linux/net/bpf/test_run.c
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   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
  17static int bpf_test_run(struct bpf_prog *prog, void *ctx, u32 repeat,
  18                        u32 *retval, u32 *time)
  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                *retval = BPF_PROG_RUN(prog, ctx);
  45
  46                if (signal_pending(current)) {
  47                        ret = -EINTR;
  48                        break;
  49                }
  50
  51                if (need_resched()) {
  52                        time_spent += ktime_get_ns() - time_start;
  53                        preempt_enable();
  54                        rcu_read_unlock();
  55
  56                        cond_resched();
  57
  58                        rcu_read_lock();
  59                        preempt_disable();
  60                        time_start = ktime_get_ns();
  61                }
  62        }
  63        time_spent += ktime_get_ns() - time_start;
  64        preempt_enable();
  65        rcu_read_unlock();
  66
  67        do_div(time_spent, repeat);
  68        *time = time_spent > U32_MAX ? U32_MAX : (u32)time_spent;
  69
  70        for_each_cgroup_storage_type(stype)
  71                bpf_cgroup_storage_free(storage[stype]);
  72
  73        return ret;
  74}
  75
  76static int bpf_test_finish(const union bpf_attr *kattr,
  77                           union bpf_attr __user *uattr, const void *data,
  78                           u32 size, u32 retval, u32 duration)
  79{
  80        void __user *data_out = u64_to_user_ptr(kattr->test.data_out);
  81        int err = -EFAULT;
  82        u32 copy_size = size;
  83
  84        /* Clamp copy if the user has provided a size hint, but copy the full
  85         * buffer if not to retain old behaviour.
  86         */
  87        if (kattr->test.data_size_out &&
  88            copy_size > kattr->test.data_size_out) {
  89                copy_size = kattr->test.data_size_out;
  90                err = -ENOSPC;
  91        }
  92
  93        if (data_out && copy_to_user(data_out, data, copy_size))
  94                goto out;
  95        if (copy_to_user(&uattr->test.data_size_out, &size, sizeof(size)))
  96                goto out;
  97        if (copy_to_user(&uattr->test.retval, &retval, sizeof(retval)))
  98                goto out;
  99        if (copy_to_user(&uattr->test.duration, &duration, sizeof(duration)))
 100                goto out;
 101        if (err != -ENOSPC)
 102                err = 0;
 103out:
 104        trace_bpf_test_finish(&err);
 105        return err;
 106}
 107
 108static void *bpf_test_init(const union bpf_attr *kattr, u32 size,
 109                           u32 headroom, u32 tailroom)
 110{
 111        void __user *data_in = u64_to_user_ptr(kattr->test.data_in);
 112        void *data;
 113
 114        if (size < ETH_HLEN || size > PAGE_SIZE - headroom - tailroom)
 115                return ERR_PTR(-EINVAL);
 116
 117        data = kzalloc(size + headroom + tailroom, GFP_USER);
 118        if (!data)
 119                return ERR_PTR(-ENOMEM);
 120
 121        if (copy_from_user(data + headroom, data_in, size)) {
 122                kfree(data);
 123                return ERR_PTR(-EFAULT);
 124        }
 125        return data;
 126}
 127
 128static void *bpf_ctx_init(const union bpf_attr *kattr, u32 max_size)
 129{
 130        void __user *data_in = u64_to_user_ptr(kattr->test.ctx_in);
 131        void __user *data_out = u64_to_user_ptr(kattr->test.ctx_out);
 132        u32 size = kattr->test.ctx_size_in;
 133        void *data;
 134        int err;
 135
 136        if (!data_in && !data_out)
 137                return NULL;
 138
 139        data = kzalloc(max_size, GFP_USER);
 140        if (!data)
 141                return ERR_PTR(-ENOMEM);
 142
 143        if (data_in) {
 144                err = bpf_check_uarg_tail_zero(data_in, max_size, size);
 145                if (err) {
 146                        kfree(data);
 147                        return ERR_PTR(err);
 148                }
 149
 150                size = min_t(u32, max_size, size);
 151                if (copy_from_user(data, data_in, size)) {
 152                        kfree(data);
 153                        return ERR_PTR(-EFAULT);
 154                }
 155        }
 156        return data;
 157}
 158
 159static int bpf_ctx_finish(const union bpf_attr *kattr,
 160                          union bpf_attr __user *uattr, const void *data,
 161                          u32 size)
 162{
 163        void __user *data_out = u64_to_user_ptr(kattr->test.ctx_out);
 164        int err = -EFAULT;
 165        u32 copy_size = size;
 166
 167        if (!data || !data_out)
 168                return 0;
 169
 170        if (copy_size > kattr->test.ctx_size_out) {
 171                copy_size = kattr->test.ctx_size_out;
 172                err = -ENOSPC;
 173        }
 174
 175        if (copy_to_user(data_out, data, copy_size))
 176                goto out;
 177        if (copy_to_user(&uattr->test.ctx_size_out, &size, sizeof(size)))
 178                goto out;
 179        if (err != -ENOSPC)
 180                err = 0;
 181out:
 182        return err;
 183}
 184
 185/**
 186 * range_is_zero - test whether buffer is initialized
 187 * @buf: buffer to check
 188 * @from: check from this position
 189 * @to: check up until (excluding) this position
 190 *
 191 * This function returns true if the there is a non-zero byte
 192 * in the buf in the range [from,to).
 193 */
 194static inline bool range_is_zero(void *buf, size_t from, size_t to)
 195{
 196        return !memchr_inv((u8 *)buf + from, 0, to - from);
 197}
 198
 199static int convert___skb_to_skb(struct sk_buff *skb, struct __sk_buff *__skb)
 200{
 201        struct qdisc_skb_cb *cb = (struct qdisc_skb_cb *)skb->cb;
 202
 203        if (!__skb)
 204                return 0;
 205
 206        /* make sure the fields we don't use are zeroed */
 207        if (!range_is_zero(__skb, 0, offsetof(struct __sk_buff, priority)))
 208                return -EINVAL;
 209
 210        /* priority is allowed */
 211
 212        if (!range_is_zero(__skb, offsetof(struct __sk_buff, priority) +
 213                           FIELD_SIZEOF(struct __sk_buff, priority),
 214                           offsetof(struct __sk_buff, cb)))
 215                return -EINVAL;
 216
 217        /* cb is allowed */
 218
 219        if (!range_is_zero(__skb, offsetof(struct __sk_buff, cb) +
 220                           FIELD_SIZEOF(struct __sk_buff, cb),
 221                           sizeof(struct __sk_buff)))
 222                return -EINVAL;
 223
 224        skb->priority = __skb->priority;
 225        memcpy(&cb->data, __skb->cb, QDISC_CB_PRIV_LEN);
 226
 227        return 0;
 228}
 229
 230static void convert_skb_to___skb(struct sk_buff *skb, struct __sk_buff *__skb)
 231{
 232        struct qdisc_skb_cb *cb = (struct qdisc_skb_cb *)skb->cb;
 233
 234        if (!__skb)
 235                return;
 236
 237        __skb->priority = skb->priority;
 238        memcpy(__skb->cb, &cb->data, QDISC_CB_PRIV_LEN);
 239}
 240
 241int bpf_prog_test_run_skb(struct bpf_prog *prog, const union bpf_attr *kattr,
 242                          union bpf_attr __user *uattr)
 243{
 244        bool is_l2 = false, is_direct_pkt_access = false;
 245        u32 size = kattr->test.data_size_in;
 246        u32 repeat = kattr->test.repeat;
 247        struct __sk_buff *ctx = NULL;
 248        u32 retval, duration;
 249        int hh_len = ETH_HLEN;
 250        struct sk_buff *skb;
 251        struct sock *sk;
 252        void *data;
 253        int ret;
 254
 255        data = bpf_test_init(kattr, size, NET_SKB_PAD + NET_IP_ALIGN,
 256                             SKB_DATA_ALIGN(sizeof(struct skb_shared_info)));
 257        if (IS_ERR(data))
 258                return PTR_ERR(data);
 259
 260        ctx = bpf_ctx_init(kattr, sizeof(struct __sk_buff));
 261        if (IS_ERR(ctx)) {
 262                kfree(data);
 263                return PTR_ERR(ctx);
 264        }
 265
 266        switch (prog->type) {
 267        case BPF_PROG_TYPE_SCHED_CLS:
 268        case BPF_PROG_TYPE_SCHED_ACT:
 269                is_l2 = true;
 270                /* fall through */
 271        case BPF_PROG_TYPE_LWT_IN:
 272        case BPF_PROG_TYPE_LWT_OUT:
 273        case BPF_PROG_TYPE_LWT_XMIT:
 274                is_direct_pkt_access = true;
 275                break;
 276        default:
 277                break;
 278        }
 279
 280        sk = kzalloc(sizeof(struct sock), GFP_USER);
 281        if (!sk) {
 282                kfree(data);
 283                kfree(ctx);
 284                return -ENOMEM;
 285        }
 286        sock_net_set(sk, current->nsproxy->net_ns);
 287        sock_init_data(NULL, sk);
 288
 289        skb = build_skb(data, 0);
 290        if (!skb) {
 291                kfree(data);
 292                kfree(ctx);
 293                kfree(sk);
 294                return -ENOMEM;
 295        }
 296        skb->sk = sk;
 297
 298        skb_reserve(skb, NET_SKB_PAD + NET_IP_ALIGN);
 299        __skb_put(skb, size);
 300        skb->protocol = eth_type_trans(skb, current->nsproxy->net_ns->loopback_dev);
 301        skb_reset_network_header(skb);
 302
 303        if (is_l2)
 304                __skb_push(skb, hh_len);
 305        if (is_direct_pkt_access)
 306                bpf_compute_data_pointers(skb);
 307        ret = convert___skb_to_skb(skb, ctx);
 308        if (ret)
 309                goto out;
 310        ret = bpf_test_run(prog, skb, repeat, &retval, &duration);
 311        if (ret)
 312                goto out;
 313        if (!is_l2) {
 314                if (skb_headroom(skb) < hh_len) {
 315                        int nhead = HH_DATA_ALIGN(hh_len - skb_headroom(skb));
 316
 317                        if (pskb_expand_head(skb, nhead, 0, GFP_USER)) {
 318                                ret = -ENOMEM;
 319                                goto out;
 320                        }
 321                }
 322                memset(__skb_push(skb, hh_len), 0, hh_len);
 323        }
 324        convert_skb_to___skb(skb, ctx);
 325
 326        size = skb->len;
 327        /* bpf program can never convert linear skb to non-linear */
 328        if (WARN_ON_ONCE(skb_is_nonlinear(skb)))
 329                size = skb_headlen(skb);
 330        ret = bpf_test_finish(kattr, uattr, skb->data, size, retval, duration);
 331        if (!ret)
 332                ret = bpf_ctx_finish(kattr, uattr, ctx,
 333                                     sizeof(struct __sk_buff));
 334out:
 335        kfree_skb(skb);
 336        bpf_sk_storage_free(sk);
 337        kfree(sk);
 338        kfree(ctx);
 339        return ret;
 340}
 341
 342int bpf_prog_test_run_xdp(struct bpf_prog *prog, const union bpf_attr *kattr,
 343                          union bpf_attr __user *uattr)
 344{
 345        u32 size = kattr->test.data_size_in;
 346        u32 repeat = kattr->test.repeat;
 347        struct netdev_rx_queue *rxqueue;
 348        struct xdp_buff xdp = {};
 349        u32 retval, duration;
 350        void *data;
 351        int ret;
 352
 353        if (kattr->test.ctx_in || kattr->test.ctx_out)
 354                return -EINVAL;
 355
 356        data = bpf_test_init(kattr, size, XDP_PACKET_HEADROOM + NET_IP_ALIGN, 0);
 357        if (IS_ERR(data))
 358                return PTR_ERR(data);
 359
 360        xdp.data_hard_start = data;
 361        xdp.data = data + XDP_PACKET_HEADROOM + NET_IP_ALIGN;
 362        xdp.data_meta = xdp.data;
 363        xdp.data_end = xdp.data + size;
 364
 365        rxqueue = __netif_get_rx_queue(current->nsproxy->net_ns->loopback_dev, 0);
 366        xdp.rxq = &rxqueue->xdp_rxq;
 367
 368        ret = bpf_test_run(prog, &xdp, repeat, &retval, &duration);
 369        if (ret)
 370                goto out;
 371        if (xdp.data != data + XDP_PACKET_HEADROOM + NET_IP_ALIGN ||
 372            xdp.data_end != xdp.data + size)
 373                size = xdp.data_end - xdp.data;
 374        ret = bpf_test_finish(kattr, uattr, xdp.data, size, retval, duration);
 375out:
 376        kfree(data);
 377        return ret;
 378}
 379
 380int bpf_prog_test_run_flow_dissector(struct bpf_prog *prog,
 381                                     const union bpf_attr *kattr,
 382                                     union bpf_attr __user *uattr)
 383{
 384        u32 size = kattr->test.data_size_in;
 385        struct bpf_flow_dissector ctx = {};
 386        u32 repeat = kattr->test.repeat;
 387        struct bpf_flow_keys flow_keys;
 388        u64 time_start, time_spent = 0;
 389        const struct ethhdr *eth;
 390        u32 retval, duration;
 391        void *data;
 392        int ret;
 393        u32 i;
 394
 395        if (prog->type != BPF_PROG_TYPE_FLOW_DISSECTOR)
 396                return -EINVAL;
 397
 398        if (kattr->test.ctx_in || kattr->test.ctx_out)
 399                return -EINVAL;
 400
 401        if (size < ETH_HLEN)
 402                return -EINVAL;
 403
 404        data = bpf_test_init(kattr, size, 0, 0);
 405        if (IS_ERR(data))
 406                return PTR_ERR(data);
 407
 408        eth = (struct ethhdr *)data;
 409
 410        if (!repeat)
 411                repeat = 1;
 412
 413        ctx.flow_keys = &flow_keys;
 414        ctx.data = data;
 415        ctx.data_end = (__u8 *)data + size;
 416
 417        rcu_read_lock();
 418        preempt_disable();
 419        time_start = ktime_get_ns();
 420        for (i = 0; i < repeat; i++) {
 421                retval = bpf_flow_dissect(prog, &ctx, eth->h_proto, ETH_HLEN,
 422                                          size);
 423
 424                if (signal_pending(current)) {
 425                        preempt_enable();
 426                        rcu_read_unlock();
 427
 428                        ret = -EINTR;
 429                        goto out;
 430                }
 431
 432                if (need_resched()) {
 433                        time_spent += ktime_get_ns() - time_start;
 434                        preempt_enable();
 435                        rcu_read_unlock();
 436
 437                        cond_resched();
 438
 439                        rcu_read_lock();
 440                        preempt_disable();
 441                        time_start = ktime_get_ns();
 442                }
 443        }
 444        time_spent += ktime_get_ns() - time_start;
 445        preempt_enable();
 446        rcu_read_unlock();
 447
 448        do_div(time_spent, repeat);
 449        duration = time_spent > U32_MAX ? U32_MAX : (u32)time_spent;
 450
 451        ret = bpf_test_finish(kattr, uattr, &flow_keys, sizeof(flow_keys),
 452                              retval, duration);
 453
 454out:
 455        kfree(data);
 456        return ret;
 457}
 458