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/* nbdkit
* Copyright Red Hat
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* * Neither the name of Red Hat nor the names of its contributors may be
* used to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY RED HAT AND CONTRIBUTORS ''AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
* PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL RED HAT OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <config.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include <unistd.h>
#include <poll.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/wait.h>
#include "array-size.h"
#include "internal.h"
#ifndef ENABLE_LIBFUZZER
#error "This file should only be compiled when libFuzzer is enabled"
#endif
/* When we're compiled with --enable-libfuzzer, the normal main()
* function is renamed to fuzzer_main. We call it with particular
* parameters to make it use the memory plugin.
*/
extern int fuzzer_main (int argc, char *argv[]);
static void server (int sock);
static void client (const uint8_t *data, size_t size, int sock);
/* This is the entry point called by libFuzzer. */
int
LLVMFuzzerTestOneInput (const uint8_t *data, size_t size)
{
pid_t pid;
int sv[2], r, status;
/* Create a connected socket. */
if (socketpair (AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC, 0, sv) == -1) {
perror ("socketpair");
exit (EXIT_FAILURE);
}
/* Fork: The parent will be the nbdkit process (server). The child
* will be the phony NBD client.
*/
pid = fork ();
if (pid == -1) {
perror ("fork");
exit (EXIT_FAILURE);
}
if (pid > 0) {
/* Parent: nbdkit server. */
close (sv[1]);
server (sv[0]);
close (sv[0]);
again:
r = wait (&status);
if (r == -1) {
if (errno == EINTR)
goto again;
perror ("wait");
exit (EXIT_FAILURE);
}
if (!WIFEXITED (status) || WEXITSTATUS (status) != 0)
fprintf (stderr, "bad exit status %d\n", status);
return 0;
}
/* Child: phony NBD client. */
close (sv[0]);
client (data, size, sv[1]);
close (sv[1]);
_exit (EXIT_SUCCESS);
}
static void
server (int sock)
{
char *argv[] = {
"nbdkit",
"-s", /* take input from stdin/stdout */
"--log=null", /* discard error messages */
"plugins/memory/.libs/nbdkit-memory-plugin." SOEXT, "1M",
NULL
};
const int argc = ARRAY_SIZE (argv) - 1;
int saved_stdin, saved_stdout;
/* Make the socket appear as stdin and stdout of the process, saving
* the existing stdin/stdout.
*/
saved_stdin = dup (0);
saved_stdout = dup (1);
dup2 (sock, 0);
dup2 (sock, 1);
/* Call nbdkit's normal main() function. */
fuzzer_main (argc, argv);
/* Restore stdin/stdout. */
dup2 (saved_stdin, 0);
dup2 (saved_stdout, 1);
close (saved_stdin);
close (saved_stdout);
}
static void
client (const uint8_t *data, size_t size, int sock)
{
struct pollfd pfds[1];
char rbuf[512];
ssize_t r;
if (size == 0)
shutdown (sock, SHUT_WR);
for (;;) {
pfds[0].fd = sock;
pfds[0].events = POLLIN;
if (size > 0) pfds[0].events |= POLLOUT;
pfds[0].revents = 0;
if (poll (pfds, 1, -1) == -1) {
if (errno == EINTR)
continue;
perror ("poll");
/* This is not an error. */
return;
}
/* We can read from the server socket. Just throw away anything sent. */
if ((pfds[0].revents & POLLIN) != 0) {
r = read (sock, rbuf, sizeof rbuf);
if (r == -1 && errno != EINTR) {
//perror ("read");
return;
}
else if (r == 0) /* end of input from the server */
return;
}
/* We can write to the server socket. */
if ((pfds[0].revents & POLLOUT) != 0) {
if (size > 0) {
r = write (sock, data, size);
if (r == -1 && errno != EAGAIN && errno != EWOULDBLOCK) {
perror ("write");
return;
}
else if (r > 0) {
data += r;
size -= r;
if (size == 0)
shutdown (sock, SHUT_WR);
}
}
}
} /* for (;;) */
}
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