61 Commits (86c5bddce20a98eb8f37de96bd08417bc594083e)

Author	SHA1	Message	Date
Josh Soref	d4811f11a0	all: fix spelling mistakes ... Signed-off-by: Josh Soref <2119212+jsoref@users.noreply.github.com>	2 years ago
Eng Zer Jun	f0347e841f	refactor: move from io/ioutil to io and os packages ... The io/ioutil package has been deprecated as of Go 1.16 [1]. This commit replaces the existing io/ioutil functions with their new definitions in io and os packages. Reference: https://golang.org/doc/go1.16#ioutil Signed-off-by: Eng Zer Jun <engzerjun@gmail.com>	2 years ago
Brad Fitzpatrick	74674b110d	envknob: support changing envknobs post-init ... Updates #5114 Change-Id: Ia423fc7486e1b3f3180a26308278be0086fae49b Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	2 years ago
Mihai Parparita	82e82d9b7a	net/dns/resolver: remove unused responseTimeout constant ... Timeout is now enforced elsewhere, see discussion in https://github.com/tailscale/tailscale/pull/4408#discussion_r970092333. Signed-off-by: Mihai Parparita <mihai@tailscale.com>	2 years ago
Brad Fitzpatrick	e7376aca25	net/dns/resolver: set DNS-over-HTTPS Accept and User-Agent header on requests ... Change-Id: I14b821771681e70405a507f43229c694159265ff Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	2 years ago
Brad Fitzpatrick	58abae1f83	net/dns/{publicdns,resolver}: add NextDNS DoH support ... NextDNS is unique in that users create accounts and then get user-specific DNS IPs & DoH URLs. For DoH, the customer ID is in the URL path. For IPv6, the IP address includes the customer ID in the lower bits. For IPv4, there's a fragile "IP linking" mechanism to associate your public IPv4 with an assigned NextDNS IPv4 and that tuple maps to your customer ID. We don't use the IP linking mechanism. Instead, NextDNS is DoH-only. Which means using NextDNS necessarily shunts all DNS traffic through 100.100.100.100 (programming the OS to use 100.100.100.100 as the global resolver) because operating systems can't usually do DoH themselves. Once it's in Tailscale's DoH client, we then connect out to the known NextDNS IPv4/IPv6 anycast addresses. If the control plane sends the client a NextDNS IPv6 address, we then map it to the corresponding NextDNS DoH with the same client ID, and we dial that DoH server using the combination of v4/v6 anycast IPs. Updates #2452 Change-Id: I3439d798d21d5fc9df5a2701839910f5bef85463 Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	2 years ago
Nahum Shalman	214242ff62	net/dns/publicdns: Add Mullvad DoH ... See https://mullvad.net/en/help/dns-over-https-and-dns-over-tls/ The Mullvad DoH servers appear to only speak HTTP/2 and the use of a non-nil DialContext in the http.Transport means that ForceAttemptHTTP2 must be set to true to be able to use them. Signed-off-by: Nahum Shalman <nahamu@gmail.com>	2 years ago
Maisem Ali	3bb57504af	net/dns/resolver: add comments clarifying nil error returns ... Signed-off-by: Maisem Ali <maisem@tailscale.com>	2 years ago
Maisem Ali	4497bb0b81	net/dns/resolver: return SERVFAIL when no upstream resolvers set ... Otherwise we just keep looping over the same thing again and again. ``` dns udp query: upstream nameservers not set dns udp query: upstream nameservers not set dns udp query: upstream nameservers not set ``` Signed-off-by: Maisem Ali <maisem@tailscale.com>	2 years ago
Maisem Ali	9bb5a038e5	all: use atomic.Pointer ... Also add some missing docs. Signed-off-by: Maisem Ali <maisem@tailscale.com>	2 years ago
Brad Fitzpatrick	a12aad6b47	all: convert more code to use net/netip directly ... perl -i -npe 's,netaddr.IPPrefixFrom,netip.PrefixFrom,' $(git grep -l -F netaddr.) perl -i -npe 's,netaddr.IPPortFrom,netip.AddrPortFrom,' $(git grep -l -F netaddr. ) perl -i -npe 's,netaddr.IPPrefix,netip.Prefix,g' $(git grep -l -F netaddr. ) perl -i -npe 's,netaddr.IPPort,netip.AddrPort,g' $(git grep -l -F netaddr. ) perl -i -npe 's,netaddr.IP\b,netip.Addr,g' $(git grep -l -F netaddr. ) perl -i -npe 's,netaddr.IPv6Raw\b,netip.AddrFrom16,g' $(git grep -l -F netaddr. ) goimports -w . Then delete some stuff from the net/netaddr shim package which is no longer neeed. Updates #5162 Change-Id: Ia7a86893fe21c7e3ee1ec823e8aba288d4566cd8 Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	2 years ago
Brad Fitzpatrick	7eaf5e509f	net/netaddr: start migrating to net/netip via new netaddr adapter package ... Updates #5162 Change-Id: Id7bdec303b25471f69d542f8ce43805328d56c12 Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	2 years ago
Tom DNetto	d6817d0f22	net/dns/resolver: respond with SERVFAIL if all upstreams fail ... Fixes #4722 Signed-off-by: Tom DNetto <tom@tailscale.com>	2 years ago
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	fd99c54e10	tailcfg,all: change structs to []*dnstype.Resolver ... Signed-off-by: Maisem Ali <maisem@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
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
Brad Fitzpatrick	f2041c9088	all: use strings.Cut even more ... Change-Id: I943ce72c6f339589235bddbe10d07799c4e37979 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	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	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	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
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
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	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
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
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	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