xref: /linux/drivers/net/hyperv/netvsc_drv.c (revision e0bf6c5ca2d3281f231c5f0c9bf145e9513644de)
1 /*
2  * Copyright (c) 2009, Microsoft Corporation.
3  *
4  * This program is free software; you can redistribute it and/or modify it
5  * under the terms and conditions of the GNU General Public License,
6  * version 2, as published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope it will be useful, but WITHOUT
9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
11  * more details.
12  *
13  * You should have received a copy of the GNU General Public License along with
14  * this program; if not, see <http://www.gnu.org/licenses/>.
15  *
16  * Authors:
17  *   Haiyang Zhang <haiyangz@microsoft.com>
18  *   Hank Janssen  <hjanssen@microsoft.com>
19  */
20 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
21 
22 #include <linux/init.h>
23 #include <linux/atomic.h>
24 #include <linux/module.h>
25 #include <linux/highmem.h>
26 #include <linux/device.h>
27 #include <linux/io.h>
28 #include <linux/delay.h>
29 #include <linux/netdevice.h>
30 #include <linux/inetdevice.h>
31 #include <linux/etherdevice.h>
32 #include <linux/skbuff.h>
33 #include <linux/if_vlan.h>
34 #include <linux/in.h>
35 #include <linux/slab.h>
36 #include <net/arp.h>
37 #include <net/route.h>
38 #include <net/sock.h>
39 #include <net/pkt_sched.h>
40 
41 #include "hyperv_net.h"
42 
43 struct net_device_context {
44 	/* point back to our device context */
45 	struct hv_device *device_ctx;
46 	struct delayed_work dwork;
47 	struct work_struct work;
48 };
49 
50 #define RING_SIZE_MIN 64
51 static int ring_size = 128;
52 module_param(ring_size, int, S_IRUGO);
53 MODULE_PARM_DESC(ring_size, "Ring buffer size (# of pages)");
54 
55 static void do_set_multicast(struct work_struct *w)
56 {
57 	struct net_device_context *ndevctx =
58 		container_of(w, struct net_device_context, work);
59 	struct netvsc_device *nvdev;
60 	struct rndis_device *rdev;
61 
62 	nvdev = hv_get_drvdata(ndevctx->device_ctx);
63 	if (nvdev == NULL || nvdev->ndev == NULL)
64 		return;
65 
66 	rdev = nvdev->extension;
67 	if (rdev == NULL)
68 		return;
69 
70 	if (nvdev->ndev->flags & IFF_PROMISC)
71 		rndis_filter_set_packet_filter(rdev,
72 			NDIS_PACKET_TYPE_PROMISCUOUS);
73 	else
74 		rndis_filter_set_packet_filter(rdev,
75 			NDIS_PACKET_TYPE_BROADCAST |
76 			NDIS_PACKET_TYPE_ALL_MULTICAST |
77 			NDIS_PACKET_TYPE_DIRECTED);
78 }
79 
80 static void netvsc_set_multicast_list(struct net_device *net)
81 {
82 	struct net_device_context *net_device_ctx = netdev_priv(net);
83 
84 	schedule_work(&net_device_ctx->work);
85 }
86 
87 static int netvsc_open(struct net_device *net)
88 {
89 	struct net_device_context *net_device_ctx = netdev_priv(net);
90 	struct hv_device *device_obj = net_device_ctx->device_ctx;
91 	struct netvsc_device *nvdev;
92 	struct rndis_device *rdev;
93 	int ret = 0;
94 
95 	netif_carrier_off(net);
96 
97 	/* Open up the device */
98 	ret = rndis_filter_open(device_obj);
99 	if (ret != 0) {
100 		netdev_err(net, "unable to open device (ret %d).\n", ret);
101 		return ret;
102 	}
103 
104 	netif_tx_start_all_queues(net);
105 
106 	nvdev = hv_get_drvdata(device_obj);
107 	rdev = nvdev->extension;
108 	if (!rdev->link_state)
109 		netif_carrier_on(net);
110 
111 	return ret;
112 }
113 
114 static int netvsc_close(struct net_device *net)
115 {
116 	struct net_device_context *net_device_ctx = netdev_priv(net);
117 	struct hv_device *device_obj = net_device_ctx->device_ctx;
118 	int ret;
119 
120 	netif_tx_disable(net);
121 
122 	/* Make sure netvsc_set_multicast_list doesn't re-enable filter! */
123 	cancel_work_sync(&net_device_ctx->work);
124 	ret = rndis_filter_close(device_obj);
125 	if (ret != 0)
126 		netdev_err(net, "unable to close device (ret %d).\n", ret);
127 
128 	return ret;
129 }
130 
131 static void *init_ppi_data(struct rndis_message *msg, u32 ppi_size,
132 				int pkt_type)
133 {
134 	struct rndis_packet *rndis_pkt;
135 	struct rndis_per_packet_info *ppi;
136 
137 	rndis_pkt = &msg->msg.pkt;
138 	rndis_pkt->data_offset += ppi_size;
139 
140 	ppi = (struct rndis_per_packet_info *)((void *)rndis_pkt +
141 		rndis_pkt->per_pkt_info_offset + rndis_pkt->per_pkt_info_len);
142 
143 	ppi->size = ppi_size;
144 	ppi->type = pkt_type;
145 	ppi->ppi_offset = sizeof(struct rndis_per_packet_info);
146 
147 	rndis_pkt->per_pkt_info_len += ppi_size;
148 
149 	return ppi;
150 }
151 
152 union sub_key {
153 	u64 k;
154 	struct {
155 		u8 pad[3];
156 		u8 kb;
157 		u32 ka;
158 	};
159 };
160 
161 /* Toeplitz hash function
162  * data: network byte order
163  * return: host byte order
164  */
165 static u32 comp_hash(u8 *key, int klen, void *data, int dlen)
166 {
167 	union sub_key subk;
168 	int k_next = 4;
169 	u8 dt;
170 	int i, j;
171 	u32 ret = 0;
172 
173 	subk.k = 0;
174 	subk.ka = ntohl(*(u32 *)key);
175 
176 	for (i = 0; i < dlen; i++) {
177 		subk.kb = key[k_next];
178 		k_next = (k_next + 1) % klen;
179 		dt = ((u8 *)data)[i];
180 		for (j = 0; j < 8; j++) {
181 			if (dt & 0x80)
182 				ret ^= subk.ka;
183 			dt <<= 1;
184 			subk.k <<= 1;
185 		}
186 	}
187 
188 	return ret;
189 }
190 
191 static bool netvsc_set_hash(u32 *hash, struct sk_buff *skb)
192 {
193 	struct flow_keys flow;
194 	int data_len;
195 
196 	if (!skb_flow_dissect(skb, &flow) ||
197 	    !(flow.n_proto == htons(ETH_P_IP) ||
198 	      flow.n_proto == htons(ETH_P_IPV6)))
199 		return false;
200 
201 	if (flow.ip_proto == IPPROTO_TCP)
202 		data_len = 12;
203 	else
204 		data_len = 8;
205 
206 	*hash = comp_hash(netvsc_hash_key, HASH_KEYLEN, &flow, data_len);
207 
208 	return true;
209 }
210 
211 static u16 netvsc_select_queue(struct net_device *ndev, struct sk_buff *skb,
212 			void *accel_priv, select_queue_fallback_t fallback)
213 {
214 	struct net_device_context *net_device_ctx = netdev_priv(ndev);
215 	struct hv_device *hdev =  net_device_ctx->device_ctx;
216 	struct netvsc_device *nvsc_dev = hv_get_drvdata(hdev);
217 	u32 hash;
218 	u16 q_idx = 0;
219 
220 	if (nvsc_dev == NULL || ndev->real_num_tx_queues <= 1)
221 		return 0;
222 
223 	if (netvsc_set_hash(&hash, skb)) {
224 		q_idx = nvsc_dev->send_table[hash % VRSS_SEND_TAB_SIZE] %
225 			ndev->real_num_tx_queues;
226 		skb_set_hash(skb, hash, PKT_HASH_TYPE_L3);
227 	}
228 
229 	return q_idx;
230 }
231 
232 static void netvsc_xmit_completion(void *context)
233 {
234 	struct hv_netvsc_packet *packet = (struct hv_netvsc_packet *)context;
235 	struct sk_buff *skb = (struct sk_buff *)
236 		(unsigned long)packet->send_completion_tid;
237 	u32 index = packet->send_buf_index;
238 
239 	kfree(packet);
240 
241 	if (skb && (index == NETVSC_INVALID_INDEX))
242 		dev_kfree_skb_any(skb);
243 }
244 
245 static u32 fill_pg_buf(struct page *page, u32 offset, u32 len,
246 			struct hv_page_buffer *pb)
247 {
248 	int j = 0;
249 
250 	/* Deal with compund pages by ignoring unused part
251 	 * of the page.
252 	 */
253 	page += (offset >> PAGE_SHIFT);
254 	offset &= ~PAGE_MASK;
255 
256 	while (len > 0) {
257 		unsigned long bytes;
258 
259 		bytes = PAGE_SIZE - offset;
260 		if (bytes > len)
261 			bytes = len;
262 		pb[j].pfn = page_to_pfn(page);
263 		pb[j].offset = offset;
264 		pb[j].len = bytes;
265 
266 		offset += bytes;
267 		len -= bytes;
268 
269 		if (offset == PAGE_SIZE && len) {
270 			page++;
271 			offset = 0;
272 			j++;
273 		}
274 	}
275 
276 	return j + 1;
277 }
278 
279 static u32 init_page_array(void *hdr, u32 len, struct sk_buff *skb,
280 			   struct hv_page_buffer *pb)
281 {
282 	u32 slots_used = 0;
283 	char *data = skb->data;
284 	int frags = skb_shinfo(skb)->nr_frags;
285 	int i;
286 
287 	/* The packet is laid out thus:
288 	 * 1. hdr
289 	 * 2. skb linear data
290 	 * 3. skb fragment data
291 	 */
292 	if (hdr != NULL)
293 		slots_used += fill_pg_buf(virt_to_page(hdr),
294 					offset_in_page(hdr),
295 					len, &pb[slots_used]);
296 
297 	slots_used += fill_pg_buf(virt_to_page(data),
298 				offset_in_page(data),
299 				skb_headlen(skb), &pb[slots_used]);
300 
301 	for (i = 0; i < frags; i++) {
302 		skb_frag_t *frag = skb_shinfo(skb)->frags + i;
303 
304 		slots_used += fill_pg_buf(skb_frag_page(frag),
305 					frag->page_offset,
306 					skb_frag_size(frag), &pb[slots_used]);
307 	}
308 	return slots_used;
309 }
310 
311 static int count_skb_frag_slots(struct sk_buff *skb)
312 {
313 	int i, frags = skb_shinfo(skb)->nr_frags;
314 	int pages = 0;
315 
316 	for (i = 0; i < frags; i++) {
317 		skb_frag_t *frag = skb_shinfo(skb)->frags + i;
318 		unsigned long size = skb_frag_size(frag);
319 		unsigned long offset = frag->page_offset;
320 
321 		/* Skip unused frames from start of page */
322 		offset &= ~PAGE_MASK;
323 		pages += PFN_UP(offset + size);
324 	}
325 	return pages;
326 }
327 
328 static int netvsc_get_slots(struct sk_buff *skb)
329 {
330 	char *data = skb->data;
331 	unsigned int offset = offset_in_page(data);
332 	unsigned int len = skb_headlen(skb);
333 	int slots;
334 	int frag_slots;
335 
336 	slots = DIV_ROUND_UP(offset + len, PAGE_SIZE);
337 	frag_slots = count_skb_frag_slots(skb);
338 	return slots + frag_slots;
339 }
340 
341 static u32 get_net_transport_info(struct sk_buff *skb, u32 *trans_off)
342 {
343 	u32 ret_val = TRANSPORT_INFO_NOT_IP;
344 
345 	if ((eth_hdr(skb)->h_proto != htons(ETH_P_IP)) &&
346 		(eth_hdr(skb)->h_proto != htons(ETH_P_IPV6))) {
347 		goto not_ip;
348 	}
349 
350 	*trans_off = skb_transport_offset(skb);
351 
352 	if ((eth_hdr(skb)->h_proto == htons(ETH_P_IP))) {
353 		struct iphdr *iphdr = ip_hdr(skb);
354 
355 		if (iphdr->protocol == IPPROTO_TCP)
356 			ret_val = TRANSPORT_INFO_IPV4_TCP;
357 		else if (iphdr->protocol == IPPROTO_UDP)
358 			ret_val = TRANSPORT_INFO_IPV4_UDP;
359 	} else {
360 		if (ipv6_hdr(skb)->nexthdr == IPPROTO_TCP)
361 			ret_val = TRANSPORT_INFO_IPV6_TCP;
362 		else if (ipv6_hdr(skb)->nexthdr == IPPROTO_UDP)
363 			ret_val = TRANSPORT_INFO_IPV6_UDP;
364 	}
365 
366 not_ip:
367 	return ret_val;
368 }
369 
370 static int netvsc_start_xmit(struct sk_buff *skb, struct net_device *net)
371 {
372 	struct net_device_context *net_device_ctx = netdev_priv(net);
373 	struct hv_netvsc_packet *packet;
374 	int ret;
375 	unsigned int num_data_pgs;
376 	struct rndis_message *rndis_msg;
377 	struct rndis_packet *rndis_pkt;
378 	u32 rndis_msg_size;
379 	bool isvlan;
380 	struct rndis_per_packet_info *ppi;
381 	struct ndis_tcp_ip_checksum_info *csum_info;
382 	struct ndis_tcp_lso_info *lso_info;
383 	int  hdr_offset;
384 	u32 net_trans_info;
385 	u32 hash;
386 	u32 skb_length = skb->len;
387 
388 
389 	/* We will atmost need two pages to describe the rndis
390 	 * header. We can only transmit MAX_PAGE_BUFFER_COUNT number
391 	 * of pages in a single packet.
392 	 */
393 	num_data_pgs = netvsc_get_slots(skb) + 2;
394 	if (num_data_pgs > MAX_PAGE_BUFFER_COUNT) {
395 		netdev_err(net, "Packet too big: %u\n", skb->len);
396 		dev_kfree_skb(skb);
397 		net->stats.tx_dropped++;
398 		return NETDEV_TX_OK;
399 	}
400 
401 	/* Allocate a netvsc packet based on # of frags. */
402 	packet = kzalloc(sizeof(struct hv_netvsc_packet) +
403 			 (num_data_pgs * sizeof(struct hv_page_buffer)) +
404 			 sizeof(struct rndis_message) +
405 			 NDIS_VLAN_PPI_SIZE + NDIS_CSUM_PPI_SIZE +
406 			 NDIS_LSO_PPI_SIZE + NDIS_HASH_PPI_SIZE, GFP_ATOMIC);
407 	if (!packet) {
408 		/* out of memory, drop packet */
409 		netdev_err(net, "unable to allocate hv_netvsc_packet\n");
410 
411 		dev_kfree_skb(skb);
412 		net->stats.tx_dropped++;
413 		return NETDEV_TX_OK;
414 	}
415 
416 	packet->vlan_tci = skb->vlan_tci;
417 
418 	packet->q_idx = skb_get_queue_mapping(skb);
419 
420 	packet->is_data_pkt = true;
421 	packet->total_data_buflen = skb->len;
422 
423 	packet->rndis_msg = (struct rndis_message *)((unsigned long)packet +
424 				sizeof(struct hv_netvsc_packet) +
425 				(num_data_pgs * sizeof(struct hv_page_buffer)));
426 
427 	/* Set the completion routine */
428 	packet->send_completion = netvsc_xmit_completion;
429 	packet->send_completion_ctx = packet;
430 	packet->send_completion_tid = (unsigned long)skb;
431 
432 	isvlan = packet->vlan_tci & VLAN_TAG_PRESENT;
433 
434 	/* Add the rndis header */
435 	rndis_msg = packet->rndis_msg;
436 	rndis_msg->ndis_msg_type = RNDIS_MSG_PACKET;
437 	rndis_msg->msg_len = packet->total_data_buflen;
438 	rndis_pkt = &rndis_msg->msg.pkt;
439 	rndis_pkt->data_offset = sizeof(struct rndis_packet);
440 	rndis_pkt->data_len = packet->total_data_buflen;
441 	rndis_pkt->per_pkt_info_offset = sizeof(struct rndis_packet);
442 
443 	rndis_msg_size = RNDIS_MESSAGE_SIZE(struct rndis_packet);
444 
445 	hash = skb_get_hash_raw(skb);
446 	if (hash != 0 && net->real_num_tx_queues > 1) {
447 		rndis_msg_size += NDIS_HASH_PPI_SIZE;
448 		ppi = init_ppi_data(rndis_msg, NDIS_HASH_PPI_SIZE,
449 				    NBL_HASH_VALUE);
450 		*(u32 *)((void *)ppi + ppi->ppi_offset) = hash;
451 	}
452 
453 	if (isvlan) {
454 		struct ndis_pkt_8021q_info *vlan;
455 
456 		rndis_msg_size += NDIS_VLAN_PPI_SIZE;
457 		ppi = init_ppi_data(rndis_msg, NDIS_VLAN_PPI_SIZE,
458 					IEEE_8021Q_INFO);
459 		vlan = (struct ndis_pkt_8021q_info *)((void *)ppi +
460 						ppi->ppi_offset);
461 		vlan->vlanid = packet->vlan_tci & VLAN_VID_MASK;
462 		vlan->pri = (packet->vlan_tci & VLAN_PRIO_MASK) >>
463 				VLAN_PRIO_SHIFT;
464 	}
465 
466 	net_trans_info = get_net_transport_info(skb, &hdr_offset);
467 	if (net_trans_info == TRANSPORT_INFO_NOT_IP)
468 		goto do_send;
469 
470 	/*
471 	 * Setup the sendside checksum offload only if this is not a
472 	 * GSO packet.
473 	 */
474 	if (skb_is_gso(skb))
475 		goto do_lso;
476 
477 	if ((skb->ip_summed == CHECKSUM_NONE) ||
478 	    (skb->ip_summed == CHECKSUM_UNNECESSARY))
479 		goto do_send;
480 
481 	rndis_msg_size += NDIS_CSUM_PPI_SIZE;
482 	ppi = init_ppi_data(rndis_msg, NDIS_CSUM_PPI_SIZE,
483 			    TCPIP_CHKSUM_PKTINFO);
484 
485 	csum_info = (struct ndis_tcp_ip_checksum_info *)((void *)ppi +
486 			ppi->ppi_offset);
487 
488 	if (net_trans_info & (INFO_IPV4 << 16))
489 		csum_info->transmit.is_ipv4 = 1;
490 	else
491 		csum_info->transmit.is_ipv6 = 1;
492 
493 	if (net_trans_info & INFO_TCP) {
494 		csum_info->transmit.tcp_checksum = 1;
495 		csum_info->transmit.tcp_header_offset = hdr_offset;
496 	} else if (net_trans_info & INFO_UDP) {
497 		/* UDP checksum offload is not supported on ws2008r2.
498 		 * Furthermore, on ws2012 and ws2012r2, there are some
499 		 * issues with udp checksum offload from Linux guests.
500 		 * (these are host issues).
501 		 * For now compute the checksum here.
502 		 */
503 		struct udphdr *uh;
504 		u16 udp_len;
505 
506 		ret = skb_cow_head(skb, 0);
507 		if (ret)
508 			goto drop;
509 
510 		uh = udp_hdr(skb);
511 		udp_len = ntohs(uh->len);
512 		uh->check = 0;
513 		uh->check = csum_tcpudp_magic(ip_hdr(skb)->saddr,
514 					      ip_hdr(skb)->daddr,
515 					      udp_len, IPPROTO_UDP,
516 					      csum_partial(uh, udp_len, 0));
517 		if (uh->check == 0)
518 			uh->check = CSUM_MANGLED_0;
519 
520 		csum_info->transmit.udp_checksum = 0;
521 	}
522 	goto do_send;
523 
524 do_lso:
525 	rndis_msg_size += NDIS_LSO_PPI_SIZE;
526 	ppi = init_ppi_data(rndis_msg, NDIS_LSO_PPI_SIZE,
527 			    TCP_LARGESEND_PKTINFO);
528 
529 	lso_info = (struct ndis_tcp_lso_info *)((void *)ppi +
530 			ppi->ppi_offset);
531 
532 	lso_info->lso_v2_transmit.type = NDIS_TCP_LARGE_SEND_OFFLOAD_V2_TYPE;
533 	if (net_trans_info & (INFO_IPV4 << 16)) {
534 		lso_info->lso_v2_transmit.ip_version =
535 			NDIS_TCP_LARGE_SEND_OFFLOAD_IPV4;
536 		ip_hdr(skb)->tot_len = 0;
537 		ip_hdr(skb)->check = 0;
538 		tcp_hdr(skb)->check =
539 		~csum_tcpudp_magic(ip_hdr(skb)->saddr,
540 				   ip_hdr(skb)->daddr, 0, IPPROTO_TCP, 0);
541 	} else {
542 		lso_info->lso_v2_transmit.ip_version =
543 			NDIS_TCP_LARGE_SEND_OFFLOAD_IPV6;
544 		ipv6_hdr(skb)->payload_len = 0;
545 		tcp_hdr(skb)->check =
546 		~csum_ipv6_magic(&ipv6_hdr(skb)->saddr,
547 				&ipv6_hdr(skb)->daddr, 0, IPPROTO_TCP, 0);
548 	}
549 	lso_info->lso_v2_transmit.tcp_header_offset = hdr_offset;
550 	lso_info->lso_v2_transmit.mss = skb_shinfo(skb)->gso_size;
551 
552 do_send:
553 	/* Start filling in the page buffers with the rndis hdr */
554 	rndis_msg->msg_len += rndis_msg_size;
555 	packet->total_data_buflen = rndis_msg->msg_len;
556 	packet->page_buf_cnt = init_page_array(rndis_msg, rndis_msg_size,
557 					skb, &packet->page_buf[0]);
558 
559 	ret = netvsc_send(net_device_ctx->device_ctx, packet);
560 
561 drop:
562 	if (ret == 0) {
563 		net->stats.tx_bytes += skb_length;
564 		net->stats.tx_packets++;
565 	} else {
566 		kfree(packet);
567 		if (ret != -EAGAIN) {
568 			dev_kfree_skb_any(skb);
569 			net->stats.tx_dropped++;
570 		}
571 	}
572 
573 	return (ret == -EAGAIN) ? NETDEV_TX_BUSY : NETDEV_TX_OK;
574 }
575 
576 /*
577  * netvsc_linkstatus_callback - Link up/down notification
578  */
579 void netvsc_linkstatus_callback(struct hv_device *device_obj,
580 				struct rndis_message *resp)
581 {
582 	struct rndis_indicate_status *indicate = &resp->msg.indicate_status;
583 	struct net_device *net;
584 	struct net_device_context *ndev_ctx;
585 	struct netvsc_device *net_device;
586 	struct rndis_device *rdev;
587 
588 	net_device = hv_get_drvdata(device_obj);
589 	rdev = net_device->extension;
590 
591 	switch (indicate->status) {
592 	case RNDIS_STATUS_MEDIA_CONNECT:
593 		rdev->link_state = false;
594 		break;
595 	case RNDIS_STATUS_MEDIA_DISCONNECT:
596 		rdev->link_state = true;
597 		break;
598 	case RNDIS_STATUS_NETWORK_CHANGE:
599 		rdev->link_change = true;
600 		break;
601 	default:
602 		return;
603 	}
604 
605 	net = net_device->ndev;
606 
607 	if (!net || net->reg_state != NETREG_REGISTERED)
608 		return;
609 
610 	ndev_ctx = netdev_priv(net);
611 	if (!rdev->link_state) {
612 		schedule_delayed_work(&ndev_ctx->dwork, 0);
613 		schedule_delayed_work(&ndev_ctx->dwork, msecs_to_jiffies(20));
614 	} else {
615 		schedule_delayed_work(&ndev_ctx->dwork, 0);
616 	}
617 }
618 
619 /*
620  * netvsc_recv_callback -  Callback when we receive a packet from the
621  * "wire" on the specified device.
622  */
623 int netvsc_recv_callback(struct hv_device *device_obj,
624 				struct hv_netvsc_packet *packet,
625 				struct ndis_tcp_ip_checksum_info *csum_info)
626 {
627 	struct net_device *net;
628 	struct sk_buff *skb;
629 
630 	net = ((struct netvsc_device *)hv_get_drvdata(device_obj))->ndev;
631 	if (!net || net->reg_state != NETREG_REGISTERED) {
632 		packet->status = NVSP_STAT_FAIL;
633 		return 0;
634 	}
635 
636 	/* Allocate a skb - TODO direct I/O to pages? */
637 	skb = netdev_alloc_skb_ip_align(net, packet->total_data_buflen);
638 	if (unlikely(!skb)) {
639 		++net->stats.rx_dropped;
640 		packet->status = NVSP_STAT_FAIL;
641 		return 0;
642 	}
643 
644 	/*
645 	 * Copy to skb. This copy is needed here since the memory pointed by
646 	 * hv_netvsc_packet cannot be deallocated
647 	 */
648 	memcpy(skb_put(skb, packet->total_data_buflen), packet->data,
649 		packet->total_data_buflen);
650 
651 	skb->protocol = eth_type_trans(skb, net);
652 	if (csum_info) {
653 		/* We only look at the IP checksum here.
654 		 * Should we be dropping the packet if checksum
655 		 * failed? How do we deal with other checksums - TCP/UDP?
656 		 */
657 		if (csum_info->receive.ip_checksum_succeeded)
658 			skb->ip_summed = CHECKSUM_UNNECESSARY;
659 		else
660 			skb->ip_summed = CHECKSUM_NONE;
661 	}
662 
663 	if (packet->vlan_tci & VLAN_TAG_PRESENT)
664 		__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q),
665 				       packet->vlan_tci);
666 
667 	skb_record_rx_queue(skb, packet->channel->
668 			    offermsg.offer.sub_channel_index);
669 
670 	net->stats.rx_packets++;
671 	net->stats.rx_bytes += packet->total_data_buflen;
672 
673 	/*
674 	 * Pass the skb back up. Network stack will deallocate the skb when it
675 	 * is done.
676 	 * TODO - use NAPI?
677 	 */
678 	netif_rx(skb);
679 
680 	return 0;
681 }
682 
683 static void netvsc_get_drvinfo(struct net_device *net,
684 			       struct ethtool_drvinfo *info)
685 {
686 	strlcpy(info->driver, KBUILD_MODNAME, sizeof(info->driver));
687 	strlcpy(info->fw_version, "N/A", sizeof(info->fw_version));
688 }
689 
690 static int netvsc_change_mtu(struct net_device *ndev, int mtu)
691 {
692 	struct net_device_context *ndevctx = netdev_priv(ndev);
693 	struct hv_device *hdev =  ndevctx->device_ctx;
694 	struct netvsc_device *nvdev = hv_get_drvdata(hdev);
695 	struct netvsc_device_info device_info;
696 	int limit = ETH_DATA_LEN;
697 
698 	if (nvdev == NULL || nvdev->destroy)
699 		return -ENODEV;
700 
701 	if (nvdev->nvsp_version >= NVSP_PROTOCOL_VERSION_2)
702 		limit = NETVSC_MTU - ETH_HLEN;
703 
704 	/* Hyper-V hosts don't support MTU < ETH_DATA_LEN (1500) */
705 	if (mtu < ETH_DATA_LEN || mtu > limit)
706 		return -EINVAL;
707 
708 	nvdev->start_remove = true;
709 	cancel_work_sync(&ndevctx->work);
710 	netif_tx_disable(ndev);
711 	rndis_filter_device_remove(hdev);
712 
713 	ndev->mtu = mtu;
714 
715 	ndevctx->device_ctx = hdev;
716 	hv_set_drvdata(hdev, ndev);
717 	device_info.ring_size = ring_size;
718 	rndis_filter_device_add(hdev, &device_info);
719 	netif_tx_wake_all_queues(ndev);
720 
721 	return 0;
722 }
723 
724 
725 static int netvsc_set_mac_addr(struct net_device *ndev, void *p)
726 {
727 	struct net_device_context *ndevctx = netdev_priv(ndev);
728 	struct hv_device *hdev =  ndevctx->device_ctx;
729 	struct sockaddr *addr = p;
730 	char save_adr[ETH_ALEN];
731 	unsigned char save_aatype;
732 	int err;
733 
734 	memcpy(save_adr, ndev->dev_addr, ETH_ALEN);
735 	save_aatype = ndev->addr_assign_type;
736 
737 	err = eth_mac_addr(ndev, p);
738 	if (err != 0)
739 		return err;
740 
741 	err = rndis_filter_set_device_mac(hdev, addr->sa_data);
742 	if (err != 0) {
743 		/* roll back to saved MAC */
744 		memcpy(ndev->dev_addr, save_adr, ETH_ALEN);
745 		ndev->addr_assign_type = save_aatype;
746 	}
747 
748 	return err;
749 }
750 
751 #ifdef CONFIG_NET_POLL_CONTROLLER
752 static void netvsc_poll_controller(struct net_device *net)
753 {
754 	/* As netvsc_start_xmit() works synchronous we don't have to
755 	 * trigger anything here.
756 	 */
757 }
758 #endif
759 
760 static const struct ethtool_ops ethtool_ops = {
761 	.get_drvinfo	= netvsc_get_drvinfo,
762 	.get_link	= ethtool_op_get_link,
763 };
764 
765 static const struct net_device_ops device_ops = {
766 	.ndo_open =			netvsc_open,
767 	.ndo_stop =			netvsc_close,
768 	.ndo_start_xmit =		netvsc_start_xmit,
769 	.ndo_set_rx_mode =		netvsc_set_multicast_list,
770 	.ndo_change_mtu =		netvsc_change_mtu,
771 	.ndo_validate_addr =		eth_validate_addr,
772 	.ndo_set_mac_address =		netvsc_set_mac_addr,
773 	.ndo_select_queue =		netvsc_select_queue,
774 #ifdef CONFIG_NET_POLL_CONTROLLER
775 	.ndo_poll_controller =		netvsc_poll_controller,
776 #endif
777 };
778 
779 /*
780  * Send GARP packet to network peers after migrations.
781  * After Quick Migration, the network is not immediately operational in the
782  * current context when receiving RNDIS_STATUS_MEDIA_CONNECT event. So, add
783  * another netif_notify_peers() into a delayed work, otherwise GARP packet
784  * will not be sent after quick migration, and cause network disconnection.
785  * Also, we update the carrier status here.
786  */
787 static void netvsc_link_change(struct work_struct *w)
788 {
789 	struct net_device_context *ndev_ctx;
790 	struct net_device *net;
791 	struct netvsc_device *net_device;
792 	struct rndis_device *rdev;
793 	bool notify, refresh = false;
794 	char *argv[] = { "/etc/init.d/network", "restart", NULL };
795 	char *envp[] = { "HOME=/", "PATH=/sbin:/usr/sbin:/bin:/usr/bin", NULL };
796 
797 	rtnl_lock();
798 
799 	ndev_ctx = container_of(w, struct net_device_context, dwork.work);
800 	net_device = hv_get_drvdata(ndev_ctx->device_ctx);
801 	rdev = net_device->extension;
802 	net = net_device->ndev;
803 
804 	if (rdev->link_state) {
805 		netif_carrier_off(net);
806 		notify = false;
807 	} else {
808 		netif_carrier_on(net);
809 		notify = true;
810 		if (rdev->link_change) {
811 			rdev->link_change = false;
812 			refresh = true;
813 		}
814 	}
815 
816 	rtnl_unlock();
817 
818 	if (refresh)
819 		call_usermodehelper(argv[0], argv, envp, UMH_WAIT_EXEC);
820 
821 	if (notify)
822 		netdev_notify_peers(net);
823 }
824 
825 
826 static int netvsc_probe(struct hv_device *dev,
827 			const struct hv_vmbus_device_id *dev_id)
828 {
829 	struct net_device *net = NULL;
830 	struct net_device_context *net_device_ctx;
831 	struct netvsc_device_info device_info;
832 	struct netvsc_device *nvdev;
833 	int ret;
834 
835 	net = alloc_etherdev_mq(sizeof(struct net_device_context),
836 				num_online_cpus());
837 	if (!net)
838 		return -ENOMEM;
839 
840 	netif_carrier_off(net);
841 
842 	net_device_ctx = netdev_priv(net);
843 	net_device_ctx->device_ctx = dev;
844 	hv_set_drvdata(dev, net);
845 	INIT_DELAYED_WORK(&net_device_ctx->dwork, netvsc_link_change);
846 	INIT_WORK(&net_device_ctx->work, do_set_multicast);
847 
848 	net->netdev_ops = &device_ops;
849 
850 	net->hw_features = NETIF_F_RXCSUM | NETIF_F_SG | NETIF_F_IP_CSUM |
851 				NETIF_F_TSO;
852 	net->features = NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_SG | NETIF_F_RXCSUM |
853 			NETIF_F_IP_CSUM | NETIF_F_TSO;
854 
855 	net->ethtool_ops = &ethtool_ops;
856 	SET_NETDEV_DEV(net, &dev->device);
857 
858 	/* Notify the netvsc driver of the new device */
859 	device_info.ring_size = ring_size;
860 	ret = rndis_filter_device_add(dev, &device_info);
861 	if (ret != 0) {
862 		netdev_err(net, "unable to add netvsc device (ret %d)\n", ret);
863 		free_netdev(net);
864 		hv_set_drvdata(dev, NULL);
865 		return ret;
866 	}
867 	memcpy(net->dev_addr, device_info.mac_adr, ETH_ALEN);
868 
869 	nvdev = hv_get_drvdata(dev);
870 	netif_set_real_num_tx_queues(net, nvdev->num_chn);
871 	netif_set_real_num_rx_queues(net, nvdev->num_chn);
872 
873 	ret = register_netdev(net);
874 	if (ret != 0) {
875 		pr_err("Unable to register netdev.\n");
876 		rndis_filter_device_remove(dev);
877 		free_netdev(net);
878 	} else {
879 		schedule_delayed_work(&net_device_ctx->dwork, 0);
880 	}
881 
882 	return ret;
883 }
884 
885 static int netvsc_remove(struct hv_device *dev)
886 {
887 	struct net_device *net;
888 	struct net_device_context *ndev_ctx;
889 	struct netvsc_device *net_device;
890 
891 	net_device = hv_get_drvdata(dev);
892 	net = net_device->ndev;
893 
894 	if (net == NULL) {
895 		dev_err(&dev->device, "No net device to remove\n");
896 		return 0;
897 	}
898 
899 	net_device->start_remove = true;
900 
901 	ndev_ctx = netdev_priv(net);
902 	cancel_delayed_work_sync(&ndev_ctx->dwork);
903 	cancel_work_sync(&ndev_ctx->work);
904 
905 	/* Stop outbound asap */
906 	netif_tx_disable(net);
907 
908 	unregister_netdev(net);
909 
910 	/*
911 	 * Call to the vsc driver to let it know that the device is being
912 	 * removed
913 	 */
914 	rndis_filter_device_remove(dev);
915 
916 	free_netdev(net);
917 	return 0;
918 }
919 
920 static const struct hv_vmbus_device_id id_table[] = {
921 	/* Network guid */
922 	{ HV_NIC_GUID, },
923 	{ },
924 };
925 
926 MODULE_DEVICE_TABLE(vmbus, id_table);
927 
928 /* The one and only one */
929 static struct  hv_driver netvsc_drv = {
930 	.name = KBUILD_MODNAME,
931 	.id_table = id_table,
932 	.probe = netvsc_probe,
933 	.remove = netvsc_remove,
934 };
935 
936 static void __exit netvsc_drv_exit(void)
937 {
938 	vmbus_driver_unregister(&netvsc_drv);
939 }
940 
941 static int __init netvsc_drv_init(void)
942 {
943 	if (ring_size < RING_SIZE_MIN) {
944 		ring_size = RING_SIZE_MIN;
945 		pr_info("Increased ring_size to %d (min allowed)\n",
946 			ring_size);
947 	}
948 	return vmbus_driver_register(&netvsc_drv);
949 }
950 
951 MODULE_LICENSE("GPL");
952 MODULE_DESCRIPTION("Microsoft Hyper-V network driver");
953 
954 module_init(netvsc_drv_init);
955 module_exit(netvsc_drv_exit);
956