build-sys: move fdset.[ch] src/basic → src/shared (#3580)

It makes use of the sd_listen_fds() call, and as such should live in
src/shared, as the distinction between src/basic and src/shared is that the
latter may use libsystemd APIs, the former does not.

Note that btrfs-util.[ch] and log.[ch] also include header files from
libsystemd, but they only need definitions, they do not invoke any function
from it. Hence they may stay in src/basic.

2 files changed, 331 insertions, 0 deletions

diff --git a/src/shared/fdset.c b/src/shared/fdset.c
new file mode 100644
index 0000000000..527f27bc67
--- /dev/null
+++ b/src/shared/fdset.c
@@ -0,0 +1,273 @@
+/***
+  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 Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 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
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <alloca.h>
+#include <dirent.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stddef.h>
+
+#include "sd-daemon.h"
+
+#include "fd-util.h"
+#include "fdset.h"
+#include "log.h"
+#include "macro.h"
+#include "parse-util.h"
+#include "path-util.h"
+#include "set.h"
+
+#define MAKE_SET(s) ((Set*) s)
+#define MAKE_FDSET(s) ((FDSet*) s)
+
+FDSet *fdset_new(void) {
+        return MAKE_FDSET(set_new(NULL));
+}
+
+int fdset_new_array(FDSet **ret, const int *fds, unsigned n_fds) {
+        unsigned i;
+        FDSet *s;
+        int r;
+
+        assert(ret);
+
+        s = fdset_new();
+        if (!s)
+                return -ENOMEM;
+
+        for (i = 0; i < n_fds; i++) {
+
+                r = fdset_put(s, fds[i]);
+                if (r < 0) {
+                        set_free(MAKE_SET(s));
+                        return r;
+                }
+        }
+
+        *ret = s;
+        return 0;
+}
+
+FDSet* 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 */
+
+                /* When reloading duplicates of the private bus
+                 * connection fds and suchlike are closed here, which
+                 * has no effect at all, since they are only
+                 * duplicates. So don't be surprised about these log
+                 * messages. */
+
+                log_debug("Closing left-over fd %i", PTR_TO_FD(p));
+                close_nointr(PTR_TO_FD(p));
+        }
+
+        set_free(MAKE_SET(s));
+        return NULL;
+}
+
+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);
+
+        copy = fcntl(fd, F_DUPFD_CLOEXEC, 3);
+        if (copy < 0)
+                return -errno;
+
+        r = fdset_put(s, copy);
+        if (r < 0) {
+                safe_close(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) {
+        _cleanup_closedir_ DIR *d = NULL;
+        struct dirent *de;
+        int r = 0;
+        FDSet *s;
+
+        assert(_s);
+
+        /* Creates an fdset and fills in all currently open file
+         * descriptors. */
+
+        d = opendir("/proc/self/fd");
+        if (!d)
+                return -errno;
+
+        s = fdset_new();
+        if (!s) {
+                r = -ENOMEM;
+                goto finish;
+        }
+
+        while ((de = readdir(d))) {
+                int fd = -1;
+
+                if (hidden_or_backup_file(de->d_name))
+                        continue;
+
+                r = safe_atoi(de->d_name, &fd);
+                if (r < 0)
+                        goto finish;
+
+                if (fd < 3)
+                        continue;
+
+                if (fd == dirfd(d))
+                        continue;
+
+                r = fdset_put(s, fd);
+                if (r < 0)
+                        goto finish;
+        }
+
+        r = 0;
+        *_s = s;
+        s = NULL;
+
+finish:
+        /* 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) {
+                r = fd_cloexec(PTR_TO_FD(p), b);
+                if (r < 0)
+                        return r;
+        }
+
+        return 0;
+}
+
+int fdset_new_listen_fds(FDSet **_s, bool unset) {
+        int n, fd, r;
+        FDSet *s;
+
+        assert(_s);
+
+        /* Creates an fdset and fills in all passed file descriptors */
+
+        s = fdset_new();
+        if (!s) {
+                r = -ENOMEM;
+                goto fail;
+        }
+
+        n = sd_listen_fds(unset);
+        for (fd = SD_LISTEN_FDS_START; fd < SD_LISTEN_FDS_START + n; fd ++) {
+                r = fdset_put(s, fd);
+                if (r < 0)
+                        goto fail;
+        }
+
+        *_s = s;
+        return 0;
+
+
+fail:
+        if (s)
+                set_free(MAKE_SET(s));
+
+        return r;
+}
+
+int fdset_close_others(FDSet *fds) {
+        void *e;
+        Iterator i;
+        int *a;
+        unsigned j, m;
+
+        j = 0, m = fdset_size(fds);
+        a = alloca(sizeof(int) * m);
+        SET_FOREACH(e, MAKE_SET(fds), i)
+                a[j++] = PTR_TO_FD(e);
+
+        assert(j == m);
+
+        return close_all_fds(a, j);
+}
+
+unsigned fdset_size(FDSet *fds) {
+        return set_size(MAKE_SET(fds));
+}
+
+bool fdset_isempty(FDSet *fds) {
+        return set_isempty(MAKE_SET(fds));
+}
+
+int fdset_iterate(FDSet *s, Iterator *i) {
+        void *p;
+
+        if (!set_iterate(MAKE_SET(s), i, &p))
+                return -ENOENT;
+
+        return PTR_TO_FD(p);
+}
+
+int fdset_steal_first(FDSet *fds) {
+        void *p;
+
+        p = set_steal_first(MAKE_SET(fds));
+        if (!p)
+                return -ENOENT;
+
+        return PTR_TO_FD(p);
+}
diff --git a/src/shared/fdset.h b/src/shared/fdset.h
new file mode 100644
index 0000000000..16efe5bdf2
--- /dev/null
+++ b/src/shared/fdset.h
@@ -0,0 +1,58 @@
+#pragma once
+
+/***
+  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 Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 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
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <stdbool.h>
+
+#include "hashmap.h"
+#include "macro.h"
+#include "set.h"
+
+typedef struct FDSet FDSet;
+
+FDSet* fdset_new(void);
+FDSet* fdset_free(FDSet *s);
+
+int fdset_put(FDSet *s, int fd);
+int fdset_put_dup(FDSet *s, int fd);
+
+bool fdset_contains(FDSet *s, int fd);
+int fdset_remove(FDSet *s, int fd);
+
+int fdset_new_array(FDSet **ret, const int *fds, unsigned n_fds);
+int fdset_new_fill(FDSet **ret);
+int fdset_new_listen_fds(FDSet **ret, bool unset);
+
+int fdset_cloexec(FDSet *fds, bool b);
+
+int fdset_close_others(FDSet *fds);
+
+unsigned fdset_size(FDSet *fds);
+bool fdset_isempty(FDSet *fds);
+
+int fdset_iterate(FDSet *s, Iterator *i);
+
+int fdset_steal_first(FDSet *fds);
+
+#define FDSET_FOREACH(fd, fds, i) \
+        for ((i) = ITERATOR_FIRST, (fd) = fdset_iterate((fds), &(i)); (fd) >= 0; (fd) = fdset_iterate((fds), &(i)))
+
+DEFINE_TRIVIAL_CLEANUP_FUNC(FDSet*, fdset_free);
+#define _cleanup_fdset_free_ _cleanup_(fdset_freep)