Extract a Bit Field from a 32-bit Register

Code

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

uint32_t extract_field(uint32_t reg, uint8_t pos, uint8_t len) {
  
    uint32_t mask = 0;
    uint32_t i = pos;
    while(len != 0)
    {
        mask |= (1<<i);
        i++;
        len--;
    }
    return (reg & mask) >> pos ;
}

int main() {
    uint32_t reg ;
    uint8_t  len ;
    uint8_t pos ;
    scanf("%u %hhu %hhu", &reg, &pos, &len);
    printf("%u", extract_field(reg, pos, len));
    return 0;
}

Solving Approach