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authorRusty Russell <rusty@rustcorp.com.au>2008-07-03 06:48:02 -0400
committerDavid S. Miller <davem@davemloft.net>2008-07-03 06:48:02 -0400
commitf43798c27684ab925adde7d8acc34c78c6e50df8 (patch)
tree21e952a07534dd382835246d02245d5e776c4d8b /drivers/net/tun.c
parent5228ddc98fa49b3cedab4024e269d62410a0d806 (diff)
tun: Allow GSO using virtio_net_hdr
Add a IFF_VNET_HDR flag. This uses the same ABI as virtio_net (ie. prepending struct virtio_net_hdr to packets) to indicate GSO and checksum information. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Acked-by: Max Krasnyansky <maxk@qualcomm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/tun.c')
-rw-r--r--drivers/net/tun.c95
1 files changed, 92 insertions, 3 deletions
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index a314955e6994..aa4ee4439f04 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -63,6 +63,7 @@
63#include <linux/if_tun.h> 63#include <linux/if_tun.h>
64#include <linux/crc32.h> 64#include <linux/crc32.h>
65#include <linux/nsproxy.h> 65#include <linux/nsproxy.h>
66#include <linux/virtio_net.h>
66#include <net/net_namespace.h> 67#include <net/net_namespace.h>
67#include <net/netns/generic.h> 68#include <net/netns/generic.h>
68 69
@@ -283,6 +284,7 @@ static __inline__ ssize_t tun_get_user(struct tun_struct *tun, struct iovec *iv,
283 struct tun_pi pi = { 0, __constant_htons(ETH_P_IP) }; 284 struct tun_pi pi = { 0, __constant_htons(ETH_P_IP) };
284 struct sk_buff *skb; 285 struct sk_buff *skb;
285 size_t len = count, align = 0; 286 size_t len = count, align = 0;
287 struct virtio_net_hdr gso = { 0 };
286 288
287 if (!(tun->flags & TUN_NO_PI)) { 289 if (!(tun->flags & TUN_NO_PI)) {
288 if ((len -= sizeof(pi)) > count) 290 if ((len -= sizeof(pi)) > count)
@@ -292,6 +294,17 @@ static __inline__ ssize_t tun_get_user(struct tun_struct *tun, struct iovec *iv,
292 return -EFAULT; 294 return -EFAULT;
293 } 295 }
294 296
297 if (tun->flags & TUN_VNET_HDR) {
298 if ((len -= sizeof(gso)) > count)
299 return -EINVAL;
300
301 if (memcpy_fromiovec((void *)&gso, iv, sizeof(gso)))
302 return -EFAULT;
303
304 if (gso.hdr_len > len)
305 return -EINVAL;
306 }
307
295 if ((tun->flags & TUN_TYPE_MASK) == TUN_TAP_DEV) { 308 if ((tun->flags & TUN_TYPE_MASK) == TUN_TAP_DEV) {
296 align = NET_IP_ALIGN; 309 align = NET_IP_ALIGN;
297 if (unlikely(len < ETH_HLEN)) 310 if (unlikely(len < ETH_HLEN))
@@ -311,6 +324,16 @@ static __inline__ ssize_t tun_get_user(struct tun_struct *tun, struct iovec *iv,
311 return -EFAULT; 324 return -EFAULT;
312 } 325 }
313 326
327 if (gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
328 if (!skb_partial_csum_set(skb, gso.csum_start,
329 gso.csum_offset)) {
330 tun->dev->stats.rx_frame_errors++;
331 kfree_skb(skb);
332 return -EINVAL;
333 }
334 } else if (tun->flags & TUN_NOCHECKSUM)
335 skb->ip_summed = CHECKSUM_UNNECESSARY;
336
314 switch (tun->flags & TUN_TYPE_MASK) { 337 switch (tun->flags & TUN_TYPE_MASK) {
315 case TUN_TUN_DEV: 338 case TUN_TUN_DEV:
316 if (tun->flags & TUN_NO_PI) { 339 if (tun->flags & TUN_NO_PI) {
@@ -337,8 +360,35 @@ static __inline__ ssize_t tun_get_user(struct tun_struct *tun, struct iovec *iv,
337 break; 360 break;
338 }; 361 };
339 362
340 if (tun->flags & TUN_NOCHECKSUM) 363 if (gso.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
341 skb->ip_summed = CHECKSUM_UNNECESSARY; 364 pr_debug("GSO!\n");
365 switch (gso.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
366 case VIRTIO_NET_HDR_GSO_TCPV4:
367 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
368 break;
369 case VIRTIO_NET_HDR_GSO_TCPV6:
370 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
371 break;
372 default:
373 tun->dev->stats.rx_frame_errors++;
374 kfree_skb(skb);
375 return -EINVAL;
376 }
377
378 if (gso.gso_type & VIRTIO_NET_HDR_GSO_ECN)
379 skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
380
381 skb_shinfo(skb)->gso_size = gso.gso_size;
382 if (skb_shinfo(skb)->gso_size == 0) {
383 tun->dev->stats.rx_frame_errors++;
384 kfree_skb(skb);
385 return -EINVAL;
386 }
387
388 /* Header must be checked, and gso_segs computed. */
389 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
390 skb_shinfo(skb)->gso_segs = 0;
391 }
342 392
343 netif_rx_ni(skb); 393 netif_rx_ni(skb);
344 tun->dev->last_rx = jiffies; 394 tun->dev->last_rx = jiffies;
@@ -384,6 +434,39 @@ static __inline__ ssize_t tun_put_user(struct tun_struct *tun,
384 total += sizeof(pi); 434 total += sizeof(pi);
385 } 435 }
386 436
437 if (tun->flags & TUN_VNET_HDR) {
438 struct virtio_net_hdr gso = { 0 }; /* no info leak */
439 if ((len -= sizeof(gso)) < 0)
440 return -EINVAL;
441
442 if (skb_is_gso(skb)) {
443 struct skb_shared_info *sinfo = skb_shinfo(skb);
444
445 /* This is a hint as to how much should be linear. */
446 gso.hdr_len = skb_headlen(skb);
447 gso.gso_size = sinfo->gso_size;
448 if (sinfo->gso_type & SKB_GSO_TCPV4)
449 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
450 else if (sinfo->gso_type & SKB_GSO_TCPV6)
451 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
452 else
453 BUG();
454 if (sinfo->gso_type & SKB_GSO_TCP_ECN)
455 gso.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
456 } else
457 gso.gso_type = VIRTIO_NET_HDR_GSO_NONE;
458
459 if (skb->ip_summed == CHECKSUM_PARTIAL) {
460 gso.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
461 gso.csum_start = skb->csum_start - skb_headroom(skb);
462 gso.csum_offset = skb->csum_offset;
463 } /* else everything is zero */
464
465 if (unlikely(memcpy_toiovec(iv, (void *)&gso, sizeof(gso))))
466 return -EFAULT;
467 total += sizeof(gso);
468 }
469
387 len = min_t(int, skb->len, len); 470 len = min_t(int, skb->len, len);
388 471
389 skb_copy_datagram_iovec(skb, 0, iv, len); 472 skb_copy_datagram_iovec(skb, 0, iv, len);
@@ -598,6 +681,11 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
598 else 681 else
599 tun->flags &= ~TUN_ONE_QUEUE; 682 tun->flags &= ~TUN_ONE_QUEUE;
600 683
684 if (ifr->ifr_flags & IFF_VNET_HDR)
685 tun->flags |= TUN_VNET_HDR;
686 else
687 tun->flags &= ~TUN_VNET_HDR;
688
601 file->private_data = tun; 689 file->private_data = tun;
602 tun->attached = 1; 690 tun->attached = 1;
603 get_net(dev_net(tun->dev)); 691 get_net(dev_net(tun->dev));
@@ -684,7 +772,8 @@ static int tun_chr_ioctl(struct inode *inode, struct file *file,
684 /* Currently this just means: "what IFF flags are valid?". 772 /* Currently this just means: "what IFF flags are valid?".
685 * This is needed because we never checked for invalid flags on 773 * This is needed because we never checked for invalid flags on
686 * TUNSETIFF. */ 774 * TUNSETIFF. */
687 return put_user(IFF_TUN | IFF_TAP | IFF_NO_PI | IFF_ONE_QUEUE, 775 return put_user(IFF_TUN | IFF_TAP | IFF_NO_PI | IFF_ONE_QUEUE |
776 IFF_VNET_HDR,
688 (unsigned int __user*)argp); 777 (unsigned int __user*)argp);
689 } 778 }
690 779