netdev - [PATCH v2 net-next 1/4] net: Add ndo_enc_hdr_len to notify extra header room for encapsulated frames

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]

Message-Id: <1445830859-4651-2-git-send-email-makita.toshiaki@lab.ntt.co.jp>
Date:	Mon, 26 Oct 2015 12:40:56 +0900
From:	Toshiaki Makita <makita.toshiaki@....ntt.co.jp>
To:	"David S . Miller" <davem@...emloft.net>
Cc:	Toshiaki Makita <makita.toshiaki@....ntt.co.jp>,
	Patrick McHardy <kaber@...sh.net>,
	Stephen Hemminger <stephen@...workplumber.org>,
	Vlad Yasevich <vyasevich@...il.com>,
	Jeff Kirsher <jeffrey.t.kirsher@...el.com>,
	intel-wired-lan@...ts.osuosl.org, toshiaki.makita1@...il.com,
	netdev@...r.kernel.org
Subject: [PATCH v2 net-next 1/4] net: Add ndo_enc_hdr_len to notify extra header room for encapsulated frames

Currently most NICs reserve 1522 bytes space for frames to handle 4
bytes VLAN header in addition to 1518, maximum size of ethernet frame.
This is, however, not sufficient when stacked vlan or other encapsulation
protocols are used.
To accommodate this, add .ndo_enc_hdr_len() and inform drivers of needed
encapsulation header size.

Signed-off-by: Toshiaki Makita <makita.toshiaki@....ntt.co.jp>
---
 include/linux/netdevice.h |  9 +++++++++
 net/core/dev.c            | 36 ++++++++++++++++++++++++++++++++++++
 2 files changed, 45 insertions(+)

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 4ac653b..1b2b587 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -1059,6 +1059,10 @@ typedef u16 (*select_queue_fallback_t)(struct net_device *dev,
  *	This function is used to get egress tunnel information for given skb.
  *	This is useful for retrieving outer tunnel header parameters while
  *	sampling packet.
+ * int (*ndo_enc_hdr_len)(struct net_device *dev, int hdr_len);
+ *	Called to notify addtional encapsulation header length to reserve.
+ *	Implements should reserve hdr_len room in addition to MTU to handle
+ *	encapsulated frames.
  *
  */
 struct net_device_ops {
@@ -1236,6 +1240,8 @@ struct net_device_ops {
 							 bool proto_down);
 	int			(*ndo_fill_metadata_dst)(struct net_device *dev,
 						       struct sk_buff *skb);
+	int			(*ndo_enc_hdr_len)(struct net_device *dev,
+						   int hdr_len);
 };
 
 /**
@@ -1396,6 +1402,7 @@ enum netdev_priv_flags {
  *	@if_port:	Selectable AUI, TP, ...
  *	@dma:		DMA channel
  *	@mtu:		Interface MTU value
+ *	@enc_hdr_len:	Additional encapsulation header length to MTU
  *	@type:		Interface hardware type
  *	@hard_header_len: Hardware header length
  *
@@ -1616,6 +1623,7 @@ struct net_device {
 	unsigned char		dma;
 
 	unsigned int		mtu;
+	unsigned int		enc_hdr_len;
 	unsigned short		type;
 	unsigned short		hard_header_len;
 
@@ -3031,6 +3039,7 @@ int dev_change_name(struct net_device *, const char *);
 int dev_set_alias(struct net_device *, const char *, size_t);
 int dev_change_net_namespace(struct net_device *, struct net *, const char *);
 int dev_set_mtu(struct net_device *, int);
+int dev_set_enc_hdr_len(struct net_device *, int);
 void dev_set_group(struct net_device *, int);
 int dev_set_mac_address(struct net_device *, struct sockaddr *);
 int dev_change_carrier(struct net_device *, bool new_carrier);
diff --git a/net/core/dev.c b/net/core/dev.c
index 13f49f8..7c4114b 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -6051,6 +6051,42 @@ int dev_set_mtu(struct net_device *dev, int new_mtu)
 EXPORT_SYMBOL(dev_set_mtu);
 
 /**
+ *	dev_set_enc_hdr_len - Expand encapsulation header room
+ *	@dev: device
+ *	@new_len: new length
+ */
+int dev_set_enc_hdr_len(struct net_device *dev, int new_len)
+{
+	const struct net_device_ops *ops = dev->netdev_ops;
+
+	if (new_len < 0)
+		return -EINVAL;
+
+	if (!netif_device_present(dev))
+		return -ENODEV;
+
+	if (new_len <= dev->enc_hdr_len)
+		return 0;
+
+	if (ops->ndo_enc_hdr_len) {
+		int err;
+
+		/* This function can be called from child user/net namespace */
+		if (!ns_capable(dev_net(dev)->user_ns, CAP_NET_ADMIN))
+			return -EPERM;
+
+		err = ops->ndo_enc_hdr_len(dev, new_len);
+		if (err)
+			return err;
+	}
+
+	dev->enc_hdr_len = new_len;
+
+	return 0;
+}
+EXPORT_SYMBOL(dev_set_enc_hdr_len);
+
+/**
  *	dev_set_group - Change group this device belongs to
  *	@dev: device
  *	@new_group: group this device should belong to
-- 
1.8.1.2


--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html