/ft_ping

Primary LanguageC

ft_ping Project

This project is a recoding of the ping command, following specific requirements and guidelines. It aims to test the accessibility of another machine through the IP network and measure the round-trip time for the response.

Prerequisites

  • Docker must be installed on your system to run the project.

Running the Project

To run the project, execute the following steps:

  1. Clone the repository to your local machine.
  2. Navigate to the project directory.
  3. Run the run.sh script to build and run the project within a Docker container.

Script: run.sh

The run.sh script automates the process of building and running the ft_ping project within a Docker container. It handles the necessary setup and execution steps to ensure a smooth running of the project.

Options

The ft_ping project includes the following options:

  • -v: Verbose mode. Displays additional information about the packets sent and received.
  • -c <count>: Specifies the number of packets to send. The default value is 5.
  • -t <ttl>: Specifies the time-to-live (TTL) value for the packets sent. The default value is 64.
  • -R: Record route. Includes the RECORD_ROUTE option in the ECHO_REQUEST packet and displays the route buffer on returned packets.
  • -d: Debug mode. Displays additional debug information for each packet, aiding in troubleshooting network issues.
  • -q: Quiet mode. Suppresses most output, showing only the final results. Useful for discreet testing.

About the Ping Command

The ping command is a network administration utility used to test the reachability of a host on an Internet Protocol (IP) network. It also measures the round-trip time for the messages sent from the originating host to a destination computer.

ping.c Original Code Summary:

Definitions and Global Variables:

  • PING_MAXWAIT: Maximum wait time for a response, in seconds.
  • PING_MAXPACKET: Maximum packet size.
  • PING_NUMERIC, PING_VERBOSE, PING_QUIET, PING_DEBUG, PING_DONTROUTE, PING_RROUTE, PING_FLOOD, PING_CISCO: Flags for ping options.
  • PING_NROUTES: Number of slots for route recording option.
  • packet: Array to store the packet.
  • s: File descriptor for the socket.
  • whereto: sockaddr structure to define where to send the ping.
  • datalen: Data size.
  • usage, hostname, hnamebuf: Variables related to display and management of hostnames.
  • npackets, preload, ntransmitted, ident: Variables for tracking statistics.
  • nreceived, timing, tmin, tmax, tsum: Variables for delay statistics.
  • finish(), catcher(), inet_ntoa(), pr_addr(): Declared but undefined functions.

Main Functions:

  1. main(argc, argv): Main function.

    • Parses command line arguments.
    • Configures socket and ping options.
    • Sets the ping destination.
    • Sends pings in a loop.
    • Handles different ping modes (flood, cisco, normal).

  2. catcher(): Handles SIGALRM signals.

    • Sends a new ping and schedules a new SIGALRM signal after 1 second.
    • Handles time offset.

  3. pinger(): Builds and sends an ICMP ECHO REQUEST packet.

    • Fills the packet with data.
    • Calculates ICMP checksum.
    • Sends the packet via the socket.

  4. pr_pack(buf, cc, from): Displays information about the received packet.

    • Checks IP and ICMP headers.
    • Processes ICMP packet types (ECHO REPLY, UNREACH, etc.).
    • Displays IP options if present.

  5. finish(): Displays ping statistics and terminates the program.

    • Handles display of statistics in flood or normal mode.

Utility Functions:

  • in_cksum(addr, len): Calculates ICMP checksum.
  • tvsub(out, in): Subtracts two timeval structures.
  • pr_icmph(icp): Displays a descriptive string for an ICMP header.
  • pr_iph(ip): Displays an IP header with its options.
  • pr_addr(l): Returns a host address in quad-dotted format or with a hostname.
  • pr_retip(ip): Displays information about an IP packet returned via ICMP.

The code is a simple C program for ping, capable of operating in normal, flood, or cisco mode. It displays detailed statistics on delays and packet loss for a given host.