From e929eb39d6d874f694cb66b7aea7d112880993c7 Mon Sep 17 00:00:00 2001
From: Jouni Malinen <j@w1.fi>
Date: Fri, 27 Nov 2015 00:10:53 +0200
Subject: [PATCH] wlantest: Add -N command line argument to remove write
 buffering

This makes it easier to do live parsing of captured pcap files from
wlantest without having to rename and restart the capture file. Packet
writes are flushed to disk after each packet if -N is included in the
command line.

Signed-off-by: Jouni Malinen <j@w1.fi>
---
 wlantest/readpcap.c  |  2 ++
 wlantest/wlantest.c  |  7 +++++--
 wlantest/wlantest.h  |  1 +
 wlantest/writepcap.c | 10 ++++++++++
 4 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/wlantest/readpcap.c b/wlantest/readpcap.c
index 7c3ce18fd..6c3853b05 100644
--- a/wlantest/readpcap.c
+++ b/wlantest/readpcap.c
@@ -102,6 +102,8 @@ int read_cap_file(struct wlantest *wt, const char *fname)
 				write_pcap_with_radiotap(wt, data, hdr->caplen);
 			else
 				pcap_dump(wt->write_pcap_dumper, hdr, data);
+			if (wt->pcap_no_buffer)
+				pcap_dump_flush(wt->write_pcap_dumper);
 		}
 		if (hdr->caplen < hdr->len) {
 			add_note(wt, MSG_DEBUG, "pcap: Dropped incomplete "
diff --git a/wlantest/wlantest.c b/wlantest/wlantest.c
index ab3b2fc6b..abe97d18f 100644
--- a/wlantest/wlantest.c
+++ b/wlantest/wlantest.c
@@ -21,7 +21,7 @@ static void wlantest_terminate(int sig, void *signal_ctx)
 
 static void usage(void)
 {
-	printf("wlantest [-cddhqqFt] [-i<ifname>] [-r<pcap file>] "
+	printf("wlantest [-cddhqqFNt] [-i<ifname>] [-r<pcap file>] "
 	       "[-p<passphrase>]\n"
 	       "         [-I<wired ifname>] [-R<wired pcap file>] "
 	       "[-P<RADIUS shared secret>]\n"
@@ -350,7 +350,7 @@ int main(int argc, char *argv[])
 	wlantest_init(&wt);
 
 	for (;;) {
-		c = getopt(argc, argv, "cdf:Fhi:I:L:n:p:P:qr:R:tT:w:W:");
+		c = getopt(argc, argv, "cdf:Fhi:I:L:n:Np:P:qr:R:tT:w:W:");
 		if (c < 0)
 			break;
 		switch (c) {
@@ -383,6 +383,9 @@ int main(int argc, char *argv[])
 		case 'n':
 			wt.pcapng_file = optarg;
 			break;
+		case 'N':
+			wt.pcap_no_buffer = 1;
+			break;
 		case 'p':
 			add_passphrase(&wt, optarg);
 			break;
diff --git a/wlantest/wlantest.h b/wlantest/wlantest.h
index ced9baa0e..530accc3b 100644
--- a/wlantest/wlantest.h
+++ b/wlantest/wlantest.h
@@ -202,6 +202,7 @@ struct wlantest {
 	int last_mgmt_valid;
 
 	unsigned int assume_fcs:1;
+	unsigned int pcap_no_buffer:1;
 
 	char *notes[MAX_NOTES];
 	size_t num_notes;
diff --git a/wlantest/writepcap.c b/wlantest/writepcap.c
index 28b306b7a..abd889fcd 100644
--- a/wlantest/writepcap.c
+++ b/wlantest/writepcap.c
@@ -59,6 +59,8 @@ void write_pcap_captured(struct wlantest *wt, const u8 *buf, size_t len)
 	h.caplen = len;
 	h.len = len;
 	pcap_dump(wt->write_pcap_dumper, &h, buf);
+	if (wt->pcap_no_buffer)
+		pcap_dump_flush(wt->write_pcap_dumper);
 }
 
 
@@ -102,6 +104,8 @@ void write_pcap_decrypted(struct wlantest *wt, const u8 *buf1, size_t len1,
 	h.caplen = len;
 	h.len = len;
 	pcap_dump(wt->write_pcap_dumper, &h, buf);
+	if (wt->pcap_no_buffer)
+		pcap_dump_flush(wt->write_pcap_dumper);
 }
 
 
@@ -181,6 +185,8 @@ int write_pcapng_init(struct wlantest *wt, const char *fname)
 	desc.link_type = LINKTYPE_IEEE802_11_RADIO;
 	desc.snap_len = 65535;
 	fwrite(&desc, sizeof(desc), 1, wt->pcapng);
+	if (wt->pcap_no_buffer)
+		fflush(wt->pcapng);
 
 	return 0;
 }
@@ -263,6 +269,8 @@ static void write_pcapng_decrypted(struct wlantest *wt)
 	*block_len = pkt->block_total_len = pos - (u8 *) pkt;
 
 	fwrite(pkt, pos - (u8 *) pkt, 1, wt->pcapng);
+	if (wt->pcap_no_buffer)
+		fflush(wt->pcapng);
 
 	os_free(pkt);
 }
@@ -337,6 +345,8 @@ void write_pcapng_write_read(struct wlantest *wt, int dlt,
 	*block_len = pkt->block_total_len = pos - (u8 *) pkt;
 
 	fwrite(pkt, pos - (u8 *) pkt, 1, wt->pcapng);
+	if (wt->pcap_no_buffer)
+		fflush(wt->pcapng);
 
 	os_free(pkt);