From patchwork Wed Mar 19 21:07:29 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Zoltan Kiss X-Patchwork-Id: 331881 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id EAC562C0096 for ; Thu, 20 Mar 2014 08:08:48 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757482AbaCSVIE (ORCPT ); Wed, 19 Mar 2014 17:08:04 -0400 Received: from smtp.citrix.com ([66.165.176.89]:29281 "EHLO SMTP.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754151AbaCSVIA (ORCPT ); Wed, 19 Mar 2014 17:08:00 -0400 X-IronPort-AV: E=Sophos;i="4.97,688,1389744000"; d="scan'208";a="113054867" Received: from accessns.citrite.net (HELO FTLPEX01CL03.citrite.net) ([10.9.154.239]) by FTLPIPO01.CITRIX.COM with ESMTP; 19 Mar 2014 21:07:58 +0000 Received: from imagesandwords.uk.xensource.com (10.80.2.133) by FTLPEX01CL03.citrite.net (10.13.107.80) with Microsoft SMTP Server id 14.2.342.4; Wed, 19 Mar 2014 17:07:58 -0400 From: Zoltan Kiss To: Jesse Gross , , , CC: "David S. Miller" , Pablo Neira Ayuso , Jozsef Kadlecsik , Eric Dumazet , Daniel Borkmann , Tom Herbert , Jason Wang , Florian Westphal , Joe Perches , Simon Horman , Jiri Pirko , "Michael S. Tsirkin" , Paul Durrant , Jan Beulich , Herbert Xu , Miklos Szeredi , , , , , , , Zoltan Kiss Subject: [PATCH v2] core, nfqueue, openvswitch: Orphan frags in skb_zerocopy and handle errors Date: Wed, 19 Mar 2014 21:07:29 +0000 Message-ID: <1395263249-16450-1-git-send-email-zoltan.kiss@citrix.com> X-Mailer: git-send-email 1.7.9.5 MIME-Version: 1.0 X-Originating-IP: [10.80.2.133] X-DLP: MIA2 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org skb_zerocopy can copy elements of the frags array between skbs, but it doesn't orphan them. Also, it doesn't handle errors, so this patch takes care of that as well. Signed-off-by: Zoltan Kiss Acked-by: Thomas Graf --- v2: orphan the frags right before touching the frags -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 03db95a..35c4e85 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -2508,8 +2508,8 @@ int skb_splice_bits(struct sk_buff *skb, unsigned int offset, unsigned int flags); void skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to); unsigned int skb_zerocopy_headlen(const struct sk_buff *from); -void skb_zerocopy(struct sk_buff *to, const struct sk_buff *from, - int len, int hlen); +int skb_zerocopy(struct sk_buff *to, const struct sk_buff *from, + int len, int hlen); void skb_split(struct sk_buff *skb, struct sk_buff *skb1, const u32 len); int skb_shift(struct sk_buff *tgt, struct sk_buff *skb, int shiftlen); void skb_scrub_packet(struct sk_buff *skb, bool xnet); diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 3f14c63..5cc99b1 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -2127,25 +2127,31 @@ EXPORT_SYMBOL_GPL(skb_zerocopy_headlen); * * The `hlen` as calculated by skb_zerocopy_headlen() specifies the * headroom in the `to` buffer. + * + * Return value: + * 0: everything is OK + * -ENOMEM: couldn't orphan frags of from due to lack of memory + * -EFAULT: skb_copy_bits() found some problem with geometry */ -void +int skb_zerocopy(struct sk_buff *to, const struct sk_buff *from, int len, int hlen) { int i, j = 0; int plen = 0; /* length of skb->head fragment */ + int ret; struct page *page; unsigned int offset; BUG_ON(!from->head_frag && !hlen); /* dont bother with small payloads */ - if (len <= skb_tailroom(to)) { - skb_copy_bits(from, 0, skb_put(to, len), len); - return; - } + if (len <= skb_tailroom(to)) + return skb_copy_bits(from, 0, skb_put(to, len), len); if (hlen) { - skb_copy_bits(from, 0, skb_put(to, hlen), hlen); + ret = skb_copy_bits(from, 0, skb_put(to, hlen), hlen); + if (unlikely(ret)) + return ret; len -= hlen; } else { plen = min_t(int, skb_headlen(from), len); @@ -2163,6 +2169,11 @@ skb_zerocopy(struct sk_buff *to, const struct sk_buff *from, int len, int hlen) to->len += len + plen; to->data_len += len + plen; + if (unlikely(skb_orphan_frags(to, GFP_ATOMIC))) { + skb_tx_error(to); + return -ENOMEM; + } + for (i = 0; i < skb_shinfo(from)->nr_frags; i++) { if (!len) break; @@ -2173,6 +2184,8 @@ skb_zerocopy(struct sk_buff *to, const struct sk_buff *from, int len, int hlen) j++; } skb_shinfo(to)->nr_frags = j; + + return 0; } EXPORT_SYMBOL_GPL(skb_zerocopy); diff --git a/net/netfilter/nfnetlink_queue_core.c b/net/netfilter/nfnetlink_queue_core.c index f072fe8..ea02d16 100644 --- a/net/netfilter/nfnetlink_queue_core.c +++ b/net/netfilter/nfnetlink_queue_core.c @@ -488,7 +488,8 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue, nla->nla_type = NFQA_PAYLOAD; nla->nla_len = nla_attr_size(data_len); - skb_zerocopy(skb, entskb, data_len, hlen); + if (skb_zerocopy(skb, entskb, data_len, hlen)) + goto nla_put_failure; } nlh->nlmsg_len = skb->len; diff --git a/net/openvswitch/datapath.c b/net/openvswitch/datapath.c index c53fe0c..9a9f668 100644 --- a/net/openvswitch/datapath.c +++ b/net/openvswitch/datapath.c @@ -464,7 +464,9 @@ static int queue_userspace_packet(struct datapath *dp, struct sk_buff *skb, } nla->nla_len = nla_attr_size(skb->len); - skb_zerocopy(user_skb, skb, skb->len, hlen); + err = skb_zerocopy(user_skb, skb, skb->len, hlen); + if (err) + goto out; /* Pad OVS_PACKET_ATTR_PACKET if linear copy was performed */ if (!(dp->user_features & OVS_DP_F_UNALIGNED)) {