netdev - Re: [PATCH net-next 4/6] net: dsa: tag_rtl8_4: add realtek 8 byte protocol 4 tag

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Wed, 13 Oct 2021 17:45:16 +0800
From:   DENG Qingfang <dqfext@...il.com>
To:     Alvin Šipraga <alvin@...s.dk>
Cc:     Linus Walleij <linus.walleij@...aro.org>,
        Andrew Lunn <andrew@...n.ch>,
        Vivien Didelot <vivien.didelot@...il.com>,
        Florian Fainelli <f.fainelli@...il.com>,
        Vladimir Oltean <olteanv@...il.com>,
        "David S. Miller" <davem@...emloft.net>,
        Jakub Kicinski <kuba@...nel.org>,
        Rob Herring <robh+dt@...nel.org>,
        Heiner Kallweit <hkallweit1@...il.com>,
        Russell King <linux@...linux.org.uk>,
        Alvin Šipraga <alsi@...g-olufsen.dk>,
        netdev@...r.kernel.org, devicetree@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH net-next 4/6] net: dsa: tag_rtl8_4: add realtek 8 byte protocol 4 tag

On Tue, Oct 12, 2021 at 02:35:53PM +0200, Alvin Šipraga wrote:
> +static struct sk_buff *rtl8_4_tag_rcv(struct sk_buff *skb,
> +				      struct net_device *dev)
> +{
> +	__be16 *tag;
> +	u16 etype;
> +	u8 proto;
> +	u8 port;
> +
> +	if (unlikely(!pskb_may_pull(skb, RTL8_4_TAG_LEN)))
> +		return NULL;
> +
> +	tag = dsa_etype_header_pos_rx(skb);
> +
> +	/* Parse Realtek EtherType */
> +	etype = ntohs(tag[0]);
> +	if (unlikely(etype != ETH_P_REALTEK)) {
> +		dev_warn_ratelimited(&dev->dev,
> +				     "non-realtek ethertype 0x%04x\n", etype);
> +		return NULL;
> +	}
> +
> +	/* Parse Protocol */
> +	proto = ntohs(tag[1]) >> 8;
> +	if (unlikely(proto != RTL8_4_PROTOCOL_RTL8365MB)) {
> +		dev_warn_ratelimited(&dev->dev,
> +				     "unknown realtek protocol 0x%02x\n",
> +				     proto);
> +		return NULL;
> +	}
> +
> +	/* Parse TX (switch->CPU) */
> +	port = ntohs(tag[3]) & 0xf; /* Port number is the LSB 4 bits */
> +	skb->dev = dsa_master_find_slave(dev, 0, port);
> +	if (!skb->dev) {
> +		dev_warn_ratelimited(&dev->dev,
> +				     "could not find slave for port %d\n",
> +				     port);
> +		return NULL;
> +	}
> +
> +	/* Remove tag and recalculate checksum */
> +	skb_pull_rcsum(skb, RTL8_4_TAG_LEN);
> +
> +	dsa_strip_etype_header(skb, RTL8_4_TAG_LEN);
> +
> +	dsa_default_offload_fwd_mark(skb);

This should not be set if the REASON is trapped to CPU.

> +
> +	return skb;
> +}