authd: implement DNS module

authd/Makefile.am

@@ -3,5 +3,5 @@ AM_CFLAGS=$(WARNFLAGS)
 AM_CPPFLAGS = -I../include -I../libratbox/include 
 
 
-authd_SOURCES = authd.c res.c reslib.c
+authd_SOURCES = authd.c res.c reslib.c dns.c
 authd_LDADD = ../libratbox/src/libratbox.la

authd/Makefile.in

@@ -107,7 +107,8 @@ CONFIG_CLEAN_FILES =
 CONFIG_CLEAN_VPATH_FILES =
 am__installdirs = "$(DESTDIR)$(pkglibexecdir)"
 PROGRAMS = $(pkglibexec_PROGRAMS)
-am_authd_OBJECTS = authd.$(OBJEXT) res.$(OBJEXT) reslib.$(OBJEXT)
+am_authd_OBJECTS = authd.$(OBJEXT) res.$(OBJEXT) reslib.$(OBJEXT) \
+	dns.$(OBJEXT)
 authd_OBJECTS = $(am_authd_OBJECTS)
 authd_DEPENDENCIES = ../libratbox/src/libratbox.la
 AM_V_lt = $(am__v_lt_@AM_V@)
@@ -358,7 +359,7 @@ top_builddir = @top_builddir@
 top_srcdir = @top_srcdir@
 AM_CFLAGS = $(WARNFLAGS)
 AM_CPPFLAGS = -I../include -I../libratbox/include 
-authd_SOURCES = authd.c res.c reslib.c
+authd_SOURCES = authd.c res.c reslib.c dns.c
 authd_LDADD = ../libratbox/src/libratbox.la
 all: all-am
 
@@ -454,6 +455,7 @@ distclean-compile:
 	-rm -f *.tab.c
 
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/authd.Po@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/dns.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/res.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/reslib.Po@am__quote@
 

authd/authd.c

@@ -24,7 +24,9 @@
 #define MAXPARA 10
 
 rb_helper *authd_helper = NULL;
-authd_cmd_handler authd_cmd_handlers[255] = {};
+authd_cmd_handler authd_cmd_handlers[255] = {
+	['D'] = resolve_dns,
+};
 
 static void
 parse_request(rb_helper *helper)
@@ -103,6 +105,11 @@ main(int argc, char *argv[])
 		exit(1);
 	}
 
+	rb_set_time();
+	setup_signals();
+	init_resolver();
+	rb_init_prng(NULL, RB_PRNG_DEFAULT);
+
 	rb_helper_loop(authd_helper, 0);
 
 	return 0;

authd/authd.h

@@ -0,0 +1,35 @@
+/* authd/dns.h - header for authd DNS functions
+ * Copyright (c) 2016 William Pitcock <nenolod@dereferenced.org>
+ *
+ * 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.
+ */
+
+#ifndef _AUTHD_H
+#define _AUTHD_H
+
+#include <ratbox_lib.h>
+#include <stdio.h>
+
+#include "setup.h"
+#include "common.h"
+
+extern rb_helper *authd_helper;
+
+typedef void (*authd_cmd_handler)(int parc, char *parv[]);
+extern authd_cmd_handler authd_cmd_handlers[255];
+
+#endif

authd/dns.c

@@ -0,0 +1,137 @@
+/* authd/dns.h - header for authd DNS functions
+ * Copyright (c) 2016 William Pitcock <nenolod@dereferenced.org>
+ *
+ * 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 "authd.h"
+#include "dns.h"
+
+static void
+submit_dns_answer(void *userdata, struct DNSReply *reply)
+{
+	struct dns_request *req = userdata;
+	char response[64] = "*";
+	char status = 'E';
+
+	if (reply == NULL)
+	{
+		rb_helper_write(authd_helper, "E %s E %c *\n", req->reqid, req->type);
+		goto cleanup;
+	}
+
+	switch (req->type)
+	{
+	case '4':
+		if (GET_SS_FAMILY(&reply->addr) == AF_INET)
+		{
+			status = 'O';
+			rb_inet_ntop_sock((struct sockaddr *) &reply->addr, response, sizeof(response));
+		}
+		break;
+#ifdef RB_IPV6
+	case '6':
+		if (GET_SS_FAMILY(&reply->addr) == AF_INET6)
+		{
+			char tmpres[63];
+			rb_inet_ntop_sock((struct sockaddr *) &reply->addr, tmpres, sizeof(tmpres));
+
+			if (*tmpres == ':')
+			{
+				rb_strlcpy(response, "0", sizeof(response));
+				rb_strlcat(response, tmpres, sizeof(response));
+			}
+			else
+				rb_strlcpy(response, tmpres, sizeof(response));
+
+			status = 'O';
+		}
+		break;
+#endif
+	case 'R':
+		{
+			struct sockaddr_in *ip, *ip_fwd;
+			ip = (struct sockaddr_in *) &req->addr;
+			ip_fwd = (struct sockaddr_in *) &reply->addr;
+
+			if(ip->sin_addr.s_addr == ip_fwd->sin_addr.s_addr && strlen(reply->h_name) < 63)
+			{
+				rb_strlcpy(response, reply->h_name, sizeof(response));
+				status = 'O';
+			}
+		}
+		break;
+#ifdef RB_IPV6
+	case 'S':
+		{
+			struct sockaddr_in6 *ip, *ip_fwd;
+			ip = (struct sockaddr_in6 *) &req->addr;
+			ip_fwd = (struct sockaddr_in6 *) &reply->addr;
+
+			if(memcmp(&ip->sin6_addr, &ip_fwd->sin6_addr, sizeof(struct in6_addr)) == 0 && strlen(reply->h_name) < 63)
+			{
+				rb_strlcpy(response, reply->h_name, sizeof(response));
+				status = 'O';
+			}
+		}
+		break;
+#endif
+	default:
+		exit(7);
+	}
+
+	rb_helper_write(authd_helper, "E %s %c %c %s\n", req->reqid, status, req->type, response);
+cleanup:
+	rb_free(req);
+}
+
+void
+resolve_dns(int parc, char *parv[])
+{
+	struct dns_request *req;
+	char *requestid = parv[1];
+	char *qtype = parv[2];
+	char *rec = parv[3];
+	int type;
+
+	req = rb_malloc(sizeof(*req));
+	rb_strlcpy(req->reqid, requestid, sizeof(req->reqid));
+	req->type = *qtype;
+
+	switch (req->type)
+	{
+	case '4':
+		type = T_A;
+		if(!rb_inet_pton_sock(rec, (struct sockaddr *) &req->addr))
+			exit(6);
+		break;
+	case '6':
+		type = T_AAAA;
+		if(!rb_inet_pton_sock(rec, (struct sockaddr *) &req->addr))
+			exit(6);
+		break;
+	case 'R':
+	case 'S':
+		type = T_PTR;
+		break;
+	}
+
+	req->query.ptr = req;
+	req->query.callback = submit_dns_answer;
+
+	gethost_byname_type(rec, &req->query, type);
+}

authd/dns.h

@@ -0,0 +1,39 @@
+/* authd/dns.h - header for authd DNS functions
+ * Copyright (c) 2016 William Pitcock <nenolod@dereferenced.org>
+ *
+ * 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.
+ */
+
+#ifndef _AUTHD_DNS_H
+#define _AUTHD_DNS_H
+
+#define DNS_REQ_IDLEN 10
+
+#include "res.h"
+#include "reslib.h"
+
+struct dns_request
+{
+	struct DNSQuery query;
+	char reqid[DNS_REQ_IDLEN];
+	struct rb_sockaddr_storage addr;
+	char type;
+};
+
+extern void resolve_dns(int parc, char *parv[]);
+
+#endif