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path: root/tcp.c
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Diffstat (limited to 'tcp.c')
-rw-r--r--tcp.c52
1 files changed, 31 insertions, 21 deletions
diff --git a/tcp.c b/tcp.c
index 787df63..1962fcc 100644
--- a/tcp.c
+++ b/tcp.c
@@ -899,13 +899,14 @@ 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
*/
@@ -913,7 +914,7 @@ 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);
@@ -932,7 +933,10 @@ 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));
@@ -941,20 +945,21 @@ 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);
@@ -973,7 +978,10 @@ 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));
@@ -987,12 +995,14 @@ 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);
@@ -1001,13 +1011,13 @@ 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);
}
/**