Thread: dotted quad netmask conversion
Hello All,
I am working with a postgresql database that has two columns.
One for an ip address and another for the netmask. Both of these
columns are char varying(30). I would like to convert to just
one column as inet. Any one know a slick way to convert the
dotted quad netmask, E.G. 255.255.128.0, to number of bits. I didn't
see any way directly looking at the network functions in the PG documentation.
Thanks in advance for your consideration.
I am working with a postgresql database that has two columns.
One for an ip address and another for the netmask. Both of these
columns are char varying(30). I would like to convert to just
one column as inet. Any one know a slick way to convert the
dotted quad netmask, E.G. 255.255.128.0, to number of bits. I didn't
see any way directly looking at the network functions in the PG documentation.
Thanks in advance for your consideration.
--
Stephen Clark
NetWolves
Sr. Software Engineer III
Phone: 813-579-3200
Fax: 813-882-0209
Email: steve.clark@netwolves.com
http://www.netwolves.com
Stephen Clark
NetWolves
Sr. Software Engineer III
Phone: 813-579-3200
Fax: 813-882-0209
Email: steve.clark@netwolves.com
http://www.netwolves.com
On Tue, Dec 7, 2010 at 9:17 AM, Steve Clark <sclark@netwolves.com> wrote: > Hello All, > > I am working with a postgresql database that has two columns. > One for an ip address and another for the netmask. Both of these > columns are char varying(30). I would like to convert to just > one column as inet. Any one know a slick way to convert the > dotted quad netmask, E.G. 255.255.128.0, to number of bits. I didn't > see any way directly looking at the network functions in the PG > documentation. select '1.2.3.4'::inet & '255.255.128.0'::inet; or select CAST('1.2.3.4' AS INET) & CAST('255.255.128.0' AS INET); Be aware that CIDR representation is not as granular as netmask. http://www.postgresql.org/docs/8.4/interactive/functions-net.html -- Jon
On 12/07/2010 10:30 AM, Jon Nelson wrote:
for network functions.
select CAST('1.2.3.4' AS INET) & CAST('255.255.128.0' AS INET);
ERROR: operator does not exist: inet & inet
HINT: No operator matches the given name and argument type(s). You may need to add explicit type casts.
Thanks for the response Jon. I should have stated this PG 8.1.x and '&' doesn't existOn Tue, Dec 7, 2010 at 9:17 AM, Steve Clark <sclark@netwolves.com> wrote:Hello All, I am working with a postgresql database that has two columns. One for an ip address and another for the netmask. Both of these columns are char varying(30). I would like to convert to just one column as inet. Any one know a slick way to convert the dotted quad netmask, E.G. 255.255.128.0, to number of bits. I didn't see any way directly looking at the network functions in the PG documentation.select '1.2.3.4'::inet & '255.255.128.0'::inet; or select CAST('1.2.3.4' AS INET) & CAST('255.255.128.0' AS INET); Be aware that CIDR representation is not as granular as netmask. http://www.postgresql.org/docs/8.4/interactive/functions-net.html
for network functions.
select CAST('1.2.3.4' AS INET) & CAST('255.255.128.0' AS INET);
ERROR: operator does not exist: inet & inet
HINT: No operator matches the given name and argument type(s). You may need to add explicit type casts.
--
Stephen Clark
NetWolves
Sr. Software Engineer III
Phone: 813-579-3200
Fax: 813-882-0209
Email: steve.clark@netwolves.com
http://www.netwolves.com
Stephen Clark
NetWolves
Sr. Software Engineer III
Phone: 813-579-3200
Fax: 813-882-0209
Email: steve.clark@netwolves.com
http://www.netwolves.com
Steve Clark <sclark@netwolves.com> writes: > Thanks for the response Jon. I should have stated this PG 8.1.x and '&' > doesn't exist for network functions. I don't think & does what you want anyway. It just does a bit AND on the two addresses, it doesn't change the masklen property. There's probably only a small number of distinct netmasks you actually need to handle in this conversion. What I'd suggest is writing a simple function with a CASE statement to translate netmask to an integer mask length, and then you can use set_masklen to merge that result into the address value. regards, tom lane
On 12/07/2010 11:43 AM, Tom Lane wrote:
seem to work.
CREATE OR REPLACE FUNCTION inet_to_longip(v_t INET)
RETURNS BIGINT AS
$inet_to_longip$
DECLARE
t1 TEXT;
t2 TEXT;
t3 TEXT;
t4 TEXT;
i BIGINT;
BEGIN
t1 := SPLIT_PART(HOST(v_t), '.',1);
t2 := SPLIT_PART(HOST(v_t), '.',2);
t3 := SPLIT_PART(HOST(v_t), '.',3);
t4 := SPLIT_PART(HOST(v_t), '.',4);
i := (t1::BIGINT << 24) + (t2::BIGINT << 16) +
(t3::BIGINT << 8) + t4::BIGINT;
RETURN i;
END;
$inet_to_longip$ LANGUAGE plpgsql STRICT IMMUTABLE;
CREATE OR REPLACE FUNCTION netmask_bits(v_i BIGINT)
RETURNS INTEGER AS
$netmask_msb$
DECLARE
n INTEGER;
BEGIN
n := (32-log(2, 4294967296 - v_i ))::integer;
RETURN n;
END;
$netmask_msb$ LANGUAGE plpgsql STRICT IMMUTABLE;
Which seems to do the trick.
select netmask_bits(inet_to_longip('255.255.255.0'));
netmask_bits
--------------
24
select netmask_bits(inet_to_longip('255.255.128.0'));
netmask_bits
--------------
17
Thanks all.
Googling on the net I found a couple of functions that with tweaks for 8.1Steve Clark <sclark@netwolves.com> writes:Thanks for the response Jon. I should have stated this PG 8.1.x and '&' doesn't exist for network functions.I don't think & does what you want anyway. It just does a bit AND on the two addresses, it doesn't change the masklen property. There's probably only a small number of distinct netmasks you actually need to handle in this conversion. What I'd suggest is writing a simple function with a CASE statement to translate netmask to an integer mask length, and then you can use set_masklen to merge that result into the address value. regards, tom lane
seem to work.
CREATE OR REPLACE FUNCTION inet_to_longip(v_t INET)
RETURNS BIGINT AS
$inet_to_longip$
DECLARE
t1 TEXT;
t2 TEXT;
t3 TEXT;
t4 TEXT;
i BIGINT;
BEGIN
t1 := SPLIT_PART(HOST(v_t), '.',1);
t2 := SPLIT_PART(HOST(v_t), '.',2);
t3 := SPLIT_PART(HOST(v_t), '.',3);
t4 := SPLIT_PART(HOST(v_t), '.',4);
i := (t1::BIGINT << 24) + (t2::BIGINT << 16) +
(t3::BIGINT << 8) + t4::BIGINT;
RETURN i;
END;
$inet_to_longip$ LANGUAGE plpgsql STRICT IMMUTABLE;
CREATE OR REPLACE FUNCTION netmask_bits(v_i BIGINT)
RETURNS INTEGER AS
$netmask_msb$
DECLARE
n INTEGER;
BEGIN
n := (32-log(2, 4294967296 - v_i ))::integer;
RETURN n;
END;
$netmask_msb$ LANGUAGE plpgsql STRICT IMMUTABLE;
Which seems to do the trick.
select netmask_bits(inet_to_longip('255.255.255.0'));
netmask_bits
--------------
24
select netmask_bits(inet_to_longip('255.255.128.0'));
netmask_bits
--------------
17
Thanks all.
--
Stephen Clark
NetWolves
Sr. Software Engineer III
Phone: 813-579-3200
Fax: 813-882-0209
Email: steve.clark@netwolves.com
http://www.netwolves.com
Stephen Clark
NetWolves
Sr. Software Engineer III
Phone: 813-579-3200
Fax: 813-882-0209
Email: steve.clark@netwolves.com
http://www.netwolves.com