/* libguestfs
- * Copyright (C) 2009-2010 Red Hat Inc.
+ * Copyright (C) 2009-2011 Red Hat Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* functions send_to_daemon and recv_from_daemon.
*/
+/* This is only used on the debug path, to generate a one-line
+ * printable summary of a protocol message. 'workspace' is scratch
+ * space used to format the message, and it must be at least
+ * MAX_MESSAGE_SUMMARY bytes in size.
+ */
+#define MAX_MESSAGE_SUMMARY 200 /* >= 5 * (4 * 3 + 2) + a few bytes overhead */
+
static int
xwrite (int fd, const void *v_buf, size_t len)
{
return 0;
}
+static const char *
+message_summary (const void *buf, size_t n, char *workspace)
+{
+ const unsigned char *cbuf = buf;
+ size_t i = 0;
+ char *p = workspace;
+ int truncate = 0;
+
+ /* Print only up to 5 x 32 bits of the message. That is enough to
+ * cover the message length, and the first four fields of the
+ * message header (prog, vers, proc, direction).
+ */
+ if (n > 5 * 4) {
+ n = 5 * 4;
+ truncate = 1;
+ }
+
+ while (n > 0) {
+ sprintf (p, "%02x ", cbuf[i]);
+ p += 3;
+ n--;
+ i++;
+
+ if ((i & 3) == 0) {
+ strcpy (p, "| ");
+ p += 2;
+ }
+ }
+
+ if (truncate)
+ strcpy (p, "...");
+
+ return workspace;
+}
+
int
guestfs___set_busy (guestfs_h *g)
{
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;
- debug (g, "check_for_daemon_cancellation_or_eof: %p g->state = %d, fd = %d",
- g, g->state, fd);
-
n = really_read_from_socket (g, fd, buf, 4);
if (n == -1)
return -1;
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);
const char *buf = v_buf;
fd_set rset, rset2;
fd_set wset, wset2;
+ char summary[MAX_MESSAGE_SUMMARY];
- debug (g, "send_to_daemon: %p g->state = %d, n = %zu", g, g->state, n);
+ debug (g, "send_to_daemon: %zu bytes: %s", n,
+ message_summary (v_buf, n, summary));
FD_ZERO (&rset);
FD_ZERO (&wset);
}
if (FD_ISSET (g->sock, &rset2)) {
r = check_for_daemon_cancellation_or_eof (g, g->sock);
- if (r < 0)
- return r;
+ 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);
int
guestfs___recv_from_daemon (guestfs_h *g, uint32_t *size_rtn, void **buf_rtn)
{
+ char summary[MAX_MESSAGE_SUMMARY];
fd_set rset, rset2;
- debug (g, "recv_from_daemon: %p g->state = %d, size_rtn = %p, buf_rtn = %p",
- g, g->state, size_rtn, buf_rtn);
-
FD_ZERO (&rset);
if (g->fd[1] >= 0) /* Read qemu stdout for log messages & EOF. */
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)
+ 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
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;
}
if (fd == -1) {
perrorf (g, "open: %s", filename);
send_file_cancellation (g);
- /* Daemon sees cancellation and won't reply, so caller can
- * just return here.
- */
return -1;
}
return 0;
}
+/* Same as guestfs___recv, but it discards the reply message. */
+int
+guestfs___recv_discard (guestfs_h *g, const char *fn)
+{
+ void *buf;
+ uint32_t size;
+ int r;
+
+ again:
+ r = guestfs___recv_from_daemon (g, &size, &buf);
+ if (r == -1)
+ return -1;
+
+ /* This can happen if a cancellation happens right at the end
+ * of us sending a FileIn parameter to the daemon. Discard. The
+ * daemon should send us an error message next.
+ */
+ if (size == GUESTFS_CANCEL_FLAG)
+ goto again;
+
+ if (size == GUESTFS_LAUNCH_FLAG) {
+ error (g, "%s: received unexpected launch flag from daemon when expecting reply", fn);
+ return -1;
+ }
+
+ return 0;
+}
+
/* Receive a file. */
/* Returns -1 = error, 0 = EOF, > 0 = more data */
git.annexia.org / libguestfs.git / blobdiff