24 Commits (1dc4151f8b96817d6e30b7b00469ebddf15ae2a5)

Author	SHA1	Message	Date
Brad Fitzpatrick	8267ea0f80	net/tstun: remove TODO that's done ... This TODO was both added and fixed in 506c727e3. As I recall, I wasn't originally going to do it because it seemed annoying, so I wrote the TODO, but then I felt bad about it and just did it, but forgot to remove the TODO. Change-Id: I8f3514809ad69b447c62bfeb0a703678c1aec9a3 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
Josh Bleecher Snyder	73beaaf360	net/tstun: rate limit "self disco out packet" logging ... When this happens, it is incredibly noisy in the logs. It accounts for about a third of all remaining "unexpected" log lines from a recent investigation. It's not clear that we know how to fix this, we have a functioning workaround, and we now have a (cheap and efficient) metric for this that we can use for measurements. So reduce the logging to approximately once per minute. Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>	3 years ago
Brad Fitzpatrick	cf06f9df37	net/tstun, wgengine: add packet-level and drop metrics ... Primarily tstun work, but some MagicDNS stuff spread into wgengine. No wireguard reconfig metrics (yet). Updates #3307 Change-Id: Ide768848d7b7d0591e558f118b553013d1ec94ad Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	3 years ago
David Anderson	0532eb30db	all: replace tailcfg.DiscoKey with key.DiscoPublic. ... Signed-off-by: David Anderson <danderson@tailscale.com>	3 years ago
Brad Fitzpatrick	080381c79f	net/tstun: block looped disco traffic, take 17 ... It was in the wrong filter direction before, per CPU profiles we now have. Updates #1526 (maybe fixes? time will tell) Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	3 years ago
Brad Fitzpatrick	dabeda21e0	net/tstun: block looped disco traffic ... Updates #1526 (maybe fixes? time will tell) Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	3 years ago
Brad Fitzpatrick	a729070252	net/tstun: add start of Linux TAP support, with DHCP+ARP server ... Still very much a prototype (hard-coded IPs, etc) but should be non-invasive enough to submit at this point and iterate from here. Updates #2589 Co-Author: David Crawshaw <crawshaw@tailscale.com> Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	3 years ago
Josh Bleecher Snyder	c2202cc27c	net/tstun: use mono.Time ... There's a call to Now once per packet. Move to mono.Now. Though the current implementation provides high precision, we document it to be coarse, to preserve the ability to switch to a coarse monotonic time later. Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>	3 years ago
Josh Bleecher Snyder	1034b17bc7	net/tstun: buffer outbound channel ... The handoff between tstun.Wrap's Read and poll methods is one of the per-packet hotspots. It shows up in pprof. Making outbound buffered increases throughput. It is hard to measure exactly how much, because the numbers are highly variable, but I'd estimate it at about 1%, using the best observed max throughput across three runs. Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>	3 years ago
Josh Bleecher Snyder	965dccd4fc	net/tstun: buffer outbound channel ... The handoff between tstun.Wrap's Read and poll methods is one of the per-packet hotspots. It shows up in pprof. Making outbound buffered increases throughput. It is hard to measure exactly how much, because the numbers are highly variable, but I'd estimate it at about 1%, using the best observed max throughput across three runs. Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>	3 years ago
Josh Bleecher Snyder	0ad92b89a6	net/tstun: fix data races ... To remove some multi-case selects, we intentionally allowed sends on closed channels (cc23049cd2). However, we also introduced concurrent sends and closes, which is a data race. This commit fixes the data race. The mutexes here are uncontended, and thus very cheap. Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>	3 years ago
Josh Bleecher Snyder	c35a832de6	net/tstun: add inner loop to poll ... This avoids re-enqueuing to t.bufferConsumed, which makes the code a bit clearer. Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>	3 years ago
Josh Bleecher Snyder	a4cc7b6d54	net/tstun: simplify code ... Calculate whether the packet is injected directly, rather than via an else branch. Unify the exit paths. It is easier here than duplicating them. Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>	3 years ago
Josh Bleecher Snyder	cc23049cd2	net/tstun: remove multi-case selects from hot code ... Every TUN Read went through several multi-case selects. We know from past experience with wireguard-go that these are slow and cause scheduler churn. The selects served two purposes: they separated errors from data and gracefully handled shutdown. The first is fairly easy to replace by sending errors and data over a single channel. The second, less so. We considered a few approaches: Intricate webs of channels, global condition variables. They all get ugly fast. Instead, let's embrace the ugly and handle shutdown ungracefully. It's horrible, but the horror is simple and localized. Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>	3 years ago
Josh Bleecher Snyder	1ece91cede	go.mod: upgrade wireguard-windows, de-fork wireguard-go ... Pull in the latest version of wireguard-windows. Switch to upstream wireguard-go. This requires reverting all of our import paths. Unfortunately, this has to happen at the same time. The wireguard-go change is very low risk, as that commit matches our fork almost exactly. (The only changes are import paths, CI files, and a go.mod entry.) So if there are issues as a result of this commit, the first place to look is wireguard-windows changes. Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>	4 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
Brad Fitzpatrick	7f2eb1d87a	net/tstun: fix TUN log spam when ACLs drop a packet ... Whenever we dropped a packet due to ACLs, wireguard-go was logging: Failed to write packet to TUN device: packet dropped by filter Instead, just lie to wireguard-go and pretend everything is okay. Fixes #1229 Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	4 years ago
Josh Bleecher Snyder	99705aa6b7	net/tstun: split TUN events channel into up/down and MTU ... We had a long-standing bug in which our TUN events channel was being received from simultaneously in two places. The first is wireguard-go. At wgengine/userspace.go:366, we pass e.tundev to wireguard-go, which starts a goroutine (RoutineTUNEventReader) that receives from that channel and uses events to adjust the MTU and bring the device up/down. At wgengine/userspace.go:374, we launch a goroutine that receives from e.tundev, logs MTU changes, and triggers state updates when up/down changes occur. Events were getting delivered haphazardly between the two of them. We don't really want wireguard-go to receive the up/down events; we control the state of the device explicitly by calling device.Up. And the userspace.go loop MTU logging duplicates logging that wireguard-go does when it received MTU updates. So this change splits the single TUN events channel into up/down and other (aka MTU), and sends them to the parties that ought to receive them. I'm actually a bit surprised that this hasn't caused more visible trouble. If a down event went to wireguard-go but the subsequent up event went to userspace.go, we could end up with the wireguard-go device disappearing. I believe that this may also (somewhat accidentally) be a fix for #1790. Signed-off-by: Josh Bleecher Snyder <josharian@gmail.com>	4 years ago
Avery Pennarun	a92b9647c5	wgengine/bench: speed test for channels, sockets, and wireguard-go. ... This tries to generate traffic at a rate that will saturate the receiver, without overdoing it, even in the event of packet loss. It's unrealistically more aggressive than TCP (which will back off quickly in case of packet loss) but less silly than a blind test that just generates packets as fast as it can (which can cause all the CPU to be absorbed by the transmitter, giving an incorrect impression of how much capacity the total system has). Initial indications are that a syscall about every 10 packets (TCP bulk delivery) is roughly the same speed as sending every packet through a channel. A syscall per packet is about 5x-10x slower than that. The whole tailscale wireguard-go + magicsock + packet filter combination is about 4x slower again, which is better than I thought we'd do, but probably has room for improvement. Note that in "full" tailscale, there is also a tundev read/write for every packet, effectively doubling the syscall overhead per packet. Given these numbers, it seems like read/write syscalls are only 25-40% of the total CPU time used in tailscale proper, so we do have significant non-syscall optimization work to do too. Sample output: $ GOMAXPROCS=2 go test -bench . -benchtime 5s ./cmd/tailbench goos: linux goarch: amd64 pkg: tailscale.com/cmd/tailbench cpu: Intel(R) Core(TM) i7-4785T CPU @ 2.20GHz BenchmarkTrivialNoAlloc/32-2 56340248 93.85 ns/op 340.98 MB/s 0 %lost 0 B/op 0 allocs/op BenchmarkTrivialNoAlloc/124-2 57527490 99.27 ns/op 1249.10 MB/s 0 %lost 0 B/op 0 allocs/op BenchmarkTrivialNoAlloc/1024-2 52537773 111.3 ns/op 9200.39 MB/s 0 %lost 0 B/op 0 allocs/op BenchmarkTrivial/32-2 41878063 135.6 ns/op 236.04 MB/s 0 %lost 0 B/op 0 allocs/op BenchmarkTrivial/124-2 41270439 138.4 ns/op 896.02 MB/s 0 %lost 0 B/op 0 allocs/op BenchmarkTrivial/1024-2 36337252 154.3 ns/op 6635.30 MB/s 0 %lost 0 B/op 0 allocs/op BenchmarkBlockingChannel/32-2 12171654 494.3 ns/op 64.74 MB/s 0 %lost 1791 B/op 0 allocs/op BenchmarkBlockingChannel/124-2 12149956 507.8 ns/op 244.17 MB/s 0 %lost 1792 B/op 1 allocs/op BenchmarkBlockingChannel/1024-2 11034754 528.8 ns/op 1936.42 MB/s 0 %lost 1792 B/op 1 allocs/op BenchmarkNonlockingChannel/32-2 8960622 2195 ns/op 14.58 MB/s 8.825 %lost 1792 B/op 1 allocs/op BenchmarkNonlockingChannel/124-2 3014614 2224 ns/op 55.75 MB/s 11.18 %lost 1792 B/op 1 allocs/op BenchmarkNonlockingChannel/1024-2 3234915 1688 ns/op 606.53 MB/s 3.765 %lost 1792 B/op 1 allocs/op BenchmarkDoubleChannel/32-2 8457559 764.1 ns/op 41.88 MB/s 5.945 %lost 1792 B/op 1 allocs/op BenchmarkDoubleChannel/124-2 5497726 1030 ns/op 120.38 MB/s 12.14 %lost 1792 B/op 1 allocs/op BenchmarkDoubleChannel/1024-2 7985656 1360 ns/op 752.86 MB/s 13.57 %lost 1792 B/op 1 allocs/op BenchmarkUDP/32-2 1652134 3695 ns/op 8.66 MB/s 0 %lost 176 B/op 3 allocs/op BenchmarkUDP/124-2 1621024 3765 ns/op 32.94 MB/s 0 %lost 176 B/op 3 allocs/op BenchmarkUDP/1024-2 1553750 3825 ns/op 267.72 MB/s 0 %lost 176 B/op 3 allocs/op BenchmarkTCP/32-2 11056336 503.2 ns/op 63.60 MB/s 0 %lost 0 B/op 0 allocs/op BenchmarkTCP/124-2 11074869 533.7 ns/op 232.32 MB/s 0 %lost 0 B/op 0 allocs/op BenchmarkTCP/1024-2 8934968 671.4 ns/op 1525.20 MB/s 0 %lost 0 B/op 0 allocs/op BenchmarkWireGuardTest/32-2 1403702 4547 ns/op 7.04 MB/s 14.37 %lost 467 B/op 3 allocs/op BenchmarkWireGuardTest/124-2 780645 7927 ns/op 15.64 MB/s 1.537 %lost 420 B/op 3 allocs/op BenchmarkWireGuardTest/1024-2 512671 11791 ns/op 86.85 MB/s 0.5206 %lost 411 B/op 3 allocs/op PASS ok tailscale.com/wgengine/bench 195.724s Updates #414. Signed-off-by: Avery Pennarun <apenwarr@tailscale.com>	4 years ago
Brad Fitzpatrick	939861773d	net/tstun: accept peerapi connections through the filter ... Fixes tailscale/corp#1545 Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	4 years ago
Brad Fitzpatrick	41e4e02e57	net/{packet,tstun}: send peerapi port in TSMP pongs ... For discovery when an explicit hostname/IP is known. We'll still also send it via control for finding peers by a list. Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	4 years ago
David Anderson	016de16b2e	net/tstun: rename TUN to Wrapper. ... The tstun packagen contains both constructors for generic tun Devices, and a wrapper that provides additional functionality. Signed-off-by: David Anderson <danderson@tailscale.com>	4 years ago
David Anderson	588b70f468	net/tstun: merge in wgengine/tstun. ... Signed-off-by: David Anderson <danderson@tailscale.com>	4 years ago