user: What would the C source look like for the assembly code provided here:

```asm
<lwwire_proto_read>:
  endbr64
  push   %r12
  mov    $0x4,%esi
  push   %rbp
  push   %rbx
  sub    $0x110,%rsp
  mov    %fs:0x28,%rax
  mov    %rax,0x108(%rsp)
  xor    %eax,%eax
  mov    %rsp,%rbp
  mov    %rbp,%rdi
  call   <lwwire_read@plt>
  test   %rax,%rax
  js     L4
  movzbl 0x1(%rsp),%esi
  movzbl 0x2(%rsp),%eax
  lea    0x1(%rsp),%r12
  movzbl (%rsp),%edi
  mov    %r12,%rdx
  shl    $0x8,%eax
  shl    $0x10,%esi
  or     %eax,%esi
  movzbl 0x3(%rsp),%eax
  or     %eax,%esi
  call   <lwwire_fetch_sector@plt>
  mov    $0x1,%esi
  mov    %rbp,%rdi
  mov    %eax,%ebx
  mov    %al,(%rsp)
  call   <lwwire_write@plt>
  test   %ebx,%ebx
  jne    L4
  pxor   %xmm2,%xmm2
  pxor   %xmm1,%xmm1
  mov    $0x102,%esi
  mov    %r12,%rdi
  movdqu 0x1(%rsp),%xmm3
  movdqa %xmm3,%xmm0
  punpckhbw %xmm2,%xmm3
  punpcklbw %xmm2,%xmm0
  movdqa %xmm0,%xmm4
  punpcklwd %xmm1,%xmm0
  punpckhwd %xmm1,%xmm4
  paddd  %xmm4,%xmm0
  movdqa %xmm3,%xmm4
  punpckhwd %xmm1,%xmm3
  punpcklwd %xmm1,%xmm4
  paddd  %xmm4,%xmm0
  paddd  %xmm3,%xmm0
  movdqu 0x11(%rsp),%xmm3
  movdqa %xmm3,%xmm4
  punpckhbw %xmm2,%xmm3
  punpcklbw %xmm2,%xmm4
  movdqa %xmm4,%xmm5
  punpckhwd %xmm1,%xmm4
  punpcklwd %xmm1,%xmm5
  paddd  %xmm5,%xmm0
  paddd  %xmm4,%xmm0
  movdqa %xmm3,%xmm4
  punpckhwd %xmm1,%xmm3
  punpcklwd %xmm1,%xmm4
  paddd  %xmm4,%xmm0
  paddd  %xmm3,%xmm0
  movdqu 0x21(%rsp),%xmm3
  movdqa %xmm3,%xmm4
  punpckhbw %xmm2,%xmm3
  punpcklbw %xmm2,%xmm4
  movdqa %xmm4,%xmm5
  punpckhwd %xmm1,%xmm4
  punpcklwd %xmm1,%xmm5
  paddd  %xmm5,%xmm0
  paddd  %xmm4,%xmm0
  movdqa %xmm3,%xmm4
  punpckhwd %xmm1,%xmm3
  punpcklwd %xmm1,%xmm4
  paddd  %xmm4,%xmm0
  paddd  %xmm3,%xmm0
  movdqu 0x31(%rsp),%xmm3
  movdqa %xmm3,%xmm4
  punpckhbw %xmm2,%xmm3
  punpcklbw %xmm2,%xmm4
  movdqa %xmm4,%xmm5
  punpckhwd %xmm1,%xmm4
  punpcklwd %xmm1,%xmm5
  paddd  %xmm5,%xmm0
  paddd  %xmm4,%xmm0
  movdqa %xmm3,%xmm4
  punpckhwd %xmm1,%xmm3
  punpcklwd %xmm1,%xmm4
  paddd  %xmm4,%xmm0
  paddd  %xmm3,%xmm0
  movdqu 0x41(%rsp),%xmm3
  movdqa %xmm3,%xmm4
  punpckhbw %xmm2,%xmm3
  punpcklbw %xmm2,%xmm4
  movdqa %xmm4,%xmm5
  punpckhwd %xmm1,%xmm4
  punpcklwd %xmm1,%xmm5
  paddd  %xmm5,%xmm0
  paddd  %xmm4,%xmm0
  movdqa %xmm3,%xmm4
  punpckhwd %xmm1,%xmm3
  punpcklwd %xmm1,%xmm4
  paddd  %xmm4,%xmm0
  paddd  %xmm3,%xmm0
  movdqu 0x51(%rsp),%xmm3
  movdqa %xmm3,%xmm4
  punpckhbw %xmm2,%xmm3
  punpcklbw %xmm2,%xmm4
  movdqa %xmm4,%xmm5
  punpckhwd %xmm1,%xmm4
  punpcklwd %xmm1,%xmm5
  paddd  %xmm5,%xmm0
  paddd  %xmm4,%xmm0
  movdqa %xmm3,%xmm4
  punpckhwd %xmm1,%xmm3
  punpcklwd %xmm1,%xmm4
  paddd  %xmm4,%xmm0
  paddd  %xmm3,%xmm0
  movdqu 0x61(%rsp),%xmm3
  movdqa %xmm3,%xmm4
  punpckhbw %xmm2,%xmm3
  punpcklbw %xmm2,%xmm4
  movdqa %xmm4,%xmm5
  punpckhwd %xmm1,%xmm4
  punpcklwd %xmm1,%xmm5
  paddd  %xmm5,%xmm0
  paddd  %xmm4,%xmm0
  movdqa %xmm3,%xmm4
  punpckhwd %xmm1,%xmm3
  punpcklwd %xmm1,%xmm4
  paddd  %xmm4,%xmm0
  paddd  %xmm3,%xmm0
  movdqu 0x71(%rsp),%xmm3
  movdqa %xmm3,%xmm4
  punpckhbw %xmm2,%xmm3
  punpcklbw %xmm2,%xmm4
  movdqa %xmm4,%xmm5
  punpckhwd %xmm1,%xmm4
  punpcklwd %xmm1,%xmm5
  paddd  %xmm5,%xmm0
  paddd  %xmm4,%xmm0
  movdqa %xmm3,%xmm4
  punpckhwd %xmm1,%xmm3
  punpcklwd %xmm1,%xmm4
  paddd  %xmm4,%xmm0
  paddd  %xmm3,%xmm0
  movdqu 0x81(%rsp),%xmm3
  movdqa %xmm3,%xmm4
  punpckhbw %xmm2,%xmm3
  punpcklbw %xmm2,%xmm4
  movdqa %xmm4,%xmm5
  punpckhwd %xmm1,%xmm4
  punpcklwd %xmm1,%xmm5
  paddd  %xmm5,%xmm0
  paddd  %xmm4,%xmm0
  movdqa %xmm3,%xmm4
  punpckhwd %xmm1,%xmm3
  punpcklwd %xmm1,%xmm4
  paddd  %xmm4,%xmm0
  paddd  %xmm3,%xmm0
  movdqu 0x91(%rsp),%xmm3
  movdqa %xmm3,%xmm4
  punpckhbw %xmm2,%xmm3
  punpcklbw %xmm2,%xmm4
  movdqa %xmm4,%xmm5
  punpckhwd %xmm1,%xmm4
  punpcklwd %xmm1,%xmm5
  paddd  %xmm5,%xmm0
  paddd  %xmm4,%xmm0
  movdqa %xmm3,%xmm4
  punpckhwd %xmm1,%xmm3
  punpcklwd %xmm1,%xmm4
  paddd  %xmm4,%xmm0
  paddd  %xmm3,%xmm0
  movdqu 0xa1(%rsp),%xmm3
  movdqa %xmm3,%xmm4
  punpckhbw %xmm2,%xmm3
  punpcklbw %xmm2,%xmm4
  movdqa %xmm4,%xmm5
  punpckhwd %xmm1,%xmm4
  punpcklwd %xmm1,%xmm5
  paddd  %xmm5,%xmm0
  paddd  %xmm4,%xmm0
  movdqa %xmm3,%xmm4
  punpckhwd %xmm1,%xmm3
  punpcklwd %xmm1,%xmm4
  paddd  %xmm4,%xmm0
  paddd  %xmm3,%xmm0
  movdqu 0xb1(%rsp),%xmm3
  movdqa %xmm3,%xmm4
  punpckhbw %xmm2,%xmm3
  punpcklbw %xmm2,%xmm4
  movdqa %xmm4,%xmm5
  punpckhwd %xmm1,%xmm4
  punpcklwd %xmm1,%xmm5
  paddd  %xmm5,%xmm0
  paddd  %xmm4,%xmm0
  movdqa %xmm3,%xmm4
  punpckhwd %xmm1,%xmm3
  punpcklwd %xmm1,%xmm4
  paddd  %xmm4,%xmm0
  paddd  %xmm3,%xmm0
  movdqu 0xc1(%rsp),%xmm3
  movdqa %xmm3,%xmm4
  punpckhbw %xmm2,%xmm3
  punpcklbw %xmm2,%xmm4
  movdqa %xmm4,%xmm5
  punpckhwd %xmm1,%xmm4
  punpcklwd %xmm1,%xmm5
  paddd  %xmm5,%xmm0
  paddd  %xmm4,%xmm0
  movdqa %xmm3,%xmm4
  punpckhwd %xmm1,%xmm3
  punpcklwd %xmm1,%xmm4
  paddd  %xmm4,%xmm0
  paddd  %xmm3,%xmm0
  movdqu 0xd1(%rsp),%xmm3
  movdqa %xmm3,%xmm4
  punpckhbw %xmm2,%xmm3
  punpcklbw %xmm2,%xmm4
  movdqa %xmm4,%xmm5
  punpckhwd %xmm1,%xmm4
  punpcklwd %xmm1,%xmm5
  paddd  %xmm5,%xmm0
  paddd  %xmm4,%xmm0
  movdqa %xmm3,%xmm4
  punpckhwd %xmm1,%xmm3
  punpcklwd %xmm1,%xmm4
  paddd  %xmm4,%xmm0
  paddd  %xmm3,%xmm0
  movdqu 0xe1(%rsp),%xmm3
  movdqa %xmm3,%xmm4
  punpckhbw %xmm2,%xmm3
  punpcklbw %xmm2,%xmm4
  movdqa %xmm4,%xmm5
  punpckhwd %xmm1,%xmm4
  punpcklwd %xmm1,%xmm5
  paddd  %xmm5,%xmm0
  paddd  %xmm4,%xmm0
  movdqa %xmm3,%xmm4
  punpckhwd %xmm1,%xmm3
  punpcklwd %xmm1,%xmm4
  paddd  %xmm4,%xmm0
  paddd  %xmm3,%xmm0
  movdqu 0xf1(%rsp),%xmm3
  movdqa %xmm3,%xmm4
  punpckhbw %xmm2,%xmm3
  punpcklbw %xmm2,%xmm4
  movdqa %xmm4,%xmm2
  punpckhwd %xmm1,%xmm4
  punpcklwd %xmm1,%xmm2
  paddd  %xmm2,%xmm0
  movdqa %xmm3,%xmm2
  punpckhwd %xmm1,%xmm3
  punpcklwd %xmm1,%xmm2
  paddd  %xmm4,%xmm0
  paddd  %xmm2,%xmm0
  paddd  %xmm3,%xmm0
  movdqa %xmm0,%xmm1
  psrldq $0x8,%xmm1
  paddd  %xmm1,%xmm0
  movdqa %xmm0,%xmm1
  psrldq $0x4,%xmm1
  paddd  %xmm1,%xmm0
  movd   %xmm0,%eax
  rol    $0x8,%ax
  mov    %ax,0x101(%rsp)
  call   <lwwire_write@plt>
L4:
  mov    0x108(%rsp),%rax
  sub    %fs:0x28,%rax
  jne    L14
  add    $0x110,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  ret
L14:
  call   <__stack_chk_fail@plt>
```

assistant: ```c
void lwwire_proto_read(void) {
  unsigned char buf[259];
  int ec;
  int lsn;
  int i;
  if (lwwire_read(buf, 4) < 0)
    return;
  lsn = (buf[1] << 16) | (buf[2] << 8) | buf[3];
  ec = lwwire_fetch_sector(buf[0], lsn, buf + 1);
  buf[0] = ec;
  lwwire_write(buf, 1);
  if (ec)
    return;
  ec = 0;
  for (i = 1; i < 257; i++)
    ec += buf[i];
  buf[257] = (ec >> 8) & 0xff;
  buf[258] = ec & 0xff;
  lwwire_write(buf + 1, 258);
}
```