esp: Add gso handlers for esp4 and esp6
This patch extends the xfrm_type by an encap function pointer
and implements esp4_gso_encap and esp6_gso_encap. These functions
doing the basic esp encapsulation for a GSO packet. In case the
GSO packet needs to be segmented in software, we add gso_segment
functions. This codepath is going to be used on esp hardware
offloads.
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
diff --git a/net/ipv6/esp6_offload.c b/net/ipv6/esp6_offload.c
index 5dd20c0..06e9721 100644
--- a/net/ipv6/esp6_offload.c
+++ b/net/ipv6/esp6_offload.c
@@ -86,6 +86,97 @@ static struct sk_buff **esp6_gro_receive(struct sk_buff **head,
return NULL;
}
+static void esp6_gso_encap(struct xfrm_state *x, struct sk_buff *skb)
+{
+ struct ip_esp_hdr *esph;
+ struct ipv6hdr *iph = ipv6_hdr(skb);
+ struct xfrm_offload *xo = xfrm_offload(skb);
+ int proto = iph->nexthdr;
+
+ skb_push(skb, -skb_network_offset(skb));
+ esph = ip_esp_hdr(skb);
+ *skb_mac_header(skb) = IPPROTO_ESP;
+
+ esph->spi = x->id.spi;
+ esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);
+
+ xo->proto = proto;
+}
+
+static struct sk_buff *esp6_gso_segment(struct sk_buff *skb,
+ netdev_features_t features)
+{
+ __u32 seq;
+ int err = 0;
+ struct sk_buff *skb2;
+ struct xfrm_state *x;
+ struct ip_esp_hdr *esph;
+ struct crypto_aead *aead;
+ struct sk_buff *segs = ERR_PTR(-EINVAL);
+ netdev_features_t esp_features = features;
+ struct xfrm_offload *xo = xfrm_offload(skb);
+
+ if (xo)
+ goto out;
+
+ seq = xo->seq.low;
+
+ x = skb->sp->xvec[skb->sp->len - 1];
+ aead = x->data;
+ esph = ip_esp_hdr(skb);
+
+ if (esph->spi != x->id.spi)
+ goto out;
+
+ if (!pskb_may_pull(skb, sizeof(*esph) + crypto_aead_ivsize(aead)))
+ goto out;
+
+ __skb_pull(skb, sizeof(*esph) + crypto_aead_ivsize(aead));
+
+ skb->encap_hdr_csum = 1;
+
+ if (!(features & NETIF_F_HW_ESP))
+ esp_features = features & ~(NETIF_F_SG | NETIF_F_CSUM_MASK);
+
+ segs = x->outer_mode->gso_segment(x, skb, esp_features);
+ if (IS_ERR_OR_NULL(segs))
+ goto out;
+
+ __skb_pull(skb, skb->data - skb_mac_header(skb));
+
+ skb2 = segs;
+ do {
+ struct sk_buff *nskb = skb2->next;
+
+ xo = xfrm_offload(skb2);
+ xo->flags |= XFRM_GSO_SEGMENT;
+ xo->seq.low = seq;
+ xo->seq.hi = xfrm_replay_seqhi(x, seq);
+
+ if(!(features & NETIF_F_HW_ESP))
+ xo->flags |= CRYPTO_FALLBACK;
+
+ x->outer_mode->xmit(x, skb2);
+
+ err = x->type_offload->xmit(x, skb2, esp_features);
+ if (err) {
+ kfree_skb_list(segs);
+ return ERR_PTR(err);
+ }
+
+ if (!skb_is_gso(skb2))
+ seq++;
+ else
+ seq += skb_shinfo(skb2)->gso_segs;
+
+ skb_push(skb2, skb2->mac_len);
+ skb2 = nskb;
+ } while (skb2);
+
+out:
+ return segs;
+}
+
static int esp6_input_tail(struct xfrm_state *x, struct sk_buff *skb)
{
struct crypto_aead *aead = x->data;
@@ -176,6 +267,7 @@ static int esp6_xmit(struct xfrm_state *x, struct sk_buff *skb, netdev_features
static const struct net_offload esp6_offload = {
.callbacks = {
.gro_receive = esp6_gro_receive,
+ .gso_segment = esp6_gso_segment,
},
};
@@ -185,6 +277,7 @@ static const struct xfrm_type_offload esp6_type_offload = {
.proto = IPPROTO_ESP,
.input_tail = esp6_input_tail,
.xmit = esp6_xmit,
+ .encap = esp6_gso_encap,
};
static int __init esp6_offload_init(void)