Convert Binary String to Integer Without strtol function or Libraries

Code

#include <stdio.h>
#include <stdint.h>

uint16_t binary_to_uint(const char *str)
{
    uint16_t val = 0;

    for (int i = 0; str[i] != 0; i++)
    {
        val <<= 1;
        if (str[i] == '1')
        {
            val |= 1;
        }
        else if (str[i] != '0')
        {
            return 0xff;
        }
     //   val = (val << 1) | (str[i] - '0');
    }

    return val;
}

int main() {
    char bin[20];
    scanf("%s", bin);

    printf("%u", binary_to_uint(bin));
    return 0;
}

Solving Approach