From 6697dabe27e03302ddfddc975275e6401defe2dd Mon Sep 17 00:00:00 2001 From: Martin Townsend Date: Tue, 19 Aug 2014 19:03:32 +0200 Subject: [PATCH] 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: Martin Townsend Signed-off-by: Alexander Aring Signed-off-by: Marcel Holtmann --- include/net/netns/ieee802154_6lowpan.h | 1 - net/ieee802154/reassembly.c | 15 +++------------ 2 files changed, 3 insertions(+), 13 deletions(-) diff --git a/include/net/netns/ieee802154_6lowpan.h b/include/net/netns/ieee802154_6lowpan.h index e2070960bac0..8170f8d7052b 100644 --- a/include/net/netns/ieee802154_6lowpan.h +++ b/include/net/netns/ieee802154_6lowpan.h @@ -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 diff --git a/net/ieee802154/reassembly.c b/net/ieee802154/reassembly.c index ffec6ce51005..32755cb7e64e 100644 --- a/net/ieee802154/reassembly.c +++ b/net/ieee802154/reassembly.c @@ -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); -- 2.39.5