solanum-vs-hackint-and-char.../authd/providers/blacklist.c

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/*
* charybdis: A slightly useful ircd.
* blacklist.c: Manages DNS blacklist entries and lookups
*
* Copyright (C) 2006-2011 charybdis development team
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* 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.
*/
/* Originally written for charybdis circa 2006 (by nenolod?).
* Tweaked for authd. Some functions and structs renamed. Public/private
* interfaces have been shifted around. Some code has been cleaned up too.
* -- Elizafox 24 March 2016
*/
#include "authd.h"
#include "defaults.h"
#include "provider.h"
#include "notice.h"
#include "stdinc.h"
#include "dns.h"
#define SELF_PID (blacklist_provider.id)
typedef enum filter_t
{
FILTER_ALL = 1,
FILTER_LAST = 2,
} filter_t;
/* Blacklist accepted IP types */
#define IPTYPE_IPV4 1
#define IPTYPE_IPV6 2
/* A configured DNSBL */
struct blacklist
{
char host[IRCD_RES_HOSTLEN + 1];
char reason[BUFSIZE]; /* Reason template (ircd fills in the blanks) */
uint8_t iptype; /* IP types supported */
rb_dlink_list filters; /* Filters for queries */
bool delete; /* If true delete when no clients */
int refcount; /* When 0 and delete is set, remove this blacklist */
unsigned int hits;
time_t lastwarning; /* Last warning about garbage replies sent */
};
/* A lookup in progress for a particular DNSBL for a particular client */
struct blacklist_lookup
{
struct blacklist *bl; /* Blacklist we're checking */
struct auth_client *auth; /* Client */
struct dns_query *query; /* DNS query pointer */
rb_dlink_node node;
};
/* A blacklist filter */
struct blacklist_filter
{
filter_t type; /* Type of filter */
char filter[HOSTIPLEN]; /* The filter itself */
rb_dlink_node node;
};
/* Blacklist user data attached to auth_client instance */
struct blacklist_user
{
rb_dlink_list queries; /* Blacklist queries in flight */
};
/* public interfaces */
static void blacklists_destroy(void);
static bool blacklists_start(struct auth_client *);
static inline void blacklists_generic_cancel(struct auth_client *, const char *);
static void blacklists_timeout(struct auth_client *);
static void blacklists_cancel(struct auth_client *);
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static void blacklists_cancel_none(struct auth_client *);
/* private interfaces */
static void unref_blacklist(struct blacklist *);
static struct blacklist *new_blacklist(const char *, const char *, uint8_t, rb_dlink_list *);
static struct blacklist *find_blacklist(const char *);
static bool blacklist_check_reply(struct blacklist_lookup *, const char *);
static void blacklist_dns_callback(const char *, bool, query_type, void *);
static void initiate_blacklist_dnsquery(struct blacklist *, struct auth_client *);
/* Variables */
static rb_dlink_list blacklist_list = { NULL, NULL, 0 };
static int blacklist_timeout = BLACKLIST_TIMEOUT_DEFAULT;
/* private interfaces */
static void
unref_blacklist(struct blacklist *bl)
{
rb_dlink_node *ptr, *nptr;
bl->refcount--;
if (bl->delete && bl->refcount <= 0)
{
RB_DLINK_FOREACH_SAFE(ptr, nptr, bl->filters.head)
{
rb_dlinkDelete(ptr, &bl->filters);
rb_free(ptr);
}
rb_dlinkFindDestroy(bl, &blacklist_list);
rb_free(bl);
}
}
static struct blacklist *
new_blacklist(const char *name, const char *reason, uint8_t iptype, rb_dlink_list *filters)
{
struct blacklist *bl;
if (name == NULL || reason == NULL || iptype == 0)
return NULL;
if((bl = find_blacklist(name)) == NULL)
{
bl = rb_malloc(sizeof(struct blacklist));
rb_dlinkAddAlloc(bl, &blacklist_list);
}
else
bl->delete = false;
rb_strlcpy(bl->host, name, IRCD_RES_HOSTLEN + 1);
rb_strlcpy(bl->reason, reason, BUFSIZE);
bl->iptype = iptype;
rb_dlinkMoveList(filters, &bl->filters);
bl->lastwarning = 0;
return bl;
}
static struct blacklist *
find_blacklist(const char *name)
{
rb_dlink_node *ptr;
RB_DLINK_FOREACH(ptr, blacklist_list.head)
{
struct blacklist *bl = (struct blacklist *)ptr->data;
if (!strcasecmp(bl->host, name))
return bl;
}
return NULL;
}
static inline bool
blacklist_check_reply(struct blacklist_lookup *bllookup, const char *ipaddr)
{
struct blacklist *bl = bllookup->bl;
const char *lastoctet;
rb_dlink_node *ptr;
/* No filters and entry found - thus positive match */
if (!rb_dlink_list_length(&bl->filters))
return true;
/* Below will prolly have to change if IPv6 address replies are sent back */
if ((lastoctet = strrchr(ipaddr, '.')) == NULL || *(++lastoctet) == '\0')
goto blwarn;
RB_DLINK_FOREACH(ptr, bl->filters.head)
{
struct blacklist_filter *filter = ptr->data;
const char *cmpstr;
if (filter->type == FILTER_ALL)
cmpstr = ipaddr;
else if (filter->type == FILTER_LAST)
cmpstr = lastoctet;
else
{
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warn_opers(L_CRIT, "Blacklist: Unknown blacklist filter type (host %s): %d",
bl->host, filter->type);
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exit(EX_PROVIDER_ERROR);
}
if (strcmp(cmpstr, filter->filter) == 0)
/* Match! */
return true;
}
return false;
blwarn:
if (bl->lastwarning + 3600 < rb_current_time())
{
warn_opers(L_WARN, "Garbage/undecipherable reply received from blacklist %s (reply %s)",
bl->host, ipaddr);
bl->lastwarning = rb_current_time();
}
return false;
}
static void
blacklist_dns_callback(const char *result, bool status, query_type type, void *data)
{
struct blacklist_lookup *bllookup = (struct blacklist_lookup *)data;
struct blacklist_user *bluser;
struct blacklist *bl;
struct auth_client *auth;
lrb_assert(bllookup != NULL);
lrb_assert(bllookup->auth != NULL);
bl = bllookup->bl;
auth = bllookup->auth;
if((bluser = get_provider_data(auth, SELF_PID)) == NULL)
return;
if (result != NULL && status && blacklist_check_reply(bllookup, result))
{
/* Match found, so proceed no further */
bl->hits++;
reject_client(auth, SELF_PID, bl->host, bl->reason);
blacklists_cancel(auth);
return;
}
unref_blacklist(bl);
cancel_query(bllookup->query); /* Ignore future responses */
rb_dlinkDelete(&bllookup->node, &bluser->queries);
rb_free(bllookup);
if(!rb_dlink_list_length(&bluser->queries))
{
/* Done here */
notice_client(auth->cid, "*** IP not found in DNS blacklist%s",
rb_dlink_list_length(&blacklist_list) > 1 ? "s" : "");
rb_free(bluser);
set_provider_data(auth, SELF_PID, NULL);
set_provider_timeout_absolute(auth, SELF_PID, 0);
provider_done(auth, SELF_PID);
auth_client_unref(auth);
}
}
static void
initiate_blacklist_dnsquery(struct blacklist *bl, struct auth_client *auth)
{
struct blacklist_lookup *bllookup = rb_malloc(sizeof(struct blacklist_lookup));
struct blacklist_user *bluser = get_provider_data(auth, SELF_PID);
char buf[IRCD_RES_HOSTLEN + 1];
int aftype;
bllookup->bl = bl;
bllookup->auth = auth;
aftype = GET_SS_FAMILY(&auth->c_addr);
if((aftype == AF_INET && (bl->iptype & IPTYPE_IPV4) == 0) ||
(aftype == AF_INET6 && (bl->iptype & IPTYPE_IPV6) == 0))
/* Incorrect blacklist type for this IP... */
{
rb_free(bllookup);
return;
}
build_rdns(buf, sizeof(buf), &auth->c_addr, bl->host);
bllookup->query = lookup_ip(buf, AF_INET, blacklist_dns_callback, bllookup);
rb_dlinkAdd(bllookup, &bllookup->node, &bluser->queries);
bl->refcount++;
}
static inline bool
lookup_all_blacklists(struct auth_client *auth)
{
struct blacklist_user *bluser = get_provider_data(auth, SELF_PID);
rb_dlink_node *ptr;
int iptype;
if(GET_SS_FAMILY(&auth->c_addr) == AF_INET)
iptype = IPTYPE_IPV4;
#ifdef RB_IPV6
else if(GET_SS_FAMILY(&auth->c_addr) == AF_INET6)
iptype = IPTYPE_IPV6;
#endif
else
return false;
notice_client(auth->cid, "*** Checking your IP against DNS blacklist%s",
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rb_dlink_list_length(&blacklist_list) > 1 ? "s" : "");
RB_DLINK_FOREACH(ptr, blacklist_list.head)
{
struct blacklist *bl = (struct blacklist *)ptr->data;
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if (!bl->delete && (bl->iptype & iptype))
initiate_blacklist_dnsquery(bl, auth);
}
if(!rb_dlink_list_length(&bluser->queries))
/* None checked. */
return false;
set_provider_timeout_relative(auth, SELF_PID, blacklist_timeout);
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return true;
}
static inline void
delete_blacklist(struct blacklist *bl)
{
if (bl->refcount > 0)
bl->delete = true;
else
{
rb_dlinkFindDestroy(bl, &blacklist_list);
rb_free(bl);
}
}
static void
delete_all_blacklists(void)
{
rb_dlink_node *ptr, *nptr;
RB_DLINK_FOREACH_SAFE(ptr, nptr, blacklist_list.head)
{
delete_blacklist(ptr->data);
}
}
/* public interfaces */
static bool
blacklists_start(struct auth_client *auth)
{
uint32_t rdns_pid, ident_pid;
lrb_assert(get_provider_data(auth, SELF_PID) == NULL);
if(!rb_dlink_list_length(&blacklist_list))
/* Nothing to do... */
return true;
auth_client_ref(auth);
set_provider_data(auth, SELF_PID, rb_malloc(sizeof(struct blacklist_user)));
if((!get_provider_id("rdns", &rdns_pid) || is_provider_done(auth, rdns_pid)) &&
(!get_provider_id("ident", &ident_pid) || is_provider_done(auth, ident_pid)))
{
/* Start the lookup if ident and rdns are finished, or not loaded. */
if(!lookup_all_blacklists(auth))
{
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blacklists_cancel_none(auth);
return true;
}
}
set_provider_running(auth, SELF_PID);
return true;
}
/* This is called every time a provider is completed as long as we are marked not done */
static void
blacklists_initiate(struct auth_client *auth, uint32_t provider)
{
struct blacklist_user *bluser = get_provider_data(auth, SELF_PID);
uint32_t rdns_pid, ident_pid;
lrb_assert(provider != SELF_PID);
lrb_assert(!is_provider_done(auth, SELF_PID));
lrb_assert(rb_dlink_list_length(&blacklist_list) > 0);
if(bluser == NULL || rb_dlink_list_length(&bluser->queries))
/* Nothing to do */
return;
else if((!get_provider_id("rdns", &rdns_pid) || is_provider_done(auth, rdns_pid)) &&
(!get_provider_id("ident", &ident_pid) || is_provider_done(auth, ident_pid)))
{
/* Don't start until ident and rdns are finished (or not loaded) */
return;
}
else
{
if(!lookup_all_blacklists(auth))
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blacklists_cancel_none(auth);
}
}
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static inline void
blacklists_generic_cancel(struct auth_client *auth, const char *message)
{
rb_dlink_node *ptr, *nptr;
struct blacklist_user *bluser = get_provider_data(auth, SELF_PID);
if(bluser == NULL)
return;
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if(rb_dlink_list_length(&bluser->queries))
{
notice_client(auth->cid, message);
RB_DLINK_FOREACH_SAFE(ptr, nptr, bluser->queries.head)
{
struct blacklist_lookup *bllookup = ptr->data;
cancel_query(bllookup->query);
unref_blacklist(bllookup->bl);
rb_dlinkDelete(&bllookup->node, &bluser->queries);
rb_free(bllookup);
}
}
rb_free(bluser);
set_provider_data(auth, SELF_PID, NULL);
set_provider_timeout_absolute(auth, SELF_PID, 0);
provider_done(auth, SELF_PID);
auth_client_unref(auth);
}
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static void
blacklists_timeout(struct auth_client *auth)
{
blacklists_generic_cancel(auth, "*** No response from DNS blacklists");
}
static void
blacklists_cancel(struct auth_client *auth)
{
blacklists_generic_cancel(auth, "*** Aborting DNS blacklist checks");
}
static void
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blacklists_cancel_none(struct auth_client *auth)
{
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blacklists_generic_cancel(auth, "*** Could not check DNS blacklists");
}
static void
blacklists_destroy(void)
{
rb_dictionary_iter iter;
struct auth_client *auth;
RB_DICTIONARY_FOREACH(auth, &iter, auth_clients)
{
blacklists_cancel(auth);
/* auth is now invalid as we have no reference */
}
delete_all_blacklists();
}
static void
add_conf_blacklist(const char *key, int parc, const char **parv)
{
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rb_dlink_list filters = { NULL, NULL, 0 };
char *tmp, *elemlist = rb_strdup(parv[2]);
uint8_t iptype;
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if(*elemlist == '*')
goto end;
for(char *elem = rb_strtok_r(elemlist, ",", &tmp); elem; elem = rb_strtok_r(NULL, ",", &tmp))
{
struct blacklist_filter *filter = rb_malloc(sizeof(struct blacklist_filter));
int dot_c = 0;
filter_t type = FILTER_LAST;
/* Check blacklist filter type and for validity */
for(char *c = elem; *c != '\0'; c++)
{
if(*c == '.')
{
if(++dot_c > 3)
{
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warn_opers(L_CRIT, "Blacklist: addr_conf_blacklist got a bad filter (too many octets)");
exit(EX_PROVIDER_ERROR);
}
type = FILTER_ALL;
}
else if(!isdigit(*c))
{
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warn_opers(L_CRIT, "Blacklist: addr_conf_blacklist got a bad filter (invalid character in blacklist filter: %c)",
*c);
exit(EX_PROVIDER_ERROR);
}
}
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if(dot_c > 0 && dot_c < 3)
{
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warn_opers(L_CRIT, "Blacklist: addr_conf_blacklist got a bad filter (insufficient octets)");
exit(EX_PROVIDER_ERROR);
}
filter->type = type;
rb_strlcpy(filter->filter, elem, sizeof(filter->filter));
rb_dlinkAdd(filter, &filter->node, &filters);
}
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end:
rb_free(elemlist);
iptype = atoi(parv[1]) & 0x3;
if(new_blacklist(parv[0], parv[3], iptype, &filters) == NULL)
{
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warn_opers(L_CRIT, "Blacklist: addr_conf_blacklist got a malformed blacklist");
exit(EX_PROVIDER_ERROR);
}
}
static void
del_conf_blacklist(const char *key, int parc, const char **parv)
{
struct blacklist *bl = find_blacklist(parv[0]);
if(bl == NULL)
{
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/* Not fatal for now... */
warn_opers(L_WARN, "Blacklist: tried to remove nonexistent blacklist %s", parv[0]);
return;
}
delete_blacklist(bl);
}
static void
del_conf_blacklist_all(const char *key, int parc, const char **parv)
{
delete_all_blacklists();
}
static void
add_conf_blacklist_timeout(const char *key, int parc, const char **parv)
{
int timeout = atoi(parv[0]);
if(timeout < 0)
{
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warn_opers(L_CRIT, "Blacklist: blacklist timeout < 0 (value: %d)", timeout);
exit(EX_PROVIDER_ERROR);
}
blacklist_timeout = timeout;
}
#if 0
static void
blacklist_stats(uint32_t rid, char letter)
{
rb_dlink_node *ptr;
RB_DLINK_FOREACH(ptr, blacklist_list.head)
{
struct blacklist *bl = ptr->data;
if(bl->delete)
continue;
stats_result(rid, letter, "%s %hhu %u", bl->host, bl->iptype, bl->hits);
}
stats_done(rid, letter);
}
#endif
struct auth_opts_handler blacklist_options[] =
{
{ "rbl", 4, add_conf_blacklist },
{ "rbl_del", 1, del_conf_blacklist },
{ "rbl_del_all", 0, del_conf_blacklist_all },
{ "rbl_timeout", 1, add_conf_blacklist_timeout },
{ NULL, 0, NULL },
};
struct auth_provider blacklist_provider =
{
.name = "blacklist",
.letter = 'B',
.destroy = blacklists_destroy,
.start = blacklists_start,
.cancel = blacklists_cancel,
.timeout = blacklists_timeout,
.completed = blacklists_initiate,
.opt_handlers = blacklist_options,
/* .stats_handler = { 'B', blacklist_stats }, */
};