Fix the bug about the name resolve

CMakeLists.txt

@@ -99,5 +99,8 @@ if(NOT NO_EXAMPLES)
 
     add_executable(http_server_simple ${PROJECT_SOURCE_DIR}/example/http/simple/server.cpp)
     target_link_libraries(http_server_simple spinet_static Threads::Threads)
+
+    add_executable(address_resolve ${PROJECT_SOURCE_DIR}/example/address/resolve.cpp)
+    target_link_libraries(address_resolve spinet_static Threads::Threads)
 endif()
 #--------------------for the examples end--------------------

example/address/resolve.cpp

@@ -0,0 +1,30 @@
+#include <iostream>
+
+#include "spinet.h"
+
+int main(int argc, char* argv[]) {
+    if (argc != 3) {
+        std::cout << "Usage: PROGRAM_NAME ${address} ${port}" << std::endl;
+        return EXIT_FAILURE;
+    }
+    char* ptr = nullptr;
+    long port = strtol(argv[2], &ptr, 10);
+    if (*ptr != 0) {
+        std::cout << "port is an invalid number." << std::endl;
+        return EXIT_FAILURE;
+    }
+    if (port < 0 || port > 65535) {
+        std::cout << "port should be between 0 and 65535." << std::endl;
+        return EXIT_FAILURE;
+    }
+    auto res = spinet::Address::resolve(argv[1], port);
+    if (res.index() == 1) {
+        std::cout << std::get<1>(res) << std::endl;
+        return EXIT_FAILURE;
+    }
+    auto addresses = std::get<0>(res);
+    for (auto& address : addresses) {
+        std::cout << address.to_string() << std::endl;
+    }
+    return EXIT_SUCCESS;
+}

src/core/address.cpp

@@ -41,21 +41,26 @@ std::variant<std::vector<Address>, std::string> Address::resolve(const char* dom
     hints.ai_family = PF_UNSPEC;
     ::addrinfo* res = nullptr;
     {
-        int ec = ::getaddrinfo(domain, std::to_string(port).c_str(), &hints, &res);
+        int ec = ::getaddrinfo(domain, nullptr, &hints, &res);
         if (ec != 0) {
             return ::gai_strerror(ec);
         }
     }
     std::vector<Address> addresses {};
     for (::addrinfo* iter = res; iter != nullptr; iter = iter->ai_next) {
+        if (iter->ai_protocol != IPPROTO_IP) {
+            continue;
+        }
         char buf[std::max(INET_ADDRSTRLEN, INET6_ADDRSTRLEN)] = { 0 };
         if (iter->ai_family == AF_INET) {
-            ::inet_ntop(AF_INET, iter->ai_addr->sa_data, buf, INET_ADDRSTRLEN);
-            Address address { IPV4, std::string { buf }, ntohs(((sockaddr_in*)iter->ai_addr)->sin_port) };
+            sockaddr_in* sockaddr = (sockaddr_in*)iter->ai_addr;
+            ::inet_ntop(AF_INET, &sockaddr->sin_addr, buf, INET_ADDRSTRLEN);
+            Address address { IPV4, std::string { buf }, port };
             addresses.push_back(address);
         } else {
-            ::inet_ntop(AF_INET6, iter->ai_addr->sa_data, buf, INET6_ADDRSTRLEN);
-            Address address { IPV6, std::string { buf }, ((sockaddr_in6*)iter->ai_addr)->sin6_port };
+            sockaddr_in6* sockaddr = (sockaddr_in6*)iter->ai_addr;
+            ::inet_ntop(AF_INET6, &sockaddr->sin6_addr, buf, INET6_ADDRSTRLEN);
+            Address address { IPV6, std::string { buf }, port };
             addresses.push_back(address);
         }
     }

src/util.h

@@ -23,9 +23,8 @@ inline void set_reuse_port(int fd) {
 }
 
 inline std::string from_sockaddr_in(const ::sockaddr_in& address) {
-    std::size_t len = address.sin_family == AF_INET ? INET_ADDRSTRLEN : INET6_ADDRSTRLEN;
     char buf[std::max(INET_ADDRSTRLEN, INET6_ADDRSTRLEN)] = { 0 };
-    ::inet_ntop(address.sin_family, &address.sin_addr, buf, len);
+    ::inet_ntop(address.sin_family, &address.sin_addr, buf, address.sin_family == AF_INET ? INET_ADDRSTRLEN : INET6_ADDRSTRLEN);
     return { buf };
 }