Create tiny ethernet router

I have a device with 2 ethernet ports. Can I get connman to setup the 
network to route traffic from the one port to the other?

I guess I would need to tether one of them? Then how would I do that?

TLDR;

Actually I have 2 devices, both are Intel Edison-Arduino. These can 
setup the usb port in either host or device mode. The one in device mode 
has a eem gadget (ethernet over usb).
The other in host mode has a smsc95xx usb to eth+4p usb hub.

As it is the one in host mode has 2 eth devices:
root@edison:~# ifconfig
enp0s17u1u1: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
         inet 192.168.178.70  netmask 255.255.255.0  broadcast 
192.168.178.255
         inet6 fe80::280:fff:fe95:1d4d  prefixlen 64  scopeid 0x20<link>
         inet6 2a02:a466:68ed:1:280:fff:fe95:1d4d  prefixlen 64  scopeid 
0x0<global>
         ether 00:80:0f:95:1d:4d  txqueuelen 1000  (Ethernet)
         RX packets 781536  bytes 224464657 (214.0 MiB)
         RX errors 0  dropped 184984  overruns 0  frame 0
         TX packets 17923  bytes 2037451 (1.9 MiB)
         TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

enp0s17u1u5i1: flags=-28605<UP,BROADCAST,RUNNING,MULTICAST,DYNAMIC>  mtu 
1500
         inet 169.254.45.35  netmask 255.255.0.0  broadcast 169.254.255.255
         inet6 fe80::f4dc:3cff:fe83:4503  prefixlen 64  scopeid 0x20<link>
         ether f6:dc:3c:83:45:03  txqueuelen 1000  (Ethernet)
         RX packets 6660  bytes 3459572 (3.2 MiB)
         RX errors 0  dropped 0  overruns 0  frame 0
         TX packets 7365  bytes 3973982 (3.7 MiB)
         TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

The one device can ping/ssh into the other. But I'd like the device in 
host mode to setup a dhcp server and route the traffic.