From 51a3d2fbbb9d82baa913a54c68cd212c29727e48 Mon Sep 17 00:00:00 2001
From: Nav <nav@navnav.me>
Date: Wed, 5 Oct 2022 20:58:25 +0100
Subject: [PATCH] Tidied Process class and moved Application::isRunningAsRoot()
 function to Process class

---
 src/Application.cpp                           |  4 ---
 src/Application.hpp                           |  7 -----
 src/Helpers/Process.cpp                       | 31 ++++++++++++++-----
 src/Helpers/Process.hpp                       | 22 ++++++++++++-
 .../TargetControllerComponent.cpp             |  6 ++--
 5 files changed, 49 insertions(+), 21 deletions(-)

diff --git a/src/Application.cpp b/src/Application.cpp
index c11b7771..b2e4c3f1 100644
--- a/src/Application.cpp
+++ b/src/Application.cpp
@@ -87,10 +87,6 @@ namespace Bloom
         return EXIT_SUCCESS;
     }
 
-    bool Application::isRunningAsRoot() {
-        return geteuid() == 0;
-    }
-
     std::map<std::string, std::function<int()>> Application::getCommandHandlersByCommandName() {
         return std::map<std::string, std::function<int()>> {
             {
diff --git a/src/Application.hpp b/src/Application.hpp
index 5f2b8e4d..d0476bbb 100644
--- a/src/Application.hpp
+++ b/src/Application.hpp
@@ -44,13 +44,6 @@ namespace Bloom
          */
         int run();
 
-        /**
-         * Checks if the current effective user running Bloom has root privileges.
-         *
-         * @return
-         */
-        static bool isRunningAsRoot();
-
     private:
         std::vector<std::string> arguments;
 
diff --git a/src/Helpers/Process.cpp b/src/Helpers/Process.cpp
index 66fc29e2..8c342c3d 100644
--- a/src/Helpers/Process.cpp
+++ b/src/Helpers/Process.cpp
@@ -4,6 +4,8 @@
 #include <string>
 #include <map>
 
+#include "src/Exceptions/Exception.hpp"
+
 namespace Bloom
 {
     ::pid_t Process::getProcessId() {
@@ -14,6 +16,26 @@ namespace Bloom
         return getppid();
     }
 
+    ::uid_t Process::getEffectiveUserId(std::optional<::pid_t> processId) {
+        if (!processId.has_value()) {
+            processId = Process::getProcessId();
+        }
+
+        const auto processInfo = Process::getProcessInfo(processId.value());
+
+        if (!processInfo) {
+            throw Exceptions::Exception(
+                "Failed to fetch process info for process ID " + std::to_string(processId.value())
+            );
+        }
+
+        return static_cast<::uid_t>(processInfo->euid);
+    }
+
+    bool Process::isRunningAsRoot(std::optional<::pid_t> processId) {
+        return Process::getEffectiveUserId(processId) == 0;
+    }
+
     bool Process::isManagedByClion(std::optional<::pid_t> parentProcessId) {
         if (!parentProcessId.has_value()) {
             parentProcessId = Process::getParentProcessId();
@@ -48,16 +70,11 @@ namespace Bloom
     }
 
     Process::Proc Process::getProcessInfo(::pid_t processId) {
-        auto proc = std::unique_ptr<::PROCTAB, decltype(&::closeproc)>(
+        const auto proc = std::unique_ptr<::PROCTAB, decltype(&::closeproc)>(
             ::openproc(PROC_FILLSTAT | PROC_FILLARG | PROC_PID, &processId),
             ::closeproc
         );
-        auto processInfo = Proc(::readproc(proc.get(), NULL), ::freeproc);
 
-        if (processInfo == NULL) {
-            return Proc(nullptr, ::freeproc);
-        }
-
-        return processInfo;
+        return Proc(::readproc(proc.get(), NULL), ::freeproc);
     }
 }
diff --git a/src/Helpers/Process.hpp b/src/Helpers/Process.hpp
index 48a0b13b..e432ea55 100644
--- a/src/Helpers/Process.hpp
+++ b/src/Helpers/Process.hpp
@@ -2,6 +2,7 @@
 
 #include <optional>
 #include <memory>
+#include <sys/types.h>
 #include <proc/readproc.h>
 
 namespace Bloom
@@ -23,6 +24,26 @@ namespace Bloom
          */
         static ::pid_t getParentProcessId();
 
+        /**
+         * Returns the effective user ID of the given process.
+         *
+         * @param processId
+         *  If not provided, this function will use the current process ID.
+         *
+         * @return
+         */
+        static ::uid_t getEffectiveUserId(std::optional<::pid_t> processId = std::nullopt);
+
+        /**
+         * Returns true if the given process is running as root.
+         *
+         * @param processId
+         *  If not provided, this function will perform the check against the current process.
+         *
+         * @return
+         */
+        static bool isRunningAsRoot(std::optional<::pid_t> processId = std::nullopt);
+
         /**
          * Returns true if the given process is managed by CLion.
          *
@@ -33,7 +54,6 @@ namespace Bloom
          */
         static bool isManagedByClion(std::optional<::pid_t> parentProcessId = std::nullopt);
 
-
     private:
         using Proc = std::unique_ptr<::proc_t, decltype(&::freeproc)>;
         static Proc getProcessInfo(::pid_t processId);
diff --git a/src/TargetController/TargetControllerComponent.cpp b/src/TargetController/TargetControllerComponent.cpp
index 84a7c22b..89e6bc20 100644
--- a/src/TargetController/TargetControllerComponent.cpp
+++ b/src/TargetController/TargetControllerComponent.cpp
@@ -5,8 +5,10 @@
 #include <typeindex>
 #include <algorithm>
 
-#include "src/Application.hpp"
+#include "Responses/Error.hpp"
+
 #include "src/Helpers/Paths.hpp"
+#include "src/Helpers/Process.hpp"
 #include "src/Logger/Logger.hpp"
 
 #include "src/TargetController/Exceptions/DeviceFailure.hpp"
@@ -446,7 +448,7 @@ namespace Bloom::TargetController
             Logger::warning("Bloom udev rules missing - attempting installation");
 
             // We can only install them if we're running as root
-            if (!Application::isRunningAsRoot()) {
+            if (!Process::isRunningAsRoot()) {
                 Logger::error("Bloom udev rules missing - cannot install udev rules without root privileges.\n"
                     "Running Bloom once with root privileges will allow it to automatically install the udev rules. "
                     "Alternatively, instructions on manually installing the udev rules can be found "