fhandler_process.cc

cygwin, 著名的在win32下模拟unix操作系统的东东

/* fhandler_process.cc: fhandler for /proc/<pid> virtual filesystem

   Copyright 2002 Red Hat, Inc.

This file is part of Cygwin.

This software is a copyrighted work licensed under the terms of the
Cygwin license.  Please consult the file "CYGWIN_LICENSE" for
details. */

#include "winsup.h"
#include <errno.h>
#include <unistd.h>
#include <stdlib.h>
#include <sys/cygwin.h>
#include <ntdef.h>
#include "cygerrno.h"
#include "security.h"
#include "fhandler.h"
#include "pinfo.h"
#include "path.h"
#include "shared_info.h"
#include "dtable.h"
#include "cygheap.h"
#include "ntdll.h"
#include <sys/param.h>
#include <assert.h>
#include <sys/sysmacros.h>

#define _COMPILING_NEWLIB
#include <dirent.h>

static const int PROCESS_PPID = 2;
static const int PROCESS_EXENAME = 3;
static const int PROCESS_WINPID = 4;
static const int PROCESS_WINEXENAME = 5;
static const int PROCESS_STATUS = 6;
static const int PROCESS_UID = 7;
static const int PROCESS_GID = 8;
static const int PROCESS_PGID = 9;
static const int PROCESS_SID = 10;
static const int PROCESS_CTTY = 11;
static const int PROCESS_STAT = 12;
static const int PROCESS_STATM = 13;
static const int PROCESS_CMDLINE = 14;

static const char * const process_listing[] =
{
  ".",
  "..",
  "ppid",
  "exename",
  "winpid",
  "winexename",
  "status",
  "uid",
  "gid",
  "pgid",
  "sid",
  "ctty",
  "stat",
  "statm",
  "cmdline",
  NULL
};

static const int PROCESS_LINK_COUNT =
  (sizeof (process_listing) / sizeof (const char *)) - 1;

static off_t format_process_stat (_pinfo *p, char *destbuf, size_t maxsize);
static off_t format_process_status (_pinfo *p, char *destbuf, size_t maxsize);
static off_t format_process_statm (_pinfo *p, char *destbuf, size_t maxsize);
static int get_process_state (DWORD dwProcessId);
static bool get_mem_values (DWORD dwProcessId, unsigned long *vmsize,
			    unsigned long *vmrss, unsigned long *vmtext,
			    unsigned long *vmdata, unsigned long *vmlib,
			    unsigned long *vmshare);

/* Returns 0 if path doesn't exist, >0 if path is a directory,
 * <0 if path is a file.
 */
int
fhandler_process::exists ()
{
  const char *path = get_name ();
  debug_printf ("exists (%s)", path);
  path += proc_len + 1;
  while (*path != 0 && !SLASH_P (*path))
    path++;
  if (*path == 0)
    return 2;

  for (int i = 0; process_listing[i]; i++)
    if (pathmatch (path + 1, process_listing[i]))
      return -1;
  return 0;
}

fhandler_process::fhandler_process ():
  fhandler_proc (FH_PROCESS)
{
}

int
fhandler_process::fstat (struct __stat64 *buf, path_conv *pc)
{
  const char *path = get_name ();
  int file_type = exists ();
  (void) fhandler_base::fstat (buf, pc);
  path += proc_len + 1;
  pid = atoi (path);
  pinfo p (pid);
  if (!p)
    {
      set_errno (ENOENT);
      return -1;
    }

  buf->st_mode &= ~_IFMT & NO_W;

  switch (file_type)
    {
    case 0:
      set_errno (ENOENT);
      return -1;
    case 1:
      buf->st_mode |= S_IFDIR | S_IXUSR | S_IXGRP | S_IXOTH;
      return 0;
    case 2:
      buf->st_ctime = buf->st_mtime = p->start_time;
      buf->st_ctim.tv_nsec = buf->st_mtim.tv_nsec = 0;
      time_as_timestruc_t (&buf->st_atim);
      buf->st_uid = p->uid;
      buf->st_gid = p->gid;
      buf->st_mode |= S_IFDIR | S_IXUSR | S_IXGRP | S_IXOTH;
      buf->st_nlink = PROCESS_LINK_COUNT;
      return 0;
    default:
    case -1:
      buf->st_uid = p->uid;
      buf->st_gid = p->gid;
      buf->st_mode |= S_IFREG | S_IRUSR | S_IRGRP | S_IROTH;
      return 0;
    }
}

struct dirent *
fhandler_process::readdir (DIR * dir)
{
  if (dir->__d_position >= PROCESS_LINK_COUNT)
    {
      set_errno (ENMFILE);
      return NULL;
    }
  strcpy (dir->__d_dirent->d_name, process_listing[dir->__d_position++]);
  syscall_printf ("%p = readdir (%p) (%s)", &dir->__d_dirent, dir,
		  dir->__d_dirent->d_name);
  return dir->__d_dirent;
}

int
fhandler_process::open (path_conv *pc, int flags, mode_t mode)
{
  int process_file_no = -1;

  int res = fhandler_virtual::open (pc, flags, mode);
  if (!res)
    goto out;

  set_nohandle (true);

  const char *path;
  path = get_name () + proc_len + 1;
  pid = atoi (path);
  while (*path != 0 && !SLASH_P (*path))
    path++;

  if (*path == 0)
    {
      if ((flags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
	{
	  set_errno (EEXIST);
	  res = 0;
	  goto out;
	}
      else if (flags & O_WRONLY)
	{
	  set_errno (EISDIR);
	  res = 0;
	  goto out;
	}
      else
	{
	  flags |= O_DIROPEN;
	  goto success;
	}
    }

  process_file_no = -1;
  for (int i = 0; process_listing[i]; i++)
    {
      if (path_prefix_p
	  (process_listing[i], path + 1, strlen (process_listing[i])))
	process_file_no = i;
    }
  if (process_file_no == -1)
    {
      if (flags & O_CREAT)
	{
	  set_errno (EROFS);
	  res = 0;
	  goto out;
	}
      else
	{
	  set_errno (ENOENT);
	  res = 0;
	  goto out;
	}
    }
  if (flags & O_WRONLY)
    {
      set_errno (EROFS);
      res = 0;
      goto out;
    }

  fileid = process_file_no;
  if (!fill_filebuf ())
	{
	  res = 0;
	  goto out;
	}

  if (flags & O_APPEND)
    position = filesize;
  else
    position = 0;

success:
  res = 1;
  set_flags ((flags & ~O_TEXT) | O_BINARY);
  set_open_status ();
out:
  syscall_printf ("%d = fhandler_proc::open (%p, %d)", res, flags, mode);
  return res;
}

bool
fhandler_process::fill_filebuf ()
{
  pinfo p (pid);

  if (!p)
    {
      set_errno (ENOENT);
      return false;
    }

  switch (fileid)
    {
    case PROCESS_UID:
    case PROCESS_GID:
    case PROCESS_PGID:
    case PROCESS_SID:
    case PROCESS_CTTY:
    case PROCESS_PPID:
      {
	filebuf = (char *) realloc (filebuf, bufalloc = 40);
	int num;
	switch (fileid)
	  {
	  case PROCESS_PPID:
	    num = p->ppid;
	    break;
	  case PROCESS_UID:
	    num = p->uid;
	    break;
	  case PROCESS_PGID:
	    num = p->pgid;
	    break;
	  case PROCESS_SID:
	    num = p->sid;
	    break;
	  case PROCESS_GID:
	    num = p->gid;
	    break;
	  case PROCESS_CTTY:
	    num = p->ctty;
	    break;
	  default: // what's this here for?
	    num = 0;
	    break;
	  }
	__small_sprintf (filebuf, "%d\n", num);
	filesize = strlen (filebuf);
	break;
      }
    case PROCESS_CMDLINE:
      {
	if (filebuf)
	  free (filebuf);
	filebuf = p->cmdline (filesize);
	if (!filebuf || !*filebuf)
	  filebuf = strdup ("<defunct>");
	break;
      }
    case PROCESS_EXENAME:
      {
	filebuf = (char *) realloc (filebuf, bufalloc = MAX_PATH);
	if (p->process_state & (PID_ZOMBIE | PID_EXITED))
	  strcpy (filebuf, "<defunct>");
	else
	  {
	    mount_table->conv_to_posix_path (p->progname, filebuf, 1);
	    int len = strlen (filebuf);
	    if (len > 4)
	      {
		char *s = filebuf + len - 4;
		if (strcasecmp (s, ".exe") == 0)
		  *s = 0;
	      }
	  }
	filesize = strlen (filebuf);
	break;
      }
    case PROCESS_WINPID:
      {
	filebuf = (char *) realloc (filebuf, bufalloc = 40);
	__small_sprintf (filebuf, "%d\n", p->dwProcessId);
	filesize = strlen (filebuf);
	break;
      }
    case PROCESS_WINEXENAME:
      {
	int len = strlen (p->progname);
	filebuf = (char *) realloc (filebuf, bufalloc = (len + 2));
	strcpy (filebuf, p->progname);
	filebuf[len] = '\n';
	filesize = len + 1;
	break;
      }
    case PROCESS_STATUS:
      {
	filebuf = (char *) realloc (filebuf, bufalloc = 2048);
	filesize = format_process_status (*p, filebuf, bufalloc);
	break;
      }
    case PROCESS_STAT:
      {
	filebuf = (char *) realloc (filebuf, bufalloc = 2048);
	filesize = format_process_stat (*p, filebuf, bufalloc);
	break;
      }
    case PROCESS_STATM:
      {
	filebuf = (char *) realloc (filebuf, bufalloc = 2048);
	filesize = format_process_statm (*p, filebuf, bufalloc);
	break;
      }
    }

  return true;
}

static
off_t
format_process_stat (_pinfo *p, char *destbuf, size_t maxsize)
{
  char cmd[MAX_PATH];
  int state = 'R';
  unsigned long fault_count = 0UL,
		utime = 0UL, stime = 0UL,
		start_time = 0UL,
		vmsize = 0UL, vmrss = 0UL, vmmaxrss = 0UL;
  int priority = 0;