user: 下面的汇编指令对应的C源代码是什么:

```asm
<reverse_services>:
  endbr64
  push   %rbp
  mov    %rsp,%rbp
  sub    $0x4d0,%rsp
  mov    %rdi,-0x4c8(%rbp)
  mov    %esi,-0x4cc(%rbp)
  mov    %edx,-0x4d0(%rbp)
  mov    %fs:0x28,%rax
  mov    %rax,-0x8(%rbp)
  xor    %eax,%eax
  lea    -0x410(%rbp),%rdx
  lea    -0x4b4(%rbp),%rax
  mov    $0x408,%ecx
  mov    %rax,%rsi
  lea    D26(%rip),%rax
  mov    %rax,%rdi
  call   <__fopen_rb_ca@plt>
  mov    %rax,-0x4a0(%rbp)
  cmpq   $0x0,-0x4a0(%rbp)
  je     L198
  jmp    L109
L42:
  lea    -0x490(%rbp),%rax
  mov    $0x23,%esi
  mov    %rax,%rdi
  call   <strchr@plt>
  mov    %rax,-0x4a8(%rbp)
  cmpq   $0x0,-0x4a8(%rbp)
  je     L77
  mov    -0x4a8(%rbp),%rax
  lea    0x1(%rax),%rdx
  mov    %rdx,-0x4a8(%rbp)
  movb   $0xa,(%rax)
  mov    -0x4a8(%rbp),%rax
  movb   $0x0,(%rax)
L77:
  lea    -0x490(%rbp),%rax
  mov    %rax,-0x4a8(%rbp)
  jmp    L217
L5:
  addq   $0x1,-0x4a8(%rbp)
L217:
  mov    -0x4a8(%rbp),%rax
  movzbl (%rax),%eax
  test   %al,%al
  je     L17
  mov    -0x4a8(%rbp),%rax
  movzbl (%rax),%eax
  movsbl %al,%eax
  mov    %eax,%edi
  call   <isspace@plt>
  test   %eax,%eax
  je     L5
L17:
  mov    -0x4a8(%rbp),%rax
  movzbl (%rax),%eax
  test   %al,%al
  jne    L112
  jmp    L109
L112:
  mov    -0x4a8(%rbp),%rax
  lea    0x1(%rax),%rdx
  mov    %rdx,-0x4a8(%rbp)
  movb   $0x0,(%rax)
  lea    -0x4b0(%rbp),%rcx
  mov    -0x4a8(%rbp),%rax
  mov    $0xa,%edx
  mov    %rcx,%rsi
  mov    %rax,%rdi
  call   <strtoul@plt>
  mov    %rax,-0x498(%rbp)
  mov    -0x4cc(%rbp),%eax
  cltq
  cmp    %rax,-0x498(%rbp)
  jne    L109
  mov    -0x4b0(%rbp),%rax
  cmp    %rax,-0x4a8(%rbp)
  jne    L34
  jmp    L109
L34:
  cmpl   $0x0,-0x4d0(%rbp)
  je     L18
  mov    -0x4b0(%rbp),%rax
  mov    $0x4,%edx
  lea    D25(%rip),%rcx
  mov    %rcx,%rsi
  mov    %rax,%rdi
  call   <strncmp@plt>
  test   %rax,%rax
  je     L18
  jmp    L109
L18:
  cmpl   $0x0,-0x4d0(%rbp)
  jne    L115
  mov    -0x4b0(%rbp),%rax
  mov    $0x4,%edx
  lea    D19(%rip),%rcx
  mov    %rcx,%rsi
  mov    %rax,%rdi
  call   <strncmp@plt>
  test   %rax,%rax
  je     L115
  jmp    L109
L115:
  lea    -0x490(%rbp),%rdx
  mov    -0x4a8(%rbp),%rax
  sub    %rdx,%rax
  cmp    $0x20,%rax
  jle    L146
  jmp    L109
L146:
  lea    -0x490(%rbp),%rdx
  mov    -0x4a8(%rbp),%rax
  sub    %rdx,%rax
  mov    %eax,%edx
  lea    -0x490(%rbp),%rcx
  mov    -0x4c8(%rbp),%rax
  mov    %rcx,%rsi
  mov    %rax,%rdi
  call   <memcpy@plt>
  jmp    L117
L109:
  mov    -0x4a0(%rbp),%rdx
  lea    -0x490(%rbp),%rax
  mov    $0x80,%esi
  mov    %rax,%rdi
  call   <fgets@plt>
  test   %rax,%rax
  jne    L42
L117:
  mov    -0x4a0(%rbp),%rax
  mov    %rax,%rdi
  call   <__fclose_ca@plt>
  jmp    L213
L198:
  nop
L213:
  mov    -0x8(%rbp),%rax
  sub    %fs:0x28,%rax
  je     L40
  call   <__stack_chk_fail@plt>
L40:
  leave
  ret
```

tool_calls: name: read_data
arguments: data_label: D26
datatype: string
name: read_data
arguments: data_label: D25
datatype: string
name: read_data
arguments: data_label: D19
datatype: string

tool: D26: /etc/services

tool: D25: /udp

tool: D19: /tcp

assistant: ```c
void reverse_services(char *buf, int port, int dgram) {
  unsigned long svport;
  char line[128], *p, *z;
  unsigned char _buf[1032];
  FILE _f, *f = __fopen_rb_ca("/etc/services", &_f, _buf, sizeof _buf);
  if (!f)
    return;
  while (fgets(line, sizeof line, f)) {
    if ((p = strchr(line, '#')))
      *p++ = '\n', *p = 0;
    for (p = line; *p && !isspace(*p); p++)
      ;
    if (!*p)
      continue;
    *p++ = 0;
    svport = strtoul(p, &z, 10);
    if (svport != port || z == p)
      continue;
    if (dgram && strncmp(z, "/udp", 4))
      continue;
    if (!dgram && strncmp(z, "/tcp", 4))
      continue;
    if (p - line > 32)
      continue;
    memcpy(buf, line, p - line);
    break;
  }
  __fclose_ca(f);
}
```