minix/lib/libfsdriver/utility.c

   1
   2 #include "fsdriver.h"
   3
   4 /*
   5  * Copy data from the caller into the local address space.
   6  */
   7 int
   8 fsdriver_copyin(const struct fsdriver_data * data, size_t off, void * ptr,
   9         size_t len)
  10 {
  11
  12         /* Do nothing for peek requests. */
  13         if (data == NULL)
  14                 return OK;
  15
  16         /* The data size field is used only for this integrity check. */
  17         if (off + len > data->size)
  18                 panic("fsdriver: copy-in buffer overflow");
  19
  20         if (data->endpt == SELF) {
  21                 memcpy(ptr, &data->ptr[off], len);
  22
  23                 return OK;
  24         }
  25
  26         return sys_safecopyfrom(data->endpt, data->grant, off, (vir_bytes)ptr,
  27             (phys_bytes)len);
  28 }
  29
  30 /*
  31  * Copy data from the local address space to the caller.
  32  */
  33 int
  34 fsdriver_copyout(const struct fsdriver_data * data, size_t off,
  35         const void * ptr, size_t len)
  36 {
  37
  38         /* Do nothing for peek requests. */
  39         if (data == NULL)
  40                 return OK;
  41
  42         /* The data size field is used only for this integrity check. */
  43         if (off + len > data->size)
  44                 panic("fsdriver: copy-out buffer overflow");
  45
  46         if (data->endpt == SELF) {
  47                 memcpy(&data->ptr[off], ptr, len);
  48
  49                 return OK;
  50         }
  51
  52         return sys_safecopyto(data->endpt, data->grant, off, (vir_bytes)ptr,
  53             (phys_bytes)len);
  54 }
  55
  56 /*
  57  * Zero out a data region in the caller.
  58  */
  59 int
  60 fsdriver_zero(const struct fsdriver_data * data, size_t off, size_t len)
  61 {
  62
  63         /* Do nothing for peek requests. */
  64         if (data == NULL)
  65                 return OK;
  66
  67         /* The data size field is used only for this integrity check. */
  68         if (off + len > data->size)
  69                 panic("fsdriver: copy-out buffer overflow");
  70
  71         if (data->endpt == SELF) {
  72                 memset(&data->ptr[off], 0, len);
  73
  74                 return OK;
  75         }
  76
  77         return sys_safememset(data->endpt, data->grant, off, 0, len);
  78 }
  79
  80 /*
  81  * Copy in a null-terminated name, and perform sanity checks.
  82  */
  83 int
  84 fsdriver_getname(endpoint_t endpt, cp_grant_id_t grant, size_t len,
  85         char * name, size_t size, int not_empty)
  86 {
  87         int r;
  88
  89         /* The given length includes the null terminator. */
  90         if (len == 0 || (not_empty && len == 1))
  91                 return EINVAL;
  92         if (len > size)
  93                 return ENAMETOOLONG;
  94
  95         if ((r = sys_safecopyfrom(endpt, grant, 0, (vir_bytes)name,
  96             (phys_bytes)len)) != OK)
  97                 return r;
  98
  99         if (name[len - 1] != 0) {
 100                 printf("fsdriver: name not null-terminated\n");
 101                 return EINVAL;
 102         }
 103
 104         return OK;
 105 }