tailscale

Commit Graph

Author	SHA1	Message	Date
Filippo Valsorda	d7ce2be5f4	net/dns/resolver: add unsecured Quad9 resolvers DNSSEC is an availability issue, as recently demonstrated by the Slack issue, with limited security advantage. DoH on the other hand is a critical security upgrade. This change adds DoH support for the non-DNSSEC endpoints of Quad9. https://www.quad9.net/service/service-addresses-and-features#unsec Signed-off-by: Filippo Valsorda <hi@filippo.io>	3 years ago
Denton Gentry	93c2882a2f	wgengine: flush DNS cache after major link change. Windows has a public dns.Flush used in router_windows.go. However that won't work for platforms like Linux, where we need a different flush mechanism for resolved versus other implementations. We're instead adding a FlushCaches method to the dns Manager, which can be made to work on all platforms as needed. Fixes https://github.com/tailscale/tailscale/issues/2132 Signed-off-by: Denton Gentry <dgentry@tailscale.com>	3 years ago
Maxim Merzhanov	d43fcd2f02	net/dns: fix error wrapping for SetLinkDefaultRoute in resolved Signed-off-by: Maxim Merzhanov <maksimmerzh@gmail.com>	3 years ago
Brad Fitzpatrick	640134421e	all: update tests to use tstest.MemLogger And give MemLogger a mutex, as one caller had, which does match the logf contract better. Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	3 years ago
David Crawshaw	9502b515f1	net/dns: replace resolver IPs with type for DoH We currently plumb full URLs for DNS resolvers from the control server down to the client. But when we pass the values into the net/dns package, we throw away any URL that isn't a bare IP. This commit continues the plumbing, and gets the URL all the way to the built in forwarder. (It stops before plumbing URLs into the OS configurations that can handle them.) For #2596 Signed-off-by: David Crawshaw <crawshaw@tailscale.com>	3 years ago
David Anderson	bb6fdfb243	net/dns: fix the build on freebsd (missing default case in switch) Signed-off-by: David Anderson <danderson@tailscale.com>	3 years ago
David Anderson	b3b1c06b3a	net/dns: only restart systemd-resolved if we changed /etc/resolv.conf. Reported on IRC: in an edge case, you can end up with a directManager DNS manager and --accept-dns=false, in which case we should do nothing, but actually end up restarting resolved whenever the netmap changes, even though the user told us to not manage DNS. Signed-off-by: David Anderson <danderson@tailscale.com>	3 years ago
David Anderson	10547d989d	net/dns: exhaustively test DNS selection paths for linux. Signed-off-by: David Anderson <danderson@tailscale.com>	3 years ago
David Anderson	c071bcda33	net/dns: relax systemd-resolved detection. Reported on IRC: a resolv.conf that contained two entries for "nameserver 127.0.0.53", which defeated our "is resolved actually in charge" check. Relax that check to allow any number of nameservers, as long as they're all 127.0.0.53. Signed-off-by: David Anderson <danderson@tailscale.com>	3 years ago
David Anderson	39748e9562	net/dns/resolver: authoritatively return NXDOMAIN for reverse zones we own. Fixes #2774 Signed-off-by: David Anderson <danderson@tailscale.com>	3 years ago
Emmanuel T Odeke	0daa32943e	all: add (*testing.B).ReportAllocs() to every benchmark This ensures that we can properly track and catch allocation slippages that could otherwise have been missed. Fixes #2748	3 years ago
Brad Fitzpatrick	065c4ffc2c	net/dns: add start of Linux newOSConfigurator tests Only one test case so far. Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	3 years ago
Brad Fitzpatrick	09a47ea3f1	net/dns: prep for writing manager_linux tests; pull some stuff out Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	3 years ago
slowy07	ac0353e982	fix: typo spelling grammar Signed-off-by: slowy07 <slowy.arfy@gmail.com>	3 years ago
David Crawshaw	0ac2130590	net/dns: resolveConfExists reading the wrong error Signed-off-by: David Crawshaw <crawshaw@tailscale.com>	3 years ago
Brad Fitzpatrick	36ffd509de	net/dns: avoid Linux PolicyKit GUI dialog during tests Fixes #2672 Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	3 years ago
Josh Bleecher Snyder	a24cee0d67	all: simplify ts_macext build tags Now that we have the easier-to-parse go:build build tags, it is straightforward to simplify them. Yay. Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>	3 years ago
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>	4 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>	4 years ago
David Anderson	7fab244614	net/dns/resolver: don't spam logs on EHOSTUNREACH. Fixes #1719. Signed-off-by: David Anderson <danderson@tailscale.com>	4 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>	4 years ago

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144 Commits (babd163aacf410bba2e3763f5b035fbf6272154d)