[Libguestfs] [PATCH v2 3/4] daemon: Allow guestfs_channel to override the virtio-serial channel.
From: "Richard W.M. Jones" <rjones(a)redhat.com>
Also if /dev/ttyS* is specified, make sure the serial port is set to
raw mode.
---
daemon/guestfsd.c | 51 +++++++++++++++++++++++++++++++++++++++++++++++----
1 file changed, 47 insertions(+), 4 deletions(-)
diff --git a/daemon/guestfsd.c b/daemon/guestfsd.c
index 580315a..fe2bd79 100644
--- a/daemon/guestfsd.c
+++ b/daemon/guestfsd.c
@@ -41,6 +41,7 @@
#include <netinet/in.h>
#include <errno.h>
#include <assert.h>
+#include <termios.h>
#ifdef HAVE_PRINTF_H
# include <printf.h>
@@ -78,6 +79,7 @@ static dev_t root_device = 0;
int verbose = 0;
+static void makeraw (const char *channel, int fd);
static int print_shell_quote (FILE *stream, const struct printf_info *info, const void
*const *args);
static int print_sysroot_shell_quote (FILE *stream, const struct printf_info *info, const
void *const *args);
#ifdef HAVE_REGISTER_PRINTF_SPECIFIER
@@ -210,8 +212,6 @@ main (int argc, char *argv[])
printf ("could not read linux command line\n");
}
- free (cmdline);
-
#ifndef WIN32
/* Make sure SIGPIPE doesn't kill us. */
struct sigaction sa;
@@ -254,7 +254,22 @@ main (int argc, char *argv[])
copy_lvm ();
/* Connect to virtio-serial channel. */
- int sock = open (VIRTIO_SERIAL_CHANNEL, O_RDWR|O_CLOEXEC);
+ char *channel, *p;
+ if (cmdline && (p = strstr (cmdline, "guestfs_channel=")) != NULL) {
+ p += 16;
+ channel = strndup (p, strcspn (p, " \n"));
+ }
+ else
+ channel = strdup (VIRTIO_SERIAL_CHANNEL);
+ if (!channel) {
+ perror ("strdup");
+ exit (EXIT_FAILURE);
+ }
+
+ if (verbose)
+ printf ("trying to open virtio-serial channel '%s'\n", channel);
+
+ int sock = open (channel, O_RDWR|O_CLOEXEC);
if (sock == -1) {
fprintf (stderr,
"\n"
@@ -269,10 +284,19 @@ main (int argc, char *argv[])
"output to the libguestfs developers, either in a bug report\n"
"or on the libguestfs redhat com mailing list.\n"
"\n");
- perror (VIRTIO_SERIAL_CHANNEL);
+ perror (channel);
exit (EXIT_FAILURE);
}
+ /* If it's a serial-port like device then it probably has echoing
+ * enabled. Put it into complete raw mode.
+ */
+ if (STRPREFIX (channel, "/dev/ttyS"))
+ makeraw (channel, sock);
+
+ /* cmdline is not used after this point */
+ free (cmdline);
+
/* Wait for udev devices to be created. If you start libguestfs,
* especially with disks that contain complex (eg. mdadm) data
* already, then it is possible for the 'mdadm' and LVM commands
@@ -355,6 +379,25 @@ read_cmdline (void)
return r;
}
+/* Try to make the socket raw, but don't fail if it's not possible. */
+static void
+makeraw (const char *channel, int fd)
+{
+ struct termios tt;
+
+ if (tcgetattr (fd, &tt) == -1) {
+ fprintf (stderr, "tcgetattr: ");
+ perror (channel);
+ return;
+ }
+
+ cfmakeraw (&tt);
+ if (tcsetattr (fd, TCSANOW, &tt) == -1) {
+ fprintf (stderr, "tcsetattr: ");
+ perror (channel);
+ }
+}
+
/* Return true iff device is the root device (and therefore should be
* ignored from the point of view of user calls).
*/
--
1.8.3.1