minix/servers/vfs/utility.c
2007-10-23 14:19:16 +00:00

154 lines
4.9 KiB
C

/* This file contains a few general purpose utility routines.
*
* The entry points into this file are
* clock_time: ask the clock task for the real time
* copy: copy a block of data
* fetch_name: go get a path name from user space
* no_sys: reject a system call that FS does not handle
* panic: something awful has occurred; MINIX cannot continue
* conv2: do byte swapping on a 16-bit int
* conv4: do byte swapping on a 32-bit long
*/
#include "fs.h"
#include <minix/com.h>
#include <minix/endpoint.h>
#include <unistd.h>
#include <stdlib.h>
#include "file.h"
#include "fproc.h"
#include "param.h"
#include "vmnt.h"
PRIVATE int panicking; /* inhibits recursive panics during sync */
/*===========================================================================*
* fetch_name *
*===========================================================================*/
PUBLIC int fetch_name(path, len, flag)
char *path; /* pointer to the path in user space */
int len; /* path length, including 0 byte */
int flag; /* M3 means path may be in message */
{
/* Go get path and put it in 'user_path'.
* If 'flag' = M3 and 'len' <= M3_STRING, the path is present in 'message'.
* If it is not, go copy it from user space.
*/
register char *rpu, *rpm;
int r;
if (len > PATH_MAX) {
err_code = ENAMETOOLONG;
return(EGENERIC);
}
if(len >= sizeof(user_fullpath)) {
panic(__FILE__, "fetch_name: len too much for user_fullpath", len);
}
/* Check name length for validity. */
if (len <= 0) {
err_code = EINVAL;
printf("vfs: fetch_name: len %d?\n", len);
return(EGENERIC);
}
if (flag == M3 && len <= M3_STRING) {
/* Just copy the path from the message to 'user_path'. */
rpu = &user_fullpath[0];
rpm = m_in.pathname; /* contained in input message */
do { *rpu++ = *rpm++; } while (--len);
r = OK;
} else {
/* String is not contained in the message. Get it from user space. */
r = sys_datacopy(who_e, (vir_bytes) path,
FS_PROC_NR, (vir_bytes) user_fullpath, (phys_bytes) len);
}
if(user_fullpath[len-1] != '\0') {
int i;
printf("vfs: fetch_name: name not null-terminated: ");
for(i = 0; i < len; i++) {
printf("%c", user_fullpath[i]);
}
printf("\n");
user_fullpath[len-1] = '\0';
}
return(r);
}
/*===========================================================================*
* no_sys *
*===========================================================================*/
PUBLIC int no_sys()
{
/* Somebody has used an illegal system call number */
printf("VFSno_sys: call %d from %d\n", call_nr, who_e);
return(SUSPEND);
}
/*===========================================================================*
* panic *
*===========================================================================*/
PUBLIC void panic(who, mess, num)
char *who; /* who caused the panic */
char *mess; /* panic message string */
int num; /* number to go with it */
{
if (!panicking) { /* do not panic during a sync */
panicking = TRUE; /* prevent another panic during the sync */
printf("VFS panic (%s): %s ", who, mess);
if (num != NO_NUM) printf("%d",num);
printf("\n");
(void) do_sync(); /* flush everything to the disk */
} else printf("VFS re-panic\n");
exit(1);
}
/*===========================================================================*
* isokendpt_f *
*===========================================================================*/
PUBLIC int isokendpt_f(char *file, int line, int endpoint, int *proc, int fatal)
{
int failed = 0;
*proc = _ENDPOINT_P(endpoint);
if(*proc < 0 || *proc >= NR_PROCS) {
printf("vfs:%s:%d: proc (%d) from endpoint (%d) out of range\n",
file, line, *proc, endpoint);
failed = 1;
} else if(fproc[*proc].fp_endpoint != endpoint) {
printf("vfs:%s:%d: proc (%d) from endpoint (%d) doesn't match "
"known endpoint (%d)\n",
file, line, *proc, endpoint, fproc[*proc].fp_endpoint);
failed = 1;
}
if(failed && fatal)
panic(__FILE__, "isokendpt_f failed", NO_NUM);
return failed ? EDEADSRCDST : OK;
}
/*===========================================================================*
* clock_time *
*===========================================================================*/
PUBLIC time_t clock_time()
{
/* This routine returns the time in seconds since 1.1.1970. MINIX is an
* astrophysically naive system that assumes the earth rotates at a constant
* rate and that such things as leap seconds do not exist.
*/
register int r;
clock_t uptime;
time_t boottime;
r= getuptime2(&uptime, &boottime);
if (r != OK)
panic(__FILE__,"clock_time err", r);
return( (time_t) (boottime + (uptime/HZ)));
}