From 68d1b0a1528d6efd0d94afa43e9fc4b4857ca694 Mon Sep 17 00:00:00 2001 From: David Gibson Date: Wed, 1 May 2024 16:53:50 +1000 Subject: tcp: Simplify packet length calculation when preparing headers tcp_fill_headers[46]() compute the L3 packet length from the L4 packet length, then their caller tcp_l2_buf_fill_headers() converts it back to the L4 packet length. We can just use the L4 length throughout. Signed-off-by: David Gibson eewwee Signed-off-by: Stefano Brivio --- tcp.c | 26 ++++++++++---------------- 1 file changed, 10 insertions(+), 16 deletions(-) (limited to 'tcp.c') diff --git a/tcp.c b/tcp.c index f8b31c1..43206d0 100644 --- a/tcp.c +++ b/tcp.c @@ -1341,7 +1341,7 @@ static void tcp_fill_header(struct tcphdr *th, * @check: Checksum, if already known * @seq: Sequence number for this segment * - * Return: The total length of the IPv4 packet, host order + * Return: The IPv4 payload length, host order */ static size_t tcp_fill_headers4(const struct ctx *c, const struct tcp_tap_conn *conn, @@ -1367,7 +1367,7 @@ static size_t tcp_fill_headers4(const struct ctx *c, tcp_update_check_tcp4(iph, th); - return l3len; + return l4len; } /** @@ -1380,7 +1380,7 @@ static size_t tcp_fill_headers4(const struct ctx *c, * @check: Checksum, if already known * @seq: Sequence number for this segment * - * Return: The total length of the IPv6 packet, host order + * Return: The IPv6 payload length, host order */ static size_t tcp_fill_headers6(const struct ctx *c, const struct tcp_tap_conn *conn, @@ -1388,7 +1388,6 @@ static size_t tcp_fill_headers6(const struct ctx *c, size_t dlen, uint32_t seq) { size_t l4len = dlen + sizeof(*th); - size_t l3len = l4len + sizeof(*ip6h); ip6h->payload_len = htons(l4len); ip6h->saddr = conn->faddr.a6; @@ -1409,7 +1408,7 @@ static size_t tcp_fill_headers6(const struct ctx *c, tcp_update_check_tcp6(ip6h, th); - return l3len; + return l4len; } /** @@ -1429,21 +1428,16 @@ static size_t tcp_l2_buf_fill_headers(const struct ctx *c, const uint16_t *check, uint32_t seq) { const struct in_addr *a4 = inany_v4(&conn->faddr); - size_t l3len, l4len; if (a4) { - l3len = tcp_fill_headers4(c, conn, iov[TCP_IOV_IP].iov_base, - iov[TCP_IOV_PAYLOAD].iov_base, dlen, - check, seq); - l4len = l3len - sizeof(struct iphdr); - } else { - l3len = tcp_fill_headers6(c, conn, iov[TCP_IOV_IP].iov_base, - iov[TCP_IOV_PAYLOAD].iov_base, dlen, - seq); - l4len = l3len - sizeof(struct ipv6hdr); + return tcp_fill_headers4(c, conn, iov[TCP_IOV_IP].iov_base, + iov[TCP_IOV_PAYLOAD].iov_base, dlen, + check, seq); } - return l4len; + return tcp_fill_headers6(c, conn, iov[TCP_IOV_IP].iov_base, + iov[TCP_IOV_PAYLOAD].iov_base, dlen, + seq); } /** -- cgit v1.2.3