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minix/servers/inet/inet.c
Cristiano Giuffrida 1f5841c8ed Basic System Event Framework (SEF) with ping and live update. 
SYSLIB CHANGES:
- SEF must be used by every system process and is thereby part of the system
library.
- The framework provides a receive() interface (sef_receive) for system
processes to automatically catch known system even messages and process them.
- SEF provides a default behavior for each type of system event, but allows
system processes to register callbacks to override the default behavior.
- Custom (local to the process) or predefined (provided by SEF) callback
implementations can be registered to SEF.
- SEF currently includes support for 2 types of system events:
  1. SEF Ping. The event occurs every time RS sends a ping to figure out
  whether a system process is still alive. The default callback implementation
  provided by SEF is to notify RS back to let it know the process is alive
  and kicking.
  2. SEF Live update. The event occurs every time RS sends a prepare to update
  message to let a system process know an update is available and to prepare
  for it. The live update support is very basic for now. SEF only deals with
  verifying if the prepare state can be supported by the process, dumping the
  state for debugging purposes, and providing an event-driven programming
  model to the process to react to state changes check-in when ready to update.
- SEF should be extended in the future to integrate support for more types of
system events. Ideally, all the cross-cutting concerns should be integrated into
SEF to avoid duplicating code and ease extensibility. Examples include:
  * PM notify messages primarily used at shutdown.
  * SYSTEM notify messages primarily used for signals.
  * CLOCK notify messages used for system alarms.
  * Debug messages. IS could still be in charge of fkey handling but would
  forward the debug message to the target process (e.g. PM, if the user
  requested debug information about PM). SEF would then catch the message and
  do nothing unless the process has registered an appropriate callback to
  deal with the event. This simplifies the programming model to print debug
  information, avoids duplicating code, and reduces the effort to print
  debug information.

SYSTEM PROCESSES CHANGES:
- Every system process registers SEF callbacks it needs to override the default
system behavior and calls sef_startup() right after being started.
- sef_startup() does almost nothing now, but will be extended in the future to
support callbacks of its own to let RS control and synchronize with every
system process at initialization time.
- Every system process calls sef_receive() now rather than receive() directly,
to let SEF handle predefined system events.

RS CHANGES:
- RS supports a basic single-component live update protocol now, as follows:
  * When an update command is issued (via "service update *"), RS notifies the
  target system process to prepare for a specific update state.
  * If the process doesn't respond back in time, the update is aborted.
  * When the process responds back, RS kills it and marks it for refreshing.
  * The process is then automatically restarted as for a buggy process and can
  start running again.
  * Live update is currently prototyped as a controlled failure.
2009-12-21 14:12:21 +00:00

383 lines
8.4 KiB
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/* this file contains the interface of the network software with rest of
minix. Furthermore it contains the main loop of the network task.
Copyright 1995 Philip Homburg
The valid messages and their parameters are:
from FS:
__________________________________________________________________
| | | | | | |
| m_type | DEVICE | PROC_NR | COUNT | POSITION | ADDRESS |
|_______________|___________|_________|_______|__________|_________|
| | | | | | |
| NW_OPEN | minor dev | proc nr | mode | | |
|_______________|___________|_________|_______|__________|_________|
| | | | | | |
| NW_CLOSE | minor dev | proc nr | | | |
|_______________|___________|_________|_______|__________|_________|
| | | | | | |
| NW_IOCTL | minor dev | proc nr | | NWIO.. | address |
|_______________|___________|_________|_______|__________|_________|
| | | | | | |
| NW_READ | minor dev | proc nr | count | | address |
|_______________|___________|_________|_______|__________|_________|
| | | | | | |
| NW_WRITE | minor dev | proc nr | count | | address |
|_______________|___________|_________|_______|__________|_________|
| | | | | | |
| NW_CANCEL | minor dev | proc nr | | | |
|_______________|___________|_________|_______|__________|_________|
from DL_ETH:
_______________________________________________________________________
| | | | | | |
| m_type | DL_PORT | DL_PROC | DL_COUNT | DL_STAT | DL_TIME |
|_______________|___________|_________|__________|____________|_________|
| | | | | | |
| DL_CONF_REPLY | minor dev | proc nr | rd_count | 0 | stat | time |
|_______________|___________|_________|__________|____________|_________|
| | | | | | |
| DL_TASK_REPLY | minor dev | proc nr | rd_count | err | stat | time |
|_______________|___________|_________|__________|____________|_________|
*/
#include "inet.h"
#define _MINIX_SOURCE 1
#include <fcntl.h>
#include <time.h>
#include <unistd.h>
#include <sys/svrctl.h>
#include <minix/ds.h>
#include <minix/endpoint.h>
#include "mq.h"
#include "qp.h"
#include "proto.h"
#include "generic/type.h"
#include "generic/arp.h"
#include "generic/assert.h"
#include "generic/buf.h"
#include "generic/clock.h"
#include "generic/eth.h"
#include "generic/event.h"
#include "generic/ip.h"
#include "generic/psip.h"
#include "generic/rand256.h"
#include "generic/sr.h"
#include "generic/tcp.h"
#include "generic/udp.h"
THIS_FILE
#define RANDOM_DEV_NAME "/dev/random"
int this_proc; /* Process number of this server. */
#ifdef __minix_vmd
static int synal_tasknr= ANY;
#endif
/* Killing Solaris */
int killer_inet= 0;
#ifdef BUF_CONSISTENCY_CHECK
extern int inet_buf_debug;
#endif
#if HZ_DYNAMIC
u32_t system_hz;
#endif
_PROTOTYPE( void main, (void) );
FORWARD _PROTOTYPE( void nw_conf, (void) );
FORWARD _PROTOTYPE( void nw_init, (void) );
/* SEF functions and variables. */
FORWARD _PROTOTYPE( void sef_local_startup, (void) );
PUBLIC void main()
{
mq_t *mq;
int r;
int source, m_type, timerand, fd;
u32_t tasknr;
struct fssignon device;
#ifdef __minix_vmd
struct systaskinfo info;
#endif
u8_t randbits[32];
struct timeval tv;
/* SEF local startup. */
sef_local_startup();
#if DEBUG
printf("Starting inet...\n");
printf("%s\n", version);
#endif
#if HZ_DYNAMIC
system_hz = sys_hz();
#endif
/* Read configuration. */
nw_conf();
/* Get a random number */
timerand= 1;
fd= open(RANDOM_DEV_NAME, O_RDONLY | O_NONBLOCK);
if (fd != -1)
{
r= read(fd, randbits, sizeof(randbits));
if (r == sizeof(randbits))
timerand= 0;
else
{
printf("inet: unable to read random data from %s: %s\n",
RANDOM_DEV_NAME, r == -1 ? strerror(errno) :
r == 0 ? "EOF" : "not enough data");
}
close(fd);
}
else
{
printf("inet: unable to open random device %s: %s\n",
RANDOM_DEV_NAME, strerror(errno));
}
if (timerand)
{
printf("inet: using current time for random-number seed\n");
#ifdef __minix_vmd
r= sysutime(UTIME_TIMEOFDAY, &tv);
#else /* Minix 3 */
r= gettimeofday(&tv, NULL);
#endif
if (r == -1)
{
printf("sysutime failed: %s\n", strerror(errno));
exit(1);
}
memcpy(randbits, &tv, sizeof(tv));
}
init_rand256(randbits);
#ifdef __minix_vmd
if (svrctl(SYSSIGNON, (void *) &info) == -1) pause();
/* Our new identity as a server. */
this_proc = info.proc_nr;
#else /* Minix 3 */
/* Our new identity as a server. */
r= ds_retrieve_u32("inet", &tasknr);
if (r != OK)
ip_panic(("inet: ds_retrieve_u32 failed for 'inet': %d", r));
this_proc= tasknr;
#endif
/* Register the device group. */
device.dev= ip_dev;
device.style= STYLE_CLONE;
if (svrctl(FSSIGNON, (void *) &device) == -1) {
printf("inet: error %d on registering ethernet devices\n",
errno);
pause();
}
#ifdef BUF_CONSISTENCY_CHECK
inet_buf_debug= (getenv("inetbufdebug") &&
(strcmp(getenv("inetbufdebug"), "on") == 0));
inet_buf_debug= 100;
if (inet_buf_debug)
{
ip_warning(( "buffer consistency check enabled" ));
}
#endif
if (getenv("killerinet"))
{
ip_warning(( "killer inet active" ));
killer_inet= 1;
}
#ifdef __minix_vmd
r= sys_findproc(SYN_AL_NAME, &synal_tasknr, 0);
if (r != OK)
ip_panic(( "unable to find synchronous alarm task: %d\n", r ));
#endif
nw_init();
while (TRUE)
{
#ifdef BUF_CONSISTENCY_CHECK
if (inet_buf_debug)
{
static int buf_debug_count= 0;
if (++buf_debug_count >= inet_buf_debug)
{
buf_debug_count= 0;
if (!bf_consistency_check())
break;
}
}
#endif
if (ev_head)
{
ev_process();
continue;
}
if (clck_call_expire)
{
clck_expire_timers();
continue;
}
mq= mq_get();
if (!mq)
ip_panic(("out of messages"));
r= sef_receive(ANY, &mq->mq_mess);
if (r<0)
{
ip_panic(("unable to receive: %d", r));
}
reset_time();
source= mq->mq_mess.m_source;
m_type= mq->mq_mess.m_type;
if (source == FS_PROC_NR)
{
sr_rec(mq);
}
#ifdef __minix_vmd
else if (source == synal_tasknr)
{
clck_tick (&mq->mq_mess);
mq_free(mq);
}
#else /* Minix 3 */
else if (is_notify(m_type))
{
if (_ENDPOINT_P(source) == CLOCK)
{
clck_tick(&mq->mq_mess);
mq_free(mq);
}
else if (_ENDPOINT_P(source) == PM_PROC_NR)
{
/* signaled */
/* probably SIGTERM */
mq_free(mq);
}
else
{
/* A driver is (re)started. */
eth_check_drivers(&mq->mq_mess);
mq_free(mq);
}
}
#endif
else if (m_type == DL_CONF_REPLY || m_type == DL_TASK_REPLY ||
m_type == DL_NAME_REPLY || m_type == DL_STAT_REPLY)
{
eth_rec(&mq->mq_mess);
mq_free(mq);
}
else
{
printf("inet: got bad message type 0x%x from %d\n",
mq->mq_mess.m_type, mq->mq_mess.m_source);
mq_free(mq);
}
}
ip_panic(("task is not allowed to terminate"));
}
/*===========================================================================*
* sef_local_startup *
*===========================================================================*/
PRIVATE void sef_local_startup()
{
/* No live update support for now. */
/* Let SEF perform startup. */
sef_startup();
}
PRIVATE void nw_conf()
{
read_conf();
eth_prep();
arp_prep();
psip_prep();
ip_prep();
tcp_prep();
udp_prep();
}
PRIVATE void nw_init()
{
mq_init();
bf_init();
clck_init();
sr_init();
qp_init();
eth_init();
arp_init();
psip_init();
ip_init();
tcp_init();
udp_init();
}
PUBLIC void panic0(file, line)
char *file;
int line;
{
printf("panic at %s, %d: ", file, line);
}
PUBLIC void inet_panic()
{
printf("\ninet stacktrace: ");
util_stacktrace();
#ifdef __minix_vmd
sys_abort(RBT_PANIC);
#else /* Minix 3 */
(panic)("INET","aborted due to a panic",NO_NUM);
#endif
for(;;);
}
#if !NDEBUG
PUBLIC void bad_assertion(file, line, what)
char *file;
int line;
char *what;
{
panic0(file, line);
printf("assertion \"%s\" failed", what);
panic();
}
PUBLIC void bad_compare(file, line, lhs, what, rhs)
char *file;
int line;
int lhs;
char *what;
int rhs;
{
panic0(file, line);
printf("compare (%d) %s (%d) failed", lhs, what, rhs);
panic();
}
#endif /* !NDEBUG */
/*
* $PchId: inet.c,v 1.23 2005/06/28 14:27:22 philip Exp $
*/
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