From patchwork Mon Apr 29 19:50:06 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pablo Neira Ayuso X-Patchwork-Id: 1092839 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=netfilter.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 44tFdV1nknz9sB8 for ; Tue, 30 Apr 2019 05:50:54 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729266AbfD2Tu3 (ORCPT ); Mon, 29 Apr 2019 15:50:29 -0400 Received: from mail.us.es ([193.147.175.20]:41666 "EHLO mail.us.es" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729140AbfD2Tu1 (ORCPT ); Mon, 29 Apr 2019 15:50:27 -0400 Received: from antivirus1-rhel7.int (unknown [192.168.2.11]) by mail.us.es (Postfix) with ESMTP id 981891031AA for ; Mon, 29 Apr 2019 21:50:25 +0200 (CEST) Received: from antivirus1-rhel7.int (localhost [127.0.0.1]) by antivirus1-rhel7.int (Postfix) with ESMTP id 84806DA710 for ; Mon, 29 Apr 2019 21:50:25 +0200 (CEST) Received: by antivirus1-rhel7.int (Postfix, from userid 99) id 8353DDA70D; Mon, 29 Apr 2019 21:50:25 +0200 (CEST) X-Spam-Checker-Version: SpamAssassin 3.4.1 (2015-04-28) on antivirus1-rhel7.int X-Spam-Level: X-Spam-Status: No, score=-108.2 required=7.5 tests=ALL_TRUSTED,BAYES_50, SMTPAUTH_US2,USER_IN_WHITELIST autolearn=disabled version=3.4.1 Received: from antivirus1-rhel7.int (localhost [127.0.0.1]) by antivirus1-rhel7.int (Postfix) with ESMTP id 4A08ADA704; Mon, 29 Apr 2019 21:50:23 +0200 (CEST) Received: from 192.168.1.97 (192.168.1.97) by antivirus1-rhel7.int (F-Secure/fsigk_smtp/550/antivirus1-rhel7.int); Mon, 29 Apr 2019 21:50:23 +0200 (CEST) X-Virus-Status: clean(F-Secure/fsigk_smtp/550/antivirus1-rhel7.int) Received: from salvia.here (sys.soleta.eu [212.170.55.40]) (Authenticated sender: pneira@us.es) by entrada.int (Postfix) with ESMTPA id 05F774265A31; Mon, 29 Apr 2019 21:50:22 +0200 (CEST) X-SMTPAUTHUS: auth mail.us.es From: Pablo Neira Ayuso To: netfilter-devel@vger.kernel.org Cc: davem@davemloft.net, netdev@vger.kernel.org, nikolay@cumulusnetworks.com, roopa@cumulusnetworks.com Subject: [PATCH 1/9 net-next,v2] net: ipv4: add skbuff fraglist splitter Date: Mon, 29 Apr 2019 21:50:06 +0200 Message-Id: <20190429195014.4724-2-pablo@netfilter.org> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20190429195014.4724-1-pablo@netfilter.org> References: <20190429195014.4724-1-pablo@netfilter.org> X-Virus-Scanned: ClamAV using ClamSMTP Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org This patch adds skbuff fraglist splitter. The API provides an iterator to perform this transformation, it consists of: * ip_fraglist_init(), that initializes the internal state of the fraglist splitter. * ip_fraglist_prepare(), that restores the IPv4 header on the fragments. * ip_fraglist_next(), that retrieves the fragment from the fraglist and it updates the internal state of the splitter to point to the next fragment in the fraglist. The ip_fraglist_iter object stores the internal state of the iterator. This code has been extracted from ip_do_fragment(). Symbols are also exported to allow to reuse this iterator from the bridge codepath to build its own refragmentation routine by reusing the existing codebase. Signed-off-by: Pablo Neira Ayuso --- v2: Fix English typo in patch description. include/net/ip.h | 23 ++++++++++++++ net/ipv4/ip_output.c | 88 ++++++++++++++++++++++++++++++++-------------------- 2 files changed, 78 insertions(+), 33 deletions(-) diff --git a/include/net/ip.h b/include/net/ip.h index 2d3cce7c3e8a..be899677504b 100644 --- a/include/net/ip.h +++ b/include/net/ip.h @@ -165,6 +165,29 @@ int ip_output(struct net *net, struct sock *sk, struct sk_buff *skb); int ip_mc_output(struct net *net, struct sock *sk, struct sk_buff *skb); int ip_do_fragment(struct net *net, struct sock *sk, struct sk_buff *skb, int (*output)(struct net *, struct sock *, struct sk_buff *)); + +struct ip_fraglist_iter { + struct sk_buff *frag_list; + struct sk_buff *frag; + struct iphdr *iph; + int offset; + unsigned int hlen; +}; + +void ip_fraglist_init(struct sk_buff *skb, struct iphdr *iph, + unsigned int hlen, struct ip_fraglist_iter *iter); +void ip_fraglist_prepare(struct sk_buff *skb, struct ip_fraglist_iter *iter); + +static inline struct sk_buff *ip_fraglist_next(struct ip_fraglist_iter *iter) +{ + struct sk_buff *skb = iter->frag; + + iter->frag = skb->next; + skb_mark_not_on_list(skb); + + return skb; +} + void ip_send_check(struct iphdr *ip); int __ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb); int ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb); diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c index 4e42c1974ba2..c03194eb1376 100644 --- a/net/ipv4/ip_output.c +++ b/net/ipv4/ip_output.c @@ -559,6 +559,54 @@ static int ip_fragment(struct net *net, struct sock *sk, struct sk_buff *skb, return ip_do_fragment(net, sk, skb, output); } +void ip_fraglist_init(struct sk_buff *skb, struct iphdr *iph, + unsigned int hlen, struct ip_fraglist_iter *iter) +{ + unsigned int first_len = skb_pagelen(skb); + + iter->frag_list = skb_shinfo(skb)->frag_list; + iter->frag = iter->frag_list; + skb_frag_list_init(skb); + + iter->offset = 0; + iter->iph = iph; + iter->hlen = hlen; + + skb->data_len = first_len - skb_headlen(skb); + skb->len = first_len; + iph->tot_len = htons(first_len); + iph->frag_off = htons(IP_MF); + ip_send_check(iph); +} +EXPORT_SYMBOL(ip_fraglist_init); + +void ip_fraglist_prepare(struct sk_buff *skb, struct ip_fraglist_iter *iter) +{ + unsigned int hlen = iter->hlen; + struct iphdr *iph = iter->iph; + struct sk_buff *frag; + + frag = iter->frag; + frag->ip_summed = CHECKSUM_NONE; + skb_reset_transport_header(frag); + __skb_push(frag, hlen); + skb_reset_network_header(frag); + memcpy(skb_network_header(frag), iph, hlen); + iter->iph = ip_hdr(frag); + iph = iter->iph; + iph->tot_len = htons(frag->len); + ip_copy_metadata(frag, skb); + if (iter->offset == 0) + ip_options_fragment(frag); + iter->offset += skb->len - hlen; + iph->frag_off = htons(iter->offset >> 3); + if (frag->next) + iph->frag_off |= htons(IP_MF); + /* Ready, complete checksum */ + ip_send_check(iph); +} +EXPORT_SYMBOL(ip_fraglist_prepare); + /* * This IP datagram is too large to be sent in one piece. Break it up into * smaller pieces (each of size equal to IP header plus @@ -576,6 +624,7 @@ int ip_do_fragment(struct net *net, struct sock *sk, struct sk_buff *skb, int offset; __be16 not_last_frag; struct rtable *rt = skb_rtable(skb); + struct ip_fraglist_iter iter; int err = 0; /* for offloaded checksums cleanup checksum before fragmentation */ @@ -640,49 +689,22 @@ int ip_do_fragment(struct net *net, struct sock *sk, struct sk_buff *skb, } /* Everything is OK. Generate! */ - - err = 0; - offset = 0; - frag = skb_shinfo(skb)->frag_list; - skb_frag_list_init(skb); - skb->data_len = first_len - skb_headlen(skb); - skb->len = first_len; - iph->tot_len = htons(first_len); - iph->frag_off = htons(IP_MF); - ip_send_check(iph); + ip_fraglist_init(skb, iph, hlen, &iter); for (;;) { /* Prepare header of the next frame, * before previous one went down. */ - if (frag) { - frag->ip_summed = CHECKSUM_NONE; - skb_reset_transport_header(frag); - __skb_push(frag, hlen); - skb_reset_network_header(frag); - memcpy(skb_network_header(frag), iph, hlen); - iph = ip_hdr(frag); - iph->tot_len = htons(frag->len); - ip_copy_metadata(frag, skb); - if (offset == 0) - ip_options_fragment(frag); - offset += skb->len - hlen; - iph->frag_off = htons(offset>>3); - if (frag->next) - iph->frag_off |= htons(IP_MF); - /* Ready, complete checksum */ - ip_send_check(iph); - } + if (iter.frag) + ip_fraglist_prepare(skb, &iter); err = output(net, sk, skb); if (!err) IP_INC_STATS(net, IPSTATS_MIB_FRAGCREATES); - if (err || !frag) + if (err || !iter.frag) break; - skb = frag; - frag = skb->next; - skb_mark_not_on_list(skb); + skb = ip_fraglist_next(&iter); } if (err == 0) { @@ -690,7 +712,7 @@ int ip_do_fragment(struct net *net, struct sock *sk, struct sk_buff *skb, return 0; } - kfree_skb_list(frag); + kfree_skb_list(iter.frag_list); IP_INC_STATS(net, IPSTATS_MIB_FRAGFAILS); return err;