xref: /linux/net/core/selftests.c (revision 8be4d31cb8aaeea27bde4b7ddb26e28a89062ebf)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (c) 2019 Synopsys, Inc. and/or its affiliates.
4  * stmmac Selftests Support
5  *
6  * Author: Jose Abreu <joabreu@synopsys.com>
7  *
8  * Ported from stmmac by:
9  * Copyright (C) 2021 Oleksij Rempel <o.rempel@pengutronix.de>
10  */
11 
12 #include <linux/phy.h>
13 #include <net/selftests.h>
14 #include <net/tcp.h>
15 #include <net/udp.h>
16 
17 struct net_packet_attrs {
18 	const unsigned char *src;
19 	const unsigned char *dst;
20 	u32 ip_src;
21 	u32 ip_dst;
22 	bool tcp;
23 	u16 sport;
24 	u16 dport;
25 	int timeout;
26 	int size;
27 	int max_size;
28 	u8 id;
29 	u16 queue_mapping;
30 	bool bad_csum;
31 };
32 
33 struct net_test_priv {
34 	struct net_packet_attrs *packet;
35 	struct packet_type pt;
36 	struct completion comp;
37 	int double_vlan;
38 	int vlan_id;
39 	int ok;
40 };
41 
42 struct netsfhdr {
43 	__be32 version;
44 	__be64 magic;
45 	u8 id;
46 } __packed;
47 
48 static u8 net_test_next_id;
49 
50 #define NET_TEST_PKT_SIZE (sizeof(struct ethhdr) + sizeof(struct iphdr) + \
51 			   sizeof(struct netsfhdr))
52 #define NET_TEST_PKT_MAGIC	0xdeadcafecafedeadULL
53 #define NET_LB_TIMEOUT		msecs_to_jiffies(200)
54 
net_test_get_skb(struct net_device * ndev,struct net_packet_attrs * attr)55 static struct sk_buff *net_test_get_skb(struct net_device *ndev,
56 					struct net_packet_attrs *attr)
57 {
58 	struct sk_buff *skb = NULL;
59 	struct udphdr *uhdr = NULL;
60 	struct tcphdr *thdr = NULL;
61 	struct netsfhdr *shdr;
62 	struct ethhdr *ehdr;
63 	struct iphdr *ihdr;
64 	int iplen, size;
65 
66 	size = attr->size + NET_TEST_PKT_SIZE;
67 
68 	if (attr->tcp)
69 		size += sizeof(struct tcphdr);
70 	else
71 		size += sizeof(struct udphdr);
72 
73 	if (attr->max_size && attr->max_size > size)
74 		size = attr->max_size;
75 
76 	skb = netdev_alloc_skb(ndev, size);
77 	if (!skb)
78 		return NULL;
79 
80 	prefetchw(skb->data);
81 
82 	ehdr = skb_push(skb, ETH_HLEN);
83 	skb_reset_mac_header(skb);
84 
85 	skb_set_network_header(skb, skb->len);
86 	ihdr = skb_put(skb, sizeof(*ihdr));
87 
88 	skb_set_transport_header(skb, skb->len);
89 	if (attr->tcp)
90 		thdr = skb_put(skb, sizeof(*thdr));
91 	else
92 		uhdr = skb_put(skb, sizeof(*uhdr));
93 
94 	eth_zero_addr(ehdr->h_dest);
95 
96 	if (attr->src)
97 		ether_addr_copy(ehdr->h_source, attr->src);
98 	if (attr->dst)
99 		ether_addr_copy(ehdr->h_dest, attr->dst);
100 
101 	ehdr->h_proto = htons(ETH_P_IP);
102 
103 	if (attr->tcp) {
104 		memset(thdr, 0, sizeof(*thdr));
105 		thdr->source = htons(attr->sport);
106 		thdr->dest = htons(attr->dport);
107 		thdr->doff = sizeof(struct tcphdr) / 4;
108 	} else {
109 		uhdr->source = htons(attr->sport);
110 		uhdr->dest = htons(attr->dport);
111 		uhdr->len = htons(sizeof(*shdr) + sizeof(*uhdr) + attr->size);
112 		if (attr->max_size)
113 			uhdr->len = htons(attr->max_size -
114 					  (sizeof(*ihdr) + sizeof(*ehdr)));
115 		uhdr->check = 0;
116 	}
117 
118 	ihdr->ihl = 5;
119 	ihdr->ttl = 32;
120 	ihdr->version = 4;
121 	if (attr->tcp)
122 		ihdr->protocol = IPPROTO_TCP;
123 	else
124 		ihdr->protocol = IPPROTO_UDP;
125 	iplen = sizeof(*ihdr) + sizeof(*shdr) + attr->size;
126 	if (attr->tcp)
127 		iplen += sizeof(*thdr);
128 	else
129 		iplen += sizeof(*uhdr);
130 
131 	if (attr->max_size)
132 		iplen = attr->max_size - sizeof(*ehdr);
133 
134 	ihdr->tot_len = htons(iplen);
135 	ihdr->frag_off = 0;
136 	ihdr->saddr = htonl(attr->ip_src);
137 	ihdr->daddr = htonl(attr->ip_dst);
138 	ihdr->tos = 0;
139 	ihdr->id = 0;
140 	ip_send_check(ihdr);
141 
142 	shdr = skb_put(skb, sizeof(*shdr));
143 	shdr->version = 0;
144 	shdr->magic = cpu_to_be64(NET_TEST_PKT_MAGIC);
145 	attr->id = net_test_next_id;
146 	shdr->id = net_test_next_id++;
147 
148 	if (attr->size) {
149 		void *payload = skb_put(skb, attr->size);
150 
151 		memset(payload, 0, attr->size);
152 	}
153 
154 	if (attr->max_size && attr->max_size > skb->len) {
155 		size_t pad_len = attr->max_size - skb->len;
156 		void *pad = skb_put(skb, pad_len);
157 
158 		memset(pad, 0, pad_len);
159 	}
160 
161 	skb->csum = 0;
162 	skb->ip_summed = CHECKSUM_PARTIAL;
163 	if (attr->tcp) {
164 		int l4len = skb->len - skb_transport_offset(skb);
165 
166 		thdr->check = ~tcp_v4_check(l4len, ihdr->saddr, ihdr->daddr, 0);
167 		skb->csum_start = skb_transport_header(skb) - skb->head;
168 		skb->csum_offset = offsetof(struct tcphdr, check);
169 
170 		if (attr->bad_csum) {
171 			/* Force mangled checksum */
172 			if (skb_checksum_help(skb)) {
173 				kfree_skb(skb);
174 				return NULL;
175 			}
176 
177 			if (thdr->check != CSUM_MANGLED_0)
178 				thdr->check = CSUM_MANGLED_0;
179 			else
180 				thdr->check = csum16_sub(thdr->check,
181 							 cpu_to_be16(1));
182 		}
183 	} else {
184 		udp4_hwcsum(skb, ihdr->saddr, ihdr->daddr);
185 	}
186 
187 	skb->protocol = htons(ETH_P_IP);
188 	skb->pkt_type = PACKET_HOST;
189 	skb->dev = ndev;
190 
191 	return skb;
192 }
193 
net_test_loopback_validate(struct sk_buff * skb,struct net_device * ndev,struct packet_type * pt,struct net_device * orig_ndev)194 static int net_test_loopback_validate(struct sk_buff *skb,
195 				      struct net_device *ndev,
196 				      struct packet_type *pt,
197 				      struct net_device *orig_ndev)
198 {
199 	struct net_test_priv *tpriv = pt->af_packet_priv;
200 	const unsigned char *src = tpriv->packet->src;
201 	const unsigned char *dst = tpriv->packet->dst;
202 	struct netsfhdr *shdr;
203 	struct ethhdr *ehdr;
204 	struct udphdr *uhdr;
205 	struct tcphdr *thdr;
206 	struct iphdr *ihdr;
207 
208 	skb = skb_unshare(skb, GFP_ATOMIC);
209 	if (!skb)
210 		goto out;
211 
212 	if (skb_linearize(skb))
213 		goto out;
214 	if (skb_headlen(skb) < (NET_TEST_PKT_SIZE - ETH_HLEN))
215 		goto out;
216 
217 	ehdr = (struct ethhdr *)skb_mac_header(skb);
218 	if (dst) {
219 		if (!ether_addr_equal_unaligned(ehdr->h_dest, dst))
220 			goto out;
221 	}
222 
223 	if (src) {
224 		if (!ether_addr_equal_unaligned(ehdr->h_source, src))
225 			goto out;
226 	}
227 
228 	ihdr = ip_hdr(skb);
229 	if (tpriv->double_vlan)
230 		ihdr = (struct iphdr *)(skb_network_header(skb) + 4);
231 
232 	if (tpriv->packet->tcp) {
233 		if (ihdr->protocol != IPPROTO_TCP)
234 			goto out;
235 
236 		thdr = (struct tcphdr *)((u8 *)ihdr + 4 * ihdr->ihl);
237 		if (thdr->dest != htons(tpriv->packet->dport))
238 			goto out;
239 
240 		shdr = (struct netsfhdr *)((u8 *)thdr + sizeof(*thdr));
241 	} else {
242 		if (ihdr->protocol != IPPROTO_UDP)
243 			goto out;
244 
245 		uhdr = (struct udphdr *)((u8 *)ihdr + 4 * ihdr->ihl);
246 		if (uhdr->dest != htons(tpriv->packet->dport))
247 			goto out;
248 
249 		shdr = (struct netsfhdr *)((u8 *)uhdr + sizeof(*uhdr));
250 	}
251 
252 	if (shdr->magic != cpu_to_be64(NET_TEST_PKT_MAGIC))
253 		goto out;
254 	if (tpriv->packet->id != shdr->id)
255 		goto out;
256 
257 	if (tpriv->packet->bad_csum && skb->ip_summed == CHECKSUM_UNNECESSARY)
258 		tpriv->ok = -EIO;
259 	else
260 		tpriv->ok = true;
261 
262 	complete(&tpriv->comp);
263 out:
264 	kfree_skb(skb);
265 	return 0;
266 }
267 
__net_test_loopback(struct net_device * ndev,struct net_packet_attrs * attr)268 static int __net_test_loopback(struct net_device *ndev,
269 			       struct net_packet_attrs *attr)
270 {
271 	struct net_test_priv *tpriv;
272 	struct sk_buff *skb = NULL;
273 	int ret = 0;
274 
275 	tpriv = kzalloc(sizeof(*tpriv), GFP_KERNEL);
276 	if (!tpriv)
277 		return -ENOMEM;
278 
279 	tpriv->ok = false;
280 	init_completion(&tpriv->comp);
281 
282 	tpriv->pt.type = htons(ETH_P_IP);
283 	tpriv->pt.func = net_test_loopback_validate;
284 	tpriv->pt.dev = ndev;
285 	tpriv->pt.af_packet_priv = tpriv;
286 	tpriv->packet = attr;
287 	dev_add_pack(&tpriv->pt);
288 
289 	skb = net_test_get_skb(ndev, attr);
290 	if (!skb) {
291 		ret = -ENOMEM;
292 		goto cleanup;
293 	}
294 
295 	ret = dev_direct_xmit(skb, attr->queue_mapping);
296 	if (ret < 0) {
297 		goto cleanup;
298 	} else if (ret > 0) {
299 		ret = -ENETUNREACH;
300 		goto cleanup;
301 	}
302 
303 	if (!attr->timeout)
304 		attr->timeout = NET_LB_TIMEOUT;
305 
306 	wait_for_completion_timeout(&tpriv->comp, attr->timeout);
307 	if (tpriv->ok < 0)
308 		ret = tpriv->ok;
309 	else if (!tpriv->ok)
310 		ret = -ETIMEDOUT;
311 	else
312 		ret = 0;
313 
314 cleanup:
315 	dev_remove_pack(&tpriv->pt);
316 	kfree(tpriv);
317 	return ret;
318 }
319 
net_test_netif_carrier(struct net_device * ndev)320 static int net_test_netif_carrier(struct net_device *ndev)
321 {
322 	return netif_carrier_ok(ndev) ? 0 : -ENOLINK;
323 }
324 
net_test_phy_phydev(struct net_device * ndev)325 static int net_test_phy_phydev(struct net_device *ndev)
326 {
327 	return ndev->phydev ? 0 : -EOPNOTSUPP;
328 }
329 
net_test_phy_loopback_enable(struct net_device * ndev)330 static int net_test_phy_loopback_enable(struct net_device *ndev)
331 {
332 	if (!ndev->phydev)
333 		return -EOPNOTSUPP;
334 
335 	return phy_loopback(ndev->phydev, true, 0);
336 }
337 
net_test_phy_loopback_disable(struct net_device * ndev)338 static int net_test_phy_loopback_disable(struct net_device *ndev)
339 {
340 	if (!ndev->phydev)
341 		return -EOPNOTSUPP;
342 
343 	return phy_loopback(ndev->phydev, false, 0);
344 }
345 
net_test_phy_loopback_udp(struct net_device * ndev)346 static int net_test_phy_loopback_udp(struct net_device *ndev)
347 {
348 	struct net_packet_attrs attr = { };
349 
350 	attr.dst = ndev->dev_addr;
351 	return __net_test_loopback(ndev, &attr);
352 }
353 
net_test_phy_loopback_udp_mtu(struct net_device * ndev)354 static int net_test_phy_loopback_udp_mtu(struct net_device *ndev)
355 {
356 	struct net_packet_attrs attr = { };
357 
358 	attr.dst = ndev->dev_addr;
359 	attr.max_size = ndev->mtu;
360 	return __net_test_loopback(ndev, &attr);
361 }
362 
net_test_phy_loopback_tcp(struct net_device * ndev)363 static int net_test_phy_loopback_tcp(struct net_device *ndev)
364 {
365 	struct net_packet_attrs attr = { };
366 
367 	attr.dst = ndev->dev_addr;
368 	attr.tcp = true;
369 	return __net_test_loopback(ndev, &attr);
370 }
371 
372 /**
373  * net_test_phy_loopback_tcp_bad_csum - PHY loopback test with a deliberately
374  *					corrupted TCP checksum
375  * @ndev: the network device to test
376  *
377  * Builds the same minimal Ethernet/IPv4/TCP frame as
378  * net_test_phy_loopback_tcp(), then flips the least-significant bit of the TCP
379  * checksum so the resulting value is provably invalid (neither 0 nor 0xFFFF).
380  * The frame is transmitted through the device’s internal PHY loopback path:
381  *
382  *   test code -> MAC driver -> MAC HW -> xMII -> PHY ->
383  *   internal PHY loopback -> xMII -> MAC HW -> MAC driver -> test code
384  *
385  * Result interpretation
386  * ---------------------
387  *  0            The frame is delivered to the stack and the driver reports
388  *               ip_summed as CHECKSUM_NONE or CHECKSUM_COMPLETE - both are
389  *               valid ways to indicate “bad checksum, let the stack verify.”
390  *  -ETIMEDOUT   The MAC/PHY silently dropped the frame; hardware checksum
391  *               verification filtered it out before the driver saw it.
392  *  -EIO         The driver returned the frame with ip_summed ==
393  *               CHECKSUM_UNNECESSARY, falsely claiming a valid checksum and
394  *               indicating a serious RX-path defect.
395  *
396  * Return: 0 on success or a negative error code on failure.
397  */
net_test_phy_loopback_tcp_bad_csum(struct net_device * ndev)398 static int net_test_phy_loopback_tcp_bad_csum(struct net_device *ndev)
399 {
400 	struct net_packet_attrs attr = { };
401 
402 	attr.dst = ndev->dev_addr;
403 	attr.tcp = true;
404 	attr.bad_csum = true;
405 	return __net_test_loopback(ndev, &attr);
406 }
407 
408 static const struct net_test {
409 	char name[ETH_GSTRING_LEN];
410 	int (*fn)(struct net_device *ndev);
411 } net_selftests[] = {
412 	{
413 		.name = "Carrier                       ",
414 		.fn = net_test_netif_carrier,
415 	}, {
416 		.name = "PHY dev is present            ",
417 		.fn = net_test_phy_phydev,
418 	}, {
419 		/* This test should be done before all PHY loopback test */
420 		.name = "PHY internal loopback, enable ",
421 		.fn = net_test_phy_loopback_enable,
422 	}, {
423 		.name = "PHY internal loopback, UDP    ",
424 		.fn = net_test_phy_loopback_udp,
425 	}, {
426 		.name = "PHY internal loopback, MTU    ",
427 		.fn = net_test_phy_loopback_udp_mtu,
428 	}, {
429 		.name = "PHY internal loopback, TCP    ",
430 		.fn = net_test_phy_loopback_tcp,
431 	}, {
432 		.name = "PHY loopback, bad TCP csum    ",
433 		.fn = net_test_phy_loopback_tcp_bad_csum,
434 	}, {
435 		/* This test should be done after all PHY loopback test */
436 		.name = "PHY internal loopback, disable",
437 		.fn = net_test_phy_loopback_disable,
438 	},
439 };
440 
net_selftest(struct net_device * ndev,struct ethtool_test * etest,u64 * buf)441 void net_selftest(struct net_device *ndev, struct ethtool_test *etest, u64 *buf)
442 {
443 	int count = net_selftest_get_count();
444 	int i;
445 
446 	memset(buf, 0, sizeof(*buf) * count);
447 	net_test_next_id = 0;
448 
449 	if (etest->flags != ETH_TEST_FL_OFFLINE) {
450 		netdev_err(ndev, "Only offline tests are supported\n");
451 		etest->flags |= ETH_TEST_FL_FAILED;
452 		return;
453 	}
454 
455 
456 	for (i = 0; i < count; i++) {
457 		buf[i] = net_selftests[i].fn(ndev);
458 		if (buf[i] && (buf[i] != -EOPNOTSUPP))
459 			etest->flags |= ETH_TEST_FL_FAILED;
460 	}
461 }
462 EXPORT_SYMBOL_GPL(net_selftest);
463 
net_selftest_get_count(void)464 int net_selftest_get_count(void)
465 {
466 	return ARRAY_SIZE(net_selftests);
467 }
468 EXPORT_SYMBOL_GPL(net_selftest_get_count);
469 
net_selftest_get_strings(u8 * data)470 void net_selftest_get_strings(u8 *data)
471 {
472 	int i;
473 
474 	for (i = 0; i < net_selftest_get_count(); i++)
475 		ethtool_sprintf(&data, "%2d. %s", i + 1,
476 				net_selftests[i].name);
477 }
478 EXPORT_SYMBOL_GPL(net_selftest_get_strings);
479 
480 MODULE_DESCRIPTION("Common library for generic PHY ethtool selftests");
481 MODULE_LICENSE("GPL v2");
482 MODULE_AUTHOR("Oleksij Rempel <o.rempel@pengutronix.de>");
483