user: 下面的汇编指令对应的C源代码是什么:

```asm
<parseLength>:
  endbr64
  push   %rbx
  mov    $0x0,%ebx
  cmpb   $0x30,(%rdi)
  je     L158
L67:
  mov    %ebx,%eax
  pop    %rbx
  ret
L158:
  mov    %rdi,%rax
  movzbl 0x1(%rdi),%edx
  test   %dl,%dl
  js     L91
  cmpb   $0x2,0x2(%rdi)
  jne    L117
  cmpb   $0x1,0x3(%rdi)
  jne    L117
  movzbl %dl,%ebx
  mov    %ebx,%ecx
  lea    D13(%rip),%rdx
  lea    D9(%rip),%rsi
  mov    $0xa,%edi
  mov    $0x0,%eax
  call   <writeError@plt>
  jmp    L67
L91:
  mov    %edx,%ecx
  and    $0x7f,%ecx
  and    $0x7f,%edx
  cmp    $0x1,%edx
  je     L167
  cmp    $0x2,%edx
  je     L41
  cmp    $0x3,%edx
  je     L68
  cmp    $0x4,%edx
  jne    L29
  movzbl 0x2(%rdi),%ebx
  shl    $0x18,%ebx
  movzbl 0x3(%rdi),%esi
  shl    $0x10,%esi
  add    %esi,%ebx
  movzbl 0x4(%rdi),%esi
  shl    $0x8,%esi
  add    %esi,%ebx
  movzbl 0x5(%rdi),%esi
  add    %esi,%ebx
  jmp    L64
L167:
  movzbl 0x2(%rdi),%ebx
L64:
  test   %ebx,%ebx
  jle    L29
  add    $0x2,%edx
  movslq %edx,%rdx
  cmpb   $0x2,(%rax,%rdx,1)
  jne    L29
  add    $0x3,%ecx
  movzbl %cl,%ecx
  cmpb   $0x1,(%rax,%rcx,1)
  jne    L29
  mov    %ebx,%ecx
  lea    D13(%rip),%rdx
  lea    D49(%rip),%rsi
  mov    $0xa,%edi
  mov    $0x0,%eax
  call   <writeError@plt>
  jmp    L67
L41:
  movzbl 0x2(%rdi),%ebx
  shl    $0x8,%ebx
  movzbl 0x3(%rdi),%esi
  add    %esi,%ebx
  jmp    L64
L68:
  movzbl 0x2(%rdi),%ebx
  shl    $0x10,%ebx
  movzbl 0x3(%rdi),%esi
  shl    $0x8,%esi
  add    %esi,%ebx
  movzbl 0x4(%rdi),%esi
  add    %esi,%ebx
  jmp    L64
L29:
  lea    D13(%rip),%rdx
  lea    D42(%rip),%rsi
  mov    $0x3,%edi
  mov    $0x0,%eax
  call   <writeError@plt>
  mov    $0xffffffff,%ebx
  jmp    L67
L117:
  lea    D13(%rip),%rdx
  lea    D41(%rip),%rsi
  mov    $0x3,%edi
  mov    $0x0,%eax
  call   <writeError@plt>
  mov    $0xffffffff,%ebx
  jmp    L67
```

tool_calls: name: unpack_data
arguments: tag: D13
datatype: string
name: unpack_data
arguments: tag: D9
datatype: string
name: unpack_data
arguments: tag: D49
datatype: string
name: unpack_data
arguments: tag: D42
datatype: string
name: unpack_data
arguments: tag: D41
datatype: string

tool: D13: snmp.mod

tool: D9: [%s] Single octet mode length: %d

tool: D49: [%s] Multi-octet mode length: %d

tool: D42: [%s] Failed to parse length or SNMP version (multi-octet mode).

tool: D41: [%s] Failed to parse length or SNMP version.

assistant: ```c
int parseLength(unsigned char *bufReceive) {
  int nLength = 0;
  int nOctets = 0;
  if (bufReceive[0] == 0x30) {
    if (bufReceive[1] & 0x80) {
      nOctets = bufReceive[1] & 0x7f;
      if (nOctets == 1)
        nLength = bufReceive[2];
      else if (nOctets == 2)
        nLength = (bufReceive[2] << 8) + bufReceive[3];
      else if (nOctets == 3)
        nLength = (bufReceive[2] << 16) + (bufReceive[3] << 8) + bufReceive[4];
      else if (nOctets == 4)
        nLength = (bufReceive[2] << 24) + (bufReceive[3] << 16) + (bufReceive[4] << 8) + bufReceive[5];
      if ((nLength > 0) && ((bufReceive[2 + nOctets] == 0x02) && (bufReceive[2 + nOctets + 1] == 0x01)))
        writeError(10, "[%s] Multi-octet mode length: %d", "snmp.mod", nLength);
      else {
        writeError(3, "[%s] Failed to parse length or SNMP version (multi-octet mode).", "snmp.mod");
        nLength = -1;
      }
    } else if ((bufReceive[2] == 0x02) && (bufReceive[3] == 0x01)) {
      nLength = bufReceive[1];
      writeError(10, "[%s] Single octet mode length: %d", "snmp.mod", nLength);
    } else {
      writeError(3, "[%s] Failed to parse length or SNMP version.", "snmp.mod");
      nLength = -1;
    }
  }
  return nLength;
}
```