xref: /openbmc/linux/net/bpf/test_run.c (revision 828ff2ad)
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 __always_inline u32 bpf_test_run_one(struct bpf_prog *prog, void *ctx,
17 		struct bpf_cgroup_storage *storage[MAX_BPF_CGROUP_STORAGE_TYPE])
18 {
19 	u32 ret;
20 
21 	preempt_disable();
22 	rcu_read_lock();
23 	bpf_cgroup_storage_set(storage);
24 	ret = BPF_PROG_RUN(prog, ctx);
25 	rcu_read_unlock();
26 	preempt_enable();
27 
28 	return ret;
29 }
30 
31 static u32 bpf_test_run(struct bpf_prog *prog, void *ctx, u32 repeat, u32 *time)
32 {
33 	struct bpf_cgroup_storage *storage[MAX_BPF_CGROUP_STORAGE_TYPE] = { 0 };
34 	enum bpf_cgroup_storage_type stype;
35 	u64 time_start, time_spent = 0;
36 	u32 ret = 0, i;
37 
38 	for_each_cgroup_storage_type(stype) {
39 		storage[stype] = bpf_cgroup_storage_alloc(prog, stype);
40 		if (IS_ERR(storage[stype])) {
41 			storage[stype] = NULL;
42 			for_each_cgroup_storage_type(stype)
43 				bpf_cgroup_storage_free(storage[stype]);
44 			return -ENOMEM;
45 		}
46 	}
47 
48 	if (!repeat)
49 		repeat = 1;
50 	time_start = ktime_get_ns();
51 	for (i = 0; i < repeat; i++) {
52 		ret = bpf_test_run_one(prog, ctx, storage);
53 		if (need_resched()) {
54 			if (signal_pending(current))
55 				break;
56 			time_spent += ktime_get_ns() - time_start;
57 			cond_resched();
58 			time_start = ktime_get_ns();
59 		}
60 	}
61 	time_spent += ktime_get_ns() - time_start;
62 	do_div(time_spent, repeat);
63 	*time = time_spent > U32_MAX ? U32_MAX : (u32)time_spent;
64 
65 	for_each_cgroup_storage_type(stype)
66 		bpf_cgroup_storage_free(storage[stype]);
67 
68 	return ret;
69 }
70 
71 static int bpf_test_finish(const union bpf_attr *kattr,
72 			   union bpf_attr __user *uattr, const void *data,
73 			   u32 size, u32 retval, u32 duration)
74 {
75 	void __user *data_out = u64_to_user_ptr(kattr->test.data_out);
76 	int err = -EFAULT;
77 
78 	if (data_out && copy_to_user(data_out, data, size))
79 		goto out;
80 	if (copy_to_user(&uattr->test.data_size_out, &size, sizeof(size)))
81 		goto out;
82 	if (copy_to_user(&uattr->test.retval, &retval, sizeof(retval)))
83 		goto out;
84 	if (copy_to_user(&uattr->test.duration, &duration, sizeof(duration)))
85 		goto out;
86 	err = 0;
87 out:
88 	return err;
89 }
90 
91 static void *bpf_test_init(const union bpf_attr *kattr, u32 size,
92 			   u32 headroom, u32 tailroom)
93 {
94 	void __user *data_in = u64_to_user_ptr(kattr->test.data_in);
95 	void *data;
96 
97 	if (size < ETH_HLEN || size > PAGE_SIZE - headroom - tailroom)
98 		return ERR_PTR(-EINVAL);
99 
100 	data = kzalloc(size + headroom + tailroom, GFP_USER);
101 	if (!data)
102 		return ERR_PTR(-ENOMEM);
103 
104 	if (copy_from_user(data + headroom, data_in, size)) {
105 		kfree(data);
106 		return ERR_PTR(-EFAULT);
107 	}
108 	return data;
109 }
110 
111 int bpf_prog_test_run_skb(struct bpf_prog *prog, const union bpf_attr *kattr,
112 			  union bpf_attr __user *uattr)
113 {
114 	bool is_l2 = false, is_direct_pkt_access = false;
115 	u32 size = kattr->test.data_size_in;
116 	u32 repeat = kattr->test.repeat;
117 	u32 retval, duration;
118 	int hh_len = ETH_HLEN;
119 	struct sk_buff *skb;
120 	struct sock *sk;
121 	void *data;
122 	int ret;
123 
124 	data = bpf_test_init(kattr, size, NET_SKB_PAD + NET_IP_ALIGN,
125 			     SKB_DATA_ALIGN(sizeof(struct skb_shared_info)));
126 	if (IS_ERR(data))
127 		return PTR_ERR(data);
128 
129 	switch (prog->type) {
130 	case BPF_PROG_TYPE_SCHED_CLS:
131 	case BPF_PROG_TYPE_SCHED_ACT:
132 		is_l2 = true;
133 		/* fall through */
134 	case BPF_PROG_TYPE_LWT_IN:
135 	case BPF_PROG_TYPE_LWT_OUT:
136 	case BPF_PROG_TYPE_LWT_XMIT:
137 		is_direct_pkt_access = true;
138 		break;
139 	default:
140 		break;
141 	}
142 
143 	sk = kzalloc(sizeof(struct sock), GFP_USER);
144 	if (!sk) {
145 		kfree(data);
146 		return -ENOMEM;
147 	}
148 	sock_net_set(sk, current->nsproxy->net_ns);
149 	sock_init_data(NULL, sk);
150 
151 	skb = build_skb(data, 0);
152 	if (!skb) {
153 		kfree(data);
154 		kfree(sk);
155 		return -ENOMEM;
156 	}
157 	skb->sk = sk;
158 
159 	skb_reserve(skb, NET_SKB_PAD + NET_IP_ALIGN);
160 	__skb_put(skb, size);
161 	skb->protocol = eth_type_trans(skb, current->nsproxy->net_ns->loopback_dev);
162 	skb_reset_network_header(skb);
163 
164 	if (is_l2)
165 		__skb_push(skb, hh_len);
166 	if (is_direct_pkt_access)
167 		bpf_compute_data_pointers(skb);
168 	retval = bpf_test_run(prog, skb, repeat, &duration);
169 	if (!is_l2) {
170 		if (skb_headroom(skb) < hh_len) {
171 			int nhead = HH_DATA_ALIGN(hh_len - skb_headroom(skb));
172 
173 			if (pskb_expand_head(skb, nhead, 0, GFP_USER)) {
174 				kfree_skb(skb);
175 				kfree(sk);
176 				return -ENOMEM;
177 			}
178 		}
179 		memset(__skb_push(skb, hh_len), 0, hh_len);
180 	}
181 
182 	size = skb->len;
183 	/* bpf program can never convert linear skb to non-linear */
184 	if (WARN_ON_ONCE(skb_is_nonlinear(skb)))
185 		size = skb_headlen(skb);
186 	ret = bpf_test_finish(kattr, uattr, skb->data, size, retval, duration);
187 	kfree_skb(skb);
188 	kfree(sk);
189 	return ret;
190 }
191 
192 int bpf_prog_test_run_xdp(struct bpf_prog *prog, const union bpf_attr *kattr,
193 			  union bpf_attr __user *uattr)
194 {
195 	u32 size = kattr->test.data_size_in;
196 	u32 repeat = kattr->test.repeat;
197 	struct netdev_rx_queue *rxqueue;
198 	struct xdp_buff xdp = {};
199 	u32 retval, duration;
200 	void *data;
201 	int ret;
202 
203 	data = bpf_test_init(kattr, size, XDP_PACKET_HEADROOM + NET_IP_ALIGN, 0);
204 	if (IS_ERR(data))
205 		return PTR_ERR(data);
206 
207 	xdp.data_hard_start = data;
208 	xdp.data = data + XDP_PACKET_HEADROOM + NET_IP_ALIGN;
209 	xdp.data_meta = xdp.data;
210 	xdp.data_end = xdp.data + size;
211 
212 	rxqueue = __netif_get_rx_queue(current->nsproxy->net_ns->loopback_dev, 0);
213 	xdp.rxq = &rxqueue->xdp_rxq;
214 
215 	retval = bpf_test_run(prog, &xdp, repeat, &duration);
216 	if (xdp.data != data + XDP_PACKET_HEADROOM + NET_IP_ALIGN ||
217 	    xdp.data_end != xdp.data + size)
218 		size = xdp.data_end - xdp.data;
219 	ret = bpf_test_finish(kattr, uattr, xdp.data, size, retval, duration);
220 	kfree(data);
221 	return ret;
222 }
223