Firefox with X11 Forwarding is not working

Question

I cannot open firefox via ssh:

I've tried with:

ssh -vvv -X [email protected]

But it outputs:

debug3: send packet: type 50
debug2: we sent a password packet, wait for reply
debug3: receive packet: type 52
debug1: Authentication succeeded (password).
Authenticated to 192.168.40.21 ([192.168.40.21]:22).
debug1: channel 0: new [client-session]
debug3: ssh_session2_open: channel_new: 0
debug2: channel 0: send open
debug3: send packet: type 90
debug1: Requesting [email protected]
debug3: send packet: type 80
debug1: Entering interactive session.
debug1: pledge: exec
debug3: receive packet: type 91
debug2: callback start
debug1: X11 forwarding requested but DISPLAY not set
debug2: fd 3 setting TCP_NODELAY
debug3: ssh_packet_set_tos: set IP_TOS 0x10
debug2: client_session2_setup: id 0
debug2: channel 0: request pty-req confirm 1
debug3: send packet: type 98
debug1: Sending environment.
debug3: Ignored env HOSTNAME
debug3: Ignored env SHELL
debug3: Ignored env TERM
debug3: Ignored env HISTSIZE
debug3: Ignored env USER
debug3: Ignored env LS_COLORS
debug3: Ignored env MAIL
debug3: Ignored env PATH
debug3: Ignored env PWD
debug1: Sending env LANG = es_AR.UTF-8
debug2: channel 0: request env confirm 0
debug3: send packet: type 98
debug3: Ignored env KDEDIRS
debug3: Ignored env HISTCONTROL
debug3: Ignored env SHLVL
debug3: Ignored env HOME
debug3: Ignored env LOGNAME
debug3: Ignored env CVS_RSH
debug3: Ignored env LESSOPEN
debug3: Ignored env _
debug2: channel 0: request shell confirm 1
debug3: send packet: type 98
debug2: callback done
debug2: channel 0: open confirm rwindow 0 rmax 32768
debug3: receive packet: type 99
debug2: channel_input_status_confirm: type 99 id 0
debug2: PTY allocation request accepted on channel 0
debug2: channel 0: rcvd adjust 2097152
debug3: receive packet: type 99
debug2: channel_input_status_confirm: type 99 id 0
debug2: shell request accepted on channel 0

And then:

Error: no display specified

And:

ls -l .Xauthority 
-rw-------. 1 user user 73 may 31 13:21 .Xauthority

UPDATE:

I've found that if I run another X app it works:

links -g
debug3: receive packet: type 90
debug1: client_input_channel_open: ctype x11 rchan 2 win 65536 max 16384
debug1: client_request_x11: request from 127.0.0.1 59036
debug2: fd 7 setting O_NONBLOCK
debug3: fd 7 is O_NONBLOCK
debug1: channel 1: new [x11]
debug1: confirm x11
debug3: send packet: type 91

But not with Firefox:

debug3: receive packet: type 90
debug1: client_input_channel_open: ctype x11 rchan 2 win 65536 max 16384
debug1: client_request_x11: request from 127.0.0.1 59038
debug2: fd 7 setting O_NONBLOCK
debug3: fd 7 is O_NONBLOCK
debug1: channel 1: new [x11]
debug1: confirm x11
debug3: send packet: type 91
debug3: receive packet: type 90
debug1: client_input_channel_open: ctype x11 rchan 3 win 65536 max 16384
debug1: client_request_x11: request from 127.0.0.1 59040
debug2: fd 8 setting O_NONBLOCK
debug3: fd 8 is O_NONBLOCK
debug1: channel 2: new [x11]
debug1: confirm x11
debug3: send packet: type 91
debug2: channel 2: rcvd adjust 40476
debug3: receive packet: type 90
debug1: client_input_channel_open: ctype x11 rchan 4 win 65536 max 16384
debug1: client_request_x11: request from 127.0.0.1 59042
debug2: fd 9 setting O_NONBLOCK
debug3: fd 9 is O_NONBLOCK
debug1: channel 3: new [x11]
debug1: confirm x11
debug3: send packet: type 91
debug2: channel 3: rcvd adjust 32792
debug3: receive packet: type 96
debug2: channel 3: rcvd eof
debug2: channel 3: output open -> drain
debug2: channel 3: obuf empty
debug2: channel 3: close_write
debug2: channel 3: output drain -> closed
debug1: channel 3: FORCE input drain
debug2: channel 3: ibuf empty
debug2: channel 3: send eof
debug3: send packet: type 96
debug2: channel 3: input drain -> closed
debug2: channel 3: send close
debug3: send packet: type 97
debug3: channel 3: will not send data after close
debug3: receive packet: type 97
debug2: channel 3: rcvd close
debug3: channel 3: will not send data after close
debug2: channel 3: is dead
debug2: channel 3: garbage collecting
debug1: channel 3: free: x11, nchannels 4
debug3: channel 3: status: The following connections are open:
  #0 client-session (t4 r0 i0/0 o0/0 fd 4/5 cc -1)
  #1 x11 (t4 r2 i0/0 o0/0 fd 7/7 cc -1)
  #2 x11 (t4 r3 i0/0 o0/0 fd 8/8 cc -1)
  #3 x11 (t4 r4 i3/0 o3/0 fd 9/9 cc -1)

UPDATE 2

I've tried even disabling xshm and adding local cookie to remoto side with xauth command

firefox --no-remote --no-xshm --display localhost:10.0
debug3: receive packet: type 90
debug1: client_input_channel_open: ctype x11 rchan 2 win 65536 max 16384
debug1: client_request_x11: request from 127.0.0.1 59181
debug2: fd 7 setting O_NONBLOCK
debug3: fd 7 is O_NONBLOCK
debug1: channel 1: new [x11]
debug1: confirm x11
debug3: send packet: type 91
debug3: receive packet: type 90
debug1: client_input_channel_open: ctype x11 rchan 3 win 65536 max 16384
debug1: client_request_x11: request from 127.0.0.1 59183
debug2: fd 8 setting O_NONBLOCK
debug3: fd 8 is O_NONBLOCK
debug1: channel 2: new [x11]
debug1: confirm x11
debug3: send packet: type 91
debug2: channel 2: rcvd adjust 39228

Just in case: SSH Server os CentOS 7.2 and SSH client os Fedora 23 ranking Xorg

Nothing at all.

What's wrong?

Solution

Firefox is using some specialities of X so it does not work over X11 forwarding out-of-the box. You need to play a bit with switches to firefox binary. Basically specifying X11 display. This works for me:

firefox --no-remote --no-xshm

or similar.

Comments

[Luciano Andress Martini]

I know is non-sense but close all firefox session in your computer and try again, this helps?

[sebelk]

I've tried disabling xshm too.

[Vasco]

When there is already a firefox instance running on the client, running "firefox" on the server will result in a new firefox window in the existing firefox instance on the client, instead of starting a new firefox instance on the server. "firefox --no-remote" fixes this unwanted behaviour.