static char *
runv_get_output(const char *const *argv)
{
int pipefds[2];
if (pipe2(pipefds, O_CLOEXEC))
fatal_perror("pipe");
pid_t pid = spawn_with_redir(argv, -1, pipefds[1]);
close(pipefds[1]);
char *output = xreadall(pipefds[0]);
close(pipefds[0]);
int status;
if (waitpid(pid, &status, 0) != pid)
fatal_perror("waitpid");
fatal_if_unsuccessful_child(argv[0], status);
return output;
}
void nbd_client_main(void)
{
int sock = -1, nbd, flags;
unsigned long timeout = 0;
char *host=toys.optargs[0], *port=toys.optargs[1], *device=toys.optargs[2];
uint64_t devsize;
// Repeat until spanked
nbd = xopen(device, O_RDWR);
for (;;) {
int temp;
// Find and connect to server
sock = xconnect(xgetaddrinfo(host, port, AF_UNSPEC, SOCK_STREAM, 0, 0));
temp = 1;
setsockopt(sock, IPPROTO_TCP, TCP_NODELAY, &temp, sizeof(int));
// Read login data
xreadall(sock, toybuf, 152);
if (memcmp(toybuf, "NBDMAGIC\x00\x00\x42\x02\x81\x86\x12\x53", 16))
error_exit("bad login %s:%s", host, port);
devsize = SWAP_BE64(*(uint64_t *)(toybuf+16));
flags = SWAP_BE32(*(int *)(toybuf+24));
// Set 4k block size. Everything uses that these days.
ioctl(nbd, NBD_SET_BLKSIZE, 4096);
ioctl(nbd, NBD_SET_SIZE_BLOCKS, devsize/4096);
ioctl(nbd, NBD_CLEAR_SOCK);
// If the sucker was exported read only, respect that locally.
temp = (flags & 2) ? 1 : 0;
xioctl(nbd, BLKROSET, &temp);
if (timeout && ioctl(nbd, NBD_SET_TIMEOUT, timeout)<0) break;
if (ioctl(nbd, NBD_SET_SOCK, sock) < 0) break;
if (toys.optflags & FLAG_s) mlockall(MCL_CURRENT|MCL_FUTURE);
// Open the device to force reread of the partition table.
if ((toys.optflags & FLAG_n) || !xfork()) {
char *s = strrchr(device, '/');
int i;
sprintf(toybuf, "/sys/block/%.32s/pid", s ? s+1 : device);
// Is it up yet? (Give it 10 seconds.)
for (i=0; i<100; i++) {
temp = open(toybuf, O_RDONLY);
if (temp == -1) msleep(100);
else {
close(temp);
break;
}
}
close(open(device, O_RDONLY));
if (!(toys.optflags & FLAG_n)) exit(0);
}
// Daemonize here.
if (daemon(0,0)) perror_exit("daemonize");
// Process NBD requests until further notice.
if (ioctl(nbd, NBD_DO_IT)>=0 || errno==EBADR) break;
close(sock);
}
// Flush queue and exit.
ioctl(nbd, NBD_CLEAR_QUE);
ioctl(nbd, NBD_CLEAR_SOCK);
if (CFG_TOYBOX_FREE) close(nbd);
}
