// SPDX-License-Identifier: GPL-2.0-only

  /* Copyright (c) 2017 Facebook

   */
  #include <linux/bpf.h>
  #include <linux/slab.h>
  #include <linux/vmalloc.h>
  #include <linux/etherdevice.h>
  #include <linux/filter.h>
  #include <linux/sched/signal.h>

  #include <net/bpf_sk_storage.h>

  #include <net/sock.h>
  #include <net/tcp.h>

  #define CREATE_TRACE_POINTS
  #include <trace/events/bpf_test_run.h>

  static int bpf_test_run(struct bpf_prog *prog, void *ctx, u32 repeat,
  			u32 *retval, u32 *time)

  {

  	struct bpf_cgroup_storage *storage[MAX_BPF_CGROUP_STORAGE_TYPE] = { NULL };

  	enum bpf_cgroup_storage_type stype;

  	u64 time_start, time_spent = 0;

  	int ret = 0;

  	u32 i;

  	for_each_cgroup_storage_type(stype) {
  		storage[stype] = bpf_cgroup_storage_alloc(prog, stype);
  		if (IS_ERR(storage[stype])) {
  			storage[stype] = NULL;
  			for_each_cgroup_storage_type(stype)
  				bpf_cgroup_storage_free(storage[stype]);
  			return -ENOMEM;
  		}
  	}

  	if (!repeat)
  		repeat = 1;

  
  	rcu_read_lock();
  	preempt_disable();

  	time_start = ktime_get_ns();
  	for (i = 0; i < repeat; i++) {

  		bpf_cgroup_storage_set(storage);
  		*retval = BPF_PROG_RUN(prog, ctx);
  
  		if (signal_pending(current)) {
  			ret = -EINTR;
  			break;
  		}

  		if (need_resched()) {

  			time_spent += ktime_get_ns() - time_start;

  			preempt_enable();
  			rcu_read_unlock();

  			cond_resched();

  
  			rcu_read_lock();
  			preempt_disable();

  			time_start = ktime_get_ns();
  		}
  	}
  	time_spent += ktime_get_ns() - time_start;

  	preempt_enable();
  	rcu_read_unlock();

  	do_div(time_spent, repeat);
  	*time = time_spent > U32_MAX ? U32_MAX : (u32)time_spent;

  	for_each_cgroup_storage_type(stype)
  		bpf_cgroup_storage_free(storage[stype]);

  	return ret;

  }

  static int bpf_test_finish(const union bpf_attr *kattr,
  			   union bpf_attr __user *uattr, const void *data,

  			   u32 size, u32 retval, u32 duration)
  {

  	void __user *data_out = u64_to_user_ptr(kattr->test.data_out);

  	int err = -EFAULT;

  	u32 copy_size = size;

  	/* Clamp copy if the user has provided a size hint, but copy the full
  	 * buffer if not to retain old behaviour.
  	 */
  	if (kattr->test.data_size_out &&
  	    copy_size > kattr->test.data_size_out) {
  		copy_size = kattr->test.data_size_out;
  		err = -ENOSPC;
  	}
  
  	if (data_out && copy_to_user(data_out, data, copy_size))

  		goto out;
  	if (copy_to_user(&uattr->test.data_size_out, &size, sizeof(size)))
  		goto out;
  	if (copy_to_user(&uattr->test.retval, &retval, sizeof(retval)))
  		goto out;
  	if (copy_to_user(&uattr->test.duration, &duration, sizeof(duration)))
  		goto out;

  	if (err != -ENOSPC)
  		err = 0;

  out:

  	trace_bpf_test_finish(&err);

  	return err;
  }
  
  static void *bpf_test_init(const union bpf_attr *kattr, u32 size,
  			   u32 headroom, u32 tailroom)
  {
  	void __user *data_in = u64_to_user_ptr(kattr->test.data_in);
  	void *data;
  
  	if (size < ETH_HLEN || size > PAGE_SIZE - headroom - tailroom)
  		return ERR_PTR(-EINVAL);
  
  	data = kzalloc(size + headroom + tailroom, GFP_USER);
  	if (!data)
  		return ERR_PTR(-ENOMEM);
  
  	if (copy_from_user(data + headroom, data_in, size)) {
  		kfree(data);
  		return ERR_PTR(-EFAULT);
  	}
  	return data;
  }

  static void *bpf_ctx_init(const union bpf_attr *kattr, u32 max_size)
  {
  	void __user *data_in = u64_to_user_ptr(kattr->test.ctx_in);
  	void __user *data_out = u64_to_user_ptr(kattr->test.ctx_out);
  	u32 size = kattr->test.ctx_size_in;
  	void *data;
  	int err;
  
  	if (!data_in && !data_out)
  		return NULL;
  
  	data = kzalloc(max_size, GFP_USER);
  	if (!data)
  		return ERR_PTR(-ENOMEM);
  
  	if (data_in) {
  		err = bpf_check_uarg_tail_zero(data_in, max_size, size);
  		if (err) {
  			kfree(data);
  			return ERR_PTR(err);
  		}
  
  		size = min_t(u32, max_size, size);
  		if (copy_from_user(data, data_in, size)) {
  			kfree(data);
  			return ERR_PTR(-EFAULT);
  		}
  	}
  	return data;
  }
  
  static int bpf_ctx_finish(const union bpf_attr *kattr,
  			  union bpf_attr __user *uattr, const void *data,
  			  u32 size)
  {
  	void __user *data_out = u64_to_user_ptr(kattr->test.ctx_out);
  	int err = -EFAULT;
  	u32 copy_size = size;
  
  	if (!data || !data_out)
  		return 0;
  
  	if (copy_size > kattr->test.ctx_size_out) {
  		copy_size = kattr->test.ctx_size_out;
  		err = -ENOSPC;
  	}
  
  	if (copy_to_user(data_out, data, copy_size))
  		goto out;
  	if (copy_to_user(&uattr->test.ctx_size_out, &size, sizeof(size)))
  		goto out;
  	if (err != -ENOSPC)
  		err = 0;
  out:
  	return err;
  }
  
  /**
   * range_is_zero - test whether buffer is initialized
   * @buf: buffer to check
   * @from: check from this position
   * @to: check up until (excluding) this position
   *
   * This function returns true if the there is a non-zero byte
   * in the buf in the range [from,to).
   */
  static inline bool range_is_zero(void *buf, size_t from, size_t to)
  {
  	return !memchr_inv((u8 *)buf + from, 0, to - from);
  }
  
  static int convert___skb_to_skb(struct sk_buff *skb, struct __sk_buff *__skb)
  {
  	struct qdisc_skb_cb *cb = (struct qdisc_skb_cb *)skb->cb;
  
  	if (!__skb)
  		return 0;
  
  	/* make sure the fields we don't use are zeroed */
  	if (!range_is_zero(__skb, 0, offsetof(struct __sk_buff, priority)))
  		return -EINVAL;
  
  	/* priority is allowed */
  
  	if (!range_is_zero(__skb, offsetof(struct __sk_buff, priority) +
  			   FIELD_SIZEOF(struct __sk_buff, priority),
  			   offsetof(struct __sk_buff, cb)))
  		return -EINVAL;
  
  	/* cb is allowed */
  
  	if (!range_is_zero(__skb, offsetof(struct __sk_buff, cb) +
  			   FIELD_SIZEOF(struct __sk_buff, cb),
  			   sizeof(struct __sk_buff)))
  		return -EINVAL;
  
  	skb->priority = __skb->priority;
  	memcpy(&cb->data, __skb->cb, QDISC_CB_PRIV_LEN);
  
  	return 0;
  }
  
  static void convert_skb_to___skb(struct sk_buff *skb, struct __sk_buff *__skb)
  {
  	struct qdisc_skb_cb *cb = (struct qdisc_skb_cb *)skb->cb;
  
  	if (!__skb)
  		return;
  
  	__skb->priority = skb->priority;
  	memcpy(__skb->cb, &cb->data, QDISC_CB_PRIV_LEN);
  }

  int bpf_prog_test_run_skb(struct bpf_prog *prog, const union bpf_attr *kattr,
  			  union bpf_attr __user *uattr)
  {
  	bool is_l2 = false, is_direct_pkt_access = false;
  	u32 size = kattr->test.data_size_in;
  	u32 repeat = kattr->test.repeat;

  	struct __sk_buff *ctx = NULL;

  	u32 retval, duration;

  	int hh_len = ETH_HLEN;

  	struct sk_buff *skb;

  	struct sock *sk;

  	void *data;
  	int ret;

  	data = bpf_test_init(kattr, size, NET_SKB_PAD + NET_IP_ALIGN,

  			     SKB_DATA_ALIGN(sizeof(struct skb_shared_info)));
  	if (IS_ERR(data))
  		return PTR_ERR(data);

  	ctx = bpf_ctx_init(kattr, sizeof(struct __sk_buff));
  	if (IS_ERR(ctx)) {
  		kfree(data);
  		return PTR_ERR(ctx);
  	}

  	switch (prog->type) {
  	case BPF_PROG_TYPE_SCHED_CLS:
  	case BPF_PROG_TYPE_SCHED_ACT:
  		is_l2 = true;
  		/* fall through */
  	case BPF_PROG_TYPE_LWT_IN:
  	case BPF_PROG_TYPE_LWT_OUT:
  	case BPF_PROG_TYPE_LWT_XMIT:
  		is_direct_pkt_access = true;
  		break;
  	default:
  		break;
  	}

  	sk = kzalloc(sizeof(struct sock), GFP_USER);
  	if (!sk) {
  		kfree(data);

  		kfree(ctx);

  		return -ENOMEM;
  	}
  	sock_net_set(sk, current->nsproxy->net_ns);
  	sock_init_data(NULL, sk);

  	skb = build_skb(data, 0);
  	if (!skb) {
  		kfree(data);

  		kfree(ctx);

  		kfree(sk);

  		return -ENOMEM;
  	}

  	skb->sk = sk;

  	skb_reserve(skb, NET_SKB_PAD + NET_IP_ALIGN);

  	__skb_put(skb, size);
  	skb->protocol = eth_type_trans(skb, current->nsproxy->net_ns->loopback_dev);
  	skb_reset_network_header(skb);
  
  	if (is_l2)

  		__skb_push(skb, hh_len);

  	if (is_direct_pkt_access)

  		bpf_compute_data_pointers(skb);

  	ret = convert___skb_to_skb(skb, ctx);
  	if (ret)
  		goto out;

  	ret = bpf_test_run(prog, skb, repeat, &retval, &duration);

  	if (ret)
  		goto out;

  	if (!is_l2) {
  		if (skb_headroom(skb) < hh_len) {
  			int nhead = HH_DATA_ALIGN(hh_len - skb_headroom(skb));
  
  			if (pskb_expand_head(skb, nhead, 0, GFP_USER)) {

  				ret = -ENOMEM;
  				goto out;

  			}
  		}
  		memset(__skb_push(skb, hh_len), 0, hh_len);
  	}

  	convert_skb_to___skb(skb, ctx);

  	size = skb->len;
  	/* bpf program can never convert linear skb to non-linear */
  	if (WARN_ON_ONCE(skb_is_nonlinear(skb)))
  		size = skb_headlen(skb);

  	ret = bpf_test_finish(kattr, uattr, skb->data, size, retval, duration);

  	if (!ret)
  		ret = bpf_ctx_finish(kattr, uattr, ctx,
  				     sizeof(struct __sk_buff));
  out:

  	kfree_skb(skb);

  	bpf_sk_storage_free(sk);

  	kfree(sk);

  	kfree(ctx);

  	return ret;
  }
  
  int bpf_prog_test_run_xdp(struct bpf_prog *prog, const union bpf_attr *kattr,
  			  union bpf_attr __user *uattr)
  {
  	u32 size = kattr->test.data_size_in;
  	u32 repeat = kattr->test.repeat;

  	struct netdev_rx_queue *rxqueue;

  	struct xdp_buff xdp = {};
  	u32 retval, duration;
  	void *data;
  	int ret;

  	if (kattr->test.ctx_in || kattr->test.ctx_out)
  		return -EINVAL;

  	data = bpf_test_init(kattr, size, XDP_PACKET_HEADROOM + NET_IP_ALIGN, 0);

  	if (IS_ERR(data))
  		return PTR_ERR(data);
  
  	xdp.data_hard_start = data;

  	xdp.data = data + XDP_PACKET_HEADROOM + NET_IP_ALIGN;

  	xdp.data_meta = xdp.data;

  	xdp.data_end = xdp.data + size;

  	rxqueue = __netif_get_rx_queue(current->nsproxy->net_ns->loopback_dev, 0);
  	xdp.rxq = &rxqueue->xdp_rxq;

  	ret = bpf_test_run(prog, &xdp, repeat, &retval, &duration);
  	if (ret)
  		goto out;

  	if (xdp.data != data + XDP_PACKET_HEADROOM + NET_IP_ALIGN ||
  	    xdp.data_end != xdp.data + size)

  		size = xdp.data_end - xdp.data;

  	ret = bpf_test_finish(kattr, uattr, xdp.data, size, retval, duration);

  out:

  	kfree(data);
  	return ret;
  }

  
  int bpf_prog_test_run_flow_dissector(struct bpf_prog *prog,
  				     const union bpf_attr *kattr,
  				     union bpf_attr __user *uattr)
  {
  	u32 size = kattr->test.data_size_in;

  	struct bpf_flow_dissector ctx = {};

  	u32 repeat = kattr->test.repeat;
  	struct bpf_flow_keys flow_keys;
  	u64 time_start, time_spent = 0;

  	const struct ethhdr *eth;

  	u32 retval, duration;

  	void *data;
  	int ret;
  	u32 i;
  
  	if (prog->type != BPF_PROG_TYPE_FLOW_DISSECTOR)
  		return -EINVAL;

  	if (kattr->test.ctx_in || kattr->test.ctx_out)
  		return -EINVAL;

  	if (size < ETH_HLEN)
  		return -EINVAL;
  
  	data = bpf_test_init(kattr, size, 0, 0);

  	if (IS_ERR(data))
  		return PTR_ERR(data);

  	eth = (struct ethhdr *)data;

  	if (!repeat)
  		repeat = 1;

  	ctx.flow_keys = &flow_keys;
  	ctx.data = data;
  	ctx.data_end = (__u8 *)data + size;

  	rcu_read_lock();
  	preempt_disable();

  	time_start = ktime_get_ns();
  	for (i = 0; i < repeat; i++) {

  		retval = bpf_flow_dissect(prog, &ctx, eth->h_proto, ETH_HLEN,

  					  size, 0);

  		if (signal_pending(current)) {
  			preempt_enable();
  			rcu_read_unlock();
  
  			ret = -EINTR;
  			goto out;
  		}

  
  		if (need_resched()) {

  			time_spent += ktime_get_ns() - time_start;

  			preempt_enable();
  			rcu_read_unlock();

  			cond_resched();

  
  			rcu_read_lock();
  			preempt_disable();

  			time_start = ktime_get_ns();
  		}
  	}
  	time_spent += ktime_get_ns() - time_start;

  	preempt_enable();
  	rcu_read_unlock();

  	do_div(time_spent, repeat);
  	duration = time_spent > U32_MAX ? U32_MAX : (u32)time_spent;
  
  	ret = bpf_test_finish(kattr, uattr, &flow_keys, sizeof(flow_keys),
  			      retval, duration);

  out:

  	kfree(data);

  	return ret;
  }