reload: implement reload/reexec logic

[elogind.git] / fdset.c

diff --git a/fdset.c b/fdset.c
new file mode 100644 (file)
index 0000000..b6d5286
--- /dev/null
+++ b/fdset.c
@@ -0,0 +1,162 @@
+/*-*- Mode: C; c-basic-offset: 8 -*-*/
+
+/***
+  This file is part of systemd.
+
+  Copyright 2010 Lennart Poettering
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU General Public License as published by
+  the Free Software Foundation; either version 2 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <errno.h>
+#include <dirent.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+#include "set.h"
+#include "util.h"
+#include "macro.h"
+#include "fdset.h"
+
+#define MAKE_SET(s) ((Set*) s)
+#define MAKE_FDSET(s) ((FDSet*) s)
+
+/* Make sure we can distuingish fd 0 and NULL */
+#define FD_TO_PTR(fd) INT_TO_PTR((fd)+1)
+#define PTR_TO_FD(p) (PTR_TO_INT(p)-1)
+
+FDSet *fdset_new(void) {
+        return MAKE_FDSET(set_new(trivial_hash_func, trivial_compare_func));
+}
+
+void fdset_free(FDSet *s) {
+        void *p;
+
+        while ((p = set_steal_first(MAKE_SET(s)))) {
+                /* Valgrind's fd might have ended up in this set here,
+                 * due to fdset_new_fill(). We'll ignore all failures
+                 * here, so that the EBADFD that valgrind will return
+                 * us on close() doesn't influence us */
+
+                log_warning("Closing left-over fd %i", PTR_TO_FD(p));
+                close_nointr(PTR_TO_FD(p));
+        }
+
+        set_free(MAKE_SET(s));
+}
+
+int fdset_put(FDSet *s, int fd) {
+        assert(s);
+        assert(fd >= 0);
+
+        return set_put(MAKE_SET(s), FD_TO_PTR(fd));
+}
+
+int fdset_put_dup(FDSet *s, int fd) {
+        int copy, r;
+
+        assert(s);
+        assert(fd >= 0);
+
+        if ((copy = fcntl(fd, F_DUPFD_CLOEXEC, 3)) < 0)
+                return -errno;
+
+        if ((r = fdset_put(s, copy)) < 0) {
+                close_nointr_nofail(copy);
+                return r;
+        }
+
+        return copy;
+}
+
+bool fdset_contains(FDSet *s, int fd) {
+        assert(s);
+        assert(fd >= 0);
+
+        return !!set_get(MAKE_SET(s), FD_TO_PTR(fd));
+}
+
+int fdset_remove(FDSet *s, int fd) {
+        assert(s);
+        assert(fd >= 0);
+
+        return set_remove(MAKE_SET(s), FD_TO_PTR(fd)) ? fd : -ENOENT;
+}
+
+int fdset_new_fill(FDSet **_s) {
+        DIR *d;
+        struct dirent *de;
+        int r = 0;
+        FDSet *s;
+
+        assert(_s);
+
+        /* Creates an fdsets and fills in all currently open file
+         * descriptors. */
+
+        if (!(d = opendir("/proc/self/fd")))
+                return -errno;
+
+        if (!(s = fdset_new())) {
+                r = -ENOMEM;
+                goto finish;
+        }
+
+        while ((de = readdir(d))) {
+                int fd = -1;
+
+                if (ignore_file(de->d_name))
+                        continue;
+
+                if ((r = safe_atoi(de->d_name, &fd)) < 0)
+                        goto finish;
+
+                if (fd < 3)
+                        continue;
+
+                if (fd == dirfd(d))
+                        continue;
+
+                if ((r = fdset_put(s, fd)) < 0)
+                        goto finish;
+        }
+
+        r = 0;
+        *_s = s;
+        s = NULL;
+
+finish:
+        closedir(d);
+
+        /* We won't close the fds here! */
+        if (s)
+                set_free(MAKE_SET(s));
+
+        return r;
+
+}
+
+int fdset_cloexec(FDSet *fds, bool b) {
+        Iterator i;
+        void *p;
+        int r;
+
+        assert(fds);
+
+        SET_FOREACH(p, MAKE_SET(fds), i)
+                if ((r = fd_cloexec(PTR_TO_FD(p), b)) < 0)
+                        return r;
+
+        return 0;
+}