--- /dev/null
+/*
+ Device File Virtualization Guest Preload Library Helpers
+
+ (c) Akhil Guliani and William Gross, 2015
+
+ Adapted from MPI module (c) 2012 Peter Dinda
+
+*/
+
+#define MAX_DEV_NAME_LENGTH 80
+#define MAX_DEVICES 100
+
+//PYTHONSCRIPTBREAK1
+#define DEV_COUNT 9
+//PYTHONSCRIPTBREAK2
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <errno.h>
+
+
+
+#define MIN(a,b) \
+ ({ __typeof__ (a) _a = (a); \
+ __typeof__ (b) _b = (b); \
+ _a < _b ? _a : _b; })
+
+
+char *strcpy(char *dest, const char *src)
+{
+ unsigned i;
+ for (i=0; src[i] != '\0'; ++i)
+ dest[i] = src[i];
+ dest[i] = '\0';
+ return dest;
+}
+
+size_t strlen(const char * str)
+{
+ const char *s;
+ for (s = str; *s; ++s) {}
+ return(s - str);
+}
+
+
+//taken from: https://stuff.mit.edu/afs/sipb/project/tcl80/src/tcl8.0/compat/strstr.c
+char* strstr(const char* string,char* substring)
+ // register char *string; /* String to search. */
+ // char *substring; /* Substring to try to find in string. */
+{
+ register char *a, *b;
+
+ /* First scan quickly through the two strings looking for a
+ * * single-character match. When it's found, then compare the
+ * * rest of the substring.
+ * */
+
+ b = substring;
+ if (*b == 0) {
+ return (char*)string;
+ }
+ for ( ; *string != 0; string += 1) {
+ if (*string != *b) {
+ continue;
+ }
+ a = (char*)string;
+ while (1) {
+ if (*b == 0) {
+ return (char*)string;
+ }
+ if (*a++ != *b++) {
+ break;
+ }
+ }
+ b = substring;
+ }
+ return (char *) 0;
+}
+
+
+//Used to keep track of the active file descriptor for the supported devices
+//Initially the fd is -1 to indicate that the device has not yet been opened
+typedef struct dev_file_fd_tracker {
+ char devName[MAX_DEV_NAME_LENGTH];
+ int devFD;
+} dev_tracker;
+
+
+dev_tracker dtrack[] = {
+//PYTHONSCRIPTBREAK3
+{"/dev/urandom",-1},
+{"/dev/input/mouse0",-1},
+{"/dev/input/event0",-1},
+{"/dev/input/event1",-1},
+{"/dev/ttyS0",-1},
+{"/dev/ttyS1",-1},
+{"/dev/ttyS2",-1},
+{"/dev/ttyS3",-1},
+{"/dev/newDevice",-1}
+//PYTHONSCRIPTBREAK4
+
+};
+
+//returns -1, means no match is found
+//other than -1, is the index in the dtracker array of the match
+int check_name(const char* path, dev_tracker tracker[]){
+ int i;
+ for(i=0; i<DEV_COUNT; i++){
+ if (strstr(path,tracker[i].devName)!=NULL){
+ return i;
+ }
+ }
+ return -1;
+}
+//returns -1, means no match found
+//other than -1, is the index in the dtracker array of the match
+int check_fd(int fd, dev_tracker tracker[]){
+ int i;
+ for(i=0; i<DEV_COUNT; i++){
+ if(tracker[i].devFD == fd){
+ return i;
+ }
+ }
+ return -1;
+}
+
+
+
