unrealircd/src/modules/extbans/timedban.c

507 lines
14 KiB
C

/*
* timedban - Timed bans that are automatically unset.
* (C) Copyright 2009-2017 Bram Matthys (Syzop) and the UnrealIRCd team.
* License: GPLv2 or later
*
* This module adds an extended ban ~t:time:mask
* Where 'time' is the time in minutes after which the ban will be removed.
* Where 'mask' is any banmask that is normally valid.
*
* Note that this extended ban is rather special in the sense that
* it permits (crazy) triple-extbans to be set, such as:
* +b ~t:1:~q:~a:Account
* (=a temporary 1min ban to mute a user with services account Account)
* +e ~t:1440:~m:moderated:*!*@host
* (=user with *!*@host may speak through +m for the next 1440m / 24h)
*
* The triple-extbans / double-stacking requires special routines that
* are based on parts of the core and special recursion checks.
* If you are looking for inspiration of coding your own extended ban
* then look at another extended ban * module as this module is not a
* good starting point ;)
*/
#include "unrealircd.h"
/* Maximum time (in minutes) for a ban */
#define TIMEDBAN_MAX_TIME 9999
/* Maximum length of a ban */
#define MAX_LENGTH 128
/* Split timeout event in <this> amount of iterations */
#define TIMEDBAN_TIMER_ITERATION_SPLIT 4
/* Call timeout event every <this> seconds.
* NOTE: until all channels are processed it takes
* TIMEDBAN_TIMER_ITERATION_SPLIT * TIMEDBAN_TIMER.
*/
#define TIMEDBAN_TIMER 2
/* We allow a ban to (potentially) expire slightly before the deadline.
* For example with TIMEDBAN_TIMER_ITERATION_SPLIT=4 and TIMEDBAN_TIMER=2
* a 1 minute ban would expire at 56-63 seconds, rather than 60-67 seconds.
* This is usually preferred.
*/
#define TIMEDBAN_TIMER_DELTA ((TIMEDBAN_TIMER_ITERATION_SPLIT*TIMEDBAN_TIMER)/2)
ModuleHeader MOD_HEADER
= {
"extbans/timedban",
"1.0",
"ExtBan ~t: automatically removed timed bans",
"UnrealIRCd Team",
"unrealircd-6",
};
/* Forward declarations */
const char *timedban_extban_conv_param(BanContext *b, Extban *extban);
int timedban_extban_is_ok(BanContext *b);
int timedban_is_banned(BanContext *b);
void add_send_mode_param(Channel *channel, Client *from, char what, char mode, char *param);
char *timedban_chanmsg(Client *, Client *, Channel *, char *, int);
EVENT(timedban_timeout);
MOD_TEST()
{
return MOD_SUCCESS;
}
MOD_INIT()
{
ExtbanInfo extban;
MARK_AS_OFFICIAL_MODULE(modinfo);
memset(&extban, 0, sizeof(ExtbanInfo));
extban.letter = 't';
extban.name = "time";
extban.options |= EXTBOPT_ACTMODIFIER; /* not really, but ours shouldn't be stacked from group 1 */
extban.options |= EXTBOPT_INVEX; /* also permit timed invite-only exceptions (+I) */
extban.conv_param = timedban_extban_conv_param;
extban.is_ok = timedban_extban_is_ok;
extban.is_banned = timedban_is_banned;
extban.is_banned_events = BANCHK_ALL;
if (!ExtbanAdd(modinfo->handle, extban))
{
config_error("timedban: unable to register 't' extban type!!");
return MOD_FAILED;
}
EventAdd(modinfo->handle, "timedban_timeout", timedban_timeout, NULL, TIMEDBAN_TIMER*1000, 0);
return MOD_SUCCESS;
}
MOD_LOAD()
{
return MOD_SUCCESS;
}
MOD_UNLOAD()
{
return MOD_SUCCESS;
}
/** Generic helper for our conv_param extban function.
* Mostly copied from clean_ban_mask()
* FIXME: Figure out why we have this one at all and not use conv_param? ;)
*/
const char *generic_clean_ban_mask(BanContext *b, Extban *extban)
{
char *cp, *x;
static char maskbuf[512];
char *mask;
/* Work on a copy */
strlcpy(maskbuf, b->banstr, sizeof(maskbuf));
mask = maskbuf;
cp = strchr(mask, ' ');
if (cp)
*cp = '\0';
/* Strip any ':' at beginning since that would cause a desync */
for (; (*mask && (*mask == ':')); mask++);
if (!*mask)
return NULL;
/* Forbid ASCII <= 32 in all bans */
for (x = mask; *x; x++)
if (*x <= ' ')
return NULL;
/* Extended ban? */
if (is_extended_ban(mask))
{
const char *nextbanstr;
Extban *extban = findmod_by_bantype(mask, &nextbanstr);
if (!extban)
return NULL; /* reject unknown extban */
if (extban->conv_param)
{
const char *ret;
static char retbuf[512];
BanContext *newb = safe_alloc(sizeof(BanContext));
newb->banstr = nextbanstr;
newb->conv_options = b->conv_options;
ret = extban->conv_param(newb, extban);
ret = prefix_with_extban(ret, newb, extban, retbuf, sizeof(retbuf));
safe_free(newb);
return ret;
}
/* else, do some basic sanity checks and cut it off at 80 bytes */
if ((mask[1] != ':') || (mask[2] == '\0'))
return NULL; /* require a ":<char>" after extban type */
if (strlen(mask) > 80)
mask[80] = '\0';
return mask;
}
return convert_regular_ban(mask, NULL, 0);
}
/** Convert ban to an acceptable format (or return NULL to fully reject it) */
const char *timedban_extban_conv_param(BanContext *b, Extban *extban)
{
static char retbuf[MAX_LENGTH+1];
char para[MAX_LENGTH+1];
char tmpmask[MAX_LENGTH+1];
char *durationstr; /**< Duration, such as '5' */
int duration;
char *matchby; /**< Matching method, such as 'n!u@h' */
const char *newmask; /**< Cleaned matching method, such as 'n!u@h' */
static int timedban_extban_conv_param_recursion = 0;
if (timedban_extban_conv_param_recursion)
return NULL; /* reject: recursion detected! */
strlcpy(para, b->banstr, sizeof(para)); /* work on a copy (and truncate it) */
/* ~t:duration:n!u@h for direct matching
* ~t:duration:~x:.... when calling another bantype
*/
durationstr = para;
matchby = strchr(para, ':');
if (!matchby || !matchby[1])
return NULL;
*matchby++ = '\0';
duration = atoi(durationstr);
if ((duration <= 0) || (duration > TIMEDBAN_MAX_TIME))
return NULL;
strlcpy(tmpmask, matchby, sizeof(tmpmask));
timedban_extban_conv_param_recursion++;
//newmask = extban_conv_param_nuh_or_extban(tmpmask);
b->banstr = matchby; // this was previously 'tmpmask' but then it's a copy-copy-copy.. :D
newmask = generic_clean_ban_mask(b, extban);
timedban_extban_conv_param_recursion--;
if (!newmask || (strlen(newmask) <= 1))
return NULL;
//snprintf(retbuf, sizeof(retbuf), "~t:%d:%s", duration, newmask);
snprintf(retbuf, sizeof(retbuf), "%d:%s", duration, newmask);
return retbuf;
}
int timedban_extban_syntax(Client *client, int checkt, char *reason)
{
if (MyUser(client) && (checkt == EXBCHK_PARAM))
{
sendnotice(client, "Error when setting timed ban: %s", reason);
sendnotice(client, " Syntax: +b ~t:duration:mask");
sendnotice(client, "Example: +b ~t:5:nick!user@host");
sendnotice(client, "Duration is the time in minutes after which the ban is removed (1-9999)");
sendnotice(client, "Valid masks are: nick!user@host or another extban type such as ~a, ~c, ~S, ..");
}
return 0; /* FAIL: ban rejected */
}
/** Generic helper for sub-bans, used by our "is this ban ok?" function */
int generic_ban_is_ok(BanContext *b)
{
if ((b->banstr[0] == '~') && MyUser(b->client))
{
Extban *extban;
const char *nextbanstr;
/* This portion is copied from clean_ban_mask() */
if (is_extended_ban(b->banstr) && MyUser(b->client))
{
if (RESTRICT_EXTENDEDBANS && !ValidatePermissionsForPath("immune:restrict-extendedbans",b->client,NULL,NULL,NULL))
{
if (!strcmp(RESTRICT_EXTENDEDBANS, "*"))
{
if (b->is_ok_check == EXBCHK_ACCESS_ERR)
sendnotice(b->client, "Setting/removing of extended bans has been disabled");
return 0; /* REJECT */
}
if (strchr(RESTRICT_EXTENDEDBANS, b->banstr[1]))
{
if (b->is_ok_check == EXBCHK_ACCESS_ERR)
sendnotice(b->client, "Setting/removing of extended bantypes '%s' has been disabled", RESTRICT_EXTENDEDBANS);
return 0; /* REJECT */
}
}
/* And next is inspired by cmd_mode */
extban = findmod_by_bantype(b->banstr, &nextbanstr);
if (extban && extban->is_ok)
{
b->banstr = nextbanstr;
if ((b->is_ok_check == EXBCHK_ACCESS) || (b->is_ok_check == EXBCHK_ACCESS_ERR))
{
if (!extban->is_ok(b) &&
!ValidatePermissionsForPath("channel:override:mode:extban",b->client,NULL,b->channel,NULL))
{
return 0; /* REJECT */
}
} else
if (b->is_ok_check == EXBCHK_PARAM)
{
if (!extban->is_ok(b))
{
return 0; /* REJECT */
}
}
}
}
}
/* ACCEPT:
* - not an extban; OR
* - extban with NULL is_ok; OR
* - non-existing extban character (handled by conv_param?)
*/
return 1;
}
/** Validate ban ("is this ban ok?") */
int timedban_extban_is_ok(BanContext *b)
{
char para[MAX_LENGTH+1];
char tmpmask[MAX_LENGTH+1];
char *durationstr; /**< Duration, such as '5' */
int duration;
char *matchby; /**< Matching method, such as 'n!u@h' */
char *newmask; /**< Cleaned matching method, such as 'n!u@h' */
static int timedban_extban_is_ok_recursion = 0;
int res;
/* Always permit deletion */
if (b->what == MODE_DEL)
return 1;
if (timedban_extban_is_ok_recursion)
return 0; /* Recursion detected (~t:1:~t:....) */
strlcpy(para, b->banstr, sizeof(para)); /* work on a copy (and truncate it) */
/* ~t:duration:n!u@h for direct matching
* ~t:duration:~x:.... when calling another bantype
*/
durationstr = para;
matchby = strchr(para, ':');
if (!matchby || !matchby[1])
return timedban_extban_syntax(b->client, b->is_ok_check, "Invalid syntax");
*matchby++ = '\0';
duration = atoi(durationstr);
if ((duration <= 0) || (duration > TIMEDBAN_MAX_TIME))
return timedban_extban_syntax(b->client, b->is_ok_check, "Invalid duration time");
strlcpy(tmpmask, matchby, sizeof(tmpmask));
timedban_extban_is_ok_recursion++;
//res = extban_is_ok_nuh_extban(b->client, b->channel, tmpmask, b->is_ok_check, b->what, b->ban_type);
b->banstr = tmpmask;
res = generic_ban_is_ok(b);
timedban_extban_is_ok_recursion--;
if (res == 0)
{
/* This could be anything ranging from:
* invalid n!u@h syntax, unknown (sub)extbantype,
* disabled extban type in conf, too much recursion, etc.
*/
return timedban_extban_syntax(b->client, b->is_ok_check, "Invalid matcher");
}
return 1; /* OK */
}
/** Check if the user is currently banned */
int timedban_is_banned(BanContext *b)
{
b->banstr = strchr(b->banstr, ':'); /* skip time argument */
if (!b->banstr)
return 0; /* invalid fmt */
b->banstr++; /* skip over final semicolon */
return ban_check_mask(b);
}
/** Helper to check if the ban has been expired.
*/
int timedban_has_ban_expired(Ban *ban)
{
char *banstr = ban->banstr;
char *p1, *p2;
int t;
time_t expire_on;
/* The caller has only performed a very light check (string starting
* with ~t, in the interest of performance), so we don't know yet if
* it REALLY is a timed ban. We check that first here...
*/
if (!strncmp(banstr, "~t:", 3))
p1 = banstr + 3;
else if (!strncmp(banstr, "~time:", 6))
p1 = banstr + 6;
else
return 0; /* not for us */
p2 = strchr(p1+1, ':'); /* skip time argument */
if (!p2)
return 0; /* invalid fmt */
*p2 = '\0'; /* danger.. must restore!! */
t = atoi(p1);
*p2 = ':'; /* restored.. */
expire_on = ban->when + (t * 60) - TIMEDBAN_TIMER_DELTA;
if (expire_on < TStime())
return 1;
return 0;
}
static char mbuf[512];
static char pbuf[512];
/** This removes any expired timedbans */
EVENT(timedban_timeout)
{
Channel *channel;
Ban *ban, *nextban;
static int current_iteration = 0;
if (++current_iteration >= TIMEDBAN_TIMER_ITERATION_SPLIT)
current_iteration = 0;
for (channel = channels; channel; channel = channel->nextch)
{
/* This is a very quick check, at the cost of it being
* biased since there's always a tendency of more channel
* names to start with one specific letter. But hashing
* is too costly. So we stick with this. It should be
* good enough. Alternative would be some channel->id value.
*/
if (((unsigned int)channel->name[1] % TIMEDBAN_TIMER_ITERATION_SPLIT) != current_iteration)
continue; /* not this time, maybe next */
*mbuf = *pbuf = '\0';
for (ban = channel->banlist; ban; ban=nextban)
{
nextban = ban->next;
if (!strncmp(ban->banstr, "~t", 2) && timedban_has_ban_expired(ban))
{
add_send_mode_param(channel, &me, '-', 'b', ban->banstr);
del_listmode(&channel->banlist, channel, ban->banstr);
}
}
for (ban = channel->exlist; ban; ban=nextban)
{
nextban = ban->next;
if (!strncmp(ban->banstr, "~t", 2) && timedban_has_ban_expired(ban))
{
add_send_mode_param(channel, &me, '-', 'e', ban->banstr);
del_listmode(&channel->exlist, channel, ban->banstr);
}
}
for (ban = channel->invexlist; ban; ban=nextban)
{
nextban = ban->next;
if (!strncmp(ban->banstr, "~t", 2) && timedban_has_ban_expired(ban))
{
add_send_mode_param(channel, &me, '-', 'I', ban->banstr);
del_listmode(&channel->invexlist, channel, ban->banstr);
}
}
if (*pbuf)
{
MessageTag *mtags = NULL;
new_message(&me, NULL, &mtags);
sendto_channel(channel, &me, NULL, 0, 0, SEND_LOCAL, mtags, ":%s MODE %s %s %s", me.name, channel->name, mbuf, pbuf);
sendto_server(NULL, 0, 0, mtags, ":%s MODE %s %s %s 0", me.id, channel->name, mbuf, pbuf);
free_message_tags(mtags);
*pbuf = 0;
}
}
}
#if MODEBUFLEN > 512
#error "add_send_mode_param() is not made for MODEBUFLEN > 512"
#endif
void add_send_mode_param(Channel *channel, Client *from, char what, char mode, char *param) {
static char *modes = NULL, lastwhat;
static short count = 0;
short send = 0;
if (!modes) modes = mbuf;
if (!mbuf[0]) {
modes = mbuf;
*modes++ = what;
*modes = 0;
lastwhat = what;
*pbuf = 0;
count = 0;
}
if (lastwhat != what) {
*modes++ = what;
*modes = 0;
lastwhat = what;
}
if (strlen(pbuf) + strlen(param) + 11 < MODEBUFLEN) {
if (*pbuf)
strcat(pbuf, " ");
strcat(pbuf, param);
*modes++ = mode;
*modes = 0;
count++;
}
else if (*pbuf)
send = 1;
if (count == MAXMODEPARAMS)
send = 1;
if (send)
{
MessageTag *mtags = NULL;
new_message(&me, NULL, &mtags);
sendto_channel(channel, &me, NULL, 0, 0, SEND_LOCAL, mtags, ":%s MODE %s %s %s", me.name, channel->name, mbuf, pbuf);
sendto_server(NULL, 0, 0, mtags, ":%s MODE %s %s %s 0", me.id, channel->name, mbuf, pbuf);
free_message_tags(mtags);
send = 0;
*pbuf = 0;
modes = mbuf;
*modes++ = what;
lastwhat = what;
if (count != MAXMODEPARAMS)
{
strlcpy(pbuf, param, sizeof(pbuf));
*modes++ = mode;
count = 1;
} else {
count = 0;
}
*modes = 0;
}
}