user: Translate the below assembly code into C programming language:

```asm
<lookup>:
  endbr64
  push   %rbp
  mov    %rsp,%rbp
  push   %r14
  push   %r13
  push   %r12
  mov    %rdi,%r12
  push   %rbx
  sub    $0x10,%rsp
  mov    %fs:0x28,%rax
  mov    %rax,-0x28(%rbp)
  xor    %eax,%eax
  call   <strlen@plt>
  mov    %rsp,%rdi
  lea    0x10(%rax),%rdx
  mov    %rax,%rcx
  mov    %rdx,%rsi
  and    $0xfffffffffffff000,%rdx
  sub    %rdx,%rdi
  and    $0xfffffffffffffff0,%rsi
  cmp    %rdi,%rsp
  je     L80
L57:
  sub    $0x1000,%rsp
  orq    $0x0,0xff8(%rsp)
  cmp    %rdi,%rsp
  jne    L57
L80:
  and    $0xfff,%esi
  sub    %rsi,%rsp
  test   %rsi,%rsi
  jne    L101
L93:
  mov    %rsp,%r13
  test   %eax,%eax
  jle    L94
  lea    -0x1(%rax),%r14d
  xor    %ebx,%ebx
  xchg   %ax,%ax
L89:
  movsbl (%r12,%rbx,1),%edi
  call   <tolower@plt>
  mov    %al,0x0(%r13,%rbx,1)
  mov    %rbx,%rax
  add    $0x1,%rbx
  cmp    %rax,%r14
  jne    L89
  mov    %r12,%rdi
  call   <strlen@plt>
  mov    %rax,%rcx
L94:
  lea    D50(%rip),%rsi
  mov    %r13,%rdi
  movb   $0x0,0x0(%r13,%rcx,1)
  call   <strcmp@plt>
  mov    %rax,%r8
  lea    D107(%rip),%rax
  test   %r8,%r8
  je     L59
  lea    D4(%rip),%rsi
  mov    %r13,%rdi
  call   <strcmp@plt>
  mov    %rax,%r8
  lea    D83(%rip),%rax
  test   %r8,%r8
  je     L59
  lea    D58(%rip),%rsi
  mov    %r13,%rdi
  call   <strcmp@plt>
  mov    %rax,%r8
  lea    D26(%rip),%rax
  test   %r8,%r8
  jne    L16
  cs nopw 0x0(%rax,%rax,1)
L59:
  mov    -0x28(%rbp),%rdx
  sub    %fs:0x28,%rdx
  jne    L41
  lea    -0x20(%rbp),%rsp
  pop    %rbx
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %rbp
  ret
L101:
  orq    $0x0,-0x8(%rsp,%rsi,1)
  jmp    L93
  nopl   0x0(%rax,%rax,1)
L16:
  lea    D38(%rip),%rsi
  mov    %r13,%rdi
  call   <strcmp@plt>
  mov    %rax,%r8
  lea    D2(%rip),%rax
  test   %r8,%r8
  je     L59
  lea    D137(%rip),%rsi
  mov    %r13,%rdi
  call   <strcmp@plt>
  mov    %rax,%r8
  lea    D5(%rip),%rax
  test   %r8,%r8
  je     L59
  lea    D101(%rip),%rsi
  mov    %r13,%rdi
  call   <strcmp@plt>
  mov    %rax,%r8
  lea    D3(%rip),%rax
  test   %r8,%r8
  je     L59
  lea    D42(%rip),%rsi
  mov    %r13,%rdi
  call   <strcmp@plt>
  mov    $0x0,%edx
  test   %rax,%rax
  lea    D104(%rip),%rax
  cmovne %rdx,%rax
  jmp    L59
L41:
  call   <__stack_chk_fail@plt>
```

tool_calls: name: disassemble_data
arguments: label: D50
type_guessed: string
name: disassemble_data
arguments: label: D107
type_guessed: string
name: disassemble_data
arguments: label: D4
type_guessed: string
name: disassemble_data
arguments: label: D83
type_guessed: string
name: disassemble_data
arguments: label: D58
type_guessed: string
name: disassemble_data
arguments: label: D26
type_guessed: string
name: disassemble_data
arguments: label: D38
type_guessed: string
name: disassemble_data
arguments: label: D2
type_guessed: string
name: disassemble_data
arguments: label: D137
type_guessed: string
name: disassemble_data
arguments: label: D5
type_guessed: string
name: disassemble_data
arguments: label: D101
type_guessed: string
name: disassemble_data
arguments: label: D3
type_guessed: string
name: disassemble_data
arguments: label: D42
type_guessed: string
name: disassemble_data
arguments: label: D104
type_guessed: string

tool: D50: css

tool: D107: text/css

tool: D4: html

tool: D83: text/html

tool: D58: js

tool: D26: text/javascript

tool: D38: gif

tool: D2: image/gif

tool: D137: ico

tool: D5: image/x-icon

tool: D101: jpg

tool: D3: image/jpg

tool: D42: png

tool: D104: image/png

assistant: ```c
const char *lookup(const char *extension) {
  char ext[strlen(extension) + 1];
  for (int i = 0, extlen = strlen(extension); i < extlen; i++)
    ext[i] = tolower(extension[i]);
  ext[strlen(extension)] = '\0';
  if (strcmp(ext, "css") == 0)
    return "text/css";
  else if (strcmp(ext, "html") == 0)
    return "text/html";
  else if (strcmp(ext, "js") == 0)
    return "text/javascript";
  else if (strcmp(ext, "gif") == 0)
    return "image/gif";
  else if (strcmp(ext, "ico") == 0)
    return "image/x-icon";
  else if (strcmp(ext, "jpg") == 0)
    return "image/jpg";
  else if (strcmp(ext, "png") == 0)
    return "image/png";
  else
    return NULL;
}
```