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Commit 6697dabe authored by Martin Townsend's avatar Martin Townsend Committed by Marcel Holtmann
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ieee802154: 6lowpan: ensure MTU of 1280 for 6lowpan 



This patch drops the userspace accessable sysfs entry for the maximum
datagram size of a 6LoWPAN fragment packet.

A fragment should not have a datagram size value greater than 1280 byte.
Instead of make this value configurable, we accept 1280 datagram size
fragment packets only.

Signed-off-by: default avatarMartin Townsend <martin.townsend@xsilon.com>
Signed-off-by: default avatarAlexander Aring <alex.aring@gmail.com>
Signed-off-by: default avatarMarcel Holtmann <marcel@holtmann.org>
parent 685d6328

include/net/netns/ieee802154_6lowpan.h

+0 −1
Original line number Diff line number Diff line
@@ -16,7 +16,6 @@ struct netns_sysctl_lowpan { 
struct netns_ieee802154_lowpan {

	struct netns_sysctl_lowpan sysctl;

	struct netns_frags	frags;

	int			max_dsize;

};



#endif

net/ieee802154/reassembly.c

+3 −12
Original line number Diff line number Diff line
@@ -355,8 +355,6 @@ int lowpan_frag_rcv(struct sk_buff *skb, const u8 frag_type) 
	struct net *net = dev_net(skb->dev);

	struct lowpan_frag_info *frag_info = lowpan_cb(skb);

	struct ieee802154_addr source, dest;

	struct netns_ieee802154_lowpan *ieee802154_lowpan =

		net_ieee802154_lowpan(net);

	int err;



	source = mac_cb(skb)->source;
@@ -366,8 +364,10 @@ int lowpan_frag_rcv(struct sk_buff *skb, const u8 frag_type) 
	if (err < 0)

		goto err;



	if (frag_info->d_size > ieee802154_lowpan->max_dsize)

	if (frag_info->d_size > IPV6_MIN_MTU) {

		net_warn_ratelimited("lowpan_frag_rcv: datagram size exceeds MTU\n");

		goto err;

	}



	fq = fq_find(net, frag_info, &source, &dest);

	if (fq != NULL) {
@@ -415,13 +415,6 @@ static struct ctl_table lowpan_frags_ns_ctl_table[] = { 
		.mode		= 0644,

		.proc_handler	= proc_dointvec_jiffies,

	},

	{

		.procname	= "6lowpanfrag_max_datagram_size",

		.data		= &init_net.ieee802154_lowpan.max_dsize,

		.maxlen		= sizeof(int),

		.mode		= 0644,

		.proc_handler	= proc_dointvec

	},

	{ }

};
@@ -458,7 +451,6 @@ static int __net_init lowpan_frags_ns_sysctl_register(struct net *net) 
		table[1].data = &ieee802154_lowpan->frags.low_thresh;

		table[1].extra2 = &ieee802154_lowpan->frags.high_thresh;

		table[2].data = &ieee802154_lowpan->frags.timeout;

		table[3].data = &ieee802154_lowpan->max_dsize;



		/* Don't export sysctls to unprivileged users */

		if (net->user_ns != &init_user_ns)
@@ -533,7 +525,6 @@ static int __net_init lowpan_frags_init_net(struct net *net) 
	ieee802154_lowpan->frags.high_thresh = IPV6_FRAG_HIGH_THRESH;

	ieee802154_lowpan->frags.low_thresh = IPV6_FRAG_LOW_THRESH;

	ieee802154_lowpan->frags.timeout = IPV6_FRAG_TIMEOUT;

	ieee802154_lowpan->max_dsize = 0xFFFF;



	inet_frags_init_net(&ieee802154_lowpan->frags);