4358. [test] Added American Fuzzy Lop harness that allows

			feeding fuzzed packets into BIND.
			[RT #41723]

CHANGES

+4358.	[test]		Added American Fuzzy Lop harness that allows
+			feeding fuzzed packets into BIND.
+			[RT #41723]
+
 4357.	[func]		Add the python RNDC module. [RT #42093]
 
 4356.	[func]		Add the ability to specify whether to wait for

bin/named/Makefile.in

@@ -86,7 +86,7 @@ TARGETS =	named@EXEEXT@ lwresd@EXEEXT@
 GEOIPLINKOBJS = geoip.@O@
 
 OBJS =		builtin.@O@ client.@O@ config.@O@ control.@O@ \
-		controlconf.@O@ @GEOIPLINKOBJS@ interfacemgr.@O@ \
+		controlconf.@O@ fuzz.@O@ @GEOIPLINKOBJS@ interfacemgr.@O@ \
 		listenlist.@O@ log.@O@ logconf.@O@ main.@O@ notify.@O@ \
 		query.@O@ server.@O@ sortlist.@O@ statschannel.@O@ \
 		tkeyconf.@O@ tsigconf.@O@ update.@O@ xfrout.@O@ \
@@ -102,7 +102,7 @@ SYMOBJS =	symtbl.@O@
 GEOIPLINKSRCS = geoip.c
 
 SRCS =		builtin.c client.c config.c control.c \
-		controlconf.c @GEOIPLINKSRCS@ interfacemgr.c \
+		controlconf.c fuzz.c @GEOIPLINKSRCS@ interfacemgr.c \
 		listenlist.c log.c logconf.c main.c notify.c \
 		query.c server.c sortlist.c statschannel.c \
 		tkeyconf.c tsigconf.c update.c xfrout.c \

bin/named/client.c

@@ -35,10 +35,12 @@
 #include <isc/timer.h>
 #include <isc/util.h>
 
+#include <dns/adb.h>
 #include <dns/badcache.h>
 #include <dns/db.h>
 #include <dns/dispatch.h>
 #include <dns/dnstap.h>
+#include <dns/cache.h>
 #include <dns/edns.h>
 #include <dns/events.h>
 #include <dns/message.h>
@@ -54,6 +56,7 @@
 #include <dns/view.h>
 #include <dns/zone.h>
 
+#include <named/fuzz.h>
 #include <named/interfacemgr.h>
 #include <named/log.h>
 #include <named/notify.h>
@@ -702,8 +705,15 @@ ns_client_endrequest(ns_client_t *client) {
 		client->next = NULL;
 	}
 
-	if (client->view != NULL)
+	if (client->view != NULL) {
+#ifdef ENABLE_AFL
+		if (ns_g_fuzz_type == ns_fuzz_resolver) {
+			dns_cache_clean(client->view->cache, INT_MAX);
+			dns_adb_flush(client->view->adb);
+		}
+#endif
 		dns_view_detach(&client->view);
+	}
 	if (client->opt != NULL) {
 		INSIST(dns_rdataset_isassociated(client->opt));
 		dns_rdataset_disassociate(client->opt);
@@ -727,6 +737,14 @@ ns_client_endrequest(ns_client_t *client) {
 	 * the request; that's all except the TCP flag.
 	 */
 	client->attributes &= NS_CLIENTATTR_TCP;
+#ifdef ENABLE_AFL
+	if (ns_g_fuzz_type == ns_fuzz_client ||
+	    ns_g_fuzz_type == ns_fuzz_tcpclient ||
+	    ns_g_fuzz_type == ns_fuzz_resolver) {
+		named_fuzz_notify();
+	}
+#endif /* ENABLE_AFL */
+
 }
 
 void

bin/named/controlconf.c

@@ -183,6 +183,11 @@ maybe_free_connection(controlconnection_t *conn) {
 	}
 
 	ISC_LIST_UNLINK(listener->connections, conn, link);
+#ifdef ENABLE_AFL
+	if (ns_g_fuzz_type == ns_fuzz_rndc) {
+		named_fuzz_notify();
+	}
+#endif
 	isc_mem_put(listener->mctx, conn, sizeof(*conn));
 }
 
@@ -600,6 +605,11 @@ newconnection(controllistener_t *listener, isc_socket_t *sock) {
 	if (conn->timer != NULL)
 		isc_timer_detach(&conn->timer);
 	isc_mem_put(listener->mctx, conn, sizeof(*conn));
+#ifdef ENABLE_AFL
+	if (ns_g_fuzz_type == ns_fuzz_rndc) {
+		named_fuzz_notify();
+	}
+#endif
 	return (result);
 }
 

bin/named/fuzz.c

+/*
+ * Copyright (C) 2015,2016  Internet Systems Consortium, Inc. ("ISC")
+ *
+ * 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 appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
+ * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
+ * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+ * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
+ * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+ * PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include "config.h"
+
+#include <named/fuzz.h>
+
+#ifdef ENABLE_AFL
+#include <named/globals.h>
+#include <named/server.h>
+#include <sys/errno.h>
+
+#include <isc/app.h>
+#include <isc/condition.h>
+#include <isc/mutex.h>
+#include <isc/thread.h>
+#include <isc/util.h>
+#include <named/log.h>
+#include <dns/log.h>
+
+#include <stdlib.h>
+#include <string.h>
+#include <signal.h>
+#include <arpa/inet.h>
+#include <unistd.h>
+#include <pthread.h>
+
+#ifndef __AFL_LOOP
+#error To use American Fuzzy Lop you have to set CC to afl-clang-fast!!!
+#endif
+
+/*
+ * We are using pthreads directly because we might be using it with unthreaded
+ * version of BIND, where all thread functions are mocks. Since AFL for now only
+ * works on Linux it's not a problem.
+ */
+static pthread_cond_t cond;
+static pthread_mutex_t mutex;
+static isc_boolean_t ready;
+
+
+static void *
+fuzz_main_client(void *arg) {
+	char *host;
+	char *port;
+	struct sockaddr_in servaddr;
+	int sockfd;
+	int loop;
+	void *buf;
+
+	UNUSED(arg);
+
+	/*
+	 * Parse named -A argument in the "address:port" syntax. Due to
+	 * the syntax used, this only supports IPv4 addresses.
+	 */
+
+	host = strdup(ns_g_fuzz_named_addr);
+	RUNTIME_CHECK(host != NULL);
+	port = strchr(host, ':');
+	RUNTIME_CHECK(port != NULL);
+	*port = 0;
+	++port;
+
+	memset(&servaddr, 0, sizeof (servaddr));
+	servaddr.sin_family = AF_INET;
+	RUNTIME_CHECK(inet_pton(AF_INET, host, &servaddr.sin_addr) == 1);
+	servaddr.sin_port = htons(atoi(port));
+
+	free(host);
+
+	/* Wait for named to start. */
+	while (!ns_g_run_done) {
+		usleep(10000);
+	}
+
+	sockfd = socket(AF_INET, SOCK_DGRAM, 0);
+	RUNTIME_CHECK(sockfd != -1);
+
+	buf = malloc(65536);
+	RUNTIME_CHECK(buf != NULL);
+
+	loop = 100000;
+	while (loop--) {
+		ssize_t length;
+
+		length = read(0, buf, 65536);
+		if (length <= 0) {
+			usleep(1000000);
+			continue;
+		}
+
+		if (length > 4096) {
+			if (getenv("AFL_CMIN")) {
+				ns_server_flushonshutdown(ns_g_server,
+							  ISC_FALSE);
+				isc_app_shutdown();
+				return (NULL);
+			}
+			raise(SIGSTOP);
+			continue;
+		}
+
+		RUNTIME_CHECK(pthread_mutex_lock(&mutex) == ISC_R_SUCCESS);
+
+		ready = ISC_FALSE;
+
+		ssize_t sent;
+
+		sent = sendto(sockfd, buf, length, 0,
+			      (struct sockaddr *) &servaddr, sizeof(servaddr));
+		RUNTIME_CHECK(sent == length);
+
+		/* unclog */
+		recvfrom(sockfd, buf, 65536, MSG_DONTWAIT, NULL, NULL);
+
+		while (!ready)
+			pthread_cond_wait(&cond, &mutex);
+
+		RUNTIME_CHECK(pthread_mutex_unlock(&mutex) == ISC_R_SUCCESS);
+	}
+
+	free(buf);
+	close(sockfd);
+
+	ns_server_flushonshutdown(ns_g_server, ISC_FALSE);
+	isc_app_shutdown();
+
+	return (NULL);
+}
+
+static void *
+fuzz_main_resolver(void *arg) {
+	char *shost, *sport, *rhost, *rport;
+	/* Query for A? aaaaaaaaaa.example. */
+	char respacket[] =
+		 "\0\0\1 \0\1\0\0\0\0\0\0\naaaaaaaaaa\7example\0\0\1\0\1";
+	struct sockaddr_in servaddr, recaddr, recvaddr;
+	int sockfd;
+	int listenfd;
+	int loop;
+	char *buf, *rbuf;
+
+	UNUSED(arg);
+
+	/*
+	 * Parse named -A argument in the "laddress:sport:raddress:rport"
+	 * syntax.  Due to the syntax used, this only supports IPv4 addresses.
+	 */
+
+	shost = strdup(ns_g_fuzz_named_addr);
+	RUNTIME_CHECK(shost != NULL);
+	sport = strchr(shost, ':');
+	RUNTIME_CHECK(sport != NULL);
+	*sport = 0;
+	sport++;
+	rhost = strchr(sport, ':');
+	RUNTIME_CHECK(rhost != NULL);
+	*rhost = 0;
+	rhost++;
+	rport = strchr(rhost, ':');
+	RUNTIME_CHECK(rport != NULL);
+	*rport = 0;
+	rport++;
+
+	memset(&servaddr, 0, sizeof (servaddr));
+	servaddr.sin_family = AF_INET;
+	RUNTIME_CHECK(inet_pton(AF_INET, shost, &servaddr.sin_addr) == 1);
+	servaddr.sin_port = htons(atoi(sport));
+
+	memset(&recaddr, 0, sizeof (recaddr));
+	recaddr.sin_family = AF_INET;
+	RUNTIME_CHECK(inet_pton(AF_INET, rhost, &recaddr.sin_addr) == 1);
+	recaddr.sin_port = htons(atoi(rport));
+
+	free(shost);
+
+	/* Wait for named to start */
+	while (!ns_g_run_done) {
+		usleep(10000);
+	}
+
+	sockfd = socket(AF_INET, SOCK_DGRAM, 0);
+	RUNTIME_CHECK(sockfd != -1);
+
+	listenfd = socket(AF_INET, SOCK_DGRAM, 0);
+	RUNTIME_CHECK(listenfd != -1);
+	RUNTIME_CHECK(bind(listenfd, (struct sockaddr *)&recaddr,
+			   sizeof(struct sockaddr_in)) == 0);
+
+	buf = malloc(65536);
+	rbuf = malloc(65536);
+	RUNTIME_CHECK(buf != NULL);
+	RUNTIME_CHECK(rbuf != NULL);
+
+	loop = 100000;
+	while (loop--) {
+		ssize_t length;
+		memset(buf, 0, 16);
+		length = read(0, buf, 65536);
+		if (length <= 0) {
+			usleep(1000000);
+			continue;
+		}
+
+		if (length > 4096) {
+			if (getenv("AFL_CMIN")) {
+				ns_server_flushonshutdown(ns_g_server,
+					ISC_FALSE);
+				isc_app_shutdown();
+				return (NULL);
+			}
+			raise(SIGSTOP);
+			continue;
+		}
+
+		if (length < 16) {
+		    length = 16;
+		}
+
+		RUNTIME_CHECK(pthread_mutex_lock(&mutex) == ISC_R_SUCCESS);
+
+		ready = ISC_FALSE;
+
+		ssize_t sent;
+		/* Randomize query ID. */
+		int id = random();
+		respacket[0] = id >> 8;
+		respacket[1] = id & 0xff;
+
+		/* flush */
+		socklen_t socklen = sizeof(recvaddr);
+		sent = recvfrom(listenfd, rbuf, 65536, MSG_DONTWAIT,
+			(struct sockaddr *) &recvaddr, &socklen);
+
+		sent = sendto(sockfd, respacket, sizeof(respacket), 0,
+		       (struct sockaddr *) &servaddr, sizeof(servaddr));
+		RUNTIME_CHECK(sent == sizeof(respacket));
+
+		socklen = sizeof(recvaddr);
+		sent = recvfrom(listenfd, rbuf, 65536, 0,
+		                (struct sockaddr *) &recvaddr, &socklen);
+		RUNTIME_CHECK(sent > 0);
+
+		/* Copy QID and set QR so that response is always processed. */
+		buf[0] = rbuf[0];
+		buf[1] = rbuf[1];
+		buf[2] |= 0x80;
+
+		sent = sendto(listenfd, buf, length, 0,
+		              (struct sockaddr *) &recvaddr, sizeof(recvaddr));
+		RUNTIME_CHECK(sent == length);
+
+		/* We might get additional questions here (e.g. for CNAME). */
+		for (;;) {
+			fd_set fds;
+			struct timeval tv;
+			int rv;
+			int max;
+
+			FD_ZERO(&fds);
+			FD_SET(listenfd, &fds);
+			FD_SET(sockfd, &fds);
+			tv.tv_sec = 10;
+			tv.tv_usec = 0;
+			max = (listenfd > sockfd ? listenfd : sockfd)+1;
+
+			rv = select(max, &fds, NULL, NULL, &tv);
+			RUNTIME_CHECK(rv > 0);
+
+			if (FD_ISSET(sockfd, &fds)) {
+				/* It's the reply, we're done. */
+				recvfrom(sockfd, buf, 65536, 0, NULL, NULL);
+				break;
+			}
+
+			/*
+			 * We've got additional question (eg. cname chain)
+			 * We are bouncing it - setting QR flag and NOERROR
+			 * rcode and sending it back.
+			 */
+
+			length = recvfrom(listenfd, buf, 65536, 0,
+				   (struct sockaddr *) &recvaddr, &socklen);
+			buf[2] |= 0x80;
+			buf[3] &= 0xF0;
+			sent = sendto(listenfd, buf, length, 0,
+				      (struct sockaddr *) &recvaddr,
+				      sizeof(recvaddr));
+			RUNTIME_CHECK(sent == length);
+		}
+
+		while (!ready)
+			pthread_cond_wait(&cond, &mutex);
+
+		RUNTIME_CHECK(pthread_mutex_unlock(&mutex) == 0);
+	}
+
+	free(buf);
+	close(sockfd);
+	ns_server_flushonshutdown(ns_g_server, ISC_FALSE);
+	isc_app_shutdown();
+
+	/*
+	 * It's here just for the signature, that's how AFL detects if it's
+	 * a 'persistent mode' binary.
+	 */
+	__AFL_LOOP(0);
+
+	return (NULL);
+}
+
+static void *
+fuzz_main_tcp(void *arg) {
+	char *host;
+	char *port;
+	struct sockaddr_in servaddr;
+	int sockfd;
+	char *buf;
+	int loop;
+
+	UNUSED(arg);
+
+	/*
+	 * Parse named -A argument in the "address:port" syntax. Due to
+	 * the syntax used, this only supports IPv4 addresses.
+	 */
+
+	host = strdup(ns_g_fuzz_named_addr);
+	RUNTIME_CHECK(host != NULL);
+	port = strchr(host, ':');
+	RUNTIME_CHECK(port != NULL);
+	*port = 0;
+	++port;
+
+	memset(&servaddr, 0, sizeof (servaddr));
+	servaddr.sin_family = AF_INET;
+	RUNTIME_CHECK(inet_pton(AF_INET, host, &servaddr.sin_addr) == 1);
+	servaddr.sin_port = htons(atoi(port));
+
+	free(host);
+
+	/* Wait for named to start */
+	while (!ns_g_run_done) {
+		usleep(10000);
+	}
+
+	buf = malloc(65539);
+	RUNTIME_CHECK(buf != NULL);
+
+	loop = 100000;
+	while (loop--) {
+		ssize_t length;
+
+		if (ns_g_fuzz_type == ns_fuzz_tcpclient) {
+			/*
+			 * To fuzz TCP client we have to put length at
+			 * the start of packet.
+			 */
+			length = read(0, buf+2, 65535);
+			buf[0] = length >> 8;
+			buf[1] = length & 0xff;
+			length += 2;
+		} else {
+			length = read(0, buf, 65535);
+		}
+		if (length <= 0) {
+			usleep(1000000);
+			continue;
+		}
+		if (ns_g_fuzz_type == ns_fuzz_http) {
+			/*
+			 * This guarantees that the request will be processed.
+			 */
+			buf[length++]='\r';
+			buf[length++]='\n';
+			buf[length++]='\r';
+			buf[length++]='\n';
+		}
+
+		RUNTIME_CHECK(pthread_mutex_lock(&mutex) == ISC_R_SUCCESS);
+
+		ready = ISC_FALSE;
+
+		ssize_t sent;
+		int yes = 1;
+		int r;
+		sockfd = socket(AF_INET, SOCK_STREAM, 0);
+
+		RUNTIME_CHECK(sockfd != -1);
+		RUNTIME_CHECK(setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR,
+					 &yes, sizeof(int)) == 0);
+
+		do {
+			r = connect(sockfd, (struct sockaddr*)&servaddr,
+				    sizeof(servaddr));
+		} while (r != 0);
+
+		sent = write(sockfd, buf, length);
+		RUNTIME_CHECK(sent == length);
+		close(sockfd);
+
+		/* unclog */
+		recvfrom(sockfd, buf, 65537, MSG_DONTWAIT, NULL, NULL);
+
+		while (!ready)
+			pthread_cond_wait(&cond, &mutex);
+
+		RUNTIME_CHECK(pthread_mutex_unlock(&mutex) == ISC_R_SUCCESS);
+	}
+
+	free(buf);
+	close(sockfd);
+	ns_server_flushonshutdown(ns_g_server, ISC_FALSE);
+	isc_app_shutdown();
+
+	return (NULL);
+}
+
+#endif /* ENABLE_AFL */
+
+void
+named_fuzz_notify(void) {
+#ifdef ENABLE_AFL
+	if (getenv("AFL_CMIN")) {
+		ns_server_flushonshutdown(ns_g_server, ISC_FALSE);
+		isc_app_shutdown();
+		return;
+	}
+
+	raise(SIGSTOP);
+
+	RUNTIME_CHECK(pthread_mutex_lock(&mutex) == 0);
+
+	ready = ISC_TRUE;
+
+	RUNTIME_CHECK(pthread_cond_signal(&cond) == 0);
+	RUNTIME_CHECK(pthread_mutex_unlock(&mutex) == 0);
+#endif /* ENABLE_AFL */
+}
+
+void
+named_fuzz_setup(void) {
+#ifdef ENABLE_AFL
+	if (getenv("__AFL_PERSISTENT") || getenv("AFL_CMIN")) {
+		pthread_t thread;
+		void *(fn) = NULL;
+
+		switch (ns_g_fuzz_type) {
+		case ns_fuzz_client:
+			fn = fuzz_main_client;
+			break;
+
+		case ns_fuzz_http:
+		case ns_fuzz_tcpclient:
+		case ns_fuzz_rndc:
+			fn = fuzz_main_tcp;
+			break;
+		case ns_fuzz_resolver:
+			fn = fuzz_main_resolver;
+			break;
+		default:
+			RUNTIME_CHECK(fn != NULL);
+		}
+
+		RUNTIME_CHECK(pthread_mutex_init(&mutex, NULL) == 0);
+		RUNTIME_CHECK(pthread_cond_init(&cond, NULL) == 0);
+		RUNTIME_CHECK(pthread_create(&thread, NULL, fn, NULL) == 0);
+	}
+#endif /* ENABLE_AFL */
+}

bin/named/include/named/fuzz.h

+/*
+ * Copyright (C) 2015  Internet Systems Consortium, Inc. ("ISC")
+ *
+ * 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 appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
+ * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
+ * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+ * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
+ * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+ * PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#ifndef NAMED_FUZZ_H
+#define NAMED_FUZZ_H
+
+void
+named_fuzz_notify(void);
+
+void
+named_fuzz_setup(void);
+
+typedef enum {
+	ns_fuzz_none,
+	ns_fuzz_client,
+	ns_fuzz_tcpclient,
+	ns_fuzz_resolver,
+	ns_fuzz_http,
+	ns_fuzz_rndc
+} ns_fuzz_t;
+
+#endif /* NAMED_FUZZ_H */

bin/named/include/named/globals.h

@@ -33,6 +33,7 @@
 #include <dst/dst.h>
 
 #include <named/types.h>
+#include <named/fuzz.h>
 
 #undef EXTERN
 #undef INIT
@@ -57,6 +58,9 @@ EXTERN isc_entropy_t *		ns_g_entropy		INIT(NULL);
 EXTERN isc_entropy_t *		ns_g_fallbackentropy	INIT(NULL);
 EXTERN unsigned int		ns_g_cpus_detected	INIT(1);
 
+#ifdef ENABLE_AFL
+EXTERN isc_boolean_t		ns_g_run_done		INIT(ISC_FALSE);
+#endif
 /*
  * XXXRTH  We're going to want multiple timer managers eventually.  One
  *         for really short timers, another for client timers, and one
@@ -186,6 +190,9 @@ EXTERN isc_boolean_t		ns_g_disable4		INIT(ISC_FALSE);
 EXTERN dns_geoip_databases_t	*ns_g_geoip		INIT(NULL);
 #endif
 
+EXTERN const char *		ns_g_fuzz_named_addr	INIT(NULL);
+EXTERN ns_fuzz_t		ns_g_fuzz_type		INIT(ns_fuzz_none);
+
 #undef EXTERN
 #undef INIT
 

bin/named/include/named/main.h

@@ -27,7 +27,7 @@
 /*
  * Commandline arguments for named; also referenced in win32/ntservice.c