@@ -423,6 +423,11 @@ func (a *agent) handleSSHSession(session ssh.Session) (retErr error) {
423423if err != nil {
424424return err
425425}
426+ // Set SSH connection environment variables, from the clients perspective.
427+ srcAddr ,srcPort := addrToSSHEnvAddr (session .RemoteAddr ())
428+ dstAddr ,dstPort := addrToSSHEnvAddr (session .LocalAddr ())
429+ cmd .Env = append (cmd .Env ,fmt .Sprintf ("SSH_CLIENT=%s %s %s" ,srcAddr ,srcPort ,dstPort ))
430+ cmd .Env = append (cmd .Env ,fmt .Sprintf ("SSH_CONNECTION=%s %s %s %s" ,srcAddr ,srcPort ,dstAddr ,dstPort ))
426431
427432if ssh .AgentRequested (session ) {
428433l ,err := ssh .NewAgentListener ()
@@ -437,6 +442,8 @@ func (a *agent) handleSSHSession(session ssh.Session) (retErr error) {
437442sshPty ,windowSize ,isPty := session .Pty ()
438443if isPty {
439444cmd .Env = append (cmd .Env ,fmt .Sprintf ("TERM=%s" ,sshPty .Term ))
445+
446+ // The pty package sets `SSH_TTY` on supported platforms.
440447ptty ,process ,err := pty .Start (cmd )
441448if err != nil {
442449return xerrors .Errorf ("start command: %w" ,err )
@@ -691,6 +698,19 @@ func (a *agent) handleReconnectingPTY(ctx context.Context, rawID string, conn ne
691698}
692699}
693700
701+ // addrToSSHEnvAddr turns the address and port into space-separated values,
702+ // works with IPv4, IPv6 and invalid addresses (such as [peer/unknown-addr]).
703+ func addrToSSHEnvAddr (a net.Addr ) (addr string ,port string ) {
704+ addr = a .String ()
705+ port = "0"
706+ li := strings .LastIndex (addr ,":" )
707+ if li != - 1 {
708+ port = addr [li + 1 :]
709+ addr = addr [:li ]
710+ }
711+ return addr ,port
712+ }
713+
694714// dialResponse is written to datachannels with protocol "dial" by the agent as
695715// the first packet to signify whether the dial succeeded or failed.
696716type dialResponse struct {