inet: Remove software UFO fragmenting code.

Rename udp{4,6}_ufo_fragment() to udp{4,6}_tunnel_segment() and only
handle tunnel segmentation.

Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv4/udp_offload.c

@@ -187,66 +187,16 @@ struct sk_buff *skb_udp_tunnel_segment(struct sk_buff *skb,
 }
 EXPORT_SYMBOL(skb_udp_tunnel_segment);
 
-static struct sk_buff *udp4_ufo_fragment(struct sk_buff *skb,
-					 netdev_features_t features)
+static struct sk_buff *udp4_tunnel_segment(struct sk_buff *skb,
+					   netdev_features_t features)
 {
 	struct sk_buff *segs = ERR_PTR(-EINVAL);
-	unsigned int mss;
-	__wsum csum;
-	struct udphdr *uh;
-	struct iphdr *iph;
 
 	if (skb->encapsulation &&
 	    (skb_shinfo(skb)->gso_type &
-	     (SKB_GSO_UDP_TUNNEL|SKB_GSO_UDP_TUNNEL_CSUM))) {
+	     (SKB_GSO_UDP_TUNNEL|SKB_GSO_UDP_TUNNEL_CSUM)))
 		segs = skb_udp_tunnel_segment(skb, features, false);
-		goto out;
-	}
-
-	if (!pskb_may_pull(skb, sizeof(struct udphdr)))
-		goto out;
-
-	mss = skb_shinfo(skb)->gso_size;
-	if (unlikely(skb->len <= mss))
-		goto out;
-
-	if (skb_gso_ok(skb, features | NETIF_F_GSO_ROBUST)) {
-		/* Packet is from an untrusted source, reset gso_segs. */
-
-		skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(skb->len, mss);
-
-		segs = NULL;
-		goto out;
-	}
-
-	/* Do software UFO. Complete and fill in the UDP checksum as
-	 * HW cannot do checksum of UDP packets sent as multiple
-	 * IP fragments.
-	 */
-
-	uh = udp_hdr(skb);
-	iph = ip_hdr(skb);
-
-	uh->check = 0;
-	csum = skb_checksum(skb, 0, skb->len, 0);
-	uh->check = udp_v4_check(skb->len, iph->saddr, iph->daddr, csum);
-	if (uh->check == 0)
-		uh->check = CSUM_MANGLED_0;
 
-	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()
-	 */
-	segs = skb_segment(skb, features);
-out:
 	return segs;
 }
 
@@ -380,7 +330,7 @@ static int udp4_gro_complete(struct sk_buff *skb, int nhoff)
 
 static const struct net_offload udpv4_offload = {
 	.callbacks = {
-		.gso_segment = udp4_ufo_fragment,
+		.gso_segment = udp4_tunnel_segment,
 		.gro_receive  =	udp4_gro_receive,
 		.gro_complete =	udp4_gro_complete,
 	},

net/ipv6/udp_offload.c

@@ -17,109 +17,15 @@
 #include <net/ip6_checksum.h>
 #include "ip6_offload.h"
 
-static struct sk_buff *udp6_ufo_fragment(struct sk_buff *skb,
-					 netdev_features_t features)
+static struct sk_buff *udp6_tunnel_segment(struct sk_buff *skb,
+					   netdev_features_t features)
 {
 	struct sk_buff *segs = ERR_PTR(-EINVAL);
-	unsigned int mss;
-	unsigned int unfrag_ip6hlen, unfrag_len;
-	struct frag_hdr *fptr;
-	u8 *packet_start, *prevhdr;
-	u8 nexthdr;
-	u8 frag_hdr_sz = sizeof(struct frag_hdr);
-	__wsum csum;
-	int tnl_hlen;
-	int err;
-
-	mss = skb_shinfo(skb)->gso_size;
-	if (unlikely(skb->len <= mss))
-		goto out;
-
-	if (skb_gso_ok(skb, features | NETIF_F_GSO_ROBUST)) {
-		/* Packet is from an untrusted source, reset gso_segs. */
-
-		skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(skb->len, mss);
-
-		/* Set the IPv6 fragment id if not set yet */
-		if (!skb_shinfo(skb)->ip6_frag_id)
-			ipv6_proxy_select_ident(dev_net(skb->dev), skb);
-
-		segs = NULL;
-		goto out;
-	}
 
 	if (skb->encapsulation && skb_shinfo(skb)->gso_type &
 	    (SKB_GSO_UDP_TUNNEL|SKB_GSO_UDP_TUNNEL_CSUM))
 		segs = skb_udp_tunnel_segment(skb, features, true);
-	else {
-		const struct ipv6hdr *ipv6h;
-		struct udphdr *uh;
-
-		if (!pskb_may_pull(skb, sizeof(struct udphdr)))
-			goto out;
-
-		/* Do software UFO. Complete and fill in the UDP checksum as HW cannot
-		 * do checksum of UDP packets sent as multiple IP fragments.
-		 */
-
-		uh = udp_hdr(skb);
-		ipv6h = ipv6_hdr(skb);
-
-		uh->check = 0;
-		csum = skb_checksum(skb, 0, skb->len, 0);
-		uh->check = udp_v6_check(skb->len, &ipv6h->saddr,
-					  &ipv6h->daddr, csum);
-		if (uh->check == 0)
-			uh->check = CSUM_MANGLED_0;
-
-		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;
-
-		/* Check if there is enough headroom to insert fragment header. */
-		tnl_hlen = skb_tnl_header_len(skb);
-		if (skb->mac_header < (tnl_hlen + frag_hdr_sz)) {
-			if (gso_pskb_expand_head(skb, tnl_hlen + frag_hdr_sz))
-				goto out;
-		}
-
-		/* Find the unfragmentable header and shift it left by frag_hdr_sz
-		 * bytes to insert fragment header.
-		 */
-		err = ip6_find_1stfragopt(skb, &prevhdr);
-		if (err < 0)
-			return ERR_PTR(err);
-		unfrag_ip6hlen = err;
-		nexthdr = *prevhdr;
-		*prevhdr = NEXTHDR_FRAGMENT;
-		unfrag_len = (skb_network_header(skb) - skb_mac_header(skb)) +
-			     unfrag_ip6hlen + tnl_hlen;
-		packet_start = (u8 *) skb->head + SKB_GSO_CB(skb)->mac_offset;
-		memmove(packet_start-frag_hdr_sz, packet_start, unfrag_len);
-
-		SKB_GSO_CB(skb)->mac_offset -= frag_hdr_sz;
-		skb->mac_header -= frag_hdr_sz;
-		skb->network_header -= frag_hdr_sz;
-
-		fptr = (struct frag_hdr *)(skb_network_header(skb) + unfrag_ip6hlen);
-		fptr->nexthdr = nexthdr;
-		fptr->reserved = 0;
-		if (!skb_shinfo(skb)->ip6_frag_id)
-			ipv6_proxy_select_ident(dev_net(skb->dev), skb);
-		fptr->identification = skb_shinfo(skb)->ip6_frag_id;
-
-		/* Fragment the skb. ipv6 header and the remaining fields of the
-		 * fragment header are updated in ipv6_gso_segment()
-		 */
-		segs = skb_segment(skb, features);
-	}
 
-out:
 	return segs;
 }
 
@@ -169,7 +75,7 @@ static int udp6_gro_complete(struct sk_buff *skb, int nhoff)
 
 static const struct net_offload udpv6_offload = {
 	.callbacks = {
-		.gso_segment	=	udp6_ufo_fragment,
+		.gso_segment	=	udp6_tunnel_segment,
 		.gro_receive	=	udp6_gro_receive,
 		.gro_complete	=	udp6_gro_complete,
 	},