SCTP binds to IPs outside of jail
Bjoern A. Zeeb
bzeeb-lists at lists.zabbadoz.net
Sun Apr 6 18:44:37 UTC 2014
On 06 Apr 2014, at 16:42 , Michael Tuexen <Michael.Tuexen at lurchi.franken.de> wrote:
> On 06 Apr 2014, at 17:05, Bjoern A. Zeeb <bzeeb-lists at lists.zabbadoz.net> wrote:
>
>>
>> On 06 Apr 2014, at 11:42 , Michael Tuexen <Michael.Tuexen at lurchi.franken.de> wrote:
>>
>>> On 05 Apr 2014, at 23:02, Bernd Walter <ticso at cicely7.cicely.de> wrote:
>>>
>>>> So far I've tested this on FreeBSD-9.2 BETA2 r254053M only.
>>>> The modifications are to allow IPv6 multicast support within jail
>>>> which only makes a difference for multicast addresses and some multicast
>>>> loopback checksum bugs - both changes are open PR.
>>>>
>>>> I've created an AF_INET6 SCTP one to many socket to receive incoming
>>>> messages.
>>>> The process was started within a jail.
>>>> Now netstat -anW lists all host IPv6 IPs, not just those of the jail.
>>>> Also not sure why this AF_INET6 socket is shown as sctp46.
>>> This should be handled as a v6 only socket depending on your
>>> setting of net.inet6.ip6.v6only sysctl variable by the SCTP stack.
>>> However, netstat has no information about this and can not distinguish
>>> between sctp6 and sctp46, so it reports sctp46 always. You can file
>>> a PR about this.
>>>
>>> The questions about the addresses and the jails: The SCTP code has
>>> no jail specific code. If you bind a socket to the wildcard address
>>> (which is what to do by not binding at all), the SCTP stack lists
>>> all addresses it know about. I'm not sure what would happen, if
>>> you send a packet to an address not owned by the jail.
>>> You might want to file a separate PR about the support of jails.
>>
>> Aehm, the SCTP code was filtering addresses at one point and made sure only jail-visible addresses were seen or bound very much like normal PCB handling. If this is not the case (anymore) SCTP shall not be allowed inside jails again.
> Can you point me to the "normal PCB handling"? Maybe I'm just overlooking something…
I guess what helps you more is looking for prison_* calls in the SCTP stack (and equally in in*_pcb*, tcp_*, udp_*).
>>> Best regards
>>> Michael
>>>>
>>>> This is the relevant C++ code part to open the socket:
>>>> int
>>>> setup_sctp_socket(uint16_t port)
>>>> {
>>>> int sc = socket(AF_INET6, SOCK_SEQPACKET, IPPROTO_SCTP);
>>>> {
>>>> // reuse address
>>>> long val = 1;
>>>> setsockopt(sc, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(val));
>>>> // XXX error handling
>>>> }
>>>> {
>>>> // no delay
>>>> long val = 1;
>>>> setsockopt(sc, SOL_SOCKET, SCTP_NODELAY, &val, sizeof(val));
>>>> // XXX error handling
>>>> }
>>>> {
>>>> // eeor mode (last write needs MSG_EOR to declare end of message)
>>>> // Linux has MSG_MORE negative send flag
>>>> long val = 1;
>>>> setsockopt(sc, SOL_SOCKET, SCTP_EXPLICIT_EOR, &val, sizeof(val));
>>>> // XXX error handling
>>>> }
>>>> #if 0
>>>> {
>>>> struct sctp_initmsg init;
>>>> bzero(&init, sizeof(init));
>>>> init.sinit_num_ostreams = HDB_STREAMS;
>>>> init.sinit_max_instreams = HDB_STREAMS;
>>>> // SOL_SCTP instead of IPPROTO_SCTP on Linux
>>>> setsockopt(sc, IPPROTO_SCTP, SCTP_INITMSG, &init, (socklen_t)sizeof(struct sctp_initmsg));
>>>> // XXX error handling
>>>> }
>>>> #endif
>>>> {
>>>> struct sockaddr_in6 addr;
>>>> bzero(&addr, sizeof(addr));
>>>> addr.sin6_len = sizeof(addr);
>>>> addr.sin6_family = AF_INET6;
>>>> addr.sin6_port = htons(port);
>>>> bind(sc, (struct sockaddr *)&addr, sizeof(struct sockaddr_in));
>>>> // XXX error handling
>>>> }
>>>> {
>>>> // enable heartbeats at 1000ms
>>>> struct sctp_paddrparams paddr_params;
>>>> bzero(&paddr_params, sizeof(paddr_params));
>>>> paddr_params.spp_address.ss_family = AF_INET6;
>>>> paddr_params.spp_flags = SPP_HB_ENABLE;
>>>> paddr_params.spp_hbinterval = 1000;
>>>> // SOL_SCTP instead of IPPROTO_SCTP on Linux
>>>> setsockopt(sc, IPPROTO_SCTP, SCTP_PEER_ADDR_PARAMS, &paddr_params, sizeof(paddr_params));
>>>> // XXX error handling
>>>> }
>>>> {
>>>> struct sctp_event_subscribe events;
>>>> bzero(&events, sizeof(events));
>>>>
>>>> events.sctp_data_io_event = 1; // we need io_events to know where the message came from
>>>>
>>>> // subscribe to other events as well for testing
>>>> events.sctp_association_event = 1;
>>>> events.sctp_address_event = 1;
>>>> events.sctp_send_failure_event = 1;
>>>> events.sctp_peer_error_event = 1;
>>>> events.sctp_shutdown_event = 1;
>>>> events.sctp_partial_delivery_event = 1;
>>>> events.sctp_adaptation_layer_event = 1;
>>>> events.sctp_authentication_event = 1;
>>>> events.sctp_sender_dry_event = 1;
>>>> events.sctp_stream_reset_event = 1;
>>>>
>>>> setsockopt(sc, IPPROTO_SCTP, SCTP_EVENTS, &events, sizeof(events));
>>>> // XXX error handling
>>>> }
>>>> {
>>>> // setup send and receive buffers (default on FreeBSD 9.x)
>>>> long val;
>>>> val = 1864135;
>>>> setsockopt(sc, SOL_SOCKET, SO_RCVBUF, &val, sizeof(val));
>>>> // XXX error handling
>>>> val = 1864135;
>>>> setsockopt(sc, SOL_SOCKET, SO_SNDBUF, &val, sizeof(val));
>>>> // XXX error handling
>>>> }
>>>> listen (sc, 1); // listen is required to allow incoming associations, but no listen queue
>>>> // XXX error handling
>>>>
>>>> return sc;
>>>> }
>>>>
>>>> --
>>>> B.Walter <bernd at bwct.de> http://www.bwct.de
>>>> Modbus/TCP Ethernet I/O Baugruppen, ARM basierte FreeBSD Rechner uvm.
>>>> _______________________________________________
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>>>>
>>>
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>>
>> —
>> Bjoern A. Zeeb ????????? ??? ??????? ??????:
>> '??? ??? ???? ?????? ??????? ?? ?? ??????? ??????? ??? ????? ????? ????
>> ?????? ?? ????? ????', ????????? ?????????, "??? ????? ?? ?????", ?.???
>>
>>
>
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'??? ??? ???? ?????? ??????? ?? ?? ??????? ??????? ??? ????? ????? ????
?????? ?? ????? ????', ????????? ?????????, "??? ????? ?? ?????", ?.???
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