tree ce27afda8c94db87270a29b4b3c923fb4f970993
parent 57c5f54dae6f34e5569e6e343a7793f7db365deb
author Ningyuan Wang <nywang@google.com> 1454111862 -0800
committer Ningyuan Wang <nywang@google.com> 1454448920 +0000

DHCPV4: use c++11 random number generator

This uses c++11 random number generator to replace the old
c-style random number generator.
In addition, this deletes the function DHCPMessage::
GenerateTransactionID(). Both the DHCP transaction id and
IP transaction id will be generated by the random engine in
DHCPV4.

Bug: 25642025
TEST=compile and unittest

Change-Id: Ie23600f08f5dab8b373bf19eac7b25c112e1a1c8