From patchwork Thu Aug 15 17:21:14 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christian Hopps X-Patchwork-Id: 13765005 X-Patchwork-Delegate: kuba@kernel.org Received: from smtp.chopps.org (smtp.chopps.org [54.88.81.56]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 3652229A1 for ; Thu, 15 Aug 2024 17:21:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=54.88.81.56 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723742517; cv=none; b=CyBPc9C+RLrxkaB0bSn9tVnQ5lLB9BtV38uN5pQwN9ZgSh7HcMEmqHJ8GzUp7ScglxYwFuiP8M3st+BPkaHnyRfEPYImCiecVKREbv/a/eJhTMDRYkm17URLZgjzZMrPprXj9ru5tTmuny+W8YQkPTpQPdXu5G2HFin0/q/MClw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723742517; c=relaxed/simple; bh=zT9VyLMVK1/XGAswxj+/VLR1yotkecG1IGtmyxPRKe4=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=HgLQ9dUgSR2RHB/QSnIL3neNw6OqldGTDho0S0zVb3qd3L/HjCc5CLd/NvG97W14HsThqq9AgAhURyLxdStx2WKAk4EwvTyXyaA7QGPTrOK9tQmr+feV0HmnfGDZmazUG0taPEIvt7e4cNZbn2PoEcP6rz9LuBcGrXBsSYfZIFE= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=chopps.org; spf=fail smtp.mailfrom=chopps.org; arc=none smtp.client-ip=54.88.81.56 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=chopps.org Authentication-Results: smtp.subspace.kernel.org; spf=fail smtp.mailfrom=chopps.org Received: from labnh.int.chopps.org (syn-172-222-091-149.res.spectrum.com [172.222.91.149]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (Client did not present a certificate) by smtp.chopps.org (Postfix) with ESMTPSA id 81CD57D065; Thu, 15 Aug 2024 17:21:53 +0000 (UTC) From: Christian Hopps To: devel@linux-ipsec.org Cc: Steffen Klassert , netdev@vger.kernel.org, "David S . Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Florian Westphal , Sabrina Dubroca , Simon Horman , Antony Antony , Christian Hopps , Christian Hopps Subject: [PATCH ipsec-next v4 1/1] net: add copy from skb_seq_state to buffer function Date: Thu, 15 Aug 2024 13:21:14 -0400 Message-ID: <20240815172114.696205-1-chopps@chopps.org> X-Mailer: git-send-email 2.46.0 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Patchwork-Delegate: kuba@kernel.org From: Christian Hopps Add an skb helper function to copy a range of bytes from within an existing skb_seq_state. Signed-off-by: Christian Hopps --- This is used in a followup patchset implementing IP-TFS/AggFrag encapsulation (https://www.rfc-editor.org/rfc/rfc9347.txt) Patchset History: v1 (8/9/2024) - Created from IP-TFS patchset v9 v2 (8/9/2024) - resend with corrected CC list. v3 (8/15/2024) - removed ___copy_skb_header refactoring v4 (8/15/2024) - change returned error from -ENOMEM to -EINVAL --- include/linux/skbuff.h | 1 + net/core/skbuff.c | 35 +++++++++++++++++++++++++++++++++++ 2 files changed, 36 insertions(+) diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 29c3ea5b6e93..a871533b8568 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -1433,6 +1433,7 @@ void skb_prepare_seq_read(struct sk_buff *skb, unsigned int from, unsigned int skb_seq_read(unsigned int consumed, const u8 **data, struct skb_seq_state *st); void skb_abort_seq_read(struct skb_seq_state *st); +int skb_copy_seq_read(struct skb_seq_state *st, int offset, void *to, int len); unsigned int skb_find_text(struct sk_buff *skb, unsigned int from, unsigned int to, struct ts_config *config); diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 83f8cd8aa2d1..fe4b2dc5c19b 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -4409,6 +4409,41 @@ void skb_abort_seq_read(struct skb_seq_state *st) } EXPORT_SYMBOL(skb_abort_seq_read); +/** + * skb_copy_seq_read() - copy from a skb_seq_state to a buffer + * @st: source skb_seq_state + * @offset: offset in source + * @to: destination buffer + * @len: number of bytes to copy + * + * Copy @len bytes from @offset bytes into the source @st to the destination + * buffer @to. `offset` should increase (or be unchanged) with each subsequent + * call to this function. If offset needs to decrease from the previous use `st` + * should be reset first. + * + * Return: 0 on success or -EINVAL if the copy ended early + */ +int skb_copy_seq_read(struct skb_seq_state *st, int offset, void *to, int len) +{ + const u8 *data; + u32 sqlen; + + for (;;) { + sqlen = skb_seq_read(offset, &data, st); + if (sqlen == 0) + return -EINVAL; + if (sqlen >= len) { + memcpy(to, data, len); + return 0; + } + memcpy(to, data, sqlen); + to += sqlen; + offset += sqlen; + len -= sqlen; + } +} +EXPORT_SYMBOL(skb_copy_seq_read); + #define TS_SKB_CB(state) ((struct skb_seq_state *) &((state)->cb)) static unsigned int skb_ts_get_next_block(unsigned int offset, const u8 **text,