REQ GID enforcement in the CM

    ret = cm_init_av_by_path(&work->path[0], &cm_id_priv->av);
        if (ret) {
                ib_get_cached_gid(work->port->cm_dev->ib_device,
                                  work->port->port_num, 0, 
&work->path[0].sgid);
                ib_send_cm_rej(cm_id, IB_CM_REJ_INVALID_GID,
&work->path[0].sgid, sizeof work->path[0].sgid,
                               NULL, 0);
                goto rejected;
        }

 read_lock_irqsave(&cm.device_lock, flags);
        list_for_each_entry(cm_dev, &cm.device_list, list) {
                if (!ib_find_cached_gid(cm_dev->ib_device, &path->sgid,
&p, NULL)) {
                        port = cm_dev->port[p-1];
                        break;
                }
        }
        read_unlock_irqrestore(&cm.device_lock, flags);

        if (!port)
                return -EINVAL;

Looking on that case, I noted that the CM code (SB) checks that the GID in the incoming REQ is present in at least of one the ports of the relevant device, but not specifically on the port this request arrived to, is that following IBTA? I thought it could be problematic e.g in the case of RC QP being set by this establishment, later the RC packets would be dropped by the device if they have GRH and the GID isn't on that port table, isn't that?

You can use the CM to establish a connection on another port, eg send CM GMPs to port 1, specify the primary data path is port 2 and specify the alternate data path is port 1. Jason

Quoted 3 lines · Jason Gunthorpe

You can use the CM to establish a connection on another port, eg send CM GMPs to port 1, specify the primary data path is port 2 and specify the alternate data path is port 1. Jason

makes sense, still, maybe the code here could/should be made more strict here for the case of a REQ sent with primary path only, agree?