xref: /openbmc/linux/net/bpf/test_run.c (revision 8bad74f9840f87661f20ced3dc80c84ab4fd55a1)
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 
14 static __always_inline u32 bpf_test_run_one(struct bpf_prog *prog, void *ctx,
15 		struct bpf_cgroup_storage *storage[MAX_BPF_CGROUP_STORAGE_TYPE])
16 {
17 	u32 ret;
18 
19 	preempt_disable();
20 	rcu_read_lock();
21 	bpf_cgroup_storage_set(storage);
22 	ret = BPF_PROG_RUN(prog, ctx);
23 	rcu_read_unlock();
24 	preempt_enable();
25 
26 	return ret;
27 }
28 
29 static u32 bpf_test_run(struct bpf_prog *prog, void *ctx, u32 repeat, u32 *time)
30 {
31 	struct bpf_cgroup_storage *storage[MAX_BPF_CGROUP_STORAGE_TYPE] = { 0 };
32 	enum bpf_cgroup_storage_type stype;
33 	u64 time_start, time_spent = 0;
34 	u32 ret = 0, i;
35 
36 	for_each_cgroup_storage_type(stype) {
37 		storage[stype] = bpf_cgroup_storage_alloc(prog, stype);
38 		if (IS_ERR(storage[stype])) {
39 			storage[stype] = NULL;
40 			for_each_cgroup_storage_type(stype)
41 				bpf_cgroup_storage_free(storage[stype]);
42 			return -ENOMEM;
43 		}
44 	}
45 
46 	if (!repeat)
47 		repeat = 1;
48 	time_start = ktime_get_ns();
49 	for (i = 0; i < repeat; i++) {
50 		ret = bpf_test_run_one(prog, ctx, storage);
51 		if (need_resched()) {
52 			if (signal_pending(current))
53 				break;
54 			time_spent += ktime_get_ns() - time_start;
55 			cond_resched();
56 			time_start = ktime_get_ns();
57 		}
58 	}
59 	time_spent += ktime_get_ns() - time_start;
60 	do_div(time_spent, repeat);
61 	*time = time_spent > U32_MAX ? U32_MAX : (u32)time_spent;
62 
63 	for_each_cgroup_storage_type(stype)
64 		bpf_cgroup_storage_free(storage[stype]);
65 
66 	return ret;
67 }
68 
69 static int bpf_test_finish(const union bpf_attr *kattr,
70 			   union bpf_attr __user *uattr, const void *data,
71 			   u32 size, u32 retval, u32 duration)
72 {
73 	void __user *data_out = u64_to_user_ptr(kattr->test.data_out);
74 	int err = -EFAULT;
75 
76 	if (data_out && copy_to_user(data_out, data, size))
77 		goto out;
78 	if (copy_to_user(&uattr->test.data_size_out, &size, sizeof(size)))
79 		goto out;
80 	if (copy_to_user(&uattr->test.retval, &retval, sizeof(retval)))
81 		goto out;
82 	if (copy_to_user(&uattr->test.duration, &duration, sizeof(duration)))
83 		goto out;
84 	err = 0;
85 out:
86 	return err;
87 }
88 
89 static void *bpf_test_init(const union bpf_attr *kattr, u32 size,
90 			   u32 headroom, u32 tailroom)
91 {
92 	void __user *data_in = u64_to_user_ptr(kattr->test.data_in);
93 	void *data;
94 
95 	if (size < ETH_HLEN || size > PAGE_SIZE - headroom - tailroom)
96 		return ERR_PTR(-EINVAL);
97 
98 	data = kzalloc(size + headroom + tailroom, GFP_USER);
99 	if (!data)
100 		return ERR_PTR(-ENOMEM);
101 
102 	if (copy_from_user(data + headroom, data_in, size)) {
103 		kfree(data);
104 		return ERR_PTR(-EFAULT);
105 	}
106 	return data;
107 }
108 
109 int bpf_prog_test_run_skb(struct bpf_prog *prog, const union bpf_attr *kattr,
110 			  union bpf_attr __user *uattr)
111 {
112 	bool is_l2 = false, is_direct_pkt_access = false;
113 	u32 size = kattr->test.data_size_in;
114 	u32 repeat = kattr->test.repeat;
115 	u32 retval, duration;
116 	int hh_len = ETH_HLEN;
117 	struct sk_buff *skb;
118 	void *data;
119 	int ret;
120 
121 	data = bpf_test_init(kattr, size, NET_SKB_PAD + NET_IP_ALIGN,
122 			     SKB_DATA_ALIGN(sizeof(struct skb_shared_info)));
123 	if (IS_ERR(data))
124 		return PTR_ERR(data);
125 
126 	switch (prog->type) {
127 	case BPF_PROG_TYPE_SCHED_CLS:
128 	case BPF_PROG_TYPE_SCHED_ACT:
129 		is_l2 = true;
130 		/* fall through */
131 	case BPF_PROG_TYPE_LWT_IN:
132 	case BPF_PROG_TYPE_LWT_OUT:
133 	case BPF_PROG_TYPE_LWT_XMIT:
134 		is_direct_pkt_access = true;
135 		break;
136 	default:
137 		break;
138 	}
139 
140 	skb = build_skb(data, 0);
141 	if (!skb) {
142 		kfree(data);
143 		return -ENOMEM;
144 	}
145 
146 	skb_reserve(skb, NET_SKB_PAD + NET_IP_ALIGN);
147 	__skb_put(skb, size);
148 	skb->protocol = eth_type_trans(skb, current->nsproxy->net_ns->loopback_dev);
149 	skb_reset_network_header(skb);
150 
151 	if (is_l2)
152 		__skb_push(skb, hh_len);
153 	if (is_direct_pkt_access)
154 		bpf_compute_data_pointers(skb);
155 	retval = bpf_test_run(prog, skb, repeat, &duration);
156 	if (!is_l2) {
157 		if (skb_headroom(skb) < hh_len) {
158 			int nhead = HH_DATA_ALIGN(hh_len - skb_headroom(skb));
159 
160 			if (pskb_expand_head(skb, nhead, 0, GFP_USER)) {
161 				kfree_skb(skb);
162 				return -ENOMEM;
163 			}
164 		}
165 		memset(__skb_push(skb, hh_len), 0, hh_len);
166 	}
167 
168 	size = skb->len;
169 	/* bpf program can never convert linear skb to non-linear */
170 	if (WARN_ON_ONCE(skb_is_nonlinear(skb)))
171 		size = skb_headlen(skb);
172 	ret = bpf_test_finish(kattr, uattr, skb->data, size, retval, duration);
173 	kfree_skb(skb);
174 	return ret;
175 }
176 
177 int bpf_prog_test_run_xdp(struct bpf_prog *prog, const union bpf_attr *kattr,
178 			  union bpf_attr __user *uattr)
179 {
180 	u32 size = kattr->test.data_size_in;
181 	u32 repeat = kattr->test.repeat;
182 	struct netdev_rx_queue *rxqueue;
183 	struct xdp_buff xdp = {};
184 	u32 retval, duration;
185 	void *data;
186 	int ret;
187 
188 	data = bpf_test_init(kattr, size, XDP_PACKET_HEADROOM + NET_IP_ALIGN, 0);
189 	if (IS_ERR(data))
190 		return PTR_ERR(data);
191 
192 	xdp.data_hard_start = data;
193 	xdp.data = data + XDP_PACKET_HEADROOM + NET_IP_ALIGN;
194 	xdp.data_meta = xdp.data;
195 	xdp.data_end = xdp.data + size;
196 
197 	rxqueue = __netif_get_rx_queue(current->nsproxy->net_ns->loopback_dev, 0);
198 	xdp.rxq = &rxqueue->xdp_rxq;
199 
200 	retval = bpf_test_run(prog, &xdp, repeat, &duration);
201 	if (xdp.data != data + XDP_PACKET_HEADROOM + NET_IP_ALIGN ||
202 	    xdp.data_end != xdp.data + size)
203 		size = xdp.data_end - xdp.data;
204 	ret = bpf_test_finish(kattr, uattr, xdp.data, size, retval, duration);
205 	kfree(data);
206 	return ret;
207 }
208