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minix/servers/rs/main.c
Cristiano Giuffrida e090013056 Drivers and servers are simply known as services. 
/etc CHANGES:
- /etc/drivers.conf has been renamed to /etc/system.conf. Every entry in 
the file is now marked as "service" rather than driver.
- user "service" has been added to password file /etc/passwd.
- docs/UPDATING updated accordingly, as well as every other mention to the old
drivers.conf in the system.

RS CHANGES:
- No more distinction between servers and drivers.
- RS_START has been renamed to RS_UP and the old legacy RS_UP and RS_UP_COPY
dropped.
- RS asks PCI to set / remove ACL entries only for services whose ACL properties
have been set. This change eliminates unnecessary warnings.
- Temporarily minimize the risk of potential races at boot time or when starting
a new service. Upcoming changes will eliminate races completely.
- General cleanup.
2009-12-17 01:53:26 +00:00

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/* Reincarnation Server. This servers starts new system services and detects
* they are exiting. In case of errors, system services can be restarted.
* The RS server periodically checks the status of all registered services
* services to see whether they are still alive. The system services are
* expected to periodically send a heartbeat message.
*
* Changes:
* Nov 22, 2009: rewrite of boot process (Cristiano Giuffrida)
* Jul 22, 2005: Created (Jorrit N. Herder)
*/
#include "inc.h"
#include <fcntl.h>
#include <a.out.h>
#include <minix/crtso.h>
#include "../../kernel/const.h"
#include "../../kernel/type.h"
#include "../../kernel/proc.h"
#include "../pm/mproc.h"
#include "../pm/const.h"
/* Declare some local functions. */
FORWARD _PROTOTYPE(void exec_image_copy, ( int boot_proc_idx,
struct boot_image *ip, struct rproc *rp) );
FORWARD _PROTOTYPE(void boot_image_info_lookup, ( endpoint_t endpoint,
struct boot_image *image,
struct boot_image **ip, struct boot_image_priv **pp,
struct boot_image_sys **sp, struct boot_image_dev **dp) );
FORWARD _PROTOTYPE(void fill_call_mask, ( int *calls, int tot_nr_calls,
bitchunk_t *call_mask, int call_base) );
FORWARD _PROTOTYPE(void init_server, (void) );
FORWARD _PROTOTYPE(void sig_handler, (void) );
FORWARD _PROTOTYPE(void get_work, (message *m) );
FORWARD _PROTOTYPE(void reply, (int whom, message *m_out) );
/* The buffer where the boot image is copied during initialization. */
PRIVATE int boot_image_buffer_size;
PRIVATE char *boot_image_buffer;
/* Macro to identify a system service in the boot image. This rules out
* kernel tasks and the root system process (RS).
*/
#define isbootsrvprocn(n) (!iskerneln((n)) && !isrootsysn((n)))
/* Flag set when memory unmapping can be done. */
EXTERN int unmap_ok;
/*===========================================================================*
* main *
*===========================================================================*/
PUBLIC int main(void)
{
/* This is the main routine of this service. The main loop consists of
* three major activities: getting new work, processing the work, and
* sending the reply. The loop never terminates, unless a panic occurs.
*/
message m; /* request message */
int call_nr, who_e,who_p; /* call number and caller */
int result; /* result to return */
sigset_t sigset; /* system signal set */
int s;
/* Initialize the server, then go to work. */
init_server();
/* Main loop - get work and do it, forever. */
while (TRUE) {
/* Wait for request message. */
get_work(&m);
who_e = m.m_source;
who_p = _ENDPOINT_P(who_e);
if(who_p < -NR_TASKS || who_p >= NR_PROCS)
panic("RS","message from bogus source", who_e);
call_nr = m.m_type;
/* Now determine what to do. Three types of requests are expected:
* - Heartbeat messages (notifications from registered system services)
* - System notifications (POSIX signals or synchronous alarm)
* - User requests (control messages to manage system services)
*/
/* Notification messages are control messages and do not need a reply.
* These include heartbeat messages and system notifications.
*/
if (is_notify(m.m_type)) {
switch (who_p) {
case CLOCK:
do_period(&m); /* check services status */
continue;
case PM_PROC_NR:
sig_handler();
continue;
default: /* heartbeat notification */
if (rproc_ptr[who_p] != NULL) { /* mark heartbeat time */
rproc_ptr[who_p]->r_alive_tm = m.NOTIFY_TIMESTAMP;
} else {
printf("Warning, RS got unexpected notify message from %d\n",
m.m_source);
}
}
}
/* If this is not a notification message, it is a normal request.
* Handle the request and send a reply to the caller.
*/
else {
if (call_nr != GETSYSINFO &&
(call_nr < RS_RQ_BASE || call_nr >= RS_RQ_BASE+0x100))
{
/* Ignore invalid requests. Do not try to reply. */
printf("RS: got invalid request %d from endpoint %d\n",
call_nr, m.m_source);
continue;
}
/* Handler functions are responsible for permission checking. */
switch(call_nr) {
case RS_UP: result = do_up(&m); break;
case RS_DOWN: result = do_down(&m); break;
case RS_REFRESH: result = do_refresh(&m); break;
case RS_RESTART: result = do_restart(&m); break;
case RS_SHUTDOWN: result = do_shutdown(&m); break;
case GETSYSINFO: result = do_getsysinfo(&m); break;
case RS_LOOKUP: result = do_lookup(&m); break;
default:
printf("Warning, RS got unexpected request %d from %d\n",
m.m_type, m.m_source);
result = EINVAL;
}
/* Finally send reply message, unless disabled. */
if (result != EDONTREPLY) {
m.m_type = result;
reply(who_e, &m);
}
}
}
}
/*===========================================================================*
* exec_image_copy *
*===========================================================================*/
PRIVATE void exec_image_copy(boot_proc_idx, ip, rp)
int boot_proc_idx;
struct boot_image *ip;
struct rproc *rp;
{
/* Copy the executable image of the given boot process. */
int s;
struct exec header;
static char *boot_image_ptr = NULL;
if(boot_image_ptr == NULL) {
boot_image_ptr = boot_image_buffer;
}
s = NO_NUM;
/* Get a.out header. */
if(boot_image_buffer+boot_image_buffer_size - boot_image_ptr < sizeof(header)
|| (s = sys_getaoutheader(&header, boot_proc_idx)) != OK) {
panic("RS", "unable to get copy of a.out header", s);
}
memcpy(boot_image_ptr, &header, header.a_hdrlen);
boot_image_ptr += header.a_hdrlen;
/* Get text segment. */
if(boot_image_buffer+boot_image_buffer_size - boot_image_ptr < header.a_text
|| (s = rs_startup_segcopy(ip->endpoint, T, D, (vir_bytes) boot_image_ptr,
header.a_text)) != OK) {
panic("RS", "unable to get copy of text segment", s);
}
boot_image_ptr += header.a_text;
/* Get data segment. */
if(boot_image_buffer+boot_image_buffer_size - boot_image_ptr < header.a_data
|| (s = rs_startup_segcopy(ip->endpoint, D, D, (vir_bytes) boot_image_ptr,
header.a_data)) != OK) {
panic("RS", "unable to get copy of data segment", s);
}
boot_image_ptr += header.a_data;
/* Set the executable image for the given boot process. */
rp->r_exec_len = header.a_hdrlen + header.a_text + header.a_data;
rp->r_exec = boot_image_ptr - rp->r_exec_len;
}
/*===========================================================================*
* boot_image_info_lookup *
*===========================================================================*/
PRIVATE void boot_image_info_lookup(endpoint, image, ip, pp, sp, dp)
endpoint_t endpoint;
struct boot_image *image;
struct boot_image **ip;
struct boot_image_priv **pp;
struct boot_image_sys **sp;
struct boot_image_dev **dp;
{
/* Lookup entries in boot image tables. */
int i;
/* When requested, locate the corresponding entry in the boot image table
* or panic if not found.
*/
if(ip) {
for (i=0; i < NR_BOOT_PROCS; i++) {
if(image[i].endpoint == endpoint) {
*ip = &image[i];
break;
}
}
if(i == NR_BOOT_PROCS) {
panic("RS", "boot image table lookup failed", NO_NUM);
}
}
/* When requested, locate the corresponding entry in the boot image priv table
* or panic if not found.
*/
if(pp) {
for (i=0; boot_image_priv_table[i].endpoint != NULL_BOOT_NR; i++) {
if(boot_image_priv_table[i].endpoint == endpoint) {
*pp = &boot_image_priv_table[i];
break;
}
}
if(i == NULL_BOOT_NR) {
panic("RS", "boot image priv table lookup failed", NO_NUM);
}
}
/* When requested, locate the corresponding entry in the boot image sys table
* or resort to the default entry if not found.
*/
if(sp) {
for (i=0; boot_image_sys_table[i].endpoint != DEFAULT_BOOT_NR; i++) {
if(boot_image_sys_table[i].endpoint == endpoint) {
*sp = &boot_image_sys_table[i];
break;
}
}
if(boot_image_sys_table[i].endpoint == DEFAULT_BOOT_NR) {
*sp = &boot_image_sys_table[i]; /* accept the default entry */
}
}
/* When requested, locate the corresponding entry in the boot image dev table
* or resort to the default entry if not found.
*/
if(dp) {
for (i=0; boot_image_dev_table[i].endpoint != DEFAULT_BOOT_NR; i++) {
if(boot_image_dev_table[i].endpoint == endpoint) {
*dp = &boot_image_dev_table[i];
break;
}
}
if(boot_image_dev_table[i].endpoint == DEFAULT_BOOT_NR) {
*dp = &boot_image_dev_table[i]; /* accept the default entry */
}
}
}
/*===========================================================================*
* fill_call_mask *
*===========================================================================*/
PRIVATE void fill_call_mask(calls, tot_nr_calls, call_mask, call_base)
int *calls; /* the unordered set of calls */
int tot_nr_calls; /* the total number of calls */
bitchunk_t *call_mask; /* the call mask to fill in */
int call_base; /* the base offset for the calls */
{
/* Fill a call mask from an unordered set of calls. */
int i;
bitchunk_t fv;
int call_mask_size, nr_calls;
call_mask_size = BITMAP_CHUNKS(tot_nr_calls);
/* Count the number of calls to fill in. */
nr_calls = 0;
for(i=0; calls[i] != SYS_NULL_C; i++) {
nr_calls++;
}
/* See if all calls are allowed and call mask must be completely filled. */
fv = 0;
if(nr_calls == 1 && calls[0] == SYS_ALL_C) {
fv = (~0);
}
/* Fill or clear call mask. */
for(i=0; i < call_mask_size; i++) {
call_mask[i] = fv;
}
/* Not all calls allowed? Enter calls bit by bit. */
if(!fv) {
for(i=0; i < nr_calls; i++) {
SET_BIT(call_mask, calls[i] - call_base);
}
}
}
/*===========================================================================*
* init_server *
*===========================================================================*/
PRIVATE void init_server(void)
{
/* Initialize the reincarnation server. */
struct sigaction sa;
struct boot_image *ip;
int s,i,j;
int nr_image_srvs, nr_image_priv_srvs;
struct rproc *rp;
struct boot_image image[NR_BOOT_PROCS];
struct mproc mproc[NR_PROCS];
struct exec header;
struct boot_image_priv *boot_image_priv;
struct boot_image_sys *boot_image_sys;
struct boot_image_dev *boot_image_dev;
/* See if we run in verbose mode. */
env_parse("rs_verbose", "d", 0, &rs_verbose, 0, 1);
/* Get a copy of the boot image table. */
if ((s = sys_getimage(image)) != OK) {
panic("RS", "unable to get copy of boot image table", s);
}
/* Determine the number of system services in the boot image table and
* compute the size required for the boot image buffer.
*/
nr_image_srvs = 0;
boot_image_buffer_size = 0;
for(i=0;i<NR_BOOT_PROCS;i++) {
ip = &image[i];
/* System services only. */
if(!isbootsrvprocn(_ENDPOINT_P(ip->endpoint))) {
continue;
}
nr_image_srvs++;
/* Lookup the corresponding entry in the boot image sys table. */
boot_image_info_lookup(ip->endpoint, image,
NULL, NULL, &boot_image_sys, NULL);
/* If we must keep a copy of this system service, read the header
* and increase the size of the boot image buffer.
*/
if(boot_image_sys->flags & SF_USE_COPY) {
if((s = sys_getaoutheader(&header, i)) != OK) {
panic("RS", "unable to get copy of a.out header", s);
}
boot_image_buffer_size += header.a_hdrlen
+ header.a_text + header.a_data;
}
}
/* Determine the number of entries in the boot image priv table and make sure
* it matches the number of system services in the boot image table.
*/
nr_image_priv_srvs = 0;
for (i=0; boot_image_priv_table[i].endpoint != NULL_BOOT_NR; i++) {
boot_image_priv = &boot_image_priv_table[i];
/* System services only. */
if(!isbootsrvprocn(_ENDPOINT_P(boot_image_priv->endpoint))) {
continue;
}
nr_image_priv_srvs++;
}
if(nr_image_srvs != nr_image_priv_srvs) {
panic("RS", "boot image table and boot image priv table mismatch",
NO_NUM);
}
/* Allocate boot image buffer. */
if(boot_image_buffer_size > 0) {
boot_image_buffer = rs_startup_sbrk(boot_image_buffer_size);
if(boot_image_buffer == (char *) -1) {
panic("RS", "unable to allocate boot image buffer", NO_NUM);
}
}
/* Initialize the system process table in 3 steps, each of them following
* the appearance of system services in the boot image priv table.
* - Step 1: get a copy of the executable image of every system service that
* requires it while it is not yet running.
* In addition, set priviliges, sys properties, and dev properties (if any)
* for every system service.
*/
for (i=0; boot_image_priv_table[i].endpoint != NULL_BOOT_NR; i++) {
boot_image_priv = &boot_image_priv_table[i];
/* System services only. */
if(!isbootsrvprocn(_ENDPOINT_P(boot_image_priv->endpoint))) {
continue;
}
/* Lookup the corresponding entries in other tables. */
boot_image_info_lookup(boot_image_priv->endpoint, image,
&ip, NULL, &boot_image_sys, &boot_image_dev);
rp = &rproc[boot_image_priv - boot_image_priv_table];
/*
* Get a copy of the executable image if required.
*/
rp->r_exec_len = 0;
rp->r_exec = NULL;
if(boot_image_sys->flags & SF_USE_COPY) {
exec_image_copy(ip - image, ip, rp);
}
/*
* Set privileges.
* XXX FIXME: We should also let RS set vm calls allowed for each sys
* service by using vm_set_priv(). We need a more uniform privilege
* management scheme in VM for this change.
*/
/* Force a static privilege id for system services in the boot image. */
rp->r_priv.s_id = static_priv_id(_ENDPOINT_P(boot_image_priv->endpoint));
/* Initialize privilege bitmaps. */
rp->r_priv.s_flags = boot_image_priv->flags; /* privilege flags */
rp->r_priv.s_trap_mask = boot_image_priv->trap_mask; /* allowed traps */
memcpy(&rp->r_priv.s_ipc_to, &boot_image_priv->ipc_to,
sizeof(rp->r_priv.s_ipc_to)); /* allowed targets */
/* Initialize call mask bitmap from unordered set. */
fill_call_mask(boot_image_priv->k_calls, NR_SYS_CALLS,
rp->r_priv.s_k_call_mask, KERNEL_CALL);
/* Set the privilege structure. */
if ((s = sys_privctl(ip->endpoint, SYS_PRIV_SET_SYS, &(rp->r_priv)))
!= OK) {
panic("RS", "unable to set privilege structure", s);
}
/* Synch the privilege structure with the kernel. */
if ((s = sys_getpriv(&(rp->r_priv), ip->endpoint)) != OK) {
panic("RS", "unable to synch privilege structure", s);
}
/*
* Set sys properties.
*/
rp->r_sys_flags = boot_image_sys->flags; /* sys flags */
/*
* Set dev properties.
*/
rp->r_dev_nr = boot_image_dev->dev_nr; /* major device number */
rp->r_dev_style = boot_image_dev->dev_style; /* device style */
rp->r_period = boot_image_dev->period; /* heartbeat period */
/* Get label. */
strcpy(rp->r_label, ip->proc_name);
/* Get command settings. */
rp->r_cmd[0]= '\0';
rp->r_argv[0] = rp->r_cmd;
rp->r_argv[1] = NULL;
rp->r_argc = 1;
rp->r_script[0]= '\0';
/* Get some settings from the boot image table. */
rp->r_nice = ip->priority;
rp->r_proc_nr_e = ip->endpoint;
/* Set some defaults. */
rp->r_uid = 0; /* root */
rp->r_check_tm = 0; /* not checked yet */
getuptime(&rp->r_alive_tm); /* currently alive */
rp->r_stop_tm = 0; /* not exiting yet */
rp->r_restarts = 0; /* no restarts so far */
rp->r_set_resources = 0; /* don't set resources */
/* Mark as in use. */
rp->r_flags = RS_IN_USE;
rproc_ptr[_ENDPOINT_P(rp->r_proc_nr_e)]= rp;
}
/* - Step 2: allow every system service in the boot image to run.
*/
for (i=0; boot_image_priv_table[i].endpoint != NULL_BOOT_NR; i++) {
boot_image_priv = &boot_image_priv_table[i];
/* System services only. */
if(!isbootsrvprocn(_ENDPOINT_P(boot_image_priv->endpoint))) {
continue;
}
/* Lookup the corresponding entry in the boot image table. */
boot_image_info_lookup(boot_image_priv->endpoint, image,
&ip, NULL, NULL, NULL);
/* Allow the process to run. */
if ((s = sys_privctl(ip->endpoint, SYS_PRIV_ALLOW, NULL)) != OK) {
panic("RS", "unable to initialize privileges", s);
}
}
/* - Step 3: all the system services in the boot image are now running.
* Complete the initialization of the system process table in collaboration
* with other system processes.
*/
if ((s = getsysinfo(PM_PROC_NR, SI_PROC_TAB, mproc)) != OK) {
panic("RS", "unable to get copy of PM process table", s);
}
for (i=0; boot_image_priv_table[i].endpoint != NULL_BOOT_NR; i++) {
boot_image_priv = &boot_image_priv_table[i];
/* System services only. */
if(!isbootsrvprocn(_ENDPOINT_P(boot_image_priv->endpoint))) {
continue;
}
/* Lookup the corresponding slot in the system process table. */
rp = &rproc[boot_image_priv - boot_image_priv_table];
/* Get pid from PM process table. */
rp->r_pid = NO_PID;
for (j = 0; j < NR_PROCS; j++) {
if (mproc[j].mp_endpoint == rp->r_proc_nr_e) {
rp->r_pid = mproc[j].mp_pid;
break;
}
}
if(j == NR_PROCS) {
panic("RS", "unable to get pid", NO_NUM);
}
/* Publish the new system service.
* XXX FIXME. Possible race condition. We should publish labels before
* allowing other processes to run.
*/
s = publish_service(rp);
if (s != OK) {
panic("RS", "unable to publish boot system service", s);
}
}
/*
* Now complete RS initialization process in collaboration with other
* system services.
*/
/* Let the rest of the system know about our dynamically allocated buffer. */
if(boot_image_buffer_size > 0) {
boot_image_buffer = rs_startup_sbrk_synch(boot_image_buffer_size);
if(boot_image_buffer == (char *) -1) {
panic("RS", "unable to synch boot image buffer", NO_NUM);
}
}
/* Set alarm to periodically check service status. */
if (OK != (s=sys_setalarm(RS_DELTA_T, 0)))
panic("RS", "couldn't set alarm", s);
/* Install signal handlers. Ask PM to transform signal into message. */
sa.sa_handler = SIG_MESS;
sigemptyset(&sa.sa_mask);
sa.sa_flags = 0;
if (sigaction(SIGCHLD,&sa,NULL)<0) panic("RS","sigaction failed", errno);
if (sigaction(SIGTERM,&sa,NULL)<0) panic("RS","sigaction failed", errno);
/* Initialize the exec pipe. */
if (pipe(exec_pipe) == -1)
panic("RS", "pipe failed", errno);
if (fcntl(exec_pipe[0], F_SETFD,
fcntl(exec_pipe[0], F_GETFD) | FD_CLOEXEC) == -1)
{
panic("RS", "fcntl set FD_CLOEXEC on pipe input failed", errno);
}
if (fcntl(exec_pipe[1], F_SETFD,
fcntl(exec_pipe[1], F_GETFD) | FD_CLOEXEC) == -1)
{
panic("RS", "fcntl set FD_CLOEXEC on pipe output failed", errno);
}
if (fcntl(exec_pipe[0], F_SETFL,
fcntl(exec_pipe[0], F_GETFL) | O_NONBLOCK) == -1)
{
panic("RS", "fcntl set O_NONBLOCK on pipe input failed", errno);
}
/* Map out our own text and data. This is normally done in crtso.o
* but RS is an exception - we don't get to talk to VM so early on.
* That's why we override munmap() and munmap_text() in utility.c.
*
* _minix_unmapzero() is the same code in crtso.o that normally does
* it on startup. It's best that it's there as crtso.o knows exactly
* what the ranges are of the filler data.
*/
unmap_ok = 1;
_minix_unmapzero();
}
/*===========================================================================*
* sig_handler *
*===========================================================================*/
PRIVATE void sig_handler()
{
sigset_t sigset;
int sig;
/* Try to obtain signal set from PM. */
if (getsigset(&sigset) != 0) return;
/* Check for known signals. */
if (sigismember(&sigset, SIGCHLD)) do_exit(NULL);
if (sigismember(&sigset, SIGTERM)) do_shutdown(NULL);
}
/*===========================================================================*
* get_work *
*===========================================================================*/
PRIVATE void get_work(m_in)
message *m_in; /* pointer to message */
{
int s; /* receive status */
if (OK != (s=receive(ANY, m_in))) /* wait for message */
panic("RS","receive failed", s);
}
/*===========================================================================*
* reply *
*===========================================================================*/
PRIVATE void reply(who, m_out)
int who; /* replyee */
message *m_out; /* reply message */
{
int s; /* send status */
s = sendnb(who, m_out); /* send the message */
if (s != OK)
printf("RS: unable to send reply to %d: %d\n", who, s);
}
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