Revision 1:feaa107f56b3, committed 2015-04-24

Comitter:

jamessayer

Date:

Fri Apr 24 03:11:02 2015 +0000

Parent:

0:852db76de235

Commit message:

first version;

Changed in this revision

diff -r 852db76de235 -r feaa107f56b3 main.cpp
--- a/main.cpp	Fri Sep 04 12:25:06 2009 +0000
+++ b/main.cpp	Fri Apr 24 03:11:02 2015 +0000
@@ -1,5 +1,9 @@
 #include "mbed.h"                                      // Importing the mbed classes and tools.
 #include "Ethernet.h"
+#include "util/types.h"
+#include "net/net.h"
+#include "sniffer.h"
+
 
 using namespace mbed;
 
@@ -20,54 +24,116 @@
   unsigned char   dhwaddr[6];                          //   Hardware address of the intended receiver. This field is ignored in requests.
   unsigned char   dipaddr[4];                          //   Protocol address of the intended receiver.
 };
-
-Ethernet eth;                                          // The ethernet device
+Sniffer sniffer;
+Ethernet_MAC your_mac;
+//Ethernet eth;                                          // The ethernet device
 DigitalOut led4(LED4);                                 // A LED for showing activity
 
 unsigned short htons(unsigned short n) {               // Host short to network shor
   return ((n & 0xff) << 8) | ((n & 0xff00) >> 8);      // Byte swapping
 }
 
-void send(const char *ipaddr) {
-  static char data[0x600];                             // Packet buffer
-  const unsigned char arplen = 6;                      // Hardware address length
-  const unsigned char ethlen = 4;                      // IP address length
-  char hwaddr[arplen];                                 // Hardware address buffer
-  struct ethpkt *pkg   = (struct ethpkt *) &data[0];   // Force the buffer to an ethpkg
-  unsigned char pos    = arplen;                       // Hardware/IP address position
-
-  eth.address(hwaddr);                                 // Get own hardware address
+#define PING_BUFEFERSIZE (sizeof(IP_PacketHeader) + sizeof(ICMP_Packet))
 
-  pkg->type            = htons(0x0806);                // Set type to ARP (0x0806)
-  pkg->hwtype          = htons(0x0001);                // Hardware type is Ethernet (0x0001)
-  pkg->proto           = htons(0x0800);                // Protocol is ARP Request (0x0800)
-  pkg->hwlen           = arplen;                       // Hardware addresses are 6 Bytes long
-  pkg->protolen        = ethlen;                       // And protocol addresses 4 Bytes
-  pkg->opcode          = htons(0x0001);                // Send: whois XX:XX:XX:XX:XX:XX?
+void send(const char *ipaddr) {
+    IP_Address dest_ip;
+    IP_Address my_ip;
+    str2ipaddr(ipaddr,&dest_ip);
+    str2ipaddr("192.168.0.16",&my_ip);
+    
+    u8 buffer[PING_BUFEFERSIZE];
+    IP_PacketHeader *ip_packet = (IP_PacketHeader*)buffer;
+    ICMP_Packet *ping_packet = (ICMP_Packet*)ip_packet->data;
+    
+    memset(buffer, '\0', PING_BUFEFERSIZE);
+    
+    *ip_packet = (IP_PacketHeader){0x04, 5, 0, sizeof(IP_PacketHeader)+sizeof(ICMP_Packet), 0, 0, 0, 0, 0, 32, IPPROTO_ICMP, 0x00, my_ip, dest_ip};
+    *ping_packet = (ICMP_Packet){ICMP_ECHO_REQUEST, 0x00, 0x00, 0x00, 0x00};
+    
+    fix_endian_icmp(ping_packet);
+    fix_endian_ip(ip_packet);
+    ip_packet->header_checksum = checksum(ip_packet, sizeof(IP_PacketHeader), &ip_packet->header_checksum, 2);
+    ping_packet->checksum = checksum(ping_packet, sizeof(ICMP_Packet), &ping_packet->checksum, 2);
+    
+    
+    printf("PING sent...\n");
+    
+    sniffer.inject(your_mac, ETHERTYPE_IPV4, buffer, PING_BUFEFERSIZE);
+    
+    
+    
+//    printf("a\n");
+//    IP_Address dest_ip;
+//    IP_Address my_ip;
+//    str2ipaddr(ipaddr,&dest_ip);
+//    str2ipaddr("192.168.0.5",&my_ip);
+//    printf("b\n");
+//    u8 buffer[PING_BUFEFERSIZE];
+//    IP_PacketHeader *ip_packet = (IP_PacketHeader*)buffer;
+//    ICMP_Packet *ping_packet = (ICMP_Packet*)ip_packet->data;
+//    printf("c\n");
+//    memset(buffer, '\0', PING_BUFEFERSIZE);
+//    printf("d\n");
+//    *ip_packet = (IP_PacketHeader){0x4, 5, 0, sizeof(IP_PacketHeader)+sizeof(ICMP_Packet), 0, 0, 0, 0, 0, 32, IPPROTO_ICMP, 0x00, my_ip, dest_ip};
+//    *ping_packet = (ICMP_Packet){ICMP_ECHO_REQUEST, 0x00, 0x00, 0x00, 0x00};
+//    printf("e\n");
+    
+    
+///    fix_endian_icmp(ping_packet);
+//    fix_endian_ip(ip_packet);
+//    printf("f\n");
+//    ip_packet->header_checksum = checksum(ip_packet, sizeof(IP_PacketHeader), &ip_packet->header_checksum, 2);
+//    ping_packet->checksum = checksum(ping_packet, sizeof(ICMP_Packet), &ping_packet->checksum, 2);
+//    printf("h\n");
+//    
+//    print_icmp(ping_packet);
+//    print_ip(ip_packet);
+//    
+//    printf("i\n");
+//    eth.write((char*)buffer, PING_BUFEFERSIZE);                                 // Write the package
+//    eth.send();                                          // Send the package
+//    printf("j\n");
   
-  while(pos-- > 0) {                                   // Write IP/MAC-Addresses (combined loop for all addresses)
-    pkg->src[pos]        = hwaddr[pos];                // Set source MAC address to hwaddr on ethernet layer
-    pkg->dest[pos]       = 0xFF;                       // Set destination MAC address to everybody (FF:FF:FF:FF:FF:FF) on ethernet layer
-    pkg->shwaddr[pos]    = hwaddr[pos];                // Set source MAC address on ARP layer
-    pkg->dhwaddr[pos]    = 0xFF;                       // Set destination MAC address on ARP layer
-    if(pos < ethlen) {                                 // Check if we can copy IP addresses too.
-      pkg->sipaddr[pos]  = 0xFF;                       // Set source ip address to 255.255.255.255
-      pkg->dipaddr[pos]  = ipaddr[pos];                // Set destination ip address to ipaddr
-    }
-  }
-
-  eth.write(data, 60);                                 // Write the package
-  eth.send();                                          // Send the package
+//  static char data[0x600];                             // Packet buffer
+//  const unsigned char arplen = 6;                      // Hardware address length
+//  const unsigned char ethlen = 4;                      // IP address length
+//  char hwaddr[arplen];                                 // Hardware address buffer
+//  struct ethpkt *pkg   = (struct ethpkt *) &data[0];   // Force the buffer to an ethpkg
+//  unsigned char pos    = arplen;                       // Hardware/IP address position
+//
+//  eth.address(hwaddr);                                 // Get own hardware address
+//
+//  pkg->type            = htons(0x0806);                // Set type to ARP (0x0806)
+//  pkg->hwtype          = htons(0x0001);                // Hardware type is Ethernet (0x0001)
+//  pkg->proto           = htons(0x0800);                // Protocol is ARP Request (0x0800)
+//  pkg->hwlen           = arplen;                       // Hardware addresses are 6 Bytes long
+//  pkg->protolen        = ethlen;                       // And protocol addresses 4 Bytes
+//  pkg->opcode          = htons(0x0001);                // Send: whois XX:XX:XX:XX:XX:XX?
+//  
+//  while(pos-- > 0) {                                   // Write IP/MAC-Addresses (combined loop for all addresses)
+//    pkg->src[pos]        = hwaddr[pos];                // Set source MAC address to hwaddr on ethernet layer
+//    pkg->dest[pos]       = 0xFF;                       // Set destination MAC address to everybody (FF:FF:FF:FF:FF:FF) on ethernet layer
+//    pkg->shwaddr[pos]    = hwaddr[pos];                // Set source MAC address on ARP layer
+//    pkg->dhwaddr[pos]    = 0xFF;                       // Set destination MAC address on ARP layer
+//    if(pos < ethlen) {                                 // Check if we can copy IP addresses too.
+//      pkg->sipaddr[pos]  = 0xFF;                       // Set source ip address to 255.255.255.255
+//      pkg->dipaddr[pos]  = ipaddr[pos];                // Set destination ip address to ipaddr
+//    }
+//  }
+//
+//  eth.write(data, 60);                                 // Write the package
+//  eth.send();                                          // Send the package
 }
                                                        // In this example we would like to make ARP requests to ask for every ip address.
 int main() {                                           // The programm starts here!
   unsigned int i = 1;                                  // The integer we use as counter and target IP address.
-  char *c        = (char *)&i;                         // We cast the integer to an array of char c[4] to handle it as IP address.
+  //char *c        = (char *)&i;                         // We cast the integer to an array of char c[4] to handle it as IP address.
   
   printf("Lowlevel Ethernet Spammer\n\n");             // Print out that the programm has been started.
 
-  while(1) {                                           // Do forever:
-    send(c);                                           //   Assamble and send our request. See eth_send function!
+  while(1) {
+    char* ip = "192.168.10.10";                                           // Do forever:
+    send(ip);                                           //   Assamble and send our request. See eth_send function!
     i++;                                               //   Increment counter. What will increment the IP (c[4]) address as well.
     
     led4 = 1;                                          //   Show activity, by blinking with led 4:

diff -r 852db76de235 -r feaa107f56b3 mbed.bld
--- a/mbed.bld	Fri Sep 04 12:25:06 2009 +0000
+++ b/mbed.bld	Fri Apr 24 03:11:02 2015 +0000
@@ -1,1 +1,1 @@
-http://mbed.org/users/mbed_official/code/mbed/builds/f63353af7be8
+http://mbed.org/users/mbed_official/code/mbed/builds/433970e64889
\ No newline at end of file

diff -r 852db76de235 -r feaa107f56b3 net/arp.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/net/arp.h	Fri Apr 24 03:11:02 2015 +0000
@@ -0,0 +1,58 @@
+#ifndef ARP_H
+#define ARP_H
+
+#include "net.h"
+
+/**
+  \file
+  \brief ARP packet
+  
+  This file contains the memory map and associated functions for ARP packet
+  creation and deconstruction. 
+*/
+
+#define ETHERTYPE_ARP 0x0806
+
+/// ARP Packet memory map
+typedef struct {
+  u16 hardware_type; ///< 0x0001 for ethernet
+  u16 protocol_type; ///< 0x0800 for IPv4
+  u8  hardware_length; ///< Bytes.  Ethernet is 6
+  u8  protocol_length; ///< Bytes.  IPv4 is 4
+  u16 operation; ///< Operation.  1 for request, 2 for reply or announce
+  // The following are only valid for IPv4 over Ethernet
+  u8  sender_hardware_address[6]; ///< Generator of the request or reply
+  u8  sender_protocol_address[4]; ///< All zeroes for an ARP probe
+  u8  target_hardware_address[6]; ///< Announce - same as SHA
+  u8  target_protocol_address[4]; ///< Announce - Same as TPA
+} ARP_Packet;
+
+/// Convert from wire to host or host to wire endianness
+inline void fix_endian_arp(ARP_Packet *packet)
+{
+  fix_endian_u16(&packet->hardware_type);
+  fix_endian_u16(&packet->protocol_type);
+  fix_endian_u16(&packet->operation);
+}
+
+/// Print the ARP packet
+inline void print_arp(ARP_Packet *packet)
+{
+    printf("ARP Packet: \n");
+    printf("  Hardware:  0x%04X \n", packet->hardware_type);
+    printf("  Protocol:  0x%04X \n", packet->protocol_type);
+    printf("  Type:      %d \n", packet->operation);
+    if (packet->hardware_type != 0x0001 || packet->protocol_type != 0x0800) return;
+    
+    u8 *bytes;
+    bytes = packet->sender_hardware_address;
+    printf("  Source:    MAC - %02X:%02X:%02X:%02X:%02X:%02X \n", bytes[0],bytes[1],bytes[2],bytes[3],bytes[4],bytes[5]);
+    bytes = packet->target_hardware_address;
+    printf("  Target:    MAC - %02X:%02X:%02X:%02X:%02X:%02X \n", bytes[0],bytes[1],bytes[2],bytes[3],bytes[4],bytes[5]);
+    bytes = packet->sender_protocol_address;
+    printf("  Source:    IP  - %03d.%03d.%03d.%03d \n", bytes[0], bytes[1], bytes[2], bytes[3]);
+    bytes = packet->target_protocol_address;
+    printf("  Target:    IP  - %03d.%03d.%03d.%03d \n", bytes[0], bytes[1], bytes[2], bytes[3]);
+}
+
+#endif
\ No newline at end of file

diff -r 852db76de235 -r feaa107f56b3 net/ethernet.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/net/ethernet.h	Fri Apr 24 03:11:02 2015 +0000
@@ -0,0 +1,49 @@
+#ifndef ETHERNET_H
+#define ETHERNET_H
+
+#include "net.h"
+
+/**
+  \file ethernet.h
+  \brief Ethernet frame header
+  
+  This file contains the memory map and associated functions for Ethernet frame header
+  creation and deconstruction. 
+*/
+
+/// Ethernet MAC address memory map
+typedef struct {
+  unsigned char octet[6]; ///< Individual octsts of the MAC address
+} Ethernet_MAC;
+
+/// Ethernet II Frame Header Memory map
+typedef struct {
+  /// Destination MAC address (6 octets)
+  Ethernet_MAC destination;
+  /// Source MAC address (6 octets)
+  Ethernet_MAC source;
+  // (optional) VLAN Tag (unsupported)
+  /// Ethernet type or length (only <0x600 or 0x0800 IPv4 supported)
+  u16 ethertype;
+  /// Payload (used for memory mapping; has zero size)
+  unsigned char payload[];
+} Ethernet_FrameHeader;
+
+/// Convert from wire to host or host to wire endian-ness
+inline void fix_endian_ethernet(Ethernet_FrameHeader *header)
+{
+  fix_endian_u16(&header->ethertype);
+}
+
+/// Print out an ethernet packet
+inline void print_ethernet(Ethernet_FrameHeader *frame)
+{
+  printf("Ethernet frame: \n");
+  u8 *src = frame->source.octet;
+  u8 *dst = frame->destination.octet;
+  printf("  Source:    MAC - %02X:%02X:%02X:%02X:%02X:%02X \n", src[6], src[7], src[8], src[9], src[10], src[11]);
+  printf("  Dest:      MAC - %02X:%02X:%02X:%02X:%02X:%02X \n", dst[0], dst[1], dst[2], dst[3], dst[4], dst[5]);
+  printf("  Ethertype: 0x%04X \n", frame->ethertype);
+}
+
+#endif
\ No newline at end of file

diff -r 852db76de235 -r feaa107f56b3 net/icmp.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/net/icmp.h	Fri Apr 24 03:11:02 2015 +0000
@@ -0,0 +1,47 @@
+#ifndef ICMP_H
+#define ICMP_H
+
+#include "net.h"
+
+/**
+  \file icmp.h
+  \brief ICMP frame header
+  
+  This file contains the memory map and associated functions for ICMP packet
+  creation and deconstruction. 
+*/
+
+#define ICMP_ECHO_REPLY   0x00
+#define ICMP_ECHO_REQUEST 0x08
+#define IPPROTO_ICMP      0x01
+
+/// ICMP packet memory map
+typedef struct {
+    u8 type;        ///< type of ICMP message
+    u8 code;        ///< code number associated with certain message types
+    u16 checksum; 
+    u16 id;         ///< ID value, returned in ECHO REPLY
+    u16 sequence;   ///< Sequence value to be returned with ECHO REPLY
+    u8 data[];      ///< Data memory map
+} ICMP_Packet;
+
+/// Convert from wire to host or host to wire endianness
+inline void fix_endian_icmp(ICMP_Packet *segment)
+{
+  fix_endian_u16(&segment->checksum);
+  fix_endian_u16(&segment->id);
+  fix_endian_u16(&segment->sequence);
+}
+
+/// Print the ICMP packet
+inline void print_icmp(ICMP_Packet *segment)
+{
+  printf("ICMP Packet:");
+  printf("  Type:      0x%02X \n", segment->type);
+  printf("  Code:      0x%02X \n", segment->code);
+  printf("  Checksum:  0x%04X \n", segment->checksum);
+  printf("  ID:        0x%04X \n", segment->id);
+  printf("  Sequence:  0x%04X \n", segment->sequence);
+}
+
+#endif
\ No newline at end of file

diff -r 852db76de235 -r feaa107f56b3 net/ip.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/net/ip.h	Fri Apr 24 03:11:02 2015 +0000
@@ -0,0 +1,115 @@
+#ifndef IP_H
+#define IP_H
+
+#include "net.h"
+
+/**
+  \file ip.h
+  \brief IP Packet header
+  
+  This file contains the memory map and associated functions for IP packet header
+  creation and deconstruction. 
+*/
+
+#define ETHERTYPE_IPV4 0x0800
+#define ETHERTYPE_IPV6 0x86DD
+
+/// IP Address memory map
+typedef struct {
+  unsigned char octet[4]; ///< Individual address octets
+} IP_Address;
+
+/// IP Packet memory map
+typedef struct {
+  /// 4 bits that contain the version, that specifies if it's an IPv4 or IPv6 packet,
+  unsigned version:4; // Only 0x4 supported
+  /// 4 bits that contain the Internet Header Length which is the length of the header in multiples of 4 bytes (eg. 5 means 20 bytes).
+  unsigned header_bytes_div4:4;
+  /// 8 bits that contain the Type of Service, also referred to as Quality of Service (QoS), which describes what priority the packet should have,
+  unsigned tos:8;
+  /// 16 bits that contain the total length of the IP packet (datagram) in bytes,
+  u16 packet_bytes;
+  /// 16 bits that contain an identification tag to help reconstruct the packet from several fragments,
+  u16 fragment_id;
+  /// 3 bits that contain a zero, a flag that says whether the packet is allowed to be fragmented or not (DF: Don't fragment), and a flag to state whether more fragments of a packet follow (MF: More Fragments)
+  unsigned unused_0:1;
+  unsigned dont_fragment:1;
+  unsigned more_follow:1;
+  /// 13 bits that contain the fragment offset, a field to identify position of fragment within original packet
+  unsigned fragment_offset:13; ///< This and the ones above may not work properly due to endianness
+  /// 8 bits that contain the Time to live (TTL) which is the number of hops (router, computer or device along a network) the packet is allowed to pass before it dies (for example, a packet with a TTL of 16 will be allowed to go across 16 routers to get to its destination before it is discarded),
+  unsigned ttl:8;
+  /// 8 bits that contain the protocol (TCP, UDP, ICMP, etc...)
+  ///   0x01 ICMP
+  ///   0x06 TCP
+  ///   0x11 UDP
+  unsigned protocol:8;
+  /// 16 bits that contain the Header Checksum, a number used in error detection,
+  u16 header_checksum;
+  /// 32 bits that contain the source IP address,
+  IP_Address source;
+  /// 32 bits that contain the destination address.
+  IP_Address destination;
+  /// Zero-length field for memory mapping the packet data
+  unsigned char data[];
+} IP_PacketHeader;
+
+/// Convert from wire to host or host to wire endianness
+inline void fix_endian_ip(IP_PacketHeader *packet)
+{
+  packet->version ^= packet->header_bytes_div4;
+  packet->header_bytes_div4 ^= packet->version;
+  packet->version ^= packet->header_bytes_div4;
+  fix_endian_u16(&packet->packet_bytes);
+  fix_endian_u16(&packet->fragment_id);
+  // Don't fix checksums; they are done bitwise
+}
+
+/// Get a constant string of the given IP protocol (e.g. "ICMP", "TCP", "UDP") if known
+inline const char *ipproto2name(u8 proto)
+{
+  switch (proto)
+  {
+    case 0x01: return "ICMP";
+    case 0x02: return "IGMP";
+    case 0x06: return "TCP";
+    case 0x11: return "UDP";
+  }
+  return "<UNKNOWN>";
+}
+
+/// Print the IP packet
+inline void print_ip(IP_PacketHeader *packet)
+{
+  printf("IPv%d Packet: \n", packet->version);
+  if (packet->version != 4)
+  {
+    printf("Not an IPv4 packet (skipping)");
+    return;
+  }
+    
+  u8 *dst = packet->destination.octet;
+  u8 *src = packet->source.octet;
+  printf("  Source:    IP - %03d.%03d.%03d.%03d \n", src[0], src[1], src[2], src[3]);
+  printf("  Dest:      IP - %03d.%03d.%03d.%03d \n", dst[0], dst[1], dst[2], dst[3]);
+  printf("  TTL:       %d \n", packet->ttl);
+  printf("  Protocol:  0x%02X (%s) \n", packet->protocol, ipproto2name(packet->protocol));
+  printf("  ToS:       0x%02X \n", packet->tos);
+  printf("  Header:    %d bytes \n", packet->header_bytes_div4*4);
+  printf("  Packet:    %d bytes \n", packet->packet_bytes);
+  printf("  Fragment:  0x%04X DF=%d MF=%d OFFSET=0x04X", packet->fragment_id, packet->dont_fragment, packet->more_follow, packet->fragment_offset);
+  printf("  Checksum:  0x%04X \n", packet->header_checksum);
+}
+
+/// Parse the string (in decimal triple-dot notation) into the IP address structure
+inline void str2ipaddr(const char *ip, IP_Address *addr)
+{
+  static short a,b,c,d;
+  sscanf(ip, "%3hd.%3hd.%3hd.%3hd", &a, &b, &c, &d);
+  addr->octet[0] = a;
+  addr->octet[1] = b;
+  addr->octet[2] = c;
+  addr->octet[3] = d;
+}
+
+#endif
\ No newline at end of file

diff -r 852db76de235 -r feaa107f56b3 net/net.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/net/net.h	Fri Apr 24 03:11:02 2015 +0000
@@ -0,0 +1,103 @@
+/**
+ @file net.h
+ @brief This file encompasses all of the networking headers and includes them automatically
+ 
+ This file has some utility functions and definitions used by all of the networking headers,
+ and includes them all.  This is the only file necessary to include to use all of the networking
+ facilities in nettool
+*/
+
+#ifndef NETWORK_H
+#define NETWORK_H
+
+#include "mbed.h"
+
+#include "ctype.h"
+
+/// General networking checksum - Used for IP, TCP, UDP, ICMP, etc.
+/// Computes the one's complement of the one's complement sum of all of the given bytes except for the memory
+/// at skip_byte for skip_count bytes (e.g. the checksum).  Optionally resumes computation from the (given) last checksum.
+inline u16 checksum(void *_mem, unsigned int bytes, void *skip_byte = NULL, unsigned int skip_count = 0, u16 last = 0)
+{
+  u32 sum = 0;
+  u16 *mem = (u16*)_mem;
+  unsigned int skip_start = (u16*)skip_byte - mem;
+  
+  if (last)
+    sum = last ^ 0xFFFF;
+  
+  //main_log.printf("CK:            0x%8X", sum);
+  for (register unsigned int i = 0; i < bytes/sizeof(u16); ++i)
+  {
+    // Skip bytes we don't use (e.g. the checksum itself)
+    if (i == skip_start)
+      i += skip_count/sizeof(u16);
+    
+    // Sum them up
+    sum += mem[i];
+    
+    //main_log.printf("CK: + 0x%04X = 0x%8X", mem[i], sum);
+  }
+    
+  // One's complement of the one's complement sum
+  sum += sum >> 16;
+  sum &= 0xFFFF;
+  sum ^= 0xFFFF;
+  
+  //main_log.printf("CK:          ~ 0x%8X", sum);
+  
+  return (u16)(sum);
+}
+
+/// Generic u16 endian swapping
+inline void fix_endian_u16(u16 *p)
+{
+  char *bytes = (char*)p;
+  bytes[0] ^= bytes[1];
+  bytes[1] ^= bytes[0];
+  bytes[0] ^= bytes[1];
+}
+
+/// Generic u32 endian swapping
+inline void fix_endian_u32(u32 *p)
+{
+  char *bytes = (char*)p;
+  // Swap outer bytes
+  bytes[0] ^= bytes[3];
+  bytes[3] ^= bytes[0];
+  bytes[0] ^= bytes[3];
+  // Swap inner bytes
+  bytes[1] ^= bytes[2];
+  bytes[2] ^= bytes[1];
+  bytes[1] ^= bytes[2];
+}
+
+/* Printing character */
+#define PCHAR(x) (isprint(x)?(x):'.')
+
+/// Hex dump a word-aligned number of bytes (will print extra bytes if length is not a multiple of 32 bits)
+inline void hex_dump(void *base, unsigned int length)
+{
+  char line[/*indent*/ 2 + /*0x*/ 2 + /*addr*/ 8 + /* : */ 3 + /*4xXXXX */ 4*5 + /*: */ 2 + /*8x.*/ 8 + /*\0*/ 1];
+  for (char *p = (char*)base; p - (char*)base < length; p += 8)
+  {
+    sprintf(line, "  0x%08X : %02X%02X %02X%02X %02X%02X %02X%02X : %c%c%c%c%c%c%c%c \n", p,
+                  p[0], p[1], p[2], p[3], p[4], p[5], p[6], p[7],
+                  PCHAR(p[0]), PCHAR(p[1]), PCHAR(p[2]), PCHAR(p[3]), PCHAR(p[4]), PCHAR(p[5]), PCHAR(p[6]), PCHAR(p[7]));
+    printf(line);
+  }
+}
+
+// Ethernet
+#include "ethernet.h"
+
+// ARP and IP
+#include "arp.h"
+#include "ip.h"
+
+// TCP, UDP, and ICMP
+#include "tcp.h"
+#include "udp.h"
+#include "icmp.h"
+
+#endif // NETWORK_H
\ No newline at end of file

diff -r 852db76de235 -r feaa107f56b3 net/tcp.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/net/tcp.h	Fri Apr 24 03:11:02 2015 +0000
@@ -0,0 +1,90 @@
+#ifndef TCP_H
+#define TCP_H
+
+#include "net.h"
+
+/**
+  \file tcp.h
+  \brief TCP segment header
+  
+  This file contains the memory map and associated functions for TCP segment header
+  creation and deconstruction. 
+*/
+
+#define IPPROTO_TCP 0x06
+
+/// TCP Segment memory map
+typedef struct {
+  u16 source_port;         ///< Source port (1-65535)
+  u16 destination_port;    ///< Destination port (1-65535)
+  u32 sequence_number;     ///< TCP Sequence number (initial one if SYN set)
+  u32 acknowledge_number;  ///< TCP Acknowledge number (valid if ACK set)
+  
+  unsigned data_offset_bytes_div4:4; ///< Length of this header (20) divided by 4 (should be 5)
+  unsigned unused_0:4;               ///< Unused, should be zero
+  
+  unsigned fin:1; ///< connection FINished (no more data from sender)
+  unsigned syn:1; ///< SYNchronize sequence numbers
+  unsigned rst:1; ///< ReSeT the connection
+  unsigned psh:1; ///< PuSH to receiving application
+  unsigned ack:1; ///< ACKnowledge fiend is significant
+  unsigned urg:1; ///< URGent field is significant
+  unsigned ece:1; ///< ECn Echo
+  unsigned cwr:1; ///< Congestion Window Reduced
+  
+  u16 window_size;    ///< TCP Maxumum window size (8192 is good)
+  u16 checksum;       ///< TCP checksum (computed with pseudo header)
+  u16 urgent_pointer; ///< Urgent pointer (valid if URG set)
+  
+  /// Memory map for data if no options are set
+  unsigned char data[];
+} TCP_SegmentHeader;
+
+/// Convert from wire to host or host to wire endianness
+inline void fix_endian_tcp(TCP_SegmentHeader *segment)
+{
+  segment->unused_0 ^= segment->data_offset_bytes_div4;
+  segment->data_offset_bytes_div4 ^= segment->unused_0;
+  segment->unused_0 ^= segment->data_offset_bytes_div4;
+  fix_endian_u16(&segment->source_port);
+  fix_endian_u16(&segment->destination_port);
+  fix_endian_u16(&segment->window_size);
+  // No fixing checksums
+  fix_endian_u16(&segment->urgent_pointer);
+  fix_endian_u32(&segment->sequence_number);
+  fix_endian_u32(&segment->acknowledge_number);
+}
+
+/// Print the TCP segment header
+inline void print_tcp(TCP_SegmentHeader *segment)
+{
+  printf("TCP Segment: \n");
+  printf("  Source:    PORT %d \n", segment->source_port);
+  printf("  Dest:      PORT %d \n", segment->destination_port);
+  printf("  TCP Seqno: 0x%08X \n", segment->sequence_number);
+  printf("  TCP Ackno: 0x%08X \n", segment->acknowledge_number);
+  printf("  Header:    %d bytes \n", segment->data_offset_bytes_div4*4);
+  if (segment->cwr) printf("  Flag:      CWR \n");
+  if (segment->ece) printf("  Flag:      ECE \n");
+  if (segment->urg) printf("  Flag:      URG \n");
+  if (segment->ack) printf("  Flag:      ACK \n");
+  if (segment->psh) printf("  Flag:      PSH \n");
+  if (segment->rst) printf("  Flag:      RST \n");
+  if (segment->syn) printf("  Flag:      SYN \n");
+  if (segment->fin) printf("  Flag:      FIN \n");
+}
+
+/// Compute the pseudo header checksum with the given source, destination, and length
+inline u16 pseudo_header_checksum(IP_Address source, IP_Address destination, u16 length)
+{
+  struct {
+    IP_Address src, dst;
+    u8 zeros;
+    u8 proto;
+    u16 length;
+  } pseudoheader = {source, destination, 0, IPPROTO_TCP, length};
+  fix_endian_u16(&pseudoheader.length);
+  return checksum(&pseudoheader, sizeof(pseudoheader));
+}
+
+#endif
\ No newline at end of file

diff -r 852db76de235 -r feaa107f56b3 net/udp.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/net/udp.h	Fri Apr 24 03:11:02 2015 +0000
@@ -0,0 +1,42 @@
+#ifndef UDP_H
+#define UDP_H
+
+#include "net.h"
+
+/**
+  \file udp.h
+  \brief UDP packet
+  
+  This file contains the memory map and associated functions for UDP packet
+  creation and deconstruction. 
+*/
+
+#define IPPROTO_UDP 0x11
+
+/// UDP Packet memory map
+typedef struct {
+  u16 source_port;       ///< Source port (1-65535)
+  u16 destination_port;  ///< Destination port (1-65535) 
+  u16 length;            ///< Entire datagram size in bytes
+  u16 checksum;          ///< Checksum
+  u8 data[];             ///< Data memory map
+} UDP_Packet;
+
+/// Convert from wire to host or host to wire endianness
+inline void fix_endian_udp(UDP_Packet *segment)
+{
+  fix_endian_u16(&segment->source_port);
+  fix_endian_u16(&segment->destination_port);
+  fix_endian_u16(&segment->length);
+}
+
+/// Print the UDP packet
+inline void print_udp(UDP_Packet *segment)
+{
+  printf("UDP Packet: \n");
+  printf("  Source:    PORT %d \n", segment->source_port);
+  printf("  Dest:      PORT %d \n", segment->destination_port);
+  printf("  Length:    %d \n", segment->length);
+}
+
+#endif
\ No newline at end of file

diff -r 852db76de235 -r feaa107f56b3 sniffer.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sniffer.h	Fri Apr 24 03:11:02 2015 +0000
@@ -0,0 +1,268 @@
+#ifndef SNIFFER_H
+#define SNIFFER_H
+
+#include "mbed.h"
+
+#include "util/types.h"
+#include "net/net.h"
+
+#include <cstdio>
+#include <cstring>
+#include <functional>
+
+/**
+  \file sniffer.h
+  \brief Ethernet packet Sniffer
+  
+  This file is the bread and butter of the NetTool; it processes and constructs ethernet frames
+  on a bitwise level.
+*/
+
+template <class Arg1, class Arg2, class Result>
+class handler
+{
+public:
+  virtual inline Result operator() (Arg1 x, Arg2 y) const {};
+};
+
+template <class Arg1, class Arg2, class Result>
+class function_handler
+: public handler <Arg1,Arg2,Result>
+{
+protected:
+  Result (*pfunc)(Arg1,Arg2);
+public:
+  explicit inline function_handler ( Result (*f)(Arg1,Arg2) ) : pfunc (f) {}
+  virtual inline Result operator() (Arg1 x, Arg2 y) const { return pfunc(x,y); }
+};
+
+template <class Type, class Arg1, class Arg2, class Result>
+class member_handler
+: public handler <Arg1,Arg2,Result>
+{
+protected:
+  Type *inst;
+  Result (Type::*pfunc)(Arg1,Arg2);
+public:
+  explicit inline member_handler ( Type *i, Result (Type::*f)(Arg1,Arg2) ) : inst(i), pfunc (f) {}
+  virtual inline Result operator() (Arg1 x, Arg2 y) const { return (inst->*pfunc)(x,y); }
+};
+
+/// Demo - Ethernet Packet Sniffer
+class Sniffer {
+public:
+  Ethernet_MAC mac;
+  
+private:
+  // Ethernet interface
+  Ethernet     eth;
+  IP_Address   addr;
+  
+  // Status LEDs
+  DigitalOut linked;
+  DigitalOut received;
+
+  // Frame data (big enough for largest ethernet frame)
+  int  frame_size;
+  char frame[0x600];
+  
+  // Outgoing frames
+  char outframe[0x600];
+  Ethernet_FrameHeader *outframe_header;
+
+public:  
+  /// Ethernet Frame Header (incoming)
+  Ethernet_FrameHeader *frame_header;
+  
+  /// IP Packet Header (incoming)
+  IP_PacketHeader *ip_packet;
+  
+  /// ARP Packet (incoming)
+  ARP_Packet *arp_packet;
+  
+  /// TCP Packet (incoming)
+  TCP_SegmentHeader *tcp_packet;
+  
+  /// UDP Packet (incoming)
+  UDP_Packet *udp_packet;
+  
+  /// ICMP Packet (incoming)
+  ICMP_Packet *icmp_packet;
+  
+  /// Generic - total data bytes
+  unsigned int data_bytes;
+
+public:
+  /// Constructor
+  inline Sniffer()
+  : linked(LED1), received(LED2)
+  {
+    eth.set_link(Ethernet::AutoNegotiate);
+    eth.address((char *)mac.octet);
+  }
+  
+  /// Inject the raw ethernet frame
+  inline bool inject(void *data, unsigned int bytes)
+  {
+    // Send the packet
+    eth.write((char*)data, bytes);
+    int send_status = eth.send();
+
+    //decode_ethernet(data);
+    
+    return send_status;
+  }
+  
+  /// Inject the raw payload into an ethernet frame with the given destination and ethertype
+  inline bool inject(Ethernet_MAC dest, u16 ethertype, void *packet, unsigned int bytes)
+  {
+    memset(outframe, 0x00, bytes);
+    
+    outframe_header = (Ethernet_FrameHeader*)outframe;
+    
+    // Set the ethernet frame source
+    memcpy(&outframe_header->source, mac.octet, 6);
+    
+    // Set the ethernet frame destination
+    outframe_header->destination = dest;
+    
+    // Set the ethernet ethertype
+    outframe_header->ethertype = ethertype;
+    
+    // Make sure the payload won't be too large
+    if (sizeof(Ethernet_FrameHeader) + bytes > sizeof(outframe))
+    {
+      printf("ERROR: Attempt to inject packet failed; Payload size of %d is too large /n", bytes);
+      return false;
+    }
+    
+    // Set the payload
+    memcpy(outframe_header->payload, packet, bytes);
+    fix_endian_ethernet(outframe_header);
+    
+    // Send the packet
+    eth.write(outframe, sizeof(Ethernet_FrameHeader) + bytes);
+    int send_status = eth.send();
+
+    //decode_ethernet(outframe);
+
+    return send_status;
+  }
+  
+  /// Wait until there is more data to receive
+  inline void wait_for_data()
+  { 
+    while (true)
+    {
+      wait(0.0001);
+      
+      if (!(linked = eth.link()))
+        continue;
+      
+      received = (frame_size = eth.receive());
+      if (!frame_size)
+        continue;
+      
+      eth.read(frame, frame_size);
+      break;
+    }
+  }
+
+  /// Wait for an ethernet frame (will be stored in appropriate class member pointers)
+  inline void next()
+  {
+    wait_for_data();
+    
+    // Zero out all of the packet pointers
+    frame_header = NULL;
+    arp_packet = NULL;
+    icmp_packet = NULL;
+    tcp_packet = NULL;
+    udp_packet = NULL;
+    data_bytes = 0;
+    
+    decode_ethernet(frame);
+  }
+  
+  /// Decode the given ethernet frame
+  inline void decode_ethernet(void *frame)
+  {
+    Ethernet_FrameHeader *header = frame_header = (Ethernet_FrameHeader*)frame;
+    fix_endian_ethernet(header);
+    
+    switch (header->ethertype)
+    {
+      case ETHERTYPE_IPV4:
+      case ETHERTYPE_IPV6:
+        decode_ip((IP_PacketHeader*)header->payload);
+        break;
+      case ETHERTYPE_ARP:
+        decode_arp((ARP_Packet*)header->payload);
+        break;
+      default:
+        break; // Unknown ethertype
+    }
+  }
+  
+  /// Decode the given ARP packet
+  inline void decode_arp(ARP_Packet *packet)
+  {
+    fix_endian_arp(packet);
+    if (packet->hardware_type != 0x0001 || packet->protocol_type != 0x0800) return;
+    arp_packet = packet;
+  }
+  
+  /// Decode the given IPv4 packet
+  inline void decode_ip(IP_PacketHeader *packet)
+  {
+    u16 chk = checksum(packet, sizeof(IP_PacketHeader), &packet->header_checksum, 2);
+    fix_endian_ip(packet);
+    ip_packet = packet;
+  
+    if (packet->version != 4) return;
+    
+    data_bytes = packet->packet_bytes;
+    data_bytes -= sizeof(IP_PacketHeader);
+    
+    if (packet->protocol == IPPROTO_UDP)
+    {
+      UDP_Packet *segment = udp_packet = (UDP_Packet*)packet->data;
+      fix_endian_udp(segment);
+      data_bytes -= sizeof(UDP_Packet);
+    }
+    else if (packet->protocol == IPPROTO_ICMP)
+    {
+      ICMP_Packet *segment = icmp_packet = (ICMP_Packet *)packet->data;
+      fix_endian_icmp(segment);
+      data_bytes -= sizeof(ICMP_Packet);
+    }
+    else if (packet->protocol == IPPROTO_TCP)
+    {
+      TCP_SegmentHeader *segment = tcp_packet = (TCP_SegmentHeader*)packet->data;
+      fix_endian_tcp(segment);
+      data_bytes -= sizeof(TCP_SegmentHeader);
+      dispatch_tcp(segment,data_bytes);
+    }
+  }
+  
+  handler<TCP_SegmentHeader*,u32,void> *tcp_handler;
+  inline void dispatch_tcp(TCP_SegmentHeader *tcp_packet, u32 data_bytes)
+  {
+    if (tcp_handler) (*tcp_handler)(tcp_packet,data_bytes);
+  }
+  
+  /// Attach a member function to be called on all TCP packets
+  template <class T>
+  inline void attach_tcp(T *inst, void (T::*func)(TCP_SegmentHeader *tcp_packet, u32 data_bytes))
+  {
+    tcp_handler = new member_handler<T,TCP_SegmentHeader*,u32,void>(inst, func);
+  }
+  
+  /// Attach a non-member function to be called on all TCP packets
+  inline void attach_tcp(void (*func)(TCP_SegmentHeader *tcp_packet, u32 data_bytes))
+  {
+    tcp_handler = new function_handler<TCP_SegmentHeader*,u32,void>(func);
+  }
+};
+
+#endif // SNIFFER_H
\ No newline at end of file

diff -r 852db76de235 -r feaa107f56b3 util/types.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/util/types.h	Fri Apr 24 03:11:02 2015 +0000
@@ -0,0 +1,20 @@
+#ifndef TYPES_H
+#define TYPES_H
+
+/**
+  \file types.h
+  \brief Type definitions
+  
+  This file contains some utility type definitions
+*/
+
+/// Unsigned 8 bit value
+typedef unsigned char u8;
+
+/// Unsigned 16 bit value
+typedef unsigned short u16;
+
+/// Unsigned 32 bit value
+typedef unsigned int u32;
+
+#endif
\ No newline at end of file

diff -r 852db76de235 -r feaa107f56b3 util/util.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/util/util.h	Fri Apr 24 03:11:02 2015 +0000
@@ -0,0 +1,35 @@
+#ifndef UTIL_H
+#define UTIL_H
+
+#include "types.h"
+
+/**
+  \file util.h
+  \brief Primary utility header
+  
+  In addition to providing some utility functions, this file also includes
+  the other utility headers automatically.
+*/
+
+/// Is any byte memory at start for bytes nonzero?
+inline bool is_nonzero_mem(u8 *start, unsigned int bytes)
+{
+  for (; bytes--; ++start) if (*start) return true;
+  return false;
+}
+
+/// Are all bytes at start for bytes zero?
+inline bool is_zero_mem(u8 *start, unsigned int bytes)
+{
+  for (; bytes--; ++start) if (*start) return false;
+  return true;
+}
+
+/// Are the memory locations at and and b equal for bytes?
+inline bool is_equal_mem(u8 *a, u8 *b, unsigned int bytes)
+{
+  for (; bytes--; ++a, ++b) if (*a != *b) return false;
+  return true;
+}
+
+#endif
\ No newline at end of file