 13ef7f1f38
			
		
	
	
		13ef7f1f38
		
	
	
	
	
		
			
			file descriptor passing, PFS does some back calls to VFS. For example, to verify the validity of a path provided by a process and to tell VFS it must copy file descriptors from one process to another.
		
			
				
	
	
		
			160 lines
		
	
	
		
			4.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			160 lines
		
	
	
		
			4.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* This file contains a few general purpose utility routines.
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|  *
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|  * The entry points into this file are
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|  *   clock_time:  ask the clock task for the real time
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|  *   copy:	  copy a block of data
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|  *   fetch_name:  go get a path name from user space
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|  *   no_sys:      reject a system call that FS does not handle
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|  *   panic:       something awful has occurred;  MINIX cannot continue
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|  *   conv2:	  do byte swapping on a 16-bit int
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|  *   conv4:	  do byte swapping on a 32-bit long
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|  *   in_group:    determines if group 'grp' is in rfp->fp_sgroups[]
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|  */
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| 
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| #include "fs.h"
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| #include <minix/com.h>
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| #include <minix/endpoint.h>
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| #include <unistd.h>
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| #include <stdlib.h>
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| #include <assert.h>
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| #include "file.h"
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| #include "fproc.h"
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| #include "param.h"
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| #include "vmnt.h"
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| 
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| /*===========================================================================*
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|  *				fetch_name				     *
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|  *===========================================================================*/
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| PUBLIC int fetch_name(path, len, flag)
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| char *path;			/* pointer to the path in user space */
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| int len;			/* path length, including 0 byte */
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| int flag;			/* M3 means path may be in message */
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| {
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| /* Go get path and put it in 'user_fullpath'.
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|  * If 'flag' = M3 and 'len' <= M3_STRING, the path is present in 'message'.
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|  * If it is not, go copy it from user space.
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|  */
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|   register char *rpu, *rpm;
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|   int r, count;
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| 
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|   if (len > PATH_MAX) {
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| 	err_code = ENAMETOOLONG;
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| 	return(EGENERIC);
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|   }
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| 
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|   if(len >= sizeof(user_fullpath)) 
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| 	panic("fetch_name: len too much for user_fullpath: %d", len);
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| 
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|   /* Check name length for validity. */
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|   if (len <= 0) {
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| 	err_code = EINVAL;
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| 	return(EGENERIC);
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|   }
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| 
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|   if (flag == M3 && len <= M3_STRING) {
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| 	/* Just copy the path from the message to 'user_fullpath'. */
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| 	rpu = &user_fullpath[0];
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| 	rpm = m_in.pathname;		/* contained in input message */
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| 	count = len;
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| 	do { *rpu++ = *rpm++; } while (--count);
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| 	r = OK;
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|   } else {
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| 	/* String is not contained in the message.  Get it from user space. */
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| 	r = sys_datacopy(who_e, (vir_bytes) path,
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| 		VFS_PROC_NR, (vir_bytes) user_fullpath, (phys_bytes) len);
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|   }
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| 
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|   if (user_fullpath[len - 1] != '\0') {
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|   	err_code = ENAMETOOLONG;
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|   	return(EGENERIC);
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|   }
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| 
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|   return(r);
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| }
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| 
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| 
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| /*===========================================================================*
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|  *				no_sys					     *
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|  *===========================================================================*/
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| PUBLIC int no_sys()
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| {
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| /* Somebody has used an illegal system call number */
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|   printf("VFS no_sys: call %d from %d (pid %d)\n", call_nr, who_e, who_p);
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|   return(ENOSYS);
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| }
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| 
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| 
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| /*===========================================================================*
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|  *				isokendpt_f				     *
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|  *===========================================================================*/
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| PUBLIC int isokendpt_f(char *file, int line, endpoint_t endpoint, int *proc, int fatal)
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| {
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|   int failed = 0;
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|   endpoint_t ke;
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|   *proc = _ENDPOINT_P(endpoint);
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|   if(endpoint == NONE) {
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| 	printf("vfs:%s:%d: endpoint is NONE\n", file, line);
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| 	failed = 1;
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|   } else if(*proc < 0 || *proc >= NR_PROCS) {
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| 	printf("vfs:%s:%d: proc (%d) from endpoint (%d) out of range\n",
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| 		file, line, *proc, endpoint);
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| 	failed = 1;
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|   } else if((ke=fproc[*proc].fp_endpoint) != endpoint) {
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| 	if(ke == NONE) {
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| 		printf("vfs:%s:%d: endpoint (%d) points to NONE slot (%d)\n",
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|                 	file, line, endpoint, *proc);
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| 		assert(fproc[*proc].fp_pid == PID_FREE);
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|   	} else {
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| 		printf("vfs:%s:%d: proc (%d) from endpoint (%d) doesn't match "
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| 			"known endpoint (%d)\n", file, line, *proc, endpoint,
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| 			fproc[*proc].fp_endpoint);
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| 		assert(fproc[*proc].fp_pid != PID_FREE);
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| 	}
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| 	failed = 1;
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|   }
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| 
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|   if(failed && fatal)
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| 	panic("isokendpt_f failed");
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| 
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|   return(failed ? EDEADEPT : OK);
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| }
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| 
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| 
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| /*===========================================================================*
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|  *				clock_time				     *
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|  *===========================================================================*/
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| PUBLIC time_t clock_time()
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| {
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| /* This routine returns the time in seconds since 1.1.1970.  MINIX is an
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|  * astrophysically naive system that assumes the earth rotates at a constant
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|  * rate and that such things as leap seconds do not exist.
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|  */
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| 
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|   register int r;
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|   clock_t uptime;
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|   time_t boottime;
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| 
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|   r = getuptime2(&uptime, &boottime);
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|   if (r != OK)
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| 	panic("clock_time err: %d", r);
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| 
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|   return( (time_t) (boottime + (uptime/system_hz)));
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| }
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| 
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| /*===========================================================================*
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|  *                              in_group                                     *
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|  *===========================================================================*/
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| PUBLIC int in_group(struct fproc *rfp, gid_t grp)
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| {
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|   int i;
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| 
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|   for (i = 0; i < rfp->fp_ngroups; i++) {
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| 	if (rfp->fp_sgroups[i] == grp) {
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| 		return(OK);
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| 	}
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|   }
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| 
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|   return(EINVAL);
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| }
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| 
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