On Thu, Jan 25, 2001 at 12:17:45AM +0000, John Fremlin wrote: > > Suppose a process has an open TCP connection to e.g. a newsserver > somewhere across the 'net. Suppose that the interface through which > this connection is made has its IP address changed. Then the process > can try to send all the data it wants without getting anywhere, but in > linux-2.4.0, at least, no errors from send(2) are returned. It's no bug but a TCP/IP design feature. Applying ftp.suse.com:/pub/people/ak/v2.2/iff-dynamic* and setting the dynamic flag on the network device using ifconfig will kill all connections bound to it. Currently for 2.2 only. > Fooling around in the source, I saw that I most probably want to catch > NETDEV_CHANGEADDR and NETDEV_DOWN as thrown by > linux/net/ipv4/devinet.c and scan the list of active connections > somehow or other and kill (tcp_write_err?) the ones that have the old > local address. Is there any reason not to do this - i.e. should it be > a sysctl? That is more or less what iff-dynamic does. There are various reasons not to do it generally because it breaks in many setups, but when the user knows what he's doing (= sets dynamic) it's probably fine. The implementation is not perfect, it would be better if the hangup was triggered by user space. -Andi - : send the line "unsubscribe linux-net" in the body of a message to majordomo@vger.kernel.org
