Network functions
[LibTDS API]

Functions for reading or writing from network. More...

Defines
#define	TEMP_FREE   ;
#define	TEMP_INIT(s)   char temp[s]
#define	TEMP_SIZE   sizeof(temp)
Typedefs
typedef unsigned int	ioctl_nonblocking_t
Functions
static int	goodread (TDSSOCKET *tds, unsigned char *buf, int buflen)
static int	read_and_convert (TDSSOCKET *tds, const TDSICONV *char_conv, size_t *wire_size, char **outbuf, size_t *outbytesleft)
int	tds7_get_instance_port (const char *ip_addr, const char *instance)
	Get port of given instance.
int	tds7_get_instance_ports (FILE *output, const char *ip_addr)
	Get port of all instances.
int	tds_close_socket (TDSSOCKET *tds)
int	tds_flush_packet (TDSSOCKET *tds)
	Flush packet to server.
unsigned char	tds_get_byte (TDSSOCKET *tds)
int	tds_get_char_data (TDSSOCKET *tds, char *row_buffer, size_t wire_size, TDSCOLUMN *curcol)
	Fetch character data the wire.
TDS_INT	tds_get_int (TDSSOCKET *tds)
	Get an int32 from the server.
TDS_INT8	tds_get_int8 (TDSSOCKET *tds)
void *	tds_get_n (TDSSOCKET *tds, void *dest, int need)
	Get N bytes from the buffer and return them in the already allocated space given to us.
TDS_SMALLINT	tds_get_smallint (TDSSOCKET *tds)
	Get an int16 from the server.
int	tds_get_string (TDSSOCKET *tds, int string_len, char *dest, size_t dest_size)
	Fetch a string from the wire.
static int	tds_goodread (TDSSOCKET *tds, unsigned char *buf, int buflen, unsigned char unfinished)
	Loops until we have received buflen characters return -1 on failure.
static int	tds_goodwrite (TDSSOCKET *tds, const unsigned char *buffer, size_t len, unsigned char last)
int	tds_init_write_buf (TDSSOCKET *tds)
int	tds_lastpacket (TDSSOCKET *tds)
TDSERRNO	tds_open_socket (TDSSOCKET *tds, const char *ip_addr, unsigned int port, int timeout, int *p_oserr)
unsigned char	tds_peek (TDSSOCKET *tds)
int	tds_put_buf (TDSSOCKET *tds, const unsigned char *buf, int dsize, int ssize)
int	tds_put_byte (TDSSOCKET *tds, unsigned char c)
int	tds_put_int (TDSSOCKET *tds, TDS_INT i)
int	tds_put_int8 (TDSSOCKET *tds, TDS_INT8 i)
int	tds_put_n (TDSSOCKET *tds, const void *buf, size_t n)
int	tds_put_smallint (TDSSOCKET *tds, TDS_SMALLINT si)
int	tds_put_string (TDSSOCKET *tds, const char *s, int len)
	Output a string to wire automatic translate string to unicode if needed.
int	tds_read_packet (TDSSOCKET *tds)
	Read in one 'packet' from the server.
static int	tds_select (TDSSOCKET *tds, unsigned tds_sel, int timeout_seconds)
	Select on a socket until it's available or the timeout expires.
void	tds_unget_byte (TDSSOCKET *tds)
	Unget will always work as long as you don't call it twice in a row.
int	tds_write_packet (TDSSOCKET *tds, unsigned char final)

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Detailed Description

Functions for reading or writing from network.

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Function Documentation

int tds7_get_instance_port	(	const char *	ip_addr,
		const char *	instance
	)

Get port of given instance.

Returns:

port number or 0 if error

int tds7_get_instance_ports	(	FILE *	output,
		const char *	ip_addr
	)

Get port of all instances.

Returns:

default port number or 0 if error

Remarks:

experimental, cf. MC-SQLR.pdf.

int tds_flush_packet

(

TDSSOCKET *

tds

)

Flush packet to server.

Returns:

TDS_FAIL or TDS_SUCCEED

int tds_get_char_data	(	TDSSOCKET *	tds,
		char *	row_buffer,
		size_t	wire_size,
		TDSCOLUMN *	curcol
	)

Fetch character data the wire.

Output is NOT null terminated. If char_conv is not NULL, convert data accordingly.

Parameters:

	tds	state information for the socket and the TDS protocol
	row_buffer	destination buffer in current_row. Can't be NULL
	wire_size	size to read from wire (in bytes)
	curcol	column information

Returns:

TDS_SUCCEED or TDS_FAIL (probably memory error on text data)

Todo:

put a TDSICONV structure in every TDSCOLUMN

void* tds_get_n	(	TDSSOCKET *	tds,
		void *	dest,
		int	need
	)

Get N bytes from the buffer and return them in the already allocated space given to us.

We ASSUME that the person calling this function has done the bounds checking for us since they know how many bytes they want here. dest of NULL means we just want to eat the bytes. (tetherow@nol.org)

int tds_get_string	(	TDSSOCKET *	tds,
		int	string_len,
		char *	dest,
		size_t	dest_size
	)

Fetch a string from the wire.

Output string is NOT null terminated. If TDS version is 7 or 8 read unicode string and convert it. This function should be use to read server default encoding strings like columns name, table names, etc, not for data (use tds_get_char_data instead)

Returns:

bytes written to dest

Parameters:

	tds	connection information
	string_len	length of string to read from wire (in server characters, bytes for tds4-tds5, ucs2 for tds7+)
	dest	destination buffer, if NULL string is read and discarded
	dest_size	destination buffer size, in bytes

static int tds_goodwrite	(	TDSSOCKET *	tds,
		const unsigned char *	buffer,
		size_t	len,
		unsigned char	last
	)			[static]

Parameters:

	tds	the famous socket
	buffer	data to send
	len	bytes in buffer
	last	1 if this is the last packet, else 0

Returns:

len on success, <0 on failure

int tds_put_string	(	TDSSOCKET *	tds,
		const char *	s,
		int	len
	)

Output a string to wire automatic translate string to unicode if needed.

Returns:

bytes written to wire

Parameters:

	tds	state information for the socket and the TDS protocol
	s	string to write
	len	length of string in characters, or -1 for null terminated

int tds_read_packet

(

TDSSOCKET *

tds

)

Read in one 'packet' from the server.

This is a wrapped outer packet of the protocol (they bundle result packets into chunks and wrap them at what appears to be 512 bytes regardless of how that breaks internal packet up. (tetherow@nol.org)

Returns:

bytes read or -1 on failure

static int tds_select	(	TDSSOCKET *	tds,
		unsigned	tds_sel,
		int	timeout_seconds
	)			[static]

Select on a socket until it's available or the timeout expires.

Meanwhile, call the interrupt function.

Returns:

>0 ready descriptors 0 timeout <0 error (cf. errno). Caller should close socket and return failure. This function does not call tdserror or close the socket because it can't know the context in which it's being called.

void tds_unget_byte

(

TDSSOCKET *

tds

)

Unget will always work as long as you don't call it twice in a row.

It it may work if you call it multiple times as long as you don't backup over the beginning of network packet boundary which can occur anywhere in the token stream.