1 files changed, 334 insertions, 127 deletions

diff --git a/net/ipv6/ip6_offload.c b/net/ipv6/ip6_offload.c
index a263b990ee11..fce91183797a 100644
--- a/net/ipv6/ip6_offload.c
+++ b/net/ipv6/ip6_offload.c
@@ -1,11 +1,7 @@
+// 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.
  */
 
 #include <linux/kernel.h>
@@ -16,68 +12,96 @@
 
 #include <net/protocol.h>
 #include <net/ipv6.h>
+#include <net/inet_common.h>
+#include <net/tcp.h>
+#include <net/udp.h>
+#include <net/gro.h>
+#include <net/gso.h>
 
 #include "ip6_offload.h"
 
-static int ipv6_gso_pull_exthdrs(struct sk_buff *skb, int proto)
+/* All GRO functions are always builtin, except UDP over ipv6, which lays in
+ * ipv6 module, as it depends on UDPv6 lookup function, so we need special care
+ * when ipv6 is built as a module
+ */
+#if IS_BUILTIN(CONFIG_IPV6)
+#define INDIRECT_CALL_L4(f, f2, f1, ...) INDIRECT_CALL_2(f, f2, f1, __VA_ARGS__)
+#else
+#define INDIRECT_CALL_L4(f, f2, f1, ...) INDIRECT_CALL_1(f, f2, __VA_ARGS__)
+#endif
+
+#define indirect_call_gro_receive_l4(f2, f1, cb, head, skb)	\
+({								\
+	unlikely(gro_recursion_inc_test(skb)) ?			\
+		NAPI_GRO_CB(skb)->flush |= 1, NULL :		\
+		INDIRECT_CALL_L4(cb, f2, f1, head, skb);	\
+})
+
+static int ipv6_gro_pull_exthdrs(struct sk_buff *skb, int off, int proto)
 {
 	const struct net_offload *ops = NULL;
+	struct ipv6_opt_hdr *opth;
 
 	for (;;) {
-		struct ipv6_opt_hdr *opth;
 		int len;
 
-		if (proto != NEXTHDR_HOP) {
-			ops = rcu_dereference(inet6_offloads[proto]);
+		ops = rcu_dereference(inet6_offloads[proto]);
 
-			if (unlikely(!ops))
-				break;
+		if (unlikely(!ops))
+			break;
 
-			if (!(ops->flags & INET6_PROTO_GSO_EXTHDR))
-				break;
-		}
+		if (!(ops->flags & INET6_PROTO_GSO_EXTHDR))
+			break;
 
-		if (unlikely(!pskb_may_pull(skb, 8)))
+		opth = skb_gro_header(skb, off + sizeof(*opth), off);
+		if (unlikely(!opth))
 			break;
 
-		opth = (void *)skb->data;
 		len = ipv6_optlen(opth);
 
-		if (unlikely(!pskb_may_pull(skb, len)))
+		opth = skb_gro_header(skb, off + len, off);
+		if (unlikely(!opth))
 			break;
-
 		proto = opth->nexthdr;
-		__skb_pull(skb, len);
+
+		off += len;
 	}
 
+	skb_gro_pull(skb, off - skb_gro_receive_network_offset(skb));
 	return proto;
 }
 
-static int ipv6_gso_send_check(struct sk_buff *skb)
+static int ipv6_gso_pull_exthdrs(struct sk_buff *skb, int proto)
 {
-	const struct ipv6hdr *ipv6h;
-	const struct net_offload *ops;
-	int err = -EINVAL;
+	const struct net_offload *ops = NULL;
 
-	if (unlikely(!pskb_may_pull(skb, sizeof(*ipv6h))))
-		goto out;
+	for (;;) {
+		struct ipv6_opt_hdr *opth;
+		int len;
 
-	ipv6h = ipv6_hdr(skb);
-	__skb_pull(skb, sizeof(*ipv6h));
-	err = -EPROTONOSUPPORT;
+		ops = rcu_dereference(inet6_offloads[proto]);
+
+		if (unlikely(!ops))
+			break;
+
+		if (!(ops->flags & INET6_PROTO_GSO_EXTHDR))
+			break;
+
+		if (unlikely(!pskb_may_pull(skb, 8)))
+			break;
+
+		opth = (void *)skb->data;
+		len = ipv6_optlen(opth);
 
-	rcu_read_lock();
-	ops = rcu_dereference(inet6_offloads[
-		ipv6_gso_pull_exthdrs(skb, ipv6h->nexthdr)]);
+		if (unlikely(!pskb_may_pull(skb, len)))
+			break;
 
-	if (likely(ops && ops->callbacks.gso_send_check)) {
-		skb_reset_transport_header(skb);
-		err = ops->callbacks.gso_send_check(skb);
+		opth = (void *)skb->data;
+		proto = opth->nexthdr;
+		__skb_pull(skb, len);
 	}
-	rcu_read_unlock();
 
-out:
-	return err;
+	return proto;
 }
 
 static struct sk_buff *ipv6_gso_segment(struct sk_buff *skb,
@@ -86,196 +110,379 @@ static struct sk_buff *ipv6_gso_segment(struct sk_buff *skb,
 	struct sk_buff *segs = ERR_PTR(-EINVAL);
 	struct ipv6hdr *ipv6h;
 	const struct net_offload *ops;
-	int proto;
+	int proto, err;
 	struct frag_hdr *fptr;
-	unsigned int unfrag_ip6hlen;
+	unsigned int payload_len;
 	u8 *prevhdr;
 	int offset = 0;
-
-	if (unlikely(skb_shinfo(skb)->gso_type &
-		     ~(SKB_GSO_UDP |
-		       SKB_GSO_DODGY |
-		       SKB_GSO_TCP_ECN |
-		       SKB_GSO_GRE |
-		       SKB_GSO_UDP_TUNNEL |
-		       SKB_GSO_MPLS |
-		       SKB_GSO_TCPV6 |
-		       0)))
-		goto out;
-
+	bool encap, udpfrag;
+	int nhoff;
+	bool gso_partial;
+
+	skb_reset_network_header(skb);
+	err = ipv6_hopopt_jumbo_remove(skb);
+	if (err)
+		return ERR_PTR(err);
+	nhoff = skb_network_header(skb) - skb_mac_header(skb);
 	if (unlikely(!pskb_may_pull(skb, sizeof(*ipv6h))))
 		goto out;
 
+	encap = SKB_GSO_CB(skb)->encap_level > 0;
+	if (encap)
+		features &= skb->dev->hw_enc_features;
+	SKB_GSO_CB(skb)->encap_level += sizeof(*ipv6h);
+
 	ipv6h = ipv6_hdr(skb);
 	__skb_pull(skb, sizeof(*ipv6h));
 	segs = ERR_PTR(-EPROTONOSUPPORT);
 
 	proto = ipv6_gso_pull_exthdrs(skb, ipv6h->nexthdr);
-	rcu_read_lock();
+
+	if (skb->encapsulation &&
+	    skb_shinfo(skb)->gso_type & (SKB_GSO_IPXIP4 | SKB_GSO_IPXIP6))
+		udpfrag = proto == IPPROTO_UDP && encap &&
+			  (skb_shinfo(skb)->gso_type & SKB_GSO_UDP);
+	else
+		udpfrag = proto == IPPROTO_UDP && !skb->encapsulation &&
+			  (skb_shinfo(skb)->gso_type & SKB_GSO_UDP);
+
 	ops = rcu_dereference(inet6_offloads[proto]);
 	if (likely(ops && ops->callbacks.gso_segment)) {
-		skb_reset_transport_header(skb);
+		if (!skb_reset_transport_header_careful(skb))
+			goto out;
+
 		segs = ops->callbacks.gso_segment(skb, features);
+		if (!segs)
+			skb->network_header = skb_mac_header(skb) + nhoff - skb->head;
 	}
-	rcu_read_unlock();
 
-	if (IS_ERR(segs))
+	if (IS_ERR_OR_NULL(segs))
 		goto out;
 
+	gso_partial = !!(skb_shinfo(segs)->gso_type & SKB_GSO_PARTIAL);
+
 	for (skb = segs; skb; skb = skb->next) {
-		ipv6h = ipv6_hdr(skb);
-		ipv6h->payload_len = htons(skb->len - skb->mac_len -
-					   sizeof(*ipv6h));
-		if (proto == IPPROTO_UDP) {
-			unfrag_ip6hlen = ip6_find_1stfragopt(skb, &prevhdr);
-			fptr = (struct frag_hdr *)(skb_network_header(skb) +
-				unfrag_ip6hlen);
+		ipv6h = (struct ipv6hdr *)(skb_mac_header(skb) + nhoff);
+		if (gso_partial && skb_is_gso(skb))
+			payload_len = skb_shinfo(skb)->gso_size +
+				      SKB_GSO_CB(skb)->data_offset +
+				      skb->head - (unsigned char *)(ipv6h + 1);
+		else
+			payload_len = skb->len - nhoff - sizeof(*ipv6h);
+		ipv6h->payload_len = htons(payload_len);
+		skb->network_header = (u8 *)ipv6h - skb->head;
+		skb_reset_mac_len(skb);
+
+		if (udpfrag) {
+			int err = ip6_find_1stfragopt(skb, &prevhdr);
+			if (err < 0) {
+				kfree_skb_list(segs);
+				return ERR_PTR(err);
+			}
+			fptr = (struct frag_hdr *)((u8 *)ipv6h + err);
 			fptr->frag_off = htons(offset);
-			if (skb->next != NULL)
+			if (skb->next)
 				fptr->frag_off |= htons(IP6_MF);
 			offset += (ntohs(ipv6h->payload_len) -
 				   sizeof(struct frag_hdr));
 		}
+		if (encap)
+			skb_reset_inner_headers(skb);
 	}
 
 out:
 	return segs;
 }
 
-static struct sk_buff **ipv6_gro_receive(struct sk_buff **head,
-					 struct sk_buff *skb)
+/* Return the total length of all the extension hdrs, following the same
+ * logic in ipv6_gso_pull_exthdrs() when parsing ext-hdrs.
+ */
+static int ipv6_exthdrs_len(struct ipv6hdr *iph,
+			    const struct net_offload **opps)
+{
+	struct ipv6_opt_hdr *opth = (void *)iph;
+	int len = 0, proto, optlen = sizeof(*iph);
+
+	proto = iph->nexthdr;
+	for (;;) {
+		*opps = rcu_dereference(inet6_offloads[proto]);
+		if (unlikely(!(*opps)))
+			break;
+		if (!((*opps)->flags & INET6_PROTO_GSO_EXTHDR))
+			break;
+
+		opth = (void *)opth + optlen;
+		optlen = ipv6_optlen(opth);
+		len += optlen;
+		proto = opth->nexthdr;
+	}
+	return len;
+}
+
+INDIRECT_CALLABLE_SCOPE struct sk_buff *ipv6_gro_receive(struct list_head *head,
+							 struct sk_buff *skb)
 {
 	const struct net_offload *ops;
-	struct sk_buff **pp = NULL;
+	struct sk_buff *pp = NULL;
 	struct sk_buff *p;
 	struct ipv6hdr *iph;
 	unsigned int nlen;
 	unsigned int hlen;
 	unsigned int off;
-	int flush = 1;
+	u16 flush = 1;
 	int proto;
-	__wsum csum;
 
 	off = skb_gro_offset(skb);
 	hlen = off + sizeof(*iph);
-	iph = skb_gro_header_fast(skb, off);
-	if (skb_gro_header_hard(skb, hlen)) {
-		iph = skb_gro_header_slow(skb, hlen, off);
-		if (unlikely(!iph))
-			goto out;
-	}
+	iph = skb_gro_header(skb, hlen, off);
+	if (unlikely(!iph))
+		goto out;
 
-	skb_gro_pull(skb, sizeof(*iph));
-	skb_set_transport_header(skb, skb_gro_offset(skb));
+	NAPI_GRO_CB(skb)->network_offsets[NAPI_GRO_CB(skb)->encap_mark] = off;
 
-	flush += ntohs(iph->payload_len) != skb_gro_len(skb);
+	flush += ntohs(iph->payload_len) != skb->len - hlen;
 
-	rcu_read_lock();
 	proto = iph->nexthdr;
 	ops = rcu_dereference(inet6_offloads[proto]);
 	if (!ops || !ops->callbacks.gro_receive) {
-		__pskb_pull(skb, skb_gro_offset(skb));
-		proto = ipv6_gso_pull_exthdrs(skb, proto);
-		skb_gro_pull(skb, -skb_transport_offset(skb));
-		skb_reset_transport_header(skb);
-		__skb_push(skb, skb_gro_offset(skb));
+		proto = ipv6_gro_pull_exthdrs(skb, hlen, proto);
 
 		ops = rcu_dereference(inet6_offloads[proto]);
 		if (!ops || !ops->callbacks.gro_receive)
-			goto out_unlock;
+			goto out;
 
-		iph = ipv6_hdr(skb);
+		iph = skb_gro_network_header(skb);
+	} else {
+		skb_gro_pull(skb, sizeof(*iph));
 	}
 
+	skb_set_transport_header(skb, skb_gro_offset(skb));
+
 	NAPI_GRO_CB(skb)->proto = proto;
 
 	flush--;
-	nlen = skb_network_header_len(skb);
+	nlen = skb_gro_offset(skb) - off;
 
-	for (p = *head; p; p = p->next) {
+	list_for_each_entry(p, head, list) {
 		const struct ipv6hdr *iph2;
 		__be32 first_word; /* <Version:4><Traffic_Class:8><Flow_Label:20> */
 
 		if (!NAPI_GRO_CB(p)->same_flow)
 			continue;
 
-		iph2 = ipv6_hdr(p);
-		first_word = *(__be32 *)iph ^ *(__be32 *)iph2 ;
-
-		/* All fields must match except length and Traffic Class. */
-		if (nlen != skb_network_header_len(p) ||
-		    (first_word & htonl(0xF00FFFFF)) ||
-		    memcmp(&iph->nexthdr, &iph2->nexthdr,
-			   nlen - offsetof(struct ipv6hdr, nexthdr))) {
+		iph2 = (struct ipv6hdr *)(p->data + off);
+		first_word = *(__be32 *)iph ^ *(__be32 *)iph2;
+
+		/* All fields must match except length and Traffic Class.
+		 * XXX skbs on the gro_list have all been parsed and pulled
+		 * already so we don't need to compare nlen
+		 * (nlen != (sizeof(*iph2) + ipv6_exthdrs_len(iph2, &ops)))
+		 * memcmp() alone below is sufficient, right?
+		 */
+		 if ((first_word & htonl(0xF00FFFFF)) ||
+		     !ipv6_addr_equal(&iph->saddr, &iph2->saddr) ||
+		     !ipv6_addr_equal(&iph->daddr, &iph2->daddr) ||
+		     iph->nexthdr != iph2->nexthdr) {
+not_same_flow:
 			NAPI_GRO_CB(p)->same_flow = 0;
 			continue;
 		}
-		/* flush if Traffic Class fields are different */
-		NAPI_GRO_CB(p)->flush |= !!(first_word & htonl(0x0FF00000));
-		NAPI_GRO_CB(p)->flush |= flush;
+		if (unlikely(nlen > sizeof(struct ipv6hdr))) {
+			if (memcmp(iph + 1, iph2 + 1,
+				   nlen - sizeof(struct ipv6hdr)))
+				goto not_same_flow;
+		}
 	}
 
 	NAPI_GRO_CB(skb)->flush |= flush;
 
-	csum = skb->csum;
-	skb_postpull_rcsum(skb, iph, skb_network_header_len(skb));
-
-	pp = ops->callbacks.gro_receive(head, skb);
+	skb_gro_postpull_rcsum(skb, iph, nlen);
 
-	skb->csum = csum;
-
-out_unlock:
-	rcu_read_unlock();
+	pp = indirect_call_gro_receive_l4(tcp6_gro_receive, udp6_gro_receive,
+					 ops->callbacks.gro_receive, head, skb);
 
 out:
-	NAPI_GRO_CB(skb)->flush |= flush;
+	skb_gro_flush_final(skb, pp, flush);
 
 	return pp;
 }
 
-static int ipv6_gro_complete(struct sk_buff *skb)
+static struct sk_buff *sit_ip6ip6_gro_receive(struct list_head *head,
+					      struct sk_buff *skb)
+{
+	/* Common GRO receive for SIT and IP6IP6 */
+
+	if (NAPI_GRO_CB(skb)->encap_mark) {
+		NAPI_GRO_CB(skb)->flush = 1;
+		return NULL;
+	}
+
+	NAPI_GRO_CB(skb)->encap_mark = 1;
+
+	return ipv6_gro_receive(head, skb);
+}
+
+static struct sk_buff *ip4ip6_gro_receive(struct list_head *head,
+					  struct sk_buff *skb)
+{
+	/* Common GRO receive for SIT and IP6IP6 */
+
+	if (NAPI_GRO_CB(skb)->encap_mark) {
+		NAPI_GRO_CB(skb)->flush = 1;
+		return NULL;
+	}
+
+	NAPI_GRO_CB(skb)->encap_mark = 1;
+
+	return inet_gro_receive(head, skb);
+}
+
+INDIRECT_CALLABLE_SCOPE int ipv6_gro_complete(struct sk_buff *skb, int nhoff)
 {
 	const struct net_offload *ops;
-	struct ipv6hdr *iph = ipv6_hdr(skb);
+	struct ipv6hdr *iph;
 	int err = -ENOSYS;
+	u32 payload_len;
+
+	if (skb->encapsulation) {
+		skb_set_inner_protocol(skb, cpu_to_be16(ETH_P_IPV6));
+		skb_set_inner_network_header(skb, nhoff);
+	}
 
-	iph->payload_len = htons(skb->len - skb_network_offset(skb) -
-				 sizeof(*iph));
+	payload_len = skb->len - nhoff - sizeof(*iph);
+	if (unlikely(payload_len > IPV6_MAXPLEN)) {
+		struct hop_jumbo_hdr *hop_jumbo;
+		int hoplen = sizeof(*hop_jumbo);
+
+		/* Move network header left */
+		memmove(skb_mac_header(skb) - hoplen, skb_mac_header(skb),
+			skb->transport_header - skb->mac_header);
+		skb->data -= hoplen;
+		skb->len += hoplen;
+		skb->mac_header -= hoplen;
+		skb->network_header -= hoplen;
+		iph = (struct ipv6hdr *)(skb->data + nhoff);
+		hop_jumbo = (struct hop_jumbo_hdr *)(iph + 1);
+
+		/* Build hop-by-hop options */
+		hop_jumbo->nexthdr = iph->nexthdr;
+		hop_jumbo->hdrlen = 0;
+		hop_jumbo->tlv_type = IPV6_TLV_JUMBO;
+		hop_jumbo->tlv_len = 4;
+		hop_jumbo->jumbo_payload_len = htonl(payload_len + hoplen);
+
+		iph->nexthdr = NEXTHDR_HOP;
+		iph->payload_len = 0;
+	} else {
+		iph = (struct ipv6hdr *)(skb->data + nhoff);
+		iph->payload_len = htons(payload_len);
+	}
 
-	rcu_read_lock();
-	ops = rcu_dereference(inet6_offloads[NAPI_GRO_CB(skb)->proto]);
+	nhoff += sizeof(*iph) + ipv6_exthdrs_len(iph, &ops);
 	if (WARN_ON(!ops || !ops->callbacks.gro_complete))
-		goto out_unlock;
-
-	err = ops->callbacks.gro_complete(skb);
+		goto out;
 
-out_unlock:
-	rcu_read_unlock();
+	err = INDIRECT_CALL_L4(ops->callbacks.gro_complete, tcp6_gro_complete,
+			       udp6_gro_complete, skb, nhoff);
 
+out:
 	return err;
 }
 
-static struct packet_offload ipv6_packet_offload __read_mostly = {
-	.type = cpu_to_be16(ETH_P_IPV6),
+static int sit_gro_complete(struct sk_buff *skb, int nhoff)
+{
+	skb->encapsulation = 1;
+	skb_shinfo(skb)->gso_type |= SKB_GSO_IPXIP4;
+	return ipv6_gro_complete(skb, nhoff);
+}
+
+static int ip6ip6_gro_complete(struct sk_buff *skb, int nhoff)
+{
+	skb->encapsulation = 1;
+	skb_shinfo(skb)->gso_type |= SKB_GSO_IPXIP6;
+	return ipv6_gro_complete(skb, nhoff);
+}
+
+static int ip4ip6_gro_complete(struct sk_buff *skb, int nhoff)
+{
+	skb->encapsulation = 1;
+	skb_shinfo(skb)->gso_type |= SKB_GSO_IPXIP6;
+	return inet_gro_complete(skb, nhoff);
+}
+
+
+static struct sk_buff *sit_gso_segment(struct sk_buff *skb,
+				       netdev_features_t features)
+{
+	if (!(skb_shinfo(skb)->gso_type & SKB_GSO_IPXIP4))
+		return ERR_PTR(-EINVAL);
+
+	return ipv6_gso_segment(skb, features);
+}
+
+static struct sk_buff *ip4ip6_gso_segment(struct sk_buff *skb,
+					  netdev_features_t features)
+{
+	if (!(skb_shinfo(skb)->gso_type & SKB_GSO_IPXIP6))
+		return ERR_PTR(-EINVAL);
+
+	return inet_gso_segment(skb, features);
+}
+
+static struct sk_buff *ip6ip6_gso_segment(struct sk_buff *skb,
+					  netdev_features_t features)
+{
+	if (!(skb_shinfo(skb)->gso_type & SKB_GSO_IPXIP6))
+		return ERR_PTR(-EINVAL);
+
+	return ipv6_gso_segment(skb, features);
+}
+
+static const struct net_offload sit_offload = {
+	.callbacks = {
+		.gso_segment	= sit_gso_segment,
+		.gro_receive    = sit_ip6ip6_gro_receive,
+		.gro_complete   = sit_gro_complete,
+	},
+};
+
+static const struct net_offload ip4ip6_offload = {
 	.callbacks = {
-		.gso_send_check = ipv6_gso_send_check,
-		.gso_segment = ipv6_gso_segment,
-		.gro_receive = ipv6_gro_receive,
-		.gro_complete = ipv6_gro_complete,
+		.gso_segment	= ip4ip6_gso_segment,
+		.gro_receive    = ip4ip6_gro_receive,
+		.gro_complete   = ip4ip6_gro_complete,
 	},
 };
 
+static const struct net_offload ip6ip6_offload = {
+	.callbacks = {
+		.gso_segment	= ip6ip6_gso_segment,
+		.gro_receive    = sit_ip6ip6_gro_receive,
+		.gro_complete   = ip6ip6_gro_complete,
+	},
+};
 static int __init ipv6_offload_init(void)
 {
 
 	if (tcpv6_offload_init() < 0)
 		pr_crit("%s: Cannot add TCP protocol offload\n", __func__);
-	if (udp_offload_init() < 0)
-		pr_crit("%s: Cannot add UDP protocol offload\n", __func__);
 	if (ipv6_exthdrs_offload_init() < 0)
 		pr_crit("%s: Cannot add EXTHDRS protocol offload\n", __func__);
 
-	dev_add_offload(&ipv6_packet_offload);
+	net_hotdata.ipv6_packet_offload = (struct packet_offload) {
+		.type = cpu_to_be16(ETH_P_IPV6),
+		.callbacks = {
+			.gso_segment = ipv6_gso_segment,
+			.gro_receive = ipv6_gro_receive,
+			.gro_complete = ipv6_gro_complete,
+		},
+	};
+	dev_add_offload(&net_hotdata.ipv6_packet_offload);
+
+	inet_add_offload(&sit_offload, IPPROTO_IPV6);
+	inet6_add_offload(&ip6ip6_offload, IPPROTO_IPV6);
+	inet6_add_offload(&ip4ip6_offload, IPPROTO_IPIP);
+
 	return 0;
 }