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authorJan Luebbe <jluebbe@debian.org>2011-03-24 07:44:22 +0000
committerDavid S. Miller <davem@davemloft.net>2011-03-27 23:35:02 -0700
commit8628bd8af7c4c14f40f5183f80f5744c4e682439 (patch)
treed931f03c6ef14ad8df7c6c697e56081f816c2af7 /net
parentdc760b375e50a47847d4942811bd9679beeb5535 (diff)
downloadlinux-8628bd8af7c4c14f40f5183f80f5744c4e682439.tar.gz
ipv4: Fix IP timestamp option (IPOPT_TS_PRESPEC) handling in ip_options_echo()
The current handling of echoed IP timestamp options with prespecified
addresses is rather broken since the 2.2.x kernels. As far as i understand
it, it should behave like when originating packets.

Currently it will only timestamp the next free slot if:
 - there is space for *two* timestamps
 - some random data from the echoed packet taken as an IP is *not* a local IP

This first is caused by an off-by-one error. 'soffset' points to the next
free slot and so we only need to have 'soffset + 7 <= optlen'.

The second bug is using sptr as the start of the option, when it really is
set to 'skb_network_header(skb)'. I just use dptr instead which points to
the timestamp option.

Finally it would only timestamp for non-local IPs, which we shouldn't do.
So instead we exclude all unicast destinations, similar to what we do in
ip_options_compile().

Signed-off-by: Jan Luebbe <jluebbe@debian.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/ipv4/ip_options.c6
1 files changed, 3 insertions, 3 deletions
diff --git a/net/ipv4/ip_options.c b/net/ipv4/ip_options.c
index 1906fa35860c..28a736f3442f 100644
--- a/net/ipv4/ip_options.c
+++ b/net/ipv4/ip_options.c
@@ -140,11 +140,11 @@ int ip_options_echo(struct ip_options * dopt, struct sk_buff * skb)
 				} else {
 					dopt->ts_needtime = 0;
 
-					if (soffset + 8 <= optlen) {
+					if (soffset + 7 <= optlen) {
 						__be32 addr;
 
-						memcpy(&addr, sptr+soffset-1, 4);
-						if (inet_addr_type(dev_net(skb_dst(skb)->dev), addr) != RTN_LOCAL) {
+						memcpy(&addr, dptr+soffset-1, 4);
+						if (inet_addr_type(dev_net(skb_dst(skb)->dev), addr) != RTN_UNICAST) {
 							dopt->ts_needtime = 1;
 							soffset += 8;
 						}