From: Laurent Vivier <lvivier@redhat.com>
To: passt-dev@passt.top
Cc: Laurent Vivier <lvivier@redhat.com>
Subject: [PATCH 2/2] tcp: Allow checksum to be disabled
Date: Mon, 16 Sep 2024 14:16:01 +0200 [thread overview]
Message-ID: <20240916121601.3655517-3-lvivier@redhat.com> (raw)
In-Reply-To: <20240916121601.3655517-1-lvivier@redhat.com>
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
next prev parent reply other threads:[~2024-09-16 12:16 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
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 ` Laurent Vivier [this message]
2024-09-17 1:23 ` [PATCH 2/2] tcp: " David Gibson
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