Garrett, Garrett Wollman wrote: > In article <[EMAIL PROTECTED]>, > Martin Burnicki <[EMAIL PROTECTED]> wrote: > >>AFAIK ntpd has to manage the binding to interfaces at least if autokey is >>enabled since the signature hash also includes the IP address of the >>interface via which a packet is sent. > > At least some operating systems (don't know about Linux) allow this to > be controlled using a control message. For example, from the FreeBSD > 6.3 ip(4) manual page: > > The source address to be used for outgoing UDP datagrams on a socket > that is not bound to a specific IP address can be specified as > ancillary data > with a type code of IP_SENDSRCADDR. The msg_control field in the > msghdr structure should point to a buffer that contains a cmsghdr > structure fol- > lowed by the IP address. The cmsghdr fields should have the > following values: > > cmsg_len = sizeof(struct in_addr) > cmsg_level = IPPROTO_IP > cmsg_type = IP_SENDSRCADDR > > For convenience, IP_SENDSRCADDR is defined to have the same value as > IP_RECVDSTADDR, so the IP_RECVDSTADDR control message from recvmsg(2) > can be used directly as a control message for sendmsg(2). > > The IPV6_PKTINFO message is used for analogous functions in IPv6. > > -GAWollman
That's interesting. However, I'm neither familiar with those techniques, nor do I know whether such an approach would be useful for ntpd, especially since ntpd is targeted for multiple platforms (Frank? Danny?) Martin -- Martin Burnicki Meinberg Funkuhren Bad Pyrmont Germany _______________________________________________ questions mailing list [email protected] https://lists.ntp.org/mailman/listinfo/questions
