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Message-Id: <1266044316.10419.3.camel@w-sridhar.beaverton.ibm.com>
Date: Fri, 12 Feb 2010 22:58:36 -0800
From: Sridhar Samudrala <sri@...ibm.com>
To: David Miller <davem@...emloft.net>
Cc: Arnd Bergmann <arnd@...db.de>,
Herbert Xu <herbert@...dor.apana.org.au>,
netdev <netdev@...r.kernel.org>
Subject: Re: [PATCH net-next-2.6] macvtap: Add GSO/csum offload support
Please ignore my original version of the patch. It has some trailing
whitespace errors. Here is an updated version that should apply cleanly.
This patch adds GSO/checksum offload support to macvtap driver and applies
on top of Arnd's refcnt bugfix.
http://patchwork.ozlabs.org/patch/45136/
Added flags field to macvtap_queue to enable/disable processing of
virtio_net_hdr via IFF_VNET_HDR. This flag is checked to prepend virtio_net_hdr
in the receive path and process/skip virtio_net_hdr in the send path.
Signed-off-by: Sridhar Samudrala <sri@...ibm.com>
diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c
index fe7656b..5f70f13 100644
--- a/drivers/net/macvtap.c
+++ b/drivers/net/macvtap.c
@@ -17,6 +17,7 @@
#include <net/net_namespace.h>
#include <net/rtnetlink.h>
#include <net/sock.h>
+#include <linux/virtio_net.h>
/*
* A macvtap queue is the central object of this driver, it connects
@@ -37,6 +38,7 @@ struct macvtap_queue {
struct socket sock;
struct macvlan_dev *vlan;
struct file *file;
+ unsigned int flags;
};
static struct proto macvtap_proto = {
@@ -286,6 +288,7 @@ static int macvtap_open(struct inode *inode, struct file *file)
sock_init_data(&q->sock, &q->sk);
q->sk.sk_allocation = GFP_ATOMIC; /* for now */
q->sk.sk_write_space = macvtap_sock_write_space;
+ q->flags = IFF_VNET_HDR;
err = macvtap_set_queue(dev, file, q);
if (err)
@@ -328,6 +331,29 @@ out:
return mask;
}
+static inline struct sk_buff *macvtap_alloc_skb(struct sock *sk, size_t prepad,
+ size_t len, size_t linear,
+ int noblock, int *err)
+{
+ struct sk_buff *skb;
+
+ /* Under a page? Don't bother with paged skb. */
+ if (prepad + len < PAGE_SIZE || !linear)
+ linear = len;
+
+ skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
+ err);
+ if (!skb)
+ return NULL;
+
+ skb_reserve(skb, prepad);
+ skb_put(skb, linear);
+ skb->data_len = len - linear;
+ skb->len += len - linear;
+
+ return skb;
+}
+
/* Get packet from user space buffer */
static ssize_t macvtap_get_user(struct macvtap_queue *q,
const struct iovec *iv, size_t count,
@@ -336,31 +362,99 @@ static ssize_t macvtap_get_user(struct macvtap_queue *q,
struct sk_buff *skb;
size_t len = count;
int err;
+ struct virtio_net_hdr vnet_hdr = { 0 };
+ int vnet_hdr_len = 0;
+ unsigned short gso_type = 0;
+
+ if (q->flags & IFF_VNET_HDR) {
+ vnet_hdr_len = sizeof(vnet_hdr);
+
+ err = -EINVAL;
+ if ((len -= vnet_hdr_len) < 0)
+ goto out;
+
+ err = (memcpy_fromiovecend((void *)&vnet_hdr, iv, 0,
+ vnet_hdr_len));
+ if (err < 0)
+ goto out;
+
+ if ((vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
+ vnet_hdr.csum_start + vnet_hdr.csum_offset + 2 >
+ vnet_hdr.hdr_len)
+ vnet_hdr.hdr_len = vnet_hdr.csum_start +
+ vnet_hdr.csum_offset + 2;
+
+ err = -EINVAL;
+ if (vnet_hdr.hdr_len > len)
+ goto out;
+
+ if (vnet_hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
+ switch (vnet_hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
+ case VIRTIO_NET_HDR_GSO_TCPV4:
+ gso_type = SKB_GSO_TCPV4;
+ break;
+ case VIRTIO_NET_HDR_GSO_TCPV6:
+ gso_type = SKB_GSO_TCPV6;
+ break;
+ case VIRTIO_NET_HDR_GSO_UDP:
+ gso_type = SKB_GSO_UDP;
+ break;
+ default:
+ goto out;
+ }
+
+ if (vnet_hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN)
+ gso_type |= SKB_GSO_TCP_ECN;
+
+ if (vnet_hdr.gso_size == 0)
+ goto out;
+ }
+ }
if (unlikely(len < ETH_HLEN))
- return -EINVAL;
+ goto out;
- skb = sock_alloc_send_skb(&q->sk, NET_IP_ALIGN + len, noblock, &err);
+ skb = macvtap_alloc_skb(&q->sk, NET_IP_ALIGN, len, vnet_hdr.hdr_len,
+ noblock, &err);
+ if (!skb)
+ goto out;
- if (!skb) {
- macvlan_count_rx(q->vlan, 0, false, false);
- return err;
- }
+ err = -EFAULT;
+ if (skb_copy_datagram_from_iovec(skb, 0, iv, vnet_hdr_len, len))
+ goto out_free;
- skb_reserve(skb, NET_IP_ALIGN);
- skb_put(skb, count);
+ skb_set_network_header(skb, ETH_HLEN);
+ skb_reset_mac_header(skb);
+ skb->protocol = eth_hdr(skb)->h_proto;
+
+ if (vnet_hdr_len) {
+ if (vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
+ err = -EINVAL;
+ if (!skb_partial_csum_set(skb, vnet_hdr.csum_start,
+ vnet_hdr.csum_offset))
+ goto out_free;
+ }
- if (skb_copy_datagram_from_iovec(skb, 0, iv, 0, len)) {
- macvlan_count_rx(q->vlan, 0, false, false);
- kfree_skb(skb);
- return -EFAULT;
- }
+ if (vnet_hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
+ skb_shinfo(skb)->gso_size = vnet_hdr.gso_size;
+ skb_shinfo(skb)->gso_type = gso_type;
- skb_set_network_header(skb, ETH_HLEN);
+ /* Header must be checked, and gso_segs computed. */
+ skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
+ skb_shinfo(skb)->gso_segs = 0;
+ }
+ }
macvlan_start_xmit(skb, q->vlan->dev);
+ macvlan_count_rx(q->vlan, skb->len, 1, 0);
return count;
+
+out_free:
+ kfree_skb(skb);
+out:
+ macvlan_count_rx(q->vlan, 0, false, false);
+ return -EINVAL;
}
static ssize_t macvtap_aio_write(struct kiocb *iocb, const struct iovec *iv,
@@ -387,14 +481,54 @@ static ssize_t macvtap_put_user(struct macvtap_queue *q,
{
struct macvlan_dev *vlan = q->vlan;
int ret;
+ int vnet_hdr_len = 0;
+
+ if (q->flags & IFF_VNET_HDR) {
+ struct virtio_net_hdr vnet_hdr = { 0 };
+
+ vnet_hdr_len = sizeof(vnet_hdr);
+ if ((len -= vnet_hdr_len) < 0)
+ return -EINVAL;
+
+ if (skb_is_gso(skb)) {
+ struct skb_shared_info *sinfo = skb_shinfo(skb);
+
+ /* This is a hint as to how much should be linear. */
+ vnet_hdr.hdr_len = skb_headlen(skb);
+ vnet_hdr.gso_size = sinfo->gso_size;
+ if (sinfo->gso_type & SKB_GSO_TCPV4)
+ vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
+ else if (sinfo->gso_type & SKB_GSO_TCPV6)
+ vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
+ else if (sinfo->gso_type & SKB_GSO_UDP)
+ vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP;
+ else
+ BUG();
+ if (sinfo->gso_type & SKB_GSO_TCP_ECN)
+ vnet_hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
+ } else
+ vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE;
+
+ if (skb->ip_summed == CHECKSUM_PARTIAL) {
+ vnet_hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
+ vnet_hdr.csum_start = skb->csum_start -
+ skb_headroom(skb);
+ vnet_hdr.csum_offset = skb->csum_offset;
+ } /* else everything is zero */
+
+ if (unlikely(memcpy_toiovecend(iv, (void *)&vnet_hdr, 0,
+ vnet_hdr_len)))
+ return -EFAULT;
+ }
+
len = min_t(int, skb->len, len);
- ret = skb_copy_datagram_const_iovec(skb, 0, iv, 0, len);
+ ret = skb_copy_datagram_const_iovec(skb, 0, iv, vnet_hdr_len, len);
macvlan_count_rx(vlan, len, ret == 0, 0);
- return ret ? ret : len;
+ return ret ? ret : (len + vnet_hdr_len);
}
static ssize_t macvtap_aio_read(struct kiocb *iocb, const struct iovec *iv,
@@ -460,14 +594,23 @@ static long macvtap_ioctl(struct file *file, unsigned int cmd,
unsigned int __user *up = argp;
unsigned int u;
char devname[IFNAMSIZ];
+ int ret;
switch (cmd) {
case TUNSETIFF:
/* ignore the name, just look at flags */
if (get_user(u, &ifr->ifr_flags))
return -EFAULT;
- if (u != (IFF_TAP | IFF_NO_PI))
- return -EINVAL;
+ q = macvtap_file_get_queue(file);
+ if (!q)
+ return -ENOLINK;
+
+ if (u & IFF_VNET_HDR)
+ q->flags |= IFF_VNET_HDR;
+ else
+ q->flags &= ~IFF_VNET_HDR;
+
+ macvtap_file_put_queue(q);
return 0;
case TUNGETIFF:
@@ -475,17 +618,23 @@ static long macvtap_ioctl(struct file *file, unsigned int cmd,
if (!q)
return -ENOLINK;
memcpy(devname, q->vlan->dev->name, sizeof(devname));
- macvtap_file_put_queue(q);
+ ret = 0;
if (copy_to_user(&ifr->ifr_name, q->vlan->dev->name, IFNAMSIZ) ||
- put_user((TUN_TAP_DEV | TUN_NO_PI), &ifr->ifr_flags))
- return -EFAULT;
- return 0;
+ put_user(q->flags, &ifr->ifr_flags))
+ ret = -EFAULT;
+ macvtap_file_put_queue(q);
+ return ret;
case TUNGETFEATURES:
- if (put_user((IFF_TAP | IFF_NO_PI), up))
- return -EFAULT;
- return 0;
+ q = macvtap_file_get_queue(file);
+ if (!q)
+ return -ENOLINK;
+ ret = 0;
+ if (put_user(q->flags, up))
+ ret = -EFAULT;
+ macvtap_file_put_queue(q);
+ return ret;
case TUNSETSNDBUF:
if (get_user(u, up))
@@ -499,18 +648,14 @@ static long macvtap_ioctl(struct file *file, unsigned int cmd,
return 0;
case TUNSETOFFLOAD:
- /* let the user check for future flags */
- if (arg & ~(TUN_F_CSUM | TUN_F_TSO4 | TUN_F_TSO6 |
- TUN_F_TSO_ECN | TUN_F_UFO))
- return -EINVAL;
-
- /* TODO: add support for these, so far we don't
- support any offload */
- if (arg & (TUN_F_CSUM | TUN_F_TSO4 | TUN_F_TSO6 |
- TUN_F_TSO_ECN | TUN_F_UFO))
- return -EINVAL;
-
- return 0;
+ q = macvtap_file_get_queue(file);
+ if (!q)
+ return -ENOLINK;
+ ret = 0;
+ if (!(q->flags & IFF_VNET_HDR))
+ ret = -EINVAL;
+ macvtap_file_put_queue(q);
+ return ret;
default:
return -EINVAL;
--
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