From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ken-ichirou MATSUZAWA Subject: [RFC PATCH 1/5] netlink: mmap: introduce mmaped skb helper functions Date: Wed, 22 Jul 2015 10:10:52 +0900 Message-ID: <20150722011052.GB30012@gmail.com> References: <20150722010938.GA30012@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii To: The netfilter developer mailinglist Return-path: Received: from mail-pa0-f42.google.com ([209.85.220.42]:36729 "EHLO mail-pa0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964802AbbGVBK5 (ORCPT ); Tue, 21 Jul 2015 21:10:57 -0400 Received: by pachj5 with SMTP id hj5so129082185pac.3 for ; Tue, 21 Jul 2015 18:10:57 -0700 (PDT) Received: from gmail.com (softbank220009032004.bbtec.net. [220.9.32.4]) by smtp.gmail.com with ESMTPSA id ok17sm29709043pdb.26.2015.07.21.18.10.55 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 21 Jul 2015 18:10:56 -0700 (PDT) Content-Disposition: inline In-Reply-To: <20150722010938.GA30012@gmail.com> Sender: netfilter-devel-owner@vger.kernel.org List-ID: It seems that we need helper functions for skb which is allocated at netlink_alloc_skb() since it does not have skb_shared_info. Signed-off-by: Ken-ichirou MATSUZAWA --- include/linux/netlink.h | 22 ++++--------- net/netlink/af_netlink.c | 81 ++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 87 insertions(+), 16 deletions(-) diff --git a/include/linux/netlink.h b/include/linux/netlink.h index 6835c12..049962e 100644 --- a/include/linux/netlink.h +++ b/include/linux/netlink.h @@ -68,6 +68,12 @@ extern void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err); extern int netlink_has_listeners(struct sock *sk, unsigned int group); extern struct sk_buff *netlink_alloc_skb(struct sock *ssk, unsigned int size, u32 dst_portid, gfp_t gfp_mask); +extern struct sk_buff *netlink_skb_copy(const struct sk_buff *skb, gfp_t gfp_mask); +extern struct sk_buff *netlink_skb_clone(struct sk_buff *skb, gfp_t gfp_mask); +extern int netlink_skb_zerocopy(struct sk_buff *to, struct sk_buff *from, int len, int hlen); +extern void netlink_free_skb(struct sk_buff *skb); +void netlink_consume_skb(struct sk_buff *skb); + extern int netlink_unicast(struct sock *ssk, struct sk_buff *skb, __u32 portid, int nonblock); extern int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, __u32 portid, __u32 group, gfp_t allocation); @@ -86,22 +92,6 @@ int netlink_attachskb(struct sock *sk, struct sk_buff *skb, void netlink_detachskb(struct sock *sk, struct sk_buff *skb); int netlink_sendskb(struct sock *sk, struct sk_buff *skb); -static inline struct sk_buff * -netlink_skb_clone(struct sk_buff *skb, gfp_t gfp_mask) -{ - struct sk_buff *nskb; - - nskb = skb_clone(skb, gfp_mask); - if (!nskb) - return NULL; - - /* This is a large skb, set destructor callback to release head */ - if (is_vmalloc_addr(skb->head)) - nskb->destructor = skb->destructor; - - return nskb; -} - /* * skb should fit one page. This choice is good for headerless malloc. * But we should limit to 8K so that userspace does not have to diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c index bf6e766..a0a32f4 100644 --- a/net/netlink/af_netlink.c +++ b/net/netlink/af_netlink.c @@ -1872,6 +1872,87 @@ out: } EXPORT_SYMBOL_GPL(netlink_alloc_skb); +struct sk_buff *netlink_skb_copy(const struct sk_buff *skb, gfp_t gfp_mask) +{ +#ifdef CONFIG_NETLINK_MMAP + if (netlink_skb_is_mmaped(skb)) { + struct sk_buff *n = alloc_skb(skb->len, gfp_mask); + if (!n) + return NULL; + + skb_put(n, skb->len); + memcpy(n->data, skb->data, skb->len); + return n; + } else +#endif + return skb_copy(skb, gfp_mask); +} +EXPORT_SYMBOL_GPL(netlink_skb_copy); + +struct sk_buff *netlink_skb_clone(struct sk_buff *skb, gfp_t gfp_mask) +{ + struct sk_buff *nskb; + +#ifdef CONFIG_NETLINK_MMAP + if (netlink_skb_is_mmaped(skb)) + return netlink_skb_copy(skb, gfp_mask); +#endif + nskb = skb_clone(skb, gfp_mask); + if (!nskb) + return NULL; + + /* This is a large skb, set destructor callback to release head */ + if (is_vmalloc_addr(skb->head)) + nskb->destructor = skb->destructor; + + return nskb; +} +EXPORT_SYMBOL_GPL(netlink_skb_clone); + +int +netlink_skb_zerocopy(struct sk_buff *to, struct sk_buff *from, int len, int hlen) +{ +#ifdef CONFIG_NETLINK_MMAP + struct page *page; + unsigned int offset; + + if (netlink_skb_is_mmaped(from)) { + if (!len) + return 0; + + page = virt_to_head_page(from->head); + offset = from->data - (unsigned char *)page_address(page); + __skb_fill_page_desc(to, 0, page, offset, len); + get_page(page); + to->truesize += len; + to->len += len; + to->data_len += len; + + return 0; + } else +#endif + + return skb_zerocopy(to, from, len, hlen); +} +EXPORT_SYMBOL_GPL(netlink_skb_zerocopy); + +void netlink_free_skb(struct sk_buff *skb) +{ + kfree_skb_partial(skb, netlink_skb_is_mmaped(skb)); +} +EXPORT_SYMBOL_GPL(netlink_free_skb); + +void netlink_consume_skb(struct sk_buff *skb) +{ +#ifdef CONFIG_NETLINK_MMAP + if (netlink_skb_is_mmaped(skb)) + kfree_skb_partial(skb, true); + else +#endif + consume_skb(skb); +} +EXPORT_SYMBOL_GPL(netlink_consume_skb); + int netlink_has_listeners(struct sock *sk, unsigned int group) { int res = 0; -- 1.7.10.4