user: Demonstrate the C code that generates the assembly output below:

```asm
<get_pci_dev_from_netdev>:
  endbr64
  push   %r15
  mov    %rdi,%rcx
  lea    D20(%rip),%rsi
  push   %r14
  lea    D39(%rip),%r14
  push   %r13
  mov    %r14,%rdx
  push   %r12
  mov    %rdi,%r12
  push   %rbp
  push   %rbx
  sub    $0x538,%rsp
  mov    %fs:0x28,%rax
  mov    %rax,0x528(%rsp)
  xor    %eax,%eax
  lea    0x18(%rsp),%r13
  mov    %r13,%rdi
  call   <asprintf@plt>
  cmp    $0xffffffff,%eax
  je     L63
  mov    0x18(%rsp),%rdi
  lea    0x120(%rsp),%rbp
  mov    $0x3ff,%edx
  mov    %rbp,%rsi
  call   <readlink@plt>
  mov    0x18(%rsp),%rdi
  mov    %eax,%ebx
  call   <free@plt>
  cmp    $0xffffffff,%ebx
  je     L72
L28:
  lea    D36(%rip),%r12
  jmp    L117
  nopl   (%rax)
L132:
  lea    0x8(%rsp),%rcx
  lea    0x4(%rsp),%rdx
  mov    %rsp,%r9
  mov    %r12,%rsi
  lea    0x1(%rax),%rdi
  lea    0xc(%rsp),%r8
  call   <sscanf@plt>
  cmp    $0x4,%eax
  je     L70
  movb   $0x0,(%rbx)
  cmp    %rbp,%rbx
  jbe    L70
L117:
  mov    $0x2f,%esi
  mov    %rbp,%rdi
  call   <strrchr@plt>
  mov    %rax,%rbx
  test   %rax,%rax
  jne    L132
L70:
  mov    (%rsp),%r9d
  mov    0xc(%rsp),%r8d
  xor    %eax,%eax
  lea    0x10(%rsp),%rdi
  mov    0x8(%rsp),%ecx
  mov    0x4(%rsp),%edx
  lea    D43(%rip),%rsi
  call   <asprintf@plt>
  cmp    $0xffffffff,%eax
  je     L63
  mov    0x10(%rsp),%rax
L99:
  mov    0x528(%rsp),%rdx
  sub    %fs:0x28,%rdx
  jne    L4
  add    $0x538,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
  nopl   0x0(%rax,%rax,1)
L72:
  mov    $0x2e,%esi
  mov    %r12,%rdi
  call   <strchr@plt>
  mov    %rax,%r15
  test   %rax,%rax
  je     L63
  mov    %r12,%rdi
  call   <strlen@plt>
  mov    %r15,%rdi
  mov    %rax,%rbx
  call   <strlen@plt>
  sub    %rax,%rbx
  cmp    $0xff,%rbx
  ja     L63
  lea    0x20(%rsp),%r15
  mov    $0xff,%edx
  mov    %r12,%rsi
  mov    %r15,%rdi
  call   <strncpy@plt>
  cmpb   $0x0,0x20(%rsp,%rbx,1)
  je     L127
  movb   $0x0,0x20(%rsp,%rbx,1)
L127:
  xor    %eax,%eax
  mov    %r15,%r8
  mov    %r12,%rcx
  mov    %r14,%rdx
  lea    D42(%rip),%rsi
  mov    %r13,%rdi
  call   <asprintf@plt>
  cmp    $0xffffffff,%eax
  je     L63
  mov    0x18(%rsp),%rdi
  mov    $0x3ff,%edx
  mov    %rbp,%rsi
  call   <readlink@plt>
  mov    0x18(%rsp),%rdi
  mov    %eax,%ebx
  call   <free@plt>
  cmp    $0xffffffff,%ebx
  jne    L28
  nop
L63:
  xor    %eax,%eax
  jmp    L99
L4:
  call   <__stack_chk_fail@plt>
```

tool_calls: name: extract_symbolic_data
arguments: label: D20
datatype: string
name: extract_symbolic_data
arguments: label: D39
datatype: string
name: extract_symbolic_data
arguments: label: D36
datatype: string
name: extract_symbolic_data
arguments: label: D43
datatype: string
name: extract_symbolic_data
arguments: label: D42
datatype: string

tool: D20: %s/%s/device

tool: D39: /sys/class/net

tool: D36: %x:%x:%x.%x

tool: D43: %04x:%02x:%02x.%x

tool: D42: %s/%s/lower_%s

assistant: ```c
char *get_pci_dev_from_netdev(const char *netdev) {
  char buf[1024];
  char *pcidev;
  char *path;
  char *cp;
  int func;
  int dom;
  int bus;
  int dev;
  int ret;
  ret = asprintf(&path, "%s/%s/device", "/sys/class/net", netdev);
  if (ret == -1)
    return NULL;
  ret = readlink(path, buf, sizeof(buf) - 1);
  free(path);
  if (ret == -1) {
    char realdev[256];
    char *subif;
    size_t len;
    subif = strchr(netdev, '.');
    if (!subif)
      return NULL;
    len = strlen(netdev) - strlen(subif);
    if (len > (sizeof(realdev) - 1))
      return NULL;
    strncpy(realdev, netdev, sizeof(realdev) - 1);
    if (realdev[len] != '\0')
      realdev[len] = '\0';
    ret = asprintf(&path, "%s/%s/lower_%s", "/sys/class/net", netdev, realdev);
    if (ret == -1)
      return NULL;
    ret = readlink(path, buf, sizeof(buf) - 1);
    free(path);
    if (ret == -1)
      return NULL;
  }
  do {
    cp = strrchr(buf, '/');
    if (!cp)
      break;
    ret = sscanf(cp + 1, "%x:%x:%x.%x", &dom, &bus, &dev, &func);
    if (ret == 4)
      break;
    *cp = '\0';
  } while (cp && cp > buf);
  ret = asprintf(&pcidev, "%04x:%02x:%02x.%x", dom, bus, dev, func);
  if (ret == -1)
    return NULL;
  return pcidev;
}
```