Network for client addr

[y-trudeau]

A simple patch to support networks like in mysql.user.host in client_addr. With this patch, a query rule can be defined with a client_addr formatted like '10.0.%' which will match all the IPs starting with '10.0.'. The patch compiles fine and does the intended job but since I am not a professional developer, I am not sure everything is thread safe.

[renecannao]

Hi Yves,
thank you for the PR!

The if statements assumes that clients use only IPv4 , while also IPv6 is supported.
I think should become:

if (strlen(qr->client_addr) >= INET6_ADDRSTRLEN) {
	proxy_error("query rule %d has an invalid client_addr\n", qr->rule_id);
	continue;
}
char net[INET6_ADDRSTRLEN];

What do you think?
Other than that, everything else makes sense to me.

[y-trudeau]

Hi René, looks good to me, I forgot about ipv6.

[renecannao]

Some extra thoughts on this, performance optimizations:
a) input validation ( if (strlen(qr->client_addr) > ) should be done only once, when the rule is loaded
b) QP_rule_t should remember if there is a wildcard in client_addr and its position if present, so to avoid strchr and few strlen, and start strncmp as soon as possible.

I will use this PR as a baseline for a new commit.

Thank you!

[renecannao]

New check implemented in d1a14e6

Input validation:

• client_addr not longer than INET6_ADDRSTRLEN
• % allowed only at the end of client_addr

Query rule itself remembers if there is a wildcard or not.
If there is a wildcard compares string till the wildcard.
If client_addr=='%' , it is a match all.