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net: Fix possible wrong checksum generation.

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Patch cef401de7b (net: fix possible wrong checksum
generation) fixed wrong checksum calculation but it broke TSO by
defining new GSO type but not a netdev feature for that type.
net_gso_ok() would not allow hardware checksum/segmentation
offload of such packets without the feature.

Following patch fixes TSO and wrong checksum. This patch uses
same logic that Eric Dumazet used. Patch introduces new flag
SKBTX_SHARED_FRAG if at least one frag can be modified by
the user. but SKBTX_SHARED_FRAG flag is kept in skb shared
info tx_flags rather than gso_type.

tx_flags is better compared to gso_type since we can have skb with
shared frag without gso packet. It does not link SHARED_FRAG to
GSO, So there is no need to define netdev feature for this.

Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Pravin B Shelar 2013-02-11 09:27:41 +00:00 committed by David S. Miller
parent b8fa410035
commit c9af6db4c1
11 changed files with 29 additions and 38 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
drivers/net/macvtap.c
View File

@ -543,7 +543,6 @@ static int zerocopy_sg_from_iovec(struct sk_buff *skb, const struct iovec *from,
skb->data_len += len;
skb->len += len;
skb->truesize += truesize;
skb_shinfo(skb)->gso_type |= SKB_GSO_SHARED_FRAG;
atomic_add(truesize, &skb->sk->sk_wmem_alloc);
while (len) {
int off = base & ~PAGE_MASK;
@ -599,7 +598,7 @@ static int macvtap_skb_from_vnet_hdr(struct sk_buff *skb,
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_shinfo(skb)->gso_type = gso_type;
/* Header must be checked, and gso_segs computed. */
skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
@ -743,6 +742,7 @@ static ssize_t macvtap_get_user(struct macvtap_queue *q, struct msghdr *m,
if (zerocopy) {
skb_shinfo(skb)->destructor_arg = m->msg_control;
skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY;
skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG;
}
if (vlan)
macvlan_start_xmit(skb, vlan->dev);

13
drivers/net/tun.c
View File

@ -1019,7 +1019,6 @@ static int zerocopy_sg_from_iovec(struct sk_buff *skb, const struct iovec *from,
skb->data_len += len;
skb->len += len;
skb->truesize += truesize;
skb_shinfo(skb)->gso_type |= SKB_GSO_SHARED_FRAG;
atomic_add(truesize, &skb->sk->sk_wmem_alloc);
while (len) {
int off = base & ~PAGE_MASK;
@ -1165,18 +1164,16 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
}
if (gso.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
unsigned short gso_type = 0;
pr_debug("GSO!\n");
switch (gso.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
case VIRTIO_NET_HDR_GSO_TCPV4:
gso_type = SKB_GSO_TCPV4;
skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
break;
case VIRTIO_NET_HDR_GSO_TCPV6:
gso_type = SKB_GSO_TCPV6;
skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
break;
case VIRTIO_NET_HDR_GSO_UDP:
gso_type = SKB_GSO_UDP;
skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
break;
default:
tun->dev->stats.rx_frame_errors++;
@ -1185,10 +1182,9 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
}
if (gso.gso_type & VIRTIO_NET_HDR_GSO_ECN)
gso_type |= SKB_GSO_TCP_ECN;
skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
skb_shinfo(skb)->gso_size = gso.gso_size;
skb_shinfo(skb)->gso_type |= gso_type;
if (skb_shinfo(skb)->gso_size == 0) {
tun->dev->stats.rx_frame_errors++;
kfree_skb(skb);
@ -1204,6 +1200,7 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
if (zerocopy) {
skb_shinfo(skb)->destructor_arg = msg_control;
skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY;
skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG;
}
skb_reset_network_header(skb);

13
drivers/net/virtio_net.c
View File

@ -227,7 +227,7 @@ static void set_skb_frag(struct sk_buff *skb, struct page *page,
skb->len += size;
skb->truesize += PAGE_SIZE;
skb_shinfo(skb)->nr_frags++;
skb_shinfo(skb)->gso_type |= SKB_GSO_SHARED_FRAG;
skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG;
*len -= size;
}
@ -387,18 +387,16 @@ static void receive_buf(struct receive_queue *rq, void *buf, unsigned int len)
ntohs(skb->protocol), skb->len, skb->pkt_type);
if (hdr->hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
unsigned short gso_type = 0;
pr_debug("GSO!\n");
switch (hdr->hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
case VIRTIO_NET_HDR_GSO_TCPV4:
gso_type = SKB_GSO_TCPV4;
skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
break;
case VIRTIO_NET_HDR_GSO_UDP:
gso_type = SKB_GSO_UDP;
skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
break;
case VIRTIO_NET_HDR_GSO_TCPV6:
gso_type = SKB_GSO_TCPV6;
skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
break;
default:
net_warn_ratelimited("%s: bad gso type %u.\n",
@ -407,7 +405,7 @@ static void receive_buf(struct receive_queue *rq, void *buf, unsigned int len)
}
if (hdr->hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN)
gso_type |= SKB_GSO_TCP_ECN;
skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
skb_shinfo(skb)->gso_size = hdr->hdr.gso_size;
if (skb_shinfo(skb)->gso_size == 0) {
@ -415,7 +413,6 @@ static void receive_buf(struct receive_queue *rq, void *buf, unsigned int len)
goto frame_err;
}
skb_shinfo(skb)->gso_type |= gso_type;
/* Header must be checked, and gso_segs computed. */
skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
skb_shinfo(skb)->gso_segs = 0;

17
include/linux/skbuff.h
View File

@ -230,6 +230,13 @@ enum {
/* generate wifi status information (where possible) */
SKBTX_WIFI_STATUS = 1 << 4,
/* This indicates at least one fragment might be overwritten
* (as in vmsplice(), sendfile() ...)
* If we need to compute a TX checksum, we'll need to copy
* all frags to avoid possible bad checksum
*/
SKBTX_SHARED_FRAG = 1 << 5,
};
/*
@ -307,13 +314,6 @@ enum {
SKB_GSO_TCPV6 = 1 << 4,
SKB_GSO_FCOE = 1 << 5,
/* This indicates at least one fragment might be overwritten
* (as in vmsplice(), sendfile() ...)
* If we need to compute a TX checksum, we'll need to copy
* all frags to avoid possible bad checksum
*/
SKB_GSO_SHARED_FRAG = 1 << 6,
};
#if BITS_PER_LONG > 32
@ -2220,7 +2220,8 @@ static inline int skb_linearize(struct sk_buff *skb)
*/
static inline bool skb_has_shared_frag(const struct sk_buff *skb)
{
return skb_shinfo(skb)->gso_type & SKB_GSO_SHARED_FRAG;
return skb_is_nonlinear(skb) &&
skb_shinfo(skb)->tx_flags & SKBTX_SHARED_FRAG;
}
/**

5
net/core/skbuff.c
View File

@ -2326,8 +2326,7 @@ void skb_split(struct sk_buff *skb, struct sk_buff *skb1, const u32 len)
{
int pos = skb_headlen(skb);
skb_shinfo(skb1)->gso_type = skb_shinfo(skb)->gso_type;
skb_shinfo(skb)->tx_flags = skb_shinfo(skb1)->tx_flags & SKBTX_SHARED_FRAG;
if (len < pos) /* Split line is inside header. */
skb_split_inside_header(skb, skb1, len, pos);
else /* Second chunk has no header, nothing to copy. */
@ -2833,7 +2832,7 @@ struct sk_buff *skb_segment(struct sk_buff *skb, netdev_features_t features)
skb_copy_from_linear_data_offset(skb, offset,
skb_put(nskb, hsize), hsize);
skb_shinfo(nskb)->gso_type = skb_shinfo(skb)->gso_type;
skb_shinfo(nskb)->tx_flags = skb_shinfo(skb)->tx_flags & SKBTX_SHARED_FRAG;
while (pos < offset + len && i < nfrags) {
*frag = skb_shinfo(skb)->frags[i];

1
net/ipv4/af_inet.c
View File

@ -1287,7 +1287,6 @@ static struct sk_buff *inet_gso_segment(struct sk_buff *skb,
SKB_GSO_UDP |
SKB_GSO_DODGY |
SKB_GSO_TCP_ECN |
SKB_GSO_SHARED_FRAG |
0)))
goto out;

1
net/ipv4/ip_output.c
View File

@ -598,6 +598,7 @@ slow_path:
/* for offloaded checksums cleanup checksum before fragmentation */
if ((skb->ip_summed == CHECKSUM_PARTIAL) && skb_checksum_help(skb))
goto fail;
iph = ip_hdr(skb);
left = skb->len - hlen; /* Space per frame */
ptr = hlen; /* Where to start from */

4
net/ipv4/tcp.c
View File

@ -897,8 +897,7 @@ new_segment:
get_page(page);
skb_fill_page_desc(skb, i, page, offset, copy);
}
skb_shinfo(skb)->gso_type |= SKB_GSO_SHARED_FRAG;
skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG;
skb->len += copy;
skb->data_len += copy;
@ -3044,7 +3043,6 @@ struct sk_buff *tcp_tso_segment(struct sk_buff *skb,
SKB_GSO_DODGY |
SKB_GSO_TCP_ECN |
SKB_GSO_TCPV6 |
SKB_GSO_SHARED_FRAG |
0) ||
!(type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6))))
goto out;

4
net/ipv4/tcp_input.c
View File

@ -1239,13 +1239,13 @@ static bool tcp_shifted_skb(struct sock *sk, struct sk_buff *skb,
*/
if (!skb_shinfo(prev)->gso_size) {
skb_shinfo(prev)->gso_size = mss;
skb_shinfo(prev)->gso_type |= sk->sk_gso_type;
skb_shinfo(prev)->gso_type = sk->sk_gso_type;
}
/* CHECKME: To clear or not to clear? Mimics normal skb currently */
if (skb_shinfo(skb)->gso_segs <= 1) {
skb_shinfo(skb)->gso_size = 0;
skb_shinfo(skb)->gso_type &= SKB_GSO_SHARED_FRAG;
skb_shinfo(skb)->gso_type = 0;
}
/* Difference in this won't matter, both ACKed by the same cumul. ACK */

4
net/ipv4/tcp_output.c
View File

@ -1133,7 +1133,6 @@ static void tcp_queue_skb(struct sock *sk, struct sk_buff *skb)
static void tcp_set_skb_tso_segs(const struct sock *sk, struct sk_buff *skb,
unsigned int mss_now)
{
skb_shinfo(skb)->gso_type &= SKB_GSO_SHARED_FRAG;
if (skb->len <= mss_now || !sk_can_gso(sk) ||
skb->ip_summed == CHECKSUM_NONE) {
/* Avoid the costly divide in the normal
@ -1141,10 +1140,11 @@ static void tcp_set_skb_tso_segs(const struct sock *sk, struct sk_buff *skb,
*/
skb_shinfo(skb)->gso_segs = 1;
skb_shinfo(skb)->gso_size = 0;
skb_shinfo(skb)->gso_type = 0;
} else {
skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(skb->len, mss_now);
skb_shinfo(skb)->gso_size = mss_now;
skb_shinfo(skb)->gso_type |= sk->sk_gso_type;
skb_shinfo(skb)->gso_type = sk->sk_gso_type;
}
}

1
net/ipv6/ip6_offload.c
View File

@ -100,7 +100,6 @@ static struct sk_buff *ipv6_gso_segment(struct sk_buff *skb,
SKB_GSO_DODGY |
SKB_GSO_TCP_ECN |
SKB_GSO_TCPV6 |
SKB_GSO_SHARED_FRAG |
0)))
goto out;