xref: /openbmc/linux/net/bpf/test_run.c (revision be709d48)
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 int bpf_test_run(struct bpf_prog *prog, void *ctx, u32 repeat,
17 			u32 *retval, u32 *time)
18 {
19 	struct bpf_cgroup_storage *storage[MAX_BPF_CGROUP_STORAGE_TYPE] = { NULL };
20 	enum bpf_cgroup_storage_type stype;
21 	u64 time_start, time_spent = 0;
22 	int ret = 0;
23 	u32 i;
24 
25 	for_each_cgroup_storage_type(stype) {
26 		storage[stype] = bpf_cgroup_storage_alloc(prog, stype);
27 		if (IS_ERR(storage[stype])) {
28 			storage[stype] = NULL;
29 			for_each_cgroup_storage_type(stype)
30 				bpf_cgroup_storage_free(storage[stype]);
31 			return -ENOMEM;
32 		}
33 	}
34 
35 	if (!repeat)
36 		repeat = 1;
37 
38 	rcu_read_lock();
39 	preempt_disable();
40 	time_start = ktime_get_ns();
41 	for (i = 0; i < repeat; i++) {
42 		bpf_cgroup_storage_set(storage);
43 		*retval = BPF_PROG_RUN(prog, ctx);
44 
45 		if (signal_pending(current)) {
46 			ret = -EINTR;
47 			break;
48 		}
49 
50 		if (need_resched()) {
51 			time_spent += ktime_get_ns() - time_start;
52 			preempt_enable();
53 			rcu_read_unlock();
54 
55 			cond_resched();
56 
57 			rcu_read_lock();
58 			preempt_disable();
59 			time_start = ktime_get_ns();
60 		}
61 	}
62 	time_spent += ktime_get_ns() - time_start;
63 	preempt_enable();
64 	rcu_read_unlock();
65 
66 	do_div(time_spent, repeat);
67 	*time = time_spent > U32_MAX ? U32_MAX : (u32)time_spent;
68 
69 	for_each_cgroup_storage_type(stype)
70 		bpf_cgroup_storage_free(storage[stype]);
71 
72 	return ret;
73 }
74 
75 static int bpf_test_finish(const union bpf_attr *kattr,
76 			   union bpf_attr __user *uattr, const void *data,
77 			   u32 size, u32 retval, u32 duration)
78 {
79 	void __user *data_out = u64_to_user_ptr(kattr->test.data_out);
80 	int err = -EFAULT;
81 	u32 copy_size = size;
82 
83 	/* Clamp copy if the user has provided a size hint, but copy the full
84 	 * buffer if not to retain old behaviour.
85 	 */
86 	if (kattr->test.data_size_out &&
87 	    copy_size > kattr->test.data_size_out) {
88 		copy_size = kattr->test.data_size_out;
89 		err = -ENOSPC;
90 	}
91 
92 	if (data_out && copy_to_user(data_out, data, copy_size))
93 		goto out;
94 	if (copy_to_user(&uattr->test.data_size_out, &size, sizeof(size)))
95 		goto out;
96 	if (copy_to_user(&uattr->test.retval, &retval, sizeof(retval)))
97 		goto out;
98 	if (copy_to_user(&uattr->test.duration, &duration, sizeof(duration)))
99 		goto out;
100 	if (err != -ENOSPC)
101 		err = 0;
102 out:
103 	return err;
104 }
105 
106 static void *bpf_test_init(const union bpf_attr *kattr, u32 size,
107 			   u32 headroom, u32 tailroom)
108 {
109 	void __user *data_in = u64_to_user_ptr(kattr->test.data_in);
110 	void *data;
111 
112 	if (size < ETH_HLEN || size > PAGE_SIZE - headroom - tailroom)
113 		return ERR_PTR(-EINVAL);
114 
115 	data = kzalloc(size + headroom + tailroom, GFP_USER);
116 	if (!data)
117 		return ERR_PTR(-ENOMEM);
118 
119 	if (copy_from_user(data + headroom, data_in, size)) {
120 		kfree(data);
121 		return ERR_PTR(-EFAULT);
122 	}
123 	return data;
124 }
125 
126 int bpf_prog_test_run_skb(struct bpf_prog *prog, const union bpf_attr *kattr,
127 			  union bpf_attr __user *uattr)
128 {
129 	bool is_l2 = false, is_direct_pkt_access = false;
130 	u32 size = kattr->test.data_size_in;
131 	u32 repeat = kattr->test.repeat;
132 	u32 retval, duration;
133 	int hh_len = ETH_HLEN;
134 	struct sk_buff *skb;
135 	struct sock *sk;
136 	void *data;
137 	int ret;
138 
139 	data = bpf_test_init(kattr, size, NET_SKB_PAD + NET_IP_ALIGN,
140 			     SKB_DATA_ALIGN(sizeof(struct skb_shared_info)));
141 	if (IS_ERR(data))
142 		return PTR_ERR(data);
143 
144 	switch (prog->type) {
145 	case BPF_PROG_TYPE_SCHED_CLS:
146 	case BPF_PROG_TYPE_SCHED_ACT:
147 		is_l2 = true;
148 		/* fall through */
149 	case BPF_PROG_TYPE_LWT_IN:
150 	case BPF_PROG_TYPE_LWT_OUT:
151 	case BPF_PROG_TYPE_LWT_XMIT:
152 		is_direct_pkt_access = true;
153 		break;
154 	default:
155 		break;
156 	}
157 
158 	sk = kzalloc(sizeof(struct sock), GFP_USER);
159 	if (!sk) {
160 		kfree(data);
161 		return -ENOMEM;
162 	}
163 	sock_net_set(sk, current->nsproxy->net_ns);
164 	sock_init_data(NULL, sk);
165 
166 	skb = build_skb(data, 0);
167 	if (!skb) {
168 		kfree(data);
169 		kfree(sk);
170 		return -ENOMEM;
171 	}
172 	skb->sk = sk;
173 
174 	skb_reserve(skb, NET_SKB_PAD + NET_IP_ALIGN);
175 	__skb_put(skb, size);
176 	skb->protocol = eth_type_trans(skb, current->nsproxy->net_ns->loopback_dev);
177 	skb_reset_network_header(skb);
178 
179 	if (is_l2)
180 		__skb_push(skb, hh_len);
181 	if (is_direct_pkt_access)
182 		bpf_compute_data_pointers(skb);
183 	ret = bpf_test_run(prog, skb, repeat, &retval, &duration);
184 	if (ret) {
185 		kfree_skb(skb);
186 		kfree(sk);
187 		return ret;
188 	}
189 	if (!is_l2) {
190 		if (skb_headroom(skb) < hh_len) {
191 			int nhead = HH_DATA_ALIGN(hh_len - skb_headroom(skb));
192 
193 			if (pskb_expand_head(skb, nhead, 0, GFP_USER)) {
194 				kfree_skb(skb);
195 				kfree(sk);
196 				return -ENOMEM;
197 			}
198 		}
199 		memset(__skb_push(skb, hh_len), 0, hh_len);
200 	}
201 
202 	size = skb->len;
203 	/* bpf program can never convert linear skb to non-linear */
204 	if (WARN_ON_ONCE(skb_is_nonlinear(skb)))
205 		size = skb_headlen(skb);
206 	ret = bpf_test_finish(kattr, uattr, skb->data, size, retval, duration);
207 	kfree_skb(skb);
208 	kfree(sk);
209 	return ret;
210 }
211 
212 int bpf_prog_test_run_xdp(struct bpf_prog *prog, const union bpf_attr *kattr,
213 			  union bpf_attr __user *uattr)
214 {
215 	u32 size = kattr->test.data_size_in;
216 	u32 repeat = kattr->test.repeat;
217 	struct netdev_rx_queue *rxqueue;
218 	struct xdp_buff xdp = {};
219 	u32 retval, duration;
220 	void *data;
221 	int ret;
222 
223 	data = bpf_test_init(kattr, size, XDP_PACKET_HEADROOM + NET_IP_ALIGN, 0);
224 	if (IS_ERR(data))
225 		return PTR_ERR(data);
226 
227 	xdp.data_hard_start = data;
228 	xdp.data = data + XDP_PACKET_HEADROOM + NET_IP_ALIGN;
229 	xdp.data_meta = xdp.data;
230 	xdp.data_end = xdp.data + size;
231 
232 	rxqueue = __netif_get_rx_queue(current->nsproxy->net_ns->loopback_dev, 0);
233 	xdp.rxq = &rxqueue->xdp_rxq;
234 
235 	ret = bpf_test_run(prog, &xdp, repeat, &retval, &duration);
236 	if (ret)
237 		goto out;
238 	if (xdp.data != data + XDP_PACKET_HEADROOM + NET_IP_ALIGN ||
239 	    xdp.data_end != xdp.data + size)
240 		size = xdp.data_end - xdp.data;
241 	ret = bpf_test_finish(kattr, uattr, xdp.data, size, retval, duration);
242 out:
243 	kfree(data);
244 	return ret;
245 }
246 
247 int bpf_prog_test_run_flow_dissector(struct bpf_prog *prog,
248 				     const union bpf_attr *kattr,
249 				     union bpf_attr __user *uattr)
250 {
251 	u32 size = kattr->test.data_size_in;
252 	u32 repeat = kattr->test.repeat;
253 	struct bpf_flow_keys flow_keys;
254 	u64 time_start, time_spent = 0;
255 	struct bpf_skb_data_end *cb;
256 	u32 retval, duration;
257 	struct sk_buff *skb;
258 	struct sock *sk;
259 	void *data;
260 	int ret;
261 	u32 i;
262 
263 	if (prog->type != BPF_PROG_TYPE_FLOW_DISSECTOR)
264 		return -EINVAL;
265 
266 	data = bpf_test_init(kattr, size, NET_SKB_PAD + NET_IP_ALIGN,
267 			     SKB_DATA_ALIGN(sizeof(struct skb_shared_info)));
268 	if (IS_ERR(data))
269 		return PTR_ERR(data);
270 
271 	sk = kzalloc(sizeof(*sk), GFP_USER);
272 	if (!sk) {
273 		kfree(data);
274 		return -ENOMEM;
275 	}
276 	sock_net_set(sk, current->nsproxy->net_ns);
277 	sock_init_data(NULL, sk);
278 
279 	skb = build_skb(data, 0);
280 	if (!skb) {
281 		kfree(data);
282 		kfree(sk);
283 		return -ENOMEM;
284 	}
285 	skb->sk = sk;
286 
287 	skb_reserve(skb, NET_SKB_PAD + NET_IP_ALIGN);
288 	__skb_put(skb, size);
289 	skb->protocol = eth_type_trans(skb,
290 				       current->nsproxy->net_ns->loopback_dev);
291 	skb_reset_network_header(skb);
292 
293 	cb = (struct bpf_skb_data_end *)skb->cb;
294 	cb->qdisc_cb.flow_keys = &flow_keys;
295 
296 	if (!repeat)
297 		repeat = 1;
298 
299 	rcu_read_lock();
300 	preempt_disable();
301 	time_start = ktime_get_ns();
302 	for (i = 0; i < repeat; i++) {
303 		retval = __skb_flow_bpf_dissect(prog, skb,
304 						&flow_keys_dissector,
305 						&flow_keys);
306 
307 		if (signal_pending(current)) {
308 			preempt_enable();
309 			rcu_read_unlock();
310 
311 			ret = -EINTR;
312 			goto out;
313 		}
314 
315 		if (need_resched()) {
316 			time_spent += ktime_get_ns() - time_start;
317 			preempt_enable();
318 			rcu_read_unlock();
319 
320 			cond_resched();
321 
322 			rcu_read_lock();
323 			preempt_disable();
324 			time_start = ktime_get_ns();
325 		}
326 	}
327 	time_spent += ktime_get_ns() - time_start;
328 	preempt_enable();
329 	rcu_read_unlock();
330 
331 	do_div(time_spent, repeat);
332 	duration = time_spent > U32_MAX ? U32_MAX : (u32)time_spent;
333 
334 	ret = bpf_test_finish(kattr, uattr, &flow_keys, sizeof(flow_keys),
335 			      retval, duration);
336 
337 out:
338 	kfree_skb(skb);
339 	kfree(sk);
340 	return ret;
341 }
342