Commit Graph

4 Commits (88179121e384afce8c33cf9b4c20684d2ffab722)

Author SHA1 Message Date
Josh Bleecher Snyder 1ebbaaaebb net/interfaces: make syscall and netstat agree when multiple gateways are present
likelyHomeRouterIPDarwinSyscall iterates through the list of routes,
looking for a private gateway, returning the first one it finds.

likelyHomeRouterIPDarwinExec does the same thing,
except that it returns the last one it finds.

As a result, when there are multiple gateways,
TestLikelyHomeRouterIPSyscallExec fails.
(At least, I think that that is what is happening;
I am going inferring from observed behavior.)

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
4 years ago
Josh Bleecher Snyder a16a793605 net/interfaces: use syscalls to find private gateway IP address
iOS doesn't let you run subprocesses,
which means we can't use netstat to get routing information.
Instead, use syscalls and grub around in the results.
We keep the old netstat version around,
both for use in non-cgo builds,
and for use testing the syscall-based version.

Note that iOS doesn't ship route.h,
so we include a copy here from the macOS 10.15 SDK
(which is itself unchanged from the 10.14 SDK).

I have tested manually that this yields the correct
gateway IP address on my own macOS and iOS devices.
More coverage would be most welcome.

Signed-off-by: Josh Bleecher Snyder <josharian@gmail.com>
4 years ago
Brad Fitzpatrick c253d4f948 net/interfaces: don't try to fork on iOS in likelyHomeRouterIPDarwin
No subprocesses allowed on iOS. Will need to do this differently later.
4 years ago
Brad Fitzpatrick 32156330a8 net/interfaces: add func LikelyHomeRouterIP
For discovering where we might direct NAT-PMP/PCP/UPnP queries at in
the future.
4 years ago