PCIe to PCIe Communications

There are two identical computers in very close proximity (nearly touching) running Fedora Linux. Computer 1 is connected via wired Ethernet to the local network. I wish to connect directly between the PCIe x1 port of Computer 1 to the PCIe x1 port of Computer 2 for network communications between them. The wired Ethernet port and the PCIe communications need to be bridged so that Computer 1 also acts as a switch, to enable Computer 2 to connect to the local network through Computer 1. The functionality can be easily achieved if I connect PCIe to Ethernet cards to each computer and then use a wired Ethernet cable between them. But the solution I am looking for is one that avoids adding cards that involve convertors. It is my understanding that I do not need to add a card of any type (whether Ethernet, Firewire, PCIe etc) but I do need drivers to manage the solution. And that is what I am wanting a Freelancer to solve for me.