livefiles_hfs_plugin/lf_hfs_utils.c

   1 /*  Copyright © 2017-2018 Apple Inc. All rights reserved.
   2  *
   3  *  lf_hfs_utils.c
   4  *  livefiles_hfs
   5  *
   6  *  Created by Yakov Ben Zaken on 19/03/2018.
   7  */
   8
   9 #include "lf_hfs_utils.h"
  10 #include "lf_hfs_vfsutils.h"
  11
  12 /*
  13  * General routine to allocate a hash table.
  14  */
  15 void *
  16 hashinit(int elements, u_long *hashmask)
  17 {
  18     int hashsize = 0;
  19     LIST_HEAD(generic, generic) *hashtbl;
  20     int i;
  21
  22     if (elements <= 0)
  23         return NULL;
  24     for (hashsize = 1; hashsize <= elements; hashsize <<= 1)
  25     {
  26         continue;
  27     }
  28
  29     hashsize >>= 1;
  30     hashtbl = hfs_malloc(hashsize * sizeof(*hashtbl));
  31     if (hashtbl != NULL)
  32     {
  33         for (i = 0; i < hashsize; i++)
  34         {
  35             LIST_INIT(&hashtbl[i]);
  36         }
  37         *hashmask = hashsize - 1;
  38     }
  39     return (hashtbl);
  40 }
  41
  42 /*
  43  * General routine to free a hash table.
  44  */
  45 void
  46 hashDeinit(void* pvHashTbl)
  47 {
  48     LIST_HEAD(generic, generic) *hashtbl = pvHashTbl;
  49     hfs_free(hashtbl);
  50 }
  51
  52 /*
  53  * to_bsd_time - convert from Mac OS time (seconds since 1/1/1904)
  54  *         to BSD time (seconds since 1/1/1970)
  55  */
  56 time_t
  57 to_bsd_time(u_int32_t hfs_time)
  58 {
  59     u_int32_t gmt = hfs_time;
  60
  61     if (gmt > MAC_GMT_FACTOR)
  62         gmt -= MAC_GMT_FACTOR;
  63     else
  64         gmt = 0;    /* don't let date go negative! */
  65
  66     return (time_t)gmt;
  67 }
  68
  69 /*
  70  * to_hfs_time - convert from BSD time (seconds since 1/1/1970)
  71  *         to Mac OS time (seconds since 1/1/1904)
  72  */
  73 u_int32_t
  74 to_hfs_time(time_t bsd_time)
  75 {
  76     u_int32_t hfs_time = (u_int32_t)bsd_time;
  77
  78     /* don't adjust zero - treat as uninitialzed */
  79     if (hfs_time != 0)
  80         hfs_time += MAC_GMT_FACTOR;
  81
  82     return (hfs_time);
  83 }
  84
  85 void
  86 microuptime(struct timeval *tvp)
  87 {
  88     struct timespec ts;
  89     clock_gettime( CLOCK_MONOTONIC, &ts );
  90     TIMESPEC_TO_TIMEVAL(tvp, &ts);
  91 }
  92
  93 void
  94 microtime(struct timeval *tvp)
  95 {
  96     struct timespec ts;
  97     clock_gettime( CLOCK_REALTIME, &ts );
  98     TIMESPEC_TO_TIMEVAL(tvp, &ts);
  99 }
 100
 101 void* lf_hfs_utils_allocate_and_copy_string( char *pcName, size_t uLen )
 102 {
 103     //Check the validity of the uLen
 104     if (uLen > kHFSPlusMaxFileNameChars) {
 105         return NULL;
 106     }
 107
 108     //Checkk the validity of the pcName
 109     if (strlen(pcName) != uLen) {
 110         return NULL;
 111     }
 112
 113     void *pvTmp = hfs_malloc( uLen+1 );
 114     if ( pvTmp == NULL ) {
 115         return NULL;
 116     }
 117
 118     memcpy(pvTmp, pcName, uLen);
 119     //Add Null terminated at the end of the name
 120     char *pcLastChar = pvTmp + uLen;
 121     *pcLastChar = '\0';
 122
 123     return pvTmp;
 124 }
 125
 126 off_t
 127 blk_to_bytes(uint32_t blk, uint32_t blk_size)
 128 {
 129     return (off_t)blk * blk_size;         // Avoid the overflow
 130 }