diff options
| -rw-r--r-- | tcp_vu.c | 64 |
1 files changed, 28 insertions, 36 deletions
@@ -298,49 +298,41 @@ static void tcp_vu_prepare(const struct ctx *c, struct tcp_tap_conn *conn, bool v6 = !(inany_v4(&toside->eaddr) && inany_v4(&toside->oaddr)); size_t hdrlen = tcp_vu_hdrlen(v6); struct iov_tail payload = IOV_TAIL(iov, iov_cnt, hdrlen); - char *base = iov[0].iov_base; - struct ipv6hdr *ip6h = NULL; - struct iphdr *ip4h = NULL; - struct tcphdr *th; - struct ethhdr *eh; - - /* we guess the first iovec provided by the guest can embed - * all the headers needed by L2 frame, including any padding - */ - assert(iov[0].iov_len >= hdrlen); - - eh = vu_eth(base); - - memcpy(eh->h_dest, c->guest_mac, sizeof(eh->h_dest)); + struct tcphdr th = { + .doff = sizeof(th) / 4, + .ack = 1, + .psh = push, + }; + struct iov_tail l2frame; + struct ipv6hdr ip6h; + struct iphdr ip4h; + struct ethhdr eh; + + memcpy(eh.h_dest, c->guest_mac, sizeof(eh.h_dest)); /* initialize header */ - if (!v6) { - eh->h_proto = htons(ETH_P_IP); - - ip4h = vu_ip(base); - *ip4h = (struct iphdr)L2_BUF_IP4_INIT(IPPROTO_TCP); - th = vu_payloadv4(base); - } else { - eh->h_proto = htons(ETH_P_IPV6); - - ip6h = vu_ip(base); - *ip6h = (struct ipv6hdr)L2_BUF_IP6_INIT(IPPROTO_TCP); + if (!v6) + ip4h = (struct iphdr)L2_BUF_IP4_INIT(IPPROTO_TCP); + else + ip6h = (struct ipv6hdr)L2_BUF_IP6_INIT(IPPROTO_TCP); - th = vu_payloadv6(base); - } + tcp_fill_headers(c, conn, &eh, v6 ? NULL : &ip4h, v6 ? &ip6h : NULL, &th, + &payload, dlen, *csum_flags, conn->seq_to_tap); - memset(th, 0, sizeof(*th)); - th->doff = sizeof(*th) / 4; - th->ack = 1; - th->psh = push; + /* Preserve TCP_CSUM, overwrite IP4_CSUM as we set the checksum */ + if (!v6) + *csum_flags = (*csum_flags & TCP_CSUM) | ip4h.check; - tcp_fill_headers(c, conn, eh, ip4h, ip6h, th, &payload, dlen, - *csum_flags, conn->seq_to_tap); + /* write headers */ + l2frame = IOV_TAIL(iov, iov_cnt, VNET_HLEN); - /* Preserve TCP_CSUM, overwrite IP4_CSUM as we set the checksum */ - if (ip4h) - *csum_flags = (*csum_flags & TCP_CSUM) | ip4h->check; + IOV_PUSH_HEADER(&l2frame, eh); + if (!v6) + IOV_PUSH_HEADER(&l2frame, ip4h); + else + IOV_PUSH_HEADER(&l2frame, ip6h); + IOV_PUSH_HEADER(&l2frame, th); } /** |