From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from dvalin.narfation.org (dvalin.narfation.org [213.160.73.56]) (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 7A2A42BEC3D for ; Sun, 28 Sep 2025 08:45:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=213.160.73.56 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1759049121; cv=none; b=HJwDxGlAyMwySGLcJ1G0un/O3aURB95kDx07QbH+La/Zp4pbXiulpxPBrPPRgv2h2xYXJhU5kr2LH8u+l/D3gCg0mL2cLa1NQ0VIuZc2DUH+MrHZx+vgg3r1PWrlGabPH45yhTZzvX7zjGEpPQPWAMKAc38vuAgpfOg53D/mlOg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1759049121; c=relaxed/simple; bh=ZUVKLe6F46uF+OsnRxkSG5JX6sgTmN/uQ+y6yqeh2K0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=sdL2YLTwhl6ZhBWumTyUGewf7WAnJULvafj+KcCXHqqjuXZ8FAQgxUNgK744Y+QeF0QdOaOZS5rjcPZBUF4xQ2raP2CIPqWlbk9YQKhUjEhX1OevX8VHnVtPQHPasnQphyM/NOkkKfGKxxok6XKfkL6Z41oEjK7FfoG6YOAJR/c= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=narfation.org; spf=pass smtp.mailfrom=narfation.org; dkim=pass (1024-bit key) header.d=narfation.org header.i=@narfation.org header.b=P91IYOJk; arc=none smtp.client-ip=213.160.73.56 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=narfation.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=narfation.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=narfation.org header.i=@narfation.org header.b="P91IYOJk" Received: by dvalin.narfation.org (Postfix) id 246D82054D; Sun, 28 Sep 2025 08:45:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=narfation.org; s=20121; t=1759049115; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=jM7Ox3+Ul4dOIfVByBI3tj0o8LxVWBiiGDPq1t2V7FY=; b=P91IYOJk5Q6yuHqV/tJlwva9JKaGlRMiHSULbqaKZbKROaV3t6vufMNH7avrjFIftjczDl sFYDKaWHVJAcmGfIQ2H0BNwUgOHthtNYhvE2fY1/Zi4yKIRuWlYF7bBH5I3pnxcz5U7Rdy lsTc5Se3ircXO/eh6PS2hbILQXR/M4I= From: Sven Eckelmann To: Eric Biggers Cc: Simon Wunderlich , kuba@kernel.org, davem@davemloft.net, netdev@vger.kernel.org, b.a.t.m.a.n@lists.open-mesh.org Subject: Re: [PATCH net-next 3/4] batman-adv: keep skb crc32 helper local in BLA Date: Sun, 28 Sep 2025 10:45:12 +0200 Message-ID: <2878689.BEx9A2HvPv@sven-desktop> In-Reply-To: <20250927205552.GD9798@quark> References: <20250916122441.89246-1-sw@simonwunderlich.de> <20250916122441.89246-4-sw@simonwunderlich.de> <20250927205552.GD9798@quark> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: multipart/signed; boundary="nextPart15571232.tv2OnDr8pf"; micalg="pgp-sha512"; protocol="application/pgp-signature" --nextPart15571232.tv2OnDr8pf Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="utf-8"; protected-headers="v1" From: Sven Eckelmann To: Eric Biggers Date: Sun, 28 Sep 2025 10:45:12 +0200 Message-ID: <2878689.BEx9A2HvPv@sven-desktop> In-Reply-To: <20250927205552.GD9798@quark> MIME-Version: 1.0 On Saturday, 27 September 2025 22:55:52 CEST Eric Biggers wrote: > Hi, > > On Tue, Sep 16, 2025 at 02:24:40PM +0200, Simon Wunderlich wrote: > > +static __be32 batadv_skb_crc32(struct sk_buff *skb, u8 *payload_ptr) > > +{ > > + unsigned int to = skb->len; > > + unsigned int consumed = 0; > > + struct skb_seq_state st; > > + unsigned int from; > > + unsigned int len; > > + const u8 *data; > > + u32 crc = 0; > > + > > + from = (unsigned int)(payload_ptr - skb->data); > > + > > + skb_prepare_seq_read(skb, from, to, &st); > > + while ((len = skb_seq_read(consumed, &data, &st)) != 0) { > > + crc = crc32c(crc, data, len); > > + consumed += len; > > + } > > + > > + return htonl(crc); > > +} > > Has using skb_crc32c() been considered here? No. At the time this was written (v3.8), skb_crc32c (v6.16) didnt exist. Also its predecessor __skb_checksum only started its existence in v3.13. And no one noticed it as candidate to replace batadv_skb_crc32 with And this patch here was just moving the function between two places - so not introducing new code. Do you want to submit a patch to integrate your new function in batman-adv? I only performed a quick-and-dirty test to see if it returns the same results and it seemed to do its job fine. diff --git c/net/batman-adv/Kconfig w/net/batman-adv/Kconfig index c299e2bc..58c408b7 100644 --- c/net/batman-adv/Kconfig +++ w/net/batman-adv/Kconfig @@ -35,6 +35,7 @@ config BATMAN_ADV_BLA bool "Bridge Loop Avoidance" depends on BATMAN_ADV && INET select CRC16 + select NET_CRC32C default y help This option enables BLA (Bridge Loop Avoidance), a mechanism diff --git c/net/batman-adv/bridge_loop_avoidance.c w/net/batman-adv/bridge_loop_avoidance.c index b992ba12..eef40b6f 100644 --- c/net/batman-adv/bridge_loop_avoidance.c +++ w/net/batman-adv/bridge_loop_avoidance.c @@ -12,7 +12,6 @@ #include #include #include -#include #include #include #include @@ -1585,45 +1584,11 @@ int batadv_bla_init(struct batadv_priv *bat_priv) return 0; } -/** - * batadv_skb_crc32() - calculate CRC32 of the whole packet and skip bytes in - * the header - * @skb: skb pointing to fragmented socket buffers - * @payload_ptr: Pointer to position inside the head buffer of the skb - * marking the start of the data to be CRC'ed - * - * payload_ptr must always point to an address in the skb head buffer and not to - * a fragment. - * - * Return: big endian crc32c of the checksummed data - */ -static __be32 batadv_skb_crc32(struct sk_buff *skb, u8 *payload_ptr) -{ - unsigned int to = skb->len; - unsigned int consumed = 0; - struct skb_seq_state st; - unsigned int from; - unsigned int len; - const u8 *data; - u32 crc = 0; - - from = (unsigned int)(payload_ptr - skb->data); - - skb_prepare_seq_read(skb, from, to, &st); - while ((len = skb_seq_read(consumed, &data, &st)) != 0) { - crc = crc32c(crc, data, len); - consumed += len; - } - - return htonl(crc); -} - /** * batadv_bla_check_duplist() - Check if a frame is in the broadcast dup. * @bat_priv: the bat priv with all the mesh interface information * @skb: contains the multicast packet to be checked - * @payload_ptr: pointer to position inside the head buffer of the skb - * marking the start of the data to be CRC'ed + * @payload_offset: offset in the skb, marking the start of the data to be CRC'ed * @orig: originator mac address, NULL if unknown * * Check if it is on our broadcast list. Another gateway might have sent the @@ -1638,16 +1603,18 @@ static __be32 batadv_skb_crc32(struct sk_buff *skb, u8 *payload_ptr) * Return: true if a packet is in the duplicate list, false otherwise. */ static bool batadv_bla_check_duplist(struct batadv_priv *bat_priv, - struct sk_buff *skb, u8 *payload_ptr, + struct sk_buff *skb, int payload_offset, const u8 *orig) { struct batadv_bcast_duplist_entry *entry; bool ret = false; + int payload_len; int i, curr; __be32 crc; /* calculate the crc ... */ - crc = batadv_skb_crc32(skb, payload_ptr); + payload_len = skb->len - payload_offset; + crc = htonl(skb_crc32c(skb, payload_offset, payload_len, 0)); spin_lock_bh(&bat_priv->bla.bcast_duplist_lock); @@ -1727,7 +1694,7 @@ static bool batadv_bla_check_duplist(struct batadv_priv *bat_priv, static bool batadv_bla_check_ucast_duplist(struct batadv_priv *bat_priv, struct sk_buff *skb) { - return batadv_bla_check_duplist(bat_priv, skb, (u8 *)skb->data, NULL); + return batadv_bla_check_duplist(bat_priv, skb, 0, NULL); } /** @@ -1745,12 +1712,10 @@ bool batadv_bla_check_bcast_duplist(struct batadv_priv *bat_priv, struct sk_buff *skb) { struct batadv_bcast_packet *bcast_packet; - u8 *payload_ptr; bcast_packet = (struct batadv_bcast_packet *)skb->data; - payload_ptr = (u8 *)(bcast_packet + 1); - return batadv_bla_check_duplist(bat_priv, skb, payload_ptr, + return batadv_bla_check_duplist(bat_priv, skb, sizeof(*bcast_packet), bcast_packet->orig); } Regards, Sven --nextPart15571232.tv2OnDr8pf Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part. 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