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Diffstat (limited to 'src/libsystemd/sd-memfd.c')
-rw-r--r--src/libsystemd/sd-memfd.c216
1 files changed, 216 insertions, 0 deletions
diff --git a/src/libsystemd/sd-memfd.c b/src/libsystemd/sd-memfd.c
new file mode 100644
index 0000000000..cd95978ac2
--- /dev/null
+++ b/src/libsystemd/sd-memfd.c
@@ -0,0 +1,216 @@
+/*-*- 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;
+}