minix/servers/vfs/utility.c
2012-02-13 16:53:21 +00:00

153 lines
4.5 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
* in_group: determines if group 'grp' is in rfp->fp_sgroups[]
*/
#include "fs.h"
#include <minix/com.h>
#include <minix/endpoint.h>
#include <unistd.h>
#include <stdlib.h>
#include <assert.h>
#include "file.h"
#include "fproc.h"
#include "param.h"
#include "vmnt.h"
/*===========================================================================*
* fetch_name *
*===========================================================================*/
PUBLIC int fetch_name(path, len, flag, dest)
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 */
char *dest; /* pointer to where path is to be stored */
{
/* Go get path and put it in 'user_fullpath'.
* 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, count;
if (len > PATH_MAX) { /* 'len' includes terminating-nul */
err_code = ENAMETOOLONG;
return(EGENERIC);
}
/* Check name length for validity. */
if (len <= 0) {
err_code = EINVAL;
return(EGENERIC);
}
if (flag == M3 && len <= M3_STRING) {
/* Just copy the path from the message to 'user_fullpath'. */
rpu = &dest[0];
rpm = m_in.pathname; /* contained in input message */
count = len;
do { *rpu++ = *rpm++; } while (--count);
r = OK;
} else {
/* String is not contained in the message. Get it from user space. */
r = sys_datacopy(who_e, (vir_bytes) path,
VFS_PROC_NR, (vir_bytes) dest, (phys_bytes) len);
}
if (dest[len - 1] != '\0') {
err_code = ENAMETOOLONG;
return(EGENERIC);
}
return(r);
}
/*===========================================================================*
* no_sys *
*===========================================================================*/
PUBLIC int no_sys()
{
/* Somebody has used an illegal system call number */
return(ENOSYS);
}
/*===========================================================================*
* isokendpt_f *
*===========================================================================*/
PUBLIC int isokendpt_f(char *file, int line, endpoint_t endpoint, int *proc, int fatal)
{
int failed = 0;
endpoint_t ke;
*proc = _ENDPOINT_P(endpoint);
if (endpoint == NONE) {
printf("VFS %s:%d: endpoint is NONE\n", file, line);
failed = 1;
} else 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 ((ke = fproc[*proc].fp_endpoint) != endpoint) {
if(ke == NONE) {
printf("VFS %s:%d: endpoint (%d) points to NONE slot (%d)\n",
file, line, endpoint, *proc);
assert(fproc[*proc].fp_pid == PID_FREE);
} else {
printf("VFS %s:%d: proc (%d) from endpoint (%d) doesn't match "
"known endpoint (%d)\n", file, line, *proc, endpoint,
fproc[*proc].fp_endpoint);
assert(fproc[*proc].fp_pid != PID_FREE);
}
failed = 1;
}
if(failed && fatal)
panic("isokendpt_f failed");
return(failed ? EDEADEPT : 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("clock_time err: %d", r);
return( (time_t) (boottime + (uptime/system_hz)));
}
/*===========================================================================*
* in_group *
*===========================================================================*/
PUBLIC int in_group(struct fproc *rfp, gid_t grp)
{
int i;
for (i = 0; i < rfp->fp_ngroups; i++)
if (rfp->fp_sgroups[i] == grp)
return(OK);
return(EINVAL);
}