This is a note to let you know that I've just added the patch titled
ip: generate unique IP identificator if local fragmentation is allowed
to the 3.0-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
ip-generate-unique-ip-identificator-if-local-fragmentation-is-allowed.patch
and it can be found in the queue-3.0 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From e5bac32e196e16f1bfac0ecc7491706c7a11fe79 Mon Sep 17 00:00:00 2001
From: Ansis Atteka <aatteka@xxxxxxxxxx>
Date: Wed, 18 Sep 2013 15:29:53 -0700
Subject: ip: generate unique IP identificator if local fragmentation is allowed
From: Ansis Atteka <aatteka@xxxxxxxxxx>
[ Upstream commit 703133de331a7a7df47f31fb9de51dc6f68a9de8 ]
If local fragmentation is allowed, then ip_select_ident() and
ip_select_ident_more() need to generate unique IDs to ensure
correct defragmentation on the peer.
For example, if IPsec (tunnel mode) has to encrypt large skbs
that have local_df bit set, then all IP fragments that belonged
to different ESP datagrams would have used the same identificator.
If one of these IP fragments would get lost or reordered, then
peer could possibly stitch together wrong IP fragments that did
not belong to the same datagram. This would lead to a packet loss
or data corruption.
Signed-off-by: Ansis Atteka <aatteka@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/net/pptp.c | 2 +-
include/net/ip.h | 12 ++++++++----
include/net/ipip.h | 2 +-
net/ipv4/igmp.c | 4 ++--
net/ipv4/inetpeer.c | 4 ++--
net/ipv4/ip_output.c | 6 +++---
net/ipv4/ipmr.c | 2 +-
net/ipv4/raw.c | 2 +-
net/ipv4/xfrm4_mode_tunnel.c | 2 +-
net/netfilter/ipvs/ip_vs_xmit.c | 2 +-
10 files changed, 21 insertions(+), 17 deletions(-)
--- a/drivers/net/pptp.c
+++ b/drivers/net/pptp.c
@@ -282,7 +282,7 @@ static int pptp_xmit(struct ppp_channel
nf_reset(skb);
skb->ip_summed = CHECKSUM_NONE;
- ip_select_ident(iph, &rt->dst, NULL);
+ ip_select_ident(skb, &rt->dst, NULL);
ip_send_check(iph);
ip_local_out(skb);
--- a/include/net/ip.h
+++ b/include/net/ip.h
@@ -262,9 +262,11 @@ int ip_dont_fragment(struct sock *sk, st
extern void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more);
-static inline void ip_select_ident(struct iphdr *iph, struct dst_entry *dst, struct sock *sk)
+static inline void ip_select_ident(struct sk_buff *skb, struct dst_entry *dst, struct sock *sk)
{
- if (iph->frag_off & htons(IP_DF)) {
+ struct iphdr *iph = ip_hdr(skb);
+
+ if ((iph->frag_off & htons(IP_DF)) && !skb->local_df) {
/* This is only to work around buggy Windows95/2000
* VJ compression implementations. If the ID field
* does not change, they drop every other packet in
@@ -276,9 +278,11 @@ static inline void ip_select_ident(struc
__ip_select_ident(iph, dst, 0);
}
-static inline void ip_select_ident_more(struct iphdr *iph, struct dst_entry *dst, struct sock *sk, int more)
+static inline void ip_select_ident_more(struct sk_buff *skb, struct dst_entry *dst, struct sock *sk, int more)
{
- if (iph->frag_off & htons(IP_DF)) {
+ struct iphdr *iph = ip_hdr(skb);
+
+ if ((iph->frag_off & htons(IP_DF)) && !skb->local_df) {
if (sk && inet_sk(sk)->inet_daddr) {
iph->id = htons(inet_sk(sk)->inet_id);
inet_sk(sk)->inet_id += 1 + more;
--- a/include/net/ipip.h
+++ b/include/net/ipip.h
@@ -50,7 +50,7 @@ struct ip_tunnel_prl_entry {
int pkt_len = skb->len - skb_transport_offset(skb); \
\
skb->ip_summed = CHECKSUM_NONE; \
- ip_select_ident(iph, &rt->dst, NULL); \
+ ip_select_ident(skb, &rt->dst, NULL); \
\
err = ip_local_out(skb); \
if (likely(net_xmit_eval(err) == 0)) { \
--- a/net/ipv4/igmp.c
+++ b/net/ipv4/igmp.c
@@ -342,7 +342,7 @@ static struct sk_buff *igmpv3_newpack(st
pip->saddr = fl4.saddr;
pip->protocol = IPPROTO_IGMP;
pip->tot_len = 0; /* filled in later */
- ip_select_ident(pip, &rt->dst, NULL);
+ ip_select_ident(skb, &rt->dst, NULL);
((u8*)&pip[1])[0] = IPOPT_RA;
((u8*)&pip[1])[1] = 4;
((u8*)&pip[1])[2] = 0;
@@ -683,7 +683,7 @@ static int igmp_send_report(struct in_de
iph->daddr = dst;
iph->saddr = fl4.saddr;
iph->protocol = IPPROTO_IGMP;
- ip_select_ident(iph, &rt->dst, NULL);
+ ip_select_ident(skb, &rt->dst, NULL);
((u8*)&iph[1])[0] = IPOPT_RA;
((u8*)&iph[1])[1] = 4;
((u8*)&iph[1])[2] = 0;
--- a/net/ipv4/inetpeer.c
+++ b/net/ipv4/inetpeer.c
@@ -31,8 +31,8 @@
* At the moment of writing this notes identifier of IP packets is generated
* to be unpredictable using this code only for packets subjected
* (actually or potentially) to defragmentation. I.e. DF packets less than
- * PMTU in size uses a constant ID and do not use this code (see
- * ip_select_ident() in include/net/ip.h).
+ * PMTU in size when local fragmentation is disabled use a constant ID and do
+ * not use this code (see ip_select_ident() in include/net/ip.h).
*
* Route cache entries hold references to our nodes.
* New cache entries get references via lookup by destination IP address in
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -161,7 +161,7 @@ int ip_build_and_send_pkt(struct sk_buff
iph->daddr = (opt && opt->opt.srr ? opt->opt.faddr : daddr);
iph->saddr = saddr;
iph->protocol = sk->sk_protocol;
- ip_select_ident(iph, &rt->dst, sk);
+ ip_select_ident(skb, &rt->dst, sk);
if (opt && opt->opt.optlen) {
iph->ihl += opt->opt.optlen>>2;
@@ -397,7 +397,7 @@ packet_routed:
ip_options_build(skb, &inet_opt->opt, inet->inet_daddr, rt, 0);
}
- ip_select_ident_more(iph, &rt->dst, sk,
+ ip_select_ident_more(skb, &rt->dst, sk,
(skb_shinfo(skb)->gso_segs ?: 1) - 1);
skb->priority = sk->sk_priority;
@@ -1340,7 +1340,7 @@ struct sk_buff *__ip_make_skb(struct soc
iph->ihl = 5;
iph->tos = inet->tos;
iph->frag_off = df;
- ip_select_ident(iph, &rt->dst, sk);
+ ip_select_ident(skb, &rt->dst, sk);
iph->ttl = ttl;
iph->protocol = sk->sk_protocol;
iph->saddr = fl4->saddr;
--- a/net/ipv4/ipmr.c
+++ b/net/ipv4/ipmr.c
@@ -1575,7 +1575,7 @@ static void ip_encap(struct sk_buff *skb
iph->protocol = IPPROTO_IPIP;
iph->ihl = 5;
iph->tot_len = htons(skb->len);
- ip_select_ident(iph, skb_dst(skb), NULL);
+ ip_select_ident(skb, skb_dst(skb), NULL);
ip_send_check(iph);
memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
--- a/net/ipv4/raw.c
+++ b/net/ipv4/raw.c
@@ -379,7 +379,7 @@ static int raw_send_hdrinc(struct sock *
iph->check = 0;
iph->tot_len = htons(length);
if (!iph->id)
- ip_select_ident(iph, &rt->dst, NULL);
+ ip_select_ident(skb, &rt->dst, NULL);
iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl);
}
--- a/net/ipv4/xfrm4_mode_tunnel.c
+++ b/net/ipv4/xfrm4_mode_tunnel.c
@@ -54,7 +54,7 @@ static int xfrm4_mode_tunnel_output(stru
top_iph->frag_off = (flags & XFRM_STATE_NOPMTUDISC) ?
0 : (XFRM_MODE_SKB_CB(skb)->frag_off & htons(IP_DF));
- ip_select_ident(top_iph, dst->child, NULL);
+ ip_select_ident(skb, dst->child, NULL);
top_iph->ttl = ip4_dst_hoplimit(dst->child);
--- a/net/netfilter/ipvs/ip_vs_xmit.c
+++ b/net/netfilter/ipvs/ip_vs_xmit.c
@@ -853,7 +853,7 @@ ip_vs_tunnel_xmit(struct sk_buff *skb, s
iph->daddr = cp->daddr.ip;
iph->saddr = saddr;
iph->ttl = old_iph->ttl;
- ip_select_ident(iph, &rt->dst, NULL);
+ ip_select_ident(skb, &rt->dst, NULL);
/* Another hack: avoid icmp_send in ip_fragment */
skb->local_df = 1;
Patches currently in stable-queue which might be from aatteka@xxxxxxxxxx are
queue-3.0/ip-generate-unique-ip-identificator-if-local-fragmentation-is-allowed.patch
--
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