netvsc: fix checksum on UDP IPV6

PATCH Superseded Stephen Hemminger 2 participants 3 messages Oct 11, 2016 – Oct 13, 2016

Subsystems (3)

Networking Network drivers Hyper-V/Azure core and drivers

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Stephen Hemminger

author

2016-10-11 21:02 UTC #0 lore raw

PATCH 1/1 netvsc: fix checksum on UDP IPV6

The software calculation of UDP checksum in Netvsc driver was only handling IPv4 case. By using skb_checksum_help() instead all protocols can be handled. Rearrange code to eliminate goto and look like other drivers.

This is a temporary solution; recent versions of Window Server etc do support UDP checksum offload, just need to do the appropriate negotiation with host to validate before using. This will be done in later patch.

Please queue this for -stable as well.

Signed-off-by Stephen Hemminger <[email protected]>

---
 drivers/net/hyperv/netvsc_drv.c | 72 +++++++++++++----------------------------
 1 file changed, 22 insertions(+), 50 deletions(-)

drivers/net/hyperv/netvsc_drv.c +22 ~~-50~~

index 52eeb2f..9570d21 100644
@@ -36,6 +36,7 @@
 #include <net/arp.h>
 #include <net/route.h>
 #include <net/sock.h>
+#include <net/udp.h>
 #include <net/pkt_sched.h>
 
 #include "hyperv_net.h"

@@ -442,8 +443,6 @@ static int netvsc_start_xmit(struct sk_buff *skb, struct net_device *net)
 	}
 
 	net_trans_info = get_net_transport_info(skb, &hdr_offset);
-	if (net_trans_info == TRANSPORT_INFO_NOT_IP)
-		goto do_send;
 
 	/*
 	 * Setup the sendside checksum offload only if this is not a

@@ -478,56 +477,29 @@ static int netvsc_start_xmit(struct sk_buff *skb, struct net_device *net)
 		}
 		lso_info->lso_v2_transmit.tcp_header_offset = hdr_offset;
 		lso_info->lso_v2_transmit.mss = skb_shinfo(skb)->gso_size;
-		goto do_send;
-	}
-
-	if ((skb->ip_summed == CHECKSUM_NONE) ||
-	    (skb->ip_summed == CHECKSUM_UNNECESSARY))
-		goto do_send;
-
-	rndis_msg_size += NDIS_CSUM_PPI_SIZE;
-	ppi = init_ppi_data(rndis_msg, NDIS_CSUM_PPI_SIZE,
-			    TCPIP_CHKSUM_PKTINFO);
-
-	csum_info = (struct ndis_tcp_ip_checksum_info *)((void *)ppi +
-			ppi->ppi_offset);
-
-	if (net_trans_info & (INFO_IPV4 << 16))
-		csum_info->transmit.is_ipv4 = 1;
-	else
-		csum_info->transmit.is_ipv6 = 1;
-
-	if (net_trans_info & INFO_TCP) {
-		csum_info->transmit.tcp_checksum = 1;
-		csum_info->transmit.tcp_header_offset = hdr_offset;
-	} else if (net_trans_info & INFO_UDP) {
-		/* UDP checksum offload is not supported on ws2008r2.
-		 * Furthermore, on ws2012 and ws2012r2, there are some
-		 * issues with udp checksum offload from Linux guests.
-		 * (these are host issues).
-		 * For now compute the checksum here.
-		 */
-		struct udphdr *uh;
-		u16 udp_len;
-
-		ret = skb_cow_head(skb, 0);
-		if (ret)
-			goto no_memory;
-
-		uh = udp_hdr(skb);
-		udp_len = ntohs(uh->len);
-		uh->check = 0;
-		uh->check = csum_tcpudp_magic(ip_hdr(skb)->saddr,
-					      ip_hdr(skb)->daddr,
-					      udp_len, IPPROTO_UDP,
-					      csum_partial(uh, udp_len, 0));
-		if (uh->check == 0)
-			uh->check = CSUM_MANGLED_0;
-
-		csum_info->transmit.udp_checksum = 0;
+	} else if (skb->ip_summed == CHECKSUM_PARTIAL) {
+		if (net_trans_info & INFO_TCP) {
+			rndis_msg_size += NDIS_CSUM_PPI_SIZE;
+			ppi = init_ppi_data(rndis_msg, NDIS_CSUM_PPI_SIZE,
+					    TCPIP_CHKSUM_PKTINFO);
+
+			csum_info = (struct ndis_tcp_ip_checksum_info *)((void *)ppi +
+									 ppi->ppi_offset);
+
+			if (net_trans_info & (INFO_IPV4 << 16))
+				csum_info->transmit.is_ipv4 = 1;
+			else
+				csum_info->transmit.is_ipv6 = 1;
+
+			csum_info->transmit.tcp_checksum = 1;
+			csum_info->transmit.tcp_header_offset = hdr_offset;
+		} else {
+			/* UDP checksum (and other) offload is not supported. */
+			if (skb_checksum_help(skb))
+				goto drop;
+		}
 	}
 
-do_send:
 	/* Start filling in the page buffers with the rndis hdr */
 	rndis_msg->msg_len += rndis_msg_size;
 	packet->total_data_buflen = rndis_msg->msg_len;

Signature · 1 line

2.9.3

Stephen Hemminger

author

2016-10-12 16:58 UTC #1 lore raw

PATCH v2 1/1 netvsc: fix checksum on UDP IPV6

From: Stephen Hemminger <[email protected]>

The software calculation of UDP checksum in Netvsc driver was only handling IPv4 case. Instead, use common code to recompute checksum as needed for all protocols.

Signed-off-by Stephen Hemminger <[email protected]>

---
v2 remove accidental udp.h inclusion

 drivers/net/hyperv/netvsc_drv.c | 71 ++++++++++++-----------------------------
 1 file changed, 21 insertions(+), 50 deletions(-)

drivers/net/hyperv/netvsc_drv.c +21 ~~-50~~

index 52eeb2f..f0919bd 100644
@@ -442,8 +442,6 @@ static int netvsc_start_xmit(struct sk_buff *skb, struct net_device *net)
 	}
 
 	net_trans_info = get_net_transport_info(skb, &hdr_offset);
-	if (net_trans_info == TRANSPORT_INFO_NOT_IP)
-		goto do_send;
 
 	/*
 	 * Setup the sendside checksum offload only if this is not a

@@ -478,56 +476,29 @@ static int netvsc_start_xmit(struct sk_buff *skb, struct net_device *net)
 		}
 		lso_info->lso_v2_transmit.tcp_header_offset = hdr_offset;
 		lso_info->lso_v2_transmit.mss = skb_shinfo(skb)->gso_size;
-		goto do_send;
-	}
-
-	if ((skb->ip_summed == CHECKSUM_NONE) ||
-	    (skb->ip_summed == CHECKSUM_UNNECESSARY))
-		goto do_send;
-
-	rndis_msg_size += NDIS_CSUM_PPI_SIZE;
-	ppi = init_ppi_data(rndis_msg, NDIS_CSUM_PPI_SIZE,
-			    TCPIP_CHKSUM_PKTINFO);
-
-	csum_info = (struct ndis_tcp_ip_checksum_info *)((void *)ppi +
-			ppi->ppi_offset);
-
-	if (net_trans_info & (INFO_IPV4 << 16))
-		csum_info->transmit.is_ipv4 = 1;
-	else
-		csum_info->transmit.is_ipv6 = 1;
-
-	if (net_trans_info & INFO_TCP) {
-		csum_info->transmit.tcp_checksum = 1;
-		csum_info->transmit.tcp_header_offset = hdr_offset;
-	} else if (net_trans_info & INFO_UDP) {
-		/* UDP checksum offload is not supported on ws2008r2.
-		 * Furthermore, on ws2012 and ws2012r2, there are some
-		 * issues with udp checksum offload from Linux guests.
-		 * (these are host issues).
-		 * For now compute the checksum here.
-		 */
-		struct udphdr *uh;
-		u16 udp_len;
-
-		ret = skb_cow_head(skb, 0);
-		if (ret)
-			goto no_memory;
-
-		uh = udp_hdr(skb);
-		udp_len = ntohs(uh->len);
-		uh->check = 0;
-		uh->check = csum_tcpudp_magic(ip_hdr(skb)->saddr,
-					      ip_hdr(skb)->daddr,
-					      udp_len, IPPROTO_UDP,
-					      csum_partial(uh, udp_len, 0));
-		if (uh->check == 0)
-			uh->check = CSUM_MANGLED_0;
-
-		csum_info->transmit.udp_checksum = 0;
+	} else if (skb->ip_summed == CHECKSUM_PARTIAL) {
+		if (net_trans_info & INFO_TCP) {
+			rndis_msg_size += NDIS_CSUM_PPI_SIZE;
+			ppi = init_ppi_data(rndis_msg, NDIS_CSUM_PPI_SIZE,
+					    TCPIP_CHKSUM_PKTINFO);
+
+			csum_info = (struct ndis_tcp_ip_checksum_info *)((void *)ppi +
+									 ppi->ppi_offset);
+
+			if (net_trans_info & (INFO_IPV4 << 16))
+				csum_info->transmit.is_ipv4 = 1;
+			else
+				csum_info->transmit.is_ipv6 = 1;
+
+			csum_info->transmit.tcp_checksum = 1;
+			csum_info->transmit.tcp_header_offset = hdr_offset;
+		} else {
+			/* UDP checksum (and other) offload is not supported. */
+			if (skb_checksum_help(skb))
+				goto drop;
+		}
 	}
 
-do_send:
 	/* Start filling in the page buffers with the rndis hdr */
 	rndis_msg->msg_len += rndis_msg_size;
 	packet->total_data_buflen = rndis_msg->msg_len;

Signature · 1 line

2.9.3

David Miller

maintainer

2016-10-13 14:48 UTC #2 lore raw

In reply to Stephen Hemminger

From: Stephen Hemminger <[email protected]>
Date: Tue, 11 Oct 2016 14:03:07 -0700

Quoted 5 lines

The software calculation of UDP checksum in Netvsc driver was only handling IPv4 case. By using skb_checksum_help() instead all protocols can be handled. Rearrange code to eliminate goto and look like other drivers.

Quoted 7 lines

This is a temporary solution; recent versions of Window Server etc do support UDP checksum offload, just need to do the appropriate negotiation with host to validate before using. This will be done in later patch.
Please queue this for -stable as well.
Signed-off-by Stephen Hemminger <[email protected]>

Applied and queued up for -stable, thanks Stephen.