5:28 a.m.
Remove the "enum nbd_server" type, and the "standard_servers" and
"use_server" variables, as no real selection is happening now.
With regard to naming: internally to "nbd.c", and in the user-visible
documentation, replace (or restrict) "NBD server" references with
"nbdkit". In source code different from "nbd.c" however, stick with
the
"NBD server" language. Rename test_nbd_servers() (plural) to
test_nbd_server() (singular).
This patch is best viewed with "git show -b"; otherwise, the
unindentations due to the switch statements' removal obscure the diff
somewhat.
Ref: https://listman.redhat.com/archives/libguestfs/2022-March/028475.html
Suggested-by: Richard W.M. Jones <rjones(a)redhat.com>
Signed-off-by: Laszlo Ersek <lersek(a)redhat.com>
Reviewed-by: Richard W.M. Jones <rjones(a)redhat.com>
---
Notes:
v2:
- pick up Rich's R-b
p2v.h | 2 +-
main.c | 2 +-
nbd.c | 110 ++++++--------------
virt-p2v.pod | 6 +-
4 files changed, 34 insertions(+), 86 deletions(-)
diff --git a/p2v.h b/p2v.h
index 3093e64ca3d7..c55f64317dde 100644
--- a/p2v.h
+++ b/p2v.h
@@ -111,7 +111,7 @@ extern const char *get_ssh_error (void);
extern int scp_file (struct config *config, const char *target, const char *local, ...)
__attribute__((sentinel));
/* nbd.c */
-extern void test_nbd_servers (void);
+extern void test_nbd_server (void);
extern pid_t start_nbd_server (int *port, const char *device);
extern int wait_for_nbd_server_to_start (int port);
const char *get_nbd_error (void);
diff --git a/main.c b/main.c
index dc411b733d31..0ebb7291c7ce 100644
--- a/main.c
+++ b/main.c
@@ -135,125 +135,125 @@ int
main (int argc, char *argv[])
{
gboolean gui_possible;
int c;
int option_index;
char **cmdline = NULL;
int cmdline_source = 0;
struct config *config = new_config ();
setlocale (LC_ALL, "");
bindtextdomain (PACKAGE, LOCALEBASEDIR);
textdomain (PACKAGE);
/* We may use random(3) in this program. */
srandom (time (NULL) + getpid ());
/* There is some raciness between slow devices being discovered by
* the kernel and udev and virt-p2v running. This is a partial
* workaround, but a real fix involves handling hotplug events
* (possible in GUI mode, not easy in kernel mode).
*/
udevadm_settle ();
gui_possible = gtk_init_check (&argc, &argv);
for (;;) {
c = getopt_long (argc, argv, options, long_options, &option_index);
if (c == -1) break;
switch (c) {
case 0: /* options which are long only */
if (STREQ (long_options[option_index].name, "long-options")) {
display_long_options (long_options);
}
else if (STREQ (long_options[option_index].name, "short-options")) {
display_short_options (options);
}
else if (STREQ (long_options[option_index].name, "cmdline")) {
cmdline = parse_cmdline_string (optarg);
cmdline_source = CMDLINE_SOURCE_COMMAND_LINE;
}
else if (STREQ (long_options[option_index].name, "color") ||
STREQ (long_options[option_index].name, "colour") ||
STREQ (long_options[option_index].name, "colors") ||
STREQ (long_options[option_index].name, "colours")) {
force_colour = 1;
}
else if (STREQ (long_options[option_index].name, "iso")) {
is_iso_environment = 1;
}
else if (STREQ (long_options[option_index].name, "test-disk")) {
if (test_disk != NULL)
error (EXIT_FAILURE, 0,
_("only a single --test-disk option can be used"));
if (optarg[0] != '/')
error (EXIT_FAILURE, 0,
_("--test-disk must be an absolute path"));
test_disk = optarg;
}
else
error (EXIT_FAILURE, 0,
_("unknown long option: %s (%d)"),
long_options[option_index].name, option_index);
break;
case 'v':
/* This option does nothing since 1.33.41. Verbose is always
* enabled.
*/
break;
case 'V':
printf ("%s %s\n", g_get_prgname (), PACKAGE_VERSION_FULL);
exit (EXIT_SUCCESS);
case HELP_OPTION:
usage (EXIT_SUCCESS);
default:
usage (EXIT_FAILURE);
}
}
if (optind != argc) {
fprintf (stderr, _("%s: unused arguments on the command line\n"),
g_get_prgname ());
usage (EXIT_FAILURE);
}
- test_nbd_servers ();
+ test_nbd_server ();
set_config_defaults (config);
/* Parse /proc/cmdline (if it exists) or use the --cmdline parameter
* to initialize the configuration. This allows defaults to be pass
* using the kernel command line, with additional GUI configuration
* later.
*/
if (cmdline == NULL) {
cmdline = parse_proc_cmdline ();
if (cmdline != NULL)
cmdline_source = CMDLINE_SOURCE_PROC_CMDLINE;
}
if (cmdline)
update_config_from_kernel_cmdline (config, cmdline);
/* If p2v.server exists, then we use the non-interactive kernel
* conversion. Otherwise we run the GUI.
*/
if (config->remote.server != NULL)
kernel_conversion (config, cmdline, cmdline_source);
else {
if (!gui_possible)
error (EXIT_FAILURE, 0,
_("gtk_init_check returned false, indicating that\n"
"a GUI is not possible on this host. Check X11, $DISPLAY
etc."));
gui_conversion (config);
}
guestfs_int_free_string_list (cmdline);
free_config (config);
exit (EXIT_SUCCESS);
}
diff --git a/nbd.c b/nbd.c
index 48926d4aec1d..e30b4a2195cb 100644
--- a/nbd.c
+++ b/nbd.c
@@ -1,66 +1,49 @@
/* virt-p2v
* Copyright (C) 2009-2019 Red Hat Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <https://www.gnu.org/licenses/>;.
*/
/* This file handles running L<nbdkit(1)>. */
#include <config.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <inttypes.h>
#include <fcntl.h>
#include <unistd.h>
#include <time.h>
#include <netdb.h>
#include <errno.h>
#include <error.h>
#include <libintl.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <assert.h>
#include "p2v.h"
-/* How long to wait for the NBD server to start (seconds). */
+/* How long to wait for nbdkit to start (seconds). */
#define WAIT_NBD_TIMEOUT 10
-/* The local port that the NBD server listens on (incremented for
- * each server which is started).
+/* The local port that nbdkit listens on (incremented for each server which is
+ * started).
*/
static int nbd_local_port;
-/* Supported server types. */
-enum nbd_server {
- /* 0 is reserved for "end of list" */
- NBDKIT = 1,
-};
-
-/* We use this standard list of nbd server types. Must match the documentation
- * in virt-p2v(1).
- */
-static const enum nbd_server standard_servers[] =
- { NBDKIT, 0 };
-
-/* After testing the list of servers passed by the user, this is
- * server we decide to use.
- */
-static enum nbd_server use_server;
-
static pid_t start_nbdkit (const char *device, int *fds, size_t nr_fds);
static int open_listening_socket (int **fds, size_t *nr_fds);
static int bind_tcpip_socket (const char *port, int **fds, size_t *nr_fds);
@@ -94,79 +77,53 @@ const char *
get_nbd_error (void)
{
return nbd_error;
}
/**
- * Test the built-in default list to see which servers are actually installed
- * and appear to be working.
- *
- * Set the C<use_server> global accordingly.
+ * Check for nbdkit.
*/
void
-test_nbd_servers (void)
+test_nbd_server (void)
{
- size_t i;
int r;
- const enum nbd_server *servers;
/* Initialize nbd_local_port. */
if (is_iso_environment)
/* The p2v ISO should allow us to open up just about any port, so
* we can fix a port number in that case. Using a predictable
* port number in this case should avoid rare errors if the port
* colides with another (ie. it'll either always fail or never
* fail).
*/
nbd_local_port = 50123;
else
/* When testing on the local machine, choose a random port. */
nbd_local_port = 50000 + (random () % 10000);
- servers = standard_servers;
-
- use_server = 0;
-
- for (i = 0; servers[i] != 0; ++i) {
#if DEBUG_STDERR
- fprintf (stderr, "checking for nbdkit ...\n");
+ fprintf (stderr, "checking for nbdkit ...\n");
#endif
- switch (servers[i]) {
- case NBDKIT: /* with socket activation */
- r = system ("nbdkit file --version"
+ r = system ("nbdkit file --version"
#ifndef DEBUG_STDERR
- " >/dev/null 2>&1"
+ " >/dev/null 2>&1"
#endif
- );
- if (r == 0) {
- use_server = servers[i];
- goto finish;
- }
- break;
-
- default:
- abort ();
- }
- }
-
- finish:
- if (use_server == 0) {
- fprintf (stderr,
- _("%s: no working NBD server was found, cannot continue.\n"),
+ );
+ if (r != 0) {
+ fprintf (stderr, _("%s: nbdkit was not found, cannot continue.\n"),
g_get_prgname ());
exit (EXIT_FAILURE);
}
#if DEBUG_STDERR
- fprintf (stderr, "picked nbdkit\n");
+ fprintf (stderr, "found nbdkit\n");
#endif
}
/**
- * Start the NBD server.
+ * Start nbdkit.
*
- * We previously tested all NBD servers (see C<test_nbd_servers>) and
- * hopefully found one which will work.
+ * We previously tested nbdkit (see C<test_nbd_server>).
*
* Returns the process ID (E<gt> 0) or C<0> if there is an error.
*/
@@ -174,28 +131,23 @@ pid_t
start_nbd_server (int *port, const char *device)
{
int *fds = NULL;
size_t i, nr_fds;
pid_t pid;
- switch (use_server) {
- case NBDKIT: /* nbdkit with socket activation */
- *port = open_listening_socket (&fds, &nr_fds);
- if (*port == -1) return -1;
- pid = start_nbdkit (device, fds, nr_fds);
- for (i = 0; i < nr_fds; ++i)
- close (fds[i]);
- free (fds);
- return pid;
- }
-
- abort ();
+ *port = open_listening_socket (&fds, &nr_fds);
+ if (*port == -1) return -1;
+ pid = start_nbdkit (device, fds, nr_fds);
+ for (i = 0; i < nr_fds; ++i)
+ close (fds[i]);
+ free (fds);
+ return pid;
}
#define FIRST_SOCKET_ACTIVATION_FD 3
/**
* Set up file descriptors and environment variables for
* socket activation.
*
* Note this function runs in the child between fork and exec.
*/
@@ -235,52 +187,50 @@ static pid_t
start_nbdkit (const char *device, int *fds, size_t nr_fds)
{
pid_t pid;
CLEANUP_FREE char *file_str = NULL;
#if DEBUG_STDERR
fprintf (stderr, "starting nbdkit for %s using socket activation\n",
device);
#endif
if (asprintf (&file_str, "file=%s", device) == -1)
error (EXIT_FAILURE, errno, "asprintf");
pid = fork ();
if (pid == -1) {
set_nbd_error ("fork: %m");
return 0;
}
if (pid == 0) { /* Child. */
close (0);
if (open ("/dev/null", O_RDONLY) == -1) {
perror ("open: /dev/null");
_exit (EXIT_FAILURE);
}
socket_activation (fds, nr_fds);
execlp ("nbdkit",
"nbdkit",
"-r", /* readonly (vital!) */
"-f", /* don't fork */
"file", /* file plugin */
file_str, /* a device like file=/dev/sda */
NULL);
perror ("nbdkit");
_exit (EXIT_FAILURE);
}
/* Parent. */
return pid;
}
/**
- * This is used when we are starting an NBD server which supports
- * socket activation. We can open a listening socket on an unused
- * local port and return it.
+ * Open a listening socket on an unused local port and return it.
*
* Returns the port number on success or C<-1> on error.
*
* The file descriptor(s) bound are returned in the array *fds, *nr_fds.
* The caller must free the array.
*/
@@ -311,160 +261,158 @@ static int
bind_tcpip_socket (const char *port, int **fds_rtn, size_t *nr_fds_rtn)
{
struct addrinfo *ai = NULL;
struct addrinfo hints;
struct addrinfo *a;
int err;
int *fds = NULL;
size_t nr_fds;
int addr_in_use = 0;
memset (&hints, 0, sizeof hints);
hints.ai_flags = AI_PASSIVE | AI_ADDRCONFIG;
hints.ai_socktype = SOCK_STREAM;
err = getaddrinfo ("localhost", port, &hints, &ai);
if (err != 0) {
#if DEBUG_STDERR
fprintf (stderr, "%s: getaddrinfo: localhost: %s: %s", g_get_prgname (),
port, gai_strerror (err));
#endif
return -1;
}
nr_fds = 0;
for (a = ai; a != NULL; a = a->ai_next) {
int sock, opt;
sock = socket (a->ai_family, a->ai_socktype, a->ai_protocol);
if (sock == -1)
error (EXIT_FAILURE, errno, "socket");
opt = 1;
if (setsockopt (sock, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof opt) == -1)
perror ("setsockopt: SO_REUSEADDR");
#ifdef IPV6_V6ONLY
if (a->ai_family == PF_INET6) {
if (setsockopt (sock, IPPROTO_IPV6, IPV6_V6ONLY, &opt, sizeof opt) == -1)
perror ("setsockopt: IPv6 only");
}
#endif
if (bind (sock, a->ai_addr, a->ai_addrlen) == -1) {
if (errno == EADDRINUSE) {
addr_in_use = 1;
close (sock);
continue;
}
perror ("bind");
close (sock);
continue;
}
if (listen (sock, SOMAXCONN) == -1) {
perror ("listen");
close (sock);
continue;
}
nr_fds++;
fds = realloc (fds, sizeof (int) * nr_fds);
if (!fds)
error (EXIT_FAILURE, errno, "realloc");
fds[nr_fds-1] = sock;
}
freeaddrinfo (ai);
if (nr_fds == 0 && addr_in_use) {
#if DEBUG_STDERR
fprintf (stderr, "%s: unable to bind to localhost:%s: %s\n",
g_get_prgname (), port, strerror (EADDRINUSE));
#endif
return -1;
}
#if DEBUG_STDERR
fprintf (stderr, "%s: bound to localhost:%s (%zu socket(s))\n",
g_get_prgname (), port, nr_fds);
#endif
*fds_rtn = fds;
*nr_fds_rtn = nr_fds;
return 0;
}
/**
- * Wait for a local NBD server to start and be listening for
- * connections.
+ * Wait for nbdkit to start and be listening for connections.
*/
int
wait_for_nbd_server_to_start (int port)
{
int sockfd = -1;
int result = -1;
time_t start_t, now_t;
struct timespec half_sec = { .tv_sec = 0, .tv_nsec = 500000000 };
struct timeval timeout = { .tv_usec = 0 };
char magic[8]; /* NBDMAGIC */
size_t bytes_read = 0;
ssize_t recvd;
time (&start_t);
for (;;) {
time (&now_t);
if (now_t - start_t >= WAIT_NBD_TIMEOUT) {
- set_nbd_error ("timed out waiting for NBD server to start");
+ set_nbd_error ("timed out waiting for nbdkit to start");
goto cleanup;
}
sockfd = connect_to_nbdkit (port);
if (sockfd >= 0)
break;
nanosleep (&half_sec, NULL);
}
time (&now_t);
timeout.tv_sec = (start_t + WAIT_NBD_TIMEOUT) - now_t;
if (setsockopt (sockfd, SOL_SOCKET, SO_RCVTIMEO, &timeout, sizeof timeout) == -1)
{
- set_nbd_error ("waiting for NBD server to start: "
- "setsockopt(SO_RCVTIMEO): %m");
+ set_nbd_error ("waiting for nbdkit to start: setsockopt(SO_RCVTIMEO):
%m");
goto cleanup;
}
do {
recvd = recv (sockfd, magic, sizeof magic - bytes_read, 0);
if (recvd == -1) {
- set_nbd_error ("waiting for NBD server to start: recv: %m");
+ set_nbd_error ("waiting for nbdkit to start: recv: %m");
goto cleanup;
}
bytes_read += recvd;
} while (bytes_read < sizeof magic);
if (memcmp (magic, "NBDMAGIC", sizeof magic) != 0) {
- set_nbd_error ("waiting for NBD server to start: "
- "'NBDMAGIC' was not received from NBD server");
+ set_nbd_error ("waiting for nbdkit to start: "
+ "'NBDMAGIC' was not received from nbdkit");
goto cleanup;
}
result = 0;
cleanup:
if (sockfd >= 0)
close (sockfd);
return result;
}
/**
* Connect to C<localhost:dest_port>, resolving the address using
* L<getaddrinfo(3)>.
*
* This may involve multiple connections - to IPv4 and IPv6 for
* instance.
*/
@@ -472,42 +420,42 @@ static int
connect_to_nbdkit (int dest_port)
{
struct addrinfo hints;
struct addrinfo *results, *rp;
char dest_port_str[16];
int r, sockfd = -1;
snprintf (dest_port_str, sizeof dest_port_str, "%d", dest_port);
memset (&hints, 0, sizeof hints);
hints.ai_family = AF_UNSPEC; /* allow IPv4 or IPv6 */
hints.ai_socktype = SOCK_STREAM;
hints.ai_flags = AI_NUMERICSERV; /* numeric dest port number */
hints.ai_protocol = 0; /* any protocol */
r = getaddrinfo ("localhost", dest_port_str, &hints, &results);
if (r != 0) {
set_nbd_error ("getaddrinfo: localhost/%s: %s",
dest_port_str, gai_strerror (r));
return -1;
}
for (rp = results; rp != NULL; rp = rp->ai_next) {
sockfd = socket (rp->ai_family, rp->ai_socktype, rp->ai_protocol);
if (sockfd == -1)
continue;
/* Connect. */
if (connect (sockfd, rp->ai_addr, rp->ai_addrlen) == -1) {
- set_nbd_error ("waiting for NBD server to start: "
+ set_nbd_error ("waiting for nbdkit to start: "
"connect to localhost/%s: %m", dest_port_str);
close (sockfd);
sockfd = -1;
continue;
}
break;
}
freeaddrinfo (results);
return sockfd;
}
diff --git a/virt-p2v.pod b/virt-p2v.pod
index 09d3c7729e38..aec5078f92db 100644
--- a/virt-p2v.pod
+++ b/virt-p2v.pod
@@ -673,9 +673,9 @@ server and terminates on the conversion server, in fact NBD requests
flow in the opposite direction. This is because the reverse port
forward feature of ssh (C<ssh -R>) is used to open a port on the
loopback interface of the conversion server which is proxied back by
-ssh to the NBD server running on the physical machine. The effect is
-that virt-v2v via libguestfs can open nbd connections which directly
-read the hard disk(s) of the physical server.
+ssh to nbdkit running on the physical machine. The effect is that
+virt-v2v via libguestfs can open nbd connections which directly read
+the hard disk(s) of the physical server.
Two layers of protection are used to ensure that there are no writes
to the hard disks: Firstly, the nbdkit I<-r> (readonly) option is
--
2.19.1.3.g30247aa5d201