tailscale

Commit Graph

Author	SHA1	Message	Date
Adrian Dewhurst	8bdf878832	net/dns/resolver: use forwarded dns txid directly Previously, we hashed the question and combined it with the original txid which was useful when concurrent queries were multiplexed on a single local source port. We encountered some situations where the DNS server canonicalizes the question in the response (uppercase converted to lowercase in this case), which resulted in responses that we couldn't match to the original request due to hash mismatches. This includes a new test to cover that situation. Fixes #2597 Signed-off-by: Adrian Dewhurst <adrian@tailscale.com>	3 years ago
Josh Bleecher Snyder	a5da4ed981	all: gofmt with Go 1.17 This adds "//go:build" lines and tidies up existing "// +build" lines. Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>	3 years ago
Denton Gentry	260b85458c	net/dns: correct log message. Signed-off-by: Denton Gentry <dgentry@tailscale.com>	3 years ago
Brad Fitzpatrick	54e33b511a	net/dns/resolver: add test that I forgot to git add earlier This was meant to be part of `53a2f63658` earlier but I guess I failed at git. Updates #2436 Updates tailscale/corp#2250 Updates tailscale/corp#2238 Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	3 years ago
Brad Fitzpatrick	be921d1a95	net/dns/resolver: fix skipped DoH test that bitrot Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	3 years ago
Josh Bleecher Snyder	881bb8bcdc	net/dns/resolver: allow an extra alloc for go closure allocation Go 1.17 switches to a register ABI on amd64 platforms. Part of that switch is that go and defer calls use an argument-less closure, which allocates. This means that we have an extra alloc in some DNS work. That's unfortunate but not a showstopper, and I don't see a clear path to fixing it. The other performance benefits from the register ABI will all but certainly outweigh this extra alloc. Fixes #2545 Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>	3 years ago
David Crawshaw	f414a9cc01	net/dns/resolver: EDNS OPT record off-by-one I don't know how to get access to a real packet. Basing this commit entirely off: +------------+--------------+------------------------------+ \| Field Name \| Field Type \| Description \| +------------+--------------+------------------------------+ \| NAME \| domain name \| MUST be 0 (root domain) \| \| TYPE \| u_int16_t \| OPT (41) \| \| CLASS \| u_int16_t \| requestor's UDP payload size \| \| TTL \| u_int32_t \| extended RCODE and flags \| \| RDLEN \| u_int16_t \| length of all RDATA \| \| RDATA \| octet stream \| {attribute,value} pairs \| +------------+--------------+------------------------------+ From https://datatracker.ietf.org/doc/html/rfc6891#section-6.1.2 Signed-off-by: David Crawshaw <crawshaw@tailscale.com>	3 years ago
Brad Fitzpatrick	53a2f63658	net/dns/resolver: race well-known resolvers less aggressively Instead of blasting away at all upstream resolvers at the same time, make a timing plan upon reconfiguration and have each upstream have an associated start delay, depending on the overall forwarding config. So now if you have two or four upstream Google or Cloudflare DNS servers (e.g. two IPv4 and two IPv6), we now usually only send a query, not four. This is especially nice on iOS where we start fewer DoH queries and thus fewer HTTP/1 requests (because we still disable HTTP/2 on iOS), fewer sockets, fewer goroutines, and fewer associated HTTP buffers, etc, saving overall memory burstiness. Fixes #2436 Updates tailscale/corp#2250 Updates tailscale/corp#2238 Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	3 years ago
Brad Fitzpatrick	e94ec448a7	net/dns/resolver: add forwardQuery type as race work prep Add a place to hang state in a future change for #2436. For now this just simplifies the send signature without any functional change. Updates #2436 Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	3 years ago
Brad Fitzpatrick	064b916b1a	net/dns/resolver: fix func used as netaddr.IP in printf Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	3 years ago
Brad Fitzpatrick	cecfc14875	net/dns: don't build init*.go on non-windows To remove the regexp dep on iOS, notably. Updates tailscale/corp#2238 Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	3 years ago
Brad Fitzpatrick	2968893add	net/dns/resolver: bound DoH usage on iOS Updates tailscale/corp#2238 Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	3 years ago
Brad Fitzpatrick	3daf27eaad	net/dns/resolver: fall back to IPv6 for well-known DoH servers if v4 fails Should help with IPv6-only environments when the tailnet admin only specified IPv4 DNS IPs. See https://github.com/tailscale/tailscale/issues/2447#issuecomment-884188562 Co-Author: Adrian Dewhurst <adrian@tailscale.com> Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	3 years ago
Brad Fitzpatrick	74eee4de1c	net/dns/resolver: use correct Cloudflare DoH hostnames We were using the wrong ones for the malware & adult content variants. Docs: https://developers.cloudflare.com/1.1.1.1/1.1.1.1-for-families/setup-instructions/dns-over-https Earlier commit which added them: `236eb4d04d` Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	3 years ago
Brad Fitzpatrick	e74d37d30f	net/dns{,/resolver}: quiet DNS output logging It was a huge chunk of the overall log output and made debugging difficult. Omit and summarize the spammy *.arpa parts instead. Fixes tailscale/corp#2066 (to which nobody had opinions, so)	3 years ago
Brad Fitzpatrick	236eb4d04d	net/dns/resolver: upgrade forwarded MagicDNS queries to DoH when IP known Recognize Cloudflare, Google, Quad9 which are by far the majority of upstream DNS servers that people use. RELNOTE=MagicDNS now uses DNS-over-HTTPS when querying popular upstream resolvers, so DNS queries aren't sent in the clear over the Internet. Updates #915 (might fix it?) Updates #988 (gets us closer, if it fixes Android) Updates #74 (not yet configurable, but progress) Updates #2056 (not yet configurable, dup of #74?) Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	3 years ago
David Crawshaw	6b9f8208f4	net/dns: do not run wsl.exe as LocalSystem It doesn't work. It needs to run as the user. https://github.com/microsoft/WSL/issues/4803 The mechanism for doing this was extracted from: https://web.archive.org/web/20101009012531/http://blogs.msdn.com/b/winsdk/archive/2009/07/14/launching-an-interactive-process-from-windows-service-in-windows-vista-and-later.aspx While here, we also reclaculate WSL distro set on SetDNS. This accounts for: 1. potential inability to access wsl.exe on startup 2. WSL being installed while Tailscale is running 3. A new WSL distrobution being installed Signed-off-by: David Crawshaw <crawshaw@tailscale.com>	3 years ago
David Crawshaw	1147c7fd4f	net/dns: set WSL /etc/resolv.conf We also have to make a one-off change to /etc/wsl.conf to stop every invocation of wsl.exe clobbering the /etc/resolv.conf. This appears to be a safe change to make permanently, as even though the resolv.conf is constantly clobbered, it is always the same stable internal IP that is set as a nameserver. (I believe the resolv.conf clobbering predates the MS stub resolver.) Tested on WSL2, should work for WSL1 too. Fixes #775 Signed-off-by: David Crawshaw <crawshaw@tailscale.com>	3 years ago
David Crawshaw	9b063b86c3	net/dns: factor directManager out over an FS interface This is preliminary work for using the directManager as part of a wslManager on windows, where in addition to configuring windows we'll use wsl.exe to edit the linux file system and modify the system resolv.conf. The pinholeFS is a little funky, but it's designed to work through simple unix tools via wsl.exe without invoking bash. I would not have thought it would stand on its own like this, but it turns out it's useful for writing a test for the directManager. Signed-off-by: David Crawshaw <crawshaw@tailscale.com>	3 years ago
julianknodt	72a0b5f042	net/dns/resolver: fmt item This has been bothering me for a while, but everytime I run format from the root directory it also formats this file. I didn't want to add it to my other PRs but it's annoying to have to revert it every time. Signed-off-by: julianknodt <julianknodt@gmail.com>	3 years ago
David Crawshaw	80b1308974	net/dns: remove ref to managerImpl Signed-off-by: David Crawshaw <crawshaw@tailscale.com>	3 years ago
Adrian Dewhurst	bcaae3e074	net/dns/resolver: clamp EDNS size This change (subject to some limitations) looks for the EDNS OPT record in queries and responses, clamping the size field to fit within our DNS receive buffer. If the size field is smaller than the DNS receive buffer then it is left unchanged. I think we will eventually need to transition to fully processing the DNS queries to handle all situations, but this should cover the most common case. Mostly fixes #2066 Signed-off-by: Adrian Dewhurst <adrian@tailscale.com>	3 years ago
David Anderson	084d48d22d	net/dns: always proxy through quad-100 on windows 8.1. Windows 8.1 incorrectly handles search paths on an interface with no associated resolver, so we have to provide a full primary DNS config rather than use Windows 8.1's nascent-but-present NRPT functionality. Fixes #2237. Signed-off-by: David Anderson <danderson@tailscale.com>	3 years ago
Brad Fitzpatrick	45e64f2e1a	net/dns{,/resolver}: refactor DNS forwarder, send out of right link on macOS/iOS Fixes #2224 Fixes tailscale/corp#2045 Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	3 years ago
Brad Fitzpatrick	733d52827b	net/dns/resolver: skip test on macOS Fixes #2229 Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	3 years ago
David Crawshaw	297b3d6fa4	staticcheck.conf: turn off noisy lint errors Signed-off-by: David Crawshaw <crawshaw@tailscale.com>	3 years ago
David Anderson	9337826011	net/dns: fix inverted test for NetworkManager version. Signed-off-by: David Anderson <danderson@tailscale.com>	3 years ago
David Anderson	320cc8fa21	net/dns: verify that systemd-resolved is actually in charge. It's possible to install a configuration that passes our current checks for systemd-resolved, without actually pointing to systemd-resolved. In that case, we end up programming DNS in resolved, but that config never applies to any name resolution requests on the system. This is quite a far-out edge case, but there's a simple additional check we can do: if the header comment names systemd-resolved, there should be a single nameserver in resolv.conf pointing to 127.0.0.53. If not, the configuration should be treated as an unmanaged resolv.conf. Fixes #2136. Signed-off-by: David Anderson <danderson@tailscale.com>	3 years ago
David Anderson	e7164425b3	net/dns: don't use NetworkManager for DNS on very old NetworkManagers. Fixes #1945. Signed-off-by: David Anderson <danderson@tailscale.com>	3 years ago
Dave Anderson	144c68b80b	net/dns: avoid using NetworkManager as much as possible. (#1945 ) Addresses #1699 as best as possible. Signed-off-by: David Anderson <danderson@tailscale.com>	3 years ago
Adrian Dewhurst	8b11937eaf	net/dns/resolver: permit larger max responses, signal truncation This raises the maximum DNS response message size from 512 to 4095. This should be large enough for almost all situations that do not need TCP. We still do not recognize EDNS, so we will still forward requests that claim support for a larger response size than 4095 (that will be solved later). For now, when a response comes back that is too large to fit in our receive buffer, we now set the truncation flag in the DNS header, which is an improvement from before but will prompt attempts to use TCP which isn't supported yet. On Windows, WSARecvFrom into a buffer that's too small returns an error in addition to the data. On other OSes, the extra data is silently discarded. In this case, we prefer the latter so need to catch the error on Windows. Partially addresses #1123 Signed-off-by: Adrian Dewhurst <adrian@tailscale.com>	3 years ago
David Anderson	7fab244614	net/dns/resolver: don't spam logs on EHOSTUNREACH. Fixes #1719. Signed-off-by: David Anderson <danderson@tailscale.com>	3 years ago
David Anderson	e2dcf63420	net/dns: replace AuthoritativeSuffixes with nil Route entries. This leads to a cleaner separation of intent vs. implementation (Routes is now the only place specifying who handles DNS requests), and allows for cleaner expression of a configuration that creates MagicDNS records without serving them to the OS. Signed-off-by: David Anderson <danderson@tailscale.com>	3 years ago
David Anderson	6690f86ef4	net/dns: always offer MagicDNS records at 100.100.100.100. Fixes #1886. Signed-off-by: David Anderson <danderson@tailscale.com>	3 years ago
Josh Bleecher Snyder	25df067dd0	all: adapt to opaque netaddr types This commit is a mishmash of automated edits using gofmt: gofmt -r 'netaddr.IPPort{IP: a, Port: b} -> netaddr.IPPortFrom(a, b)' -w . gofmt -r 'netaddr.IPPrefix{IP: a, Port: b} -> netaddr.IPPrefixFrom(a, b)' -w . gofmt -r 'a.IP.Is4 -> a.IP().Is4' -w . gofmt -r 'a.IP.As16 -> a.IP().As16' -w . gofmt -r 'a.IP.Is6 -> a.IP().Is6' -w . gofmt -r 'a.IP.As4 -> a.IP().As4' -w . gofmt -r 'a.IP.String -> a.IP().String' -w . And regexps: \w(.)\.Port = (.) -> $1 = $1.WithPort($2) \w(.)\.IP = (.) -> $1 = $1.WithIP($2) And lots of manual fixups. Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>	3 years ago
David Anderson	cfde997699	net/dns: don't use interfaces.Tailscale to find the tailscale interface index. interfaces.Tailscale only returns an interface if it has at least one Tailscale IP assigned to it. In the resolved DNS manager, when we're called upon to tear down DNS config, the interface no longer has IPs. Instead, look up the interface index on construction and reuse it throughout the daemon lifecycle. Fixes #1892. Signed-off-by: David Anderson <dave@natulte.net>	3 years ago
David Anderson	3c8e230ee1	Revert "net/dns: set IPv4 auto mode in NM, so it lets us set DNS." This reverts commit `7d16c8228b`. I have no idea how I ended up here. The bug I was fixing with this change fails to reproduce on Ubuntu 18.04 now, and this change definitely does break 20.04, 20.10, and Debian Buster. So, until we can reliably reproduce the problem this was meant to fix, reverting. Part of #1875 Signed-off-by: David Anderson <dave@natulte.net>	3 years ago
David Anderson	5bd38b10b4	net/dns: log the correct error when NM Reapply fails. Found while debugging #1870. Signed-off-by: David Anderson <danderson@tailscale.com>	3 years ago
David Anderson	7d16c8228b	net/dns: set IPv4 auto mode in NM, so it lets us set DNS. Part of #1870. Signed-off-by: David Anderson <danderson@tailscale.com>	3 years ago
David Anderson	77e2375501	net/dns: don't try to configure LLMNR or mdns in NetworkManager. Fixes #1870. Signed-off-by: David Anderson <danderson@tailscale.com>	3 years ago
Josh Bleecher Snyder	20e04418ff	net/dns: add GOOS build tags Fixes #1786 Signed-off-by: Josh Bleecher Snyder <josharian@gmail.com>	3 years ago
David Anderson	bf9ef1ca27	net/dns: stop NetworkManager breaking v6 connectivity when setting DNS. Tentative fix for #1699 Signed-off-by: David Anderson <danderson@tailscale.com>	3 years ago
David Anderson	44c2b7dc79	net/dns: on windows, skip site-local v6 resolvers. Further refinement for tailscale/corp#1662. Signed-off-by: David Anderson <danderson@tailscale.com>	3 years ago
David Anderson	97d2fa2f56	net/dns: work around WSL DNS implementation flaws. Fixes tailscale/corp#1662 Signed-off-by: David Anderson <danderson@tailscale.com>	3 years ago
David Anderson	f6b7d08aea	net/dns: work around new NetworkManager in other selection paths. Further bits of #1788 Signed-off-by: David Anderson <danderson@tailscale.com>	3 years ago
David Anderson	25ce9885a2	net/dns: don't use NM+resolved for NM >=1.26.6. NetworkManager fixed the bug that forced us to use NetworkManager if it's programming systemd-resolved, and in the same release also made NetworkManager ignore DNS settings provided for unmanaged interfaces... Which breaks what we used to do. So, with versions 1.26.6 and above, we MUST NOT use NetworkManager to indirectly program systemd-resolved, but thankfully we can talk to resolved directly and get the right outcome. Fixes #1788 Signed-off-by: David Anderson <danderson@tailscale.com>	3 years ago
David Anderson	30f5d706a1	net/dns/resolver: remove unnecessary/racy WaitGroup. Fixes #1663 Signed-off-by: David Anderson <danderson@tailscale.com>	3 years ago
David Anderson	89c81c26c5	net/dns: fix resolved match domains when no nameservers are provided. Signed-off-by: David Anderson <danderson@tailscale.com>	3 years ago
David Anderson	4be26b269f	net/dns: correctly capture all traffic in non-split configs. Signed-off-by: David Anderson <danderson@tailscale.com>	3 years ago
David Anderson	ca283ac899	net/dns: remove config in openresolv when given an empty DNS config. Part of #1720. Signed-off-by: David Anderson <danderson@tailscale.com>	3 years ago

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127 Commits (26b6fe7f02fef6a5ed999d33daf844cbd2e5f331)