From b0c4881ea924d21ca819b6cf999e97c3efd040b4 Mon Sep 17 00:00:00 2001
From: Steve Muckle <smuckle@google.com>
Date: Fri, 29 May 2020 16:30:33 -0700
Subject: [PATCH] add libmodprobe api to query the number of modules loaded

In the short term this will be used to help implement support for
multiple kernel module directories but it may be useful in other
contexts as well.

Bug: 157645635
Change-Id: I15a252b6e9394292c8f3557ed65112c935830441
---
 libmodprobe/include/modprobe/modprobe.h | 3 +++
 libmodprobe/libmodprobe_ext.cpp         | 1 +
 libmodprobe/libmodprobe_ext_test.cpp    | 1 +
 libmodprobe/libmodprobe_test.cpp        | 1 +
 4 files changed, 6 insertions(+)

diff --git a/libmodprobe/include/modprobe/modprobe.h b/libmodprobe/include/modprobe/modprobe.h
index 297036e41..a7687af16 100644
--- a/libmodprobe/include/modprobe/modprobe.h
+++ b/libmodprobe/include/modprobe/modprobe.h
@@ -34,6 +34,8 @@ class Modprobe {
     bool GetAllDependencies(const std::string& module, std::vector<std::string>* pre_dependencies,
                             std::vector<std::string>* dependencies,
                             std::vector<std::string>* post_dependencies);
+    void ResetModuleCount() { module_count_ = 0; }
+    int GetModuleCount() { return module_count_; }
     void EnableBlacklist(bool enable);
     void EnableVerbose(bool enable);
 
@@ -65,5 +67,6 @@ class Modprobe {
     std::unordered_map<std::string, std::string> module_options_;
     std::set<std::string> module_blacklist_;
     std::unordered_set<std::string> module_loaded_;
+    int module_count_ = 0;
     bool blacklist_enabled = false;
 };
diff --git a/libmodprobe/libmodprobe_ext.cpp b/libmodprobe/libmodprobe_ext.cpp
index 99472c14d..658970874 100644
--- a/libmodprobe/libmodprobe_ext.cpp
+++ b/libmodprobe/libmodprobe_ext.cpp
@@ -63,6 +63,7 @@ bool Modprobe::Insmod(const std::string& path_name, const std::string& parameter
 
     LOG(INFO) << "Loaded kernel module " << path_name;
     module_loaded_.emplace(canonical_name);
+    module_count_++;
     return true;
 }
 
diff --git a/libmodprobe/libmodprobe_ext_test.cpp b/libmodprobe/libmodprobe_ext_test.cpp
index 057dea3a0..9ee5ba7ab 100644
--- a/libmodprobe/libmodprobe_ext_test.cpp
+++ b/libmodprobe/libmodprobe_ext_test.cpp
@@ -56,6 +56,7 @@ bool Modprobe::Insmod(const std::string& path_name, const std::string& parameter
     }
 
     modules_loaded.emplace_back(path_name + options);
+    module_count_++;
     return true;
 }
 
diff --git a/libmodprobe/libmodprobe_test.cpp b/libmodprobe/libmodprobe_test.cpp
index 879c7f2e9..eea0abd52 100644
--- a/libmodprobe/libmodprobe_test.cpp
+++ b/libmodprobe/libmodprobe_test.cpp
@@ -161,6 +161,7 @@ TEST(libmodprobe, Test) {
 
     EXPECT_TRUE(modules_loaded == expected_modules_loaded);
 
+    EXPECT_TRUE(m.GetModuleCount() == 15);
     EXPECT_TRUE(m.Remove("test4"));
 
     GTEST_LOG_(INFO) << "Expected modules loaded after removing test4 (in order):";