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/* NBD client library in userspace
* Copyright Red Hat
*
* This library 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 of the License, or (at your option) any later version.
*
* This library 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 this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/* Test structured reply read callback. */
#include <config.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include <unistd.h>
#include <assert.h>
#include <stdbool.h>
#include <errno.h>
#include <libnbd.h>
/* Depends on structured-read.sh setting things up so that qemu-nbd
* exposes an image with a 512-byte hole at offset 2048 followed by a
* 512-byte data section containing all '1' bytes at offset 2560
* (non-zero offsets to test that everything is calculated correctly).
*/
static char rbuf[1024];
struct data {
bool df; /* input: true if DF flag was passed to request */
int count; /* input: count of expected remaining calls */
bool fail; /* input: true to return failure */
bool seen_hole; /* output: true if hole encountered */
bool seen_data; /* output: true if data encountered */
};
static int
read_cb (void *opaque,
const void *bufv, size_t count, uint64_t offset,
unsigned status, int *error)
{
struct data *data = opaque;
const char *buf = bufv;
/* The NBD spec allows chunks to be reordered; we are relying on the
* fact that qemu-nbd does not do so.
*/
assert (!*error || (data->fail && data->count == 1 && *error == EPROTO));
assert (data->count-- > 0);
switch (status) {
case LIBNBD_READ_DATA:
if (data->df) {
assert (buf == rbuf);
assert (count == 1024);
assert (offset == 2048);
assert (buf[0] == 0 && memcmp (buf, buf + 1, 511) == 0);
assert (buf[512] == 1 && memcmp (buf + 512, buf + 513, 511) == 0);
}
else {
assert (buf == rbuf + 512);
assert (count == 512);
assert (offset == 2048 + 512);
assert (buf[0] == 1 && memcmp (buf, buf + 1, 511) == 0);
}
assert (!data->seen_data);
data->seen_data = true;
break;
case LIBNBD_READ_HOLE:
assert (!data->df); /* Relies on qemu-nbd's behavior */
assert (buf == rbuf);
assert (count == 512);
assert (offset == 2048);
assert (buf[0] == 0 && memcmp (buf, buf + 1, 511) == 0);
assert (!data->seen_hole);
data->seen_hole = true;
break;
case LIBNBD_READ_ERROR:
/* For now, qemu-nbd cannot provoke this status. */
default:
assert (false);
}
if (data->fail) {
/* Something NBD servers can't send */
*error = data->count == 1 ? EPROTO : ECONNREFUSED;
return -1;
}
return 0;
}
int
main (int argc, char *argv[])
{
struct nbd_handle *nbd;
int64_t exportsize;
struct data data;
nbd_chunk_callback chunk_callback = { .callback = read_cb,
.user_data = &data };
char c;
if (argc < 2) {
fprintf (stderr, "%s qemu-nbd [args ...]\n", argv[0]);
exit (EXIT_FAILURE);
}
nbd = nbd_create ();
if (nbd == NULL) {
fprintf (stderr, "%s\n", nbd_get_error ());
exit (EXIT_FAILURE);
}
if (nbd_connect_systemd_socket_activation (nbd, &argv[1]) == -1) {
fprintf (stderr, "%s\n", nbd_get_error ());
exit (EXIT_FAILURE);
}
exportsize = nbd_get_size (nbd);
if (exportsize == -1) {
fprintf (stderr, "%s\n", nbd_get_error ());
exit (EXIT_FAILURE);
}
if (exportsize != 3072) {
fprintf (stderr, "unexpected file size\n");
exit (EXIT_FAILURE);
}
if (nbd_can_df (nbd) != 1) {
fprintf (stderr, "skipping test: qemu too old to use structured reads\n");
exit (77);
}
memset (rbuf, 2, sizeof rbuf);
data = (struct data) { .count = 2, };
if (nbd_pread_structured (nbd, rbuf, sizeof rbuf, 2048, chunk_callback, 0) ==
-1) {
fprintf (stderr, "%s\n", nbd_get_error ());
exit (EXIT_FAILURE);
}
assert (data.seen_data && data.seen_hole);
/* Repeat with DF flag. */
memset (rbuf, 2, sizeof rbuf);
data = (struct data) { .df = true, .count = 1, };
if (nbd_pread_structured (nbd, rbuf, sizeof rbuf, 2048, chunk_callback,
LIBNBD_CMD_FLAG_DF) == -1) {
fprintf (stderr, "%s\n", nbd_get_error ());
exit (EXIT_FAILURE);
}
assert (data.seen_data && !data.seen_hole);
/* Trigger a failed callback, to prove connection stays up. With
* reads, all chunks trigger a callback even after failure, but the
* first errno sticks.
*/
memset (rbuf, 2, sizeof rbuf);
data = (struct data) { .count = 2, .fail = true, };
if (nbd_pread_structured (nbd, rbuf, sizeof rbuf, 2048, chunk_callback, 0) !=
-1) {
fprintf (stderr, "unexpected pread callback success\n");
exit (EXIT_FAILURE);
}
assert (nbd_get_errno () == EPROTO && nbd_aio_is_ready (nbd));
assert (data.seen_data && data.seen_hole);
if (nbd_pread (nbd, &c, 1, 0, 0) == -1) {
fprintf (stderr, "%s\n", nbd_get_error ());
exit (EXIT_FAILURE);
}
if (nbd_shutdown (nbd, 0) == -1) {
fprintf (stderr, "%s\n", nbd_get_error ());
exit (EXIT_FAILURE);
}
nbd_close (nbd);
exit (EXIT_SUCCESS);
}
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