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/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
/***
This file is part of systemd.
Copyright 2013 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 <stdio.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include "util.h"
#include "kdbus.h"
#include "sd-memfd.h"
struct sd_memfd {
int fd;
FILE *f;
};
_public_ int sd_memfd_new(sd_memfd **m) {
_cleanup_close_ int kdbus = -1;
sd_memfd *n;
int fd;
assert_return(m, -EINVAL);
kdbus = open("/dev/kdbus/control", O_RDWR|O_NOCTTY|O_CLOEXEC);
if (kdbus < 0)
return -errno;
if (ioctl(kdbus, KDBUS_CMD_MEMFD_NEW, &fd) < 0)
return -errno;
n = new0(struct sd_memfd, 1);
if (!n)
return -ENOMEM;
n->fd = fd;
*m = n;
return 0;
}
_public_ int sd_memfd_make(int fd, sd_memfd **m) {
sd_memfd *n;
uint64_t sz;
assert_return(m, -EINVAL);
assert_return(fd >= 0, -EINVAL);
/* Check if this is a valid memfd */
if (ioctl(fd, KDBUS_CMD_MEMFD_SIZE_GET, &sz) < 0)
return -ENOTTY;
n = new0(struct sd_memfd, 1);
if (!n)
return -ENOMEM;
n->fd = fd;
*m = n;
return 0;
}
_public_ void sd_memfd_free(sd_memfd *m) {
if (!m)
return;
if (m->f)
fclose(m->f);
else
close_nointr_nofail(m->fd);
free(m);
}
_public_ int sd_memfd_get_fd(sd_memfd *m) {
assert_return(m, -EINVAL);
return m->fd;
}
_public_ int sd_memfd_get_file(sd_memfd *m, FILE **f) {
assert_return(m, -EINVAL);
assert_return(f, -EINVAL);
if (!m->f) {
m->f = fdopen(m->fd, "r+");
if (!m->f)
return -errno;
}
*f = m->f;
return 0;
}
_public_ int sd_memfd_dup_fd(sd_memfd *m) {
int fd;
assert_return(m, -EINVAL);
fd = fcntl(m->fd, F_DUPFD_CLOEXEC, 3);
if (fd < 0)
return -errno;
return fd;
}
_public_ int sd_memfd_map(sd_memfd *m, uint64_t offset, size_t size, void **p) {
void *q;
int sealed;
assert_return(m, -EINVAL);
assert_return(size > 0, -EINVAL);
assert_return(p, -EINVAL);
sealed = sd_memfd_get_sealed(m);
if (sealed < 0)
return sealed;
q = mmap(NULL, size, sealed ? PROT_READ : PROT_READ|PROT_WRITE, MAP_SHARED, m->fd, offset);
if (q == MAP_FAILED)
return -errno;
*p = q;
return 0;
}
_public_ int sd_memfd_set_sealed(sd_memfd *m, int b) {
int r;
assert_return(m, -EINVAL);
r = ioctl(m->fd, KDBUS_CMD_MEMFD_SEAL_SET, b);
if (r < 0)
return -errno;
return 0;
}
_public_ int sd_memfd_get_sealed(sd_memfd *m) {
int r, b;
assert_return(m, -EINVAL);
r = ioctl(m->fd, KDBUS_CMD_MEMFD_SEAL_GET, &b);
if (r < 0)
return -errno;
return !!b;
}
_public_ int sd_memfd_get_size(sd_memfd *m, uint64_t *sz) {
int r;
assert_return(m, -EINVAL);
assert_return(sz, -EINVAL);
r = ioctl(m->fd, KDBUS_CMD_MEMFD_SIZE_GET, sz);
if (r < 0)
return -errno;
return r;
}
_public_ int sd_memfd_set_size(sd_memfd *m, uint64_t sz) {
int r;
assert_return(m, -EINVAL);
r = ioctl(m->fd, KDBUS_CMD_MEMFD_SIZE_SET, &sz);
if (r < 0)
return -errno;
return r;
}
_public_ int sd_memfd_new_and_map(sd_memfd **m, size_t sz, void **p) {
sd_memfd *n;
int r;
r = sd_memfd_new(&n);
if (r < 0)
return r;
r = sd_memfd_set_size(n, sz);
if (r < 0) {
sd_memfd_free(n);
return r;
}
r = sd_memfd_map(n, 0, sz, p);
if (r < 0) {
sd_memfd_free(n);
return r;
}
*m = n;
return 0;
}
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