xref: /openbmc/linux/arch/um/drivers/vector_transports.c (revision 9c6d26df1fae6ad4718d51c48e6517913304ed27)
1 /*
2  * Copyright (C) 2017 - Cambridge Greys Limited
3  * Copyright (C) 2011 - 2014 Cisco Systems Inc
4  * Licensed under the GPL.
5  */
6 
7 #include <linux/etherdevice.h>
8 #include <linux/netdevice.h>
9 #include <linux/skbuff.h>
10 #include <linux/slab.h>
11 #include <asm/byteorder.h>
12 #include <uapi/linux/ip.h>
13 #include <uapi/linux/virtio_net.h>
14 #include <linux/virtio_net.h>
15 #include <linux/virtio_byteorder.h>
16 #include <linux/netdev_features.h>
17 #include "vector_user.h"
18 #include "vector_kern.h"
19 
20 #define GOOD_LINEAR 512
21 #define GSO_ERROR "Incoming GSO frames and GRO disabled on the interface"
22 
23 struct gre_minimal_header {
24 	uint16_t header;
25 	uint16_t arptype;
26 };
27 
28 
29 struct uml_gre_data {
30 	uint32_t rx_key;
31 	uint32_t tx_key;
32 	uint32_t sequence;
33 
34 	bool ipv6;
35 	bool has_sequence;
36 	bool pin_sequence;
37 	bool checksum;
38 	bool key;
39 	struct gre_minimal_header expected_header;
40 
41 	uint32_t checksum_offset;
42 	uint32_t key_offset;
43 	uint32_t sequence_offset;
44 
45 };
46 
47 struct uml_l2tpv3_data {
48 	uint64_t rx_cookie;
49 	uint64_t tx_cookie;
50 	uint64_t rx_session;
51 	uint64_t tx_session;
52 	uint32_t counter;
53 
54 	bool udp;
55 	bool ipv6;
56 	bool has_counter;
57 	bool pin_counter;
58 	bool cookie;
59 	bool cookie_is_64;
60 
61 	uint32_t cookie_offset;
62 	uint32_t session_offset;
63 	uint32_t counter_offset;
64 };
65 
66 static int l2tpv3_form_header(uint8_t *header,
67 	struct sk_buff *skb, struct vector_private *vp)
68 {
69 	struct uml_l2tpv3_data *td = vp->transport_data;
70 	uint32_t *counter;
71 
72 	if (td->udp)
73 		*(uint32_t *) header = cpu_to_be32(L2TPV3_DATA_PACKET);
74 	(*(uint32_t *) (header + td->session_offset)) = td->tx_session;
75 
76 	if (td->cookie) {
77 		if (td->cookie_is_64)
78 			(*(uint64_t *)(header + td->cookie_offset)) =
79 				td->tx_cookie;
80 		else
81 			(*(uint32_t *)(header + td->cookie_offset)) =
82 				td->tx_cookie;
83 	}
84 	if (td->has_counter) {
85 		counter = (uint32_t *)(header + td->counter_offset);
86 		if (td->pin_counter) {
87 			*counter = 0;
88 		} else {
89 			td->counter++;
90 			*counter = cpu_to_be32(td->counter);
91 		}
92 	}
93 	return 0;
94 }
95 
96 static int gre_form_header(uint8_t *header,
97 		struct sk_buff *skb, struct vector_private *vp)
98 {
99 	struct uml_gre_data *td = vp->transport_data;
100 	uint32_t *sequence;
101 	*((uint32_t *) header) = *((uint32_t *) &td->expected_header);
102 	if (td->key)
103 		(*(uint32_t *) (header + td->key_offset)) = td->tx_key;
104 	if (td->has_sequence) {
105 		sequence = (uint32_t *)(header + td->sequence_offset);
106 		if (td->pin_sequence)
107 			*sequence = 0;
108 		else
109 			*sequence = cpu_to_be32(++td->sequence);
110 	}
111 	return 0;
112 }
113 
114 static int raw_form_header(uint8_t *header,
115 		struct sk_buff *skb, struct vector_private *vp)
116 {
117 	struct virtio_net_hdr *vheader = (struct virtio_net_hdr *) header;
118 
119 	virtio_net_hdr_from_skb(
120 		skb,
121 		vheader,
122 		virtio_legacy_is_little_endian(),
123 		false
124 	);
125 
126 	return 0;
127 }
128 
129 static int l2tpv3_verify_header(
130 	uint8_t *header, struct sk_buff *skb, struct vector_private *vp)
131 {
132 	struct uml_l2tpv3_data *td = vp->transport_data;
133 	uint32_t *session;
134 	uint64_t cookie;
135 
136 	if ((!td->udp) && (!td->ipv6))
137 		header += sizeof(struct iphdr) /* fix for ipv4 raw */;
138 
139 	/* we do not do a strict check for "data" packets as per
140 	 * the RFC spec because the pure IP spec does not have
141 	 * that anyway.
142 	 */
143 
144 	if (td->cookie) {
145 		if (td->cookie_is_64)
146 			cookie = *(uint64_t *)(header + td->cookie_offset);
147 		else
148 			cookie = *(uint32_t *)(header + td->cookie_offset);
149 		if (cookie != td->rx_cookie) {
150 			if (net_ratelimit())
151 				netdev_err(vp->dev, "uml_l2tpv3: unknown cookie id");
152 			return -1;
153 		}
154 	}
155 	session = (uint32_t *) (header + td->session_offset);
156 	if (*session != td->rx_session) {
157 		if (net_ratelimit())
158 			netdev_err(vp->dev, "uml_l2tpv3: session mismatch");
159 		return -1;
160 	}
161 	return 0;
162 }
163 
164 static int gre_verify_header(
165 	uint8_t *header, struct sk_buff *skb, struct vector_private *vp)
166 {
167 
168 	uint32_t key;
169 	struct uml_gre_data *td = vp->transport_data;
170 
171 	if (!td->ipv6)
172 		header += sizeof(struct iphdr) /* fix for ipv4 raw */;
173 
174 	if (*((uint32_t *) header) != *((uint32_t *) &td->expected_header)) {
175 		if (net_ratelimit())
176 			netdev_err(vp->dev, "header type disagreement, expecting %0x, got %0x",
177 				*((uint32_t *) &td->expected_header),
178 				*((uint32_t *) header)
179 			);
180 		return -1;
181 	}
182 
183 	if (td->key) {
184 		key = (*(uint32_t *)(header + td->key_offset));
185 		if (key != td->rx_key) {
186 			if (net_ratelimit())
187 				netdev_err(vp->dev, "unknown key id %0x, expecting %0x",
188 						key, td->rx_key);
189 			return -1;
190 		}
191 	}
192 	return 0;
193 }
194 
195 static int raw_verify_header(
196 	uint8_t *header, struct sk_buff *skb, struct vector_private *vp)
197 {
198 	struct virtio_net_hdr *vheader = (struct virtio_net_hdr *) header;
199 
200 	if ((vheader->gso_type != VIRTIO_NET_HDR_GSO_NONE) &&
201 		(vp->req_size != 65536)) {
202 		if (net_ratelimit())
203 			netdev_err(
204 				vp->dev,
205 				GSO_ERROR
206 		);
207 	}
208 	if ((vheader->flags & VIRTIO_NET_HDR_F_DATA_VALID) > 0)
209 		return 1;
210 
211 	virtio_net_hdr_to_skb(skb, vheader, virtio_legacy_is_little_endian());
212 	return 0;
213 }
214 
215 static bool get_uint_param(
216 	struct arglist *def, char *param, unsigned int *result)
217 {
218 	char *arg = uml_vector_fetch_arg(def, param);
219 
220 	if (arg != NULL) {
221 		if (kstrtoint(arg, 0, result) == 0)
222 			return true;
223 	}
224 	return false;
225 }
226 
227 static bool get_ulong_param(
228 	struct arglist *def, char *param, unsigned long *result)
229 {
230 	char *arg = uml_vector_fetch_arg(def, param);
231 
232 	if (arg != NULL) {
233 		if (kstrtoul(arg, 0, result) == 0)
234 			return true;
235 		return true;
236 	}
237 	return false;
238 }
239 
240 static int build_gre_transport_data(struct vector_private *vp)
241 {
242 	struct uml_gre_data *td;
243 	int temp_int;
244 	int temp_rx;
245 	int temp_tx;
246 
247 	vp->transport_data = kmalloc(sizeof(struct uml_gre_data), GFP_KERNEL);
248 	if (vp->transport_data == NULL)
249 		return -ENOMEM;
250 	td = vp->transport_data;
251 	td->sequence = 0;
252 
253 	td->expected_header.arptype = GRE_IRB;
254 	td->expected_header.header = 0;
255 
256 	vp->form_header = &gre_form_header;
257 	vp->verify_header = &gre_verify_header;
258 	vp->header_size = 4;
259 	td->key_offset = 4;
260 	td->sequence_offset = 4;
261 	td->checksum_offset = 4;
262 
263 	td->ipv6 = false;
264 	if (get_uint_param(vp->parsed, "v6", &temp_int)) {
265 		if (temp_int > 0)
266 			td->ipv6 = true;
267 	}
268 	td->key = false;
269 	if (get_uint_param(vp->parsed, "rx_key", &temp_rx)) {
270 		if (get_uint_param(vp->parsed, "tx_key", &temp_tx)) {
271 			td->key = true;
272 			td->expected_header.header |= GRE_MODE_KEY;
273 			td->rx_key = cpu_to_be32(temp_rx);
274 			td->tx_key = cpu_to_be32(temp_tx);
275 			vp->header_size += 4;
276 			td->sequence_offset += 4;
277 		} else {
278 			return -EINVAL;
279 		}
280 	}
281 
282 	td->sequence = false;
283 	if (get_uint_param(vp->parsed, "sequence", &temp_int)) {
284 		if (temp_int > 0) {
285 			vp->header_size += 4;
286 			td->has_sequence = true;
287 			td->expected_header.header |= GRE_MODE_SEQUENCE;
288 			if (get_uint_param(
289 				vp->parsed, "pin_sequence", &temp_int)) {
290 				if (temp_int > 0)
291 					td->pin_sequence = true;
292 			}
293 		}
294 	}
295 	vp->rx_header_size = vp->header_size;
296 	if (!td->ipv6)
297 		vp->rx_header_size += sizeof(struct iphdr);
298 	return 0;
299 }
300 
301 static int build_l2tpv3_transport_data(struct vector_private *vp)
302 {
303 
304 	struct uml_l2tpv3_data *td;
305 	int temp_int, temp_rxs, temp_txs;
306 	unsigned long temp_rx;
307 	unsigned long temp_tx;
308 
309 	vp->transport_data = kmalloc(
310 		sizeof(struct uml_l2tpv3_data), GFP_KERNEL);
311 
312 	if (vp->transport_data == NULL)
313 		return -ENOMEM;
314 
315 	td = vp->transport_data;
316 
317 	vp->form_header = &l2tpv3_form_header;
318 	vp->verify_header = &l2tpv3_verify_header;
319 	td->counter = 0;
320 
321 	vp->header_size = 4;
322 	td->session_offset = 0;
323 	td->cookie_offset = 4;
324 	td->counter_offset = 4;
325 
326 
327 	td->ipv6 = false;
328 	if (get_uint_param(vp->parsed, "v6", &temp_int)) {
329 		if (temp_int > 0)
330 			td->ipv6 = true;
331 	}
332 
333 	if (get_uint_param(vp->parsed, "rx_session", &temp_rxs)) {
334 		if (get_uint_param(vp->parsed, "tx_session", &temp_txs)) {
335 			td->tx_session = cpu_to_be32(temp_txs);
336 			td->rx_session = cpu_to_be32(temp_rxs);
337 		} else {
338 			return -EINVAL;
339 		}
340 	} else {
341 		return -EINVAL;
342 	}
343 
344 	td->cookie_is_64  = false;
345 	if (get_uint_param(vp->parsed, "cookie64", &temp_int)) {
346 		if (temp_int > 0)
347 			td->cookie_is_64  = true;
348 	}
349 	td->cookie = false;
350 	if (get_ulong_param(vp->parsed, "rx_cookie", &temp_rx)) {
351 		if (get_ulong_param(vp->parsed, "tx_cookie", &temp_tx)) {
352 			td->cookie = true;
353 			if (td->cookie_is_64) {
354 				td->rx_cookie = cpu_to_be64(temp_rx);
355 				td->tx_cookie = cpu_to_be64(temp_tx);
356 				vp->header_size += 8;
357 				td->counter_offset += 8;
358 			} else {
359 				td->rx_cookie = cpu_to_be32(temp_rx);
360 				td->tx_cookie = cpu_to_be32(temp_tx);
361 				vp->header_size += 4;
362 				td->counter_offset += 4;
363 			}
364 		} else {
365 			return -EINVAL;
366 		}
367 	}
368 
369 	td->has_counter = false;
370 	if (get_uint_param(vp->parsed, "counter", &temp_int)) {
371 		if (temp_int > 0) {
372 			td->has_counter = true;
373 			vp->header_size += 4;
374 			if (get_uint_param(
375 				vp->parsed, "pin_counter", &temp_int)) {
376 				if (temp_int > 0)
377 					td->pin_counter = true;
378 			}
379 		}
380 	}
381 
382 	if (get_uint_param(vp->parsed, "udp", &temp_int)) {
383 		if (temp_int > 0) {
384 			td->udp = true;
385 			vp->header_size += 4;
386 			td->counter_offset += 4;
387 			td->session_offset += 4;
388 			td->cookie_offset += 4;
389 		}
390 	}
391 
392 	vp->rx_header_size = vp->header_size;
393 	if ((!td->ipv6) && (!td->udp))
394 		vp->rx_header_size += sizeof(struct iphdr);
395 
396 	return 0;
397 }
398 
399 static int build_raw_transport_data(struct vector_private *vp)
400 {
401 	if (uml_raw_enable_vnet_headers(vp->fds->rx_fd)) {
402 		if (!uml_raw_enable_vnet_headers(vp->fds->tx_fd))
403 			return -1;
404 		vp->form_header = &raw_form_header;
405 		vp->verify_header = &raw_verify_header;
406 		vp->header_size = sizeof(struct virtio_net_hdr);
407 		vp->rx_header_size = sizeof(struct virtio_net_hdr);
408 		vp->dev->hw_features |= (NETIF_F_TSO | NETIF_F_GRO);
409 		vp->dev->features |=
410 			(NETIF_F_RXCSUM | NETIF_F_HW_CSUM |
411 				NETIF_F_TSO | NETIF_F_GRO);
412 		netdev_info(
413 			vp->dev,
414 			"raw: using vnet headers for tso and tx/rx checksum"
415 		);
416 	}
417 	return 0;
418 }
419 
420 static int build_tap_transport_data(struct vector_private *vp)
421 {
422 	if (uml_raw_enable_vnet_headers(vp->fds->rx_fd)) {
423 		vp->form_header = &raw_form_header;
424 		vp->verify_header = &raw_verify_header;
425 		vp->header_size = sizeof(struct virtio_net_hdr);
426 		vp->rx_header_size = sizeof(struct virtio_net_hdr);
427 		vp->dev->hw_features |=
428 			(NETIF_F_TSO | NETIF_F_GSO | NETIF_F_GRO);
429 		vp->dev->features |=
430 			(NETIF_F_RXCSUM | NETIF_F_HW_CSUM |
431 				NETIF_F_TSO | NETIF_F_GSO | NETIF_F_GRO);
432 		netdev_info(
433 			vp->dev,
434 			"tap/raw: using vnet headers for tso and tx/rx checksum"
435 		);
436 	} else {
437 		return 0; /* do not try to enable tap too if raw failed */
438 	}
439 	if (uml_tap_enable_vnet_headers(vp->fds->tx_fd))
440 		return 0;
441 	return -1;
442 }
443 
444 int build_transport_data(struct vector_private *vp)
445 {
446 	char *transport = uml_vector_fetch_arg(vp->parsed, "transport");
447 
448 	if (strncmp(transport, TRANS_GRE, TRANS_GRE_LEN) == 0)
449 		return build_gre_transport_data(vp);
450 	if (strncmp(transport, TRANS_L2TPV3, TRANS_L2TPV3_LEN) == 0)
451 		return build_l2tpv3_transport_data(vp);
452 	if (strncmp(transport, TRANS_RAW, TRANS_RAW_LEN) == 0)
453 		return build_raw_transport_data(vp);
454 	if (strncmp(transport, TRANS_TAP, TRANS_TAP_LEN) == 0)
455 		return build_tap_transport_data(vp);
456 	return 0;
457 }
458 
459