fdset.c revision 3cc2aff1abff9e34f9fec282d970204dc1eab6f1
/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
/***
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 <errno.h>
#include <dirent.h>
#include <fcntl.h>
#include "set.h"
#include "util.h"
#include "macro.h"
#include "fdset.h"
#include "sd-daemon.h"
#define MAKE_SET(s) ((Set*) s)
#define MAKE_FDSET(s) ((FDSet*) s)
/* Make sure we can distinguish 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(NULL));
}
int fdset_new_array(FDSet **ret, 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_consume(FDSet *s, int fd) {
int r;
assert(s);
assert(fd >= 0);
r = fdset_put(s, fd);
if (r <= 0)
safe_close(fd);
return r;
}
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_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);
}