tree 8bf9cb65b82803d3d799d95d6a125237af8906fa
parent d1f41b67ff7735193bc8b418b98ac99a448833e2
author David Ward <david.ward@ll.mit.edu> 1362503192 +0000
committer David S. Miller <davem@davemloft.net> 1362556026 -0500

net/ipv4: Timestamp option cannot overflow with prespecified addresses

When a router forwards a packet that contains the IPv4 timestamp option,
if there is no space left in the option for the router to add its own
timestamp, then the router increments the Overflow value in the option.

However, if the addresses of the routers are prespecified in the option,
then the overflow condition cannot happen: the option is structured so
that each prespecified router has a place to write its timestamp. Other
routers do not add a timestamp, so there will never be a lack of space.

This fix ensures that the Overflow value in the IPv4 timestamp option is
not incremented when the addresses of the routers are prespecified, even
if the Pointer value is greater than the Length value.

Signed-off-by: David Ward <david.ward@ll.mit.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>