RosettaCodeData/Task/Parse-an-IP-Address/C++/parse-an-ip-address.cpp

107 lines
3.1 KiB
C++

#include <boost/asio/ip/address.hpp>
#include <cstdint>
#include <iostream>
#include <iomanip>
#include <limits>
#include <string>
using boost::asio::ip::address;
using boost::asio::ip::address_v4;
using boost::asio::ip::address_v6;
using boost::asio::ip::make_address;
using boost::asio::ip::make_address_v4;
using boost::asio::ip::make_address_v6;
template<typename uint>
bool parse_int(const std::string& str, int base, uint& n) {
try {
size_t pos = 0;
unsigned long u = stoul(str, &pos, base);
if (pos != str.length() || u > std::numeric_limits<uint>::max())
return false;
n = static_cast<uint>(u);
return true;
} catch (const std::exception& ex) {
return false;
}
}
//
// Parse an IP address and port from the given input string.
//
// Throws an exception if the input is not valid.
//
// Valid formats are:
// [ipv6_address]:port
// ipv4_address:port
// ipv4_address
// ipv6_address
//
void parse_ip_address_and_port(const std::string& input, address& addr, uint16_t& port) {
size_t pos = input.rfind(':');
if (pos != std::string::npos && pos > 1 && pos + 1 < input.length()
&& parse_int(input.substr(pos + 1), 10, port) && port > 0) {
if (input[0] == '[' && input[pos - 1] == ']') {
// square brackets so can only be an IPv6 address
addr = make_address_v6(input.substr(1, pos - 2));
return;
} else {
try {
// IPv4 address + port?
addr = make_address_v4(input.substr(0, pos));
return;
} catch (const std::exception& ex) {
// nope, might be an IPv6 address
}
}
}
port = 0;
addr = make_address(input);
}
void print_address_and_port(const address& addr, uint16_t port) {
std::cout << std::hex << std::uppercase << std::setfill('0');
if (addr.is_v4()) {
address_v4 addr4 = addr.to_v4();
std::cout << "address family: IPv4\n";
std::cout << "address number: " << std::setw(8) << addr4.to_uint() << '\n';
} else if (addr.is_v6()) {
address_v6 addr6 = addr.to_v6();
address_v6::bytes_type bytes(addr6.to_bytes());
std::cout << "address family: IPv6\n";
std::cout << "address number: ";
for (unsigned char byte : bytes)
std::cout << std::setw(2) << static_cast<unsigned int>(byte);
std::cout << '\n';
}
if (port != 0)
std::cout << "port: " << std::dec << port << '\n';
else
std::cout << "port not specified\n";
}
void test(const std::string& input) {
std::cout << "input: " << input << '\n';
try {
address addr;
uint16_t port = 0;
parse_ip_address_and_port(input, addr, port);
print_address_and_port(addr, port);
} catch (const std::exception& ex) {
std::cout << "parsing failed\n";
}
std::cout << '\n';
}
int main(int argc, char** argv) {
test("127.0.0.1");
test("127.0.0.1:80");
test("::ffff:127.0.0.1");
test("::1");
test("[::1]:80");
test("1::80");
test("2605:2700:0:3::4713:93e3");
test("[2605:2700:0:3::4713:93e3]:80");
return 0;
}