*/
#include <linux/skbuff.h>
+#include <linux/init.h>
#include <net/protocol.h>
#include <net/gre.h>
{
struct sk_buff *segs = ERR_PTR(-EINVAL);
netdev_features_t enc_features;
- int ghl = GRE_HEADER_SECTION;
+ int ghl;
struct gre_base_hdr *greh;
u16 mac_offset = skb->mac_header;
int mac_len = skb->mac_len;
greh = (struct gre_base_hdr *)skb_transport_header(skb);
- if (greh->flags & GRE_KEY)
- ghl += GRE_HEADER_SECTION;
- if (greh->flags & GRE_SEQ)
- ghl += GRE_HEADER_SECTION;
- if (greh->flags & GRE_CSUM) {
- ghl += GRE_HEADER_SECTION;
- csum = true;
- } else
- csum = false;
+ ghl = skb_inner_network_header(skb) - skb_transport_header(skb);
+ if (unlikely(ghl < sizeof(*greh)))
+ goto out;
+
+ csum = !!(greh->flags & GRE_CSUM);
if (unlikely(!pskb_may_pull(skb, ghl)))
goto out;
return segs;
}
+/* Compute the whole skb csum in s/w and store it, then verify GRO csum
+ * starting from gro_offset.
+ */
+static __sum16 gro_skb_checksum(struct sk_buff *skb)
+{
+ __sum16 sum;
+
+ skb->csum = skb_checksum(skb, 0, skb->len, 0);
+ NAPI_GRO_CB(skb)->csum = csum_sub(skb->csum,
+ csum_partial(skb->data, skb_gro_offset(skb), 0));
+ sum = csum_fold(NAPI_GRO_CB(skb)->csum);
+ if (unlikely(skb->ip_summed == CHECKSUM_COMPLETE)) {
+ if (unlikely(!sum))
+ netdev_rx_csum_fault(skb->dev);
+ } else
+ skb->ip_summed = CHECKSUM_COMPLETE;
+
+ return sum;
+}
+
+static struct sk_buff **gre_gro_receive(struct sk_buff **head,
+ struct sk_buff *skb)
+{
+ struct sk_buff **pp = NULL;
+ struct sk_buff *p;
+ const struct gre_base_hdr *greh;
+ unsigned int hlen, grehlen;
+ unsigned int off;
+ int flush = 1;
+ struct packet_offload *ptype;
+ __be16 type;
+
+ off = skb_gro_offset(skb);
+ hlen = off + sizeof(*greh);
+ greh = skb_gro_header_fast(skb, off);
+ if (skb_gro_header_hard(skb, hlen)) {
+ greh = skb_gro_header_slow(skb, hlen, off);
+ if (unlikely(!greh))
+ goto out;
+ }
+
+ /* Only support version 0 and K (key), C (csum) flags. Note that
+ * although the support for the S (seq#) flag can be added easily
+ * for GRO, this is problematic for GSO hence can not be enabled
+ * here because a GRO pkt may end up in the forwarding path, thus
+ * requiring GSO support to break it up correctly.
+ */
+ if ((greh->flags & ~(GRE_KEY|GRE_CSUM)) != 0)
+ goto out;
+
+ type = greh->protocol;
+
+ rcu_read_lock();
+ ptype = gro_find_receive_by_type(type);
+ if (ptype == NULL)
+ goto out_unlock;
+
+ grehlen = GRE_HEADER_SECTION;
+
+ if (greh->flags & GRE_KEY)
+ grehlen += GRE_HEADER_SECTION;
+
+ if (greh->flags & GRE_CSUM)
+ grehlen += GRE_HEADER_SECTION;
+
+ hlen = off + grehlen;
+ if (skb_gro_header_hard(skb, hlen)) {
+ greh = skb_gro_header_slow(skb, hlen, off);
+ if (unlikely(!greh))
+ goto out_unlock;
+ }
+ if (greh->flags & GRE_CSUM) { /* Need to verify GRE csum first */
+ __sum16 csum = 0;
+
+ if (skb->ip_summed == CHECKSUM_COMPLETE)
+ csum = csum_fold(NAPI_GRO_CB(skb)->csum);
+ /* Don't trust csum error calculated/reported by h/w */
+ if (skb->ip_summed == CHECKSUM_NONE || csum != 0)
+ csum = gro_skb_checksum(skb);
+
+ /* GRE CSUM is the 1's complement of the 1's complement sum
+ * of the GRE hdr plus payload so it should add up to 0xffff
+ * (and 0 after csum_fold()) just like the IPv4 hdr csum.
+ */
+ if (csum)
+ goto out_unlock;
+ }
+ flush = 0;
+
+ for (p = *head; p; p = p->next) {
+ const struct gre_base_hdr *greh2;
+
+ if (!NAPI_GRO_CB(p)->same_flow)
+ continue;
+
+ /* The following checks are needed to ensure only pkts
+ * from the same tunnel are considered for aggregation.
+ * The criteria for "the same tunnel" includes:
+ * 1) same version (we only support version 0 here)
+ * 2) same protocol (we only support ETH_P_IP for now)
+ * 3) same set of flags
+ * 4) same key if the key field is present.
+ */
+ greh2 = (struct gre_base_hdr *)(p->data + off);
+
+ if (greh2->flags != greh->flags ||
+ greh2->protocol != greh->protocol) {
+ NAPI_GRO_CB(p)->same_flow = 0;
+ continue;
+ }
+ if (greh->flags & GRE_KEY) {
+ /* compare keys */
+ if (*(__be32 *)(greh2+1) != *(__be32 *)(greh+1)) {
+ NAPI_GRO_CB(p)->same_flow = 0;
+ continue;
+ }
+ }
+ }
+
+ skb_gro_pull(skb, grehlen);
+
+ /* Adjusted NAPI_GRO_CB(skb)->csum after skb_gro_pull()*/
+ skb_gro_postpull_rcsum(skb, greh, grehlen);
+
+ pp = ptype->callbacks.gro_receive(head, skb);
+
+out_unlock:
+ rcu_read_unlock();
+out:
+ NAPI_GRO_CB(skb)->flush |= flush;
+
+ return pp;
+}
+
+static int gre_gro_complete(struct sk_buff *skb, int nhoff)
+{
+ struct gre_base_hdr *greh = (struct gre_base_hdr *)(skb->data + nhoff);
+ struct packet_offload *ptype;
+ unsigned int grehlen = sizeof(*greh);
+ int err = -ENOENT;
+ __be16 type;
+
+ type = greh->protocol;
+ if (greh->flags & GRE_KEY)
+ grehlen += GRE_HEADER_SECTION;
+
+ if (greh->flags & GRE_CSUM)
+ grehlen += GRE_HEADER_SECTION;
+
+ rcu_read_lock();
+ ptype = gro_find_complete_by_type(type);
+ if (ptype != NULL)
+ err = ptype->callbacks.gro_complete(skb, nhoff + grehlen);
+
+ rcu_read_unlock();
+ return err;
+}
+
static const struct net_offload gre_offload = {
.callbacks = {
.gso_send_check = gre_gso_send_check,
.gso_segment = gre_gso_segment,
+ .gro_receive = gre_gro_receive,
+ .gro_complete = gre_gro_complete,
},
};
-int __init gre_offload_init(void)
+static int __init gre_offload_init(void)
{
return inet_add_offload(&gre_offload, IPPROTO_GRE);
}
-
-void __exit gre_offload_exit(void)
-{
- inet_del_offload(&gre_offload, IPPROTO_GRE);
-}
+device_initcall(gre_offload_init);
projects / karo-tx-linux.git / blobdiff