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Diffstat (limited to 'net/ipv4/udp_offload.c')
-rw-r--r--net/ipv4/udp_offload.c107
1 files changed, 58 insertions, 49 deletions
diff --git a/net/ipv4/udp_offload.c b/net/ipv4/udp_offload.c
index 4c519c1..8a3405a 100644
--- a/net/ipv4/udp_offload.c
+++ b/net/ipv4/udp_offload.c
@@ -32,42 +32,64 @@ static struct sk_buff *__skb_udp_tunnel_segment(struct sk_buff *skb,
netdev_features_t features),
__be16 new_protocol, bool is_ipv6)
{
+ int tnl_hlen = skb_inner_mac_header(skb) - skb_transport_header(skb);
+ bool remcsum, need_csum, offload_csum, ufo;
struct sk_buff *segs = ERR_PTR(-EINVAL);
+ struct udphdr *uh = udp_hdr(skb);
u16 mac_offset = skb->mac_header;
- int mac_len = skb->mac_len;
- int tnl_hlen = skb_inner_mac_header(skb) - skb_transport_header(skb);
__be16 protocol = skb->protocol;
- netdev_features_t enc_features;
+ u16 mac_len = skb->mac_len;
int udp_offset, outer_hlen;
- unsigned int oldlen;
- bool need_csum = !!(skb_shinfo(skb)->gso_type &
- SKB_GSO_UDP_TUNNEL_CSUM);
- bool remcsum = !!(skb_shinfo(skb)->gso_type & SKB_GSO_TUNNEL_REMCSUM);
- bool offload_csum = false, dont_encap = (need_csum || remcsum);
-
- oldlen = (u16)~skb->len;
+ __wsum partial;
if (unlikely(!pskb_may_pull(skb, tnl_hlen)))
goto out;
+ /* Adjust partial header checksum to negate old length.
+ * We cannot rely on the value contained in uh->len as it is
+ * possible that the actual value exceeds the boundaries of the
+ * 16 bit length field due to the header being added outside of an
+ * IP or IPv6 frame that was already limited to 64K - 1.
+ */
+ partial = csum_sub(csum_unfold(uh->check),
+ (__force __wsum)htonl(skb->len));
+
+ /* setup inner skb. */
skb->encapsulation = 0;
__skb_pull(skb, tnl_hlen);
skb_reset_mac_header(skb);
skb_set_network_header(skb, skb_inner_network_offset(skb));
skb->mac_len = skb_inner_network_offset(skb);
skb->protocol = new_protocol;
+
+ need_csum = !!(skb_shinfo(skb)->gso_type & SKB_GSO_UDP_TUNNEL_CSUM);
skb->encap_hdr_csum = need_csum;
+
+ remcsum = !!(skb_shinfo(skb)->gso_type & SKB_GSO_TUNNEL_REMCSUM);
skb->remcsum_offload = remcsum;
+ ufo = !!(skb_shinfo(skb)->gso_type & SKB_GSO_UDP);
+
/* Try to offload checksum if possible */
offload_csum = !!(need_csum &&
- ((skb->dev->features & NETIF_F_HW_CSUM) ||
- (skb->dev->features & (is_ipv6 ?
- NETIF_F_IPV6_CSUM : NETIF_F_IP_CSUM))));
+ (skb->dev->features &
+ (is_ipv6 ? (NETIF_F_HW_CSUM | NETIF_F_IPV6_CSUM) :
+ (NETIF_F_HW_CSUM | NETIF_F_IP_CSUM))));
+
+ features &= skb->dev->hw_enc_features;
+
+ /* The only checksum offload we care about from here on out is the
+ * outer one so strip the existing checksum feature flags and
+ * instead set the flag based on our outer checksum offload value.
+ */
+ if (remcsum || ufo) {
+ features &= ~NETIF_F_CSUM_MASK;
+ if (!need_csum || offload_csum)
+ features |= NETIF_F_HW_CSUM;
+ }
/* segment inner packet. */
- enc_features = skb->dev->hw_enc_features & features;
- segs = gso_inner_segment(skb, enc_features);
+ segs = gso_inner_segment(skb, features);
if (IS_ERR_OR_NULL(segs)) {
skb_gso_error_unwind(skb, protocol, tnl_hlen, mac_offset,
mac_len);
@@ -78,17 +100,13 @@ static struct sk_buff *__skb_udp_tunnel_segment(struct sk_buff *skb,
udp_offset = outer_hlen - tnl_hlen;
skb = segs;
do {
- struct udphdr *uh;
- int len;
- __be32 delta;
+ __be16 len;
- if (dont_encap) {
- skb->encapsulation = 0;
+ if (remcsum)
skb->ip_summed = CHECKSUM_NONE;
- } else {
- /* Only set up inner headers if we might be offloading
- * inner checksum.
- */
+
+ /* Set up inner headers if we are offloading inner checksum */
+ if (skb->ip_summed == CHECKSUM_PARTIAL) {
skb_reset_inner_headers(skb);
skb->encapsulation = 1;
}
@@ -96,43 +114,27 @@ static struct sk_buff *__skb_udp_tunnel_segment(struct sk_buff *skb,
skb->mac_len = mac_len;
skb->protocol = protocol;
- skb_push(skb, outer_hlen);
+ __skb_push(skb, outer_hlen);
skb_reset_mac_header(skb);
skb_set_network_header(skb, mac_len);
skb_set_transport_header(skb, udp_offset);
- len = skb->len - udp_offset;
+ len = htons(skb->len - udp_offset);
uh = udp_hdr(skb);
- uh->len = htons(len);
+ uh->len = len;
if (!need_csum)
continue;
- delta = htonl(oldlen + len);
+ uh->check = ~csum_fold(csum_add(partial, (__force __wsum)len));
- uh->check = ~csum_fold((__force __wsum)
- ((__force u32)uh->check +
- (__force u32)delta));
- if (offload_csum) {
- skb->ip_summed = CHECKSUM_PARTIAL;
- skb->csum_start = skb_transport_header(skb) - skb->head;
- skb->csum_offset = offsetof(struct udphdr, check);
- } else if (remcsum) {
- /* Need to calculate checksum from scratch,
- * inner checksums are never when doing
- * remote_checksum_offload.
- */
-
- skb->csum = skb_checksum(skb, udp_offset,
- skb->len - udp_offset,
- 0);
- uh->check = csum_fold(skb->csum);
- if (uh->check == 0)
- uh->check = CSUM_MANGLED_0;
- } else {
+ if (skb->encapsulation || !offload_csum) {
uh->check = gso_make_checksum(skb, ~uh->check);
-
if (uh->check == 0)
uh->check = CSUM_MANGLED_0;
+ } else {
+ skb->ip_summed = CHECKSUM_PARTIAL;
+ skb->csum_start = skb_transport_header(skb) - skb->head;
+ skb->csum_offset = offsetof(struct udphdr, check);
}
} while ((skb = skb->next));
out:
@@ -235,6 +237,13 @@ static struct sk_buff *udp4_ufo_fragment(struct sk_buff *skb,
skb->ip_summed = CHECKSUM_NONE;
+ /* If there is no outer header we can fake a checksum offload
+ * due to the fact that we have already done the checksum in
+ * software prior to segmenting the frame.
+ */
+ if (!skb->encap_hdr_csum)
+ features |= NETIF_F_HW_CSUM;
+
/* Fragment the skb. IP headers of the fragments are updated in
* inet_gso_segment()
*/
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