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xcsl: Check encoding of characters 

Separate the tokens in xcsl using tvb_ws_mempbrk_pattern_guint8
instead of the dissector doing it manually.
Retrieve the ASCII token strings with tvb_get_string_enc to do
conversion to UTF-8.

Fix #18587
This commit is contained in:
John Thacker 2022-11-03 07:17:55 -04:00
parent 49d21db1a7
commit 5fa07d18ec
1 changed files with 15 additions and 35 deletions
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50
epan/dissectors/packet-xcsl.c
View File

@ -62,36 +62,8 @@ static const value_string xcsl_action_vals[] = {
{ 0, NULL }
};
/* This routine gets the next item from the ';' separated list */
static gboolean get_next_item(tvbuff_t *tvb, gint offset, gint maxlen, guint8 *str, gint *next_offset, guint *len)
{
guint idx = 0;
guint8 ch;
/* Obtain items */
while (maxlen > 1) {
ch = tvb_get_guint8(tvb, offset+idx);
if (ch == ';' || ch == '\r' || ch == '\n')
break;
/* Array protect */
if (idx == MAXLEN - 1) {
*next_offset = offset + idx;
*len = idx;
return FALSE;
}
/* Copy data into string array */
str[idx++] = ch;
maxlen--;
}
/* Null terminate the item */
str[idx] = '\0';
/* Update admin for next item */
*next_offset = offset + idx;
*len = idx;
return TRUE;
}
/* patterns used for tvb_ws_mempbrk_pattern_guint8 */
static ws_mempbrk_pattern pbrk_param_end;
/* Dissector for xcsl */
static void dissect_xcsl_tcp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree) {
@ -101,7 +73,7 @@ static void dissect_xcsl_tcp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree
guint8 idx;
gboolean request;
guint8 par;
guint8 str[MAXLEN];
guint8 *str;
guint8 result;
const gchar *code;
guint len;
@ -131,17 +103,22 @@ static void dissect_xcsl_tcp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree
while ((length_remaining = tvb_reported_length_remaining(tvb, offset)) > 0) {
/* get next item */
if (!(get_next_item(tvb, offset, length_remaining, str, &next_offset, &len))) {
/* do not continue when get_next_item returns false */
return;
next_offset = tvb_ws_mempbrk_pattern_guint8(tvb, offset, length_remaining, &pbrk_param_end, NULL);
if (next_offset == -1) {
len = length_remaining;
next_offset = offset + len;
} else {
len = next_offset - offset;
}
/* do not add to the tree when the string is of zero length */
if ( strlen(str) == 0 ) {
if ( len == 0 ) {
offset = next_offset + 1;
continue;
}
str = tvb_get_string_enc(pinfo->pool, tvb, offset, len, ENC_ASCII);
/* Xcsl (Call Specification Language) protocol in brief :
*
* Request :
@ -312,6 +289,9 @@ void proto_register_xcsl(void) {
proto_xcsl = proto_register_protocol("Call Specification Language (Xcsl)", "XCSL", "xcsl");
proto_register_field_array(proto_xcsl, hf, array_length(hf));
proto_register_subtree_array(ett, array_length(ett));
/* compile patterns */
ws_mempbrk_compile(&pbrk_param_end, ";\r\n");
}
/* In case it concerns TCP, try to match on the xcsl header */