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>
diff --git a/net/ipv4/ip_options.c b/net/ipv4/ip_options.c
index 1906fa3..28a736f 100644
--- a/net/ipv4/ip_options.c
+++ b/net/ipv4/ip_options.c
@@ -140,11 +140,11 @@
} 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;
}
