Is there way to match IP with IP+CIDR straight from SELECT query?

Remember that IPs are not a textual address, but a numeric ID. I have a similar situation (we're doing geo-ip lookups), and if you store all your IP addresses as integers (for example, my IP address is 192.115.22.33 so it is stored as 3228767777), then you can lookup IPs easily by using right shift operators.

The downside of all these types of lookups is that you can't benefit from indexes and you have to do a full table scan whenever you do a lookup. The above scheme can be improved by storing both the network IP address of the CIDR network (the beginning of the range) and the broadcast address (the end of the range), so for example to store 192.168.1.0/24 you can store two columns:

network     broadcast
3232235776, 3232236031 

And then you can to match it you simply do

SELECT count(*) FROM bans WHERE 3232235876 >= network AND 3232235876 <= broadcast

This would let you store CIDR networks in the database and match them against IP addresses quickly and efficiently by taking advantage of quick numeric indexes.

Note from discussion below:

MySQL 5.0 includes a ranged query optimization called "index merge intersect" which allows to speed up such queries (and avoid full table scans), as long as:

• There is a multi-column index that matches exactly the columns in the query, in order. So - for the above query example, the index would need to be (network, broadcast).
• All the data can be retrieved from the index. This is true for COUNT(*), but is not true for SELECT * ... LIMIT 1.

MySQL 5.6 includes an optimization called MRR which would also speed up full row retrieval, but that is out of scope of this answer.

For IPv4, you can use:

SET @length = 4;

SELECT  INET_NTOA(ipaddr), INET_NTOA(searchaddr), INET_NTOA(mask)
FROM  (
  SELECT
        (1 << (@length * 8)) - 1 & ~((1 << (@length * 8 - cidr)) - 1) AS mask,
        CAST(CONV(SUBSTR(HEX(ipaddr), 1, @length * 2), 16, 10) AS DECIMAL(20)) AS ipaddr,
        CAST(CONV(SUBSTR(HEX(@myaddr), 1, @length * 2), 16, 10) AS DECIMAL(20)) AS searchaddr
  FROM  ip
) ipo
WHERE ipaddr & mask = searchaddr & mask

IPv4 addresses, network addresses and netmasks are all UINT32 numbers and are presented in human-readable form as "dotted-quads". The routing table code in the kernel performs a very fast bit-wise AND comparison when checking if an address is in a given network space (network/netmask). The trick here is to store the dotted-quad IP addresses, network addresses and netmasks in your tables as UINT32, and then perform the same 32-bit bit-wise AND for your matching. eg

SET @test_addr = inet_aton('1.2.3.4');
SET @network_one = inet_aton('1.2.3.0');
SET @network_two = inet_aton('4.5.6.0');
SET @network_netmask = inet_aton('255.255.255.0');

SELECT (@test_addr & @network_netmask) = @network_one AS IS_MATCHED;
+------------+
| IS_MATCHED |
+------------+
|          1 |
+------------+

SELECT (@test_addr & @network_netmask) = @network_two AS IS_NOT_MATCHED;
+----------------+
| IS_NOT_MATCHED |
+----------------+
|              0 |
+----------------+