141 Commits (aadb8d9d21938110e34af35c28fe7324cef809e4)

Author	SHA1	Message	Date
Brad Fitzpatrick	aa37aece9c	ipn/ipnlocal, net/dns*, util/cloudenv: add AWS DNS support ... And remove the GCP special-casing from ipn/ipnlocal; do it only in the forwarder for *.internal. Fixes #4980 Fixes #4981 Change-Id: I5c481e96d91f3d51d274a80fbd37c38f16dfa5cb Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	2 years ago
Brad Fitzpatrick	88c2afd1e3	ipn/ipnlocal, net/dns*, util/cloudenv: specialize DNS config on Google Cloud ... This does three things: * If you're on GCP, it adds a *.internal DNS split route to the metadata server, so we never break GCP DNS names. This lets people have some Tailscale nodes on GCP and some not (e.g. laptops at home) without having to add a Tailnet-wide *.internal DNS route. If you already have such a route, though, it won't overwrite it. * If the 100.100.100.100 DNS forwarder has nowhere to forward to, it forwards it to the GCP metadata IP, which forwards to 8.8.8.8. This means there are never errNoUpstreams ("upstream nameservers not set") errors on GCP due to e.g. mangled /etc/resolv.conf (GCP default VMs don't have systemd-resolved, so it's likely a DNS supremacy fight) * makes the DNS fallback mechanism use the GCP metadata IP as a fallback before our hosted HTTP-based fallbacks I created a default GCP VM from their web wizard. It has no systemd-resolved. I then made its /etc/resolv.conf be empty and deleted its GCP hostnames in /etc/hosts. I then logged in to a tailnet with no global DNS settings. With this, tailscaled writes /etc/resolv.conf (direct mode, as no systemd-resolved) and sets it to 100.100.100.100, which then has regular DNS via the metadata IP and *.internal DNS via the metadata IP as well. If the tailnet configures explicit DNS servers, those are used instead, except for *.internal. This also adds a new util/cloudenv package based on version/distro where the cloud type is only detected once. We'll likely expand it in the future for other clouds, doing variants of this change for other popular cloud environments. Fixes #4911 RELNOTES=Google Cloud DNS improvements Change-Id: I19f3c2075983669b2b2c0f29a548da8de373c7cf Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	2 years ago
Maisem Ali	80157f3f37	net/dns/resolver: add support for <IPv4>.via-<site-id> ... Currently we only support "via-<site-id>.<IPv4>", however that does not work with Google Chrome which parses `http://via-1.10.0.0.1` as a search string and not as a URL. This commit introduces "<IPv4>.via-<site-id>" (`http://10.0.0.1.via-1`) which is parsed correctly by Chrome. Updates #3616 Signed-off-by: Maisem Ali <maisem@tailscale.com>	2 years ago
Tom	acfe5bd33b	net/dns{., resolver}: time out DNS queries after 10 seconds (#4690) ... Fixes https://github.com/tailscale/corp/issues/5198 The upstream forwarder will block indefinitely on `udpconn.ReadFrom` if no reply is recieved, due to the lack of deadline on the connection object. There still isn't a deadline on the connection object, but the automatic closing of the context on deadline expiry will close the connection via `closeOnCtxDone`, unblocking the read and resulting in a normal teardown. Signed-off-by: Tom DNetto <tom@tailscale.com>	3 years ago
Maisem Ali	fd99c54e10	tailcfg,all: change structs to []*dnstype.Resolver ... Signed-off-by: Maisem Ali <maisem@tailscale.com>	3 years ago
Tom DNetto	2a0b5c21d2	net/dns/{., resolver}, wgengine: fix goroutine leak on shutdown ... Signed-off-by: Tom DNetto <tom@tailscale.com>	3 years ago
Tom DNetto	5b85f848dd	net/dns,net/dns/resolver: refactor channels/magicDNS out of Resolver ... Moves magicDNS-specific handling out of Resolver & into dns.Manager. This greatly simplifies the Resolver to solely issuing queries and returning responses, without channels. Enforcement of max number of in-flight magicDNS queries, assembly of synthetic UDP datagrams, and integration with wgengine for recieving/responding to magicDNS traffic is now entirely in Manager. This path is being kept around, but ultimately aims to be deleted and replaced with a netstack-based path. This commit is part of a series to implement magicDNS using netstack. Signed-off-by: Tom DNetto <tom@tailscale.com>	3 years ago
Tom DNetto	5fb8e01a8b	net/dns/resolver: add metric for number of truncated dns packets ... Updates #2067 This should help us determine if more robust control of edns parameters + implementing answer truncation is warranted, given its likely complexity. Signed-off-by: Tom DNetto <tom@tailscale.com>	3 years ago
Tom DNetto	78fededaa5	net/dns/resolver: support magic resolution of via-<siteid>.<ip4> domains ... Updates #3616 Signed-off-by: Tom DNetto <tom@tailscale.com>	3 years ago
Tom DNetto	df26c63793	net/dns/resolver, net/tsaddr: fix reverse lookups in 4to6 IP range ... Fixes #4439 Signed-off-by: Tom DNetto <tom@tailscale.com>	3 years ago
Brad Fitzpatrick	cc575fe4d6	net/dns: schedule DoH upgrade explicitly, fix Resolver.Addr confusion ... Two changes in one: * make DoH upgrades an explicitly scheduled send earlier, when we come up with the resolvers-and-delay send plan. Previously we were getting e.g. four Google DNS IPs and then spreading them out in time (for back when we only did UDP) but then later we added DoH upgrading at the UDP packet layer, which resulted in sometimes multiple DoH queries to the same provider running (each doing happy eyeballs dialing to 4x IPs themselves) for each of the 4 source IPs. Instead, take those 4 Google/Cloudflare IPs and schedule 5 things: first the DoH query (which can use all 4 IPs), and then each of the 4 IPs as UDP later. * clean up the dnstype.Resolver.Addr confusion; half the code was using it as an IP string (as documented) as half was using it as an IP:port (from some prior type we used), primarily for tests. Instead, document it was being primarily an IP string but also accepting an IP:port for tests, then add an accessor method on it to get the IPPort and use that consistently everywhere. Change-Id: Ifdd72b9e45433a5b9c029194d50db2b9f9217b53 Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	3 years ago
Brad Fitzpatrick	e3a4952527	net/dns/resolver: count errors when racing DNS queries, fail earlier ... If all N queries failed, we waited until context timeout (in 5 seconds) to return. This makes (*forwarder).forward fail fast when the network's unavailable. Change-Id: Ibbb3efea7ed34acd3f3b29b5fee00ba8c7492569 Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	3 years ago
Brad Fitzpatrick	ecea6cb994	net/dns/resolver: make DoH dialer use existing dnscache happy eyeball dialer ... Simplify the ability to reason about the DoH dialing code by reusing the dnscache's dialer we already have. Also, reduce the scope of the "ip" variable we don't want to close over. This necessarily adds a new field to dnscache.Resolver: SingleHostStaticResult, for when the caller already knows the IPs to be returned. Change-Id: I9f2aef7926f649137a5a3e63eebad6a3fffa48c0 Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	3 years ago
phirework	83c734a6e0	net/dns, util/publicdns: extract public DNS mapping into own package (#4405) ... This extracts DOH mapping of known public DNS providers in forwarder.go into its own package, to be consumed by other repos Signed-off-by: Jenny Zhang <jz@tailscale.com>	3 years ago
Tom	24bdcbe5c7	net/dns, net/dns/resolver, wgengine: refactor DNS request path (#4364) ... * net/dns, net/dns/resolver, wgengine: refactor DNS request path Previously, method calls into the DNS manager/resolver types handled DNS requests rather than DNS packets. This is fine for UDP as one packet corresponds to one request or response, however will not suit an implementation that supports DNS over TCP. To support PRs implementing this in the future, wgengine delegates all handling/construction of packets to the magic DNS endpoint, to the DNS types themselves. Handling IP packets at this level enables future support for both UDP and TCP. Signed-off-by: Tom DNetto <tom@tailscale.com>	3 years ago
Tom	6be7931eb4	net/dns/resolver: return symbolic PTR records for TS service IPs (#4361) ... Fixes #1233 Signed-off-by: Tom DNetto <tom@tailscale.com> Co-authored-by: Tom DNetto <tom@tailscale.com>	3 years ago
Brad Fitzpatrick	f2041c9088	all: use strings.Cut even more ... Change-Id: I943ce72c6f339589235bddbe10d07799c4e37979 Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	3 years ago
Josh Bleecher Snyder	0868329936	all: use any instead of interface{} ... My favorite part of generics. Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>	3 years ago
Brad Fitzpatrick	61ee72940c	all: use Go 1.18's strings.Cut ... More remain. Change-Id: I6ec562cc1f687600758deae1c9d7dbd0d04004cb Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	3 years ago
Josh Bleecher Snyder	0ef74f37a5	net/dns/resolver: remove closure allocation explanation ... As of Go 1.18, the register ABI list includes arm64, amd64, ppc64, and ppc64le. This is a large enough percentage of the architectures that it's not worth explaining. Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>	3 years ago
Brad Fitzpatrick	c988bd6ed1	net/dns/resolvconffile: unify three /etc/resolv.conf parsers into new package ... Change-Id: I2120893ca802d12f1bd0407d49077d3672627d33 Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	3 years ago
Brad Fitzpatrick	24a04d07d1	net/dns/resolver: handle tabs as whitespace when ExitDNS parses resolv.conf ... On Synology, the /etc/resolv.conf has tabs in it, which this resolv.conf parser (we have two, sigh) didn't handle. Updates #3710 Change-Id: I86f8e09ad1867ee32fa211e85c382a27191418ea Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	3 years ago
Brad Fitzpatrick	8d0ed1c9ba	net/dns/resolver: on Android, make ExitDNS use net package for DNS ... Like Windows. Updates #1738 Change-Id: I9f26bc58ce7e760c749786fbe5d9952c99eeb91c Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	3 years ago
Brad Fitzpatrick	506c727e30	ipnlocal, net/{dns,tsaddr,tstun}, wgengine: support MagicDNS on IPv6 ... Fixes #3660 RELNOTE=MagicDNS now works over IPv6 when CGNAT IPv4 is disabled. Change-Id: I001e983df5feeb65289abe5012dedd177b841b45 Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	3 years ago
Brad Fitzpatrick	2513d2d728	net/{neterror,dns/resolver}: move PacketWasTruncated to neterror from DNS code ... And delete the unused code in net/dns/resolver/neterr_*.go. Change-Id: Ibe62c486bacce2733eb9968c96a98cbbdb2758bd Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	3 years ago
Brad Fitzpatrick	0aa4c6f147	net/dns/resolver: add debug HTML handler to see what DNS traffic was forwarded ... Change-Id: I6b790e92dcc608515ac8b178f2271adc9fd98f78 Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	3 years ago
Brad Fitzpatrick	0848b36dd2	net/dns/resolver: add metrics to PTR lookup misses ... Updates tailscale/corp#3326 Change-Id: I58077d889a3b58ef0633267c92ffb265686ce152 Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	3 years ago
Brad Fitzpatrick	39f22a357d	net/dns/resolver: send NXDOMAIN to iOS DNS-SD/Bonjour queries ... Don't just ignore them. See if this makes them calm down. Updates #3363 Change-Id: Id1d66308e26660d26719b2538b577522a1e36b63 Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	3 years ago
Brad Fitzpatrick	394c9de02b	net/dns/resolver: add nameFromQuery benchmark ... To convince me it's not as alloc-y as it looks. Change-Id: I503a0cc267268a23d2973dfde9833c420be4e868 Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	3 years ago
Brad Fitzpatrick	c7052154d5	net/dns/resolver: fix the subject in a func comment ... Change-Id: I519268c20dbd2c2da92da565839d3c1c84612dcc Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	3 years ago
Brad Fitzpatrick	486059589b	all: gofmt -w -s (simplify) tests ... And it updates the build tag style on a couple files. Change-Id: I84478d822c8de3f84b56fa1176c99d2ea5083237 Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	3 years ago
Brad Fitzpatrick	cced414c7d	net/dns/resolver: add Windows ExitDNS service support, using net package ... Updates #1713 Updates #835 Change-Id: Ia71e96d0632c2d617b401695ad68301b07c1c2ec Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	3 years ago
Brad Fitzpatrick	c37af58ea4	net/tsdial: move more weirdo dialing into new tsdial package, plumb ... Not done yet, but this move more of the outbound dial special casing from random packages into tsdial, which aspires to be the one unified place for all outbound dialing shenanigans. Then this plumbs it all around, so everybody is ultimately holding on to the same dialer. As of this commit, macOS/iOS using an exit node should be able to reach to the exit node's DoH DNS proxy over peerapi, doing the sockopt to stay within the Network Extension. A number of steps remain, including but limited to: * move a bunch more random dialing stuff * make netstack-mode tailscaled be able to use exit node's DNS proxy, teaching tsdial's resolver to use it when an exit node is in use. Updates #1713 Change-Id: I1e8ee378f125421c2b816f47bc2c6d913ddcd2f5 Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	3 years ago
Brad Fitzpatrick	3ae6f898cf	ipn/ipnlocal, net/dns/resolver: use exit node's DoH proxy when available ... Updates #1713 Change-Id: I3695a40ec12d2b4e6dac41cf4559daca6dddd68e Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	3 years ago
Brad Fitzpatrick	135580a5a8	tailcfg, ipn/ipnlocal, net/dns: forward exit node DNS on Unix to system DNS ... Updates #1713 Change-Id: I4c073fec0992d9e01a9a4ce97087d5af0efdc68d Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	3 years ago
Brad Fitzpatrick	78b0bd2957	net/dns/resolver: add clientmetrics for DNS ... Fixes tailscale/corp#1811 Change-Id: I864d11e0332a177e8c5ff403591bff6fec548f5a Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	3 years ago
Brad Fitzpatrick	25525b7754	net/dns/resolver, ipn/ipnlocal: wire up peerapi DoH server to DNS forwarder ... Updates #1713 Change-Id: Ia4ed9d8c9cef0e70aa6d30f2852eaab80f5f695a Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	3 years ago
Josh Bleecher Snyder	758c37b83d	net/netns: thread logf into control functions ... So that darwin can log there without panicking during tests. Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>	3 years ago
Josh Bleecher Snyder	94fb42d4b2	all: use testingutil.MinAllocsPerRun ... There are a few remaining uses of testing.AllocsPerRun: Two in which we only log the number of allocations, and one in which dynamically calculate the allocations target based on a different AllocsPerRun run. This also allows us to tighten the "no allocs" test in wgengine/filter. Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>	3 years ago
Maisem Ali	7817ab6b20	net/dns/resolver: set maxDoHInFlight to 1000 on iOS 15+. ... Signed-off-by: Maisem Ali <maisem@tailscale.com>	3 years ago
David Crawshaw	77696579f5	net/dns/resolver: drop dropping log ... Signed-off-by: David Crawshaw <crawshaw@tailscale.com>	3 years ago
Brad Fitzpatrick	676fb458c3	net/dns/resolver: make hasRDNSBonjourPrefix match shorter queries too ... Fixes tailscale/corp#2886 Updates tailscale/corp#2820 Updates #2442 Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	3 years ago
nicksherron	f01ff18b6f	all: fix spelling mistakes ... Signed-off-by: nicksherron <nsherron90@gmail.com>	3 years ago
Smitty	b382161fe5	tsdns: don't forward transient DNS errors ... When a DNS server claims to be unable or unwilling to handle a request, instead of passing that refusal along to the client, just treat it as any other error trying to connect to the DNS server. This prevents DNS requests from failing based on if a server can respond with a transient error before another server is able to give an actual response. DNS requests only failing *sometimes* is really hard to find the cause of (#1033). Signed-off-by: Smitty <me@smitop.com>	3 years ago
Denton Gentry	d883747d8b	net/dns/resolver: don't forward DNS-SD on all platforms ... We added the initial handling only for macOS and iOS. With 1.16.0 now released, suppress forwarding DNS-SD on all platforms to test it through the 1.17.x cycle. Updates #2442 Signed-off-by: Denton Gentry <dgentry@tailscale.com>	3 years ago
Brad Fitzpatrick	297d1b7cb6	net/dns/resolver: don't forward DNS-SD queries ... Updates #2442 Fixes tailscale/corp#2820 Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	3 years ago
Brad Fitzpatrick	47044f3af7	net/dns/resolver: fix log prefix ... The passed in logf already has a "dns: " prefix so they were doubled up.	3 years ago
Brad Fitzpatrick	7634af5c6f	all: gofmt ... Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	3 years ago
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
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	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
slowy07	ac0353e982	fix: typo spelling grammar ... Signed-off-by: slowy07 <slowy.arfy@gmail.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
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	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
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
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
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
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
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>	4 years ago
David Anderson	30f5d706a1	net/dns/resolver: remove unnecessary/racy WaitGroup. ... Fixes #1663 Signed-off-by: David Anderson <danderson@tailscale.com>	4 years ago
David Anderson	1a371b93be	util/dnsname: add FQDN type, use throughout codebase. ... Signed-off-by: David Anderson <danderson@tailscale.com>	4 years ago
David Anderson	6def647514	net/dns/resolver: don't avoid tailscale routes for DNS forwarding. ... Signed-off-by: David Anderson <danderson@tailscale.com>	4 years ago
David Anderson	0ba6d03768	net/dns/resolver: add a test helper to get at the resolver config. ... Signed-off-by: David Anderson <danderson@tailscale.com>	4 years ago
David Anderson	1bf91c8123	net/dns/resolver: remove unused err return value. ... Signed-off-by: David Anderson <danderson@tailscale.com>	4 years ago
David Anderson	c4530971db	net/dns/resolver: remove leftover debug print. ... Signed-off-by: David Anderson <danderson@tailscale.com>	4 years ago
David Anderson	9f105d3968	net/dns/resolver: teach the forwarder to do per-domain routing. ... Given a DNS route map, the forwarder selects the right set of upstreams for a given name. Signed-off-by: David Anderson <danderson@tailscale.com>	4 years ago
David Anderson	90f82b6946	net/dns/resolver: add live reconfig, plumb through to ipnlocal. ... The resolver still only supports a single upstream config, and ipn/wgengine still have to split up the DNS config, but this moves closer to unifying the DNS configs. As a handy side-effect of the refactor, IPv6 MagicDNS records exist now. Signed-off-by: David Anderson <danderson@tailscale.com>	4 years ago
David Anderson	caeafc4a32	net/dns/resolver: fix package docstring. ... Signed-off-by: David Anderson <danderson@tailscale.com>	4 years ago
David Anderson	dbe4f6f42d	net/dns/resolver: unexport Resolve and ResolveReverse. ... They're only used internally and in tests, and have surprising semantics in that they only resolve MagicDNS names, not upstream resolver queries. Signed-off-by: David Anderson <danderson@tailscale.com>	4 years ago
David Anderson	cdeb8d6816	net/dns/resolver: fix staticcheck error. ... Signed-off-by: David Anderson <danderson@tailscale.com>	4 years ago
David Anderson	f185d62dc8	net/dns/resolver: unexport Packet, only use it internally. ... Signed-off-by: David Anderson <danderson@tailscale.com>	4 years ago
David Anderson	5fb9e00ecf	net/dns/resolver: remove Start method, fully spin up in New instead. ... Signed-off-by: David Anderson <danderson@tailscale.com>	4 years ago
David Anderson	075fb93e69	net/dns/resolver: remove the Config struct. ... In preparation for reintroducing a runtime reconfig Config struct. Signed-off-by: David Anderson <danderson@tailscale.com>	4 years ago
David Anderson	bc81dd4690	net/dns/resolver: rename ResolverConfig to just Config. ... Signed-off-by: David Anderson <danderson@tailscale.com>	4 years ago
David Anderson	d99f5b1596	net/dns/resolver: factor the resolver out into a sub-package. ... Signed-off-by: David Anderson <danderson@tailscale.com>	4 years ago