solanum/ircd/ratelimit.c

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/*
2020-10-15 14:51:12 +00:00
* Solanum: a slightly advanced ircd
* ratelimit.c: Per-client ratelimiting for high-bandwidth commands.
*
* Copyright (c) 2012 Keith Buck <mr_flea -at- esper.net>
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice is present in all copies.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include "stdinc.h"
#include "s_conf.h"
#include "s_stats.h"
#include "ratelimit.h"
#include "s_assert.h"
/*
* ratelimit_client(struct Client *client_p, int penalty)
*
* Applies a penalty to a client for executing a rate-limited command.
*
* Inputs:
* - the client to be rate-limited
* - the penalty to apply
*
* Outputs:
* - 1 if the user has been penalized and the command should be
* allowed to execute
* - 0 if the command should not execute and the user has not
* been penalized (they are executing commands too fast and have
* been rate-limited)
* The caller should return RPL_LOAD2HI
*
* Side effects:
* - The ratelimit for the user will be initialized if it hasn't
* been initialized yet.
*/
int ratelimit_client(struct Client *client_p, unsigned int penalty)
{
s_assert(client_p);
s_assert(MyClient(client_p));
if (!client_p->localClient->ratelimit)
{
/* Not initialized yet - do it now. */
client_p->localClient->ratelimit = rb_current_time() - ConfigFileEntry.max_ratelimit_tokens;
}
/* Don't make it impossible to execute anything. */
if (penalty > (unsigned int)ConfigFileEntry.max_ratelimit_tokens)
penalty = ConfigFileEntry.max_ratelimit_tokens;
if (client_p->localClient->ratelimit <= rb_current_time() - ConfigFileEntry.max_ratelimit_tokens)
{
client_p->localClient->ratelimit = rb_current_time() - ConfigFileEntry.max_ratelimit_tokens + penalty;
return 1;
}
if (client_p->localClient->ratelimit + penalty > rb_current_time())
{
ServerStats.is_rl++;
return 0;
}
client_p->localClient->ratelimit += penalty;
return 1;
}
/*
* ratelimit_client_who(struct Client *client_p, int penalty)
*
* Rate-limits a client for a WHO query if they have no remaining "free"
* WHO queries to execute.
*
* Inputs:
* - same as ratelimit_client
*
* Outputs:
* - same as ratelimit_client
*
* Side effects:
* - A "free who" token will be removed from the user if one exists.
* If one doesn't exist, the user will be ratelimited as normal.
*/
int ratelimit_client_who(struct Client *client_p, unsigned int penalty)
{
s_assert(client_p);
s_assert(MyClient(client_p));
if (client_p->localClient->join_who_credits)
{
--client_p->localClient->join_who_credits;
return 1;
}
return ratelimit_client(client_p, penalty);
}
/*
* credit_client_join(struct Client *client_p)
*
* Gives a user a credit to execute a WHO for joining a channel.
*
* Inputs:
* - the client to be credited
*
* Outputs:
* - (none)
*
* Side effects:
* - (none)
*/
void credit_client_join(struct Client *client_p)
{
s_assert(client_p);
s_assert(MyClient(client_p));
++client_p->localClient->join_who_credits;
}