on invalid IPv4 addresses, assume it's a hostname and do a DNS lookup

Enable the full keyboard to enter non-numbers and increase max length from 15 to 50 for longer hostnames.

I know FQDNs can be longer than 50 characters, but that's less common (and painful to type on the Switch).

include/Keyboard.hpp

@@ -7,7 +7,6 @@
 #include "nn/swkbd/swkbd.h"
 
 #include "logger.hpp"
-#include "sead/prim/seadSafeString.h"
 
 typedef void (*KeyboardSetup)(nn::swkbd::KeyboardConfig&);
 
@@ -37,7 +36,7 @@ class Keyboard {
         al::AsyncFunctorThread* mThread;
         nn::swkbd::String mResultString;
 
-        sead::FixedSafeString<0x10> mInitialText;
+        hostname mInitialText;
         KeyboardSetup mSetupFunc;
 
         const char16_t *mHeaderText = u"Enter Server IP Here!";

include/nn/socket.h

@@ -17,6 +17,15 @@ struct sockaddr
     u8 _8[8];           // 8
 };
 
+struct hostent
+{
+    char*   h_name;
+    char**  h_aliases;
+    int     h_addrtype;
+    int     h_length;
+    char**  h_addr_list;
+};
+
 
 namespace nn { namespace socket {
 
@@ -34,6 +43,8 @@ s32 Recv(s32 socket, void* out, ulong outLen, s32 flags);
 u16 InetHtons(u16 val);
 s32 InetAton(const char* addressStr, in_addr* addressOut);
 
+struct hostent* GetHostByName(const char* name);
+
 u32 GetLastErrno();
 
 } }

include/server/Client.hpp

@@ -259,7 +259,7 @@ class Client {
 
         Keyboard* mKeyboard = nullptr; // keyboard for setting server IP
 
-        sead::FixedSafeString<0x10> mServerIP;
+        hostname mServerIP;
 
         int mServerPort = 0;
 

include/server/SocketClient.hpp

@@ -33,4 +33,11 @@ class SocketClient : public SocketBase {
 
     private:
         int maxBufSize = 100;
+
+        /**
+         * @param str a string containing an IPv4 address or a hostname that can be resolved via DNS
+         * @param out IPv4 address
+         * @return if this function was successfull and out contains a valid IP address
+         */
+        bool stringToIPAddress(const char* str, in_addr* out);
 };

include/types.h

@@ -5,6 +5,7 @@
 #include <stdbool.h>
 #include <stddef.h>
 #include <stdint.h>
+#include "sead/prim/seadSafeString.h"
 
 typedef unsigned char       u8;
 typedef unsigned short      u16;
@@ -41,6 +42,9 @@ typedef unsigned int    undefined3;
 typedef unsigned int    undefined4;
 typedef unsigned long    undefined8;
 
+const u8 MAX_HOSTNAME_LENGTH = 50;
+typedef sead::FixedSafeString<MAX_HOSTNAME_LENGTH + 1> hostname;
+
 enum SocketLogState {
     SOCKET_LOG_UNINITIALIZED = 0,
     SOCKET_LOG_CONNECTED = 1,

source/server/Client.cpp

@@ -30,7 +30,6 @@
 #include "packets/PlayerConnect.h"
 #include "packets/PlayerDC.h"
 #include "packets/TagInf.h"
-#include "prim/seadSafeString.h"
 #include "puppets/PuppetInfo.h"
 #include "sead/basis/seadRawPrint.h"
 #include "sead/math/seadQuat.h"
@@ -300,13 +299,13 @@ bool Client::openKeyboardIP() {
         sInstance->mServerIP.cstr(), [](nn::swkbd::KeyboardConfig& config) {
             config.keyboardMode = nn::swkbd::KeyboardMode::ModeNumeric;
             config.leftOptionalSymbolKey = '.';
-            config.textMaxLength = 15;
+            config.textMaxLength = MAX_HOSTNAME_LENGTH;
             config.textMinLength = 1;
             config.isUseUtf8 = true;
             config.inputFormMode = nn::swkbd::InputFormMode::OneLine;
         });
 
-    sead::FixedSafeString<0x10> prevIp = sInstance->mServerIP;
+    hostname prevIp = sInstance->mServerIP;
 
     while (true) {
         if (sInstance->mKeyboard->isThreadDone()) {

source/server/SocketClient.cpp

@@ -11,11 +11,10 @@
 
 nn::Result SocketClient::init(const char* ip, u16 port) {
 
-    sock_ip = ip;
+    this->sock_ip = ip;
+    this->port    = port;
     
-    this->port = port;
-    
-    in_addr hostAddress = { 0 };
+    in_addr  hostAddress   = { 0 };
     sockaddr serverAddress = { 0 };
 
     Logger::log("SocketClient::init: %s:%d sock %s\n", ip, port, getStateChar());
@@ -36,16 +35,18 @@ nn::Result SocketClient::init(const char* ip, u16 port) {
     #endif
 
     if ((this->socket_log_socket = nn::socket::Socket(2, 1, 6)) < 0) {
-
         Logger::log("Socket Unavailable.\n");
-
         this->socket_errno = nn::socket::GetLastErrno();
         this->socket_log_state = SOCKET_LOG_UNAVAILABLE;
         return -1;
     }
 
-    
-    nn::socket::InetAton(this->sock_ip, &hostAddress);
+    if (! this->stringToIPAddress(this->sock_ip, &hostAddress)) {
+        Logger::log("IP address is invalid or hostname not resolveable.\n");
+        this->socket_errno = nn::socket::GetLastErrno();
+        this->socket_log_state = SOCKET_LOG_UNAVAILABLE;
+        return -1;
+    }
 
     serverAddress.address = hostAddress;
     serverAddress.port = nn::socket::InetHtons(this->port);
@@ -206,3 +207,23 @@ bool SocketClient::closeSocket() {
 
     return result;
 }
+
+bool SocketClient::stringToIPAddress(const char* str, in_addr* out) {
+    // string to IPv4
+    if (nn::socket::InetAton(str, out)) {
+        return true;
+    }
+
+    // get IPs via DNS
+    struct hostent *he = nn::socket::GetHostByName(str);
+    if (! he) { return false; }
+
+    // might give us multiple IP addresses, so pick the first one
+    struct in_addr **addr_list = (struct in_addr **) he->h_addr_list;
+    for (int i = 0 ; addr_list[i] != NULL ; i++) {
+        *out = *addr_list[i];
+        return true;
+    }
+
+    return false;
+}