Rewrite FS fstab flag processing

* If 'ro' fsflag detected, set Mount_Read_Only = true
* Only output human readable Mount_Options to log
* Match fsflags identically (not just first n chars) since there are
  no fs_flags which take arguments
* Match new processing method introduced in TW fstab flag processing

Change-Id: Iefdb76016be90a131b0d627d0cd3f18d2eb1a008

partition.cpp

@@ -82,7 +82,7 @@ struct flag_list {
 	unsigned flag;
 };
 
-static struct flag_list mount_flags[] = {
+const struct flag_list mount_flags[] = {
 	{ "noatime",    MS_NOATIME },
 	{ "noexec",     MS_NOEXEC },
 	{ "nosuid",     MS_NOSUID },
@@ -512,36 +512,40 @@ bool TWPartition::Process_Fstab_Line(string Line, bool Display_Error) {
 	return true;
 }
 
-bool TWPartition::Process_FS_Flags(string& Options, int& Flags) {
-	int i;
-	char *p;
-	char *savep;
-	char fs_options[250];
+void TWPartition::Process_FS_Flags(const char *str) {
+	char *options = strdup(str);
+	char *ptr, *savep;
 
-	strlcpy(fs_options, Options.c_str(), sizeof(fs_options));
-	Options = "";
+	Mount_Options = "";
 
-	p = strtok_r(fs_options, ",", &savep);
-	while (p) {
-		/* Look for the flag "p" in the flag list "fl"
-		* If not found, the loop exits with fl[i].name being null.
-		*/
-		for (i = 0; mount_flags[i].name; i++) {
-			if (strncmp(p, mount_flags[i].name, strlen(mount_flags[i].name)) == 0) {
-				Flags |= mount_flags[i].flag;
+	// Avoid issues with potentially nested strtok by using strtok_r
+	ptr = strtok_r(options, ",", &savep);
+	while (ptr) {
+		const struct flag_list* mount_flag = mount_flags;
+
+		for (; mount_flag->name; mount_flag++) {
+			// mount_flags are never postfixed by '=',
+			// so only match identical strings (including length)
+			if (strcmp(ptr, mount_flag->name) == 0) {
+				Mount_Flags |= mount_flag->flag;
 				break;
 			}
 		}
 
-		if (!mount_flags[i].name) {
-			if (Options.size() > 0)
-				Options += ",";
-			Options += p;
-		}
-		p = strtok_r(NULL, ",", &savep);
-	}
+		if (mount_flag->flag == MS_RDONLY)
+			Mount_Read_Only = true;
 
-	return true;
+		if (mount_flag->name != 0) {
+			if (!Mount_Options.empty())
+				Mount_Options += ",";
+			Mount_Options += mount_flag->name;
+		} else {
+			LOGINFO("Unhandled mount flag: '%s'\n", ptr);
+		}
+
+		ptr = strtok_r(NULL, ",", &savep);
+	}
+	free(options);
 }
 
 void TWPartition::Apply_TW_Flag(const unsigned flag, const char* str, const bool val) {
@@ -578,8 +582,7 @@ void TWPartition::Apply_TW_Flag(const unsigned flag, const char* str, const bool
 			Can_Flash_Img = val;
 			break;
 		case TWFLAG_FSFLAGS:
-			Mount_Options = str;
-			Process_FS_Flags(Mount_Options, Mount_Flags);
+			Process_FS_Flags(str);
 			break;
 		case TWFLAG_IGNOREBLKID:
 			Ignore_Blkid = val;

partitionmanager.cpp

@@ -326,7 +326,7 @@ void TWPartitionManager::Output_Partition(TWPartition* Part) {
 	string back_meth = Part->Backup_Method_By_Name();
 	printf("   Backup_Method: %s\n", back_meth.c_str());
 	if (Part->Mount_Flags || !Part->Mount_Options.empty())
-		printf("   Mount_Flags=0x%8x, Mount_Options=%s\n", Part->Mount_Flags, Part->Mount_Options.c_str());
+		printf("   Mount_Options: %s\n", Part->Mount_Options.c_str());
 	if (Part->MTP_Storage_ID)
 		printf("   MTP_Storage_ID: %i\n", Part->MTP_Storage_ID);
 	printf("\n");

partitions.hpp

@@ -100,7 +100,7 @@ private:
 
 	void Apply_TW_Flag(const unsigned flag, const char* str, const bool val); // Apply custom twrp fstab flags
 	void Process_TW_Flags(char *flags, bool Display_Error);                   // Process custom twrp fstab flags
-	bool Process_FS_Flags(string& Options, int& Flags);                       // Process standard fstab fs flags
+	void Process_FS_Flags(const char *str);                                   // Process standard fstab fs flags
 	bool Is_File_System(string File_System);                                  // Checks to see if the file system given is considered a file system
 	bool Is_Image(string File_System);                                        // Checks to see if the file system given is considered an image
 	void Setup_File_System(bool Display_Error);                               // Sets defaults for a file system partition