181 Commits (209567e7a0b939cbc3b2067cb5ef5f89305bd075)

Author	SHA1	Message	Date
Percy Wegmann	ecc451501c	ssh/tailssh: add ability to force V2 behavior using new feature flag ... Introduces ssh-behavior-v2 node attribute to override ssh-behavior-v1. Updates #11854 Signed-off-by: Percy Wegmann <percy@tailscale.com>	2 months ago
Brad Fitzpatrick	0ff474ff37	all: fix new lint warnings from bumping staticcheck ... In prep for updating to new staticcheck required for Go 1.23. Updates #12912 Change-Id: If77892a023b79c6fa798f936fc80428fd4ce0673 Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	2 months ago
Percy Wegmann	4b525fdda0	ssh/tailssh: only chdir incubator process to user's homedir when necessary and possible ... Instead of changing the working directory before launching the incubator process, this now just changes the working directory after dropping privileges, at which point we're more likely to be able to enter the user's home directory since we're running as the user. For paths that use the 'login' or 'su -l' commands, those already take care of changing the working directory to the user's home directory. Fixes #13120 Signed-off-by: Percy Wegmann <percy@tailscale.com>	2 months ago
Percy Wegmann	7d83056a1b	ssh/tailssh: fix SSH on busybox systems ... This involved the following: 1. Pass the su command path as first of args in call to unix.Exec to make sure that busybox sees the correct program name. Busybox is a single executable userspace that implements various core userspace commands in a single binary. You'll see it used via symlinking, so that for example /bin/su symlinks to /bin/busybox. Busybox knows that you're trying to execute /bin/su because argv[0] is '/bin/su'. When we called unix.Exec, we weren't including the program name for argv[0], which caused busybox to fail with 'applet not found', meaning that it didn't know which command it was supposed to run. 2. Tell su to whitelist the SSH_AUTH_SOCK environment variable in order to support ssh agent forwarding. 3. Run integration tests on alpine, which uses busybox. 4. Increment CurrentCapabilityVersion to allow turning on SSH V2 behavior from control. Fixes #12849 Signed-off-by: Percy Wegmann <percy@tailscale.com>	2 months ago
Irbe Krumina	a21bf100f3	cmd/k8s-operator,k8s-operator/sessionrecording,sessionrecording,ssh/tailssh: refactor session recording functionality (#12945) ... cmd/k8s-operator,k8s-operator/sessionrecording,sessionrecording,ssh/tailssh: refactor session recording functionality Refactor SSH session recording functionality (mostly the bits related to Kubernetes API server proxy 'kubectl exec' session recording): - move the session recording bits used by both Tailscale SSH and the Kubernetes API server proxy into a shared sessionrecording package, to avoid having the operator to import ssh/tailssh - move the Kubernetes API server proxy session recording functionality into a k8s-operator/sessionrecording package, add some abstractions in preparation for adding support for a second streaming protocol (WebSockets) Updates tailscale/corp#19821 Signed-off-by: Irbe Krumina <irbe@tailscale.com>	3 months ago
Irbe Krumina	ba517ab388	cmd/k8s-operator,ssh/tailssh,tsnet: optionally record 'kubectl exec' sessions via Kubernetes operator's API server proxy (#12274) ... cmd/k8s-operator,ssh/tailssh,tsnet: optionally record kubectl exec sessions The Kubernetes operator's API server proxy, when it receives a request for 'kubectl exec' session now reads 'RecorderAddrs', 'EnforceRecorder' fields from tailcfg.KubernetesCapRule. If 'RecorderAddrs' is set to one or more addresses (of a tsrecorder instance(s)), it attempts to connect to those and sends the session contents to the recorder before forwarding the request to the kube API server. If connection cannot be established or fails midway, it is only allowed if 'EnforceRecorder' is not true (fail open). Updates tailscale/corp#19821 Signed-off-by: Irbe Krumina <irbe@tailscale.com> Co-authored-by: Maisem Ali <maisem@tailscale.com>	4 months ago
Irbe Krumina	07063bc5c7	ssh/tailssh: fix integration test (#12562) ... Updates#cleanup Signed-off-by: Irbe Krumina <irbe@tailscale.com>	4 months ago
Percy Wegmann	730f0368d0	ssh/tailssh: replace incubator process with su instead of running su as child ... This allows the SSH_AUTH_SOCK environment variable to work inside of su and agent forwarding to succeed. Fixes #12467 Signed-off-by: Percy Wegmann <percy@tailscale.com>	4 months ago
Andrew Dunham	45d2f4301f	proxymap, various: distinguish between different protocols ... Previously, we were registering TCP and UDP connections in the same map, which could result in erroneously removing a mapping if one of the two connections completes while the other one is still active. Add a "proto string" argument to these functions to avoid this. Additionally, take the "proto" argument in LocalAPI, and plumb that through from the CLI and add a new LocalClient method. Updates tailscale/corp#20600 Signed-off-by: Andrew Dunham <andrew@du.nham.ca> Change-Id: I35d5efaefdfbf4721e315b8ca123f0c8af9125fb	5 months ago
Percy Wegmann	d7fdc01f7f	ssh/tailssh: check IsSELinuxEnforcing in tailscaled process ... Checking in the incubator as this used to do fails because the getenforce command is not on the PATH. Updates #12442 Signed-off-by: Percy Wegmann <percy@tailscale.com>	5 months ago
Percy Wegmann	08a9551a73	ssh/tailssh: fall back to using su when no TTY available on Linux ... This allows pam authentication to run for ssh sessions, triggering automation like pam_mkhomedir. Updates #11854 Signed-off-by: Percy Wegmann <percy@tailscale.com>	5 months ago
Brad Fitzpatrick	46f3feae96	ssh/tailssh: plumb health.Tracker in test ... In prep for it being required in more places. Updates #11874 Change-Id: Ib743205fc2a6c6ff3d2c4ed3a2b28cac79156539 Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	6 months ago
Brad Fitzpatrick	4fa6cbec27	ssh/tailssh: use ptr.To in test ... Updates #cleanup Change-Id: Ic98ba1b63c8205084b30f59f0ca343788edea5b0 Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	6 months ago
Percy Wegmann	843afe7c53	ssh/tailssh: add integration test ... Updates tailscale/corp#11854 Signed-off-by: Percy Wegmann <percy@tailscale.com>	6 months ago
Andrew Dunham	e985c6e58f	ssh/tailssh: try fetching group IDs for user with the 'id' command ... Since the tailscaled binaries that we distribute are static and don't link cgo, we previously wouldn't fetch group IDs that are returned via NSS. Try shelling out to the 'id' command, similar to how we call 'getent', to detect such cases. Updates #11682 Signed-off-by: Andrew Dunham <andrew@du.nham.ca> Change-Id: I9bdc938bd76c71bc130d44a97cc2233064d64799	6 months ago
Andrew Lytvynov	b743b85dad	ipn/ipnlocal,ssh/tailssh: reject c2n /update if SSH conns are active (#11820) ... Since we already track active SSH connections, it's not hard to proactively reject updates until those finish. We attempt to do the same on the control side, but the detection latency for new connections is in the minutes, which is not fast enough for common short sessions. Handle a `force=true` query parameter to override this behavior, so that control can still trigger an update on a server where some long-running abandoned SSH session is open. Updates https://github.com/tailscale/corp/issues/18556 Signed-off-by: Andrew Lytvynov <awly@tailscale.com>	6 months ago
Brad Fitzpatrick	7c1d6e35a5	all: use Go 1.22 range-over-int ... Updates #11058 Change-Id: I35e7ef9b90e83cac04ca93fd964ad00ed5b48430 Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	7 months ago
Joe Tsai	94a4f701c2	all: use reflect.TypeFor now available in Go 1.22 (#11078) ... Updates #cleanup Signed-off-by: Joe Tsai <joetsai@digital-static.net>	9 months ago
Andrew Lytvynov	29e98e18f8	ssh/tailssh: use a local error instead of gossh.ErrDenied (#10743) ... ErrDenied was added in [our fork of x/crypto/ssh](acc6f8fe8d) to short-circuit auth attempts once one fails. In the case of our callbacks, this error is returned when SSH policy check determines that a connection should not be allowed. Both `NoClientAuthCallback` and `PublicKeyHandler` check the policy and will fail anyway. The `fakePasswordHandler` returns true only if `NoClientAuthCallback` succeeds the policy check, so it checks it indirectly too. The difference here is that a client might attempt all 2-3 auth methods instead of just `none` but will fail to authenticate regardless. Updates #8593 Signed-off-by: Andrew Lytvynov <awly@tailscale.com>	10 months ago
Andrew Lytvynov	1302bd1181	all: cleanup unused code, part 1 (#10661) ... Run `staticcheck` with `U1000` to find unused code. This cleans up about a half of it. I'll do the other half separately to keep PRs manageable. Updates #cleanup Signed-off-by: Andrew Lytvynov <awly@tailscale.com>	11 months ago
Ox Cart	719ee4415e	ssh/tailssh: use control server time instead of local time ... This takes advantage of existing functionality in ipn/ipnlocal to adjust the local clock based on periodic time signals from the control server. This way, when checking things like SSHRule expirations, calculations are protected incorrectly set local clocks. Fixes tailscale/corp#15796 Signed-off-by: Percy Wegmann <percy@tailscale.com>	12 months ago
Brad Fitzpatrick	53c4adc982	ssh/tailssh: add envknobs to force override forwarding, sftp, pty ... Updates tailscale/corp#15735 Change-Id: Ib1303406be925c3231ce7e0950a173ad12626492 Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	12 months ago
Brad Fitzpatrick	ffabe5fe21	ssh/tailssh: fix sftp metric increment location ... We were incrementing the sftp metric on regular sessions too, not just sftp. Updates #cleanup Change-Id: I63027a39cffb3e03397c6e4829b1620c10fa3130 Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	12 months ago
Andrew Lytvynov	1fc1077052	ssh/tailssh,util: extract new osuser package from ssh code (#10170) ... This package is a wrapper for os/user that handles non-cgo builds, gokrazy and user shells. Updates tailscale/corp#15405 Signed-off-by: Andrew Lytvynov <awly@tailscale.com>	12 months ago
Brad Fitzpatrick	b775a3799e	util/httpm, all: add a test to make sure httpm is used consistently ... Updates #cleanup Change-Id: I7dbf8a02de22fc6b317ab5e29cc97792dd75352c Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	1 year ago
Joe Tsai	0a0adb68ad	ssh/tailssh: log when recording starts and finishes (#9294) ... Updates tailscale/corp#14579 Signed-off-by: Joe Tsai <joetsai@digital-static.net>	1 year ago
Marwan Sulaiman	9c07f4f512	all: replace deprecated ioutil references ... This PR removes calls to ioutil library and replaces them with their new locations in the io and os packages. Fixes #9034 Updates #5210 Signed-off-by: Marwan Sulaiman <marwan@tailscale.com>	1 year ago
Brad Fitzpatrick	84b94b3146	types/netmap, all: make NetworkMap.SelfNode a tailcfg.NodeView ... Updates #1909 Change-Id: I8c470cbc147129a652c1d58eac9b790691b87606 Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	1 year ago
Brad Fitzpatrick	58a4fd43d8	types/netmap, all: use read-only tailcfg.NodeView in NetworkMap ... Updates #8948 Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	1 year ago
Brad Fitzpatrick	e8551d6b40	all: use Go 1.21 slices, maps instead of x/exp/{slices,maps} ... Updates #8419 Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	1 year ago
Brad Fitzpatrick	bd02d00608	ssh/tailssh: fix gokrazy SSH crash ... Stupid mistake in earlier refactor. Updates gokrazy/gokrazy#209 Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	1 year ago
Joe Tsai	bb4b35e923	ssh: ignore io.EOF from sftp.Server.Serve ... If the connection provided to sftp.NewServer is closed, Serve returns the io.EOF error verbatim from io.Reader.Read. This is an odd error since this is an expected situation, so we manually ignore io.EOF. This is somewhat buggy since the sftp package itself incorrectly reports io.EOF in cases where it should actually be reporting io.ErrUnexpectedEOF. See https://github.com/pkg/sftp/pull/554 which patches Serve to return nil on clean closes and fixes buggy uses of io.ReadFull. Fixes #8592 Signed-off-by: Joe Tsai <joetsai@digital-static.net>	1 year ago
Joe Tsai	61886e031e	ssh/tailssh: fix double race condition with non-pty command (#8405) ... There are two race conditions in output handling. The first race condition is due to a misuse of exec.Cmd.StdoutPipe. The documentation explicitly forbids concurrent use of StdoutPipe with exec.Cmd.Wait (see golang/go#60908) because Wait will close both sides of the pipe once the process ends without any guarantees that all data has been read from the pipe. To fix this, we allocate the os.Pipes ourselves and manage cleanup ourselves when the process has ended. The second race condition is because sshSession.run waits upon exec.Cmd to finish and then immediately proceeds to call ss.Exit, which will close all output streams going to the SSH client. This may interrupt any asynchronous io.Copy still copying data. To fix this, we close the write-side of the os.Pipes after the process has finished (and before calling ss.Exit) and synchronously wait for the io.Copy routines to finish. Fixes #7601 Signed-off-by: Joe Tsai <joetsai@digital-static.net> Co-authored-by: Maisem Ali <maisem@tailscale.com>	1 year ago
Brad Fitzpatrick	32b8f25ed1	Revert "ssh/tailssh: change to user directory when running login/command" ... This reverts commit dc5bc32d8f. It broke tests. (sadly, ones which we have disabled on CI, but go test ./ssh/tailssh broke)	1 year ago
Derek Burdick	dc5bc32d8f	ssh/tailssh: change to user directory when running login/command ... On redhat 9 and similarly locked down systems, root user does not have access to a users directory. This fix does not set a directory for the incubator process and instead sets the directory when the actual process requested by remote user is executed. Fixes #8118 Signed-off-by: Derek Burdick <derek-burdick@users.noreply.github.com>	1 year ago
Maisem Ali	2ae670eb71	ssh/tailssh: work around lack of scontext in SELinux ... Trying to SSH when SELinux is enforced results in errors like: ``` ➜ ~ ssh ec2-user@<ip> Last login: Thu Jun 1 22:51:44 from <ip2> ec2-user: no shell: Permission denied Connection to <ip> closed. ``` while the `/var/log/audit/audit.log` has ``` type=AVC msg=audit(1685661291.067:465): avc: denied { transition } for pid=5296 comm="login" path="/usr/bin/bash" dev="nvme0n1p1" ino=2564 scontext=system_u:system_r:unconfined_service_t:s0 tcontext=unconfined_u:unconfined_r:unconfined_t:s0 tclass=process permissive=0 ``` The right fix here would be to somehow install the appropriate context when tailscale is installed on host, but until we figure out a way to do that stop using the `login` cmd in these situations. Updates #4908 Signed-off-by: Maisem Ali <maisem@tailscale.com>	1 year ago
Maisem Ali	2e0aa151c9	ssh/tailssh: add support for remote/reverse port forwarding ... This basically allows running services on the SSH client and reaching them from the SSH server during the session. Updates #6575 Signed-off-by: Maisem Ali <maisem@tailscale.com>	1 year ago
Derek Burdick	d3c8c3dd00	ssh/tailssh: Max Username Length 256 for linux ... Max username length is increased to 256 on linux to match /usr/include/bits/local_lim.h Fixes #8277 Signed-off-by: Derek Burdick <derek-burdick@users.noreply.github.com>	1 year ago
Charlotte Brandhorst-Satzkorn	4e86857313	ssh/tailssh: add ssh session recording failed event type ... This change introduces a SSHSessionRecordingFailed event type that is used when a session recording fails to start or fails during a session, and the on failure indicates that it should fail open. Updates tailscale/corp#9967 Signed-off-by: Charlotte Brandhorst-Satzkorn <charlotte@tailscale.com>	1 year ago
Brad Fitzpatrick	a4fd4fd845	ssh/tailssh: fix regression after LDAP support ... 58ab66ec51 added LDAP support for #4945 by shelling out to getdent. It was supposed to fall back to the old method when getdent wasn't found, but some variable name confusion (uid vs username) meant the old path wasn't calling the right lookup function (user.LookupId instead of user.Lookup). Which meant that changed probably also broke FreeBSD and macOS SSH support in addition to the reported OpenWRT regression. The gokrazy support didn't look right either. Fixes #8180 Change-Id: I273bbe96fe98b2517fbf0335fd476b483c051554 Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	1 year ago
Maisem Ali	0ca8bf1e26	ssh/tailssh: close tty on session close ... We were only closing on side of the pty/tty pair. Close the other side too. Thanks to @fritterhoff for reporting and debugging the issue! Fixes #8119 Signed-off-by: Maisem Ali <maisem@tailscale.com>	1 year ago
Brad Fitzpatrick	a743b66f9d	ssh/tailssh: move some user-related code into new user.go ... The previous commit 58ab66e added ssh/tailssh/user.go as part of working on #4945. So move some more user-related code over to it. Updates #cleanup Change-Id: I24de66df25ffb8f867e1a0a540d410f9ef16d7b0 Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	2 years ago
Brad Fitzpatrick	58ab66ec51	ssh/tailssh: support LDAP users for Tailscale SSH ... Fixes #4945 Change-Id: Ie013cb47684cb87928a44f92c66352310bfe53f1 Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	2 years ago
Charlotte Brandhorst-Satzkorn	29ded8f9f9	ssh/tailssh,tailcfg: add connID to ssheventnotifyrequest and castheader ... This change adds a ConnectionID field to both SSHEventNotifyRequest and CastHeader that identifies the ID of a connection to the SSH server. Updates tailscale/corp#9967 Signed-off-by: Charlotte Brandhorst-Satzkorn <charlotte@tailscale.com>	2 years ago
Charlotte Brandhorst-Satzkorn	68307c1411	ssh/tailssh: send ssh event notifications on recording failures ... This change sends an SSHEventNotificationRequest over noise when a SSH session is set to fail closed and the session is unable to start because a recorder is not available or a session is terminated because connection to the recorder is ended. Each of these scenarios have their own event type. Updates tailscale/corp#9967 Signed-off-by: Charlotte Brandhorst-Satzkorn <charlotte@tailscale.com>	2 years ago
Brad Fitzpatrick	6e967446e4	tsd: add package with System type to unify subsystem init, discovery ... This is part of an effort to clean up tailscaled initialization between tailscaled, tailscaled Windows service, tsnet, and the mac GUI. Updates #8036 Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	2 years ago
Maisem Ali	be190e990f	ssh/tailssh: restore support for recording locally ... We removed it earlier in 916aa782af, but we still want to support it for some time longer. Updates tailscale/corp#9967 Signed-off-by: Maisem Ali <maisem@tailscale.com>	2 years ago
Tom DNetto	c5bf868940	ssh/tailssh: improve debug logging around revoked sessions ... Updates https://github.com/tailscale/corp/issues/10943 Signed-off-by: Tom DNetto <tom@tailscale.com>	2 years ago
Maisem Ali	1b8a0dfe5e	ssh/tailssh: also handle recording upload failure during writes ... Previously we would error out when the recording server disappeared after the in memory buffer filled up for the io.Copy. This makes it so that we handle failing open correctly in that path. Updates tailscale/corp#9967 Signed-off-by: Maisem Ali <maisem@tailscale.com>	2 years ago
Maisem Ali	7778d708a6	ssh/tailssh: handle dialing multiple recorders and failing open ... This adds support to try dialing out to multiple recorders each with a 5s timeout and an overall 30s timeout. It also starts respecting the actions `OnRecordingFailure` field if set, if it is not set it fails open. Updates tailscale/corp#9967 Signed-off-by: Maisem Ali <maisem@tailscale.com>	2 years ago