unsigned char
tds_peek(TDSSOCKET * tds)
{
unsigned char result = tds_get_byte(tds);
if (tds->in_pos > 0)
--tds->in_pos;
return result;
} /* tds_peek() */
/**
* Read a TDS5 tokenized query.
*/
char *
tds_get_query(TDSSOCKET * tds)
{
int len;
if (query_buflen == 0) {
query_buflen = 1024;
query = (char *) malloc(query_buflen);
}
tds_get_byte(tds); /* 33 */
len = tds_get_int(tds); /* query size +1 */
tds_get_byte(tds); /* has args, ignored TODO */
assert(len >= 1); /* TODO handle correctly */
if (len > query_buflen) {
query_buflen = len;
query = (char *) realloc(query, query_buflen);
}
--len;
tds_get_n(tds, query, len);
query[len] = 0;
return query;
}
/**
* Read a query, and return it as an ASCII string with a \0 terminator. This
* should work for TDS4, TDS5, and TDS7+ connections. Also, it converts RPC
* calls into stored procedure queries, and it skips CANCEL packets. The query
* string is returned in a static buffer which is overwritten each time this
* function is called.
* \param tds The socket to read from.
* \return A query string if successful, or NULL if we either can't read from
* the socket or we read something that we can't handle.
*/
char *tds_get_generic_query(TDSSOCKET * tds)
{
int token, byte;
int len, more, i, j;
for (;;) {
/*
* Read a new packet. We must explicitly read it,
* instead of letting functions such as tds_get_byte()
* to read it for us, so that we can examine the packet
* type via tds->in_flag.
*/
if (tds_read_packet(tds) < 0) {
return NULL;
}
/* Queries can arrive in a couple different formats. */
switch (tds->in_flag) {
case TDS_RPC:
/* TODO */
case TDS_NORMAL: /* TDS5 query packet */
/* get the token */
token = tds_get_byte(tds);
switch (token) {
case TDS_LANGUAGE_TOKEN:
/* SQL query */
len = tds_get_int(tds); /* query size +1 */
assert(len >= 1); /* TODO handle */
tds_get_byte(tds); /* has args, ignored TODO */
if (len > query_buflen) {
query_buflen = len;
query = (char *) realloc(query, query_buflen);
}
--len;
tds_get_n(tds, query, len);
query[len] = 0;
return query;
case TDS_DBRPC_TOKEN:
/* RPC call -- make it look like a query */
/* skip the overall length */
(void)tds_get_smallint(tds);
/* get the length of the stored procedure's name */
len = tds_get_byte(tds) + 1;/* sproc name size +1 */
if (len > query_buflen) {
query_buflen = len;
query = (char *) realloc(query, query_buflen);
}
/*
* Read the chars of the name. Skip NUL
* bytes, as a cheap way to convert
* Unicode to ASCII. (For TDS7+, the
* name is sent in Unicode.)
*/
for (i = j = 0; i < len - 1; i++) {
byte = tds_get_byte(tds);
if (byte != '\0')
query[j++] = byte;
}
query[j] = '\0';
/* TODO: WE DON'T HANDLE PARAMETERS YET! */
/* eat the rest of the packet */
while (!tds_lastpacket(tds) && tds_read_packet(tds) > 0) {
}
return query;
default:
/* unexpected token */
/* eat the rest of the packet */
while (!tds_lastpacket(tds) && tds_read_packet(tds) > 0) {
}
return NULL;
}
break;
case TDS_QUERY:
/* TDS4 and TDS7+ fill the whole packet with a query */
len = 0;
for (;;) {
const char *src;
/* If buffer needs to grow, then grow */
more = tds->in_len - tds->in_pos;
src = (char *) (tds->in_buf + tds->in_pos);
if ((size_t)(len + more + 1) > query_buflen)
{
query_buflen = len + more + 1024u;
query_buflen -= query_buflen % 1024u;
query = (char *)realloc(query, query_buflen);
}
/*
* Pull new data into the query buffer.
* Ignore NUL bytes -- this is a cheap way
* to convert Unicode to Latin-1/ASCII.
*/
while (--more >= 0)
{
query[len] = *src++;
if (query[len] != '\0')
len++;
}
/* if more then read it */
if (tds_lastpacket(tds))
break;
if (tds_read_packet(tds) < 0)
return NULL;
}
/* add a NUL to mark the end */
query[len] = '\0';
return query;
case TDS_CANCEL:
/*
* ignore cancel requests -- if we're waiting
* for the next query then it's obviously too
* late to cancel the previous query.
*/
/* TODO it's not too late -- freddy77 */
break;
default:
/* not a query packet */
return NULL;
}
}
}
