Use opendir(/proc/self/fd) when we don't have closefrom(). Fixes #1757

diff --git a/src/lib/misc.c b/src/lib/misc.c
index f062ecf..79bae9a 100644 (file)
--- a/src/lib/misc.c
+++ b/src/lib/misc.c
@@ -31,6 +31,24 @@ RCSID("$Id$")
 #include <pwd.h>
 #include <sys/uio.h>
 
+/*
+ *     Some versions of Linux don't have closefrom(), but they will
+ *     have /proc.
+ *
+ *     BSD systems will generally have closefrom(), but not proc.
+ *
+ *     If a system doesn't have closefrom() and isn't Linux, it
+ *     doesn't have /proc, either.  So don't waste time trying
+ *     to open /proc.
+ */
+#ifdef HAVE_DIRENT_H
+#ifdef __linux__
+#include <dirent.h>
+#else
+#undef HAVE_DIRENT_H
+#endif
+#endif
+
 #define FR_PUT_LE16(a, val)\
        do {\
                a[1] = ((uint16_t) (val)) >> 8;\
@@ -1359,6 +1377,9 @@ int closefrom(int fd)
 {
        int i;
        int maxfd = 256;
+#ifdef HAVE_DIRENT_H
+       DIR *dir;
+#endif
 
 #ifdef F_CLOSEM
        if (fcntl(fd, F_CLOSEM) == 0) {
@@ -1378,6 +1399,31 @@ int closefrom(int fd)
        }
 #endif
 
+#ifdef HAVE_DIRENT_H
+       /*
+        *      Use /proc/self/fd directory if it exists.
+        */
+       dir = opendir("/proc/self/fd");
+       if (dir != NULL) {
+               long my_fd;
+               char *endp;
+               struct dirent *dp;
+
+               while ((dp = readdir(dir)) != NULL) {
+                       my_fd = strtol(dp->d_name, &endp, 10);
+                       if (my_fd <= 0) continue;
+                       if ((dp->d_name != endp) && !*endp) continue;
+
+                       if (my_fd == dirfd(dir)) continue;
+                       if ((my_fd >= fd) && (my_fd <= maxfd)) {
+                               (void) close((int) fd);
+                       }
+               }
+               (void) closedir(dir);
+               return 0;
+       }
+#endif
+
 #ifdef F_MAXFD
 do_close:
 #endif