Thanks Ursula, I wasn't clear if this was a call for me to justify what I am trying to do, but I thought I might mention it.
> Probably not: Either there is a good idea why to include message_send2way into the standard socket interface AF_IUCV, My use-case is that I want userspace in zLinux to call other other VMs over IUCV. I would prefer to use a standardized interface to this as much as possible as that would mean I can release general purpose libraries to do IUCV operations in z/VM environments. E.g. in my case I have already contributed support for opening and connecting to IUCV sockets in Go. That is now part of the official Go libraries. The next step I want to do is to be able to do is 2WAY SEND, again preferably in a way that allows me to craft libraries that other developers can use on a zLinux with a new enough kernel. If I have to invent my custom kernel driver to do this, so be it - but that is significantly more time consuming and a higher bar for adoption. On Tue, Aug 18, 2020 at 3:46 PM Ursula Braun <[email protected]> wrote: > > On 8/17/20 6:56 PM, Christian Svensson wrote: > > [+linux-390 mailing list] > > > > On Mon, Aug 17, 2020 at 6:55 PM Christian Svensson <[email protected]> wrote: > >> > >> Hi, > >> > >> I am trying to call TCPIP service using IUCV. > >> I found AF_IUCV which seemed to do what I want, but reading > >> more into it it looks like AF_IUCV only ever implemented one-way > >> SEND operations. > >> > >> Is that correct? > >> > > Yes, that's correct. The intention of the socket family AF_IUCV has been to > come up with a socket interface of types SOCK_STREAM and SOCK_SEQPACKET on top > of IUCV as transport layer. Later we added HiperSockets as another transport > layer. > > >> There appears to exist a message_send and a message_send2way in > >> the Linux IUCV interface, however only message_send appears to be used > >> by AF_IUCV. > >> > > There is a base IUCV layer in net/iucv/iucv.c offering message_send2way. > The base layer is used by several other kernel components, among them > net/iucv/af_iucv.c. > But for the AF_IUCV socket family there has been no need to exploit > message_send2way. > > >> If my reading is correct, is there any way I can work around this > >> without writing a kernel module? > >> > > Probably not: Either there is a good idea why to include message_send2way into > the standard socket interface AF_IUCV, or there is a new kernel module for > communication with the TCPIP service, built on top of net/iucv/iucv.c similar > to other specific IUCV exploiters like drivers/s390/char/vmlogrdr.c, > drivers/s390/net/netiucv.c, drivers/s390/net/smsgiucv.c, drivers/tty/hvc/... > > >> Thanks > > > > ---------------------------------------------------------------------- > > For LINUX-390 subscribe / signoff / archive access instructions, > > send email to [email protected] with the message: INFO LINUX-390 or > > visit > > http://www2.marist.edu/htbin/wlvindex?LINUX-390 > > > > ---------------------------------------------------------------------- > For LINUX-390 subscribe / signoff / archive access instructions, > send email to [email protected] with the message: INFO LINUX-390 or visit > http://www2.marist.edu/htbin/wlvindex?LINUX-390 ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO LINUX-390 or visit http://www2.marist.edu/htbin/wlvindex?LINUX-390
