From patchwork Tue Dec 17 20:38:07 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mat Martineau X-Patchwork-Id: 1211693 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 (no SPF record) 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=linux.intel.com Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 47cqjW1QYTz9sR8 for ; Wed, 18 Dec 2019 07:38:39 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726967AbfLQUih (ORCPT ); Tue, 17 Dec 2019 15:38:37 -0500 Received: from mga18.intel.com ([134.134.136.126]:16399 "EHLO mga18.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728143AbfLQUib (ORCPT ); Tue, 17 Dec 2019 15:38:31 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga001.jf.intel.com ([10.7.209.18]) by orsmga106.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 17 Dec 2019 12:38:30 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.69,326,1571727600"; d="scan'208";a="298171948" Received: from mjmartin-nuc02.mjmartin-nuc02 (HELO mjmartin-nuc02.sea.intel.com) ([10.251.1.107]) by orsmga001.jf.intel.com with ESMTP; 17 Dec 2019 12:38:26 -0800 From: Mat Martineau To: netdev@vger.kernel.org, mptcp@lists.01.org Cc: Paolo Abeni , Mat Martineau Subject: [PATCH net-next v3 11/11] skb: add helpers to allocate ext independently from sk_buff Date: Tue, 17 Dec 2019 12:38:07 -0800 Message-Id: <20191217203807.12579-12-mathew.j.martineau@linux.intel.com> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20191217203807.12579-1-mathew.j.martineau@linux.intel.com> References: <20191217203807.12579-1-mathew.j.martineau@linux.intel.com> MIME-Version: 1.0 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Paolo Abeni Currently we can allocate the extension only after the skb, this change allows the user to do the opposite, will simplify allocation failure handling from MPTCP. Signed-off-by: Paolo Abeni Signed-off-by: Mat Martineau --- include/linux/skbuff.h | 3 +++ net/core/skbuff.c | 35 +++++++++++++++++++++++++++++++++-- 2 files changed, 36 insertions(+), 2 deletions(-) diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 1a261c3ee074..af9b6cf79a65 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -4115,6 +4115,9 @@ struct skb_ext { char data[0] __aligned(8); }; +struct skb_ext *__skb_ext_alloc(void); +void *__skb_ext_set(struct sk_buff *skb, enum skb_ext_id id, + struct skb_ext *ext); void *skb_ext_add(struct sk_buff *skb, enum skb_ext_id id); void __skb_ext_del(struct sk_buff *skb, enum skb_ext_id id); void __skb_ext_put(struct skb_ext *ext); diff --git a/net/core/skbuff.c b/net/core/skbuff.c index fa67036dd928..504e9bd5ebce 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -5983,7 +5983,14 @@ static void *skb_ext_get_ptr(struct skb_ext *ext, enum skb_ext_id id) return (void *)ext + (ext->offset[id] * SKB_EXT_ALIGN_VALUE); } -static struct skb_ext *skb_ext_alloc(void) +/** + * __skb_ext_alloc - allocate a new skb extensions storage + * + * Returns the newly allocated pointer. The pointer can later attached to a + * skb via __skb_ext_set(). + * Note: caller must handle the skb_ext as an opaque data. + */ +struct skb_ext *__skb_ext_alloc(void) { struct skb_ext *new = kmem_cache_alloc(skbuff_ext_cache, GFP_ATOMIC); @@ -6023,6 +6030,30 @@ static struct skb_ext *skb_ext_maybe_cow(struct skb_ext *old, return new; } +/** + * __skb_ext_set - attach the specified extension storage to this skb + * @skb: buffer + * @id: extension id + * @ext: extension storage previously allocated via __skb_ext_alloc() + * + * Existing extensions, if any, are cleared. + * + * Returns the pointer to the extension. + */ +void *__skb_ext_set(struct sk_buff *skb, enum skb_ext_id id, + struct skb_ext *ext) +{ + unsigned int newlen, newoff = SKB_EXT_CHUNKSIZEOF(*ext); + + skb_ext_put(skb); + newlen = newoff + skb_ext_type_len[id]; + ext->chunks = newlen; + ext->offset[id] = newoff; + skb->extensions = ext; + skb->active_extensions = 1 << id; + return skb_ext_get_ptr(ext, id); +} + /** * skb_ext_add - allocate space for given extension, COW if needed * @skb: buffer @@ -6056,7 +6087,7 @@ void *skb_ext_add(struct sk_buff *skb, enum skb_ext_id id) } else { newoff = SKB_EXT_CHUNKSIZEOF(*new); - new = skb_ext_alloc(); + new = __skb_ext_alloc(); if (!new) return NULL; }