Não é possível conectar-se à VPN PPTP com o ufw ativado no Ubuntu 14.04 com o kernel 3.18

Question

De repente, a VPN foi desconectada e não pode mais se reconectar no kernel 3.18.1, então eu tento instalar o kernel 3.18.2, mas meu problema ainda existe. Mas eu posso conectar VPN com o kernel 3.14 facilmente.

A saída do syslog:

Jan 11 17:43:51 DEMON NetworkManager[7443]: <info> Starting VPN service 'pptp'...
Jan 11 17:43:51 DEMON NetworkManager[7443]: <info> VPN service 'pptp' started (org.freedesktop.NetworkManager.pptp), PID 8741
Jan 11 17:43:51 DEMON NetworkManager[7443]: <info> VPN service 'pptp' appeared; activating connections
Jan 11 17:43:51 DEMON NetworkManager[7443]: <info> VPN plugin state changed: starting (3)
Jan 11 17:43:51 DEMON NetworkManager[7443]: <info> VPN connection 'VPN connection 1' (Connect) reply received.
Jan 11 17:43:51 DEMON pppd[8742]: Plugin /usr/lib/pppd/2.4.5/nm-pptp-pppd-plugin.so loaded.
Jan 11 17:43:51 DEMON pppd[8742]: pppd 2.4.5 started by root, uid 0
Jan 11 17:43:51 DEMON pppd[8742]: Using interface ppp0
Jan 11 17:43:51 DEMON pppd[8742]: Connect: ppp0 <--> /dev/pts/25
Jan 11 17:43:51 DEMON pptp[8747]: nm-pptp-service-8741 log[main:pptp.c:314]: The synchronous pptp option is NOT activated
Jan 11 17:43:51 DEMON NetworkManager[7443]:    SCPlugin-Ifupdown: devices added (path: /sys/devices/virtual/net/ppp0, iface: ppp0)
Jan 11 17:43:51 DEMON NetworkManager[7443]:    SCPlugin-Ifupdown: device added (path: /sys/devices/virtual/net/ppp0, iface: ppp0): no ifupdown configuration found.
Jan 11 17:43:51 DEMON NetworkManager[7443]: <warn> /sys/devices/virtual/net/ppp0: couldn't determine device driver; ignoring...
Jan 11 17:43:51 DEMON pptp[8761]: nm-pptp-service-8741 log[ctrlp_rep:pptp_ctrl.c:251]: Sent control packet type is 1 'Start-Control-Connection-Request'
Jan 11 17:43:51 DEMON pptp[8761]: nm-pptp-service-8741 log[ctrlp_disp:pptp_ctrl.c:739]: Received Start Control Connection Reply
Jan 11 17:43:51 DEMON pptp[8761]: nm-pptp-service-8741 log[ctrlp_disp:pptp_ctrl.c:773]: Client connection established.
Jan 11 17:43:52 DEMON pptp[8761]: nm-pptp-service-8741 log[ctrlp_rep:pptp_ctrl.c:251]: Sent control packet type is 7 'Outgoing-Call-Request'
Jan 11 17:43:52 DEMON pptp[8761]: nm-pptp-service-8741 log[ctrlp_disp:pptp_ctrl.c:858]: Received Outgoing Call Reply.
Jan 11 17:43:52 DEMON pptp[8761]: nm-pptp-service-8741 log[ctrlp_disp:pptp_ctrl.c:897]: Outgoing call established (call ID 0, peer's call ID 37038).
Jan 11 17:43:53 DEMON vnstatd[1509]: Interface "ppp0" enabled.
Jan 11 17:43:55 DEMON kernel: [  921.480993] [UFW BLOCK] IN=wlan0 OUT= MAC=74:de:2b:02:0b:da:50:1c:bf:61:6f:41:08:00 SRC=192.168.0.1 DST=192.168.74.15 LEN=55 TOS=0x00 PREC=0x00 TTL=63 ID=64925 PROTO=47 
Jan 11 17:43:55 DEMON kernel: [  922.096723] [UFW BLOCK] IN=wlan0 OUT= MAC=74:de:2b:02:0b:da:50:1c:bf:61:6f:41:08:00 SRC=192.168.0.1 DST=192.168.74.15 LEN=54 TOS=0x00 PREC=0x00 TTL=63 ID=64926 PROTO=47 
Jan 11 17:43:57 DEMON kernel: [  923.911774] [UFW BLOCK] IN=wlan0 OUT= MAC=74:de:2b:02:0b:da:50:1c:bf:61:6f:41:08:00 SRC=192.168.0.1 DST=192.168.74.15 LEN=55 TOS=0x00 PREC=0x00 TTL=63 ID=64927 PROTO=47 
Jan 11 17:44:16 DEMON kernel: [  943.116984] [UFW BLOCK] IN=wlan0 OUT= MAC=74:de:2b:02:0b:da:50:1c:bf:61:6f:41:08:00 SRC=192.168.0.1 DST=192.168.74.15 LEN=54 TOS=0x00 PREC=0x00 TTL=63 ID=64937 PROTO=47 
Jan 11 17:44:22 DEMON pppd[8742]: LCP: timeout sending Config-Requests
Jan 11 17:44:22 DEMON pppd[8742]: Connection terminated.
Jan 11 17:44:22 DEMON NetworkManager[7443]: <warn> VPN plugin failed: 1
Jan 11 17:44:22 DEMON NetworkManager[7443]:    SCPlugin-Ifupdown: devices removed (path: /sys/devices/virtual/net/ppp0, iface: ppp0)
Jan 11 17:44:22 DEMON pppd[8742]: Modem hangup
Jan 11 17:44:22 DEMON pptp[8747]: nm-pptp-service-8741 warn[decaps_hdlc:pptp_gre.c:204]: short read (-1): Input/output error
Jan 11 17:44:22 DEMON pptp[8747]: nm-pptp-service-8741 warn[decaps_hdlc:pptp_gre.c:216]: pppd may have shutdown, see pppd log
Jan 11 17:44:22 DEMON pptp[8761]: nm-pptp-service-8741 log[callmgr_main:pptp_callmgr.c:234]: Closing connection (unhandled)
Jan 11 17:44:22 DEMON pptp[8761]: nm-pptp-service-8741 log[ctrlp_rep:pptp_ctrl.c:251]: Sent control packet type is 12 'Call-Clear-Request'
Jan 11 17:44:22 DEMON pppd[8742]: Exit.
Jan 11 17:44:22 DEMON NetworkManager[7443]: <warn> VPN plugin failed: 1
Jan 11 17:44:22 DEMON pptp[8761]: nm-pptp-service-8741 log[call_callback:pptp_callmgr.c:79]: Closing connection (call state)
Jan 11 17:44:22 DEMON NetworkManager[7443]: <warn> VPN plugin failed: 1
Jan 11 17:44:22 DEMON NetworkManager[7443]: <info> VPN plugin state changed: stopped (6)
Jan 11 17:44:22 DEMON NetworkManager[7443]: <info> VPN plugin state change reason: 0
Jan 11 17:44:22 DEMON NetworkManager[7443]: <info> Policy set '4r@z31' (wlan0) as default for IPv4 routing and DNS.
Jan 11 17:44:22 DEMON NetworkManager[7443]: <warn> error disconnecting VPN: Could not process the request because no VPN connection was active.
Jan 11 17:44:23 DEMON vnstatd[1509]: Interface "ppp0" disabled.
Jan 11 17:44:28 DEMON NetworkManager[7443]: <info> VPN service 'pptp' disappeared

UPDATE

Meu problema foi resolvido desabilitando o ufw, poderia me ajudar a resolver esse conflito de firewall e vpn?

UPDATE 2

Então, tento adicionar

-A ufw-before-input -p 47 -j ACCEPT
-A ufw-before-output -p 47 -j ACCEPT

em /etc/ufw/before.rules , mas meu problema ainda existe.

    

Answer 1

Isso é causado por uma alteração por motivo de segurança no kernel 3.18 [1] . Existem duas maneiras de corrigir isso.

A primeira abordagem é adicionar essa regra ao arquivo /etc/ufw/before.rules antes da linha # drop INVALID packets ...

-A ufw-before-input -p 47 -j ACCEPT

A segunda abordagem é carregar manualmente o módulo nf_conntrack_pptp . Você pode fazer isso executando

sudo modprobe nf_conntrack_pptp

Para carregar este módulo em cada inicialização no Ubuntu, adicione-o ao arquivo /etc/modules .

    

Answer 2

Adicione nf_conntrack_pptp a /etc/modules-load.d/pptp.conf

Um forro

echo nf_conntrack_pptp | sudo tee /etc/modules-load.d/pptp.conf

Explicação

A resposta aceita funciona para mim, especialmente a segunda sugestão - carregar o módulo do kernel nf_conntrack_pptp - ao contrário de modificar meu firewall do iptables. O firewall do meu laptop não está modificado. sudo ufw enable sem exceções é bom e limpo. Mas eu não gosto de editar /etc/modules à mão ... futuras atualizações de pacotes podem ter conflitos. /etc/modules-load.d/ fornece uma maneira fácil de atualizar e automatizar mais facilmente o carregamento do módulo.

Veja também

Existe um diretório" .d "para carregar módulos no momento da inicialização, em oposição a / etc / modules?

Tiro parcial: não use PPTP!

• link
• link
• link

Tente o openvpn em seu lugar.

    

Answer 3

Para versões mais recentes da solução ufw a (completa) é:

sudo ufw allow proto gre from [PPTP gateway IP address]
sudo systemctl restart ufw