network.c

postgresql8.3.4源码,开源数据库

	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 (IS_HIGHBIT_SET(lb) != IS_HIGHBIT_SET(rb))
		{
			if (IS_HIGHBIT_SET(lb))
				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();

	clean_ipv6_addr(port->raddr.addr.ss_family, remote_host);

	PG_RETURN_INET_P(network_in(remote_host, false));
}


/*
 * 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();

	clean_ipv6_addr(port->laddr.addr.ss_family, local_host);

	PG_RETURN_INET_P(network_in(local_host, false));
}


/*
 * 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)));
}


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

	dst = (inet *) palloc0(sizeof(inet));

	{
		int			nb = ip_addrsize(ip);
		unsigned char *pip = ip_addr(ip);
		unsigned char *pdst = ip_addr(dst);

		while (nb-- > 0)
			pdst[nb] = ~pip[nb];
	}
	ip_bits(dst) = ip_bits(ip);

	ip_family(dst) = ip_family(ip);
	SET_INET_VARSIZE(dst);

	PG_RETURN_INET_P(dst);
}


Datum
inetand(PG_FUNCTION_ARGS)
{
	inet	   *ip = PG_GETARG_INET_P(0);
	inet	   *ip2 = PG_GETARG_INET_P(1);
	inet	   *dst;

	dst = (inet *) palloc0(sizeof(inet));

	if (ip_family(ip) != ip_family(ip2))
		ereport(ERROR,
				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
				 errmsg("cannot AND inet values of different sizes")));
	else
	{
		int			nb = ip_addrsize(ip);
		unsigned char *pip = ip_addr(ip);
		unsigned char *pip2 = ip_addr(ip2);
		unsigned char *pdst = ip_addr(dst);

		while (nb-- > 0)
			pdst[nb] = pip[nb] & pip2[nb];
	}
	ip_bits(dst) = Max(ip_bits(ip), ip_bits(ip2));

	ip_family(dst) = ip_family(ip);
	SET_INET_VARSIZE(dst);

	PG_RETURN_INET_P(dst);
}


Datum
inetor(PG_FUNCTION_ARGS)
{
	inet	   *ip = PG_GETARG_INET_P(0);
	inet	   *ip2 = PG_GETARG_INET_P(1);
	inet	   *dst;

	dst = (inet *) palloc0(sizeof(inet));

	if (ip_family(ip) != ip_family(ip2))
		ereport(ERROR,
				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
				 errmsg("cannot OR inet values of different sizes")));
	else
	{
		int			nb = ip_addrsize(ip);
		unsigned char *pip = ip_addr(ip);
		unsigned char *pip2 = ip_addr(ip2);
		unsigned char *pdst = ip_addr(dst);

		while (nb-- > 0)
			pdst[nb] = pip[nb] | pip2[nb];
	}
	ip_bits(dst) = Max(ip_bits(ip), ip_bits(ip2));

	ip_family(dst) = ip_family(ip);
	SET_INET_VARSIZE(dst);

	PG_RETURN_INET_P(dst);
}


static inet *
internal_inetpl(inet *ip, int64 addend)
{
	inet	   *dst;

	dst = (inet *) palloc0(sizeof(inet));

	{
		int			nb = ip_addrsize(ip);
		unsigned char *pip = ip_addr(ip);
		unsigned char *pdst = ip_addr(dst);
		int			carry = 0;

		while (nb-- > 0)
		{
			carry = pip[nb] + (int) (addend & 0xFF) + carry;
			pdst[nb] = (unsigned char) (carry & 0xFF);
			carry >>= 8;

			/*
			 * We have to be careful about right-shifting addend because
			 * right-shift isn't portable for negative values, while simply
			 * dividing by 256 doesn't work (the standard rounding is in the
			 * wrong direction, besides which there may be machines out there
			 * that round the wrong way).  So, explicitly clear the low-order
			 * byte to remove any doubt about the correct result of the
			 * division, and then divide rather than shift.
			 */
			addend &= ~((int64) 0xFF);
			addend /= 0x100;
		}

		/*
		 * At this point we should have addend and carry both zero if original
		 * addend was >= 0, or addend -1 and carry 1 if original addend was <
		 * 0.  Anything else means overflow.
		 */
		if (!((addend == 0 && carry == 0) ||
			  (addend == -1 && carry == 1)))
			ereport(ERROR,
					(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
					 errmsg("result is out of range")));
	}

	ip_bits(dst) = ip_bits(ip);
	ip_family(dst) = ip_family(ip);
	SET_INET_VARSIZE(dst);

	return dst;
}


Datum
inetpl(PG_FUNCTION_ARGS)
{
	inet	   *ip = PG_GETARG_INET_P(0);
	int64		addend = PG_GETARG_INT64(1);

	PG_RETURN_INET_P(internal_inetpl(ip, addend));
}


Datum
inetmi_int8(PG_FUNCTION_ARGS)
{
	inet	   *ip = PG_GETARG_INET_P(0);
	int64		addend = PG_GETARG_INT64(1);

	PG_RETURN_INET_P(internal_inetpl(ip, -addend));
}


Datum
inetmi(PG_FUNCTION_ARGS)
{
	inet	   *ip = PG_GETARG_INET_P(0);
	inet	   *ip2 = PG_GETARG_INET_P(1);
	int64		res = 0;

	if (ip_family(ip) != ip_family(ip2))
		ereport(ERROR,
				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
				 errmsg("cannot subtract inet values of different sizes")));
	else
	{
		/*
		 * We form the difference using the traditional complement, increment,
		 * and add rule, with the increment part being handled by starting the
		 * carry off at 1.	If you don't think integer arithmetic is done in
		 * two's complement, too bad.
		 */
		int			nb = ip_addrsize(ip);
		int			byte = 0;
		unsigned char *pip = ip_addr(ip);
		unsigned char *pip2 = ip_addr(ip2);
		int			carry = 1;

		while (nb-- > 0)
		{
			int			lobyte;

			carry = pip[nb] + (~pip2[nb] & 0xFF) + carry;
			lobyte = carry & 0xFF;
			if (byte < sizeof(int64))
			{
				res |= ((int64) lobyte) << (byte * 8);
			}
			else
			{
				/*
				 * Input wider than int64: check for overflow.	All bytes to
				 * the left of what will fit should be 0 or 0xFF, depending on
				 * sign of the now-complete result.
				 */
				if ((res < 0) ? (lobyte != 0xFF) : (lobyte != 0))
					ereport(ERROR,
							(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
							 errmsg("result is out of range")));
			}
			carry >>= 8;
			byte++;
		}

		/*
		 * If input is narrower than int64, overflow is not possible, but we
		 * have to do proper sign extension.
		 */
		if (carry == 0 && byte < sizeof(int64))
			res |= ((int64) -1) << (byte * 8);
	}

	PG_RETURN_INT64(res);
}


/*
 * clean_ipv6_addr --- remove any '%zone' part from an IPv6 address string
 *
 * XXX This should go away someday!
 *
 * This is a kluge needed because we don't yet support zones in stored inet
 * values.	Since the result of getnameinfo() might include a zone spec,
 * call this to remove it anywhere we want to feed getnameinfo's output to
 * network_in.	Beats failing entirely.
 *
 * An alternative approach would be to let network_in ignore %-parts for
 * itself, but that would mean we'd silently drop zone specs in user input,
 * which seems not such a good idea.
 */
void
clean_ipv6_addr(int addr_family, char *addr)
{
#ifdef HAVE_IPV6
	if (addr_family == AF_INET6)
	{
		char	   *pct = strchr(addr, '%');

		if (pct)
			*pct = '\0';
	}
#endif
}