/* Generate a string describing an enumerated bitfield (an N-bit field
with various specific values having particular names). */
const char *
decode_enumerated_bitfield(guint32 val, guint32 mask, int width,
const value_string *tab, const char *fmt)
{
static char buf[1025];
char *p;
p = decode_bitfield_value(buf, val, mask, width);
g_snprintf(p, (gulong) (1024-(p-buf)), fmt, val_to_str(val & mask, tab, "Unknown"));
return buf;
}
/*
* Decode the SAP value as a bitfield into a string, skipping the GI/CR bit.
* Ordinarily, this could be done easily by specifying a bitmask in the
* corresponding hf_ entry for the DSAP/SSAP value and simply using a
* proto_tree_add_... function to add the item into a proto tree. The
* problem is that the proto_tree_add_... functions always bitshift the
* value if a bitmask is specified. A SAP value always comprises the entire
* octet, however, and must not be shifted. Therefore, using a simple
* proto_tree_add_... function to display the topmost 7 bits of the SAP
* value as a bitfield produces incorrect results (while the bitfield is
* displayed correctly, Wireshark uses the bitshifted value to display the
* associated name and for filtering purposes). This function calls the
* Wireshark routine to decode the SAP value as a bitfield into a given
* string without performing any bitshift of the original value.
*
* The string passed to this function must be of ITEM_LABEL_LENGTH size.
* The SAP value passed to this function must be complete (not masked).
*
*/
static gchar *
decode_sap_value_as_bitfield(gchar *buffer, guint32 sap)
{
char *p;
memset (buffer, '\0', ITEM_LABEL_LENGTH);
p = decode_bitfield_value (buffer, sap, SAP_MASK, 8);
g_snprintf(p, (gulong)(ITEM_LABEL_LENGTH-strlen(buffer)-1), "SAP: %s",
val_to_str_const(sap, sap_vals, "Unknown"));
return buffer;
}
/* Generate a string describing an enumerated bitfield (an N-bit field
with various specific values having particular names). */
const char *
decode_enumerated_bitfield_shifted(guint32 val, guint32 mask, int width,
const value_string *tab, const char *fmt)
{
static char buf[1025];
char *p;
int shift = 0;
/* Compute the number of bits we have to shift the bitfield right
to extract its value. */
while ((mask & (1<<shift)) == 0)
shift++;
p = decode_bitfield_value(buf, val, mask, width);
g_snprintf(p, (gulong) (1024-(p-buf)), fmt, val_to_str((val & mask) >> shift, tab, "Unknown"));
return buf;
}
