TretornESP/RAWRP

Sends raw arp requests

RAWRP

It just sends an ARP request.

Connection schema:

• the method for sending data is specified on net.c@send_packet, it goes like this

1. Opens a socket with socket():

-Domain: PF_PACKET
-Type:   SOCK_RAW
-Proto:  ETH_P_ALL

2. Creates an address struct (sockaddr_ll) to specify our interface:

-sll_family:    AF_PACKET
-sll_ifindex:   (the index of our network interface calculated at net.c@get_if_info)
-sll_protocol:  ETH_P_ALL

3. Binds the socket to the network card with bind():

-Socket:  sockfd
-Address: sll
-Addrlen: sizeof(sll)

3. Writes data to the socket with write():

-Descriptor: sockfd
-Data:       payload to send
-Length:     len of payload

TLDR:

  s = socket()
  sockaddr_ll sll
  sll. [] = stuff
  bind(s, sll, sizeof(sll))
  write(s, payload, len)
  close(s)

ARP packets:

ARP packets are handcrafted in arp.c

ETH frames:

ETH frames are also handcrafted in ether.c CRC calculations were boring so i stole the code from somewhere i cannot recall crc.c

Usage:

1. Edit the call to rawrp in main.c with your interface name and the ip to request MAC for.
2. save changes and compile with gcc *.c
3. execute with ./a.out

TODO:

1. Improve the ether interface to fit arp model (we create the header and then we calculate the packet from it)
2. Implement Ethernet fragmentation
3. Improve file structure (probably a folder per OSI layer) and create a makefile
4. Expand functionality, maybe start building layer 3?