WiFi card configuration

Makefile

@@ -1,5 +1,5 @@
 test:
-	gcc main.c -o bin/wipacket -liw
+	gcc main.c if_helper.c -o bin/wipacket -liw
 
 clean:
 	rm wipacket

if_helper.c

@@ -0,0 +1,45 @@
+#include "if_helper.h"
+
+// Either I'm blind, or libiw API documentation is very hard to find,
+// so for now system() calls will have to do for configuring the
+// wireless interface.
+
+int if_up(char *name) {
+    char buf[128];
+    snprintf(buf, sizeof(buf), "ifconfig %s up", name);
+    int ret = system(buf);
+    if (ret != 0) {
+        printf("Could not bring up interface %s\n", name);
+    }
+    return ret;
+}
+
+int if_down(char *name) {
+    char buf[128];
+    snprintf(buf, sizeof(buf), "ifconfig %s down", name);
+    int ret = system(buf);
+    if (ret != 0) {
+        printf("Could not bring down interface %s\n", name);
+    }
+    return ret;
+}
+
+int if_enable_ibss(char *name) {
+    char buf[128];
+    snprintf(buf, sizeof(buf), "iw %s set type ibss", name);
+    int ret = system(buf);
+    if (ret != 0) {
+        printf("Could not enable IBSS on %s\n", name);
+    }
+    return ret;
+}
+
+int if_join_ibss(char *name, char *essid, int frequency) {
+    char buf[128];
+    snprintf(buf, sizeof(buf), "iw %s ibss join %s %d", name, essid, frequency);
+    int ret = system(buf);
+    if (ret != 0) {
+        printf("Interface %s failed enabling ESSID \"%s\" on frequency %d \n", name, essid, frequency);
+    }
+    return ret;
+}

if_helper.h

@@ -0,0 +1,7 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+int if_up(char *name);
+int if_down(char *name);
+int if_enable_ibss(char *name);
+int if_join_ibss(char *name, char *essid, int frequency);

main.c

@@ -9,6 +9,8 @@
 
 #include <net/ethernet.h>
 #include <linux/if_packet.h>
+
+#include "if_helper.h"
 //#include <linux/if_ether.h>
 //#include <linux/if_arp.h>
 
@@ -23,6 +25,10 @@ void cleanup();
 // Ethernet protocol ID
 #define PROTOCOL_IDENTIFIER 0x9f77
 
+// ESSID and frequency for network
+#define ESSID "wipacket"
+#define FREQUENCY 2412
+
 // The ethernet broadcast address
 const unsigned char broadcast_addr[] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
 
@@ -120,7 +126,12 @@ void prepeareBroadcastHeader() {
 }
 
 void configureInterface() {
+    int status;
     printf("Configuring interface %s...\n", if_name);
+    if_down(if_name);
+    if_enable_ibss(if_name);
+    if_up(if_name);
+    if_join_ibss(if_name, ESSID, FREQUENCY);
 }
 
 void cleanup() {