dns: new WIP client which queries authd for DNS records, not yet in use

This commit is contained in:
William Pitcock 2016-01-06 04:28:34 -06:00
parent b5e4f39625
commit 7d2852b4d1
5 changed files with 374 additions and 17 deletions

41
include/dns.h Normal file
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@ -0,0 +1,41 @@
/*
* charybdis
* dns.h: A header with the DNS functions.
*
* Copyright (C) 1990 Jarkko Oikarinen and University of Oulu, Co Center
* Copyright (C) 1996-2002 Hybrid Development Team
* Copyright (C) 2002-2012 ircd-ratbox development team
* Copyright (C) 2016 William Pitcock <nenolod@dereferenced.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301
* USA
*/
#ifndef CHARYBDIS_DNS_H
#define CHARYBDIS_DNS_H
typedef void (*DNSCB)(const char *res, int status, int aftype, void *data);
void init_authd(void);
void restart_authd(void);
void rehash_authd(void);
uint16_t lookup_hostname(const char *hostname, int aftype, DNSCB callback, void *data);
uint16_t lookup_ip(const char *hostname, int aftype, DNSCB callback, void *data);
void cancel_lookup(uint16_t xid);
void report_dns_servers(struct Client *);
#endif

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@ -23,6 +23,7 @@ libircd_la_SOURCES = \
chmode.c \
class.c \
client.c \
dns.c \
extban.c \
getopt.c \
hash.c \

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@ -137,8 +137,8 @@ am__installdirs = "$(DESTDIR)$(libircddir)" "$(DESTDIR)$(bindir)"
LTLIBRARIES = $(libircd_LTLIBRARIES)
libircd_la_DEPENDENCIES =
am_libircd_la_OBJECTS = bandbi.lo blacklist.lo cache.lo capability.lo \
channel.lo chmode.lo class.lo client.lo extban.lo getopt.lo \
hash.lo hook.lo hostmask.lo ipv4_from_ipv6.lo \
channel.lo chmode.lo class.lo client.lo dns.lo extban.lo \
getopt.lo hash.lo hook.lo hostmask.lo ipv4_from_ipv6.lo \
irc_dictionary.lo ircd.lo ircd_parser.lo ircd_lexer.lo \
ircd_signal.lo listener.lo logger.lo match.lo modules.lo \
monitor.lo newconf.lo operhash.lo packet.lo parse.lo \
@ -437,6 +437,7 @@ libircd_la_SOURCES = \
chmode.c \
class.c \
client.c \
dns.c \
extban.c \
getopt.c \
hash.c \
@ -627,6 +628,7 @@ distclean-compile:
@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/chmode.Plo@am__quote@
@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/class.Plo@am__quote@
@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/client.Plo@am__quote@
@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/dns.Plo@am__quote@
@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/extban.Plo@am__quote@
@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/getopt.Plo@am__quote@
@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/hash.Plo@am__quote@

328
ircd/dns.c Normal file
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@ -0,0 +1,328 @@
/*
* dns.c: An interface to the resolver module in authd
* (based somewhat on ircd-ratbox dns.c)
*
* Copyright (C) 2005 Aaron Sethman <androsyn@ratbox.org>
* Copyright (C) 2005-2012 ircd-ratbox development team
* Copyright (C) 2016 William Pitcock <nenolod@dereferenced.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301
* USA
*/
#include <stdinc.h>
#include <ratbox_lib.h>
#include <struct.h>
#include <ircd_defs.h>
#include <parse.h>
#include <dns.h>
#include <match.h>
#include <logger.h>
#include <s_conf.h>
#include <client.h>
#include <send.h>
#include <numeric.h>
#include <msg.h>
#define DNS_IDTABLE_SIZE 0x2000
#define DNS_HOST ((char)'H')
#define DNS_REVERSE ((char)'I')
static void submit_dns(const char, uint16_t id, int aftype, const char *addr);
static int start_authd(void);
static void parse_authd_reply(rb_helper * helper);
static void restart_authd_cb(rb_helper * helper);
static rb_helper *authd_helper;
struct dnsreq
{
DNSCB callback;
void *data;
};
static struct dnsreq querytable[DNS_IDTABLE_SIZE];
static uint16_t
assign_dns_id(void)
{
static uint16_t id = 1;
int loopcnt = 0;
while(1)
{
if(++loopcnt > DNS_IDTABLE_SIZE)
return 0;
if(id < DNS_IDTABLE_SIZE - 1 || id == 0)
id++;
else
id = 1;
if(querytable[id].callback == NULL)
break;
}
return (id);
}
static inline void
check_authd(void)
{
if(authd_helper == NULL)
restart_authd();
}
static void
handle_dns_failure(uint16_t xid)
{
struct dnsreq *req;
req = &querytable[xid];
if(req->callback == NULL)
return;
req->callback("FAILED", 0, 0, req->data);
req->callback = NULL;
req->data = NULL;
}
void
cancel_lookup(uint16_t xid)
{
querytable[xid].callback = NULL;
querytable[xid].data = NULL;
}
uint16_t
lookup_hostname(const char *hostname, int aftype, DNSCB callback, void *data)
{
struct dnsreq *req;
int aft;
uint16_t nid;
check_authd();
nid = assign_dns_id();
if((nid = assign_dns_id()) == 0)
return 0;
req = &querytable[nid];
req->callback = callback;
req->data = data;
#ifdef RB_IPV6
if(aftype == AF_INET6)
aft = 6;
else
#endif
aft = 4;
submit_dns(DNS_HOST, nid, aft, hostname);
return (nid);
}
uint16_t
lookup_ip(const char *addr, int aftype, DNSCB callback, void *data)
{
struct dnsreq *req;
int aft;
uint16_t nid;
check_authd();
if((nid = assign_dns_id()) == 0)
return 0;
req = &querytable[nid];
req->callback = callback;
req->data = data;
#ifdef RB_IPV6
if(aftype == AF_INET6)
aft = 6;
else
#endif
aft = 4;
submit_dns(DNS_REVERSE, nid, aft, addr);
return (nid);
}
static void
results_callback(const char *callid, const char *status, const char *aftype, const char *results)
{
struct dnsreq *req;
uint16_t nid;
int st;
int aft;
long lnid = strtol(callid, NULL, 16);
if(lnid > DNS_IDTABLE_SIZE || lnid == 0)
return;
nid = (uint16_t)lnid;
req = &querytable[nid];
st = atoi(status);
aft = atoi(aftype);
if(req->callback == NULL)
{
/* got cancelled..oh well */
req->data = NULL;
return;
}
#ifdef RB_IPV6
if(aft == 6)
aft = AF_INET6;
else
#endif
aft = AF_INET;
req->callback(results, st, aft, req->data);
req->callback = NULL;
req->data = NULL;
}
static char *resolver_path;
static int
start_authd(void)
{
char fullpath[PATH_MAX + 1];
#ifdef _WIN32
const char *suffix = ".exe";
#else
const char *suffix = "";
#endif
if(resolver_path == NULL)
{
snprintf(fullpath, sizeof(fullpath), "%s/authd%s", PKGLIBEXECDIR, suffix);
if(access(fullpath, X_OK) == -1)
{
snprintf(fullpath, sizeof(fullpath), "%s/libexec/charybdis/authd%s",
ConfigFileEntry.dpath, suffix);
if(access(fullpath, X_OK) == -1)
{
ilog(L_MAIN,
"Unable to execute authd in %s or %s/libexec/charybdis",
PKGLIBEXECDIR, ConfigFileEntry.dpath);
sendto_realops_snomask(SNO_GENERAL, L_ALL,
"Unable to execute resolver in %s or %s/libexec/charybdis",
PKGLIBEXECDIR, ConfigFileEntry.dpath);
return 1;
}
}
resolver_path = rb_strdup(fullpath);
}
authd_helper = rb_helper_start("authd", resolver_path, parse_authd_reply, restart_authd_cb);
if(authd_helper == NULL)
{
ilog(L_MAIN, "Unable to start authd helper: %s", strerror(errno));
sendto_realops_snomask(SNO_GENERAL, L_ALL, "Unable to start authd helper: %s", strerror(errno));
return 1;
}
ilog(L_MAIN, "resolver helper started");
sendto_realops_snomask(SNO_GENERAL, L_ALL, "resolver helper started");
rb_helper_run(authd_helper);
return 0;
}
void
report_dns_servers(struct Client *source_p)
{
#if 0
rb_dlink_node *ptr;
RB_DLINK_FOREACH(ptr, nameservers.head)
{
sendto_one_numeric(source_p, RPL_STATSDEBUG, "A %s", (char *)ptr->data);
}
#endif
}
static void
parse_authd_reply(rb_helper * helper)
{
ssize_t len;
int parc;
char dnsBuf[READBUF_SIZE];
char *parv[MAXPARA + 1];
while((len = rb_helper_read(helper, dnsBuf, sizeof(dnsBuf))) > 0)
{
parc = rb_string_to_array(dnsBuf, parv, MAXPARA+1);
if(*parv[0] == 'R')
{
if(parc != 5)
{
ilog(L_MAIN, "authd sent a result with wrong number of arguments: got %d", parc);
restart_authd();
return;
}
results_callback(parv[1], parv[2], parv[3], parv[4]);
}
else
return;
}
}
static void
submit_dns(char type, uint16_t nid, int aftype, const char *addr)
{
if(authd_helper == NULL)
{
handle_dns_failure(nid);
return;
}
rb_helper_write(authd_helper, "%c %x %d %s", type, nid, aftype, addr);
}
void
init_authd(void)
{
if(start_authd())
{
ilog(L_MAIN, "Unable to start authd helper: %s", strerror(errno));
exit(0);
}
}
static void
restart_authd_cb(rb_helper * helper)
{
ilog(L_MAIN, "authd: restart_authd_cb called, authd died?");
sendto_realops_snomask(SNO_GENERAL, L_ALL, "authd - restart_authd_cb called, authd died?");
if(helper != NULL)
{
rb_helper_close(helper);
authd_helper = NULL;
}
start_authd();
}
void
restart_authd(void)
{
restart_authd_cb(authd_helper);
}
void
rehash_resolver(void)
{
rb_helper_write(authd_helper, "R");
}

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@ -920,18 +920,3 @@ static struct DNSReply *make_dnsreply(struct reslist *request)
memcpy(&cp->addr, &request->addr, sizeof(cp->addr));
return (cp);
}
void report_dns_servers(struct Client *source_p)
{
int i;
char ipaddr[128];
for (i = 0; i < irc_nscount; i++)
{
if (!rb_inet_ntop_sock((struct sockaddr *)&(irc_nsaddr_list[i]),
ipaddr, sizeof ipaddr))
rb_strlcpy(ipaddr, "?", sizeof ipaddr);
sendto_one_numeric(source_p, RPL_STATSDEBUG,
"A %s %d", ipaddr, ns_failure_count[i]);
}
}