network.c

PostgreSQL 8.1.4的源码 适用于Linux下的开源数据库系统

Datum
network_abbrev(PG_FUNCTION_ARGS)
{
	inet	   *ip = PG_GETARG_INET_P(0);
	text	   *ret;
	char	   *dst;
	int			len;
	char		tmp[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255/128")];

	if (ip_type(ip))
		dst = inet_cidr_ntop(ip_family(ip), ip_addr(ip),
							 ip_bits(ip), tmp, sizeof(tmp));
	else
		dst = inet_net_ntop(ip_family(ip), ip_addr(ip),
							ip_bits(ip), tmp, sizeof(tmp));

	if (dst == NULL)
		ereport(ERROR,
				(errcode(ERRCODE_INVALID_BINARY_REPRESENTATION),
				 errmsg("could not format inet value: %m")));

	/* Return string as a text datum */
	len = strlen(tmp);
	ret = (text *) palloc(len + VARHDRSZ);
	VARATT_SIZEP(ret) = len + VARHDRSZ;
	memcpy(VARDATA(ret), tmp, len);
	PG_RETURN_TEXT_P(ret);
}

Datum
network_masklen(PG_FUNCTION_ARGS)
{
	inet	   *ip = PG_GETARG_INET_P(0);

	PG_RETURN_INT32(ip_bits(ip));
}

Datum
network_family(PG_FUNCTION_ARGS)
{
	inet	   *ip = PG_GETARG_INET_P(0);

	switch (ip_family(ip))
	{
		case PGSQL_AF_INET:
			PG_RETURN_INT32(4);
			break;
		case PGSQL_AF_INET6:
			PG_RETURN_INT32(6);
			break;
		default:
			PG_RETURN_INT32(0);
			break;
	}
}

Datum
network_broadcast(PG_FUNCTION_ARGS)
{
	inet	   *ip = PG_GETARG_INET_P(0);
	inet	   *dst;
	int			byte;
	int			bits;
	int			maxbytes;
	unsigned char mask;
	unsigned char *a,
			   *b;

	/* make sure any unused bits are zeroed */
	dst = (inet *) palloc0(VARHDRSZ + sizeof(inet_struct));

	if (ip_family(ip) == PGSQL_AF_INET)
		maxbytes = 4;
	else
		maxbytes = 16;

	bits = ip_bits(ip);
	a = ip_addr(ip);
	b = ip_addr(dst);

	for (byte = 0; byte < maxbytes; byte++)
	{
		if (bits >= 8)
		{
			mask = 0x00;
			bits -= 8;
		}
		else if (bits == 0)
			mask = 0xff;
		else
		{
			mask = 0xff >> bits;
			bits = 0;
		}

		b[byte] = a[byte] | mask;
	}

	ip_family(dst) = ip_family(ip);
	ip_bits(dst) = ip_bits(ip);
	ip_type(dst) = 0;
	VARATT_SIZEP(dst) = VARHDRSZ
		+ ((char *) ip_addr(dst) - (char *) VARDATA(dst))
		+ ip_addrsize(dst);

	PG_RETURN_INET_P(dst);
}

Datum
network_network(PG_FUNCTION_ARGS)
{
	inet	   *ip = PG_GETARG_INET_P(0);
	inet	   *dst;
	int			byte;
	int			bits;
	unsigned char mask;
	unsigned char *a,
			   *b;

	/* make sure any unused bits are zeroed */
	dst = (inet *) palloc0(VARHDRSZ + sizeof(inet_struct));

	bits = ip_bits(ip);
	a = ip_addr(ip);
	b = ip_addr(dst);

	byte = 0;
	while (bits)
	{
		if (bits >= 8)
		{
			mask = 0xff;
			bits -= 8;
		}
		else
		{
			mask = 0xff << (8 - bits);
			bits = 0;
		}

		b[byte] = a[byte] & mask;
		byte++;
	}

	ip_family(dst) = ip_family(ip);
	ip_bits(dst) = ip_bits(ip);
	ip_type(dst) = 1;
	VARATT_SIZEP(dst) = VARHDRSZ
		+ ((char *) ip_addr(dst) - (char *) VARDATA(dst))
		+ ip_addrsize(dst);

	PG_RETURN_INET_P(dst);
}

Datum
network_netmask(PG_FUNCTION_ARGS)
{
	inet	   *ip = PG_GETARG_INET_P(0);
	inet	   *dst;
	int			byte;
	int			bits;
	unsigned char mask;
	unsigned char *b;

	/* make sure any unused bits are zeroed */
	dst = (inet *) palloc0(VARHDRSZ + sizeof(inet_struct));

	bits = ip_bits(ip);
	b = ip_addr(dst);

	byte = 0;
	while (bits)
	{
		if (bits >= 8)
		{
			mask = 0xff;
			bits -= 8;
		}
		else
		{
			mask = 0xff << (8 - bits);
			bits = 0;
		}

		b[byte] = mask;
		byte++;
	}

	ip_family(dst) = ip_family(ip);
	ip_bits(dst) = ip_maxbits(ip);
	ip_type(dst) = 0;
	VARATT_SIZEP(dst) = VARHDRSZ
		+ ((char *) ip_addr(dst) - (char *) VARDATA(dst))
		+ ip_addrsize(dst);

	PG_RETURN_INET_P(dst);
}

Datum
network_hostmask(PG_FUNCTION_ARGS)
{
	inet	   *ip = PG_GETARG_INET_P(0);
	inet	   *dst;
	int			byte;
	int			bits;
	int			maxbytes;
	unsigned char mask;
	unsigned char *b;

	/* make sure any unused bits are zeroed */
	dst = (inet *) palloc0(VARHDRSZ + sizeof(inet_struct));

	if (ip_family(ip) == PGSQL_AF_INET)
		maxbytes = 4;
	else
		maxbytes = 16;

	bits = ip_maxbits(ip) - ip_bits(ip);
	b = ip_addr(dst);

	byte = maxbytes - 1;
	while (bits)
	{
		if (bits >= 8)
		{
			mask = 0xff;
			bits -= 8;
		}
		else
		{
			mask = 0xff >> (8 - bits);
			bits = 0;
		}

		b[byte] = mask;
		byte--;
	}

	ip_family(dst) = ip_family(ip);
	ip_bits(dst) = ip_maxbits(ip);
	ip_type(dst) = 0;
	VARATT_SIZEP(dst) = VARHDRSZ
		+ ((char *) ip_addr(dst) - (char *) VARDATA(dst))
		+ ip_addrsize(dst);

	PG_RETURN_INET_P(dst);
}

/*
 * Convert a value of a network datatype to an approximate scalar value.
 * This is used for estimating selectivities of inequality operators
 * involving network types.
 *
 * Currently, inet/cidr values are simply converted to the IPv4 address;
 * this will need more thought when IPv6 is supported too.	MAC addresses
 * are converted to their numeric equivalent as well (OK since we have a
 * double to play in).
 */
double
convert_network_to_scalar(Datum value, Oid typid)
{
	switch (typid)
	{
		case INETOID:
		case CIDROID:
			{
				inet	   *ip = DatumGetInetP(value);
				int			len;
				double		res;
				int			i;

				/*
				 * Note that we don't use the full address here.
				 */
				if (ip_family(ip) == PGSQL_AF_INET)
					len = 4;
				else
					len = 5;

				res = ip_family(ip);
				for (i = 0; i < len; i++)
				{
					res *= 256;
					res += ip_addr(ip)[i];
				}
				return res;

				break;
			}
		case MACADDROID:
			{
				macaddr    *mac = DatumGetMacaddrP(value);
				double		res;

				res = (mac->a << 16) | (mac->b << 8) | (mac->c);
				res *= 256 * 256 * 256;
				res += (mac->d << 16) | (mac->e << 8) | (mac->f);
				return res;
			}
	}

	/*
	 * Can't get here unless someone tries to use scalarltsel/scalargtsel on
	 * an operator with one network and one non-network operand.
	 */
	elog(ERROR, "unsupported type: %u", typid);
	return 0;
}

/*
 * int
 * bitncmp(l, r, n)
 *		compare bit masks l and r, for n bits.
 * return:
 *		-1, 1, or 0 in the libc tradition.
 * note:
 *		network byte order assumed.  this means 192.5.5.240/28 has
 *		0x11110000 in its fourth octet.
 * author:
 *		Paul Vixie (ISC), June 1996
 */
static int
bitncmp(void *l, void *r, int n)
{
	u_int		lb,
				rb;
	int			x,
				b;

	b = n / 8;
	x = memcmp(l, r, b);
	if (x)
		return (x);

	lb = ((const u_char *) l)[b];
	rb = ((const u_char *) r)[b];
	for (b = n % 8; b > 0; b--)
	{
		if ((lb & 0x80) != (rb & 0x80))
		{
			if (lb & 0x80)
				return (1);
			return (-1);
		}
		lb <<= 1;
		rb <<= 1;
	}
	return (0);
}

static bool
addressOK(unsigned char *a, int bits, int family)
{
	int			byte;
	int			nbits;
	int			maxbits;
	int			maxbytes;
	unsigned char mask;

	if (family == PGSQL_AF_INET)
	{
		maxbits = 32;
		maxbytes = 4;
	}
	else
	{
		maxbits = 128;
		maxbytes = 16;
	}
	Assert(bits <= maxbits);

	if (bits == maxbits)
		return true;

	byte = bits / 8;
	nbits = bits % 8;
	mask = 0xff;
	if (bits != 0)
		mask >>= nbits;

	while (byte < maxbytes)
	{
		if ((a[byte] & mask) != 0)
			return false;
		mask = 0xff;
		byte++;
	}

	return true;
}


/*
 * These functions are used by planner to generate indexscan limits
 * for clauses a << b and a <<= b
 */

/* return the minimal value for an IP on a given network */
Datum
network_scan_first(Datum in)
{
	return DirectFunctionCall1(network_network, in);
}

/*
 * return "last" IP on a given network. It's the broadcast address,
 * however, masklen has to be set to its max btis, since
 * 192.168.0.255/24 is considered less than 192.168.0.255/32
 *
 * inet_set_masklen() hacked to max out the masklength to 128 for IPv6
 * and 32 for IPv4 when given '-1' as argument.
 */
Datum
network_scan_last(Datum in)
{
	return DirectFunctionCall2(inet_set_masklen,
							   DirectFunctionCall1(network_broadcast, in),
							   Int32GetDatum(-1));
}


/*
 * IP address that the client is connecting from (NULL if Unix socket)
 */
Datum
inet_client_addr(PG_FUNCTION_ARGS)
{
	Port	   *port = MyProcPort;
	char		remote_host[NI_MAXHOST];
	int			ret;

	if (port == NULL)
		PG_RETURN_NULL();

	switch (port->raddr.addr.ss_family)
	{
		case AF_INET:
#ifdef HAVE_IPV6
		case AF_INET6:
#endif
			break;
		default:
			PG_RETURN_NULL();
	}

	remote_host[0] = '\0';

	ret = pg_getnameinfo_all(&port->raddr.addr, port->raddr.salen,
							 remote_host, sizeof(remote_host),
							 NULL, 0,
							 NI_NUMERICHOST | NI_NUMERICSERV);
	if (ret)
		PG_RETURN_NULL();

	PG_RETURN_INET_P(network_in(remote_host, 0));
}


/*
 * port that the client is connecting from (NULL if Unix socket)
 */
Datum
inet_client_port(PG_FUNCTION_ARGS)
{
	Port	   *port = MyProcPort;
	char		remote_port[NI_MAXSERV];
	int			ret;

	if (port == NULL)
		PG_RETURN_NULL();

	switch (port->raddr.addr.ss_family)
	{
		case AF_INET:
#ifdef HAVE_IPV6
		case AF_INET6:
#endif
			break;
		default:
			PG_RETURN_NULL();
	}

	remote_port[0] = '\0';

	ret = pg_getnameinfo_all(&port->raddr.addr, port->raddr.salen,
							 NULL, 0,
							 remote_port, sizeof(remote_port),
							 NI_NUMERICHOST | NI_NUMERICSERV);
	if (ret)
		PG_RETURN_NULL();

	PG_RETURN_DATUM(DirectFunctionCall1(int4in, CStringGetDatum(remote_port)));
}


/*
 * IP address that the server accepted the connection on (NULL if Unix socket)
 */
Datum
inet_server_addr(PG_FUNCTION_ARGS)
{
	Port	   *port = MyProcPort;
	char		local_host[NI_MAXHOST];
	int			ret;

	if (port == NULL)
		PG_RETURN_NULL();

	switch (port->laddr.addr.ss_family)
	{
		case AF_INET:
#ifdef HAVE_IPV6
		case AF_INET6:
#endif
			break;
		default:
			PG_RETURN_NULL();
	}

	local_host[0] = '\0';

	ret = pg_getnameinfo_all(&port->laddr.addr, port->laddr.salen,
							 local_host, sizeof(local_host),
							 NULL, 0,
							 NI_NUMERICHOST | NI_NUMERICSERV);
	if (ret)
		PG_RETURN_NULL();

	PG_RETURN_INET_P(network_in(local_host, 0));
}


/*
 * port that the server accepted the connection on (NULL if Unix socket)
 */
Datum
inet_server_port(PG_FUNCTION_ARGS)
{
	Port	   *port = MyProcPort;
	char		local_port[NI_MAXSERV];
	int			ret;

	if (port == NULL)
		PG_RETURN_NULL();

	switch (port->laddr.addr.ss_family)
	{
		case AF_INET:
#ifdef HAVE_IPV6
		case AF_INET6:
#endif
			break;
		default:
			PG_RETURN_NULL();
	}

	local_port[0] = '\0';

	ret = pg_getnameinfo_all(&port->laddr.addr, port->laddr.salen,
							 NULL, 0,
							 local_port, sizeof(local_port),
							 NI_NUMERICHOST | NI_NUMERICSERV);
	if (ret)
		PG_RETURN_NULL();

	PG_RETURN_DATUM(DirectFunctionCall1(int4in, CStringGetDatum(local_port)));
}