About

isinetaddr is a clang library that provides a set of functions for IP address validation. The library is guided by testcases that help verify safety and correctness.

Examples

isinetaddr4

The isinetaddr4 function returns true when given a valid IPv4 address:

#include <isinetaddr.h>
#include <stdio.h>
#include <stdlib.h>

const char *ipv4[] = {
  /* valid */
  "127.0.0.1", "1.1.1.1", "0.0.0.0",
  /* invalid */
  "0.0.0.0.0", "foobar" 
};

int
main(void)
{
  for (int i = 0; i < 5; i++) {
    if (isinetaddr4(ipv4[i])) {
      printf("%s is a valid IPv4 address.\n", ipv4[i]);
    } else {
      printf("%s is an invalid IPv4 address.\n", ipv4[i]);
    }
  }
  return (EXIT_SUCCESS);
}

iscidraddr4

The iscidraddr4 function supports the same features as isinetaddr4 plus CIDR notation. The following example builds on the previous example:

#include <isinetaddr.h>
#include <stdio.h>
#include <stdlib.h>

const char *ipv4[] = {
  /* valid */
  "127.0.0.1", "192.168.2.1/32", "192.168.2.1/0",
  /* invalid */
  "192.168.2.1/33", "foobar" 
};

int
main(void)
{
  for (int i = 0; i < 5; i++) {
    if (iscidraddr4(ipv4[i])) {
      printf("%s is a valid IPv4 address.\n", ipv4[i]);
    } else {
      printf("%s is an invalid IPv4 address.\n", ipv4[i]);
    }
  }
  return (EXIT_SUCCESS);
}

isinetaddr6

The isinetaddr6 function returns true when given a valid IPv6 address:

#include <isinetaddr.h>
#include <stdio.h>
#include <stdlib.h>

const char *ipv6[] = {
  /* valid */
  "::", "::1", "0000:0000:0000:0000:0000:0000:0000:0000",
  /* invalid */
  "foobar", "00:::0" 
};


int
main(void)
{
  for (int i = 0; i < 5; i++) {
    if (isinetaddr6(ipv6[i])) {
      printf("%s is a valid IPv4 address.\n", ipv6[i]);
    } else {
      printf("%s is an invalid IPv4 address.\n", ipv6[i]);
    }
  }
  return (EXIT_SUCCESS);
}

Sources

• GitHub
• GitLab
• brew.bsd.cafe/@0x1eef

License

BSD Zero Clause
See LICENSE