Segmentation fault when trying to access pointer in struct [closed] - c

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I'm trying to access a pointer inside of a struct, I tried placing * in front of the struct pointer
to access the pointer inside the struct, but it segfaults.
code segfaults on *ptr->numberOfClients = clients;
int getNumberOfClients(struct fuzzerObj *ptr)
{
int rtrn;
long clients;
char *input;
char *holder = NULL;
printf(BOLDBLUE"How many clients will you be connecting to this fuzz server?\n"RESET);
printf(BOLDBLUE"---> "RESET);
rtrn = getUserInput(&input);
if(rtrn < 0)
{
errorHandler("Can't Get User input\n", FUNCTION_ID_GET_NUMBER_OF_CLIENTS);
return -1;
}
if (strlen(input))
{
clients = strtol(input, &holder, 10);
if (input == holder)
{
errorHandler("invalid long conversion\n", FUNCTION_ID_GET_NUMBER_OF_CLIENTS);
return -1;
}
}
else
{
errorHandler("No Value To Compute\n", FUNCTION_ID_GET_NUMBER_OF_CLIENTS);
return -1;
}
*ptr->numberOfClients = clients;
free(input);
return 0;
}
int getUserInput(char **buf)
{
int i = 0, max = 1024, c;
*buf = reallocarray(NULL, 1025, sizeof(char *));
if(*buf == NULL)
{
errorHandler("Mem Error\n", FUNCTION_ID_GET_USER_INPUT);
free(*buf);
return -1;
}
while (true) { // skip leading whitespace
c = getchar();
if (c == EOF) break; // end of file
if (!isspace(c)) {
ungetc(c, stdin);
break;
}
}
while (true) {
c = getchar();
if (isspace(c) || c == EOF) // at end, add terminating zero
buf[i] = 0;
break;
}
*buf[i] = c;
if (i==max-1) { // buffer full
max = max+max;
*buf = (char*)realloc(*buf,max); // get a new and larger buffer
if (buf == 0)
{
errorHandler("Realloc Error\n", FUNCTION_ID_GET_USER_INPUT);
return -1;
}
}
i++;
return 0;
}
and here's the struct
struct fuzzerObj
{
int parserResponse;
int *numberOfClients;
int *clientFuzzerType[1024];
int *clientSockets[1024];
int *clientApplication[1024];
int *clientFuzzer[1024];
int *connectedClients;
int *socket;
int *fuzzer;
int *application;
dispatch_queue_t queue;
};

Answer 1

There is a major problem that I see (unless you've not shown it in your code snippets). numberOfClients is declared as such:
struct fuzzerObj
{
...
int *numberOfClients;
...
};
Before you assign an int to it. You must assign memory to store the int:
1.
ptr->numberOfClients = malloc(sizeof(*(ptr->numberOfClients)));
*(ptr->numberOfClients) = clients;
...
free(ptr->numberOfClients);
2.
int temp;
ptr->numberOfClients = &temp;
*(ptr->numberOfClients) = clients;
...
// Write to a file here???
Another question... why are the fields of fuzzerObj pointers? If you make them ints instead of pointers to ints, you wouldn't have the difficulties you're experiencing.
EDIT
The second method shown above is not safe because once the function that has declared temp returns, temp no longer exists, and therefore numberOfClients doesn't have valid memory, and should not be used.

Answer 2

It is totally unclear why data member numberOfClients defined as a pointer instead of to be an object of type int
int *numberOfClients;
Try the following
ptr->numberOfClients = ( int * )malloc( sizeof( int ) );
if ( ptr->numberOfClients ) *ptr->numberOfClients = clients;
Also take into account that variable clients is defined as
long clients;
In some implementations sizeof( lomg ) can be greater than sizeof( int ).
It is in general a bad design. It is unclear whether data members of the structures were initialized and corresponding memory were allocated.