree(ctx);
 417         return ret;
 418 }
 419
 420 int bpf_prog_test_run_xdp(struct bpf_prog *prog, const union bpf_attr *kattr,
 421                           union bpf_attr __user *uattr)
 422 {
 423         u32 size = kattr->test.data_size_in;
 424         u32 repeat = kattr->test.repeat;
 425         struct netdev_rx_queue *rxqueue;
 426         struct xdp_buff xdp = {};
 427         u32 retval, duration;
 428         void *data;
 429         int ret;
 430
 431         if (kattr->test.ctx_in || kattr->test.ctx_out)
 432                 return -EINVAL;
 433
 434         data = bpf_test_init(kattr, size, XDP_PACKET_HEADROOM + NET_IP_ALIGN, 0);
 435         if (IS_ERR(data))
 436                 return PTR_ERR(data);
 437
 438         xdp.data_hard_start = data;
 439         xdp.data = data + XDP_PACKET_HEADROOM + NET_IP_ALIGN;
 440         xdp.data_meta = xdp.data;
 441         xdp.data_end = xdp.data + size;
 442
 443         rxqueue = __netif_get_rx_queue(current->nsproxy->net_ns->loopback_dev, 0);
 444         xdp.rxq = &rxqueue->xdp_rxq;
 445         bpf_prog_change_xdp(NULL, prog);
 446         ret = bpf_test_run(prog, &xdp, repeat, &retval, &duration, true);
 447         if (ret)
 448                 goto out;
 449         if (xdp.data != data + XDP_PACKET_HEADROOM + NET_IP_ALIGN ||
 450             xdp.data_end != xdp.data + size)
 451                 size = xdp.data_end - xdp.data;
 452         ret = bpf_test_finish(kattr, uattr, xdp.data, size, retval, duration);
 453 out:
 454         bpf_prog_change_xdp(prog, NULL);
 455         kfree(data);
 456         return ret;
 457 }
 458
 459 static int verify_user_bpf_flow_keys(struct bpf_flow_keys *ctx)
 460 {
 461         /* make sure the fields we don't use are zeroed */
 462         if (!range_is_zero(ctx, 0, offsetof(struct bpf_flow_keys, flags)))
 463                 return -EINVAL;
 464
 465         /* flags is allowed */
 466
 467         if (!range_is_zero(ctx, offsetofend(struct bpf_flow_keys, flags),
 468                            sizeof(struct bpf_flow_keys)))
 469                 return -EINVAL;
 470
 471         return 0;
 472 }
 473
 474 int bpf_prog_test_run_flow_dissector(struct bpf_prog *prog,
 475                                      const union bpf_attr *kattr,
 476                                      union bpf_attr __user *uattr)
 477 {
 478         u32 size = kattr->test.data_size_in;
 479         struct bpf_flow_dissector ctx = {};
 480         u32 repeat = kattr->test.repeat;
 481         struct bpf_flow_keys *user_ctx;
 482         struct bpf_flow_keys flow_keys;
 483         u64 time_start, time_spent = 0;
 484         const struct ethhdr *eth;
 485         unsigned int flags = 0;
 486         u32 retval, duration;
 487         void *data;
 488         int ret;
 489         u32 i;
 490
 491         if (prog->type != BPF_PROG_TYPE_FLOW_DISSECTOR)
 492                 return -EINVAL;
 493
 494         if (size < ETH_HLEN)
 495                 return -EINVAL;
 496
 497         data = bpf_test_init(kattr, size, 0, 0);
 498         if (IS_ERR(data))
 499                 return PTR_ERR(data);
 500
 501         eth = (struct ethhdr *)data;
 502
 503         if (!repeat)
 504                 repeat = 1;
 505
 506         user_ctx = bpf_ctx_init(kattr, sizeof(struct bpf_flow_keys));
 507         if (IS_ERR(user_ctx)) {
 508                 kfree(data);
 509                 return PTR_ERR(user_ctx);
 510         }
 511         if (user_ctx) {
 512                 ret = verify_user_bpf_flow_keys(user_ctx);
 513                 if (ret)
 514                         goto out;
 515                 flags = user_ctx->flags;
 516         }
 517
 518         ctx.flow_keys = &flow_keys;
 519         ctx.data = data;
 520         ctx.data_end = (__u8 *)data + size;
 521
 522         rcu_read_lock();
 523         preempt_disable();
 524         time_start = ktime_get_ns();
 525         for (i = 0; i < repeat; i++) {
 526                 retval = bpf_flow_dissect(prog, &ctx, eth->h_proto, ETH_HLEN,
 527                                           size, flags);
 528
 529                 if (signal_pending(current)) {
 530                         preempt_enable();
 531                         rcu_read_unlock();
 532
 533                         ret = -EINTR;
 534                         goto out;
 535                 }
 536
 537                 if (need_resched()) {
 538                         time_spent += ktime_get_ns() - time_start;
 539                         preempt_enable();
 540                         rcu_read_unlock();
 541
 542                         cond_resched();
 543
 544                         rcu_read_lock();
 545                         preempt_disable();
 546                         time_start = ktime_get_ns();
 547                 }
 548         }
 549         time_spent += ktime_get_ns() - time_start;
 550         preempt_enable();
 551         rcu_read_unlock();
 552
 553         do_div(time_spent, repeat);
 554         duration = time_spent > U32_MAX ? U32_MAX : (u32)time_spent;
 555
 556         ret = bpf_test_finish(kattr, uattr, &flow_keys, sizeof(flow_keys),
 557                               retval, duration);
 558         if (!ret)
 559                 ret = bpf_ctx_finish(kattr, uattr, user_ctx,
 560                                      sizeof(struct bpf_flow_keys));
 561
 562 out:
 563         kfree(user_ctx);
 564         kfree(data);
 565         return ret;
 566 }