static int
check_for_daemon_cancellation_or_eof (guestfs_h *g, int fd)
{
char summary[MAX_MESSAGE_SUMMARY];
char buf[4];
ssize_t n;
uint32_t flag;
XDR xdr;
n = really_read_from_socket (g, fd, buf, 4);
if (n == -1)
return -1;
if (n == 0) {
/* Hopefully this indicates the qemu child process has died. */
child_cleanup (g);
return -1;
}
debug (g, "check_for_daemon_cancellation_or_eof: %s",
message_summary (buf, 4, summary));
xdrmem_create (&xdr, buf, 4, XDR_DECODE);
xdr_uint32_t (&xdr, &flag);
xdr_destroy (&xdr);
/* Read and process progress messages that happen during FileIn. */
if (flag == GUESTFS_PROGRESS_FLAG) {
char buf[PROGRESS_MESSAGE_SIZE];
guestfs_progress message;
n = really_read_from_socket (g, fd, buf, PROGRESS_MESSAGE_SIZE);
if (n == -1)
return -1;
if (n == 0) {
child_cleanup (g);
return -1;
}
xdrmem_create (&xdr, buf, PROGRESS_MESSAGE_SIZE, XDR_DECODE);
xdr_guestfs_progress (&xdr, &message);
xdr_destroy (&xdr);
guestfs___progress_message_callback (g, &message);
return 0;
}
if (flag != GUESTFS_CANCEL_FLAG) {
error (g, _("check_for_daemon_cancellation_or_eof: read 0x%x from daemon, expected 0x%x\n"),
flag, GUESTFS_CANCEL_FLAG);
return -1;
}
return -2;
}
static int sdap_child_destructor(void *ptr)
{
struct sdap_child *child = talloc_get_type(ptr, struct sdap_child);
child_cleanup(child->read_from_child_fd, child->write_to_child_fd);
return 0;
}
int
guestfs___recv_from_daemon (guestfs_h *g, uint32_t *size_rtn, void **buf_rtn)
{
char summary[MAX_MESSAGE_SUMMARY];
fd_set rset, rset2;
FD_ZERO (&rset);
if (g->fd[1] >= 0) /* Read qemu stdout for log messages & EOF. */
FD_SET (g->fd[1], &rset);
FD_SET (g->sock, &rset); /* Read socket for data & EOF. */
int max_fd = MAX (g->sock, g->fd[1]);
*size_rtn = 0;
*buf_rtn = NULL;
char lenbuf[4];
/* nr is the size of the message, but we prime it as -4 because we
* have to read the message length word first.
*/
ssize_t nr = -4;
for (;;) {
ssize_t message_size =
*size_rtn != GUESTFS_PROGRESS_FLAG ?
*size_rtn : PROGRESS_MESSAGE_SIZE;
if (nr >= message_size)
break;
rset2 = rset;
int r = select (max_fd+1, &rset2, NULL, NULL, NULL);
if (r == -1) {
if (errno == EINTR || errno == EAGAIN)
continue;
perrorf (g, "select");
free (*buf_rtn);
*buf_rtn = NULL;
return -1;
}
if (g->fd[1] >= 0 && FD_ISSET (g->fd[1], &rset2)) {
if (read_log_message_or_eof (g, g->fd[1], 0) == -1) {
free (*buf_rtn);
*buf_rtn = NULL;
return -1;
}
}
if (FD_ISSET (g->sock, &rset2)) {
if (nr < 0) { /* Have we read the message length word yet? */
r = read (g->sock, lenbuf+nr+4, -nr);
if (r == -1) {
if (errno == EINTR || errno == EAGAIN)
continue;
int err = errno;
perrorf (g, "read");
/* Under some circumstances we see "Connection reset by peer"
* here when the child dies suddenly. Catch this and call
* the cleanup function, same as for EOF.
*/
if (err == ECONNRESET)
child_cleanup (g);
return -1;
}
if (r == 0) {
unexpected_end_of_file_from_daemon_error (g);
child_cleanup (g);
return -1;
}
nr += r;
if (nr < 0) /* Still not got the whole length word. */
continue;
XDR xdr;
xdrmem_create (&xdr, lenbuf, 4, XDR_DECODE);
xdr_uint32_t (&xdr, size_rtn);
xdr_destroy (&xdr);
/* *size_rtn changed, recalculate message_size */
message_size =
*size_rtn != GUESTFS_PROGRESS_FLAG ?
*size_rtn : PROGRESS_MESSAGE_SIZE;
if (*size_rtn == GUESTFS_LAUNCH_FLAG) {
if (g->state != LAUNCHING)
error (g, _("received magic signature from guestfsd, but in state %d"),
g->state);
else {
g->state = READY;
guestfs___call_callbacks_void (g, GUESTFS_EVENT_LAUNCH_DONE);
}
debug (g, "recv_from_daemon: received GUESTFS_LAUNCH_FLAG");
return 0;
}
else if (*size_rtn == GUESTFS_CANCEL_FLAG) {
debug (g, "recv_from_daemon: received GUESTFS_CANCEL_FLAG");
return 0;
}
else if (*size_rtn == GUESTFS_PROGRESS_FLAG)
/*FALLTHROUGH*/;
/* If this happens, it's pretty bad and we've probably lost
* synchronization.
*/
else if (*size_rtn > GUESTFS_MESSAGE_MAX) {
error (g, _("message length (%u) > maximum possible size (%d)"),
(unsigned) *size_rtn, GUESTFS_MESSAGE_MAX);
return -1;
}
/* Allocate the complete buffer, size now known. */
*buf_rtn = safe_malloc (g, message_size);
/*FALLTHROUGH*/
}
size_t sizetoread = message_size - nr;
if (sizetoread > BUFSIZ) sizetoread = BUFSIZ;
r = read (g->sock, (char *) (*buf_rtn) + nr, sizetoread);
if (r == -1) {
if (errno == EINTR || errno == EAGAIN)
continue;
perrorf (g, "read");
free (*buf_rtn);
*buf_rtn = NULL;
return -1;
}
if (r == 0) {
unexpected_end_of_file_from_daemon_error (g);
child_cleanup (g);
free (*buf_rtn);
*buf_rtn = NULL;
return -1;
}
nr += r;
}
}
/* Got the full message, caller can start processing it. */
#ifdef ENABLE_PACKET_DUMP
if (g->verbose) {
ssize_t i, j;
for (i = 0; i < nr; i += 16) {
printf ("%04zx: ", i);
for (j = i; j < MIN (i+16, nr); ++j)
printf ("%02x ", (*(unsigned char **)buf_rtn)[j]);
for (; j < i+16; ++j)
printf (" ");
printf ("|");
for (j = i; j < MIN (i+16, nr); ++j)
if (c_isprint ((*(char **)buf_rtn)[j]))
printf ("%c", (*(char **)buf_rtn)[j]);
else
printf (".");
for (; j < i+16; ++j)
printf (" ");
printf ("|\n");
}
}
#endif
if (*size_rtn == GUESTFS_PROGRESS_FLAG) {
guestfs_progress message;
XDR xdr;
xdrmem_create (&xdr, *buf_rtn, PROGRESS_MESSAGE_SIZE, XDR_DECODE);
xdr_guestfs_progress (&xdr, &message);
xdr_destroy (&xdr);
guestfs___progress_message_callback (g, &message);
free (*buf_rtn);
*buf_rtn = NULL;
/* Process next message. */
return guestfs___recv_from_daemon (g, size_rtn, buf_rtn);
}
debug (g, "recv_from_daemon: %" PRIu32 " bytes: %s", *size_rtn,
message_summary (*buf_rtn, *size_rtn, summary));
return 0;
}
/* This writes the whole N bytes of BUF to the daemon socket.
*
* If the whole write is successful, it returns 0.
* If there was an error, it returns -1.
* If the daemon sent a cancellation message, it returns -2.
*
* It also checks qemu stdout for log messages and passes those up
* through log_message_cb.
*
* It also checks for EOF (qemu died) and passes that up through the
* child_cleanup function above.
*/
int
guestfs___send_to_daemon (guestfs_h *g, const void *v_buf, size_t n)
{
const char *buf = v_buf;
fd_set rset, rset2;
fd_set wset, wset2;
char summary[MAX_MESSAGE_SUMMARY];
debug (g, "send_to_daemon: %zu bytes: %s", n,
message_summary (v_buf, n, summary));
FD_ZERO (&rset);
FD_ZERO (&wset);
if (g->fd[1] >= 0) /* Read qemu stdout for log messages & EOF. */
FD_SET (g->fd[1], &rset);
FD_SET (g->sock, &rset); /* Read socket for cancellation & EOF. */
FD_SET (g->sock, &wset); /* Write to socket to send the data. */
int max_fd = MAX (g->sock, g->fd[1]);
while (n > 0) {
rset2 = rset;
wset2 = wset;
int r = select (max_fd+1, &rset2, &wset2, NULL, NULL);
if (r == -1) {
if (errno == EINTR || errno == EAGAIN)
continue;
perrorf (g, "select");
return -1;
}
if (g->fd[1] >= 0 && FD_ISSET (g->fd[1], &rset2)) {
if (read_log_message_or_eof (g, g->fd[1], 0) == -1)
return -1;
}
if (FD_ISSET (g->sock, &rset2)) {
r = check_for_daemon_cancellation_or_eof (g, g->sock);
if (r == -1)
return r;
if (r == -2) {
/* Daemon sent cancel message. But to maintain
* synchronization we must write out the remainder of the
* write buffer before we return (RHBZ#576879).
*/
if (xwrite (g->sock, buf, n) == -1) {
perrorf (g, "write");
return -1;
}
return -2; /* cancelled */
}
}
if (FD_ISSET (g->sock, &wset2)) {
r = write (g->sock, buf, n);
if (r == -1) {
if (errno == EINTR || errno == EAGAIN)
continue;
perrorf (g, "write");
if (errno == EPIPE) /* Disconnected from guest (RHBZ#508713). */
child_cleanup (g);
return -1;
}
buf += r;
n -= r;
}
}
return 0;
}
static int
read_log_message_or_eof (guestfs_h *g, int fd, int error_if_eof)
{
char buf[BUFSIZ];
ssize_t n;
#if 0
debug (g, "read_log_message_or_eof: %p g->state = %d, fd = %d",
g, g->state, fd);
#endif
/* QEMU's console emulates a 16550A serial port. The real 16550A
* device has a small FIFO buffer (16 bytes) which means here we see
* lots of small reads of 1-16 bytes in length, usually single
* bytes. Sleeping here for a very brief period groups reads
* together (so we usually get a few lines of output at once) and
* improves overall throughput, as well as making the event
* interface a bit more sane for callers. With a virtio-serial
* based console (not yet implemented) we may be able to remove
* this. XXX
*/
usleep (1000);
n = read (fd, buf, sizeof buf);
if (n == 0) {
/* Hopefully this indicates the qemu child process has died. */
child_cleanup (g);
if (error_if_eof) {
/* We weren't expecting eof here (called from launch) so place
* something in the error buffer. RHBZ#588851.
*/
error (g, "child process died unexpectedly");
}
return -1;
}
if (n == -1) {
if (errno == EINTR || errno == EAGAIN)
return 0;
perrorf (g, "read");
return -1;
}
/* It's an actual log message, send it upwards if anyone is listening. */
guestfs___call_callbacks_message (g, GUESTFS_EVENT_APPLIANCE, buf, n);
/* This is a gross hack. See the comment above
* guestfs___launch_send_progress.
*/
if (g->state == LAUNCHING) {
const char *sentinel;
size_t len;
sentinel = "Linux version"; /* kernel up */
len = strlen (sentinel);
if (memmem (buf, n, sentinel, len) != NULL)
guestfs___launch_send_progress (g, 6);
sentinel = "Starting /init script"; /* /init running */
len = strlen (sentinel);
if (memmem (buf, n, sentinel, len) != NULL)
guestfs___launch_send_progress (g, 9);
}
return 0;
}
/**
* This function reads a single message, file chunk, launch flag or
* cancellation flag from the daemon. If something was read, it
* returns C<0>, otherwise C<-1>.
*
* Both C<size_rtn> and C<buf_rtn> must be passed by the caller as
* non-NULL.
*
* C<*size_rtn> returns the size of the returned message or it may be
* C<GUESTFS_LAUNCH_FLAG> or C<GUESTFS_CANCEL_FLAG>.
*
* C<*buf_rtn> is returned containing the message (if any) or will be
* set to C<NULL>. C<*buf_rtn> must be freed by the caller.
*
* This checks for EOF (appliance died) and passes that up through the
* child_cleanup function above.
*
* Log message, progress messages are handled transparently here.
*/
static int
recv_from_daemon (guestfs_h *g, uint32_t *size_rtn, void **buf_rtn)
{
char lenbuf[4];
ssize_t n;
XDR xdr;
size_t message_size;
*size_rtn = 0;
*buf_rtn = NULL;
/* RHBZ#914931: Along some (rare) paths, we might have closed the
* socket connection just before this function is called, so just
* return an error if this happens.
*/
if (!g->conn) {
guestfs_int_unexpected_close_error (g);
return -1;
}
/* Read the 4 byte size / flag. */
n = g->conn->ops->read_data (g, g->conn, lenbuf, 4);
if (n == -1)
return -1;
if (n == 0) {
guestfs_int_unexpected_close_error (g);
child_cleanup (g);
return -1;
}
xdrmem_create (&xdr, lenbuf, 4, XDR_DECODE);
xdr_uint32_t (&xdr, size_rtn);
xdr_destroy (&xdr);
if (*size_rtn == GUESTFS_LAUNCH_FLAG) {
if (g->state != LAUNCHING)
error (g, _("received magic signature from guestfsd, but in state %d"),
(int) g->state);
else {
g->state = READY;
guestfs_int_call_callbacks_void (g, GUESTFS_EVENT_LAUNCH_DONE);
}
debug (g, "recv_from_daemon: received GUESTFS_LAUNCH_FLAG");
return 0;
}
else if (*size_rtn == GUESTFS_CANCEL_FLAG) {
debug (g, "recv_from_daemon: received GUESTFS_CANCEL_FLAG");
return 0;
}
else if (*size_rtn == GUESTFS_PROGRESS_FLAG)
/*FALLTHROUGH*/;
else if (*size_rtn > GUESTFS_MESSAGE_MAX) {
/* If this happens, it's pretty bad and we've probably lost
* synchronization.
*/
error (g, _("message length (%u) > maximum possible size (%d)"),
(unsigned) *size_rtn, GUESTFS_MESSAGE_MAX);
return -1;
}
/* Calculate the message size. */
message_size =
*size_rtn != GUESTFS_PROGRESS_FLAG ? *size_rtn : PROGRESS_MESSAGE_SIZE;
/* Allocate the complete buffer, size now known. */
*buf_rtn = safe_malloc (g, message_size);
/* Read the message. */
n = g->conn->ops->read_data (g, g->conn, *buf_rtn, message_size);
if (n == -1) {
free (*buf_rtn);
*buf_rtn = NULL;
return -1;
}
if (n == 0) {
guestfs_int_unexpected_close_error (g);
child_cleanup (g);
free (*buf_rtn);
*buf_rtn = NULL;
return -1;
}
/* ... it's a normal message (not progress/launch/cancel) so display
* it if we're debugging.
*/
#ifdef ENABLE_PACKET_DUMP
if (g->verbose) {
ssize_t i, j;
for (i = 0; i < n; i += 16) {
printf ("%04zx: ", i);
for (j = i; j < MIN (i+16, n); ++j)
printf ("%02x ", (*(unsigned char **)buf_rtn)[j]);
for (; j < i+16; ++j)
printf (" ");
printf ("|");
for (j = i; j < MIN (i+16, n); ++j)
if (c_isprint ((*(char **)buf_rtn)[j]))
printf ("%c", (*(char **)buf_rtn)[j]);
else
printf (".");
for (; j < i+16; ++j)
printf (" ");
printf ("|\n");
}
}
#endif
return 0;
}
static int
send_file_chunk (guestfs_h *g, int cancel, const char *buf, size_t buflen)
{
uint32_t len;
ssize_t r;
guestfs_chunk chunk;
XDR xdr;
CLEANUP_FREE char *msg_out = NULL;
size_t msg_out_size;
/* Allocate the chunk buffer. Don't use the stack to avoid
* excessive stack usage and unnecessary copies.
*/
msg_out = safe_malloc (g, GUESTFS_MAX_CHUNK_SIZE + 4 + 48);
xdrmem_create (&xdr, msg_out + 4, GUESTFS_MAX_CHUNK_SIZE + 48, XDR_ENCODE);
/* Serialize the chunk. */
chunk.cancel = cancel;
chunk.data.data_len = buflen;
chunk.data.data_val = (char *) buf;
if (!xdr_guestfs_chunk (&xdr, &chunk)) {
error (g, _("xdr_guestfs_chunk failed (buf = %p, buflen = %zu)"),
buf, buflen);
xdr_destroy (&xdr);
return -1;
}
len = xdr_getpos (&xdr);
xdr_destroy (&xdr);
/* Reduce the size of the outgoing message buffer to the real length. */
msg_out = safe_realloc (g, msg_out, len + 4);
msg_out_size = len + 4;
xdrmem_create (&xdr, msg_out, 4, XDR_ENCODE);
xdr_uint32_t (&xdr, &len);
/* Did the daemon send a cancellation message? */
r = check_daemon_socket (g);
if (r == -2) {
debug (g, "got daemon cancellation");
return -2;
}
if (r == -1)
return -1;
if (r == 0) {
guestfs_int_unexpected_close_error (g);
child_cleanup (g);
return -1;
}
/* Send the chunk. */
r = g->conn->ops->write_data (g, g->conn, msg_out, msg_out_size);
if (r == -1)
return -1;
if (r == 0) {
guestfs_int_unexpected_close_error (g);
child_cleanup (g);
return -1;
}
return 0;
}
int
guestfs_int_send (guestfs_h *g, int proc_nr,
uint64_t progress_hint, uint64_t optargs_bitmask,
xdrproc_t xdrp, char *args)
{
struct guestfs_message_header hdr;
XDR xdr;
uint32_t len;
int serial = g->msg_next_serial++;
ssize_t r;
CLEANUP_FREE char *msg_out = NULL;
size_t msg_out_size;
if (!g->conn) {
guestfs_int_unexpected_close_error (g);
return -1;
}
/* We have to allocate this message buffer on the heap because
* it is quite large (although will be mostly unused). We
* can't allocate it on the stack because in some environments
* we have quite limited stack space available, notably when
* running in the JVM.
*/
msg_out = safe_malloc (g, GUESTFS_MESSAGE_MAX + 4);
xdrmem_create (&xdr, msg_out + 4, GUESTFS_MESSAGE_MAX, XDR_ENCODE);
/* Serialize the header. */
hdr.prog = GUESTFS_PROGRAM;
hdr.vers = GUESTFS_PROTOCOL_VERSION;
hdr.proc = proc_nr;
hdr.direction = GUESTFS_DIRECTION_CALL;
hdr.serial = serial;
hdr.status = GUESTFS_STATUS_OK;
hdr.progress_hint = progress_hint;
hdr.optargs_bitmask = optargs_bitmask;
if (!xdr_guestfs_message_header (&xdr, &hdr)) {
error (g, _("xdr_guestfs_message_header failed"));
return -1;
}
/* Serialize the args. If any, because some message types
* have no parameters.
*/
if (xdrp) {
if (!(*xdrp) (&xdr, args, 0)) {
error (g, _("dispatch failed to marshal args"));
return -1;
}
}
/* Get the actual length of the message, resize the buffer to match
* the actual length, and write the length word at the beginning.
*/
len = xdr_getpos (&xdr);
xdr_destroy (&xdr);
msg_out = safe_realloc (g, msg_out, len + 4);
msg_out_size = len + 4;
xdrmem_create (&xdr, msg_out, 4, XDR_ENCODE);
xdr_uint32_t (&xdr, &len);
/* Look for stray daemon cancellation messages from earlier calls
* and ignore them.
*/
r = check_daemon_socket (g);
/* r == -2 (cancellation) is ignored */
if (r == -1)
return -1;
if (r == 0) {
guestfs_int_unexpected_close_error (g);
child_cleanup (g);
return -1;
}
/* Send the message. */
r = g->conn->ops->write_data (g, g->conn, msg_out, msg_out_size);
if (r == -1)
return -1;
if (r == 0) {
guestfs_int_unexpected_close_error (g);
child_cleanup (g);
return -1;
}
return serial;
}
