Hello, guys. So, here's transparent TCP connection hijacking (ie. checkpointing in one process and restoring in another) which adds only relatively small pieces to the kernel. It's by no means complete but already works rather reliably in my test setup even with heavy delay induced with tc. I wrote a rather long README describing how it's working, what's missing which is appended at the end of this mail so if you're interested in the details please go ahead and read. Several ioctls are added to enable TCP connection CR, which adds around 130 lines of code. Note that the interface is ugly. As said above, it's proof-of-concept. We'll need a bit more information exported and knobs to turn and hopefully prettier interface. As my knowledge of networking is fairly rudimentary, I only tried to get the basics working. e.g. I didn't try to store negotiated options and re-establish them on restoration (ie. window scaling, mss, various extra features), and am likely to have made wrong assumptions even on the basics. If you spot some, please shout. The source is available in the following git branch (just git clone from the URL) https://htejun@code.google.com/p/ptrace-parasite/ and can be browsed at http://code.google.com/p/ptrace-parasite/source/browse/ I'm attaching the tcp-ioctls.patch and the source tarball. Thanks. http://lwn.net/Articles/454304/