user: What is the c source code of the assembly code below:

```asm
<hexdump>:
  endbr64
  push   %r15
  push   %r14
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  sub    $0x38,%rsp
  mov    %esi,0x18(%rsp)
  mov    %edx,0x4(%rsp)
  mov    %fs:0x28,%rax
  mov    %rax,0x28(%rsp)
  xor    %eax,%eax
  mov    %esi,%eax
  add    %rdi,%rax
  mov    %rax,0x8(%rsp)
  test   %edx,%edx
  jle    L45
  add    $0x10,%rax
  xor    %r12d,%r12d
  mov    $0x1,%ebp
  xor    %r13d,%r13d
  mov    %rax,0x10(%rsp)
  lea    0x24(%rsp),%r14
  jmp    L22
  nopw   0x0(%rax,%rax,1)
L123:
  cmp    %r13d,0x4(%rsp)
  jle    L43
L22:
  mov    0x8(%rsp),%rax
  movslq %r13d,%rbx
  lea    (%rax,%rbx,1),%r15
  test   $0xf,%r13b
  jne    L132
  or     %r12d,%ebp
  je     L81
L32:
  mov    0x4(%rsp),%eax
  lea    D7(%rip),%rdi
  sub    %r13d,%eax
  cmp    $0xf,%eax
  mov    $0x1,%eax
  cmovle %eax,%r12d
  mov    0x18(%rsp),%eax
  xor    %ebp,%ebp
  lea    0x0(%r13,%rax,1),%esi
  xor    %eax,%eax
  call   <printf@plt>
L132:
  mov    $0x4,%edx
  mov    %r15,%rsi
  mov    %r14,%rdi
  add    $0x4,%r13d
  call   <memcpy@plt>
  movzbl 0x26(%rsp),%ecx
  xor    %eax,%eax
  mov    %r13d,%ebx
  movzbl 0x25(%rsp),%edx
  movzbl 0x24(%rsp),%esi
  lea    D4(%rip),%rdi
  movzbl 0x27(%rsp),%r8d
  call   <printf@plt>
  and    $0xf,%ebx
  jne    L123
  mov    $0xa,%edi
  call   <putchar@plt>
  cmp    %r13d,0x4(%rsp)
  jg     L22
L43:
  test   %ebx,%ebx
  jne    L89
L45:
  mov    0x28(%rsp),%rax
  sub    %fs:0x28,%rax
  jne    L116
  add    $0x38,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
  nopl   (%rax)
L81:
  mov    %r12d,0x1c(%rsp)
  add    0x10(%rsp),%rbx
  mov    %r14,%r12
  mov    %r15,%r14
L104:
  mov    $0x4,%edx
  mov    %r14,%rsi
  mov    %r12,%rdi
  call   <memcpy@plt>
  movzbl 0x24(%rsp),%eax
  or     0x25(%rsp),%al
  or     0x26(%rsp),%al
  or     0x27(%rsp),%al
  jne    L130
  add    $0x4,%r14
  cmp    %rbx,%r14
  jne    L104
  add    $0x10,%r13d
  mov    %r12,%r14
  xor    %r12d,%r12d
  mov    %r13d,%ebx
  and    $0xf,%ebx
  jmp    L123
  nopl   0x0(%rax)
L89:
  mov    $0xa,%edi
  call   <putchar@plt>
  jmp    L45
  nop
L130:
  mov    %r12,%r14
  mov    0x1c(%rsp),%r12d
  jmp    L32
L116:
  call   <__stack_chk_fail@plt>
```

tool_calls: name: unpack_data
arguments: label: D7
type: string
name: unpack_data
arguments: label: D4
type: string

tool: D7: %04x:

tool: D4:  %02x %02x %02x %02x 

assistant: ```c
void hexdump(const unsigned char *base, unsigned int offset, int len) {
  const unsigned char *b = base + offset;
  unsigned char bb[4];
  int i;
  int first, last;
  last = 0;
  first = 1;
  for (i = 0; i < len; i++) {
    if ((i % 16) == 0) {
      if (!first && !last) {
        int j;
        for (j = 0; j < 4; j++) {
          memcpy(bb, b + i + 4 * j, 4);
          if (bb[0] || bb[1] || bb[2] || bb[3])
            break;
        }
        if (j == 4) {
          i = i + 15;
          continue;
        }
      }
      if ((len - i) < 16)
        last = 1;
      first = 0;
      printf("%04x:", offset + i);
    }
    memcpy(bb, b + i, 4);
    printf(" %02x %02x %02x %02x ", bb[0], bb[1], bb[2], bb[3]);
    i += 3;
    if (!((i + 1) % 16)) {
      printf("\n");
    }
  }
  if (i % 16) {
    printf("\n");
  }
}
```