tailscale

Commit Graph

Author	SHA1	Message	Date
Maisem Ali	1cff719015	net/dns: [win] respond with SERVFAIL queries when no resolvers Currently we forward unmatched queries to the default resolver on Windows. This results in duplicate queries being issued to the same resolver which is just wasted. Updates #1659 Signed-off-by: Maisem Ali <maisem@tailscale.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	a9f6cd41fd	all: use syncs.AtomicValue 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	8725b14056	all: migrate more code code to net/netip directly Instead of going through the tailscale.com/net/netaddr transitional wrappers. Updates #5162 Change-Id: I3dafd1c2effa1a6caa9b7151ecf6edd1a3fda3dd Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	2 years ago
Brad Fitzpatrick	116f55ff66	all: gofmt for Go 1.19 Updates #5210 Change-Id: Ib02cd5e43d0a8db60c1f09755a8ac7b140b670be Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	2 years ago
nyghtowl	e6e1976c3a	net/dns: remove systemd-resolved ping Ping only needed to ensure system awak otherwise utilizing resolvConf to set dns mode. Signed-off-by: nyghtowl <warrick@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	6a396731eb	all: use various net/netip parse funcs directly Mechanical change with perl+goimports. Changed {Must,}Parse{IP,IPPrefix,IPPort} to their netip variants, then goimports -d . Finally, removed the net/netaddr wrappers, to prevent future use. Updates #5162 Change-Id: I59c0e38b5fbca5a935d701645789cddf3d7863ad 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
Aaron Klotz	1cae618b03	net/dns: add Windows group policy notifications to the NRPT rule manager As discussed in previous PRs, we can register for notifications when group policies are updated and act accordingly. This patch changes nrptRuleDatabase to receive notifications that group policy has changed and automatically move our NRPT rules between the local and group policy subkeys as needed. Signed-off-by: Aaron Klotz <aaron@tailscale.com>	2 years ago
Melanie Warrick	f17873e0f4	net/dns: handle D-Bus restarts in resolved manager (#5026 ) When dbus restarts it can cause the tailscaled to crash because the nil signal was not handled in resolved.Fixing so the nil signal leads to a connection reset and tailscaled stays connected to systemd when dbus restarted. Fixes #4645 Co-authored-by: James Tucker <james@tailscale.com> Signed-off-by: nyghtowl <warrick@tailscale.com> Co-authored-by: James Tucker <james@tailscale.com>	2 years ago
Andrew Dunham	c7993d2b88	net/dns/resolver: add fuzz/unit test for #2533 (#5018 ) Signed-off-by: Andrew Dunham <andrew@du.nham.ca>	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
Aaron Klotz	4baf34cf25	net/dns: set appropriate Windows registry values to prevent it from sending DNS changes concerning our interface to AD domain controllers. We do this unconditionally inside SetDNS such that the values are always set before we make any other changes to DNS configurations. It should not be harmful for the settings to remain even when other DNS settings are cleared out (since they only affect our network interface). See https://docs.microsoft.com/en-us/troubleshoot/windows-server/networking/configure-dns-dynamic-updates-windows-server-2003 for details about the registry value. Fixes https://github.com/tailscale/tailscale/issues/4829 Signed-off-by: Aaron Klotz <aaron@tailscale.com>	2 years ago
Aaron Klotz	8cdfd12977	net/dns: update Windows split DNS settings to work alongside other NRPT entries set by group policy. When there are group policy entries for the NRPT that do not belong to Tailscale, we recognize that we need to add ourselves to group policy and use that registry key instead of the local one. We also refresh the group policy settings as necessary to ensure that our changes take effect immediately. Fixes https://github.com/tailscale/tailscale/issues/4607 Signed-off-by: Aaron Klotz <aaron@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
Aaron Klotz	b005b79236	net/dns, paths, util/winutil: change net/dns/windowsManager NRPT management to support more than 50 domains. AFAICT this isn't documented on MSDN, but based on the issue referenced below, NRPT rules are not working when a rule specifies > 50 domains. This patch modifies our NRPT rule generator to split the list of domains into chunks as necessary, and write a separate rule for each chunk. For compatibility reasons, we continue to use the hard-coded rule ID, but as additional rules are required, we generate new GUIDs. Those GUIDs are stored under the Tailscale registry path so that we know which rules are ours. I made some changes to winutils to add additional helper functions in support of both the code and its test: I added additional registry accessors, and also moved some token accessors from paths to util/winutil. Fixes https://github.com/tailscale/coral/issues/63 Signed-off-by: Aaron Klotz <aaron@tailscale.com>	3 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	d1d6ab068e	net/dns, wgengine: implement DNS over TCP (#4598 ) * net/dns, wgengine: implement DNS over TCP Signed-off-by: Tom DNetto <tom@tailscale.com> * wgengine/netstack: intercept only relevant port/protocols to quad-100 Signed-off-by: Tom DNetto <tom@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	7f45734663	assorted: documentation and readability fixes This were intended to be pushed to #4408, but in my excitement I forgot to git push :/ better late than never. 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
Brad Fitzpatrick	e97209c6bf	net/dns: add tailscaled-on-macOS DNS OSConfigurator This populates DNS suffixes ("ts.net", etc) in /etc/resolver/* files to point to 100.100.100.100 so MagicDNS works. It also sets search domains. Updates #4276 Signed-off-by: Brad Fitzpatrick <bradfitz@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	d9efbd97cb	net/dns: remove an unused function Change-Id: I7c920c76223ffac37954ef2a18754afc52177598 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	52d32c94d8	net/dns/publicdns: add missing call to sync.Once.Do (#4410 ) Signed-off-by: Jenny Zhang <jz@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	7d897229d9	net/dns: ignore permission errors on Synology DSM7 for now Updates #4017 Change-Id: Ia7fd4df47588c010dea8e63d88f397cc8eb748e5 Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	3 years ago
Brad Fitzpatrick	2ff481ff10	net/dns: add health check for particular broken-ish Linux DNS config Updates #3937 (need to write docs before closing) Change-Id: I1df7244cfbb0303481e2621ee750d21358bd67c6 Signed-off-by: Brad Fitzpatrick <bradfitz@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	21358cf2f5	net/dns: slightly optimize dbusPing for non-dbus case [Linux] Avoid some work when D-Bus isn't running. Change-Id: I6f89bb75fdb24c13f61be9b400610772756db1ef Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	3 years ago
Brad Fitzpatrick	37e7a387ff	net/dns: remove some unused code for detecting systemd-resolved [Linux] Change-Id: I19c5fd2cdacfb9e5b688ccd9b4336ae4edffc445 Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	3 years ago
Brad Fitzpatrick	15599323a1	net/dns: fix systemd-resolved detection race at boot If systemd-resolved is enabled but not running (or not yet running, such as early boot) and resolv.conf is old/dangling, we weren't detecting systemd-resolved. This moves its ping earlier, which will trigger it to start up and write its file. Updates #3362 (likely fixes) Updates #3531 (likely fixes) Change-Id: I6392944ac59f600571c43b8f7a677df224f2beed Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	3 years ago
Denton Gentry	dbea8217ac	net/dns: add NetworkManager regression test Use the exact /etc/resolv.conf file from a user report. Updates https://github.com/tailscale/tailscale/issues/3531 Signed-off-by: Denton Gentry <dgentry@tailscale.com>	3 years ago
Aaron Bieber	e5cd765e00	net/dns/resolvd: properly handle not having "search" entries This prevents adding an empty "search" line when no search domains are set. Signed-off-by: Aaron Bieber <aaron@bolddaemon.com>	3 years ago
Brad Fitzpatrick	41fd4eab5c	envknob: add new package for all the strconv.ParseBool(os.Getenv(..)) A new package can also later record/report which knobs are checked and set. It also makes the code cleaner & easier to grep for env knobs. Change-Id: Id8a123ab7539f1fadbd27e0cbeac79c2e4f09751 Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	3 years ago
Brad Fitzpatrick	6feb8f4c51	net/dns: log why resolved does not look like it's on use [Linux] Updates #3742 Updates #3531 Change-Id: I9fc7fa0f4bcab1cf8001ba92408c660a5b25f105 Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	3 years ago
Aaron Bieber	411c6c316c	net/dns/resolvd: store nameservers Currently only search domains are stored. This was an oversight (under?) on my part. As things are now, when MagicDNS is on and "Override local DNS" is off, the dns forwarder has to timeout before names resolve. This introduces a pretty annoying lang that makes everything feel extremely slow. You will also see an error: "upstream nameservers not set". I tested with "Override local DNS" on and off. In both situations things seem to function as expected (and quickly). Signed-off-by: Aaron Bieber <aaron@bolddaemon.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	8df3fa4638	net/dns: make WSL network configuration opt-in for now Tailscale seems to be breaking WSL configurations lately. Until we understand what changed, turn off Tailscale's involvement by default and make it opt-in. Updates #2815 Change-Id: I9977801f8debec7d489d97761f74000a4a33f71b Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	3 years ago
Aaron Bieber	189f359609	net/dns: teach OpenBSD's manager to talk to resolvd(8). (#2789 ) OpenBSD 6.9 and up has a daemon which handles nameserver configuration. This PR teaches the OpenBSD dns manager to check if resolvd is being used. If it is, it will use the route(8) command to tell resolvd to add the Tailscale dns entries to resolv.conf Signed-off-by: Aaron Bieber <aaron@bolddaemon.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	eb26c081b1	net/dns: bound time we wait on restarting systemd-resolved in another place Fixes #3629 Updates #3537 Change-Id: I5d4b6acfcfdf0e3efcf6eb49c5e6cf4521e4baed 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	cab5c46481	net/dns: bound how long we block looking for, restarting systemd-resolved Fixes #3537 Change-Id: Iba6a3cde75983490d4072b5341f48dbfa2f997c0 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
Aaron Klotz	f93cf6fa03	net/dns: fix checking for wrapped error when attempting to read wsl.conf for Windows WSL2 Fixes https://github.com/tailscale/tailscale/issues/3437 Signed-off-by: Aaron Klotz <aaron@tailscale.com>	3 years ago
David Anderson	124363e0ca	net/dns: detect and decode UTF-16 from wsl.exe earlier. Fixes #3170 Signed-off-by: David Anderson <danderson@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	d10cefdb9b	net/dns: require space after nameserver/search parsing resolv.conf Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>	3 years ago
Josh Bleecher Snyder	9f00510833	net/dns: handle comments in resolv.conf Currently, comments in resolv.conf cause our parser to fail, with error messages like: ParseIP("192.168.0.100 # comment"): unexpected character (at " # comment") Fix that. Noticed while looking through logs. Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>	3 years ago
Brad Fitzpatrick	283ae702c1	ipn/ipnlocal: start adding DoH DNS server to peerapi when exit node Updates #1713 Change-Id: I8d9c488f779e7acc811a9bc18166a2726198a429 Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	3 years ago
David Anderson	88b8a09d37	net/dns: make constants for the various DBus strings. Signed-off-by: David Anderson <danderson@tailscale.com>	3 years ago
David Anderson	6c82cebe57	health: add a health state for net/dns.OSConfigurator. Lets the systemd-resolved OSConfigurator report health changes for out of band config resyncs. Updates #3327 Signed-off-by: David Anderson <danderson@tailscale.com>	3 years ago
David Anderson	4ef3fed100	net/dns: resync config to systemd-resolved when it restarts. Fixes #3327 Signed-off-by: David Anderson <danderson@tailscale.com>	3 years ago
David Anderson	cf9169e4be	net/dns: remove unused Config struct element. Signed-off-by: David Anderson <danderson@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
Brad Fitzpatrick	400ed799e6	net/dns: work around old systemd-resolved setLinkDomain length limit Don't set all the *.arpa. reverse DNS lookup domains if systemd-resolved is old and can't handle them. Fixes #3188 Change-Id: I283f8ce174daa8f0a972ac7bfafb6ff393dde41d Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	3 years ago
David Anderson	c5d572f371	net/dns: correctly handle NetworkManager-managed DNS that points to resolved. Fixes #3304 Signed-off-by: David Anderson <danderson@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
Denton Gentry	139a6c4c9c	net/dns: detect when resolvconf points to systemd-resolved. There are /etc/resolv.conf files out there where resolvconf wrote the file but pointed to systemd-resolved as the nameserver. We're better off handling those as systemd-resolved. > # Dynamic resolv.conf(5) file for glibc resolver(3) generated by resolvconf(8) > # DO NOT EDIT THIS FILE BY HAND -- YOUR CHANGES WILL BE OVERWRITTEN > # 127.0.0.53 is the systemd-resolved stub resolver. > # run "systemd-resolve --status" to see details about the actual nameservers. Fixes https://github.com/tailscale/tailscale/issues/3026 Signed-off-by: Denton Gentry <dgentry@tailscale.com>	3 years ago
David Anderson	a320d70614	net/dns: fall back to copy+delete/truncate if moving to/from /etc/resolv.conf fails. In some containers, /etc/resolv.conf is a bind-mount from outside the container. This prevents renaming to or from /etc/resolv.conf, because it's on a different filesystem from linux's perspective. It also prevents removing /etc/resolv.conf, because doing so would break the bind-mount. If we find ourselves within this environment, fall back to using copy+delete when renaming to /etc/resolv.conf, and copy+truncate when renaming from /etc/resolv.conf. Fixes #3000 Co-authored-by: Denton Gentry <dgentry@tailscale.com> Signed-off-by: David Anderson <danderson@tailscale.com>	3 years ago
David Anderson	04d24d3a38	net/dns: move directManager function below directManager's definition. Signed-off-by: David Anderson <danderson@tailscale.com>	3 years ago
David Anderson	422ea4980f	net/dns: remove a tiny wrapper function that isn't contributing anything. Signed-off-by: David Anderson <danderson@tailscale.com>	3 years ago
Maxim Merzhanov	9f954628e5	net/dns: ignore UnknownMethod error in SetLinkDefaultRoute for resolved manager Signed-off-by: Maxim Merzhanov <maksimmerzh@gmail.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
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>	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

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345 Commits (1e6cdb7d86b49e4cd2dceb6e001c939859684b34)