user: What would the C source look like for the assembly code provided here?

```asm
<getbsize>:
  endbr64
  push   %rbp
  mov    %rsp,%rbp
  sub    $0x50,%rsp
  mov    %rdi,-0x48(%rbp)
  mov    %rsi,-0x50(%rbp)
  mov    %fs:0x28,%rax
  mov    %rax,-0x8(%rbp)
  xor    %eax,%eax
  lea    D62(%rip),%rax
  mov    %rax,-0x18(%rbp)
  lea    D71(%rip),%rax
  mov    %rax,%rdi
  call   <getenv@plt>
  mov    %rax,-0x10(%rbp)
  cmpq   $0x0,-0x10(%rbp)
  je     L172
  mov    -0x10(%rbp),%rax
  movzbl (%rax),%eax
  test   %al,%al
  je     L172
  lea    -0x40(%rbp),%rcx
  mov    -0x10(%rbp),%rax
  mov    $0xa,%edx
  mov    %rcx,%rsi
  mov    %rax,%rdi
  call   <strtol@plt>
  mov    %rax,-0x38(%rbp)
  cmpq   $0x0,-0x38(%rbp)
  js     L54
  cmpq   $0x0,-0x38(%rbp)
  jne    L99
  movq   $0x1,-0x38(%rbp)
L99:
  mov    -0x40(%rbp),%rax
  movzbl (%rax),%eax
  test   %al,%al
  je     L37
  mov    -0x40(%rbp),%rax
  add    $0x1,%rax
  movzbl (%rax),%eax
  test   %al,%al
  jne    L17
L37:
  mov    -0x40(%rbp),%rax
  movzbl (%rax),%eax
  movsbl %al,%eax
  test   %eax,%eax
  je     L81
  test   %eax,%eax
  js     L151
  cmp    $0x6d,%eax
  jg     L151
  cmp    $0x47,%eax
  jl     L151
  sub    $0x47,%eax
  mov    $0x1,%edx
  mov    %eax,%ecx
  shl    %cl,%rdx
  mov    %rdx,%rax
  movabs $0x4000000040,%rdx
  and    %rax,%rdx
  test   %rdx,%rdx
  setne  %dl
  test   %dl,%dl
  jne    L174
  movabs $0x1000000010,%rdx
  and    %rax,%rdx
  test   %rdx,%rdx
  setne  %dl
  test   %dl,%dl
  jne    L77
  movabs $0x100000001,%rdx
  and    %rdx,%rax
  test   %rax,%rax
  setne  %al
  test   %al,%al
  je     L151
  lea    D90(%rip),%rax
  mov    %rax,-0x18(%rbp)
  movq   $0x1,-0x30(%rbp)
  movq   $0x40000000,-0x28(%rbp)
  jmp    L19
L77:
  lea    D10(%rip),%rax
  mov    %rax,-0x18(%rbp)
  movq   $0x100000,-0x30(%rbp)
  movq   $0x400,-0x28(%rbp)
  jmp    L19
L174:
  lea    D1(%rip),%rax
  mov    %rax,-0x18(%rbp)
  movq   $0x400,-0x30(%rbp)
  movq   $0x100000,-0x28(%rbp)
  jmp    L19
L81:
  movq   $0x40000000,-0x30(%rbp)
  movq   $0x1,-0x28(%rbp)
  jmp    L19
L17:
  nop
L151:
  mov    -0x10(%rbp),%rax
  mov    %rax,%rsi
  lea    D75(%rip),%rax
  mov    %rax,%rdi
  mov    $0x0,%eax
  call   <warnx@plt>
  movq   $0x200,-0x38(%rbp)
  movq   $0x40000000,-0x30(%rbp)
  movq   $0x1,-0x28(%rbp)
  nop
L19:
  mov    -0x38(%rbp),%rax
  cmp    -0x30(%rbp),%rax
  jle    L208
  mov    $0x1,%esi
  lea    D126(%rip),%rax
  mov    %rax,%rdi
  mov    $0x0,%eax
  call   <warnx@plt>
  mov    -0x30(%rbp),%rax
  mov    %rax,-0x38(%rbp)
L208:
  mov    -0x38(%rbp),%rax
  imul   -0x28(%rbp),%rax
  mov    %rax,-0x20(%rbp)
  cmpq   $0x1ff,-0x20(%rbp)
  jg     L166
  jmp    L177
L54:
  nop
L177:
  lea    D19(%rip),%rax
  mov    %rax,%rdi
  mov    $0x0,%eax
  call   <warnx@plt>
  lea    D62(%rip),%rax
  mov    %rax,-0x18(%rbp)
  movq   $0x200,-0x38(%rbp)
  mov    -0x38(%rbp),%rax
  mov    %rax,-0x20(%rbp)
  jmp    L166
L172:
  movq   $0x200,-0x38(%rbp)
  mov    -0x38(%rbp),%rax
  mov    %rax,-0x20(%rbp)
L166:
  mov    -0x18(%rbp),%rdx
  mov    -0x38(%rbp),%rax
  mov    %rdx,%r8
  mov    %rax,%rcx
  lea    D118(%rip),%rax
  mov    %rax,%rdx
  mov    $0x14,%esi
  lea    D38(%rip),%rax
  mov    %rax,%rdi
  call   <snprintf@plt>
  lea    D38(%rip),%rax
  mov    %rax,%rdi
  call   <strlen@plt>
  mov    -0x48(%rbp),%rdx
  mov    %eax,(%rdx)
  mov    -0x50(%rbp),%rax
  mov    -0x20(%rbp),%rdx
  mov    %rdx,(%rax)
  lea    D38(%rip),%rax
  mov    -0x8(%rbp),%rdx
  sub    %fs:0x28,%rdx
  je     L163
  call   <__stack_chk_fail@plt>
L163:
  leave
  ret
```

tool_calls: name: read_data
arguments: data_label: D62
type_infered: string
name: read_data
arguments: data_label: D71
type_infered: string
name: read_data
arguments: data_label: D90
type_infered: string
name: read_data
arguments: data_label: D10
type_infered: string
name: read_data
arguments: data_label: D1
type_infered: string
name: read_data
arguments: data_label: D75
type_infered: string
name: read_data
arguments: data_label: D126
type_infered: string
name: read_data
arguments: data_label: D19
type_infered: string
name: read_data
arguments: data_label: D118
type_infered: string

tool: 

tool: D71: BLOCKSIZE

tool: D90: G

tool: D10: K

tool: D1: M

tool: D75: %s: unknown blocksize

tool: D126: maximum blocksize is %ldG

tool: D19: minimum blocksize is 512

tool: D118: %ld%s-blocks

assistant: ```c
char *getbsize(int *headerlenp, long *blocksizep) {
  static char header[20];
  long n, max, mul, blocksize;
  char *ep, *p;
  const char *form;
  form = "";
  if ((p = getenv("BLOCKSIZE")) != NULL && *p != '\0') {
    if ((n = strtol(p, &ep, 10)) < 0)
      goto underflow;
    if (n == 0)
      n = 1;
    if (*ep && ep[1])
      goto fmterr;
    switch (*ep) {
    case 'G':
    case 'g':
      form = "G";
      max = (1024L * 1024L * 1024L) / (1024L * 1024L * 1024L);
      mul = (1024L * 1024L * 1024L);
      break;
    case 'K':
    case 'k':
      form = "K";
      max = (1024L * 1024L * 1024L) / (1024L);
      mul = (1024L);
      break;
    case 'M':
    case 'm':
      form = "M";
      max = (1024L * 1024L * 1024L) / (1024L * 1024L);
      mul = (1024L * 1024L);
      break;
    case '\0':
      max = (1024L * 1024L * 1024L);
      mul = 1;
      break;
    default:
    fmterr:
      warnx("%s: unknown blocksize", p);
      n = 512;
      max = (1024L * 1024L * 1024L);
      mul = 1;
      break;
    }
    if (n > max) {
      warnx("maximum blocksize is %ldG", (1024L * 1024L * 1024L) / (1024L * 1024L * 1024L));
      n = max;
    }
    if ((blocksize = n * mul) < 512) {
    underflow:
      warnx("minimum blocksize is 512");
      form = "";
      blocksize = n = 512;
    }
  } else
    blocksize = n = 512;
  (void)snprintf(header, sizeof(header), "%ld%s-blocks", n, form);
  *headerlenp = strlen(header);
  *blocksizep = blocksize;
  return (header);
}
```