newlib-cygwin/winsup/cygwin/dtable.cc

815 lines
19 KiB
C++

/* dtable.cc: file descriptor support.
Copyright 1996, 1997, 1998, 1999, 2000, 2001, 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. */
#define __INSIDE_CYGWIN_NET__
#include "winsup.h"
#include <errno.h>
#include <sys/socket.h>
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <sys/cygwin.h>
#include <assert.h>
#include <ntdef.h>
#include <winnls.h>
#define USE_SYS_TYPES_FD_SET
#include <winsock.h>
#include "pinfo.h"
#include "cygerrno.h"
#include "perprocess.h"
#include "security.h"
#include "fhandler.h"
#include "path.h"
#include "dtable.h"
#include "cygheap.h"
#include "ntdll.h"
static const NO_COPY DWORD std_consts[] = {STD_INPUT_HANDLE, STD_OUTPUT_HANDLE,
STD_ERROR_HANDLE};
static const char *handle_to_fn (HANDLE, char *);
static const char NO_COPY unknown_file[] = "some disk file";
/* Set aside space for the table of fds */
void
dtable_init (void)
{
if (!cygheap->fdtab.size)
cygheap->fdtab.extend (NOFILE_INCR);
}
void __stdcall
set_std_handle (int fd)
{
if (fd == 0)
SetStdHandle (std_consts[fd], cygheap->fdtab[fd]->get_handle ());
else if (fd <= 2)
SetStdHandle (std_consts[fd], cygheap->fdtab[fd]->get_output_handle ());
}
void
dtable::dec_console_fds ()
{
if (console_fds > 0 && !--console_fds &&
myself->ctty != TTY_CONSOLE && !check_pty_fds())
FreeConsole ();
}
int
dtable::extend (int howmuch)
{
int new_size = size + howmuch;
fhandler_base **newfds;
if (howmuch <= 0)
return 0;
/* Try to allocate more space for fd table. We can't call realloc ()
here to preserve old table if memory allocation fails */
if (!(newfds = (fhandler_base **) ccalloc (HEAP_ARGV, new_size, sizeof newfds[0])))
{
debug_printf ("calloc failed");
return 0;
}
if (fds)
{
memcpy (newfds, fds, size * sizeof (fds[0]));
cfree (fds);
}
size = new_size;
fds = newfds;
debug_printf ("size %d, fds %p", size, fds);
return 1;
}
void
dtable::get_debugger_info ()
{
if (being_debugged ())
{
char std[3][sizeof ("/dev/ttyNNNN")];
std[0][0] = std[1][0] = std [2][0] = '\0';
char buf[sizeof ("cYgstd %x") + 32];
sprintf (buf, "cYgstd %x %x %x", (unsigned) &std, sizeof (std[0]), 3);
OutputDebugString (buf);
for (int i = 0; i < 3; i++)
if (std[i][0])
{
path_conv pc;
HANDLE h = GetStdHandle (std_consts[i]);
fhandler_base *fh = build_fhandler_from_name (i, std[i], NULL, pc);
if (!fh)
continue;
if (!fh->open (&pc, (i ? O_WRONLY : O_RDONLY) | O_BINARY, 0777))
release (i);
else
CloseHandle (h);
}
}
}
/* Initialize the file descriptor/handle mapping table.
This function should only be called when a cygwin function is invoked
by a non-cygwin function, i.e., it should only happen very rarely. */
void
dtable::stdio_init ()
{
extern void set_console_ctty ();
/* Set these before trying to output anything from strace.
Also, always set them even if we're to pick up our parent's fds
in case they're missed. */
if (myself->ppid_handle || ISSTATE (myself, PID_CYGPARENT))
return;
HANDLE in = GetStdHandle (STD_INPUT_HANDLE);
HANDLE out = GetStdHandle (STD_OUTPUT_HANDLE);
HANDLE err = GetStdHandle (STD_ERROR_HANDLE);
init_std_file_from_handle (0, in);
/* STD_ERROR_HANDLE has been observed to be the same as
STD_OUTPUT_HANDLE. We need separate handles (e.g. using pipes
to pass data from child to parent). */
if (out == err)
{
/* Since this code is not invoked for forked tasks, we don't have
to worry about the close-on-exec flag here. */
if (!DuplicateHandle (hMainProc, out, hMainProc, &err, 0,
1, DUPLICATE_SAME_ACCESS))
{
/* If that fails, do this as a fall back. */
err = out;
system_printf ("couldn't make stderr distinct from stdout");
}
}
init_std_file_from_handle (1, out);
init_std_file_from_handle (2, err);
/* Assign the console as the controlling tty for this process if we actually
have a console and no other controlling tty has been assigned. */
if (myself->ctty < 0 && GetConsoleCP () > 0)
set_console_ctty ();
}
int
dtable::find_unused_handle (int start)
{
AssertResourceOwner (LOCK_FD_LIST, READ_LOCK);
do
{
for (size_t i = start; i < size; i++)
/* See if open -- no need for overhead of not_open */
if (fds[i] == NULL)
return i;
}
while (extend (NOFILE_INCR));
return -1;
}
void
dtable::release (int fd)
{
if (!not_open (fd))
{
switch (fds[fd]->get_device ())
{
case FH_SOCKET:
dec_need_fixup_before ();
break;
case FH_CONSOLE:
dec_console_fds ();
break;
}
delete fds[fd];
fds[fd] = NULL;
}
}
extern "C" int
cygwin_attach_handle_to_fd (char *name, int fd, HANDLE handle, mode_t bin,
DWORD myaccess)
{
if (fd == -1)
fd = cygheap->fdtab.find_unused_handle ();
path_conv pc;
fhandler_base *res = cygheap->fdtab.build_fhandler_from_name (fd, name, handle,
pc);
res->init (handle, myaccess, bin ?: pc.binmode ());
return fd;
}
void
dtable::init_std_file_from_handle (int fd, HANDLE handle)
{
const char *name;
CONSOLE_SCREEN_BUFFER_INFO buf;
struct sockaddr sa;
int sal = sizeof (sa);
DCB dcb;
unsigned bin = O_BINARY;
first_fd_for_open = 0;
if (!not_open (fd))
return;
SetLastError (0);
DWORD ft = GetFileType (handle);
if (ft == FILE_TYPE_UNKNOWN && GetLastError () == ERROR_INVALID_HANDLE)
name = NULL;
else
{
/* See if we can consoleify it */
if (GetConsoleScreenBufferInfo (handle, &buf))
{
if (ISSTATE (myself, PID_USETTY))
name = "/dev/tty";
else
name = "/dev/conout";
}
else if (GetNumberOfConsoleInputEvents (handle, (DWORD *) &buf))
{
if (ISSTATE (myself, PID_USETTY))
name = "/dev/tty";
else
name = "/dev/conin";
}
else if (ft == FILE_TYPE_PIPE)
{
if (fd == 0)
name = "/dev/piper";
else
name = "/dev/pipew";
}
else if (wsock_started && getpeername ((SOCKET) handle, &sa, &sal) == 0)
name = "/dev/socket";
else if (GetCommState (handle, &dcb))
name = "/dev/ttyS0"; // FIXME - determine correct device
else
{
name = handle_to_fn (handle, (char *) alloca (MAX_PATH + 100));
bin = 0;
}
}
if (!name)
fds[fd] = NULL;
else
{
path_conv pc;
fhandler_base *fh = build_fhandler_from_name (fd, name, handle, pc);
if (!bin)
{
bin = fh->get_default_fmode (O_RDWR);
if (!bin && name != unknown_file)
bin = pc.binmode ();
}
fh->init (handle, GENERIC_READ | GENERIC_WRITE, bin);
set_std_handle (fd);
paranoid_printf ("fd %d, handle %p", fd, handle);
}
}
fhandler_base *
dtable::build_fhandler_from_name (int fd, const char *name, HANDLE handle,
path_conv& pc, unsigned opt, suffix_info *si)
{
pc.check (name, opt | PC_NULLEMPTY | PC_FULL | PC_POSIX, si);
if (pc.error)
{
set_errno (pc.error);
return NULL;
}
if (!pc.exists () && handle)
pc.fillin (handle);
fhandler_base *fh = build_fhandler (fd, pc.get_devn (),
pc.return_and_clear_normalized_path (),
pc, pc.get_unitn ());
return fh;
}
fhandler_base *
dtable::build_fhandler (int fd, DWORD dev, const char *unix_name,
const char *win32_name, int unit)
{
return build_fhandler (fd, dev, cstrdup (unix_name), win32_name, unit);
}
#define cnew(name) new ((void *) ccalloc (HEAP_FHANDLER, 1, sizeof (name))) name
fhandler_base *
dtable::build_fhandler (int fd, DWORD dev, char *unix_name,
const char *win32_name, int unit)
{
fhandler_base *fh;
dev &= FH_DEVMASK;
switch (dev)
{
case FH_TTYM:
fh = cnew (fhandler_tty_master) (unit);
break;
case FH_CONSOLE:
case FH_CONIN:
case FH_CONOUT:
if ((fh = cnew (fhandler_console) ()))
inc_console_fds ();
break;
case FH_PTYM:
fh = cnew (fhandler_pty_master) ();
break;
case FH_TTYS:
if (unit < 0)
fh = cnew (fhandler_tty_slave) ();
else
fh = cnew (fhandler_tty_slave) (unit);
break;
case FH_WINDOWS:
fh = cnew (fhandler_windows) ();
break;
case FH_SERIAL:
fh = cnew (fhandler_serial) (unit);
break;
case FH_PIPE:
case FH_PIPER:
case FH_PIPEW:
fh = cnew (fhandler_pipe) (dev);
break;
case FH_SOCKET:
if ((fh = cnew (fhandler_socket) ()))
inc_need_fixup_before ();
break;
case FH_DISK:
fh = cnew (fhandler_disk_file) ();
break;
case FH_CYGDRIVE:
fh = cnew (fhandler_cygdrive) (unit);
break;
case FH_FLOPPY:
fh = cnew (fhandler_dev_floppy) (unit);
break;
case FH_TAPE:
fh = cnew (fhandler_dev_tape) (unit);
break;
case FH_NULL:
fh = cnew (fhandler_dev_null) ();
break;
case FH_ZERO:
fh = cnew (fhandler_dev_zero) ();
break;
case FH_RANDOM:
fh = cnew (fhandler_dev_random) (unit);
break;
case FH_MEM:
fh = cnew (fhandler_dev_mem) (unit);
break;
case FH_CLIPBOARD:
fh = cnew (fhandler_dev_clipboard) ();
break;
case FH_OSS_DSP:
fh = cnew (fhandler_dev_dsp) ();
break;
case FH_PROC:
fh = cnew (fhandler_proc) ();
break;
case FH_REGISTRY:
fh = cnew (fhandler_registry) ();
break;
case FH_PROCESS:
fh = cnew (fhandler_process) ();
break;
default:
system_printf ("internal error -- unknown device - %p", dev);
fh = NULL;
}
if (unix_name)
{
char new_win32_name[strlen (unix_name) + 1];
if (!win32_name)
{
char *p;
/* FIXME: ? Should we call win32_device_name here?
It seems like overkill, but... */
win32_name = strcpy (new_win32_name, unix_name);
for (p = (char *) win32_name; (p = strchr (p, '/')); p++)
*p = '\\';
}
fh->set_name (unix_name, win32_name, fh->get_unit ());
}
debug_printf ("fd %d, fh %p", fd, fh);
return fd >= 0 ? (fds[fd] = fh) : fh;
}
fhandler_base *
dtable::dup_worker (fhandler_base *oldfh)
{
fhandler_base *newfh = build_fhandler (-1, oldfh->get_device ());
*newfh = *oldfh;
newfh->set_io_handle (NULL);
if (oldfh->dup (newfh))
{
cfree (newfh);
newfh = NULL;
return NULL;
}
newfh->set_close_on_exec_flag (0);
MALLOC_CHECK;
debug_printf ("duped '%s' old %p, new %p", oldfh->get_name (), oldfh->get_io_handle (), newfh->get_io_handle ());
return newfh;
}
int
dtable::dup2 (int oldfd, int newfd)
{
int res = -1;
fhandler_base *newfh = NULL; // = NULL to avoid an incorrect warning
MALLOC_CHECK;
debug_printf ("dup2 (%d, %d)", oldfd, newfd);
SetResourceLock (LOCK_FD_LIST, WRITE_LOCK | READ_LOCK, "dup");
if (not_open (oldfd))
{
syscall_printf ("fd %d not open", oldfd);
set_errno (EBADF);
goto done;
}
if (newfd < 0)
{
syscall_printf ("new fd out of bounds: %d", newfd);
set_errno (EBADF);
goto done;
}
if (newfd == oldfd)
{
res = 0;
goto done;
}
if ((newfh = dup_worker (fds[oldfd])) == NULL)
{
res = -1;
goto done;
}
debug_printf ("newfh->io_handle %p, oldfh->io_handle %p",
newfh->get_io_handle (), fds[oldfd]->get_io_handle ());
if (!not_open (newfd))
close (newfd);
else if ((size_t) newfd < size)
/* nothing to do */;
else if (find_unused_handle (newfd) < 0)
{
newfh->close ();
res = -1;
goto done;
}
fds[newfd] = newfh;
if ((res = newfd) <= 2)
set_std_handle (res);
done:
MALLOC_CHECK;
ReleaseResourceLock (LOCK_FD_LIST, WRITE_LOCK | READ_LOCK, "dup");
syscall_printf ("%d = dup2 (%d, %d)", res, oldfd, newfd);
return res;
}
select_record *
dtable::select_read (int fd, select_record *s)
{
if (not_open (fd))
{
set_errno (EBADF);
return NULL;
}
fhandler_base *fh = fds[fd];
s = fh->select_read (s);
s->fd = fd;
s->fh = fh;
s->saw_error = 0;
debug_printf ("%s fd %d", fh->get_name (), fd);
return s;
}
select_record *
dtable::select_write (int fd, select_record *s)
{
if (not_open (fd))
{
set_errno (EBADF);
return NULL;
}
fhandler_base *fh = fds[fd];
s = fh->select_write (s);
s->fd = fd;
s->fh = fh;
s->saw_error = 0;
debug_printf ("%s fd %d", fh->get_name (), fd);
return s;
}
select_record *
dtable::select_except (int fd, select_record *s)
{
if (not_open (fd))
{
set_errno (EBADF);
return NULL;
}
fhandler_base *fh = fds[fd];
s = fh->select_except (s);
s->fd = fd;
s->fh = fh;
s->saw_error = 0;
debug_printf ("%s fd %d", fh->get_name (), fd);
return s;
}
/* Function to walk the fd table after an exec and perform
per-fhandler type fixups. */
void
dtable::fixup_before_fork (DWORD target_proc_id)
{
SetResourceLock (LOCK_FD_LIST, WRITE_LOCK | READ_LOCK, "fixup_before_fork");
fhandler_base *fh;
for (size_t i = 0; i < size; i++)
if ((fh = fds[i]) != NULL)
{
debug_printf ("fd %d (%s)", i, fh->get_name ());
fh->fixup_before_fork_exec (target_proc_id);
}
ReleaseResourceLock (LOCK_FD_LIST, WRITE_LOCK | READ_LOCK, "fixup_before_fork");
}
void
dtable::fixup_before_exec (DWORD target_proc_id)
{
SetResourceLock (LOCK_FD_LIST, WRITE_LOCK | READ_LOCK, "fixup_before_exec");
fhandler_base *fh;
for (size_t i = 0; i < size; i++)
if ((fh = fds[i]) != NULL && !fh->get_close_on_exec ())
{
debug_printf ("fd %d (%s)", i, fh->get_name ());
fh->fixup_before_fork_exec (target_proc_id);
}
ReleaseResourceLock (LOCK_FD_LIST, WRITE_LOCK | READ_LOCK, "fixup_before_exec");
}
void
dtable::set_file_pointers_for_exec ()
{
SetResourceLock (LOCK_FD_LIST, WRITE_LOCK | READ_LOCK, "set_file_pointers_for_exec");
fhandler_base *fh;
for (size_t i = 0; i < size; i++)
if ((fh = fds[i]) != NULL && fh->get_flags () & O_APPEND)
SetFilePointer (fh->get_handle (), 0, 0, FILE_END);
ReleaseResourceLock (LOCK_FD_LIST, WRITE_LOCK | READ_LOCK, "fixup_before_exec");
}
void
dtable::fixup_after_exec (HANDLE parent)
{
first_fd_for_open = 0;
fhandler_base *fh;
for (size_t i = 0; i < size; i++)
if ((fh = fds[i]) != NULL)
{
fh->clear_readahead ();
if (fh->get_close_on_exec ())
release (i);
else
{
fh->fixup_after_exec (parent);
if (i == 0)
SetStdHandle (std_consts[i], fh->get_io_handle ());
else if (i <= 2)
SetStdHandle (std_consts[i], fh->get_output_handle ());
}
}
}
void
dtable::fixup_after_fork (HANDLE parent)
{
fhandler_base *fh;
for (size_t i = 0; i < size; i++)
if ((fh = fds[i]) != NULL)
{
if (fh->get_close_on_exec () || fh->get_need_fork_fixup ())
{
debug_printf ("fd %d (%s)", i, fh->get_name ());
fh->fixup_after_fork (parent);
}
if (i == 0)
SetStdHandle (std_consts[i], fh->get_io_handle ());
else if (i <= 2)
SetStdHandle (std_consts[i], fh->get_output_handle ());
}
}
int
dtable::vfork_child_dup ()
{
fhandler_base **newtable;
SetResourceLock (LOCK_FD_LIST, WRITE_LOCK | READ_LOCK, "dup");
newtable = (fhandler_base **) ccalloc (HEAP_ARGV, size, sizeof (fds[0]));
int res = 1;
/* Remove impersonation */
if (cygheap->user.issetuid ())
RevertToSelf ();
for (size_t i = 0; i < size; i++)
if (not_open (i))
continue;
else if ((newtable[i] = dup_worker (fds[i])) != NULL)
newtable[i]->set_close_on_exec (fds[i]->get_close_on_exec ());
else
{
res = 0;
set_errno (EBADF);
goto out;
}
fds_on_hold = fds;
fds = newtable;
out:
/* Restore impersonation */
if (cygheap->user.issetuid ())
ImpersonateLoggedOnUser (cygheap->user.token);
ReleaseResourceLock (LOCK_FD_LIST, WRITE_LOCK | READ_LOCK, "dup");
return 1;
}
void
dtable::vfork_parent_restore ()
{
SetResourceLock (LOCK_FD_LIST, WRITE_LOCK | READ_LOCK, "restore");
close_all_files ();
fhandler_base **deleteme = fds;
assert (fds_on_hold != NULL);
fds = fds_on_hold;
fds_on_hold = NULL;
cfree (deleteme);
ReleaseResourceLock (LOCK_FD_LIST, WRITE_LOCK | READ_LOCK, "restore");
return;
}
void
dtable::vfork_child_fixup ()
{
if (!fds_on_hold)
return;
debug_printf ("here");
fhandler_base **saveme = fds;
fds = fds_on_hold;
fhandler_base *fh;
for (int i = 0; i < (int) cygheap->fdtab.size; i++)
if ((fh = cygheap->fdtab[i]) != NULL)
{
fh->clear_readahead ();
if (fh->get_close_on_exec ())
release (i);
else
{
fh->close ();
cygheap->fdtab.release (i);
}
}
fds = saveme;
cfree (fds_on_hold);
fds_on_hold = NULL;
return;
}
#define DEVICE_PREFIX "\\device\\"
#define DEVICE_PREFIX_LEN sizeof (DEVICE_PREFIX) - 1
#define REMOTE "\\Device\\LanmanRedirector\\"
#define REMOTE_LEN sizeof (REMOTE) - 1
static const char *
handle_to_fn (HANDLE h, char *posix_fn)
{
OBJECT_NAME_INFORMATION *ntfn;
char fnbuf[32768];
memset (fnbuf, 0, sizeof (fnbuf));
ntfn = (OBJECT_NAME_INFORMATION *) fnbuf;
ntfn->Name.MaximumLength = sizeof (fnbuf) - sizeof (*ntfn);
ntfn->Name.Buffer = (WCHAR *) (ntfn + 1);
DWORD res = NtQueryObject (h, ObjectNameInformation, ntfn, sizeof (fnbuf), NULL);
if (res)
{
strcpy (posix_fn, unknown_file);
debug_printf ("NtQueryObject failed");
return unknown_file;
}
// NT seems to do this on an unopened file
if (!ntfn->Name.Buffer)
{
debug_printf ("nt->Name.Buffer == NULL");
return NULL;
}
ntfn->Name.Buffer[ntfn->Name.Length / sizeof (WCHAR)] = 0;
char win32_fn[MAX_PATH + 100];
sys_wcstombs (win32_fn, ntfn->Name.Buffer, ntfn->Name.Length);
debug_printf ("nt name '%s'", win32_fn);
if (!strncasematch (win32_fn, DEVICE_PREFIX, DEVICE_PREFIX_LEN)
|| !QueryDosDevice (NULL, fnbuf, sizeof (fnbuf)))
return strcpy (posix_fn, win32_fn);
char *p = strchr (win32_fn + DEVICE_PREFIX_LEN, '\\');
if (!p)
p = strchr (win32_fn + DEVICE_PREFIX_LEN, '\0');
int n = p - win32_fn;
int maxmatchlen = 0;
char *maxmatchdos = NULL;
for (char *s = fnbuf; *s; s = strchr (s, '\0') + 1)
{
char device[MAX_PATH + 10];
device[MAX_PATH + 9] = '\0';
if (strchr (s, ':') == NULL)
continue;
if (!QueryDosDevice (s, device, sizeof (device) - 1))
continue;
char *q = strrchr (device, ';');
if (q)
{
char *r = strchr (q, '\\');
if (r)
strcpy (q, r + 1);
}
int devlen = strlen (device);
if (device[devlen - 1] == '\\')
device[--devlen] = '\0';
if (devlen < maxmatchlen)
continue;
if (!strncasematch (device, win32_fn, devlen) ||
(win32_fn[devlen] != '\0' && win32_fn[devlen] != '\\'))
continue;
maxmatchlen = devlen;
maxmatchdos = s;
debug_printf ("current match '%s'", device);
}
char *w32 = win32_fn;
if (maxmatchlen)
{
n = strlen (maxmatchdos);
if (maxmatchdos[n - 1] == '\\')
n--;
w32 += maxmatchlen - n;
memcpy (w32, maxmatchdos, n);
w32[n] = '\\';
}
else if (strncasematch (w32, REMOTE, REMOTE_LEN))
{
w32 += REMOTE_LEN - 2;
*w32 = '\\';
debug_printf ("remote drive");
}
debug_printf ("derived path '%s'", w32);
cygwin_conv_to_full_posix_path (w32, posix_fn);
return posix_fn;
}