wlantest: Add radiotap header when re-writing DLT_IEEE802_11 file

When using DLT_IEEE802_11 datalink type in a pcap file, wlantest will now
add a radiotap header to the re-written pcap file to make sure all frames
in the output file will include the radiotap header.

Signed-hostap: Jouni Malinen <jouni@qca.qualcomm.com>

wlantest/readpcap.c

@@ -13,6 +13,39 @@
 #include "wlantest.h"
 
 
+static void write_pcap_with_radiotap(struct wlantest *wt,
+				     const u8 *data, size_t data_len)
+{
+	struct pcap_pkthdr h;
+	u8 rtap[] = {
+		0x00 /* rev */,
+		0x00 /* pad */,
+		0x0a, 0x00, /* header len */
+		0x02, 0x00, 0x00, 0x00, /* present flags */
+		0x00, /* flags */
+		0x00 /* pad */
+	};
+	u8 *buf;
+	size_t len;
+
+	if (wt->assume_fcs)
+		rtap[8] |= 0x10;
+
+	os_memset(&h, 0, sizeof(h));
+	h.ts = wt->write_pcap_time;
+	len = sizeof(rtap) + data_len;
+	buf = os_malloc(len);
+	if (buf == NULL)
+		return;
+	os_memcpy(buf, rtap, sizeof(rtap));
+	os_memcpy(buf + sizeof(rtap), data, data_len);
+	h.caplen = len;
+	h.len = len;
+	pcap_dump(wt->write_pcap_dumper, &h, buf);
+	os_free(buf);
+}
+
+
 int read_cap_file(struct wlantest *wt, const char *fname)
 {
 	char errbuf[PCAP_ERRBUF_SIZE];
@@ -61,7 +94,10 @@ int read_cap_file(struct wlantest *wt, const char *fname)
 			   hdr->caplen, hdr->len);
 		if (wt->write_pcap_dumper) {
 			wt->write_pcap_time = hdr->ts;
-			pcap_dump(wt->write_pcap_dumper, hdr, data);
+			if (dlt == DLT_IEEE802_11)
+				write_pcap_with_radiotap(wt, data, hdr->caplen);
+			else
+				pcap_dump(wt->write_pcap_dumper, hdr, data);
 		}
 		if (hdr->caplen < hdr->len) {
 			wpa_printf(MSG_DEBUG, "pcap: Dropped incomplete frame "