site_archiver@lists.apple.com Delivered-To: darwin-kernel@lists.apple.com On Nov 10, 2007, at 3:35 AM, Terry Lambert wrote: why does solisten() in Leopard contain if ((so->so_proto->pr_flags & PR_CONNREQUIRED) == 0) { error = EOPNOTSUPP; goto out; } This was not there in Tiger. I do understand that you can not use listen() for UDP sockets, but this should be handled in UDP specific code. But this shouldn't stop you from being able to do what you want. -- Terry _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-kernel mailing list (Darwin-kernel@lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-kernel/site_archiver%40lists.a... On Nov 9, 2007, at 1:37 PM, Michael Tuexen wrote: On Nov 9, 2007, at 9:56 PM, Michael Smith wrote: On Nov 9, 2007, at 12:13 PM, Michael Tuexen wrote: Without actually knowing why the change was made, I would point out that saying "this is a UDP thing" specifically fails to notice that the code in question basically says "if the protocol does not require connections, you cannot listen for a connection". Which is not OK for one2many style sockets for SCTP. SCTP is connection oriented but does implicit connection management for you in case of one2many style sockets. To allow connections being accepted on these sockets you need to call listen(). Actually, just the fact of having opened a socket in that case should imply a listen. We think that this would be a bad idea. If someone writes a client he might not want to handle incoming connections. The user has explicitly allow the kernel to accept incoming connections on a socket(AF_INET, SOCK_SEQPACKET, IPPROTO_SCTP) I agree that it's inappropriate for protocols which *can* have a connection, but do not require them, and would prefer a PR_CANLISTEN or something similar, since listening implies specification of a queue depth, which can be usedful. We use the backlog parameter on this kind of socket just as a flag to enable/disable accepting new SCTP associations. Is it supposed to be possible to send without a connection? If so, then the SS_ISCONNECTED check of so_state in sosendcheck(), soreceive(), etc., might end up being problematic (this would be why I'd have a preference for PR_CANLISTEN/PR_CANCONNECT vs. PR_CONNREQUIRED, to accomodate protocols wher ethat's the case). Yes, you can just call sendmsg() and if there is no association, the kernel will automatically start one. I agree, PR_CANLISTEN or so would be much better. Another alternative would be to have separate socket types for connection required vs. not sockets, though the software would then have to treat them as distinct. Well, we have this: socket(AF_INET, SOCK_STREAM, IPPROTO_SCTP) gives you an SCTP socket which behaves pretty similar to an TCP socket, except that it is a message oriented protocol. Here PR_CONNREQUIRED is appropriate. socket(AF_INET, SOCK_SEQPACKET, IPPROTO_SCTP) gives you an SCTP socket which behaves pretty similar to an UDP socket, but you need to call listen(fd, 1) to allow the kernel to accept associations. The management of the associations is done completely by the kernel. This email sent to site_archiver@lists.apple.com