user: What is the c source code of the assembly code below?

```asm
<receive_packet>:
  endbr64
  push   %rbp
  mov    %rsp,%rbp
  push   %r15
  push   %r14
  push   %r13
  push   %r12
  push   %rbx
  sub    $0x88,%rsp
  mov    %edi,-0x94(%rbp)
  mov    %rsi,-0xa0(%rbp)
  mov    %rdx,-0xa8(%rbp)
  mov    %ecx,-0x98(%rbp)
  mov    %r8,-0xb0(%rbp)
  mov    %fs:0x28,%rax
  mov    %rax,-0x38(%rbp)
  xor    %eax,%eax
  mov    %rsp,%rax
  mov    %rax,%rbx
  mov    $0x4,%edi
  call   <CMSG_SPACE@plt>
  mov    %eax,%ecx
  movslq %ecx,%rax
  sub    $0x1,%rax
  mov    %rax,-0x80(%rbp)
  movslq %ecx,%rax
  mov    %rax,%r14
  mov    $0x0,%r15d
  movslq %ecx,%rax
  mov    %rax,%r12
  mov    $0x0,%r13d
  movslq %ecx,%rax
  mov    $0x10,%edx
  sub    $0x1,%rdx
  add    %rdx,%rax
  mov    $0x10,%edi
  mov    $0x0,%edx
  div    %rdi
  imul   $0x10,%rax,%rax
  mov    %rax,%rsi
  and    $0xfffffffffffff000,%rsi
  mov    %rsp,%rdx
  sub    %rsi,%rdx
L113:
  cmp    %rdx,%rsp
  je     L97
  sub    $0x1000,%rsp
  orq    $0x0,0xff8(%rsp)
  jmp    L113
L97:
  mov    %rax,%rdx
  and    $0xfff,%edx
  sub    %rdx,%rsp
  mov    %rax,%rdx
  and    $0xfff,%edx
  test   %rdx,%rdx
  je     L4
  and    $0xfff,%eax
  sub    $0x8,%rax
  add    %rsp,%rax
  orq    $0x0,(%rax)
L4:
  mov    %rsp,%rax
  add    $0x0,%rax
  mov    %rax,-0x78(%rbp)
  mov    -0xa0(%rbp),%rax
  mov    %rax,-0x70(%rbp)
  mov    -0xa8(%rbp),%rax
  mov    %rax,-0x68(%rbp)
  movl   $0x4,-0x60(%rbp)
  movl   $0x1,-0x5c(%rbp)
  mov    -0x78(%rbp),%rax
  mov    %rax,-0x58(%rbp)
  mov    %ecx,-0x50(%rbp)
  lea    -0x70(%rbp),%rax
  mov    %rax,-0x48(%rbp)
  mov    -0xb0(%rbp),%rax
  mov    %rax,-0x40(%rbp)
  mov    -0x98(%rbp),%edx
  lea    -0x60(%rbp),%rcx
  mov    -0x94(%rbp),%eax
  mov    %rcx,%rsi
  mov    %eax,%edi
  call   <recvmsg@plt>
  mov    %eax,-0x8c(%rbp)
  cmpl   $0xffffffff,-0x8c(%rbp)
  jne    L16
  mov    -0x8c(%rbp),%eax
  jmp    L86
L16:
  lea    -0x60(%rbp),%rax
  mov    %rax,%rdi
  call   <CMSG_FIRSTHDR@plt>
  mov    %rax,-0x88(%rbp)
  jmp    L7
L87:
  mov    -0x88(%rbp),%rax
  mov    (%rax),%rdx
  mov    D6(%rip),%rax
  mov    (%rax),%rax
  cmp    %rax,%rdx
  jne    L46
  mov    -0x88(%rbp),%rax
  mov    0x8(%rax),%rdx
  mov    D33(%rip),%rax
  mov    (%rax),%rax
  cmp    %rax,%rdx
  jne    L46
  mov    -0x88(%rbp),%rax
  mov    %rax,%rdi
  call   <CMSG_DATA@plt>
  mov    (%rax),%eax
  cmp    $0xff,%eax
  je     L46
  mov    D27(%rip),%rax
  mov    (%rax),%edx
  mov    D15(%rip),%rax
  mov    %edx,(%rax)
  mov    $0xffffffff,%eax
  jmp    L86
L46:
  mov    -0x88(%rbp),%rdx
  lea    -0x60(%rbp),%rax
  mov    %rdx,%rsi
  mov    %rax,%rdi
  call   <CMSG_NXTHDR@plt>
  mov    %rax,-0x88(%rbp)
L7:
  cmpq   $0x0,-0x88(%rbp)
  jne    L87
  mov    -0x8c(%rbp),%eax
L86:
  mov    %rbx,%rsp
  mov    -0x38(%rbp),%rdx
  sub    %fs:0x28,%rdx
  je     L42
  call   <__stack_chk_fail@plt>
L42:
  lea    -0x28(%rbp),%rsp
  pop    %rbx
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  pop    %rbp
  ret
```

assistant: ```c
ssize_t receive_packet(int fd, void *buf, size_t len, int flags, struct sockaddr_in6 *addr) {
  char cbuf[CMSG_SPACE(sizeof(int))];
  struct iovec iov = {.iov_base = buf, .iov_len = len};
  struct msghdr hdr = {.msg_name = addr, .msg_namelen = sizeof(*addr), .msg_iov = &iov, .msg_iovlen = 1, .msg_control = cbuf, .msg_controllen = sizeof(cbuf)};
  ssize_t val = recvmsg(fd, &hdr, flags);
  if (val == -1)
    return val;
  for (struct cmsghdr *cmsg = CMSG_FIRSTHDR(&hdr); cmsg != NULL; cmsg = CMSG_NXTHDR(&hdr, cmsg)) {
    if ((cmsg->cmsg_level == IPPROTO_IPV6) && (cmsg->cmsg_type == IPV6_HOPLIMIT)) {
      if (255 != *(int *)CMSG_DATA(cmsg)) {
        errno = EAGAIN;
        return -1;
      }
    }
  }
  return val;
}
```