> On 8. Sep 2017, at 11:37, David Laight <David.Laight@xxxxxxxxxx> wrote: > > From: Michael Tuexen >> Sent: 08 September 2017 10:30 >>> On 8. Sep 2017, at 11:03, David Laight <David.Laight@xxxxxxxxxx> wrote: >>> >>> Can anyone think how to create multiple outgoing connections >>> from the same subset of local IP addresses and the same port? >>> >>> We bind() to the first IP address and port, then use >>> SCTP_SOCKOPT_BINDX_ADD to add the second IP address. >>> But even with IP_REUASADDR set you can't repeat that on >>> a second socket. >>> >>> It is possible to bind a second socket by reversing the >>> order of the IP addresses (this might be deemed to be a bug!) >>> >>> If you bind to IN_ADDR_ANY then a second socket can be bound >>> to the same port once the outgoing connection has been made >>> (and the actual local address assigned). >>> This works for TCP, but for SCTP you almost always need to >>> constrain the local addresses advertised on the connection. >>> >>> Ideas? >> Why not use a 1-to-many style socket? > > Because we don't know until we try to make a connection > that the local addresses match an existing one. > And it would complicate the code horribly. OK, I see. I just double checked. If Linux follows RFC 6458, it should be possible to do fd = socket(AF_INET, SOCK_STREAM, IPPROTO_SCTP); setsockopt(fd, IPPROTO_SCTP, SCTP_REUSE_PORT, &on, sizeof(int)); and then call bind(). I can run this kind of program on FreeBSD multiple times in parallel, each one talking to a different end-point. I'm not sure if Linux supports SCTP_REUSE_PORT. Best regards Michael > > In principle it could be a completely separate application. > (Although in our case it is a kernel M3UA driver.) > > David > -- To unsubscribe from this list: send the line "unsubscribe linux-sctp" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
