From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: passt.top; dmarc=none (p=none dis=none) header.from=gibson.dropbear.id.au Authentication-Results: passt.top; dkim=pass (2048-bit key; secure) header.d=gibson.dropbear.id.au header.i=@gibson.dropbear.id.au header.a=rsa-sha256 header.s=202410 header.b=o5+FSZxa; dkim-atps=neutral Received: from mail.ozlabs.org (gandalf.ozlabs.org [150.107.74.76]) by passt.top (Postfix) with ESMTPS id 81CD95A061B for ; Wed, 27 Nov 2024 04:54:28 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gibson.dropbear.id.au; s=202410; t=1732679649; bh=oDoArASoIuuJu32stYpiuvDwI78viY2D65VY3flBPCE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=o5+FSZxaTznbLBrsK0rDj34EiRF+RW8YwUsGIICUb2XzE/14dBtWuKK2u4QRs4C0X +V+x09wiTRqngD47hdpEryvN6VzFIqUIdBywu6MP3Y4q9jr05Eb9GG7tNMgLL5HSQz FP9zHPHpJ/7oxbE4JiBZ798qsZ80pILvAsaT18a2CIZpJKpnInA4EeGysb1sqw7J+w r6Ow58zVJJ5DwVuM4fH5RFFdWe3nGlCfrWIpdhP+FI50Ww2lX0ZTDDC/jLpDH6RaDJ 2bmrJg6Y/gvWe31YRqfzovEm1YY4ca23da2OT0YxYwgiiH4LyZTGHFtdu2sBsGNuWM F/j1/uNJtwJ5A== Received: by gandalf.ozlabs.org (Postfix, from userid 1007) id 4XyltT5fcdz4xgn; Wed, 27 Nov 2024 14:54:09 +1100 (AEDT) From: David Gibson To: Stefano Brivio , passt-dev@passt.top Subject: [PATCH 6/7] tcp: Merge tcp_fill_headers[46]() with each other Date: Wed, 27 Nov 2024 14:54:09 +1100 Message-ID: <20241127035410.1167773-7-david@gibson.dropbear.id.au> X-Mailer: git-send-email 2.47.0 In-Reply-To: <20241127035410.1167773-1-david@gibson.dropbear.id.au> References: <20241127035410.1167773-1-david@gibson.dropbear.id.au> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Message-ID-Hash: HKW2MS3DEYNOPZLDP2R6AMD57Z4PKPFA X-Message-ID-Hash: HKW2MS3DEYNOPZLDP2R6AMD57Z4PKPFA X-MailFrom: dgibson@gandalf.ozlabs.org X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header CC: David Gibson X-Mailman-Version: 3.3.8 Precedence: list List-Id: Development discussion and patches for passt Archived-At: Archived-At: List-Archive: List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: We have different versions of this function for IPv4 and IPv6, but the caller already requires some IP version specific code to get the right header pointers. Instead, have a common function that fills either an IPv4 or an IPv6 header based on which header pointer it is passed. This allows us to remove a small amount of code duplication and make a few slightly ugly conditionals. Signed-off-by: David Gibson --- tcp.c | 108 ++++++++++++++++++++++--------------------------- tcp_buf.c | 19 ++++----- tcp_internal.h | 13 +++--- tcp_vu.c | 32 ++++++--------- 4 files changed, 75 insertions(+), 97 deletions(-) diff --git a/tcp.c b/tcp.c index 482e460..1872ccb 100644 --- a/tcp.c +++ b/tcp.c @@ -877,94 +877,82 @@ static void tcp_fill_header(struct tcphdr *th, } /** - * tcp_fill_headers4() - Fill 802.3, IPv4, TCP headers in pre-cooked buffers + * tcp_fill_headers() - Fill 802.3, IP, TCP headers * @conn: Connection pointer * @taph: tap backend specific header - * @iph: Pointer to IPv4 header + * @ip4h: Pointer to IPv4 header, or NULL + * @ip6h: Pointer to IPv6 header, or NULL * @th: Pointer to TCP header * @payload: TCP payload - * @check: Checksum, if already known + * @ip4_check: IPv4 checksum, if already known * @seq: Sequence number for this segment * @no_tcp_csum: Do not set TCP checksum */ -void tcp_fill_headers4(const struct tcp_tap_conn *conn, - struct tap_hdr *taph, struct iphdr *iph, - struct tcphdr *th, struct iov_tail *payload, - const uint16_t *check, uint32_t seq, bool no_tcp_csum) +void tcp_fill_headers(const struct tcp_tap_conn *conn, + struct tap_hdr *taph, + struct iphdr *ip4h, struct ipv6hdr *ip6h, + struct tcphdr *th, struct iov_tail *payload, + const uint16_t *ip4_check, uint32_t seq, bool no_tcp_csum) { const struct flowside *tapside = TAPFLOW(conn); - const struct in_addr *src4 = inany_v4(&tapside->oaddr); - const struct in_addr *dst4 = inany_v4(&tapside->eaddr); size_t l4len = iov_tail_size(payload) + sizeof(*th); - size_t l3len = l4len + sizeof(*iph); + size_t l3len = l4len; + uint32_t psum = 0; - ASSERT(src4 && dst4); + if (ip4h) { + const struct in_addr *src4 = inany_v4(&tapside->oaddr); + const struct in_addr *dst4 = inany_v4(&tapside->eaddr); - iph->tot_len = htons(l3len); - iph->saddr = src4->s_addr; - iph->daddr = dst4->s_addr; + ASSERT(src4 && dst4); - iph->check = check ? *check : - csum_ip4_header(l3len, IPPROTO_TCP, *src4, *dst4); + l3len += + sizeof(*ip4h); - tcp_fill_header(th, conn, seq); + ip4h->tot_len = htons(l3len); + ip4h->saddr = src4->s_addr; + ip4h->daddr = dst4->s_addr; - if (no_tcp_csum) { - th->check = 0; - } else { - uint32_t psum = proto_ipv4_header_psum(l4len, IPPROTO_TCP, - *src4, *dst4); + if (ip4_check) + ip4h->check = *ip4_check; + else + ip4h->check = csum_ip4_header(l3len, IPPROTO_TCP, + *src4, *dst4); - tcp_update_csum(psum, th, payload); + if (!no_tcp_csum) { + psum = proto_ipv4_header_psum(l4len, IPPROTO_TCP, + *src4, *dst4); + } } - tap_hdr_update(taph, l3len + sizeof(struct ethhdr)); -} + if (ip6h) { + l3len += sizeof(*ip6h); -/** - * 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 - * @payload: TCP payload - * @check: Checksum, if already known - * @seq: Sequence number for this segment - * @no_tcp_csum: Do not set TCP checksum - */ -void tcp_fill_headers6(const struct tcp_tap_conn *conn, - struct tap_hdr *taph, struct ipv6hdr *ip6h, - struct tcphdr *th, struct iov_tail *payload, - uint32_t seq, bool no_tcp_csum) -{ - size_t l4len = iov_tail_size(payload) + sizeof(*th); - const struct flowside *tapside = TAPFLOW(conn); + ip6h->payload_len = htons(l4len); + ip6h->saddr = tapside->oaddr.a6; + ip6h->daddr = tapside->eaddr.a6; - ip6h->payload_len = htons(l4len); - ip6h->saddr = tapside->oaddr.a6; - ip6h->daddr = tapside->eaddr.a6; + ip6h->hop_limit = 255; + ip6h->version = 6; + ip6h->nexthdr = IPPROTO_TCP; - ip6h->hop_limit = 255; - ip6h->version = 6; - ip6h->nexthdr = IPPROTO_TCP; + ip6h->flow_lbl[0] = (conn->sock >> 16) & 0xf; + ip6h->flow_lbl[1] = (conn->sock >> 8) & 0xff; + ip6h->flow_lbl[2] = (conn->sock >> 0) & 0xff; - ip6h->flow_lbl[0] = (conn->sock >> 16) & 0xf; - ip6h->flow_lbl[1] = (conn->sock >> 8) & 0xff; - ip6h->flow_lbl[2] = (conn->sock >> 0) & 0xff; + if (!no_tcp_csum) { + psum = proto_ipv6_header_psum(l4len, IPPROTO_TCP, + &ip6h->saddr, + &ip6h->daddr); + } + } tcp_fill_header(th, conn, seq); - if (no_tcp_csum) { + if (no_tcp_csum) th->check = 0; - } else { - uint32_t psum = proto_ipv6_header_psum(l4len, IPPROTO_TCP, - &ip6h->saddr, - &ip6h->daddr); - + else tcp_update_csum(psum, th, payload); - } - tap_hdr_update(taph, l4len + sizeof(*ip6h) + sizeof(struct ethhdr)); + tap_hdr_update(taph, l3len + sizeof(struct ethhdr)); } /** diff --git a/tcp_buf.c b/tcp_buf.c index 830c23d..a975a55 100644 --- a/tcp_buf.c +++ b/tcp_buf.c @@ -161,18 +161,19 @@ static void tcp_l2_buf_fill_headers(const struct tcp_tap_conn *conn, { struct iov_tail tail = IOV_TAIL(&iov[TCP_IOV_PAYLOAD], 1, 0); struct tcphdr *th = IOV_REMOVE_HEADER(&tail, struct tcphdr); + struct tap_hdr *taph = iov[TCP_IOV_TAP].iov_base; const struct flowside *tapside = TAPFLOW(conn); const struct in_addr *a4 = inany_v4(&tapside->oaddr); + struct ipv6hdr *ip6h = NULL; + struct iphdr *ip4h = NULL; - if (a4) { - tcp_fill_headers4(conn, iov[TCP_IOV_TAP].iov_base, - iov[TCP_IOV_IP].iov_base, th, - &tail, check, seq, no_tcp_csum); - } else { - tcp_fill_headers6(conn, iov[TCP_IOV_TAP].iov_base, - iov[TCP_IOV_IP].iov_base, th, - &tail, seq, no_tcp_csum); - } + if (a4) + ip4h = iov[TCP_IOV_IP].iov_base; + else + ip6h = iov[TCP_IOV_IP].iov_base; + + tcp_fill_headers(conn, taph, ip4h, ip6h, th, &tail, + check, seq, no_tcp_csum); } /** diff --git a/tcp_internal.h b/tcp_internal.h index cff06e0..94e5780 100644 --- a/tcp_internal.h +++ b/tcp_internal.h @@ -164,14 +164,11 @@ struct tcp_info_linux; void tcp_update_csum(uint32_t psum, struct tcphdr *th, struct iov_tail *payload); -void tcp_fill_headers4(const struct tcp_tap_conn *conn, - struct tap_hdr *taph, struct iphdr *iph, - struct tcphdr *th, struct iov_tail *payload, - const uint16_t *check, uint32_t seq, bool no_tcp_csum); -void tcp_fill_headers6(const struct tcp_tap_conn *conn, - struct tap_hdr *taph, struct ipv6hdr *ip6h, - struct tcphdr *th, struct iov_tail *payload, - uint32_t seq, bool no_tcp_csum); +void tcp_fill_headers(const struct tcp_tap_conn *conn, + struct tap_hdr *taph, + struct iphdr *ip4h, struct ipv6hdr *ip6h, + struct tcphdr *th, struct iov_tail *payload, + const uint16_t *ip4_check, uint32_t seq, bool no_tcp_csum); int tcp_update_seqack_wnd(const struct ctx *c, struct tcp_tap_conn *conn, bool force_seq, struct tcp_info_linux *tinfo); diff --git a/tcp_vu.c b/tcp_vu.c index 081c752..a611a5b 100644 --- a/tcp_vu.c +++ b/tcp_vu.c @@ -110,9 +110,9 @@ int tcp_vu_send_flag(const struct ctx *c, struct tcp_tap_conn *conn, int flags) size_t optlen, hdrlen; struct vu_virtq_element flags_elem[2]; struct ipv6hdr *ip6h = NULL; + struct iphdr *ip4h = NULL; struct iovec flags_iov[2]; struct tcp_syn_opts *opts; - struct iphdr *iph = NULL; struct iov_tail payload; struct tcphdr *th; struct ethhdr *eh; @@ -143,8 +143,8 @@ int tcp_vu_send_flag(const struct ctx *c, struct tcp_tap_conn *conn, int flags) if (CONN_V4(conn)) { eh->h_proto = htons(ETH_P_IP); - iph = vu_ip(flags_elem[0].in_sg[0].iov_base); - *iph = (struct iphdr)L2_BUF_IP4_INIT(IPPROTO_TCP); + ip4h = vu_ip(flags_elem[0].in_sg[0].iov_base); + *ip4h = (struct iphdr)L2_BUF_IP4_INIT(IPPROTO_TCP); th = vu_payloadv4(flags_elem[0].in_sg[0].iov_base); } else { @@ -170,12 +170,8 @@ int tcp_vu_send_flag(const struct ctx *c, struct tcp_tap_conn *conn, int flags) flags_elem[0].in_sg[0].iov_len = hdrlen + optlen; payload = IOV_TAIL(flags_elem[0].in_sg, 1, hdrlen); - if (CONN_V4(conn)) { - tcp_fill_headers4(conn, NULL, iph, th, &payload, - NULL, seq, true); - } else { - tcp_fill_headers6(conn, NULL, ip6h, th, &payload, seq, true); - } + tcp_fill_headers(conn, NULL, ip4h, ip6h, th, &payload, + NULL, seq, true); if (*c->pcap) { tcp_vu_update_check(tapside, &flags_elem[0].in_sg[0], 1); @@ -338,7 +334,7 @@ static void tcp_vu_prepare(const struct ctx *c, struct tcp_tap_conn *conn, struct iov_tail payload = IOV_TAIL(iov, iov_cnt, hdrlen); char *base = iov[0].iov_base; struct ipv6hdr *ip6h = NULL; - struct iphdr *iph = NULL; + struct iphdr *ip4h = NULL; struct tcphdr *th; struct ethhdr *eh; @@ -357,8 +353,8 @@ static void tcp_vu_prepare(const struct ctx *c, struct tcp_tap_conn *conn, if (!v6) { eh->h_proto = htons(ETH_P_IP); - iph = vu_ip(base); - *iph = (struct iphdr)L2_BUF_IP4_INIT(IPPROTO_TCP); + 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); @@ -373,14 +369,10 @@ static void tcp_vu_prepare(const struct ctx *c, struct tcp_tap_conn *conn, th->doff = sizeof(*th) / 4; th->ack = 1; - if (!v6) { - tcp_fill_headers4(conn, NULL, iph, th, &payload, - *check, conn->seq_to_tap, true); - *check = &iph->check; - } else { - tcp_fill_headers6(conn, NULL, ip6h, th, &payload, - conn->seq_to_tap, true); - } + tcp_fill_headers(conn, NULL, ip4h, ip6h, th, &payload, + *check, conn->seq_to_tap, true); + if (ip4h) + *check = &ip4h->check; } /** -- 2.47.0