Merge tag 'debian/1.8.5p2-1' into squeeze

[debian/sudo] / compat / closefrom.c

diff --git a/compat/closefrom.c b/compat/closefrom.c
new file mode 100644 (file)
index 0000000..71777e7
--- /dev/null
+++ b/compat/closefrom.c
@@ -0,0 +1,118 @@
+/*
+ * Copyright (c) 2004-2005, 2007, 2010
+ *     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 <sys/param.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>
+#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
+
+#include "missing.h"
+
+#ifndef HAVE_FCNTL_CLOSEM
+# ifndef HAVE_DIRFD
+#   define closefrom_fallback  closefrom
+# endif
+#endif
+
+/*
+ * Close all file descriptors greater than or equal to lowfd.
+ * This is the expensive (ballback) 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++)
+       (void) close((int) fd);
+}
+
+/*
+ * Close all file descriptors greater than or equal to lowfd.
+ * We try the fast way first, falling back on the slow method.
+ */
+#ifdef HAVE_FCNTL_CLOSEM
+void
+closefrom(int lowfd)
+{
+    if (fcntl(lowfd, F_CLOSEM, 0) == -1)
+       closefrom_fallback(lowfd);
+}
+#else
+# ifdef HAVE_DIRFD
+void
+closefrom(int lowfd)
+{
+    struct dirent *dent;
+    DIR *dirp;
+    char *endp;
+    long fd;
+
+    /* Use /proc/self/fd directory if it exists. */
+    if ((dirp = opendir("/proc/self/fd")) != NULL) {
+       while ((dent = readdir(dirp)) != NULL) {
+           fd = strtol(dent->d_name, &endp, 10);
+           if (dent->d_name != endp && *endp == '\0' &&
+               fd >= 0 && fd < INT_MAX && fd >= lowfd && fd != dirfd(dirp))
+               (void) close((int) fd);
+       }
+       (void) closedir(dirp);
+    } else
+       closefrom_fallback(lowfd);
+}
+#endif /* HAVE_DIRFD */
+#endif /* HAVE_FCNTL_CLOSEM */