Notes

1. An example HTTPS server
   • Based off Unix networking
   • Add route handlers and request configurations
     • Use callbacks for route handlers
   • It will parse HTTP requests for you
   • server script has ability to read config file as no code option
2. A server using a custom networking protocol
   • Built off on top of existing Unix networking
   • Built in HTTP headers for request and validations
     • Ensures you are following best practices
   • Test this server with nodejs frameworks, python frameworks
   • Able to create requests
   • Able to create servers
   • Uses standardized return system
     • [-Infinity, 0] error
     • (1, Infinity) success
   • Has metrics to see sockets open, cpu usage, etc /**
     • Child prcess
     • Add metrics from getrlimit(2)
     • To print out real time stats about server
     • An array of connections
     • struct connection
     • • pid
     • • rlimit information */
   • start_server returns a Server struct
   • you can add functions to the server struct
   • create a function that you can pass configurations too

• man getaddrinfo

• ai_family: Only accept protocols supported by the os

• ai_socktype: Stream or datagram (ssh && HTTP use stream sockets)

  • SOCK_STREAM uses TCP: Transmission Control Protocol
  • SOCK_DGRAM uses UDP: may arrive out of order
    • Just ignore em or approximate it

• flags: first 10 bits matter

  • AI_ADDRCONFIG System decides IVP4 or IPV6

  • AI_ALL

  • AI_CANNONAME

  • AI_NUMERICHOST hostname is IPv4 or IP6 or DNS should be performed

  • AI_NUMERICSERV

  • AI_PASSIVE

    • TCP: returned socket address structure will use bind
      • hostname will be null pointer
      • IP address will be set
        • INADDR_ANY for IPv4
        • IN6ADDR_ANY_INIT for IPv6
    • UDP: returned socket address struct will use connect, sendto, sendmsg
      • if hostname is null pointer && AI_PASSIVE === 0
        • IP address will be set to loopback addresss

  • AI_V4MAPPED

  • AI_V4MAPPED_CFG

  • AI_DEFAULT

  • AI_UNUSABLE

• man page

• getaddrinfo gets a list of IP addresses and port names for hostname and servname

  • hostname & servname are null pointer or null terminated strings - Neither can be null - One must be string - Both can be string - Neither can't be strings
  • hostname is valid host name or string IPv4/6 addresss
  • servname is port number of service name listed in /etc/services services(5)

• char *host = "addy.address"
• Map to /etc/hosts localhost
• Now go to addy.address in chrome browser
• Useful if TLS cert != localhost and running locally
• replaces gethostbyname and getservbyname()