[PATCH v3 0/2] Allow UDP and TCP checksum to be disabled

[PATCH v3 0/2] Allow UDP and TCP checksum to be disabled

[Laurent Vivier]

With vhost-user we can disable the checksum of UDP and TCP.

Add a generic parameter for each of them to disable the
checksum.

v3: align parameters description with tab
    s/O/0/

v2: s/UPD/UDP/
    Add David's R-b in PATCH 2

Laurent Vivier (2):
  udp: Allow checksum to be disabled
  tcp: Allow checksum to be disabled

 tcp.c          | 52 ++++++++++++++++++++++++++------------------
 tcp_buf.c      |  8 ++++---
 tcp_internal.h |  3 ++-
 udp.c          | 58 ++++++++++++++++++++++++++++++++++----------------
 4 files changed, 78 insertions(+), 43 deletions(-)

-- 
2.46.0

[PATCH v3 1/2] udp: Allow checksum to be disabled

[Laurent Vivier]

We can need not to set the UDP checksum. Add a parameter to
udp_update_hdr4() and udp_update_hdr6() to disable it.

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
---

Notes:
    v3: align parameters description with tab
        s/O/0/
    
    v2: s/UPD/UDP/

 udp.c | 58 ++++++++++++++++++++++++++++++++++++++++------------------
 1 file changed, 40 insertions(+), 18 deletions(-)

diff --git a/udp.c b/udp.c
index 2ba00c9c20a8..7b2831386db8 100644
--- a/udp.c
+++ b/udp.c
@@ -294,15 +294,17 @@ static void udp_splice_send(const struct ctx *c, size_t start, size_t n,
 
 /**
  * udp_update_hdr4() - Update headers for one IPv4 datagram
- * @ip4h:	Pre-filled IPv4 header (except for tot_len and saddr)
- * @bp:		Pointer to udp_payload_t to update
- * @toside:	Flowside for destination side
- * @dlen:	Length of UDP payload
+ * @ip4h:		Pre-filled IPv4 header (except for tot_len and saddr)
+ * @bp:			Pointer to udp_payload_t to update
+ * @toside:		Flowside for destination side
+ * @dlen:		Length of UDP payload
+ * @no_udp_csum:	Do not set UDP checksum
  *
  * Return: size of IPv4 payload (UDP header + data)
  */
 static size_t udp_update_hdr4(struct iphdr *ip4h, struct udp_payload_t *bp,
-			      const struct flowside *toside, size_t dlen)
+			      const struct flowside *toside, size_t dlen,
+			      bool no_udp_csum)
 {
 	const struct in_addr *src = inany_v4(&toside->oaddr);
 	const struct in_addr *dst = inany_v4(&toside->eaddr);
@@ -319,22 +321,28 @@ static size_t udp_update_hdr4(struct iphdr *ip4h, struct udp_payload_t *bp,
 	bp->uh.source = htons(toside->oport);
 	bp->uh.dest = htons(toside->eport);
 	bp->uh.len = htons(l4len);
-	csum_udp4(&bp->uh, *src, *dst, bp->data, dlen);
+	if (no_udp_csum)
+		bp->uh.check = 0;
+	else
+		csum_udp4(&bp->uh, *src, *dst, bp->data, dlen);
 
 	return l4len;
 }
 
 /**
  * udp_update_hdr6() - Update headers for one IPv6 datagram
- * @ip6h:	Pre-filled IPv6 header (except for payload_len and addresses)
- * @bp:		Pointer to udp_payload_t to update
- * @toside:	Flowside for destination side
- * @dlen:	Length of UDP payload
+ * @ip6h:		Pre-filled IPv6 header (except for payload_len and
+ * 			addresses)
+ * @bp:			Pointer to udp_payload_t to update
+ * @toside:		Flowside for destination side
+ * @dlen:		Length of UDP payload
+ * @no_udp_csum:	Do not set UDP checksum
  *
  * Return: size of IPv6 payload (UDP header + data)
  */
 static size_t udp_update_hdr6(struct ipv6hdr *ip6h, struct udp_payload_t *bp,
-			      const struct flowside *toside, size_t dlen)
+			      const struct flowside *toside, size_t dlen,
+			      bool no_udp_csum)
 {
 	uint16_t l4len = dlen + sizeof(bp->uh);
 
@@ -348,7 +356,16 @@ static size_t udp_update_hdr6(struct ipv6hdr *ip6h, struct udp_payload_t *bp,
 	bp->uh.source = htons(toside->oport);
 	bp->uh.dest = htons(toside->eport);
 	bp->uh.len = ip6h->payload_len;
-	csum_udp6(&bp->uh, &toside->oaddr.a6, &toside->eaddr.a6, bp->data, dlen);
+	if (no_udp_csum) {
+		/* 0 is an invalid checksum for UDP IPv6 and dropped by
+		 * the kernel stack, even if the checksum is disabled by virtio
+		 * flags. We need to put any non-zero value here.
+		 */
+		bp->uh.check = 0xffff;
+	} else {
+		csum_udp6(&bp->uh, &toside->oaddr.a6, &toside->eaddr.a6,
+			  bp->data, dlen);
+	}
 
 	return l4len;
 }
@@ -358,9 +375,11 @@ static size_t udp_update_hdr6(struct ipv6hdr *ip6h, struct udp_payload_t *bp,
  * @mmh:	Receiving mmsghdr array
  * @idx:	Index of the datagram to prepare
  * @toside:	Flowside for destination side
+ * @no_udp_csum: Do not set UDP checksum
  */
-static void udp_tap_prepare(const struct mmsghdr *mmh, unsigned idx,
-			    const struct flowside *toside)
+static void udp_tap_prepare(const struct mmsghdr *mmh,
+			    unsigned idx, const struct flowside *toside,
+			    bool no_udp_csum)
 {
 	struct iovec (*tap_iov)[UDP_NUM_IOVS] = &udp_l2_iov[idx];
 	struct udp_payload_t *bp = &udp_payload[idx];
@@ -368,13 +387,15 @@ static void udp_tap_prepare(const struct mmsghdr *mmh, unsigned idx,
 	size_t l4len;
 
 	if (!inany_v4(&toside->eaddr) || !inany_v4(&toside->oaddr)) {
-		l4len = udp_update_hdr6(&bm->ip6h, bp, toside, mmh[idx].msg_len);
+		l4len = udp_update_hdr6(&bm->ip6h, bp, toside,
+					mmh[idx].msg_len, no_udp_csum);
 		tap_hdr_update(&bm->taph, l4len + sizeof(bm->ip6h) +
 			       sizeof(udp6_eth_hdr));
 		(*tap_iov)[UDP_IOV_ETH] = IOV_OF_LVALUE(udp6_eth_hdr);
 		(*tap_iov)[UDP_IOV_IP] = IOV_OF_LVALUE(bm->ip6h);
 	} else {
-		l4len = udp_update_hdr4(&bm->ip4h, bp, toside, mmh[idx].msg_len);
+		l4len = udp_update_hdr4(&bm->ip4h, bp, toside,
+					mmh[idx].msg_len, no_udp_csum);
 		tap_hdr_update(&bm->taph, l4len + sizeof(bm->ip4h) +
 			       sizeof(udp4_eth_hdr));
 		(*tap_iov)[UDP_IOV_ETH] = IOV_OF_LVALUE(udp4_eth_hdr);
@@ -565,7 +586,8 @@ void udp_listen_sock_handler(const struct ctx *c, union epoll_ref ref,
 				udp_splice_prepare(udp_mh_recv, i);
 			} else if (batchpif == PIF_TAP) {
 				udp_tap_prepare(udp_mh_recv, i,
-						flowside_at_sidx(batchsidx));
+						flowside_at_sidx(batchsidx),
+						false);
 			}
 
 			if (++i >= n)
@@ -636,7 +658,7 @@ void udp_reply_sock_handler(const struct ctx *c, union epoll_ref ref,
 		if (pif_is_socket(topif))
 			udp_splice_prepare(udp_mh_recv, i);
 		else if (topif == PIF_TAP)
-			udp_tap_prepare(udp_mh_recv, i, toside);
+			udp_tap_prepare(udp_mh_recv, i, toside, false);
 		/* Restore sockaddr length clobbered by recvmsg() */
 		udp_mh_recv[i].msg_hdr.msg_namelen = sizeof(udp_meta[i].s_in);
 	}
-- 
@@ -294,15 +294,17 @@ static void udp_splice_send(const struct ctx *c, size_t start, size_t n,
 
 /**
  * udp_update_hdr4() - Update headers for one IPv4 datagram
- * @ip4h:	Pre-filled IPv4 header (except for tot_len and saddr)
- * @bp:		Pointer to udp_payload_t to update
- * @toside:	Flowside for destination side
- * @dlen:	Length of UDP payload
+ * @ip4h:		Pre-filled IPv4 header (except for tot_len and saddr)
+ * @bp:			Pointer to udp_payload_t to update
+ * @toside:		Flowside for destination side
+ * @dlen:		Length of UDP payload
+ * @no_udp_csum:	Do not set UDP checksum
  *
  * Return: size of IPv4 payload (UDP header + data)
  */
 static size_t udp_update_hdr4(struct iphdr *ip4h, struct udp_payload_t *bp,
-			      const struct flowside *toside, size_t dlen)
+			      const struct flowside *toside, size_t dlen,
+			      bool no_udp_csum)
 {
 	const struct in_addr *src = inany_v4(&toside->oaddr);
 	const struct in_addr *dst = inany_v4(&toside->eaddr);
@@ -319,22 +321,28 @@ static size_t udp_update_hdr4(struct iphdr *ip4h, struct udp_payload_t *bp,
 	bp->uh.source = htons(toside->oport);
 	bp->uh.dest = htons(toside->eport);
 	bp->uh.len = htons(l4len);
-	csum_udp4(&bp->uh, *src, *dst, bp->data, dlen);
+	if (no_udp_csum)
+		bp->uh.check = 0;
+	else
+		csum_udp4(&bp->uh, *src, *dst, bp->data, dlen);
 
 	return l4len;
 }
 
 /**
  * udp_update_hdr6() - Update headers for one IPv6 datagram
- * @ip6h:	Pre-filled IPv6 header (except for payload_len and addresses)
- * @bp:		Pointer to udp_payload_t to update
- * @toside:	Flowside for destination side
- * @dlen:	Length of UDP payload
+ * @ip6h:		Pre-filled IPv6 header (except for payload_len and
+ * 			addresses)
+ * @bp:			Pointer to udp_payload_t to update
+ * @toside:		Flowside for destination side
+ * @dlen:		Length of UDP payload
+ * @no_udp_csum:	Do not set UDP checksum
  *
  * Return: size of IPv6 payload (UDP header + data)
  */
 static size_t udp_update_hdr6(struct ipv6hdr *ip6h, struct udp_payload_t *bp,
-			      const struct flowside *toside, size_t dlen)
+			      const struct flowside *toside, size_t dlen,
+			      bool no_udp_csum)
 {
 	uint16_t l4len = dlen + sizeof(bp->uh);
 
@@ -348,7 +356,16 @@ static size_t udp_update_hdr6(struct ipv6hdr *ip6h, struct udp_payload_t *bp,
 	bp->uh.source = htons(toside->oport);
 	bp->uh.dest = htons(toside->eport);
 	bp->uh.len = ip6h->payload_len;
-	csum_udp6(&bp->uh, &toside->oaddr.a6, &toside->eaddr.a6, bp->data, dlen);
+	if (no_udp_csum) {
+		/* 0 is an invalid checksum for UDP IPv6 and dropped by
+		 * the kernel stack, even if the checksum is disabled by virtio
+		 * flags. We need to put any non-zero value here.
+		 */
+		bp->uh.check = 0xffff;
+	} else {
+		csum_udp6(&bp->uh, &toside->oaddr.a6, &toside->eaddr.a6,
+			  bp->data, dlen);
+	}
 
 	return l4len;
 }
@@ -358,9 +375,11 @@ static size_t udp_update_hdr6(struct ipv6hdr *ip6h, struct udp_payload_t *bp,
  * @mmh:	Receiving mmsghdr array
  * @idx:	Index of the datagram to prepare
  * @toside:	Flowside for destination side
+ * @no_udp_csum: Do not set UDP checksum
  */
-static void udp_tap_prepare(const struct mmsghdr *mmh, unsigned idx,
-			    const struct flowside *toside)
+static void udp_tap_prepare(const struct mmsghdr *mmh,
+			    unsigned idx, const struct flowside *toside,
+			    bool no_udp_csum)
 {
 	struct iovec (*tap_iov)[UDP_NUM_IOVS] = &udp_l2_iov[idx];
 	struct udp_payload_t *bp = &udp_payload[idx];
@@ -368,13 +387,15 @@ static void udp_tap_prepare(const struct mmsghdr *mmh, unsigned idx,
 	size_t l4len;
 
 	if (!inany_v4(&toside->eaddr) || !inany_v4(&toside->oaddr)) {
-		l4len = udp_update_hdr6(&bm->ip6h, bp, toside, mmh[idx].msg_len);
+		l4len = udp_update_hdr6(&bm->ip6h, bp, toside,
+					mmh[idx].msg_len, no_udp_csum);
 		tap_hdr_update(&bm->taph, l4len + sizeof(bm->ip6h) +
 			       sizeof(udp6_eth_hdr));
 		(*tap_iov)[UDP_IOV_ETH] = IOV_OF_LVALUE(udp6_eth_hdr);
 		(*tap_iov)[UDP_IOV_IP] = IOV_OF_LVALUE(bm->ip6h);
 	} else {
-		l4len = udp_update_hdr4(&bm->ip4h, bp, toside, mmh[idx].msg_len);
+		l4len = udp_update_hdr4(&bm->ip4h, bp, toside,
+					mmh[idx].msg_len, no_udp_csum);
 		tap_hdr_update(&bm->taph, l4len + sizeof(bm->ip4h) +
 			       sizeof(udp4_eth_hdr));
 		(*tap_iov)[UDP_IOV_ETH] = IOV_OF_LVALUE(udp4_eth_hdr);
@@ -565,7 +586,8 @@ void udp_listen_sock_handler(const struct ctx *c, union epoll_ref ref,
 				udp_splice_prepare(udp_mh_recv, i);
 			} else if (batchpif == PIF_TAP) {
 				udp_tap_prepare(udp_mh_recv, i,
-						flowside_at_sidx(batchsidx));
+						flowside_at_sidx(batchsidx),
+						false);
 			}
 
 			if (++i >= n)
@@ -636,7 +658,7 @@ void udp_reply_sock_handler(const struct ctx *c, union epoll_ref ref,
 		if (pif_is_socket(topif))
 			udp_splice_prepare(udp_mh_recv, i);
 		else if (topif == PIF_TAP)
-			udp_tap_prepare(udp_mh_recv, i, toside);
+			udp_tap_prepare(udp_mh_recv, i, toside, false);
 		/* Restore sockaddr length clobbered by recvmsg() */
 		udp_mh_recv[i].msg_hdr.msg_namelen = sizeof(udp_meta[i].s_in);
 	}
-- 
2.46.0

[PATCH v3 2/2] tcp: Allow checksum to be disabled

[Laurent Vivier]

We can need not to set TCP checksum. Add a parameter to
tcp_fill_headers4() and tcp_fill_headers6() to disable it.

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
---

Notes:
    v3: align parameters description with tab

 tcp.c          | 52 ++++++++++++++++++++++++++++++--------------------
 tcp_buf.c      |  8 +++++---
 tcp_internal.h |  3 ++-
 3 files changed, 38 insertions(+), 25 deletions(-)

diff --git a/tcp.c b/tcp.c
index f9fe1b9a1330..7307ea74f25c 100644
--- a/tcp.c
+++ b/tcp.c
@@ -896,13 +896,14 @@ static void tcp_fill_header(struct tcphdr *th,
 
 /**
  * tcp_fill_headers4() - Fill 802.3, IPv4, TCP headers in pre-cooked buffers
- * @conn:	Connection pointer
- * @taph:	tap backend specific header
- * @iph:	Pointer to IPv4 header
- * @th:		Pointer to TCP header
- * @dlen:	TCP payload length
- * @check:	Checksum, if already known
- * @seq:	Sequence number for this segment
+ * @conn:		Connection pointer
+ * @taph:		tap backend specific header
+ * @iph:		Pointer to IPv4 header
+ * @th:			Pointer to TCP header
+ * @dlen:		TCP payload length
+ * @check:		Checksum, if already known
+ * @seq:		Sequence number for this segment
+ * @no_tcp_csum:	Do not set TCP checksum
  *
  * Return: The IPv4 payload length, host order
  */
@@ -910,7 +911,7 @@ static size_t tcp_fill_headers4(const struct tcp_tap_conn *conn,
 				struct tap_hdr *taph,
 				struct iphdr *iph, struct tcphdr *th,
 				size_t dlen, const uint16_t *check,
-				uint32_t seq)
+				uint32_t seq, bool no_tcp_csum)
 {
 	const struct flowside *tapside = TAPFLOW(conn);
 	const struct in_addr *src4 = inany_v4(&tapside->oaddr);
@@ -929,7 +930,10 @@ static size_t tcp_fill_headers4(const struct tcp_tap_conn *conn,
 
 	tcp_fill_header(th, conn, seq);
 
-	tcp_update_check_tcp4(iph, th);
+	if (no_tcp_csum)
+		th->check = 0;
+	else
+		tcp_update_check_tcp4(iph, th);
 
 	tap_hdr_update(taph, l3len + sizeof(struct ethhdr));
 
@@ -938,20 +942,21 @@ static size_t tcp_fill_headers4(const struct tcp_tap_conn *conn,
 
 /**
  * tcp_fill_headers6() - Fill 802.3, IPv6, TCP headers in pre-cooked buffers
- * @conn:	Connection pointer
- * @taph:	tap backend specific header
- * @ip6h:	Pointer to IPv6 header
- * @th:		Pointer to TCP header
- * @dlen:	TCP payload length
- * @check:	Checksum, if already known
- * @seq:	Sequence number for this segment
+ * @conn:		Connection pointer
+ * @taph:		tap backend specific header
+ * @ip6h:		Pointer to IPv6 header
+ * @th:			Pointer to TCP header
+ * @dlen:		TCP payload length
+ * @check:		Checksum, if already known
+ * @seq:		Sequence number for this segment
+ * @no_tcp_csum:	Do not set TCP checksum
  *
  * Return: The IPv6 payload length, host order
  */
 static size_t tcp_fill_headers6(const struct tcp_tap_conn *conn,
 				struct tap_hdr *taph,
 				struct ipv6hdr *ip6h, struct tcphdr *th,
-				size_t dlen, uint32_t seq)
+				size_t dlen, uint32_t seq, bool no_tcp_csum)
 {
 	const struct flowside *tapside = TAPFLOW(conn);
 	size_t l4len = dlen + sizeof(*th);
@@ -970,7 +975,10 @@ static size_t tcp_fill_headers6(const struct tcp_tap_conn *conn,
 
 	tcp_fill_header(th, conn, seq);
 
-	tcp_update_check_tcp6(ip6h, th);
+	if (no_tcp_csum)
+		th->check = 0;
+	else
+		tcp_update_check_tcp6(ip6h, th);
 
 	tap_hdr_update(taph, l4len + sizeof(*ip6h) + sizeof(struct ethhdr));
 
@@ -984,12 +992,14 @@ static size_t tcp_fill_headers6(const struct tcp_tap_conn *conn,
  * @dlen:	TCP payload length
  * @check:	Checksum, if already known
  * @seq:	Sequence number for this segment
+ * @no_tcp_csum: Do not set TCP checksum
  *
  * Return: IP payload length, host order
  */
 size_t tcp_l2_buf_fill_headers(const struct tcp_tap_conn *conn,
 			       struct iovec *iov, size_t dlen,
-			       const uint16_t *check, uint32_t seq)
+			       const uint16_t *check, uint32_t seq,
+			       bool no_tcp_csum)
 {
 	const struct flowside *tapside = TAPFLOW(conn);
 	const struct in_addr *a4 = inany_v4(&tapside->oaddr);
@@ -998,13 +1008,13 @@ size_t tcp_l2_buf_fill_headers(const struct tcp_tap_conn *conn,
 		return tcp_fill_headers4(conn, iov[TCP_IOV_TAP].iov_base,
 					 iov[TCP_IOV_IP].iov_base,
 					 iov[TCP_IOV_PAYLOAD].iov_base, dlen,
-					 check, seq);
+					 check, seq, no_tcp_csum);
 	}
 
 	return tcp_fill_headers6(conn, iov[TCP_IOV_TAP].iov_base,
 				 iov[TCP_IOV_IP].iov_base,
 				 iov[TCP_IOV_PAYLOAD].iov_base, dlen,
-				 seq);
+				 seq, no_tcp_csum);
 }
 
 /**
diff --git a/tcp_buf.c b/tcp_buf.c
index 1a398461a34b..10a663bdfc26 100644
--- a/tcp_buf.c
+++ b/tcp_buf.c
@@ -320,7 +320,7 @@ int tcp_buf_send_flag(struct ctx *c, struct tcp_tap_conn *conn, int flags)
 		return ret;
 	}
 
-	l4len = tcp_l2_buf_fill_headers(conn, iov, optlen, NULL, seq);
+	l4len = tcp_l2_buf_fill_headers(conn, iov, optlen, NULL, seq, false);
 	iov[TCP_IOV_PAYLOAD].iov_len = l4len;
 
 	if (flags & DUP_ACK) {
@@ -381,7 +381,8 @@ static void tcp_data_to_tap(struct ctx *c, struct tcp_tap_conn *conn,
 		tcp4_frame_conns[tcp4_payload_used] = conn;
 
 		iov = tcp4_l2_iov[tcp4_payload_used++];
-		l4len = tcp_l2_buf_fill_headers(conn, iov, dlen, check, seq);
+		l4len = tcp_l2_buf_fill_headers(conn, iov, dlen, check, seq,
+						false);
 		iov[TCP_IOV_PAYLOAD].iov_len = l4len;
 		if (tcp4_payload_used > TCP_FRAMES_MEM - 1)
 			tcp_payload_flush(c);
@@ -389,7 +390,8 @@ static void tcp_data_to_tap(struct ctx *c, struct tcp_tap_conn *conn,
 		tcp6_frame_conns[tcp6_payload_used] = conn;
 
 		iov = tcp6_l2_iov[tcp6_payload_used++];
-		l4len = tcp_l2_buf_fill_headers(conn, iov, dlen, NULL, seq);
+		l4len = tcp_l2_buf_fill_headers(conn, iov, dlen, NULL, seq,
+						false);
 		iov[TCP_IOV_PAYLOAD].iov_len = l4len;
 		if (tcp6_payload_used > TCP_FRAMES_MEM - 1)
 			tcp_payload_flush(c);
diff --git a/tcp_internal.h b/tcp_internal.h
index aa8bb64f1f33..e7fe735bfcb4 100644
--- a/tcp_internal.h
+++ b/tcp_internal.h
@@ -91,7 +91,8 @@ void tcp_rst_do(struct ctx *c, struct tcp_tap_conn *conn);
 
 size_t tcp_l2_buf_fill_headers(const struct tcp_tap_conn *conn,
 			       struct iovec *iov, size_t dlen,
-			       const uint16_t *check, uint32_t seq);
+			       const uint16_t *check, uint32_t seq,
+			       bool no_tcp_csum);
 int tcp_update_seqack_wnd(const struct ctx *c, struct tcp_tap_conn *conn,
 			  int force_seq, struct tcp_info *tinfo);
 int tcp_prepare_flags(struct ctx *c, struct tcp_tap_conn *conn, int flags,
-- 
@@ -91,7 +91,8 @@ void tcp_rst_do(struct ctx *c, struct tcp_tap_conn *conn);
 
 size_t tcp_l2_buf_fill_headers(const struct tcp_tap_conn *conn,
 			       struct iovec *iov, size_t dlen,
-			       const uint16_t *check, uint32_t seq);
+			       const uint16_t *check, uint32_t seq,
+			       bool no_tcp_csum);
 int tcp_update_seqack_wnd(const struct ctx *c, struct tcp_tap_conn *conn,
 			  int force_seq, struct tcp_info *tinfo);
 int tcp_prepare_flags(struct ctx *c, struct tcp_tap_conn *conn, int flags,
-- 
2.46.0

Re: [PATCH v3 0/2] Allow UDP and TCP checksum to be disabled

[Stefano Brivio]

On Wed, 18 Sep 2024 15:13:26 +0200
Laurent Vivier <lvivier@redhat.com> wrote:

> With vhost-user we can disable the checksum of UDP and TCP.
> 
> Add a generic parameter for each of them to disable the
> checksum.
> 
> v3: align parameters description with tab
>     s/O/0/
> 
> v2: s/UPD/UDP/
>     Add David's R-b in PATCH 2
> 
> Laurent Vivier (2):
>   udp: Allow checksum to be disabled
>   tcp: Allow checksum to be disabled

Applied.

-- 
Stefano