#ifndef _CONNECT_HELP #define _CONNECT_HELP #include #include #include #include #include #include #include "includes/numeric_base.hpp" namespace connect_code { namespace { /* Since these are internal function, I have wrapped them in an anonymous namespace, to prevent outside access to them */ /* Tokenizes a string, based on the given delimiter */ std::vector tokenize_str(std::string str, std::string delim) { std::vector result; char* c_str = str.data(); char* c_delim = delim.data(); char* tok = strtok(c_str, c_delim); while (tok != NULL) { result.push_back(std::string(tok)); tok = strtok(NULL, c_delim); } return result; } /* Convert an IPv4 address from decimal to dotted decimal notation */ std::string dec_to_dotted_dec(std::string addr) { uint32_t addr_val = std::stoul(addr); /* 32 bit address */ uint8_t addr_1 = (addr_val & (0xFF << 24)) >> 24; /* First octet (Bitwise AND the address with 255.0.0.0, and shift it to the right to obtain the first octet) */ uint8_t addr_2 = (addr_val & (0xFF << 16)) >> 16; uint8_t addr_3 = (addr_val & (0xFF << 8)) >> 8; uint8_t addr_4 = (addr_val & 0xFF); std::string ret_val = std::string(std::to_string(addr_1) + "." + std::to_string(addr_2) + "." + std::to_string(addr_3) + "." + std::to_string(addr_4)); return ret_val; } /* Convert an IPv4 address from dotted deecimal to decimal */ std::string dotted_dec_to_dec(std::string addr) { std::vector octets = tokenize_str(addr, "."); uint32_t addr_val = (std::stoul(octets[0]) << 24) + (std::stoul(octets[1]) << 16) + (std::stoul(octets[2]) << 8) + (std::stoul(octets[3])); return std::to_string(addr_val); } } /* Given an address and a port, return a 'code' which has the address and port encoded in it */ std::string encode(std::string address, std::string port) { /* Convert the address to decimal, and convert that to hex */ std::string addr_coded = dotted_dec_to_dec(address); addr_coded = base_convert(addr_coded, 10, 32); /* Convert the port to hex */ std::string port_coded = base_convert(port, 10, 32); std::string ret_val = addr_coded + "_" + port_coded; return ret_val; } /* Given a code, decode it and return a vector with the address and port */ std::vector decode(std::string connect_code) { if (connect_code.find("_") == std::string::npos) { throw std::invalid_argument("Invalid code entered."); } std::vector result = tokenize_str(connect_code, "_"); /* Split the string into address and port */ std::string address = result[0]; /* Address (in base 16) */ std::string port = result[1]; /* Port (in base 16) */ /* Base 16 to base 10 - These lines convert the string to a base 10 number, and convert the result back into a string */ address = std::to_string(std::stoul(address, 0, 32)); port = std::to_string(std::stoul(address, 0, 32)); /* Convert decimal address to dotted decimal */ address = dec_to_dotted_dec(address); std::vector ret_val; ret_val.push_back(address); ret_val.push_back(port); return ret_val; } } #endif