Currently, we get the "likely home router" gateway IP and then iterate
through all IPs for all interfaces trying to match IPs to determine the
source IP. However, on many platforms we know what interface the gateway
is through, and thus we don't need to iterate through all interfaces
checking IPs. Instead, use the IP address of the associated interface.
This better handles the case where we have multiple interfaces on a
system all connected to the same gateway, and where the first interface
that we visit (as iterated by ForeachInterfaceAddress) isn't also the
default internet route.
Updates #8992
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: I8632f577f1136930f4ec60c76376527a19a47d1f
Before this fix, LikelyHomeRouterIP could return a 'self' IP that
doesn't correspond to the gateway address, since it picks the first
private address when iterating over the set interfaces as the 'self' IP,
without checking that the address corresponds with the
previously-detected gateway.
This behaviour was introduced by accident in aaf2df7, where we deleted
the following code:
for _, prefix := range privatev4s {
if prefix.Contains(gateway) && prefix.Contains(ip) {
myIP = ip
ok = true
return
}
}
Other than checking that 'gateway' and 'ip' were private IP addresses
(which were correctly replaced with a call to the netip.Addr.IsPrivate
method), it also implicitly checked that both 'gateway' and 'ip' were a
part of the *same* prefix, and thus likely to be the same interface.
Restore that behaviour by explicitly checking pfx.Contains(gateway),
which, given that the 'ip' variable is derived from our prefix 'pfx',
ensures that the 'self' IP will correspond to the returned 'gateway'.
Fixes#10466
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: Iddd2ee70cefb9fb40071986fefeace9ca2441ee6
This removes a lot of API from net/interfaces (including all the
filter types, EqualFiltered, active Tailscale interface func, etc) and
moves the "major" change detection to net/netmon which knows more
about the world and the previous/new states.
Updates #9040
Change-Id: I7fe66a23039c6347ae5458745b709e7ebdcce245
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This adds an initial and intentionally minimal configuration for
golang-ci, fixes the issues reported, and adds a GitHub Action to check
new pull requests against this linter configuration.
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: I8f38fbc315836a19a094d0d3e986758b9313f163
Return a mock set of interfaces and a mock gateway during this test and
verify that LikelyHomeRouterIP returns the outcome we expect. Also
verify that we return an error if there are no IPv4 addresses available.
Follow-up to #7447
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: I8f06989e7f1f0bebd108861cbff17b820ed2e6e4
This updates all source files to use a new standard header for copyright
and license declaration. Notably, copyright no longer includes a date,
and we now use the standard SPDX-License-Identifier header.
This commit was done almost entirely mechanically with perl, and then
some minimal manual fixes.
Updates #6865
Signed-off-by: Will Norris <will@tailscale.com>
It was pretty ill-defined before and mostly for logging. But I wanted
to start depending on it, so define what it is and make Windows match
the other operating systems, without losing the log output we had
before. (and add tests for that)
Change-Id: I0fbbba1cfc67a265d09dd6cb738b73f0f6005247
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
One of the most common "unexpected" log lines is:
"network state changed, but stringification didn't"
One way that this can occur is if an interesting interface
(non-Tailscale, has interesting IP address)
gains or loses an uninteresting IP address (link local or loopback).
The fact that the interface is interesting is enough for EqualFiltered
to inspect it. The fact that an IP address changed is enough for
EqualFiltered to declare that the interfaces are not equal.
But the State.String method reasonably declines to print any
uninteresting IP addresses. As a result, the network state appears
to have changed, but the stringification did not.
The String method is correct; nothing interesting happened.
This change fixes this by adding an IP address filter to EqualFiltered
in addition to the interface filter. This lets the network monitor
ignore the addition/removal of uninteresting IP addresses.
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
Split out of Denton's #2164, to make that diff smaller to review.
This change has no behavior changes.
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
IPv6 Unique Local Addresses are sometimes used with Network
Prefix Translation to reach the Internet. In that respect
their use is similar to the private IPv4 address ranges
10/8, 172.16/12, and 192.168/16.
Treat them as sufficient for AnyInterfaceUp(), but specifically
exclude Tailscale's own IPv6 ULA prefix to avoid mistakenly
trying to bootstrap Tailscale using Tailscale.
This helps in supporting Google Cloud Run, where the addresses
are 169.254.8.1/32 and fddf:3978:feb1:d745::c001/128 on eth1.
Signed-off-by: Denton Gentry <dgentry@tailscale.com>
Now callers (wgengine/monitor) don't need to mutate the state to remove
boring interfaces before calling State.Equal. Instead, the methods
to remove boring interfaces from the State are removed, as is
the reflect-using Equal method itself, and in their place is
a new EqualFiltered method that takes a func predicate to match
interfaces to compare.
And then the FilterInteresting predicate is added for use
with EqualFiltered to do the job that that wgengine/monitor
previously wanted.
Now wgengine/monitor can keep the full interface state around,
including the "boring" interfaces, which we'll need for peerapi on
macOS/iOS to bind to the interface index of the utunN device.
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Basically, don't trust the OS-level link monitor to only tell you
interesting things. Sanity check it.
Also, move the interfaces package into the net directory now that we
have it.
