Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761813Ab2FHFMy (ORCPT ); Fri, 8 Jun 2012 01:12:54 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:43259 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1761309Ab2FHFHb (ORCPT ); Fri, 8 Jun 2012 01:07:31 -0400 Message-Id: <20120608041850.814187846@decadent.org.uk> User-Agent: quilt/0.60-1 Date: Fri, 08 Jun 2012 05:19:54 +0100 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Benjamin Poirier , "David S. Miller" Subject: [ 74/82] xfrm: take net hdr len into account for esp payload size calculation In-Reply-To: <20120608041840.861504477@decadent.org.uk> X-SA-Exim-Connect-IP: 2001:470:1f08:1539:21c:bfff:fe03:f805 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3195 Lines: 104 3.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: Benjamin Poirier [ Upstream commit 91657eafb64b4cb53ec3a2fbc4afc3497f735788 ] Corrects the function that determines the esp payload size. The calculations done in esp{4,6}_get_mtu() lead to overlength frames in transport mode for certain mtu values and suboptimal frames for others. According to what is done, mainly in esp{,6}_output() and tcp_mtu_to_mss(), net_header_len must be taken into account before doing the alignment calculation. Signed-off-by: Benjamin Poirier Signed-off-by: David S. Miller Signed-off-by: Ben Hutchings --- net/ipv4/esp4.c | 24 +++++++++--------------- net/ipv6/esp6.c | 18 +++++++----------- 2 files changed, 16 insertions(+), 26 deletions(-) diff --git a/net/ipv4/esp4.c b/net/ipv4/esp4.c index a5b4134..530787b 100644 --- a/net/ipv4/esp4.c +++ b/net/ipv4/esp4.c @@ -457,28 +457,22 @@ static u32 esp4_get_mtu(struct xfrm_state *x, int mtu) struct esp_data *esp = x->data; u32 blksize = ALIGN(crypto_aead_blocksize(esp->aead), 4); u32 align = max_t(u32, blksize, esp->padlen); - u32 rem; - - mtu -= x->props.header_len + crypto_aead_authsize(esp->aead); - rem = mtu & (align - 1); - mtu &= ~(align - 1); + unsigned int net_adj; switch (x->props.mode) { - case XFRM_MODE_TUNNEL: - break; - default: case XFRM_MODE_TRANSPORT: - /* The worst case */ - mtu -= blksize - 4; - mtu += min_t(u32, blksize - 4, rem); - break; case XFRM_MODE_BEET: - /* The worst case. */ - mtu += min_t(u32, IPV4_BEET_PHMAXLEN, rem); + net_adj = sizeof(struct iphdr); break; + case XFRM_MODE_TUNNEL: + net_adj = 0; + break; + default: + BUG(); } - return mtu - 2; + return ((mtu - x->props.header_len - crypto_aead_authsize(esp->aead) - + net_adj) & ~(align - 1)) + (net_adj - 2); } static void esp4_err(struct sk_buff *skb, u32 info) diff --git a/net/ipv6/esp6.c b/net/ipv6/esp6.c index 1ac7938..65dd543 100644 --- a/net/ipv6/esp6.c +++ b/net/ipv6/esp6.c @@ -411,19 +411,15 @@ static u32 esp6_get_mtu(struct xfrm_state *x, int mtu) struct esp_data *esp = x->data; u32 blksize = ALIGN(crypto_aead_blocksize(esp->aead), 4); u32 align = max_t(u32, blksize, esp->padlen); - u32 rem; + unsigned int net_adj; - mtu -= x->props.header_len + crypto_aead_authsize(esp->aead); - rem = mtu & (align - 1); - mtu &= ~(align - 1); - - if (x->props.mode != XFRM_MODE_TUNNEL) { - u32 padsize = ((blksize - 1) & 7) + 1; - mtu -= blksize - padsize; - mtu += min_t(u32, blksize - padsize, rem); - } + if (x->props.mode != XFRM_MODE_TUNNEL) + net_adj = sizeof(struct ipv6hdr); + else + net_adj = 0; - return mtu - 2; + return ((mtu - x->props.header_len - crypto_aead_authsize(esp->aead) - + net_adj) & ~(align - 1)) + (net_adj - 2); } static void esp6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/