From patchwork Thu Nov 14 07:07:09 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christian Hopps X-Patchwork-Id: 13874645 X-Patchwork-Delegate: kuba@kernel.org Received: from smtp.chopps.org (smtp.chopps.org [54.88.81.56]) by smtp.subspace.kernel.org (Postfix) with ESMTP id ADB361F8934 for ; Thu, 14 Nov 2024 07:07:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=54.88.81.56 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731568059; cv=none; b=VdSyx6h0lz01w6/Js8rUfIAEcl1+apczZM3XXzhtVoQqJuAHvlnsgUuaJRSQbytPH1z9d2Jh/EGwV3BjqOrSVoZ6u+1Ztz7Dtb9BsVSnL9Vt7i2g5OsK8uI2AtZam3xXZwmiNdj8Xj9uiyvFjGT+JvIMl86DuFLf1eAzCU3RW9Y= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731568059; c=relaxed/simple; bh=b5xQyP3s1s2E9yN+Ow8+riULqcHPQjmN7aslfx6gD38=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=MFQlWShx3NgQe+nFlAMnjcKRG4lMDbJz/w472cQfllajYdFtobFLMGd8Ih5CZmlF0Q9jTjjV4OEh9PzSXlOCEUpKCMDFWfQ040pSOCvoL2Ux9mppj590oAthzO8exZO0tJneI7mCOcWjALPVG6nOu60I5CZxCJJAoay6NJCp/04= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=chopps.org; spf=fail smtp.mailfrom=chopps.org; arc=none smtp.client-ip=54.88.81.56 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=chopps.org Authentication-Results: smtp.subspace.kernel.org; spf=fail smtp.mailfrom=chopps.org Received: from labnh.big (syn-172-222-091-149.res.spectrum.com [172.222.91.149]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (Client did not present a certificate) by smtp.chopps.org (Postfix) with ESMTPSA id 0E2D57D136; Thu, 14 Nov 2024 07:07:35 +0000 (UTC) From: Christian Hopps To: devel@linux-ipsec.org Cc: Steffen Klassert , netdev@vger.kernel.org, Florian Westphal , Sabrina Dubroca , Simon Horman , Antony Antony , Christian Hopps , Christian Hopps Subject: [PATCH ipsec-next v14 12/15] xfrm: iptfs: add reusing received skb for the tunnel egress packet Date: Thu, 14 Nov 2024 02:07:09 -0500 Message-ID: <20241114070713.3718740-13-chopps@chopps.org> X-Mailer: git-send-email 2.47.0 In-Reply-To: <20241114070713.3718740-1-chopps@chopps.org> References: <20241114070713.3718740-1-chopps@chopps.org> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Patchwork-Delegate: kuba@kernel.org From: Christian Hopps Add an optimization of re-using the tunnel outer skb re-transmission of the inner packet to avoid skb allocation and copy. Signed-off-by: Christian Hopps --- net/xfrm/xfrm_iptfs.c | 123 ++++++++++++++++++++++++++++++++++++------ 1 file changed, 108 insertions(+), 15 deletions(-) diff --git a/net/xfrm/xfrm_iptfs.c b/net/xfrm/xfrm_iptfs.c index 4af1f7b5818e..8538fb02ae8a 100644 --- a/net/xfrm/xfrm_iptfs.c +++ b/net/xfrm/xfrm_iptfs.c @@ -601,12 +601,12 @@ static bool __input_process_payload(struct xfrm_state *x, u32 data, struct list_head *sublist) { u8 hbytes[sizeof(struct ipv6hdr)]; - struct sk_buff *first_skb, *next, *skb; + struct sk_buff *defer, *first_skb, *next, *skb; const unsigned char *old_mac; struct xfrm_iptfs_data *xtfs; struct iphdr *iph; struct net *net; - u32 remaining, iplen, iphlen, tail; + u32 first_iplen, iphlen, iplen, remaining, tail; u32 capturelen; u64 seq; @@ -614,6 +614,7 @@ static bool __input_process_payload(struct xfrm_state *x, u32 data, net = xs_net(x); skb = skbseq->root_skb; first_skb = NULL; + defer = NULL; seq = __esp_seq(skb); @@ -688,23 +689,92 @@ static bool __input_process_payload(struct xfrm_state *x, u32 data, skb_prepare_seq_read(save, data, tail, skbseq); } - if (!first_skb) + if (first_skb) { + skb = NULL; + } else { first_skb = skb; + first_iplen = iplen; + + /* We are going to skip over `data` bytes to reach the + * start of the IP header of `iphlen` len for `iplen` + * inner packet. + */ + + if (skb_has_frag_list(skb)) { + defer = skb; + skb = NULL; + } else if (data + iphlen <= skb_headlen(skb) && + /* make sure our header is 32-bit aligned? */ + /* ((uintptr_t)(skb->data + data) & 0x3) == 0 && */ + skb_tailroom(skb) + tail - data >= iplen) { + /* Reuse the received skb. + * + * We have enough headlen to pull past any + * initial fragment data, leaving at least the + * IP header in the linear buffer space. + * + * For linear buffer space we only require that + * linear buffer space is large enough to + * eventually hold the entire reassembled + * packet (by including tailroom in the check). + * + * For non-linear tailroom is 0 and so we only + * re-use if the entire packet is present + * already. + * + * NOTE: there are many more options for + * sharing, KISS for now. Also, this can produce + * skb's with the IP header unaligned to 32 + * bits. If that ends up being a problem then a + * check should be added to the conditional + * above that the header lies on a 32-bit + * boundary as well. + */ + skb_pull(skb, data); + + /* our range just changed */ + data = 0; + tail = skb->len; + remaining = skb->len; + + skb->protocol = protocol; + skb_mac_header_rebuild(skb); + if (skb->mac_len) + eth_hdr(skb)->h_proto = skb->protocol; + + /* all pointers could be changed now reset walk */ + skb_abort_seq_read(skbseq); + skb_prepare_seq_read(skb, data, tail, skbseq); + } else { + /* We couldn't reuse the input skb so allocate a + * new one. + */ + defer = skb; + skb = NULL; + } + + /* Don't trim `first_skb` until the end as we are + * walking that data now. + */ + } capturelen = min(iplen, remaining); - skb = iptfs_pskb_extract_seq(iplen, skbseq, data, capturelen); if (!skb) { - /* skip to next packet or done */ - data += capturelen; - continue; - } + skb = iptfs_pskb_extract_seq(iplen, skbseq, data, + capturelen); + if (!skb) { + /* skip to next packet or done */ + data += capturelen; + continue; + } - skb->protocol = protocol; - if (old_mac) { - /* rebuild the mac header */ - skb_set_mac_header(skb, -first_skb->mac_len); - memcpy(skb_mac_header(skb), old_mac, first_skb->mac_len); - eth_hdr(skb)->h_proto = skb->protocol; + skb->protocol = protocol; + if (old_mac) { + /* rebuild the mac header */ + skb_set_mac_header(skb, -first_skb->mac_len); + memcpy(skb_mac_header(skb), old_mac, first_skb->mac_len); + eth_hdr(skb)->h_proto = skb->protocol; + } } data += capturelen; @@ -735,6 +805,16 @@ static bool __input_process_payload(struct xfrm_state *x, u32 data, /* this should not happen from the above code */ XFRM_INC_STATS(net, LINUX_MIB_XFRMINIPTFSERROR); + if (first_skb && first_iplen && !defer && first_skb != xtfs->ra_newskb) { + /* first_skb is queued b/c !defer and not partial */ + if (pskb_trim(first_skb, first_iplen)) { + /* error trimming */ + list_del(&first_skb->list); + defer = first_skb; + } + first_skb->ip_summed = CHECKSUM_NONE; + } + /* Send the packets! */ list_for_each_entry_safe(skb, next, sublist, list) { skb_list_del_init(skb); @@ -742,7 +822,20 @@ static bool __input_process_payload(struct xfrm_state *x, u32 data, kfree_skb(skb); } done: - return false; + skb = skbseq->root_skb; + skb_abort_seq_read(skbseq); + + if (defer) { + consume_skb(defer); + } else if (!first_skb) { + /* skb is the original passed in skb, but we didn't get far + * enough to process it as the first_skb, if we had it would + * either be save in ra_newskb, trimmed and sent on as an skb or + * placed in defer to be freed. + */ + kfree_skb(skb); + } + return true; } /**