answered 2018-01-15 15:12:16 +0200

DrYak
9624 ●93 ●134 ●128

http://www.sympato.ch/

Using a laptop/PC/Raspberry Pi, it's possible to do it on any Sailfish powered device, including older devices like the Jolla 1 which lack actual OTG support. The name of this class of access is called Reverse Tethering.

There's currently NO nice user-friend interface to help automate the manipulations.

On the other hand, as Sailfish is basically a full blown GNU/Linux under the hood, any HOWTO explaining how to do it on the command-line should do (ArchLinux and Ubuntu Ask tend to have nice and clear one).

Basically, you want to do two things :

Networking on the phone

• First you need to connect the phone in Developer Mode (it shows up as a USB Networking device to the PC).
• Then, either by using a terminal on the phone, or using SSH ( <- if you have SSH keys, you can even automate this ) you need to add the PC as a default route :

• For IPv4:

  ip -4 route add default via 192.168.2.1 dev rndis0 metric 10 protocol static
  

  replace 192.168.2.1 with IP address of the PC side of the connection, it might be a higher number if you use DHCP (e.g.: 192.168.2.13)

• For IPv6, if your laptop actually support masquerading it:

  ip -6 route add default via fe80:: dev rndis0 metric 10 protocol static
  

  replace fe80:: with the actual link-local random IPv6 of the PC side of the connection that was randomly generated upon pluging up. (e.g.: fe80::15d8:83f2:8d62:d74b)

Masquareding on the PC

• You need to enable IP forwarding and Masquerading
• Usually, most distro will have user-friendly tools (e.g.: Suse has SuseFirewall, RedHat/CentOS have firewalld, Ubuntu has Uncomplicated Firewall, other might use Shorewall, etc.)
• Generally, in a user friendly firewall, you can simply assign the ethernet port to some 'external' group, assign the USB Networking to 'internal' group, and enable masquerading between the two.

• The not user friendly solution :

  echo "1" > /proc/sys/net/ipv4/ip_forward
  iptables -t nat -A POSTROUTING -o rndi0 -j MASQUERADE
  

  Where rndis0 is the name of the USB Network device as seen on the PC. (Modern distro might assign instead static names like enp0s29u1u6i7

• It is also possible to assign an actual internet-routable IPv6 address to an internal network (if you treat it as a subnetwork with a "longer-than-64bits prefix", with a statically assigned "less than 64bits" suffix, and play around with ndpproxy :

  ip -6 neigh add proxy 2001:: dev rndis0
  

  Where 2001::should be the actual static address that you assign to the smartphone, and rndis0 is the name of the USB interface on the PC.