Differential D25978 Diff 75790 tools/build/cross-build/closefrom.c

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tools/build/cross-build/closefrom.c

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				/*
				* Copyright (c) 2004-2005, 2007, 2010, 2012-2014
				* Todd C. Miller <Todd.Miller@courtesan.com>
				*
				* Permission to use, copy, modify, and distribute this software for any
				* purpose with or without fee is hereby granted, provided that the above
				* copyright notice and this permission notice appear in all copies.
				*
				* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
				* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
				* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
				* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
				* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
				* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
				* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
				*/

				// #include <config.h>

				#include <sys/types.h>
				#include <unistd.h>
				#include <stdio.h>
				#ifdef STDC_HEADERS
				# include <stdlib.h>
				# include <stddef.h>
				#else
				# ifdef HAVE_STDLIB_H
				# include <stdlib.h>
				# endif
				#endif /* STDC_HEADERS */
				#include <fcntl.h>
				#include <limits.h>
				#ifdef HAVE_PSTAT_GETPROC
				# include <sys/param.h>
				# include <sys/pstat.h>
				#else
				# ifdef HAVE_DIRENT_H
				# include <dirent.h>
				# define NAMLEN(dirent) strlen((dirent)->d_name)
				# else
				# define dirent direct
				# define NAMLEN(dirent) (dirent)->d_namlen
				# ifdef HAVE_SYS_NDIR_H
				# include <sys/ndir.h>
				# endif
				# ifdef HAVE_SYS_DIR_H
				# include <sys/dir.h>
				# endif
				# ifdef HAVE_NDIR_H
				# include <ndir.h>
				# endif
				# endif
				#endif

				#ifndef OPEN_MAX
				# define OPEN_MAX 256
				#endif

				#if defined(HAVE_FCNTL_CLOSEM) && !defined(HAVE_DIRFD)
				# define closefrom closefrom_fallback
				#endif

				static inline void
				closefrom_close(int fd)
				{
				#ifdef __APPLE__
				/* Avoid potential libdispatch crash when we close its fds. */
				(void)fcntl(fd, F_SETFD, FD_CLOEXEC);
				#else
				(void)close(fd);
				#endif
				}

				/*
				* Close all file descriptors greater than or equal to lowfd.
				* This is the expensive (fallback) method.
				*/
				void
				closefrom_fallback(int lowfd)
				{
				long fd, maxfd;

				/*
				* Fall back on sysconf() or getdtablesize(). We avoid checking
				* resource limits since it is possible to open a file descriptor
				* and then drop the rlimit such that it is below the open fd.
				*/
				#ifdef HAVE_SYSCONF
				maxfd = sysconf(_SC_OPEN_MAX);
				#else
				maxfd = getdtablesize();
				#endif /* HAVE_SYSCONF */
				if (maxfd < 0)
				maxfd = OPEN_MAX;

				for (fd = lowfd; fd < maxfd; fd++)
				closefrom_close(fd);
				}

				/*
				* Close all file descriptors greater than or equal to lowfd.
				* We try the fast way first, falling back on the slow method.
				*/
				#if defined(HAVE_FCNTL_CLOSEM)
				void
				closefrom(int lowfd)
				{
				if (fcntl(lowfd, F_CLOSEM, 0) == -1)
				closefrom_fallback(lowfd);
				}
				#elif defined(HAVE_PSTAT_GETPROC)
				void
				closefrom(int lowfd)
				{
				struct pst_status pstat;
				int fd;

				if (pstat_getproc(&pstat, sizeof(pstat), 0, getpid()) != -1) {
				for (fd = lowfd; fd <= pstat.pst_highestfd; fd++)
				(void)close(fd);
				} else {
				closefrom_fallback(lowfd);
				}
				}
				#elif defined(HAVE_DIRFD)
				static int
				closefrom_procfs(int lowfd)
				{
				const char *path;
				DIR *dirp;
				struct dirent *dent;
				int *fd_array = NULL;
				int fd_array_used = 0;
				int fd_array_size = 0;
				int ret = 0;
				int i;

				/* Use /proc/self/fd (or /dev/fd on FreeBSD) if it exists. */
				# if defined(__FreeBSD__) \|\| defined(__FreeBSD_kernel__) \|\| defined(__APPLE__)
				path = "/dev/fd";
				# else
				path = "/proc/self/fd";
				# endif
				dirp = opendir(path);
				if (dirp == NULL)
				return -1;

				while ((dent = readdir(dirp)) != NULL) {
				const char *errstr;
				int fd;

				fd = strtonum(dent->d_name, lowfd, INT_MAX, &errstr);
				if (errstr != NULL \|\| fd == dirfd(dirp))
				continue;

				if (fd_array_used >= fd_array_size) {
				int *ptr;

				if (fd_array_size > 0)
				fd_array_size *= 2;
				else
				fd_array_size = 32;

				ptr = reallocarray(fd_array, fd_array_size, sizeof(int));
				if (ptr == NULL) {
				ret = -1;
				break;
				}
				fd_array = ptr;
				}

				fd_array[fd_array_used++] = fd;
				}

				for (i = 0; i < fd_array_used; i++)
				closefrom_close(fd_array[i]);

				free(fd_array);
				(void)closedir(dirp);

				return ret;
				}

				void
				closefrom(int lowfd)
				{
				if (closefrom_procfs(lowfd) == 0)
				return;

				closefrom_fallback(lowfd);
				}
				#endif /* HAVE_FCNTL_CLOSEM */