test-bus-memfd.c revision 7f96b1d8147b164bc7c8ce119aeea5fed6ceecb7
/*-*- 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 <sys/mman.h>
#include <sys/uio.h>
#include "log.h"
#include "macro.h"
#include "util.h"
#include "sd-memfd.h"
int main(int argc, char *argv[]) {
sd_memfd *m;
char *s, *name;
uint64_t sz;
int r, fd;
FILE *f;
char buf[3] = {};
struct iovec iov[3] = {};
char bufv[3][3] = {};
log_set_max_level(LOG_DEBUG);
r = sd_memfd_new(NULL, &m);
if (r == -ENOENT)
return EXIT_TEST_SKIP;
assert_se(r >= 0);
assert_se(sd_memfd_get_name(m, &name) >= 0);
log_info("name: %s", name);
free(name);
r = sd_memfd_map(m, 0, 12, (void**) &s);
assert_se(r >= 0);
strcpy(s, "----- world");
r = sd_memfd_set_sealed(m, 1);
assert_se(r == -ETXTBSY);
assert_se(write(sd_memfd_get_fd(m), "he", 2) == 2);
assert_se(write(sd_memfd_get_fd(m), "XXX", 3) == 3);
assert_se(streq(s, "heXXX world"));
/* fix "hello" */
assert_se(lseek(sd_memfd_get_fd(m), 2, SEEK_SET) == 2);
assert_se(write(sd_memfd_get_fd(m), "ll", 2) == 2);
assert_se(sd_memfd_get_file(m, &f) >= 0);
fputc('o', f);
fflush(f);
/* check content */
assert_se(streq(s, "hello world"));
assert_se(munmap(s, 12) == 0);
r = sd_memfd_get_sealed(m);
assert_se(r == 0);
r = sd_memfd_get_size(m, &sz);
assert_se(r >= 0);
assert_se(sz = page_size());
/* truncate it */
r = sd_memfd_set_size(m, 6);
assert_se(r >= 0);
/* get back new value */
r = sd_memfd_get_size(m, &sz);
assert_se(r >= 0);
assert_se(sz == 6);
r = sd_memfd_set_sealed(m, 1);
assert_se(r >= 0);
r = sd_memfd_get_sealed(m);
assert_se(r == 1);
fd = sd_memfd_dup_fd(m);
assert_se(fd >= 0);
sd_memfd_free(m);
/* new sd_memfd, same underlying memfd */
r = sd_memfd_make(fd, &m);
assert_se(r >= 0);
/* we did truncate it to 6 */
r = sd_memfd_get_size(m, &sz);
assert_se(r >= 0 && sz == 6);
/* map it, check content */
r = sd_memfd_map(m, 0, 12, (void **)&s);
assert_se(r >= 0);
/* we only see the truncated size */
assert_se(streq(s, "hello "));
/* it was already sealed */
r = sd_memfd_set_sealed(m, 1);
assert_se(r == -EALREADY);
/* we cannot break the seal, it is mapped */
r = sd_memfd_set_sealed(m, 0);
assert_se(r == -ETXTBSY);
/* unmap it; become the single owner */
assert_se(munmap(s, 12) == 0);
/* now we can do flip the sealing */
r = sd_memfd_set_sealed(m, 0);
assert_se(r == 0);
r = sd_memfd_get_sealed(m);
assert_se(r == 0);
r = sd_memfd_set_sealed(m, 1);
assert_se(r == 0);
r = sd_memfd_get_sealed(m);
assert_se(r == 1);
r = sd_memfd_set_sealed(m, 0);
assert_se(r == 0);
r = sd_memfd_get_sealed(m);
assert_se(r == 0);
/* seek at 2, read() 2 bytes */
assert_se(lseek(fd, 2, SEEK_SET) == 2);
assert_se(read(fd, buf, 2) == 2);
/* check content */
assert_se(memcmp(buf, "ll", 2) == 0);
/* writev it out*/
iov[0].iov_base = (char *)"ABC";
iov[0].iov_len = 3;
iov[1].iov_base = (char *)"DEF";
iov[1].iov_len = 3;
iov[2].iov_base = (char *)"GHI";
iov[2].iov_len = 3;
assert_se(pwritev(fd, iov, 3, 0) == 9);
/* readv it back */
iov[0].iov_base = bufv[0];
iov[0].iov_len = 3;
iov[1].iov_base = bufv[1];
iov[1].iov_len = 3;
iov[2].iov_base = bufv[2];
iov[2].iov_len = 3;
assert_se(preadv(fd, iov, 3, 0) == 9);
/* check content */
assert_se(memcmp(bufv[0], "ABC", 3) == 0);
assert_se(memcmp(bufv[1], "DEF", 3) == 0);
assert_se(memcmp(bufv[2], "GHI", 3) == 0);
sd_memfd_free(m);
return 0;
}