339 lines
		
	
	
		
			10 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			339 lines
		
	
	
		
			10 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* This file contains the device dependent part of the drivers for the
 | |
|  * following special files:
 | |
|  *     /dev/random	- random number generator
 | |
|  */
 | |
| 
 | |
| #include "../drivers.h"
 | |
| #include "../libdriver/driver.h"
 | |
| #include <minix/type.h>
 | |
| 
 | |
| #include "assert.h"
 | |
| #include "random.h"
 | |
| 
 | |
| #define NR_DEVS            1		/* number of minor devices */
 | |
| #  define RANDOM_DEV  0			/* minor device for /dev/random */
 | |
| 
 | |
| #define KRANDOM_PERIOD    1 		/* ticks between krandom calls */
 | |
| 
 | |
| PRIVATE struct device m_geom[NR_DEVS];  /* base and size of each device */
 | |
| PRIVATE int m_device;			/* current device */
 | |
| 
 | |
| extern int errno;			/* error number for PM calls */
 | |
| 
 | |
| FORWARD _PROTOTYPE( char *r_name, (void) );
 | |
| FORWARD _PROTOTYPE( struct device *r_prepare, (int device) );
 | |
| FORWARD _PROTOTYPE( int r_transfer, (int proc_nr, int opcode, u64_t position,
 | |
| 				iovec_t *iov, unsigned nr_req) );
 | |
| FORWARD _PROTOTYPE( int r_do_open, (struct driver *dp, message *m_ptr) );
 | |
| FORWARD _PROTOTYPE( int r_ioctl, (struct driver *dp, message *m_ptr) );
 | |
| FORWARD _PROTOTYPE( void r_geometry, (struct partition *entry) );
 | |
| FORWARD _PROTOTYPE( void r_random, (struct driver *dp, message *m_ptr) );
 | |
| FORWARD _PROTOTYPE( void r_updatebin, (int source, struct k_randomness_bin *rb));
 | |
| 
 | |
| /* Entry points to this driver. */
 | |
| PRIVATE struct driver r_dtab = {
 | |
|   r_name,	/* current device's name */
 | |
|   r_do_open,	/* open or mount */
 | |
|   do_nop,	/* nothing on a close */
 | |
|   r_ioctl,	/* specify ram disk geometry */
 | |
|   r_prepare,	/* prepare for I/O on a given minor device */
 | |
|   r_transfer,	/* do the I/O */
 | |
|   nop_cleanup,	/* no need to clean up */
 | |
|   r_geometry,	/* device "geometry" */
 | |
|   nop_signal,	/* system signals */
 | |
|   r_random, 	/* get randomness from kernel (alarm) */
 | |
|   nop_cancel,
 | |
|   nop_select,
 | |
|   NULL,
 | |
|   NULL
 | |
| };
 | |
| 
 | |
| /* Buffer for the /dev/random number generator. */
 | |
| #define RANDOM_BUF_SIZE 		1024
 | |
| PRIVATE char random_buf[RANDOM_BUF_SIZE];
 | |
| 
 | |
| /* SEF functions and variables. */
 | |
| FORWARD _PROTOTYPE( void sef_local_startup, (void) );
 | |
| FORWARD _PROTOTYPE( int sef_cb_init_fresh, (int type, sef_init_info_t *info) );
 | |
| 
 | |
| /*===========================================================================*
 | |
|  *				   main 				     *
 | |
|  *===========================================================================*/
 | |
| PUBLIC int main(void)
 | |
| {
 | |
|   /* SEF local startup. */
 | |
|   sef_local_startup();
 | |
| 
 | |
|   /* Call the generic receive loop. */
 | |
|   driver_task(&r_dtab, DRIVER_ASYN);
 | |
| 
 | |
|   return(OK);
 | |
| }
 | |
| 
 | |
| /*===========================================================================*
 | |
|  *			       sef_local_startup			     *
 | |
|  *===========================================================================*/
 | |
| PRIVATE void sef_local_startup()
 | |
| {
 | |
|   /* Register init callbacks. */
 | |
|   sef_setcb_init_fresh(sef_cb_init_fresh);
 | |
|   sef_setcb_init_lu(sef_cb_init_fresh);
 | |
|   sef_setcb_init_restart(sef_cb_init_fresh);
 | |
| 
 | |
|   /* Register live update callbacks. */
 | |
|   sef_setcb_lu_prepare(sef_cb_lu_prepare_always_ready);
 | |
|   sef_setcb_lu_state_isvalid(sef_cb_lu_state_isvalid_standard);
 | |
| 
 | |
|   /* Let SEF perform startup. */
 | |
|   sef_startup();
 | |
| }
 | |
| 
 | |
| /*===========================================================================*
 | |
|  *		            sef_cb_init_fresh                                *
 | |
|  *===========================================================================*/
 | |
| PRIVATE int sef_cb_init_fresh(int type, sef_init_info_t *info)
 | |
| {
 | |
| /* Initialize the random driver. */
 | |
|   static struct k_randomness krandom;
 | |
|   int i, s;
 | |
| 
 | |
|   random_init();
 | |
|   r_random(NULL, NULL);				/* also set periodic timer */
 | |
| 
 | |
|   /* Retrieve first randomness buffer with parameters. */
 | |
|   if (OK != (s=sys_getrandomness(&krandom))) {
 | |
|   	report("RANDOM", "sys_getrandomness failed", s);
 | |
| 	exit(1);
 | |
|   }
 | |
| 
 | |
|   /* Do sanity check on parameters. */
 | |
|   if(krandom.random_sources != RANDOM_SOURCES ||
 | |
|      krandom.random_elements != RANDOM_ELEMENTS) {
 | |
|      printf("random: parameters (%d, %d) don't match kernel's (%d, %d)\n",
 | |
| 	RANDOM_SOURCES, RANDOM_ELEMENTS,
 | |
| 	krandom.random_sources, krandom.random_elements);
 | |
|      exit(1);
 | |
|   }
 | |
| 
 | |
|   /* Feed initial batch. */
 | |
|   for(i = 0; i < RANDOM_SOURCES; i++)
 | |
| 	r_updatebin(i, &krandom.bin[i]);
 | |
| 
 | |
|   return(OK);
 | |
| }
 | |
| 
 | |
| /*===========================================================================*
 | |
|  *				 r_name					     *
 | |
|  *===========================================================================*/
 | |
| PRIVATE char *r_name()
 | |
| {
 | |
| /* Return a name for the current device. */
 | |
|   static char name[] = "random";
 | |
|   return name;  
 | |
| }
 | |
| 
 | |
| /*===========================================================================*
 | |
|  *				r_prepare				     *
 | |
|  *===========================================================================*/
 | |
| PRIVATE struct device *r_prepare(device)
 | |
| int device;
 | |
| {
 | |
| /* Prepare for I/O on a device: check if the minor device number is ok. */
 | |
| 
 | |
|   if (device < 0 || device >= NR_DEVS) return(NIL_DEV);
 | |
|   m_device = device;
 | |
| 
 | |
|   return(&m_geom[device]);
 | |
| }
 | |
| 
 | |
| /*===========================================================================*
 | |
|  *				r_transfer				     *
 | |
|  *===========================================================================*/
 | |
| PRIVATE int r_transfer(proc_nr, opcode, position, iov, nr_req)
 | |
| int proc_nr;			/* process doing the request */
 | |
| int opcode;			/* DEV_GATHER or DEV_SCATTER */
 | |
| u64_t position;			/* offset on device to read or write */
 | |
| iovec_t *iov;			/* pointer to read or write request vector */
 | |
| unsigned nr_req;		/* length of request vector */
 | |
| {
 | |
| /* Read or write one the driver's minor devices. */
 | |
|   unsigned count, left, chunk;
 | |
|   vir_bytes user_vir;
 | |
|   struct device *dv;
 | |
|   unsigned long dv_size;
 | |
|   int r;
 | |
|   size_t vir_offset = 0;
 | |
| 
 | |
|   /* Get minor device number and check for /dev/null. */
 | |
|   dv = &m_geom[m_device];
 | |
|   dv_size = cv64ul(dv->dv_size);
 | |
| 
 | |
|   while (nr_req > 0) {
 | |
| 
 | |
| 	/* How much to transfer and where to / from. */
 | |
| 	count = iov->iov_size;
 | |
| 	user_vir = iov->iov_addr;
 | |
| 
 | |
| 	switch (m_device) {
 | |
| 
 | |
| 	/* Random number generator. Character instead of block device. */
 | |
| 	case RANDOM_DEV:
 | |
| 	    if (opcode == DEV_GATHER_S && !random_isseeded())
 | |
| 		    return(EAGAIN);
 | |
| 	    left = count;
 | |
| 	    while (left > 0) {
 | |
| 	    	chunk = (left > RANDOM_BUF_SIZE) ? RANDOM_BUF_SIZE : left;
 | |
|  	        if (opcode == DEV_GATHER_S) {
 | |
| 		    random_getbytes(random_buf, chunk);
 | |
| 		    r= sys_safecopyto(proc_nr, user_vir, vir_offset,
 | |
| 			(vir_bytes) random_buf, chunk, D);
 | |
| 		    if (r != OK)
 | |
| 		    {
 | |
| 			printf(
 | |
| 			"random: sys_safecopyto failed for proc %d, grant %d\n",
 | |
| 				proc_nr, user_vir);
 | |
| 			return r;
 | |
| 		    }
 | |
|  	        } else if (opcode == DEV_SCATTER_S) {
 | |
| 		    r= sys_safecopyfrom(proc_nr, user_vir, vir_offset,
 | |
| 			(vir_bytes) random_buf, chunk, D);
 | |
| 		    if (r != OK)
 | |
| 		    {
 | |
| 			printf(
 | |
| 		"random: sys_safecopyfrom failed for proc %d, grant %d\n",
 | |
| 				proc_nr, user_vir);
 | |
| 			return r;
 | |
| 		    }
 | |
| 	    	    random_putbytes(random_buf, chunk);
 | |
|  	        }
 | |
|  	        vir_offset += chunk;
 | |
| 	    	left -= chunk;
 | |
| 	    }
 | |
| 	    break;
 | |
| 
 | |
| 	/* Unknown (illegal) minor device. */
 | |
| 	default:
 | |
| 	    return(EINVAL);
 | |
| 	}
 | |
| 
 | |
| 	/* Book the number of bytes transferred. */
 | |
| 	position= add64u(position, count);
 | |
|   	if ((iov->iov_size -= count) == 0) { iov++; nr_req--; vir_offset = 0; }
 | |
| 
 | |
|   }
 | |
|   return(OK);
 | |
| }
 | |
| 
 | |
| /*============================================================================*
 | |
|  *				r_do_open				      *
 | |
|  *============================================================================*/
 | |
| PRIVATE int r_do_open(dp, m_ptr)
 | |
| struct driver *dp;
 | |
| message *m_ptr;
 | |
| {
 | |
| /* Check device number on open.  
 | |
|  */
 | |
|   if (r_prepare(m_ptr->DEVICE) == NIL_DEV) return(ENXIO);
 | |
| 
 | |
|   return(OK);
 | |
| }
 | |
| 
 | |
| /*===========================================================================*
 | |
|  *				r_ioctl					     *
 | |
|  *===========================================================================*/
 | |
| PRIVATE int r_ioctl(dp, m_ptr)
 | |
| struct driver *dp;			/* pointer to driver structure */
 | |
| message *m_ptr;				/* pointer to control message */
 | |
| {
 | |
|   struct device *dv;
 | |
|   if ((dv = r_prepare(m_ptr->DEVICE)) == NIL_DEV) return(ENXIO);
 | |
| 
 | |
|   switch (m_ptr->REQUEST) {
 | |
| 
 | |
|     default:
 | |
|   	return(do_diocntl(&r_dtab, m_ptr));
 | |
|   }
 | |
|   return(OK);
 | |
| }
 | |
| 
 | |
| #define UPDATE(binnumber, bp, startitem, elems) 	{	\
 | |
| 		rand_t *r, *r2;					\
 | |
| 		int n = elems, item = startitem;\
 | |
| 		int high;					\
 | |
| 		assert(binnumber >= 0 && binnumber < RANDOM_SOURCES);	 \
 | |
| 		assert(item >= 0 && item < RANDOM_ELEMENTS);	\
 | |
| 		if(n > 0) {					\
 | |
| 			high = item+n-1;			\
 | |
| 			assert(high >= item);				\
 | |
| 			assert(high >= 0 && high < RANDOM_ELEMENTS);	\
 | |
| 			r = &bp->r_buf[item];		\
 | |
| 			r2 = &bp->r_buf[high];		\
 | |
| 	  		random_update(binnumber, r, n);			\
 | |
| 		}							\
 | |
| }
 | |
| 
 | |
| PRIVATE void r_updatebin(int source, struct k_randomness_bin *rb)
 | |
| {
 | |
|   	int r_next, r_size, r_high;
 | |
| 
 | |
|   	r_next= rb->r_next;
 | |
|   	r_size= rb->r_size;
 | |
| 
 | |
| 	assert(r_next >= 0 && r_next < RANDOM_ELEMENTS);
 | |
| 	assert(r_size >= 0 && r_size <= RANDOM_ELEMENTS);
 | |
| 
 | |
|   	r_high= r_next+r_size;
 | |
| 
 | |
|   	if (r_high <= RANDOM_ELEMENTS) {
 | |
| 		UPDATE(source, rb, r_next, r_size);
 | |
| 	} else {
 | |
| 		assert(r_next < RANDOM_ELEMENTS);
 | |
| 		UPDATE(source, rb, r_next, RANDOM_ELEMENTS-r_next);
 | |
| 		UPDATE(source, rb, 0, r_high-RANDOM_ELEMENTS);
 | |
| 	}
 | |
| 
 | |
| 	return;
 | |
| }
 | |
| 
 | |
| /*============================================================================*
 | |
|  *				r_random				      *
 | |
|  *============================================================================*/
 | |
| PRIVATE void r_random(dp, m_ptr)
 | |
| struct driver *dp;			/* pointer to driver structure */
 | |
| message *m_ptr;				/* pointer to alarm message */
 | |
| {
 | |
|   /* Fetch random information from the kernel to update /dev/random. */
 | |
|   int s;
 | |
|   static int bin = 0;
 | |
|   static struct k_randomness_bin krandom_bin;
 | |
|   u32_t hi, lo;
 | |
|   rand_t r;
 | |
| 
 | |
|   bin = (bin+1) % RANDOM_SOURCES;
 | |
| 
 | |
|   if(sys_getrandom_bin(&krandom_bin, bin) == OK)
 | |
| 	r_updatebin(bin, &krandom_bin);
 | |
| 
 | |
|   /* Add our own timing source. */
 | |
|   read_tsc(&hi, &lo);
 | |
|   r = lo;
 | |
|   random_update(RND_TIMING, &r, 1);
 | |
| 
 | |
|   /* Schedule new alarm for next m_random call. */
 | |
|   if (OK != (s=sys_setalarm(KRANDOM_PERIOD, 0)))
 | |
|   	report("RANDOM", "sys_setalarm failed", s);
 | |
| }
 | |
| 
 | |
| /*============================================================================*
 | |
|  *				r_geometry				      *
 | |
|  *============================================================================*/
 | |
| PRIVATE void r_geometry(entry)
 | |
| struct partition *entry;
 | |
| {
 | |
|   /* Memory devices don't have a geometry, but the outside world insists. */
 | |
|   entry->cylinders = div64u(m_geom[m_device].dv_size, SECTOR_SIZE) / (64 * 32);
 | |
|   entry->heads = 64;
 | |
|   entry->sectors = 32;
 | |
| }
 | |
| 
 | 
