1 files changed, 170 insertions, 94 deletions

diff --git a/net/ipv6/udp_offload.c b/net/ipv6/udp_offload.c
index 5d1b8d7ac993..046f13b1d77a 100644
--- a/net/ipv6/udp_offload.c
+++ b/net/ipv6/udp_offload.c
@@ -1,46 +1,23 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  *	IPV6 GSO/GRO offload support
  *	Linux INET6 implementation
  *
- *	This program is free software; you can redistribute it and/or
- *      modify it under the terms of the GNU General Public License
- *      as published by the Free Software Foundation; either version
- *      2 of the License, or (at your option) any later version.
- *
  *      UDPv6 GSO support
  */
 #include <linux/skbuff.h>
+#include <linux/netdevice.h>
+#include <linux/indirect_call_wrapper.h>
 #include <net/protocol.h>
 #include <net/ipv6.h>
 #include <net/udp.h>
 #include <net/ip6_checksum.h>
 #include "ip6_offload.h"
-
-static int udp6_ufo_send_check(struct sk_buff *skb)
-{
-	const struct ipv6hdr *ipv6h;
-	struct udphdr *uh;
-
-	/* UDP Tunnel offload on ipv6 is not yet supported. */
-	if (skb->encapsulation)
-		return -EINVAL;
-
-	if (!pskb_may_pull(skb, sizeof(*uh)))
-		return -EINVAL;
-
-	ipv6h = ipv6_hdr(skb);
-	uh = udp_hdr(skb);
-
-	uh->check = ~csum_ipv6_magic(&ipv6h->saddr, &ipv6h->daddr, skb->len,
-				     IPPROTO_UDP, 0);
-	skb->csum_start = skb_transport_header(skb) - skb->head;
-	skb->csum_offset = offsetof(struct udphdr, check);
-	skb->ip_summed = CHECKSUM_PARTIAL;
-	return 0;
-}
+#include <net/gro.h>
+#include <net/gso.h>
 
 static struct sk_buff *udp6_ufo_fragment(struct sk_buff *skb,
-	netdev_features_t features)
+					 netdev_features_t features)
 {
 	struct sk_buff *segs = ERR_PTR(-EINVAL);
 	unsigned int mss;
@@ -49,84 +26,183 @@ static struct sk_buff *udp6_ufo_fragment(struct sk_buff *skb,
 	u8 *packet_start, *prevhdr;
 	u8 nexthdr;
 	u8 frag_hdr_sz = sizeof(struct frag_hdr);
-	int offset;
 	__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. */
-		int type = skb_shinfo(skb)->gso_type;
+	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 (unlikely(type & ~(SKB_GSO_UDP |
-				      SKB_GSO_DODGY |
-				      SKB_GSO_UDP_TUNNEL |
-				      SKB_GSO_GRE |
-				      SKB_GSO_MPLS) ||
-			     !(type & (SKB_GSO_UDP))))
+		if (!(skb_shinfo(skb)->gso_type & (SKB_GSO_UDP | SKB_GSO_UDP_L4)))
 			goto out;
 
-		skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(skb->len, mss);
+		if (!pskb_may_pull(skb, sizeof(struct udphdr)))
+			goto out;
 
-		segs = NULL;
-		goto out;
-	}
+		if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4)
+			return __udp_gso_segment(skb, features, true);
 
-	/* Do software UFO. Complete and fill in the UDP checksum as HW cannot
-	 * do checksum of UDP packets sent as multiple IP fragments.
-	 */
-	offset = skb_checksum_start_offset(skb);
-	csum = skb_checksum(skb, offset, skb->len - offset, 0);
-	offset += skb->csum_offset;
-	*(__sum16 *)(skb->data + offset) = csum_fold(csum);
-	skb->ip_summed = CHECKSUM_NONE;
-
-	/* Check if there is enough headroom to insert fragment header. */
-	tnl_hlen = skb_tnl_header_len(skb);
-	if (skb_headroom(skb) < (tnl_hlen + frag_hdr_sz)) {
-		if (gso_pskb_expand_head(skb, tnl_hlen + frag_hdr_sz))
+		mss = skb_shinfo(skb)->gso_size;
+		if (unlikely(skb->len <= mss))
 			goto out;
-	}
 
-	/* Find the unfragmentable header and shift it left by frag_hdr_sz
-	 * bytes to insert fragment header.
-	 */
-	unfrag_ip6hlen = ip6_find_1stfragopt(skb, &prevhdr);
-	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;
-	ipv6_select_ident(fptr, (struct rt6_info *)skb_dst(skb));
-
-	/* Fragment the skb. ipv6 header and the remaining fields of the
-	 * fragment header are updated in ipv6_gso_segment()
-	 */
-	segs = skb_segment(skb, features);
+		/* 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_UNNECESSARY;
+
+		/* 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;
+		fptr->identification = ipv6_proxy_select_ident(dev_net(skb->dev), skb);
+
+		/* 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;
 }
-static const struct net_offload udpv6_offload = {
-	.callbacks = {
-		.gso_send_check =	udp6_ufo_send_check,
-		.gso_segment	=	udp6_ufo_fragment,
-	},
-};
-
-int __init udp_offload_init(void)
+
+static struct sock *udp6_gro_lookup_skb(struct sk_buff *skb, __be16 sport,
+					__be16 dport)
+{
+	const struct ipv6hdr *iph = skb_gro_network_header(skb);
+	struct net *net = dev_net_rcu(skb->dev);
+	struct sock *sk;
+	int iif, sdif;
+
+	sk = udp_tunnel_sk(net, true);
+	if (sk && dport == htons(sk->sk_num))
+		return sk;
+
+	inet6_get_iif_sdif(skb, &iif, &sdif);
+
+	return __udp6_lib_lookup(net, &iph->saddr, sport,
+				 &iph->daddr, dport, iif,
+				 sdif, net->ipv4.udp_table, NULL);
+}
+
+INDIRECT_CALLABLE_SCOPE
+struct sk_buff *udp6_gro_receive(struct list_head *head, struct sk_buff *skb)
+{
+	struct udphdr *uh = udp_gro_udphdr(skb);
+	struct sock *sk = NULL;
+	struct sk_buff *pp;
+
+	if (unlikely(!uh))
+		goto flush;
+
+	/* Don't bother verifying checksum if we're going to flush anyway. */
+	if (NAPI_GRO_CB(skb)->flush)
+		goto skip;
+
+	if (skb_gro_checksum_validate_zero_check(skb, IPPROTO_UDP, uh->check,
+						 ip6_gro_compute_pseudo))
+		goto flush;
+	else if (uh->check)
+		skb_gro_checksum_try_convert(skb, IPPROTO_UDP,
+					     ip6_gro_compute_pseudo);
+
+skip:
+	if (static_branch_unlikely(&udpv6_encap_needed_key))
+		sk = udp6_gro_lookup_skb(skb, uh->source, uh->dest);
+
+	pp = udp_gro_receive(head, skb, uh, sk);
+	return pp;
+
+flush:
+	NAPI_GRO_CB(skb)->flush = 1;
+	return NULL;
+}
+
+INDIRECT_CALLABLE_SCOPE int udp6_gro_complete(struct sk_buff *skb, int nhoff)
+{
+	const u16 offset = NAPI_GRO_CB(skb)->network_offsets[skb->encapsulation];
+	const struct ipv6hdr *ipv6h = (struct ipv6hdr *)(skb->data + offset);
+	struct udphdr *uh = (struct udphdr *)(skb->data + nhoff);
+
+	/* do fraglist only if there is no outer UDP encap (or we already processed it) */
+	if (NAPI_GRO_CB(skb)->is_flist && !NAPI_GRO_CB(skb)->encap_mark) {
+		uh->len = htons(skb->len - nhoff);
+
+		skb_shinfo(skb)->gso_type |= (SKB_GSO_FRAGLIST|SKB_GSO_UDP_L4);
+		skb_shinfo(skb)->gso_segs = NAPI_GRO_CB(skb)->count;
+
+		__skb_incr_checksum_unnecessary(skb);
+
+		return 0;
+	}
+
+	if (uh->check)
+		uh->check = ~udp_v6_check(skb->len - nhoff, &ipv6h->saddr,
+					  &ipv6h->daddr, 0);
+
+	return udp_gro_complete(skb, nhoff, udp6_lib_lookup_skb);
+}
+
+int __init udpv6_offload_init(void)
+{
+	net_hotdata.udpv6_offload = (struct net_offload) {
+		.callbacks = {
+			.gso_segment	=	udp6_ufo_fragment,
+			.gro_receive	=	udp6_gro_receive,
+			.gro_complete	=	udp6_gro_complete,
+		},
+	};
+	return inet6_add_offload(&net_hotdata.udpv6_offload, IPPROTO_UDP);
+}
+
+int udpv6_offload_exit(void)
 {
-	return inet6_add_offload(&udpv6_offload, IPPROTO_UDP);
+	return inet6_del_offload(&net_hotdata.udpv6_offload, IPPROTO_UDP);
 }