```python
from bcc import BPF
import time

# BPF program for counting return values
bpf_program_count = """
BPF_HISTOGRAM(dist);
int kretprobe__strlen(char *ctx) {
    u64 ret = PT_REGS_RC(ctx);
    dist.increment(bpf_log2l(ret));
    return 0;
}
"""

# BPF program for submitting addresses
bpf_program_submit = """
BPF_HASH(addresses, u64, u64);
int submit_addresses() {
    u64 resolver_addr = ...; // Placeholder for resolver address
    u64 implementation_addr = ...; // Placeholder for implementation address
    addresses.update(&resolver_addr, &implementation_addr);
    return 0;
}
"""

def get_symbol_address(symbol):
    # Placeholder function to get the address of a symbol
    return 0x1234

def set_resolver_and_implementation_addresses(bpf, resolver_symbol, implementation_symbol):
    resolver_addr = get_symbol_address(resolver_symbol)
    implementation_addr = get_symbol_address(implementation_symbol)
    bpf["addresses"][ctypes.c_ulonglong(resolver_addr)] = ctypes.c_ulonglong(implementation_addr)

def find_implementation_offset(resolver_symbol, implementation_symbol):
    # Placeholder function to find the offset of the implementation function
    return 0x10

def main():
    # Load BPF programs
    bpf_count = BPF(text=bpf_program_count)
    bpf_submit = BPF(text=bpf_program_submit)

    # Get symbol of the indirect function
    resolver_symbol = "strlen"
    implementation_symbol = "strlen"

    # Find the offset of the implementation function
    offset = find_implementation_offset(resolver_symbol, implementation_symbol)

    # Attach the counting BPF program to the implementation function
    bpf_count.attach_kretprobe(event=implementation_symbol, fn_name="kretprobe__strlen")

    try:
        while True:
            time.sleep(1)
            print("Histogram of strlen return values:")
            bpf_count["dist"].print_log2_hist("Size (bytes)")
            bpf_count["dist"].clear()
    except KeyboardInterrupt:
        pass

if __name__ == "__main__":
    main()
```