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, write to the Free Software Foundation, Inc., 59 Temple
 15 * Place - Suite 330, Boston, MA 02111-1307 USA.
 16 *
 17 * Authors:
 18 *   Haiyang Zhang <haiyangz@microsoft.com>
 19 *   Hank Janssen  <hjanssen@microsoft.com>
 20 */
 21#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 22
 23#include <linux/init.h>
 24#include <linux/atomic.h>
 25#include <linux/module.h>
 26#include <linux/highmem.h>
 27#include <linux/device.h>
 28#include <linux/io.h>
 29#include <linux/delay.h>
 30#include <linux/netdevice.h>
 31#include <linux/inetdevice.h>
 32#include <linux/etherdevice.h>
 33#include <linux/skbuff.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
 43struct 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
 51static int ring_size = 128;
 52module_param(ring_size, int, S_IRUGO);
 53MODULE_PARM_DESC(ring_size, "Ring buffer size (# of pages)");
 54
 55static 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
 80static 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
 87static 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	int ret = 0;
 92
 93	/* Open up the device */
 94	ret = rndis_filter_open(device_obj);
 95	if (ret != 0) {
 96		netdev_err(net, "unable to open device (ret %d).\n", ret);
 97		return ret;
 98	}
 99
100	netif_start_queue(net);
101
102	return ret;
103}
104
105static int netvsc_close(struct net_device *net)
106{
107	struct net_device_context *net_device_ctx = netdev_priv(net);
108	struct hv_device *device_obj = net_device_ctx->device_ctx;
109	int ret;
110
111	netif_tx_disable(net);
112
113	/* Make sure netvsc_set_multicast_list doesn't re-enable filter! */
114	cancel_work_sync(&net_device_ctx->work);
115	ret = rndis_filter_close(device_obj);
116	if (ret != 0)
117		netdev_err(net, "unable to close device (ret %d).\n", ret);
118
119	return ret;
120}
121
122static void netvsc_xmit_completion(void *context)
123{
124	struct hv_netvsc_packet *packet = (struct hv_netvsc_packet *)context;
125	struct sk_buff *skb = (struct sk_buff *)
126		(unsigned long)packet->completion.send.send_completion_tid;
127
128	kfree(packet);
129
130	if (skb)
131		dev_kfree_skb_any(skb);
132}
133
134static int netvsc_start_xmit(struct sk_buff *skb, struct net_device *net)
135{
136	struct net_device_context *net_device_ctx = netdev_priv(net);
137	struct hv_netvsc_packet *packet;
138	int ret;
139	unsigned int i, num_pages, npg_data;
140
141	/* Add multipages for skb->data and additional 2 for RNDIS */
142	npg_data = (((unsigned long)skb->data + skb_headlen(skb) - 1)
143		>> PAGE_SHIFT) - ((unsigned long)skb->data >> PAGE_SHIFT) + 1;
144	num_pages = skb_shinfo(skb)->nr_frags + npg_data + 2;
145
146	/* Allocate a netvsc packet based on # of frags. */
147	packet = kzalloc(sizeof(struct hv_netvsc_packet) +
148			 (num_pages * sizeof(struct hv_page_buffer)) +
149			 sizeof(struct rndis_filter_packet) +
150			 NDIS_VLAN_PPI_SIZE, GFP_ATOMIC);
151	if (!packet) {
152		/* out of memory, drop packet */
153		netdev_err(net, "unable to allocate hv_netvsc_packet\n");
154
155		dev_kfree_skb(skb);
156		net->stats.tx_dropped++;
157		return NETDEV_TX_OK;
158	}
159
160	packet->vlan_tci = skb->vlan_tci;
161
162	packet->extension = (void *)(unsigned long)packet +
163				sizeof(struct hv_netvsc_packet) +
164				    (num_pages * sizeof(struct hv_page_buffer));
165
166	/* If the rndis msg goes beyond 1 page, we will add 1 later */
167	packet->page_buf_cnt = num_pages - 1;
168
169	/* Initialize it from the skb */
170	packet->total_data_buflen = skb->len;
171
172	/* Start filling in the page buffers starting after RNDIS buffer. */
173	packet->page_buf[1].pfn = virt_to_phys(skb->data) >> PAGE_SHIFT;
174	packet->page_buf[1].offset
175		= (unsigned long)skb->data & (PAGE_SIZE - 1);
176	if (npg_data == 1)
177		packet->page_buf[1].len = skb_headlen(skb);
178	else
179		packet->page_buf[1].len = PAGE_SIZE
180			- packet->page_buf[1].offset;
181
182	for (i = 2; i <= npg_data; i++) {
183		packet->page_buf[i].pfn = virt_to_phys(skb->data
184			+ PAGE_SIZE * (i-1)) >> PAGE_SHIFT;
185		packet->page_buf[i].offset = 0;
186		packet->page_buf[i].len = PAGE_SIZE;
187	}
188	if (npg_data > 1)
189		packet->page_buf[npg_data].len = (((unsigned long)skb->data
190			+ skb_headlen(skb) - 1) & (PAGE_SIZE - 1)) + 1;
191
192	/* Additional fragments are after SKB data */
193	for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
194		const skb_frag_t *f = &skb_shinfo(skb)->frags[i];
195
196		packet->page_buf[i+npg_data+1].pfn =
197			page_to_pfn(skb_frag_page(f));
198		packet->page_buf[i+npg_data+1].offset = f->page_offset;
199		packet->page_buf[i+npg_data+1].len = skb_frag_size(f);
200	}
201
202	/* Set the completion routine */
203	packet->completion.send.send_completion = netvsc_xmit_completion;
204	packet->completion.send.send_completion_ctx = packet;
205	packet->completion.send.send_completion_tid = (unsigned long)skb;
206
207	ret = rndis_filter_send(net_device_ctx->device_ctx,
208				  packet);
209	if (ret == 0) {
210		net->stats.tx_bytes += skb->len;
211		net->stats.tx_packets++;
212	} else {
213		kfree(packet);
214		if (ret != -EAGAIN) {
215			dev_kfree_skb_any(skb);
216			net->stats.tx_dropped++;
217		}
218	}
219
220	return (ret == -EAGAIN) ? NETDEV_TX_BUSY : NETDEV_TX_OK;
221}
222
223/*
224 * netvsc_linkstatus_callback - Link up/down notification
225 */
226void netvsc_linkstatus_callback(struct hv_device *device_obj,
227				       unsigned int status)
228{
229	struct net_device *net;
230	struct net_device_context *ndev_ctx;
231	struct netvsc_device *net_device;
232
233	net_device = hv_get_drvdata(device_obj);
234	net = net_device->ndev;
235
236	if (!net) {
237		netdev_err(net, "got link status but net device "
238				"not initialized yet\n");
239		return;
240	}
241
242	if (status == 1) {
243		netif_carrier_on(net);
244		netif_wake_queue(net);
245		ndev_ctx = netdev_priv(net);
246		schedule_delayed_work(&ndev_ctx->dwork, 0);
247		schedule_delayed_work(&ndev_ctx->dwork, msecs_to_jiffies(20));
248	} else {
249		netif_carrier_off(net);
250		netif_tx_disable(net);
251	}
252}
253
254/*
255 * netvsc_recv_callback -  Callback when we receive a packet from the
256 * "wire" on the specified device.
257 */
258int netvsc_recv_callback(struct hv_device *device_obj,
259				struct hv_netvsc_packet *packet)
260{
261	struct net_device *net;
262	struct sk_buff *skb;
263
264	net = ((struct netvsc_device *)hv_get_drvdata(device_obj))->ndev;
265	if (!net) {
266		netdev_err(net, "got receive callback but net device"
267			" not initialized yet\n");
268		return 0;
269	}
270
271	/* Allocate a skb - TODO direct I/O to pages? */
272	skb = netdev_alloc_skb_ip_align(net, packet->total_data_buflen);
273	if (unlikely(!skb)) {
274		++net->stats.rx_dropped;
275		return 0;
276	}
277
278	/*
279	 * Copy to skb. This copy is needed here since the memory pointed by
280	 * hv_netvsc_packet cannot be deallocated
281	 */
282	memcpy(skb_put(skb, packet->total_data_buflen), packet->data,
283		packet->total_data_buflen);
284
285	skb->protocol = eth_type_trans(skb, net);
286	skb->ip_summed = CHECKSUM_NONE;
287	skb->vlan_tci = packet->vlan_tci;
288
289	net->stats.rx_packets++;
290	net->stats.rx_bytes += packet->total_data_buflen;
291
292	/*
293	 * Pass the skb back up. Network stack will deallocate the skb when it
294	 * is done.
295	 * TODO - use NAPI?
296	 */
297	netif_rx(skb);
298
299	return 0;
300}
301
302static void netvsc_get_drvinfo(struct net_device *net,
303			       struct ethtool_drvinfo *info)
304{
305	strcpy(info->driver, KBUILD_MODNAME);
306	strcpy(info->version, HV_DRV_VERSION);
307	strcpy(info->fw_version, "N/A");
308}
309
310static int netvsc_change_mtu(struct net_device *ndev, int mtu)
311{
312	struct net_device_context *ndevctx = netdev_priv(ndev);
313	struct hv_device *hdev =  ndevctx->device_ctx;
314	struct netvsc_device *nvdev = hv_get_drvdata(hdev);
315	struct netvsc_device_info device_info;
316	int limit = ETH_DATA_LEN;
317
318	if (nvdev == NULL || nvdev->destroy)
319		return -ENODEV;
320
321	if (nvdev->nvsp_version == NVSP_PROTOCOL_VERSION_2)
322		limit = NETVSC_MTU;
323
324	if (mtu < 68 || mtu > limit)
325		return -EINVAL;
326
327	nvdev->start_remove = true;
328	cancel_delayed_work_sync(&ndevctx->dwork);
329	cancel_work_sync(&ndevctx->work);
330	netif_tx_disable(ndev);
331	rndis_filter_device_remove(hdev);
332
333	ndev->mtu = mtu;
334
335	ndevctx->device_ctx = hdev;
336	hv_set_drvdata(hdev, ndev);
337	device_info.ring_size = ring_size;
338	rndis_filter_device_add(hdev, &device_info);
339	netif_wake_queue(ndev);
340
341	return 0;
342}
343
344static const struct ethtool_ops ethtool_ops = {
345	.get_drvinfo	= netvsc_get_drvinfo,
346	.get_link	= ethtool_op_get_link,
347};
348
349static const struct net_device_ops device_ops = {
350	.ndo_open =			netvsc_open,
351	.ndo_stop =			netvsc_close,
352	.ndo_start_xmit =		netvsc_start_xmit,
353	.ndo_set_rx_mode =		netvsc_set_multicast_list,
354	.ndo_change_mtu =		netvsc_change_mtu,
355	.ndo_validate_addr =		eth_validate_addr,
356	.ndo_set_mac_address =		eth_mac_addr,
357};
358
359/*
360 * Send GARP packet to network peers after migrations.
361 * After Quick Migration, the network is not immediately operational in the
362 * current context when receiving RNDIS_STATUS_MEDIA_CONNECT event. So, add
363 * another netif_notify_peers() into a delayed work, otherwise GARP packet
364 * will not be sent after quick migration, and cause network disconnection.
365 */
366static void netvsc_send_garp(struct work_struct *w)
367{
368	struct net_device_context *ndev_ctx;
369	struct net_device *net;
370	struct netvsc_device *net_device;
371
372	ndev_ctx = container_of(w, struct net_device_context, dwork.work);
373	net_device = hv_get_drvdata(ndev_ctx->device_ctx);
374	net = net_device->ndev;
375	netif_notify_peers(net);
376}
377
378
379static int netvsc_probe(struct hv_device *dev,
380			const struct hv_vmbus_device_id *dev_id)
381{
382	struct net_device *net = NULL;
383	struct net_device_context *net_device_ctx;
384	struct netvsc_device_info device_info;
385	int ret;
386
387	net = alloc_etherdev(sizeof(struct net_device_context));
388	if (!net)
389		return -ENOMEM;
390
391	/* Set initial state */
392	netif_carrier_off(net);
393
394	net_device_ctx = netdev_priv(net);
395	net_device_ctx->device_ctx = dev;
396	hv_set_drvdata(dev, net);
397	INIT_DELAYED_WORK(&net_device_ctx->dwork, netvsc_send_garp);
398	INIT_WORK(&net_device_ctx->work, do_set_multicast);
399
400	net->netdev_ops = &device_ops;
401
402	/* TODO: Add GSO and Checksum offload */
403	net->hw_features = NETIF_F_SG;
404	net->features = NETIF_F_SG | NETIF_F_HW_VLAN_TX;
405
406	SET_ETHTOOL_OPS(net, &ethtool_ops);
407	SET_NETDEV_DEV(net, &dev->device);
408
409	ret = register_netdev(net);
410	if (ret != 0) {
411		pr_err("Unable to register netdev.\n");
412		free_netdev(net);
413		goto out;
414	}
415
416	/* Notify the netvsc driver of the new device */
417	device_info.ring_size = ring_size;
418	ret = rndis_filter_device_add(dev, &device_info);
419	if (ret != 0) {
420		netdev_err(net, "unable to add netvsc device (ret %d)\n", ret);
421		unregister_netdev(net);
422		free_netdev(net);
423		hv_set_drvdata(dev, NULL);
424		return ret;
425	}
426	memcpy(net->dev_addr, device_info.mac_adr, ETH_ALEN);
427
428	netif_carrier_on(net);
429
430out:
431	return ret;
432}
433
434static int netvsc_remove(struct hv_device *dev)
435{
436	struct net_device *net;
437	struct net_device_context *ndev_ctx;
438	struct netvsc_device *net_device;
439
440	net_device = hv_get_drvdata(dev);
441	net = net_device->ndev;
442
443	if (net == NULL) {
444		dev_err(&dev->device, "No net device to remove\n");
445		return 0;
446	}
447
448	net_device->start_remove = true;
449
450	ndev_ctx = netdev_priv(net);
451	cancel_delayed_work_sync(&ndev_ctx->dwork);
452	cancel_work_sync(&ndev_ctx->work);
453
454	/* Stop outbound asap */
455	netif_tx_disable(net);
456
457	unregister_netdev(net);
458
459	/*
460	 * Call to the vsc driver to let it know that the device is being
461	 * removed
462	 */
463	rndis_filter_device_remove(dev);
464
465	free_netdev(net);
466	return 0;
467}
468
469static const struct hv_vmbus_device_id id_table[] = {
470	/* Network guid */
471	{ VMBUS_DEVICE(0x63, 0x51, 0x61, 0xF8, 0x3E, 0xDF, 0xc5, 0x46,
472		       0x91, 0x3F, 0xF2, 0xD2, 0xF9, 0x65, 0xED, 0x0E) },
473	{ },
474};
475
476MODULE_DEVICE_TABLE(vmbus, id_table);
477
478/* The one and only one */
479static struct  hv_driver netvsc_drv = {
480	.name = KBUILD_MODNAME,
481	.id_table = id_table,
482	.probe = netvsc_probe,
483	.remove = netvsc_remove,
484};
485
486static void __exit netvsc_drv_exit(void)
487{
488	vmbus_driver_unregister(&netvsc_drv);
489}
490
491static int __init netvsc_drv_init(void)
492{
493	return vmbus_driver_register(&netvsc_drv);
494}
495
496MODULE_LICENSE("GPL");
497MODULE_VERSION(HV_DRV_VERSION);
498MODULE_DESCRIPTION("Microsoft Hyper-V network driver");
499
500module_init(netvsc_drv_init);
501module_exit(netvsc_drv_exit);