From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8A4771A5B85; Sun, 11 May 2025 00:41:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746924098; cv=none; b=XokIHpypDLhjEFY5A/iuRUvg5rFfBxIA40FrvuZUsVWUQ/ivbwDtodOqaapN5vM2xLVD2RUMCaoOQ9W+0sHbFmRdAoiaJTKfdZmtUEOFD6+TzIkf60pF63ComhxyqRkXdNLlz1/R3UGjAb8sic4pukaEKAiQ6pc3mm7YrWa1rT0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746924098; c=relaxed/simple; bh=LyWew4r7C8/s4G5rA7UFXiI52nXjAIqNl5KwWhIs7mU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=pKhkSTuxe/subqwJ6MaMtVIpOaVreaLbdgOEEgcxD+6Du+ClaEy2g2gG27uj/2wIJwaCVwGL7OhTzk/LxhPxcDUWzVY3oxWriPeDdb3DrzbLOnaBN5ptak32Tc246YxC7cl5nb6FfJL5FrlUeJ9k53MNHlrygH3kWLLjRRE5RIo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=oV1P3UPx; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="oV1P3UPx" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 180BBC4CEEE; Sun, 11 May 2025 00:41:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1746924097; bh=LyWew4r7C8/s4G5rA7UFXiI52nXjAIqNl5KwWhIs7mU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=oV1P3UPxoSVSGXQHgQoCgxQxJfnGE9kH5epMt277/kKhANGjbgtMM1DFdm4rIsSS4 TnqojLLfFjobtF4Q71jGxB0fWr/mtuVa8bD54vddcKJX3zFoYSvOFokidXlrJSQxBd N8KAuZAcGjDhA53zHmLcWxQ419JOB0h5aM46AgVj/JXtv85HaFzbPl952PqFtWtcCG qOP47npu4FmQUYlvlZnrcatvjepKQFdB3TsehGMLv2FgrV+8Dd6g1AYGbFPaV+uZpX CWOCT2fkIgnWxKg2w3yg/yEvNkNvuXOo2ZiY8ekqJVAOxhmnz63kyMtqLjRGHgnLAD EfxeNQc950JnQ== From: Eric Biggers To: netdev@vger.kernel.org Cc: linux-nvme@lists.infradead.org, linux-sctp@vger.kernel.org, linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org, Daniel Borkmann , Marcelo Ricardo Leitner , Sagi Grimberg , Ard Biesheuvel Subject: [PATCH net-next 08/10] net: add skb_copy_and_crc32c_datagram_iter() Date: Sat, 10 May 2025 17:41:08 -0700 Message-ID: <20250511004110.145171-9-ebiggers@kernel.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250511004110.145171-1-ebiggers@kernel.org> References: <20250511004110.145171-1-ebiggers@kernel.org> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Eric Biggers Since skb_copy_and_hash_datagram_iter() is used only with CRC32C, the crypto_ahash abstraction provides no value. Add skb_copy_and_crc32c_datagram_iter() which just calls crc32c() directly. This is faster and simpler. It also doesn't have the weird dependency issue where skb_copy_and_hash_datagram_iter() depends on CONFIG_CRYPTO_HASH=y without that being expressed explicitly in the kconfig (presumably because it was too heavyweight for NET to select). The new function is conditional on the hidden boolean symbol NET_CRC32C, which selects CRC32. So it gets compiled only when something that actually needs CRC32C packet checksums is enabled, it has no implicit dependency, and it doesn't depend on the heavyweight crypto layer. Signed-off-by: Eric Biggers --- include/linux/skbuff.h | 2 ++ net/core/datagram.c | 31 +++++++++++++++++++++++++++++++ 2 files changed, 33 insertions(+) diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index eac5c8dde4a5..0027f2977c02 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -4126,10 +4126,12 @@ static inline int skb_copy_datagram_msg(const struct sk_buff *from, int offset, int skb_copy_and_csum_datagram_msg(struct sk_buff *skb, int hlen, struct msghdr *msg); int skb_copy_and_hash_datagram_iter(const struct sk_buff *skb, int offset, struct iov_iter *to, int len, struct ahash_request *hash); +int skb_copy_and_crc32c_datagram_iter(const struct sk_buff *skb, int offset, + struct iov_iter *to, int len, u32 *crcp); int skb_copy_datagram_from_iter(struct sk_buff *skb, int offset, struct iov_iter *from, int len); int zerocopy_sg_from_iter(struct sk_buff *skb, struct iov_iter *frm); void skb_free_datagram(struct sock *sk, struct sk_buff *skb); int skb_kill_datagram(struct sock *sk, struct sk_buff *skb, unsigned int flags); diff --git a/net/core/datagram.c b/net/core/datagram.c index f0634f0cb834..47a6eef83162 100644 --- a/net/core/datagram.c +++ b/net/core/datagram.c @@ -50,10 +50,11 @@ #include #include #include #include #include +#include #include #include #include @@ -515,10 +516,40 @@ int skb_copy_and_hash_datagram_iter(const struct sk_buff *skb, int offset, return __skb_datagram_iter(skb, offset, to, len, true, hash_and_copy_to_iter, hash); } EXPORT_SYMBOL(skb_copy_and_hash_datagram_iter); +#ifdef CONFIG_NET_CRC32C +static size_t crc32c_and_copy_to_iter(const void *addr, size_t bytes, + void *_crcp, struct iov_iter *i) +{ + u32 *crcp = _crcp; + size_t copied; + + copied = copy_to_iter(addr, bytes, i); + *crcp = crc32c(*crcp, addr, copied); + return copied; +} + +/** + * skb_copy_and_crc32c_datagram_iter - Copy datagram to an iovec iterator + * and update a CRC32C value. + * @skb: buffer to copy + * @offset: offset in the buffer to start copying from + * @to: iovec iterator to copy to + * @len: amount of data to copy from buffer to iovec + * @crcp: pointer to CRC32C value to update + */ +int skb_copy_and_crc32c_datagram_iter(const struct sk_buff *skb, int offset, + struct iov_iter *to, int len, u32 *crcp) +{ + return __skb_datagram_iter(skb, offset, to, len, true, + crc32c_and_copy_to_iter, crcp); +} +EXPORT_SYMBOL(skb_copy_and_crc32c_datagram_iter); +#endif /* CONFIG_NET_CRC32C */ + static size_t simple_copy_to_iter(const void *addr, size_t bytes, void *data __always_unused, struct iov_iter *i) { return copy_to_iter(addr, bytes, i); } -- 2.49.0