62 Commits (71029cea2ddf82007b80f465b256d027eab0f02d)

Author	SHA1	Message	Date
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
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
Adrian Dewhurst	8b11937eaf	net/dns/resolver: permit larger max responses, signal truncation ... This raises the maximum DNS response message size from 512 to 4095. This should be large enough for almost all situations that do not need TCP. We still do not recognize EDNS, so we will still forward requests that claim support for a larger response size than 4095 (that will be solved later). For now, when a response comes back that is too large to fit in our receive buffer, we now set the truncation flag in the DNS header, which is an improvement from before but will prompt attempts to use TCP which isn't supported yet. On Windows, WSARecvFrom into a buffer that's too small returns an error in addition to the data. On other OSes, the extra data is silently discarded. In this case, we prefer the latter so need to catch the error on Windows. Partially addresses #1123 Signed-off-by: Adrian Dewhurst <adrian@tailscale.com>	4 years ago
David Anderson	7fab244614	net/dns/resolver: don't spam logs on EHOSTUNREACH. ... Fixes #1719. Signed-off-by: David Anderson <danderson@tailscale.com>	4 years ago
David Anderson	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	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	f185d62dc8	net/dns/resolver: unexport Packet, only use it internally. ... 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