user: 请从给定的汇编指令推导出C源代码：

```asm
<validate_netmask>:
  endbr64
  push   %r15
  push   %r14
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  sub    $0x38,%rsp
  mov    %rdi,%rbp
  mov    %fs:0x28,%rax
  mov    %rax,0x28(%rsp)
  xor    %eax,%eax
  call   <strlen@plt>
  mov    $0x0,%ebx
  cmp    $0x12,%eax
  jg     L109
  mov    $0x0,%ebx
  mov    $0x0,%r13d
  mov    $0x0,%r12d
  mov    $0x0,%r14d
  jmp    L213
L180:
  movzbl 0x0(%rbp,%rbx,1),%eax
  and    $0xffffffdf,%eax
  mov    %r14d,%r12d
  cmp    $0x58,%al
  jne    L44
L226:
  add    $0x1,%r13d
  mov    %r14d,%r12d
L44:
  add    $0x1,%rbx
L213:
  mov    %rbp,%rdi
  call   <strlen@plt>
  mov    %eax,%edx
  test   %r12d,%r12d
  sete   %al
  cmp    %ebx,%edx
  jle    L112
  test   %al,%al
  je     L112
  movsbl 0x0(%rbp,%rbx,1),%edi
  call   <isxdigit@plt>
  test   %eax,%eax
  jne    L180
  movzbl 0x0(%rbp,%rbx,1),%eax
  and    $0xffffffdf,%eax
  mov    $0x1,%r12d
  cmp    $0x58,%al
  je     L226
  jmp    L44
L112:
  cmp    $0x1,%r13d
  jne    L350
  test   %al,%al
  je     L350
  movzbl 0x0(%rbp),%eax
  mov    %eax,%edx
  and    $0xffffffdf,%edx
  mov    $0x3,%ebx
  cmp    $0x58,%dl
  je     L109
  cmp    $0x30,%al
  je     L24
L350:
  lea    0x10(%rsp),%rdi
  mov    $0x10,%edx
  mov    $0x0,%esi
  call   <memset@plt>
  mov    $0x2f,%esi
  mov    %rbp,%rdi
  call   <strchr@plt>
  test   %rax,%rax
  je     L355
  movzbl 0x0(%rbp),%edx
  cmp    $0x2f,%dl
  je     L76
  mov    $0x1,%eax
  lea    0xf(%rsp),%rdi
L59:
  mov    %dl,(%rdi,%rax,1)
  movzbl 0x0(%rbp,%rax,1),%edx
  cmp    $0xe,%eax
  setle  %sil
  cmp    $0x2f,%dl
  setne  %cl
  add    $0x1,%rax
  test   %cl,%sil
  jne    L59
L76:
  lea    0xc(%rsp),%rsi
  lea    0x10(%rsp),%rdi
  call   <quadtonum@plt>
  mov    $0x0,%ebx
  test   %rax,%rax
  jne    L109
  mov    $0x2f,%esi
  mov    %rbp,%rdi
  call   <strchr@plt>
  mov    %rax,%rbp
  test   %rax,%rax
  je     L158
  lea    0x1(%rax),%r13
  mov    %r13,%rdi
  call   <strlen@plt>
  mov    $0x0,%ebx
  test   %eax,%eax
  jle    L109
  mov    %r13,%rdi
  call   <strlen@plt>
  cmp    $0x2,%eax
  jg     L109
  cmpb   $0x2e,0x1(%rbp)
  je     L109
  cmpb   $0x2e,0x2(%rbp)
  je     L109
  mov    $0x0,%r15d
  lea    D4(%rip),%r14
L79:
  mov    %r13,%rdi
  call   <strlen@plt>
  cmp    %r15d,%eax
  jg     L63
  mov    %r13,%rdi
  call   <atoi@plt>
  cmp    $0x20,%eax
  setbe  %bl
  movzbl %bl,%ebx
  add    %ebx,%ebx
  jmp    L109
L24:
  movzbl 0x1(%rbp),%eax
  and    $0xffffffdf,%eax
  cmp    $0x58,%al
  jne    L350
  jmp    L109
L355:
  lea    0x10(%rsp),%rdi
  mov    $0x10,%edx
  mov    %rbp,%rsi
  call   <strlcpy@plt>
  jmp    L76
L158:
  mov    0xc(%rsp),%esi
  mov    $0x1f,%ecx
  mov    $0x0,%eax
  mov    $0x1,%edi
  jmp    L67
L139:
  cmp    $0x1,%eax
  jne    L230
  mov    %esi,%eax
  sar    %cl,%eax
  and    $0x1,%eax
  add    $0x1,%eax
L230:
  sub    $0x1,%ecx
  cmp    $0xffffffff,%ecx
  je     L148
L67:
  test   %eax,%eax
  jne    L139
  mov    %esi,%edx
  sar    %cl,%edx
  and    $0x1,%edx
  mov    %edi,%eax
  sub    %edx,%eax
  jmp    L230
L148:
  cmp    $0x2,%eax
  setne  %bl
  movzbl %bl,%ebx
  lea    -0x1(%rbx,%rbx,1),%ebx
L109:
  mov    0x28(%rsp),%rax
  sub    %fs:0x28,%rax
  jne    L177
  mov    %ebx,%eax
  add    $0x38,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
L176:
  movzbl (%r14,%r12,1),%eax
  cmp    %al,0x1(%rbp,%r15,1)
  sete   %bl
  movzbl %bl,%ebx
  add    $0x1,%r12
L175:
  mov    %r14,%rdi
  call   <strlen@plt>
  test   %ebx,%ebx
  jne    L197
  cmp    %r12d,%eax
  jg     L176
L197:
  add    $0x1,%r15
  test   %ebx,%ebx
  jne    L79
  jmp    L109
L63:
  mov    $0x0,%r12d
  mov    $0x0,%ebx
  jmp    L175
L177:
  call   <__stack_chk_fail@plt>
```

tool_calls: name: unpack_data
arguments: data_tag: D4
datatype: string

tool: D4: 0123456789.

assistant: ```c
int validate_netmask(char *in_addr) {
  int i = 0, j = 0, k = 0, m;
  char addr[16];
  char *sl;
  u_int32_t sm;
  if (strlen(in_addr) > 18)
    return 0;
  while (i < (int)strlen(in_addr) && !j) {
    if (!isxdigit(in_addr[i]) && in_addr[i] != 'x' && in_addr[i] != 'X')
      j = 1;
    if (in_addr[i] == 'x' || in_addr[i] == 'X') {
      k++;
      j = 0;
    }
    i++;
  }
  i = 0;
  if (!j && k == 1) {
    i = 0;
    if (in_addr[0] == 'x' || in_addr[0] == 'X')
      i = 1;
    if (!i && in_addr[0] == '0' && (in_addr[1] == 'x' || in_addr[1] == 'X'))
      i = 1;
  }
  if (i == 1)
    return 3;
  memset(addr, 0, sizeof(addr));
  if (strstr(in_addr, "/")) {
    i = 0;
    while (in_addr[i] != '/' && i < 15) {
      addr[i] = in_addr[i];
      i++;
    }
  } else {
    strlcpy(addr, in_addr, sizeof(addr));
  }
  if (quadtonum(addr, &sm))
    return 0;
  if (!(sl = strstr(in_addr, "/"))) {
    j = 0;
    for (i = 0; i < 32; i++) {
      if (!j && !((sm >> (31 - i)) & 1))
        j = 1;
      if (j == 1 && ((sm >> (31 - i)) & 1))
        j = 2;
    }
    if (j == 2)
      return -1;
    return 1;
  }
  sl++;
  if (strlen(sl) < 1 || strlen(sl) > 2)
    return 0;
  if (sl[0] == '.' || sl[1] == '.')
    return 0;
  i = 0;
  j = 0;
  while (i < (int)strlen(sl)) {
    k = 0;
    j = 0;
    while (k < (int)strlen("0123456789.") && !j) {
      if (sl[i] == "0123456789."[k])
        j = 1;
      k++;
    }
    if (!j)
      return 0;
    i++;
  }
  m = atoi(sl);
  if (m < 0 || m > 32)
    return 0;
  return 2;
}
```