isodrive: fix usb gadget

- correctly get gadget
- fix writing to sysfs
- allow umounting iso

src/configfsisomanager.cpp

@@ -6,12 +6,14 @@
 #include "configfsisomanager.h"
 #include <dirent.h>
 #include <unistd.h>
+#include <string.h>
 
 char *get_gadget_root()
 {
 	char *configFsRoot = fs_mount_point("configfs");
 	char *usbGadgetRoot = strjin(configFsRoot, "/usb_gadget/"); 
 	char *gadgetRoot = nullptr;
+	char *udc = nullptr;
 
 	struct dirent *entry = nullptr;
 	DIR *dp = nullptr;
@@ -22,7 +24,9 @@ char *get_gadget_root()
 			if (entry->d_name[0] != '.')
 			{
 				gadgetRoot = strjin(usbGadgetRoot, entry->d_name);
-				break;
+				udc = strjin(gadgetRoot, "/UDC");
+				if (strcmp(udc, getprop("sys.usb.controller")) == 1)
+					break;
 			}
 		}
 	return gadgetRoot;
@@ -65,6 +69,7 @@ void mount_iso(char *iso_path)
 	char *lunRo = strjin(lunRoot, "/ro");
 
 	reset_udc();
+	
 	if (!isdir(massStorageRoot))
 	{
 		mkdir(massStorageRoot, S_IRWXU | S_IRWXG | S_IROTH | S_IXOTH);

src/include/util.h

@@ -4,6 +4,7 @@
 char *fs_mount_point(char *filesystem_type);
 char *strjin(char *w1, char *w2);
 bool isdir(char *path);
+char *sysfs_read(char *path);
 void sysfs_write(char *path, char *content);
 char *getprop(char *key);
 void trim(char *s);

src/main.cpp

@@ -12,13 +12,7 @@ int main(int argc, char* argv[]){
 	}
 	if (argc == 1)
 	{
-		std::cerr << "Not enough args" << std::endl;
+		iso_target = "";
-		return 1;
-	}
-	if (iso_target[0] != '/')
-	{
-		std::cerr << "Iso path is not absolute" << std::endl;
-		return 1;
 	}
 	mount_iso(iso_target);
 }

src/util.cpp

@@ -9,7 +9,7 @@
 #include <sstream>
 #include <array>
 #include <memory>
-
+#include <cstdio>
 
 // https://stackoverflow.com/a/123724
 void trim(char *s)
@@ -58,15 +58,18 @@ bool isdir(char *path)
 void sysfs_write(char *path, char *content)
 {
 	std::cout << "Write: " << content << " -> " << path << std::endl;
-	std::ofstream sysfsFile;
+	std::ofstream sysfsFile(path);
-	sysfsFile.open(path);
+	sysfsFile << content << std::endl;
-	if (!sysfsFile.is_open()) {
-		perror("Failed to open sysfs path");
-	}
-	sysfsFile << content;
-	perror("Status");
 	sysfsFile.close();
-	std::cout << std::endl;
+}
+
+char *sysfs_read(char *path)
+{
+	char *value = nullptr;
+	std::ifstream sysfsFile(path);
+	sysfsFile >> path;
+	sysfsFile.close();
+	return value;
 }