2 * Copyright (C) 2009-2011 Red Hat Inc.
4 * This library is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Lesser General Public
6 * License as published by the Free Software Foundation; either
7 * version 2 of the License, or (at your option) any later version.
9 * This library is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Lesser General Public License for more details.
14 * You should have received a copy of the GNU Lesser General Public
15 * License along with this library; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 #define _BSD_SOURCE /* for mkdtemp, usleep */
34 #include <sys/select.h>
38 #include <rpc/types.h>
45 #ifdef HAVE_SYS_TYPES_H
46 #include <sys/types.h>
49 #ifdef HAVE_SYS_WAIT_H
53 #ifdef HAVE_SYS_SOCKET_H
54 #include <sys/socket.h>
61 #include <arpa/inet.h>
62 #include <netinet/in.h>
65 #include "glthread/lock.h"
66 #include "ignore-value.h"
69 #include "guestfs-internal.h"
70 #include "guestfs-internal-actions.h"
71 #include "guestfs_protocol.h"
73 /* Size of guestfs_progress message on the wire. */
74 #define PROGRESS_MESSAGE_SIZE 24
76 /* This is the code used to send and receive RPC messages and (for
77 * certain types of message) to perform file transfers. This code is
78 * driven from the generated actions (src/actions.c). There
79 * are five different cases to consider:
81 * (1) A non-daemon function. There is no RPC involved at all, it's
82 * all handled inside the library.
84 * (2) A simple RPC (eg. "mount"). We write the request, then read
85 * the reply. The sequence of calls is:
92 * (3) An RPC with FileOut parameters (eg. "upload"). We write the
93 * request, then write the file(s), then read the reply. The sequence
98 * guestfs___send_file (possibly multiple times)
102 * (4) An RPC with FileIn parameters (eg. "download"). We write the
103 * request, then read the reply, then read the file(s). The sequence
109 * guestfs___recv_file (possibly multiple times)
112 * (5) Both FileOut and FileIn parameters. There are no calls like
113 * this in the current API, but they would be implemented as a
114 * combination of cases (3) and (4).
116 * During all writes and reads, we also select(2) on qemu stdout
117 * looking for messages (guestfsd stderr and guest kernel dmesg), and
118 * anything received is passed up through the log_message_cb. This is
119 * also the reason why all the sockets are non-blocking. We also have
120 * to check for EOF (qemu died). All of this is handled by the
121 * functions send_to_daemon and recv_from_daemon.
124 /* This is only used on the debug path, to generate a one-line
125 * printable summary of a protocol message. 'workspace' is scratch
126 * space used to format the message, and it must be at least
127 * MAX_MESSAGE_SUMMARY bytes in size.
129 #define MAX_MESSAGE_SUMMARY 200 /* >= 5 * (4 * 3 + 2) + a few bytes overhead */
132 xwrite (int fd, const void *v_buf, size_t len)
134 const char *buf = v_buf;
138 r = write (fd, buf, len);
150 message_summary (const void *buf, size_t n, char *workspace)
152 const unsigned char *cbuf = buf;
157 /* Print only up to 5 x 32 bits of the message. That is enough to
158 * cover the message length, and the first four fields of the
159 * message header (prog, vers, proc, direction).
167 sprintf (p, "%02x ", cbuf[i]);
185 guestfs___set_busy (guestfs_h *g)
187 if (g->state != READY) {
188 error (g, _("guestfs_set_busy: called when in state %d != READY"),
197 guestfs___end_busy (guestfs_h *g)
211 error (g, _("guestfs_end_busy: called when in state %d"), g->state);
217 /* This is called if we detect EOF, ie. qemu died. */
219 child_cleanup (guestfs_h *g)
221 debug (g, "child_cleanup: %p: child process died", g);
223 /*if (g->pid > 0) kill (g->pid, SIGTERM);*/
224 if (g->recoverypid > 0) kill (g->recoverypid, 9);
225 waitpid (g->pid, NULL, 0);
226 if (g->recoverypid > 0) waitpid (g->recoverypid, NULL, 0);
227 if (g->fd[0] >= 0) close (g->fd[0]);
228 if (g->fd[1] >= 0) close (g->fd[1]);
235 memset (&g->launch_t, 0, sizeof g->launch_t);
237 guestfs___call_callbacks_void (g, GUESTFS_EVENT_SUBPROCESS_QUIT);
241 read_log_message_or_eof (guestfs_h *g, int fd, int error_if_eof)
247 debug (g, "read_log_message_or_eof: %p g->state = %d, fd = %d",
251 /* QEMU's console emulates a 16550A serial port. The real 16550A
252 * device has a small FIFO buffer (16 bytes) which means here we see
253 * lots of small reads of 1-16 bytes in length, usually single
256 n = read (fd, buf, sizeof buf);
258 /* Hopefully this indicates the qemu child process has died. */
262 /* We weren't expecting eof here (called from launch) so place
263 * something in the error buffer. RHBZ#588851.
265 error (g, "child process died unexpectedly");
271 if (errno == EINTR || errno == EAGAIN)
278 /* It's an actual log message, send it upwards if anyone is listening. */
279 guestfs___call_callbacks_message (g, GUESTFS_EVENT_APPLIANCE, buf, n);
284 /* Read 'n' bytes, setting the socket to blocking temporarily so
285 * that we really read the number of bytes requested.
286 * Returns: 0 == EOF while reading
287 * -1 == error, error() function has been called
288 * n == read 'n' bytes in full
291 really_read_from_socket (guestfs_h *g, int sock, char *buf, size_t n)
297 /* Set socket to blocking. */
298 flags = fcntl (sock, F_GETFL);
300 perrorf (g, "fcntl");
303 if (fcntl (sock, F_SETFL, flags & ~O_NONBLOCK) == -1) {
304 perrorf (g, "fcntl");
310 r = read (sock, &buf[got], n-got);
320 /* Restore original socket flags. */
321 if (fcntl (sock, F_SETFL, flags) == -1) {
322 perrorf (g, "fcntl");
326 return (ssize_t) got;
329 /* Convenient wrapper to generate a progress message callback. */
331 guestfs___progress_message_callback (guestfs_h *g,
332 const guestfs_progress *message)
336 array[0] = message->proc;
337 array[1] = message->serial;
338 array[2] = message->position;
339 array[3] = message->total;
341 guestfs___call_callbacks_array (g, GUESTFS_EVENT_PROGRESS,
342 array, sizeof array / sizeof array[0]);
346 check_for_daemon_cancellation_or_eof (guestfs_h *g, int fd)
348 char summary[MAX_MESSAGE_SUMMARY];
354 n = really_read_from_socket (g, fd, buf, 4);
358 /* Hopefully this indicates the qemu child process has died. */
363 debug (g, "check_for_daemon_cancellation_or_eof: %s",
364 message_summary (buf, 4, summary));
366 xdrmem_create (&xdr, buf, 4, XDR_DECODE);
367 xdr_uint32_t (&xdr, &flag);
370 /* Read and process progress messages that happen during FileIn. */
371 if (flag == GUESTFS_PROGRESS_FLAG) {
372 char buf[PROGRESS_MESSAGE_SIZE];
374 n = really_read_from_socket (g, fd, buf, PROGRESS_MESSAGE_SIZE);
382 if (g->state == BUSY) {
383 guestfs_progress message;
385 xdrmem_create (&xdr, buf, PROGRESS_MESSAGE_SIZE, XDR_DECODE);
386 xdr_guestfs_progress (&xdr, &message);
389 guestfs___progress_message_callback (g, &message);
395 if (flag != GUESTFS_CANCEL_FLAG) {
396 error (g, _("check_for_daemon_cancellation_or_eof: read 0x%x from daemon, expected 0x%x\n"),
397 flag, GUESTFS_CANCEL_FLAG);
404 /* This writes the whole N bytes of BUF to the daemon socket.
406 * If the whole write is successful, it returns 0.
407 * If there was an error, it returns -1.
408 * If the daemon sent a cancellation message, it returns -2.
410 * It also checks qemu stdout for log messages and passes those up
411 * through log_message_cb.
413 * It also checks for EOF (qemu died) and passes that up through the
414 * child_cleanup function above.
417 guestfs___send_to_daemon (guestfs_h *g, const void *v_buf, size_t n)
419 const char *buf = v_buf;
422 char summary[MAX_MESSAGE_SUMMARY];
424 debug (g, "send_to_daemon: %zu bytes: %s", n,
425 message_summary (v_buf, n, summary));
430 if (g->fd[1] >= 0) /* Read qemu stdout for log messages & EOF. */
431 FD_SET (g->fd[1], &rset);
432 FD_SET (g->sock, &rset); /* Read socket for cancellation & EOF. */
433 FD_SET (g->sock, &wset); /* Write to socket to send the data. */
435 int max_fd = MAX (g->sock, g->fd[1]);
440 int r = select (max_fd+1, &rset2, &wset2, NULL, NULL);
442 if (errno == EINTR || errno == EAGAIN)
444 perrorf (g, "select");
448 if (g->fd[1] >= 0 && FD_ISSET (g->fd[1], &rset2)) {
449 if (read_log_message_or_eof (g, g->fd[1], 0) == -1)
452 if (FD_ISSET (g->sock, &rset2)) {
453 r = check_for_daemon_cancellation_or_eof (g, g->sock);
457 /* Daemon sent cancel message. But to maintain
458 * synchronization we must write out the remainder of the
459 * write buffer before we return (RHBZ#576879).
461 if (xwrite (g->sock, buf, n) == -1) {
462 perrorf (g, "write");
465 return -2; /* cancelled */
468 if (FD_ISSET (g->sock, &wset2)) {
469 r = write (g->sock, buf, n);
471 if (errno == EINTR || errno == EAGAIN)
473 perrorf (g, "write");
474 if (errno == EPIPE) /* Disconnected from guest (RHBZ#508713). */
486 /* This reads a single message, file chunk, launch flag or
487 * cancellation flag from the daemon. If something was read, it
488 * returns 0, otherwise -1.
490 * Both size_rtn and buf_rtn must be passed by the caller as non-NULL.
492 * *size_rtn returns the size of the returned message or it may be
493 * GUESTFS_LAUNCH_FLAG or GUESTFS_CANCEL_FLAG.
495 * *buf_rtn is returned containing the message (if any) or will be set
496 * to NULL. *buf_rtn must be freed by the caller.
498 * It also checks qemu stdout for log messages and passes those up
499 * through log_message_cb.
501 * It also checks for EOF (qemu died) and passes that up through the
502 * child_cleanup function above.
504 * Progress notifications are handled transparently by this function.
505 * If the callback exists, it is called. The caller of this function
506 * will not see GUESTFS_PROGRESS_FLAG.
510 guestfs___recv_from_daemon (guestfs_h *g, uint32_t *size_rtn, void **buf_rtn)
512 char summary[MAX_MESSAGE_SUMMARY];
517 if (g->fd[1] >= 0) /* Read qemu stdout for log messages & EOF. */
518 FD_SET (g->fd[1], &rset);
519 FD_SET (g->sock, &rset); /* Read socket for data & EOF. */
521 int max_fd = MAX (g->sock, g->fd[1]);
527 /* nr is the size of the message, but we prime it as -4 because we
528 * have to read the message length word first.
533 ssize_t message_size =
534 *size_rtn != GUESTFS_PROGRESS_FLAG ?
535 *size_rtn : PROGRESS_MESSAGE_SIZE;
536 if (nr >= message_size)
540 int r = select (max_fd+1, &rset2, NULL, NULL, NULL);
542 if (errno == EINTR || errno == EAGAIN)
544 perrorf (g, "select");
550 if (g->fd[1] >= 0 && FD_ISSET (g->fd[1], &rset2)) {
551 if (read_log_message_or_eof (g, g->fd[1], 0) == -1) {
557 if (FD_ISSET (g->sock, &rset2)) {
558 if (nr < 0) { /* Have we read the message length word yet? */
559 r = read (g->sock, lenbuf+nr+4, -nr);
561 if (errno == EINTR || errno == EAGAIN)
565 /* Under some circumstances we see "Connection reset by peer"
566 * here when the child dies suddenly. Catch this and call
567 * the cleanup function, same as for EOF.
569 if (err == ECONNRESET)
574 error (g, _("unexpected end of file when reading from daemon"));
580 if (nr < 0) /* Still not got the whole length word. */
584 xdrmem_create (&xdr, lenbuf, 4, XDR_DECODE);
585 xdr_uint32_t (&xdr, size_rtn);
588 /* *size_rtn changed, recalculate message_size */
590 *size_rtn != GUESTFS_PROGRESS_FLAG ?
591 *size_rtn : PROGRESS_MESSAGE_SIZE;
593 if (*size_rtn == GUESTFS_LAUNCH_FLAG) {
594 if (g->state != LAUNCHING)
595 error (g, _("received magic signature from guestfsd, but in state %d"),
599 guestfs___call_callbacks_void (g, GUESTFS_EVENT_LAUNCH_DONE);
601 debug (g, "recv_from_daemon: received GUESTFS_LAUNCH_FLAG");
604 else if (*size_rtn == GUESTFS_CANCEL_FLAG) {
605 debug (g, "recv_from_daemon: received GUESTFS_CANCEL_FLAG");
608 else if (*size_rtn == GUESTFS_PROGRESS_FLAG)
610 /* If this happens, it's pretty bad and we've probably lost
613 else if (*size_rtn > GUESTFS_MESSAGE_MAX) {
614 error (g, _("message length (%u) > maximum possible size (%d)"),
615 (unsigned) *size_rtn, GUESTFS_MESSAGE_MAX);
619 /* Allocate the complete buffer, size now known. */
620 *buf_rtn = safe_malloc (g, message_size);
624 size_t sizetoread = message_size - nr;
625 if (sizetoread > BUFSIZ) sizetoread = BUFSIZ;
627 r = read (g->sock, (char *) (*buf_rtn) + nr, sizetoread);
629 if (errno == EINTR || errno == EAGAIN)
637 error (g, _("unexpected end of file when reading from daemon"));
647 /* Got the full message, caller can start processing it. */
648 #ifdef ENABLE_PACKET_DUMP
652 for (i = 0; i < nr; i += 16) {
653 printf ("%04zx: ", i);
654 for (j = i; j < MIN (i+16, nr); ++j)
655 printf ("%02x ", (*(unsigned char **)buf_rtn)[j]);
656 for (; j < i+16; ++j)
659 for (j = i; j < MIN (i+16, nr); ++j)
660 if (c_isprint ((*(char **)buf_rtn)[j]))
661 printf ("%c", (*(char **)buf_rtn)[j]);
664 for (; j < i+16; ++j)
671 if (*size_rtn == GUESTFS_PROGRESS_FLAG) {
672 if (g->state == BUSY) {
673 guestfs_progress message;
675 xdrmem_create (&xdr, *buf_rtn, PROGRESS_MESSAGE_SIZE, XDR_DECODE);
676 xdr_guestfs_progress (&xdr, &message);
679 guestfs___progress_message_callback (g, &message);
685 /* Process next message. */
686 return guestfs___recv_from_daemon (g, size_rtn, buf_rtn);
689 debug (g, "recv_from_daemon: %" PRIu32 " bytes: %s", *size_rtn,
690 message_summary (*buf_rtn, *size_rtn, summary));
695 /* This is very much like recv_from_daemon above, but g->sock is
696 * a listening socket and we are accepting a new connection on
697 * that socket instead of reading anything. Returns the newly
701 guestfs___accept_from_daemon (guestfs_h *g)
705 debug (g, "accept_from_daemon: %p g->state = %d", g, g->state);
709 if (g->fd[1] >= 0) /* Read qemu stdout for log messages & EOF. */
710 FD_SET (g->fd[1], &rset);
711 FD_SET (g->sock, &rset); /* Read socket for accept. */
713 int max_fd = MAX (g->sock, g->fd[1]);
717 /* If the qemu process has died, clean up the zombie (RHBZ#579155).
718 * By partially polling in the select below we ensure that this
719 * function will be called eventually.
721 waitpid (g->pid, NULL, WNOHANG);
725 struct timeval tv = { .tv_sec = 1, .tv_usec = 0 };
726 int r = select (max_fd+1, &rset2, NULL, NULL, &tv);
728 if (errno == EINTR || errno == EAGAIN)
730 perrorf (g, "select");
734 if (g->fd[1] >= 0 && FD_ISSET (g->fd[1], &rset2)) {
735 if (read_log_message_or_eof (g, g->fd[1], 1) == -1)
738 if (FD_ISSET (g->sock, &rset2)) {
739 sock = accept (g->sock, NULL, NULL);
741 if (errno == EINTR || errno == EAGAIN)
743 perrorf (g, "accept");
753 guestfs___send (guestfs_h *g, int proc_nr,
754 uint64_t progress_hint, uint64_t optargs_bitmask,
755 xdrproc_t xdrp, char *args)
757 struct guestfs_message_header hdr;
760 int serial = g->msg_next_serial++;
765 if (g->state != BUSY) {
766 error (g, _("guestfs___send: state %d != BUSY"), g->state);
770 /* We have to allocate this message buffer on the heap because
771 * it is quite large (although will be mostly unused). We
772 * can't allocate it on the stack because in some environments
773 * we have quite limited stack space available, notably when
774 * running in the JVM.
776 msg_out = safe_malloc (g, GUESTFS_MESSAGE_MAX + 4);
777 xdrmem_create (&xdr, msg_out + 4, GUESTFS_MESSAGE_MAX, XDR_ENCODE);
779 /* Serialize the header. */
780 hdr.prog = GUESTFS_PROGRAM;
781 hdr.vers = GUESTFS_PROTOCOL_VERSION;
783 hdr.direction = GUESTFS_DIRECTION_CALL;
785 hdr.status = GUESTFS_STATUS_OK;
786 hdr.progress_hint = progress_hint;
787 hdr.optargs_bitmask = optargs_bitmask;
789 if (!xdr_guestfs_message_header (&xdr, &hdr)) {
790 error (g, _("xdr_guestfs_message_header failed"));
794 /* Serialize the args. If any, because some message types
795 * have no parameters.
798 if (!(*xdrp) (&xdr, args)) {
799 error (g, _("dispatch failed to marshal args"));
804 /* Get the actual length of the message, resize the buffer to match
805 * the actual length, and write the length word at the beginning.
807 len = xdr_getpos (&xdr);
810 msg_out = safe_realloc (g, msg_out, len + 4);
811 msg_out_size = len + 4;
813 xdrmem_create (&xdr, msg_out, 4, XDR_ENCODE);
814 xdr_uint32_t (&xdr, &len);
817 r = guestfs___send_to_daemon (g, msg_out, msg_out_size);
818 if (r == -2) /* Ignore stray daemon cancellations. */
831 static int cancel = 0; /* XXX Implement file cancellation. */
832 static int send_file_chunk (guestfs_h *g, int cancel, const char *buf, size_t len);
833 static int send_file_data (guestfs_h *g, const char *buf, size_t len);
834 static int send_file_cancellation (guestfs_h *g);
835 static int send_file_complete (guestfs_h *g);
841 * -2 daemon cancelled (we must read the error message)
844 guestfs___send_file (guestfs_h *g, const char *filename)
846 char buf[GUESTFS_MAX_CHUNK_SIZE];
849 fd = open (filename, O_RDONLY);
851 perrorf (g, "open: %s", filename);
852 send_file_cancellation (g);
856 /* Send file in chunked encoding. */
858 r = read (fd, buf, sizeof buf);
859 if (r == -1 && (errno == EINTR || errno == EAGAIN))
862 err = send_file_data (g, buf, r);
864 if (err == -2) /* daemon sent cancellation */
865 send_file_cancellation (g);
870 if (cancel) { /* cancel from either end */
871 send_file_cancellation (g);
876 perrorf (g, "read: %s", filename);
877 send_file_cancellation (g);
881 /* End of file, but before we send that, we need to close
882 * the file and check for errors.
884 if (close (fd) == -1) {
885 perrorf (g, "close: %s", filename);
886 send_file_cancellation (g);
890 return send_file_complete (g);
893 /* Send a chunk of file data. */
895 send_file_data (guestfs_h *g, const char *buf, size_t len)
897 return send_file_chunk (g, 0, buf, len);
900 /* Send a cancellation message. */
902 send_file_cancellation (guestfs_h *g)
904 return send_file_chunk (g, 1, NULL, 0);
907 /* Send a file complete chunk. */
909 send_file_complete (guestfs_h *g)
912 return send_file_chunk (g, 0, buf, 0);
916 send_file_chunk (guestfs_h *g, int cancel, const char *buf, size_t buflen)
925 if (g->state != BUSY) {
926 error (g, _("send_file_chunk: state %d != READY"), g->state);
930 /* Allocate the chunk buffer. Don't use the stack to avoid
931 * excessive stack usage and unnecessary copies.
933 msg_out = safe_malloc (g, GUESTFS_MAX_CHUNK_SIZE + 4 + 48);
934 xdrmem_create (&xdr, msg_out + 4, GUESTFS_MAX_CHUNK_SIZE + 48, XDR_ENCODE);
936 /* Serialize the chunk. */
937 chunk.cancel = cancel;
938 chunk.data.data_len = buflen;
939 chunk.data.data_val = (char *) buf;
941 if (!xdr_guestfs_chunk (&xdr, &chunk)) {
942 error (g, _("xdr_guestfs_chunk failed (buf = %p, buflen = %zu)"),
948 len = xdr_getpos (&xdr);
951 /* Reduce the size of the outgoing message buffer to the real length. */
952 msg_out = safe_realloc (g, msg_out, len + 4);
953 msg_out_size = len + 4;
955 xdrmem_create (&xdr, msg_out, 4, XDR_ENCODE);
956 xdr_uint32_t (&xdr, &len);
958 r = guestfs___send_to_daemon (g, msg_out, msg_out_size);
960 /* Did the daemon send a cancellation message? */
962 debug (g, "got daemon cancellation");
978 /* Receive a reply. */
980 guestfs___recv (guestfs_h *g, const char *fn,
981 guestfs_message_header *hdr,
982 guestfs_message_error *err,
983 xdrproc_t xdrp, char *ret)
991 r = guestfs___recv_from_daemon (g, &size, &buf);
995 /* This can happen if a cancellation happens right at the end
996 * of us sending a FileIn parameter to the daemon. Discard. The
997 * daemon should send us an error message next.
999 if (size == GUESTFS_CANCEL_FLAG)
1002 if (size == GUESTFS_LAUNCH_FLAG) {
1003 error (g, "%s: received unexpected launch flag from daemon when expecting reply", fn);
1007 xdrmem_create (&xdr, buf, size, XDR_DECODE);
1009 if (!xdr_guestfs_message_header (&xdr, hdr)) {
1010 error (g, "%s: failed to parse reply header", fn);
1015 if (hdr->status == GUESTFS_STATUS_ERROR) {
1016 if (!xdr_guestfs_message_error (&xdr, err)) {
1017 error (g, "%s: failed to parse reply error", fn);
1023 if (xdrp && ret && !xdrp (&xdr, ret)) {
1024 error (g, "%s: failed to parse reply", fn);
1036 /* Same as guestfs___recv, but it discards the reply message. */
1038 guestfs___recv_discard (guestfs_h *g, const char *fn)
1045 r = guestfs___recv_from_daemon (g, &size, &buf);
1049 /* This can happen if a cancellation happens right at the end
1050 * of us sending a FileIn parameter to the daemon. Discard. The
1051 * daemon should send us an error message next.
1053 if (size == GUESTFS_CANCEL_FLAG)
1056 if (size == GUESTFS_LAUNCH_FLAG) {
1057 error (g, "%s: received unexpected launch flag from daemon when expecting reply", fn);
1064 /* Receive a file. */
1066 /* Returns -1 = error, 0 = EOF, > 0 = more data */
1067 static ssize_t receive_file_data (guestfs_h *g, void **buf);
1070 guestfs___recv_file (guestfs_h *g, const char *filename)
1075 fd = open (filename, O_WRONLY|O_CREAT|O_TRUNC|O_NOCTTY, 0666);
1077 perrorf (g, "open: %s", filename);
1081 /* Receive the file in chunked encoding. */
1082 while ((r = receive_file_data (g, &buf)) > 0) {
1083 if (xwrite (fd, buf, r) == -1) {
1084 perrorf (g, "%s: write", filename);
1092 error (g, _("%s: error in chunked encoding"), filename);
1096 if (close (fd) == -1) {
1097 perrorf (g, "close: %s", filename);
1104 /* Send cancellation message to daemon, then wait until it
1105 * cancels (just throwing away data).
1109 uint32_t flag = GUESTFS_CANCEL_FLAG;
1111 debug (g, "%s: waiting for daemon to acknowledge cancellation",
1114 xdrmem_create (&xdr, fbuf, sizeof fbuf, XDR_ENCODE);
1115 xdr_uint32_t (&xdr, &flag);
1118 if (xwrite (g->sock, fbuf, sizeof fbuf) == -1) {
1119 perrorf (g, _("write to daemon socket"));
1123 while (receive_file_data (g, NULL) > 0)
1124 ; /* just discard it */
1129 /* Receive a chunk of file data. */
1130 /* Returns -1 = error, 0 = EOF, > 0 = more data */
1132 receive_file_data (guestfs_h *g, void **buf_r)
1138 guestfs_chunk chunk;
1140 r = guestfs___recv_from_daemon (g, &len, &buf);
1142 error (g, _("receive_file_data: parse error in reply callback"));
1146 if (len == GUESTFS_LAUNCH_FLAG || len == GUESTFS_CANCEL_FLAG) {
1147 error (g, _("receive_file_data: unexpected flag received when reading file chunks"));
1151 memset (&chunk, 0, sizeof chunk);
1153 xdrmem_create (&xdr, buf, len, XDR_DECODE);
1154 if (!xdr_guestfs_chunk (&xdr, &chunk)) {
1155 error (g, _("failed to parse file chunk"));
1160 /* After decoding, the original buffer is no longer used. */
1164 error (g, _("file receive cancelled by daemon"));
1165 free (chunk.data.data_val);
1169 if (chunk.data.data_len == 0) { /* end of transfer */
1170 free (chunk.data.data_val);
1174 if (buf_r) *buf_r = chunk.data.data_val;
1175 else free (chunk.data.data_val); /* else caller frees */
1177 return chunk.data.data_len;