user: 请将这段汇编代码片段转换成等效的C代码：

```asm
<main>:
  endbr64
  push   %r15
  lea    D39(%rip),%rdi
  push   %r14
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  sub    $0x448,%rsp
  mov    %fs:0x28,%rax
  mov    %rax,0x438(%rsp)
  xor    %eax,%eax
  movl   $0x4b4341,0x2c(%rsp)
  call   <open_telnet@plt>
  test   %eax,%eax
  js     L0
  mov    $0x1,%esi
  mov    $0x1,%edi
  mov    %eax,%ebp
  call   <daemon@plt>
  lea    D97(%rip),%rdi
  lea    0x1(%rbp),%r12d
  call   <printf@plt>
  lea    0x28(%rsp),%rbx
  lea    0x20(%rsp),%r15
  movl   $0x0,0x14(%rsp)
  lea    0x230(%rsp),%rax
  lea    0x24(%rsp),%r14
  mov    %rax,0x8(%rsp)
  lea    0x2c(%rsp),%rax
  lea    0x30(%rsp),%r13
  mov    %rax,0x18(%rsp)
  nopl   0x0(%rax,%rax,1)
L25:
  mov    %rbx,%rdi
  call   <FD_ZERO@plt>
  mov    %rbx,%rsi
  mov    %ebp,%edi
  call   <FD_SET@plt>
  xor    %r8d,%r8d
  xor    %ecx,%ecx
  xor    %edx,%edx
  mov    %rbx,%rsi
  mov    %r12d,%edi
  call   <select@plt>
  test   %eax,%eax
  jle    L25
  xor    %ecx,%ecx
  mov    %r15,%r9
  mov    %r14,%r8
  mov    $0x200,%edx
  mov    %r13,%rsi
  mov    %ebp,%edi
  movl   $0x4,0x20(%rsp)
  call   <recvfrom@plt>
  test   %eax,%eax
  mov    %eax,0x10(%rsp)
  jle    L25
  mov    0x8(%rsp),%rdi
  call   <fill_payload@plt>
  mov    0x10(%rsp),%edx
  cmp    %eax,%edx
  jne    L25
  mov    0x8(%rsp),%rsi
  mov    %r13,%rdi
  call   <memcmp@plt>
  test   %rax,%rax
  jne    L25
  mov    0x14(%rsp),%eax
  test   %eax,%eax
  je     L117
L45:
  mov    0x20(%rsp),%r9d
  mov    0x18(%rsp),%rsi
  mov    %r14,%r8
  xor    %ecx,%ecx
  mov    $0x3,%edx
  mov    %ebp,%edi
  call   <sendto@plt>
  jmp    L25
L117:
  lea    D47(%rip),%rdi
  call   <cat_file@plt>
  mov    $0x2,%edx
  lea    D26(%rip),%rsi
  mov    %eax,%edi
  call   <strncmp@plt>
  test   %rax,%rax
  je     L45
  lea    D47(%rip),%rdi
  call   <cat_file@plt>
  mov    $0x2,%edx
  lea    D38(%rip),%rsi
  mov    %eax,%edi
  call   <strncmp@plt>
  test   %rax,%rax
  jne    L71
  lea    D29(%rip),%rdi
  call   <config_get@plt>
  lea    D48(%rip),%rsi
  mov    %eax,%edi
  call   <strcmp@plt>
  test   %rax,%rax
  je     L45
L71:
  lea    D109(%rip),%rdi
  call   <printf@plt>
  lea    D99(%rip),%rdi
  call   <system@plt>
  movl   $0x1,0x14(%rsp)
  jmp    L45
L0:
  lea    D20(%rip),%rdi
  call   <printf@plt>
  mov    0x438(%rsp),%rax
  sub    %fs:0x28,%rax
  jne    L30
  add    $0x448,%rsp
  or     $0xffffffff,%eax
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
L30:
  call   <__stack_chk_fail@plt>
```

tool_calls: name: unpack_data
arguments: data_tag: D39
datatype: string
name: unpack_data
arguments: data_tag: D97
datatype: string
name: unpack_data
arguments: data_tag: D47
datatype: string
name: unpack_data
arguments: data_tag: D26
datatype: string
name: unpack_data
arguments: data_tag: D38
datatype: string
name: unpack_data
arguments: data_tag: D29
datatype: string
name: unpack_data
arguments: data_tag: D48
datatype: string
name: unpack_data
arguments: data_tag: D109
datatype: string
name: unpack_data
arguments: data_tag: D99
datatype: string
name: unpack_data
arguments: data_tag: D20
datatype: string

tool: D39: br0

tool: D97: The telnetenable is running ...


tool: D47: /tmp/firmware_region

tool: D26: PR

tool: D38: WW

tool: D29: GUI_Region

tool: D48: Chinese

tool: D109: The telnet server is enabled now!!!


tool: D99: /usr/sbin/utelnetd -d -i br0

tool: D20: Can't open the socket!


assistant: ```c
int main(int argc, char *argv[]) {
  int fd;
  socklen_t slen;
  struct sockaddr_in from;
  fd_set readable;
  int telnet_enabled = 0;
  int r, datasize;
  char rbuf[512], output_buf[512];
  char ack[] = "ACK";
  fd = open_telnet("br0");
  if (fd < 0) {
    printf("Can't open the socket!\n");
    return -1;
  }
  daemon(1, 1);
  printf("The telnetenable is running ...\n");
  for (;;) {
    FD_ZERO(&readable);
    FD_SET(fd, &readable);
    if (select(fd + 1, &readable, NULL, NULL, NULL) < 1)
      continue;
    slen = sizeof(struct sockaddr_in);
    r = recvfrom(fd, rbuf, sizeof(rbuf), 0, (struct sockaddr *)&from, &slen);
    if (r < 1)
      continue;
    datasize = fill_payload(output_buf);
    if (r == datasize && memcmp(rbuf, output_buf, r) == 0) {
      if (telnet_enabled == 0 && ((strncmp(cat_file("/tmp/firmware_region"), "PR", 2) != 0) && !((strncmp(cat_file("/tmp/firmware_region"), "WW", 2) == 0) && (strcmp(config_get("GUI_Region"), "Chinese") == 0)))) {
        printf("The telnet server is enabled now!!!\n");
        system("/usr/sbin/utelnetd -d -i "
               "br0");
        telnet_enabled = 1;
      }
      sendto(fd, ack, 3, 0, (struct sockaddr *)&from, slen);
    }
  }
  return 0;
}
```