firebird/firebird-mirror
firebird/firebird-mirror
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Code Issues

Slightly refactored the BLR parser routines to avoid crazy error reporting and protect against NULL pointer dereference. The error handling still sucks, but it was the case before me ;-)

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This commit is contained in:
dimitr 2015-01-05 16:08:21 +00:00
parent bf8ed546e4
commit 5d3fd3dbe0
4 changed files with 333 additions and 326 deletions
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63
src/remote/client/interface.cpp
View File

@ -1203,9 +1203,8 @@ Firebird::IRequest* Attachment::compileRequest(IStatus* status,
RMessage* message = PARSE_messages(blr, blr_length);
USHORT max_msg = 0;
for (next = message; next; next = next->msg_next) {
for (next = message; next; next = next->msg_next)
max_msg = MAX(max_msg, next->msg_number);
}
// Allocate request block
Rrq* request = new Rrq(max_msg + 1);
@ -1737,14 +1736,7 @@ Firebird::ITransaction* Statement::execute(IStatus* status, Firebird::ITransacti
// Parse the blr describing the message, if there is any.
if (in_blr_length)
{
RMessage* message = PARSE_messages(in_blr, in_blr_length);
if (message != (RMessage*) - 1)
{
statement->rsr_bind_format = (rem_fmt*) message->msg_address;
delete message;
}
}
statement->rsr_bind_format = PARSE_msg_format(in_blr, in_blr_length);
// Parse the blr describing the output message. This is not the fetch
// message! That comes later.
@ -1754,12 +1746,7 @@ Firebird::ITransaction* Statement::execute(IStatus* status, Firebird::ITransacti
if (!port->port_statement)
port->port_statement = new Rsr;
RMessage* message = PARSE_messages(out_blr, out_blr_length);
if (message != (RMessage*) - 1)
{
port->port_statement->rsr_select_format = (rem_fmt*) message->msg_address;
delete message;
}
port->port_statement->rsr_select_format = PARSE_msg_format(out_blr, out_blr_length);
if (!port->port_statement->rsr_buffer)
{
@ -1932,14 +1919,7 @@ ResultSet* Statement::openCursor(IStatus* status, Firebird::ITransaction* apiTra
// Parse the blr describing the message, if there is any.
if (in_blr_length)
{
RMessage* message = PARSE_messages(in_blr, in_blr_length);
if (message != (RMessage*) -1)
{
statement->rsr_bind_format = (rem_fmt*) message->msg_address;
delete message;
}
}
statement->rsr_bind_format = PARSE_msg_format(in_blr, in_blr_length);
RMessage* message = NULL;
if (!statement->rsr_buffer)
@ -2113,23 +2093,10 @@ ITransaction* Attachment::execute(IStatus* status, ITransaction* apiTra,
if (in_msg_length || out_msg_length)
{
if (in_blr_length)
{
RMessage* message = PARSE_messages(in_blr, in_blr_length);
if (message != (RMessage*) - 1)
{
statement->rsr_bind_format = (rem_fmt*) message->msg_address;
delete message;
}
}
statement->rsr_bind_format = PARSE_msg_format(in_blr, in_blr_length);
if (out_blr_length)
{
RMessage* message = PARSE_messages(out_blr, out_blr_length);
if (message != (RMessage*) - 1)
{
statement->rsr_select_format = (rem_fmt*) message->msg_address;
delete message;
}
}
statement->rsr_select_format = PARSE_msg_format(out_blr, out_blr_length);
}
RMessage* message = 0;
@ -2830,14 +2797,9 @@ int ResultSet::fetchNext(IStatus* status, void* buffer)
{
delete statement->rsr_user_select_format;
}
RMessage* message = PARSE_messages(blr, blr_length);
if (message != (RMessage*) - 1)
{
statement->rsr_user_select_format = (rem_fmt*) message->msg_address;
delete message;
}
else
statement->rsr_user_select_format = NULL;
statement->rsr_user_select_format = PARSE_msg_format(blr, blr_length);
if (statement->rsr_flags.test(Rsr::FETCHED))
blr_length = 0;
else
@ -5034,8 +4996,6 @@ void Attachment::transactRequest(IStatus* status, ITransaction* apiTra,
procedure->rpr_out_format = NULL;
RMessage* message = PARSE_messages(blr, blr_length);
if (message != (RMessage*) - 1)
{
while (message)
{
switch (message->msg_number)
@ -5061,9 +5021,6 @@ void Attachment::transactRequest(IStatus* status, ITransaction* apiTra,
break;
}
}
}
//else
// error
PACKET* packet = &rdb->rdb_packet;

1
src/remote/parse_proto.h
View File

@ -25,5 +25,6 @@
#define REMOTE_PARSE_PROTO_H
struct RMessage* PARSE_messages(const UCHAR*, size_t);
struct rem_fmt* PARSE_msg_format(const UCHAR*, size_t);
#endif // REMOTE_PARSE_PROTO_H

165
src/remote/parser.cpp
View File

@ -36,7 +36,7 @@
#endif
static RMessage* parse_error(rem_fmt* format, RMessage* mesage);
static rem_fmt* parse_format(const UCHAR*& blr, size_t& blr_length);
RMessage* PARSE_messages(const UCHAR* blr, size_t blr_length)
@ -49,50 +49,129 @@ RMessage* PARSE_messages(const UCHAR* blr, size_t blr_length)
*
* Functional description
* Parse the messages of a blr request. For each message, allocate
* a message (msg) and a format (fmt) block. Return the number of
* messages found. If an error occurs, return -1;
* a message (msg) and a format (fmt) block.
*
**************************************/
if (blr_length < 2)
return (RMessage*) -1;
blr_length -= 2;
if (blr_length < 3)
return NULL;
blr_length -= 3;
const SSHORT version = *blr++;
if (version != blr_version4 && version != blr_version5)
return (RMessage*) -1;
return NULL;
if (*blr++ != blr_begin)
return 0;
return NULL;
RMessage* message = NULL;
ULONG net_length = 0;
bool error = false;
while (*blr++ == blr_message)
{
if (blr_length < 4)
return parse_error(0, message);
blr_length -= 4;
if (blr_length-- == 0)
{
error = true;
break;
}
const USHORT msg_number = *blr++;
rem_fmt* const format = parse_format(blr, blr_length);
if (!format)
{
error = true;
break;
}
RMessage* next = new RMessage(format->fmt_length);
next->msg_next = message;
message = next;
message->msg_address = reinterpret_cast<UCHAR*>(format);
message->msg_number = msg_number;
if (blr_length-- == 0)
{
error = true;
break;
}
}
if (error)
{
for (RMessage* next = message; next; next = message)
{
message = message->msg_next;
delete next->msg_address;
delete next;
}
return NULL;
}
return message;
}
rem_fmt* PARSE_msg_format(const UCHAR* blr, size_t blr_length)
{
/**************************************
*
* P A R S E _ m s g _ f o r m a t
*
**************************************
*
* Functional description
* Parse the message of a blr request and return its format.
*
**************************************/
if (blr_length < 4)
return NULL;
blr_length -= 4;
const SSHORT version = *blr++;
if (version != blr_version4 && version != blr_version5)
return NULL;
if (*blr++ != blr_begin)
return NULL;
if (*blr++ != blr_message)
return NULL;
blr++; // skip message number
return parse_format(blr, blr_length);
}
static rem_fmt* parse_format(const UCHAR*& blr, size_t& blr_length)
{
if (blr_length < 2)
return NULL;
blr_length -= 2;
USHORT count = *blr++;
count += (*blr++) << 8;
rem_fmt* const format = new rem_fmt(count);
#ifdef DEBUG_REMOTE_MEMORY
printf("PARSE_messages allocate format %x\n", format);
#endif
Firebird::AutoPtr<rem_fmt> format(new rem_fmt(count));
ULONG net_length = 0;
ULONG offset = 0;
for (dsc* desc = format->fmt_desc.begin(); count; --count, ++desc)
{
if (blr_length-- == 0)
return parse_error(format, message);
return NULL;
USHORT align = 4;
switch (*blr++)
{
case blr_text:
if (blr_length < 2)
return parse_error(format, message);
return NULL;
blr_length -= 2;
desc->dsc_dtype = dtype_text;
desc->dsc_length = *blr++;
@ -102,7 +181,7 @@ RMessage* PARSE_messages(const UCHAR* blr, size_t blr_length)
case blr_varying:
if (blr_length < 2)
return parse_error(format, message);
return NULL;
blr_length -= 2;
desc->dsc_dtype = dtype_varying;
desc->dsc_length = *blr++ + sizeof(SSHORT);
@ -112,7 +191,7 @@ RMessage* PARSE_messages(const UCHAR* blr, size_t blr_length)
case blr_cstring:
if (blr_length < 2)
return parse_error(format, message);
return NULL;
blr_length -= 2;
desc->dsc_dtype = dtype_cstring;
desc->dsc_length = *blr++;
@ -124,7 +203,7 @@ RMessage* PARSE_messages(const UCHAR* blr, size_t blr_length)
case blr_text2:
if (blr_length < 4)
return parse_error(format, message);
return NULL;
blr_length -= 4;
desc->dsc_dtype = dtype_text;
desc->dsc_scale = *blr++;
@ -136,7 +215,7 @@ RMessage* PARSE_messages(const UCHAR* blr, size_t blr_length)
case blr_varying2:
if (blr_length < 4)
return parse_error(format, message);
return NULL;
blr_length -= 4;
desc->dsc_dtype = dtype_varying;
desc->dsc_scale = *blr++;
@ -148,7 +227,7 @@ RMessage* PARSE_messages(const UCHAR* blr, size_t blr_length)
case blr_cstring2:
if (blr_length < 4)
return parse_error(format, message);
return NULL;
blr_length -= 4;
desc->dsc_dtype = dtype_cstring;
desc->dsc_scale = *blr++;
@ -160,7 +239,7 @@ RMessage* PARSE_messages(const UCHAR* blr, size_t blr_length)
case blr_short:
if (blr_length-- == 0)
return parse_error(format, message);
return NULL;
desc->dsc_dtype = dtype_short;
desc->dsc_length = sizeof(SSHORT);
desc->dsc_scale = *blr++;
@ -169,7 +248,7 @@ RMessage* PARSE_messages(const UCHAR* blr, size_t blr_length)
case blr_long:
if (blr_length-- == 0)
return parse_error(format, message);
return NULL;
desc->dsc_dtype = dtype_long;
desc->dsc_length = sizeof(SLONG);
desc->dsc_scale = *blr++;
@ -178,7 +257,7 @@ RMessage* PARSE_messages(const UCHAR* blr, size_t blr_length)
case blr_int64:
if (blr_length-- == 0)
return parse_error(format, message);
return NULL;
desc->dsc_dtype = dtype_int64;
desc->dsc_length = sizeof(SINT64);
desc->dsc_scale = *blr++;
@ -187,7 +266,7 @@ RMessage* PARSE_messages(const UCHAR* blr, size_t blr_length)
case blr_quad:
if (blr_length-- == 0)
return parse_error(format, message);
return NULL;
desc->dsc_dtype = dtype_quad;
desc->dsc_length = sizeof(SLONG) * 2;
desc->dsc_scale = *blr++;
@ -219,7 +298,7 @@ RMessage* PARSE_messages(const UCHAR* blr, size_t blr_length)
case blr_blob2:
{
if (blr_length < 4)
return parse_error(format, message);
return NULL;
blr_length -= 4;
desc->dsc_dtype = dtype_blob;
desc->dsc_length = sizeof(SLONG) * 2;
@ -259,42 +338,24 @@ RMessage* PARSE_messages(const UCHAR* blr, size_t blr_length)
break;
default:
fb_assert(FALSE);
return parse_error(format, message);
fb_assert(false);
return NULL;
}
if (desc->dsc_dtype == dtype_varying)
net_length += 4 + ((desc->dsc_length - 2 + 3) & ~3);
else
net_length += (desc->dsc_length + 3) & ~3;
if (align > 1)
offset = FB_ALIGN(offset, align);
desc->dsc_address = (UCHAR*) (IPTR) offset;
offset += desc->dsc_length;
}
format->fmt_length = offset;
format->fmt_net_length = net_length;
RMessage* next = new RMessage(format->fmt_length);
#ifdef DEBUG_REMOTE_MEMORY
printf("PARSE_messages allocate message %x\n", next);
#endif
next->msg_next = message;
message = next;
message->msg_address = reinterpret_cast<UCHAR*>(format);
message->msg_number = msg_number;
}
return message;
}
static RMessage* parse_error(rem_fmt* format, RMessage* message)
{
delete format;
for (RMessage* next = message; next; next = message)
{
message = message->msg_next;
delete next->msg_address;
delete next;
}
return (RMessage*) -1;
return format.release();
}

14
src/remote/protocol.cpp
View File

@ -1544,14 +1544,7 @@ static bool_t xdr_sql_blr(XDR* xdrs,
// setting up a format
if (blr->cstr_length)
{
RMessage* temp_msg = (RMessage*) PARSE_messages(blr->cstr_address, blr->cstr_length);
if (temp_msg != (RMessage*) -1)
{
*fmt_ptr = (rem_fmt*) temp_msg->msg_address;
delete temp_msg;
}
}
*fmt_ptr = PARSE_msg_format(blr->cstr_address, blr->cstr_length);
}
// If we know the length of the message, make sure there is a buffer
@ -1781,8 +1774,6 @@ static bool_t xdr_trrq_blr(XDR* xdrs, CSTRING* blr)
procedure->rpr_out_format = NULL;
RMessage* message = PARSE_messages(blr->cstr_address, blr->cstr_length);
if (message != (RMessage*) -1)
{
while (message)
{
switch (message->msg_number)
@ -1810,9 +1801,6 @@ static bool_t xdr_trrq_blr(XDR* xdrs, CSTRING* blr)
break;
}
}
}
else
fb_assert(FALSE);
return TRUE;
}