Patch for reaver-wps-svn in ArchLinux to avoid empty wash output (as for me, it was because of pcap_next sometimes returning NULL and wash giveup). Maybe best used with -p -1 -C.

PKGBUILD

# Maintainer: Xiao-Long Chen <chenxiaolong@cxl.epac.to>

pkgname=reaver-wps-svn
pkgver=119
pkgrel=1
pkgdesc="Brute force attack against Wifi Protected Setup (WPS) registrar PINs in order to recover WPA/WPA2 passphrases"
arch=('i686' 'x86_64' 'mips64el' 'armv6h')
url="http://code.google.com/p/reaver-wps/"
license=('GPL')
depends=('libpcap' 'sqlite')
makedepends=('subversion')
provides=('reaver-wps')
conflicts=('reaver-wps')
source=('svn+http://reaver-wps.googlecode.com/svn/trunk/'
	'wash-max-pcap-next-failures.patch')
sha512sums=('SKIP'
	'242a6f7d77e111b95ddc313c0bf8cb8b4d25e13ae233202eaa984064ff10ab4c5b602daa7724a8ee7dc16f0d831d6605aa2508c72beb699442d5796b2feb5577')

pkgver() {
  cd "${SRCDEST}/trunk/"
  svnversion
}

prepare() {
  patch -p1 -i wash-max-pcap-next-failures.patch # Patch to avoid empty wash output. Maybe best used with -p -1 -C.
}

build() {
  cd "${srcdir}/trunk/src/"

  ./configure --prefix=/usr --sysconfdir=/etc
  make
}

package() {
  cd "${srcdir}/trunk/"
  pushd src
  install -dm755 "${pkgdir}/usr/bin/"
  install -m755 reaver "${pkgdir}/usr/bin/"
  install -m755 wash "${pkgdir}/usr/bin/"
  install -dm755 "${pkgdir}/etc/reaver/"
  install -m644 reaver.db "${pkgdir}/etc/reaver/"
  popd
  pushd docs
  install -dm755 "${pkgdir}/usr/share/man/man1/"
  install -m644 reaver.1.gz "${pkgdir}/usr/share/man/man1/"
  popd
}

# vim:set ts=2 sw=2 et:

wash-max-pcap-next-failures.patch

--- a/trunk/src/80211.c	2014-06-22 16:19:30.329975344 +0400
+++ b/trunk/src/80211.c	2014-06-22 17:04:28.357220443 +0400
@@ -37,10 +37,23 @@
 const u_char *next_packet(struct pcap_pkthdr *header)
 {
 	const u_char *packet = NULL;
+	int pcap_next_failures = 0;
+	const int max_pcap_next_failures = get_max_pcap_next_failures();
 
-	/* Loop until we get a valid packet, or until we run out of packets */
-	while((packet = pcap_next(get_handle(), header)) != NULL)
+	/* Loop until we get a valid packet, or until we run out of packets, or until pcap_next_failures >= max_pcap_next_failures */
+	while( ( max_pcap_next_failures < 0 ) || ( (pcap_next_failures <= max_pcap_next_failures) && ( pcap_next_failures != INT_MAX ) ) )
 	{
+		packet = pcap_next(get_handle(), header);
+		
+		if (packet == NULL)
+		{
+			if ( (pcap_next_failures < INT_MAX) && (max_pcap_next_failures >= 0) )
+			{
+				pcap_next_failures++;
+			}
+			continue;
+		}
+		
 		if(get_validate_fcs())
 		{
 			if(check_fcs(packet, header->len))
--- a/trunk/src/80211.h	2014-06-22 16:19:30.352975324 +0400
+++ b/trunk/src/80211.h	2014-06-22 17:00:28.885292972 +0400
@@ -34,6 +34,7 @@
 #ifndef DOT11_H
 #define DOT11_H
 
+#include <limits.h>
 #include "defs.h"
 #include "globule.h"
 #include "argsparser.h"
--- a/trunk/src/defs.h	2014-06-22 16:19:30.352975324 +0400
+++ b/trunk/src/defs.h	2014-06-22 16:39:26.930865469 +0400
@@ -46,6 +46,7 @@
 
 #define NULL_MAC		"\x00\x00\x00\x00\x00\x00"
 #define DEFAULT_MAX_NUM_PROBES	15
+#define DEFAULT_MAX_NUM_PCAP_NEXT_FAILURES	10
 #define MAX_ASSOC_FAILURES	10
 
 #define TIMESTAMP_LEN		8
--- a/trunk/src/globule.c	2014-06-22 16:19:30.353975323 +0400
+++ b/trunk/src/globule.c	2014-06-22 16:49:54.379776855 +0400
@@ -258,6 +258,15 @@
 	return globule->max_num_probes;
 }
 
+void set_max_pcap_next_failures(int value)
+{
+	globule->max_pcap_next_failures = value;
+}
+int get_max_pcap_next_failures()
+{
+	return globule->max_pcap_next_failures;
+}
+
 void set_rx_timeout(int value)
 {
 	globule->rx_timeout = value;
--- a/trunk/src/globule.h	2014-06-22 16:19:29.199976328 +0400
+++ b/trunk/src/globule.h	2014-06-22 17:08:55.101148732 +0400
@@ -102,6 +102,8 @@
 
 	int max_num_probes;		/* Maximum number of probe requests to send to an AP during survey mode */
 	
+	int max_pcap_next_failures;		/* Maximum number of pcap_next() failures (returning NULL) before giving up on it */
+	
 	int validate_fcs;		/* If 1, validate each packet's FCS. If 0, process packets even with invalid FCS. */
 
         enum wsc_op_code opcode;        /* WFA opcode, received by exchange.c and used by builder.c */
@@ -178,6 +180,8 @@
 int get_max_pin_attempts();
 int get_max_num_probes();
 void set_max_num_probes(int value);
+void set_max_pcap_next_failures(int value);
+int get_max_pcap_next_failures();
 void set_rx_timeout(int value);
 int get_rx_timeout();
 void set_timeout_is_nack(int value);
--- a/trunk/src/wpsmon.c	2014-06-22 16:19:29.524976045 +0400
+++ b/trunk/src/wpsmon.c	2014-06-22 17:02:21.205257967 +0400
@@ -41,13 +41,14 @@
 	int source = INTERFACE, ret_val = EXIT_FAILURE;
 	struct bpf_program bpf = { 0 };
 	char *out_file = NULL, *last_optarg = NULL, *target = NULL, *bssid = NULL;
-	char *short_options = "i:c:n:o:b:5sfuCDh";
+	char *short_options = "i:c:n:p:o:b:5sfuCDh";
         struct option long_options[] = {
 		{ "bssid", required_argument, NULL, 'b' },
                 { "interface", required_argument, NULL, 'i' },
                 { "channel", required_argument, NULL, 'c' },
 		{ "out-file", required_argument, NULL, 'o' },
 		{ "probes", required_argument, NULL, 'n' },
+		{ "max-pcap-next-failures", required_argument, NULL, 'p' },
 		{ "daemonize", no_argument, NULL, 'D' },
 		{ "file", no_argument, NULL, 'f' },
 		{ "ignore-fcs", no_argument, NULL, 'C' },
@@ -70,6 +71,7 @@
 	set_validate_fcs(1);
 	set_log_file(stdout);
 	set_max_num_probes(DEFAULT_MAX_NUM_PROBES);
+	set_max_pcap_next_failures(DEFAULT_MAX_NUM_PCAP_NEXT_FAILURES);
 
 	while((c = getopt_long(argc, argv, short_options, long_options, &long_opt_index)) != -1)
         {
@@ -94,6 +96,9 @@
 			case 'n':
 				set_max_num_probes(atoi(optarg));
 				break;
+			case 'p':
+				set_max_pcap_next_failures(atoi(optarg));
+				break;
 			case 'o':
 				out_file = strdup(optarg);
 				break;
@@ -426,6 +431,7 @@
 	fprintf(stderr, "\t-c, --channel=<num>                  Channel to listen on [auto]\n");
 	fprintf(stderr, "\t-o, --out-file=<file>                Write data to file\n");
 	fprintf(stderr, "\t-n, --probes=<num>                   Maximum number of probes to send to each AP in scan mode [%d]\n", DEFAULT_MAX_NUM_PROBES);
+	fprintf(stderr, "\t-p, --max-pcap-next-failures=<num>   Maximum number of pcap_next failures before giving up (set it to -1 to wait forever, maximum is %d) [%d]\n", INT_MAX, DEFAULT_MAX_NUM_PCAP_NEXT_FAILURES);
 	fprintf(stderr, "\t-D, --daemonize                      Daemonize wash\n");
 	fprintf(stderr, "\t-C, --ignore-fcs                     Ignore frame checksum errors\n");
 	fprintf(stderr, "\t-5, --5ghz                           Use 5GHz 802.11 channels\n");
--- a/trunk/src/wpsmon.h	2014-06-22 16:19:29.524976045 +0400
+++ b/trunk/src/wpsmon.h	2014-06-22 17:00:08.605299492 +0400
@@ -39,6 +39,7 @@
 #include <sys/time.h>
 #include <arpa/inet.h>
 #include <libwps.h>
+#include <limits.h>
 #include "defs.h"
 #include "globule.h"
 #include "misc.h"