linux/include/net/sctp/command.h

225 lines
8.8 KiB

sctp: Enforce retransmission limit during shutdown When initiating a graceful shutdown while having data chunks on the retransmission queue with a peer which is in zero window mode the shutdown is never completed because the retransmission error count is reset periodically by the following two rules: - Do not timeout association while doing zero window probe. - Reset overall error count when a heartbeat request has been acknowledged. The graceful shutdown will wait for all outstanding TSN to be acknowledged before sending the SHUTDOWN request. This never happens due to the peer's zero window not acknowledging the continuously retransmitted data chunks. Although the error counter is incremented for each failed retransmission, the receiving of the SACK announcing the zero window clears the error count again immediately. Also heartbeat requests continue to be sent periodically. The peer acknowledges these requests causing the error counter to be reset as well. This patch changes behaviour to only reset the overall error counter for the above rules while not in shutdown. After reaching the maximum number of retransmission attempts, the T5 shutdown guard timer is scheduled to give the receiver some additional time to recover. The timer is stopped as soon as the receiver acknowledges any data. The issue can be easily reproduced by establishing a sctp association over the loopback device, constantly queueing data at the sender while not reading any at the receiver. Wait for the window to reach zero, then initiate a shutdown by killing both processes simultaneously. The association will never be freed and the chunks on the retransmission queue will be retransmitted indefinitely. Signed-off-by: Thomas Graf <tgraf@infradead.org> Acked-by: Vlad Yasevich <vladislav.yasevich@hp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-07-07 00:28:35 +00:00
sctp: Fix oops when sending queued ASCONF chunks When we finish processing ASCONF_ACK chunk, we try to send the next queued ASCONF. This action runs the sctp state machine recursively and it's not prepared to do so. kernel BUG at kernel/timer.c:790! invalid opcode: 0000 [#1] SMP last sysfs file: /sys/module/ipv6/initstate Modules linked in: sha256_generic sctp libcrc32c ipv6 dm_multipath uinput 8139too i2c_piix4 8139cp mii i2c_core pcspkr virtio_net joydev floppy virtio_blk virtio_pci [last unloaded: scsi_wait_scan] Pid: 0, comm: swapper Not tainted 2.6.34-rc4 #15 /Bochs EIP: 0060:[<c044a2ef>] EFLAGS: 00010286 CPU: 0 EIP is at add_timer+0xd/0x1b EAX: cecbab14 EBX: 000000f0 ECX: c0957b1c EDX: 03595cf4 ESI: cecba800 EDI: cf276f00 EBP: c0957aa0 ESP: c0957aa0 DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068 Process swapper (pid: 0, ti=c0956000 task=c0988ba0 task.ti=c0956000) Stack: c0957ae0 d1851214 c0ab62e4 c0ab5f26 0500ffff 00000004 00000005 00000004 <0> 00000000 d18694fd 00000004 1666b892 cecba800 cecba800 c0957b14 00000004 <0> c0957b94 d1851b11 ceda8b00 cecba800 cf276f00 00000001 c0957b14 000000d0 Call Trace: [<d1851214>] ? sctp_side_effects+0x607/0xdfc [sctp] [<d1851b11>] ? sctp_do_sm+0x108/0x159 [sctp] [<d1863386>] ? sctp_pname+0x0/0x1d [sctp] [<d1861a56>] ? sctp_primitive_ASCONF+0x36/0x3b [sctp] [<d185657c>] ? sctp_process_asconf_ack+0x2a4/0x2d3 [sctp] [<d184e35c>] ? sctp_sf_do_asconf_ack+0x1dd/0x2b4 [sctp] [<d1851ac1>] ? sctp_do_sm+0xb8/0x159 [sctp] [<d1863334>] ? sctp_cname+0x0/0x52 [sctp] [<d1854377>] ? sctp_assoc_bh_rcv+0xac/0xe1 [sctp] [<d1858f0f>] ? sctp_inq_push+0x2d/0x30 [sctp] [<d186329d>] ? sctp_rcv+0x797/0x82e [sctp] Tested-by: Wei Yongjun <yjwei@cn.fujitsu.com> Signed-off-by: Yuansong Qiao <ysqiao@research.ait.ie> Signed-off-by: Shuaijun Zhang <szhang@research.ait.ie> Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-28 08:47:22 +00:00