Changeset 87337dc5 in mainline

Timestamp:

2018-07-09T15:00:24Z (6 years ago)

Author:

Jiri Svoboda <jiri@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

d054ad3

Parents:

914c693

git-author:

Jiri Svoboda <jiri@…> (2018-07-08 19:58:56)

git-committer:

Jiri Svoboda <jiri@…> (2018-07-09 15:00:24)

Message:

Random number generator interface. FAT and exFAT should be created with random volume serial numbers.

Location:

uspace

Files:

• app/mkexfat/mkexfat.c (modified) (5 diffs)
• app/mkfat/mkfat.c (modified) (9 diffs)
• lib/c/Makefile (modified) (1 diff)
• lib/c/generic/rndgen.c (added)
• lib/c/generic/uuid.c (modified) (3 diffs)
• lib/c/include/rndgen.h (added)

uspace/app/mkexfat/mkexfat.c

@@ -46 +46 @@
 #include <byteorder.h>
 #include <align.h>
+#include <rndgen.h>
 #include <str.h>
 #include <getopt.h>
@@ -243 +244 @@
  * @param mbs Pointer to the Main Boot Sector structure.
  * @param cfg Pointer to the exFAT configuration structure.
- * @return    Initial checksum value.
+ * @param chksum Place to store initial checksum value.
+ * @return EOK on success or error code
  */
 static uint32_t
-vbr_initialize(exfat_bs_t *mbs, exfat_cfg_t *cfg)
-{
+vbr_initialize(exfat_bs_t *mbs, exfat_cfg_t *cfg, uint32_t *chksum)
+{
+        rndgen_t *rndgen;
+        errno_t rc;
+        uint32_t vsn;
+
+        /* Generate volume serial number */
+
+        rc = rndgen_create(&rndgen);
+        if (rc != EOK)
+                return rc;
+
+        rc = rndgen_uint32(rndgen, &vsn);
+        if (rc != EOK) {
+                rndgen_destroy(rndgen);
+                return rc;
+        }
+
+        rndgen_destroy(rndgen);
+
         /* Fill the structure with zeroes */
         memset(mbs, 0, sizeof(exfat_bs_t));
@@ -268 +288 @@
 
         mbs->rootdir_cluster = host2uint32_t_le(cfg->rootdir_cluster);
-        mbs->volume_serial = host2uint32_t_le(0xe1028172);
+        mbs->volume_serial = host2uint32_t_le(vsn);
         mbs->version.major = 1;
         mbs->version.minor = 0;
@@ -283 +303 @@
         mbs->signature = host2uint16_t_le(0xAA55);
 
-        return vbr_checksum_start(mbs, sizeof(exfat_bs_t));
+        *chksum = vbr_checksum_start(mbs, sizeof(exfat_bs_t));
+        return EOK;
 }
 
@@ -299 +320 @@
                 return ENOMEM;
 
-        vbr_checksum = vbr_initialize(&mbs, cfg);
+        rc = vbr_initialize(&mbs, cfg, &vbr_checksum);
+        if (rc != EOK)
+                goto exit;
 
         /* Write the Main Boot Sector to disk */

uspace/app/mkfat/mkfat.c

@@ -48 +48 @@
 #include <inttypes.h>
 #include <errno.h>
+#include <rndgen.h>
 #include <str.h>
 #include "fat.h"
@@ -89 +90 @@
 static errno_t fat_params_compute(struct fat_cfg *cfg);
 static errno_t fat_blocks_write(struct fat_cfg const *cfg, service_id_t service_id);
-static void fat_bootsec_create(struct fat_cfg const *cfg, struct fat_bs *bs);
+static errno_t fat_bootsec_create(struct fat_cfg const *cfg, struct fat_bs *bs);
 
 int main(int argc, char **argv)
@@ -376 +377 @@
         fat_dentry_t *de;
 
-        fat_bootsec_create(cfg, &bs);
+        rc = fat_bootsec_create(cfg, &bs);
+        if (rc != EOK)
+                return rc;
 
         rc = block_write_direct(service_id, BS_BLOCK, 1, &bs);
@@ -442 +445 @@
                         (void) fat_label_encode(&de->name, cfg->label);
                         de->attr = FAT_ATTR_VOLLABEL;
-                        de->mtime = 0x1234;
-                        de->mdate = 0x1234;
+                        de->mtime = 0x1234; // XXX Proper time
+                        de->mdate = 0x1234; // XXX Proper date
                 } else if (idx == 1) {
                         /* Clear volume label entry */
@@ -462 +465 @@
 
 /** Construct boot sector with the given parameters. */
-static void fat_bootsec_create(struct fat_cfg const *cfg, struct fat_bs *bs)
+static errno_t fat_bootsec_create(struct fat_cfg const *cfg, struct fat_bs *bs)
 {
         const char *bs_label;
+        rndgen_t *rndgen;
+        uint32_t vsn;
+        errno_t rc;
+
+        /* Generate a volume serial number */
+        rc = rndgen_create(&rndgen);
+        if (rc != EOK)
+                return rc;
+
+        rc = rndgen_uint32(rndgen, &vsn);
+        if (rc != EOK) {
+                rndgen_destroy(rndgen);
+                return rc;
+        }
+
+        rndgen_destroy(rndgen);
 
         /*
@@ -503 +522 @@
         bs->hidden_sec = host2uint32_t_le(0);
 
+
         if (cfg->fat_type == FAT32) {
                 bs->sec_per_fat = 0;
@@ -509 +529 @@
                 bs->fat32.pdn = 0x80;
                 bs->fat32.ebs = 0x29;
-                bs->fat32.id = host2uint32_t_be(0x12345678);
+                bs->fat32.id = host2uint32_t_be(vsn);
                 bs->fat32.root_cluster = 2;
 
@@ -518 +538 @@
                 bs->pdn = 0x80;
                 bs->ebs = 0x29;
-                bs->id = host2uint32_t_be(0x12345678);
+                bs->id = host2uint32_t_be(vsn);
 
                 (void) fat_label_encode(&bs->label, bs_label);
@@ -526 +546 @@
                         memcpy(bs->type, "FAT16   ", 8);
         }
+
+        return EOK;
 }
 

uspace/lib/c/Makefile

@@ -133 +133 @@
         generic/double_to_str.c \
         generic/malloc.c \
+        generic/rndgen.c \
         generic/stdio/scanf.c \
         generic/stdio/sprintf.c \

uspace/lib/c/generic/uuid.c

@@ -35 +35 @@
 #include <errno.h>
 #include <uuid.h>
+#include <rndgen.h>
 #include <stdlib.h>
 #include <stddef.h>
-#include <time.h>
 #include <str.h>
 
@@ -48 +48 @@
 {
         int i;
-        struct timeval tv;
+        rndgen_t *rndgen;
+        errno_t rc;
 
-        /* XXX This is a rather poor way of generating random numbers */
-        gettimeofday(&tv, NULL);
-        srand(tv.tv_sec ^ tv.tv_usec);
+        rc = rndgen_create(&rndgen);
+        if (rc != EOK)
+                return EIO;
 
-        for (i = 0; i < uuid_bytes; i++)
-                uuid->b[i] = rand();
+        for (i = 0; i < uuid_bytes; i++) {
+                rc = rndgen_uint8(rndgen, &uuid->b[i]);
+                if (rc != EOK) {
+                        rc = EIO;
+                        goto error;
+                }
+        }
 
         /* Version 4 UUID from random or pseudo-random numbers */
@@ -62 +68 @@
 
         return EOK;
+error:
+        rndgen_destroy(rndgen);
+        return rc;
 }