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/*
minfd.c
Author: David Mazieres <dm@lcs.mit.edu>
Contributed to be part of ssh.
Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
All rights reserved
Created: Tue Aug 22 17:25:30 1995 ylo
*/
#include "includes.h"
RCSID("$Id: minfd.c,v 1.2 1999/09/30 05:43:33 deraadt Exp $");
#include <sys/resource.h> /* Needed by fdlim.h */
#include "fdlim.h"
#include "minfd.h"
static int
_get_permanent_fd(const char *shellpath)
{
const char *shell;
struct passwd *pwd;
int fdmin;
int fdlim;
int fd;
int i;
if (!shellpath)
{
if (!shellpath)
shellpath = getenv("SHELL");
if (!shellpath)
if ((pwd = getpwuid(getuid())))
shellpath = pwd->pw_shell;
if (!shellpath)
shellpath = _PATH_BSHELL;
}
if ((shell = strrchr(shellpath, '/')))
shell++;
else
shell = shellpath;
for (i = 0; strcmp(mafd[i].shell, shell); i++)
if (i == MAFD_MAX - 1)
return -1;
fdmin = mafd[i].fd;
fdlim = fdlim_get(0);
if (fdmin < fdlim)
{
/* First try to find a file descriptor as high as possible without
upping the limit */
fd = fdlim - 1;
while (fd >= fdmin)
{
if (fcntl(fd, F_GETFL, NULL) < 0)
return fd;
fd--;
}
}
fd = fdlim;
for (;;)
{
if (fdlim_set(fd + 1) < 0)
return -1;
if (fcntl(fd, F_GETFL, NULL) < 0)
break;
fd++;
}
return fd;
}
int
get_permanent_fd(const char *shellpath)
{
static int fd = -2;
if (fd >= -1)
return fd;
fd = _get_permanent_fd(shellpath);
if (fd < 0)
fd = -1;
return fd;
}
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