From 9a0d2c2f99df42d6e183e4d34c385553d3604fd1 Mon Sep 17 00:00:00 2001
From: Johnathon Slightham <slighthamj@gmail.com>
Date: Sat, 28 Feb 2026 22:37:58 -0500
Subject: [PATCH] Fix mDNS int parse crash, print errno on TCP connection
 failure

---
 include/util/log.h           |  4 ++--
 include/util/string.h        | 13 +++++++++++++
 src/TCPClient.cpp            |  4 +++-
 src/mDNSDiscoveryService.cpp | 12 +++++++++---
 4 files changed, 27 insertions(+), 6 deletions(-)

diff --git a/include/util/log.h b/include/util/log.h
index 31a69ac..654b0ea 100644
--- a/include/util/log.h
+++ b/include/util/log.h
@@ -11,7 +11,7 @@
 
 #ifdef _WIN32
 
-void print_errno() {
+inline void print_errno() {
     char errbuf[ERRBUF_SIZE];
     FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM, NULL, WSAGetLastError(), 0, errbuf, sizeof(errbuf),
                   NULL);
@@ -23,7 +23,7 @@ void print_errno() {
 #include <errno.h>
 #include <string.h>
 
-void print_errno() {
+inline void print_errno() {
     spdlog::error("{}", strerror(errno));
 }
 
diff --git a/include/util/string.h b/include/util/string.h
index 45b8ef9..7f5b412 100644
--- a/include/util/string.h
+++ b/include/util/string.h
@@ -7,6 +7,8 @@
 #include <sstream>
 #include <string>
 #include <vector>
+#include <cctype>
+#include <algorithm>
 
 inline std::vector<std::string> split(const std::string &str, const char delimiter) {
     std::vector<std::string> result;
@@ -20,4 +22,15 @@ inline std::vector<std::string> split(const std::string &str, const char delimit
     return result;
 }
 
+inline bool is_integer(const std::string& s) {
+    if (s.empty()) return false;
+
+    size_t start = 0;
+    if (s[0] == '-' || s[0] == '+')
+        start = 1;
+
+    return start < s.size() &&
+           std::all_of(s.begin() + start, s.end(), ::isdigit);
+}
+
 #endif // STRING_H
diff --git a/src/TCPClient.cpp b/src/TCPClient.cpp
index 8884d6b..ae146c4 100644
--- a/src/TCPClient.cpp
+++ b/src/TCPClient.cpp
@@ -9,6 +9,7 @@
 #include "TCPClient.h"
 #include "constants.h"
 #include "spdlog/spdlog.h"
+#include "util/log.h"
 
 constexpr auto SLEEP_WHILE_INITIALIZING = std::chrono::milliseconds(250);
 constexpr int PORT = 3001;
@@ -55,7 +56,8 @@ int TCPClient::init() {
 #endif
 
     if (connect(this->m_socket, reinterpret_cast<sockaddr *>(&serv_addr), sizeof(serv_addr)) < 0) {
-        spdlog::error("[TCP] Connection failed");
+        spdlog::error("[TCP] Connection failed to connect");
+        print_errno();
         deinit();
         return -1;
     }
diff --git a/src/mDNSDiscoveryService.cpp b/src/mDNSDiscoveryService.cpp
index ec3257d..2338d09 100644
--- a/src/mDNSDiscoveryService.cpp
+++ b/src/mDNSDiscoveryService.cpp
@@ -300,17 +300,23 @@ std::optional<mDNSRobotModule> mDNSDiscoveryService::parse_response(uint8_t *buf
                 }
 
                 if (split_string[0] == MODULE_ID_STR) {
-                    response.id = stoi(split_string[1]);
+                    if (is_integer(std::string(split_string[1]))) {
+                        response.id = stoi(split_string[1]);
+                    }
                 }
 
                 if (split_string[0] == MODULE_TYPE_STR) {
-                    response.module_type = static_cast<ModuleType>(stoi(split_string[1]));
+                    if (is_integer(std::string(split_string[1]))) {
+                        response.module_type = static_cast<ModuleType>(stoi(split_string[1]));
+                    }
                 }
 
                 if (split_string[0] == CONNECTED_MODULES_STR) {
                     for (const auto connected_modules = split(split_string[1], ',');
                          const auto &module_id : connected_modules) {
-                        response.connected_module_ids.emplace_back(stoi(module_id));
+                         if (is_integer(module_id)) {
+                             response.connected_module_ids.emplace_back(stoi(module_id));
+                         }
                     }
                 }
             }