newlib/winsup/cygwin/dtable.cc

602 lines
14 KiB
C++

/* hinfo.cc: file descriptor support.
Copyright 1996, 1997, 1998, 1999, 2000 Cygnus Solutions.
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 <errno.h>
#include <sys/socket.h>
#include <stdlib.h>
#include <stdio.h>
#include <ctype.h>
#include <unistd.h>
#include <fcntl.h>
#define Win32_Winsock
#include "winsup.h"
hinfo dtable;
/* Set aside space for the table of fds */
void
dtable_init (void)
{
if (!dtable.size)
dtable.extend(NOFILE_INCR);
}
void __stdcall
set_std_handle (int fd)
{
if (fd == 0)
SetStdHandle (STD_INPUT_HANDLE, dtable[fd]->get_handle ());
else if (fd == 1)
SetStdHandle (STD_OUTPUT_HANDLE, dtable[fd]->get_output_handle ());
else if (fd == 2)
SetStdHandle (STD_ERROR_HANDLE, dtable[fd]->get_output_handle ());
}
int
hinfo::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 **) calloc (new_size, sizeof newfds[0])))
{
debug_printf ("calloc failed");
return 0;
}
if (fds)
{
memcpy (newfds, fds, size * sizeof (fds[0]));
free (fds);
}
size = new_size;
fds = newfds;
debug_printf ("size %d, fds %p", size, fds);
return 1;
}
/* Initialize the file descriptor/handle mapping table.
We only initialize the parent table here. The child table is
initialized at each fork () call. */
void
hinfo_init (void)
{
/* 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 (!parent_alive && NOTSTATE(myself, PID_CYGPARENT))
{
HANDLE in = GetStdHandle (STD_INPUT_HANDLE);
HANDLE out = GetStdHandle (STD_OUTPUT_HANDLE);
HANDLE err = GetStdHandle (STD_ERROR_HANDLE);
dtable.init_std_file_from_handle (0, in, GENERIC_READ, "{stdin}");
/* 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");
}
}
dtable.init_std_file_from_handle (1, out, GENERIC_WRITE, "{stdout}");
dtable.init_std_file_from_handle (2, err, GENERIC_WRITE, "{stderr}");
}
}
int
hinfo::not_open (int fd)
{
SetResourceLock(LOCK_FD_LIST,READ_LOCK," not_open");
int res = fd < 0 || fd >= (int)size || fds[fd] == NULL;
ReleaseResourceLock(LOCK_FD_LIST,READ_LOCK," not open");
return res;
}
int
hinfo::find_unused_handle (int start)
{
AssertResourceOwner(LOCK_FD_LIST,READ_LOCK);
do
{
for (int i = start; i < (int) size; i++)
if (not_open (i))
return i;
}
while (extend (NOFILE_INCR));
return -1;
}
void
hinfo::release (int fd)
{
if (!not_open (fd))
{
MALLOC_CHECK;
delete (fds[fd]);
MALLOC_CHECK;
fds[fd] = NULL;
}
}
void
hinfo::init_std_file_from_handle (int fd, HANDLE handle,
DWORD myaccess, const char *name)
{
int bin = __fmode;
/* Check to see if we're being redirected - if not then
we open then as consoles */
if (fd == 0 || fd == 1 || fd == 2)
{
first_fd_for_open = 0;
/* See if we can consoleify it - if it is a console,
don't open it in binary. That will screw up our crlfs*/
CONSOLE_SCREEN_BUFFER_INFO buf;
if (GetConsoleScreenBufferInfo (handle, &buf))
{
bin = 0;
if (ISSTATE (myself, PID_USETTY))
name = "/dev/tty";
else
name = "/dev/conout";
}
else if (FlushConsoleInputBuffer (handle))
{
bin = 0;
if (ISSTATE (myself, PID_USETTY))
name = "/dev/tty";
else
name = "/dev/conin";
}
}
build_fhandler (fd, name, handle)->init (handle, myaccess, bin);
set_std_handle (fd);
paranoid_printf ("fd %d, handle %p", fd, handle);
}
extern "C"
int
cygwin_attach_handle_to_fd (char *name, int fd, HANDLE handle, mode_t bin,
DWORD myaccess)
{
if (fd == -1)
fd = dtable.find_unused_handle();
fhandler_base *res = dtable.build_fhandler (fd, name, handle);
res->init (handle, myaccess, bin);
return fd;
}
fhandler_base *
hinfo::build_fhandler (int fd, const char *name, HANDLE handle)
{
int unit;
DWORD devn;
if ((devn = get_device_number (name, unit)) == FH_BAD)
{
struct sockaddr sa;
int sal = sizeof (sa);
CONSOLE_SCREEN_BUFFER_INFO cinfo;
DCB dcb;
if (handle == NULL)
devn = FH_DISK;
else if (GetNumberOfConsoleInputEvents (handle, (DWORD *) &cinfo))
devn = FH_CONIN;
else if (GetConsoleScreenBufferInfo (handle, &cinfo))
devn= FH_CONOUT;
else if (wsock32_handle && getpeername ((SOCKET) handle, &sa, &sal))
devn = FH_SOCKET;
else if (GetFileType (handle) == FILE_TYPE_PIPE)
devn = FH_PIPE;
else if (GetCommState (handle, &dcb))
devn = FH_SERIAL;
else
devn = FH_DISK;
}
return build_fhandler (fd, devn, name, unit);
}
fhandler_base *
hinfo::build_fhandler (int fd, DWORD dev, const char *name, int unit)
{
fhandler_base *fh;
void *buf = calloc (1, sizeof (fhandler_union) + 100);
switch (dev & FH_DEVMASK)
{
case FH_TTYM:
fh = new (buf) fhandler_tty_master (name, unit);
break;
case FH_CONSOLE:
case FH_CONIN:
case FH_CONOUT:
fh = new (buf) fhandler_console (name);
break;
case FH_PTYM:
fh = new (buf) fhandler_pty_master (name);
break;
case FH_TTYS:
if (unit < 0)
fh = new (buf) fhandler_tty_slave (name);
else
fh = new (buf) fhandler_tty_slave (unit, name);
break;
case FH_WINDOWS:
fh = new (buf) fhandler_windows (name);
break;
case FH_SERIAL:
fh = new (buf) fhandler_serial (name, FH_SERIAL, unit);
break;
case FH_PIPE:
case FH_PIPER:
case FH_PIPEW:
fh = new (buf) fhandler_pipe (name);
break;
case FH_SOCKET:
fh = new (buf) fhandler_socket (name);
break;
case FH_DISK:
fh = new (buf) fhandler_disk_file (NULL);
break;
case FH_FLOPPY:
fh = new (buf) fhandler_dev_floppy (name, unit);
break;
case FH_TAPE:
fh = new (buf) fhandler_dev_tape (name, unit);
break;
case FH_NULL:
fh = new (buf) fhandler_dev_null (name);
break;
case FH_ZERO:
fh = new (buf) fhandler_dev_zero (name);
break;
default:
/* FIXME - this could recurse forever */
return build_fhandler (fd, name, NULL);
}
debug_printf ("%s - cb %d, fd %d, fh %p", fh->get_name () ?: "", fh->cb,
fd, fh);
return fd >= 0 ? (fds[fd] = fh) : fh;
}
fhandler_base *
hinfo::dup_worker (fhandler_base *oldfh)
{
fhandler_base *newfh = build_fhandler (-1, oldfh->get_device (), NULL);
*newfh = *oldfh;
newfh->set_io_handle (NULL);
if (oldfh->dup (newfh))
{
free (newfh);
newfh = NULL;
return NULL;
}
newfh->set_close_on_exec_flag (0);
MALLOC_CHECK;
return newfh;
}
int
hinfo::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);
if (not_open (oldfd))
{
syscall_printf("dup2: fd %d not open", oldfd);
set_errno (EBADF);
goto done;
}
if (newfd == oldfd)
{
res = 0;
goto done;
}
if ((newfh = dup_worker (fds[oldfd])) == NULL)
{
res = -1;
goto done;
}
SetResourceLock(LOCK_FD_LIST,WRITE_LOCK|READ_LOCK,"dup");
if (!not_open (newfd))
_close (newfd);
fds[newfd] = newfh;
ReleaseResourceLock(LOCK_FD_LIST,WRITE_LOCK|READ_LOCK,"dup");
MALLOC_CHECK;
if ((res = newfd) <= 2)
set_std_handle (res);
MALLOC_CHECK;
done:
syscall_printf ("%d = dup2 (%d, %d)", res, oldfd, newfd);
return res;
}
select_record *
hinfo::select_read (int fd, select_record *s)
{
if (dtable.not_open (fd))
{
set_errno (EBADF);
return NULL;
}
fhandler_base *fh = dtable[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 *
hinfo::select_write (int fd, select_record *s)
{
if (dtable.not_open (fd))
{
set_errno (EBADF);
return NULL;
}
fhandler_base *fh = dtable[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 *
hinfo::select_except (int fd, select_record *s)
{
if (dtable.not_open (fd))
{
set_errno (EBADF);
return NULL;
}
fhandler_base *fh = dtable[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 take an existant hinfo array
* and linearize it into a memory buffer.
* If memory buffer is NULL, it returns the size
* of memory buffer needed to do the linearization.
* On error returns -1.
*/
int
hinfo::linearize_fd_array (unsigned char *in_buf, int buflen)
{
/* If buf == NULL, just precalculate length */
if (in_buf == NULL)
{
buflen = sizeof (size_t);
for (int i = 0, max_used_fd = -1; i < (int)size; i++)
if (!not_open (i) && !fds[i]->get_close_on_exec ())
{
buflen += i - (max_used_fd + 1);
buflen += fds[i]->cb + strlen (fds[i]->get_name ()) + 1
+ strlen (fds[i]->get_win32_name ()) + 1;
max_used_fd = i;
}
debug_printf ("needed buflen %d", buflen);
return buflen;
}
debug_printf ("in_buf = %x, buflen = %d", in_buf, buflen);
/*
* Now linearize each open fd (write a 0xff byte for a closed fd).
* Write the name of the open fd first (null terminated). This
* allows the de_linearizeing code to determine what kind of fhandler_xxx
* to create.
*/
size_t i;
int len, total_size;
total_size = sizeof (size_t);
if (total_size > buflen)
{
system_printf ("FATAL: linearize_fd_array exceeded buffer size");
return -1;
}
unsigned char *buf = in_buf;
buf += sizeof (size_t); /* skip over length which is added later */
for (i = 0, total_size = sizeof (size_t); total_size < buflen; i++)
{
if (not_open (i) || fds[i]->get_close_on_exec ())
{
debug_printf ("linearizing closed fd %d",i);
*buf = 0xff; /* place holder */
len = 1;
}
else
{
len = fds[i]->linearize (buf);
debug_printf ("fd %d, len %d, name %s, device %p", i, len, buf,
fds[i]->get_device ());
}
total_size += len;
buf += len;
}
i--;
memcpy (in_buf, &i, sizeof (size_t));
if (total_size != buflen)
system_printf ("out of sync %d != %d", total_size, buflen);
return total_size;
}
/*
* Function to take a linearized hinfo array in a memory buffer and
* re-create the original hinfo array.
*/
LPBYTE
hinfo::de_linearize_fd_array (LPBYTE buf)
{
int len;
size_t max_used_fd, inc_size;
debug_printf ("buf %x", buf);
/* First get the number of fd's - use this to set the dtablesize.
NB. This is the only place in the code this should be done !!
*/
memcpy ((char *) &max_used_fd, buf, sizeof (int));
buf += sizeof (size_t);
inc_size = NOFILE_INCR * ((max_used_fd + NOFILE_INCR - 1) / NOFILE_INCR) -
size;
debug_printf ("max_used_fd %d, inc size %d", max_used_fd, inc_size);
if (inc_size > 0 && !extend (inc_size))
{
system_printf ("out of memory");
return NULL;
}
for (size_t i = 0; i <= max_used_fd; i++)
{
/* 0xFF means closed */
if (*buf == 0xff)
{
fds[i] = NULL;
buf++;
debug_printf ("closed fd %d", i);
continue;
}
/* fd was open - de_linearize it */
/* Get the null-terminated name. It is followed by an image of
the actual fhandler_* structure. Use the status field from
this to build a new fhandler type. */
DWORD status;
LPBYTE obuf = buf;
char *win32;
win32 = strchr ((char *)obuf, '\0') + 1;
buf = (LPBYTE)strchr ((char *)win32, '\0') + 1;
memcpy ((char *)&status, buf + FHSTATOFF, sizeof(DWORD));
debug_printf ("fd %d, name %s, win32 name %s, status %p",
i, obuf, win32, status);
len = build_fhandler (i, status, (const char *) NULL)->
de_linearize ((char *) buf, (char *) obuf, win32);
set_std_handle (i);
buf += len;
debug_printf ("len %d", buf - obuf);
}
first_fd_for_open = 0;
return buf;
}
void
hinfo::fixup_after_fork (HANDLE parent)
{
SetResourceLock(LOCK_FD_LIST,WRITE_LOCK|READ_LOCK,"dup");
for (size_t i = 0; i < size; i++)
if (!not_open (i))
{
fhandler_base *fh = fds[i];
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);
}
}
ReleaseResourceLock(LOCK_FD_LIST,WRITE_LOCK|READ_LOCK,"dup");
}
int
hinfo::vfork_child_dup ()
{
fhandler_base **newtable;
newtable = (fhandler_base **) calloc (size, sizeof(fds[0]));
int res = 1;
SetResourceLock(LOCK_FD_LIST,WRITE_LOCK|READ_LOCK,"dup");
for (size_t i = 0; i < size; i++)
if (not_open (i))
continue;
else if ((newtable[i] = dup_worker (fds[i])) == NULL)
{
res = 0;
set_errno (EBADF);
goto out;
}
fds_on_hold = fds;
fds = newtable;
out:
ReleaseResourceLock(LOCK_FD_LIST,WRITE_LOCK|READ_LOCK,"dup");
return 1;
}
void
hinfo::vfork_parent_restore ()
{
SetResourceLock(LOCK_FD_LIST,WRITE_LOCK|READ_LOCK,"dup");
close_all_files ();
fhandler_base **deleteme = fds;
fds = fds_on_hold;
fds_on_hold = NULL;
free (deleteme);
ReleaseResourceLock(LOCK_FD_LIST,WRITE_LOCK|READ_LOCK,"dup");
return;
}