On 7/31/08 5:35 PM, "James.Smart@xxxxxxxxxx" <James.Smart@xxxxxxxxxx> wrote: > > > David Somayajulu wrote: >>> I'm a little bothered that there's nothing that qualifies the driver >>> to the shost before invoking the LLDD handler (e.g. driver has a >>> signature, message header contains signature, and the two >> must match). >> The idea was to let the Low Level Driver validate the message >> contents - >> signature, etc. > > But that's the point - if we have a common action and a common point, > lets > do it once. Why have all LLDs perform the same kind of thing but in > completely different manners ? And worse, what happens if one doesn't > validate ? The check doesn't have to be extensive, and the LLD > can certainly do more checks. In that case is it o.k to have the first 4 bytes of the LLD payload (i.e., following struct scsi_nl_hdr) define a signature. Let us also define the signature to be the first 4 bytes in shost->hostt->name. This we can still have some validation without much overhead. > >> I would appreciate if you can explain your comment a bit more, if my >> reasoning below does not suffice. I have already provided a function >> "fc_host_post_vendor_event_to_pid() [in >> scsi_transport_fc.c]", which enables >> an LLD to post a message to a specific pid. This may be used >> by the LLD to >> send response messages to the pid, for command messages sent >> by the pid. > > it's not about sending... > > What happens if the pid unexpectedly dies ? The event notices are an > easy way to find out that it died - thus releasing the "cached pid", or > terminating partial transactions, and not abusing the netlink socket > with data destined to a dead pid. Good point. I will add a check to make sure we have a live pid. Thanks David S. -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
