minix/servers/pm/misc.c

/* Miscellaneous system calls.				Author: Kees J. Bot
 *								31 Mar 2000
 * The entry points into this file are:
 *   do_reboot: kill all processes, then reboot system
 *   do_procstat: request process status  (Jorrit N. Herder)
 *   do_getsysinfo: request copy of PM data structure  (Jorrit N. Herder)
 *   do_getprocnr: lookup process slot number  (Jorrit N. Herder)
 *   do_allocmem: allocate a chunk of memory  (Jorrit N. Herder)
 *   do_freemem: deallocate a chunk of memory  (Jorrit N. Herder)
 *   do_getsetpriority: get/set process priority
 *   do_svrctl: process manager control
 */

#define brk _brk

#include "pm.h"
#include <minix/callnr.h>
#include <signal.h>
#include <sys/svrctl.h>
#include <sys/resource.h>
#include <sys/utsname.h>
#include <minix/com.h>
#include <minix/config.h>
#include <minix/type.h>
#include <string.h>
#include <lib.h>
#include "mproc.h"
#include "param.h"
#include "../../kernel/proc.h"

PUBLIC struct utsname uts_val = {
  "Minix",		/* system name */
  "noname",		/* node/network name */
  OS_RELEASE,		/* O.S. release (e.g. 1.5) */
  OS_VERSION,		/* O.S. version (e.g. 10) */
  "xyzzy",		/* machine (cpu) type (filled in later) */
#if __i386
  "i386",		/* architecture */
#else
#error			/* oops, no 'uname -mk' */
#endif
};

PRIVATE char *uts_tbl[] = {
  uts_val.arch,
  NULL,			/* No kernel architecture */
  uts_val.machine,
  NULL,			/* No hostname */
  uts_val.nodename,
  uts_val.release,
  uts_val.version,
  uts_val.sysname,
  NULL,			/* No bus */			/* No bus */
};

#if ENABLE_SYSCALL_STATS
PUBLIC unsigned long calls_stats[NCALLS];
#endif

/*===========================================================================*
 *				do_allocmem				     *
 *===========================================================================*/
PUBLIC int do_allocmem()
{
  vir_clicks mem_clicks;
  phys_clicks mem_base;

  /* This call is dangerous. Memory will be lost of the requesting process
   * forgets about it.
   */
  if (mp->mp_effuid != 0)
  {
	printf("PM: unauthorized call of do_allocmem by proc %d\n",
		mp->mp_endpoint);
	return EPERM;
  }

  mem_clicks = (m_in.memsize + CLICK_SIZE -1 ) >> CLICK_SHIFT;
  mem_base = alloc_mem(mem_clicks);
  if (mem_base == NO_MEM) return(ENOMEM);
  mp->mp_reply.membase =  (phys_bytes) (mem_base << CLICK_SHIFT);
  return(OK);
}

/*===========================================================================*
 *				do_freemem				     *
 *===========================================================================*/
PUBLIC int do_freemem()
{
  vir_clicks mem_clicks;
  phys_clicks mem_base;

  /* This call is dangerous. Even memory belonging to other processes can
   * be freed.
   */
  if (mp->mp_effuid != 0)
  {
	printf("PM: unauthorized call of do_freemem by proc %d\n",
		mp->mp_endpoint);
	return EPERM;
  }

  mem_clicks = (m_in.memsize + CLICK_SIZE -1 ) >> CLICK_SHIFT;
  mem_base = (m_in.membase + CLICK_SIZE -1 ) >> CLICK_SHIFT;
  free_mem(mem_base, mem_clicks);
  return(OK);
}

/*===========================================================================*
 *				do_procstat				     *
 *===========================================================================*/
PUBLIC int do_procstat()
{ 
  /* For the moment, this is only used to return pending signals to 
   * system processes that request the PM for their own status. 
   *
   * Future use might include the FS requesting for process status of
   * any user process. 
   */
  
  /* This call should be removed, or made more general. */
  if (mp->mp_effuid != 0)
  {
	printf("PM: unauthorized call of do_procstat by proc %d\n",
		mp->mp_endpoint);
	return EPERM;
  }

  if (m_in.stat_nr == SELF) {
      mp->mp_reply.sig_set = mp->mp_sigpending;
      sigemptyset(&mp->mp_sigpending);
  } 
  else {
      return(ENOSYS);
  }
  return(OK);
}

/*===========================================================================*
 *				do_sysuname				     *
 *===========================================================================*/
PUBLIC int do_sysuname()
{
/* Set or get uname strings. */

  int r;
  size_t n, len;
  char *string, *t;
#if 0 /* for updates */
  char tmp[sizeof(uts_val.nodename)];
  static short sizes[] = {
	0,	/* arch, (0 = read-only) */
	0,	/* kernel */
	0,	/* machine */
	0,	/* sizeof(uts_val.hostname), */
	sizeof(uts_val.nodename),
	0,	/* release */
	0,	/* version */
	0,	/* sysname */
  };
#endif

  if ((unsigned) m_in.sysuname_field >= _UTS_MAX) return(EINVAL);

  string = uts_tbl[m_in.sysuname_field];
  if (string == NULL)
	return EINVAL;	/* Unsupported field */

  switch (m_in.sysuname_req) {
  case _UTS_GET:
	/* Copy an uname string to the user. */
	n = strlen(string) + 1;
	if (n > m_in.sysuname_len) n = m_in.sysuname_len;
	r = sys_vircopy(SELF, D, (phys_bytes) string, 
		mp->mp_endpoint, D, (phys_bytes) m_in.sysuname_value,
		(phys_bytes) n);
	if (r < 0) return(r);
	break;

#if 0	/* no updates yet */
  case _UTS_SET:
	/* Set an uname string, needs root power. */
	len = sizes[m_in.sysuname_field];
	if (mp->mp_effuid != 0 || len == 0) return(EPERM);
	n = len < m_in.sysuname_len ? len : m_in.sysuname_len;
	if (n <= 0) return(EINVAL);
	r = sys_vircopy(mp->mp_endpoint, D, (phys_bytes) m_in.sysuname_value,
		SELF, D, (phys_bytes) tmp, (phys_bytes) n);
	if (r < 0) return(r);
	tmp[n-1] = 0;
	strcpy(string, tmp);
	break;
#endif

  default:
	return(EINVAL);
  }
  /* Return the number of bytes moved. */
  return(n);
}


/*===========================================================================*
 *				do_getsysinfo			       	     *
 *===========================================================================*/
PUBLIC int do_getsysinfo()
{
  struct mproc *proc_addr;
  vir_bytes src_addr, dst_addr;
  struct kinfo kinfo;
  struct loadinfo loadinfo;
  static struct proc proctab[NR_PROCS+NR_TASKS];
  size_t len;
  static struct pm_mem_info pmi;
  int s, r;
  size_t holesize;

  /* This call leaks important information (the contents of registers).
   * harmless data (such as the load should get their own calls)
   */
  if (mp->mp_effuid != 0)
  {
	printf("PM: unauthorized call of do_getsysinfo by proc %d '%s'\n",
		mp->mp_endpoint, mp->mp_name);
	sig_proc(mp, SIGEMT);
	return EPERM;
  }

  switch(m_in.info_what) {
  case SI_KINFO:			/* kernel info is obtained via PM */
        sys_getkinfo(&kinfo);
        src_addr = (vir_bytes) &kinfo;
        len = sizeof(struct kinfo);
        break;
  case SI_PROC_ADDR:			/* get address of PM process table */
  	proc_addr = &mproc[0];
  	src_addr = (vir_bytes) &proc_addr;
  	len = sizeof(struct mproc *);
  	break; 
  case SI_PROC_TAB:			/* copy entire process table */
        src_addr = (vir_bytes) mproc;
        len = sizeof(struct mproc) * NR_PROCS;
        break;
  case SI_KPROC_TAB:			/* copy entire process table */
	if((r=sys_getproctab(proctab)) != OK)
		return r;
	src_addr = (vir_bytes) proctab;
	len = sizeof(proctab);
        break;
  case SI_MEM_ALLOC:
  	holesize = sizeof(pmi.pmi_holes);
	if((r=mem_holes_copy(pmi.pmi_holes, &holesize,
	   &pmi.pmi_hi_watermark)) != OK)
		return r;
	src_addr = (vir_bytes) &pmi;
	len = sizeof(pmi);
	break;
  case SI_LOADINFO:			/* loadinfo is obtained via PM */
        sys_getloadinfo(&loadinfo);
        src_addr = (vir_bytes) &loadinfo;
        len = sizeof(struct loadinfo);
        break;
#if ENABLE_SYSCALL_STATS
  case SI_CALL_STATS:
  	src_addr = (vir_bytes) calls_stats;
  	len = sizeof(calls_stats);
  	break; 
#endif
  default:
  	return(EINVAL);
  }

  dst_addr = (vir_bytes) m_in.info_where;
  if (OK != (s=sys_datacopy(SELF, src_addr, who_e, dst_addr, len)))
  	return(s);
  return(OK);
}

/*===========================================================================*
 *				do_getprocnr			             *
 *===========================================================================*/
PUBLIC int do_getprocnr()
{
  register struct mproc *rmp;
  static char search_key[PROC_NAME_LEN+1];
  int key_len;
  int s;

  /* This call should be moved to DS. */
  if (mp->mp_effuid != 0)
  {
	printf("PM: unauthorized call of do_procstat by proc %d\n",
		mp->mp_endpoint);
	return EPERM;
  }

  if (m_in.pid >= 0) {			/* lookup process by pid */
  	for (rmp = &mproc[0]; rmp < &mproc[NR_PROCS]; rmp++) {
		if ((rmp->mp_flags & IN_USE) && (rmp->mp_pid==m_in.pid)) {
  			mp->mp_reply.endpt = rmp->mp_endpoint;
  			return(OK);
		} 
	}
  	return(ESRCH);			
  } else if (m_in.namelen > 0) {	/* lookup process by name */
  	key_len = MIN(m_in.namelen, PROC_NAME_LEN);
 	if (OK != (s=sys_datacopy(who_e, (vir_bytes) m_in.addr, 
 			SELF, (vir_bytes) search_key, key_len))) 
 		return(s);
 	search_key[key_len] = '\0';	/* terminate for safety */
  	for (rmp = &mproc[0]; rmp < &mproc[NR_PROCS]; rmp++) {
		if (((rmp->mp_flags & (IN_USE | ZOMBIE)) == IN_USE) && 
			strncmp(rmp->mp_name, search_key, key_len)==0) {
  			mp->mp_reply.endpt = rmp->mp_endpoint;
  			return(OK);
		} 
	}
  	return(ESRCH);			
  } else {			/* return own/parent process number */
  	mp->mp_reply.endpt = who_e;
	mp->mp_reply.pendpt = mproc[mp->mp_parent].mp_endpoint;
  }

  return(OK);
}

/*===========================================================================*
 *				do_reboot				     *
 *===========================================================================*/
PUBLIC int do_reboot()
{
  int r;

  /* Check permission to abort the system. */
  if (mp->mp_effuid != SUPER_USER) return(EPERM);

  /* See how the system should be aborted. */
  abort_flag = (unsigned) m_in.reboot_flag;
  if (abort_flag >= RBT_INVALID) return(EINVAL); 
  if (RBT_MONITOR == abort_flag) {
	int r;
	if(m_in.reboot_strlen >= sizeof(monitor_code))
		return EINVAL;
	if((r = sys_datacopy(who_e, (vir_bytes) m_in.reboot_code,
		SELF, (vir_bytes) monitor_code, m_in.reboot_strlen)) != OK)
		return r;
	monitor_code[m_in.reboot_strlen] = '\0';
  }
  else
	monitor_code[0] = '\0';

  /* Order matters here. When FS is told to reboot, it exits all its
   * processes, and then would be confused if they're exited again by
   * SIGKILL. So first kill, then reboot. 
   */

  check_sig(-1, SIGKILL); 		/* kill all users except init */
  sys_nice(INIT_PROC_NR, PRIO_STOP);	/* stop init, but keep it around */

  report_reboot= 1;
  r= notify(FS_PROC_NR);
  if (r != OK) panic("pm", "do_reboot: unable to notify FS", r);
  
  return(SUSPEND);			/* don't reply to caller */
}

/*===========================================================================*
 *				do_getsetpriority			     *
 *===========================================================================*/
PUBLIC int do_getsetpriority()
{
	int arg_which, arg_who, arg_pri;
	int rmp_nr;
	struct mproc *rmp;

	arg_which = m_in.m1_i1;
	arg_who = m_in.m1_i2;
	arg_pri = m_in.m1_i3;	/* for SETPRIORITY */

	/* Code common to GETPRIORITY and SETPRIORITY. */

	/* Only support PRIO_PROCESS for now. */
	if (arg_which != PRIO_PROCESS)
		return(EINVAL);

	if (arg_who == 0)
		rmp_nr = who_p;
	else
		if ((rmp_nr = proc_from_pid(arg_who)) < 0)
			return(ESRCH);

	rmp = &mproc[rmp_nr];

	if (mp->mp_effuid != SUPER_USER &&
	   mp->mp_effuid != rmp->mp_effuid && mp->mp_effuid != rmp->mp_realuid)
		return EPERM;

	/* If GET, that's it. */
	if (call_nr == GETPRIORITY) {
		return(rmp->mp_nice - PRIO_MIN);
	}

	/* Only root is allowed to reduce the nice level. */
	if (rmp->mp_nice > arg_pri && mp->mp_effuid != SUPER_USER)
		return(EACCES);
	
	/* We're SET, and it's allowed. Do it and tell kernel. */
	rmp->mp_nice = arg_pri;
	return sys_nice(rmp->mp_endpoint, arg_pri);
}

/*===========================================================================*
 *				do_svrctl				     *
 *===========================================================================*/
PUBLIC int do_svrctl()
{
  int s, req;
  vir_bytes ptr;
#define MAX_LOCAL_PARAMS 2
  static struct {
  	char name[30];
  	char value[30];
  } local_param_overrides[MAX_LOCAL_PARAMS];
  static int local_params = 0;

  req = m_in.svrctl_req;
  ptr = (vir_bytes) m_in.svrctl_argp;

  /* Is the request indeed for the MM? */
  if (((req >> 8) & 0xFF) != 'M') return(EINVAL);

  /* Control operations local to the PM. */
  switch(req) {
  case MMSETPARAM:
  case MMGETPARAM: {
      struct sysgetenv sysgetenv;
      char search_key[64];
      char *val_start;
      size_t val_len;
      size_t copy_len;

      /* Copy sysgetenv structure to PM. */
      if (sys_datacopy(who_e, ptr, SELF, (vir_bytes) &sysgetenv, 
              sizeof(sysgetenv)) != OK) return(EFAULT);  

      /* Set a param override? */
      if (req == MMSETPARAM) {
  	if (local_params >= MAX_LOCAL_PARAMS) return ENOSPC;
  	if (sysgetenv.keylen <= 0
  	 || sysgetenv.keylen >=
  	 	 sizeof(local_param_overrides[local_params].name)
  	 || sysgetenv.vallen <= 0
  	 || sysgetenv.vallen >=
  	 	 sizeof(local_param_overrides[local_params].value))
  		return EINVAL;
  		
          if ((s = sys_datacopy(who_e, (vir_bytes) sysgetenv.key,
            SELF, (vir_bytes) local_param_overrides[local_params].name,
               sysgetenv.keylen)) != OK)
               	return s;
          if ((s = sys_datacopy(who_e, (vir_bytes) sysgetenv.val,
            SELF, (vir_bytes) local_param_overrides[local_params].value,
              sysgetenv.keylen)) != OK)
               	return s;
            local_param_overrides[local_params].name[sysgetenv.keylen] = '\0';
            local_param_overrides[local_params].value[sysgetenv.vallen] = '\0';

  	local_params++;

  	return OK;
      }

      if (sysgetenv.keylen == 0) {	/* copy all parameters */
          val_start = monitor_params;
          val_len = sizeof(monitor_params);
      } 
      else {				/* lookup value for key */
      	  int p;
          /* Try to get a copy of the requested key. */
          if (sysgetenv.keylen > sizeof(search_key)) return(EINVAL);
          if ((s = sys_datacopy(who_e, (vir_bytes) sysgetenv.key,
                  SELF, (vir_bytes) search_key, sysgetenv.keylen)) != OK)
              return(s);

          /* Make sure key is null-terminated and lookup value.
           * First check local overrides.
           */
          search_key[sysgetenv.keylen-1]= '\0';
          for(p = 0; p < local_params; p++) {
          	if (!strcmp(search_key, local_param_overrides[p].name)) {
          		val_start = local_param_overrides[p].value;
          		break;
          	}
          }
          if (p >= local_params && (val_start = find_param(search_key)) == NULL)
               return(ESRCH);
          val_len = strlen(val_start) + 1;
      }

      /* See if it fits in the client's buffer. */
      if (val_len > sysgetenv.vallen)
      	return E2BIG;

      /* Value found, make the actual copy (as far as possible). */
      copy_len = MIN(val_len, sysgetenv.vallen); 
      if ((s=sys_datacopy(SELF, (vir_bytes) val_start, 
              who_e, (vir_bytes) sysgetenv.val, copy_len)) != OK)
          return(s);

      return OK;
  }

#if ENABLE_SWAP
  case MMSWAPON: {
	struct mmswapon swapon;

	if (mp->mp_effuid != SUPER_USER) return(EPERM);

	if (sys_datacopy(who_e, (phys_bytes) ptr,
		PM_PROC_NR, (phys_bytes) &swapon,
		(phys_bytes) sizeof(swapon)) != OK) return(EFAULT);

	return(swap_on(swapon.file, swapon.offset, swapon.size)); }

  case MMSWAPOFF: {
	if (mp->mp_effuid != SUPER_USER) return(EPERM);

	return(swap_off()); }
#endif /* SWAP */

  default:
	return(EINVAL);
  }
}

/*===========================================================================*
 *				_brk				             *
 *===========================================================================*/

extern char *_brksize;
PUBLIC int brk(brk_addr)
char *brk_addr;
{
/* PM wants to call brk() itself. */
	if(real_brk(&mproc[PM_PROC_NR], (vir_bytes) brk_addr) != OK) {
		return -1;
	}
	_brksize = brk_addr;
	return 0;
}