user: Converte this assembly snippet into its equivalent C code:

```asm
<parse_line>:
  endbr64
  push   %rbp
  push   %rbx
  sub    $0x18,%rsp
  mov    %rdi,%rbp
  mov    %fs:0x28,%rax
  mov    %rax,0x8(%rsp)
  xor    %eax,%eax
  movl   $0x0,0x4(%rsp)
  call   <entry_malloc@plt>
  mov    %rax,%rbx
  lea    0x4(%rsp),%rdx
  mov    %rbp,%rsi
  mov    %rax,%rdi
  call   <parse_client_field@plt>
  test   %eax,%eax
  je     L25
  lea    0x4(%rsp),%rdx
  mov    %rbp,%rsi
  mov    %rbx,%rdi
  call   <parse_identity_field@plt>
  test   %eax,%eax
  je     L137
  lea    0x4(%rsp),%rdx
  mov    %rbp,%rsi
  mov    %rbx,%rdi
  call   <parse_user_id_field@plt>
  test   %eax,%eax
  je     L182
  lea    0x4(%rsp),%rdx
  mov    %rbp,%rsi
  mov    %rbx,%rdi
  call   <parse_time_field@plt>
  test   %eax,%eax
  je     L47
  lea    0x4(%rsp),%rdx
  mov    %rbp,%rsi
  mov    %rbx,%rdi
  call   <parse_request_field@plt>
  test   %eax,%eax
  je     L168
  lea    0x4(%rsp),%rdx
  mov    %rbp,%rsi
  mov    %rbx,%rdi
  call   <parse_status_code_field@plt>
  test   %eax,%eax
  je     L106
  lea    0x4(%rsp),%rdx
  mov    %rbp,%rsi
  mov    %rbx,%rdi
  call   <parse_size_field@plt>
  test   %eax,%eax
  je     L147
  lea    0x4(%rsp),%rdx
  mov    %rbp,%rsi
  mov    %rbx,%rdi
  call   <parse_referer_field@plt>
  test   %eax,%eax
  je     L125
  lea    0x4(%rsp),%rdx
  mov    %rbp,%rsi
  mov    %rbx,%rdi
  call   <parse_user_agent_field@plt>
  test   %eax,%eax
  je     L70
L34:
  mov    0x8(%rsp),%rax
  sub    %fs:0x28,%rax
  jne    L81
  mov    %rbx,%rax
  add    $0x18,%rsp
  pop    %rbx
  pop    %rbp
  ret
L25:
  mov    %rbx,%rdi
  call   <free_entry@plt>
  mov    $0x0,%ebx
  jmp    L34
L137:
  mov    %rbx,%rdi
  call   <free_entry@plt>
  mov    $0x0,%ebx
  jmp    L34
L182:
  mov    %rbx,%rdi
  call   <free_entry@plt>
  mov    $0x0,%ebx
  jmp    L34
L47:
  mov    %rbx,%rdi
  call   <free_entry@plt>
  mov    $0x0,%ebx
  jmp    L34
L168:
  mov    %rbx,%rdi
  call   <free_entry@plt>
  mov    $0x0,%ebx
  jmp    L34
L106:
  mov    %rbx,%rdi
  call   <free_entry@plt>
  mov    $0x0,%ebx
  jmp    L34
L147:
  mov    %rbx,%rdi
  call   <free_entry@plt>
  mov    $0x0,%ebx
  jmp    L34
L125:
  mov    %rbx,%rdi
  call   <free_entry@plt>
  mov    $0x0,%ebx
  jmp    L34
L70:
  mov    %rbx,%rdi
  call   <free_entry@plt>
  mov    $0x0,%ebx
  jmp    L34
L81:
  call   <__stack_chk_fail@plt>
```

assistant: ```c
struct log_file_entry *parse_line(const char *line) {
  struct log_file_entry *entry;
  int current_position = 0;
  entry = entry_malloc();
  if (!parse_client_field(entry, line, &current_position)) {
    free_entry(entry);
    return NULL;
  }
  if (!parse_identity_field(entry, line, &current_position)) {
    free_entry(entry);
    return NULL;
  }
  if (!parse_user_id_field(entry, line, &current_position)) {
    free_entry(entry);
    return NULL;
  }
  if (!parse_time_field(entry, line, &current_position)) {
    free_entry(entry);
    return NULL;
  }
  if (!parse_request_field(entry, line, &current_position)) {
    free_entry(entry);
    return NULL;
  }
  if (!parse_status_code_field(entry, line, &current_position)) {
    free_entry(entry);
    return NULL;
  }
  if (!parse_size_field(entry, line, &current_position)) {
    free_entry(entry);
    return NULL;
  }
  if (!parse_referer_field(entry, line, &current_position)) {
    free_entry(entry);
    return NULL;
  }
  if (!parse_user_agent_field(entry, line, &current_position)) {
    free_entry(entry);
    return NULL;
  }
  return entry;
}
```