minix/lib/libnetdriver/netdriver.c

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Driver refactory for live update and crash recovery. SYSLIB CHANGES: - DS calls to publish / retrieve labels consider endpoints instead of u32_t. VFS CHANGES: - mapdriver() only adds an entry in the dmap table in VFS. - dev_up() is only executed upon reception of a driver up event. INET CHANGES: - INET no longer searches for existing drivers instances at startup. - A newtwork driver is (re)initialized upon reception of a driver up event. - Networking startup is now race-free by design. No need to waste 5 seconds at startup any more. DRIVER CHANGES: - Every driver publishes driver up events when starting for the first time or in case of restart when recovery actions must be taken in the upper layers. - Driver up events are published by drivers through DS. - For regular drivers, VFS is normally the only subscriber, but not necessarily. For instance, when the filter driver is in use, it must subscribe to driver up events to initiate recovery. - For network drivers, inet is the only subscriber for now. - Every VFS driver is statically linked with libdriver, every network driver is statically linked with libnetdriver. DRIVER LIBRARIES CHANGES: - Libdriver is extended to provide generic receive() and ds_publish() interfaces for VFS drivers. - driver_receive() is a wrapper for sef_receive() also used in driver_task() to discard spurious messages that were meant to be delivered to a previous version of the driver. - driver_receive_mq() is the same as driver_receive() but integrates support for queued messages. - driver_announce() publishes a driver up event for VFS drivers and marks the driver as initialized and expecting a DEV_OPEN message. - Libnetdriver is introduced to provide similar receive() and ds_publish() interfaces for network drivers (netdriver_announce() and netdriver_receive()). - Network drivers all support live update with no state transfer now. KERNEL CHANGES: - Added kernel call statectl for state management. Used by driver_announce() to unblock eventual callers sendrecing to the driver.
2010-04-08 15:41:35 +02:00
/* This file contains device independent network device driver interface.
*
* Changes:
* Apr 01, 2010 Created (Cristiano Giuffrida)
*
* The file contains the following entry points:
*
* netdriver_announce: called by a network driver to announce it is up
* netdriver_receive: receive() interface for network drivers
*/
#include <minix/drivers.h>
#include <minix/endpoint.h>
#include <minix/netdriver.h>
#include <minix/ds.h>
PRIVATE int conf_expected = TRUE;
/*===========================================================================*
* netdriver_announce *
*===========================================================================*/
PUBLIC void netdriver_announce()
{
/* Announce we are up after a fresh start or restart. */
int r;
char key[DS_MAX_KEYLEN];
char label[DS_MAX_KEYLEN];
char *driver_prefix = "drv.net.";
/* Publish a driver up event. */
r = ds_retrieve_label_name(label, getprocnr());
if (r != OK) {
panic("driver_announce: unable to get own label: %d\n", r);
}
snprintf(key, DS_MAX_KEYLEN, "%s%s", driver_prefix, label);
r = ds_publish_u32(key, DS_DRIVER_UP, DSF_OVERWRITE);
if (r != OK) {
panic("driver_announce: unable to publish driver up event: %d\n", r);
}
conf_expected = TRUE;
}
/*===========================================================================*
* netdriver_receive *
*===========================================================================*/
PUBLIC int netdriver_receive(src, m_ptr, status_ptr)
endpoint_t src;
message *m_ptr;
int *status_ptr;
{
/* receive() interface for drivers. */
int r;
while (TRUE) {
/* Wait for a request. */
r = sef_receive_status(src, m_ptr, status_ptr);
if (r != OK) {
return r;
}
/* See if only DL_CONF is to be expected. */
if(conf_expected) {
if(m_ptr->m_type == DL_CONF) {
conf_expected = FALSE;
}
else if(m_ptr->m_type != DL_GETNAME) {
continue;
}
}
break;
}
return OK;
}