2 files changed, 101 insertions, 0 deletions

@@ -0,0 +1,23 @@
+# Generating 802.11 RTS and CTS Frames
+This example shows the reader how to generate an RTS and a CTS Frame, with a random transmitter and a 32ms duration.
+
+# Building and Using
+```
+>> cd examples/generate_rtscts/
+>> make
+clang -Wall -Werror -O3 -o generate_rtscts   -c -o generate_rtscts.o generate_rtscts.c
+clang -Wall -Werror -O3 -o generate_rtscts generate_rtscts.c -lpcap -lwifi
+>> ./generate_rtscts --file rtscts.pcap
+[+] Setup Complete
+[*] Creating RTS Frame
+[*] Writing RTS Frame to pcap
+[*] Creating CTS Frame
+[*] Writing CTS Frame to pcap
+>> tshark -r rtscts.pcap
+    1   0.000000 J125Nati_aa:bb:cc (00:20:91:aa:bb:cc) (TA) → Broadcast (ff:ff:ff:ff:ff:ff) (RA) 802.11 16 Request-to-send, Flags=........
+    2   0.000008              → Broadcast (ff:ff:ff:ff:ff:ff) (RA) 802.11 10 Clear-to-send, Flags=........
+>>
+```
+
+# Output
+![image](https://user-images.githubusercontent.com/4153572/143601868-da7e9c99-2534-4fe6-9608-68f5af1ad882.png)
@@ -0,0 +1,78 @@
+#include <libwifi.h>
+
+#include <pcap.h>
+
+#include <bits/types/struct_timeval.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/time.h>
+
+pcap_dumper_t *filedumper = NULL;
+
+void create_write_rtscts() {
+    printf("[*] Creating RTS Frame\n");
+    struct libwifi_rts rts = {0};
+    unsigned char transmitter[6] = "\x00\x20\x91\xAA\xBB\xCC";
+    unsigned char receiver[6] = "\xFF\xFF\xFF\xFF\xFF\xFF";
+    libwifi_create_rts(&rts, transmitter, receiver, 32);
+
+    printf("[*] Writing RTS Frame to pcap\n");
+    struct pcap_pkthdr pkt_hdr = {0};
+    struct timeval tv = {0};
+    pkt_hdr.caplen = sizeof(struct libwifi_rts);
+    pkt_hdr.len = sizeof(struct libwifi_rts);
+    gettimeofday(&tv, NULL);
+    pkt_hdr.ts = tv;
+    pcap_dump((unsigned char *) filedumper, &pkt_hdr, (const unsigned char *) &rts);
+
+    printf("[*] Creating CTS Frame\n");
+    struct libwifi_cts cts = {0};
+    libwifi_create_cts(&cts, receiver, 32);
+
+    printf("[*] Writing CTS Frame to pcap\n");
+    memset(&pkt_hdr, 0, sizeof(struct pcap_pkthdr));
+    memset(&tv, 0, sizeof(struct timeval));
+    pkt_hdr.caplen = sizeof(struct libwifi_cts);
+    pkt_hdr.len = sizeof(struct libwifi_cts);
+    gettimeofday(&tv, NULL);
+    pkt_hdr.ts = tv;
+    pcap_dump((unsigned char *) filedumper, &pkt_hdr, (const unsigned char *) &cts);
+}
+
+void helpexit() {
+    fprintf(stderr, "[!] Usage: ./generate_beacon --file <file.pcap>\n");
+    exit(EXIT_FAILURE);
+}
+
+int main(int argc, char **argv) {
+    pcap_t *handle = NULL;
+    char errbuf[PCAP_ERRBUF_SIZE] = {0};
+    FILE *pcapfile = NULL;
+
+    if (argc < 2) {
+        helpexit();
+    }
+    if (strcmp(argv[1], "--file") == 0) {
+        pcapfile = fopen(argv[2], "w+");
+        if ((handle = pcap_open_dead(DLT_IEEE802_11, BUFSIZ)) == NULL) {
+            fprintf(stderr, "[!] Error opening dead capture (%s)\n", errbuf);
+            exit(EXIT_FAILURE);
+        }
+        if ((filedumper = pcap_dump_fopen(handle, pcapfile)) == NULL) {
+            fprintf(stderr, "[!] Error opening file %s (%s)\n", argv[2], errbuf);
+            exit(EXIT_FAILURE);
+        }
+    } else {
+        helpexit();
+    }
+
+    printf("[+] Setup Complete\n");
+
+    create_write_rtscts();
+
+    pcap_dump_close(filedumper);
+    pcap_close(handle);
+    return 0;
+}