From 2053c36dec4ce3e5bfddb52f5f2957165a692f1d Mon Sep 17 00:00:00 2001 From: Jon Maloy Date: Mon, 28 Oct 2024 22:13:59 -0400 Subject: [PATCH] tcp: set ip and eth headers in l2 tap queues on the fly l2 tap queue entries are currently initialized at system start, and reused with preset headers through its whole life time. The only fields we need to update per message are things like payload size and checksums. If we want to reuse these entries between ipv4 and ipv6 messages we will need to set the pointer to the right header on the fly per message, since the header type may differ between entries in the same queue. The same needs to be done for the ethernet header. We do these changes here. Signed-off-by: Jon Maloy Reviewed-by: David Gibson Signed-off-by: Stefano Brivio --- tcp_buf.c | 50 ++++++++++++++++++++++++++++---------------------- 1 file changed, 28 insertions(+), 22 deletions(-) diff --git a/tcp_buf.c b/tcp_buf.c index cb6742c..e249c6b 100644 --- a/tcp_buf.c +++ b/tcp_buf.c @@ -130,8 +130,7 @@ void tcp_sock4_iov_init(const struct ctx *c) iov = tcp4_l2_iov[i]; iov[TCP_IOV_TAP] = tap_hdr_iov(c, &tcp4_payload_tap_hdr[i]); - iov[TCP_IOV_ETH] = IOV_OF_LVALUE(tcp4_eth_src); - iov[TCP_IOV_IP] = IOV_OF_LVALUE(tcp4_payload_ip[i]); + iov[TCP_IOV_ETH].iov_len = sizeof(struct ethhdr); iov[TCP_IOV_PAYLOAD].iov_base = &tcp4_payload[i]; } @@ -173,8 +172,7 @@ void tcp_sock6_iov_init(const struct ctx *c) iov = tcp6_l2_iov[i]; iov[TCP_IOV_TAP] = tap_hdr_iov(c, &tcp6_payload_tap_hdr[i]); - iov[TCP_IOV_ETH] = IOV_OF_LVALUE(tcp6_eth_src); - iov[TCP_IOV_IP] = IOV_OF_LVALUE(tcp6_payload_ip[i]); + iov[TCP_IOV_ETH].iov_len = sizeof(struct ethhdr); iov[TCP_IOV_PAYLOAD].iov_base = &tcp6_payload[i]; } @@ -273,11 +271,17 @@ int tcp_buf_send_flag(const struct ctx *c, struct tcp_tap_conn *conn, int flags) uint32_t seq; int ret; - if (CONN_V4(conn)) - iov = tcp4_l2_flags_iov[tcp4_flags_used++]; - else - iov = tcp6_l2_flags_iov[tcp6_flags_used++]; - + if (CONN_V4(conn)) { + iov = tcp4_l2_flags_iov[tcp4_flags_used]; + iov[TCP_IOV_IP] = IOV_OF_LVALUE(tcp4_flags_ip[tcp4_flags_used]); + iov[TCP_IOV_ETH].iov_base = &tcp4_eth_src; + tcp4_flags_used++; + } else { + iov = tcp6_l2_flags_iov[tcp6_flags_used]; + iov[TCP_IOV_IP] = IOV_OF_LVALUE(tcp6_flags_ip[tcp6_flags_used]); + iov[TCP_IOV_ETH].iov_base = &tcp6_eth_src; + tcp6_flags_used++; + } payload = iov[TCP_IOV_PAYLOAD].iov_base; seq = conn->seq_to_tap; @@ -296,21 +300,19 @@ int tcp_buf_send_flag(const struct ctx *c, struct tcp_tap_conn *conn, int flags) if (flags & DUP_ACK) { struct iovec *dup_iov; - int i; if (CONN_V4(conn)) dup_iov = tcp4_l2_flags_iov[tcp4_flags_used++]; else dup_iov = tcp6_l2_flags_iov[tcp6_flags_used++]; - for (i = 0; i < TCP_NUM_IOVS; i++) { - /* All frames share the same ethernet header buffer */ - if (i != TCP_IOV_ETH) { - memcpy(dup_iov[i].iov_base, iov[i].iov_base, - iov[i].iov_len); - } - } - dup_iov[TCP_IOV_PAYLOAD].iov_len = iov[TCP_IOV_PAYLOAD].iov_len; + memcpy(dup_iov[TCP_IOV_TAP].iov_base, iov[TCP_IOV_TAP].iov_base, + iov[TCP_IOV_TAP].iov_len); + dup_iov[TCP_IOV_ETH].iov_base = iov[TCP_IOV_ETH].iov_base; + dup_iov[TCP_IOV_IP] = iov[TCP_IOV_IP]; + memcpy(dup_iov[TCP_IOV_PAYLOAD].iov_base, + iov[TCP_IOV_PAYLOAD].iov_base, l4len); + dup_iov[TCP_IOV_PAYLOAD].iov_len = l4len; } if (CONN_V4(conn)) { @@ -350,8 +352,10 @@ static void tcp_data_to_tap(const struct ctx *c, struct tcp_tap_conn *conn, } tcp4_frame_conns[tcp4_payload_used] = conn; - - iov = tcp4_l2_iov[tcp4_payload_used++]; + iov = tcp4_l2_iov[tcp4_payload_used]; + iov[TCP_IOV_IP] = + IOV_OF_LVALUE(tcp4_payload_ip[tcp4_payload_used++]); + iov[TCP_IOV_ETH].iov_base = &tcp4_eth_src; l4len = tcp_l2_buf_fill_headers(conn, iov, dlen, check, seq, false); iov[TCP_IOV_PAYLOAD].iov_len = l4len; @@ -359,8 +363,10 @@ static void tcp_data_to_tap(const struct ctx *c, struct tcp_tap_conn *conn, tcp_payload_flush(c); } else if (CONN_V6(conn)) { tcp6_frame_conns[tcp6_payload_used] = conn; - - iov = tcp6_l2_iov[tcp6_payload_used++]; + iov = tcp6_l2_iov[tcp6_payload_used]; + iov[TCP_IOV_IP] = + IOV_OF_LVALUE(tcp6_payload_ip[tcp6_payload_used++]); + iov[TCP_IOV_ETH].iov_base = &tcp6_eth_src; l4len = tcp_l2_buf_fill_headers(conn, iov, dlen, NULL, seq, false); iov[TCP_IOV_PAYLOAD].iov_len = l4len;