* [PATCH 0/2] Allow UDP and TCP checksum to be disabled
@ 2024-09-16 12:15 Laurent Vivier
2024-09-16 12:16 ` [PATCH 1/2] udp: Allow " Laurent Vivier
2024-09-16 12:16 ` [PATCH 2/2] tcp: " Laurent Vivier
0 siblings, 2 replies; 5+ messages in thread
From: Laurent Vivier @ 2024-09-16 12:15 UTC (permalink / raw)
To: passt-dev; +Cc: 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.
Laurent Vivier (2):
udp: Allow checksum to be disabled
tcp: Allow checksum to be disabled
tcp.c | 24 +++++++++++++++++-------
tcp_buf.c | 8 +++++---
tcp_internal.h | 3 ++-
udp.c | 41 +++++++++++++++++++++++++++++++----------
4 files changed, 55 insertions(+), 21 deletions(-)
--
2.46.0
^ permalink raw reply [flat|nested] 5+ messages in thread
* [PATCH 1/2] udp: Allow checksum to be disabled
2024-09-16 12:15 [PATCH 0/2] Allow UDP and TCP checksum to be disabled Laurent Vivier
@ 2024-09-16 12:16 ` Laurent Vivier
2024-09-17 1:23 ` David Gibson
2024-09-16 12:16 ` [PATCH 2/2] tcp: " Laurent Vivier
1 sibling, 1 reply; 5+ messages in thread
From: Laurent Vivier @ 2024-09-16 12:16 UTC (permalink / raw)
To: passt-dev; +Cc: 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>
---
udp.c | 41 +++++++++++++++++++++++++++++++----------
1 file changed, 31 insertions(+), 10 deletions(-)
diff --git a/udp.c b/udp.c
index 2ba00c9c20a8..64a0d9f9dba2 100644
--- a/udp.c
+++ b/udp.c
@@ -298,11 +298,13 @@ static void udp_splice_send(const struct ctx *c, size_t start, size_t n,
* @bp: Pointer to udp_payload_t to update
* @toside: Flowside for destination side
* @dlen: Length of UDP payload
+ * @no_udp_csum: Do not set UPD 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);
@@ -319,7 +321,10 @@ 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;
}
@@ -330,11 +335,13 @@ static size_t udp_update_hdr4(struct iphdr *ip4h, struct udp_payload_t *bp,
* @bp: Pointer to udp_payload_t to update
* @toside: Flowside for destination side
* @dlen: Length of UDP payload
+ * @no_udp_csum: Do not set UPD 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 +355,16 @@ 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) {
+ /* O 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 +374,11 @@ 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 UPD 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 +386,15 @@ 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 +585,8 @@ 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 +657,7 @@ 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);
}
--
@@ -298,11 +298,13 @@ static void udp_splice_send(const struct ctx *c, size_t start, size_t n,
* @bp: Pointer to udp_payload_t to update
* @toside: Flowside for destination side
* @dlen: Length of UDP payload
+ * @no_udp_csum: Do not set UPD 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);
@@ -319,7 +321,10 @@ 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;
}
@@ -330,11 +335,13 @@ static size_t udp_update_hdr4(struct iphdr *ip4h, struct udp_payload_t *bp,
* @bp: Pointer to udp_payload_t to update
* @toside: Flowside for destination side
* @dlen: Length of UDP payload
+ * @no_udp_csum: Do not set UPD 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 +355,16 @@ 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) {
+ /* O 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 +374,11 @@ 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 UPD 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 +386,15 @@ 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 +585,8 @@ 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 +657,7 @@ 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
^ permalink raw reply related [flat|nested] 5+ messages in thread
* [PATCH 2/2] tcp: Allow checksum to be disabled
2024-09-16 12:15 [PATCH 0/2] Allow UDP and TCP checksum to be disabled Laurent Vivier
2024-09-16 12:16 ` [PATCH 1/2] udp: Allow " Laurent Vivier
@ 2024-09-16 12:16 ` Laurent Vivier
2024-09-17 1:23 ` David Gibson
1 sibling, 1 reply; 5+ messages in thread
From: Laurent Vivier @ 2024-09-16 12:16 UTC (permalink / raw)
To: passt-dev; +Cc: 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>
---
tcp.c | 24 +++++++++++++++++-------
tcp_buf.c | 8 +++++---
tcp_internal.h | 3 ++-
3 files changed, 24 insertions(+), 11 deletions(-)
diff --git a/tcp.c b/tcp.c
index f9fe1b9a1330..a44d7b977214 100644
--- a/tcp.c
+++ b/tcp.c
@@ -903,6 +903,7 @@ static void tcp_fill_header(struct tcphdr *th,
* @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));
@@ -945,13 +949,14 @@ static size_t tcp_fill_headers4(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: 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
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH 1/2] udp: Allow checksum to be disabled
2024-09-16 12:16 ` [PATCH 1/2] udp: Allow " Laurent Vivier
@ 2024-09-17 1:23 ` David Gibson
0 siblings, 0 replies; 5+ messages in thread
From: David Gibson @ 2024-09-17 1:23 UTC (permalink / raw)
To: Laurent Vivier; +Cc: passt-dev
[-- Attachment #1: Type: text/plain, Size: 5485 bytes --]
On Mon, Sep 16, 2024 at 02:16:00PM +0200, Laurent Vivier wrote:
> 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>
> ---
> udp.c | 41 +++++++++++++++++++++++++++++++----------
> 1 file changed, 31 insertions(+), 10 deletions(-)
>
> diff --git a/udp.c b/udp.c
> index 2ba00c9c20a8..64a0d9f9dba2 100644
> --- a/udp.c
> +++ b/udp.c
> @@ -298,11 +298,13 @@ static void udp_splice_send(const struct ctx *c, size_t start, size_t n,
> * @bp: Pointer to udp_payload_t to update
> * @toside: Flowside for destination side
> * @dlen: Length of UDP payload
> + * @no_udp_csum: Do not set UPD checksum
s/UPD/UDP/g :)
Otherwise LGTM.
> *
> * 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);
> @@ -319,7 +321,10 @@ 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;
> }
> @@ -330,11 +335,13 @@ static size_t udp_update_hdr4(struct iphdr *ip4h, struct udp_payload_t *bp,
> * @bp: Pointer to udp_payload_t to update
> * @toside: Flowside for destination side
> * @dlen: Length of UDP payload
> + * @no_udp_csum: Do not set UPD 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 +355,16 @@ 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) {
> + /* O 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 +374,11 @@ 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 UPD 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 +386,15 @@ 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 +585,8 @@ 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 +657,7 @@ 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);
> }
--
David Gibson (he or they) | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you, not the other way
| around.
http://www.ozlabs.org/~dgibson
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^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH 2/2] tcp: Allow checksum to be disabled
2024-09-16 12:16 ` [PATCH 2/2] tcp: " Laurent Vivier
@ 2024-09-17 1:23 ` David Gibson
0 siblings, 0 replies; 5+ messages in thread
From: David Gibson @ 2024-09-17 1:23 UTC (permalink / raw)
To: Laurent Vivier; +Cc: passt-dev
[-- Attachment #1: Type: text/plain, Size: 6093 bytes --]
On Mon, Sep 16, 2024 at 02:16:01PM +0200, Laurent Vivier wrote:
> 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>
> ---
> tcp.c | 24 +++++++++++++++++-------
> tcp_buf.c | 8 +++++---
> tcp_internal.h | 3 ++-
> 3 files changed, 24 insertions(+), 11 deletions(-)
>
> diff --git a/tcp.c b/tcp.c
> index f9fe1b9a1330..a44d7b977214 100644
> --- a/tcp.c
> +++ b/tcp.c
> @@ -903,6 +903,7 @@ static void tcp_fill_header(struct tcphdr *th,
> * @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));
>
> @@ -945,13 +949,14 @@ static size_t tcp_fill_headers4(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: 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,
--
David Gibson (he or they) | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you, not the other way
| around.
http://www.ozlabs.org/~dgibson
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^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2024-09-17 1:24 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2024-09-16 12:15 [PATCH 0/2] Allow UDP and TCP checksum to be disabled Laurent Vivier
2024-09-16 12:16 ` [PATCH 1/2] udp: Allow " Laurent Vivier
2024-09-17 1:23 ` David Gibson
2024-09-16 12:16 ` [PATCH 2/2] tcp: " Laurent Vivier
2024-09-17 1:23 ` David Gibson
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