## About isinetaddr is a simple C library that provides an interface that can be used to validate an IPv(4|6) address (with optional support for CIDR notation included). The library is guided by easy to extend [testcases](test/) that help verify safety and correctness. ## Examples ### IPv4 The following example demonstrates the `isinetaddr4` function with both valid and invalid inputs. The `isinetaddr4` function returns 1 when the input given is a valid IPv4 address, and otherwise returns 0. ```C #include #include #include const char *valid[] = { "127.0.0.1", "1.1.1.1", "0.0.0.0" }; const char *invalid[] = { "foobar", "0.0.0.0.0", NULL }; void validate(const char *str); int main(void) { printf("// valid\n"); for (int i = 0; i < 3; i++) { validate(valid[i]); } printf("// invalid\n"); for (int i = 0; i < 3; i++) { validate(invalid[i]); } return EXIT_SUCCESS; } void validate(const char *str) { if (isinetaddr4(str)) { printf("%s is a valid IPv4 address.\n", str); } else { printf("%s is an invalid IPv4 address.\n", str); } } ``` Expected output: ``` $ cc -Iinclude src/*.c share/isinetaddr/examples/isinetaddr4.c -o example $ ./example // valid 127.0.0.1 is a valid IPv4 address. 1.1.1.1 is a valid IPv4 address. 0.0.0.0 is a valid IPv4 address. // invalid foobar is an invalid IPv4 address. 0.0.0.0.0 is an invalid IPv4 address. (null) is an invalid IPv4 address. ``` ### CIDR notation (IPv4) The `iscidraddr4` function supports the same feature set as `isinetaddr4`, and in addition supports [CIDR notation](https://en.wikipedia.org/wiki/Classless_Inter-Domain_Routing#CIDR_notation). The following example builds on the previous example: ```C #include #include #include const char *valid[] = { "127.0.0.1", "192.168.2.1/32", "192.168.2.1/0" }; const char *invalid[] = { "foobar", "0.0.0.0.0", "192.168.2.1/33" }; void validate(const char *str); int main(void) { printf("// valid\n"); for (int i = 0; i < 3; i++) { validate(valid[i]); } printf("// invalid\n"); for (int i = 0; i < 3; i++) { validate(invalid[i]); } return EXIT_SUCCESS; } void validate(const char *str) { if (iscidraddr4(str)) { printf("%s is a valid IPv4 address.\n", str); } else { printf("%s is an invalid IPv4 address.\n", str); } } ``` Expected output: ``` $ cc -Iinclude src/*.c share/isinetaddr/examples/iscidraddr4.c -o example $ ./example // valid 127.0.0.1 is a valid IPv4 address. 192.168.2.1/32 is a valid IPv4 address. 192.168.2.1/0 is a valid IPv4 address. // invalid foobar is an invalid IPv4 address. 0.0.0.0.0 is an invalid IPv4 address. 192.168.2.1/33 is an invalid IPv4 address. ``` ### IPv6 The following example demonstrates the `isinetaddr6` function with both valid and invalid inputs. The `isinetaddr6` function returns 1 when the input given is a valid IPv6 address, and otherwise returns 0. ```C #include #include #include const char *valid[] = { "::", "::1", "0000:0000:0000:0000:0000:0000:0000:0000" }; const char *invalid[] = { "foobar", "00:::0", NULL }; void validate(const char *str); int main(void) { printf("// valid\n"); for (int i = 0; i < 3; i++) { validate(valid[i]); } printf("// invalid\n"); for (int i = 0; i < 3; i++) { validate(invalid[i]); } return EXIT_SUCCESS; } void validate(const char *str) { if (isinetaddr6(str)) { printf("%s is a valid IPv6 address.\n", str); } else { printf("%s is an invalid IPv6 address.\n", str); } } ``` Expected output: ``` $ cc -Iinclude src/*.c share/isinetaddr/examples/isinetaddr6.c -o example $ ./example // valid :: is a valid IPv6 address. ::1 is a valid IPv6 address. 0000:0000:0000:0000:0000:0000:0000:0000 is a valid IPv6 address. // invalid foobar is an invalid IPv6 address. 00:::0 is an invalid IPv6 address. (null) is an invalid IPv6 address. ``` ## Sources * [Source code (GitHub)](https://github.com/0x1eef/isinetaddr#readme) * [Source code (GitLab)](https://gitlab.com/0x1eef/isinetaddr#about) ## License [BSD Zero Clause](https://choosealicense.com/licenses/0bsd/).
See [LICENSE](./LICENSE).