[NETFILTER]: nf_nat_sip: translate all Contact headers
[linux-2.6/sactl.git] / drivers / net / virtio_net.c
blobb58472cf76f862c16fa861b02bcb494008c00f90
1 /* A simple network driver using virtio.
3 * Copyright 2007 Rusty Russell <rusty@rustcorp.com.au> IBM Corporation
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 //#define DEBUG
20 #include <linux/netdevice.h>
21 #include <linux/etherdevice.h>
22 #include <linux/module.h>
23 #include <linux/virtio.h>
24 #include <linux/virtio_net.h>
25 #include <linux/scatterlist.h>
27 static int napi_weight = 128;
28 module_param(napi_weight, int, 0444);
30 static int csum = 1, gso = 1;
31 module_param(csum, bool, 0444);
32 module_param(gso, bool, 0444);
34 /* FIXME: MTU in config. */
35 #define MAX_PACKET_LEN (ETH_HLEN+ETH_DATA_LEN)
37 struct virtnet_info
39 struct virtio_device *vdev;
40 struct virtqueue *rvq, *svq;
41 struct net_device *dev;
42 struct napi_struct napi;
44 /* Number of input buffers, and max we've ever had. */
45 unsigned int num, max;
47 /* Receive & send queues. */
48 struct sk_buff_head recv;
49 struct sk_buff_head send;
52 static inline struct virtio_net_hdr *skb_vnet_hdr(struct sk_buff *skb)
54 return (struct virtio_net_hdr *)skb->cb;
57 static inline void vnet_hdr_to_sg(struct scatterlist *sg, struct sk_buff *skb)
59 sg_init_one(sg, skb_vnet_hdr(skb), sizeof(struct virtio_net_hdr));
62 static void skb_xmit_done(struct virtqueue *svq)
64 struct virtnet_info *vi = svq->vdev->priv;
66 /* Suppress further interrupts. */
67 svq->vq_ops->disable_cb(svq);
68 /* We were waiting for more output buffers. */
69 netif_wake_queue(vi->dev);
72 static void receive_skb(struct net_device *dev, struct sk_buff *skb,
73 unsigned len)
75 struct virtio_net_hdr *hdr = skb_vnet_hdr(skb);
77 if (unlikely(len < sizeof(struct virtio_net_hdr) + ETH_HLEN)) {
78 pr_debug("%s: short packet %i\n", dev->name, len);
79 dev->stats.rx_length_errors++;
80 goto drop;
82 len -= sizeof(struct virtio_net_hdr);
83 BUG_ON(len > MAX_PACKET_LEN);
85 skb_trim(skb, len);
86 skb->protocol = eth_type_trans(skb, dev);
87 pr_debug("Receiving skb proto 0x%04x len %i type %i\n",
88 ntohs(skb->protocol), skb->len, skb->pkt_type);
89 dev->stats.rx_bytes += skb->len;
90 dev->stats.rx_packets++;
92 if (hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
93 pr_debug("Needs csum!\n");
94 if (!skb_partial_csum_set(skb,hdr->csum_start,hdr->csum_offset))
95 goto frame_err;
98 if (hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) {
99 pr_debug("GSO!\n");
100 switch (hdr->gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
101 case VIRTIO_NET_HDR_GSO_TCPV4:
102 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
103 break;
104 case VIRTIO_NET_HDR_GSO_UDP:
105 skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
106 break;
107 case VIRTIO_NET_HDR_GSO_TCPV6:
108 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
109 break;
110 default:
111 if (net_ratelimit())
112 printk(KERN_WARNING "%s: bad gso type %u.\n",
113 dev->name, hdr->gso_type);
114 goto frame_err;
117 if (hdr->gso_type & VIRTIO_NET_HDR_GSO_ECN)
118 skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
120 skb_shinfo(skb)->gso_size = hdr->gso_size;
121 if (skb_shinfo(skb)->gso_size == 0) {
122 if (net_ratelimit())
123 printk(KERN_WARNING "%s: zero gso size.\n",
124 dev->name);
125 goto frame_err;
128 /* Header must be checked, and gso_segs computed. */
129 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
130 skb_shinfo(skb)->gso_segs = 0;
133 netif_receive_skb(skb);
134 return;
136 frame_err:
137 dev->stats.rx_frame_errors++;
138 drop:
139 dev_kfree_skb(skb);
142 static void try_fill_recv(struct virtnet_info *vi)
144 struct sk_buff *skb;
145 struct scatterlist sg[1+MAX_SKB_FRAGS];
146 int num, err;
148 sg_init_table(sg, 1+MAX_SKB_FRAGS);
149 for (;;) {
150 skb = netdev_alloc_skb(vi->dev, MAX_PACKET_LEN);
151 if (unlikely(!skb))
152 break;
154 skb_put(skb, MAX_PACKET_LEN);
155 vnet_hdr_to_sg(sg, skb);
156 num = skb_to_sgvec(skb, sg+1, 0, skb->len) + 1;
157 skb_queue_head(&vi->recv, skb);
159 err = vi->rvq->vq_ops->add_buf(vi->rvq, sg, 0, num, skb);
160 if (err) {
161 skb_unlink(skb, &vi->recv);
162 kfree_skb(skb);
163 break;
165 vi->num++;
167 if (unlikely(vi->num > vi->max))
168 vi->max = vi->num;
169 vi->rvq->vq_ops->kick(vi->rvq);
172 static void skb_recv_done(struct virtqueue *rvq)
174 struct virtnet_info *vi = rvq->vdev->priv;
175 /* Schedule NAPI, Suppress further interrupts if successful. */
176 if (netif_rx_schedule_prep(vi->dev, &vi->napi)) {
177 rvq->vq_ops->disable_cb(rvq);
178 __netif_rx_schedule(vi->dev, &vi->napi);
182 static int virtnet_poll(struct napi_struct *napi, int budget)
184 struct virtnet_info *vi = container_of(napi, struct virtnet_info, napi);
185 struct sk_buff *skb = NULL;
186 unsigned int len, received = 0;
188 again:
189 while (received < budget &&
190 (skb = vi->rvq->vq_ops->get_buf(vi->rvq, &len)) != NULL) {
191 __skb_unlink(skb, &vi->recv);
192 receive_skb(vi->dev, skb, len);
193 vi->num--;
194 received++;
197 /* FIXME: If we oom and completely run out of inbufs, we need
198 * to start a timer trying to fill more. */
199 if (vi->num < vi->max / 2)
200 try_fill_recv(vi);
202 /* Out of packets? */
203 if (received < budget) {
204 netif_rx_complete(vi->dev, napi);
205 if (unlikely(!vi->rvq->vq_ops->enable_cb(vi->rvq))
206 && napi_schedule_prep(napi)) {
207 vi->rvq->vq_ops->disable_cb(vi->rvq);
208 __netif_rx_schedule(vi->dev, napi);
209 goto again;
213 return received;
216 static void free_old_xmit_skbs(struct virtnet_info *vi)
218 struct sk_buff *skb;
219 unsigned int len;
221 while ((skb = vi->svq->vq_ops->get_buf(vi->svq, &len)) != NULL) {
222 pr_debug("Sent skb %p\n", skb);
223 __skb_unlink(skb, &vi->send);
224 vi->dev->stats.tx_bytes += len;
225 vi->dev->stats.tx_packets++;
226 kfree_skb(skb);
230 static int start_xmit(struct sk_buff *skb, struct net_device *dev)
232 struct virtnet_info *vi = netdev_priv(dev);
233 int num, err;
234 struct scatterlist sg[1+MAX_SKB_FRAGS];
235 struct virtio_net_hdr *hdr;
236 const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest;
237 DECLARE_MAC_BUF(mac);
239 sg_init_table(sg, 1+MAX_SKB_FRAGS);
241 pr_debug("%s: xmit %p %s\n", dev->name, skb, print_mac(mac, dest));
243 /* Encode metadata header at front. */
244 hdr = skb_vnet_hdr(skb);
245 if (skb->ip_summed == CHECKSUM_PARTIAL) {
246 hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
247 hdr->csum_start = skb->csum_start - skb_headroom(skb);
248 hdr->csum_offset = skb->csum_offset;
249 } else {
250 hdr->flags = 0;
251 hdr->csum_offset = hdr->csum_start = 0;
254 if (skb_is_gso(skb)) {
255 hdr->hdr_len = skb_transport_header(skb) - skb->data;
256 hdr->gso_size = skb_shinfo(skb)->gso_size;
257 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
258 hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
259 else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)
260 hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
261 else if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
262 hdr->gso_type = VIRTIO_NET_HDR_GSO_UDP;
263 else
264 BUG();
265 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCP_ECN)
266 hdr->gso_type |= VIRTIO_NET_HDR_GSO_ECN;
267 } else {
268 hdr->gso_type = VIRTIO_NET_HDR_GSO_NONE;
269 hdr->gso_size = hdr->hdr_len = 0;
272 vnet_hdr_to_sg(sg, skb);
273 num = skb_to_sgvec(skb, sg+1, 0, skb->len) + 1;
274 __skb_queue_head(&vi->send, skb);
276 again:
277 /* Free up any pending old buffers before queueing new ones. */
278 free_old_xmit_skbs(vi);
279 err = vi->svq->vq_ops->add_buf(vi->svq, sg, num, 0, skb);
280 if (err) {
281 pr_debug("%s: virtio not prepared to send\n", dev->name);
282 netif_stop_queue(dev);
284 /* Activate callback for using skbs: if this returns false it
285 * means some were used in the meantime. */
286 if (unlikely(!vi->svq->vq_ops->enable_cb(vi->svq))) {
287 printk("Unlikely: restart svq race\n");
288 vi->svq->vq_ops->disable_cb(vi->svq);
289 netif_start_queue(dev);
290 goto again;
292 __skb_unlink(skb, &vi->send);
294 return NETDEV_TX_BUSY;
296 vi->svq->vq_ops->kick(vi->svq);
298 return 0;
301 #ifdef CONFIG_NET_POLL_CONTROLLER
302 static void virtnet_netpoll(struct net_device *dev)
304 struct virtnet_info *vi = netdev_priv(dev);
306 napi_schedule(&vi->napi);
308 #endif
310 static int virtnet_open(struct net_device *dev)
312 struct virtnet_info *vi = netdev_priv(dev);
314 napi_enable(&vi->napi);
316 /* If all buffers were filled by other side before we napi_enabled, we
317 * won't get another interrupt, so process any outstanding packets
318 * now. virtnet_poll wants re-enable the queue, so we disable here.
319 * We synchronize against interrupts via NAPI_STATE_SCHED */
320 if (netif_rx_schedule_prep(dev, &vi->napi)) {
321 vi->rvq->vq_ops->disable_cb(vi->rvq);
322 __netif_rx_schedule(dev, &vi->napi);
324 return 0;
327 static int virtnet_close(struct net_device *dev)
329 struct virtnet_info *vi = netdev_priv(dev);
331 napi_disable(&vi->napi);
333 return 0;
336 static int virtnet_probe(struct virtio_device *vdev)
338 int err;
339 struct net_device *dev;
340 struct virtnet_info *vi;
342 /* Allocate ourselves a network device with room for our info */
343 dev = alloc_etherdev(sizeof(struct virtnet_info));
344 if (!dev)
345 return -ENOMEM;
347 /* Set up network device as normal. */
348 dev->open = virtnet_open;
349 dev->stop = virtnet_close;
350 dev->hard_start_xmit = start_xmit;
351 dev->features = NETIF_F_HIGHDMA;
352 #ifdef CONFIG_NET_POLL_CONTROLLER
353 dev->poll_controller = virtnet_netpoll;
354 #endif
355 SET_NETDEV_DEV(dev, &vdev->dev);
357 /* Do we support "hardware" checksums? */
358 if (csum && vdev->config->feature(vdev, VIRTIO_NET_F_CSUM)) {
359 /* This opens up the world of extra features. */
360 dev->features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
361 if (gso && vdev->config->feature(vdev, VIRTIO_NET_F_GSO)) {
362 dev->features |= NETIF_F_TSO | NETIF_F_UFO
363 | NETIF_F_TSO_ECN | NETIF_F_TSO6;
367 /* Configuration may specify what MAC to use. Otherwise random. */
368 if (vdev->config->feature(vdev, VIRTIO_NET_F_MAC)) {
369 vdev->config->get(vdev,
370 offsetof(struct virtio_net_config, mac),
371 dev->dev_addr, dev->addr_len);
372 } else
373 random_ether_addr(dev->dev_addr);
375 /* Set up our device-specific information */
376 vi = netdev_priv(dev);
377 netif_napi_add(dev, &vi->napi, virtnet_poll, napi_weight);
378 vi->dev = dev;
379 vi->vdev = vdev;
380 vdev->priv = vi;
382 /* We expect two virtqueues, receive then send. */
383 vi->rvq = vdev->config->find_vq(vdev, 0, skb_recv_done);
384 if (IS_ERR(vi->rvq)) {
385 err = PTR_ERR(vi->rvq);
386 goto free;
389 vi->svq = vdev->config->find_vq(vdev, 1, skb_xmit_done);
390 if (IS_ERR(vi->svq)) {
391 err = PTR_ERR(vi->svq);
392 goto free_recv;
395 /* Initialize our empty receive and send queues. */
396 skb_queue_head_init(&vi->recv);
397 skb_queue_head_init(&vi->send);
399 err = register_netdev(dev);
400 if (err) {
401 pr_debug("virtio_net: registering device failed\n");
402 goto free_send;
405 /* Last of all, set up some receive buffers. */
406 try_fill_recv(vi);
408 /* If we didn't even get one input buffer, we're useless. */
409 if (vi->num == 0) {
410 err = -ENOMEM;
411 goto unregister;
414 pr_debug("virtnet: registered device %s\n", dev->name);
415 return 0;
417 unregister:
418 unregister_netdev(dev);
419 free_send:
420 vdev->config->del_vq(vi->svq);
421 free_recv:
422 vdev->config->del_vq(vi->rvq);
423 free:
424 free_netdev(dev);
425 return err;
428 static void virtnet_remove(struct virtio_device *vdev)
430 struct virtnet_info *vi = vdev->priv;
431 struct sk_buff *skb;
433 /* Stop all the virtqueues. */
434 vdev->config->reset(vdev);
436 /* Free our skbs in send and recv queues, if any. */
437 while ((skb = __skb_dequeue(&vi->recv)) != NULL) {
438 kfree_skb(skb);
439 vi->num--;
441 while ((skb = __skb_dequeue(&vi->send)) != NULL)
442 kfree_skb(skb);
444 BUG_ON(vi->num != 0);
446 vdev->config->del_vq(vi->svq);
447 vdev->config->del_vq(vi->rvq);
448 unregister_netdev(vi->dev);
449 free_netdev(vi->dev);
452 static struct virtio_device_id id_table[] = {
453 { VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID },
454 { 0 },
457 static struct virtio_driver virtio_net = {
458 .driver.name = KBUILD_MODNAME,
459 .driver.owner = THIS_MODULE,
460 .id_table = id_table,
461 .probe = virtnet_probe,
462 .remove = __devexit_p(virtnet_remove),
465 static int __init init(void)
467 return register_virtio_driver(&virtio_net);
470 static void __exit fini(void)
472 unregister_virtio_driver(&virtio_net);
474 module_init(init);
475 module_exit(fini);
477 MODULE_DEVICE_TABLE(virtio, id_table);
478 MODULE_DESCRIPTION("Virtio network driver");
479 MODULE_LICENSE("GPL");