3 Commits (0e62a7d1a247eb312f340b08e92942f73149f11f)

Author	SHA1	Message	Date
Brad Fitzpatrick	73280595a8	derp: accept dup clients without closing prior's connection ... A public key should only have max one connection to a given DERP node (or really: one connection to a node in a region). But if people clone their machine keys (e.g. clone their VM, Raspbery Pi SD card, etc), then we can get into a situation where a public key is connected multiple times. Originally, the DERP server handled this by just kicking out a prior connections whenever a new one came. But this led to reconnect fights where 2+ nodes were in hard loops trying to reconnect and kicking out their peer. Then a909d37a59 tried to add rate limiting to how often that dup-kicking can happen, but empirically it just doesn't work and ~leaks a bunch of goroutines and TCP connections, tying them up for hour+ while more and more accumulate and waste memory. Mostly because we were doing a time.Sleep forever while not reading from their TCP connections. Instead, just accept multiple connections per public key but track which is the most recent. And if two both are writing back & forth, then optionally disable them both. That last part is only enabled in tests for now. The current default policy is just last-sender-wins while we gather the next round of stats. Updates #2751 Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	3 years ago
Josh Bleecher Snyder	0ec9040c5e	scripts: remove special case for _strings.go files in check license headers ... And add a license header for derp/dropreason_string.go to make it happy. Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>	3 years ago
David Anderson	36492ace9d	derp: add counters to track the type of dropped packets. ... Signed-off-by: David Anderson <danderson@tailscale.com>	3 years ago