add scripts and tuntap.c

Blatt02/Blatt02.md

@@ -0,0 +1 @@
+![image-20241110210209022](./assets/image-20241110210209022.png)

Blatt02/scripts/103.sh

@@ -0,0 +1,71 @@
+#!/bin/bash
+
+bash /home/rnp/2/101.sh
+
+echo "Now running 103.sh"
+
+assign_vlan(){
+	local dev=$1
+	local eth=$2
+	local id=$3
+	local ip=$4
+	ssh $dev "ip link add link $eth name $eth.$id type vlan id $id"
+	ssh $dev "ip link set dev $eth.$id up"
+	ssh $dev "ip addr flush dev $eth"
+	ssh $dev "ip addr add $ip dev $eth.$id"
+}
+
+assign_vlan "router4" "eth1" "100" "10.5.1.4/24"
+assign_vlan "pc3" "eth1" "100" "10.5.1.3/24"
+assign_vlan "pc2" "eth1" "200" "10.5.1.2/24"
+assign_vlan "pc1" "eth1" "200" "10.5.1.1/24"
+
+ping_dev(){
+	local dev=$1
+	local ip=$2
+	local eth_n=$3
+	# ssh "$dev" $cmd 
+	loss=$(ssh $dev "ping -c 5 -W 2 -I eth$eth_n $ip | awk -F', ' '/packet loss/ {print \$3}' | awk '{print int(\$1)}'")
+	echo $loss
+}
+
+check(){
+	local dev1=$1
+	local dev2=$2
+	local ping_loss=$3
+	local num=$4
+	echo $ping_loss
+	if [ $ping_loss -eq $num ]; then
+		echo -e "from $dev1 to $dev2: \t yes"
+	else
+		echo -e "from $dev1 to $dev2: \t no"
+	fi
+}
+
+loss=$(ping_dev "router4" "10.5.1.1" "1.100")
+check "router4" "pc1" "$loss" 100
+loss=$(ping_dev "router4" "10.5.1.2" "1.100")
+check "router4" "pc2" "$loss" 100
+loss=$(ping_dev "router4" "10.5.1.3" "1.100")
+check "router4" "pc3" "$loss" 0
+
+loss=$(ping_dev "pc1" "10.5.1.2" "1.200")
+check "pc1" "pc2" "$loss" 0
+loss=$(ping_dev "pc1" "10.5.1.3" "1.200")
+check "pc1" "pc3" "$loss" 100
+loss=$(ping_dev "pc1" "10.5.1.4" "1.200")
+check "pc1" "router4" "$loss" 100
+
+loss=$(ping_dev "pc2" "10.5.1.1" "1.200")
+check "pc2" "pc1" "$loss" 0
+loss=$(ping_dev "pc2" "10.5.1.3" "1.200")
+check "pc2" "pc3" "$loss" 100
+loss=$(ping_dev "pc2" "10.5.1.4" "1.200")
+check "pc2" "router4" "$loss" 100
+
+loss=$(ping_dev "pc3" "10.5.1.1" "1.100")
+check "pc3" "pc1" "$loss" 100
+loss=$(ping_dev "pc3" "10.5.1.2" "1.100")
+check "pc3" "pc2" "$loss" 100
+loss=$(ping_dev "pc3" "10.5.1.4" "1.100")
+check "pc3" "router4" "$loss" 0

Blatt02/tuntap.c

@@ -0,0 +1,87 @@
+#include <assert.h>
+#include <sys/ioctl.h>
+#include <net/if.h>
+#include <linux/if_tun.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <stdint.h>
+
+#define CLEAR(x) memset(&(x), 0x00, sizeof(x))
+
+#define IFNAME "tap0"
+
+#define BUFLEN 1600
+
+static int tun_alloc(char *dev)
+{
+    struct ifreq ifr;
+    int fd, err;
+
+    if( (fd = open("/dev/net/tun", O_RDWR)) < 0 ) {
+        perror("Cannot open TUN/TAP dev\n"
+                    "Make sure one exists with "
+                    "'$ mknod /dev/net/tun c 10 200'");
+        exit(1);
+    }
+
+    CLEAR(ifr);
+
+    /* Flags: IFF_TUN   - TUN device (no Ethernet headers)
+     *        IFF_TAP   - TAP device
+     *
+     *        IFF_NO_PI - Do not provide packet information
+     */
+    ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
+    if( *dev ) {
+        strncpy(ifr.ifr_name, dev, IFNAMSIZ);
+    }
+
+    if( (err = ioctl(fd, TUNSETIFF, (void *) &ifr)) < 0 ){
+        perror("ERR: Could not ioctl tun");
+        close(fd);
+        return err;
+    }
+
+    strcpy(dev, ifr.ifr_name);
+    return fd;
+}
+
+int main(int argc, char** argv) {
+
+  char dev[IFNAMSIZ];
+  int tun_fd;
+
+  if (argc > 1) {
+    assert(strlen(argv[1]) < IFNAMSIZ);
+    strcpy(dev, argv[1]);
+  } else {
+    strcpy(dev, IFNAME);
+  }
+
+  printf("device name: %s\n", dev);
+
+  tun_fd = tun_alloc(dev);
+
+  int running = 1;
+
+  uint8_t buf[BUFLEN];
+  while (running) {
+    int nread;
+
+    if ((nread = read(tun_fd, buf, BUFLEN)) < 0) {
+      perror("ERR: Read from tun_fd");
+      break;
+    }
+
+    printf("Read %d bytes from device %s\n", nread, dev);
+  }
+
+  close(tun_fd);
+
+  return EXIT_SUCCESS;
+}