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

include/dns.h

@@ -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

ircd/Makefile.am

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

ircd/Makefile.in

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

ircd/dns.c

@@ -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");
+}
+

ircd/res.c

@@ -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]);
-	}
-}